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.
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.
40481011
Quark number susceptibilities, strangeness, and dynamical confinement
We report the first results on the strange quark number susceptibility ${\ensuremath{\chi}}_{s}$ over a large range of temperatures, mainly in the plasma phase of QCD. ${\ensuremath{\chi}}_{s}$ jumps across the phase transition temperature ${T}_{c}$ and grows rapidly with temperature above but close to ${T}_{c}.$ For all quark masses and susceptibilities in the entire temperature range studied, we find a significant departure from ideal-gas values. We also observe a strong correlation between these quantities and the susceptibility in the pseudoscalar channel, supporting ideas of ``dynamical confinement'' in the high temperature phase of the QCD plasma.
35885424
Stabilizing hadron resonance gas models
We examine the stability of hadron resonance gas models by extending them to include undiscovered resonances through the Hagedorn formula. We find that the influence of unknown resonances on thermodynamics is large but bounded. We model the decays of resonances and investigate the ratios of particle yields in heavy-ion collisions. We find that observables such as hydrodynamics and hadron yield ratios change little upon extending the model. As a result, heavy-ion collisions at the RHIC and LHC are insensitive to a possible exponential rise in the hadronic density of states, thus increasing the stability of the predictions of hadron resonance gas models in this context. Hadron resonance gases are internally consistent up to a temperature higher than the crossover temperature in QCD, but by examining quark number susceptibilities we find that their region of applicability ends below the QCD crossover.
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.
14688147
Finding the critical end point of QCD: lattice and experiment
The current status of the search for the critical end point on the lattice and in experiments is discussed. A naive extrapolation is given of lattice results on the location of the critical end point to the continuum limit with the correct pion mass. An interpretation of current results on fluctuations is provided. A new method of analysis of experimental data is discussed, which provides a check on the removal of backgrounds, comparisons with QCD, and signals an approach to the critical end point.
119030036
Grand canonical model predictions for nuclear fragmentation
The grand canonical ensemble has been used to make predictions for composite yields using simple models for nuclear fragmentation. While this gives correct model prediction for high energy collisions, it can give very inaccurate results at intermediate energy.
121995970
A check on the geometrical assumptions in models of relativistic heavy ion collisions
Abstract The results of a recent experiment can be used to test clearly the geometrical assumptions of a variety of models for heavy ion collisions. Frequently used models are seen to fail quantitatively; the data show the need for incorporating nuclear transparency; both multiple and clean knockout collisions are needed.
123435107
Systematics in the volume integrals of the imaginary part of the alpha-nucleus optical potentials
From a systematic analysis of the imaginary part of the alpha-nucleus phenomenological optical model potentials covering a large range of mass numbers and energies, it has been shown that the volume integral per target-projectile pair increases with increase of energy and saturates to a value in the neighborhood of 100 MeV fm3 at higher energies. Interestingly, this value is in remarkable agreement with those obtained using nucleons, deuterons, 3He, and t, as projectiles.
119235806
CP-odd weak basis invariants for neutrino mass matrices with a texture zero and a vanishing minor
We construct the CP-odd weak basis invariants in the flavor basis for all the phenomenologically viable neutrino mass matrices with a texture zero and a vanishing minor and, also, find the necessary and sufficient conditions for CP invariance. We examine the interrelationships between different CP-odd weak basis invariants for these texture structures and investigate their implications for Dirac- and Majorana-type CP violation.
14302099
Right-chiral sneutrinos and long-lived staus: Event characteristics at the CERN Large Hadron Collider
We investigate the signals of a supersymmetric scenario where the lighter tau-sneutrino is the lightest supersymmetric particle, while the lighter stau-state is the next lightest. We confirm that such a scenario can be motivated within the framework of minimal supergravity, with just the addition of a right-chiral neutrino superfield. Such a spectrum leads to rather unusual signals of supersymmetry, showing stable tracks of the stau in the muon chambers. We have studied two types of signals, namely (a) two or more hard jets and two stau tracks, and (b) hard jets with two muons and two stau tracks. We demonstrate that the stau tracks can be distinguished from the muonic ones through proper kinematic cuts which also enable one to remove all standard model backgrounds.