Liberty University
University of Nevada, Las Vegas
Korea Advanced Institute of Science and Technology
California Polytechnic State University - San Luis Obispo
Phenix Upgrade: Novel Stripixel Detector For Heavy Quark Detection And Proton Spin Structure Measurements At Rhic Energies,
2017
Brookhaven National Laboratory
Phenix Upgrade: Novel Stripixel Detector For Heavy Quark Detection And Proton Spin Structure Measurements At Rhic Energies, R. Nouicer, Sergey Belikov, S. Bhagavatula, Paul Constantin, Nathan C. Grau, John C. Hill, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, Jan Rak, Marzia Rosati, F. K. Wohn, Et Al.
Craig Ogilvie
New design of silicon stripixel sensor has been developed at BNL for PHENIX upgrade. The sensor is a single-sided, DC-coupled, two-dimensional position sensitive device with good position resolution. This design is simpler for sensor fabrication and signal processing than the conventional double-sided strip sensor. HPK has produced pre-production stripixel sensors with thickness of 625 μm. The quality assurance tests show that the very low leakage current 0.12 nA per strip allows the use of the SVX4 chip. A long term stability test shows that the leakage current is stable over a long period of time. The study of the ...
Detailed Measurement Of The E(+)E(-) Pair Continuum In P Plus P And Au Plus Au Collisions At Root S(Nn)=200 Gev And Implications For Direct Photon Production,
2017
University of Colorado, Boulder
Detailed Measurement Of The E(+)E(-) Pair Continuum In P Plus P And Au Plus Au Collisions At Root S(Nn)=200 Gev And Implications For Direct Photon Production, Andrew Adare, Sergey Belikov, Paul Constantin, Nathan C. Grau, John C. Hill, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, H. Pei, Jan Rak, Marzia Rosati, S. Skutnik, Carla Vale, Et Al.
Craig Ogilvie
PHENIX has measured the e(+)e(-) pair continuum in root s(NN) = 200 GeV Au+Au and p+p collisions over a wide range of mass and transverse momenta. The e(+)e(-) yield is compared to the expectations from hadronic sources, based on PHENIX measurements. In the intermediate-mass region, between the masses of the phi and the J/psi meson, the yield is consistent with expectations from correlated c (c) over bar production, although other mechanisms are not ruled out. In the low-mass region, below the phi, the p+p inclusive mass spectrum is well described by known contributions from ...
Dihadron Azimuthal Correlations In Au+Au Collisions At Root S(Nn)=200 Gev,
2017
University of Colorado, Boulder
Dihadron Azimuthal Correlations In Au+Au Collisions At Root S(Nn)=200 Gev, Andrew Adare, Sergey Belikov, Paul Constantin, Nathan C. Grau, John C. Hill, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, H. Pei, Jan Rak, Marzia Rosati, S. Skutnik, Carla Vale, Et Al.
Craig Ogilvie
Azimuthal angle (Delta phi) correlations are presented for a broad range of transverse momentum (0.4 < p(T) < 10 GeV/c) and centrality (0-92%) selections for charged hadrons from dijets in Au+Au collisions at root s(NN) = 200 GeV. With increasing p(T), the away-side Delta phi distribution evolves from a broad and relatively flat shape to a concave shape, then to a convex shape. Comparisons with p + p data suggest that the away-side distribution can be divided into a partially suppressed "head" region centered at Delta phi similar to pi, and an enhanced "shoulder" region centered at Delta ...
Detailed Study Of High-P(T) Neutral Pion Suppression And Azimuthal Anisotropy In Au Plus Au Collisions At Root S(Nn) =200 Gev,
2017
Brookhaven National Laboratory
Detailed Study Of High-P(T) Neutral Pion Suppression And Azimuthal Anisotropy In Au Plus Au Collisions At Root S(Nn) =200 Gev, S. S. Adler, Sergey Belikov, S. Bhagavatula, Paul Constantin, Nathan C. Grau, John C. Hill, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, Jan Rak, Marzia Rosati, F. K. Wohn, Et Al.
