Transverse single-spin asymmetry of midrapidity $\pi^{0}$ and $\eta$ mesons in $p$+Au and $p$+Al collisions at $\sqrt{s_{_{NN}}}=$ 200 GeV

The PHENIX collaboration Abdulameer, N.J. ; Acharya, U. ; Aidala, C. ; et al.
Phys.Rev.D 107 (2023) 112004, 2023.
Inspire Record 2641468 DOI 10.17182/hepdata.139098

Presented are the first measurements of the transverse single-spin asymmetries ($A_N$) for neutral pions and eta mesons in $p$+Au and $p$+Al collisions at $\sqrt{s_{_{NN}}}=200$ GeV in the pseudorapidity range $|\eta|<$0.35 with the PHENIX detector at the Relativistic Heavy Ion Collider. The asymmetries are consistent with zero, similar to those for midrapidity neutral pions and eta mesons produced in $p$+$p$ collisions. These measurements show no evidence of additional effects that could potentially arise from the more complex partonic environment present in proton-nucleus collisions.

2 data tables

Data from Figure 2 (a) of the $\pi^{0}$ transverse single-spin asymmetry in $\sqrt{s_{NN}}=200$ GeV $p^{\uparrow}+$Au and $p^{\uparrow}+$Al collisions as a function of $p_{T}$.

Data from Figure 2 (b) of the $\eta$ transverse single-spin asymmetry in $\sqrt{s_{NN}}=200$ GeV $p^{\uparrow}+$Au and $p^{\uparrow}+$Al collisions as a function of $p_{T}$.


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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Search for dark matter produced in association with a dark Higgs boson decaying into $W^{+}W^{-}$ in the one-lepton final state at $\sqrt{s}$=13 TeV using 139 fb$^{-1}$ of $pp$ collisions recorded with the ATLAS detector

The ATLAS collaboration Aad, G. ; Abbott, B. ; Abbott, D.C. ; et al.
JHEP 07 (2023) 116, 2023.
Inspire Record 2181868 DOI 10.17182/hepdata.132484

Several extensions of the Standard Model predict the production of dark matter particles at the LHC. A search for dark matter particles produced in association with a dark Higgs boson decaying into $W^{+}W^{-}$ in the $\ell^\pm\nu q \bar q'$ final states with $\ell=e,\mu$ is presented. This analysis uses 139 fb$^{-1}$ of $pp$ collisions recorded by the ATLAS detector at a centre-of-mass energy of 13 TeV. The $W^\pm \to q\bar q'$ decays are reconstructed from pairs of calorimeter-measured jets or from track-assisted reclustered jets, a technique aimed at resolving the dense topology from a pair of boosted quarks using jets in the calorimeter and tracking information. The observed data are found to agree with Standard Model predictions. Scenarios with dark Higgs boson masses ranging between 140 and 390 GeV are excluded.

25 data tables

Probability of finding at least one TAR jet, where the p<sub>T</sub>-leading TAR jet passes the m<sub>Wcand</sub> and D<sub>2</sub><sup>&beta;=1</sup> requirements, as a function of m<sub>s</sub>. The probability is determined in a sample of signal events with m<sub>Z'</sub>=500 GeV, with the preselections applied.

Probability of finding at least one TAR jet, where the p<sub>T</sub>-leading TAR jet passes the m<sub>Wcand</sub> and D<sub>2</sub><sup>&beta;=1</sup> requirements, as a function of m<sub>s</sub>. The probability is determined in a sample of signal events with m<sub>Z'</sub>=1000 GeV, with the preselections applied.

Probability of finding at least one TAR jet, where the p<sub>T</sub>-leading TAR jet passes the m<sub>Wcand</sub> and D<sub>2</sub><sup>&beta;=1</sup> requirements, as a function of m<sub>s</sub>. The probability is determined in a sample of signal events with m<sub>Z'</sub>=1700 GeV, with the preselections applied.

