Date

Evidence from d + Au measurements for final-state suppression of high p(T) hadrons in Au + Au collisions at RHIC.

The STAR collaboration Adams, J. ; Adler, C. ; Aggarwal, M.M. ; et al.
Phys.Rev.Lett. 91 (2003) 072304, 2003.
Inspire Record 621394 DOI 10.17182/hepdata.98576

We report measurements of single-particle inclusive spectra and two-particle azimuthal distributions of charged hadrons at high transverse momentum (high $p_T$) in minimum bias and central d+Au collisions at $\sqrt{s_{NN}}$=200 GeV. The inclusive yield is enhanced in d+Au collisions relative to binary-scaled p+p collisions, while the two-particle azimuthal distributions are very similar to those observed in p+p collisions. These results demonstrate that the strong suppression of the inclusive yield and back-to-back correlations at high $p_T$ previously observed in central Au+Au collisions are due to final-state interactions with the dense medium generated in such collisions.

5 data tables

Uncorrected charged particle multiplicity distributions measured in −3.8 < $\eta$ < −2.8 (Au-direction) for d+Au collisions. Points are for minimum bias (triangles) and peripheral (circles, ZDC-d single neutron) collisions. Both are normalized to the total number of d+Au collisions. Histograms are Glauber model calculations.

Inclusive $p_{T}$ distributions for minimum bias and central d+Au collisions, and non-singly diffractive p+p collisions. Hash marks at the top indicate bin boundaries for $p_{T}$ > 3.8 GeV/c.

$R_{AB}(p_{T})$ from Eq. 1 for minimum bias and central d+Au collisions, and central Au+Au collisions. The minimum bias d+Au data are displaced 100 MeV/c to the right for clarity. The error bars are the quadrature sum of the statistical and point-to-point systematic uncertainties. The bands show the normalization uncertainties, which are highly correlated point-to-point and between the two d+Au distributions.

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Particle dependence of azimuthal anisotropy and nuclear modification of particle production at moderate p(T) in Au + Au collisions at s(NN)**(1/2) = 200-GeV.

The STAR collaboration Adams, John ; Adler, C. ; Aggarwal, M.M. ; et al.
Phys.Rev.Lett. 92 (2004) 052302, 2004.
Inspire Record 620309 DOI 10.17182/hepdata.93260

We present STAR measurements of the azimuthal anisotropy parameter $v_2$ and the binary-collision scaled centrality ratio $R_{CP}$ for kaons and lambdas ($\Lambda+\bar{\Lambda}$) at mid-rapidity in Au+Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV. In combination, the $v_2$ and $R_{CP}$ particle-type dependencies contradict expectations from partonic energy loss followed by standard fragmentation in vacuum. We establish $p_T \approx 5$ GeV/c as the value where the centrality dependent baryon enhancement ends. The $K_S^0$ and $\Lambda+\bar{\Lambda}$ $v_2$ values are consistent with expectations of constituent-quark-number scaling from models of hadron fromation by parton coalescence or recombination.

9 data tables

The minimum bias (0-80% of the collision cross-section) v2(pT) of K0s. Errors listed include statistical and point-to-point systematic uncertainties from the background. Additional non-flow systematic uncertainties are approximately -20%.

The minimum bias (0-80% of the collision cross-section) v2(pT) of Lambda+Lambdabar. Errors listed include statistical and point-to-point systematic uncertainties from the background. Additional non-flow systematic uncertainties are approximately -20%.

The minimum bias (0-80% of the collision cross-section) v2(pT) of charged hadrons. Errors listed include statistical and point-to-point systematic uncertainties from the background. Additional non-flow systematic uncertainties are approximately -20%.

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Absence of suppression in particle production at large transverse momentum in s(NN)**(1/2) = 200-GeV d + Au collisions.

