Measurement of semi-inclusive {pi}{sup +} electroproduction off the proton

Journal Article · Sat Aug 01 04:00:00 EDT 2009 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.80.032004· OSTI ID:21322318

Osipenko, M ^[1]; Ripani, M; Ricco, G; De Vita, R; Anghinolfi, M; Battaglieri, M; Corvisiero, P; Taiuti, M ^[1]; Avakian, H; Burkert, V D; Carman, D S; Degtyarenko, P V; Deur, A; Elouadrhiri, L; Guo, L; Gyurjyan, V; Heddle, D; Ito, M M; Mecking, B A; Mestayer, M D ^[2]

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1. INFN, Sezione di Genova, 16146 Genova (Italy)
2. Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States)

Semi-inclusive {pi}{sup +} electroproduction on protons has been measured with the CLAS detector at Jefferson Lab. The measurement was performed on a liquid-hydrogen target using a 5.75 GeV electron beam. The complete five-fold differential cross sections were measured over a wide kinematic range including the complete range of azimuthal angles between hadronic and leptonic planes, {phi}, enabling us to separate the {phi}-dependent terms. Our measurements of the {phi}-independent term of the cross section at low Bjorken x were found to be in fairly good agreement with pQCD calculations. Indeed, the conventional current fragmentation calculation can account for almost all of the observed cross section, even at small {pi}{sup +} momentum. The measured center-of-momentum spectra are in qualitative agreement with high-energy data, which suggests a surprising numerical similarity between the spectator diquark fragmentation in the present reaction and the antiquark fragmentation measured in e{sup +}e{sup -} collisions. We have observed that the two {phi}-dependent terms of the cross section are small. Within our precision the cos2{phi} term is compatible with zero, except for the low-z region, and the measured cos{phi} term is much smaller in magnitude than the sum of the Cahn and Berger effects.

• OSTI ID: 21322318
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 3 Vol. 80; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANTIQUARKS
CEBAF ACCELERATOR
DIFFERENTIAL CROSS SECTIONS
ELECTRON BEAMS
ELECTRON-POSITRON COLLISIONS
ELECTROPRODUCTION
FRAGMENTATION
GEV RANGE 01-10
HYDROGEN 1 TARGET
PIONS PLUS
PROTONS
SPECTRA
TEMPERATURE RANGE 0013-0065 K