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arXiv · 1405.5134

Precision Measurement of the Longitudinal Double-spin Asymmetry for Inclusive Jet Production in Polarized Proton Collisions at $\sqrt{s}=200$ GeV

STAR Collaboration·L. Adamczyk·J. K. Adkins·G. Agakishiev·M. M. Aggarwal·Z. Ahammed·I. Alekseev·J. Alford·C. D. Anson·A. Aparin·D. Arkhipkin·E. C. Aschenauer·G. S. Averichev·A. Banerjee·D. R. Beavis·R. Bellwied·A. Bhasin·A. K. Bhati·P. Bhattarai·H. Bichsel·J. Bielcik·J. Bielcikova·L. C. Bland·I. G. Bordyuzhin·W. Borowski·J. Bouchet·A. V. Brandin·S. G. Brovko·S. Bultmann·I. Bunzarov·T. P. Burton·J. Butterworth·H. Caines·M. Calderon de la Barca Sanchez·J. M. Campbell·D. Cebra·R. Cendejas·M. C. Cervantes·P. Chaloupka·Z. Chang·S. Chattopadhyay·H. F. Chen·J. H. Chen·L. Chen·J. Cheng·M. Cherney·A. Chikanian·W. Christie·J. Chwastowski·M. J. M. Codrington·G. Contin·J. G. Cramer·H. J. Crawford·A. B. Cudd·X. Cui·S. Das·A. Davila Leyva·L. C. De Silva·R. R. Debbe·T. G. Dedovich·J. Deng·A. A. Derevschikov·R. Derradi de Souza·S. Dhamija·B. di Ruzza·L. Didenko·C. Dilks·F. Ding·P. Djawotho·X. Dong·J. L. Drachenberg·J. E. Draper·C. M. Du·L. E. Dunkelberger·J. C. Dunlop·L. G. Efimov·J. Engelage·K. S. Engle·G. Eppley·L. Eun·O. Evdokimov·O. Eyser·R. Fatemi·S. Fazio·J. Fedorisin·P. Filip·E. Finch·Y. Fisyak·C. E. Flores·C. A. Gagliardi·D. R. Gangadharan·D. Garand·F. Geurts·A. Gibson·M. Girard·S. Gliske·L. Greiner·D. Grosnick·D. S. Gunarathne·Y. Guo
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Abstract

We report a new high-precision measurement of the mid-rapidity inclusive jet longitudinal double-spin asymmetry, $A_{LL}$, in polarized $pp$ collisions at center-of-mass energy $\sqrt{s}=200$ GeV. The STAR data place stringent constraints on polarized parton distribution functions extracted at next-to-leading order from global analyses of inclusive deep inelastic scattering (DIS), semi-inclusive DIS, and RHIC $pp$ data. The measured asymmetries provide evidence for positive gluon polarization in the Bjorken-$x$ region $x>0.05$.

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STAR Collaboration, L. Adamczyk, J. K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, E. C. Aschenauer, G. S. Averichev, A. Banerjee, D. R. Beavis, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, H. Bichsel, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, W. Borowski, J. Bouchet, A. V. Brandin, S. G. Brovko, S. Bultmann, I. Bunzarov, T. P. Burton, J. Butterworth, H. Caines, M. Calderon de la Barca Sanchez, J. M. Campbell, D. Cebra, R. Cendejas, M. C. Cervantes, P. Chaloupka, Z. Chang, S. Chattopadhyay, H. F. Chen, J. H. Chen, L. Chen, J. Cheng, M. Cherney, A. Chikanian, W. Christie, J. Chwastowski, M. J. M. Codrington, G. Contin, J. G. Cramer, H. J. Crawford, A. B. Cudd, X. Cui, S. Das, A. Davila Leyva, L. C. De Silva, R. R. Debbe, T. G. Dedovich, J. Deng, A. A. Derevschikov, R. Derradi de Souza, S. Dhamija, B. di Ruzza, L. Didenko, C. Dilks, F. Ding, P. Djawotho, X. Dong, J. L. Drachenberg, J. E. Draper, C. M. Du, L. E. Dunkelberger, J. C. Dunlop, L. G. Efimov, J. Engelage, K. S. Engle, G. Eppley, L. Eun, O. Evdokimov, O. Eyser, R. Fatemi, S. Fazio, J. Fedorisin, P. Filip, E. Finch, Y. Fisyak, C. E. Flores, C. A. Gagliardi, D. R. Gangadharan, D. Garand, F. Geurts, A. Gibson, M. Girard, S. Gliske, L. Greiner, D. Grosnick, D. S. Gunarathne, Y. Guo. 2014-05-20. Precision Measurement of the Longitudinal Double-spin Asymmetry for Inclusive Jet Production in Polarized Proton Collisions at $\sqrt{s}=200$ GeV. https://doi.org/10.1103/physrevlett.115.092002

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