Craig Ogilvie
Measurements of neutral pion (pi(0)) production at midrapidity in root s(NN)=200 GeV Au+Au collisions as a function of transverse momentum, p(T), collision centrality, and angle with respect to reaction plane are presented. The data represent the final pi(0) results from the PHENIX experiment for the first RHIC Au+Au run at design center-of-mass energy. They include additional data obtained using the PHENIX Level-2 trigger with more than a factor of 3 increase in statistics over previously published results for p(T)>6 GeV/c. We evaluate the suppression in the yield of high-p(T ...
Cold Nuclear Matter Effects On J/Psi Production As Constrained By Deuteron-Gold Measurements At Root S-Nn=200 Gev,
2017
University of Colorado, Boulder
Cold Nuclear Matter Effects On J/Psi Production As Constrained By Deuteron-Gold Measurements At Root S-Nn=200 Gev, Andrew Adare, Paul Constantin, Nathan C. Grau, John C. Hill, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, H. Pei, Jan Rak, Marzia Rosati, S. Skutnik, Carla Vale, F. K. Wohn, X. Zong, Et Al.
Craig Ogilvie
We present a new analysis of J/psi production yields in deuteron-gold collisions at root s(NN) =200 GeV using data taken from the PHENIX experiment in 2003 and previously published in S. S. Adler [Phys. Rev. Lett 96, 012304 (2006)]. The high statistics proton-proton J/psi data taken in 2005 are used to improve the baseline measurement and thus construct updated cold nuclear matter modification factors (R-dAu). A suppression of J/psi in cold nuclear matter is observed as one goes forward in rapidity (in the deuteron-going direction), corresponding to a region more sensitive to initial-state low-x gluons in ...
Charged Hadron Multiplicity Fluctuations In Au+Au And Cu+Cu Collisions From Root S-Nn = 22.5 To 200 Gev,
2017
University of Colorado, Boulder
Charged Hadron Multiplicity Fluctuations In Au+Au And Cu+Cu Collisions From Root S-Nn = 22.5 To 200 Gev, Andrew Adare, Sergey Belikov, Paul Constantin, Nathan C. Grau, John C. Hill, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, H. Pei, Jan Rak, Marzia Rosati, S. Skutnik, Carla Vale, F. K. Wohn, X. Zong, Et Al.
Craig Ogilvie
A comprehensive survey of event-by-event fluctuations of charged hadron multiplicity in relativistic heavy ions is presented. The survey covers Au+Au collisions at s(NN)=62.4 and 200 GeV, and Cu+Cu collisions at s(NN)=22.5,62.4, and 200 GeV. Fluctuations are measured as a function of collision centrality, transverse momentum range, and charge sign. After correcting for nondynamical fluctuations due to fluctuations in the collision geometry within a centrality bin, the remaining dynamical fluctuations expressed as the variance normalized by the mean tend to decrease with increasing centrality. The dynamical fluctuations are consistent with or ...
Common Suppression Pattern Of Eta And Pi(0) Mesons At High Transverse Momentum In Au Plus Au Collisions At Root Snn=200 Gev,
2017
Brookhaven National Laboratory
Common Suppression Pattern Of Eta And Pi(0) Mesons At High Transverse Momentum In Au Plus Au Collisions At Root Snn=200 Gev, S. S. Adler, Sergey Belikov, S. Bhagavatula, Paul Constantin, Nathan C. Grau, John C. Hill, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, Jan Rak, Marzia Rosati, F. K. Wohn, Et Al.
