cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.17182/hepdata.95748.v1/t4
title: "Systematic uncertainties impact" of "Measurement of the $t\bar{t}$ production cross-section in the lepton+jets channel at $\sqrt{s}=13\;$TeV with the ATLAS experiment"

description: Impact of different categories of systematic uncertainties on the fiducial and inclusive measurements. The quoted values are obtained by repeating the fit, fixing a set of nuisance parameters of the sources corresponding to the considered category, and subtracting in quadrature the resulting uncertainty from the total uncertainty of the nominal fit. The total uncertainty is different from the sum in quadrature of the different components due to correlations between nuisance parameters built by the fit.
description: The $t\bar{t}$ production cross-section is measured in the lepton+jets channel using proton-proton collision data at a centre-of-mass energy of $\sqrt{s}=13$ TeV collected with the ATLAS detector at the LHC. The dataset corresponds to an integrated luminosity of 139 fb$^{-1}$. Events with exactly one charged lepton and four or more jets in the final state, with at least one jet containing $b$-hadrons, are used to determine the $t\bar{t}$ production cross-section through a profile-likelihood fit. The inclusive cross-section is measured to be ${\sigma_{\text{inc}} = 830 \pm 0.4 \text{(stat.)} \pm 36 \text{(syst.)}\pm 14 \text{(lumi.)} \mathrm{pb}}$ with a relative uncertainty of 4.6 %. The result is consistent with theoretical calculations at next-to-next-to-leading order in perturbative QCD.
DOI: 10.17182/hepdata.95748.v1/t5
title: "Fiducial region definition" of "Measurement of the $t\bar{t}$ production cross-section in the lepton+jets channel at $\sqrt{s}=13\;$TeV with the ATLAS experiment"

description: Fiducial region definition
description: The $t\bar{t}$ production cross-section is measured in the lepton+jets channel using proton-proton collision data at a centre-of-mass energy of $\sqrt{s}=13$ TeV collected with the ATLAS detector at the LHC. The dataset corresponds to an integrated luminosity of 139 fb$^{-1}$. Events with exactly one charged lepton and four or more jets in the final state, with at least one jet containing $b$-hadrons, are used to determine the $t\bar{t}$ production cross-section through a profile-likelihood fit. The inclusive cross-section is measured to be ${\sigma_{\text{inc}} = 830 \pm 0.4 \text{(stat.)} \pm 36 \text{(syst.)}\pm 14 \text{(lumi.)} \mathrm{pb}}$ with a relative uncertainty of 4.6 %. The result is consistent with theoretical calculations at next-to-next-to-leading order in perturbative QCD.
DOI: 10.17182/hepdata.95748.v2/t1
title: "Fitted cross-sections" of "Measurement of the $t\bar{t}$ production cross-section in the lepton+jets channel at $\sqrt{s}=13\;$TeV with the ATLAS experiment"

description: The results of fitted inclusive and fiducial ${t\bar{t}}$ cross-sections
description: The $t\bar{t}$ production cross-section is measured in the lepton+jets channel using proton-proton collision data at a centre-of-mass energy of $\sqrt{s}=13$ TeV collected with the ATLAS detector at the LHC. The dataset corresponds to an integrated luminosity of 139 fb$^{-1}$. Events with exactly one charged lepton and four or more jets in the final state, with at least one jet containing $b$-hadrons, are used to determine the $t\bar{t}$ production cross-section through a profile-likelihood fit. The inclusive cross-section is measured to be ${\sigma_{\text{inc}} = 830 \pm 0.4 \text{(stat.)} \pm 36 \text{(syst.)}\pm 14 \text{(lumi.)} \mathrm{pb}}$ with a relative uncertainty of 4.6 %. The result is consistent with theoretical calculations at next-to-next-to-leading order in perturbative QCD.
DOI: 10.17182/hepdata.95748.v2/t2
title: "Ranking Inclusive" of "Measurement of the $t\bar{t}$ production cross-section in the lepton+jets channel at $\sqrt{s}=13\;$TeV with the ATLAS experiment"

