Measurement of Bottom versus Charm as a Function of Transverse Momentum with Electron-Hadron Correlations in p+p Collisions at sqrt(s)=200 GeV

The PHENIX collaboration Adare, A. ; Afanasiev, S. ; Aidala, C. ; et al.
Phys.Rev.Lett. 103 (2009) 082002, 2009.
Inspire Record 816469 DOI 10.17182/hepdata.57326

The momentum distribution of electrons from semi-leptonic decays of charm and bottom for mid-rapidity |y|<0.35 in p+p collisions at sqrt(s)=200 GeV is measured by the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) over the transverse momentum range 2 < p_T < 7 GeV/c. The ratio of the yield of electrons from bottom to that from charm is presented. The ratio is determined using partial D/D^bar --> e^{+/-} K^{-/+} X (K unidentified) reconstruction. It is found that the yield of electrons from bottom becomes significant above 4 GeV/c in p_T. A fixed-order-plus-next-to-leading-log (FONLL) perturbative quantum chromodynamics (pQCD) calculation agrees with the data within the theoretical and experimental uncertainties. The extracted total bottom production cross section at this energy is \sigma_{b\b^bar}= 3.2 ^{+1.2}_{-1.1}(stat) ^{+1.4}_{-1.3}(syst) micro b.

6 data tables

Bottom contribution to the electrons from heavy flavor decay as a function of PT. These values has been obtained using g3data software which to extract the data from the plot and should therefore be used with caution. The g3data program indicates an extra uncertainty of 0.01 on these values.

Differential bottom production cross section at mid rapidity (y=0) To obtain this value, the differential "bottom-decay" electrons cross-section has been extrapolated to PT=0 using the spectrum shape predicted by pQCD. The b->e branching ratio used was 10 +-1%.

Invariant cross section of electrons from heavy flavor decay versus PT These values has been obtained using g3data software which to extract the data from the plot and should therefore be used with caution. The values in the last column indicate the level of uncertainty intoduced by g3data.

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Photon-Hadron Jet Correlations in p+p and Au+Au Collisions at sqrt(s_NN) = 200 GeV

The PHENIX collaboration Adare, A. ; Afanasiev, S. ; Aidala, C. ; et al.
Phys.Rev.C 80 (2009) 024908, 2009.
Inspire Record 815824 DOI 10.17182/hepdata.95790

We report the observation at the Relativistic Heavy Ion Collider (RHIC) of suppression of back-to-back correlations in the direct photon+jet channel in Au+Au relative to p+p collisions. Two-particle correlations of direct photon triggers with associated hadrons are obtained by statistical subtraction of the decay photon-hadron background. The initial momentum of the away-side parton is tightly constrained, because the parton-photon pair exactly balance in momentum at leading order in perturbative quantum chromodynamics (pQCD), making such correlations a powerful probe of the in-medium parton energy loss. The away-side nuclear suppression factor, I_AA, in central Au+Au collisions, is 0.32 +/- 0.12(stat) +/- 0.09(syst) for hadrons of 3 < p_T < 5 in coincidence with photons of 5 < p_T < 15 GeV/c. The suppression is comparable to that observed for high-p_T single hadrons and dihadrons. The direct photon associated yields in p+p collisions scale approximately with the momentum balance, z_T = p_T^hadron/p_T^photon, as expected for a measure of the away-side parton fragmentation function. We compare to Au+Au collisions for which the momentum balance dependence of the nuclear modification should be sensitive to the path-length dependence of parton energy loss.

24 data tables

direct $\gamma$-hadron yields per trigger p+p and Au+Au at 5<$p_{T}^{\gamma}$<7 GeV/c.

direct $\gamma$-hadron yields per trigger p+p and Au+Au at 7<$p_{T}^{\gamma}$<9 GeV/c.

direct $\gamma$-hadron yields per trigger p+p and Au+Au at 9<$p_{T}^{\gamma}$<12 GeV/c.

