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 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 Particle Correlations in Fixed Target Pb Pb Collisions at 158 GeV c Per Nucleon written by Hanspeter Naef and published by . This book was released on 1997 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: L'originalité de WA98 vient de sa grande variété de signaux mesurés; une étude sur leurs corrélations est également présentées.
Download or read book Two Particle Correlations at 40 80 and 158 AGeV Pb Au Collisions written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, a centrality dependent study of tow-particle momentum correlations of like-sign pions (HBT interferometry) from Pb-Au collisions at beam energies of 40, 80 and 158 AGeV is presented. The three-dimensional correlation function C_2, depending on the relative momentum components of the particle pair, was parameterized using a three-dimensional Gaussian, modified to consider the final state Coulomb repulsion. The parameterization was done in the Cartesian out-side-long system as proposed by G. Bertsch and S. Pratt. A differential analysis of the HBT radius parameters as a function of the mean transverse pair momentum k_perp allowed to determine transverse geometrical source sizes of about 5.5 fm to 7 fm, increasing with energy and centrality. The mean transverse flow velocity v_perp was found to be of the order 0.5--0.6 c. For the freeze-out time tau_f values between 6 and 8 fm/c were obtained with a duration of particle emission compatible with zero. The beam energy dependence of the HBT radii provide evidence for a universal pion freeze-out condition. The analyzed data have been recorded with the CERES spectrometer at the Super Proton Synchrotron (SPS) accelerator at CERN.
Download or read book Neutral Kaon Correlations in Au au Collisions at Center of Mass Energy of 200 GeV Per Nucleon Pair written by Selemon Bekele and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: A few microseconds after the Big Bang, the universe is believed to have existed in the form of a plasma composed of strongly interacting particles known as quarks and gluons. Although the quarks and gluons behave as asymptotically free particles in a Quark Gluon Plasma (QGP), free quarks and gluons have never been discovered in the laboratory. Experiments at the Relativistic Heavy Ion Collider (RHIC) aim to create conditions similar to the early universe by colliding heavy ions at the highest energies possible in the hope of observing a phase transition from a QGP into hadronic degrees of freedom. The response of the space time structure of the hot reaction zone created in a heavy ion collision to a phase transition is one of the many observables being studied at RHIC. Making use of the techniques of two particle intensity interferometry, also known as the HBT effect, the RHIC experiments are studying the space-time structure and dynamical properties of the region from which particles are emitted. A large spatial size and long duration of particle emission are the predicted signals for a phase transition from a QGP to a hadronic phase. In this thesis we present results on the first measurement of one dimensional K0[subscript s] K0[subscript s] interferometry by the STAR experiment at RHIC in central (small impact parameter) Au-Au collisions at center of mass energy of 200 GeV per nucleon pair. The lambda parameter, which is a measure of the sources chaoticity, is found to be consistent with unity confirming the fact that the source is mostly chaotic as measured by STAR using three particle correlations. Without taking into account the effect of the strong interaction, the invariant radius R inv is found to be large for the mean transverse mass M [subscript t] of the pair, which is about 980 MeV/c, compared to expectations from charged pion correlations at the same M [subscript t]. Including the effect of the strong interactions makes the radius parameter for the K0[subscript s] K0[subscript s] system fall within the charged pion M [subscript t] systematics. Our result serves as a valuable cross-check of charged pion measurements which are mainly affected by contributions from resonance decays and final state interactions. This is also an important first step towards a full three dimensional analysis of neutral kaon correlations as high statistics data from RHIC will be available in the near future.
Download or read book What Invariant One particle Multiplicity Distributions and Two particle Correlations are Telling Us about Relativistic Heavy ion Collisions written by and published by . This book was released on 1998 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors have used a nine-parameter expanding source model that includes special relativity, quantum statistics, resonance decays, and freeze-out on a realistic hypersurface in spacetime to analyze in detail invariant?, K+, and K− one-particle multiplicity distributions and?+ and?− two-particle correlations in nearly central collisions of Pb + Pb at p{sub lab}/A = 158 GeV/c. These studies confirm an earlier conclusion for nearly central collisions of Si + Au at p{sub lab}/A = 14.6 GeV/c that the freeze-out temperature is less than 100 meV and that both the longitudinal and transverse collective velocities -- which are anti-correlated with the temperature -- are substantial. The authors also reconciled their current results with those of previous analyses that yielded a much higher freeze-out temperature of approximately 140 meV for both Pb + Pb collisions at p{sub lab}/A = 158 GeV/c and other reactions. One type of analysis was based upon the use of a heuristic equation that neglects relativity to extrapolate slope parameters to zero particle mass. Another type of analysis utilized a thermal model in which there was an accumulation of effects from several approximations. The future should witness the arrival of much new data on invariant one-particle multiplicity distributions and two-particle correlations as functions of bombarding energy and/or size of the colliding nuclei. The proper analysis of these data in terms of a realistic model could yield accurate values for the density, temperature, collective velocity, size, and other properties of the expanding matter as it freezes out into a collection of noninteracting hadrons. A sharp discontinuity in the value of one or more of these properties could conceivably be the long-awaited signal for the formation of a quark-gluon plasma or other new physics.