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Evidence for the charge asymmetry in $pp \rightarrow t\bar{t}$ production at $\sqrt{s}= 13$ TeV with the ATLAS detector

The ATLAS collaboration Aad, G. ; Abbott, B. ; Abbott, D.C. ; et al.
JHEP 08 (2023) 077, 2023.
Inspire Record 2141752 DOI 10.17182/hepdata.132116

Inclusive and differential measurements of the top-antitop ($t\bar{t}$) charge asymmetry $A_\text{C}^{t\bar{t}}$ and the leptonic asymmetry $A_\text{C}^{\ell\bar{\ell}}$ are presented in proton-proton collisions at $\sqrt{s} = 13$ TeV recorded by the ATLAS experiment at the CERN Large Hadron Collider. The measurement uses the complete Run 2 dataset, corresponding to an integrated luminosity of 139 fb$^{-1}$, combines data in the single-lepton and dilepton channels, and employs reconstruction techniques adapted to both the resolved and boosted topologies. A Bayesian unfolding procedure is performed to correct for detector resolution and acceptance effects. The combined inclusive $t\bar{t}$ charge asymmetry is measured to be $A_\text{C}^{t\bar{t}} = 0.0068 \pm 0.0015$, which differs from zero by 4.7 standard deviations. Differential measurements are performed as a function of the invariant mass, transverse momentum and longitudinal boost of the $t\bar{t}$ system. Both the inclusive and differential measurements are found to be compatible with the Standard Model predictions, at next-to-next-to-leading order in quantum chromodynamics perturbation theory with next-to-leading-order electroweak corrections. The measurements are interpreted in the framework of the Standard Model effective field theory, placing competitive bounds on several Wilson coefficients.

