Measurement of sigma(chi(c2)B(chi(c2) ---> J / psi gamma) / sigma(chi(c1)B(chi(c1) ---> J / psi gamma) in p anti-p collisions at s**(1/2) = 1.96-TeV

The CDF collaboration Abulencia, A. ; Adelman, Jahred A. ; Affolder, T. ; et al.
Phys.Rev.Lett. 98 (2007) 232001, 2007.
Inspire Record 746743 DOI 10.17182/hepdata.57248

We measure the ratio of cross section times branching fraction, $R_p \equiv \sigma_{\chi_{c2}} {\cal B}(\chi_{c2} \to J/\psi \gamma)/ \sigma_{\chi_{c1}} {\cal B}(\chi_{c1} \to J/\psi \gamma)$, in 1.1 fb$^{-1}$ of $p\bar{p}$ collisions at $\sqrt{s} =$ 1.96 TeV. This measurement covers the kinematic range $p_T(J/\psi)>4.0$ GeV/$c$, $|\eta(J/\psi)| < 1.0$, and $p_T(\gamma)>1.0$ GeV/$c$. For events due to prompt processes, we find $R_p = 0.395\pm0.016(stat.)\pm0.015(sys.)$. This result represents a significant improvement in precision over previous measurements of prompt $\chi_{c1,2}$ hadroproduction.

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Nonperturbative-transverse-momentum effects and evolution in dihadron and direct photon-hadron angular correlations in $p$$+$$p$ collisions at $\sqrt{s}$=510 GeV

The PHENIX collaboration Adare, A. ; Aidala, C. ; Ajitanand, N.N. ; et al.
Phys.Rev.D 95 (2017) 072002, 2017.
Inspire Record 1486678 DOI 10.17182/hepdata.143252

Dihadron and isolated direct photon-hadron angular correlations are measured in $p$$+$$p$ collisions at $\sqrt{s}=510$ GeV. Correlations of charged hadrons of $0.7<p_T<10$ GeV/$c$ with $\pi^0$ mesons of $4<p_T<15$ GeV/$c$ or isolated direct photons of $7<p_T<15$ GeV/$c$ are used to study nonperturbative effects generated by initial-state partonic transverse momentum and final-state transverse momentum from fragmentation. The nonperturbative behavior is characterized by measuring the out-of-plane transverse momentum component $p_{\rm out}$ perpendicular to the axis of the trigger particle, which is the high-$p_T$ direct photon or $\pi^0$. Nonperturbative evolution effects are extracted from Gaussian fits to the away-side inclusive-charged-hadron yields for different trigger-particle transverse momenta ($p_T^{\rm trig}$). The Gaussian widths and root mean square of $p_{\rm out}$ are reported as a function of the interaction hard scale $p_T^{\rm trig}$ to investigate possible transverse-momentum-dependent evolution differences between the $\pi^0$-h$^\pm$ and direct photon-h$^\pm$ correlations and factorization breaking effects. The widths are found to decrease with $p_T^{\rm trig}$, which indicates that the Collins-Soper-Sterman soft factor is not driving the evolution with the hard scale in nearly back-to-back dihadron and direct photon-hadron production in $p$$+$$p$ collisions. This behavior is in contrast to Drell-Yan and semi-inclusive deep-inelastic scattering measurements.

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Measurement of jet-medium interactions via direct photon-hadron correlations in Au$+$Au and $d$$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV

The PHENIX collaboration Acharya, U. ; Adare, A. ; Afanasiev, S. ; et al.
Phys.Rev.C 102 (2020) 054910, 2020.
Inspire Record 1798493 DOI 10.17182/hepdata.101752

We present direct photon-hadron correlations in 200 GeV/A Au+Au, d+Au, and p+p collisions, for direct photon pT from 5–12 GeV/c, collected by the PHENIX Collaboration in the years from 2006 to 2011. We observe no significant modification of jet fragmentation in d+Au collisions, indicating that cold nuclear matter effects are small or absent. Hadrons carrying a large fraction of the quark's momentum are suppressed in Au+Au compared to p+p and d+Au. As the momentum fraction decreases, the yield of hadrons in Au+Au increases to an excess over the yield in p+p collisions. The excess is at large angles and at low hadron pT and is most pronounced for hadrons associated with lower momentum direct photons. Comparison to theoretical calculations suggests that the hadron excess arises from medium response to energy deposited by jets.

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Angular decay coefficients of $J/\psi$ mesons at forward rapidity from $p+p$ collisions at $\sqrt{s}=510$ GeV

The PHENIX collaboration Adare, A. ; Aidala, C. ; Ajitanand, N.N. ; et al.
Phys.Rev.D 95 (2017) 092003, 2017.
Inspire Record 1505176 DOI 10.17182/hepdata.141939

We report the first measurement of the full angular distribution for inclusive $J/\psi\rightarrow\mu^{+}\mu^{-}$ decays in $p$$+$$p$ collisions at $\sqrt{s}=510$ GeV. The measurements are made for $J/\psi$ transverse momentum $2<p_{T}<10$ GeV/$c$ and rapidity $1.2<y<2.2$ in the Helicity, Collins-Soper, and Gottfried-Jackson reference frames. In all frames the polar coefficient $\lambda_{\theta}$ is strongly negative at low $p_{T}$ and becomes close to zero at high $p_{T}$, while the azimuthal coefficient $\lambda_{\phi}$ is close to zero at low $p_{T}$, and becomes slightly negative at higher $p_{T}$. The frame-independent coefficient $\tilde{\lambda}$ is strongly negative at all $p_{T}$ in all frames. The data are compared to the theoretical predictions provided by nonrelativistic quantum chromodynamics models.

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Measurements of $B \rightarrow J/\psi$ at forward rapidity in $p+p$ collisions at $\sqrt{s}=510$ GeV

The PHENIX collaboration Aidala, C. ; Ajitanand, N.N. ; Akiba, Y. ; et al.
Phys.Rev.D 95 (2017) 092002, 2017.
Inspire Record 1507891 DOI 10.17182/hepdata.140435

We report the first measurement of the fraction of $J/\psi$ mesons coming from $B$-meson decay ($F_{B{\rightarrow}J/\psi}$) in $p$+$p$ collisions at $\sqrt{s}=$ 510 GeV. The measurement is performed using the forward silicon vertex detector and central vertex detector at PHENIX, which provide precise tracking and distance-of-closest-approach determinations, enabling the statistical separation of $J/\psi$ due to $B$-meson decays from prompt $J/\psi$. The measured value of $F_{B{\rightarrow}J/\psi}$ is 8.1\%$\pm$2.3\% (stat)$\pm$1.9\% (syst) for $J/\psi$ with transverse momenta $0<p_T<5$ GeV/$c$ and rapidity $1.2<|y|<2.2$. The measured fraction $F_{B{\rightarrow}J/\psi}$ at PHENIX is compared to values measured by other experiments at higher center of mass energies and to fixed-order-next-to-leading-logarithm and color-evaporation-model predictions. The $b\bar{b}$ cross section per unit rapidity ($d\sigma/dy(pp{\rightarrow}b\bar{b})$) extracted from the obtained $F_{B{\rightarrow}J/\psi}$ and the PHENIX inclusive $J/\psi$ cross section measured at 200 GeV scaled with color-evaporation-model calculations, at the mean $B$ hadron rapidity $y={\pm}1.7$ in 510 GeV $p$$+$$p$ collisions, is $3.63^{+1.92}_{-1.70}\mu$b, and it is consistent with the fixed-order-next-to-leading-logarithm calculations.

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Beam-energy and centrality dependence of direct-photon emission from ultra-relativistic heavy-ion collisions

The PHENIX collaboration Adare, A. ; Afanasiev, S. ; Aidala, C. ; et al.
Phys.Rev.Lett. 123 (2019) 022301, 2019.
Inspire Record 1672476 DOI 10.17182/hepdata.110699

The PHENIX collaboration presents first measurements of low-momentum ($0.4<p_T<3$ GeV/$c$) direct-photon yields from Au$+$Au collisions at $\sqrt{s_{_{NN}}}$=39 and 62.4 GeV. For both beam energies the direct-photon yields are substantially enhanced with respect to expectations from prompt processes, similar to the yields observed in Au$+$Au collisions at $\sqrt{s_{_{NN}}}$=200. Analyzing the photon yield as a function of the experimental observable $dN_{\rm ch}/d\eta$ reveals that the low-momentum ($>$1\,GeV/$c$) direct-photon yield $dN_{\gamma}^{\rm dir}/d\eta$ is a smooth function of $dN_{\rm ch}/d\eta$ and can be well described as proportional to $(dN_{\rm ch}/d\eta)^\alpha$ with $\alpha{\sim}$1.25. This new scaling behavior holds for a wide range of beam energies at the Relativistic Heavy Ion Collider and Large Hadron Collider, for centrality selected samples, as well as for different, $A$$+$$A$ collision systems. At a given beam energy the scaling also holds for high $p_T$ ($>5$\,GeV/$c$) but when results from different collision energies are compared, an additional $\sqrt{s_{_{NN}}}$-dependent multiplicative factor is needed to describe the integrated-direct-photon yield.

