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Full-Text Articles in Physical Sciences and Mathematics
Dielectron Azimuthal Anisotropy At Mid-Rapidity In Au + Au Collisions At √SNn=200 Gev, J. Kevin Adkins, Renee Fatemi, Suvarna Ramachandran, G. Webb, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin
Dielectron Azimuthal Anisotropy At Mid-Rapidity In Au + Au Collisions At √SNn=200 Gev, J. Kevin Adkins, Renee Fatemi, Suvarna Ramachandran, G. Webb, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin
Physics and Astronomy Faculty Publications
We report on the first measurement of the azimuthal anisotropy (v2) of dielectrons (e+e− pairs) at mid-rapidity from √SNN=200 GeV Au + Au collisions with the STAR detector at the Relativistic Heavy Ion Collider (RHIC), presented as a function of transverse momentum (pT) for different invariant-mass regions. In the mass region Meec2 the dielectron v2 measurements are found to be consistent with expectations from π0, η, ω, and ϕ decay contributions. In the mass region 1.1<Mee<2.9GeV/c …2.9gev/
Observation Of D0 Meson Nuclear Modifications In Au+Au Collisions At √SNn=200 Gev, J. Kevin Adkins, Renee Fatemi, Suvarna Ramachandran, G. Webb, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, E. C. Aschenauer
Observation Of D0 Meson Nuclear Modifications In Au+Au Collisions At √SNn=200 Gev, J. Kevin Adkins, Renee Fatemi, Suvarna Ramachandran, G. Webb, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, E. C. Aschenauer
Physics and Astronomy Faculty Publications
We report the first measurement of charmed-hadron (D0) production via the hadronic decay channel (D0→K−+π+) in Au+Au collisions at √SNN=200 GeV with the STAR experiment. The charm production cross section per nucleon-nucleon collision at midrapidity scales with the number of binary collisions, Nbin, from p+p to central Au+Au collisions. The D0 meson yields in central Au+Au collisions are strongly suppressed compared to those in p+p scaled by Nbin, for transverse momenta pT>3 GeV/c …
Beam Energy Dependence Of Moments Of The Net-Charge Multiplicity Distributions In Au+Au Collisions At Rhic, J. Kevin Adkins, Renee Fatemi, Wolfgang Korsch, Suvarna Ramachandran, G. Webb, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, E. C. Aschenauer
Beam Energy Dependence Of Moments Of The Net-Charge Multiplicity Distributions In Au+Au Collisions At Rhic, J. Kevin Adkins, Renee Fatemi, Wolfgang Korsch, Suvarna Ramachandran, G. Webb, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, E. C. Aschenauer
Physics and Astronomy Faculty Publications
We report the first measurements of the moments—mean (M), variance (σ2), skewness (S), and kurtosis (κ)—of the net-charge multiplicity distributions at midrapidity in Au+Au collisions at seven energies, ranging from √SNN=7.7 to 200 GeV, as a part of the Beam Energy Scan program at RHIC. The moments are related to the thermodynamic susceptibilities of net charge, and are sensitive to the location of the QCD critical point. We compare the products of the moments, σ2/M, Sσ, and κσ2, with the expectations …
J/Ψ Production At Low PT In Au + Au And Cu + Cu Collisions At √SNn = 200 Gev With The Star Detector, J. Kevin Adkins, Renee Fatemi, Suvarna Ramachandran, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin
J/Ψ Production At Low PT In Au + Au And Cu + Cu Collisions At √SNn = 200 Gev With The Star Detector, J. Kevin Adkins, Renee Fatemi, Suvarna Ramachandran, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin
Physics and Astronomy Faculty Publications
The J/ψ pT spectrum and nuclear modification factor (RAA) are reported for pT < 5 GeV/c and |y| < 1 from 0% to 60% central Au + Au and Cu + Cu collisions at √SNN = 200 GeV at STAR. A significant suppression of pT-integrated J/ψ production is observed in central Au + Au events. The Cu + Cu data are consistent with no suppression, although the precision is limited by the available statistics. RAA in Au + Au collisions exhibits a strong suppression at low transverse momentum and gradually increases with pT. The data are compared to high-pT …
Beam-Energy Dependence Of Charge Separation Along The Magnetic Field In Au+Au Collisions At Rhic, J. Kevin Adkins, Renee Fatemi, Suvarna Ramachandran, G. Webb, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, E. C. Aschenauer
Beam-Energy Dependence Of Charge Separation Along The Magnetic Field In Au+Au Collisions At Rhic, J. Kevin Adkins, Renee Fatemi, Suvarna Ramachandran, G. Webb, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, E. C. Aschenauer
Physics and Astronomy Faculty Publications
Local parity-odd domains are theorized to form inside a quark-gluon plasma which has been produced in high-energy heavy-ion collisions. The local parity-odd domains manifest themselves as charge separation along the magnetic field axis via the chiral magnetic effect. The experimental observation of charge separation has previously been reported for heavy-ion collisions at the top RHIC energies. In this Letter, we present the results of the beam-energy dependence of the charge correlations in Au+Au collisions at midrapidity for center-of-mass energies of 7.7, 11.5, 19.6, 27, 39, and 62.4 GeV from the STAR experiment. After background subtraction, the signal gradually reduces with …
