Double Longitudinal Spin Asymmetries of Inclusive Charged Pion Production in Polarized p + p Collisions at 200 GeV

Journal Article · Wed Jun 13 04:00:00 EDT 2007 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2750795· OSTI ID:21061913

Kocoloski, Adam ^[1]

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1. Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States)

A primary goal of the STAR Spin program at RHIC is the measurement of the polarized gluon distribution function {delta}G, which can be obtained from a global analysis incorporating measurements of the double spin asymmetry ALL in various final state channels of polarized p + p collisions. Final states with large production cross sections such as inclusive jet and hadron production are analyzed as the program moves towards the measurement of ALL in the theoretically clean channel of prompt photon production. The channels p + p {yields} {pi}+/- + X are unique in that the ordering of the measurements of ALL in these two channels is sensitive to the sign of {delta}G. Moreover, STAR has already established the procedure for the identification of charged pions and the calculation of their production cross-sections over a broad kinematic range.This contribution will present first measurements of double longitudinal spin asymmetries for inclusive charged pion production extracted from 3 pb-1 of data at {radical}(s)=200 GeV and 50% beam polarizations. The asymmetries are calculated over the transverse momentum region 2 < pT < 10 GeV/c and compared with theoretical predictions incorporating several gluon polarization scenarios. A systematic bias introduced by the selection of charged pions from events satisfying electromagnetic energy triggers will be discussed and estimated using Monte Carlo.

• OSTI ID: 21061913
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 915; ISSN 0094-243X; ISSN APCPCS
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ASYMMETRY
BARYONS
BROOKHAVEN RHIC
CROSS SECTIONS
DISTRIBUTION FUNCTIONS
GEV RANGE
GLUONS
INCLUSIVE INTERACTIONS
JET MODEL
MONTE CARLO METHOD
MULTIPARTICLE SPECTROMETERS
PARTICLE IDENTIFICATION
PARTICLE PRODUCTION
PIONS
POLARIZATION
PROTON-PROTON INTERACTIONS
SPIN
TRANSVERSE MOMENTUM