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Cross section and transverse single-spin asymmetry of muons from open heavy-flavor decays in polarized $p$+$p$ collisions at $\sqrt{s}=200$ GeV

The PHENIX collaboration Aidala, C. ; Ajitanand, N.N. ; Akiba, Y. ; et al.
Phys.Rev.D 95 (2017) 112001, 2017.
Inspire Record 1519828 DOI 10.17182/hepdata.142661

The cross section and transverse single-spin asymmetries of $\mu^{-}$ and $\mu^{+}$ from open heavy-flavor decays in polarized $p$+$p$ collisions at $\sqrt{s}=200$ GeV were measured by the PHENIX experiment during 2012 at the Relativistic Heavy Ion Collider. Because heavy-flavor production is dominated by gluon-gluon interactions at $\sqrt{s}=200$ GeV, these measurements offer a unique opportunity to obtain information on the trigluon correlation functions. The measurements are performed at forward and backward rapidity ($1.4<|y|<2.0$) over the transverse momentum range of $1.25<p_T<7$ GeV/$c$ for the cross section and $1.25<p_T<5$ GeV/$c$ for the asymmetry measurements. The obtained cross section is compared to a fixed-order-plus-next-to-leading-log perturbative-quantum-chromodynamics calculation. The asymmetry results are consistent with zero within uncertainties, and a model calculation based on twist-3 three-gluon correlations agrees with the data.

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Observation of Two Resonant Structures in e+e- to pi+ pi- psi(2S) via Initial State Radiation at Belle

The Belle collaboration Wang, X.L. ; Yuan, C.Z. ; Shen, C.P. ; et al.
Phys.Rev.Lett. 99 (2007) 142002, 2007.
Inspire Record 756643 DOI 10.17182/hepdata.51373

The cross section for e+e- to pi+ pi- psi(2S) between threshold and \sqrt{s}=5.5 GeV is measured using 673 fb^{-1} of data on and off the \Upsilon(4S) resonance collected with the Belle detector at KEKB. Two resonant structures are observed in the pi+ pi- psi(2S) invariant mass distribution, one at 4361\pm 9\pm 9 MeV/c2 with a width of 74\pm 15\pm 10 MeV/c2, and another at 4664\pm 11\pm 5 MeV/c2 with a width of 48\pm 15\pm 3 MeV/c2, if the mass spectrum is parameterized with the coherent sum of two Breit-Wigner functions. These values do not match those of any of the known charmonium states.

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Version 3
Single electron yields from semileptonic charm and bottom hadron decays in Au$+$Au collisions at $\sqrt{s_{NN}}=200$ GeV

The PHENIX collaboration Adare, A. ; Aidala, C. ; Ajitanand, N.N. ; et al.
Phys.Rev.C 93 (2016) 034904, 2016.
Inspire Record 1393529 DOI 10.17182/hepdata.99752

The PHENIX Collaboration at the Relativistic Heavy Ion Collider has measured open heavy-flavor production in minimum bias Au$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV via the yields of electrons from semileptonic decays of charm and bottom hadrons. Previous heavy-flavor electron measurements indicated substantial modification in the momentum distribution of the parent heavy quarks due to the quark-gluon plasma created in these collisions. For the first time, using the PHENIX silicon vertex detector to measure precision displaced tracking, the relative contributions from charm and bottom hadrons to these electrons as a function of transverse momentum are measured in Au$+$Au collisions. We compare the fraction of electrons from bottom hadrons to previously published results extracted from electron-hadron correlations in $p$$+$$p$ collisions at $\sqrt{s_{_{NN}}}=200$ GeV and find the fractions to be similar within the large uncertainties on both measurements for $p_T>4$ GeV/$c$. We use the bottom electron fractions in Au$+$Au and $p$$+$$p$ along with the previously measured heavy flavor electron $R_{AA}$ to calculate the $R_{AA}$ for electrons from charm and bottom hadron decays separately. We find that electrons from bottom hadron decays are less suppressed than those from charm for the region $3<p_T<4$ GeV/$c$.

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Measurement of two-particle correlations with respect to second- and third-order event planes in Au$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV

The PHENIX collaboration Adare, A. ; Afanasiev, S. ; Aidala, C. ; et al.
Phys.Rev.C 99 (2019) 054903, 2019.
Inspire Record 1658594 DOI 10.17182/hepdata.115992

We present measurements of azimuthal correlations of charged hadron pairs in $\sqrt{s_{_{NN}}}=200$ GeV Au$+$Au collisions after subtracting an underlying event using a model that includes higher-order azimuthal anisotropy $v_2$, $v_3$, and $v_4$. After subtraction, the away-side ($\Delta\phi\sim\pi)$ of the highest transverse-momentum trigger ($p_T>4$ GeV/$c$) correlations is suppressed compared to that of correlations measured in $p$$+$$p$ collisions. At the lowest associated particle $p_T$, the away-side shape and yield are modified. These observations are consistent with the scenario of radiative-jet energy loss. For the lowest-$p_T$ trigger correlations, an away-side yield exists and we explore the dependence of the shape of the away-side within the context of an underlying-event model. Correlations are also studied differentially versus event-plane angle $\Psi_n$. The angular correlations show an asymmetry when selecting the sign of the trigger-particle azimuthal angle with respect to the $\Psi_2$ event plane. This asymmetry and the measured suppression of the pair yield out of plane is consistent with a path-length-dependent energy loss. No $\Psi_3$ dependence can be resolved within experimental uncertainties.

1 data table match query

Per-trigger yields $Y(\Delta\phi)$ of dihadrons pairs measured in Au$+$Au collisions at $\sqrt{s_{_{NN}}}=200~{\rm GeV}$ after subtracting the underlying event model with several $p_T$ selections. Systematic uncertainties due to track matching are given.


Kinematic dependence of azimuthal anisotropies in $p$ $+$ Au, $d$ $+$ Au, $^3$He $+$ Au at $\sqrt{s_{_{NN}}}$ = 200 GeV 

The PHENIX collaboration Acharya, U.A. ; Adare, A. ; Aidala, C. ; et al.
Phys.Rev.C 105 (2022) 024901, 2022.
Inspire Record 2026169 DOI 10.17182/hepdata.132366

There is strong evidence for the formation of small droplets of quark-gluon plasma in $p/d/^{3}$He+Au collisions at the Relativistic Heavy Ion Collider (RHIC) and in $p$+$p$/Pb collisions at the Large Hadron Collider. In particular, the analysis of data at RHIC for different geometries obtained by varying the projectile size and shape has proven insightful. In the present analysis, we find excellent agreement with the previously published PHENIX at RHIC results on elliptical and triangular flow with an independent analysis via the two-particle correlation method, which has quite different systematic uncertainties and an independent code base. In addition, the results are extended to other detector combinations with different kinematic (pseudorapidity) coverage. These results provide additional constraints on contributions from nonflow and longitudinal decorrelations.

1 data table match query

$v_2$ vs $p_T$, p+Au at 200 GeV, 0-5% central, BBCS-FVTXS-CNT detector combination


Lévy-stable two-pion Bose-Einstein correlations in $\sqrt{s_{NN}}=200$ GeV Au$+$Au collisions

The PHENIX collaboration Adare, A. ; Aidala, C. ; Ajitanand, N.N. ; et al.
Phys.Rev.C 97 (2018) 064911, 2018.
Inspire Record 1624209 DOI 10.17182/hepdata.144180

We present a detailed measurement of charged two-pion correlation functions in 0%-30% centrality $\sqrt{s_{_{NN}}}=200$ GeV Au$+$Au collisions by the PHENIX experiment at the Relativistic Heavy Ion Collider. The data are well described by Bose-Einstein correlation functions stemming from L\'evy-stable source distributions. Using a fine transverse momentum binning, we extract the correlation strength parameter $\lambda$, the L\'evy index of stability $\alpha$ and the L\'evy length scale parameter $R$ as a function of average transverse mass of the pair $m_T$. We find that the positively and the negatively charged pion pairs yield consistent results, and their correlation functions are represented, within uncertainties, by the same L\'evy-stable source functions. The $\lambda(m_T)$ measurements indicate a decrease of the strength of the correlations at low $m_T$. The L\'evy length scale parameter $R(m_T)$ decreases with increasing $m_T$, following a hydrodynamically predicted type of scaling behavior. The values of the L\'evy index of stability $\alpha$ are found to be significantly lower than the Gaussian case of $\alpha=2$, but also significantly larger than the conjectured value that may characterize the critical point of a second-order quark-hadron phase transition.