The PHENIX collaboration Adler, S.S. ; Afanasiev, S. ; Aidala, C. ; et al.
Phys.Rev.Lett. 91 (2003) 072303, 2003.
Inspire Record 621391 DOI 10.17182/hepdata.143668

Transverse momentum spectra of charged hadrons with p_T < 8 GeV/c and neutral pions with p_T < 10 GeV/c have been measured at mid-rapidity by the PHENIX experiment at RHIC in d+Au collisions at sqrt(s_NN) = 200 GeV. The measured yields are compared to those in p+p collisions at the same sqrt(s_NN) scaled up by the number of underlying nucleon-nucleon collisions in d+Au. The yield ratio does not show the suppression observed in central Au+Au collisions at RHIC. Instead, there is a small enhancement in the yield of high momentum particles.

10 data tables

Midrapidity $p_T$ spectra for charged hadrons.

Midrapidity $p_T$ spectra for $\pi^0$.

Nuclear modification factor $R_{dA}$ for $\pi^0$ in the PbGl and PbSc calorimeters in minimum bias $d$+$Au$.

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Measurement of isolated prompt photon production in photon photon collisions at s(ee)**(1/2) = 183-GeV - 209-GeV.

The OPAL collaboration Abbiendi, G. ; Ainsley, C. ; Akesson, P.F. ; et al.
Eur.Phys.J.C 31 (2003) 491-502, 2003.
Inspire Record 619533 DOI 10.17182/hepdata.48831

For the first time at LEP the production of prompt photons is studied in the collisions of quasi-real photons using the OPAL data taken at e+e- centre-of-mass energies between 183 GeV and 209 GeV. The total inclusive production cross-section for isolated prompt photons in the kinematic range of photon transverse momentum larger than 3.0 GeV and absolute photon pseudorapidity less than 1 is determined to be 0.32 +- 0.04 (stat) +- 0.04 (sys) pb. Differential cross-sections are compared to the predictions of a next-to-leading-order (NLO) calculation.

5 data tables

The total prompt photon cross section in the kinematic range defined by theanti tagging condition.

Differential cross section in PT.

Differential cross section in ETARAP.

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Transverse momentum and collision energy dependence of high p(T) hadron suppression in Au + Au collisions at ultrarelativistic energies.

The STAR collaboration Adams, J. ; Adler, C. ; Aggarwal, M.M. ; et al.
Phys.Rev.Lett. 91 (2003) 172302, 2003.
Inspire Record 619063 DOI 10.17182/hepdata.93908

We report high statistics measurements of inclusive charged hadron production in Au+Au and p+p collisions at \sqrtsNN=200 GeV. A large, approximately constant hadron suppression is observed in central Au+Au collisions for $5\lt\pT\lt12$ GeV/c. The collision energy dependence of the yields and the centrality and \pT dependence of the suppression provide stringent constraints on theoretical models of suppression. Models incorporating initial-state gluon saturation or partonic energy loss in dense matter are largely consistent with observations. We observe no evidence of \pT-dependent suppression, which may be expected from models incorporating jet attentuation in cold nuclear matter or scattering of fragmentation hadrons.

4 data tables

Inclusive invariant pT distributions of (h+ + h−)/2 for centrality-selected Au+Au and p+p NSD interactions. Hash marks at the top indicate bin boundaries for pT>4 GeV/c.The invariant cross section for p+p is indicated on the right vertical axis.

R200/130(pT ) vs. pT for (h+ + h−)/2 for four different centrality bins. The overall normalization uncertainty is +6−14% for the 40-60% bin and is negligible for the other panels. Calculations are described in the text.

RAA(pT) (Eq. 1) for (h+ + h−)/2 in |η|<0.5, for centrality-selected Au+Au spectra relative to the measured p+p spectrum. The p+p spectrum is common to all panels. Calculations are described in the text.

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Di-jet production in photon photon collisions at s(ee)**(1/2) = from 189-GeV to 209-GeV.

