Download or read book Pion Interferometry in Au Au and Cu Cu Collisions at Sqrt SNN written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a systematic analysis of two-pion interferometry in Au+Au collisions at (square root)sNN = 62.4 GeV and Cu+Cu collisions at (square root)sNN = 62.4 and 200 GeV using the STAR detector at RHIC. The multiplicity and transverse momentum dependences of the extracted correlation lengths (radii) are studied. The scaling with charged particle multiplicity of the apparent system volume at final interaction is studied for the RHIC energy domain. The multiplicity scaling of the measured correlation radii is found to be independent of colliding system and collision energy.

Download or read book Identified Particle Production Azimuthal Anisotropy and Interferometry Measurements in Au Au Collisions at Sqrt SNN written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the first measurements of identified hadron production, azimuthal anisotropy, and pion interferometry from Au+Au collisions below the nominal injection energy at the Relativistic Heavy-Ion Collider (RHIC) facility. The data were collected using the large acceptance STAR detector at (square root)s{sub NN} = 9.2 GeV from a test run of the collider in the year 2008. Midrapidity results on multiplicity density (dN/dy) in rapidity (y), average transverse momentum (p{sub T}), particle ratios, elliptic flow, and HBT radii are consistent with the corresponding results at similar (square root)s{sub NN} from fixed target experiments. Directed flow measurements are presented for both midrapidity and forward rapidity regions. Furthermore the collision centrality dependence of identified particle dN/dy, p{sub T}, and particle ratios are discussed. These results also demonstrate that the capabilities of the STAR detector, although optimized for (square root)s{sub NN} = 200 GeV, are suitable for the proposed QCD critical point search and exploration of the QCD phase diagram at RHIC.

Download or read book Neutral Pion Production in Au Au Collisions at Sqrt SNN written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The results of mid-rapidity (0

Download or read book Two Pion Intensity Interferometry in Collisions of Au Au at sNN written by Robert Greifenhagen and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of K0S and K 0 in P p D Au and Cu Cu Collisions at Sqrt SNN written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The PHENIX experiment at the Relativistic Heavy Ion Collider has performed a systematic study of K0S and K*0 meson production at midrapidity in p+p, d+Au, and Cu+Cu collisions at sqrt SNN = 200 GeV. The K0S and K*0 mesons are reconstructed via their K0S and [pi]0(2!gamma][gamma])[pi]0 (2!gamma][gamma]) and K*0 2!K "[pi]" decay modes, respectively. The measured transverse-momentum spectra are used to determine the nuclear modification factor of K0S and K*0 mesons in d+Au and Cu+Cu collisions at different centralities. In the d+Au collisions, the nuclear modification factor of K0S and K*0 mesons is almost constant as a function of transverse momentum and is consistent with unity showing that cold-nuclear-matter effects do not play a significant role in the measured kinematic range. In Cu+Cu collisions, within the uncertainties no nuclear modification is registered in peripheral collisions. In central collisions, both mesons show suppression relative to the expectations from the p+p yield scaled by the number of binary nucleon-nucleon collisions in the Cu+Cu system. In the pT range 2-5 GeV/c, the strange mesons (K0S, K*0) similarly to the.

Download or read book Pion Interferometry in AU AU Collisions at the AGS written by and published by . This book was released on 1999 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two-pion Bose-Einstein correlations have been studied using the BNL-E866 Forward Spectrometer in 11.6 A · GeV/c Au + Au collisions. The data were analyzed using three-dimensional correlation parameterizations to study transverse momentum-dependent source parameters. The freeze-out time and the duration of emission were derived from the source radii parameters.

Download or read book Trotsky jug par L nine textes et documents choisis par M S Olminsky en opposition Trotsky written by and published by . This book was released on 1925 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Pion kaon Correlations in Central Au Au Collisions at square Root s sub NN written by and published by . This book was released on 2003 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Pion Interferometry in AuAu Collisions at a Center of Mass Energy Per Nucleon of 200 GeV written by Mercedes López Noriega and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Quantum Chromodynamics predicts a phase transition from a state formed by hadrons to a plasma of deconfined quarks and gluons, the Quark Gluon Plasma, as a the energy density exceeds a critical value. This deconfined phase is believed to be the one in which the early universe existed in a time-scale [approx.] 10−5 s after the Big Bang. Ultrarelativistic Heavy Ion Collisions, like the ones that take place at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory, reach energy densities above the critical value creating a deconfined phase of quarks and gluons that can be studied at the laboratory. This gives us the opportunity to study a phase of matter in the deconfined region of QCD, the properties of the strong interaction, the formation of hadronic matter and the interaction between hadrons. In the analysis presented in this thesis, the dynamical evolution of the particle emitting source and its space-time structure at freeze-out is studied using the two particle intensity interferometry technique. The expansion of the source is also studied. We find indications that this expansion may be caused by the initial pressure gradient generated in the initial stages of the collision through particle rescattering in a very dense medium.

Download or read book Neutral Kaon Interferometry in Au Au Collisions at Sqrt s NN written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the first statistically meaningful results fromtwo-K0s interferometry in heavy-ion collisions. A model that takes theeffect of the strong interaction into account has been used to fit themeasured correlation function. The effects of single and coupled channelwere explored. At the mean transverse mass m_T = 1.07 GeV, we obtain thevalues R = 4.09 +- 0.46 (stat.) +- 0.31 (sys) fm and lambda = 0.92 +-0.23 (stat) +- 0.13 (sys), where R and lambda are the invariant radiusand chaoticity parameters respectively. The results are qualitativelyconsistent with m_T systematics established with pions in a scenariocharacterized by a strong collective flow.