1 data table match query

Example fits of Bose-Einstein correlation functions of (a) $\pi^{-}\pi^{-}$ pair with $m_{T}$ between 0.331 and 0.349 GeV/$c^2$ and of (b) $\pi^{+}\pi^{+}$ pair with $m_T$ between 0.655 and 0.675 GeV/$c^2$, as a function $Q$ ≡ |$q_{LCMS}$|, defined in Eq. (26). Both fits show the measured correlation function and the complete fit function (described in VI A), while a Bose-Einstein fit function $C^{(0)}_{2} (Q)$ is also shown, with the Coulomb-corrected data, i.e. the raw data multiplied by $C^{(0)}_{2} (Q)/C_{2}(Q)$. In this analysis we measured 62 such correlation functions (for ++ and -- pairs, in 31 $m_T$ bins), and fitted all of them with the method described in VIA. The first visible point on both panels corresponds to $Q$ values below the accessible range (based on an evaluation of the two-track cuts), these were not taken into account in the fitting.


Measurement of the Inclusive Jet Cross Section at the Fermilab Tevatron p-pbar Collider Using a Cone-Based Jet Algorithm

The CDF collaboration Aaltonen, T. ; Adelman, Jahred A. ; Akimoto, T. ; et al.
Phys.Rev.D 78 (2008) 052006, 2008.
Inspire Record 790693 DOI 10.17182/hepdata.52402

We present a measurement of the inclusive jet cross section in p-pbar collisions at sqrt{s}=1.96 TeV based on data collected by the CDF II detector with an integrated luminosity of 1.13 fb^-1. The measurement was made using the cone-based Midpoint jet clustering algorithm in the rapidity region of |y|<2.1. The results are consistent with next-to-leading-order perturbative QCD predictions based on recent parton distribution functions (PDFs), and are expected to provide increased precision in PDFs at high parton momentum fraction x. The results are also compared to the recent inclusive jet cross section measurement using the k_T jet clustering algorithm, and we find that the ratio of the cross sections measured with the two algorithms is in agreement with theoretical expectations over a large range of jet transverse momentum and rapidity.

11 data tables match query

Measured inclusive jet cross section as a function of jet transverse momentum in the absolute rapidity region < 0.1. The bin-by-bin correction factors from parton to hadron-level are also tabulated.

Measured inclusive jet cross section as a function of jet transverse momentum in the absolute rapidity region 0.1 to 0.7. The bin-by-bin correction factors from parton to hadron-level are also tabulated.

Measured inclusive jet cross section as a function of jet transverse momentum in the absolute rapidity region 0.7 to 1.1. The bin-by-bin correction factors from parton to hadron-level are also tabulated.

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Transverse-Momentum Dependence of the J/psi Nuclear Modification in d+Au Collisions at sqrt(s_NN)=200 GeV

The PHENIX collaboration Adare, A. ; Afanasiev, S. ; Aidala, C. ; et al.
Phys.Rev.C 87 (2013) 034904, 2013.
Inspire Record 1102930 DOI 10.17182/hepdata.142077

We present measured J/psi production rates in d+Au collisions at sqrt(s_NN) = 200 GeV over a broad range of transverse momentum (p_T=0-14 GeV/c) and rapidity (-2.2<y<2.2). We construct the nuclear-modification factor R_dAu for these kinematics and as a function of collision centrality (related to impact parameter for the R_dAu collision). We find that the modification is largest for collisions with small impact parameters, and observe a suppression (R_dAu<1) for p_T<4 GeV/c at positive rapidities. At negative rapidity we observe a suppression for p_T<2 GeV/c then an enhancement (R_dAu>1) for p_T>2 GeV/c. The observed enhancement at negative rapidity has implications for the observed modification in heavy-ion collisions at high p_T.

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Energy scan of the $e^+e^- \to h_b(nP)\pi^+\pi^-$ $(n=1,2)$ cross sections and evidence for the $\Upsilon(11020)$ decays into charged bottomonium-like states

The Belle collaboration Abdesselam, A. ; Adachi, I. ; Adamczyk, K. ; et al.
Phys.Rev.Lett. 117 (2016) 142001, 2016.
Inspire Record 1389855 DOI 10.17182/hepdata.74710

Using data collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider, we measure the energy dependence of the $e^+e^- \to h_b(nP)\pi^+\pi^-$ $(n=1,2)$ cross sections from thresholds up to $11.02\,$GeV. We find clear $\Upsilon(10860)$ and $\Upsilon(11020)$ peaks with little or no continuum contribution. We study the resonant substructure of the $\Upsilon(11020) \to h_b(nP)\pi^+\pi^-$ transitions and find evidence that they proceed entirely via the intermediate isovector states $Z_b(10610)$ and $Z_b(10650)$. The relative fraction of these states is loosely constrained by the current data: the hypothesis that only $Z_b(10610)$ is produced is excluded at the level of 3.3 standard deviations, while the hypothesis that only $Z_b(10650)$ is produced is not excluded at a significant level.

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Systematic study of nuclear effects in $p$ $+$Al, $p$ $+$Au, $d$ $+$Au, and $^{3}$He$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV using $\pi^0$ production

The PHENIX collaboration Acharya, U.A. ; Adare, A. ; Aidala, C. ; et al.
Phys.Rev.C 105 (2022) 064902, 2022.
Inspire Record 1965617 DOI 10.17182/hepdata.115023

The PHENIX collaboration presents a systematic study of $\pi^0$ production from $p$ $+$ $p$, $p$ $+$Al, $p$ $+$Au, $d$ $+$Au, and $^{3}$He$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV. Measurements were performed with different centrality selections as well as the total inelastic, 0%--100%, selection for all collision systems. For 0%--100% collisions, the nuclear modification factors, $R_{xA}$, are consistent with unity for $p_T$ above 8 GeV/$c$, but exhibit an enhancement in peripheral collisions and a suppression in central collisions. The enhancement and suppression characteristics are similar for all systems for the same centrality class. It is shown that for high-$p_T$-$\pi^0$ production, the nucleons in the $d$ and $^3$He interact mostly independently with the Au nucleus and that the counter intuitive centrality dependence is likely due to a physical correlation between multiplicity and the presence of a hard scattering process. These observations disfavor models where parton energy loss has a significant contribution to nuclear modifications in small systems. Nuclear modifications at lower $p_T$ resemble the Cronin effect -- an increase followed by a peak in central or inelastic collisions and a plateau in peripheral collisions. The peak height has a characteristic ordering by system size as $p$ $+$Au $>$ $d$ $+$Au $>$ $^{3}$He$+$Au $>$ $p$ $+$Al. For collisions with Au ions, current calculations based on initial state cold nuclear matter effects result in the opposite order, suggesting the presence of other contributions to nuclear modifications, in particular at lower $p_T$.

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Direct measurement of the top quark mass at D\O

The D0 collaboration Abbott, B. ; Abolins, M. ; Acharya, B.S. ; et al.
Phys.Rev.D 58 (1998) 052001, 1998.
Inspire Record 466578 DOI 10.17182/hepdata.42170

We determine the top quark mass m_t using t-tbar pairs produced in the D0 detector by \sqrt{s} = 1.8 TeV p-pbar collisions in a 125 pb^-1 exposure at the Fermilab Tevatron. We make a two constraint fit to m_t in t-tbar -> b W^+bbar W^- final states with one W boson decaying to q-qbar and the other to e-nu or mu-nu. Likelihood fits to the data yield m_t(l+jets) = 173.3 +- 5.6 (stat) +- 5.5 (syst) GeV/c^2. When this result is combined with an analysis of events in which both W bosons decay into leptons, we obtain m_t = 172.1 +- 5.2 (stat) +- 4.9 (syst) GeV/c^2. An alternate analysis, using three constraint fits to fixed top quark masses, gives m_t(l+jets) = 176.0 +- 7.9 (stat) +- 4.8 (syst) GeV/C^2, consistent with the above result. Studies of kinematic distributions of the top quark candidates are also presented.

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Version 2
Search for long-lived particles decaying to a pair of muons in proton-proton collisions at $\sqrt{s}$ = 13 TeV

The CMS collaboration Tumasyan, Armen ; Adam, Wolfgang ; Andrejkovic, Janik Walter ; et al.
JHEP 05 (2023) 228, 2023.
Inspire Record 2083735 DOI 10.17182/hepdata.129518

An inclusive search for long-lived exotic particles decaying to a pair of muons is presented. The search uses data collected by the CMS experiment at the CERN LHC in proton-proton collisions at $\sqrt{s}$ = 13 TeV in 2016 and 2018 and corresponding to an integrated luminosity of 97.6 fb$^{-1}$. The experimental signature is a pair of oppositely charged muons originating from a common secondary vertex spatially separated from the pp interaction point by distances ranging from several hundred $\mu$m to several meters. The results are interpreted in the frameworks of the hidden Abelian Higgs model, in which the Higgs boson decays to a pair of long-lived dark photons Z$_\mathrm{D}$, and of a simplified model, in which long-lived particles are produced in decays of an exotic heavy neutral scalar boson. For the hidden Abelian Higgs model with $m_\mathrm{Z_D}$ greater than 20 GeV and less than half the mass of the Higgs boson, they provide the best limits to date on the branching fraction of the Higgs boson to dark photons for $c\tau$(Z$_\mathrm{D}$) (varying with $m_\mathrm{Z_D}$) between 0.03 and ${\approx}$ 0.5 mm, and above ${\approx}$ 0.5 m. Our results also yield the best constraints on long-lived particles with masses larger than 10 GeV produced in decays of an exotic scalar boson heavier than the Higgs boson and decaying to a pair of muons.

