Observation of Transverse Spin-Dependent Azimuthal Correlations of Charged Pion Pairs in p^{↑}+p at sqrt[s]=200  GeV.

We report the observation of transverse polarization-dependent azimuthal correlations in charged pion pair production with the STAR experiment in p^{↑}+p collisions at RHIC. These correlations directly probe quark transversity distributions. We measure signals in excess of 5 standard deviations at high transverse momenta, at high pseudorapidities η>0.5, and for pair masses around the mass of the ρ meson. This is the first direct transversity measurement in p+p collisions.

G. S. Averichev | Abdel Nasser Tawfik | Y. Wang | J. Thomas | B. Di Ruzza | D. Hofman | R. Pak | H. Jang | T. Nayak | J. Sandweiss | L. Adamczyk | R. Debbe | S. Fazio | P. Federič | A. Gibson | S. Kabana | G. Wang | Z. Zhang | H. Spinka | P. Yepes | I. Chakaberia | F. Geurts | S. Salur | O. Evdokimov | Y. Guo | J. Roberts | D. Smirnov | Z. Ye | K. Yip | J. Chen | A. Roy | B. Pawlik | D. Underwood | M. Shao | A. Hirsch | R. Scharenberg | B. Stringfellow | J. Zhao | P. Sahu | Y. Yang | J. Lauret | A. Poskanzer | H. Ritter | Y. Pan | L. He | Z. Ahammed | R. Bellwied | L. Bland | A. Brandin | H. Caines | D. Cebra | M. Cherney | W. Christie | H. Crawford | A. Derevschikov | L. Didenko | J. Draper | J. Dunlop | L. Efimov | J. Engelage | G. Eppley | Y. Fisyak | J. Harris | G. Hoffmann | H. Huang | T. Humanic | G. Igo | W. Jacobs | E. Judd | D. Keane | A. Kisiel | P. Kravtsov | K. Krueger | M. Lamont | J. Landgraf | A. Lebedev | R. Lednický | M. Lisa | T. Ljubičić | W. Llope | R. Longacre | R. Majka | S. Margetis | H. Matis | N. Minaev | L. Nogach | S. Nurushev | G. Odyniec | A. Ogawa | V. Okorokov | Y. Panebratsev | J. Pluta | J. Porter | R. Ray | J. Romero | I. Sakrejda | J. Schambach | N. Schmitz | J. Seger | P. Seyboth | E. Shahaliev | B. Srivastava | R. Stock | M. Strikhanov | M. Šumbera | A. Tang | S. Trentalange | M. Tokarev | O. Tsai | T. Ullrich | A. Vasiliev | S. Voloshin | F. Wang | G. Westfall | H. Wieman | S. Wissink | R. Witt | N. Xu | Z. Xu | P. Shanmuganathan | M. Planinić | A. Vossen | M. K. Mustafa | W. Xie | C. Flores | C. Markert | X. Chen | Y. Sun | M. Szelezniak | B. Mohanty | S. Chattopadhyay | J. Cheng | X. Zhu | B. Huang | N. Smirnov | J. Webb | A. Gupta | H. Qiu | N. Sahoo | M. Calderón de la Barca Sánchez | S. Das | M. Sharma | M. Vandenbroucke | J. Campbell | W. Schmidke | A. Bhasin | J. Bielčík | J. Bielčíková | G. Contin | L. Greiner | R. Haque | I. Kisel | T. Kollegger | L. Kumar | B. Nandi | H. Pei | N. Poljak | R. Raniwala | S. Raniwala | A. Schmah | Q. Shou | A. Timmins | B. Trzeciak | R. Vértesi | I. Yoo | H. Zbroszczyk | D. Kikola | Y. Viyogi | M. Aggarwal | D. Tlustý | X. Zhang | Y. Li | J. Putschke | R. Varma | R. Ma | A. K. Bhati | P. Tribedy | M. Girard | I. Kulakov | S. Yang | M. Zyzak | D. Mcdonald | H. Masui | J. K. Adkins | G. Agakishiev | I. Alekseev | A. Aparin | E. Aschenauer | I. Bordyuzhin | J. Butterworth | P. Chaloupka | Z. Chang | T. Dedovich | X. Dong | J. Drachenberg | R. Esha | O. Eyser | R. Fatémi | J. Fedorišin | P. Filip | L. Fulek | C. Gagliardi | D. Grosnick | W. Guryn | A. Hamad | Ahmed M. Hamed | S. Heppelmann | S. Horvat | X. Huang | K. Jiang | D. Kalinkin | K. Kang | K. Kauder | H. Ke | A. Kechechyan | L. Kochenda | L. Kosarzewski | J. Lee | C. Li | W. Li | X. Li | F. Liu | X. Luo | G. Ma | L. Ma | Y. Ma | N. Magdy | S. Mioduszewski | D. Morozov | M. Nasim | G. Nigmatkulov | B. Page | C. Perkins | M. Posik | N. Pruthi | A. Quintero | S. Ramachandran | O. Rogachevskiy | L. Ruan | J. Rusnak | N. Shah | W. Shen | S. Shi | E. Sichtermann | R. Sikora | M. Simko | P. Sorensen | T. Stanislaus | B. Summa | X. Sun | B. Surrow | Z. Tang | T. Tarnowsky | R. Tribble | S. Tripathy | I. Upsal | S. Vokál | J. Wang | L. Wen | Y. Wu | Z. Xiao | H. Xu | Q. Xu | Y. Xu | C. Yang | Q. Yang | L. Yi | W. Zha | S. Zhang | Y. Zhang | C. Zhong | A. Sarkar | Z. Feng | Z. Li | Z. Sun | L. Song | P. Pile | D. Koetke | A. Manion | M. Stepanov | Y. Guo | C. Du | D. Arkhipkin | J. Bouchet | G. Van Buren | Y. Zoulkarneeva | T. Burton | M. Cervantes | M. Skoby | I. Bunzarov | C. Dilks | M. Lomnitz | K. Meehan | K. Oh | O. Rusňáková | N. Yu | D. Gunarathne | A. Kraishan | D. Olvitt | M. Mondal | J. Zhang | L. Zhou | J. Alford | A. Banerjee | L. Dunkelberger | S. Gupta | P. Huck | J. Novak | Y. Pandit | B. Sharma | H. Wang | G. Webb | K. Xin | P. Bhattarai | D. Garand | Z. Khan | K. Landry | K. Poniatowska | L. D. De Silva | J. Deng | R. Kycia | S. Noh | G. V. van Nieuwenhuizen | F. Videbæk | A. Peterson | N. Svirida | H. Huang | Q. Xu | M. Sharma | M. Mustafa | X. Luo | L. De Silva | D. Kikoła | J. Bielcik | L. He | X. Luo | C. Yang | A. Vossen | M. Calderon De La Barca Sanchez | A. Gupta | X. Luo | P. Federic | L. Kumar | S. Yang | X. Dong | A. Lebedev | N. Xu | S. Zhang | X. Li | G. van Nieuwenhuizen | A. Bhati | R. Fatemi

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