$J/\psi$ polarization in p+p collisions at $\sqrt{s}$ = 200 GeV in STAR

The STAR collaboration Adamczyk, L. ; Adkins, J.K. ; Agakishiev, G. ; et al.
Phys.Lett.B 739 (2014) 180-188, 2014.
Inspire Record 1263695 DOI 10.17182/hepdata.96232

We report on a polarization measurement of inclusive $J/\psi$ mesons in the di-electron decay channel at mid-rapidity at 2 $<p_{T}<$ 6 GeV/$c$ in $p+p$ collisions at $\sqrt{s}$ = 200 GeV. Data were taken with the STAR detector at RHIC. The $J/\psi$ polarization measurement should help to distinguish between different models of the $J/\psi$ production mechanism since they predict different $p_{T}$ dependences of the $J/\psi$ polarization. In this analysis, $J/\psi$ polarization is studied in the helicity frame. The polarization parameter $\lambda_{\theta}$ measured at RHIC becomes smaller towards high $p_{T}$, indicating more longitudinal $J/\psi$ polarization as $p_{T}$ increases. The result is compared with predictions of presently available models.

13 data tables

Uncorrected cos$\theta$ distribution after the combinatorial background subtraction for $2 < p_{T}^{J/\psi} < 3$ GeV/c

Uncorrected cos$\theta$ distribution after the combinatorial background subtraction for $3 < p_{T}^{J/\psi} < 4$ GeV/c

Uncorrected cos$\theta$ distribution after the combinatorial background subtraction for $4 < p_{T}^{J/\psi} < 6$ GeV/c

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$J/\psi$ production at low $p_T$ in Au+Au and Cu+Cu collisions at $\sqrt{s_{_{NN}}}$ = 200 GeV at STAR

The STAR collaboration Adamczyk, L. ; Adkins, J.K. ; Agakishiev, G. ; et al.
Phys.Rev.C 90 (2014) 024906, 2014.
Inspire Record 1258446 DOI 10.17182/hepdata.99158

The $\jpsi$ $\pt$ spectrum and nuclear modification factor ($\raa$) are reported for $\pt < 5 \ \gevc$ and $|y|<1$ from 0\% to 60\% central Au+Au and Cu+Cu collisions at $\snn = 200 \ \gev$ at STAR. A significant suppression of $\pt$-integrated $\jpsi$ production is observed in central Au+Au events. The Cu+Cu data are consistent with no suppression, although the precision is limited by the available statistics. $\raa$ in Au+Au collisions exhibits a strong suppression at low transverse momentum and gradually increases with $\pt$. The data are compared to high-$\pt$ STAR results and previously published BNL Relativistic Heavy Ion Collider results. Comparing with model calculations, it is found that the invariant yields at low $\pt$ are significantly above hydrodynamic flow predictions but are consistent with models that include color screening and regeneration.

11 data tables

The invariant yield versus transverse momentum for |y| < 1 in 0-20% centrality in Au+Au collisions (solid circles). The results are compared to high-$p_T$ (3 < $p_T$ < 10 GeV/c) results from STAR [9] (solid squares) and PHENIX data [8] (open squares).

The invariant yield versus transverse momentum for |y| < 1 in 20-40% centrality in Au+Au collisions (solid circles). The results are compared to high-$p_T$ (3 < $p_T$ < 10 GeV/c) results from STAR [9] (solid squares) and PHENIX data [8] (open squares).

The invariant yield versus transverse momentum for |y| < 1 in 40-60% centrality in Au+Au collisions (solid circles). The results are compared to high-$p_T$ (3 < $p_T$ < 10 GeV/c) results from STAR [9] (solid squares) and PHENIX data [8] (open squares).

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$J/\psi$ suppression at forward rapidity in Pb-Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV

The ALICE collaboration Abelev, Betty ; Adam, Jaroslav ; Adamova, Dagmar ; et al.
Phys.Rev.Lett. 109 (2012) 072301, 2012.
Inspire Record 1088222 DOI 10.17182/hepdata.60297

The ALICE experiment has measured the inclusive J/$\psi$ production in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}} } = 2.76$ TeV down to zero transverse momentum in the rapidity range $2.5 < y < 4$. A suppression of the inclusive J/$\psi$ yield in Pb-Pb is observed with respect to the one measured in pp collisions scaled by the number of binary nucleon-nucleon collisions. The nuclear modification factor, integrated over the 0-80% most central collisions, is $0.545 \pm 0.032 \rm{(stat.)} \pm 0.083 \rm{(syst.)}$ and does not exhibit a significant dependence on the collision centrality. These features appear significantly different from measurements at lower collision energies. Models including J/$\psi$ production from charm quarks in a deconfined partonic phase can describe our data.

2 data tables

Jpsi Nuclear Modification Factor (Raa) measured in Pb-Pb collisions at sqrt(sNN) = 2.76 TeV in 2.5 < y < 4 and pt > 0 GeV/c, as a function of - the average number of participating nucleons (<Npart>), - the average number of participating nucleons (<Npart,w>) weigthed by the average number of binary collisions, - the mid-rapidity charged-particle density measured at pseudo-rapidity eta = 0 dNch,w/deta|eta=0 weigthed by the average number of binary collisions.

Centrality integrated (0%-80%) inclusive Jpsi Nuclear Modification Factor (Raa) measured in Pb-Pb collisions at sqrt(sNN) = 2.76 TeV as a function of rapidity for two transverse momentum ranges.


$K^- p$ and $\bar{p} p$ Elastic Scattering at 10.1-{GeV}/$c$

Berglund, A. ; Buran, T. ; Carlson, P.J. ; et al.
Nucl.Phys.B 176 (1980) 346-354, 1980.
Inspire Record 133174 DOI 10.17182/hepdata.34457

The differential cross sections for K − p and p p elastic scattering have been measured over the range of four-momentum transfer squared 0.18<− t <3.3 (GeV/ c ) 2 . The K − p data decrease smoothly as a function of − t , whereas, the p p data shows a break at − t = 0.6 (GeV/ c ) 2 followed by a fast drop to − t ≅ 1.6 (GeV/ c ) 2 where the differential cross section levels off and stays constant out to − t = 3 (GeV/ c ) 2 .

2 data tables

No description provided.

No description provided.


$\Lambda$ Production in $e^+ e^-$ Annihilation at 29-{GeV}

de la Vaissiere, C. ; Luth, V. ; Abrams, G.S. ; et al.
Phys.Rev.Lett. 54 (1985) 2071-2074, 1985.
Inspire Record 209198 DOI 10.17182/hepdata.20378

The production of Λ hyperons in e+e− annihilation has been measured as a function of their total momenta, transverse momenta, and the event thrust. The total production rate is 0.213±0.012±0.018 Λ or Λ¯ per hadronic event. The observation of correlations in rapidity and angles for events with two detected Λ decays supports fragmentation models with local baryon-number compensation.

3 data tables

No description provided.

No description provided.

No description provided.


$\Lambda$(c)+ Production and Semileptonic Decay in 29-{GeV} $e^+ e^-$ Annihilation

Klein, S. ; Himel, T. ; Abrams, G.S. ; et al.
Phys.Rev.Lett. 62 (1989) 2444, 1989.
Inspire Record 277034 DOI 10.17182/hepdata.20042

We present results on Λc+ production in 29-GeV e+e− annihilation. The Λc+ are observed via their semileptonic decays to Λe+X and Λμ+X. With radiative corrections, we find σ(e+e−→Λc+X)〉BΛc+→eΛX)= 1.5±0.6±0.5 pb or 0.0038±0.0015±0.0012 Λc+→Λe+X decay per hadronic event, and σ(e+e−Λc+X)B(Λc+→μΛX)= 1.4±1.4±0.4 pb or 0.0035±0.0035±0.0011 Λc+→Λμ+X decay per hadronic event. These results can be used to place constraints on the predictions of various production models.

2 data tables

Cross sections * branching ratio for LAMBDA/C+ production in LAMBDA E+ decay channel.

Cross sections * branching ratio for LAMBDA/C+ production in LAMBDA MU+ decay channel.