description: Ranking of the systematic uncertainties on the measured cross-section, normalised to the predicted value, in the inclusive fit to data. 
 The impact of each nuisance parameter, $\Delta \sigma_{\text{inc}}/\sigma^{\text{pred.}}_{\text{inc}}$, is computed by comparing the nominal best-fit value of $\sigma_{\text{inc}}/\sigma^{\text{pred}}_{\text{inc}}$ with the result of the fit when fixing the considered nuisance parameter to its best-fit value, $\theta$, shifted by its pre-fit (post-fit) uncertainties $\pm \Delta \theta$ ($\pm \Delta \hat{\theta}$). The figure shows the effect of the ten most significant uncertainties.
description: The $t\bar{t}$ production cross-section is measured in the lepton+jets channel using proton-proton collision data at a centre-of-mass energy of $\sqrt{s}=13$ TeV collected with the ATLAS detector at the LHC. The dataset corresponds to an integrated luminosity of 139 fb$^{-1}$. Events with exactly one charged lepton and four or more jets in the final state, with at least one jet containing $b$-hadrons, are used to determine the $t\bar{t}$ production cross-section through a profile-likelihood fit. The inclusive cross-section is measured to be ${\sigma_{\text{inc}} = 830 \pm 0.4 \text{(stat.)} \pm 36 \text{(syst.)}\pm 14 \text{(lumi.)} \mathrm{pb}}$ with a relative uncertainty of 4.6 %. The result is consistent with theoretical calculations at next-to-next-to-leading order in perturbative QCD.
DOI: 10.17182/hepdata.95748.v2/t3
title: "Ranking Fiducial" of "Measurement of the $t\bar{t}$ production cross-section in the lepton+jets channel at $\sqrt{s}=13\;$TeV with the ATLAS experiment"

description: Ranking of the systematic uncertainties on the measured cross-section, normalised to the predicted value, in the fiducial fit to data. 
 The impact of each nuisance parameter, $\Delta \sigma_{\text{fid}}/\sigma^{\text{pred.}}_{\text{fid}}$, is computed by comparing the nominal best-fit value of $\sigma_{\text{fid}}/\sigma^{\text{pred}}_{\text{fid}}$ with the result of the fit when fixing the considered nuisance parameter to its best-fit value, $\theta$, shifted by its pre-fit (post-fit) uncertainties $\pm \Delta \theta$ ($\pm \Delta \hat{\theta}$). The figure shows the effect of the ten most significant uncertainties.
description: The $t\bar{t}$ production cross-section is measured in the lepton+jets channel using proton-proton collision data at a centre-of-mass energy of $\sqrt{s}=13$ TeV collected with the ATLAS detector at the LHC. The dataset corresponds to an integrated luminosity of 139 fb$^{-1}$. Events with exactly one charged lepton and four or more jets in the final state, with at least one jet containing $b$-hadrons, are used to determine the $t\bar{t}$ production cross-section through a profile-likelihood fit. The inclusive cross-section is measured to be ${\sigma_{\text{inc}} = 830 \pm 0.4 \text{(stat.)} \pm 36 \text{(syst.)}\pm 14 \text{(lumi.)} \mathrm{pb}}$ with a relative uncertainty of 4.6 %. The result is consistent with theoretical calculations at next-to-next-to-leading order in perturbative QCD.
DOI: 10.17182/hepdata.95748.v2/t4
title: "Systematic uncertainties impact" of "Measurement of the $t\bar{t}$ production cross-section in the lepton+jets channel at $\sqrt{s}=13\;$TeV with the ATLAS experiment"

description: Impact of different categories of systematic uncertainties on the fiducial and inclusive measurements. The quoted values are obtained by repeating the fit, fixing a set of nuisance parameters of the sources corresponding to the considered category, and subtracting in quadrature the resulting uncertainty from the total uncertainty of the nominal fit. The total uncertainty is different from the sum in quadrature of the different components due to correlations between nuisance parameters built by the fit.
description: The $t\bar{t}$ production cross-section is measured in the lepton+jets channel using proton-proton collision data at a centre-of-mass energy of $\sqrt{s}=13$ TeV collected with the ATLAS detector at the LHC. The dataset corresponds to an integrated luminosity of 139 fb$^{-1}$. Events with exactly one charged lepton and four or more jets in the final state, with at least one jet containing $b$-hadrons, are used to determine the $t\bar{t}$ production cross-section through a profile-likelihood fit. The inclusive cross-section is measured to be ${\sigma_{\text{inc}} = 830 \pm 0.4 \text{(stat.)} \pm 36 \text{(syst.)}\pm 14 \text{(lumi.)} \mathrm{pb}}$ with a relative uncertainty of 4.6 %. The result is consistent with theoretical calculations at next-to-next-to-leading order in perturbative QCD.
DOI: 10.17182/hepdata.95748.v2/t5
title: "Fiducial region definition" of "Measurement of the $t\bar{t}$ production cross-section in the lepton+jets channel at $\sqrt{s}=13\;$TeV with the ATLAS experiment"

