Measurement of J/[psi] and [psi](2S) at Forward and Backward Rapidity in P+p, P+Al, P+Au, and 3He+Au Collisions at √snn

Measurement of J/[psi] and [psi](2S) at Forward and Backward Rapidity in P+p, P+Al, P+Au, and 3He+Au Collisions at √snn
Author: Krista Lizbeth Smith
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Total Pages: 173
Release: 2021
Genre: Nuclear physics
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Suppression of the J/psi nuclear modification factor has been seen as a trademark signature of final state effects in large collision systems for decades. In small systems, the nuclear modification was attributed to cold nuclear matter effects until the observation of strong differential suppression of the psi(2S) state in p/d+A collisions suggested the presence of final state effects. Results of J/psi and psi(2S) measurements in the dimuon decay channel are presented here for a collection of different small systems at the same collision energy. These small systems include: p+p, p+Al, p+Au and 3He+Au at collision energy square root s_NN = 200 GeV. The results are predominantly shown in the form of the nuclear modification factor, R_AB, the ratio of the J/psi or psi(2S) invariant yield per nucleon-nucleon collision in collisions of projectile A on target B to that in p+p collisions. Measurements of the J/psi and psi(2S) nuclear modification factor are then compared with shadowing and transport model predictions, as well as to complementary measurements at LHC energies.

J/psi Production in Au-Au Collisions at Square Root (s/sub NN)

J/psi Production in Au-Au Collisions at Square Root (s/sub NN)
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Release: 2003
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This thesis presents the first J/psi production analysis of Au+Au reactions at forward rapidity at [square root]sNN = 200 GeV. In the second year of RHIC running, design energy was achieved in the collisions of both Au+Au ions and proton+proton reactions. The production of the J/psi is measured by the PHENIX experiment in Au+Au collisions as well as in proton-proton collisions. The scientific goal is to investigate the nature of hot, dense nuclear matter capitalizing on the unique properties of the J/psi as a probe of this matter. Recent experimental results by the NA50 collaboration at CERN strongly deviate from the conventional picture that successfully describes data at lower energies. The importance of such a measurement is demonstrated by the wide spectrum of theoretical explanations concerning the existing data. The merits of these models will be explored in a systematic and comprehensive study of the J/psi and open charm in collisions of a variety of species and energy. A survey of the theoretical models is presented and the relevant open charm and J/psi PHENIX measurements are compared.

Measurement of Prompt Psi(2S) to J/psi Yield Ratios in PbPb and Pp Collisions at Sqrt(s[NN]

Measurement of Prompt Psi(2S) to J/psi Yield Ratios in PbPb and Pp Collisions at Sqrt(s[NN]
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Total Pages: 15
Release: 2014
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The ratio between the prompt psi(2S) and J/psi yields, reconstructed via their decays into muon pairs, is measured in PbPb and pp collisions at sqrt(s[NN]) = 2.76 TeV. The analysis is based on PbPb and pp data samples collected by CMS at the LHC, corresponding to integrated luminosities of 150 inverse microbarns and 5.4 inverse picobarns, respectively. The double ratio of measured yields, (N[psi(2S)]/N[J/psi])[PbPb] / (N[psi(2S)]/ N[J/psi])[pp], is computed in three PbPb collision centrality bins and two kinematic ranges: one at midrapidity, abs(y)

J/psi Production at High Transverse Momenta in P+p and Cu+Cu Collisions at Sqrt SNN

J/psi Production at High Transverse Momenta in P+p and Cu+Cu Collisions at Sqrt SNN
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Release: 2009
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The STAR collaboration at RHIC presents measurements of J/[psi] → e+e− at mid-rapidity and high transverse momentum (p{sub T} > 5 GeV/c) in p+p and central Cu+Cu collisions at √sNN = 200 GeV. The inclusive J/[psi] production cross section for Cu+Cu collisions is found to be consistent at high p{sub T} with the binary collision-scaled cross section for p+p collisions, in contrast to previous measurements at lower p{sub T}, where a suppression of J/[psi] production is observed relative to the expectation from binary scaling. Azimuthal correlations of J/[psi] with charged hadrons in p+p collisions provide an estimate of the contribution of B-meson decays to J/[psi] production of 13% ± 5%.

