首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
We present the next-to-leading order (NLO) QCD results for W+4-jet production at hadron colliders. This is the first hadron-collider process with five final-state objects to be computed at NLO. It represents an important background to many searches for new physics at the energy frontier. Total cross sections, as well as distributions in the jet transverse momenta, are provided for the initial LHC energy of √s = 7 TeV. We use a leading-color approximation, known to be accurate to 3% for W production with fewer jets. The calculation uses the BLACKHAT library along with the SHERPA package.  相似文献   

2.
3.
The advent of high-energy hadron colliders necessitates efficient and accurate computation of multi-jet production processes, both as QCD processes in their own right and as backgrounds for other physics. The algorithm that performs these tasks and a brief numerical study of multi-jet processes are presented. Received: 21 February 2002 / Published online: 22 May 2002  相似文献   

4.
The non-relativistic wave function framework is applied to study the production and decay of exotic hadrons, which can be effectively described as bound states of other hadrons. Employing the factorized formulation,with the help of event generators, we investigate the production of exotic hadrons in multiproduction processes at high energy hadron colliders. This study provides crucial information for the measurements of the relevant exotic hadrons.  相似文献   

5.
6.
7.
《Nuclear Physics A》2006,764(1-2):52-77
We discuss new physical phenomena expected in particle production in hadron–hadron collisions at high energy, as a consequence of pomeron loop effects in the evolution equations for the color glass condensate. We focus on gluon production in asymmetric, ‘dilute–dense’, collisions: a dilute projectile scatters off a dense hadronic target, whose gluon distribution is highly evolved. This situation is representative for particle production in proton–proton collisions at forward rapidities (say, at LHC) and admits a dipole factorization similar to that of deep inelastic scattering (DIS). We show that at sufficiently large forward rapidities, where the pomeron loop effects become important in the evolution of the target wavefunction, gluon production is dominated by ‘black spots’ (saturated gluon configurations) up to very large values of the transverse momentum, well above the average saturation momentum in the target. In this regime, the produced gluon spectrum exhibits diffusive scaling, so like DIS at sufficiently high energy.  相似文献   

8.
9.
10.
The production of backward pions in lepton-nucleus collisions is analyzed. We show that a large yield of high momentum backward pions can be explained by the Regge asymptotic of the distribution of nucleons carrying a large momentum fraction in the nuclear target. The calculated spectra of pions emitted in the ν+ Ne →μ+π+ X and ν+2H →μ+π+ X reactions are in satisfactory agreement with the available experimental data. Received: 22 July 1999 / Revised version: 22 November 1999  相似文献   

11.
The most abundantly produced hadron species in Si - Au collisions at the BNL-AGS (nucleons, pions, kaons, antikaons and hyperons) are shown to be in accord with emission from a thermal resonance gas source. Within the uncertainties of the present data, two freeze-out points are possible. The best agreement is obtained for a temperature T ? 110 MeV and a baryochemical potential μB ? 540 MeV, corresponding to about 1/3 standard nuclear density. Another possible point lies at about twice nuclear density, with T ? 160 MeV and μB ? 620 MeV. Our analysis takes the isopin asymmetry of the initial state fully into account.  相似文献   

12.
13.
We calculate baryon distributions in the fragmentation region ofpp collision using Das and Hwa picture of quark recombination. A new estimation of the sea quark distributions in proton is obtained by fitting the pseudoscalar meson data at fixedP T taking account of parton transverse momenta.  相似文献   

14.
Analysis of diffractive production on nuclei implied cross sections of the diffractively produced system on nucleons which are smaller than the corresponding projectile nucleon cross sections. We provide a natural explanation for this feature in the Good-Walker coherent production formalism. A specific realization of the Good-Walker formalism stated in terms of quarks and connecting electric flux tubes and some ensuing consequences are also discussed briefly.  相似文献   

15.
16.
《Nuclear Physics B》1986,263(1):37-60
We consider the problem of how to compute the cross section for producing heavy strongly interacting particles (quarks, gluinos, squarks …) in high-energy hadron collisions, supposing that the heavy particle masses are large compared to 1 GeV. We use heavy quark production as an example. We consider several low-order graphs in the kinematic region expected to produce the bulk of the total production cross section. Based on the structure of the low-order graphs, we argue that the cross section can be reliably computed in QCD by using the same factorization formula that is used for jet production and W and Z production, but inserting the appropriate parton level cross sections for the heavy particle production. We emphasize that an analysis at all orders of perturbation theory is needed to reliably establish this conjecture.  相似文献   

17.
Multihadron production in high energy collisions, from e+e- annihilation to heavy ion interactions, shows remarkable thermal behaviour, specified by a universal “Hagedorn” temperature. We argue that this hadronic radiation is formed by tunneling through the event horizon of colour confinement, i.e., that it is the QCD counterpart of Hawking-Unruh radiation from black holes. It is shown to be emitted at a universal temperature TH ≃ (σ/2 π)1/2, where σ denotes the string tension. Since the event horizon does not allow information transfer, the radiation is thermal “at birth”.  相似文献   

18.
Using a non-relativistic gluon bound-state model for glueballs (G), we compute the subprocess $q\bar q \to G\pi $ , and we therefrom derive the yield of the overall reaction $p\bar p \to G\pi X$ , assuming the glueball and the pion to be emitted with their transverse momenta large, opposite and approximately equal. Numerical results are presented in the form ofp T spectra for various glueball candidates and their possible quantum states, assuming those particles to be produced, in the type of reactions here considered, at high-energy $p\bar p$ colliders such as the CERN $Sp\bar pS$ .  相似文献   

19.
《Nuclear Physics A》1997,624(4):738-754
Hadrons emitted by the pre-surface layer of a quark-gluon plasma (QGP) before the phase transition into a hadronic gas are considered as possible sources of direct information about QGP. It is shown that if QGP is created in ultrarelativistic heavy-ion collisions, then these hadrons strongly contribute at soft pt at SpS energy and dominate up to an order of magnitude at LHC energy.  相似文献   

20.
We consider the possible contribution of odderon (reggeon with α Odd(0)∼1 and negative signature) exchange to the differences in the inclusive spectra of particle and antiparticle in the central region. The energies and/or accuracy of the currently available experimental data do not allow for a clear conclusion on the presence of an odderon component, but the upcoming LHC data should finally elucidate the question of the existence of the odderon.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号