50 data tables

- - - - - - - - Overview of HEPData Record - - - - - - - - <br/><br/> <b>Results:</b> <ul> <li><a href="132116?version=1&table=Resultsforchargeasymmetryinclusive">$A_C^{t\bar{t}}$</a> <li><a href="132116?version=1&table=Resultsforchargeasymmetryvsmtt">$A_C^{t\bar{t}}$ vs $m_{t\bar{t}}$</a> <li><a href="132116?version=1&table=Resultsforchargeasymmetryvspttt">$A_C^{t\bar{t}}$ vs $p_{T,t\bar{t}}$</a> <li><a href="132116?version=1&table=Resultsforchargeasymmetryvsbetatt">$A_C^{t\bar{t}}$ vs $\beta_{z,t\bar{t}}$</a> <li><a href="132116?version=1&table=Resultsforleptonicchargeasymmetryinclusive">$A_C^{\ell\bar{\ell}}$</a> <li><a href="132116?version=1&table=Resultsforchargeasymmetryvsllmll">$A_C^{\ell\bar{\ell}}$ vs $m_{\ell\bar{\ell}}$</a> <li><a href="132116?version=1&table=Resultsforchargeasymmetryvsllptll">$A_C^{\ell\bar{\ell}}$ vs $p_{T,\ell\bar{\ell}}$</a> <li><a href="132116?version=1&table=Resultsforchargeasymmetryvsllbetall">$A_C^{\ell\bar{\ell}}$ vs $\beta_{z,\ell\bar{\ell}}$</a> </ul> <b>Bounds on the Wilson coefficients:</b> <ul> <li><a href="132116?version=1&table=BoundsonWilsoncoefficientschargeasymmetryinclusive">$A_C^{t\bar{t}}$</a> <li><a href="132116?version=1&table=BoundsonWilsoncoefficientschargeasymmetryvsmtt">$A_C^{t\bar{t}}$ vs $m_{t\bar{t}}$</a> </ul> <b>Ranking of systematic uncertainties:</b></br> Inclusive:<a href="132116?version=1&table=NPrankingchargeasymmetryinclusive">$A_C^{t\bar{t}}$</a></br> <b>$A_C^{t\bar{t}}$ vs $\beta_{z,t\bar{t}}$:</b> <ul> <li><a href="132116?version=1&table=NPrankingchargeasymmetryvsbetattbin0">$\beta_{z,t\bar{t}} \in[0,0.3]$</a> <li><a href="132116?version=1&table=NPrankingchargeasymmetryvsbetattbin1">$\beta_{z,t\bar{t}} \in[0.3,0.6]$</a> <li><a href="132116?version=1&table=NPrankingchargeasymmetryvsbetattbin2">$\beta_{z,t\bar{t}} \in[0.6,0.8]$</a> <li><a href="132116?version=1&table=NPrankingchargeasymmetryvsbetattbin3">$\beta_{z,t\bar{t}} \in[0.8,1]$</a> </ul> <b>$A_C^{t\bar{t}}$ vs $m_{t\bar{t}}$:</b> <ul> <li><a href="132116?version=1&table=NPrankingchargeasymmetryvsmttbin0">$m_{t\bar{t}}$ &lt; $500$GeV</a> <li><a href="132116?version=1&table=NPrankingchargeasymmetryvsmttbin1">$m_{t\bar{t}} \in [500,750]$GeV</a> <li><a href="132116?version=1&table=NPrankingchargeasymmetryvsmttbin2">$m_{t\bar{t}} \in [750,1000]$GeV</a> <li><a href="132116?version=1&table=NPrankingchargeasymmetryvsmttbin3">$m_{t\bar{t}} \in [1000,1500]$GeV</a> <li><a href="132116?version=1&table=NPrankingchargeasymmetryvsmttbin4">$m_{t\bar{t}}$ &gt; $1500$GeV</a> </ul> <b>$A_C^{t\bar{t}}$ vs $p_{T,t\bar{t}}$:</b> <ul> <li><a href="132116?version=1&table=NPrankingchargeasymmetryvsptttbin0">$p_{T,t\bar{t}} \in [0,30]$GeV</a> <li><a href="132116?version=1&table=NPrankingchargeasymmetryvsptttbin1">$p_{T,t\bar{t}} \in[30,120]$GeV</a> <li><a href="132116?version=1&table=NPrankingchargeasymmetryvsptttbin2">$p_{T,t\bar{t}}$ &gt; $120$GeV</a> </ul> Inclusive leptonic:<a href="132116?version=1&table=NPrankingleptonicchargeasymmetryinclusive">$A_C^{\ell\bar{\ell}}$</a></br> <b>$A_C^{\ell\bar{\ell}}$ vs $\beta_{z,\ell\bar{\ell}}$</b> <ul> <li><a href="132116?version=1&tableNPrankingchargeasymmetry=vsllbetallbin0">$\beta_{z,\ell\bar{\ell}} \in [0,0.3]$</a> <li><a href="132116?version=1&tableNPrankingchargeasymmetry=vsllbetallbin1">$\beta_{z,\ell\bar{\ell}} \in [0.3,0.6]$</a> <li><a href="132116?version=1&tableNPrankingchargeasymmetry=vsllbetallbin2">$\beta_{z,\ell\bar{\ell}} \in [0.6,0.8]$</a> <li><a href="132116?version=1&tableNPrankingchargeasymmetry=vsllbetallbin3">$\beta_{z,\ell\bar{\ell}} \in [0.8,1]$</a> </ul> <b>$A_C^{\ell\bar{\ell}}$ vs $m_{\ell\bar{\ell}}$</b> <ul> <li><a href="132116?version=1&table=NPrankingchargeasymmetryvsllmllbin0">$m_{\ell\bar{\ell}}$ &lt; $200$GeV</a> <li><a href="132116?version=1&table=NPrankingchargeasymmetryvsllmllbin1">$m_{\ell\bar{\ell}} \in [200,300]$GeV</a> <li><a href="132116?version=1&table=NPrankingchargeasymmetryvsllmllbin2">$m_{\ell\bar{\ell}} \in [300,400]$Ge$</a> <li><a href="132116?version=1&table=NPrankingchargeasymmetryvsllmllbin3">$m_{\ell\bar{\ell}}$ &gt; $400$GeV</a> </ul> <b>$A_C^{\ell\bar{\ell}}$ vs $p_{T,\ell\bar{\ell}}$</b> <ul> <li><a href="132116?version=1&table=NPrankingchargeasymmetryvsllptllbin0">$p_{T,\ell\bar{\ell}}\in [0,20]$GeV</a> <li><a href="132116?version=1&table=NPrankingchargeasymmetryvsllptllbin1">$p_{T,\ell\bar{\ell}}\in[20,70]$GeV</a> <li><a href="132116?version=1&table=NPrankingchargeasymmetryvsllptllbin2">$p_{T,\ell\bar{\ell}}$ &gt; $70$GeV</a> </ul> <b>NP correlations:</b> <ul> <li><a href="132116?version=1&table=NPcorrelationschargeasymmetryinclusive">$A_C^{t\bar{t}}$</a> <li><a href="132116?version=1&table=NPcorrelationschargeasymmetryvsmtt">$A_C^{t\bar{t}}$ vs $m_{t\bar{t}}$</a> <li><a href="132116?version=1&table=NPcorrelationschargeasymmetryvspttt">$A_C^{t\bar{t}}$ vs $p_{T,t\bar{t}}$</a> <li><a href="132116?version=1&table=NPcorrelationschargeasymmetryvsbetatt">$A_C^{t\bar{t}}$ vs $\beta_{z,t\bar{t}}$</a> <li><a href="132116?version=1&table=NPcorrelationsleptonicchargeasymmetryinclusive">$A_c^{\ell\bar{\ell}}$</a> <li><a href="132116?version=1&table=NPcorrelationschargeasymmetryvsllmll">$A_c^{\ell\bar{\ell}}$ vs $m_{\ell\bar{\ell}}$</a> <li><a href="132116?version=1&table=NPcorrelationschargeasymmetryvsllptll">$A_C^{\ell\bar{\ell}}$ vs $p_{T,\ell\bar{\ell}}$</a> <li><a href="132116?version=1&table=NPcorrelationschargeasymmetryvsllbetall">$A_C^{\ell\bar{\ell}}$ vs $\beta_{z,\ell\bar{\ell}}$</a> </ul> <b>Covariance matrices:</b> <ul> <li><a href="132116?version=1&table=Covariancematrixchargeasymmetryvsmtt">$A_C^{t\bar{t}}$ vs $m_{t\bar{t}}$</a> <li><a href="132116?version=1&table=Covariancematrixchargeasymmetryvspttt">$A_C^{t\bar{t}}$ vs $p_{T,t\bar{t}}$</a> <li><a href="132116?version=1&table=Covariancematrixchargeasymmetryvsbetatt">$A_C^{t\bar{t}}$ vs $\beta_{z,t\bar{t}}$</a> <li><a href="132116?version=1&table=Covariancematrixleptonicchargeasymmetryvsllmll">$A_c^{\ell\bar{\ell}}$ vs $m_{\ell\bar{\ell}}$</a> <li><a href="132116?version=1&table=Covariancematrixleptonicchargeasymmetryvsllptll">$A_C^{\ell\bar{\ell}}$ vs $p_{T,\ell\bar{\ell}}$</a> <li><a href="132116?version=1&table=Covariancematrixleptonicchargeasymmetryvsllbetall">$A_C^{\ell\bar{\ell}}$ vs $\beta_{z,\ell\bar{\ell}}$</a> </ul>