0 data tables match query

Study of $\phi$-meson production in $p+$Al, $p+$Au, $d+$Au, and $^3$He$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV

The PHENIX collaboration Acharya, U. ; Adare, A. ; Aidala, C. ; et al.
Phys.Rev.C 106 (2022) 014908, 2022.
Inspire Record 2050486 DOI 10.17182/hepdata.130267

Small nuclear collisions are mainly sensitive to cold-nuclear-matter effects; however, the collective behavior observed in these collisions shows a hint of hot-nuclear-matter effects. The identified-particle spectra, especially the $\phi$ mesons which contain strange and antistrange quarks and have a relatively small hadronic-interaction cross section, are a good tool to study these effects. The PHENIX experiment has measured $\phi$ mesons in a specific set of small collision systems $p$$+$Al, $p$$+$Au, and $^3$He$+$Au, as well as $d$$+$Au [Phys. Rev. C {\bf 83}, 024909 (2011)], at $\sqrt{s_{_{NN}}}=200$ GeV. The transverse-momentum spectra and nuclear-modification factors are presented and compared to theoretical-model predictions. The comparisons with different calculations suggest that quark-gluon plasma may be formed in these small collision systems at $\sqrt{s_{_{NN}}}=200$ GeV. However, the volume and the lifetime of the produced medium may be insufficient for observing strangeness-enhancement and jet-quenching effects. Comparison with calculations suggests that the main production mechanisms of $\phi$ mesons at midrapidity may be different in $p$$+$Al versus $p/d/$$^3$He$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV. While thermal quark recombination seems to dominate in $p/d/$$^3$He$+$Au collisions, fragmentation seems to be the main production mechanism in $p$$+$Al collisions.

0 data tables match query

Upsilon dipion transitions at energies near the Upsilon(4S).

The CLEO collaboration Glenn, S. ; Kwon, Y. ; Lyon, Adam L. ; et al.
Phys.Rev.D 59 (1999) 052003, 1999.
Inspire Record 474676 DOI 10.17182/hepdata.47202

Using a data sample collected with the CLEO II detector at CESR, we have searched for dipion transitions between pairs of $\Upsilon$ resonances at energies near the $\Upsilon(4S)$. We obtain upper limits $B(\Upsilon(4S)\to \Upsilon(2S)\pi^+\pi^-) < 3.9 \times 10^{-4}$ and $B(\Upsilon(4S)\to \Upsilon(1S)\pi^+\pi^-) < 1.2 \times 10^{-4}$. We also observe the transitions $\Upsilon(3S)\to \Upsilon(1S)$, $\Upsilon(3S)\to \Upsilon(2S)$, and $\Upsilon(2S)\to \Upsilon(1S)$, from which we measure the cross-sections for the radiative processes $e^+e^- \to \Upsilon(3S)\gamma$ and $e^+e^- \to \Upsilon(2S)\gamma$.

0 data tables match query

Low-momentum direct photon measurement in Cu$+$Cu collisions at $\sqrt{s_{_{NN}}}=200$ GeV

The PHENIX collaboration Adare, A. ; Afanasiev, S. ; Aidala, C. ; et al.
Phys.Rev.C 98 (2018) 054902, 2018.
Inspire Record 1672473 DOI 10.17182/hepdata.143521

We have measured direct photons for $p_T<5~$GeV/$c$ in minimum bias and 0\%--40\% most central events at midrapidity for Cu$+$Cu collisions at $\sqrt{s_{_{NN}}}=200$ GeV. The $e^{+}e^{-}$ contribution from quasi-real direct virtual photons has been determined as an excess over the known hadronic contributions in the $e^{+}e^{-}$ mass distribution. A clear enhancement of photons over the binary scaled $p$$+$$p$ fit is observed for $p_T<4$ GeV/$c$ in Cu$+$Cu data. The $p_T$ spectra are consistent with the Au$+$Au data covering a similar number of participants. The inverse slopes of the exponential fits to the excess after subtraction of the $p$$+$$p$ baseline are 285$\pm$53(stat)$\pm$57(syst)~MeV/$c$ and 333$\pm$72(stat)$\pm$45(syst)~MeV/$c$ for minimum bias and 0\%--40\% most central events, respectively. The rapidity density, $dN/dy$, of photons demonstrates the same power law as a function of $dN_{\rm ch}/d\eta$ observed in Au$+$Au at the same collision energy.

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Azimuthal anisotropy of dijet events in PbPb collisions at $\sqrt{s_\mathrm{NN}}$ = 5.02 TeV

The CMS collaboration Tumasyan, Armen ; Adam, Wolfgang ; Andrejkovic, Janik Walter ; et al.
JHEP 07 (2023) 139, 2023.
Inspire Record 2165916 DOI 10.17182/hepdata.130961

The path-length dependent parton energy loss within the dense partonic medium created in lead-lead collisions at a nucleon-nucleon center-of-mass energy of $\sqrt{s_\mathrm{NN}}$ = 5.02 TeV is studied by determining the azimuthal anisotropies for dijets with high transverse momentum. The data were collected by the CMS experiment in 2018 and correspond to an integrated luminosity of 1.69 nb$^{-1}$. For events containing back-to-back jets, correlations in relative azimuthal angle and pseudorapidity ($\eta$) between jets and hadrons, and between two hadrons, are constructed. The anisotropies are expressed as the Fourier expansion coefficients $v_n$, $n = $ 2-4 of these azimuthal distributions. The dijet $v_n$ values are extracted from long-range (1.5 $\lt$$\vert\Delta\eta\vert$$\lt$ 2.5) components of these correlations, which suppresses the background contributions from jet fragmentation processes. Positive dijet $v_2$ values are observed which increase from central to more peripheral events, while the $v_3$ and $v_4$ values are consistent with zero within experimental uncertainties.

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Search for $B^{+}\to K^{+}\nu\bar{\nu}$ decays using an inclusive tagging method at Belle II

The Belle-II collaboration Abudinén, F. ; Adachi, I. ; Adamczyk, K. ; et al.
Phys.Rev.Lett. 127 (2021) 181802, 2021.
Inspire Record 1860766 DOI 10.17182/hepdata.130199

A search for the flavor-changing neutral-current decay $B^{+}\to K^{+}\nu\bar{\nu}$ is performed at the Belle II experiment at the SuperKEKB asymmetric energy electron-positron collider. The results are based on a data sample corresponding to an integrated luminosity of $63\,\mbox{fb}^{-1}$ collected at the $\Upsilon{(4S)}$ resonance and a sample of $9\,\mbox{fb}^{-1}$ collected at an energy $60\mathrm{\,Me\kern -0.1em V}$ below the resonance. A novel measurement method is employed, which exploits topological properties of the $B^{+}\to K^{+}\nu\bar{\nu}$ decay that differ from both generic bottom-meson decays and light-quark pair production. This inclusive tagging approach offers a higher signal efficiency compared to previous searches. No significant signal is observed. An upper limit on the branching fraction of $B^{+}\to K^{+}\nu\bar{\nu}$ of $4.1 \times 10^{-5}$ is set at the 90% confidence level.

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Measurement of $e^+e^- \to \pi^+\pi^-\psi(2S)$ via Initial State Radiation at Belle

The Belle collaboration Wang, X.L. ; Yuan, C.Z. ; Shen, C.P. ; et al.
Phys.Rev.D 91 (2015) 112007, 2015.
Inspire Record 1324785 DOI 10.17182/hepdata.71501

We report measurement of the cross section of $e^+e^-\to \pi^+\pi^-\psi(2S)$ between 4.0 and $5.5 {\rm GeV}$, based on an analysis of initial state radiation events in a $980 \rm fb^{-1}$ data sample recorded with the Belle detector. The properties of the $Y(4360)$ and $Y(4660)$ states are determined. Fitting the mass spectrum of $\pi^+\pi^-\psi(2S)$ with two coherent Breit-Wigner functions, we find two solutions with identical mass and width but different couplings to electron-positron pairs: $M_{Y(4360)} = (4347\pm 6\pm 3) {\rm MeV}/c^2$, $\Gamma_{Y(4360)} = (103\pm 9\pm 5) {\rm MeV}$, $M_{Y(4660)} = (4652\pm10\pm 8) {\rm MeV}/c^2$, $\Gamma_{Y(4660)} = (68\pm 11\pm 1) \rm MeV$; and ${\cal{B}}[Y(4360)\to \pi^+\pi^-\psi(2S)]\cdot \Gamma_{Y(4360)}^{e^+e^-} = (10.9\pm 0.6\pm 0.7) \rm eV$ and ${\cal{B}}[Y(4660)\to \pi^+\pi^-\psi(2S)]\cdot \Gamma_{Y(4660)}^{e^+e^-} = (8.1\pm 1.1\pm 0.5) \rm eV$ for one solution; or ${\cal{B}}[Y(4360)\to \pi^+\pi^-\psi(2S)]\cdot \Gamma_{Y(4360)}^{e^+e^-} = (9.2\pm 0.6\pm 0.6) \rm eV$ and ${\cal{B}}[Y(4660)\to \pi^+\pi^-\psi(2S)]\cdot \Gamma_{Y(4660)}^{e^+e^-} = (2.0\pm 0.3\pm 0.2) \rm eV$ for the other. Here, the first errors are statistical and the second systematic. Evidence for a charged charmoniumlike structure at $4.05 {\rm GeV}/c^2$ is observed in the $\pi^{\pm}\psi(2S)$ intermediate state in the $Y(4360)$ decays.