$\eta$ and $\eta^\prime$ Production in $e^+ e^-$ Annihilation at 29-{GeV}: Indications for the $D(s$)+- Decays Into $\eta \pi^\pm$ and $\eta^\prime \pi^\pm$

Wormser, G. ; Abrams, G.S. ; Amidei, D. ; et al.
Phys.Rev.Lett. 61 (1988) 1057, 1988.
Inspire Record 261194 DOI 10.17182/hepdata.20080

η production has been investigated by the Mark II collaboration at the SLAC e+e− storage ring PEP. η particles are reconstructed by their γγ decay mode. The η fragmentation function has been measured and found to be in good agreement with the Lund-model prediction. η′ production has been measured for the first time in high-energy e+e− annihilation. There is evidence at the 3σ level for Ds± decay into ηπ± and η′π±.

4 data tables

Numerical values supplied by G.Wormser.

Z = 0.0 point extrapolated using LUND fragmentation model.

Z = 0.0 point extrapolated using LUND fragmentation model.

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$\phi$-meson production at forward rapidity in p-Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV and in pp collisions at $\sqrt{s}$ = 2.76 TeV

The ALICE collaboration Adam, Jaroslav ; Adamova, Dagmar ; Aggarwal, Madan Mohan ; et al.
Phys.Lett.B 768 (2017) 203-217, 2016.
Inspire Record 1380453 DOI 10.17182/hepdata.77057

The first study of $\phi$-meson production in p-Pb collisions at forward and backward rapidity, at a nucleon-nucleon centre-of-mass energy $\sqrt{s_{\rm NN}} = 5.02$~TeV, has been performed with the ALICE apparatus at the LHC. The $\phi$-mesons have been identified in the dimuon decay channel in the transverse momentum ($p_{\rm T}$) range $1 < p_{\rm T} < 7$ GeV/$c$, both in the p-going ($2.03 < y < 3.53$) and the Pb-going ($-4.46 < y < -2.96$) directions, where $y$ stands for the rapidity in the nucleon-nucleon centre-of-mass, the integrated luminosity amounting to $5.01 \pm 0.19$~nb$^{-1}$ and $5.81 \pm 0.20$~nb$^{-1}$, respectively, for the two data samples. Differential cross sections as a function of transverse momentum and rapidity are presented. The forward-backward ratio for $\phi$-meson production is measured for $2.96<|y|<3.53$, resulting in a ratio $\sim 0.5$ with no significant $p_{\rm T}$ dependence within the uncertainties. The $p_{\rm T}$ dependence of the $\phi$ nuclear modification factor $R_{\rm pPb}$ exhibits an enhancement up to a factor 1.6 at $p_{\rm T}$ = 3-4 GeV/$c$ in the Pb-going direction. The $p_{\rm T}$ dependence of the $\phi$-meson cross section in pp collisions at $\sqrt{s}$ = 2.76 TeV, which is used to determine a reference for the p-Pb results, is also presented here for $1 < p_{\rm T} < 5$ GeV/$c$ and $2.5 <y < 4$ for a $78 \pm 3$~nb$^{-1}$ integrated luminosity sample.

4 data tables

$p_{\rm T}$-differential production cross section of $\phi$ in pp at $\sqrt{s_{\rm NN}}$=2.76 TeV, in the rapidity range 2.5 < y < 4

$p_{\rm T}$-differential production cross section of $\phi$ in p-Pb at $\sqrt{s_{\rm NN}}$=5.02 TeV, in the rapidity range 4.46 < y < 2.96

$p_{\rm T}$-differential production cross section of $\phi$ in p-Pb at $\sqrt{s_{\rm NN}}$=5.02 TeV, in the rapidity range 2.03 < y < 3.53

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Version 2
$\pi^0$ and $\eta$ meson production in proton-proton collisions at $\sqrt{s}=8$ TeV

The ALICE collaboration Acharya, Shreyasi ; Adam, Jaroslav ; Adamova, Dagmar ; et al.
Eur.Phys.J.C 78 (2018) 263, 2018.
Inspire Record 1620477 DOI 10.17182/hepdata.79044

An invariant differential cross section measurement of inclusive $\pi^{0}$ and $\eta$ meson production at mid-rapidity in pp collisions at $\sqrt{s}=8$ TeV was carried out by the ALICE experiment at the LHC. The spectra of $\pi^{0}$ and $\eta$ mesons were measured in transverse momentum ranges of $0.3<p_{\rm T}<35$ GeV/$c$ and $0.5<p_{\rm T}<35$ GeV/$c$, respectively. Next-to-leading order perturbative QCD calculations using fragmentation functions DSS14 for the $\pi^{0}$ and AESSS for the $\eta$ overestimate the cross sections of both neutral mesons, although such calculations agree with the measured $\eta/\pi^{0}$ ratio within uncertainties. The results were also compared with PYTHIA~8.2 predictions for which the Monash~2013 tune yields the best agreement with the measured neutral meson spectra. The measurements confirm a universal behavior of the $\eta/\pi^{0}$ ratio seen for NA27, PHENIX and ALICE data for pp collisions from $\sqrt{s}=27.5$ GeV to $\sqrt{s}=8$ TeV within experimental uncertainties. A relation between the $\pi^{0}$ and $\eta$ production cross sections for pp collisions at $\sqrt{s}=8$ TeV is given by $m_{\rm T}$ scaling for $p_{\rm T}>3.5$ GeV/$c$. However, a deviation from this empirical scaling rule is observed for transverse momenta below $p_{\rm T}<3.5$ GeV/$c$ in the $\eta/\pi^0$ ratio with a significance of $6.2\sigma$.

16 data tables

Invariant differential cross section of $\pi^0$ produced in inelastic pp collisions at center-of-mass energy 8 TeV, the uncertainty of $\sigma_{MB}$ of 2.6% is not included in the systematic error.

Invariant differential cross section of $\pi^0$ produced in inelastic pp collisions at center of mass energy 8 TeV, the uncertainty of $\sigma_{MB}$ of 2.6% is not included in the systematic error.

Invariant differential cross section of $\eta$ produced in inelastic pp collisions at center-of-mass energy 8 TeV, the uncertainty of $\sigma_{MB}$ of 2.6% is not included in the systematic error.

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$\rho^{0}$ Photoproduction in AuAu Collisions at $\sqrt{s_{NN}}$=62.4 GeV with STAR

The STAR collaboration Agakishiev, G. ; Aggarwal, M.M. ; Ahammed, Z. ; et al.
Phys.Rev.C 85 (2012) 014910, 2012.
Inspire Record 919778 DOI 10.17182/hepdata.101342

Vector mesons may be photoproduced in relativistic heavy-ion collisions when a virtual photon emitted by one nucleus scatters from the other nucleus, emerging as a vector meson. The STAR Collaboration has previously presented measurements of coherent $\rho^0$ photoproduction at center of mass energies of 130 GeV and 200 GeV in AuAu collisions. Here, we present a measurement of the cross section at 62.4 GeV; we find that the cross section for coherent $\rho^0$ photoproduction with nuclear breakup is $10.5\pm1.5\pm 1.6$ mb at 62.4 GeV. The cross-section ratio between 200 GeV and 62.4 GeV is $2.8\pm0.6$, less than is predicted by most theoretical models. It is, however, proportionally much larger than the previously observed $15\pm 55$% increase between 130 GeV and 200 GeV.

5 data tables

Acceptance corrected invariant mass distributions for the coherently produced $\rho^0$ candidates collected with trigger A (left) and B (right). The fit function (solid) encompasses the Breit-Wigner (dashed), the mass independent contribution from direct $\pi^+\pi^-$ production (dash-dotted), and the interference term (dotted). The hatched area is the contribution from the combinatorial background. The statistical errors are shown.

Acceptance corrected invariant mass distributions for the coherently produced $\rho^0$ candidates collected with trigger A (left) and B (right). The fit function (solid) encompasses the Breit-Wigner (dashed), the mass independent contribution from direct $\pi^+\pi^-$ production (dash-dotted), and the interference term (dotted). The hatched area is the contribution from the combinatorial background. The statistical errors are shown.

Transverse momentum distribution of the $\rho^0$ candidates (open distribution) overlaid by the combinatorial background estimated with like-sign pairs (not corrected to the acceptance and reconstruction efficiency) and scaled to match in the high transverse momentum region, $p_T$ ≥ 250 MeV/$c$ (hatched distribution). The plot is based on the dataset collected with trigger B.

