14037021
Double asymptotic scaling in Drell-Yan processes
Double scaling may be observed in the Drell-Yan process at the Tevatron and in the ALICE detector at the Large Hadron Collider in a window of masses. In the double scaling limit of the cross section, the higher order QCD corrections are quite large, and are driven by the rise in gluon densities in the double scaling regime. The naive parton model cannot be valid even at asymptotic energies in the region of phase space where double scaling holds.
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.
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.
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.
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.
121643346
Study on nuclear composition of cosmic rays around the knee utilizing muon multiplicity with GRAPES-3 experiment at Ooty
The composition and energy spectrum of primary cosmic rays (PCRs) are the only observables available at ultra-high energies to understand the nature of sources accelerating protons and other nuclei to 1000 TeV and beyond. These observables have been measured up to 1000 TeV, directly with detectors flown aboard balloons and satellites. The measurements at > 1000  TeV are obtained indirectly, from ground based observations of extensive air showers (EAS). However, their interpretation depends on rather inadequate knowledge of hadronic interactions at > 1000  TeV . The GRAPES-3 experiment has been designed to study the EAS at ∼ 30  TeV to provide a sizable overlap with the results from direct measurements, enabling selection of a suitable model of hadronic interactions. We present here the salient features of GRAPES-3 experiment and some details of muon multiplicity distributions (MMDs) observed with a 560 m2 muon detector as a function of shower size ( N e ) fro analysis of 560 days of data. A comparison of GRAPES-3 results with direct measurements over the energy region 100 – 1000 TeV is presented to show the suitability of hadronic interaction generator “SIBYLL” for the interpretation of EAS data. We presented the energy spectrum of five nuclear groups (H, He, N, Al and Fe) with good statistics for 100 – 10, 000 TeV.
120756008
Supercooling in viscous hydrodynamics for QCD phase transition
First order quark hadron phase transition is considered in scaling hydrodynamics including the Csernai-Kapusta model of nucleation of hadronic bubbles leading to supercooling. The effect of viscosity on the entropy production is studied in ideal as well as in viscous hydrodynamics with and without supercooling. It is found that the excess entropy produced due to supercooling depends weakly on viscosity.
123179533
Fusion barriers for heavy-ion systems
Analytical expressions for the fusion barrier height and radius have been derived from a four-parameter empirical fusion cross section formula for heavy ions. The fusion barrier parameters calculated, using these expressions, are in good agreement with the literature values.
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).
14528390
Distinguishing the Littlest Higgs model with T-parity from supersymmetry at the LHC using trileptons
Abstract We analyse hadronically quiet trilepton signatures in the T-parity conserving Littlest Higgs model and in R-parity conserving supersymmetry at the Large Hadron Collider. We identify the regions of the parameter space where such signals can reveal the presence of these new physics models above the Standard Model background and distinguish them from each other, even in a situation when the mass spectrum of the Littlest Higgs model resembles the supersymmetric pattern.