Measurements of the suppression and correlations of dijets in Xe+Xe collisions at $\sqrt{s_{NN}}$ = 5.44 TeV

The ATLAS collaboration Aad, G. ; Abbott, B. ; Abeling, K. ; et al.
Phys.Rev.C 108 (2023) 024906, 2023.
Inspire Record 2630510 DOI 10.17182/hepdata.139684

Measurements of the suppression and correlations of dijets is performed using 3 $\mu$b$^{-1}$ of Xe+Xe data at $\sqrt{s_{\mathrm{NN}}} = 5.44$ TeV collected with the ATLAS detector at the LHC. Dijets with jets reconstructed using the $R=0.4$ anti-$k_t$ algorithm are measured differentially in jet $p_{\text{T}}$ over the range of 32 GeV to 398 GeV and the centrality of the collisions. Significant dijet momentum imbalance is found in the most central Xe+Xe collisions, which decreases in more peripheral collisions. Results from the measurement of per-pair normalized and absolutely normalized dijet $p_{\text{T}}$ balance are compared with previous Pb+Pb measurements at $\sqrt{s_{\mathrm{NN}}} =5.02$ TeV. The differences between the dijet suppression in Xe+Xe and Pb+Pb are further quantified by the ratio of pair nuclear-modification factors. The results are found to be consistent with those measured in Pb+Pb data when compared in classes of the same event activity and when taking into account the difference between the center-of-mass energies of the initial parton scattering process in Xe+Xe and Pb+Pb collisions. These results should provide input for a better understanding of the role of energy density, system size, path length, and fluctuations in the parton energy loss.

62 data tables

The centrality intervals in Xe+Xe collisions and their corresponding TAA with absolute uncertainties.

The centrality intervals in Xe+Xe and Pb+Pb collisions for matching SUM ET FCAL intervals and respective TAA values for Xe+Xe collisions.

The performance of the jet energy scale (JES) for jets with $|y| < 2.1$ evaluated as a function of pT_truth in different centrality bins. Simulated hard scatter events were overlaid onto events from a dedicated sample of minimum-bias Xe+Xe data.

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Charged-hadron production in $pp$, $p$+Pb, Pb+Pb, and Xe+Xe collisions at $\sqrt{s_{_\text{NN}}}=5$ TeV with the ATLAS detector at the LHC

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abeling, Kira ; et al.
JHEP 07 (2023) 074, 2023.
Inspire Record 2601282 DOI 10.17182/hepdata.135676

This paper presents measurements of charged-hadron spectra obtained in $pp$, $p$+Pb, and Pb+Pb collisions at $\sqrt{s}$ or $\sqrt{s_{_\text{NN}}}=5.02$ TeV, and in Xe+Xe collisions at $\sqrt{s_{_\text{NN}}}=5.44$ TeV. The data recorded by the ATLAS detector at the LHC have total integrated luminosities of 25 pb${}^{-1}$, 28 nb${}^{-1}$, 0.50 nb${}^{-1}$, and 3 $\mu$b${}^{-1}$, respectively. The nuclear modification factors $R_{p\text{Pb}}$ and $R_\text{AA}$ are obtained by comparing the spectra in heavy-ion and $pp$ collisions in a wide range of charged-particle transverse momenta and pseudorapidity. The nuclear modification factor $R_{p\text{Pb}}$ shows a moderate enhancement above unity with a maximum at $p_{\mathrm{T}} \approx 3$ GeV; the enhancement is stronger in the Pb-going direction. The nuclear modification factors in both Pb+Pb and Xe+Xe collisions feature a significant, centrality-dependent suppression. They show a similar distinct $p_{\mathrm{T}}$-dependence with a local maximum at $p_{\mathrm{T}} \approx 2$ GeV and a local minimum at $p_{\mathrm{T}} \approx 7$ GeV. This dependence is more distinguishable in more central collisions. No significant $|\eta|$-dependence is found. A comprehensive comparison with several theoretical predictions is also provided. They typically describe $R_\text{AA}$ better in central collisions and in the $p_{\mathrm{T}}$ range from about 10 to 100 GeV.

