Leading role pseudovector and vector mesons in quasielastic pion electroproduction on a nucleon by longitudinal photons at comparatively high virtual momenta in the range 0.4 {<=} vertical bar k vertical bar {<=} 1 GeV/c

Journal Article · Sat Mar 15 04:00:00 EDT 2008 · Physics of Atomic Nuclei

DOI:https://doi.org/10.1007/S11450-008-3016-1· OSTI ID:21077520

Neudatchin, V G; Obukhovsky, I T; Fedorov, D K; Yudin, N P ^[1]

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1. Moscow State University, Institute of Nuclear Physics (Russian Federation)

It is shown that, under kinematical conditions of quasielastic knockout, the differential cross section for the exclusive process p(e, e'{pi}{sup +})n induced by longitudinal virtual photons {gamma}*{sub L} changes its physical nature as the recoil momentum vertical bar k vertical bar of the spectator nucleon grows from values in the range vertical bar k vertical bar {approx} 0.1-0.4 GeV/c, which are typical in studying the pion cloud of the nucleon, to values around vertical bar k vertical bar {approx} 1 GeV/c. Calculations within the {sup 3}P{sub 0} quark microscopic model reveal that the amplitudes for the deexcitation of vector and pseudovector mesons via the processes {rho}{sup +} + {gamma}*{sub L} {sup {yields}} {pi}{sup +} and b{sub 1}{sup +} + {gamma}*{sub L} {sup {yields}} {pi}{sup +} become dominant here. Concurrently, the effective momentum distributions develop a substantial angular anisotropy of about 50% with respect to the angle between the momentum of the photon {gamma}*{sub L} and the recoil momentum of the spectator nucleon, the longitudinal differential cross sections undergoing respective changes. In this region, the energy of knock-on pions is expected to be about 5 GeV under conditions of quasielastic kinematics.

• OSTI ID: 21077520
• Journal Information: Physics of Atomic Nuclei, Journal Name: Physics of Atomic Nuclei Journal Issue: 3 Vol. 71; ISSN 1063-7788; ISSN PANUEO
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AMPLITUDES
ANISOTROPY
AXIAL VECTOR MESONS
DE-EXCITATION
DIFFERENTIAL CROSS SECTIONS
DISTRIBUTION
ELECTROPRODUCTION
GEV RANGE 01-10
KNOCK-ON
KNOCK-OUT REACTIONS
NUCLEONS
PHOTONS
PIONS PLUS
QUARKS
RECOILS
VECTOR MESONS