Recent Measurements of the cos(n{phi}{sub h}) Azimuthal Modulations of the Unpolarized Deep Inelastic Scattering Cross-section at HERMES

Journal Article · Thu Dec 17 00:00:00 EST 2009 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3293873· OSTI ID:21325695

Lamb, Rebecca; Giordano, Francesca ^[1]

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1. University of Illinois (United States)

The cross section for hadron production in deep-inelastic lepton scattering contains azimuthal modulations which can be related to transverse momentum dependent (TMD) distribution and fragmentation functions. The former provide a picture of how the quarks are moving within nucleons. Specifically, the cos{phi}{sub h} and cos2{phi}{sub h} modulations of the unpolarized cross section relate quark spin and quark transverse momentum. These moments have been carefully measured at the HERMES experiment in a fully differential way, as a function of x, y, z, and P{sub hperpendicular} for positive and negative hadrons produced from hydrogen and deuterium targets. These measurements give new access to the flavor dependent TMDs via their charge and target dependence. These data must be compared to comprehensive models to determine which terms contribute significantly to the cos{phi}{sub h} and cos2{phi}{sub h} moments and allow access to the underlying structure functions.

• OSTI ID: 21325695
• Journal Information: AIP Conference Proceedings, Vol. 1182, Issue 1; Conference: 10. conference on the intersections of particle and nuclear physics, San Diego, CA (United States), 26-31 May 2009; Other Information: DOI: 10.1063/1.3293873; (c) 2009 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CROSS SECTIONS
DEEP INELASTIC SCATTERING
DEUTERIUM TARGET
ELECTRIC MOMENTS
FLAVOR MODEL
HERA STORAGE RING
HYDROGEN 1 TARGET
LEPTON-NUCLEON INTERACTIONS
LEPTONS
MODULATION
MULTIPARTICLE SPECTROMETERS
NUCLEONS
PARTICLE IDENTIFICATION
PARTICLE PRODUCTION
POLARIZATION
QUARKS
SPIN
STRUCTURE FUNCTIONS
TRANSVERSE MOMENTUM