140 data tables

- - - - - - - - - - - - - - - - - - - - <br><b>charged-hadron spectra:</b> <br><i>pp reference:</i>&nbsp;&nbsp; <a href="?version=1&table=Table1">for p+Pb</a>&nbsp;&nbsp; <a href="?version=1&table=Table10">for Pb+Pb</a>&nbsp;&nbsp; <a href="?version=1&table=Table19">for Xe+Xe</a>&nbsp;&nbsp; <br><i>p+Pb:</i>&nbsp;&nbsp; <a href="?version=1&table=Table2">0-5%</a>&nbsp;&nbsp; <a href="?version=1&table=Table3">5-10%</a>&nbsp;&nbsp; <a href="?version=1&table=Table4">10-20%</a>&nbsp;&nbsp; <a href="?version=1&table=Table5">20-30%</a>&nbsp;&nbsp; <a href="?version=1&table=Table6">30-40%</a>&nbsp;&nbsp; <a href="?version=1&table=Table7">40-60%</a>&nbsp;&nbsp; <a href="?version=1&table=Table8">60-90%</a>&nbsp;&nbsp; <a href="?version=1&table=Table9">0-90%</a>&nbsp;&nbsp; <br><i>Pb+Pb:</i>&nbsp;&nbsp; <a href="?version=1&table=Table11">0-5%</a>&nbsp;&nbsp; <a href="?version=1&table=Table12">5-10%</a>&nbsp;&nbsp; <a href="?version=1&table=Table13">10-20%</a>&nbsp;&nbsp; <a href="?version=1&table=Table14">20-30%</a>&nbsp;&nbsp; <a href="?version=1&table=Table15">30-40%</a>&nbsp;&nbsp; <a href="?version=1&table=Table16">40-50%</a>&nbsp;&nbsp; <a href="?version=1&table=Table17">50-60%</a>&nbsp;&nbsp; <a href="?version=1&table=Table18">60-80%</a>&nbsp;&nbsp; <br><i>Xe+Xe:</i>&nbsp;&nbsp; <a href="?version=1&table=Table20">0-5%</a>&nbsp;&nbsp; <a href="?version=1&table=Table21">5-10%</a>&nbsp;&nbsp; <a href="?version=1&table=Table22">10-20%</a>&nbsp;&nbsp; <a href="?version=1&table=Table23">20-30%</a>&nbsp;&nbsp; <a href="?version=1&table=Table24">30-40%</a>&nbsp;&nbsp; <a href="?version=1&table=Table25">40-50%</a>&nbsp;&nbsp; <a href="?version=1&table=Table26">50-60%</a>&nbsp;&nbsp; <a href="?version=1&table=Table27">60-80%</a>&nbsp;&nbsp; </br>- - - - - - - - - - - - - - - - - - - - <br><b>nuclear modification factors (p<sub>T</sub>):</b> <br><i>R<sub>pPb</sub>:</i>&nbsp;&nbsp; <a href="?version=1&table=Table28">0-5%</a>&nbsp;&nbsp; <a href="?version=1&table=Table29">5-10%</a>&nbsp;&nbsp; <a href="?version=1&table=Table30">10-20%</a>&nbsp;&nbsp; <a href="?version=1&table=Table31">20-30%</a>&nbsp;&nbsp; <a href="?version=1&table=Table32">30-40%</a>&nbsp;&nbsp; <a href="?version=1&table=Table33">40-60%</a>&nbsp;&nbsp; <a href="?version=1&table=Table34">60-90%</a>&nbsp;&nbsp; <a href="?version=1&table=Table35">0-90%</a>&nbsp;&nbsp; <br><i>R<sub>AA</sub> (Pb+Pb):</i>&nbsp;&nbsp; <a href="?version=1&table=Table36">0-5%</a>&nbsp;&nbsp; <a href="?version=1&table=Table37">5-10%</a>&nbsp;&nbsp; <a href="?version=1&table=Table38">10-20%</a>&nbsp;&nbsp; <a href="?version=1&table=Table39">20-30%</a>&nbsp;&nbsp; <a href="?version=1&table=Table40">30-40%</a>&nbsp;&nbsp; <a href="?version=1&table=Table41">40-50%</a>&nbsp;&nbsp; <a href="?version=1&table=Table42">50-60%</a>&nbsp;&nbsp; <a href="?version=1&table=Table43">60-80%</a>&nbsp;&nbsp; <br><i>R<sub>AA</sub> (Xe+Xe):</i>&nbsp;&nbsp; <a href="?version=1&table=Table44">0-5%</a>&nbsp;&nbsp; <a href="?version=1&table=Table45">5-10%</a>&nbsp;&nbsp; <a href="?version=1&table=Table46">10-20%</a>&nbsp;&nbsp; <a href="?version=1&table=Table47">20-30%</a>&nbsp;&nbsp; <a href="?version=1&table=Table48">30-40%</a>&nbsp;&nbsp; <a href="?version=1&table=Table49">40-50%</a>&nbsp;&nbsp; <a href="?version=1&table=Table50">50-60%</a>&nbsp;&nbsp; <a href="?version=1&table=Table51">60-80%</a>&nbsp;&nbsp; </br>- - - - - - - - - - - - - - - - - - - - <br><b>nuclear modification factors (y*/eta):</b> <br><i>R<sub>pPb</sub>:</i> <br>&nbsp;&nbsp;0-5%:&nbsp;&nbsp; <a href="?version=1&table=Table52">0.66-0.755GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table53">2.95-3.35GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table54">7.65-8.8GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table55">15.1-17.3GeV</a>&nbsp;&nbsp; <br>&nbsp;&nbsp;5-10%:&nbsp;&nbsp; <a href="?version=1&table=Table56">0.66-0.755GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table57">2.95-3.35GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table58">7.65-8.8GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table59">15.1-17.3GeV</a>&nbsp;&nbsp; <br>&nbsp;&nbsp;10-20%:&nbsp;&nbsp; <a href="?version=1&table=Table60">0.66-0.755GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table61">2.95-3.35GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table62">7.65-8.8GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table63">15.1-17.3GeV</a>&nbsp;&nbsp; <br>&nbsp;&nbsp;20-30%:&nbsp;&nbsp; <a href="?version=1&table=Table64">0.66-0.755GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table65">2.95-3.35GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table66">7.65-8.8GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table67">15.1-17.3GeV</a>&nbsp;&nbsp; <br>&nbsp;&nbsp;30-40%:&nbsp;&nbsp; <a href="?version=1&table=Table68">0.66-0.755GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table69">2.95-3.35GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table70">7.65-8.8GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table71">15.1-17.3GeV</a>&nbsp;&nbsp; <br>&nbsp;&nbsp;40-60%:&nbsp;&nbsp; <a href="?version=1&table=Table72">0.66-0.755GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table73">2.95-3.35GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table74">7.65-8.8GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table75">15.1-17.3GeV</a>&nbsp;&nbsp; <br>&nbsp;&nbsp;60-90%:&nbsp;&nbsp; <a href="?version=1&table=Table76">0.66-0.755GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table77">2.95-3.35GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table78">7.65-8.8GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table79">15.1-17.3GeV</a>&nbsp;&nbsp; <br>&nbsp;&nbsp;0-90%:&nbsp;&nbsp; <a href="?version=1&table=Table80">0.66-0.755GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table81">2.95-3.35GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table82">7.65-8.8GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table83">15.1-17.3GeV</a>&nbsp;&nbsp; <br><i>R<sub>AA</sub> (Pb+Pb):</i> <br>&nbsp;&nbsp;0-5%:&nbsp;&nbsp; <a href="?version=1&table=Table84">1.7-1.95GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table85">6.7-7.65GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table86">20-23GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table87">60-95GeV</a>&nbsp;&nbsp; <br>&nbsp;&nbsp;5-10%:&nbsp;&nbsp; <a href="?version=1&table=Table88">1.7-1.95GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table89">6.7-7.65GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table90">20-23GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table91">60-95GeV</a>&nbsp;&nbsp; <br>&nbsp;&nbsp;10-20%:&nbsp;&nbsp; <a href="?version=1&table=Table92">1.7-1.95GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table93">6.7-7.65GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table94">20-23GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table95">60-95GeV</a>&nbsp;&nbsp; <br>&nbsp;&nbsp;20-30%:&nbsp;&nbsp; <a href="?version=1&table=Table96">1.7-1.95GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table97">6.7-7.65GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table98">20-23GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table99">60-95GeV</a>&nbsp;&nbsp; <br>&nbsp;&nbsp;30-40%:&nbsp;&nbsp; <a href="?version=1&table=Table100">1.7-1.95GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table101">6.7-7.65GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table102">20-23GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table103">60-95GeV</a>&nbsp;&nbsp; <br>&nbsp;&nbsp;40-50%:&nbsp;&nbsp; <a href="?version=1&table=Table104">1.7-1.95GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table105">6.7-7.65GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table106">20-23GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table107">60-95GeV</a>&nbsp;&nbsp; <br>&nbsp;&nbsp;50-60%:&nbsp;&nbsp; <a href="?version=1&table=Table108">1.7-1.95GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table109">6.7-7.65GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table110">20-23GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table111">60-95GeV</a>&nbsp;&nbsp; <br>&nbsp;&nbsp;60-80%:&nbsp;&nbsp; <a href="?version=1&table=Table112">1.7-1.95GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table113">6.7-7.65GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table114">20-23GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table115">60-95GeV</a>&nbsp;&nbsp; <br><i>R<sub>AA</sub> (Xe+Xe):</i> <br>&nbsp;&nbsp;0-5%:&nbsp;&nbsp; <a href="?version=1&table=Table116">1.7-1.95GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table117">6.7-7.65GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table118">20-23GeV</a>&nbsp;&nbsp; <br>&nbsp;&nbsp;5-10%:&nbsp;&nbsp; <a href="?version=1&table=Table119">1.7-1.95GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table120">6.7-7.65GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table121">20-23GeV</a>&nbsp;&nbsp; <br>&nbsp;&nbsp;10-20%:&nbsp;&nbsp; <a href="?version=1&table=Table122">1.7-1.95GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table123">6.7-7.65GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table124">20-23GeV</a>&nbsp;&nbsp; <br>&nbsp;&nbsp;20-30%:&nbsp;&nbsp; <a href="?version=1&table=Table125">1.7-1.95GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table126">6.7-7.65GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table127">20-23GeV</a>&nbsp;&nbsp; <br>&nbsp;&nbsp;30-40%:&nbsp;&nbsp; <a href="?version=1&table=Table128">1.7-1.95GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table129">6.7-7.65GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table130">20-23GeV</a>&nbsp;&nbsp; <br>&nbsp;&nbsp;40-50%:&nbsp;&nbsp; <a href="?version=1&table=Table131">1.7-1.95GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table132">6.7-7.65GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table133">20-23GeV</a>&nbsp;&nbsp; <br>&nbsp;&nbsp;50-60%:&nbsp;&nbsp; <a href="?version=1&table=Table134">1.7-1.95GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table135">6.7-7.65GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table136">20-23GeV</a>&nbsp;&nbsp; <br>&nbsp;&nbsp;60-80%:&nbsp;&nbsp; <a href="?version=1&table=Table137">1.7-1.95GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table138">6.7-7.65GeV</a>&nbsp;&nbsp; <a href="?version=1&table=Table139">20-23GeV</a>&nbsp;&nbsp; <br>- - - - - - - - - - - - - - - - - - - -