Craig Ogilvie
Inclusive transverse momentum spectra of eta mesons have been measured within p(T)=2-10 GeV/c at midrapidity by the PHENIX experiment in Au+Au collisions at root s(NN) = 200 GeV. In central Au+Au the eta yields are significantly suppressed compared to peripheral Au+Au, d+Au, and p+p yields scaled by the corresponding number of nucleon-nucleon collisions. The magnitude, centrality, and p(T) dependence of the suppression is common, within errors, for eta and pi(0). The ratio of eta to pi(0) spectra at high p(T) amounts to 0.40 < R-eta/pi(0)< 0 ...
Cross Section And Parity-Violating Spin Asymmetries Of W-+/- Boson Production In Polarized P Plus P Collisions At Root S=500 Gev,
2017
University of Colorado, Boulder
Cross Section And Parity-Violating Spin Asymmetries Of W-+/- Boson Production In Polarized P Plus P Collisions At Root S=500 Gev, Andrew Adare, Alan Dion, John C. Hill, Todd Kempel, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, H. Pei, Marzia Rosati, C. L. Silva, Feng Wei, Et Al.
Craig Ogilvie
Large parity-violating longitudinal single-spin asymmetries A(L)(e+) = 0.86(-0.14)(+0.30) and Ae(L)(e-) = 0.88(-0.71)(+0.12) are observed for inclusive high transverse momentum electrons and positrons in polarized p + p collisions at a center-of-mass energy of root s = 500 GeV with the PHENIX detector at RHIC. These e(+/-) come mainly from the decay of W-+/- and Z(0) bosons, and their asymmetries directly demonstrate parity violation in the couplings of the W-+/- to the light quarks. The observed electron and positron yields were used to estimate W-+/- boson production cross sections for ...
Dense-Medium Modifications To Jet-Induced Hadron Pair Distributions In Au+Au Collisions At Root(Nn)-N-S=200 Gev,
2017
Brookhaven National Laboratory
Dense-Medium Modifications To Jet-Induced Hadron Pair Distributions In Au+Au Collisions At Root(Nn)-N-S=200 Gev, S. S. Adler, Sergey Belikov, S. Bhagavatula, Paul Constantin, Nathan C. Grau, John C. Hill, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, Jan Rak, Marzia Rosati, F. K. Wohn, Et Al.
Craig Ogilvie
Azimuthal correlations of jet-induced high-p(T) charged hadron pairs are studied at midrapidity in Au+Au collisions at root s(NN)=200 GeV. The distribution of jet-associated partner hadrons (1.0 < p(T)< 2.5 GeV/c) per trigger hadron (2.5 < p(T)< 4.0 GeV/c) is found to vary with collision centrality, in both shape and yield, indicating a significant effect of the nuclear collision medium on the jet fragmentation process.
Correlated Production Of P And P¯ In Au+Au Collisions At √Snn=200 Gev,
2017
University of Colorado, Boulder
Correlated Production Of P And P¯ In Au+Au Collisions At √Snn=200 Gev, Andrew Adare, Sergey Belikov, Paul Constantin, Nathan C. Grau, John C. Hill, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, H. Pei, Jan Rak, Marzia Rosati, S. Skutnik, Carla Vale, Et Al.
Craig Ogilvie
Correlations between p and p¯ at transverse momenta typical of enhanced baryon production in Au + Au collisions are reported. The PHENIX experiment has measured same and opposite sign baryon pairs in Au + Au collisions at √sNN=200 GeV. Correlated production of p and p¯ with the trigger particle from the range 2.5 < pT <4.0 GeV/c and the associated particle with 1.8 < pT < 2.5 GeV/c is observed to be nearly independent of the centrality of the collisions. Same sign pairs show no correlation at any centrality. The conditional yield of mesons triggered by baryons (and ...
Azimuthal Correlations Of Electrons From Heavy-Flavor Decay With Hadrons In P Plus P And Au Plus Au Collisions At Root S(Nn)=200 Gev,
2017
University of Colorado, Boulder
Azimuthal Correlations Of Electrons From Heavy-Flavor Decay With Hadrons In P Plus P And Au Plus Au Collisions At Root S(Nn)=200 Gev, Andrew Adare, John C. Hill, Todd Kempel, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, H. Pei, Marzia Rosati, Alexey Yu. Semenov, Carla Vale, Feng Wei, Et Al.