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High-pT pi^zero Production with Respect to the Reaction Plane in Au + Au Collisions at sqrt(s_NN) = 200 GeV

The PHENIX collaboration Afanasiev, S. ; Aidala, C. ; Ajitanand, N.N. ; et al.
Phys.Rev.C 80 (2009) 054907, 2009.
Inspire Record 816486 DOI 10.17182/hepdata.95817

Measurements of the azimuthal anisotropy of high-\pT neutral pion neutral pion production in Au+Au collisions at sqrt(s_NN) = 200 GeV by the PHENIX experiment are presented. The data included in this paper were collected during the 2004 RHIC running period and represent approximately an order of magnitude increase in the number of analyzed events relative to previously published results. Azimuthal angle distributions of pi^0s detected in the PHENIX electromagnetic calorimeters are measured relative to the reaction plane determined event-by-event using the forward and backward beam-beam counters. Amplitudes of the second Fourier component (v_2) of the angular distributions are presented as a function of pi^0 transverse momentum p_T for different bins in collision centrality. Measured reaction plane dependent pi^0 yields are used to determine the azimuthal dependence of the pi^0 suppression as a function of p_T, R_AA (Delta phi,p_T). A jet-quenching motivated geometric analysis is presented that attempts to simultaneously describe the centrality dependence and reaction plane angle dependence of the pi^0 suppression in terms of the path lengths of hypothetical parent partons in the medium. This set of results allows for a detailed examination of the influence of geometry in the collision region, and of the interplay between collective flow and jet-quenching effects along the azimuthal axis.

4 data tables

$\pi^0 v_2$ as function of centrality. All errors are absolute.

$\pi^0 v_2$ as function of centrality. All errors are absolute.

Rebinned $R_{AA}$ for $\Delta \phi$, $p_T$, and path length dependence,

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Pion Interferometry in Au+Au and Cu+Cu Collisions at RHIC

The STAR collaboration Abelev, B.I. ; Aggarwal, M.M. ; Ahammed, Z. ; et al.
Phys.Rev.C 80 (2009) 024905, 2009.
Inspire Record 814937 DOI 10.17182/hepdata.97124

We present a systematic analysis of two-pion interferometry in Au+Au collisions at $\sqrt{s_{\rm{NN}}}$ = 62.4 GeV and Cu+Cu collisions at $\sqrt{s_{\rm{NN}}}$ = 62.4 and 200 GeV using the STAR detector at RHIC. The multiplicity and transverse momentum dependences of the extracted femtoscopic radii are studied. The scaling of the apparent freeze-out volume with charged particle multiplicity is studied for the RHIC energy domain. The multiplicity scaling of the measured radii is found to be independent of colliding system and collision energy.

12 data tables

HBT parameters for all centralities of 62.4 GeV Au+Au

HBT parameters for 200 and 62.4 GeV Au+Au, 0-5%

Energy dependence of the pi- HBT parameters for central Au+Au, Pb+Pb, and Pb+Au collisions (AGS,SPS and RHIC) at midrapidity and k_T ~ 0.2-0.3 GeV/c.

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Kaon interferometric probes of space-time evolution in Au+Au collisions at sqrt(s_NN) = 200 GeV

The PHENIX collaboration Afanasiev, S. ; Aidala, C. ; Ajitanand, N.N. ; et al.
Phys.Rev.Lett. 103 (2009) 142301, 2009.
Inspire Record 816475 DOI 10.17182/hepdata.141728

Bose-Einstein correlations of charged kaons are measured for Au+Au collisions at sqrt(s_NN) = 200 GeV and are compared to charged pion probes, which have a larger hadronic scattering cross section. Three dimensional Gaussian source radii are extracted, along with a one-dimensional kaon emission source function. The centrality dependences of the three Gaussian radii are well described by a single linear function if N_part^1/3 with zero intercept. Imaging analysis shows a deviation from a Gaussian tail at r >~ 10 fm, although the bulk emission at lower radius is well-described by a Gaussian. The presence of a non-Gaussian tail in the kaon source reaffirms that the particle emission region in a heavy ion collision is extended, and that similar measurements with pions are not solely due to the decay of long-lived resonances.

7 data tables

3D correlation function of charged kaon pairs measured for 0.3 < $k_T$ < 1.5 GeV/$c$ at 0-30% centrality in Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV.