Charged-hadron cross-section in pp collisions. The systematic uncertainties are described in the section 7 of the paper. The total systematic uncertainties are determined by adding the contributions from all relevant sources in quadrature.

Charged-hadron spectrum in the centrality interval 0-5% for p+Pb, divided by &#9001;TPPB&#9002;. The systematic uncertainties are described in the section 7 of the paper. The total systematic uncertainties are determined by adding the contributions from all relevant sources in quadrature.

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Strong constraints on jet quenching in centrality-dependent $p$+Pb collisions at 5.02 TeV from ATLAS

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abbott, D.C. ; et al.
Phys.Rev.Lett. 131 (2023) 072301, 2023.
Inspire Record 2090791 DOI 10.17182/hepdata.130943

Jet quenching is the process of color-charged partons losing energy via interactions with quark-gluon plasma droplets created in heavy-ion collisions. The collective expansion of such droplets is well described by viscous hydrodynamics. Similar evidence of collectivity is consistently observed in smaller collision systems, including $pp$ and $p$+Pb collisions. In contrast, while jet quenching is observed in Pb+Pb collisions, no evidence has been found in these small systems to date, raising fundamental questions about the nature of the system created in these collisions. The ATLAS experiment at the Large Hadron Collider has measured the yield of charged hadrons correlated with reconstructed jets in 0.36 nb$^{-1}$ of $p$+Pb and 3.6 pb$^{-1}$ of $pp$ collisions at 5.02 TeV. The yields of charged hadrons with $p_\mathrm{T}^\mathrm{ch} >0.5$ GeV near and opposite in azimuth to jets with $p_\mathrm{T}^\mathrm{jet} > 30$ or $60$ GeV, and the ratios of these yields between $p$+Pb and $pp$ collisions, $I_{p\mathrm{Pb}}$, are reported. The collision centrality of $p$+Pb events is categorized by the energy deposited by forward neutrons from the struck nucleus. The $I_{p\mathrm{Pb}}$ values are consistent with unity within a few percent for hadrons with $p_\mathrm{T}^\mathrm{ch} >4$ GeV at all centralities. These data provide new, strong constraints which preclude almost any parton energy loss in central $p$+Pb collisions.

8 data tables

The per-jet charged particle yield in pPb and pp collisions for hadrons near a $p_{T}^{\textrm{jet}} > 30~\textrm{GeV}$ jet ($\Delta\phi_{\textrm{ch,jet}} < \pi/8$).

The per-jet charged particle yield in pPb and pp collisions for hadrons opposite to a $p_{T}^{\textrm{jet}} > 30~\textrm{GeV}$ jet ($\Delta\phi_{\textrm{ch,jet}} > 7\pi/8$).

The per-jet charged particle yield in pPb and pp collisions for hadrons near a $p_{T}^{\textrm{jet}} > 60~\textrm{GeV}$ jet ($\Delta\phi_{\textrm{ch,jet}} < \pi/8$).

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Measurements of the suppression and correlations of dijets in Pb+Pb collisions at $\sqrt{s_{_\text{NN}}}$ = 5.02 TeV

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abbott, D.C. ; et al.
Phys.Rev.C 107 (2023) 054908, 2023.
Inspire Record 2075431 DOI 10.17182/hepdata.145875

Studies of the correlations of the two highest transverse momentum (leading) jets in individual Pb+Pb collision events can provide information about the mechanism of jet quenching by the hot and dense matter created in such collisions. In Pb+Pb and pp collisions at $\sqrt{s_{_\text{NN}}}$ = 5.02 TeV, measurements of the leading dijet transverse momentum ($p_{\mathrm{T}}$) correlations are presented. Additionally, measurements in Pb+Pb collisions of the dijet pair nuclear modification factors projected along leading and subleading jet $p_{\mathrm{T}}$ are made. The measurements are performed using the ATLAS detector at the LHC with 260 pb$^{-1}$ of pp data collected in 2017 and 2.2 nb$^{-1}$ of Pb+Pb data collected in 2015 and 2018. An unfolding procedure is applied to the two-dimensional leading and subleading jet $p_{\mathrm{T}}$ distributions to account for experimental effects in the measurement of both jets. Results are provided for dijets with leading jet $p_{\mathrm{T}}$ greater than 100 GeV. Measurements of the dijet-yield-normalized $x_{\mathrm{J}}$ distributions in Pb+Pb collisions show an increased fraction of imbalanced jets compared to pp collisions; these measurements are in agreement with previous measurements of the same quantity at 2.76 TeV in the overlapping kinematic range. Measurements of the absolutely-normalized dijet rate in Pb+Pb and pp collisions are also presented, and show that balanced dijets are significantly more suppressed than imbalanced dijets in Pb+Pb collisions. It is observed in the measurements of the pair nuclear modification factors that the subleading jets are significantly suppressed relative to leading jets with $p_{\mathrm{T}}$ between 100 and 316 GeV for all centralities in Pb+Pb collisions.

23 data tables

absolutely normalized dijet cross sections from pp collisions

absolutely normalized dijet yields scaled by 1/<TAA> in 0-10% central PbPb collisions

absolutely normalized dijet yields scaled by 1/<TAA> in 10-20% central PbPb collisions

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Correlations between flow and transverse momentum in Xe+Xe and Pb+Pb collisions at the LHC with the ATLAS detector: a probe of the heavy-ion initial state and nuclear deformation

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abbott, D.C. ; et al.
Phys.Rev.C 107 (2023) 054910, 2023.
Inspire Record 2075412 DOI 10.17182/hepdata.139082

The correlations between flow harmonics $v_n$ for $n=2$, 3 and 4 and mean transverse momentum $[p_\mathrm{T}]$ in $^{129}$Xe+$^{129}$Xe and $^{208}$Pb+$^{208}$Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.44$ TeV and 5.02 TeV, respectively, are measured using charged particles with the ATLAS detector. The correlations are sensitive to the shape and size of the initial geometry, nuclear deformation, and initial momentum anisotropy. The effects from non-flow and centrality fluctuations are minimized, respectively, via a subevent cumulant method and event activity selection based on particle production in the very forward rapidity. The results show strong dependences on centrality, harmonic number $n$, $p_{\mathrm{T}}$ and pseudorapidity range. Current models describe qualitatively the overall centrality- and system-dependent trends but fail to quantitatively reproduce all the data. In the central collisions, where models generally show good agreement, the $v_2$-$[p_\mathrm{T}]$ correlations are sensitive to the triaxiality of the quadruple deformation. The comparison of model to the Pb+Pb and Xe+Xe data suggests that the $^{129}$Xe nucleus is a highly deformed triaxial ellipsoid that is neither a prolate nor an oblate shape. This provides strong evidence for a triaxial deformation of $^{129}$Xe nucleus using high-energy heavy-ion collision.

