Centrality Dependence Of Low Momentum Direct Photon Production In Math Mrow Mi Au Mi Mo Mo Mi Au Mi Mrow Math Collisions At Math Mrow Msqrt Msub Mi Mi Mrow Mi Mathvariant
DOWNLOAD
Download Centrality Dependence Of Low Momentum Direct Photon Production In Math Mrow Mi Au Mi Mo Mo Mi Au Mi Mrow Math Collisions At Math Mrow Msqrt Msub Mi Mi Mrow Mi Mathvariant PDF/ePub or read online books in Mobi eBooks. Click Download or Read Online button to get Centrality Dependence Of Low Momentum Direct Photon Production In Math Mrow Mi Au Mi Mo Mo Mi Au Mi Mrow Math Collisions At Math Mrow Msqrt Msub Mi Mi Mrow Mi Mathvariant book now. This website allows unlimited access to, at the time of writing, more than 1.5 million titles, including hundreds of thousands of titles in various foreign languages. If the content not found or just blank you must refresh this page
Centrality Dependence Of Low Momentum Direct Photon Production In Math Mrow Mi Au Mi Mo Mo Mi Au Mi Mrow Math Collisions At Math Mrow Msqrt Msub Mi Mi Mrow Mi Mathvariant
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2015
Centrality Dependence Of Low Momentum Direct Photon Production In Math Mrow Mi Au Mi Mo Mo Mi Au Mi Mrow Math Collisions At Math Mrow Msqrt Msub Mi Mi Mrow Mi Mathvariant written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2015 with categories.
The PHENIX experiment at RHIC has measured the centrality dependence of the direct photon yield from Au+Au collisions at √sNN = 200 GeV down to pT = 0.4 GeV/c. Photons are detected via photon conversions to e+e− pairs and an improved technique is applied that minimizes the systematic uncertainties that usually limit direct photon measurements, in particular at low pT . We find an excess of direct photons above the Ncoll-scaled yield measured in p+p collisions. This excess yield is well described by an exponential distribution with an inverse slope of about 240 MeV/c in the pT range from 0.6-2.0 GeV/c. In this study, while the shape of the pT distribution is independent of centrality within the experimental uncertainties, the yield increases rapidly with increasing centrality, scaling approximately with N [alpha] part, where [alpha] = 1.38±0.03(stat)±0.07(syst).
Centrality Rapidity And Transverse Momentum Dependence Of Isolated Prompt Photon Production In Lead Lead Collisions At Math Mrow Msqrt Msub Mi Mi Mrow Mi N Mi Mi N Mi Mrow Msub Msqrt Mo
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2016
Centrality Rapidity And Transverse Momentum Dependence Of Isolated Prompt Photon Production In Lead Lead Collisions At Math Mrow Msqrt Msub Mi Mi Mrow Mi N Mi Mi N Mi Mrow Msub Msqrt Mo written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2016 with categories.
In this study, prompt photon production in √sNN = 2.76-TeV Pb+Pb collisions has been measured by the ATLAS experiment at the Large Hadron Collider using data collected in 2011 with an integrated luminosity of 0.14 nb-1. Inclusive photon yields, scaled by the mean nuclear thickness function, are presented as a function of collision centrality and transverse momentum in two pseudorapidity intervals,
Centrality Dependence Of Particle Production In Math Mi P Mi Mo Mo Mi Pb Mi Math Collisions At Math Mrow Msqrt Msub Mi Mi Mi Mathvariant
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2015
Centrality Dependence Of Particle Production In Math Mi P Mi Mo Mo Mi Pb Mi Math Collisions At Math Mrow Msqrt Msub Mi Mi Mi Mathvariant written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2015 with categories.
