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D. M. Ostrovsky

Publications and source records attributed to D. M. Ostrovsky.

8 recordsLinked to original sources
arXiv2002

Forced Tunneling and Turning State Explosion in Pure Yang-Mills Theory

We consider forced tunneling in QCD, described semiclassically by instanton-antiinstanton field configurations. By separating topologically different minima we obtain details of the effective potential and study the turning states, which are similar to the sphaleron solution in electroweak theory. These states are alternatively derived as minima of the energy under the constraints of fixed size and Chern-Simons number. We study, both analytically and numerically, the subsequent evolution of such states by solving the classical Yang-Mills equations in real time, and find that the gauge field strength is quickly localized into an expanding shell of radiating gluons. The relevance to high-energy collisions of hadrons and nuclei is briefly discussed.

hep-ph↗
arXiv2001

Instanton-induced Semi-hard Parton Interactions and Phenomenology of High Energy Hadron Collisions

We phenomenologically study whether partonic collisions responsible for the growth of hadron-hadron cross sections at high energy can be ascribed to instanton-induced processes. Although non-perturbative in nature, these interactions occur at the semi-hard scale $Q\sim 1-2$ GeV, and should therefore be described using information from deep inelastic leptonic scattering on the partonic constituents in nucleons, pions, and photons. After considering shadowing corrections in nucleon-nucleon scattering, we fix a free instanton tail suppression parameter and determine the effective quark-quark cross section. The resulting contributions to $NN$, $πN$, $γN$, and $γγ$ cross sections all $increase$ with energy differently, but in reasonable agreement with experimental data. We then proceed to an estimate of the number of such processes present in high energy Au-Au collisions at RHIC, finding that the amount of entropy produced by instanton/sphaleron events matches the observed amount.

hep-ph↗
arXiv2000

Angular pattern of minijet transverse energy flow in hadron and nuclear collisions

The azimuthal asymmetry of minijet system produced at the early stage of nucleon-nucleon and nuclear collisions in a central rapidity window is studied. We show that in pp collisions the minijet transverse energy production in a central rapidity window is essentially unbalanced in azimuth due to asymmetric contributions in which only one minijet hits the acceptance window. We further study the angular pattern of transverse energy flow generated by semihard degrees of freedom at the early stage of high energy nuclear collisions and its dependence on the number of semihard collisions in the models both including and neglecting soft contributions to the inelastic cross section at RHIC and LHC energies as well as on the choice of the infrared cutoff.

hep-ph↗
arXiv1998

Minijet transverse energy production in the next-to-leading order in hadron and nuclear collisions

The transverse energy flow generated by minijets in hadron and nuclear collisions into a given rapidity window in the central region is calculated in the next-to-leading (NLO) order in QCD at RHIC and LHC energies. The NLO transverse energy production in pp collisions cross sections are larger than the LO ones by the factors of K_{RHIC} ~ 1.9 and K_{LHC} ~ 2.1 at RHIC and LHC energies correspondingly. These results were then used to calculate transverse energy spectrum in nuclear collisions in a Glauber geometrical model. We show that accounting for NLO corrections in the elementary pp collisions leads to a substantial broadening of the E_{perp} distribution for the nuclear ones, while its form remains practically unchanged.

hep-ph↗
arXiv1997

Nonperturbative Violation of Factorial Moments Scaling in Dissipative QCD jets

The nonperturbative modification of the evolution equation for QCD generating functional is applied to the analysis of the factorial moments of the intrajet particle distributions in QCD. Nonperturbative preasymptotic correction to the factorial moments scaling (F-scaling) is calculated. The results are compared with the available experimental data. The data show the possible presence of such a nonperturbative effect.

hep-ph↗
arXiv1996

Nonperturbative dissipation in QCD jets

The phenomenological energy dissipation in QCD jets evolution with colour coherence is considered and the corresponding modified parton multiplicity and distribution function are computed.

hep-ph↗