Download or read book Two particle Correlations at 40 80 and 158 AGeV Pb Au Collisions written by Heinz Tilsner and published by . This book was released on 2002 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Die sieben hohen und kr ftigen Namen Gottes Ms 267 written by and published by . This book was released on 1752 with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quark Gluon Plasma 3 written by Rudolph C. Hwa and published by World Scientific. This book was released on 2004 with total page 786 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation. Text reviews the major topics in Quark-Gluon Plasma, including: the QCD phase diagram, the transition temperature, equation of state, heavy quark free energies, and thermal modifications of hadron properties. Includes index, references, and appendix. For researchers and practitioners.
Download or read book NA49 Results on Single Particle and Correlation Measurements in Central PB PB Collisions written by and published by . This book was released on 1998 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Single-particle spectra and two-particle correlation functions measured by the NA49 collaboration in central Pb+Pb collisions at 158 GeV/nucleon are presented. These measurements are used to study the kinetic and chemical freeze-out conditions in heavy ion collisions. We conclude that large baryon stopping, high baryon density and strong transverse radial flow are achieved in central Pb+Pb collisions at the SPS.
Download or read book Advances in Nuclear Dynamics written by Benito Arruñada and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of nuclear dynamics is now in one of its most interesting phases. The theory is in the process of establishing an increasingly reliable transport description of heavy ion reactions from the initial violent phase dominated by first collisions to the more thermalized later stages of the reaction. This is true for the low-to-medium energy reactions, where the dynamics is formulated in terms of nucleonic, or in general hadronic, degrees of freedom. And it is also becoming a reality in ultrarelativistic heavy-ion reactions, where partonic elementary degrees of freedom have to be used. Experiments are now able to 'utilize the existing accelerators and multiparticle detec tion systems to conduct unprecedented studies of heavy-ion collisions on an event-by-event basis. In addition, the field anticipates the completion of the construction of the Relativistic Heavy Ion Collider and the proposed upgrade of the National Superconducting Cyclotron Laboratory, promising qualitatively new data for the near future. All of these efforts are basically directed to the exploration of the change the nuclear medium provides for the properties and interactions of individual nucleons and, ultimately, the exploration of the nuclear matter phase diagram. The investigation of this phase dia gram, including all of the interesting phase transitions predicted from theoretical grounds, is the focus of most of the theoretical and experimental investigations of nuclear dynamics conducted today.
Download or read book Quark Matter written by and published by . This book was released on 2005 with total page 1004 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Using the Balance Function to Search for Late Hadronization in Au Au Collisions at a Center of Mass Energy of 130 GeV Per Nucleon Pair written by Marguerite Belt Tonjes and published by . This book was released on 2002 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurements of Lambda Lambda bar and K short from Pb Pb Collisions at 158 GeV Per Nucleon in a Large Acceptance Experiment written by Lee S. Barnby and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The main reason for studying relativistic heavy-ion collisions is to discover the phase transition from nuclear matter to the Quark-Gluon Plasma. Such a transition is predicted to occur under conditions of high temperature and density. The predicted state features deconfined quarks and gluons as the relevant degrees of freedom instead of colour-singlet hadrons. These new degrees of freedom should lead to an enhanced production of strange quarks which has directly observable consequences on the composition of the final state hadrons detected in such a collision. The NA49 experiment is able to measure hadronic production in central Pb+Pb collisions. It uses a Pb beam, of energy 158 GeV per nucleon, from the CERN SPS with a fixed Pb target. The experiment features four large tracking detectors which can measure the trajectories of charged particles. In this thesis the method of reconstructing neutral strange particles, Lambda, Lambda-bar and K-short from their charged decay products is described. The procedure for correcting the raw yields for losses due to the limited experimental acceptance and efficiency in reconstruction is explained. An estimate of some systematic errors is made. The resulting rapidity distributions, which span either side of mid-rapidity are peaked (with the possible exception of Lambda) and the transverse momentum spectra fit the Hagedorn distribution. The inverse slope parameters, T_Lambda = 274? 5 MeV, T_Lambda-bar = 279? 10 MeV and T_K = 238? 5 MeV are consistent with the picture of transverse flow observed in these collisions. These results are compared with other measurements.
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 Relative Yields of Antiparticles to Particles in Au Au Collisions at 130 and 200 GeV Per Nucleon Pair written by Kristján Herlache Gulbrandsen and published by . This book was released on 2004 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: Au+Au collisions at [square root of] [superscript]s nn = 130 and 200 GeV at the Relativistic Heavy Ion Collider have opened a new energy regime for studying nucleus-nucleus collisions. A search for the formation of a phase of matter in which quarks and gluons interact strongly over an extended deconfined volume is of primary importance. The PHOBOS detector was constructed to measure many observables at RHIC. The primary subsystem used in this analysis is the PHOBOS spectrometer. The spectrometer is a multiplane silicon pad detector which detects particles traversing its pads as they propagate through a strong magnetic field. The hit positions are used along with energy loss information in the silicon pads to determine both the momentum and velocity of the particles, allowing for the identification of the particle species. One of the most basic pieces of information to be determined is the baryochemical potential of the system. This information has been determined through the measurement of the relative yields of antiparticles to particles in RHIC collisions ... These values are compared to model predictions and are used to evaluate the contribution of baryon transport relative to particle production in determining the yields of baryon at midrapidity in central Au+Au collisions at RHIC energies.
