Backward dilepton production in color dipole and parton models

Journal Article · Mon Mar 01 00:00:00 EST 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.81.054015· OSTI ID:21409847

Gay Ducati, Maria Beatriz; Graeve de Oliveira, Emmanuel ^[1]

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1. Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, 91501-970 Porto Alegre, Rio Grande do Sul (Brazil)

The Drell-Yan dilepton production at backward rapidities is studied in proton-nucleus collisions at Relativistic Heavy Ion Collider and LHC energies by comparing two different approaches: the k{sub T} factorization at next-to-leading order with intrinsic transverse momentum and the same process formulated in the target rest frame, i.e., the color dipole approach. Our results are expressed in terms of the ratio between p(d)-A and p-p collisions as a function of transverse momentum and rapidity. Three nuclear parton distribution functions are used: EKS (Eskola, Kolhinen, and Ruuskanen), EPS08, and EPS09 and, in both approaches, dileptons show sensitivity to nuclear effects, specially regarding the intrinsic transverse momentum. Also, there is room to discriminate between formalisms: the color dipole approach lacks soft effects introduced by the intrinsic k{sub T}. Geometric scaling GBW (Golec-Biernat and Wusthoff) and BUW (Boer, Utermann, and Wessels) color dipole cross section models and also a DHJ (Dumitru, Hayashigaki, and Jalilian-Marian) model, which breaks geometric scaling, are used. No change in the ratio between collisions is observed, showing that this observable is not changed by the particular shape of the color dipole cross section. Furthermore, our k{sub T} factorization results are compared with color glass condensate results at forward rapidities: the results agree at Relativistic Heavy Ion Collider although disagree at LHC, mainly due to the different behavior of target gluon and quark shadowing.

• OSTI ID: 21409847
• Journal Information: Physical Review. D, Particles Fields, Vol. 81, Issue 5; Other Information: DOI: 10.1103/PhysRevD.81.054015; (c) 2010 The American Physical Society; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BROOKHAVEN RHIC
CERN LHC
COLLISIONS
COLOR MODEL
CONDENSATES
CROSS SECTIONS
DIPOLES
DISTRIBUTION FUNCTIONS
DRELL MODEL
FACTORIZATION
GLUONS
PARTICLE RAPIDITY
PROTON-NUCLEON INTERACTIONS
QUARK MODEL
QUARKS
SCALING
SENSITIVITY
TRANSVERSE MOMENTUM
ACCELERATORS
BARYON-BARYON INTERACTIONS
BOSONS
COMPOSITE MODELS
CYCLIC ACCELERATORS
FERMIONS
FUNCTIONS
HADRON-HADRON INTERACTIONS
HEAVY ION ACCELERATORS
INTERACTIONS
LINEAR MOMENTUM
MATHEMATICAL MODELS
MULTIPOLES
NUCLEON-NUCLEON INTERACTIONS
PARTICLE INTERACTIONS
PARTICLE MODELS
PARTICLE PROPERTIES
STORAGE RINGS
SYNCHROTRONS