Date

Constraining the initial conditions and temperature dependent transport with three-particle correlations in Au+Au collisions

The STAR collaboration Adamczyk, L. ; Adkins, J.K. ; Agakishiev, G. ; et al.
Phys.Lett.B 790 (2019) 81-88, 2019.
Inspire Record 1510301 DOI 10.17182/hepdata.101355

We present three-particle mixed-harmonic correlations $\la \cos (m\phi_a + n\phi_b - (m+n) \phi_c)\ra$ for harmonics $m,n=1-3$ for charged particles in $\sqrt{s_{NN}}=$200 GeV Au+Au collisions at RHIC. These measurements provide information on the three-dimensional structure of the initial collision zone and are important for constraining models of a subsequent low-viscosity quark-gluon plasma expansion phase. We investigate correlations between the first, second and third harmonics predicted as a consequence of fluctuations in the initial state. The dependence of the correlations on the pseudorapidity separation between particles show hints of a breaking of longitudinal invariance. We compare our results to a number of state-of-the art hydrodynamic calculations with different initial states and temperature dependent viscosities. These measurements provide important steps towards constraining the temperature dependent transport and the longitudinal structure of the initial state at RHIC.

2 data tables

Dependence of mixed harmonic correlators $C_{1,2,3}$ and $C_{2,2,4}$ on relative pseudorapidity.

Centrality dependence of mixed harmonic correlators $C_{m,n,m+n}$.


Measurement of $D^0$ azimuthal anisotropy at mid-rapidity in Au+Au collisions at \sNN = 200\,GeV

The STAR collaboration Adamczyk, L. ; Adkins, J.K. ; Agakishiev, G. ; et al.
Phys.Rev.Lett. 118 (2017) 212301, 2017.
Inspire Record 1510298 DOI 10.17182/hepdata.101749

We report the first measurement of the elliptic anisotropy ($v_2$) of the charm meson $D^0$ at mid-rapidity ($|y|$\,$<$\,1) in Au+Au collisions at \sNN = 200\,GeV. The measurement was conducted by the STAR experiment at RHIC utilizing a new high-resolution silicon tracker. The measured $D^0$ $v_2$ in 0--80\% centrality Au+Au collisions can be described by a viscous hydrodynamic calculation for transverse momentum ($p_{\rm T}$) less than 4\,GeV/$c$. The $D^0$ $v_2$ as a function of transverse kinetic energy ($m_{\rm T} - m_0$, where $m_{\rm T} = \sqrt{p_{\rm T}^2 + m_0^2}$) is consistent with that of light mesons in 10--40\% centrality Au+Au collisions. These results suggest that charm quarks have achieved local thermal equilibrium with the medium created in such collisions. Several theoretical models, with the temperature--dependent, dimensionless charm spatial diffusion coefficient ($2{\pi}TD_s$) in the range of $\sim$2--12, are able to simultaneously reproduce our $D^0$ $v_2$ result and our previously published results for the $D^0$ nuclear modification factor.

2 data tables

Azimuthal anisotropy $v_2$ as a function of $p_{\rm T}$ for $D^0$ in 10%–40% centrality Au+Au collisions.

Azimuthal anisotropy $v_2$ as a function of $p_{\rm T}$ for $D^0$ in 0%–80% centrality Au+Au collisions.


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.

3 data tables

Fraction of $B$-meson decays in $J/\psi$ samples obtained in $p$+$p$ collisions at $\sqrt{S}$ = 510 GeV.

Fraction of $B$-meson decays in $J/\psi$ samples obtained in $p$+$p$ collisions at $\sqrt{S}$ = 510 GeV.

The $b\bar{b}$ cross section per unit rapidity ($d\sigma/dy(pp→b\bar{b})$) 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.


Study of $\eta$ and $\eta'$ photoproduction at MAMI

The A2 collaboration Kashevarov, V.L. ; Ott, P. ; Prakhov, S. ; et al.
Phys.Rev.Lett. 118 (2017) 212001, 2017.
Inspire Record 1509373 DOI 10.17182/hepdata.116258

The reactions $\gamma p\to \eta p$ and $\gamma p\to \eta' p$ have been measured from their thresholds up to the center-of-mass energy $W=1.96$GeV with the tagged-photon facilities at the Mainz Microtron, MAMI. Differential cross sections were obtained with unprecedented accuracy, providing fine energy binning and full production-angle coverage. A strong cusp is observed in the total cross section and excitation functions for $\eta$ photoproduction at the energies in vicinity of the $\eta'$ threshold, $W=1896$MeV ($E_\gamma=1447$MeV). This behavior is explained in a revised $\eta$MAID isobar model by a significant branching of the $N(1895)1/2^-$ nucleon resonance to both, $\eta p$ and $\eta' p$, confirming the existence and constraining the properties of this poorly known state.

76 data tables

Run 1. Total cross section as a function of c.m. energy W.

Run 2. Total cross section as a function of c.m. energy W.

