寻找π⁺π⁺π⁻系统中奇异介子的光激发。

Search for the photoexcitation of exotic mesons in the pi+pi+pi- system.

作者信息

Nozar M, Salgado C, Weygand D P, Guo L, Adams G, Li Ji, Eugenio P, Amaryan M J, Anghinolfi M, Asryan G, Avakian H, Bagdasaryan H, Baillie N, Ball J P, Baltzell N A, Barrow S, Battaglieri M, Bedlinskiy I, Bektasoglu M, Bellis M, Benmouna N, Berman B L, Biselli A S, Blaszczyk L, Bonner B E, Bouchigny S, Boiarinov S, Bradford R, Branford D, Briscoe W J, Brooks W K, Bültmann S, Burkert V D, Butuceanu C, Calarco J R, Careccia S L, Carman D S, Carnahan B, Casey L, Cazes A, Chen S, Cheng L, Cole P L, Collins P, Coltharp P, Cords D, Corvisiero P, Crabb D, Crannell H, Crede V, Cummings J P, Dale D, Dashyan N, De Masi R, De Vita R, De Sanctis E, Degtyarenko P V, Denizli H, Dennis L, Deur A, Dharmawardane K V, Dhuga K S, Dickson R, Djalali C, Dodge G E, Doughty D, Dugger M, Dytman S, Dzyubak O P, Egiyan H, Egiyan K S, El Fassi L, Elouadrhiri L, Fatemi R, Fedotov G, Feuerbach R J, Forest T A, Fradi A, Funsten H, Garçon M, Gavalian G, Gevorgyan N, Gilfoyle G P, Giovanetti K L, Girod F X, Goetz J T, Gothe R W, Griffioen K A, Guidal M, Guillo M, Guler N, Gyurjyan V, Hadjidakis C, Hafidi K, Hakobyan H, Hanretty C, Hardie J, Hassall N, Heddle D, Hersman F W, Hicks K, Hleiqawi I, Holtrop M, Hyde-Wright C E, Ilieva Y, Ireland D G, Ishkhanov B S, Isupov E L, Ito M M, Jenkins D, Jo H S, Johnstone J R, Joo K, Juengst H G, Kalantarians N, Kellie J D, Khandaker M, Kim W, Klein A, Klein F J, Kossov M, Krahn Z, Kramer L H, Kubarovsky V, Kuhn J, Kuhn S E, Kuleshov S V, Kuznetsov V, Lachniet J, Laget J M, Langheinrich J, Lawrence D, Livingston K, Lu H Y, Maccormick M, Markov N, Mattione P, McAleer S, McKinnon B, McNabb J W C, Mecking B A, Mehrabyan S, Mestayer M D, Meyer C A, Mibe T, Mikhailov K, Mirazita M, Miskimen R, Mokeev V, Moreno B, Moriya K, Morrow S A, Moteabbed M, Mueller J, Munevar E, Mutchler G S, Nadel-Turonski P, Nasseripour R, Niccolai S, Niculescu G, Niculescu I, Niczyporuk B B, Niroula M R, Niyazov R A, O'Rielly G V, Osipenko M, Ostrovidov A I, Park K, Pasyuk E, Paterson C, Anefalos Pereira S, Philips S A, Pierce J, Pivnyuk N, Pocanic D, Pogorelko O, Polli E, Popa I, Pozdniakov S, Preedom B M, Price J W, Prok Y, Protopopescu D, Qin L M, Raue B A, Riccardi G, Ricco G, Ripani M, Ritchie B G, Ronchetti F, Rosner G, Rossi P, Rubin P D, Sabatié F, Salamanca J, Santoro J P, Sapunenko V, Schumacher R A, Serov V S, Sharabian Y G, Sharov D, Shvedunov N V, Skabelin A V, Smith E S, Smith L C, Sober D I, Sokhan D, Stavinsky A, Stepanyan S S, Stepanyan S, Stokes B E, Stoler P, Strakovsky I I, Strauch S, Taiuti M, Tedeschi D J, Thoma U, Tkabladze A, Tkachenko S, Todor L, Ungaro M, Vineyard M F, Vlassov A V, Watts D P, Weinstein L B, Williams M, Wolin E, Wood M H, Yegneswaran A, Zana L, Zhang J, Zhao B, Zhao Z W

机构信息

Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA.

出版信息

Phys Rev Lett. 2009 Mar 13;102(10):102002. doi: 10.1103/PhysRevLett.102.102002. Epub 2009 Mar 12.

DOI:10.1103/PhysRevLett.102.102002

PMID:19392105

Abstract

A search for exotic mesons in the pi;{+}pi;{+}pi;{-} system photoproduced by the charge exchange reaction gammap-->pi;{+}pi;{+}pi;{-}(n) was carried out by the CLAS Collaboration at Jefferson Lab. A tagged-photon beam with energies in the 4.8 to 5.4 GeV range, produced through bremsstrahlung from a 5.744 GeV electron beam, was incident on a liquid-hydrogen target. A partial wave analysis was performed on a sample of 83 000 events, the highest such statistics to date in this reaction at these energies. The main objective of this study was to look for the photoproduction of an exotic J;{PC}=1;{-+} resonant state in the 1 to 2 GeV mass range. Our partial wave analysis shows production of the a_{2}(1320) and the pi_{2}(1670) mesons, but no evidence for the a_{1}(1260), nor the pi_{1}(1600) exotic state at the expected levels. An upper limit of 13.5 nb is determined for the exotic pi_{1}(1600) cross section, less than 2% of the a_{2}(1320) production.

摘要

杰斐逊实验室的CLAS合作组开展了一项研究，通过电荷交换反应γp→π⁺π⁺π⁻（n）寻找在π⁺π⁺π⁻系统中光生的奇特介子。一束能量在4.8至5.4 GeV范围内的标记光子束，由5.744 GeV电子束通过轫致辐射产生，入射到液氢靶上。对83000个事例样本进行了分波分析，这是该能量下此反应迄今最高的统计量。本研究的主要目标是寻找质量在1至2 GeV范围内奇特的JPC = 1⁻⁺共振态的光生过程。我们的分波分析显示了a₂（1320）和π₂（1670）介子的产生，但未发现预期水平的a₁（1260）和π₁（1600）奇特态的证据。确定了奇特的π₁（1600）截面的上限为13.5 nb，小于a₂（1320）产生截面的2%。