651. Observation of a New Narrow Axial-Vector Meson a1(1420).
- Author
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Adolph C, Akhunzyanov R, Alexeev MG, Alexeev GD, Amoroso A, Andrieux V, Anosov V, Austregesilo A, Azevedo C, Badełek B, Balestra F, Barth J, Beck R, Bedfer Y, Bernhard J, Bicker K, Bielert ER, Birsa R, Bisplinghoff J, Bodlak M, Boer M, Bordalo P, Bradamante F, Braun C, Bressan A, Büchele M, Burtin E, Chang WC, Chiosso M, Choi I, Chung SU, Cicuttin A, Crespo ML, Curiel Q, Dalla Torre S, Dasgupta SS, Dasgupta S, Denisov OY, Dhara L, Donskov SV, Doshita N, Dünnweber W, Duic V, Dziewiecki M, Efremov A, Eversheim PD, Eyrich W, Faessler M, Ferrero A, Finger M, Finger M, Fischer H, Franco C, du Fresne von Hohenesche N, Friedrich JM, Frolov V, Gautheron F, Gavrichtchouk OP, Gerassimov S, Gnesi I, Gorzellik M, Grabmüller S, Grasso A, Grosse-Perdekamp M, Grube B, Grussenmeyer T, Guskov A, Haas F, Hahne D, von Harrach D, Hashimoto R, Heinsius FH, Herrmann F, Hinterberger F, Horikawa N, d'Hose N, Hsieh CY, Huber S, Ishimoto S, Ivanov A, Ivanshin Y, Iwata T, Jahn R, Jary V, Jörg P, Joosten R, Kabuß E, Ketzer B, Khaustov GV, Khokhlov YA, Kisselev Y, Klein F, Klimaszewski K, Koivuniemi JH, Kolosov VN, Kondo K, Königsmann K, Konorov I, Konstantinov VF, Kotzinian AM, Kouznetsov O, Krämer M, Kremser P, Krinner F, Kroumchtein ZV, Kuchinski N, Kunne F, Kurek K, Kurjata RP, Lednev AA, Lehmann A, Levillain M, Levorato S, Lichtenstadt J, Maggiora A, Magnon A, Makins N, Makke N, Mallot GK, Marchand C, Martin A, Marzec J, Matousek J, Matsuda H, Matsuda T, Meshcheryakov G, Meyer W, Michigami T, Mikhailov YV, Miyachi Y, Nagaytsev A, Nagel T, Nerling F, Neyret D, Nikolaenko VI, Novy J, Nowak WD, Nunes AS, Olshevsky AG, Orlov I, Ostrick M, Panzieri D, Parsamyan B, Paul S, Peng JC, Pereira F, Pesek M, Peshekhonov DV, Platchkov S, Pochodzalla J, Polyakov VA, Pretz J, Quaresma M, Quintans C, Ramos S, Regali C, Reicherz G, Riedl C, Rocco E, Rossiyskaya NS, Ryabchikov DI, Rychter A, Samoylenko VD, Sandacz A, Santos C, Sarkar S, Savin IA, Sbrizzai G, Schiavon P, Schmeing S, Schmidt K, Schmieden H, Schönning K, Schopferer S, Schlüter T, Selyunin A, Shevchenko OY, Silva L, Sinha L, Sirtl S, Slunecka M, Sozzi F, Srnka A, Stolarski M, Sulc M, Suzuki H, Szabelski A, Szameitat T, Sznajder P, Takekawa S, Ter Wolbeek J, Tessaro S, Tessarotto F, Thibaud F, Tskhay V, Uhl S, Veloso J, Virius M, Wallner S, Weisrock T, Wilfert M, Zaremba K, Zavertyaev M, Zemlyanichkina E, Ziembicki M, and Zink A
- Abstract
The COMPASS Collaboration at CERN has measured diffractive dissociation of 190 GeV/c pions into the π(-)π(-)π(+) final state using a stationary hydrogen target. A partial-wave analysis (PWA) was performed in bins of 3π mass and four-momentum transfer using the isobar model and the so far largest PWA model consisting of 88 waves. A narrow peak is observed in the f0(980)π channel with spin, parity and C-parity quantum numbers J(PC)=1(++). We present a resonance-model study of a subset of the spin-density matrix selecting 3π states with J(PC)=2(++) and 4(++) decaying into ρ(770)π and with J(PC)=1(++) decaying into f0(980)π. We identify a new a1 meson with mass (1414(-13)(+15)) MeV/c2 and width (153(-23)(+8)) MeV/c2. Within the final states investigated in our analysis, we observe the new a1(1420) decaying only into f0(980)π, suggesting its exotic nature.
- Published
- 2015
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