Download or read book Charged Kaon Production in P p and D Au Collisions the Baseline Comparison Systems for Understanding Au Au Collisions at RHIC written by Camelia M. Mironov and published by . This book was released on 2005 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the primary challenges in modern nuclear physics is to understand the properties of hot nuclear matter. The expectation is that at sufficiently high energy densities, nuclear matter undergoes a phase transition where individual nucleons 'dissolve' and a plasma of freely moving quarks and gluons is formed. To accomplish this in the laboratory, normal nuclear matter is heated and compressed through collisions of heavy nuclei at relativistic energies. The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory is a dedicated particle accelerator, capable of colliding nuclear beams to energies up to 100 GeV per nucleon per beam. Particle species ranging from protons (A =1) to gold (A =197) are accelerated in this state-of-the-art facility and collide at selected intersection points. In this dissertation, a detailed transverse momentum (p T) analysis is made at central rapidities, using the STAR Time Projection Chamber (TPC). The data set is comprised of about 10 million d+Au and about 6 million p+p events at 200 GeV. Previously analyzed data from a 2002 Au+Au run are also used. This work concentrates on the study of identified charged kaons (K +, K - ), which are the lightest strange mesons and hence the particles that dominate strangeness production. Charged kaons are identified using a topological reconstruction method which has relatively large p T coverage. In this dissertation, we present p T and yield systematics. We find that the particle to anti-particle ratio is p T independent in all colliding systems studied, an indication that in the p T range studied, the pQCD regime is not reached yet. The ratios, close to unity, signal a rather net-baryon-free mid-rapidity region. The in central d+Au collisions is larger than in peripheral Au+Au collisions, which might hint at the presence of 'Cronin effect' in the dAu system as explained. We also obtain results on nuclear modification factors (R dA CP - central to peripheral ratio, R dA, R AA - geometrically scaled Au+Au(d+Au) to p+p ratios) which are presented for various mesons and baryons. In d+Au collisions, an enhancement compared to binary scaling of both R dA CP and R dA is observed, an experimental observation called 'Cronin effect'. This result is thought to be an initial-state effect. In contrast, the same ratio in central Au+Au collisions exhibits a suppression instead of an enhancement. This was understood in terms of a dense partonic medium which induces energy loss via gluon radiation by a high-energy parton traversing the medium, and leads, after fragmentation, to hadrons with lower . The meson-baryon differences, first observed in Au+Au R AA CP, also exist in d+Au collisions.

Download or read book Kaon Production and Kaon to Pion Ratio in Au Au Collisions at s sub NN written by and published by . This book was released on 2002 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mid-rapidity transverse mass spectra and multiplicity densities of charged and neutral kaons are reported for Au+Au collisions at √s{sub NN}=130 GeV at RHIC. The spectra are exponential in transverse mass, with an inverse slope of about 280 MeV in central collisions. The multiplicity densities for these particles scale with the negative hadron pseudo-rapidity density. The charged kaon to pion ratios are K/?− = 0.161 ± 0.002(stat) ± 0.024(syst) and K−/?− = 0.146 ± 0.002(stat) ± 0.022(syst) for the most central collisions. The K+/?− ratio is lower than the same ratio observed at the SPS while the K−/?− is higher than the SPS result. Both ratios are enhanced by about 50% relative to p+p and {bar p}+p collision data at similar energies.

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2006 with total page 860 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Charged Kaon Production in Au Au Collisions at center of mass Energy Per Nucleon Pair written by Wensheng Deng and published by . This book was released on 2002 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Properties of Charged particle Production at Mid rapidity for Au Au Collisions at RHIC Energies written by Aneta Iordanova and published by . This book was released on 2005 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Identified Particle Distributions in Pp and Au Au Collisions Atsqrt SNN written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Transverse mass and rapidity distributions for charged pions, charged kaons, protons and antiprotons are reported for √sNN = 200 GeV pp and Au+Au collisions at RHIC. The transverse mass distributions are rapidity independent within.