Craig Ogilvie
Measurements of electrons from the decay of open-heavy-flavor mesons have shown that the yields are suppressed in Au+Au collisions compared to expectations from binary-scaled p+p collisions. These measurements indicate that charm and bottom quarks interact with the hot dense matter produced in heavy-ion collisions much more than expected. Here we extend these studies to two-particle correlations where one particle is an electron from the decay of a heavy-flavor meson and the other is a charged hadron from either the decay of the heavy meson or from jet fragmentation. These measurements provide more detailed information about the interactions between ...
Centrality Dependence Of Charged Hadron Production In Deuteron Plus Gold And Nucleon Plus Gold Collisions At Root S-Nn=200 Gev,
2017
Brookhaven National Laboratory
Centrality Dependence Of Charged Hadron Production In Deuteron Plus Gold And Nucleon Plus Gold Collisions At Root S-Nn=200 Gev, S. S. Adler, Sergey Belikov, Paul Constantin, Nathan C. Grau, John C. Hill, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, H. Pei, Jan Rak, Marzia Rosati, F. K. Wohn, X. Zong, Et Al.
Craig Ogilvie
We present transverse momentum (p(T)) spectra of charged hadrons measured in deuteron-gold and nucleon-gold collisions at root s(NN)=200 GeV for four centrality classes. Nucleon-gold collisions were selected by tagging events in which a spectator nucleon was observed in one of two forward rapidity detectors. The spectra and yields were investigated as a function of the number of binary nucleon-nucleon collisions, nu, suffered by deuteron nucleons. A comparison of charged particle yields to those in p+p collisions show that yield per nucleon-nucleon collision saturates with nu for high momentum particles. We also present the charged hadron to ...
Azimuthal Angle Correlations For Rapidity Separated Hadron Pairs In D+Au Collisions At Root S(Nn)=200 Gev,
2017
Brookhaven National Laboratory
Azimuthal Angle Correlations For Rapidity Separated Hadron Pairs In D+Au Collisions At Root S(Nn)=200 Gev, S. S. Adler, Sergey Belikov, Paul Constantin, Nathan C. Grau, John C. Hill, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, H. Pei, Jan Rak, Marzia Rosati, F. K. Wohn, X. Zong, Et Al.
Craig Ogilvie
Deuteron-gold (d+Au) collisions at the Relativistic Heavy Ion Collider provide ideal platforms for testing QCD theories in dense nuclear matter at high energy. In particular, models suggesting strong saturation effects for partons carrying small nucleon momentum fraction (x) predict modifications to jet production at forward rapidity (deuteron-going direction) in d+Au collisions. We report on two-particle azimuthal angle correlations between charged hadrons at forward/backward (deuteron/gold going direction) rapidity and charged hadrons at midrapidity in d+Au and p+p collisions at root s(NN)=200 GeV. Jet structures observed in the correlations are quantified in terms of ...
System Size And Energy Dependence Of Jet-Induced Hadron Pair Correlation Shapes In Cu+Cu And Au+Au Collisions At Root S-Nn 200 And 62.4 Gev,
2017
University of Colorado, Boulder
System Size And Energy Dependence Of Jet-Induced Hadron Pair Correlation Shapes In Cu+Cu And Au+Au Collisions At Root S-Nn 200 And 62.4 Gev, Andrew Adare, Sergey Belikov, Paul Constantin, Nathan C. Grau, John C. Hill, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, H. Pei, Jan Rak, Marzia Rosati, S. Skutnik, Carla Vale, F. K. Wohn, X. Zong, Et Al.
