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Bathe, S.

Publications and source records attributed to Bathe, S..

At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Production of $π^0$ and $\eta$ mesons in $\mathrm{U+U}$ collisions at $\sqrt {s_{NN}} = 192$ $\mathrm {GeV}$

The PHENIX experiment at the Relativistic Heavy Ion Collider measured $π^0$ and $\eta$ mesons at midrapidity in $\mathrm{U+U}$ collisions at $\sqrt {s_{NN}} = 192$ $\mathrm {GeV}$ in a wide transverse momentum range. Measurements were performed in the $π^0(η) → γγ$ decay modes. A strong suppression of $π^0$ and $\eta$ meson production at high transverse momentum was observed in central $\mathrm{U+U}$ collisions relative to binary scaled p + p results. Yields of $π^0$ and $\eta$ mesons measured in $\mathrm{U+U}$ collisions show similar suppression pattern to those measured in Au + Au collisions at $\sqrt {s_{NN}} = 200$ $\mathrm {GeV}$ for similar numbers of participant nucleons. The $η/π^0$ ratios do not show dependence on centrality or transverse momentum and are consistent with previously measured values in hadron-hadron, hadron-nucleus, nucleus-nucleus, and $e^+e^-$ collisions.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2020

Production of b b ¯ at forward rapidity in p + p collisions at s = 510 GeV

The cross section of bottom quark-antiquark ( b b ¯ ) production in p + p collisions at s = 510 GeV is measured with the PHENIX detector at the Relativistic Heavy Ion Collider. The results are based on the yield of high mass, like-sign muon pairs measured within the PHENIX muon arm acceptance ( 1.2 < | y | < 2.2 ). The b b ¯ signal is extracted from like-sign dimuons by utilizing the unique properties of neutral B meson oscillation. We report a differential cross section of d σ b b ¯ → μ ± μ ± / d y = 0.16 ± 0.01 ( stat ) ± 0.02 ( syst ) ± 0.02 ( global ) nb for like-sign muons in the rapidity and p T ranges 1.2 < | y | < 2.2 and p T > 1 GeV / c , and dimuon mass of 5 – 10 GeV / c 2 . The extrapolated total cross section at this energy for b b ¯ production is 13.1 ± 0.6 ( stat ) ± 1.5 ( syst ) ± 2.7 ( global ) μ b . The total cross section is compared to a perturbative quantum chromodynamics calculation and is consistent within uncertainties. The azimuthal opening angle between muon pairs from b b ¯ decays and their p T distributions are compared to distributions generated using ps pythia 6, which includes next-to-leading order processes. The azimuthal correlations and pair p T distribution are not very well described by pythia calculations, but are still consistent within uncertainties. Flavor creation and flavor excitation subprocesses are favored over gluon splitting.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2019

Nuclear Dependence of the Transverse Single-Spin Asymmetry in the Production of Charged Hadrons at Forward Rapidity in Polarized p + p , p + Al , and p + Au Collisions at s N N = 200 GeV

We report on the nuclear dependence of transverse single-spin asymmetries (TSSAs) in the production of positively charged hadrons in polarized p ↑ + p , p ↑ + Al , and p ↑ + Au collisions at √ s N N = 200 GeV . The measurements have been performed at forward rapidity ( 1.4 < η < 2.4 ) over the range of transverse momentum ( 1.8 < p T < 7.0 G eV / c ) and Feynman x ( 0.1 < x F < 0.2 ). We observed positive asymmetries for positively charged hadrons in p ↑ + p collisions, and significantly reduced asymmetries in p ↑ + A collisions. These results reveal a nuclear dependence of TSSAs for charged-hadron production in a regime where perturbative techniques are applicable. These results provide new opportunities to use p ↑ + A collisions as a tool to investigate the rich phenomena behind TSSAs in hadronic collisions and to use TSSAs as a new handle in studying small-system collisions.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