445 data tables

$\rho_{2}$ Standard method, for Pb+Pb 5.02 TeV, $|\eta|$<2.5, 0.5< $p_{T}$ <5.0 GeV vs $\Sigma E_{T}$ based Centrality

$\rho_{2}$ Two_subevent method, for Pb+Pb 5.02 TeV, $|\eta|$<2.5, 0.5< $p_{T}$ <5.0 GeV vs $\Sigma E_{T}$ based Centrality

$\rho_{2}$ Three_subevent method, for Pb+Pb 5.02 TeV, $|\eta|$<2.5, 0.5< $p_{T}$ <5.0 GeV vs $\Sigma E_{T}$ based Centrality

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Measurements of azimuthal anisotropies of jet production in Pb+Pb collisions at $\sqrt{s_{NN}} =$ 5.02 TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abbott, Dale ; et al.
Phys.Rev.C 105 (2022) 064903, 2022.
Inspire Record 1967021 DOI 10.17182/hepdata.132663

The azimuthal variation of jet yields in heavy-ion collisions provides information about the path-length dependence of the energy loss experienced by partons passing through the hot, dense nuclear matter known as the quark-gluon plasma. This paper presents the azimuthal anisotropy coefficients $v_2$, $v_3$, and $v_4$ measured for jets in Pb+Pb collisions at $\sqrt{s_{NN}} =$ 5.02 TeV using the ATLAS detector at the LHC. The measurement uses data collected in 2015 and 2018, corresponding to an integrated luminosity of 2.2 nb$^{-1}$. The $v_n$ values are measured as a function of the transverse momentum of the jets between 71 GeV and 398 GeV and the event centrality. A nonzero value of $v_2$ is observed in all but the most central collisions. The value of $v_2$ is largest for jets with lower transverse momentum, with values up to 0.05 in mid-central collisions. A smaller, nonzero value of $v_3$ of approximately 0.01 is measured with no significant dependence on jet $p_T$ or centrality, suggesting that fluctuations in the initial state play a small but distinct role in jet energy loss. No significant deviation of $v_4$ from zero is observed in the measured kinematic region.

44 data tables

The JES for R = 0.2 jets in Pb+Pb collisions as a function of $p_T^{truth}$ for centrality selections of 0-5%, 5-10%, 10-20%, 20-40% and 40-60%.

The JER for R = 0.2 jets in Pb+Pb collisions as a function of $p_T^{truth}$ for centrality selections of 0-5%, 5-10%, 10-20%, 20-40% and 40-60%.

The JES for R = 0.2 jets in Pb+Pb collisions as a function of $2|\Psi_2-\phi^{reco}|$ for centrality selections of 0-5%, 5-10%, 10-20%, 20-40% and 40-60%.

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Version 2
Measurements of $\pi^\pm$, $K^\pm$, $p$ and $\bar{p}$ spectra in $^7$Be+$^9$Be collisions at beam momenta from 19$A$ to 150$A$ GeV/$c$ with the NA61/SHINE spectrometer at the CERN SPS

The NA61/SHINE collaboration Acharya, A. ; Adhikary, H. ; Aduszkiewicz, A. ; et al.
Eur.Phys.J.C 81 (2021) 73, 2021.
Inspire Record 1821464 DOI 10.17182/hepdata.101373

The NA61/SHINE experiment at the CERN Super Proton Synchrotron (SPS) studies the onset of deconfinement in hadron matter by a scan of particle production in collisions of nuclei with various sizes at a set of energies covering the SPS energy range. This paper presents results on inclusive double-differential spectra, transverse momentum and rapidity distributions and mean multiplicities of $\pi^\pm$, $K^\pm$, $p$ and $\bar{p}$ produced in the 20$\%$ most $central$$^7$Be+$^9$Be collisions at beam momenta of 19$A$, 30$A$, 40$A$, 75$A$ and 150$A$ GeV/$c$. The energy dependence of the $K^\pm$/$\pi^\pm$ ratios as well as of inverse slope parameters of the $K^\pm$ transverse mass distributions are close to those found in inelastic $p$+$p$ reactions. The new results are compared to the world data on $p$+$p$ and Pb+Pb collisions as well as to predictions of the EPOS, UrQMD, AMPT, PHSD and SMASH models.

102 data tables

Transverse momentum spectra in rapidity slices of K+ produced in the 20% most central Be+Be collisions at beam momentum 19A GeV/c (collision energy 6.27 GeV). Rapidity values given in the legends correspond to the middle of the corresponding interval. Results presented in this table were obtained using dE/dx analysis method.

Transverse momentum spectra in rapidity slices of K+ produced in the 20% most central Be+Be collisions at beam momentum 19A GeV/c (collision energy 6.27 GeV). Rapidity values given in the legends correspond to the middle of the corresponding interval. Results presented in this table were obtained using dE/dx analysis method.

Transverse momentum spectra in rapidity slices of K+ produced in the 20% most central Be+Be collisions at beam momentum 30A GeV/c (collision energy 7.62 GeV). Rapidity values given in the legends correspond to the middle of the corresponding interval. Results presented in this table were obtained using dE/dx analysis method.

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Measurements of $\pi^-$ production in $^7$Be+$^9$Be collisions at beam momenta from 19$A$ to 15$A$GeV/$c$ in the NA61/SHINE experiment at the CERN SPS

The NA61/SHINE collaboration Acharya, A. ; Adhikary, H. ; Aduszkiewicz, A. ; et al.
Eur.Phys.J.C 80 (2020) 961, 2020.
Inspire Record 1811793 DOI 10.17182/hepdata.98673

The NA61/SHINE collaboration studies at the CERN Super Proton Synchrotron (SPS) the onset of deconfinement in hadronic matter by the measurement of particle production in collisions of nuclei with various sizes at a set of energies covering the SPS energy range. This paper presents results on inclusive double-differential spectra and mean multiplicities of $\pi^{-}$ mesons produced in the 5\% most \textit{central} $^7$Be+$^9$Be collisions at beam momenta of 19$A$, 30$A$, 40$A$, 75$A$ and 150$A$ GeV/$c$ obtained by the so-called $h^-$ method which does not require any particle identification. The shape of the transverse mass spectra differs from the shapes measured in central Pb+Pb collisions and inelastic p+p interactions. The normalized width of the rapidity distribution decreases with increasing collision energy and is in between the results for inelastic nucleon-nucleon and central Pb+Pb collisions. The mean multiplicity of pions per wounded nucleon in \textit{central} $^7$Be+$^9$Be collisions is close to that in central Pb+Pb collisions up to 75$A$GeV/$c$. However, at the top SPS energy the result is close to the one for inelastic nucleon-nucleon interactions. The results are discussed in the context of predictions for the onset of deconfinement at the CERN SPS collision energies.

