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Title: Longitudinal Double-Spin Asymmetry and Cross Section for Inclusive Jet Production in Polarized Proton Collisions at {radical}(s)=200 GeV

Abstract

We report a measurement of the longitudinal double-spin asymmetry A{sub LL} and the differential cross section for inclusive midrapidity jet production in polarized proton collisions at {radical}(s)=200 GeV. The cross section data cover transverse momenta 5<p{sub T}<50 GeV/c and agree with next-to-leading order perturbative QCD evaluations. The A{sub LL} data cover 5<p{sub T}<17 GeV/c and disfavor at 98% C.L. maximal positive gluon polarization in the polarized nucleon.

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;  [1]; ;  [2]
  1. Yale University, New Haven, Connecticut 06520 (United States)
  2. Panjab University, Chandigarh 160014 (India) (and others)
Publication Date:
OSTI Identifier:
20861514
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review Letters; Journal Volume: 97; Journal Issue: 25; Other Information: DOI: 10.1103/PhysRevLett.97.252001; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ASYMMETRY; DIFFERENTIAL CROSS SECTIONS; GEV RANGE 100-1000; GLUONS; POLARIZATION; POLARIZED BEAMS; PROTON BEAMS; PROTONS; QUANTUM CHROMODYNAMICS; SPIN; TRANSVERSE MOMENTUM