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$\rm{J}/\psi$ production at low transverse momentum in p+p and d+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV

The STAR collaboration Adamczyk, L. ; Adkins, J.K. ; Agakishiev, G. ; et al.
Phys.Rev.C 93 (2016) 064904, 2016.
Inspire Record 1420183 DOI 10.17182/hepdata.73526

We report on the measurement of $\rm{J}/\psi$ production in the dielectron channel at mid-rapidity (|y|<1) in p+p and d+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV from the STAR experiment at the Relativistic Heavy Ion Collider. The transverse momentum $p_{T}$ spectra in p+p for $p_{T}$ < 4 GeV/c and d+Au collisions for $p_{T}$ < 3 GeV/c are presented. These measurements extend the STAR coverage for $\rm{J}/\psi$ production in p+p collisions to low $p_{T}$. The $<p_{T}^{2}>$ from the measured $\rm{J}/\psi$ invariant cross section in p+p and d+Au collisions are evaluated and compared to similar measurements at other collision energies. The nuclear modification factor for $\rm{J}/\psi$ is extracted as a function of $p_{T}$ and collision centrality in d+Au and compared to model calculations using the modified nuclear Parton Distribution Function and a final-state $\rm{J}/\psi$ nuclear absorption cross section.

6 data tables

The mean square of $p_T$.

Nuclear absorption cross section.

The nuclear modicifation factor vs. $p_T$ for $J\psi$ with |y| < 1 in 0-100 percent central d+Au collisions.

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$^{3}_{\Lambda}\mathrm H$ and $^{3}_{\bar{\Lambda}} \overline{\mathrm H}$ production in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV

The ALICE collaboration Adam, Jaroslav ; Adamova, Dagmar ; Aggarwal, Madan Mohan ; et al.
Phys.Lett.B 754 (2016) 360-372, 2016.
Inspire Record 1380234 DOI 10.17182/hepdata.70861

The production of the hypertriton nuclei $^{3}_{\Lambda}\mathrm H$ and $^{3}_{\bar{\Lambda}} \overline{\mathrm H}$ has been measured for the first time in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV with the ALICE experiment at LHC energies. The total yield, d$N$/d$y$ $\times \mathrm{B.R.}_{\left( ^{3}_{\Lambda}\mathrm H \rightarrow ^{3}\mathrm{He},\pi^{-} \right)} = \left( 3.86 \pm 0.77 (\mathrm{stat.}) \pm 0.68 (\mathrm{syst.})\right) \times 10^{-5}$ in the 0-10% most central collisions, is consistent with the predictions from a statistical thermal model using the same temperature as for the light hadrons. The coalescence parameter $B_3$ shows a dependence on the transverse momentum, similar to the $B_2$ of deuterons and the $B_3$ of $^{3}\mathrm{He}$ nuclei. The ratio of yields $S_3$ = $^{3}_{\Lambda}\mathrm H$/($^{3}\mathrm{He}$ $\times \Lambda/\mathrm{p}$) was measured to be $S_3$ = 0.60 $\pm$ 0.13 (stat.) $\pm$ 0.21 (syst.) in 0-10% centrality events; this value is compared to different theoretical models. The measured $S_3$ is fully compatible with thermal model predictions. The measured $^{3}_{\Lambda}\mathrm H$ lifetime, $ \tau = 181^{+54}_{-39} (\mathrm{stat.}) \pm 33 (\mathrm{syst.})\ \mathrm{ps}$ is compatible within 1$\sigma$ with the world average value.

4 data tables

(Hypertriton + Anti-Hypertriton)dN/d(ct) distribution.

Hypertriton and Anti-hypertriton $p_{\rm T}$ spectra x B.R.

$B_2$ as a function of $p_{\rm T}$/A for Hypertriton.

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A Comparison of the Particle Flow in Three Jet and Radiative Two Jet Events From $e^+ e^-$ Annihilation at $e$({CM}) = 29-{GeV}

Sheldon, P.D. ; Trilling, G. ; Petersen, A. ; et al.
Phys.Rev.Lett. 57 (1986) 1398, 1986.
Inspire Record 230941 DOI 10.17182/hepdata.20219

We have made a detailed comparison of the charged-particle flow in three-jet events (e+e−→qq¯g) and radiative two-jet events (e+e−→qq¯γ) from e+e− annihilation at Ec.m.=29 GeV. Accurate comparisons can be made because these two event types have similar topologies. In the angular region between the quark and antiquark jets, we observe substantially fewer charged tracks in the two-jet events than in the radiative three-jet events.

4 data tables

No description provided.

No description provided.

No description provided.

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A Determination of the strong coupling constant alpha-s from W production at the CERN p anti-p collider

The UA2 collaboration Alitti, J. ; Ambrosini, G. ; Ansari, R. ; et al.
Phys.Lett.B 263 (1991) 563-572, 1991.
Inspire Record 315374 DOI 10.17182/hepdata.29394

The large sample of W→eν events collected by the UA2 experiment at the CERN pp̄ collider between 1988 and 1990 has been used to determine the strong coupling constant α s . From a measurement of the ratio of the production rate of W events with one jet to that with no jets, α s has been extracted to second order in the MS ̄ scheme: α s (M 2 w )=0.123±0.0.18( stat .)±0.017 ( syst .) .

1 data table

ALP_S extracted to second order in the MSbar scheme.


A MEASUREMENT OF THE TOTAL HADRONIC CROSS-SECTION IN TAGGED gamma gamma REACTIONS

The TPC/Two Gamma collaboration Aihara, H. ; Alston-Garnjost, M. ; Avery, R.E. ; et al.
Phys.Rev.D 41 (1990) 2667, 1990.
Inspire Record 281351 DOI 10.17182/hepdata.22991

We present a measurement of the total cross section for γγ→hadrons, with one photon quasireal and the other a spacelike photon of mass squared −Q2. Results are presented as a function of Q2 and the γγ center-of-mass energy W, with the Q2 range extending from 0.2 to 60 GeV2, and W in the range from 2 to 10 GeV. The data were taken with the TPC/Two-Gamma facility at the SLAC e+e− storage ring PEP, which was operated at a beam energy of 14.5 GeV. The cross section exhibits a gentle falloff with increasing W. Its Q2 dependence is shown to be well described by an incoherent sum of vector-meson and pointlike scattering over most of the observed W range. Agreement at high Q2 is improved if a minimum-pT cutoff (motivated by QCD) is imposed on the pointlike contribution.

4 data tables

Errors are statistical only.

Errors are statistical only.

Errors are statistical only.

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A Measurement of D* Production in Jets from anti-p p Collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Amidei, D. ; Apollinari, G. ; et al.
Phys.Rev.Lett. 64 (1990) 348, 1990.
Inspire Record 283351 DOI 10.17182/hepdata.19973

The production rate of charged D* mesons in jets has been measured in 1.8-TeV p¯p collisions at the Fermilab Tevatron with the Collider Detector at Fermilab. In a sample of approximately 32 300 jets with a mean transverse energy of 47 GeV obtained from an exposure of 21.1 nb−1, a signal corresponding to 25.0±7.5(stat)±2.0(syst) D*±→K∓π±π± events is seen above background. This corresponds to a ratio N(D*++D*−)/N(jet) =0.10±0.03±0.03 for D* mesons with fractional momentum z greater than 0.1.

1 data table

Mean jet transverse energy is 47 GeV. Branching rates for D* --> D0 PI of 0.57 +- 0.04 (DSYS=0.04) and D0 --> K- PI+ of 0.042 +- 0.004 (DSYS=0.004), from MARK-III have been used.


A Measurement of W Boson Production in 1.8-TeV anti-p p Collisions

The CDF collaboration Abe, F. ; Amidei, D. ; Apollinari, G. ; et al.
Phys.Rev.Lett. 62 (1989) 1005, 1989.
Inspire Record 267998 DOI 10.17182/hepdata.20078

The cross section for the production and subsequent decay to electron and neutrino of the W intermediate vector boson has been measured in 1.8-TeV p¯p collisions at the Fermilab Tevatron Collider. An analysis of events with missing transverse energy greater than 25 GeV and with an electron of transverse energy greater than 15 GeV from a datum sample of 25.3 nb−1 gives σB=2.6±0.6±0.5 nb.

1 data table

Branching ratio to electron and neutrino.


