Search for $h_b(2P)\toγχ_{bJ}(1P)$ at $\sqrt{s} = 10.860$ GeV
Creators: name: Belle Collaboration
name: Boschetti, A.
name: Mussa, R.
name: Tamponi, U.
name: Adachi, I.
name: Aihara, H.
name: Asner, D. M.
name: Aushev, T.
name: Ayad, R.
name: Banerjee, Sw.
name: Belous, K.
name: Bennett, J.
name: Bessner, M.
name: Biswas, D.
name: Bobrov, A.
name: Bodrov, D.
name: Bozek, A.
name: Bračko, M.
name: Branchini, P.
name: Browder, T. E.
name: Budano, A.
name: Chang, M. -C.
name: Cheon, B. G.
name: Chilikin, K.
name: Cho, K.
name: Choi, S. -K.
name: Choi, Y.
name: Choudhury, S.
name: De Nardo, G.
name: De Pietro, G.
name: Dhamija, R.
name: Di Capua, F.
name: Doležal, Z.
name: Dong, T. V.
name: Ecker, P.
name: Epifanov, D.
name: Ferlewicz, D.
name: Fulsom, B. G.
name: Garg, R.
name: Gaur, V.
name: Garmash, A.
name: Giri, A.
name: Goldenzweig, P.
name: Graziani, E.
name: Gu, T.
name: Guan, Y.
name: Gudkova, K.
name: Hadjivasiliou, C.
name: Hara, T.
name: Hayasaka, K.
name: Hayashii, H.
name: Hazra, S.
name: Hou, W. -S.
name: Hsu, C. -L.
name: Inami, K.
name: Ipsita, N.
name: Itoh, R.
name: Iwasaki, M.
name: Jacobs, W. W.
name: Jin, Y.
name: Kawasaki, T.
name: Kiesling, C.
name: Kim, C. H.
name: Kim, D. Y.
name: Kim, K. -H.
name: Kim, Y. -K.
name: Kinoshita, K.
name: Kodyš, P.
name: Korpar, S.
name: Kovalenko, E.
name: Križan, P.
name: Krokovny, P.
name: Kumar, R.
name: Kumara, K.
name: Kwon, Y. -J.
name: Lam, T.
name: Levit, D.
name: Li, L. K.
name: Li, Y. B.
name: Gioi, L. Li
name: Liventsev, D.
name: Ma, Y.
name: Masuda, M.
name: Matsuda, T.
name: Matvienko, D.
name: Meier, F.
name: Merola, M.
name: Miyabayashi, K.
name: Mizuk, R.
name: Mohanty, G. B.
name: Nakao, M.
name: Natkaniec, Z.
name: Natochii, A.
name: Nayak, L.
name: Nayak, M.
name: Nishida, S.
name: Ogawa, S.
name: Ono, H.
name: Pakhlova, G.
name: Park, J.
name: Park, S. -H.
name: Passeri, A.
name: Patra, S.
name: Paul, S.
name: Pedlar, T. K.
name: Pestotnik, R.
name: Piilonen, L. E.
name: Podobnik, T.
name: Prencipe, E.
name: Prim, M. T.
name: Rout, N.
name: Russo, G.
name: Sandilya, S.
name: Santelj, L.
name: Savinov, V.
name: Schnell, G.
name: Schwanda, C.
name: Seino, Y.
name: Senyo, K.
name: Shan, W.
name: Shen, C. P.
name: Shiu, J. -G.
name: Sokolov, A.
name: Solovieva, E.
name: Starič, M.
name: Sumihama, M.
name: Takizawa, M.
name: Tanida, K.
name: Tenchini, F.
name: Tiwary, R.
name: Uchida, M.
name: Unno, Y.
name: Uno, S.
name: Vinokurova, A.
name: Wang, E.
name: Wang, M. -Z.
name: Wang, X. L.
name: Won, E.
name: Yabsley, B. D.
name: Yelton, J.
name: Yin, J. H.
name: Yook, Y.
name: Yuan, L.
Publisher: name: arXiv
Year: 2024
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: In the bottomonium sector, the hindered magnetic dipole (M1) transitions between P-wave states $h_b(2P) \rightarrow χ_{bJ}(1P) γ$, $J=0, \, 1, \, 2$, are expected to be severely suppressed according to the Relativized Quark Model, due to the spin flip of the $b$ quark. Nevertheless, a recent model following the coupled-channel approach predicts the corresponding branching fractions to be enhanced by orders of magnitude. In this Letter, we report the first search for such transitions. We find no significant signals and set upper limits at 90% CL on the corresponding branching fractions: $\mathcal{B}[h_b(2P)\toγχ_{b0}(1P)] &lt; 2.7 \times 10^{-1}$, $\mathcal{B}[h_b(2P)\toγχ_{b1}(1P)] &lt; 5.4 \times 10^{-3}$ and $\mathcal{B}[h_b(2P)\toγχ_{b2}(1P)] &lt; 1.3 \times 10^{-2}$. These values help to constrain the parameters of the coupled-channel models. The results are obtained using a $121.4 \, fb^{-1}$ data sample taken around $\sqrt{s}= 10.860 \, GeV$ with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider.