Directed Flow of Identified Particles inAu+AuCollisions atSNN=200  GeVat RHIC

L Adamczyk,W Xie,S K Pal,F Wang,S R Klein,J Lauret,A R Timmins,J P Hays-Wehle,K Oh,W Peryt,P Sorensen,P Filip,X Luo,O D Tsai,L Li,Y Pandit,B Surrow,L H Tarini,P Djawotho,J Kiryluk,J G Cramer,J Konzer,H S Matis,M J Skoby,G Wang,J Bouchet,J Takahashi,O V Rogachevskiy,C K Riley,T J Humanic,R Varma,S Gupta,H Bichsel,A Vossen,A Kechechyan,M M Aggarwal,S Lapointe,X Zhu,Z P Zhang,K Xin,R Stock,J Zhao,E W Oldag,C Perkins,T Kollegger,D Prindle,R Witt,J M Landgraf,B Morozov,N Schmitz,D G Underwood,D Plyku,J H Lee,Y X Pan,I Sakrejda,B D Anderson,A Szanto De Toledo,T A Trainor,R P Scharenberg,S Horvat,E Sangaline,S Margetis,T Pawlak,S G Steadman,K Kauder,A Hamed,W M Zhang,D N Svirida,D Grosnick,E Shahaliev,L G Efimov,S W Wissink,R Majka,R L Ray,H F Chen,H Caines,R Bellwied,J Seger,I Bunzarov,H Wieman,A Sarkar,D R Gangadharan,Y Li,L Eun,A M Poskanzer,J H Chen,D D Koetke,K Kang,R Derradi De Souza,A Bhasin,S G Brovko,C B Powell,L Huo,L Xue,M G Munhoz,C A Gagliardi,W Xu,R Reed,C Li,H Masui,H Pei,Y Yi,L C Bland,S S Shi,H G Ritter,X P Zhang,M Strikhanov,J Putschke,B Sharma,X Cui,S Chattopadhyay,A Kesich,A K Bhati,S Zhang,A Hirsch,Y Sun,X Z Cai,P Pile,Q Wang,M Pachr,J Engelage,S Mioduszewski,N K Pruthi,J Porter,G Eppley,L Chen,J B Zhang,R Redwine,M C Suarez,A Banerjee,P Tribedy,M Tokarev,M C Cervantes,Md Nasim,L C De Silva,A Chikanian,S Gliske,G Igo,P Yepes,G W Hoffmann,X Li,M J Levine,M Elnimr,B Huang,J H Thomas,E G Judd,G D Westfall,L Kotchenda,I G Bordyuzhin,K Yip,Q H Xu,J Tian,H Z Huang,J W Harris,M Wada,J L Drachenberg,A Kisiel,T Tarnowsky,J Cheng,C Pruneau,Y Zhang,R Fatemi,R Raniwala,B Pawlik,Y Lu,B Mohanty,N Shah,Y N Gorbunov,V Okorokov,M Zawisza,J Pluta,L Kumar,J A Vanfossen,S Bueltmann,B Haag,P R Pujahari,L V Nogach,Y Xu,J C Webb,E Bruna,U G Desouza,Z Sun,P Huck,B Srivastava,W J Llope,R G Fersch,J Joseph,B A Trzeciak,Z M Li,O Evdokimov,J Turnau,G S Averichev,N Smirnov,H Qiu,G Odyniec,B Stringfellow,F Liu,D Thein,J L Romero,H M Spinka,S Heppelmann,J Schambach,O G Grebenyuk,P Chung,Y F Wu,F Ding,S A Voloshin,W Korsch,J Deng,S Kabana,Y Mohammed,J E Draper,Y Panebratsev,R E Tribble,R R Betts,M Naglis,M A Lisa,A Ogawa,H Zbroszczyk,P Seyboth,W Borowski,C Jena,N Xu,L Ruan,D Arkhipkin,S Dhamija,S Raniwala,A Lebedev,J Y Chen,J C Dunlop,J Seele,D Cebra,E P Sichtermann,T D S Stanislaus,W Li,A H Tang,X Dong,N Poljak,D P Mahapatra,Z Ahammed,C Whitten,H Xu,T K Nayak,R Corliss,J Sandweiss,Z Tang,D Olson,K Krueger,L Didenko,G Agakishiev,T S Mcshane,J R Stevens,T G Dedovich,I Alekseev,T Ullrich,D Solanki,C Markert,F Videbæk,I Koralt,E Finch,T J M Symons,Y P Viyogi,M K Mustafa,M Calderón De La Barca Sánchez,A V Brandin,J Balewski,B K Nandi,A V Alakhverdyants,G Van Buren,W W Jacobs,Y Fisyak,J S Wang,D Keane,H J Crawford,V Kizka,P Chaloupka,H Wang,D Tlusty,W Christie,W Guryn,R S Longacre,B S Page,S Salur,L M Lima,M Shao,Z Barnovska,J Kapitan,W Witzke,L E Dunkelberger,G Webb,H W Ke,X L Wang,Y Zoulkarneeva,Z Xu,C M Du,M Cherney,T P Burton,R Cendejas,A Davila Leyva,G Van Nieuwenhuizen,O Hajkova,M J M Codrington,S Trentalange,D Mcdonald,J Alford,A Ohlson,D J Hofman,Y Wang,Feng Zhao ,T Ljubičić ,J Fedorišin ,J J Chwastowski ,W A Leight ,П Кравцов ,Alexandre Alarcon Do Passo Suaide ,Y Zhu ,David Kettler ,T Schuster ,Zhong Chen ,A Schmah ,M Przybycień ,F J M Geurts ,O Mall ,M Planinić ,M Šumbera ,I K Yoo ,D P Kikoła ,J Bielčíková ,G M.s Vasconcelos ,Xiao Zhang ,S Vokál ,L I Koroleva ,D Beavis ,M A.c Lamont ,Q Shou ,R Debbe ,M Mitrovski ,J M Butterworth ,Yi Yang ,A Łuszczak ,Y G ,R Singaraju ,G L ,C Anson ,J Roberts ,J Rusňák ,Meenakshi Sharma ,N Sahoo ,L Han ,J Bielčík ,M Betancourt ,R Lednický ,R A Negrao De Oliveira ,X Sun

doi:10.1103/physrevlett.108.202301

Abstract

STAR’s measurements of directed flow (v1) around midrapidity for π±, K±, KS0, p, and p¯ in Au+Au collisions at sNN=200 GeV are presented. A negative v1(y) slope is observed for most of produced particles (π±, K±, KS0, and p¯). In 5%–30% central collisions, a sizable difference is present between the v1(y) slope of protons and antiprotons, with the former being consistent with zero within errors. The v1 excitation function is presented. Comparisons to model calculations (RQMD, UrQMD, AMPT, QGSM with parton recombination, and a hydrodynamics model with a tilted source) are made. For those models which have calculations of v1 for both pions and protons, none of them can describe v1(y) for pions and protons simultaneously. The hydrodynamics model with a tilted source as currently implemented cannot explain the centrality dependence of the difference between the v1(y) slopes of protons and antiprotons.Received 16 December 2011DOI:https://doi.org/10.1103/PhysRevLett.108.202301© 2012 American Physical Society

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