Measurement of the Cross Section and Longitudinal Double-Spin Asymmetry for Dijet Production in Polarized pp Collisions at √s = 200 GeV

Authors

L. Adamczyk, AGH University of Science and Technology, Poland
James K. Adkins, University of KentuckyFollow
G. Agakishiev, Joint Institute for Nuclear Research, Russia
M. M. Aggarwal, Panjab University, India
Z. Ahammed, Variable Energy Cyclotron Centre, India
N. N. Ajitanand, State University of New York - Stony Brook
I. Alekseev, Alikhanov Institute for Theoretical and Experimental Physics, Russia
D. M. Anderson, Texas A&M University
R. Aoyama, University of Tsukuba, Japan
A. Aparin, Joint Institute for Nuclear Research, Russia
D. Arkhipkin, Brookhaven National Laboratory
E. C. Aschenauer, Brookhaven National Laboratory
M. U. Ashraf, Tsinghua University, China
A. Attri, Panjab University, India
G. S. Averichev, Joint Institute for Nuclear Research, Russia
X. Bai, Central China Normal University, China
V. Bairathi, National Institute of Science Education and Research, India
K. Barish, University of California - Riverside
A. Behera, State University of New York - Stony Brook
R. Bellwied, University of Houston
A. Bhasin, University of Jammu, India
A. K. Bhati, Panjab University, India
P. Bhattarai, University of Texas at Austin
J. Bielcik, Czech Technical University in Prague, Czech Republic
J. Bielcikova, Nuclear Physics Institute AS CR, Czech Republic
L. C. Bland, Brookhaven National Laboratory
I. G. Bordyuzhin, Alikhanov Institute for Theoretical and Experimental Physics, Russia
J. Bouchet, Kent State University
J. D. Brandenburg, Rice University
A. V. Brandin, National Research Nuclear University MEPhI, Russia
Renee H. Fatemi, University of KentuckyFollow
Suvarna Ramachandran, University of KentuckyFollow

Abstract

We report the first measurement of the longitudinal double-spin asymmetry A_LL for midrapidity dijet production in polarized pp collisions at a center-of-mass energy of √s = 200  GeV. The dijet cross section was measured and is shown to be consistent with next-to-leading order (NLO) perturbative QCD predictions. A_LL results are presented for two distinct topologies, defined by the jet pseudorapidities, and are compared to predictions from several recent NLO global analyses. The measured asymmetries, the first such correlation measurements, support those analyses that find positive gluon polarization at the level of roughly 0.2 over the region of Bjorken-x > 0.05.

Document Type

Article

Publication Date

4-28-2017

Notes/Citation Information

Published in Physical Review D, v. 95, issue 7, 071103, p. 1-8.

© 2017 American Physical Society

The copyright holder has granted permission for posting the article here.

Due to the large number of authors, only the first 30 and the authors affiliated with the University of Kentucky are listed in the author section above. For the complete list of authors, please download this article or visit: https://doi.org/10.1103/PhysRevD.95.071103

This group of authors is collectively known as the STAR Collaboration.

Digital Object Identifier (DOI)

https://doi.org/10.1103/PhysRevD.95.071103

Related Content

See Supplemental Material at http://link.aps.org/supplemental/10.1103/PhysRevD.95.071103 for tables of values and associated systematic uncertainties.

Repository Citation

Adamczyk, L.; Adkins, James K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Ajitanand, N. N.; Alekseev, I.; Anderson, D. M.; Aoyama, R.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Ashraf, M. U.; Attri, A.; Averichev, G. S.; Bai, X.; Bairathi, V.; Barish, K.; Behera, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, J. D.; Brandin, A. V.; Fatemi, Renee H.; and Ramachandran, Suvarna, "Measurement of the Cross Section and Longitudinal Double-Spin Asymmetry for Dijet Production in Polarized pp Collisions at √s = 200 GeV" (2017). Physics and Astronomy Faculty Publications. 546.
https://uknowledge.uky.edu/physastron_facpub/546