Here, we report measurements of the primary charged-particle pseudorapidity density and transverse momentum distributions in p-Pb collisions at √sNN = 5.02TeV and investigate their correlation with experimental observables sensitive to the centrality of the collision. Centrality classes are defined by using different event-activity estimators, i.e., charged-particle multiplicities measured in three different pseudorapidity regions as well as the energy measured at beam rapidity (zero degree). The procedures to determine the centrality, quantified by the number of participants (Npart) or the number of nucleon-nucleon binary collisions (Ncoll) are described. We show that, in contrast to Pb-Pb collisions, in p-Pb collisions large multiplicity fluctuations together with the small range of participants available generate a dynamical bias in centrality classes based on particle multiplicity. We propose to use the zero-degree energy, which we expect not to introduce a dynamical bias, as an alternative event-centrality estimator. Based on zero-degree energy-centrality classes, the Npart dependence of particle production is studied. Under the assumption that the multiplicity measured in the Pb-going rapidity region scales with the number of Pb participants, an approximate independence of the multiplicity per participating nucleon measured at mid-rapidity of the number of participating nucleons is observed. Furthermore, at high-pT the p-Pb spectra are found to be consistent with the pp spectra scaled by Ncoll for all centrality classes. Our results represent valuable input for the study of the event-activity dependence of hard probes in p-Pb collisions and, hence, help to establish baselines for the interpretation of the Pb-Pb data.
Centrality Dependence Of Identified Particle Elliptic Flow In Relativistic Heavy Ion Collisions At Math Mrow Msqrt Msub Mi Mi Mrow Mi N Mi Mi N Mi Mrow Msub Msqrt Mo
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2016
Centrality Dependence Of Identified Particle Elliptic Flow In Relativistic Heavy Ion Collisions At Math Mrow Msqrt Msub Mi Mi Mrow Mi N Mi Mi N Mi Mrow Msub Msqrt Mo written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2016 with categories.
Here, elliptic flow (v2) values for identified particles at midrapidity in Au + Au collisions measured by the STAR experiment in the Beam Energy Scan at the Relativistic Heavy Ion Collider at √sNN = 7.7-62.4 GeV are presented for three centrality classes. The centrality dependence and the data at √sNN = 14.5 GeV are new. Except at the lowest beam energies, we observe a similar relative v2 baryon-meson splitting for all centrality classes which is in agreement within 15% with the number-of-constituent quark scaling. The larger v2 for most particles relative to antiparticles, already observed for minimum bias collisions, shows a clear centrality dependence, with the largest difference for the most central collisions. Also, the results are compared with a multiphase transport (AMPT) model and fit with a blast wave model.
Onset Of Radial Flow In Math Mrow Mi P Mi Mo Mo Mi P Mi Mrow Math Collisions
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2015
Onset Of Radial Flow In Math Mrow Mi P Mi Mo Mo Mi P Mi Mrow Math Collisions written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2015 with categories.
It has been debated for decades whether hadrons emerging from p+p collisions exhibit collective expansion. The signal of the collective motion in p+p collisions is not as clear as in heavy-ion collisions because of the low multiplicity and large fluctuation in p+p collisions. Tsallis Blast-Wave (TBW) model is a thermodynamic approach, introduced to handle the overwhelming correlation and fluctuation in the hadronic processes. We have systematically studied the identified particle spectra in p+p collisions from RHIC to LHC using TBW and found no appreciable radial flow in p+p collisions below √s = 900 GeV. At LHC higher energy of 7 TeV in p+p collisions, the radial flow velocity achieves an average of ([beta]) = 0.320 ± 0.005. This flow velocity is comparable to that in peripheral (40-60%) Au+Au collisions at RHIC. In addition, breaking of the identified particle spectra mT scaling was also observed at LHC from a model independent test.
Measurement Of Math Mrow Mi Upsilon Mi Mo Mo Mn 1 Mn Mi Mi Mspace Width
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2015
Measurement Of Math Mrow Mi Upsilon Mi Mo Mo Mn 1 Mn Mi Mi Mspace Width written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2015 with categories.
