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.

Prompt and Non-prompt J/psi Production in Pp Collisions at Sqrt(s)

Prompt and Non-prompt J/psi Production in Pp Collisions at Sqrt(s)
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Total Pages: 36
Release: 2011
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ISBN:

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The production of J/psi mesons is studied in pp collisions at sqrt(s)=7 TeV with the CMS experiment at the LHC. The measurement is based on a dimuon sample corresponding to an integrated luminosity of 314 inverse nanobarns. The J/psi differential cross section is determined, as a function of the J/psi transverse momentum, in three rapidity ranges. A fit to the decay length distribution is used to separate the prompt from the non-prompt (b hadron to J/psi) component. Integrated over J/psi transverse momentum from 6.5 to 30 GeV/c and over rapidity in the range.

Measurement of Prompt and Nonprompt J/psi Production in Pp and PPb Collisions at Sqrt(s[NN]

Measurement of Prompt and Nonprompt J/psi Production in Pp and PPb Collisions at Sqrt(s[NN]
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Total Pages:
Release: 2017
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ISBN:

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This paper reports the measurement of J/psi meson production in proton-proton (pp) and proton-lead (pPb) collisions at a center-of-mass energy per nucleon pair of 5.02 TeV by the CMS experiment at the LHC. The data samples used in the analysis correspond to integrated luminosities of 28 inverse picobarns and 35 inverse nanobarns for pp and pPb collisions, respectively. Prompt and nonprompt J/psi mesons, the latter issuing from the decay of B mesons, are measured in their dimuon decay channels. Differential cross sections are measured in the transverse momentum range of 2

Measurement of the Prompt Double J/psi Production Cross Section in Pp Collisions at Sqrt(s)

Measurement of the Prompt Double J/psi Production Cross Section in Pp Collisions at Sqrt(s)
Author: Andrew David York
Publisher:
Total Pages: 205
Release: 2013
Genre: Mesons
ISBN:

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The simultaneous production of two J/psi mesons has been significantly observed in proton-proton collisions at a center-of-mass energy of 7 TeV with the CMS detector. The two J/psi mesons are fully reconstructed in their decay to muons. The signal yield is extracted with an extended maximum likelihood fit based on four event variables. A method was developed to correct for detector acceptances and efficiencies based on the measured momenta of the J/psi and their decay muons to maintain the least model dependence possible. The measurement is performed in an acceptance region defined by the individual J/psi transverse momentum and rapidity. From the measured signal yield of 446 events corresponding to an integrated luminosity of 4:7 inverse femtobarn. The total cross section is found to be 1:49 nanobarn, with 0:07 statistical and 0:13 nb systematic error, and unpolarizaed production was assumed. Most predictions for particle production at the LHC assume dominance of single parton interaction for proton-proton collisions, which can be tested with the final state measured in this analysis. The differential cross section is measured in bins of the double J/psi invariant mass, the double J/psi transverse momentum, and the absolute difference in rapidity of the two J/psi. The reconstruction of the four charged muon trajectories heavily relies on the Pixel subdetector located close to the beampipe. Systematic studies with cosmic muons and tracks from collision events are presented. The development of the Pixel RawToDigi package, data quality monitoring packages, commissioning studies of Pixel data and tracks in first collisions, and realistic simulations of decay signals in the pixel subdetector were all performed as a part of this dissertation work.

Measurement of Prompt $J/\psi$ Pair Production in Pp Collisions at $ \sqrt{s} $

Measurement of Prompt $J/\psi$ Pair Production in Pp Collisions at $ \sqrt{s} $
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Total Pages: 35
Release: 2014
Genre:
ISBN:

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Production of prompt J/[psi] meson pairs in proton-proton collisions at √s = 7 TeV is measured with the CMS experiment at the LHC in a data sample corresponding to an integrated luminosity of about 4.7 fb-1. The two J/[psi] mesons are fully reconstructed via their decays into [mu] + [mu] - pairs. This observation provides for the first time access to the high-transverse-momentum region of J/[psi] pair production where model predictions are not yet established. The total and differential cross sections are measured in a phase space defined by the individual J/[psi] transverse momentum (p T J/[psi] ) and rapidity (

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 the Prompt J/Psi Pair Production Cross Section in Pp Collisions at Sqrt(s)

Measurement of the Prompt J/Psi Pair Production Cross Section in Pp Collisions at Sqrt(s)
Author: Grant Valentine Riley
Publisher:
Total Pages: 141
Release: 2017
Genre: Collisions (Nuclear physics)
ISBN:

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The cross section for the prompt production of [J/Psi] meson pairs in proton-proton collisions at √ s[sqrt(s)] = 8 TeV at the LHC from a sample corresponding to an integrated luminosity of 20.2±0.5 fb−1 [inverse femtobarns] has been measured with the CMS detector. It provides unique insight into particle production and proton structure in proton-proton (pp) collisions. The two [J/Psi] mesons are fully reconstructed in their [mu+ mu-] decay. An acceptance region is defined by the individual [J/Psi] transverse momentum p [J/Psi pT] and rapidity y [J/Psi Rapidity]. The total fiducial cross section assuming unpolarized prompt [J/Psi] pair production is found to be [sigma_fid] = 195.7 ± 11.1 (stat) ± 22.1 (syst) ± 5.1 (lumi) ± 2.3 (BF) pb. The differential cross sections for prompt [J/Psi] pair production within this acceptance region are measured in eight event variables. Most predictions for particle production in pp collisions at the LHC assume dominance of single parton (gluon, quark) interactions (SPS) at the leading order perturbation theory. This assumption is tested with the final state measured in this analysis. Significant contributions from next-to-leading order processes and double parton scattering (DPS) are observed. In addition, the single [J/Psi] production cross section is estimated from theory and measured with pp collision data. Single [J/Psi] production is compared to the pair production via DPS and quantified via an effective cross section. This quantity is further compared to several particle pair production processes. In particular, the [J/Psi] pair production probes the contributions of gluons. All particle production measurements with CMS depend on the precise knowledge of the LHC luminosity. A detector, the Pixel Luminosity Telescope, based on solid state technology is used to count charged particle tracks from pp collisions, a measure of the instantaneous luminosity. The measurement is provided online for every crossing of the LHC beams. Tests of sensors and the development work for the detector are presented.