A Measurement of sigma B (W ---> e neutrino) and sigma B (Z0 ---> e+ e-) in anti-p p collisions at s**(1/2) = 1800-GeV

The CDF collaboration Abe, F. ; Amidei, D. ; Apollinari, G. ; et al.
Phys.Rev.D 44 (1991) 29-52, 1991.
Inspire Record 302820 DOI 10.17182/hepdata.42696

An analysis of high-transverse-momentum electrons using data from the Collider Detector at Fermilab (CDF) of p¯p collisions at s=1800 GeV yields values of the production cross section times branching ratio for W and Z0 bosons of σ(p¯p→WX→eνX)=2.19±0.04(stat)±0.21(syst) nb and σ(p¯p→Z0X→e+e−X)=0.209±0.013(stat)±0.017(syst) nb. Detailed descriptions of the CDF electron identification, background, efficiency, and acceptance are included. Theoretical predictions of the cross sections that include a mass for the top quark larger than the W mass, current values of the W and Z0 masses, and higher-order QCD corrections are in good agreement with these measured values.

1 data table

No description provided.


A Measurement of single and double prompt photon production at the CERN anti-p p collider

The UA2 collaboration Alitti, J. ; Ambrosini, G. ; Ansari, R. ; et al.
Phys.Lett.B 288 (1992) 386-394, 1992.
Inspire Record 336186 DOI 10.17182/hepdata.29113

A measurement of the cross-sections for single and double prompt photon production in p p interactions at s = 630 GeV is presented. The data sample corresponds to an integrated luminosity of 13.2 pb −1 . The results are in good agreement with the predictions of perturbative QCD. The signal from double prompt photon production has a statistical significance of 4.3 standard deviations.

2 data tables

There is an overall systematic error of 9 pct not included in the table.

Errors quoted include statistical and all PT dependent systematic uncertainties. There is in addition a 6.8 pct overall normalization uncertainty.


A Measurement of the W and Z production cross-sections and a determination of Gamma (W) at the CERN anti-p p collider

The UA2 collaboration Alitti, J. ; Ambrosini, G. ; Ansari, R. ; et al.
Phys.Lett.B 276 (1992) 365-374, 1992.
Inspire Record 319671 DOI 10.17182/hepdata.29256

The decays W → ev and Z → e + e − are studied in [ovbar|p]p collisions at √ s =630 GeV . The products of production cross section and branching ratio are measured as σ e w =682±12±40 pb and σ e w =65.6±4.0±3.8 pb. The results are in good agreement with O(α 2 s ) calculations of the production cross sections. Many systematic effects cancel in the ratio, R =10.4± 0.7 0.6 ±0.3, which can be used to give an indirect measurement of the total width of the W boson: Γ w =2.10±0.13±0.09 GeV . The width gives a limit on the top quark mass, m top >53 GeV (95% CL), which is independent of the top decay mode.

1 data table

No description provided.


A Measurement of the direct photon production cross-section at the CERN anti-p p collider

The UA2 collaboration Alitti, J. ; Ambrosini, G. ; Ansari, R. ; et al.
Phys.Lett.B 263 (1991) 544-550, 1991.
Inspire Record 315377 DOI 10.17182/hepdata.47328

A measurement of the inclusive cross-section for production of direct photons in p̄p collisions at a centre of mass energy of 630 GeV is presented as a function of the photon transverse momentum. The data correspond to a total integrated luminosity of 7.4 pb −1 . The results support predictions from QCD theory.

1 data table

No description provided.


A Measurement of two jet decays of the W and Z bosons at the CERN anti-p p collider

The UA2 collaboration Alitti, J. ; Ansari, R. ; Ansorge, R.E. ; et al.
Z.Phys.C 49 (1991) 17-28, 1991.
Inspire Record 298412 DOI 10.17182/hepdata.15084

A study of the two-jet mass spectrum measured with the UA 2 calorimeter has revealed a signal from hadronic decays ofW andZ bosons above a large background. Production and decay properties of the signal have been measured. The combined production cross-section σ·B(W, Z → two jets) is 9.6±2.3 (stat.)±1.1 (syst.) nb, compared with an expectation of 5.8 nb calculated to order αs2. A limit on the production cross-section of additional heavy vector bosons decaying into two jets is given as a function of the boson mass.

1 data table

No description provided.


A Prompt photon cross-section measurement in anti-p p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Albrow, M. ; Amidei, D. ; et al.
Phys.Rev.D 48 (1993) 2998-3025, 1993.
Inspire Record 353026 DOI 10.17182/hepdata.22677

The first prompt photon measurement from the CDF experiment at the Fermilab pp¯ Collider is presented. Two independent methods are used to measure the cross section: one for high transverse momentum (PT) and one for lower PT. Comparisons to various theoretical calculations are shown. The cross section agrees qualitatively with QCD calculations but has a steeper slope at low PT.

4 data tables

Cross section using profile method and an isolation cut of 2 GeV in a cone around the photon. There is an additional 27 pct systematic uncertainty in addition to the PT dependent systematic errors shown in the table.

Cross section using conversion method and an isolation cut of 2 GeV in a cone around the photon. There is an additional +32,-46 pct systematic uncertainty in addition to the PT dependent systematic errors shown in the table.

Cross section using profile method and an isolation cut of 15 pct of the photon PT in a cone around the photon. There is an additional 29 pct systematic uncertainty in addition to the PT dependent systematic errors shown in the table.

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A STUDY OF NONCOLLINEAR TWO CHARGED PARTICLE EVENTS PRODUCED IN 29-GeV ELECTRON - POSITRON ANNIHILATION

Perl, Martin L. ; Muller, L. ; Barklow, T. ; et al.
Phys.Rev.D 34 (1986) 3321, 1986.
Inspire Record 223166 DOI 10.17182/hepdata.23431

This paper presents a study of events produced in 29-GeV electron-positron annihilation in which there are just two noncollinear charged particles, no detected photons, and two or more undetected particles. These events can be explained by attributing them primarily to the reactions e+e−→e+e−e+e− and e+e−→e+e−μ+μ− where just two particles appear in the Mark II detector. There is no evidence for unconventional sources for such events.

9 data tables

No description provided.

No description provided.

No description provided.

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A STUDY OF eta FORMATION IN PHOTON-PHOTON COLLISIONS AT PEP

The TPC/Two Gamma collaboration Aihara, H. ; Alston-Garnjost, M. ; Armitage, J.C. ; et al.
Phys.Rev.D 33 (1986) 844, 1986.
Inspire Record 217503 DOI 10.17182/hepdata.23508

The two-photon production of the η meson has been observed, and a value has been determined for the two-photon η decay width by a measurement of the cross section σ(e+e−→e+e−η) where η→γγ. The measurement was made with the TPC/Two-Gamma facility at the SLAC e+e− collider PEP, with an accumulated data sample of 64.5 pb−1. The η→γγ events were both triggered and detected by the pole-tip calorimeter. The measured two-photon η decay width is Γη→γγ=0.64±0.14 (statistical) ±0.13 (systematic) keV, in agreement with earlier similarly determined values.

1 data table

No description provided.


A Search for Elastic Nondiagonal Lepton Pair Production in $e^+ e^-$ Annihilation at $\sqrt{s}=29$-{GeV}

Gomez Cadenas, J.J. ; Heusch, C.A. ; Abrams, G.S. ; et al.
Phys.Rev.Lett. 66 (1991) 1007-1010, 1991.
Inspire Record 295203 DOI 10.17182/hepdata.19918

We have searched for the annihilation of e+e− into the exclusive channels e±τ∓ and μ±τ∓ at √s =29 GeV, using 226 and 133 pb−1, respectively, of data taken with the Mark II detector at the SLAC storage ring PEP. The resulting candidate sample is compatible with the expected background from τ pair production. Our analysis yields 95%-C.L. cross-section limits of σeτ/σμμ<1.8×10−3 and σμτ/σμμ<6.1×10−3, where σμμ is the QED cross section for production of a lepton pair. This is the first high-Q2 test of lepton-flavor conservation involving τ leptons.

1 data table

95 pct confidence upper limits.