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B-meson production at forward and backward rapidity in $p$+$p$ and Cu+Au collisions at $\sqrt{s_{_{NN}}}$=200 GeV

The PHENIX collaboration Aidala, C. ; Ajitanand, N.N. ; Akiba, Y. ; et al.
Phys.Rev.C 96 (2017) 064901, 2017.
Inspire Record 1512141 DOI 10.17182/hepdata.141715

The fraction of $J/\psi$ mesons which come from B-meson decay, $\textrm{F}_{B{\rightarrow}J/\psi}$, is measured for J/$\psi$ rapidity \mbox{$1.2<|y|<2.2$} and $p_T>0$ in $p$+$p$ and Cu+Au collisions at $\sqrt{s_{_{NN}}}$=200 GeV with the PHENIX detector. The extracted fraction is $\textrm{F}_{B{\rightarrow}J/\psi}$ = 0.025 $\pm$ 0.006(stat) $\pm$ 0.010(syst) for $p$+$p$ collisions. For Cu+Au collisions, $\textrm{F}_{B{\rightarrow}J/\psi}$ is 0.094 $\pm$ 0.028(stat) $\pm$ 0.037(syst) in the Au-going direction ($-2.2<y<-1.2$) and 0.089 $\pm$ 0.026(stat) $\pm$ 0.040(syst) in the Cu-going direction ($1.2<y<2.2$). The nuclear modification factor, $R_{\rm CuAu}$, of B mesons in Cu+Au collisions is consistent with binary scaling of measured yields in $p$+$p$ at both forward and backward rapidity.

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Nuclear modification factors of phi mesons in d+Au, Cu+Cu and Au+Au collisions at sqrt(S_NN)=200 GeV

The PHENIX collaboration Adare, A. ; Afanasiev, S. ; Aidala, C. ; et al.
Phys.Rev.C 83 (2011) 024909, 2011.
Inspire Record 852260 DOI 10.17182/hepdata.141454

The PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) has performed systematic measurements of phi meson production in the K+K- decay channel at midrapidity in p+p, d+Au, Cu+Cu and Au+Au collisions at sqrt(S_NN)=200 GeV. Results are presented on the phi invariant yield and the nuclear modification factor R_AA for Au+Au and Cu+Cu, and R_dA for d+Au collisions, studied as a function of transverse momentum (1&lt;p_T&lt;7 GeV/c) and centrality. In central and mid-central Au+Au collisions, the R_AA of phi exhibits a suppression relative to expectations from binary scaled p+p results. The amount of suppression is smaller than that of the neutral pion and the eta meson in the intermediate p_T range (2--5 GeV/c); whereas at higher p_T the phi, pi^0, and eta show similar suppression. The baryon (protons and anti-protons) excess observed in central Au+Au collisions at intermediate p_T is not observed for the phi meson despite the similar mass of the proton and the phi. This suggests that the excess is linked to the number of constituent quarks rather than the hadron mass. The difference gradually disappears with decreasing centrality and for peripheral collisions the R_AA values for both particles are consistent with binary scaling. Cu+Cu collisions show the same yield and suppression as Au+Au collisions for the same number of N_part. The R_dA of phi shows no evidence for cold nuclear effects within uncertainties.

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Total p-p and 'p-n' Cross Sections at Cosmotron Energies

Chen, Francis F. ; Leavitt, Christopher P. ; Shapiro, Anatole M. ;
Phys.Rev. 103 (1956) 211-225, 1956.
Inspire Record 46809 DOI 10.17182/hepdata.828

The total proton-proton cross section (excluding Coulomb scattering) has been measured at energies from 410 Mev up to 2.6 Bev, using external beams from the Cosmotron. Fast counting equipment was used to measure the attenuation of the beams through polyethylene, carbon, and liquid H2 absorbers. At each energy E, σp−p(E, Ω) was measured as a function of the solid angle Ω subtended by the rear counter at the center of the absorber. The total cross section σp−p was obtained by a least squares straight line extrapolation to Ω=0. The measured σp−p as a function of energy rises sharply from 26.5 mb at 410 Mev to 47.8 mb at 830 Mev and then remains approximately constant out to 1.4 Bev, above which energy it decreases gradually to about 42 mb at 2.6 Bev. Using the same equipment and procedure, we have also measured the D2O-H2O difference cross section, called "σp−n," for protons over the same energy range. From a comparison of "σp−n," and σp−p, with the n−p and n−d measurements of Coor et al. at 1.4 Bev, it is apparent that one nucleon is "shielded" by the other in the deuteron. This effect is not present at energies below 410 Mev. Comparing the measured p−p and "p−n" (corrected) cross sections with the results of other high-energy experiments, one may infer the following conclusions: (1) The sharp rise in σp−p from 400 to 800 Mev results from increasing single pion production, which may proceed through the T=32, J=32 excited nucleon state. (2) Above 1 Bev the inelastic (meson production) p−p cross section appears to be approximately saturated at 27-29 mb. (3) The rise in cross section for n−p interaction in the T=0 state, associated with the rise in double pion production, implies that double meson production also proceeds through the T=32 nucleon state. (4) The probable equality of σp−d and σn−d at 1.4 Bev implies the validity of charge symmetry at this energy.

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Study of $e^+e^- \rightarrow p\bar{p}$ in the vicinity of $\psi(3770)$

The BESIII collaboration Ablikim, M. ; Achasov, M.N. ; Ai, X.C. ; et al.
Phys.Lett.B 735 (2014) 101-107, 2014.
Inspire Record 1286898 DOI 10.17182/hepdata.64597

Using 2917 $\rm{pb}^{-1}$ of data accumulated at 3.773~$\rm{GeV}$, 44.5~$\rm{pb}^{-1}$ of data accumulated at 3.65~$\rm{GeV}$ and data accumulated during a $\psi(3770)$ line-shape scan with the BESIII detector, the reaction $e^+e^-\rightarrow p\bar{p}$ is studied considering a possible interference between resonant and continuum amplitudes. The cross section of $e^+e^-\rightarrow\psi(3770)\rightarrow p\bar{p}$, $\sigma(e^+e^-\rightarrow\psi(3770)\rightarrow p\bar{p})$, is found to have two solutions, determined to be ($0.059\pm0.032\pm0.012$) pb with the phase angle $\phi = (255.8\pm37.9\pm4.8)^\circ$ ($<$0.11 pb at the 90% confidence level), or $\sigma(e^+e^-\rightarrow\psi(3770)\rightarrow p\bar{p}) = (2.57\pm0.12\pm0.12$) pb with $\phi = (266.9\pm6.1\pm0.9)^\circ$ both of which agree with a destructive interference. Using the obtained cross section of $\psi(3770)\rightarrow p\bar{p}$, the cross section of $p\bar{p}\rightarrow \psi(3770)$, which is useful information for the future PANDA experiment, is estimated to be either ($9.8\pm5.7$) nb ($<17.2$ nb at 90% C.L.) or $(425.6\pm42.9)$ nb.

0 data tables match query

Distributions of charged hadrons associated with high transverse momentum particles in p p and Au + Au collisions at s(NN)**(1/2) = 200-GeV.

The STAR collaboration Adams, J. ; Adler, C. ; Aggarwal, M.M. ; et al.
Phys.Rev.Lett. 95 (2005) 152301, 2005.
Inspire Record 675307 DOI 10.17182/hepdata.96233

Charged hadrons in 0.15 < pt < 4 GeV/c associated with particles of pt^trig > 4 GeV/c are reconstructed in pp and Au+Au collisions at sqrt(s_NN)=200 GeV. The associated multiplicity and pt magnitude sum are found to increase from pp to central Au+Au collisions. The associated pt distributions, while similar in shape on the near side, are significantly softened on the away side in central Au+Au relative to pp and not much harder than that of inclusive hadrons. The results, consistent with jet quenching, suggest that the away-side fragments approach equilibration with the medium traversed.

