Observation of I (2S) →γηb (1S) Decay

Date Issued
03-12-2018
Author(s)
Fulsom, B. G.
Pedlar, T. K.
Adachi, I.
Aihara, H.
Al Said, S.
Asner, D. M.
Atmacan, H.
Aulchenko, V.
Aushev, T.
Ayad, R.
Babu, V.
Badhrees, I.
Bakich, A. M.
Bansal, V.
Behera, P.
Beleño, C.
Berger, M.
Bhardwaj, V.
Bhuyan, B.
Bilka, T.
Biswal, J.
Bondar, A.
Bonvicini, G.
Bozek, A.
BraÄ ko, M.
Browder, T. E.
Cao, L.
ÄŒervenkov, D.
Chekelian, V.
Chen, A.
Cheon, B. G.
Chilikin, K.
Cho, K.
Choi, S. K.
Choi, Y.
Choudhury, S.
Cinabro, D.
Cunliffe, S.
Dash, N.
Di Carlo, S.
Dingfelder, J.
DoleŽal, Z.
Dong, T. V.
Drásal, Z.
Eidelman, S.
Epifanov, D.
Fast, J. E.
Ferber, T.
Garg, R.
Gaur, V.
Gabyshev, N.
Garmash, A.
Gelb, M.
Giri, A.
Goldenzweig, P.
Guido, E.
Haba, J.
Hayasaka, K.
Hayashii, H.
Hirose, S.
Hou, W. S.
Iijima, T.
Inami, K.
Inguglia, G.
Ishikawa, A.
Itoh, R.
Iwasaki, M.
Iwasaki, Y.
Jacobs, W. W.
Jeon, H. B.
Jia, S.
Jin, Y.
Joffe, D.
Joo, K. K.
Julius, T.
Kawasaki, T.
Kichimi, H.
Kiesling, C.
Kim, D. Y.
Kim, H. J.
Kim, J. B.
Kim, K. T.
Kim, S. H.
Kinoshita, K.
Kodyš, P.
Korpar, S.
Kotchetkov, D.
KriŽan, P.
Kroeger, R.
Krokovny, P.
Kuhr, T.
Kulasiri, R.
Kuzmin, A.
Kwon, Y. J.
Lange, J. S.
Lee, I. S.
Lee, S. C.
Li, L. K.
Li, Y. B.
Li Gioi, L.
DOI
Abstract
We report the observation of I(2S)→γηb(1S) decay based on an analysis of the inclusive photon spectrum of 24.7 fb-1 of e+e- collisions at the I(2S) center-of-mass energy collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. We measure a branching fraction of B[I(2S)→γηb(1S)]=(6.1-0.7-0.6+0.6+0.9)×10-4 and derive an ηb(1S) mass of 9394.8-3.1-2.7+2.7+4.5 MeV/c2, where the uncertainties are statistical and systematic, respectively. The significance of our measurement is greater than 7 standard deviations, constituting the first observation of this decay mode.
Volume
121