A Search for Supersymmetric Electrons

Gladney, Larry D. ; Hollebeek, R.J. ; LeClaire, B. ; et al.
Phys.Rev.Lett. 51 (1983) 2253, 1983.
Inspire Record 192285 DOI 10.17182/hepdata.20505

A search for single electrons from the decay of singly produced scalar electrons has been made at the PEP storage ring at SLAC. No events of this type have been found in 123 pb−1 of data, resulting in a cross-section limit of less than 2.4×10−2 pb within the detector acceptance, and a 95%-confidence-level lower limit on the scalar-electron mass of 22.2 GeV/c2.

1 data table

No description provided.


A Study of Three Jet Events at the {CERN} $\bar{p} p$ Collider

The UA2 collaboration Appel, J.A. ; Bagnaia, P. ; Banner, M. ; et al.
Z.Phys.C 30 (1986) 341, 1986.
Inspire Record 219453 DOI 10.17182/hepdata.15897

The UA2 experiment, running at the CERN SPS\(\bar pp\) Collider, has performed a study of events containing three hard jets in the final state. The angular distributions of the three jets show evidence for gluon bremsstrahlung, in good agreement with a QCD model to leading order in the strong coupling constant αs. The yield of three-jet events relative to that of two-jet events provides a measure of the strong coupling constant: ;3K3/K2=0.23±0.01±0.04, whereK2 andK3 represent the contributions arising from higher order corrections in α3 to the two- and three-jet exclusive cross-sections. A detailed discussion of the systematic and theoretical uncertainties is given.

1 data table

No description provided.


A Study of multi - jet events at the CERN anti-p p collider and a search for double parton scattering

The UA2 collaboration Alitti, J. ; Ambrosini, G. ; Ansari, R. ; et al.
Phys.Lett.B 268 (1991) 145-154, 1991.
Inspire Record 317817 DOI 10.17182/hepdata.29361

A study of events containing at least four high transverse momentum jets and a search for double parton scattering (DPS) have been performed using data collected with the UA2 detector at the CERN p p Collider (√ s =630 GeV). The results are in good agreement with leading order QCD calculations. A value of σ DPS <0.82 nb at 95% confidence level (CL) is obtained for the DPS cross section.

3 data tables

Data requested from authors.

Uncorrected cross sections.

Upper limit to DPS contribution to 4JET production.


A Study of the Line Reversed Hypercharge Exchange Reactions pi+ p --> K+ Sigma+ (1385) and K- p --> pi- Sigma+ (1385) at 10-GeV/c

Berglund, A. ; Buran, T. ; Carlson, P.J. ; et al.
Phys.Lett.B 60 (1975) 117-120, 1975.
Inspire Record 100190 DOI 10.17182/hepdata.27751

We present results on the differential cross-sections for the reactions π + p → K + Σ + (1385) and K − p → π − Σ + (1385) at 10 GeV/ c . For the first time, the same equipment has been used in measuring both reactions, in order to obtain good relative normalization. In the region of low t ( t min to −0.3 (GeV/ c ) 2 ) the two differential cross-sections have similar shape, and show a sharp forward dip indicating a dominant helicity flip contribution. However, the magnitudes of the cross-sections are significantly different, indicating substantial exchange degeneracy breaking. We find the ratio of the integrated cross-sections for the reactions K − p → π − Σ + (1385) and π + p → K + Σ + (1385) over the range −0.3 < t ′ < 0.0 (GeV/ c ) 2 to be 2.0 ± 0.2.

2 data tables

TMIN = -0.013 GEV**2.

TMIN = +0.012 GEV**2.


A Study of the Reaction anti-p p --> pi- pi+ at 10-GeV/c

Berglund, A. ; Buran, T. ; Carlson, P.J. ; et al.
Nucl.Phys.B 137 (1978) 276-282, 1978.
Inspire Record 135348 DOI 10.17182/hepdata.35092

The reaction p p → π − π + has been studied at 10.1 GeV/ c in the − t interval from 0.15 to 1.5 (GeV/ c ) 2 . A line-reversal comparison with backward elastic scattering π + p → p π + shows good agreement for − t > 0.3 (GeV/ c ) 2 .

2 data tables

No description provided.

No description provided.


A Study of the Reactions pi+ p --> K+ Sigma+ and K- p --> pi- Sigma+ at 10-GeV/c

Berglund, A. ; Buran, T. ; Carlson, P.J. ; et al.
Phys.Lett.B 57 (1975) 100, 1975.
Inspire Record 99264 DOI 10.17182/hepdata.27855

For the first time, the reactions π + p →K + ∑ + and K − p→ π − ∑ + have been studied in the same apparatus. This has been done at an adequately high momentum (10.1 GeV/ c ) to allow a check of the prediction of exchange degeneracy, that the differential cross sections should be converging at high energy. We have measured the cross section for momentum transfers t between t min and t = −0.3 (GeV/ c ) 2 . We find that for both reactions the differential cross section shows an exponential fall, with no deviations right in to t = t min (where some other experiments have shown a dip in the cross section). Furthermore, we find the magnitude of the differential cross sections to be closely similar at t = 0, with a ratio R= ( d σ d t) t=0 ( K − p →π − ∑ + ) ( d σ d t) t=0 (π + p → K + ∑ + However, the slope for the positive reaction is about 19% steeper than that for the negative reaction.

1 data table

No description provided.


A Study of the strong coupling constant using W + jets processes

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Rev.Lett. 75 (1995) 3226-3231, 1995.
Inspire Record 394610 DOI 10.17182/hepdata.42454

The ratio of the number of W+1 jet to W+0 jet events is measured with the D0 detector using data from the 1992–93 Tevatron Collider run. For the W→eν channel with a minimum jet ET cutoff of 25 GeV, the experimental ratio is 0.065±0.003stat±0.007syst. Next-to-leading order QCD predictions for various parton distributions agree well with each other and are all over 1 standard deviation below the measurement. Varying the strong coupling constant αs in both the parton distributions and the partonic cross sections simultaneously does not remove this discrepancy.

1 data table

Two values of ALPHA_S corresponds the two different parton distribution functions (pdf) used in extraction of ALPHA_S from the ratio. The dominant systematic error is from the jet energy scale uncertainty.


A detailed map of Higgs boson interactions by the ATLAS experiment ten years after the discovery

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abbott, Dale ; et al.
Nature 607 (2022) 52-59, 2022.
Inspire Record 2104706 DOI 10.17182/hepdata.130266

The Standard Model of particle physics describes the known fundamental particles and forces that make up our universe, with the exception of gravity. One of the central features of the Standard Model is a field that permeates all of space and interacts with fundamental particles. The quantum excitation of this field, known as Higgs field, manifests itself as the Higgs boson, the only fundamental particle with no spin. In 2012, a particle with properties consistent with the Higgs boson of the Standard Model was observed by the ATLAS and CMS experiments at the Large Hadron Collider at CERN. Since then, more than 30 times as many Higgs bosons have been recorded by the ATLAS experiment, allowing much more precise measurements and new tests of the theory. Here, on the basis of this larger dataset, we combine an unprecedented number of production and decay processes of the Higgs boson to scrutinize its interactions with elementary particles. Interactions with gluons, photons, and $W$ and $Z$ bosons -- the carriers of the strong, electromagnetic, and weak forces -- are studied in detail. Interactions with three third-generation matter particles (bottom ($b$) and top ($t$) quarks, and tau leptons ($\tau$)) are well measured and indications of interactions with a second-generation particle (muons, $\mu$) are emerging. These tests reveal that the Higgs boson discovered ten years ago is remarkably consistent with the predictions of the theory and provide stringent constraints on many models of new phenomena beyond the Standard Model.

57 data tables

Observed and predicted cross sections for different Higgs boson production processes, measured assuming SM values for the decay branching fractions. The lower panels show the ratios of the measured values to their SM predictions. The $p$-value for compatibility of the measurement and the SM prediction is 65%.

Observed and predicted branching fractions for different Higgs boson decay modes measured assuming SM values for the production cross sections. The lower panels show the ratios of the measured values to their SM predictions. The $p$-value for compatibility of the measurement and the SM prediction is 56%.

Ratio of observed rate to predicted SM event rate for different combinations of Higgs boson production and decay processes. The narrow grey bands indicate the theory uncertainties in the SM cross-section times the branching fraction predictions. The $p$-value for compatibility of the measurement and the SM prediction is 72%.

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A measurement of the b anti-b cross section in 800-GeV/c proton silicon interactions.

