학술논문
Search for $B^+ \to \mu^+\, \nu_\mu$ and $B^+ \to \mu^+\, N$ with inclusive tagging
Document Type
Working Paper
Author
Prim, M. T.; Bernlochner, F. U.; Goldenzweig, P.; Heck, M.; Adachi, I.; Adamczyk, K.; Aihara, H.; Said, S. Al; Asner, D. M.; Atmacan, H.; Aulchenko, V.; Aushev, T.; Ayad, R.; Babu, V.; Bakich, A. M.; Bansal, V.; Behera, P.; Beleño, C.; Bhardwaj, V.; Bhuyan, B.; Bilka, T.; Biswal, J.; Bobrov, A.; Bozek, A.; Bračko, M.; Braun, N.; Browder, T. E.; Campajola, M.; Cao, L.; Červenkov, D.; Chang, P.; Chekelian, V.; Chen, A.; Cheon, B. G.; Chilikin, K.; Cho, H. E.; Cho, K.; Choi, Y.; Choudhury, S.; Cinabro, D.; Cunliffe, S.; Doležal, Z.; Eidelman, S.; Epifanov, D.; Fast, J. E.; Ferber, T.; Fulsom, B. G.; Garg, R.; Gaur, V.; Garmash, A.; Giri, A.; Grzymkowska, O.; Guan, Y.; Haba, J.; Hara, T.; Hayasaka, K.; Hayashii, H.; Hou, W. -S.; Iijima, T.; Inami, K.; Inguglia, G.; Ishikawa, A.; Iwasaki, M.; Iwasaki, Y.; Jia, S.; Jin, Y.; Joffe, D.; Joo, K. K.; Kaliyar, A. B.; Karyan, G.; Kawasaki, T.; Kichimi, H.; Kiesling, C.; Kim, C. H.; Kim, D. Y.; Kim, K. T.; Kim, S. H.; Kinoshita, K.; Kodyš, P.; Korpar, S.; Kotchetkov, D.; Križan, P.; Kroeger, R.; Krokovny, P.; Kuhr, T.; Kulasiri, R.; Kumar, R.; Kumita, T.; Kuzmin, A.; Kwon, Y. -J.; Lalwani, K.; Lange, J. S.; Lee, I. S.; Lee, J. K.; Lee, J. Y.; Lee, S. C.; Lewis, P.; Li, C. H.; Gioi, L. Li; Libby, J.; Lieret, K.; Liventsev, D.; Lu, P. -C.; Luo, T.; MacNaughton, J.; Masuda, M.; Matsuda, T.; Matvienko, D.; Merola, M.; Metzner, F.; Miyabayashi, K.; Mizuk, R.; Mohanty, G. B.; Mussa, R.; Nakao, M.; De Nardo, G.; Nath, K. J.; Natkaniec, Z.; Nayak, M.; Niiyama, M.; Nisar, N. K.; Nishida, S.; Nishimura, K.; Ogawa, S.; Ono, H.; Onuki, Y.; Pakhlov, P.; Pakhlova, G.; Pal, B.; Pardi, S.; Park, H.; Park, S. -H.; Patra, S.; Paul, S.; Pedlar, T. K.; Pestotnik, R.; Piilonen, L. E.; Popov, V.; Prencipe, E.; Ritter, M.; Rostomyan, A.; Rozanska, M.; Russo, G.; Sahoo, D.; Sakai, Y.; Santelj, L.; Savinov, V.; Schneider, O.; Schnell, G.; Schueler, J.; Schwanda, C.; Seino, Y.; Senyo, K.; Sevior, M. E.; Shebalin, V.; Shiu, J. -G.; Shwartz, B.; Simon, F.; Sokolov, A.; Solovieva, E.; Starič, M.; Strube, J. F.; Sumihama, M.; Sumiyoshi, T.; Sutcliffe, W.; Takizawa, M.; Tamponi, U.; Tao, Y.; Tenchini, F.; Uchida, M.; Uglov, T.; Unno, Y.; Uno, S.; Ushiroda, Y.; Usov, Y.; Vahsen, S. E.; Van Tonder, R.; Varner, G.; Varvell, K. E.; Vinokurova, A.; Wang, B.; Wang, C. H.; Wang, M. -Z.; Wang, P.; Watanuki, S.; Won, E.; Yang, S. B.; Ye, H.; Yin, J. H.; Yusa, Y.; Zhang, Z. P.; Zhilich, V.; Zhukova, V.; Zhulanov, V.
Source
Phys. Rev. D 101, 032007 (2020)
Subject
Language
Abstract
We report the result for a search for the leptonic decay of $B^+ \to \mu^+ \, \nu_{\mu}$ using the full Belle data set of 711 fb${}^{-1}$ of integrated luminosity at the $\Upsilon(4S)$ resonance. In the Standard Model leptonic $B$-meson decays are helicity and CKM suppressed. To maximize sensitivity an inclusive tagging approach is used to reconstruct the second $B$ meson produced in the collision. The directional information from this second $B$ meson is used to boost the observed $\mu$ into the signal $B$ meson rest-frame, in which the $\mu$ has a monochromatic momentum spectrum. Though its momentum is smeared by the experimental resolution, this technique improves the analysis sensitivity considerably. Analyzing the $\mu$ momentum spectrum in this frame we find $\mathcal{B}(B^+ \to \mu^+ \, \nu_\mu) = \left( 5.3 \pm 2.0 \pm 0.9 \right) \times 10^{-7}$ with a one-sided significance of 2.8 standard deviations over the background-only hypothesis. This translates to a frequentist upper limit of $\mathcal{B}(B^+ \to \mu^+ \, \nu_{\mu}) < 8.6 \times 10^{-7}$ at 90% CL. The experimental spectrum is then used to search for a massive sterile neutrino, $B^+ \to \mu^+ \, N$, but no evidence is observed for a sterile neutrino with a mass in a range of 0 - 1.5 GeV. The determined $B^+ \to \mu^+ \, \nu_{\mu}$ branching fraction limit is further used to constrain the mass and coupling space of the type II and type III two-Higgs-doublet models.