Run 3. Total cross section as a function of c.m. energy W.

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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.

4 data tables

Polar angular decay coefficient $\lambda_{\theta}$ as a function of transverse momentum for four reference frames and three $p_T$ bins. The numbers in the CS frame for the $p_T$ = 2-3 GeV/$c$ bin are 90% confidence level upper limits.

"Mixed" angular decay coefficient $\lambda_{\theta \phi}$ as a function of transverse momentum for four reference frames and three $p_T$ bins.

Azimuthal angular decay coefficient $\lambda_{\phi}$ as a function of transverse momentum for four reference frames and three $p_T$ bins.

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Measurement of Jet Production Cross Sections in Deep-inelastic $ep$ Scattering at HERA

The H1 collaboration Andreev, V. ; Baghdasaryan, A. ; Andreev, Vladimir ; et al.
Eur.Phys.J.C 77 (2017) 215, 2017.
Inspire Record 1496981 DOI 10.17182/hepdata.86390

A precision measurement of jet cross sections in neutral current deep-inelastic scattering for photon virtualities $5.5<Q^2<80\,{\rm GeV}^2$ and inelasticities $0.2<y<0.6$ is presented, using data taken with the H1 detector at HERA, corresponding to an integrated luminosity of $290\,{\rm pb}^{-1}$. Double-differential inclusive jet, dijet and trijet cross sections are measured simultaneously and are presented as a function of jet transverse momentum observables and as a function of $Q^2$. Jet cross sections normalised to the inclusive neutral current DIS cross section in the respective $Q^2$-interval are also determined. Previous results of inclusive jet cross sections in the range $150<Q^2<15\,000\,{\rm GeV}^2$ are extended to low transverse jet momenta $5<P_{T}^{\rm jet}<7\,{\rm GeV}$. The data are compared to predictions from perturbative QCD in next-to-leading order in the strong coupling, in approximate next-to-next-to-leading order and in full next-to-next-to-leading order. Using also the recently published H1 jet data at high values of $Q^2$, the strong coupling constant $\alpha_s(M_Z)$ is determined in next-to-leading order.

55 data tables

Inclusive jet cross sections measured as a function of $P_T^{\rm jet}$ for $Q^2$ = 5.5-8.0 GeV$^2$. The correction factors on the theoretical cross sections $c^{\rm had}$ are listed together with their uncertainties. The radiative correction factors $c^{\rm rad}$ are already included in the quoted cross sections. Note that the uncertainties labelled $\delta^{E_{e^\prime}}$ and $\delta^{\theta_{e^\prime}}$ in Table 6 of the paper (arXiv:1611.03421v3) should be swapped. See Table 5 of arXiv:1406.4709v2 for details of the correlation model.

Inclusive jet cross sections measured as a function of $P_T^{\rm jet}$ for $Q^2$ = 8.0-11.0 GeV$^2$. The correction factors on the theoretical cross sections $c^{\rm had}$ are listed together with their uncertainties. The radiative correction factors $c^{\rm rad}$ are already included in the quoted cross sections. Note that the uncertainties labelled $\delta^{E_{e^\prime}}$ and $\delta^{\theta_{e^\prime}}$ in Table 6 of the paper (arXiv:1611.03421v3) should be swapped. See Table 5 of arXiv:1406.4709v2 for details of the correlation model.

Inclusive jet cross sections measured as a function of $P_T^{\rm jet}$ for $Q^2$ = 11.0-16.0 GeV$^2$. The correction factors on the theoretical cross sections $c^{\rm had}$ are listed together with their uncertainties. The radiative correction factors $c^{\rm rad}$ are already included in the quoted cross sections. Note that the uncertainties labelled $\delta^{E_{e^\prime}}$ and $\delta^{\theta_{e^\prime}}$ in Table 6 of the paper (arXiv:1611.03421v3) should be swapped. See Table 5 of arXiv:1406.4709v2 for details of the correlation model.

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Measurement of the cross section and longitudinal double-spin asymmetry for di-jet production in polarized $pp$ collisions at $\sqrt{s}$ = 200 GeV

The STAR collaboration Adamczyk, L. ; Adkins, J.K. ; Agakishiev, G. ; et al.
Phys.Rev.D 95 (2017) 071103, 2017.
Inspire Record 1493842 DOI 10.17182/hepdata.77208

We report the first measurement of the longitudinal double-spin asymmetry $A_{LL}$ for mid-rapidity di-jet production in polarized $pp$ collisions at a center-of-mass energy of $\sqrt{s} = 200$ GeV. The di-jet cross section was measured and is shown to be consistent with next-to-leading order (NLO) perturbative QCD predictions. $A_{LL}$ results are presented for two distinct topologies, defined by the jet pseudorapidities, and are compared to predictions from several recent NLO global analyses. The measured asymmetries, the first such correlation measurements, support those analyses that find positive gluon polarization at the level of roughly 0.2 over the region of Bjorken-$x > 0.05$.