The E771 collaboration Alexopoulos, T. ; Antoniazzi, L. ; Arenton, M. ; et al.
Phys.Rev.Lett. 82 (1999) 41-44, 1999.
Inspire Record 447430 DOI 10.17182/hepdata.42183

The cross section for bb¯ production in 800GeV/c pN interactions has been measured in Fermilab experiment E771 to be 43−17+27(stat)−7+7(syst)nb per nucleon from the observation of events in which both the b and the b¯ decay semimuonically or a B decays into a J/ψ followed by J/ψ→μ+μ−.

1 data table

No description provided.


A precise measurement of the Z-boson double-differential transverse momentum and rapidity distributions in the full phase space of the decay leptons with the ATLAS experiment at $\sqrt s$ = 8 TeV

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abeling, Kira ; et al.
Eur.Phys.J.C 84 (2024) 315, 2024.
Inspire Record 2698794 DOI 10.17182/hepdata.144246

This paper presents for the first time a precise measurement of the production properties of the Z boson in the full phase space of the decay leptons. The measurement is obtained from proton-proton collision data collected by the ATLAS experiment in 2012 at $\sqrt s$ = 8 TeV at the LHC and corresponding to an integrated luminosity of 20.2 fb$^{-1}$. The results, based on a total of 15.3 million Z-boson decays to electron and muon pairs, extend and improve a previous measurement of the full set of angular coefficients describing Z-boson decay. The double-differential cross-section distributions in Z-boson transverse momentum p$_T$ and rapidity y are measured in the pole region, defined as 80 $<$ m $<$ 100 GeV, over the range $|y| <$ 3.6. The total uncertainty of the normalised cross-section measurements in the peak region of the p$_T$ distribution is dominated by statistical uncertainties over the full range and increases as a function of rapidity from 0.5-1.0% for $|y| <$ 2.0 to 2-7% at higher rapidities. The results for the rapidity-dependent transverse momentum distributions are compared to state-of-the-art QCD predictions, which combine in the best cases approximate N$^4$LL resummation with N$^3$LO fixed-order perturbative calculations. The differential rapidity distributions integrated over p$_T$ are even more precise, with accuracies from 0.2-0.3% for $|y| <$ 2.0 to 0.4-0.9% at higher rapidities, and are compared to fixed-order QCD predictions using the most recent parton distribution functions. The agreement between data and predictions is quite good in most cases.

10 data tables

Measured $p_T$ cross sections in full-lepton phase space for |y| < 0.4.

Measured $p_T$ cross sections in full-lepton phase space for 0.4 < |y| < 0.8.

Measured $p_T$ cross sections in full-lepton phase space for 0.8 < |y| < 1.2.

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A search for heavy Higgs bosons decaying into vector bosons in same-sign two-lepton final states in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abbott, D.C. ; et al.
JHEP 07 (2023) 200, 2023.
Inspire Record 2176695 DOI 10.17182/hepdata.129285

A search for heavy Higgs bosons produced in association with a vector boson and decaying into a pair of vector bosons is performed in final states with two leptons (electrons or muons) of the same electric charge, missing transverse momentum and jets. A data sample of proton-proton collisions at a centre-of-mass energy of 13 TeV recorded with the ATLAS detector at the Large Hadron Collider between 2015 and 2018 is used. The data correspond to a total integrated luminosity of 139 fb$^{-1}$. The observed data are in agreement with Standard Model background expectations. The results are interpreted using higher-dimensional operators in an effective field theory. Upper limits on the production cross-section are calculated at 95% confidence level as a function of the heavy Higgs boson's mass and coupling strengths to vector bosons. Limits are set in the Higgs boson mass range from 300 to 1500 GeV, and depend on the assumed couplings. The highest excluded mass for a heavy Higgs boson with the coupling combinations explored is 900 GeV. Limits on coupling strengths are also provided.

16 data tables

Comparison between data and SM predictions for the meff distributions in the boosted SR. The background predictions are obtained through a background-only simultaneous fit and are shown as filled histograms. The entries in overflow are included in the last bin. The size of the combined statistical and systematic uncertainty for the sum of the fitted background is indicated by the hatched band. The ratio of the data to the sum of the fitted background is shown in the lower panel. Two benchmark signal samples, as indicated in the legend, are also shown as unstacked unfilled histograms normalised to the integrated luminosity of the data using the theoretical cross-sections.

Comparison between data and SM predictions for the meff distributions in the resolved SR. The background predictions are obtained through a background-only simultaneous fit and are shown as filled histograms. The entries in overflow are included in the last bin. The size of the combined statistical and systematic uncertainty for the sum of the fitted background is indicated by the hatched band. The ratio of the data to the sum of the fitted background is shown in the lower panel. Two benchmark signal samples, as indicated in the legend, are also shown as unstacked unfilled histograms normalised to the integrated luminosity of the data using the theoretical cross-sections.

Expected 95% CL upper limits on the production of a heavy Higgs boson as functions of fw and fww with mass equal to 300 GeV.

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A search for heavy pointlike Dirac monopoles

The D0 collaboration Abbott, B. ; Abolins, M. ; Acharya, Bannanje Sripath ; et al.
Phys.Rev.Lett. 81 (1998) 524-529, 1998.
Inspire Record 468445 DOI 10.17182/hepdata.42158

We have searched for central production of a pair of photons with high transverse energies in $p\bar p$ collisions at $\sqrt{s} = 1.8$ TeV using $70 pb^{-1}$ of data collected with the D\O detector at the Fermilab Tevatron in 1994--1996. If they exist, virtual heavy pointlike Dirac monopoles could rescatter pairs of nearly real photons into this final state via a box diagram. We observe no excess of events above background, and set lower 95% C.L. limits of $610, 870, or 1580 GeV/c^2$ on the mass of a spin 0, 1/2, or 1 Dirac monopole.

1 data table

No description provided.


A search for new resonances in multiple final states with a high transverse momentum $Z$ boson in $\sqrt{s}=13$ TeV $pp$ collisions with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abbott, D.C. ; et al.
JHEP 06 (2023) 036, 2023.
Inspire Record 2158974 DOI 10.17182/hepdata.132793

A generic search for resonances is performed with events containing a $Z$ boson with transverse momentum greater than 100 GeV, decaying into $e^+e^-$ or $\mu^+\mu^-$. The analysed data collected with the ATLAS detector in proton-proton collisions at a centre-of-mass energy of 13 TeV at the Large Hadron Collider correspond to an integrated luminosity of 139 fb$^{-1}$. Two invariant mass distributions are examined for a localised excess relative to the expected Standard Model background in six independent event categories (and their inclusive sum) to increase the sensitivity. No significant excess is observed. Exclusion limits at 95% confidence level are derived for two cases: a model-independent interpretation of Gaussian-shaped resonances with the mass width between 3% and 10% of the resonance mass, and a specific heavy vector triplet model with the decay mode $W'\to ZW \to \ell\ell qq$.

62 data tables

Results of applying the BH algorithm to the mass spectra in the leading small-R jet category, using the fitted background estimations from the initial step

Results of applying the BH algorithm to the mass spectra in the leading bjet category, using the fitted background estimations from the initial step

Results of applying the BH algorithm to the mass spectra in the leading large-R jet category, using the fitted background estimations from the initial step

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A statistical combination of ATLAS Run 2 searches for charginos and neutralinos at the LHC

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abeling, Kira ; et al.
CERN-EP-2024-018, 2024.
Inspire Record 2758009 DOI 10.17182/hepdata.149530

Statistical combinations of searches for charginos and neutralinos using various decay channels are performed using $139\,$fb$^{-1}$ of $pp$ collision data at $\sqrt{s}=13\,$TeV with the ATLAS detector at the Large Hadron Collider. Searches targeting pure-wino chargino pair production, pure-wino chargino-neutralino production, or higgsino production decaying via Standard Model $W$, $Z$, or $h$ bosons are combined to extend the mass reach to the produced SUSY particles by 30-100 GeV. The depth of the sensitivity of the original searches is also improved by the combinations, lowering the 95% CL cross-section upper limits by 15%-40%.

38 data tables

Expected 95% CL exclusion limits on the simplified models of chargino-pair production decaying via W bosons.

$+1\sigma$ expected 95% CL exclusion limits on the simplified models of chargino-pair production decaying via W bosons.

