Dihadron correlations at high pT

Jet quenching in the matter created in high energy nucleus-nucleus collisions provides a tomographic tool to probe the medium properties. Recent experimental results from the Relativistic Heavy-Ion Collider (RHIC) on characterization of jet production via dihadron correlations at high transverse momentum are reviewed. Expectations from the dihadron measurements for the lower energy \sqrtsNN=62.4 GeV RHIC run are discussed.Comment: Talk given at Hot Quarks 2004: Workshop for Young Scientists on the Physics of Ultrarelativistic Nucleus-Nucleus Collisions (HQ'04), Taos Valley, New Mexico, 18-24 Jul 200

High pTp_T hadrons in Au+Au collisions at RHIC

High pT hadrons produced in ultra-relativistic heavy-ion collisions at RHIC probe nuclear matter at extreme conditions of high energy density. Experimental measurements in Au+Au collisions at \sqrtsNN=130, 200 GeV establish the existence of strong medium effects on hadron production well into the perturbative regime.Comment: 4 pages, Talk given at 32nd International Symposium on Multiparticle Dynamics (ISMD 2002), Alushta, Ukraine, 7-13 Sep 200

On the structure of the seminal receptacle in cyclopids (Copepoda, Cyclopoida). [Translation from: Informatsionnyi Byulleten Biologiya Vnutrennikh Vod (6) 26-31, 1970.]

The seminal bag, or seminal receptacle, forms a characteristic organ of cyclopids, serving for retention of the sperms discharged from the spermatophores. The structure of the seminal receptacle, more precisely its form, is fairly widely used in diagnosis and undoubtedly can be more widely applied in the systematics of the group. Within the limits of the family Cyclopidae it is possible to distinguish crustaceans with three basic types of seminal bag. The differences consist of the position which this organ occupies in the genital segment. of one species, we carried out a series of observations on its formation in ontogenesis and during the life of the adult stage. As material for observation the study used laboratory cultures of three species; Acanthocyclops americanus (Marsh) from the plankton of the Moscow River, Cyclops vicinus Uljan and Mesocyclops leuckarti Glaus from the plankton of the channel section of the upper part of the Gorkovsk reservoir. The author concluded that the irreversibility of the changes in the seminal receptacle presents the possibility of utilising this structure as one of the indicators of the growth of the individual

Parallel Splitting and Decomposition Method for Computations of Heat Distribution in Permafrost

A mathematical model, numerical algorithm and program code for simulation and long-term forecasting of changes in permafrost as a result of operation of a multiple well pad of northern oil and gas field are presented. In the model the most significant climatic and physical factors are taken into account such as solar radiation, determined by specific geographical location, heterogeneous structure of frozen soil, thermal stabilization of soil, possible insulation of the objects, seasonal fluctuations in air temperature, and freezing and thawing of the upper soil layer. A parallel algorithm of decomposition with splitting by spatial variables is presented

Overview of results from the STAR experiment at RHIC

The Relativistic Heavy-Ion Collider (RHIC) provides Au+Au collisions at energies up to \sqrtsNN=200 GeV. STAR experiment was designed and constructed to investigate the behavior of strongly interacting matter at high energy density. An overview of some of the recent results from the STAR collaboration is given.Comment: Invited talk at International Conference "I. Ya. Pomeranchuk and physics at the turn of centuries" (January 24-28, 2003, Moscow

Low-Mass Lepton Pair Production in Pb-Au Collisions at 40 AGeV

The CERES/NA45 experiment at the CERN SPS has previously measured $e^{+}e^{-}$ pair production in 160 AGeV Pb-Au collisions. In the mass region m>0.2 GeV/c$^{2}$, an enhancement of $2.7\pm0.4(statist.)\pm0.5(syst.)$ compared to the expectation from known hadronic decay sources was observed. In the 40 AGeV data taken in 1999, an enhancement is again found; a preliminary analysis gives the even larger value of $4.5\pm1.2(statist.)$. The results are compared to theoretical model calculations based on $\pi^{+}\pi^{-}$ annihilation with a modified $\rho$-propagator.Comment: To appear in the proceedings of International Europhysics Conference on High-Energy Physics (HEP 2001), Budapest, Hungary, 12-18 Jul 200

Self-Excited Multifractal Dynamics

We introduce the self-excited multifractal (SEMF) model, defined such that the amplitudes of the increments of the process are expressed as exponentials of a long memory of past increments. The principal novel feature of the model lies in the self-excitation mechanism combined with exponential nonlinearity, i.e. the explicit dependence of future values of the process on past ones. The self- excitation captures the microscopic origin of the emergent endogenous self-organization properties, such as the energy cascade in turbulent flows, the triggering of aftershocks by previous earthquakes and the "reflexive" interactions of financial markets. The SEMF process has all the standard stylized facts found in financial time series, which are robust to the specification of the parameters and the shape of the memory kernel: multifractality, heavy tails of the distribution of increments with intermediate asymptotics, zero correlation of the signed increments and long-range correlation of the squared increments, the asymmetry (called "leverage" effect) of the correlation between increments and absolute value of the increments and statistical asymmetry under time reversal