The OPAL collaboration Abbiendi, G. ; Ainsley, C. ; Akesson, P.F. ; et al.
Eur.Phys.J.C 31 (2003) 307-325, 2003.
Inspire Record 611415 DOI 10.17182/hepdata.49662

Di-jet producion is studied in collisions of quasi-real photons at e+e- centre- of-mass energies sqrt(s)ee from 189 to 209 GeV at LEP. The data were collected with the OPAL detector. Jets are reconstructed using an inclusive k_t clustering algorithm for all cross-section measurements presented. A cone jet algorithm is used in addition to study the different structure of the jets resulting from either of the algorithms. The inclusive di-jet cross-section is measured as a function of the mean transverse energy Etm(jet) of the two leading jets, and as a functiuon of the estimated fraction of the photon momentum carried by the parton entering the hard sub-process, xg, for different regions of Etm (jet). Angular distribution in di-jet events are measured and used to demonstrate the dominance of quark and gluon initiated processes in different regions of phase space. Furthermore the inclusive di-jet cross-section as a function of |eta(jet)| and |delta eta (jet)| is presented where eta(jet) is the jet pseudo-rapidity. Different regions of the xg+ -xg- -space are explored to study and control the influence of an underlying event. The results are compared to next-to-leading order perturbative QCD calculations and to the predictions of the leading order Monte Carlo generator PYTHIA.

21 data tables

The di-jet cross section as a function of the angle between the jet and thedirection of the incoming parton in the centre-of-mass frame for the region whe re both X(C=GAMMA+) and X(C=GAMMA-) are > 0.75.

The di-jet cross section as a function of the angle between the jet and thedirection of the incoming parton in the centre-of-mass frame for the region whe re both X(C=GAMMA+) and X(C=GAMMA-) are < 0.75.

The di-jet cross section as a function of the mean transverse energy of thedi-jet system for the full X(C=GAMMA+) and X(C=GAMMA-) region.

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Narrowing of the balance function with centrality in Au + Au collisions s(NN)**(1/2) = 130-GeV.

The STAR collaboration Adams, J. ; Adler, C. ; Ahammed, Z. ; et al.
Phys.Rev.Lett. 90 (2003) 172301, 2003.
Inspire Record 612248 DOI 10.17182/hepdata.98620

The balance function is a new observable based on the principle that charge is locally conserved when particles are pair produced. Balance functions have been measured for charged particle pairs and identified charged pion pairs in Au+Au collisions at $\sqrt{s_{NN}}$ = 130 GeV at the Relativistic Heavy Ion Collider using STAR. Balance functions for peripheral collisions have widths consistent with model predictions based on a superposition of nucleon-nucleon scattering. Widths in central collisions are smaller, consistent with trends predicted by models incorporating late hadronization.

6 data tables

The balance function versus ∆η for charged particle pairs from a) central and peripheral Au+Au collisions at $\sqrt{s_{NN}}$ = 130 GeV and mixed events from central and peripheral Au+Au collisions, and b) HIJING events filtered with GEANT [16] and shuffled pseudorapidity events from central and peripheral Au+Au collisions. To guide the eye, Gaussian fits excluding the lowest bin in ∆η are shown. The error bars shown are statistical. The balance function for HIJING events is independent of centrality.

The balance function versus ∆η for charged particle pairs from a) central and peripheral Au+Au collisions at $\sqrt{s_{NN}}$ = 130 GeV and mixed events from central and peripheral Au+Au collisions, and b) HIJING events filtered with GEANT [16] and shuffled pseudorapidity events from central and peripheral Au+Au collisions. To guide the eye, Gaussian fits excluding the lowest bin in ∆η are shown. The error bars shown are statistical. The balance function for HIJING events is independent of centrality.

The width of the balance function for charged particles, $⟨\Delta \eta⟩$, as a function of normalized impact parameter $(b/b_{max})$. Error bars shown are statistical. The width of the balance function from HIJING events is shown as a band whose height reflects the statistical uncertainty. Also shown are the widths from the shuffled pseudorapidity events.