The unfolded inclusive charge asymmetry. The measured values are given with statistical and systematic uncertainties. The SM theory predictions calculated at NNLO in QCD and NLO in EW theory are listed, and the impact of the linear term of the Wilson coefficient on the $A_C^{t\bar{t}}$ prediction is shown for two different values. The scale uncertainty is obtained by varying renormalisation and factorisation scales independently by a factor of 2 or 0.5 around $\mu_0$ to calculate the maximum and minimum value of the asymmetry, respectively. The nominal value $\mu_0$ is chosen as $H_T/4$. The variations in which one scale is multiplied by 2 while the other scale is divided by 2 are excluded. Finally, the scale and MC integration uncertainties are added in quadrature.

The unfolded differential charge asymmetry as a function of the invariant mass of the top pair system. The measured values are given with statistical and systematic uncertainties. The SM theory predictions calculated at NNLO in QCD and NLO in EW theory are listed, and the impact of the linear term of the Wilson coefficient on the $A_C^{t\bar{t}}$ prediction is shown for two different values. The scale uncertainty is obtained by varying renormalisation and factorisation scales independently by a factor of 2 or 0.5 around $\mu_0$ to calculate the maximum and minimum value of the asymmetry, respectively. The nominal value $\mu_0$ is chosen as $H_T/4$. The variations in which one scale is multiplied by 2 while the other scale is divided by 2 are excluded. Finally, the scale and MC integration uncertainties are added in quadrature.

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Measurement of $\phi$-meson production in Cu$+$Au at $\sqrt{s_{_{NN}}}=200$ GeV and U$+$U at $\sqrt{s_{_{NN}}}=193$ GeV

The PHENIX collaboration Abdulameer, N.J. ; Acharya, U. ; Aidala, C. ; et al.
Phys.Rev.C 107 (2023) 014907, 2023.
Inspire Record 2623245 DOI 10.17182/hepdata.132483