description: Fiducial region definition
description: The $t\bar{t}$ production cross-section is measured in the lepton+jets channel using proton-proton collision data at a centre-of-mass energy of $\sqrt{s}=13$ TeV collected with the ATLAS detector at the LHC. The dataset corresponds to an integrated luminosity of 139 fb$^{-1}$. Events with exactly one charged lepton and four or more jets in the final state, with at least one jet containing $b$-hadrons, are used to determine the $t\bar{t}$ production cross-section through a profile-likelihood fit. The inclusive cross-section is measured to be ${\sigma_{\text{inc}} = 830 \pm 0.4 \text{(stat.)} \pm 36 \text{(syst.)}\pm 14 \text{(lumi.)} \mathrm{pb}}$ with a relative uncertainty of 4.6 %. The result is consistent with theoretical calculations at next-to-next-to-leading order in perturbative QCD.
DOI: 10.17182/hepdata.95749.v1/t1
title: "Figure 1.1: Invariant yield vs $p_T$ in p+p collisions." of "Identified hadron compositions in p+p and Au+Au collisions at high transverse momenta at $\sqrt{s_{_{NN}}} = 200$ GeV"

description: 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.
description: BNL-RHIC. We report transverse momentum ($p_T \leq 15$ GeV/c) spectra of $\pi^{\pm}$, $K^{\pm}$ and $p$, $\bar{p}$, $K^0_S$, 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 $p_T &gt; 8$ GeV/c are measured to be similar to the p+p results, despite the expected Casimir effect for parton energy loss.
DOI: 10.17182/hepdata.95749.v1/t2
title: "Figure 1.2: Invariant yield vs $p_T$ in p+p collisions." of "Identified hadron compositions in p+p and Au+Au collisions at high transverse momenta at $\sqrt{s_{_{NN}}} = 200$ GeV"

description: 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.
description: BNL-RHIC. We report transverse momentum ($p_T \leq 15$ GeV/c) spectra of $\pi^{\pm}$, $K^{\pm}$ and $p$, $\bar{p}$, $K^0_S$, 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 $p_T &gt; 8$ GeV/c are measured to be similar to the p+p results, despite the expected Casimir effect for parton energy loss.
DOI: 10.17182/hepdata.95749.v1/t3
title: "Figure 1.3: Invariant yield vs $p_T$ in p+p collisions." of "Identified hadron compositions in p+p and Au+Au collisions at high transverse momenta at $\sqrt{s_{_{NN}}} = 200$ GeV"

description: 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.
description: BNL-RHIC. We report transverse momentum ($p_T \leq 15$ GeV/c) spectra of $\pi^{\pm}$, $K^{\pm}$ and $p$, $\bar{p}$, $K^0_S$, 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 $p_T &gt; 8$ GeV/c are measured to be similar to the p+p results, despite the expected Casimir effect for parton energy loss.
DOI: 10.17182/hepdata.95749.v1/t4
title: "Figure 1.4: Invariant yield vs $p_T$ in Au+Au (0-12%) collisions" of "Identified hadron compositions in p+p and Au+Au collisions at high transverse momenta at $\sqrt{s_{_{NN}}} = 200$ GeV"

description: The invariant yields $d^2N/(2\pi p_T dp_T dy)$ of $K + p(\bar{p})$ in central Au+Au collisions, 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.
description: BNL-RHIC. We report transverse momentum ($p_T \leq 15$ GeV/c) spectra of $\pi^{\pm}$, $K^{\pm}$ and $p$, $\bar{p}$, $K^0_S$, 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 $p_T &gt; 8$ GeV/c are measured to be similar to the p+p results, despite the expected Casimir effect for parton energy loss.
DOI: 10.17182/hepdata.95749.v1/t5
title: "Figure 1.5: Invariant yield vs $p_T$ in Au+Au (0-12%) collisions" of "Identified hadron compositions in p+p and Au+Au collisions at high transverse momenta at $\sqrt{s_{_{NN}}} = 200$ GeV"

description: The invariant yields $d^2N/(2\pi p_T dp_T dy)$ of $\rho^0$ in central Au+Au collisions, 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.
description: BNL-RHIC. We report transverse momentum ($p_T \leq 15$ GeV/c) spectra of $\pi^{\pm}$, $K^{\pm}$ and $p$, $\bar{p}$, $K^0_S$, 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 $p_T &gt; 8$ GeV/c are measured to be similar to the p+p results, despite the expected Casimir effect for parton energy loss.
DOI: 10.17182/hepdata.95749.v1/t6
title: "Figure 1.6: Invariant yield vs $p_T$ in Au+Au (0-12%) collisions" of "Identified hadron compositions in p+p and Au+Au collisions at high transverse momenta at $\sqrt{s_{_{NN}}} = 200$ GeV"

description: The invariant yields $d^2N/(2\pi p_T dp_T dy)$ of $K^0_S$ in central Au+Au collisions, 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.
description: BNL-RHIC. We report transverse momentum ($p_T \leq 15$ GeV/c) spectra of $\pi^{\pm}$, $K^{\pm}$ and $p$, $\bar{p}$, $K^0_S$, 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 $p_T &gt; 8$ GeV/c are measured to be similar to the p+p results, despite the expected Casimir effect for parton energy loss.
DOI: 10.17182/hepdata.95749.v1/t7
title: "Figure 2.1: Particle ratios vs $p_T$ in p+p collisions." of "Identified hadron compositions in p+p and Au+Au collisions at high transverse momenta at $\sqrt{s_{_{NN}}} = 200$ GeV"