$-1\sigma$ expected 95% CL exclusion limits on the simplified models of chargino-pair production decaying via W bosons.

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A study of S wave pi pi scattering in the reaction pi+ n ---> pi0 pi0 p at 2.15 gev/c

Bensinger, J.R. ; Erwin, A.R. ; Thompson, M.A. ; et al.
Phys.Lett.B 36 (1971) 134-138, 1971.
Inspire Record 69178 DOI 10.17182/hepdata.28409

We have studied the 2 π 0 final states in the reaction π + d → π 0 π 0 p(p) at 2.15 GeV/ c in a 2 million picture exposure of the PPA rapid cycling deuterium bubble chamber. Two tantalum plates were added to the bubble chamber to convert γ rays which were kinematically constrained to a 2 π 0 hypothesis. The 2 π 0 mass spectrum is observed to saturate s-wave unitarity in the ππ mass region between 0.6 and 0.9 GeV/ c 2 , clearly favoring the ‘up-down’ or broad resonance solution for s-wave, I = 0, ππ scattering.

1 data table

No description provided.


A-dependence of Polarization of $\Lambda^0$ Produced Inclusively in Neutron - Nucleus Interactions

The BIS-2 collaboration Aleev, A.N. ; Arefev, V.A. ; Balandin, V.P. ; et al.
Z.Phys.C 36 (1987) 27, 1987.
Inspire Record 237043 DOI 10.17182/hepdata.39599

TheA-dependence of the polarization ofΛ0,s produced inclusively in neutron-nucleus interactions at a mean neutron momentum of about 40 GeV/c has been measured in an experiment performed using the BIS-2 spectrometer at the Serpukhov accelerator. Carbon, Aluminium and Copper targets were used. TheΛ0,s were produced in the kinematical region of 0.6<pT<1.3 GeV/c and 0.2<xF<0.9. Describing the polarization of theΛ0,s by ℘=a·A a value of (−0.15+0.07/−0.60) was obtained by a fit to our data.

2 data tables

POLARIZATION IS DESCRIBED BY A POWER LOW: POL = C*A**B, WHERE C = -1.1, +0.4, -0.3 , A- ATOMIC NUMBER AND B = -0.15, +0.07, -0.6.


A-dependence of the Production Cross-section of $\Lambda(c$)+ Charmed Baryons in Neutron - Nucleus Interactions

The BIS-2 collaboration Aleev, A.N. ; Arefev, V.A. ; Balandin, V.P. ; et al.
Sov.J.Nucl.Phys. 46 (1987) 657, 1987.
Inspire Record 235393 DOI 10.17182/hepdata.39661

None

1 data table

No description provided.


AN EXPERIMENTAL TEST OF EXCHANGE DEGENERACY IN THE HYPERCHARGE EXCHANGE REACTIONS PI+ P ---> K+ SIGMA+ AND K- P ---> PI- SIGMA+

Berglund, A. ; Buran, T. ; Carlson, P.J. ; et al.
Phys.Lett.B 73 (1978) 369-374, 1978.
Inspire Record 134098 DOI 10.17182/hepdata.27470

For the first time, the line reversed reactions π + p→K + Σ + and K − p→ π − Σ + have been studied in the same apparatus. We present the differential cross sections and polarizations over a large t range and at two momenta, 7.0 and 10.1 GeV/ c . The differential cross sections as a function of t are shown for the first time to cross over. Going from the lower to the higher momentum, the differences in cross section between the two reactions diminish at low | t | by about a factor 2. We find large polarizations of opposite sign for the two reactions. The momentum dependence, presented in the form of α eff ( t ) for the t range 0 to −2 (GeV/ c ) 2 , is compared with the expectations from the K ∗ −K ∗∗ trajectory.

10 data tables

-TMIN = 0.0100 GEV**2.

-TMIN = -0.0087 GEV**2.

-TMIN = 0.0067 GEV**2.

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ATLAS Run 2 searches for electroweak production of supersymmetric particles interpreted within the pMSSM

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abeling, Kira ; et al.
CERN-EP-2024-021, 2024.
Inspire Record 2755168 DOI 10.17182/hepdata.149493

A summary of the constraints from searches performed by the ATLAS Collaboration for the electroweak production of charginos and neutralinos is presented. Results from eight separate ATLAS searches are considered, each using 140 fb$^{-1}$ of proton-proton data at a centre-of-mass energy of $\sqrt{s}$=13 TeV collected at the Large Hadron Collider during its second data-taking run. The results are interpreted in the context of the 19-parameter phenomenological minimal supersymmetric standard model, where R-parity conservation is assumed and the lightest supersymmetric particle is assumed to be the lightest neutralino. Constraints from previous electroweak, flavour and dark matter related measurements are also considered. The results are presented in terms of constraints on supersymmetric particle masses and are compared with limits from simplified models. Also shown is the impact of ATLAS searches on parameters such as the dark matter relic density and the spin-dependent and spin-independent scattering cross-sections targeted by direct dark matter detection experiments. The Higgs boson and Z boson `funnel regions', where a low-mass neutralino would not oversaturate the dark matter relic abundance, are almost completely excluded by the considered constraints. Example spectra for non-excluded supersymmetric models with light charginos and neutralinos are also presented.

2 data tables

SLHA files and exclusion information (in CSV format) are available to download for the pMSSM models in this paper. Please refer to <a href="https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/SUSY-2020-15/inputs/ATLAS_EW_pMSSM_Run2.html">this web page</a> for download links along with a description of the contents.

SLHA files and exclusion information (in CSV format) are available to download for the pMSSM models in this paper. Please refer to <a href="https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/SUSY-2020-15/inputs/ATLAS_EW_pMSSM_Run2.html">this web page</a> for download links along with a description of the contents.


An Experimental Test of Exchange Degeneracy in the Reactions $\pi^+ p \to K^+ \Sigma^+$, $\pi^+ p \to K^+ \Sigma^+$ (1385) and Their Line Reversed Partners

Berglund, A. ; Buran, T. ; Carlson, P.J. ; et al.
Nucl.Phys.B 166 (1980) 25-61, 1980.
Inspire Record 143535 DOI 10.17182/hepdata.34526

A description is given of an experimental study of exchange degeneracy (EXD) in hypercharge-exchange reactions using the line-reversed partners π + p→K + Σ + (K − p→ π − Σ + ) and π + p→ K + Σ + (1385) (K − p→ π − Σ + (1385)) at incident momenta of 7.0 and 10.1 GeV/ c . Both pairs of reaction were measured in the same apparatus, with particular care being taken to minimize relative normalization errors. For the Σ production reactions we present high statistics measurements of the differential cross sections and polarizations from t ′=0 to large t . The general trends of the data agree with naive expectations from weak EXD. The cross-section difference in the extreme forward direction at the higher momentum is consistent with zero and there is a general reduction in the cross-section differences going from the lower to the higher momentum. The polarizations are approximately equal in magnitude and of opposite sign between the two reactions. On the other hand, the data do not agree with the detailed predictions of EXD. The slope for the positive reaction is systematically steeper in the forward region than for the negative reaction and there is a complex s and t dependence for the cross-section differences including a cross-over at t ⋍ −0.8( GeV /c) 2 . For the Σ(1385) production reactions, we present differential cross-section measurements in the forward region (| t |<0.3(GeV/ c ) 2 ). The cross-section differences are substantial and essentially constant over the s and t ranges studied.

2 data tables

THESE RESULTS WERE BRIEFLY REPORTED IN A. BERGLUND ET AL., PL 73B, 369 (1978), THE RECORD OF WHICH INCLUDES THE TABULATED DATA.

THE RESULTS AT 10.1 GEV WERE FIRST PUBLISHED IN A. BERGLUND ET AL., PL 60B, 117 (1975), THE RECORD OF WHICH INCLUDES THE TABULATED DATA.