The PHENIX experiment reports systematic measurements at the Relativistic Heavy Ion Collider of $\phi$-meson production in asymmetric Cu$+$Au collisions at $\sqrt{s_{_{NN}}}$=200 GeV and in U$+$U collisions at $\sqrt{s_{_{NN}}}$=193 GeV. Measurements were performed via the $\phi\rightarrow K^{+}K^{-}$ decay channel at midrapidity $|\eta|<0.35$. Features of $\phi$-meson production measured in Cu$+$Cu, Cu$+$Au, Au$+$Au, and U$+$U collisions were found to not depend on the collision geometry, which was expected because the yields are averaged over the azimuthal angle and follow the expected scaling with nuclear-overlap size. The elliptic flow of the $\phi$ meson in Cu$+$Au, Au$+$Au, and U$+$U collisions scales with second-order-participant eccentricity and the length scale of the nuclear-overlap region (estimated with the number of participating nucleons). At moderate $p_T$, $\phi$-meson production measured in Cu$+$Au and U$+$U collisions is consistent with coalescence-model predictions, whereas at high $p_T$ the production is in agreement with expectations for in-medium energy loss of parent partons prior to their fragmentation. The elliptic flow for $\phi$ mesons measured in Cu$+$Au and U$+$U collisions is well described by a (2+1)D viscous-hydrodynamic model with specific-shear viscosity $\eta/s=1/4\pi$.

14 data tables

Invariant transverse momentum spectra measured for $\phi$ mesons in (a) Cu+Au and (b) U+U collisions at $\sqrt{s}$ = 200 GeV at midrapidity

Invariant transverse momentum spectra measured for $\phi$ mesons in (c) Cu+Au and (d) U+U collisions at $\sqrt{s}$ = 200 GeV at midrapidity. Data-to- Levy fit ratios.

The $\phi$-meson nuclear modification factors $R_{AB}$ measured as a function of $p_T$ in different centrality intervals of (a) to (d) Cu+Au collisions at $\sqrt{s}$ = 200 GeV and (e) to (h) U+U collisions at $\sqrt{s}$ = 193 GeV at midrapidity $|\eta|<0.35$. The normalization uncertainty from p+p of about $\sim9.7\%$ is not shown.

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Combination of inclusive top-quark pair production cross-section measurements using ATLAS and CMS data at $\sqrt{s}= 7$ and 8 TeV

The ATLAS & CMS collaborations Aad, G. ; Abbott, B. ; Abbott, D.C. ; et al.
JHEP 07 (2023) 213, 2023.
Inspire Record 2088291 DOI 10.17182/hepdata.110250

A combination of measurements of the inclusive top-quark pair production cross-section performed by ATLAS and CMS in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV at the LHC is presented. The cross-sections are obtained using top-quark pair decays with an opposite-charge electron-muon pair in the final state and with data corresponding to an integrated luminosity of about 5 fb$^{-1}$ at $\sqrt{s}=7$ TeV and about 20 fb$^{-1}$ at $\sqrt{s}=8$ TeV for each experiment. The combined cross-sections are determined to be $178.5 \pm 4.7$ pb at $\sqrt{s}=7$ TeV and $243.3^{+6.0}_{-5.9}$ pb at $\sqrt{s}=8$ TeV with a correlation of 0.41, using a reference top-quark mass value of 172.5 GeV. The ratio of the combined cross-sections is determined to be $R_{8/7}= 1.363\pm 0.032$. The combined measured cross-sections and their ratio agree well with theory calculations using several parton distribution function (PDF) sets. The values of the top-quark pole mass (with the strong coupling fixed at 0.118) and the strong coupling (with the top-quark pole mass fixed at 172.5 GeV) are extracted from the combined results by fitting a next-to-next-to-leading-order plus next-to-next-to-leading-log QCD prediction to the measurements. Using a version of the NNPDF3.1 PDF set containing no top-quark measurements, the results obtained are $m_t^\text{pole} = 173.4^{+1.8}_{-2.0}$ GeV and $\alpha_\text{s}(m_Z)= 0.1170^{+ 0.0021}_{-0.0018}$.

2 data tables

Full covariance matrix including all systematic uncertainties expressed as nuisance parameters. With the exception of the cross section parameters, all parameters were normalised to 1 before the fit. Therefore, the diagonal elements represent the constraint in quadrature.

Full covariance matrix including all systematic uncertainties expressed as nuisance parameters. With the exception of the cross section parameters, all parameters were normalised to 1 before the fit. Therefore, the diagonal elements represent the constraint in quadrature.