description: Yield ratios $\pi^−/\pi^+$, $\bar{p}/p$, $K^−/K^+$, $p/\pi^+$, $\bar{p}/\pi^−$, and $K^{\pm}/\pi^{\pm}$ versus $p_T$ in p+p collisions, and nominal NLO calculations with AKK [9] and DSS [10] FFs without theoretical uncertainties. Bars and boxes (bands) represent statistical and systematic uncertainties, respectively.
description: BNL-RHIC. We report transverse momentum ($p_T \leq 15$ GeV/c) spectra of $\pi^{\pm}$, $K^{\pm}$ and $p$, $\bar{p}$, $K^0_S$, 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 $p_T &gt; 8$ GeV/c are measured to be similar to the p+p results, despite the expected Casimir effect for parton energy loss.
DOI: 10.17182/hepdata.95749.v1/t8
title: "Figure 2.2: Particle ratios vs $p_T$ in p+p collisions." of "Identified hadron compositions in p+p and Au+Au collisions at high transverse momenta at $\sqrt{s_{_{NN}}} = 200$ GeV"

description: Yield ratio $K^0_S$)/$\pi^{\pm}$ versus $p_T$ in p+p collisions, and nominal NLO calculations with AKK [9] and DSS [10] FFs without theoretical uncertainties. Bars and boxes (bands) represent statistical and systematic uncertainties, respectively.
description: BNL-RHIC. We report transverse momentum ($p_T \leq 15$ GeV/c) spectra of $\pi^{\pm}$, $K^{\pm}$ and $p$, $\bar{p}$, $K^0_S$, 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 $p_T &gt; 8$ GeV/c are measured to be similar to the p+p results, despite the expected Casimir effect for parton energy loss.
DOI: 10.17182/hepdata.95749.v1/t9
title: "Figure 2.3: Particle ratios vs $p_T$ in Au+Au collisions." of "Identified hadron compositions in p+p and Au+Au collisions at high transverse momenta at $\sqrt{s_{_{NN}}} = 200$ GeV"

description: Yield ratios $p/\pi^+$ and $\bar{p}/\pi^−$ versus $p_T$ in central Au+Au collisions [14] with updated uncertainties at high $p_T$. Bars and boxes (bands) represent statistical and systematic uncertainties, respectively.
description: BNL-RHIC. We report transverse momentum ($p_T \leq 15$ GeV/c) spectra of $\pi^{\pm}$, $K^{\pm}$ and $p$, $\bar{p}$, $K^0_S$, 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 $p_T &gt; 8$ GeV/c are measured to be similar to the p+p results, despite the expected Casimir effect for parton energy loss.
DOI: 10.17182/hepdata.95749.v1/t10
title: "Figure3.1: RAA vs $p_T$ in 0-12% Au+Au collisions." of "Identified hadron compositions in p+p and Au+Au collisions at high transverse momenta at $\sqrt{s_{_{NN}}} = 200$ GeV"

description: $R_{AA}$ of $\pi^{\pm} in central Au+Au collisions as a function of $p_T$. Bars and boxes (bands) represent statistical and systematic uncertainties, respectively. The height of the band at unity represents the normalization uncertainty.
description: BNL-RHIC. We report transverse momentum ($p_T \leq 15$ GeV/c) spectra of $\pi^{\pm}$, $K^{\pm}$ and $p$, $\bar{p}$, $K^0_S$, 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 $p_T &gt; 8$ GeV/c are measured to be similar to the p+p results, despite the expected Casimir effect for parton energy loss.
DOI: 10.17182/hepdata.95749.v1/t11
title: "Figure3.2: RAA vs $p_T$ in 0-12% Au+Au collisions." of "Identified hadron compositions in p+p and Au+Au collisions at high transverse momenta at $\sqrt{s_{_{NN}}} = 200$ GeV"

description: $R_{AA}$ of $K^{\pm}+p(\bar{p})$ in central Au+Au collisions as a function of $p_T$. Bars and boxes (bands) represent statistical and systematic uncertainties, respectively. The height of the band at unity represents the normalization uncertainty.
description: BNL-RHIC. We report transverse momentum ($p_T \leq 15$ GeV/c) spectra of $\pi^{\pm}$, $K^{\pm}$ and $p$, $\bar{p}$, $K^0_S$, 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 $p_T &gt; 8$ GeV/c are measured to be similar to the p+p results, despite the expected Casimir effect for parton energy loss.