Download or read book Determination of Elliptic Flow and Other Properties of Charged Kaons in Relativistic Au Au Collisions Using Decay topology Identification written by John Amonett and published by . This book was released on 2008 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the beginning, there was quark gluon plasma (QGP). QGP persisted for only on the order of microseconds after the Big Bang. This exotic state of matter consists of deconfined quarks and gluons under extreme conditions. It is believed that the QGP state can be recreated in the laboratory through heavy-ion collisions at ultra-high energies. The Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory appears to produce sufficiently high energy to exceed the threshold for creating the QGP phase. There are four experiments at RHIC, and one of the largest is the Solenoidal Tracker at RHIC (STAR). The STAR detector utilizes a Time Projection Chamber with full azimuthal acceptance to track as many as thousands of produced particles from a single nucleus-nucleus collision. The QGP state of matter has many proposed signatures. This project explores the anisotropic elliptic flow properties of gold (Au) on gold collisions. Elliptic flow corresponds to the second harmonic coefficient (v2) of a Fourier decomposition of the transverse momentum distribution of emitted particles. Elliptic flow is the dominant term in the quantitative description of the collective motion among the particles produced in this type of heavy-ion collision. The focus of this dissertation is on a single type of particle, the charged kaon (K"). Charged kaons are the least massive particles that contain strange quarks. Using conventional techniques based on rate of energy loss, identification of charged kaons becomes difficult above a momentum of ~ 600 MeV/c. This project uses a topological method to identify decaying charged kaons up to transverse momenta ~ 4 GeV/c. Our topological method has the drawback of relatively low efficiency, which decreases with increasing momentum. The data set studied in this dissertation corresponds to gold on gold interactions at the maximum energy of the RHIC machine, and collisions across the full range of impact parameters are analyzed. Possible charged kaons are tagged from a list of candidates. The viable charged kaons are chosen using a series of stringent identification criteria. The reaction plane is determined for each event, and elliptic flow is calculated, correcting for the systematic effects caused by the finite reaction plane resolution. The dependence of elliptic flow on transverse momentum is highly significant when different particle types can be compared. The data for charged kaons falls into a pattern where there is a universal curve for the amount of flow per constituent quark as a function of the quark's transverse momentum. This universal curve can account for the flow observed for all known particle types. It suggests that the collective motion must have been imparted during the early phase of the collision when a QGP state existed. A different pattern would be expected if the collective motion had been imparted after the quarks had coalesced into hadrons, or if the QGP state had not been formed at all. The dissertation discusses the significance of the new evidence, and the caveats and possible alternative explanations.

Download or read book Charged particle Production in Au Au Collisions at square Root S NN written by Hironori Ito and published by . This book was released on 2002 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Kaon Production and K Ratios in Au Au Collisions at 11 09 A GeV c at the AGS written by Fuqiang Wang and published by . This book was released on 1996 with total page 910 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Charged Kaon and Reconstruction in Au Au Collisions at 1 23 AGeV written by Heidi Schuldes and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book UNIVERSAL BEHAVIOR OF CHARGED PARTICLE PRODUCTION IN HEAVY ION COLLISIONS AT RHIC ENERGIES written by and published by . This book was released on 2002 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: The PHOBOS experiment at RHIC has measured the multiplicity of primary charged particles as a function of centrality and pseudorapidity in Au+Au collisions at (square root)(s{sub NN}) = 19.6, 130 and 200 GeV. Two observations indicate universal behavior of charged particle production in heavy ion collisions. The first is that forward particle production, over a range of energies, follows a universal limiting curve with a non-trivial centrality dependence. The second arises from comparisons with pp/{bar p}p and ee− data. N{sub ch}/N{sub part}/2 in nuclear collisions at high energy scales with (square root)s in a similar way as N{sub ch} in ee− collisions and has a very weak centrality dependence. These features may be related to a reduction in the leading particle effect due to the multiple collisions suffered per participant in heavy ion collisions.

Download or read book Identified Particle Production in P p and D Au Collisions at RHIC Energies written by Eftychios Felix Matathias and published by . This book was released on 2004 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Systematic Study of Charged pion and Kaon Femtoscopy in 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 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 Kaon Production in Au Au Collisions at 11 6 GEV c Per Nucleon written by Larry Ahle and published by . This book was released on 1997 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 High P perp Inclusive Charged Hadron Distributions in Au Au Collisions at u221A sNN written by and published by . This book was released on 2003 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis reports the measurement of the inclusive charged particle (h+ + h-) p$\perp$ spectra for 1.7 psub$\perp$

Download or read book Kaon and Lambda Production in Intermediate Pt written by Paul Richard Sorensen and published by . This book was released on 2003 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: