The cross sections for π±, K±, p, and production in pp collisions have been measured at transverse momenta from 0.48 up to 2.21 GeV/c at 70 GeV. The data are compared with results obtained at lower and higher proton energies and also with the quantum chromodynamics parton model (QPM) calculations. Common behaviour of the cross sections of the form in the energy range above 200 GeV does not take place at lower energies. Qualitatively QPM fits the data and the best agreement is for π+/π? and K+/π+ ratios. 相似文献
The integrodifferential equation for the spatial motion of the interface of two fluids of differing weights and differing viscosities in a porous medium is presented. Results of its numerical solution are given. The general solution is given for the problem of the dynamics of a gently sloping surface.The author wishes to thank V. L. Danilov for his interest in the study and valuable advice. 相似文献
We report on a study of the ratio of inclusive three-jet to inclusive two-jet production cross sections as a function of total transverse energy in p&pmacr; collisions at a center-of-mass energy sqrt[s] = 1.8 TeV, using data collected with the D0 detector during the 1992-1993 run of the Fermilab Tevatron Collider. The measurements are used to deduce preferred renormalization scales in perturbative O(alpha(3)(s)) QCD calculations in modeling soft-jet emission. 相似文献
We introduce the notion of a resolving sequence of (scalar) operators for a given differential or difference system with coefficients in some differential or difference field K. We propose an algorithm to construct, such a sequence, and give some examples of the use of this sequence as a suitable auxiliary tool for finding certain kinds of solutions of differential and difference systems of arbitrary order. Some experiments with our implementation of the algorithm are reported. 相似文献
Journal of Structural Chemistry - As a result of crystallization from a solution containing Na5[H3PtW6O24] and Cs2SO4, yellow crystals of a complex are obtained. The composition and structure of... 相似文献
Active but unselective : Nucleoside triphosphates possessing glucose moieties (such as those depicted) instead of the natural furanose rings are recognised by the active sites of polymerases. Polymerases therefore seem to be very unspecific in their recognition patterns.