Improving constraints on gluon spin-momentum correlations in transversely polarized protons via midrapidity open-heavy-flavor electrons in $p^{\uparrow}+p$ collisions at $\sqrt{s}=200$ GeV

The PHENIX collaboration Abdulameer, N.J. ; Acharya, U. ; Aidala, C. ; et al.
Phys.Rev.D 107 (2023) 052012, 2023.
Inspire Record 2072832 DOI 10.17182/hepdata.130883

Polarized proton-proton collisions provide leading-order access to gluons, presenting an opportunity to constrain gluon spin-momentum correlations within transversely polarized protons and enhance our understanding of the three-dimensional structure of the proton. Midrapidity open-heavy-flavor production at $\sqrt{s}=200$ GeV is dominated by gluon-gluon fusion, providing heightened sensitivity to gluon dynamics relative to other production channels. Transverse single-spin asymmetries of positrons and electrons from heavy-flavor hadron decays are measured at midrapidity using the PHENIX detector at the Relativistic Heavy Ion Collider. These charge-separated measurements are sensitive to gluon correlators that can in principle be related to gluon orbital angular momentum via model calculations. Explicit constraints on gluon correlators are extracted for two separate models, one of which had not been constrained previously.

1 data table

Data from Figure 1 of open heavy flavor $e^{\pm}$ transverse single-spin asymmetries in transversely polarized p+p collisions as a function of $p_{T}$.


Nonprompt direct-photon production in Au$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV

The PHENIX collaboration Abdulameer, N.J. ; Acharya, U.A. ; Adare, A. ; et al.
Phys.Rev.C 109 (2024) 044912, 2024.
Inspire Record 2061074 DOI 10.17182/hepdata.129292

The measurement of the direct-photon spectrum from Au$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV is presented by the PHENIX collaboration using the external-photon-conversion technique for 0%--93% central collisions in a transverse-momentum ($p_T$) range of 0.8--10 GeV/$c$. An excess of direct photons, above prompt-photon production from hard-scattering processes, is observed for $p_T<6$ GeV/$c$. Nonprompt direct photons are measured by subtracting the prompt component, which is estimated as $N_{\rm coll}$-scaled direct photons from $p$ $+$ $p$ collisions at 200 GeV, from the direct-photon spectrum. Results are obtained for $0.8<p_T<6.0$ GeV/$c$ and suggest that the spectrum has an increasing inverse slope from ${\approx}0.2$ to 0.4 GeV/$c$ with increasing $p_T$, which indicates a possible sensitivity of the measurement to photons from earlier stages of the evolution of the collision. In addition, like the direct-photon production, the $p_T$-integrated nonprompt direct-photon yields also follow a power-law scaling behavior as a function of collision-system size. The exponent, $\alpha$, for the nonprompt component is found to be consistent with 1.1 with no apparent $p_T$ dependence.

9 data tables

Direct photon $R_{\gamma}$, every 20% centrality

Direct photon $R_{\gamma}$, every 10% centrality

Invariant yield of direct photons, every 10% centrality

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Low-$p_T$ direct-photon production in Au$+$Au collisions at $\sqrt{s_{_{NN}}}=39$ and 62.4 GeV

The PHENIX collaboration Abdulameer, N.J. ; Acharya, U. ; Adare, A. ; et al.
Phys.Rev.C 107 (2023) 024914, 2023.
Inspire Record 2057344 DOI 10.17182/hepdata.133218

The measurement of direct photons from Au$+$Au collisions at $\sqrt{s_{_{NN}}}=39$ and 62.4 GeV in the transverse-momentum range $0.4<p_T<3$ Gev/$c$ is presented by the PHENIX collaboration at the Relativistic Heavy Ion Collider. A significant direct-photon yield is observed in both collision systems. A universal scaling is observed when the direct-photon $p_T$ spectra for different center-of-mass energies and for different centrality selections at $\sqrt{s_{_{NN}}}=62.4$ GeV is scaled with $(dN_{\rm ch}/d\eta)^{\alpha}$ for $\alpha=1.21{\pm}0.04$. This scaling also holds true for direct-photon spectra from Au$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV measured earlier by PHENIX, as well as the spectra from Pb$+$Pb at $\sqrt{s_{_{NN}}}=2760$ GeV published by ALICE. The scaling power $\alpha$ seems to be independent of $p_T$, center of mass energy, and collision centrality. The spectra from different collision energies have a similar shape up to $p_T$ of 2 GeV/$c$. The spectra have a local inverse slope $T_{\rm eff}$ increasing with $p_T$ of $0.174\pm0.018$ GeV/$c$ in the range $0.4<p_T<1.3$ GeV/$c$ and increasing to $0.289\pm0.024$ GeV/$c$ for $0.9<p_T<2.1$ GeV/$c$. The observed similarity of low-$p_T$ direct-photon production from $\sqrt{s_{_{NN}}}= 39$ to 2760 GeV suggests a common source of direct photons for the different collision energies and event centrality selections, and suggests a comparable space-time evolution of direct-photon emission.

