1. Observation of a J(PC)=1-+ exotic resonance in diffractive dissociation of 190 GeV/c π- into π- π- π+.
- Author
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Alekseev MG, Alexakhin VY, Alexandrov Y, Alexeev GD, Amoroso A, Austregesilo A, Badełek B, Balestra F, Ball J, Barth J, Baum G, Bedfer Y, Bernhard J, Bertini R, Bettinelli M, Birsa R, Bisplinghoff J, Bordalo P, Bradamante F, Bravar A, Bressan A, Brona G, Burtin E, Bussa MP, Chapiro A, Chiosso M, Chung SU, Cicuttin A, Colantoni M, Crespo ML, Dalla Torre S, Dafni T, Das S, Dasgupta SS, Denisov OY, Dhara L, Diaz V, Dinkelbach AM, Donskov SV, Doshita N, Duic V, Dünnweber W, Efremov A, El Alaoui A, Eversheim PD, Eyrich W, Faessler M, Ferrero A, Finger M, Finger M Jr, Fischer H, Franco C, Friedrich JM, Garfagnini R, Gautheron F, Gavrichtchouk OP, Gazda R, Gerassimov S, Geyer R, Giorgi M, Gobbo B, Goertz S, Grabmüller S, Grajek OA, Grasso A, Grube B, Gushterski R, Guskov A, Haas F, von Harrach D, Hasegawa T, Heckmann J, Heinsius FH, Hermann R, Herrmann F, Hess C, Hinterberger F, Horikawa N, Höppner Ch, d'Hose N, Ilgner C, Ishimoto S, Ivanov O, Ivanshin Y, Iwata T, Jahn R, Jasinski P, Jegou G, Joosten R, Kabuss E, Kang D, Ketzer B, Khaustov GV, Khokhlov YA, Kisselev Y, Klein F, Klimaszewski K, Koblitz S, Koivuniemi JH, Kolosov VN, Komissarov EV, Kondo K, Königsmann K, Konopka R, Konorov I, Konstantinov VF, Korzenev A, Kotzinian AM, Kouznetsov O, Kowalik K, Krämer M, Kral A, Kroumchtein ZV, Kuhn R, Kunne F, Kurek K, Lauser L, Le Goff JM, Lednev AA, Lehmann A, Levorato S, Lichtenstadt J, Liska T, Maggiora A, Maggiora M, Magnon A, Mallot GK, Mann A, Marchand C, Marroncle J, Martin A, Marzec J, Massmann F, Matsuda T, Maximov AN, Meyer W, Michigami T, Mikhailov YV, Moinester MA, Mutter A, Nagaytsev A, Nagel T, Nassalski J, Negrini T, Nerling F, Neubert S, Neyret D, Nikolaenko VI, Olshevsky AG, Ostrick M, Padee A, Panknin R, Panzieri D, Parsamyan B, Paul S, Pawlukiewicz-Kaminska B, Perevalova E, Pesaro G, Peshekhonov DV, Piragino G, Platchkov S, Pochodzalla J, Polak J, Polyakov VA, Pontecorvo G, Pretz J, Quintans C, Rajotte JF, Ramos S, Rapatsky V, Reicherz G, Reggiani D, Richter A, Robinet F, Rocco E, Rondio E, Ryabchikov DI, Samoylenko VD, Sandacz A, Santos H, Sapozhnikov MG, Sarkar S, Savin IA, Sbrizzai G, Schiavon P, Schill C, Schlüter T, Schmitt L, Schopferer S, Schröder W, Shevchenko OY, Siebert HW, Silva L, Sinha L, Sissakian AN, Slunecka M, Smirnov GI, Sosio S, Sozzi F, Srnka A, Stolarski M, Sulc M, Sulej R, Takekawa S, Tessaro S, Tessarotto F, Teufel A, Tkatchev LG, Uhl S, Uman I, Venugopal G, Virius M, Vlassov NV, Vossen A, Weitzel Q, Windmolders R, Wiślicki W, Wollny H, Zaremba K, Zavertyaev M, Zemlyanichkina E, Ziembicki M, Zhao J, Zhuravlev N, and Zvyagin A
- Abstract
The COMPASS experiment at the CERN SPS has studied the diffractive dissociation of negative pions into the π- π- π+ final state using a 190 GeV/c pion beam hitting a lead target. A partial wave analysis has been performed on a sample of 420,000 events taken at values of the squared 4-momentum transfer t' between 0.1 and 1 GeV2/c2. The well-known resonances a1(1260), a2(1320), and π2(1670) are clearly observed. In addition, the data show a significant natural-parity exchange production of a resonance with spin-exotic quantum numbers J(PC)=1-+ at 1.66 GeV/c2 decaying to ρπ. The resonant nature of this wave is evident from the mass-dependent phase differences to the J(PC)=2-+ and 1++ waves. From a mass-dependent fit a resonance mass of (1660±10(-64)(+0)) MeV/c2 and a width of (269±21(-64)(+42)) MeV/c2 are deduced, with an intensity of (1.7±0.2)% of the total intensity.
- Published
- 2010
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