Search for Higgs Boson at LHC in the Reaction pp->gamma+gamma+jet at a Low Luminosity

We discuss the SM Higgs discovery potential of the LHC in the channel pp->H+jet->gamma+gamma+jet when the jet is observed at sufficiently high Pt and a small rapidity to be reliably identified. We calculate all the signal subprocesses and the irreducible background with realistic kinematical cuts. The reducible QCD background is also estimated. We conclude that the channel gamma+gamma+jet can give about 120-200 signal events for Higgs mass MH=100-140 GeV at the integrated luminosity of 30 inverse fb. This signal rate should be compared with only 330-600 events for the irreducible background per two-photon invariant mass interval of 2 GeV. We estimate the QCD reducible background at the level of 20% of the irreducible one. Thus, one may hope that the Higgs boson can be discovered already during the LHC operation at a low luminosity. At a high luminosity the observation of several hundreds of high Pt Higgs bosons in this channel will be possible with significance higher than 15 for L=100 inverse fb.Comment: 21 pages (LaTeX code, epsf.sty), 2 tables, 9 figures; to appear in the Proceedings of XIIth International Workshop on High Energy Physics and Quantum Field Theory (QFTHEP-97), Samara, Russia, September 4-10, 199

Genome Data Integration and Index Optimization Based on JBrowse

随着基因组计划对物种遗传信息研究的发展，基因组注释、短序列比对分析已成为生物信息学研究的热点问题。为此，需要建立能够集成并可视化包含基因组注释、短序列比对等基因组数据的综合平台，采用相关的计算机技术有效管理数据，并能使生物学家在web上访问和使用。JBrowse等基因组浏览器将基因组数据在浏览器中以简单、直观方式综合查看已经成为解决此类问题的有效途径。JBrowse以其基于AJAX的交互操作、多轨道浏览、采用索引技术等多个特点成为使用广泛的基因浏览器之一。为了提高JBrowse的平台通用性和检索效率，本文基于该平台进行数据集成及数据检索改进，集成基因组注释和比对短序列并实现基因组数据可视化的综...The research that Genome Project carried out into the species genomic information develops, which has made genomic annotations and short reads alignment become the hot spots in bioinformatics studies. For this reason, it is necessary to build a comprehensive platform including genomic data such as genomic annotations and short reads alignment and so on, using the computer technology concerned to m...学位：工学硕士院系专业：信息科学与技术学院自动化系_系统工程学号：2322009115290

CompHEP: specialized package for automatic calculations of elementary particle decays and collisions

At present time when a new generation of TeV colliders are beginning to operate one needs to calculate cross-sections for a great number of various reactions. Such calculations are united in the framework of the collider physical program, providing definite predictions how to detect the signatures of the new physics and separate them from the background. The CompHEP package was created for calculation of decay and high energy collision processes of elementary particles in the lowest order (tree) approximation. The main idea put into the CompHEP was to make available passing from the lagrangian to the final distributions effectively with the high level of automatization what is extremely needed in collider physics

CompHEP-PYTHIA interface: integrated package for the collision events generation based on exact matrix elements

CompHEP, as a partonic event generator, and PYTHIA, as a generator of final states of detectable objects, are interfaced. Thus, integrated tool is proposed for simulation of (almost) arbitrary collision processes at the level of detectable particles. Exact (multiparticle) matrix elements, convolution with structure functions, decays, partons hadronization and (optionally) parton shower evolution are basic stages of calculations. The PEVLIB library of event generators for LHC processes is described.Comment: Standard LaTeX, 4 pages. To appear in the proceedings of the Seventh International Workshop on Advanced Computing and Analysis Technics in Physics Research (ACAT2000, Fermilab, October 16-20, 2000

New analytic unitarization schemes

We consider two well-known classes of unitarization of Born amplitudes of hadron elastic scattering. The standard class, which saturates at the black disk limit includes the standard eikonal representation, while the other class, which goes beyond the black-disk limit to reach the full unitarity circle, includes the U matrix. It is shown that the basic properties of these schemes are independent of the functional form used for the unitarisation, and that U matrix and eikonal schemes can be extended to have similar properties. A common form of unitarisation is proposed interpolating between both classes. The correspondence with different nonlinear equations are also briefly examined.Comment: 6 pages, 10 figures, corrected typos, 1 fig. redro

CMS ridge effect at LHC as a manifestation of bremstralung of gluons due to the quark-anti-quark string formation

The recently reported effect of long-range near-side angular correlations at LHC occurs for large multiplicities of particles with $1\,GeV\,<p_T\,<\,3\,GeV$. To understand the effect several possibilities have been discussed. In the letter we propose a simple qualitative mechanism which corresponds to gluon bremstralung of quarks moving with acceleration appropriate to the quark--anti-quark string. The smallness of azimuthal angle difference $\Delta \phi$ along with large $\Delta \eta$ at large multiplicities in this interval of $p_T$ are natural in the mechanism. The mechanism predicts also bremstralung photons with mean values of $p_T \approx 2.9$ and $0.72\,GeV$.Comment: 5 pages, 3 figure