122166973
The phase diagram of QCD: methods and logic of the comparison of experiments and theory
Abstract A small review of the phase diagram of QCD is presented. This is followed by a discussion of the conditions under which experimental data on the fluctuations of conserved quantities in heavy-ion collisions can be treated in the grand canonical ensemble. A robust method for detecting the presence of a nearby critical point in experiments is given. There is a short discussion of the need for non-Gaussian error analysis.
123004962
Flavour degrees of freedom and the transition temperature in QCD
We study the finite temperature transition in QCD with four flavours of dynamical quarks. Our simulation is performed on an 8×16 3 lattice for quarks of mass ma=0.01. At the coupling β c =5.15, we find long-lived metastable states, as well as an abrupt change in the entropy density, suggesting a first order phase transition. Using presently available results from corresponding calculations of the hadron masses and the chiral condensate, this gives us a transition temperature T c ≅100 MeV, which is a factor two lower than the transition temperature found in quenched QCD.
121387686
Hybrid Monte Carlo simulations of a two-dimensional gauge theory
Through a study of the dynamics of the two-dimensional U(1) pure gauge theory we find exponential slowing down in barrier penetration problems. We verify that the dynamical critical exponent in HMC can be tuned exactly to 1, and that normal and gauge fixed updates have equal cost.
123580970
Implication of the EMC-effect on high transverse momentum jets
We show that the extension of nuclear structure functions to the regionx>1 can give rise to an enhancement of high-pT jet cross sections in hadron nucleus collisions. Such extensions are expected in a class of models proposed to explain the EMC-effect. Since these models are completely parametrized by the deep inelastic scattering data, the jet cross section emerge as parameter free predictions.
18872395
Quarkonium polarization in nonrelativistic QCD and the quark-gluon plasma
We examine angular distributions of leptons arising from the decay of $J/\ensuremath{\psi}$ in inclusive hadroproduction. Taking into account feed-down contributions from ${\ensuremath{\chi}}_{1,2},$ a flat distribution emerges without fine tuning parameters. Changes in the ratio of direct to total $J/\ensuremath{\psi}$ cross sections would change this distribution significantly. Such angular distributions are, therefore, confirmatory tests of the $J/\ensuremath{\psi}$ suppression signal for the production of a quark-gluon plasma. Related effects are predicted for the $\ensuremath{\Upsilon}.$
17443615
Lattice QCD for RHIC
I briefly introduce the methods by which lattice QCD predictions for RHIC are obtained. Next I deal with lattice determinations of strangeness production and event-to-event fluctuations of conserved quantities. I also present a new diagrammatic method for computing derivatives with respect to chemical potentials, and conclude with discussions of some tests of thermal perturbation theory which follow.
117748187
Nonlinear Hadron Couplings from Divergence Conditions. II. varrho Mesons, Pions, and Nucleons
119300069
Parallel hybrid textures of lepton mass matrices
We analyse the parallel hybrid texture structures in the charged lepton and the neutrino sector. These parallel hybrid texture structures have physical implications as they cannot be obtained from arbitrary lepton mass matrices through weak basis transformations. The total sixty parallel hybrid texture structures can be grouped into twelve classes, and all the hybrid textures in the same class have identical physical implications. We examine all the twelve classes under the assumption of non-factorizable phases in the neutrino mass matrix. Five out of the total twelve classes are found to be phenomenologically disallowed. We study the phenomenological implications of the allowed classes for 1-3 mixing angle, Majorana and Dirac-type CP violating phases. Interesting constraints on effective Majorana mass are obtained for all the allowed classes.
121068931
The thermodynamic model for relativistic heavy ion collisions
Abstract The collision between two heavy ions at high energies is discussed within the framework of a statistical model which is developed step by step so that it can be followed by a reader unfamiliar with this approach. As we hope to show, the statistical model forms a comprehensive framework for investigating various aspects of such collisions. When statistical thermodynamics is coupled with a one and two fireball model or a firestreak model, single particle and multiparticle inclusive cross sections can be evaluated. Specifically, single particle proton, deuteron, triton and pion cross sections are calculated and compared with experiment. Two particle correlations are discussed using the microcanonical ensemble. Multiplicity distributions are evaluated using the canonical ensemble and composite particle formation is simply obtained from the grand canonical ensemble. The power law behaviour of composite particle cross sections is studied. The thermodynamic model is justified by calculating various reaction rates. Many comparisons with experimental data are made.
119186084
Bimodality and Coulomb effects with a canonical thermodynamic model
Abstract The effect of the Coulomb interaction on the phase diagram of finite nuclei is studied within the Canonical Thermodynamic Model. If Coulomb effects are artificially switched off, this model shows a phenomenology consistent with the liquid–gas phase transition. The inclusion of Coulomb does not significantly affect the phase diagram but it drastically modifies the nature and order parameter of the transition. A clear understanding of the phenomenon can be achieved looking at the distribution of the largest fragment produced in each fragmentation event. Possible connections with experimental observations are outlined.
109607695
Vacuum system design for twenty-cell PWT Linac structure
This paper describes the vacuum system design for a 20-cell Plane Wave Transformer (PWT) type LINear ACcelerator (LINAC) structure to obtain a vacuum better than 5×10−8 mbar everywhere inside the linac structure. Specific material out-gassing rate for a 20-cell linac is determined on the basis of vacuum achieved in a similar type of 8-cell linac structure, which is smaller in length, and presently under operation in the Compact Ultrafast TEra-hertz Free Electron Laser (CUTE-FEL) beam transport line at RRCAT.