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Cross-section for forward J / psi production in p anti-p collisions at S = 1.8-TeV

The CDF collaboration Acosta, D. ; Affolder, T. ; Akimoto, H. ; et al.
Phys.Rev.D 66 (2002) 092001, 2002.
Inspire Record 603674 DOI 10.17182/hepdata.22217

The inclusive cross section for J/ψ production times the branching ratio B(J/ψ→μ+μ−) has been measured in the forward pseudorapidity region: B×dσ[p¯+p→J/ψ(pT>10GeV/c,2.1<|η|<2.6)+X]/dη=192±9(stat)±29(syst)pb. The results are based on 74.1±5.2pb−1 of data collected by the CDF Collaboration at the Fermilab Tevatron Collider. The measurements extend earlier measurements of the D0 Collaboration to higher pTJ/ψ. In the kinematic range where the experiments partially overlap, these data are in good agreement with previous measurements.

2 data tables

The integrated cross section for J/PSI --> MU+ MU- decay.

Cross section as a function of PT. Statistical errors only.


Strange anti-particle to particle ratios at mid-rapidity in s(NN)**(1/2) = 130-GeV Au + Au collisions.

The STAR collaboration Adams, John ; Adler, C. ; Ahammed, Z. ; et al.
Phys.Lett.B 567 (2003) 167-174, 2003.
Inspire Record 602867 DOI 10.17182/hepdata.98924

Values of the ratios in the mid-rapidity yields of anti-Lambda/Lambda = 0.71 +/- 0.01(stat.) +/- 0.04(sys.), anti-Xi+/Xi- = 0.83 +/- 0.04(stat.) +/- 0.05 (sys.), anti-Omega+/Omega- = 0.95 +/- 0.15(stat) +/- 0.05(sys.) and K+/K- 1.092 +/- 0.023(combined) were obtained in central sqrt(s_NN) = 130 GeV Au+Au collisions using the STAR detector. The ratios indicate that a fraction of the net-baryon number from the initial system is present in the excess of hyperons over anti-hyperons at mid-rapidity. The trend in the progression of the baryon ratios, with increasing strange quark content, is similar to that observed in heavy-ion collisions at lower energies. The value of these ratios may be related to the charged kaon ratio in the framework of simple quark-counting and thermal models.

5 data tables

Invariant mass distributions for $\Lambda$ and Anti-$\Lambda$

Invariant mass distributions for $\Xi$ and Anti-$\Xi$

Invariant mass distributions for $\Omega$ and Anti-$\Omega$

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Charged particle multiplicities in heavy and light quark initiated events above the Z0 peak.

The OPAL collaboration Abbiendi, G. ; Ainsley, C. ; Akesson, P.F. ; et al.
Phys.Lett.B 550 (2002) 33-46, 2002.
Inspire Record 601225 DOI 10.17182/hepdata.49792

We have measured the mean charged particle multiplicities separately for bbbar, ccbar and light quark (uubar, ddbar, ssbar) initiated events produced in e+e- annihilations at LEP. The data were recorded with the OPAL detector at eleven different energies above Z0 peak, corresponding to the full statistics collected at LPE1.5 and LEP2. The difference in mean charged and particle multiplicities for bbbar and light quark events, delta_bl, measured over this energy range is consistent with an energy independent behaviour, as predicted by QCD, but is inconsistent with the prediction of a more phenomenological approach which assumes that the multiplicity accompanying the decay of a heavy quark is independent of the quark mass itself. Our results, which can be combined into the single measurement delta_bl = 3.44+-0.40(stat)+-0.89(syst) at a luminosity weighted average centre-of mass energy of 195 GeV, are also consistent with an energy independent behaviour as extrapolated from lower energy data.

1 data table

Corrected mean charged particle multiplicities for the different quark quarkbar initiated events.