Download or read book Two Particle Correlations with Direct Photon and pi 0 Triggers in 200 GeV P p and Au Au Collisions written by Matthew Nguyen and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Jet like Correlations with Direct photon and Neutral pion Triggers at mml written by and published by . This book was released on 2016 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Azimuthal correlations of charged hadrons with direct-photon ([gamma]dir) and neutral-pion ([pi]0) trigger particles are analyzed in central Au+Au and minimum-bias p+p collisions at $\sqrt{s}$$_{NN}$ =200 GeV in the STAR experiment. The charged-hadron per-trigger yields at mid-rapidity from central Au+Au collisions are compared with p+p collisions to quantify the suppression in Au+Au collisions. The suppression of the away-side associated-particle yields per [gamma]dir trigger is independent of the transverse momentum of the trigger particle (P$trig\atop{T}$, whereas the suppression is smaller at low transverse momentum of the associated charged hadrons (P$assoc\atop{T}$). Within uncertainty, similar levels of suppression are observed for [gamma]dir and [pi]0 triggers as a function of zT ($\equiv$ P$assoc\atop{T}$$/$P$trig\atop{T}$). The results are compared with energy-loss-inspired theoretical model predictions. In conclusion, our studies support previous conclusions that the lost energy reappears predominantly at low transverse momentum, regardless of the trigger energy.

Download or read book Properties of Fragmentation Photons in P p Collisions at 200 GeV Center of Mass Energy written by Janette Alice Hanks and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of two-particle correlations coupled with a sophisticated method for identifying and removing decay photons has made it possible to further study the jet properties of these fragmentation photons, in the form of pout and root mean square jT. These results will help to constrain both the underlying theoretical description of direct photon production in p + p, and modifications expected in heavy ion collisions.

Download or read book Les 600 ans de l Universit jagellonne written by and published by . This book was released on 1964 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Photon and Neutral Pi 0 Production in 197 Au 197 Au Collisions at Sqrt S NN written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Inclusive transverse momentum spectra of photons and[pi][sup 0]s at mid-rapidity are studied as a function of collision centrality for[sup 197]Au+[sup 197]Au collisions at[radical]s[sub NN]= 130 GeV. Photon pair conversions have been reconstructed from charged tracks measured by the main Time Project Chamber of the STAR experiment at the RHIC heavy ion facility. The transverse momentum resolution of photons with this method is estimated to be[Delta]p[sub t]/p[sub t]= 2% at 0.125 GeV/c and 5% at 2.5 GeV/c. Photon spectra were measured up to a transverse momentum of 2.4 GeV/c between[+-] 0.5 units of rapidity. The dominant photon production mechanism, the[pi][sup 0][yields][gamma][gamma] decay, was measured between 0.25-2.5 GeV/c and[+-] 1 units of rapidity. Spectra are reported for the top 11%, 11-34% and 34-85% centrality classes. It was observed that in mid-central and central collisions the relative contribution of the[pi][sup 0][yields][gamma][gamma] decay to the inclusive photon spectrum decreases above a transverse momentum of 1.65 GeV/c. In central collisions the magnitude of the decrease from p[sub t]= 1.65 GeV/c to 2.4 GeV/c is 20%. It is unlikely that contributions from other[pi][sup 0] decay channels and other particle decays fully explain this decrease. The centrality dependence on the shapes of the[pi][sup 0] spectra was analyzed with Boltmann and Bose-Einstein functions. In the transverse momentum windows of the spectra, the extracted temperatures are near 0.295 GeV. These temperatures are substantially higher than those extracted from[pi][sup[+-]] spectra in a lower range of transverse momentum. This is an indication that the shapes of the pion spectra deviate from purely exponential shapes.

Download or read book Pi Spectra and Correlations from 16O Au Collisions at 200 A GeV written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The production of neutral pions by the interaction of 200 A GeV proton and 16O projectiles with an Au target has been studied for 1.5 d"[eta] d"2.1. Transverse momentum spectra have been measured between 0.4 GeV/c and 2.8 GeV/c and their dependence on the centrality of the reaction has been investigated. The peripheral spectrum shows a marked change of slope with a hard component starting at about 1.8 GeV/c in close similarity to p + p data. Preliminary analyses of photon data yield an excess over known photon sources for central data which is absent for peripheral reactions. Correlations of 4 photons representing neutral pions have been studied in ultrarelativistic heavy ion collisions. Data were taken in the WA80 experiment at the CERN-SPS with a 200 A GeV oxygen beam. The .pi.° are detected via their decay photons with a high-granularity lead glass array. Special features of interferometry using neutral pions will be discussed. The extracted preliminary parameters for high p/sub T/ pions emitted near midrapidity in O + Au collisions lead to rather small effective source sizes. 23 refs., 8 figs.

Download or read book Inclusive Pi 0 Eta and Direct Photon Production at High Transverse Momentum in P p and D Au Collisions at Sqrt s NN written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report a measurement of high-p{sub T} inclusive [pi]°, [eta], and direct photon production in p + p and d + Au collisions at √s{sub NN} = 200 GeV at midrapidity (0

Download or read book Two Particle Correlations in Au Au Collisions at 11 5 GeV c Per Nucleon written by Thongbay Vongpaseuth and published by . This book was released on 1999 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Two Particle Interferometry of 200 GeV Au Au Collisions at PHENIX written by M. Heffner and published by . This book was released on 2004 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The PHENIX experiment has measured pion-pion, kaon-kaon, and proton-proton correlations in Au+Au collisions at {radical}S{sub NN} = 200GeV. The correlations are fit to extract radii using both the Bowler Coulomb correction and full calculation of the two-particle wave function. The resulting radii are similar for all three species and decrease with increasing k{sub t} as expected for collective flow. The R{sub out} and R{sub side} radii are approximately equal indicating a short emission duration.

