Parton intrinsic motion: Suppression of the Collins mechanism for transverse single spin asymmetries in p{sup {up_arrow}}p{yields}{pi}X

Journal Article · Sat Jan 01 04:00:00 EST 2005 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PhysRevD.71.014002· OSTI ID:20705699

Anselmino, M; Boglione, M ^[1]; D'Alesio, U; Murgia, F ^[2]; Leader, E ^[3]

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1. Dipartimento di Fisica Teorica, Universita di Torino and INFN, Sezione di Torino, Via P. Giuria 1, I-10125 Torino (Italy)
2. INFN, Sezione di Cagliari and Dipartimento di Fisica, Universita di Cagliari, C.P. 170, I-09042 Monserrato, CA (Italy)
3. Imperial College, Prince Consort Road, London, SW7 2BW (United Kingdom)

We consider a general formalism to compute inclusive polarized and unpolarized cross sections within pQCD and the factorization scheme, taking into account parton intrinsic motion in distribution and fragmentation functions, as well as in the elementary dynamics. Surprisingly, the intrinsic partonic motion, with all the correct azimuthal angular dependences, produces a strong suppression of the transverse single spin asymmetry arising from the Collins mechanism. As a consequence, and in contradiction with earlier claims, the Collins mechanism is unable to explain the large asymmetries found in p{sup {up_arrow}}p{yields}{pi}X at moderate to large Feynman x{sub F}. The Sivers effect is not suppressed.

• OSTI ID: 20705699
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 1 Vol. 71; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ASYMMETRY
BARYONS
DISTRIBUTION
FACTORIZATION
INCLUSIVE INTERACTIONS
PARTICLE PRODUCTION
PARTON MODEL
PARTONS
PERTURBATION THEORY
POLARIZATION
POLARIZED BEAMS
PROTON BEAMS
PROTON-PROTON INTERACTIONS
QUANTUM CHROMODYNAMICS
SPIN