Double helicity asymmetry in inclusive midrapidity pi(0) production for polarized p+p collisions at root s=200 GeV

Summary, in English

We present a measurement of the double longitudinal spin asymmetry in inclusive pi(0) production in polarized proton-proton collisions at roots=200 GeV. The data were taken at the Relativistic Heavy Ion Collider with average beam polarizations of 0.27. The measurements are the first in a program to study the longitudinal spin structure of the proton, using strongly interacting probes, at collider energies. The asymmetry is presented for transverse momenta 1-5 GeV/c at midrapidity, where next-to-leading-order perturbative quantum chromodynamic (NLO pQCD) calculations well describe the unpolarized cross section. The observed asymmetry is small and is compared to a NLO pQCD calculation with a range of polarized gluon distributions.

• Author: SS Adler; S Afanasiev; C Aidala; NN Ajitanand; Y Akiba; A Al-Jamel; J Alexander; K Aoki; L Aphecetche; R Armendariz; SH Aronson; R Averbeck; TC Awes; V Babintsev; A Baldisseri; KN Barish; PD Barnes; B Bassalleck; S Bathe; S Batsouli; V Baublis; F Bauer; A Bazilevsky; S Belikov; MT Bjorndal; JG Boissevain; H Borel; ML Brooks; DS Brown; N Bruner; D Bucher; H Buesching; V Bumazhnov; G Bunce; JM Burward-Hoy; S Butsyk; X Camard; P Chand; WC Chang; S Chernichenko; CY Chi; J Chiba; M Chiu; IJ Choi; RK Choudhury; T Chujo; V Cianciolo; Y Cobigo; BA Cole; MP Comets; P Constantin; M Csanad; T Csorgo; JP Cussonneau; D d'Enterria; K Das; G David; F Deak; H Delagrange; A Denisov; A Deshpande; EJ Desmond; A Devismes; O Dietzsch; JL Drachenberg; O Drapier; A Drees; A Durum; D Dutta; V Dzhordzhadze; YV Efremenko; H En'yo; B Espagnon; S Esumi; DE Fields; C Finck; F Fleuret; SL Fokin; BD Fox; Z Fraenkel; JE Frantz; A Franz; AD Frawley; Y Fukao; SY Fung; S Gadrat; M Germain; A Glenn; M Gonin; J Gosset; Y Goto; RG de Cassagnac; N Grau; SV Greene; MG Perdekamp; Hans-Åke Gustafsson; T Hachiya; JS Haggerty; H Hamagaki; AG Hansen; EP Hartouni; M Harvey; K Hasuko; R Hayano; X He; M Heffner; TK Hemmick; JM Heuser; P Hidas; H Hiejima; JC Hill; R Hobbs; W Holzmann; K Homma; B Hong; A Hoover; T Horaguchi; T Ichihara; VV Ikonnikov; K Imai; M Inaba; M Inuzuka; D Isenhower; L Isenhower; M Ishihara; M Issah; A Isupov; BV Jacak; J Jia; O Jinnouchi; BM Johnson; SC Johnson; KS Joo; D Jouan; F Kajihara; S Kametani; N Kamihara; M Kaneta; JH Kang; K Katou; T Kawabata; A Kazantsev; S Kelly; B Khachaturov; A Khanzadeev; J Kikuchi; DJ Kim; E Kim; GB Kim; HJ Kim; E Kinney; A Kiss; E Kistenev; A Kiyomichi; C Klein-Boesing; H Kobayashi; V Kochetkov; R Kohara; B Komkov; M Konno; D Kotchetkov; A Kozlov; PJ Kroon; CH Kuberg; GJ Kunde; K Kurita; MJ Kweon; Y Kwon; GS Kyle; R Lacey; JG Lajoie; Y Le Bornec; A Lebedev; S Leckey; DM Lee; MJ Leitch; MAL Leite; X Li; XH Li; H Lim; A Litvinenko; MX Liu; CF Maguire; YI Makdisi; A Malakhov; VI Manko; Y Mao; G Martinez; H Masui; F Matathias; T Matsumoto; MC McCain; PL McGaughey; Y Miake; TE Miller; A Milov; S Mioduszewski; GC Mishra; JT Mitchell; AK Mohanty; DP Morrison; JM Moss; D Mukhopadhyay; M Muniruzzaman; S Nagamiya; JL Nagle; T Nakamura; J Newby; AS Nyanin; Joakim Nystrand; E O'Brien; CA Ogilvie; H Ohnishi; ID Ojha; H Okada; K Okada; Anders Oskarsson; Ingvar Otterlund; K Oyama; K Ozawa; D Pal; APT Palounek; V Pantuev; V Papavassiliou; J Park; WJ Park; SF Pate; H Pei; V Penev; JC Peng; H Pereira; V Peresedov; A Pierson; C Pinkenburg; RP Pisani; ML Purschke; AK Purwar; J Qualls; J Rak; I Ravinovich; KF Read; M Reuter; K Reygers; V Riabov; Y Riabov; G Roche; A Romana; M Rosati; Sarah Rosendahl; P Rosnet; VL Rykov; SS Ryu; N Saito; T Sakaguchi; S Sakai; V Samsonov; L Sanfratello; R Santo; HD Sato; S Sato; S Sawada; Y Schutz; V Semenov; R Seto; TK Shea; I Shein; TA Shibata; K Shigaki; M Shimomura; A Sickles; CL Silva; D Silvermyr; KS Sim; A Soldatov; RA Soltz; WE Sondheim; S Sorensen; IV Sourikova; F Staley; PW Stankus; Evert Stenlund; M Stepanov; A Ster; SP Stoll; T Sugitate; JP Sullivan; S Takagi; EM Takagui; A Taketani; KH Tanaka; Y Tanaka; K Tanida; MJ Tannenbaum; A Taranenko; P Tarjan; TL Thomas; M Togawa; J Tojo; H Torii; RS Towell; VN Tram; I Tserruya; Y Tsuchimoto; Henrik Tydesjö; N Tyurin; TJ Uam; HW van Hecke; J Velkovska; M Velkovsky; V Veszpremi; AA Vinogradov; MA Volkov; E Vznuzdaev; XR Wang; Y Watanabe; SN White; N Willis; FK Wohn; CL Woody; W Xie; A Yanovich; S Yokkaichi; GR Young; IE Yushmanov; WA Zajc; O Zaudtke; C Zhang; S Zhou; J Zimanyi; L Zolin; X Zong
• Department/s: Particle and nuclear physics
• Publishing year: 2004
• Language: English
• Publication/Series: Physical Review Letters
• Volume: 93
• Issue: 20: 202002
• Links: http://dx.doi.org/10.1103/PhysRevLett.93.202002
• Document type: Journal article
• Publisher: American Physical Society
• Topic: Subatomic Physics
• Status: Published
• ISBN/ISSN/Other: ISSN: 1079-7114