4,756 research outputs found
Meson Production in Proton-Proton Collisions in the Naive Non-Abelianization Approximation and the Role of Infrared Renormalons
We calculate the "naive non-abelianization" (NNA) contributions of the
higher-twist Feynman diagrams to the large- 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
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
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 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 2 creation mechanism production, including the result
Brodsky-Kinoshita-Terazawa, is given.Comment: 25 pages, 4 figures, 5 table
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