123608845
Sign-Posting the Phase Diagram of QCD
The good agreement between lattice predictions and data for the shape of the distribution of event-by-event fluctuations of the baryon number is discussed. Such comparisons can give fine probes of thermalization, and can be used to provide a direct determination of the crossover temperature of QCD, Tc. The logic of these comparisons and the systematics involved are discussed. The same methods can be used to further explore the phase diagram.
41160767
Chiral dynamics in QCD at finite chemical potential
We present the renormalized Taylor expansion of the chiral condensate with chemical potential. The relation with the Taylor coefficients of meson susceptibilities and the quark mass dependence of the quark number susceptibilities are obtained through chiral Ward identities and Maxwell relations. The continuum limit is obtained in quenched and two flavor QCD. In N{sub f}=2 QCD, the quadratic response coefficients of the chiral condensate to chemical potential indicate that pion fluctuations decrease at finite chemical potential toward the critical end point. We discuss how these observables can be used to test other features of the QCD phase diagram.
119431013
A precise determination of T_c in QCD from scaling
Existing lattice data on the QCD phase transition are analyzed in renormalized perturbation theory. In quenched QCD it is found that T_c scales for lattices with only 3 time slices, and that T_c/Lambda_msbar=1.15 \pm 0.05. A preliminary estimate in QCD with two flavours of dynamical quarks shows that this ratio depends on the quark mass. For realistic quark masses we estimate T_c/Lambda_msbar=0.49 \pm 0.02. We also investigate the equation of state in quenched QCD at 1-loop order in renormalised perturbation theory.
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 $\ensuremath{\Upsilon}.$
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.
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.
92994920
Energy and spatial resolution of a Shashlik calorimeter and a silicon preshower detector
New projective prototypes of a scintillator/lead sandwich type sampling calorimeter Shashlik with a silicon preshower detector have been constructed and tested with an electron beam at CERN-SPS. The energy resolution is measured to be 8.7%E(GeV) in stochastic term, 0.330/E(GeV) in noise term and 0.5% in constant term. The angular resolution is better than 70 mradE(GeV).
121879312
Isobaric analog impurity from total and differential neutron scattering cross sections of silicon
Resonance parameters for sour resonances in Si have been obtained by analyzing measured differential neutron scattering cross sections combined with the total neutron cross section in the neutron energy range 1.05--1.40 MeV and applying R-matrix single channel multilevel theory. The resonance at 1254 krB has been identified as the s-wave analog resonance in /sup 29/Si. The identification also takes into account experimental radiative neutron capture data and shell model calculations for the radiative width. Estimates of the isospin mixing matrix elements are given.
119119867
Phase diagram for asymmetric nuclear matter in the multifragmentation model
We assume that, in equilibrium, nuclear matter at reduced density and moderate finite temperature breaks up into many fragments. Strong support for this assumption is provided by data accumulated from intermediate-energy heavy ion collisions. The breakup of hot and expanded nuclear matter according to the rules of equilibrium statistical mechanics is the multifragmentation model, which gives a first-order phase transition. This is studied in detail here. Phase-equilibrium lines for different degrees of asymmetry are computed.
123456693
NONLINEAR LAGRANGIAN TRANSFORMATIONS.
39289287
Model of multifragmentation, equation of state, and phase transition
We consider a soluble model of multifragmentation which is similar in spirit to many models which have been used to fit intermediate energy heavy ion collision data. We draw a p-V diagram for the model and compare with a p-V diagram obtained from a mean-field theory. We investigate the question of chemical instability in the multifragmentation model. Phase transitions in the model are discussed.