Citation Formats

Abelev, B. I., Bielcik, J., Bielcikova, J., Caines, H., Catu, O., Chikanian, A., Du, F., Finch, E., Harris, J. W., Heinz, M., Lamont, M. A. C., Lin, G., Majka, R., Nattrass, C., Salur, S., Sandweiss, J., Smirnov, N., Witt, R., Aggarwal, M. M., and Bhati, A. K.. Longitudinal Double-Spin Asymmetry and Cross Section for Inclusive Jet Production in Polarized Proton Collisions at {radical}(s)=200 GeV. United States: N. p., 2006. Web. doi:10.1103/PHYSREVLETT.97.252001.
Abelev, B. I., Bielcik, J., Bielcikova, J., Caines, H., Catu, O., Chikanian, A., Du, F., Finch, E., Harris, J. W., Heinz, M., Lamont, M. A. C., Lin, G., Majka, R., Nattrass, C., Salur, S., Sandweiss, J., Smirnov, N., Witt, R., Aggarwal, M. M., & Bhati, A. K.. Longitudinal Double-Spin Asymmetry and Cross Section for Inclusive Jet Production in Polarized Proton Collisions at {radical}(s)=200 GeV. United States. doi:10.1103/PHYSREVLETT.97.252001.
Abelev, B. I., Bielcik, J., Bielcikova, J., Caines, H., Catu, O., Chikanian, A., Du, F., Finch, E., Harris, J. W., Heinz, M., Lamont, M. A. C., Lin, G., Majka, R., Nattrass, C., Salur, S., Sandweiss, J., Smirnov, N., Witt, R., Aggarwal, M. M., and Bhati, A. K.. Fri . "Longitudinal Double-Spin Asymmetry and Cross Section for Inclusive Jet Production in Polarized Proton Collisions at {radical}(s)=200 GeV". United States. doi:10.1103/PHYSREVLETT.97.252001.
@article{osti_20861514,
title = {Longitudinal Double-Spin Asymmetry and Cross Section for Inclusive Jet Production in Polarized Proton Collisions at {radical}(s)=200 GeV},
author = {Abelev, B. I. and Bielcik, J. and Bielcikova, J. and Caines, H. and Catu, O. and Chikanian, A. and Du, F. and Finch, E. and Harris, J. W. and Heinz, M. and Lamont, M. A. C. and Lin, G. and Majka, R. and Nattrass, C. and Salur, S. and Sandweiss, J. and Smirnov, N. and Witt, R. and Aggarwal, M. M. and Bhati, A. K.},
abstractNote = {We report a measurement of the longitudinal double-spin asymmetry A{sub LL} and the differential cross section for inclusive midrapidity jet production in polarized proton collisions at {radical}(s)=200 GeV. The cross section data cover transverse momenta 5<p{sub T}<50 GeV/c and agree with next-to-leading order perturbative QCD evaluations. The A{sub LL} data cover 5<p{sub T}<17 GeV/c and disfavor at 98% C.L. maximal positive gluon polarization in the polarized nucleon.},
doi = {10.1103/PHYSREVLETT.97.252001},
journal = {Physical Review Letters},
number = 25,
volume = 97,
place = {United States},
year = {Fri Dec 22 00:00:00 EST 2006},
month = {Fri Dec 22 00:00:00 EST 2006}
}
  • We report a measurement of the longitudinal double-spin asymmetry A{sub LL} and the differential cross section for inclusive midrapidity jet production in polarized proton collisions at {radical}s = 200 GeV. The cross section data cover transverse momenta 5 < p{sub T} < 50 GeV/c and agree with next-to-leading order perturbative QCD evaluations. The A{sub LL} data cover 5 < p{sub T} < 17 GeV/c and disfavor at 98% C.L. maximal positive gluon polarization in the polarized nucleon.
  • We report a measurement of the longitudinal double-spin asymmetry A{sub LL} and the differential cross section for inclusive {pi}{sup 0} production at midrapidity in polarized proton collisions at {radical}s = 200 GeV. The cross section was measured over a transverse momentum range of 1 < p{sub T} < 17 GeV/c and found to be in good agreement with a next-to-leading order perturbative QCD calculation. The longitudinal double-spin asymmetry was measured in the range of 3.7 < p{sub T} < 11 GeV/c and excludes a maximal positive gluon polarization in the proton. The mean transverse momentum fraction of {pi}{sup 0}'s inmore » their parent jets was found to be around 0.7 for electromagnetically triggered events.« less
  • We report a measurement of the longitudinal double-spin asymmetry A{sub LL} and the differential cross section for inclusive {pi}{sup 0} production at midrapidity in polarized proton collisions at {radical}(s)=200 GeV. The cross section was measured over a transverse momentum range of 1<p{sub T}<17 GeV/c and found to be in good agreement with a next-to-leading order perturbative QCD calculation. The longitudinal double-spin asymmetry was measured in the range of 3.7<p{sub T}<11 GeV/c and excludes a maximal positive gluon polarization in the proton. The mean transverse momentum fraction of {pi}{sup 0}'s in their parent jets was found to be around 0.7 formore » electromagnetically triggered events.« less
  • We present preliminary results for the first measurements of the double longitudinal spin asymmetry ALL in inclusive jet production at mid-rapidity in polarized proton-proton collisions at {radical}(s) = 200GeV. The data amount to {approx} 0 5 pb-1 collected at RHIC in 2003 and 2004 with beam polarizations up to 45%. The jet transverse energies are in the range of 5 pT 17GeV c. The data are consistent with theoretical evaluations using deep-inelastic scattering parametrizations for gluon polarization in the nucleon, and tend to disfavor large positive values of gluon polarization.
  • One of the primary goals of the STAR spin program at RHIC is the measurement of the double longitudinal asymmetry ALL in inclusive jet production. This measurement will allow STAR to determine the polarized gluon distribution function {delta}G in the Bjorken x region of 0.03<x<0.3. Inclusive jet production is a theoretically desirable way to measure {delta}G, as it is independent of fragmentation functions. This contribution presents STAR's preliminary 2005 measurements of ALL for inclusive jet production extracted from 3.1 pb-1 of data at {radical}s=200 GeV and 50% beam polarization. The asymmetry is calculated over the transverse momentum region 5 <more » pT < 30 GeV/c and compared with theoretical predictions incorporating several gluon polarization scenarios. Systematic uncertainties from false asymmetries, jet reconstruction, and triggering are discussed. At the present level of statistics, the measured asymmetry disfavors maximal gluon polarization but cannot yet distinguish between other theoretical scenarios.« less