Craig Ogilvie
We present azimuthal angle correlations of intermediate transverse momentum (1-4 GeV/c) hadrons from dijets in Cu+Cu and Au+Au collisions at root s(NN)=62.4 and 200 GeV. The away-side dijet induced azimuthal correlation is broadened, non-Gaussian, and peaked away from Delta phi=pi in central and semicentral collisions in all the systems. The broadening and peak location are found to depend upon the number of participants in the collision, but not on the collision energy or beam nuclei. These results are consistent with sound or shock wave models, but pose challenges to Cherenkov gluon radiation models.
Transverse Momentum Dependence Of Eta Meson Suppression In Au Plus Au Collisions At Root S(Nn)=200 Gev,
2017
University of Colorado, Boulder
Transverse Momentum Dependence Of Eta Meson Suppression In Au Plus Au Collisions At Root S(Nn)=200 Gev, Andrew Adare, John C. Hill, Todd Kempel, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, H. Pei, Marzia Rosati, Alexey Yu. Semenov, Carla Vale, Feng Wei, Et Al.
Craig Ogilvie
New measurements by the PHENIX experiment at the Relativistic Heavy Ion Collider for. production at midrapidity as a function of transverse momentum ((PT)) and collision centrality in root s(NN) = 200 GeV Au + Au and p + p collisions are presented. They indicate nuclear modification factors (R-AA) which are similar in both magnitude and trend to those found in earlier pi(0) measurements. Linear fits to R-AA as a function of (PT) in 5-20 GeV/c show that the slope is consistent with zero within two standard deviations at all centralities, although a slow rise cannot be excluded. Having different statistical ...
Systematic Studies Of Elliptic Flow Measurements In Au Plus Au Collisions At S(Nn)=200 Gev,
2017
Joint Institute for Nuclear Research
Systematic Studies Of Elliptic Flow Measurements In Au Plus Au Collisions At S(Nn)=200 Gev, S. Afanasiev, Sergey Belikov, Paul Constantin, Nathan C. Grau, John C. Hill, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, H. Pei, Jan Rak, Marzia Rosati, S. Skutnik, Carla Vale, Et Al.
Craig Ogilvie
We present inclusive charged hadron elliptic flow (v(2)) measured over the pseudorapidity range vertical bar eta vertical bar < 0.35 in Au+Au collisions at s(NN)=200 GeV. Results for v(2) are presented over a broad range of transverse momentum (p(T)=0.2-8.0 GeV/c) and centrality (0-60%). To study nonflow effects that are correlations other than collective flow, as well as the fluctuations of v(2), we compare two different analysis methods: (1) the event-plane method from two independent subdetectors at forward (vertical bar eta vertical bar=3.1-3.9) and beam (vertical bar eta vertical bar>6.5) pseudorapidities and (2) the two-particle cumulant method extracted using correlations between particles detected at midrapidity. The two event-plane results are consistent within systematic uncertainties over the measured p(T) and in centrality 0-40%. There is at most a 20% difference in the v(2) between the two event-plane methods in peripheral (40-60%) collisions. The comparisons between the two-particle cumulant results and the standard event-plane measurements are discussed.
Systematic Studies Of The Centrality And Root S(Nn) Dependence Of The De(T)/D Eta And Dn(Ch)/D Eta In Heavy Ion Collisions At Midrapidity,
2017
Brookhaven National Laboratory
Systematic Studies Of The Centrality And Root S(Nn) Dependence Of The De(T)/D Eta And Dn(Ch)/D Eta In Heavy Ion Collisions At Midrapidity, S. S. Adler, Sergey Belikov, S. Bhagavatula, Paul Constantin, Nathan C. Grau, John C. Hill, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, Jan Rak, Marzia Rosati, F. K. Wohn, Et Al.
