Longitudinal Momentum Fraction X_L for Two High P_t Protons in pp->ppX Reaction

We present an analysis of new data from Experiment E850 at BNL. We have characterized the inclusive cross section near the endpoint for pp exclusive scattering in Hydrogen and in Carbon with incident beam energy of 6 GeV. We select events with a pair of back-to-back hadrons at large transverse momentum. These cross sections are parameterized with a form $\frac{d \sigma}{d X_{L}}$ $\sim(1-X_{L})^{p}$, where ${X_{L}}$ is the ratio of the longitudinal momentum of the observed pair to the total incident beam momentum. Small value of $p$ may suggest that the number of partons participating in the reaction is large and reaction has a strong dependence on the center-of-mass energy. We also discuss nuclear effects observed in our kinematic region.Comment: 4 pages, 2 figures, to be published in Proceedings of CIPANP2000, Quebec, May 22-28, 2000, requires aipproc.sty(included

Задача № 3 Дифференциальная диагностика кистозных образований легких

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Energy Dependence of Nuclear Transparency in C(p,2p) Scattering

The transparency of carbon for (p,2p) quasi-elastic events was measured at beam energies ranging from 6 to 14.5 GeV at 90 degrees c.m. The four momentum transfer squared q*q ranged from 4.8 to 16.9 (GeV/c)**2. We present the observed energy dependence of the ratio of the carbon to hydrogen cross sections. We also apply a model for the nuclear momentum distribution of carbon to normalize this transparency ratio. We find a sharp rise in transparency as the beam energy is increased to 9 GeV and a reduction to approximately the Glauber level at higher energies.Comment: 4 pages, 2figures, submitted to PR

Тяжелая форма гриппа A (H1N1) — патологическая анатомия легких

Twenty-five autopsy cases of influenza А (НШ1) in Moscow were analyzed. Primary pathological changes were found in the trachea and lung. The lung showed a pattern of the exudative and proliferative stages of diffuse alveolar damage. In addition, there were signs of infectious-toxic shock associated with viremia. Bacterial bronchopneumonia with confluent foci was detected in only 20% of the dead cases. Key words: influenza А (НШ1), diffuse alveolar damage.Проанализировано 25 аутопсийных наблюдений погибших от гриппа А (НШ1) в Москве. Было обнаружено, что основные патологические изменения имеют место в трахее и легких. В легких наблюдали картину экссудативной и про-лиферативной стадий острого диффузного альвеолярного повреждения. Кроме того, выявлены признаки инфекцион-но-токсического шока, связанного с виремией. Бактериальная очагово-сливная бронхопневмония обнаружена только у 20% умерших при тяжелом течении гриппа А/НШ1. Ключевые слова: грипп А (НШ1), диффузное альвеолярное повреждение

Practical divide-and-conquer algorithms for polynomial arithmetic

We investigate two practical divide-and-conquer style algorithms for univariate polynomial arithmetic. First we revisit an algorithm originally described by Brent and Kung for composition of power series, showing that it can be applied practically to composition of polynomials in Z[x] given in the standard monomial basis. We offer a complexity analysis, showing that it is asymptotically fast, avoiding coefficient explosion in Z[x]. Secondly we provide an improvement to Mulders' polynomial division algorithm. We show that it is particularly efficient compared with the multimodular algorithm. The algorithms are straightforward to implement and available in the open source FLINT C library. We offer a practical comparison of our implementations with various computer algebra systems