Rapidity Dependence of the Inclusive J/[psi] Production in P[bar P] Collisions At[radical]

Rapidity Dependence of the Inclusive J/[psi] Production in P[bar P] Collisions At[radical]
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Release: 2001
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We have studied the[ital J]/[psi] production in[ital p][ital[anti p]] collisions at[radical]s= 1.8 TeV with the D[null] detector at the Fermilab Tevatron, using a[mu][sup+][mu][sup -] data sample collected during the 1994-95 running period. We have measured the inclusive[ital J]/[psi] production cross section as a function of the[ital J]/[psi] transverse momentum, [ital P][sub T][sup[ital J]/[psi]] in the central and forward rapidity regions. The new measurement of the cross section[ital d[sigma]/dp][sub T][sup[ital J]/[psi]] for[vert-bar][eta][sup[ital J]/[psi]][vert-bar][lt] 0.6 is in a good agreement with the CDF and earlier D[null] results. The cross section measurement[ital d[sigma]/dp][sub T][sup[ital J]/[psi]] for 2.5[lt][vert-bar][eta][sup[ital J]/[psi]][vert-bar][lt] 3.7 covers the[ital p][sub T][sup[ital J]/[psi]] range from 1 to 16 GeV/c. We combine the measurements in several[vert-bar][eta][sup[ital J]/[psi]][vert-bar] regions to discuss[ital d[sigma]/d[eta]][sup[ital J]/[psi]] for[ital p][sub T][sup[ital J]/[psi]][gt] 8 GeV/c. The data are compared with the next-to- leading order (NLO) QCD calculations, which take into account different[ital J]/[psi] production mechanisms.

Measurement of Prompt $\psi(2S) \to J/\psi$ Yield Ratios in Pb-Pb and $p-p$ Collisions at $\sqrt {s_{NN}}

Measurement of Prompt $\psi(2S) \to J/\psi$ Yield Ratios in Pb-Pb and $p-p$ Collisions at $\sqrt {s_{NN}}
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Release: 2014
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The ratio between the prompt [psi](2S) and J/[psi] yields, reconstructed via their decays into [mu]+[mu]-, is measured in Pb-Pb and p-p collisions at √sNN=2.76 TeV. Likewise, the analysis is based on Pb-Pb and p-p data samples collected by CMS at the Large Hadron Collider, corresponding to integrated luminosities of 150 [mu]b-1 and 5.4 pb-1, respectively. The double ratio of measured yields (N[psi](2S)/NJ/[psi])Pb-Pb/(N[psi](2S)/NJ/[psi])p-p is computed in three Pb-Pb collision centrality bins and two kinematic ranges: one at midrapidity,

J/psi and Psi(2S) Production in Pp Collisions at Sqrt(s)

J/psi and Psi(2S) Production in Pp Collisions at Sqrt(s)
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Total Pages: 39
Release: 2012
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A measurement of the J/psi and psi(2S) production cross sections in pp collisions at sqrt(s)=7 TeV with the CMS experiment at the LHC is presented. The data sample corresponds to an integrated luminosity of 37 inverse picobarns. Using a fit to the invariant mass and decay length distributions, production cross sections have been measured separately for prompt and non-prompt charmonium states, as a function of the meson transverse momentum in several rapidity ranges. In addition, cross sections restricted to the acceptance of the CMS detector are given, which are not affected by the polarization of the charmonium states. The ratio of the differential production cross sections of the two states, where systematic uncertainties largely cancel, is also determined. The branching fraction of the inclusive B to psi(2S) X decay is extracted from the ratio of the non-prompt cross sections to be: BR(B to psi(2S) X) = (3.08 +/- 0.12(stat.+syst.) +/- 0.13(theor.) +/- 0.42(BR[PDG])) 10-̂3.