Longitudinal double-spin asymmetry for inclusive jet and dijet production in polarized proton collisions at √s=200 GeV

Authors：Abdallah, M. S.; Adam, J.; Adamczyk, L.; Adams, J. R.; Adkins, J. K.; Agakishiev, G.; Aggarwal, I; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I; Anderson, D. M.; Aparin, A.; Aschenauer, E. C.; Ashraf, M. U.; Atetalla, F. G.; Attri, A.; Averichev, G. S.; Bairathi, V; Baker, W.; Cap, J. G. Ball; Barish, K.; Behera, A.; Bellwied, R.; Bhagat, P.; Bhasin, A.; Bielcik, J.; Bielcikova, J.; Bordyuzhin, I. G.; Brandenburg, J. D.; Brandin, A., V; Bunzarov, I; Butterworth, J.; Cai, X. Z.; Caines, H.

Source：Physical Review D, 2021, 103(9): L091103.

DOI：10.1103/PhysRevD.103.L091103

• DEPENDENT STRUCTURE-FUNCTION
• DEEP-INELASTIC-SCATTERING
• HELICITY DISTRIBUTIONS
• QUARK DISTRIBUTIONS
• G(1)(P)
• NUCLEON
• HE-3

We report high-precision measurements of the longitudinal double-spin asymmetry, A(LL), for midrapidity inclusive jet and dijet production in polarized pp collisions at a center-of-mass energy of root s = 200 GeV. The new inclusive jet data are sensitive to the gluon helicity distribution, Delta g(x, Q(2)), for gluon momentum fractions in the range from x similar or equal to 0.05 to x similar or equal to 0.5, while the new dijet data provide further constraints on the x dependence of Delta g(x, Q(2)). The results are in good agreement with previous measurements at root s = 200 GeV and with recent theoretical evaluations of prior world data. Our new results have better precision and thus strengthen the evidence that Delta g(x, Q(2)) is positive for x > 0.05.