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A glimpse of gluons through deeply virtual compton scattering on the proton

Defurne, M. ; Martí Jiménez-Argüello, A. ; Ahmed, Z. ; et al.
Nature Commun. 8 (2017) 1408, 2017.
Inspire Record 1519829 DOI 10.17182/hepdata.78261

The proton is composed of quarks and gluons, bound by the most elusive mechanism of strong interaction called confinement. In this work, the dynamics of quarks and gluons are investigated using deeply virtual Compton scattering (DVCS): produced by a multi-GeV electron, a highly virtual photon scatters off the proton which subsequently radiates a high energy photon. Similarly to holography, measuring not only the magnitude but also the phase of the DVCS amplitude allows to perform 3D images of the internal structure of the proton. The phase is made accessible through the quantum-mechanical interference of DVCS with the Bethe-Heitler (BH) process, in which the final photon is emitted by the electron rather than the proton. We report herein the first full determination of the BH-DVCS interference by exploiting the distinct energy dependences of the DVCS and BH amplitudes. In the high energy regime where the scattering process is expected to occur off a single quark in the proton, these accurate measurements show an intriguing sensitivity to gluons, the carriers of the strong interaction.

1 data table match query

Beam helicity dependent cross sections. The first systematic uncertainty is the combined correlated systematic uncertainty, the second is the point-to-point systematic uncertainty to add quadratically to the statistical uncertainty.


Studies of topological distributions of inclusive the three and four jet events in anti-P P collisions at s**(1/2) = 1800-GeV with the D0 detector

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Rev.D 53 (1996) 6000-6016, 1996.
Inspire Record 399364 DOI 10.17182/hepdata.11124

The global topologies of inclusive three-- and four--jet events produced in $\pp$ interactions are described. The three-- and four--jet events are selected from data recorded by the D\O\ detector at the Tevatron Collider operating at a center--of--mass energy of $\sqrt{s} = 1800$ GeV. The measured, normalized distributions of various topological variables are compared with parton--level predictions of tree--level QCD calculations. The parton--level QCD calculations are found to be in good agreement with the data. The studies also show that the topological distributions of the different subprocesses involving different numbers of quarks are very similar and reproduce the measured distributions well. The parton shower Monte Carlo generators provide a less satisfactory description of the topologies of the three-- and four--jet events.

29 data tables match query

The estimated systematic uncertainty is 6 PCT.

The estimated systematic uncertainty is 6 PCT.

The estimated systematic uncertainty is 6 PCT.

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Measurement of J / psi and psi(2S) polarization in p anti-p collisions at S**(1/2) = 1.8-TeV

The CDF collaboration Affolder, T. ; Akimoto, H. ; Akopian, A. ; et al.
Phys.Rev.Lett. 85 (2000) 2886-2891, 2000.
Inspire Record 526553 DOI 10.17182/hepdata.42989

We have measured the polarization of J/Psi and Psi(2S) mesons produced in p\bar{p} collisions at \sqrt{s} = 1.8 TeV, using data collected at CDF during 1992-95. The polarization of promptly produced J/Psi [Psi(2S)] mesons is isolated from those produced in B-hadron decay, and measured over the kinematic range 4[5.5] < P_T < 20 GeV/c and |y| < 0.6. For P_T \gessim 12 GeV/c we do not observe significant polarization in the prompt component.

0 data tables match query

Observation of the antimatter helium-4 nucleus

The STAR collaboration Agakishiev, H. ; Aggarwal, M.M. ; Ahammed, Z. ; et al.
Nature 473 (2011) 353, 2011.
Inspire Record 893021 DOI 10.17182/hepdata.58495

High-energy nuclear collisions create an energy density similar to that of the universe microseconds after the Big Bang, and in both cases, matter and antimatter are formed with comparable abundance. However, the relatively short-lived expansion in nuclear collisions allows antimatter to decouple quickly from matter, and avoid annihilation. Thus, a high energy accelerator of heavy nuclei is an efficient means of producing and studying antimatter. The antimatter helium-4 nucleus ($^4\bar{He}$), also known as the anti-{\alpha} ($\bar{\alpha}$), consists of two antiprotons and two antineutrons (baryon number B=-4). It has not been observed previously, although the {\alpha} particle was identified a century ago by Rutherford and is present in cosmic radiation at the 10% level. Antimatter nuclei with B < -1 have been observed only as rare products of interactions at particle accelerators, where the rate of antinucleus production in high-energy collisions decreases by about 1000 with each additional antinucleon. We present the observation of the antimatter helium-4 nucleus, the heaviest observed antinucleus. In total 18 $^4\bar{He}$ counts were detected at the STAR experiment at RHIC in 10$^9$ recorded Au+Au collisions at center-of-mass energies of 200 GeV and 62 GeV per nucleon-nucleon pair. The yield is consistent with expectations from thermodynamic and coalescent nucleosynthesis models, which has implications beyond nuclear physics.

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Transverse momentum and pseudorapidity distributions of charged hadrons in pp collisions at sqrt(s) = 0.9 and 2.36 TeV

The CMS collaboration Khachatryan, Vardan ; Sirunyan, Albert M. ; Tumasyan, Armen ; et al.
JHEP 02 (2010) 041, 2010.
Inspire Record 845323 DOI 10.17182/hepdata.54829

Measurements of inclusive charged-hadron transverse-momentum and pseudorapidity distributions are presented for proton-proton collisions at sqrt(s) = 0.9 and 2.36 TeV. The data were collected with the CMS detector during the LHC commissioning in December 2009. For non-single-diffractive interactions, the average charged-hadron transverse momentum is measured to be 0.46 +/- 0.01 (stat.) +/- 0.01 (syst.) GeV/c at 0.9 TeV and 0.50 +/- 0.01 (stat.) +/- 0.01 (syst.) GeV/c at 2.36 TeV, for pseudorapidities between -2.4 and +2.4. At these energies, the measured pseudorapidity densities in the central region, dN(charged)/d(eta) for |eta| < 0.5, are 3.48 +/- 0.02 (stat.) +/- 0.13 (syst.) and 4.47 +/- 0.04 (stat.) +/- 0.16 (syst.), respectively. The results at 0.9 TeV are in agreement with previous measurements and confirm the expectation of near equal hadron production in p-pbar and pp collisions. The results at 2.36 TeV represent the highest-energy measurements at a particle collider to date.

0 data tables match query

Combination of CMS searches for heavy resonances decaying to pairs of bosons or leptons

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Lett.B 798 (2019) 134952, 2019.
Inspire Record 1737724 DOI 10.17182/hepdata.88899

A statistical combination of searches for heavy resonances decaying to pairs of bosons or leptons is presented. The data correspond to an integrated luminosity of 35.9 fb$^{-1}$ collected during 2016 by the CMS experiment at the LHC in proton-proton collisions at a center-of-mass energy of 13 TeV. The data are found to be consistent with expectations from the standard model background. Exclusion limits are set in the context of models of spin-1 heavy vector triplets and of spin-2 bulk gravitons. For mass-degenerate W' and Z' resonances that predominantly couple to the standard model gauge bosons, the mass exclusion at 95% confidence level of heavy vector bosons is extended to 4.5 TeV as compared to 3.8 TeV determined from the best individual channel. This excluded mass increases to 5.0 TeV if the resonances couple predominantly to fermions.

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Measurements of the S-wave fraction in $B^{0}\rightarrow K^{+}\pi^{-}\mu^{+}\mu^{-}$ decays and the $B^{0}\rightarrow K^{\ast}(892)^{0}\mu^{+}\mu^{-}$ differential branching fraction

The LHCb collaboration Aaij, Roel ; Adeva, Bernardo ; Adinolfi, Marco ; et al.
JHEP 11 (2016) 047, 2016.
Inspire Record 1469448 DOI 10.17182/hepdata.82576

A measurement of the differential branching fraction of the decay ${B^{0}\rightarrow K^{\ast}(892)^{0}\mu^{+}\mu^{-}}$ is presented together with a determination of the S-wave fraction of the $K^+\pi^-$ system in the decay $B^{0}\rightarrow K^{+}\pi^{-}\mu^{+}\mu^{-}$. The analysis is based on $pp$-collision data corresponding to an integrated luminosity of 3\,fb$^{-1}$ collected with the LHCb experiment. The measurements are made in bins of the invariant mass squared of the dimuon system, $q^2$. Precise theoretical predictions for the differential branching fraction of $B^{0}\rightarrow K^{\ast}(892)^{0}\mu^{+}\mu^{-}$ decays are available for the $q^2$ region $1.1<q^2<6.0\,{\rm GeV}^2/c^4$. In this $q^2$ region, for the $K^+\pi^-$ invariant mass range $796 < m_{K\pi} < 996\,{\rm MeV}/c^2$, the S-wave fraction of the $K^+\pi^-$ system in $B^{0}\rightarrow K^{+}\pi^{-}\mu^{+}\mu^{-}$ decays is found to be \begin{equation*} F_{\rm S} = 0.101\pm0.017({\rm stat})\pm0.009 ({\rm syst}), \end{equation*} and the differential branching fraction of $B^{0}\rightarrow K^{\ast}(892)^{0}\mu^{+}\mu^{-}$ decays is determined to be \begin{equation*} {\rm d}\mathcal{B}/{\rm d} q^2 = (0.342_{\,-0.017}^{\,+0.017}({\rm stat})\pm{0.009}({\rm syst})\pm0.023({\rm norm}))\times 10^{-7}c^{4}/{\rm GeV}^{2}. \end{equation*} The differential branching fraction measurements presented are the most precise to date and are found to be in agreement with Standard Model predictions.