10 data tables

Transverse momentum spectra of PI− in rapidity slices produced in the 5% most central Be+Be collisions at 19A GeV/c.

Transverse momentum spectra of PI− in rapidity slices produced in the 5% most central Be+Be collisions at 30A GeV/c.

Transverse momentum spectra of PI− in rapidity slices produced in the 5% most central Be+Be collisions at 40A GeV/c.

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Measurements of $\Xi^{-}$ and $\overline{\Xi}^{+}$ production in proton-proton interactions at $\sqrt{s_{NN}}$ = 17.3 GeV in the NA61/SHINE experiment

The NA61/SHINE collaboration Aduszkiewicz, A. ; Andronov, E.V. ; Antićić, T. ; et al.
Eur.Phys.J.C 80 (2020) 833, 2020.
Inspire Record 1799187 DOI 10.17182/hepdata.98674

The production of $\Xi(1321)^{-}$ and $\overline{\Xi}(1321)^{+}$ hyperons in inelastic p+p interactions is studied in a fixed target experiment at a beam momentum of 158 GeV/textitc. Double differential distributions in rapidity y and transverse momentum $p_{T}$ are obtained from a sample of 33M inelastic events. They allow to extrapolate the spectra to full phase space and to determine the mean multiplicity of both $\Xi^{-}$ and $\overline{\Xi}^{+}$. The rapidity and transverse momentum spectra are compared to transport model predictions. The $\Xi^{-}$ mean multiplicity in inelastic p+p interactions at 158~\GeVc is used to quantify the strangeness enhancement in A+A collisions at the same centre-of-mass energy per nucleon pair.

6 data tables

Transverse momentum spectra in rapidity slices of Xi- produced in inelastic p+p interactions at 158 GeV/c. Rapidity values given in the legends correspond to the middle of the corresponding interval.

Transverse momentum spectra in rapidity slices of bar{Xi+} produced in inelastic p+p interactions at 158 GeV/c. Rapidity values given in the legends correspond to the middle of the corresponding interval.

Rapidity spectra of Xi- and XIBAR+ produced in inelastic p+p interactions at 158 GeV/c.

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$K^{*}(892)^0$ meson production in inelastic p+p interactions at 158 GeV/$c$ beam momentum measured by NA61/SHINE at the CERN SPS

The NA61/SHINE collaboration Aduszkiewicz, A. ; Andronov, E.V. ; Antićić, T. ; et al.
Eur.Phys.J.C 80 (2020) 460, 2020.
Inspire Record 1775731 DOI 10.17182/hepdata.94255

The measurement of $K^{*}(892)^0$ resonance production via its $K^{+}\pi^{-}$ decay mode in inelastic p+p collisions at beam momentum 158 GeV/$c$ ($\sqrt{s_{NN}}=17.3$ GeV) is presented. The data were recorded by the NA61/SHINE hadron spectrometer at the CERN Super Proton Synchrotron. The $\textit{template}$ method was used to extract the $K^{*}(892)^0$ signal and double differential transverse momentum and rapidity spectra were obtained. The full phase-space mean multiplicity of $K^{*}(892)^0$ mesons was found to be $(78.44 \pm 0.38 \mathrm{(stat)} \pm 6.0 \mathrm{(sys)) \cdot 10^{-3}}$. The NA61/SHINE results are compared with the E$_{POS}$1.99 and Hadron Resonance Gas models as well as with world data from p+p and nucleus-nucleus collisions.

11 data tables

Numerical values of mass and width of $K^{∗}(892)^0$ mesons fitted in 0<y<0.5 and presented in Fig.8. The first uncertainty is statistical, while the second one is systematic.

Numerical values of double-differential yields $d^{2}n/dydp_{T}$ presented in Fig. 10, given in units of $10^{−3} (GeV/c)^{−1}$. The first uncertainty is statistical, while the second one is systematic

Numerical values of double-differential yields $d^{2}n/dydp_{T}$ presented in Fig. 10, given in units of $10^{−3} (GeV/c)^{−1}$. The first uncertainty is statistical, while the second one is systematic

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Measurements of hadron production in $\pi^{+}$ + C and $\pi^{+}$ + Be interactions at 60 GeV/$c$

The NA61/SHINE collaboration Aduszkiewicz, A. ; Andronov, E.V. ; Antićić, T. ; et al.
Phys.Rev.D 100 (2019) 112004, 2019.
Inspire Record 1754136 DOI 10.17182/hepdata.91220

Precise knowledge of hadron production rates in the generation of neutrino beams is necessary for accelerator-based neutrino experiments to achieve their physics goals. NA61/SHINE, a large-acceptance hadron spectrometer, has recorded hadron+nucleus interactions relevant to ongoing and future long-baseline neutrino experiments at Fermi National Accelerator Laboratory. This paper presents three analyses of interactions of 60 GeV/$c$ $\pi^+$ with thin, fixed carbon and beryllium targets. Integrated production and inelastic cross sections were measured for both of these reactions. In an analysis of strange, neutral hadron production, differential production multiplicities of $K^0_{S}$, $\Lambda$ and anti-$\Lambda$ were measured. Lastly, in an analysis of charged hadron production, differential production multiplicities of $\pi^+$, $\pi^-$, $K^+$, $K^-$ and protons were measured. These measurements will enable long-baseline neutrino experiments to better constrain predictions of their neutrino flux in order to achieve better precision on their neutrino cross section and oscillation measurements.

16 data tables

Doubly differential multiplicity measurements of produced pi+ from 60 GeV/c pi+ + C interactions. Statistical and systematic uncertainties are shown. Additionally, a normalization uncertainty of [-1.1%,+1.9%] applies to all of the measurements for this reaction.

Doubly differential multiplicity measurements of produced pi- from 60 GeV/c pi+ + C interactions. Statistical and systematic uncertainties are shown. Additionally, a normalization uncertainty of [-1.1%,+1.9%] applies to all of the measurements for this reaction.

Doubly differential multiplicity measurements of produced K+ from 60 GeV/c pi+ + C interactions. Statistical and systematic uncertainties are shown. Additionally, a normalization uncertainty of [-1.1%,+1.9%] applies to all of the measurements for this reaction.

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Measurements of production and inelastic cross sections for $\mbox{p}+\mbox{C}$, $\mbox{p}+\mbox{Be}$, and $\mbox{p}+\mbox{Al}$ at 60 GeV/$c$ and $\mbox{p}+\mbox{C}$ and $\mbox{p}+\mbox{Be}$ at 120 GeV/$c$

The NA61/SHINE collaboration Aduszkiewicz, A. ; Andronov, E.V. ; Antićić, T. ; et al.
Phys.Rev.D 100 (2019) 112001, 2019.
Inspire Record 1753094 DOI 10.17182/hepdata.95181

This paper presents measurements of production cross sections and inelastic cross sections for the following reactions: 60 GeV/$c$ protons with C, Be, Al targets and 120 GeV/$c$ protons with C and Be targets. The analysis was performed using the NA61/SHINE spectrometer at the CERN SPS. First measurements were obtained using protons at 120 GeV/$c$, while the results for protons at 60 GeV/$c$ were compared with previously published measurements. These interaction cross section measurements are critical inputs for neutrino flux prediction in current and future accelerator-based long-baseline neutrino experiments.