Download or read book Azimuthally Sensitive Hanbury Brown twiss Interferometry in Au Au Collisions Sqrt S Sub NN written by and published by . This book was released on 2004 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the results of a systematic study of the shape of the pion distribution in coordinate space at freeze-out in Au+Au collisions at RHIC using two-pion Hanbury Brown-Twiss (HBT) interferometry. Oscillations of the extracted HBT radii vs. emission angle indicate sources elongated perpendicular to the reaction plane. The results indicate that the pressure and expansion time of the collision system are not sufficient to completely quench its initial shape.

Download or read book Beam energy dependent Two pion Interferometry and the Freeze out Eccentricity of Pions Measured in Heavy Ion Collisions at the STAR Detector written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this study, we present results of analyses of two-pion interferometry in Au+Au collisions at √sNN = 7.7, 11.5, 19.6, 27, 39, 62.4, and 200 GeV measured in the STAR detector as part of the RHIC Beam Energy Scan program. The extracted correlation lengths (HBT radii) are studied as a function of beam energy, azimuthal angle relative to the reaction plane, centrality, and transverse mass (mT) of the particles. The azimuthal analysis allows extraction of the eccentricity of the entire fireball at kinetic freeze-out. The energy dependence of this observable is expected to be sensitive to changes in the equation of state. A new global fit method is studied as an alternate method to directly measure the parameters in the azimuthal analysis. The eccentricity shows a monotonic decrease with beam energy that is qualitatively consistent with the trend from all model predictions and quantitatively consistent with a hadronic transport model.

Download or read book Systematic Study of Charged pion and Kaon Femtoscopy in Au Au Collisions at math mrow msqrt msub mi mi mi Mathvariant written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this paper, we present a systematic study of charged pion and kaon interferometry in Au+Au collisions at √sNN=200 GeV. The kaon mean source radii are found to be larger than pion radii in the outward and longitudinal directions for the same transverse mass; this difference increases for more central collisions. The azimuthal-angle dependence of the radii was measured with respect to the second-order event plane and similar oscillations of the source radii were found for pions and kaons. Finally, hydrodynamic models qualitatively describe the similar oscillations of the mean source radii for pions and kaons, but they do not fully describe the transverse-mass dependence of the oscillations.

Download or read book Systematic Study of Azimuthal Anisotropy in Cu Cu and Au Au Collisions at SNN written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this paper, we have studied the dependence of azimuthal anisotropy v2 for inclusive and identified charged hadrons in Au+Au and Cu+Cu collisions on collision energy, species, and centrality. The values of v2 as a function of transverse momentum pT and centrality in Au+Au collisions at √sNN=200 and 62.4 GeV are the same within uncertainties. However, in Cu+Cu collisions we observe a decrease in v2 values as the collision energy is reduced from 200 to 62.4 GeV. The decrease is larger in the more peripheral collisions. By examining both Au+Au and Cu+Cu collisions we find that v2 depends both on eccentricity and the number of participants, Npart. We observe that v2 divided by eccentricity (?) monotonically increases with Npart and scales as N1/3part. Thus, the Cu+Cu data at 62.4 GeV falls below the other scaled v2 data. For identified hadrons, v2 divided by the number of constituent quarks nq is independent of hadron species as a function of transverse kinetic energy KET=mT–m between 0.1KEsubT/sub/nsubq/sub1 GeV. Finally, combining all of the above scaling and normalizations, we observe a near-universal scaling, with the exception of the Cu+Cu data at 62.4 GeV, of vsub2/sub/(nsubq/sub∙????????Nsup1/3/supsubpart/sub) vs KEsubT/sub/n

Download or read book Charged and Strange Hadron Elliptic Flow in Cu Cu Collisions at Sqrt SNN written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the results of an elliptic flow, v2, analysis of Cu+Cu collisions recorded with the STAR detector at RHIC at √s{sub NN} = 62.4 and 200 GeV. Elliptic flow as a function of transverse momentum, v2(p{sub T}), is reported for different collision centralities for charged hadrons h{sup {+-}}, and strangeness containing hadrons K{sub S}°, [Lambda], [Xi], [phi] in the midrapidity region.

Download or read book Systematic Study of Charged pion and Kaon Femtoscopy in Au Au Collisions at u221A sNN written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a systematic study of charged pion and kaon interferometry in Au+Au collisions at √sNN=200 GeV. The kaon mean source radii are found to be larger than pion radii in the outward and longitudinal directions for the same transverse mass; this difference increases for more central collisions. The azimuthal-angle dependence of the radii was measured with respect to the second-order event plane and similar oscillations of the source radii were found for pions and kaons. Hydrodynamic models qualitatively describe the similar oscillations of the mean source radii for pions and kaons, but they do not fully describe the transverse-mass dependence of the oscillations.

Download or read book Nuclear Matter Effects on J psi Production in Asymmetric Cu Au Collisions at sqrt s mathrm NN written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report on J/[psi] production from asymmetric Cu+Au heavy-ion collisions at \(\sqrt{s_{\mathrm{NN}}} = 200\) GeV at the Relativistic Heavy Ion Collider at both forward (Cu-going direction) and backward (Au-going direction) rapidities. The nuclear modification of J/[psi] yields in Cu+Au collisions in the Au-going direction is found to be comparable to that in Au+Au collisions when plotted as a function of the number of participating nucleons. In the Cu-going direction, J/[psi] production shows a stronger suppression. This difference is comparable in magnitude and has the same sign as the difference expected from shadowing effects due to stronger low-x gluon suppression in the larger Au nucleus. Thus, the relative suppression is opposite to that expected from hot nuclear matter dissociation, since a higher energy density is expected in the Au-going direction.