We study precise calculation of neutralino relic density in the minimal supergravity model. We compare the exact formula for the thermal average of the neutralino annihilation cross section times relative velocity with the expansion formula in terms of the temperature, including all the contributions to neutralino annihilation cross section analytically. We confirm that the expansion formula fa...

In this paper we consider a simultaneous system of spatially interrelated cross sectional equations. Our speci...cation incorporates spatial lags in the endogenous and exogenous variables. In modelling the disturbance process we allow for both spatial correlation as well as correlation across equations. The data set is taken to be a single cross section of observations. The model may be viewed ...

The study of top quark pair production at the Tevatron is now entering the realm of precision physics. With 2.8 fb−1 of CDF data there are over 1200 reconstructed tt̄ events in the lepton + jets channel. As the integrated luminosity increases, it is possible to improve not only measurements of the properties of the top quark but also maybe to search for new physics by comparing the tt̄ cross sect...

We study the effects of threshold resummation on the rapidity dependence of singleparticle-inclusive cross sections, using the prompt photon cross section as an example. We make use of the full resummation formula at next-to-leading logarithmic accuracy and develop a new technique for treating rapidity in resummation. We compare our phenomenological results with those of previous studies and di...

The 23gPrr(n,2n) and the 235u(r,,.2n) ~roSSsection are estimated by aPPIYing unit arit y in several approaches: a subtraction method and also by using a ratio approach that relates the above cross sections to the 23sU(n,2n) cross 239pu(n,@ cross section tO the section and the 235U(n)2n) cross section, respectively. Also, a self-consistent, simultaneous analysis of the cross section data of four...

The presence of 2γ-exchange in electron proton elastic scattering is discussed. From C-invariance and crossing symmetry, 2γ contribution induces a specific dependence of the reduced cross section on the variable ǫ. No evidence of such dependence exists in the available experimental data.