Measurement of azimuthal asymmetries in inclusive production of hadron pairs ine+e−annihilation ats=10.58  GeV

R Seidl,K Hayasaka,B Golob,H Ha,Y Teramoto,D Liventsev,R Mizuk,S Nishida,C Liu,N Gabyshev,H J Hyun,G Varner,Y Iwasaki,G Pakhlova,D H Kah,T Sumiyoshi,W.-S Hou,S Uehara,D Heffernan,Y Usov,T Lesiak,J Dalseno,W Bartel,H Hayashii,Y I Kim,Y Unno,M Grosse Perdekamp,G R Moloney,T E Browder,R Chistov,C W Park,Y Yamashita,A Sekiya,J S Lee,L S Peak,E Nakano,M Hazumi,Z P Zhang,A Zupanc,B G Cheon,H Nakazawa,K Senyo,S Uno,K Miyabayashi,Y Watanabe,A M Bakich,M J Lee,T Uglov,S Stanič,P Urquijo,I Adachi,A Limosani,M Dash,S Okuno,H O Kim,Y J Kim,Y Hoshi,O Schneider,K Vervink,R Wedd,J Brodzicka,V Zhilich,M E Sevior,R Kumar,J S Lange,J B Singh,M Shapkin,H Sahoo,E Won,P Pakhlov,M Bračko,X L Wang,J Li,S Ogawa,C P Shen,P Wang,Y Miyazaki,L E Piilonen,Y Sakai,F Mandl,A Ogawa,H K Park,M Starič,C H Wang,S Eidelman,A Ishikawa,P Križan,S Mconie,I Tikhomirov,U Bitenc,T Ohshima,M Tanaka,A Bondar,Y Choi,H Miyake,A Drutskoy,A Chen,O Nitoh,T Medvedeva,H Miyata,H J Kim,S Bahinipati,H Aihara,T Kawasaki,H Park,H Kawai,O Zyukova,T Živko ,Hiroshi Kaji ,Y Kwon ,H Pałka ,I S Cho ,B Yabsley ,Y Chào ,J G Shiu ,A Bożek ,S H Kyeong

doi:10.1103/physrevd.78.032011

Abstract

The Collins effect connects transverse quark spin with a measurable azimuthal asymmetry in the yield of hadronic fragments around the quark's momentum vector. Using two different reconstruction methods we measure statistically significant azimuthal asymmetries for charged pion pairs in e+e- annihilation at center-of-mass energies of 10.52 GeV and 10.58 GeV, which can be attributed to the fragmentation of primordial quarks with transverse spin components. The measurement was performed using a data set of 547fb-1 collected by the Belle detector at KEKB improving the statistics of the previously published results by nearly a factor of 20. © 2008 The American Physical Society.

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