Dielectron Mass Spectra From Au+Au Collisions At √SNn<=200 Gev, J. Kevin Adkins, Renee Fatemi, Wolfgang Korsch, Suvarna Ramachandran, G. Webb, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, E. C. Aschenauer
Dielectron Mass Spectra From Au+Au Collisions At √SNn<=200 Gev, J. Kevin Adkins, Renee Fatemi, Wolfgang Korsch, Suvarna Ramachandran, G. Webb, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, E. C. Aschenauer
Physics and Astronomy Faculty Publications
We report the STAR measurements of dielectron (e+e−) production at midrapidity (|yee|SNN=200 GeV. The measurements are evaluated in different invariant mass regions with a focus on 0.30–0.76 (ρ-like), 0.76–0.80 (ω-like), and 0.98–1.05 (ϕ-like) GeV/c2. The spectrum in the ω-like and ϕ-like regions can be well described by the hadronic cocktail simulation. In the ρ-like region, however, the vacuum ρ spectral function cannot describe the shape of the dielectron excess. In this range, an enhancement of 1.77±0.11(stat)±0.24(syst)±0.33(cocktail) is determined …
Initial Conditions In High-Energy Collisions, Elena Petreska
Initial Conditions In High-Energy Collisions, Elena Petreska
Dissertations, Theses, and Capstone Projects
This thesis is focused on the initial stages of high-energy collisions in the saturation regime. We start by extending the McLerran-Venugopalan distribution of color sources in the initial wave-function of nuclei in heavy-ion collisions. We derive a fourth-order operator in the action and discuss its relevance for the description of color charge distributions in protons in high-energy experiments. We calculate the dipole scattering amplitude in proton-proton collisions with the quartic action and find an agreement with experimental data. We also obtain a modification to the fluctuation parameter of the negative binomial distribution of particle multiplicities in proton-proton experiments. The result …
Jet Measurements With Proton-Proton Collisions At 7 Tev In Alice, Kevin Thompson
Jet Measurements With Proton-Proton Collisions At 7 Tev In Alice, Kevin Thompson
Physics
The CERN Large Hadron Collider (LHC) is the world's largest and most complex particle accelerator, with several experiments making discoveries at the frontiers of particle and nuclear physics. The ALICE experiment at the LHC explores the nature of the early Universe through relativistic nuclear collisions. The properties of the "quark-gluon" plasma of subatomic particles created can be investigated with particle jets, which are produced in the earliest moments of the collision. This paper will provide an overview of the analysis of particle jets in 7 TeV proton-proton collisions, which forms the baseline for understanding jet production in collisions of heavy …
Energy Dependence Of Moments Of Net-Proton Multiplicity Distributions At Rhic, L. Adamczyk, J. K. Adkins, S. Bültmann, I. Koralt, D. Plyku, Star Collaboration
Energy Dependence Of Moments Of Net-Proton Multiplicity Distributions At Rhic, L. Adamczyk, J. K. Adkins, S. Bültmann, I. Koralt, D. Plyku, Star Collaboration
Physics Faculty Publications
We report the beam energy (√ˢᴺᴺ = 7.7-200 GeV) and collision centrality dependence of the mean (M), standard deviation (σ), skewness (S), and kurtosis (κ) of the net-proton multiplicity distributions in Au + Au collisions. The measurements are carried out by the STAR experiment at midrapidity (|y| < 0.5) and within the transverse momentum range 0.4 < pT < 0.8 GeV/c in the first phase of the Beam Energy Scan program at the Relativistic Heavy Ion Collider. These measurements are important for understanding the quantum chromodynamic phase diagram. The products of the moments, Sσ and Kσ2, are sensitive to the correlation length of the hot and dense medium created in the collisions and are related to the ratios of baryon number susceptibilities of corresponding orders. The products of moments are found to have values significantly below the Skellam expectation and close to expectations based on independent …
Beam-Energy Dependence Of Charge Separation Along The Magnetic Field In Au + Au Collisions At Rhic, L. Adamczyk, J. K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, E. C. Aschenauer, G. S. Averichev, A. Banerjee, D. R. Beavis, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, H. Bichsel, M. Zyzak, Et Al., Star Collaboration
Beam-Energy Dependence Of Charge Separation Along The Magnetic Field In Au + Au Collisions At Rhic, L. Adamczyk, J. K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, E. C. Aschenauer, G. S. Averichev, A. Banerjee, D. R. Beavis, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, H. Bichsel, M. Zyzak, Et Al., Star Collaboration
Physics Faculty Publications
Local parity-odd domains are theorized to form inside a quark-gluon plasma which has been produced in high-energy heavy-ion collisions. The local parity-odd domains manifest themselves as charge separation along the magnetic field axis via the chiral magnetic effect. The experimental observation of charge separation has previously been reported for heavy-ion collisions at the top RHIC energies. In this Letter, we present the results of the beam-energy dependence of the charge correlations in Au+Au collisions at midrapidity for center-of-mass energies of 7.7, 11.5, 19.6, 27, 39, and 62.4 GeV from the STAR experiment. After background subtraction, the signal gradually reduces with …