119426627
Prompt contributions to the dilepton yield in heavy ion collisions

Abstract: The mass spectrum is calculated for those dileptons which are produced in the early phase of a heavy ion collisions via the direct production NN → l+l−X and via the Compton process GN → l+l−X with prompt gluons radiated in preceding NN interactions. Both mechanisms produce a mass spectrum which decreases steeply with invariant mass of the l+l− pair and which is below the CERES data for Pb-Au collisions by about one order of magnitude.
182432079
SPECTRALITY OF GELL-MANN-LOW FUNCTION
119138207
Lepton flavor violating photoleptonic effect
We study lepton flavor violating analogs of the photoelectric effect, with a final μ or T instead of an electron: γe → μ and γe → T. On the basis of the general parametrization of the matrix element of the electromagnetic current we estimate the upper limits for the cross sections and event rates of these processes, imposed by the current experimental bounds on μ → ey and T → eγ decays.
118014393
QCD analysis of deep inelastic lepton-scattering data
We have carried out a QCD analysis of data on deep inelastic lepton-scattering (using data of the collaborations BCDMS, EMC, and CDHS) in the leading and next-to-leading orders in the coupling constant ..cap alpha../sub s/. We have considered the effect of the sea quarks and gluons. We discuss the dependence of our results for ..lambda.. on effects of twist corrections, nuclear target effects, and heavy-quark production thresholds.
117509698
QCD NUCLEON MODEL WITH RELATIVISTIC OSCILLATOR INTERACTION BETWEEN CONSTITUENT QUARK
896237
Electroproduction of charmonia off nuclei
In a recent publication we have calculated elastic charmonium production in ep collisions employing realistic charmonia wave functions and dipole cross sections and have found good agreement with the data in a wide range of s and Q^2. Using the ingredients from those calculations we calculate exclusive electroproduction of charmonia off nuclei. Here new effects become important, (i) color filtering of the c-cbar pair on its trajectory through nuclear matter, (ii) dependence on the finite lifetime of the c-cbar fluctuation (coherence length) and (iii) gluon shadowing in a nucleus compared to the one in a nucleon. Total coherent and incoherent cross sections for C, Cu and Pb as functions of s and Q^2 are presented together with some differential cross sections. The results can be tested with future electron-nucleus colliders or in peripheral collisions of ultrarelativistic heavy ions.
116272686
Dynamical Instabilities in Relativistic Heavy-Ion Collisions and Associated Phenomena
125142837
The effect of a hot jet in the hydrodynamic theory of heavy ion collisions
120459019
Medium-modified interaction induced by fluctuations
Abstract Statistical averaging of the Boltzmann-Langevin equation is performed. It is shown that at the averaged level the fluctuations induce an additional collision term with a medium-modified transition rate, which can give rise to a critical scattering phenomena in the vicinity of unstable regions. In order to illustrate the effect of this additional collision term, the single-particle relaxation time in nuclear matter is estimated. It is shown that the fluctuation-induced contribution to the relaxation time is indeed comparable with that of the BUU collision term in the vicinity of spinoidal region.
118464063
On freeze-out problem in relativistic hydrodynamics
A finite unbound system which is equilibrium in one reference frame is in general nonequilibrium in another frame. This is a consequence of the relative character of the time synchronization in the relativistic physics. This puzzle was a prime motivation of the Cooper-Frye approach to the freeze-out in relativistic hydrodynamics. Solution of the puzzle reveals that the Cooper-Frye recipe is far not a unique phenomenological method that meets requirements of energy-momentum conservation. Alternative freeze-out recipes are considered and discussed.
123789985
Relativistic mean field kinetics and dynamical instabilities in relativistic heavy ion collisions