학술논문
Measurement of the decay $\eta^{\prime}\to\pi^{0}\pi^{0}\eta$ at MAMI
Document Type
Working Paper
Author
Adlarson, P.; Afzal, F.; Akondi, C. S.; Annand, J. R. M.; Arends, H. J.; Beck, R.; Borisov, N.; Braghieri, A.; Briscoe, W. J.; Cividini, F.; Collicott, C.; Costanza, S.; Denig, A.; Downie, E. J.; Dieterle, M.; Bondy, M. I. Ferretti; Gardner, S.; Garni, S.; Glazier, D. I.; Glowa, D.; Gradl, W.; Gurevich, G.; Hamilton, D. J.; Hornidge, D.; Huber, G. M.; Käser, A.; Kashevarov, V. L.; Kay, S.; Keshelashvili, I.; Kondratiev, R.; Korolija, M.; Krusche, B.; Lazarev, A.; Linturi, J.; Livingston, K.; MacGregor, I. J. D.; Manley, D. M.; Martel, P. P.; McGeorge, J. C.; Middleton, D. G.; Miskimen, R.; Mushkarenkov, A.; Neganov, A.; Neiser, A.; Oberle, M.; Ostrick, M.; Ott, P.; Otte, P. B.; Oussena, B.; Paudyal, D.; Pedroni, P.; Polonski, A.; Prakhov, S.; Rajabi, A.; Ron, G.; Rostomyan, T.; Sarty, A.; Sfienti, C.; Sokhoyan, V.; Spieker, K.; Steffen, O.; Strakovsky, I. I.; Strub, T.; Supek, I.; Thiel, A.; Thiel, M.; Tiator, L.; Thomas, A.; Unverzagt, M.; Usov, Y. A.; Wagner, S.; Watts, D. P.; Werthmüller, D.; Wettig, J.; Witthauer, L.; Wolfes, M.; Workman, R. L.; Zana, L. A.
Source
Phys. Rev. D 98, 012001 (2018)
Subject
Language
Abstract
An experimental study of the $\eta'\to \pi^0\pi^0\eta \to 6\gamma$ decay has been conducted with the best up-to-date statistical accuracy, by measuring $\eta'$ mesons produced in the $\gamma p \to \eta' p$ reaction with the A2 tagged-photon facility at the Mainz Microtron, MAMI. The results obtained for the standard parametrization of the $\eta'\to \pi^0\pi^0\eta$ matrix element are consistent with the most recent results for $\eta'\to\pi\pi\eta$ decays, but have smaller uncertainties. The available statistics and experimental resolution allowed, for the first time, an observation of a structure below the $\pi^+\pi^-$ mass threshold, the magnitude and sign of which, checked within the framework of the nonrelativistic effective-field theory, demonstrated good agreement with the cusp that was predicted based on the $\pi\pi$ scattering length combination, $a_0-a_2$, extracted from $K \to 3\pi$ decays.
Comment: 15 pages, 8 figures, 2 tables, accepted for publication in Phys. Rev. D
Comment: 15 pages, 8 figures, 2 tables, accepted for publication in Phys. Rev. D