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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Anisotropic flow of charged hadrons, pions and (anti-)protons measured at high transverse momentum in Pb-Pb collisions at $\snn=2.76$ TeV

The ALICE collaboration Abelev, Betty ; Adam, Jaroslav ; Adamova, Dagmar ; et al.
Phys.Lett.B 719 (2013) 18-28, 2013.
Inspire Record 1116150 DOI 10.17182/hepdata.62177

The elliptic, $v_2$, triangular, $v_3$, and quadrangular, $v_4$, azimuthal anisotropic flow coefficients are measured for unidentified charged particles, pions and (anti-)protons in Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV with the ALICE detector at the Large Hadron Collider. Results obtained with the event plane and four-particle cumulant methods are reported for the pseudo-rapidity range $|\eta|<0.8$ at different collision centralities and as a function of transverse momentum, $p_{\rm T}$, out to $p_{\rm T}=20$ GeV/$c$. The observed non-zero elliptic and triangular flow depends only weakly on transverse momentum for $p_{\rm T}>8$ GeV/$c$. The small $p_{\rm T}$ dependence of the difference between elliptic flow results obtained from the event plane and four-particle cumulant methods suggests a common origin of flow fluctuations up to $p_{\rm T}=8$ GeV/$c$. The magnitude of the (anti-)proton elliptic and triangular flow is larger than that of pions out to at least $p_{\rm T}=8$ GeV/$c$ indicating that the particle type dependence persists out to high $p_{\rm T}$.

16 data tables

Elliptic flow (v2) estimated with Event Plane method (with eta gap of 2.0) measured for unidentified charged particles as a function of transverse momentum for various centrality classes.

Elliptic flow (v2) estimated with four-particle cumulants measured for unidentified charged particles as a function of transverse momentum for various centrality classes.

Triangular flow (v3) estimated with Event Plane method (with eta gap of 2.0) measured for unidentified charged particles as a function of transverse momentum for various centrality classes.

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Version 2
Anisotropic flow of charged particles in Pb-Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV

The ALICE collaboration Adam, Jaroslav ; Adamova, Dagmar ; Aggarwal, Madan Mohan ; et al.
Phys.Rev.Lett. 116 (2016) 132302, 2016.
Inspire Record 1419244 DOI 10.17182/hepdata.72886

We report the first results of elliptic ($v_2$), triangular ($v_3$) and quadrangular flow ($v_4$) of charged particles in Pb-Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV with the ALICE detector at the CERN Large Hadron Collider. The measurements are performed in the central pseudorapidity region $|\eta|<0.8$ and for the transverse momentum range $0.2<p_{\rm T}<5$ GeV/$c$. The anisotropic flow is measured using two-particle correlations with a pseudorapidity gap greater than one unit and with the multi-particle cumulant method. Compared to results from Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76$ TeV, the anisotropic flow coefficients $v_{2}$, $v_{3}$ and $v_{4}$ are found to increase by ($3.0\pm0.6$)%, ($4.3\pm1.4$)% and ($10.2\pm3.8$)%, respectively, in the centrality range 0-50%. This increase can be attributed mostly to an increase of the average transverse momentum between the two energies. The measurements are found to be compatible with hydrodynamic model calculations. This comparison provides a unique opportunity to test the validity of the hydrodynamic picture and the power to further discriminate between various possibilities for the temperature dependence of shear viscosity to entropy density ratio of the produced matter in heavy-ion collisions at the highest energies.

22 data tables

Centrality dependence of $v_2$, with two- and multi-particle correlations, integrated over the $p_{\rm T}$ range 0.2 < $p_{\rm T}$ < 5.0 GeV/$c$, at $\sqrt{s_{\rm NN}}$ = 5.02 TeV.

Centrality dependence of $v_2$, with two- and multi-particle correlations, integrated over the $p_{\rm T}$ range 0.2 < $p_{\rm T}$ < 5.0 GeV/$c$, at $\sqrt{s_{\rm NN}}$ = 5.02 TeV.

Centrality dependence of $v_3$ and $v_4$, with two-particle correlations, integrated over the $p_{\rm T}$ range 0.2 < $p_{\rm T}$ < 5.0 GeV/c, at $\sqrt{s_{\rm NN}}$ = 5.02 TeV.

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Anomalous centrality evolution of two-particle angular correlations from Au-Au collisions at $\sqrt{s_{\rm NN}}$ = 62 and 200 GeV

The STAR collaboration Agakishiev, G. ; Aggarwal, M.M. ; Ahammed, Z. ; et al.
Phys.Rev.C 86 (2012) 064902, 2012.
Inspire Record 927960 DOI 10.17182/hepdata.101346

We present two-dimensional (2D) two-particle angular correlations on relative pseudorapidity $\eta$ and azimuth $\phi$ for charged particles from Au-Au collisions at $\sqrt{s_{\rm NN}} = 62$ and 200 GeV with transverse momentum $p_t \geq 0.15$ GeV/$c$, $|\eta| \leq 1$ and $2\pi$ azimuth. Observed correlations include a {same-side} (relative azimuth $< \pi/2$) 2D peak, a closely-related away-side azimuth dipole, and an azimuth quadrupole conventionally associated with elliptic flow. The same-side 2D peak and away-side dipole are explained by semihard parton scattering and fragmentation (minijets) in proton-proton and peripheral nucleus-nucleus collisions. Those structures follow N-N binary-collision scaling in Au-Au collisions until mid-centrality where a transition to a qualitatively different centrality trend occurs within a small centrality interval. Above the transition point the number of same-side and away-side correlated pairs increases rapidly {relative to} binary-collision scaling, the $\eta$ width of the same-side 2D peak also increases rapidly ($\eta$ elongation) and the $\phi$ width actually decreases significantly. Those centrality trends are more remarkable when contrasted with expectations of jet quenching in a dense medium. Observed centrality trends are compared to {\sc hijing} predictions and to the expected trends for semihard parton scattering and fragmentation in a thermalized opaque medium. We are unable to reconcile a semihard parton scattering and fragmentation origin for the observed correlation structure and centrality trends with heavy ion collision scenarios which invoke rapid parton thermalization. On the other hand, if the collision system is effectively opaque to few-GeV partons the observations reported here would be inconsistent with a minijet picture.

21 data tables

FIG. 1. (Color online) Perspective views of $2 \mathrm{D}$ charge-independent angular correlations $\Delta \rho / \sqrt{\rho_{\mathrm{ref}}}$ on $\left(\eta_{\Delta}, \phi_{\Delta}\right)$ for Au-Au collisions at $\sqrt{s_{N N}}=200$ and $62 \mathrm{GeV}$ (top and bottom rows, respectively). Centrality increases left to right from most peripheral to most central. Corrected total cross-section fractions are (left to right) $84 \%-93 \%, 55 \%-64 \%, 18 \%-28 \%,$ and $0 \%-5 \%$ for the $200-\mathrm{GeV}$ data and $84 \%-95 \%, 56 \%-65 \%$ $18 \%-28 \%,$ and $0 \%-5 \%$ for the $62 \mathrm{GeV}$ data (see Tables III and IV).

FIG. 1. (Color online) Perspective views of $2 \mathrm{D}$ charge-independent angular correlations $\Delta \rho / \sqrt{\rho_{\mathrm{ref}}}$ on $\left(\eta_{\Delta}, \phi_{\Delta}\right)$ for Au-Au collisions at $\sqrt{s_{N N}}=200$ and $62 \mathrm{GeV}$ (top and bottom rows, respectively). Centrality increases left to right from most peripheral to most central. Corrected total cross-section fractions are (left to right) $84 \%-93 \%, 55 \%-64 \%, 18 \%-28 \%,$ and $0 \%-5 \%$ for the $200-\mathrm{GeV}$ data and $84 \%-95 \%, 56 \%-65 \%$ $18 \%-28 \%,$ and $0 \%-5 \%$ for the $62 \mathrm{GeV}$ data (see Tables III and IV).

FIG. 1. (Color online) Perspective views of $2 \mathrm{D}$ charge-independent angular correlations $\Delta \rho / \sqrt{\rho_{\mathrm{ref}}}$ on $\left(\eta_{\Delta}, \phi_{\Delta}\right)$ for Au-Au collisions at $\sqrt{s_{N N}}=200$ and $62 \mathrm{GeV}$ (top and bottom rows, respectively). Centrality increases left to right from most peripheral to most central. Corrected total cross-section fractions are (left to right) $84 \%-93 \%, 55 \%-64 \%, 18 \%-28 \%,$ and $0 \%-5 \%$ for the $200-\mathrm{GeV}$ data and $84 \%-95 \%, 56 \%-65 \%$ $18 \%-28 \%,$ and $0 \%-5 \%$ for the $62 \mathrm{GeV}$ data (see Tables III and IV).

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