arXiv subjects

J. T. Mitchell

Publications and source records attributed to J. T. Mitchell.

9 recordsLinked to original sources

arXiv2016

Tests of constituent-quark generation methods which maintain both the nucleon center of mass and the desired radial distribution in Monte Carlo Glauber models

Several methods of generating three constituent-quarks in a nucleon are evaluated which explicitly maintain the nucleon's center of mass and desired radial distribution and can be used within Monte Carlo Glauber frameworks. The geometric models provided by each method are used to generate distributions over the number of constituent-quark participants ($N_{qp}$) in $p+p$, $d+$Au and Au$+$Au collisions. The results are compared with each other and to a previous result of $N_{qp}$ calculations, without this explicit constraint, used in measurements of $\sqrt{s_{_{NN}}}$=200 GeV $p+p$, $d+$Au and Au$+$Au collisions at RHIC.

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arXiv2016

Transverse Energy Measurements from the Beam Energy Scan in PHENIX

Transverse energy distributions at midrapidity have been measured by the PHENIX experiment at the BNL Relativistic Heavy Ion Collider (RHIC) for Au+Au, U+U, Cu+Au, Cu+Cu, He+Au, d+Au, and p+p collisions over a wide energy range from $\sqrt{s_{NN}}$ = 7.7 GeV to $\sqrt{s_{NN}}$ = 200 GeV as a function of centrality. For central Au+Au collisions, it is observed that the midrapidity Bjorken energy density demonstrates a power law behavior from $\sqrt{s_{NN}}$ = 7.7 GeV to $\sqrt{s_{NN}}$ = 2.76 TeV. At a given collision energy, the data presented as a function of $N_{part}$ are independent of the size of the collision system. For Au+Au, Cu+Au, and Cu+Cu collisions, the centrality-dependent data are better described by scaling with the number of constituent quark participants than scaling with the number of nucleon participants.

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arXiv2013

PHENIX Experiment Results from the RHIC Beam Energy Scan Program

The PHENIX Experiment at RHIC has conducted a beam energy scan at several collision energies in order to search for signatures of the QCD critical point and the onset of deconfinement. PHENIX has conducted measurements of transverse energy production, muliplicity fluctuations, the skewness and kurtosis of net charge distributions, Hanbury-Brown Twiss correlations, charged hadron flow, and energy loss. The data analyzed to date show no significant indications of the presence of the critical point.

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arXiv2012

The RHIC Beam Energy Scan Program: Results from the PHENIX Experiment

The PHENIX Experiment at RHIC has conducted a beam energy scan at several collision energies in order to search for signatures of the QCD critical point and the onset of deconfinement. PHENIX has conducted measurements of transverse energy production, muliplicity fluctuations, and the skewness and kurtosis of net charge distributions. The data analyzed to date show no significant indications of the presence of the critical point.

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arXiv2007

The PHENIX Potential in the Search for the QCD Critical Point

With the measurement of several observables at SPS energies that demonstrate non-monotonic behavior as a function of centrality and $\sqrt{s_{NN}}$, there is growing interest in pursuing a scan of relativistic heavy ion collisions at low energies at the Relativistic Heavy Ion Collider. The capabilities of the PHENIX experiment to take quality measurements at low RHIC energies is described and directly demonstrated with analyses of Au+Au collisions at $\sqrt{s_{NN}}$ = 19.6 GeV and Cu+Cu collisions at $\sqrt{s_{NN}}$ = 22.5 GeV. The contribution of upgrades to the PHENIX detector in the upcoming years will also be discussed in the context of a low energy RHIC run.

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arXiv2007

Fluctuations and low transverse momentum correlation results from PHENIX

The PHENIX Experiment at the Relativistic Heavy Ion Collider has conducted a survey of fluctuations in charged hadron multiplicity in Au+Au and Cu+Cu collisions at $\sqrt{s_{NN}}$ = 22, 62, and 200 GeV. A universal power law scaling for multiplicity fluctuations expressed as $σ^2/μ^2$ is observed as a function of $N_{part}$ for all species studied that is independent of the transverse momentum range of the measurement. PHENIX has also measured transverse momentum correlation amplitudes in p+p, d+Au, and Au+Au collisions. At low transverse momentum, significant differences in the correlations between the baseline p+p and d+Au data and the Au+Au data are presented.

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arXiv2007

Scaling Properties of Fluctuation and Correlation Results from PHENIX

Recent surveys of multiplicity fluctuations, transverse momentum fluctuations, and two-particle azimuthal correlations are presented for several collision systems as a function of centrality and transverse momentum. Both multiplicity and transverse momentum fluctuations exhibit a power law scaling as a function of the number of participants that is independent of the collision system. Although these observations are consistent with critical behavior, the critical exponent $η$ measured using azimuthal correlations is seen to be independent of centrality and collision system. Also observed in the azimuthal correlations is a displaced away side peak in central Au+Au collisions when the pairs are restricted to low transverse momentum.

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arXiv2005

Fluctuation Results from PHENIX

The PHENIX Experiment at the Relativistic Heavy Ion Collider has made measurements of event-by-event fluctuations in the net charge, the mean transverse momentum, and the charged particle multiplicity as a function of collision energy, centrality, and transverse momentum in heavy ion collisions. The results of these measurements will be reviewed and discussed.

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arXiv2002

Event Reconstruction in the PHENIX Central Arm Spectrometers

The central arm spectrometers for the PHENIX experiment at the Relativistic Heavy Ion Collider have been designed for the optimization of particle identification in relativistic heavy ion collisions. The spectrometers present a challenging environment for event reconstruction due to a very high track multiplicity in a complicated, focusing, magnetic field. In order to meet this challenge, nine distinct detector types are integrated for charged particle tracking, momentum reconstruction, and particle identification. The techniques which have been developed for the task of event reconstruction are described.

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