4,289 research outputs found

    Meson Production in Proton-Proton Collisions in the Naive Non-Abelianization Approximation and the Role of Infrared Renormalons

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    We calculate the "naive non-abelianization" (NNA) contributions of the higher-twist Feynman diagrams to the large-pTp_T inclusive pion production cross section in proton-proton collisions in the case of the running coupling and frozen coupling approaches. We compare the resummed "naive non-abelianization" higher-twist cross sections with the ones obtained in the framework of the frozen coupling approach and leading-twist cross section. The structure of infrared renormalon singularities of the higher twist subprocess cross section and it's resummed expression are found. We discuss the phenomenological consequences of possible higher-twist contributions to the pion production in proton-proton collisions in within NNA.Comment: 17 pages, 9 figure

    Charge-odd correlation of lepton and pion pair production in electron-proton scattering

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    Charge-odd correlation of the charged pair components produced at electron-proton scattering can measure three current correlation averaged by proton state. In general these type correlation can be described by 14 structure functions. We restrict here by consideration of inclusive distributions of a pair components, which is the light-cone projection of the relevant hadronic tensor. Besides we consider the point-like approximation for proton and pion. Numerical estimations show that charge-odd effects can be measured in exclusive ep -> 2 pi X experiments.Comment: 10 pages, 4 figure

    Processes of heavy quark pair (lepton pair) and two gluon (two photon) production in the high energy quark (electron) proton peripheral collisions

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    We considered the three jet production processes in the region of the incident lepton, photon, quark or gluon fragmentation. The fourth jet is created by the recoil proton. The kinematics of jet production is discussed in jets production in the fragmentation region. The non-trivial relation between the momenta of the recoil proton and the polar angle of its emission was derived. Based on this formalism the differential cross sections of QCD processes gp→(ggg)p;   qp→(qQˉQ)p;   gp→(gQQˉ)pgp \to (ggg) p; \,\,\,qp \to (q \bar{Q} Q) p; \,\,\, gp \to (g Q \bar{Q})p were obtained, including the distribution on transverse momentum component of jets fragments. It was shown that the role of the contribution of "non-Abelian" nature may become dominant in a particular kinematics of the final particles. The kinematics, in which the initial particle changes the direction of movement to the opposite one, was considered in the case of heavy quark-antiquark pair production. Different distributions, including spectral, azimuthal and polar angle distribution on the fragments of jets can be arranged using our results. We present besides the behavior of the ratio of non-Abelian contribution to the cross section to the total contribution. We show that it dominates for large values of the transverse momenta of jets component (gluons or quarks). Some historical introduction to the cross-sections of peripheral processes, including 2γ\gamma creation mechanism production, including the result Brodsky-Kinoshita-Terazawa, is given.Comment: 25 pages, 4 figures, 5 table
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