We present measurements of bottomonium production in heavy-ion and p+p collisions at the Relativistic Heavy Ion Collider (RHIC). The inclusive yield of the three [Upsilon] states, [Upsilon](1S+2S+3S), was measured in the PHENIX experiment via electron-positron decay pairs at midrapidity for Au+Au and p+p collisions at sNN=200 GeV. The [Upsilon](1S+2S+3S)→e+e- differential cross section at midrapidity was found to be Beed[sigma]/dy=108±38(stat)±15(syst)±11(luminosity) pb in p+p collisions. The nuclear modification factor in the 30% most central Au+Au collisions indicates a suppression of the total [Upsilon] state yield relative to the extrapolation from p+p collision data. In conclusion, the suppression is consistent with measurements made by STAR at RHIC and at higher energies by the CMS experiment at the Large Hadron Collider.
Production Of Light Nuclei And Anti Nuclei In Math Mrow Mi P Mi Mi P Mi Mrow Math And Pb Pb Collisions At Energies Available At The Cern Large Hadron Collider
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2016
Production Of Light Nuclei And Anti Nuclei In Math Mrow Mi P Mi Mi P Mi Mrow Math And Pb Pb Collisions At Energies Available At The Cern Large Hadron Collider written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2016 with categories.
The production of (anti-)deuteron and (anti-) 3He nuclei in Pb-Pb collisions at √sNN = 2.76 TeV has been studied using the ALICE detector at the LHC. The spectra exhibit a significant hardening with increasing centrality. Combined blast-wave fits of several particles support the interpretation that this behavior is caused by an increase of radial flow. The integrated particle yields are discussed in the context of coalescence and thermal-statistical model expectations. The particle ratios, 3He /d and 3He /p, in Pb-Pb collisions are found to be in agreement with a common chemical freeze-out temperature of Tchem ≈ 156 MeV. These ratios do not vary with centrality which is in agreement with the thermal-statistical model. In a coalescence approach, it excludes models in which nucleus production is proportional to the particle multiplicity and favors those in which it is proportional to the particle density instead. In addition, the observation of 31 anti-tritons in Pb-Pb collisions is reported. For comparison, the deuteron spectrum in pp collisions at √s = 7 TeV is also presented. While the p/[pi] ratio is similar in pp and Pb-Pb collisions, the d/p ratio in pp collisions is found to be lower by a factor of 2.2 than in Pb-Pb collisions.
Search For Dark Photons From Neutral Meson Decays In Math Mi P Mi Mo Mo Mi P Mi Math And Math Mi D Mi Mo Mo Mi Mathvariant
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2015
Search For Dark Photons From Neutral Meson Decays In Math Mi P Mi Mo Mo Mi P Mi Math And Math Mi D Mi Mo Mo Mi Mathvariant written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2015 with categories.
The standard model (SM) of particle physics is spectacularly successful, yet the measured value of the muon anomalous magnetic moment (g-2)[mu] deviates from SM calculations by 3.6[sigma]. Several theoretical models attribute this to the existence of a "dark photon," an additional U(1) gauge boson, which is weakly coupled to ordinary photons. For this study, the PHENIX experiment at the Relativistic Heavy Ion Collider has searched for a dark photon, U, in [pi]0, [eta]2!gamma]e+e- decays and obtained upper limits of [theta](2×10-6) on U-[gamma] mixing at 90% C.L. for the mass range 30
Measurement Of Long Range Pseudorapidity Correlations And Azimuthal Harmonics In Math Mrow Msqrt Msub Mi Mi Mrow Mi N Mi Mi N Mi Mrow Msub Msqrt Mo
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2014
Measurement Of Long Range Pseudorapidity Correlations And Azimuthal Harmonics In Math Mrow Msqrt Msub Mi Mi Mrow Mi N Mi Mi N Mi Mrow Msub Msqrt Mo written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2014 with categories.
We present measurements of two-particle correlation functions and the first five azimuthal harmonics, v1 to v5, using 28 nb−1 of p+Pb collisions at a nucleon-nucleon center-of-mass energy of √sNN =5.02 TeV measured with the ATLAS detector at the LHC. Significant long-range "ridgelike" correlations are observed for pairs with small relative azimuthal angle (
Photon And Neutral Pi 0 Production In 197 Au 197 Au Collisions At Sqrt S Nn
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 2003
Photon And Neutral Pi 0 Production In 197 Au 197 Au Collisions At Sqrt S Nn written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2003 with categories.
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.