12 data tables

$R_{\gamma}$ for minimum bias (0-86%) Au+Au collision at $\sqrt{s_{NN}} = 62.4$ GeV (a) and $39$ GeV (b). For $62.4$ GeV also centrality bins of 0-20% (c) and 20-40% (d) are shown. Data points are shown with statistical (bar) and systematic uncertainties (box)

$R_{\gamma}$ for minimum bias (0-86%) Au+Au collision at $\sqrt{s_{NN}} = 62.4$ GeV (a) and $39$ GeV (b). For $62.4$ GeV also centrality bins of 0-20% (c) and 20-40% (d) are shown. Data points are shown with statistical (bar) and systematic uncertainties (box)

Direct photon spectra for minimum bias (0-86%) Au+Au collision at $\sqrt{s_{NN}} = 62.4$ GeV (a) and $39$ GeV (b). For $62.4$ GeV also centrality bins of 0-20% (c) and 20-40% (d) are shown. Data points are shown with statistical and systematic uncertainties, unless the central value is negative (arrows) or is consistent with zero within the statistical uncertainties (arrows with data point). In these cases upper limit with CL = 95$%$ are given.

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Measurements of second-harmonic Fourier coefficients from azimuthal anisotropies in $p+p, p$+Au $d$+Au, and $^3$He + Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV

The PHENIX collaboration Abdulameer, N.J. ; Acharya, U. ; Adare, A. ; et al.
Phys.Rev.C 107 (2023) 024907, 2023.
Inspire Record 2054927 DOI 10.17182/hepdata.136560

Recently, the PHENIX Collaboration has published second- and third-harmonic Fourier coefficients $v_2$ and $v_3$ for midrapidity ($|\eta|<0.35$) charged hadrons in 0%--5% central $p$$+$Au, $d$ $+$Au, and $^3$He$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV utilizing three sets of two-particle correlations for two detector combinations with different pseudorapidity acceptance [Phys. Rev. C {\bf 105}, 024901 (2022)]. This paper extends these measurements of $v_2$ to all centralities in $p$ $+$Au, $d$ $+$Au, and $^3$He$+$Au collisions, as well as $p$$+$$p$ collisions, as a function of transverse momentum ($p_T$) and event multiplicity. The kinematic dependence of $v_2$ is quantified as the ratio $R$ of $v_2$ between the two detector combinations as a function of event multiplicity for $0.5$ $<$ $p_T$ $<$ $1$ and $2$ $<$ $p_T$ $<$ $2.5$ GeV/$c$. A multiphase-transport (AMPT) model can reproduce the observed $v_2$ in most-central to midcentral $d$$+$Au and $^3$He$+$Au collisions. However, the AMPT model systematically overestimates the measurements in $p$ $+$ $p$, $p$ $+$Au, and peripheral $d$$+$Au and $^3$He$+$Au collisions, indicating a higher nonflow contribution in AMPT than in the experimental data. The AMPT model fails to describe the observed $R$ for $0.5$ $<$ $p_T$$<$ $1$ GeV/$c$, but there is qualitative agreement with the measurements for $2$ $<$ $p_T$ $<$ $2.5$ GeV/$c$.

18 data tables

Azimuthal anisotropy $v_2\{BB\}$ as a function of transverse momentum $p_T$ in $p$+Au collisions at $\sqrt{s_{NN}} =$ 200 GeV.

Azimuthal anisotropy $v_2\{BF\}$ as a function of transverse momentum $p_T$ in $p$+Au collisions at $\sqrt{s_{NN}} =$ 200 GeV.

Azimuthal anisotropy $v_2\{BB\}$ as a function of transverse momentum $p_T$ in $d$+Au collisions at $\sqrt{s_{NN}} =$ 200 GeV.

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