Craig Ogilvie
The PHENIX experiment at the relativistic heavy ion collider (RHIC) has measured transverse energy and charged particle multiplicity at midrapidity in Au+Au collisions at center-of-mass energies √sNN=19.6,130, and 200GeV as a function of centrality. The presented results are compared to measurements from other RHIC experiments and experiments at lower energies. The √sNN dependence of dET/dη and dNch/dη per pair of participants is consistent with logarithmic scaling for the most central events. The centrality dependence of dET/dη and dNch/dη is similar at all measured incident energies. At RHIC energies, the ratio of transverse ...
Transverse Momentum And Centrality Dependence Of Dihadron Correlations In Au Plus Au Collisions At Root S(Nn)=200 Gev: Jet Quenching And The Response Of Partonic Matter,
2017
University of Colorado, Boulder
Transverse Momentum And Centrality Dependence Of Dihadron Correlations In Au Plus Au Collisions At Root S(Nn)=200 Gev: Jet Quenching And The Response Of Partonic Matter, Andrew Adare, Sergey Belikov, Paul Constantin, Nathan C. Grau, John C. Hill, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, H. Pei, Jan Rak, Marzia Rosati, S. Skutnik, Carla Vale, Et Al.
Craig Ogilvie
Azimuthal angle (Delta phi) correlations are presented for charged hadrons from dijets for 0.4 < p(T)< 10 GeV/c in Au+Au collisions at root s(NN)=200 GeV. With increasing p(T), the away-side distribution evolves from a broad and relatively flat shape to a concave shape, then to a convex shape. Comparisons to p+p data suggest that the away-side can be divided into a partially suppressed "head" region centered at Delta phi similar to pi and an enhanced "shoulder" region centered at Delta phi similar to pi +/- 1.1. The p(T) spectrum for the head ...
Suppression Pattern Of Neutral Pions At High Transverse Momentum In Au Plus Au Collisions At Root S-Nn=200 Gev And Constraints On Medium Transport Coefficients,
2017
University of Colorado, Boulder
Suppression Pattern Of Neutral Pions At High Transverse Momentum In Au Plus Au Collisions At Root S-Nn=200 Gev And Constraints On Medium Transport Coefficients, Andrew Adare, Sergey Belikov, Paul Constantin, Nathan C. Grau, John C. Hill, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, H. Pei, Jan Rak, Marzia Rosati, S. Skutnik, Carla Vale, Et Al.
Craig Ogilvie
For Au + Au collisions at 200 GeV, we measure neutral pion production with good statistics for transverse momentum, p(T), up to 20 GeV/c. A fivefold suppression is found, which is essentially constant for 5 < p(T) < 20 GeV/c. Experimental uncertainties are small enough to constrain any model-dependent parametrization for the transport coefficient of the medium, e. g., <(q) over cap > in the parton quenching model. The spectral shape is similar for all collision classes, and the suppression does not saturate in Au + Au collisions.
Photon-Hadron Jet Correlations In P Plus P And Au Plus Au Collisions At S(Nn)=200 Gev,
2017
University of Colorado, Boulder
Photon-Hadron Jet Correlations In P Plus P And Au Plus Au Collisions At S(Nn)=200 Gev, Andrew Adare, Sergey Belikov, Paul Constantin, Nathan C. Grau, John C. Hill, Todd Kempel, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, H. Pei, Jan Rak, Marzia Rosati, Alexey Yu. Semenov, S. Skutnik, Carla Vale, Feng Wei, Et Al.
Craig Ogilvie
We report the observation at the Relativistic Heavy Ion Collider of suppression of back-to-back correlations in the direct photon+jet channel in Au+Au relative to p+p collisions. Two-particle correlations of direct photon triggers with associated hadrons are obtained by statistical subtraction of the decay photon-hadron (gamma-h) background. The initial momentum of the away-side parton is tightly constrained, because the parton-photon pair exactly balance in momentum at leading order in perturbative quantum chromodynamics, making such correlations a powerful probe of the in-medium parton energy loss. The away-side nuclear suppression factor, I-AA, in central Au+Au collisions, is 0.32 ...
