Hydrogen-like Atoms from Ultrarelativistic Nuclear Collisions

The number of hydrogen-like atoms produced when heavy nuclei collide is estimated for central collisions at the Relativistic Heavy Ion Collider using the sudden approximation of Baym et al. As first suggested by Schwartz, a simultaneous measurement of the hydrogen and hadron spectra will allow an inference of the electron or muon spectra at low momentum where a direct experimental measurement is not feasible.Comment: 6 pages, 4 figure

Friction in inflaton equations of motion

The possibility of a friction term in the equation of motion for a scalar field is investigated in non-equilibrium field theory. The results obtained differ greatly from existing estimates based on linear response theory, and suggest that dissipation is not well represented by a term of the form $\eta\dot{\phi}$.Comment: 4 pages, 2 figures, RevTex4. An obscurity in the original version has been clarifie

Nucleus-Nucleus Bremsstrahlung from Ultrarelativistic Collisions

The bremsstrahlung produced when heavy nuclei collide is estimated for central collisions at the Relativistic Heavy Ion Collider. Soft photons can be used to infer the rapidity distribution of the outgoing charge. An experimental design is outlined.Comment: 12 pages, 7 figures, uses revte

Neutron and muon-induced background studies for the AMoRE double-beta decay experiment

AMoRE (Advanced Mo-based Rare process Experiment) is an experiment to search a neutrinoless double-beta decay of $^{100}$Mo in molybdate crystals. The neutron and muon-induced backgrounds are crucial to obtain the zero-background level (<$10^{-5}$ counts/(keV$\cdot$kg$\cdot$yr)) for the AMoRE-II experiment, which is the second phase of the AMoRE project, planned to run at YEMI underground laboratory. To evaluate the effects of neutron and muon-induced backgrounds, we performed Geant4 Monte Carlo simulations and studied a shielding strategy for the AMORE-II experiment. Neutron-induced backgrounds were also included in the study. In this paper, we estimated the background level in the presence of possible shielding structures, which meet the background requirement for the AMoRE-II experiment

Balance Functions, Correlations, Charge Fluctuations and Interferometry

Connections between charge balance functions, charge fluctuations and correlations are presented. It is shown that charge fluctuations can be directly expressed in terms of a balance functions under certain assumptions. The distortion of charge balance functions due to experimental acceptance is discussed and the effects of identical boson interference is illustrated with a simple model.Comment: 1 eps figure included. 5 pages in revtex

Particle number fluctuations in nuclear collisions within excluded volume hadron gas model

The multiplicity fluctuations are studied in the van der Waals excluded volume hadron-resonance gas model. The calculations are done in the grand canonical ensemble within the Boltzmann statistics approximation. The scaled variances for positive, negative and all charged hadrons are calculated along the chemical freeze-out line of nucleus-nucleus collisions at different collision energies. The multiplicity fluctuations are found to be suppressed in the van der Waals gas. The numerical calculations are presented for two values of hard-core hadron radius, $r=0.3$ fm and 0.5 fm, as well as for the upper limit of the excluded volume suppression effects.Comment: 19 pages, 4 figure

Quark Number Fluctuations in a Chiral Model at Finite Baryon Chemical Potential

We discuss the net quark and isovector fluctuations as well as off-diagonal quark flavor susceptibilities along the chiral phase transition line in the Nambu--Jona-Lasinio (NJL) model. The model is formulated at non-zero quark and isospin chemical potentials with non-vanishing vector couplings in the iso-scalar and iso-vector channels. We study the influence of the quark chemical potential on the quark flavour susceptibilities in detail and the dependence of the results on model parameters as well as on the quark mass. The NJL model findings are compared with recent lattice results obtained in two--flavor QCD at finite chemical potential. On a qualitative level, the NJL model provides a consistent description of the dependence of quark number fluctuations on temperature and baryon chemical potential. The phase diagram and the position of the tricritical point in the NJL model are also discussed for different parameter sets.Comment: 33 pages, 11 figures; final version accepted for publication in Phys. Rev.