0 data tables match query

Transverse-momentum p(t) correlations on (eta,Phi) from mean-p(t) fluctuations in Au - Au collisions at s(NN)**(1/2) = 200-GeV.

The STAR collaboration Adams, John ; Aggarwal, M.M. ; Ahammed, Z. ; et al.
J.Phys.G 32 (2006) L37-L48, 2006.
Inspire Record 693136 DOI 10.17182/hepdata.102092

We present first measurements of the pseudorapidity and azimuth $(\eta,\phi)$ bin-size dependence of event-wise mean transverse momentum $<p_{t} >$ fluctuations for Au-Au collisions at $\sqrt{s_{NN}} = 200$ GeV. We invert that dependence to obtain $p_t$ autocorrelations on differences $(\eta_\Delta,\phi_\Delta)$ interpreted to represent velocity/temperature distributions on ($\eta,\phi$). The general form of the autocorrelations suggests that the basic correlation mechanism is parton fragmentation. The autocorrelations vary strongly with collision centrality, which suggests that fragmentation is strongly modified by a dissipative medium in the more central

0 data tables match query

Energy dependence of $\pi^{\pm}$, $p$ and $\bar{p}$ transverse momentum spectrafor Au+Au collisions at $\sqrt{s_{\mathrm {NN}}}$~=~62.4 and 200 GeV

The STAR collaboration Abelev, B.I. ; Aggarwal, M.M. ; Ahammed, Z. ; et al.
Phys.Lett.B 655 (2007) 104-113, 2007.
Inspire Record 747299 DOI 10.17182/hepdata.100592

We study the energy dependence of the transverse momentum (pT) spectra for charged pions, protons and anti-protons for Au+Au collisions at \sqrt{s_NN} = 62.4 and 200 GeV. Data are presented at mid-rapidity (|y| &lt; 0.5) for 0.2 &lt; pT &lt; 12 GeV/c. In the intermediate pT region (2 &lt; pT &lt; 6 GeV/c), the nuclear modification factor is higher at 62.4 GeV than at 200 GeV, while at higher pT (pT >7 GeV/c) the modification is similar for both energies. The p/pi+ and pbar/pi- ratios for central collisions at \sqrt{s_NN} = 62.4 GeV peak at pT ~ 2 GeV/c. In the pT range where recombination is expected to dominate, the p/pi+ ratios at 62.4 GeV are larger than at 200 GeV, while the pbar/pi- ratios are smaller. For pT > 2 GeV/c, the pbar/pi- ratios at the two beam energies are independent of pT and centrality indicating that the dependence of the pbar/pi- ratio on pT does not change between 62.4 and 200 GeV. These findings challenge various models incorporating jet quenching and/or constituent quark coalescence.

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Version 2
Search for heavy Higgs bosons decaying to a top quark pair in proton-proton collisions at $\sqrt{s} =$ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP 04 (2020) 171, 2020.
Inspire Record 1747886 DOI 10.17182/hepdata.89937

A search is presented for additional scalar (H) or pseudoscalar (A) Higgs bosons decaying to a top quark pair in proton-proton collisions at a center-of-mass energy of 13 TeV. The data set analyzed corresponds to an integrated luminosity of 35.9 fb$^{-1}$ collected by the CMS experiment at the LHC. Final states with one or two charged leptons are considered. The invariant mass of the reconstructed top quark pair system and variables that are sensitive to the spin of the particles decaying into the top quark pair are used to search for signatures of the H or A bosons. The interference with the standard model top quark pair background is taken into account. A moderate signal-like deviation compatible with an A boson with a mass of 400 GeV is observed with a global significance of 1.9 standard deviations. New stringent constraints are reported on the strength of the coupling of the hypothetical bosons to the top quark, with the mass of the bosons ranging from 400 to 750 GeV and their total relative width from 0.5 to 25%. The results of the search are also interpreted in a minimal supersymmetric standard model scenario. Values of $m_\mathrm{A}$ from 400 to 700 GeV are probed, and a region with values of $\tan\beta$ below 1.0 to 1.5, depending on $m_\mathrm{A}$, is excluded at 95% confidence level.

0 data tables match query

Version 2
Measurement of the jet mass distribution and top quark mass in hadronic decays of boosted top quarks in pp collisions at $\sqrt{s} =$ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Rev.Lett. 124 (2020) 202001, 2020.
Inspire Record 1764472 DOI 10.17182/hepdata.93067

A measurement is reported of the jet mass distribution in hadronic decays of boosted top quarks produced in pp collisions at $\sqrt{s} =$ 13 TeV. The data were collected with the CMS detector at the LHC and correspond to an integrated luminosity of 35.9 fb$^{-1}$. The measurement is performed in the lepton+jets channel of $\mathrm{t\bar{t}}$ events, where the lepton is an electron or muon. The products of the hadronic top quark decay t $\to$ bW $\to$ bq$\mathrm{\bar{q}}'$ are reconstructed as a single jet with transverse momentum larger than 400 GeV. The $\mathrm{t\bar{t}}$ cross section as a function of the jet mass is unfolded at the particle level and used to extract a value of the top quark mass of 172.6 $\pm$ 2.5 GeV. A novel jet reconstruction technique is used for the first time at the LHC, which improves the precision by a factor of three relative to an earlier measurement. This highlights the potential of measurements using boosted top quarks, where the new technique will enable future precision measurements.

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Measurement of the top-quark mass using a leptonic invariant mass in $pp$ collisions at $\sqrt{s}=13~\textrm{TeV}$ with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abbott, D.C. ; et al.
JHEP 06 (2023) 019, 2023.
Inspire Record 2145514 DOI 10.17182/hepdata.91999

A measurement of the top-quark mass ($m_t$) in the $t\bar{t}\rightarrow~\textrm{lepton}+\textrm{jets}$ channel is presented, with an experimental technique which exploits semileptonic decays of $b$-hadrons produced in the top-quark decay chain. The distribution of the invariant mass $m_{\ell\mu}$ of the lepton, $\ell$ (with $\ell=e,\mu$), from the $W$-boson decay and the muon, $\mu$, originating from the $b$-hadron decay is reconstructed, and a binned-template profile likelihood fit is performed to extract $m_t$. The measurement is based on data corresponding to an integrated luminosity of 36.1 fb$^{-1}$ of $\sqrt{s} = 13~\textrm{TeV}$$pp$ collisions provided by the Large Hadron Collider and recorded by the ATLAS detector. The measured value of the top-quark mass is $m_{t} = 174.41\pm0.39~(\textrm{stat.})\pm0.66~(\textrm{syst.})\pm0.25~(\textrm{recoil})~\textrm{GeV}$, where the third uncertainty arises from changing the PYTHIA8 parton shower gluon-recoil scheme, used in top-quark decays, to a recently developed setup.

0 data tables match query

Hadronization geometry and charge-dependent number autocorrelations on axial momentum space in Au Au collisions at s(NN)**(1/2) = 130-GeV.

The STAR collaboration Adams, John ; Aggarwal, M.M. ; Ahammed, Z. ; et al.
Phys.Lett.B 634 (2006) 347-355, 2006.
Inspire Record 653486 DOI 10.17182/hepdata.102088

We present the first measurements of charge-dependent correlations on angular difference variables $\eta_1 - \eta_2$ (pseudorapidity) and $\phi_1 - \phi_2$ (azimuth) for primary charged hadrons with transverse momentum $0.15 \leq p_t \leq 2$ GeV/$c$ and $|\eta| \leq 1.3$ from Au-Au collisions at $\sqrt{s_{NN}} = 130$ GeV. We observe correlation structures not predicted by theory but consistent with evolution of hadron emission geometry with increasing centrality from one-dimensional fragmentation of color strings along the beam direction to an at least two-dimensional hadronization geometry along the beam and azimuth directions of a hadron-opaque bulk medium.

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Search for Dark Photons with the FASER detector at the LHC

The FASER collaboration Abreu, Henso ; Anders, John ; Antel, Claire ; et al.
Phys.Lett.B 848 (2024) 138378, 2024.
Inspire Record 2687000 DOI 10.17182/hepdata.143251

The FASER experiment at the LHC is designed to search for light, weakly-interacting particles produced in proton-proton collisions at the ATLAS interaction point that travel in the far-forward direction. The first results from a search for dark photons decaying to an electron-positron pair, using a dataset corresponding to an integrated luminosity of 27.0 fb$^{-1}$ collected at center-of-mass energy $\sqrt{s} = 13.6$ TeV in 2022 in LHC Run 3, are presented. No events are seen in an almost background-free analysis, yielding world-leading constraints on dark photons with couplings $\epsilon \sim 2 \times 10^{-5} - 1 \times 10^{-4}$ and masses $\sim$ 17 MeV - 70 MeV. The analysis is also used to probe the parameter space of a massive gauge boson from a U(1)$_{B-L}$ model, with couplings $g_{B-L} \sim 5 \times 10^{-6} - 2 \times 10^{-5}$ and masses $\sim$ 15 MeV - 40 MeV excluded for the first time.