2 data tables

Results of production cross section measurements on proton beams. Measured channeles are p+C/Be/Al at 60 GeV and p+C/Be at 120 GeV.

Results of inelastic cross section measurements on proton beams. Measured channeles are p+C/Be/Al at 60 GeV and p+C/Be at 120 GeV.


Measurement of $\phi $ meson production in $p + p$ interactions at 40, 80 and $158 \, \hbox {GeV}/c$ with the NA61/SHINE spectrometer at the CERN SPS

The NA61/SHINE collaboration Aduszkiewicz, A. ; Andronov, E.V. ; Antićić, T. ; et al.
Eur.Phys.J.C 80 (2020) 199, 2020.
Inspire Record 1749613 DOI 10.17182/hepdata.93228

Results on $\phi$ meson production in inelastic p+p collisions at CERN SPS energies are presented. They are derived from data collected by the NA61/SHINE fixed target experiment, by means of invariant mass spectra fits in the $\phi \to K^+K^-$ decay channel. They include the first ever measured double differential spectra of $\phi$ mesons as a function of rapidity $y$ and transverse momentum $p_T$ for proton beam momenta of 80 GeV/c and 158 GeV/c, as well as single differential spectra of $y$ or $p_T$ for beam momentum of 40 GeV/c. The corresponding total $\phi$ yields per inelastic p+p event are obtained. These results are compared with existing data on $\phi$ meson production in p+p collisions. The comparison shows consistency but superior accuracy of the present measurements. The emission of $\phi$ mesons in p+p reactions is confronted with that occurring in Pb+Pb collisions, and the experimental results are compared with model predictions. It appears that none of the considered models can properly describe all the experimental observables.

17 data tables

Double differential multiplicity of $\phi$ mesons produced in minimum bias p+p collisions at beam momentum of 158 GeV/c, as a function of transverse momentum $p_T$ and rapidity $y$.

Double differential multiplicity of $\phi$ mesons produced in minimum bias p+p collisions at beam momentum of 80 GeV/c, as a function of transverse momentum $p_T$ and rapidity $y$.

Transverse momentum $p_T$ spectrum of $\phi$ mesons produced in minimum bias p+p collisions at beam momentum of 40 GeV/c, in a broad rapidity $y$ bin of (0, 1.5).

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Measurements of $\pi^{\pm}$, $K^{\pm}$ and proton yields from the surface of the T2K replica target for incoming 31 GeV/c protons with the NA61/SHINE spectrometer at the CERN SPS

The NA61/SHINE collaboration Abgrall, N. ; Aduszkiewicz, A. ; Andronov, E.V. ; et al.
Eur.Phys.J.C 79 (2019) 100, 2019.
Inspire Record 1687433 DOI 10.17182/hepdata.88360

Measurements of the $\pi^{\pm}$, $K^{\pm}$, and proton double differential yields emitted from the surface of the 90-cm-long carbon target (T2K replica) were performed for the incoming 31 GeV/c protons with the NA61/SHINE spectrometer at the CERN SPS using data collected during 2010 run. The double differential $\pi^{\pm}$ yields were measured with increased precision compared to the previously published NA61/SHINE results, while the $K^{\pm}$ and proton yields were obtained for the first time. A strategy for dealing with the dependence of the results on the incoming proton beam profile is proposed. The purpose of these measurements is to reduce significantly the (anti)neutrino flux uncertainty in the T2K long-baseline neutrino experiment by constraining the production of (anti)neutrino ancestors coming from the T2K target.

272 data tables

Double differential yiedls of positively charged pions emitted from the surface of the T2K replica target, in the polar angle range from 0 to 20 mrad and in the longitudinal range from 0 to 18cm, as a function of momentum. The normalization is per proton on target.

Double differential yiedls of positively charged pions emitted from the surface of the T2K replica target, in the polar angle range from 20 to 40 mrad and in the longitudinal range from 0 to 18cm, as a function of momentum. The normalization is per proton on target.

Double differential yiedls of positively charged pions emitted from the surface of the T2K replica target, in the polar angle range from 40 to 60 mrad and in the longitudinal range from 0 to 18cm, as a function of momentum. The normalization is per proton on target.

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Event-plane dependent dihadron correlations with harmonic $v_n$ subtraction in Au+Au Collisions at $\sqrt{s_{_{\rm NN}}}=200$ GeV

The STAR collaboration Agakishiev, H. ; Aggarwal, M.M. ; Ahammed, Z. ; et al.
Phys.Rev.C 89 (2014) 041901, 2014.
Inspire Record 1288534 DOI 10.17182/hepdata.97120

STAR measurements of dihadron azimuthal correlations ($\Delta\phi$) are reported in mid-central (20-60\%) Au+Au collisions at $\sqrt{s_{_{\rm NN}}}=200$ GeV as a function of the trigger particle's azimuthal angle relative to the event plane, $\phi_{s}=|\phi_{t}-\psi_{\rm EP}|$. The elliptic ($v_2$), triangular ($v_3$), and quadratic ($v_4$) flow harmonic backgrounds are subtracted using the Zero Yield At Minimum (ZYAM) method. The results are compared to minimum-bias d+Au collisions. It is found that a finite near-side ($|\Delta\phi|<\pi/2$) long-range pseudorapidity correlation (ridge) is present in the in-plane direction ($\phi_{s}\sim 0$). The away-side ($|\Delta\phi|>\pi/2$) correlation shows a modification from d+Au data, varying with $\phi_{s}$. The modification may be a consequence of pathlength-dependent jet-quenching and may lead to a better understanding of high-density QCD.

58 data tables

raw correlation, Au+Au 200 GeV, 20-60%, 3<p_{T}^{(t)}<4 GeV/c, 1<p_{T}^{(a)}<2 GeV/c, |#eta|<1, slice 0.

raw correlation, Au+Au 200 GeV, 20-60%, 3<p_{T}^{(t)}<4 GeV/c, 1<p_{T}^{(a)}<2 GeV/c, |#eta|<1, slice 1.

raw correlation, Au+Au 200 GeV, 20-60%, 3<p_{T}^{(t)}<4 GeV/c, 1<p_{T}^{(a)}<2 GeV/c, |#eta|<1, slice 2.

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Version 2
Energy and system-size dependence of two- and four-particle $v_2$ measurements in heavy-ion collisions at RHIC and their implications on flow fluctuations and nonflow

The STAR collaboration Agakishiev, G. ; Aggarwal, M.M. ; Ahammed, Z. ; et al.
Phys.Rev.C 86 (2012) 014904, 2012.
Inspire Record 955160 DOI 10.17182/hepdata.101341

We present STAR measurements of azimuthal anisotropy by means of the two- and four-particle cumulants $v_2$ ($v_2\{2\}$ and $v_2\{4\}$) for Au+Au and Cu+Cu collisions at center of mass energies $\sqrt{s_{_{\mathrm{NN}}}} = 62.4$ and 200 GeV. The difference between $v_2\{2\}^2$ and $v_2\{4\}^2$ is related to $v_{2}$ fluctuations ($\sigma_{v_2}$) and nonflow $(\delta_{2})$. We present an upper limit to $\sigma_{v_2}/v_{2}$. Following the assumption that eccentricity fluctuations $\sigma_{\epsilon}$ dominate $v_2$ fluctuations $\frac{\sigma_{v_2}}{v_2} \approx \frac{\sigma_{\epsilon}}{\epsilon}$ we deduce the nonflow implied for several models of eccentricity fluctuations that would be required for consistency with $v_2\{2\}$ and $v_2\{4\}$. We also present results on the ratio of $v_2$ to eccentricity.

