Bulletin of the American Physical Society
2015 Annual Spring Meeting of the APS Ohio-Region Section
Volume 60, Number 3
Friday–Saturday, March 27–28, 2015; Kent, Ohio
Session E3: Heavy Ion Experiment I |
Hide Abstracts |
Chair: Mike Lisa, Ohio State University Room: KSU Student Center 315 |
Saturday, March 28, 2015 10:10AM - 10:25AM |
E3.00001: Jet production in pp, pA and AA collisions Rosi Reed Particle jets, formed when a hard scattered parton fragments into a ``jet'' of hadrons, are an ideal probe of the medium formed in heavy-ion collisions. At LHC energies, the larger parton production cross-section compared to RHIC, allowed jets to be reconstructed over a much wider kinematic range. As the cross-section for the underlying soft-background did not increase at the same rate, this allowed a multitude of jet reconstruction techniques to be developed. In this talk, jet spectra from 2.76 TeV Pb-Pb and pp collisions will be presented, along with the techniques required to remove the underlying event in heavy ion collisions. In particular, the centrality and event-plane dependence of the measured spectra and the background will be discussed. The reconstruction and correction procedures for jets will be shown. Results from Pb-Pb events will be compared to the baseline pp and p-Pb results, which allow the effect of the initial state and cold nuclear matter effects to be disentangled from hot medium effects. A comparison of the jet nuclear modification factor from both the LHC and RHIC will be made. [Preview Abstract] |
Saturday, March 28, 2015 10:25AM - 10:40AM |
E3.00002: A New Observable for Di-Jet Di-hadron Jet Suppression for Small Collision Systems Justin Frantz In Relativistic Heavy Ion collisions with at least one small nuclear species type, like p$+$A collisions, effects of jet suppression from jet energy loss may be expected to accompany the signals seen in hydrodynamic flow which seem to indicate the presence of QGP. We present a new two particle correlations observable, and discuss its systematics and interpretations from model studies, as well as comparison to existing from d$+$Au collision measurements at RHIC. [Preview Abstract] |
Saturday, March 28, 2015 10:40AM - 10:55AM |
E3.00003: $p-p$, $p-\bar{p}$, and $\bar{p}-\bar{p}$ Femtoscopic Correlations in the RHIC Beam Energy Scan in STAR Andrew Peterson In heavy-ion collisions, observables are known to differ significantly for $p$ and $\bar{p}$. This may purely be an effect of differing emission region geometry for $p$'s and $\bar{p}$'s within the hot, dense matter produced in heavy-ion collisions with flow. Femtoscopic analysis is sensitive to the size of the emission region of pairs of particles and, for non-identical species pairs, the separation between their emission regions. Qualitative predictions for the separation between $p$ and $\bar{p}$ emission regions in the transverse plane have been made that contradict in regards to which species comes from deeper within the source. We present femtoscopic correlation functions, decomposed in Spherical Harmonics, from identified pairs of protons and anti-protons measured in the STAR detector during the RHIC Beam Energy Scan. [Preview Abstract] |
Saturday, March 28, 2015 10:55AM - 11:10AM |
E3.00004: Azimuthally-sensitive two-pion interferometry in U+U collisions at STAR John Campbell Collisions between uranium nuclei have been produced at the Relativistic Heavy Ion Collider and measured in the STAR detector. Due to the prolate deformation of the nuclei, fully overlapping U+U collisions offer the opportunity to produce highly anisotropic participant zones, similar in shape to mid-central Au+Au collisions, but with twice the size. The larger fireball should be characterized by a long lifetime over which it collectively evolves from its non-trivial initial shape to its final one. The final-state anisotropy of zero-spectator collisions in momentum space (v$_{n}$) is under study. We will present an analysis of the coordinate-space anisotropy, measured via azimuthally-sensitive two-pion interferometry (``HBT'') of full-overlap collisions, performed differentially via the reduced flow parameter q$_{2}$ in U+U collisions at $\sqrt{s_{NN}}$ 193 GeV. [Preview Abstract] |
Saturday, March 28, 2015 11:10AM - 11:25AM |
E3.00005: Methods for Determining Elliptic Flow of Isolated Photons and $\pi_{0}$'s Tyler Danley We present methods for measurements of second order flow coefficients and derivations of reaction plane dependent efficiencies of isolated photons and $\pi^{0}$'s in relativistic heavy ion collisions. The method involves isolation cuts similar to those used in direct photon identification where the energy is summed inside an angular cone and cut if greater than a threshold energy. We show that this will result in a reaction plane dependent efficiency. We derive and verify azimuthal single and two particle correlation functions, including this efficiency, up to harmonic second order. We show that the standard $v_{2}$ extraction method is only sensitive to an effective $v_{2}$, which includes the sum of true $v_{2}$ and the $v_{2}$ of the isolation efficiency, which is generally negative. We will also present the status of applying these methods to PHENIX $\sqrt{s_{NN}} = 200 GeV$ Au+Au data. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700