Download or read book Strange Particle Production in Awayside Jets in High PT pi 0 and Direct Photon Triggered Events in pi Be Cu Interactions at 515 GeV written by John Bacigalupi and published by . This book was released on 1996 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Centrality Dependence of Two particle Correlations in Relativistic Heavy Ion Collisions written by Youngsoo Park and published by . This book was released on 2009 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results on the centrality dependence of two-particle correlations in Au+Au collisions at ... 200GeV are presented. A particular focus is devoted to investigating any anomalous behavior in the centrality dependence of correlation functions, as previous results suggest existence of such tendencies around Npart [approx.] 50. Correlation functions are calculated for a wide kinematic region of ... from data obtained by the PHOBOS experiment at RHIC. The RHIC layout and the PHOBOS detector setup is discussed. Data acquisition method employed by the PHOBOS experiment, data processing procedures and event selection criteria are presented. The two-particle correlation function is defined and calculation procedures are described. Decomposition analysis is explained as the fit function and the constituting components are introduced. Analysis results for correlation functions and fits are presented. The results suggest that in the kinematic region covered by the analysis of this thesis, no anomalous trends in component behavior exists.

Download or read book Detailed Analysis of Two Particle Correlations in Central Pb Au Collisions at 158 GeV Per Nucleon written by Dariusz Antończyk and published by . This book was released on 2006 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Correlations with Non Photonic Electrons in 200 GeV Au Au Collisions in STAR written by Lloyd Edward Dunkelberger and published by . This book was released on 2016 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: At sufficiently high temperatures and densities quarks and gluons exist in a deconfined state called Quark Gluon Plasma (QGP). QGP existed in the Universe shortly after the Big Bang, and today is created in accelerator based experiments which collide heavy nuclei at high energies. Results from these experiments point to a hot, dense and strongly interacting state of deconfined quarks and gluons. The study of heavy flavor probes (those originating from $c$ and $b$ quarks) is an active area of research in heavy ion collisions. Heavy quarks are produced in the initial hard scatterings of collisions and thus are sensitive to the entire evolution of the medium. They also potentially have different sensitivity to medium induced energy loss compared to light flavors. This dissertation investigates the interactions of heavy flavor quarks with the medium by studying correlations between electrons from heavy flavor decays and hadrons. At high transverse momentum, the direction of the electron is highly correlated with the direction of the parent heavy flavor meson. We look for evidence of energy loss in the QGP as well as jet induced effects on the medium. We present electron-hadron correlations from Au+Au collisions in a wide range of centrality bins as well as correlations from p+p. The datasets used are the best currently available due to high statistics and low material in the detector. We also investigate the dependence on the orientation of the trigger particle to the event plane to look for path length dependent effects on the correlation as well as non-flow contributions to electron electron $v_2$.

Download or read book Fluctuations in Multi particle Production and gamma pi 0 ratios in 200 A GeV 16O Au Collisions written by I. Lund and published by . This book was released on 1989 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Energy Physics Index written by and published by . This book was released on 1990 with total page 786 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Two particle Correlations in Angular and Momentum Space in Heavy Ion Collisions at STAR written by Elizabeth Wingfield Oldag and published by . This book was released on 2013 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: For over a decade studies of the strong interaction in extremely dense nuclear environments have been done at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. It is hypothesized that colliding two beams of Au nuclei at relativistic speeds creates an environment of hot dense nuclear matter where the quarks and gluons inside the nucleus, which are normally confined within the protons and neutrons, become deconfined into a soup called the quark-gluon plasma. Since direct observation of this short-lived phase is impossible, many sophisticated analysis techniques attempt to study the early interactions via the final state particles. What has emerged from analyses of the data are two, contradictory paradigms for understanding the results. On the one hand the colliding quarks and gluons are thought to strongly interact and reach thermal equilibrium. The other view is that primary parton-parton scattering leads directly to jet fragmentation with little effect from re-scattering. It is in principle possible to distinguish and perhaps falsify one or both of these models of relativistic heavy ion collisions via the analysis of two-particle correlations among all charged particles produced in [mathematical symbols] = 200 GeV Au+Au collisions at the STAR experiment at RHIC. This dissertation presents studies of two-particle correlations, whose derivation can be traced back to Pearson's correlation coefficient, in transverse momentum and angular space. In momentum space a broad peak is observed extending from 0.5-4.0 GeV/c which, as a function of nuclear overlap, remains at a fixed position while monotonically increasing in amplitude. Comparisons to theoretical models suggests this peak is from jet fragmentation. In a complementary study the momentum distribution of correlations in ([eta],[phi]) space is investigated. The momentum distribution of correlated pairs that contribute to the peak near the origin, commonly associated with jet fragmentation, is peaked around 1.5 GeV/c and does not soften with increased centrality. These measurements present important aspects of the available six dimensional correlation space and provide definitive tests for theoretical models. Preliminary findings do not appear to support the hypothesis of a strongly interacting QGP where back-to-back jets are expected to be significantly suppressed.

Download or read book PHENIX Results on Centrality Dependence of Yields and Correlations in D Plus Au Collisions at Root S NN written by and published by . This book was released on 2016 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: PHENIX has measured the transverse momentum (pT) spectra and two particle angular correlations for high pT particles in d+Au collisions at psNN=200 GeV using the RHIC Year-2008 run data. The azimuthal angle correlations for two particles with a large rapidity gap exhibit a ridge-like structure. Using the pi-0s reconstructed in the EMCal, we have successfully extended the pT reach of the correlation up to 8 GeV/c. We find that the azimuthal anisotropy of hadrons found at low pT persists up to 6 GeV/c with a significant centrality and pT dependence, similar to what was observed in A+A collisions.