3D Gaussian HBT radius parameters for charged kaon pairs as a function of $N_{part}^{1/3}$ measured for 0.3 < $k_T$ < 1.5 GeV/$c$ and $m_T$ measured for 0-30% centrality in Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV.

3D Gaussian HBT radius parameters for charged kaon pairs as a function of $N_{part}^{1/3}$ measured for 0.3 < $k_T$ < 1.5 GeV/$c$ and $m_T$ measured for 0-30% centrality in Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV.

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Measurements of differential cross sections of $Z /\gamma^\ast$+jets+X events in proton anti-proton collisions at $\sqrt{s}$=1.96 TeV

The D0 collaboration Abazov, V.M. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Lett.B 678 (2009) 45-54, 2009.
Inspire Record 815094 DOI 10.17182/hepdata.51854

We present cross section measurements for Z/gamma*+jets+X production, differential in the transverse momenta of the three leading jets. The data sample was collected with the D0 detector at the Fermilab Tevatron proton anti-proton collider at a center-of-mass energy of 1.96 TeV and corresponds to an integrated luminosity of 1 fb-1. Leading and next-to-leading order perturbative QCD predictions are compared with the measurements, and agreement is found within the theoretical and experimental uncertainties. We also make comparisons with the predictions of four event generators. Two parton-shower-based generators show significant shape and normalization differences with respect to the data. In contrast, two generators combining tree-level matrix elements with a parton shower give a reasonable description of the the shapes observed in data, but the predicted normalizations show significant differences with respect to the data, reflecting large scale uncertainties. For specific choices of scales, the normalizations for either generator can be made to agree with the measurements.

6 data tables

PT distribution of the first jet in events with one or more jets with additional constraints on the electrons.

PT distribution of the first jet in events with one or more jets.

PT distribution of the second jet in events with two or more jets with additional constraints on the electrons.

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Observation of an ABC effect in proton-proton collisions

Dymov, S. ; Hartmann, M. ; Kacharava, A. ; et al.
Phys.Rev.Lett. 102 (2009) 192301, 2009.
Inspire Record 812534 DOI 10.17182/hepdata.51593

The cross section for inclusive multipion production in the pp->ppX reaction was measured at COSY-ANKE at four beam energies, 0.8, 1.1, 1.4, and 2.0 GeV, for low excitation energy in the final pp system, such that the diproton quasi-particle is in the 1S0 state. At the three higher energies the missing mass Mx spectra show a strong enhancement at low Mx, corresponding to an ABC effect that moves steadily to larger values as the energy is increased. Despite the missing-mass structure looking very different at 0.8 GeV, the variation with Mx and beam energy are consistent with two-pion production being mediated through the excitation of two Delta(1232) isobars, coupled to S-- and D-- states of the initial pp system.

4 data tables

The P P --> P P X differential cross section as a function of the square ofthe missing mass (X) at incident beam energy of 0.8 GeV.

The P P --> P P X differential cross section as a function of the square ofthe missing mass (X) at incident beam energy of 1.1 GeV.

The P P --> P P X differential cross section as a function of the square ofthe missing mass (X) at incident beam energy of 1.4 GeV.

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Forward production of charged pions with incident $\pi^{\pm}$ on nuclear targets measured at the CERN PS

The HARP collaboration Apollonio, M. ; Artamonov, A. ; Bagulya, A. ; et al.
Nucl.Phys.A 821 (2009) 118-192, 2009.
Inspire Record 813159 DOI 10.17182/hepdata.51841

Measurements of the double-differential $\pi^{\pm}$ production cross-section in the range of momentum $0.5 \GeVc \leq p \le 8.0 \GeVc$ and angle $0.025 \rad \leq \theta \le 0.25 \rad$ in interactions of charged pions on beryllium, carbon, aluminium, copper, tin, tantalum and lead are presented. These data represent the first experimental campaign to systematically measure forward pion hadroproduction. The data were taken with the large acceptance HARP detector in the T9 beam line of the CERN PS. Incident particles, impinging on a 5% nuclear interaction length target, were identified by an elaborate system of beam detectors. The tracking and identification of the produced particles was performed using the forward spectrometer of the HARP detector. Results are obtained for the double-differential cross-sections $ {{\mathrm{d}^2 \sigma}}/{{\mathrm{d}p\mathrm{d}\Omega}} $ mainly at four incident pion beam momenta (3 \GeVc, 5 \GeVc, 8 \GeVc and 12 \GeVc). The measurements are compared with the GEANT4 and MARS Monte Carlo simulation

154 data tables

Double differential PI+ and PI- production cross section in the laboratory system for PI- BE interactions at 3, 5, 8 and 12 GeV for the angular range 0.05 to 0.10 radians.