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Polarization and cross section of midrapidity J/$\psi$ production in proton-proton collisions at $\sqrt{s}=510$ GeV

The PHENIX collaboration Acharya, U. ; Adare, A. ; Aidala, C. ; et al.
Phys.Rev.D 102 (2020) 072008, 2020.
Inspire Record 1798581 DOI 10.17182/hepdata.141538

The PHENIX experiment has measured the spin alignment for inclusive $J/\psi\rightarrow e^{+}e^{-}$ decays in $p$+$p$ collisions at $\sqrt{s}=510$ GeV at midrapidity. The angular distributions have been measured in three different polarization frames, and the three decay angular coefficients have been extracted in a full two-dimensional analysis. Previously, PHENIX saw large longitudinal net polarization at forward rapidity at the same collision energy. This analysis at midrapidity, complementary to the previous PHENIX results, sees no sizable polarization in the measured transverse momentum range of $0.0<p_T<10.0$ GeV/$c$. The results are consistent with a previous one-dimensional analysis at midrapidity at $\sqrt{s}=200$ GeV. The transverse-momentum-dependent cross section for midrapidity $J/\psi$ production has additionally been measured, and after comparison to world data we find a simple logarithmic dependence of the cross section on $\sqrt{s}$.

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$J/\psi$ and $\psi(2S)$ production at forward rapidity in $p$+$p$ collisions at $\sqrt{s}=510$ GeV

The PHENIX collaboration Acharya, U.A. ; Adare, A. ; Aidala, C. ; et al.
Phys.Rev.D 101 (2020) 052006, 2020.
Inspire Record 1773662 DOI 10.17182/hepdata.140524

The PHENIX experiment at the Relativistic Heavy Ion Collider has measured the differential cross section, mean transverse momentum, mean transverse momentum squared of inclusive $J/\psi$ and cross-section ratio of $\psi(2S)$ to $J/\psi$ at forward rapidity in \pp collisions at \sqrts = 510 GeV via the dimuon decay channel. Comparison is made to inclusive $J/\psi$ cross sections measured at \sqrts = 200 GeV and 2.76--13 TeV. The result is also compared to leading-order nonrelativistic QCD calculations coupled to a color-glass-condensate description of the low-$x$ gluons in the proton at low transverse momentum ($p_T$) and to next-to-leading order nonrelativistic QCD calculations for the rest of the $p_T$ range. These calculations overestimate the data at low $p_T$. While consistent with the data within uncertainties above $\approx3$ GeV/$c$, the calculations are systematically below the data. The total cross section times the branching ratio is BR $d\sigma^{J/\psi}_{pp}/dy (1.2<|y|<2.2, 0<p_T<10~\mbox{GeV/$c$}) =$ 54.3 $\pm$ 0.5 (stat) $\pm$ 5.5 (syst) nb.

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Measurement of the proton form factor by studying $e^{+} e^{-}\rightarrow p\bar{p}$

The BESIII collaboration Ablikim, M. ; Achasov, M.N. ; Ai, X.C. ; et al.
Phys.Rev.D 91 (2015) 112004, 2015.
Inspire Record 1358937 DOI 10.17182/hepdata.73442

Using data samples collected with the BESIII detector at the BEPCII collider, we measure the Born cross section of $e^{+}e^{-}\rightarrow p\bar{p}$ at 12 center-of-mass energies from 2232.4 to 3671.0 MeV. The corresponding effective electromagnetic form factor of the proton is deduced under the assumption that the electric and magnetic form factors are equal $(|G_{E}|= |G_{M}|)$. In addition, the ratio of electric to magnetic form factors, $|G_{E}/G_{M}|$, and $|G_{M}|$ are extracted by fitting the polar angle distribution of the proton for the data samples with larger statistics, namely at $\sqrt{s}=$ 2232.4 and 2400.0 MeV and a combined sample at $\sqrt{s}$ = 3050.0, 3060.0 and 3080.0 MeV, respectively. The measured cross sections are in agreement with recent results from BaBar, improving the overall uncertainty by about 30\%. The $|G_{E}/G_{M}|$ ratios are close to unity and consistent with BaBar results in the same $q^{2}$ region, which indicates the data are consistent with the assumption that $|G_{E}|=|G_{M}|$ within uncertainties.

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Azimuthal anisotropy and correlations at large transverse momenta in p + p and Au + Au collisions at s(NN)**(1/2) = 200-GeV.

The STAR collaboration Adams, J. ; Aggarwal, M.M. ; Ahammed, Z. ; et al.
Phys.Rev.Lett. 93 (2004) 252301, 2004.
Inspire Record 654226 DOI 10.17182/hepdata.100594

Results on high transverse momentum charged particle emission with respect to the reaction plane are presented for Au+Au collisions at $\sqrt{s_{_{NN}}}$= 200 GeV. Two- and four-particle correlations results are presented as well as a comparison of azimuthal correlations in Au+Au collisions to those in $p+p$ at the same energy. Elliptic anisotropy, $v_2$, is found to reach its maximum at $p_t \sim 3$ GeV/c, then decrease slowly and remain significant up to $p_t\approx 7$ -- 10 GeV/c. Stronger suppression is found in the back-to-back high-$p_t$ particle correlations for particles emitted out-of-plane compared to those emitted in-plane. The centrality dependence of $v_2$ at intermediate $p_t$ is compared to simple models based on jet quenching.

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Properties of Hadronic Events in e$^{+} $e$^{-}$ Annihilation at $S^{(1/2)}=91$-{GeV}

The ALEPH collaboration Decamp, D. ; Deschizeaux, B. ; Lees, J.P. ; et al.
Phys.Lett.B 234 (1990) 209-218, 1990.
Inspire Record 283354 DOI 10.17182/hepdata.29739

We report on properties of hadronic events from e + e − annihilation observed by the ALEPH detector at the large Electron Positron Collider at CERN. The center-of-mass energy was s =91.0−91.3 GeV . Measured distributions of the global event-shape variables sphericity, aplanarity, thrust and minor value, and of the inclusive variables x p , p ⊥ in , p ⊥ out and y are presented. We measure a mean charged multiplicity in hadronic events of 〈 N ch 〉=21.3±0.1 (statistical)±0.6 (systematic). The data are in good agreement with QCD-based models which use the leading-logarithm approximation, and are less well described by a model using O( α s 2 ) QCD.

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The Multiplicity dependence of inclusive p(t) spectra from p-p collisions at s**(1/2) = 200-GeV

The STAR collaboration Adams, J. ; Aggarwal, M.M. ; Ahammed, Z. ; et al.
Phys.Rev.D 74 (2006) 032006, 2006.
Inspire Record 719969 DOI 10.17182/hepdata.102084

We report measurements of transverse momentum $p_t$ spectra for ten event multiplicity classes of p-p collisions at $\sqrt{s} = 200$ GeV. By analyzing the multiplicity dependence we find that the spectrum shape can be decomposed into a part with amplitude proportional to multiplicity and described by a L\'evy distribution on transverse mass $m_t$, and a part with amplitude proportional to multiplicity squared and described by a gaussian distribution on transverse rapidity $y_t$. The functional forms of the two parts are nearly independent of event multiplicity. The two parts can be identified with the soft and hard components of a two-component model of p-p collisions. This analysis then provides the first isolation of the hard component of the $p_t$ spectrum as a distribution of simple form on $y_t$.

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Pion, kaon, proton and anti-proton transverse momentum distributions from p + p and d + Au collisions at s(NN)**1/2 = 200-GeV.

The STAR collaboration Adams, John ; Aggarwal, M.M. ; Ahammed, Z. ; et al.
Phys.Lett.B 616 (2005) 8-16, 2005.
Inspire Record 628232 DOI 10.17182/hepdata.98859

Identified mid-rapidity particle spectra of $\pi^{\pm}$, $K^{\pm}$, and $p(\bar{p})$ from 200 GeV p+p and d+Au collisions are reported. A time-of-flight detector based on multi-gap resistive plate chamber technology is used for particle identification. The particle-species dependence of the Cronin effect is observed to be significantly smaller than that at lower energies. The ratio of the nuclear modification factor ($R_{dAu}$) between protons $(p+\bar{p})$ and charged hadrons ($h$) in the transverse momentum range $1.2<{p_{T}}<3.0$ GeV/c is measured to be $1.19\pm0.05$(stat)$\pm0.03$(syst) in minimum-bias collisions and shows little centrality dependence. The yield ratio of $(p+\bar{p})/h$ in minimum-bias d+Au collisions is found to be a factor of 2 lower than that in Au+Au collisions, indicating that the Cronin effect alone is not enough to account for the relative baryon enhancement observed in heavy ion collisions at RHIC.

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