28 data tables

The two-particle cumulant $v_2\{2\}^2$ for Au+Au collisions at 200 and 62.4 GeV. Results are shown with like-sign combinations (LS) and charge-independent results (CI) for $0.15 < p_T < 2.0$ GeV/$c$.

The two-particle cumulant $v_2\{2\}^2$ for Au+Au collisions at 200 and 62.4 GeV. Results are shown with like-sign combinations (LS) and charge-independent results (CI) for $0.15 < p_T < 2.0$ GeV/$c$.

The same as the left but for Cu+Cu collisions. The systematic errors are shown as thin lines with wide caps at the ends and statistical errors are shown as thick lines with small caps at the end. Statistical and systematic errors are very small.

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System size and energy dependence of near-side di-hadron correlations

The STAR collaboration Agakishiev, G. ; Aggarwal, M.M. ; Ahammed, Z. ; et al.
Phys.Rev.C 85 (2012) 014903, 2012.
Inspire Record 943192 DOI 10.17182/hepdata.77720

Two-particle azimuthal ($\Delta\phi$) and pseudorapidity ($\Delta\eta$) correlations using a trigger particle with large transverse momentum ($p_T$) in $d$+Au, Cu+Cu and Au+Au collisions at $\sqrt{s_{{NN}}}$ =\xspace 62.4 GeV and 200~GeV from the STAR experiment at RHIC are presented. The \ns correlation is separated into a jet-like component, narrow in both $\Delta\phi$ and $\Delta\eta$, and the ridge, narrow in $\Delta\phi$ but broad in $\Delta\eta$. Both components are studied as a function of collision centrality, and the jet-like correlation is studied as a function of the trigger and associated $p_T$. The behavior of the jet-like component is remarkably consistent for different collision systems, suggesting it is produced by fragmentation. The width of the jet-like correlation is found to increase with the system size. The ridge, previously observed in Au+Au collisions at $\sqrt{s_{{NN}}}$ = 200 GeV, is also found in Cu+Cu collisions and in collisions at $\sqrt{s_{{NN}}}$ =\xspace 62.4 GeV, but is found to be substantially smaller at $\sqrt{s_{{NN}}}$ =\xspace 62.4 GeV than at $\sqrt{s_{{NN}}}$ = 200 GeV for the same average number of participants ($ \langle N_{\mathrm{part}}\rangle$). Measurements of the ridge are compared to models.

40 data tables

Parameterizations of the transverse momentum dependence of the reconstruction efficiency of charged particles in the TPC in various collision systems, energies and centrality bins for the track selection cuts used in this analysis.

The raw correlation in $\Delta\eta$ for di-hadron correlations for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for 0-12% central \Au collisions for $|\Delta\phi|<$ 0.78 before and after the track merging correction is applied. The data have been reflected about $\Delta\eta$=0.

Sample correlations in $\Delta\eta$ ($|\Delta\phi|<$ 0.78) for 3 $<$ $p_T^{trigger}$ $<$ 6 GeV/$c$ and 1.5 GeV/$c$ $<$ $p_T^{associated}$ $<$ $p_T^{trigger}$ for 0-60% Cu+Cu at $\sqrt{s_{NN}}$ = 62.4 GeV, 0-80% Au+Au at $\sqrt{s_{NN}}$ = 62.4 GeV, 0-95% $d$+Au at $\sqrt{s_{NN}}$ = 200 GeV, 0-60% Cu+Cu at $\sqrt{s_{NN}}$ = 200 GeV, 40-80% Au+Au at $\sqrt{s_{NN}}$ = 200 GeV, and 0-12% central Au+Au at $\sqrt{s_{NN}}$ = 200 GeV. The data are averaged between positive and negative $\Delta\eta$. 5% systematic uncertainty due to track reconstruction efficiency not listed below.

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Identified hadron compositions in p+p and Au+Au collisions at high transverse momenta at $\sqrt{s_{_{NN}}} = 200$ GeV

The STAR collaboration Agakishiev, G. ; Aggarwal, M.M. ; Ahammed, Z. ; et al.
Phys.Rev.Lett. 108 (2012) 072302, 2012.
Inspire Record 930463 DOI 10.17182/hepdata.95749

We report transverse momentum ($p_{T} \leq15$ GeV/$c$) spectra of $\pi^{\pm}$, $K^{\pm}$, $p$, $\bar{p}$, $K_{S}^{0}$, and $\rho^{0}$ at mid-rapidity in p+p and Au+Au collisions at $\sqrt{s_{_{NN}}}$ = 200 GeV. Perturbative QCD calculations are consistent with $\pi^{\pm}$ spectra in p+p collisions but do not reproduce $K$ and $p(\bar{p})$ spectra. The observed decreasing antiparticle-to-particle ratios with increasing $p_T$ provide experimental evidence for varying quark and gluon jet contributions to high-$p_T$ hadron yields. The relative hadron abundances in Au+Au at $p_{T}{}^{>}_{\sim}8$ GeV/$c$ are measured to be similar to the p+p results, despite the expected Casimir effect for parton energy loss.

16 data tables

The invariant yields $d^2N/(2\pi p_T dp_T dy)$ of $\pi^{\pm}$, $K^{\pm}$, $p$, and $\bar{p}$ from non-singly diffractive p+p collisions ($\sigma_{NSD} = 30.0 \pm 3.5$ mb), and NLO calculations with AKK [9] and DSS [10] FF. The uncertainty of yields due to the scale dependence as evaluated in [10] is about a factor of 2. Bars and boxes (bands) represent statistical and systematic uncertainties, respectively.

The invariant yields $d^2N/(2\pi p_T dp_T dy)$ of $K^0_S$ from non-singly diffractive p+p collisions ($\sigma_{NSD} = 30.0 \pm 3.5$ mb), and NLO calculations with AKK [9] and DSS [10] FF. The uncertainty of yields due to the scale dependence as evaluated in [10] is about a factor of 2. Bars and boxes (bands) represent statistical and systematic uncertainties, respectively.

The invariant yields $d^2N/(2\pi p_T dp_T dy)$ of $\rho^0$ from non-singly diffractive p+p collisions ($\sigma_{NSD} = 30.0 \pm 3.5$ mb), and NLO calculations with AKK [9] and DSS [10] FF. The uncertainty of yields due to the scale dependence as evaluated in [10] is about a factor of 2. Bars and boxes (bands) represent statistical and systematic uncertainties, respectively.