Double differential PI+ and PI- production cross section in the laboratory system for PI- BE interactions at 3, 5, 8 and 12 GeV for the angular range 0.10 to 0.15 radians.

Double differential PI+ and PI- production cross section in the laboratory system for PI- BE interactions at 3, 5, 8 and 12 GeV for the angular range 0.15 to 0.20 radians.

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Inclusive Photoproduction of rho0, K*0 and phi Mesons at HERA

The H1 collaboration Aaron, F.D. ; Alexa, C. ; Andreev, V. ; et al.
Phys.Lett.B 673 (2009) 119-126, 2009.
Inspire Record 810285 DOI 10.17182/hepdata.45313

Inclusive non-diffractive photoproduction of rho(770)^0, K^*(892)^0 and phi(1020) mesons is investigated with the H1 detector in ep collisions at HERA. The corresponding average \gamma p centre-of-mass energy is 210 GeV. The mesons are measured in the transverse momentum range 0.5&lt;p_T&lt;7 GeV and the rapidity range |y_{lab}|&lt;1. Differential cross sections are presented as a function of transverse momentum and rapidity, and are compared to the predictions of hadroproduction models.

4 data tables

Inclusive non-diffractive photoproduction cross sections in the specified kinematic region.

Ratios of cross sections.

Inclusive non-diffractive photoproduction invariant differential cross sections as a function of PT in the specified kinematic range.

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Observation of exclusive charmonium production and $\gamma+\gamma$ to $\mu^+\mu^-$ in $p\bar{p}$ collisions at $\sqrt{s} = 1.96$ TeV

The CDF collaboration Aaltonen, T. ; Adelman, Jahred A. ; Akimoto, T. ; et al.
Phys.Rev.Lett. 102 (2009) 242001, 2009.
Inspire Record 812821 DOI 10.17182/hepdata.55758

We have observed the reactions p+pbar --> p+X+pbar, with X being a centrally produced J/psi, psi(2S) or chi_c0, and gamma+gamma --> mu+mu-, in proton- antiproton collisions at sqrt{s} = 1.96 TeV using the Run II Collider Detector at Fermilab. The event signature requires two oppositely charged muons, each with pseudorapidity |eta| < 0.6, with M(mumu) in [3.0,4.0] GeV/c2, and either no other particles, or one additional photon, detected. The J/psi and the psi(2S) are prominent, on a continuum consistent with the QED process gamma+gamma --> mu+mu-. Events with a J/psi and an associated photon candidate are consistent with exclusive chi_c0 production through double pomeron exchange. The exclusive vector meson production is as expected for elastic photo- production, gamma+p --> J/psi(psi(2S)) + p, which is observed here for the first time in hadron-hadron collisions. The cross sections ds/dy(y=0) for p + pbar --> p + X + pbar with X = J/psi, psi(2S) orchi_c0 are 3.92+/-0.62 nb, 0.53+/-0.14 nb, and 75+/-14 nb respectively. The cross section for the continuum, with |eta(mu+/-)| < 0.6, M(mumu) in [3.0,4.0] GeV/c2, is [Integral ds/(dM.deta1.deta2)] = 2.7+/-0.5 pb, consistent with QED predictions. We put an upper limit on the cross section for odderon exchange in J/psi production: ds/dy(y=0) (J/psi_O/IP) < 2.3 nb at 95% C.L.

5 data tables

Prompt J/psi cross section from exclusive photoproduction at mid rapidity.

Prompt Psi(2S) cross section from exclusive photoproduction at mid rapidity.

Prompt photoproduction cross-section ratio Psi(2S)/(J/psi) at mid rapidity.

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