10 data tables

Data simulation comparison (with arbitrary normalization). Di-jet invariant mass.

Data simulation comparison (with arbitrary normalization). Difference between jet pseudorapidities.

Data simulation comparison (with arbitrary normalization). Difference between jet azimuthal angles.

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Two-particle correlations in azimuthal angle and pseudorapidity in inelastic p+p interactions at the CERN Super Proton Synchrotron

The NA61/SHINE collaboration Aduszkiewicz, A. ; Ali, Y. ; Andronov, E. ; et al.
Eur.Phys.J.C 77 (2017) 59, 2017.
Inspire Record 1489238 DOI 10.17182/hepdata.76899

Results on two-particle $\Delta\eta\Delta\phi$ correlations in inelastic p+p interactions at 20, 31, 40, 80, and 158~GeV/c are presented. The measurements were performed using the large acceptance NA61/SHINE hadron spectrometer at the CERN Super Proton Synchrotron. The data show structures which can be attributed mainly to effects of resonance decays, momentum conservation, and quantum statistics. The results are compared with the EPOS and UrQMD models.

20 data tables

Two-particle correlation function C(Delta eta, Delta phi) for all charge pairs in inelastic p+p interactions at 20 GeV/c.

Two-particle correlation function C(Delta eta, Delta phi) for all charge pairs in inelastic p+p interactions at 31 GeV/c.

Two-particle correlation function C(Delta eta, Delta phi) for all charge pairs in inelastic p+p interactions at 40 GeV/c.

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Measurement of Elastic pp Scattering at $\sqrt{s}$ = 8 TeV in the Coulomb-Nuclear Interference Region - Determination of the $\rho$-Parameter and the Total Cross-Section

The TOTEM collaboration Antchev, G. ; Aspell, P. ; Atanassov, I. ; et al.
Eur.Phys.J.C 76 (2016) 661, 2016.
Inspire Record 1489188 DOI 10.17182/hepdata.127946

The TOTEM experiment at the CERN LHC has measured elastic proton-proton scattering at the centre-of-mass energy $\sqrt{s}$ = 8 TeV and four-momentum transfers squared, |t|, from 6 x $10^{-4}$ GeV$^2$ to 0.2 GeV$^2$. Near the lower end of the |t|-interval the differential cross-section is sensitive to the interference between the hadronic and the electromagnetic scattering amplitudes. This article presents the elastic cross-section measurement and the constraints it imposes on the functional forms of the modulus and phase of the hadronic elastic amplitude. The data exclude the traditional Simplified West and Yennie interference formula that requires a constant phase and a purely exponential modulus of the hadronic amplitude. For parametrisations of the hadronic modulus with second- or third-order polynomials in the exponent, the data are compatible with hadronic phase functions giving either central or peripheral behaviour in the impact parameter picture of elastic scattering. In both cases, the $\rho$-parameter is found to be 0.12 $\pm$ 0.03. The results for the total hadronic cross-section are $\sigma_{tot}$ = (102.9 $\pm$ 2.3) mb and (103.0 $\pm$ 2.3) mb for central and peripheral phase formulations, respectively. Both are consistent with previous TOTEM measurements.

1 data table

Differential cross-section.


Measurement of the relative yields of $\psi(2S)$ to $\psi(1S)$ mesons produced at forward and backward rapidity in $p$$+$$p$, $p$$+$Al, $p$$+$Au, and $^{3}$He$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV

The PHENIX collaboration Adare, A. ; Aidala, C. ; Ajitanand, N.N. ; et al.
Phys.Rev.C 95 (2017) 034904, 2017.
Inspire Record 1487575 DOI 10.17182/hepdata.149529

The PHENIX Collaboration has measured the ratio of the yields of $\psi(2S)$ to $\psi(1S)$ mesons produced in $p$$+$$p$, $p$$+$Al, $p$$+$Au, and $^{3}$He$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV over the forward and backward rapidity intervals $1.2<|y|<2.2$. We find that the ratio in $p$$+$$p$ collisions is consistent with measurements at other collision energies. In collisions with nuclei, we find that in the forward ($p$-going or $^{3}$He-going) direction, the relative yield of $\psi(2S)$ mesons to $\psi(1S)$ mesons is consistent with the value measured in \pp collisions. However, in the backward (nucleus-going) direction, the $\psi(2S)$ is preferentially suppressed by a factor of $\sim$2. This suppression is attributed in some models to breakup of the weakly-bound $\psi(2S)$ through final state interactions with comoving particles, which have a higher density in the nucleus-going direction. These breakup effects may compete with color screening in a deconfined quark-gluon plasma to produce sequential suppression of excited quarkonia states.

9 data tables

Summary of the measured ratios of $\Psi$(2S)/$\Psi$(1S) mesons.

Summary of the measured ratios of $\Psi$(2S)/$\Psi$(1S) mesons.

Summary of the measured ratios of $\Psi$(2S)/$\Psi$(1S) mesons.

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