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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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Directed and elliptic flow of charged particles in Cu+Cu collisions at $\sqrt{\bm {s_{NN}}} =$ 22.4 GeV

The STAR collaboration Agakishiev, G. ; Aggarwal, M.M. ; Ahammed, Z. ; et al.
Phys.Rev.C 85 (2012) 014901, 2012.
Inspire Record 929522 DOI 10.17182/hepdata.98622

This paper reports results for directed flow $v_{1}$ and elliptic flow $v_{2}$ of charged particles in Cu+Cu collisions at $\sqrt{s_{NN}}=$ 22.4 GeV at the Relativistic Heavy Ion Collider. The measurements are for the 0-60% most central collisions, using charged particles observed in the STAR detector. Our measurements extend to 22.4 GeV Cu+Cu collisions the prior observation that $v_1$ is independent of the system size at 62.4 and 200 GeV, and also extend the scaling of $v_1$ with $\eta/y_{\rm beam}$ to this system. The measured $v_2(p_T)$ in Cu+Cu collisions is similar for $\sqrt{s_{NN}} = 22.4-200$ GeV. We also report a comparison with results from transport model (UrQMD and AMPT) calculations. The model results do not agree quantitatively with the measured $v_1(\eta), v_2(p_T)$ and $v_2(\eta)$.

6 data tables

The event plane resolution measured using the TPC (second order) and using the BBC (first order) are shown as a function of collision centrality for Cu+Cu collisions at $\sqrt{s_{NN}}$ = 22.4 GeV. Errors are statistical only.

Charged hadron $v_{1}${BBC} vs. $\eta$ for 0-60% centrality Cu+Cu collisions at $\sqrt{s_{NN}}$ = 22.4 GeV. The errors shown are statistical. Systematic errors are discussed in Section III.C. Results are compared to $v_{1}$ from 0-40% centrality Au+Au collisions at $\sqrt{s_{NN}}$ = 19.6 GeV from the PHOBOS collaboration [10].

Comparison of the measured $v_{1}${BBC} as a function of η in 0-60% Cu+Cu collisions at $\sqrt{s_{NN}}$ = 22.4 GeV with model predictions. The inset shows the central $\eta$ region in more detail. The errors are statistical only.

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Strangeness Enhancement in Cu+Cu and Au+Au Collisions at \sqrt{s_{NN}} = 200 GeV

The STAR collaboration Agakishiev, G. ; Aggarwal, M.M. ; Ahammed, Z. ; et al.
Phys.Rev.Lett. 108 (2012) 072301, 2012.
Inspire Record 918779 DOI 10.17182/hepdata.95886

We report new STAR measurements of mid-rapidity yields for the $\Lambda$, $\bar{\Lambda}$, $K^{0}_{S}$, $\Xi^{-}$, $\bar{\Xi}^{+}$, $\Omega^{-}$, $\bar{\Omega}^{+}$ particles in Cu+Cu collisions at \sNN{200}, and mid-rapidity yields for the $\Lambda$, $\bar{\Lambda}$, $K^{0}_{S}$ particles in Au+Au at \sNN{200}. We show that at a given number of participating nucleons, the production of strange hadrons is higher in Cu+Cu collisions than in Au+Au collisions at the same center-of-mass energy. We find that aspects of the enhancement factors for all particles can be described by a parameterization based on the fraction of participants that undergo multiple collisions.

14 data tables

$K^0_S$ invariant mass spectra from Cu+Cu $\sqrt{s_{NN}} = 200$ GeV collisions, where $|y| < 0.5$. The uncertainties on the spectra points are statistical and systematic combined.

$\Lambda$ and $\bar{\Lambda}$ invariant mass spectra from Cu+Cu $\sqrt{s_{NN}} = 200$ GeV collisions, where $|y| < 0.5$. The $\Lambda$ and $\bar{\Lambda}$ yields have not been feed down subtracted from weak decays. The uncertainties on the spectra points are statistical and systematic combined.

$\Xi$ and $\bar{\Xi}$ invariant mass spectra from Cu+Cu $\sqrt{s_{NN}} = 200$ GeV collisions, where $|y| < 0.5$. The uncertainties on the spectra points are statistical and systematic combined.

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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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Version 2
Evolution of the differential transverse momentum correlation function with centrality in Au+Au collisions at $\sqrt{s_{NN}} = 200$ GeV

The STAR collaboration Agakishiev, H. ; Aggarwal, M.M. ; Ahammed, Z. ; et al.
Phys.Lett.B 704 (2011) 467-473, 2011.
Inspire Record 914546 DOI 10.17182/hepdata.102406

We present first measurements of the evolution of the differential transverse momentum correlation function, {\it C}, with collision centrality in Au+Au interactions at $\sqrt{s_{NN}} = 200$ GeV. {\it C} exhibits a strong dependence on collision centrality that is qualitatively similar to that of number correlations previously reported. We use the observed longitudinal broadening of the near-side peak of {\it C} with increasing centrality to estimate the ratio of the shear viscosity to entropy density, $\eta/s$, of the matter formed in central Au+Au interactions. We obtain an upper limit estimate of $\eta/s$ that suggests that the produced medium has a small viscosity per unit entropy.

14 data tables

The correlation function C, C is plotted in units of (GeV/c)$^2$ and the relative azimuthal angle ∆φ in radians for 70-80% centrality in Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. Relative statistical errors range from 0.8% in peripheral collisions to 0.9% in the most central collisions at the peak of the distribution.

The correlation function C, C is plotted in units of (GeV/c)$^2$ and the relative azimuthal angle ∆φ in radians for 70-80% centrality in Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. Relative statistical errors range from 0.8% in peripheral collisions to 0.9% in the most central collisions at the peak of the distribution.

The correlation function C, C is plotted in units of (GeV/c)$^2$ and the relative azimuthal angle ∆φ in radians for 30-40% centrality in Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. Relative statistical errors range from 0.8% in peripheral collisions to 0.9% in the most central collisions at the peak of the distribution.

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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.

1 data table

Differential invariant yields of (anti)baryons evaluated at pT/B =0.875 GeV/c, in central 200 GeV Au+Au collisions.


High $p_{T}$ non-photonic electron production in $p$+$p$ collisions at $\sqrt{s}$ = 200 GeV

The STAR collaboration Agakishiev, H. ; Aggarwal, M.M. ; Ahammed, Z. ; et al.
Phys.Rev.D 83 (2011) 052006, 2011.
Inspire Record 889563 DOI 10.17182/hepdata.96051

We present the measurement of non-photonic electron production at high transverse momentum ($p_T > $ 2.5 GeV/$c$) in $p$ + $p$ collisions at $\sqrt{s}$ = 200 GeV using data recorded during 2005 and 2008 by the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The measured cross-sections from the two runs are consistent with each other despite a large difference in photonic background levels due to different detector configurations. We compare the measured non-photonic electron cross-sections with previously published RHIC data and pQCD calculations. Using the relative contributions of B and D mesons to non-photonic electrons, we determine the integrated cross sections of electrons ($\frac{e^++e^-}{2}$) at 3 GeV/$c < p_T <~$10 GeV/$c$ from bottom and charm meson decays to be ${d\sigma_{(B\to e)+(B\to D \to e)} \over dy_e}|_{y_e=0}$ = 4.0$\pm0.5$({\rm stat.})$\pm1.1$({\rm syst.}) nb and ${d\sigma_{D\to e} \over dy_e}|_{y_e=0}$ = 6.2$\pm0.7$({\rm stat.})$\pm1.5$({\rm syst.}) nb, respectively.

48 data tables

The electron pair invariant mass distributions for electrons at $2.5 < p_{T} < 3.0$ GeV/c

The electron pair invariant mass distributions for electrons at $8 < p_{T} < 10$ GeV/c

The simulated electron pair invariant mass distributions for electrons at $2.5 < p_{T} < 3$ GeV/c

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