585 research outputs found

    略论《共产党宣言》中的马克思主义自由观

    Get PDF
    本文着眼于《共产党宣言》中若干与马克思主义自由观有关的论述,从马克思主义自由观的历史发展,信仰自由、宗教自由、政治自由等精神领域的自由、无产阶级争取自由的斗争,以及社会自由与个人自由的发展的关系等角度进行了一些探讨,并简要分析了个人自由的发展与社会自由的发展之间的关系的现实意义

    Transverse mass and invariant mass observables for measuring the mass of a semi-invisibly decaying heavy particle

    Full text link
    Formulae are derived for the positions of end-points in the invariant mass and transverse mass distributions obtained from the products of heavy states decaying to pairs of semi-invisibly decaying lighter states. Formulae are derived both for the special case where the two decay chains are identical and the more general case where they are different. The formulae are tested with a simple case study of heavy SUSY higgs particles decaying to gauginos at the LHC.Comment: 13 pages, 8 eps figure

    The Analysis of Multijet Events Produced at High Energy Hadron Colliders

    Get PDF
    We define and discuss a set of (4N - 4) parameters that can be used to analyse events in which N jets have been produced in high energy hadron-hadron collisions. These multijet variables are the multijet mass and (4N - 5) independent dimensionless parameters. To illustrate the use of the variables QCD predictions are presented for events with up to five jets produced at the Fermilab Tevatron Proton-Antiproton Collider. These QCD predictions are compared with the predictions of a model in which multijet events uniformly populate the N-body phase-space

    Sqrt{shat}_{min} resurrected

    Full text link
    We discuss the use of the variable sqrt{shat}_{min}, which has been proposed in order to measure the hard scale of a multi parton final state event using inclusive quantities only, on a SUSY data sample for a 14 TeV LHC. In its original version, where this variable was proposed on calorimeter level, the direct correlation to the hard scattering scale does not survive when effects from soft physics are taken into account. We here show that when using reconstructed objects instead of calorimeter energy and momenta as input, we manage to actually recover this correlation for the parameter point considered here. We furthermore discuss the effect of including W + jets and t tbar+jets background in our analysis and the use of sqrt{shat}_{min} for the suppression of SM induced background in new physics searches.Comment: 23 pages, 9 figures; v2: 1 figure, several subsections and references as well as new author affiliation added. Corresponds to published versio

    Elastic pp Scattering at LHC Energies

    Full text link
    We consider the first LHC data for elastic pp scattering in the framework of Regge theory with multiple Pomeron exchanges. The simplest eikonal approach allows one to describe differential elastic cross sections at LHC, as well as pp and pˉp\bar{p}p scattering at lower collider energies, on a reasonable level.Comment: 11 pages, 5 figures, and 1 tabl

    Proton-nucleus cross section at high energies

    Full text link
    Cross sections for proton inelastic collision with different nuclei are described within the Glauber and multiple scattering approximations. A significant difference between approximate `Glauber' formula and exact calculations with a geometrical scaling assumption for very high-energy cross section is shown. Experimental values of proton-proton cross sections obtained using extensive air shower data are based on the relationship of proton-proton and respective proton-air absorption cross sections. According to obtained results values reported by the Akeno and Fly's Eye experimental groups are about 10% overestimated. The proper energy dependence of absorption cross section for collisions with air nuclei is of a great importance for studies of high energy cosmic rays using the Monte Carlo technique.Comment: 9pp (9 eps figures

    Extraction and Partial Characterization of Cellulases from Expanding Pea Epicotyls

    Full text link

    How to Make Large Domains of Disoriented Chiral Condensate

    Full text link
    Rajagopal and Wilczek have proposed that relativistic nuclear collisions can generate domains in which the chiral condensate is disoriented. If sufficiently large ({\it i.e.} nucleus sized), such domains can yield measurable fluctuations in the number of neutral and charged pions. However, by numerical simulation of the zero-temperature two-flavor linear sigma model, we find that domains are essentially {\it pion} sized. Nevertheless, we show that large domains can occur if the effective mesons masses are much lighter.Comment: 6 pages and 2 postscript figures, BNL-GGP-

    Effect of friction on disoriented chiral condensate formation

    Full text link
    We have investigated the effect of friction on the DCC domain formation. We solve the Newton equation of motion for the O(4) fields, with quenched initial condition. The initial fields are randomly distributed in a Gaussian form. In one dimensional expansion, on the average, large DCC domains can not be formed. However, in some particular orbits, large instabilities may occur. This possibility also greatly diminishes with the introduction of friction. But, if the friction is large, the system may be overdamped and then, there is a possibility of large DCC domain formation in some events.Comment: 9 pages, including figure

    Hadronic Total Cross-sections Through Soft Gluon Summation in Impact Parameter Space

    Get PDF
    The Bloch-Nordsieck model for the parton distribution of hadrons in impact parameter space, constructed using soft gluon summation, is investigated in detail. Its dependence upon the infrared structure of the strong coupling constant αs\alpha_s is discussed, both for finite as well as singular, but integrable, αs\alpha_s. The formalism is applied to the prediction of total proton-proton and proton-antiproton cross-sections, where screening, due to soft gluon emission from the initial valence quarks, becomes evident.Comment: 20 pages, Latex2e, input FEYNMAN,12 postscipt figures. Submitted to PR
    corecore