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Articles 1 - 4 of 4
Full-Text Articles in Physical Sciences and Mathematics
Improved Measurement Of The Longitudinal Spin Transfer To Λ And Λ¯ Hyperons In Polarized Proton-Proton Collisions At √S = 200 Gev, J. Adam, L. Adamczyk, J. R. Adams, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, D. M. Anderson, R. Aoyama, A. Aparin, D. Arkhipkin, E. C. Aschenauer, M. U. Ashraf, F. Atetalla, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, K. Barish, A. J. Bassill, A. Behera, R. Bellwied, A. Bhasin, A. K. Bhati, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. D. Brandenburg, Renee H. Fatemi, Suvarna Ramachandran
Improved Measurement Of The Longitudinal Spin Transfer To Λ And Λ¯ Hyperons In Polarized Proton-Proton Collisions At √S = 200 Gev, J. Adam, L. Adamczyk, J. R. Adams, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, D. M. Anderson, R. Aoyama, A. Aparin, D. Arkhipkin, E. C. Aschenauer, M. U. Ashraf, F. Atetalla, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, K. Barish, A. J. Bassill, A. Behera, R. Bellwied, A. Bhasin, A. K. Bhati, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. D. Brandenburg, Renee H. Fatemi, Suvarna Ramachandran
Physics and Astronomy Faculty Publications
The longitudinal spin transfer DLL to Λ and Λ¯ hyperons produced in high-energy polarized proton-proton collisions is expected to be sensitive to the helicity distribution functions of strange quarks and antiquarks of the proton, and to longitudinally polarized fragmentation functions. We report an improved measurement of DLL from data obtained at a center-of-mass energy of √s = 200 GeV with the STAR detector at RHIC. The data have an approximately twelve times larger figure of merit than prior results and cover |η| < 1.2 in pseudorapidity with transverse momenta pT up to 6 GeV/c. In the forward scattering hemisphere …
Longitudinal Double-Spin Asymmetries For Dijet Production At Intermediate Pseudorapidity In Polarized Pp Collisions At √S = 200 Gev, J. Adam, L. Adamczyk, J. R. Adams, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, N. N. Ajitanand, I. Alekseev, D. M. Anderson, R. Aoyama, A. Aparin, D. Arkhipkin, E. C. Aschenauer, M. U. Ashraf, F. Atetalla, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, K. Barish, A. J. Bassill, A. Behera, R. Bellwied, A. Bhasin, A. K. Bhati, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, Renee H. Fatemi, Suvarna Ramachandran
Longitudinal Double-Spin Asymmetries For Dijet Production At Intermediate Pseudorapidity In Polarized Pp Collisions At √S = 200 Gev, J. Adam, L. Adamczyk, J. R. Adams, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, N. N. Ajitanand, I. Alekseev, D. M. Anderson, R. Aoyama, A. Aparin, D. Arkhipkin, E. C. Aschenauer, M. U. Ashraf, F. Atetalla, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, K. Barish, A. J. Bassill, A. Behera, R. Bellwied, A. Bhasin, A. K. Bhati, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, Renee H. Fatemi, Suvarna Ramachandran
Physics and Astronomy Faculty Publications
We present the first measurements of the longitudinal double-spin asymmetry ALL for dijets with at least one jet reconstructed within the pseudorapidity range 0.8 < η < 1.8. The dijets were measured in polarized pp collisions at a center-of-mass energy √s = 200 GeV. Values for ALL are determined for several distinct event topologies, defined by the jet pseudorapidities, and span a range of parton momentum fraction x down to x ∼ 0.01. The measured asymmetries are found to be consistent with the predictions of global analyses that incorporate the results of previous RHIC measurements. They will provide new constraints on Δg(x) in this poorly constrained region when included in …
Measurement Of The Cross Section And Longitudinal Double-Spin Asymmetry For Dijet Production In Polarized Pp Collisions At √S = 200 Gev, L. Adamczyk, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, N. N. Ajitanand, I. Alekseev, D. M. Anderson, R. Aoyama, A. Aparin, D. Arkhipkin, E. C. Aschenauer, M. U. Ashraf, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, K. Barish, A. Behera, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. Bouchet, J. D. Brandenburg, A. V. Brandin, Renee H. Fatemi, Suvarna Ramachandran
Measurement Of The Cross Section And Longitudinal Double-Spin Asymmetry For Dijet Production In Polarized Pp Collisions At √S = 200 Gev, L. Adamczyk, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, N. N. Ajitanand, I. Alekseev, D. M. Anderson, R. Aoyama, A. Aparin, D. Arkhipkin, E. C. Aschenauer, M. U. Ashraf, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, K. Barish, A. Behera, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. Bouchet, J. D. Brandenburg, A. V. Brandin, Renee H. Fatemi, Suvarna Ramachandran
Physics and Astronomy Faculty Publications
We report the first measurement of the longitudinal double-spin asymmetry ALL 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. ALL 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 …
Measurement Of The Transverse Single-Spin Asymmetry In P↑+P→W±/Z0 At Rhic, L. Adamczyk, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, A. Aparin, D. Arkhipkin, E. C. Aschenauer, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, A. Banerjee, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. Bouchet, J. D. Brandenburg, A. V. Brandin, I. Bunzarov, J. Butterworth, H. Caines, M. Calderón De La Barca Sánchez, J. M. Campbell, Renee H. Fatemi, Suvarna Ramachandran
Measurement Of The Transverse Single-Spin Asymmetry In P↑+P→W±/Z0 At Rhic, L. Adamczyk, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, A. Aparin, D. Arkhipkin, E. C. Aschenauer, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, A. Banerjee, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. Bouchet, J. D. Brandenburg, A. V. Brandin, I. Bunzarov, J. Butterworth, H. Caines, M. Calderón De La Barca Sánchez, J. M. Campbell, Renee H. Fatemi, Suvarna Ramachandran
Physics and Astronomy Faculty Publications
We present the measurement of the transverse single-spin asymmetry of weak boson production in transversely polarized proton-proton collisions at √s = 500 GeV by the STAR experiment at RHIC. The measured observable is sensitive to the Sivers function, one of the transverse-momentum-dependent parton distribution functions, which is predicted to have the opposite sign in proton-proton collisions from that observed in deep inelastic lepton-proton scattering. These data provide the first experimental investigation of the nonuniversality of the Sivers function, fundamental to our understanding of QCD.