A calibration of the Belle II hadronic tag-side reconstruction algorithm with B→Xℓν decays
Belle II Collaboration, F. Abudinén, I. Adachi, R. Adak, K. Adamczyk, P. Ahlburg, J. K. Ahn, H. Aihara, N. Akopov, A. Aloisio, F. Ameli, L. Andricek, N. Anh Ky, D. M. Asner, H. Atmacan, V. Aulchenko, T. Aushev, V. Aushev, T. Aziz, V. Babu, S. Bacher, S. Baehr, S. Bahinipati, A. M. Bakich, P. Bambade, Sw. Banerjee, S. Bansal, M. Barrett, G. Batignani, J. Baudot, A. Beaulieu, J. Becker, P. K. Behera, M. Bender, J. V. Bennett, E. Bernieri, F. U. Bernlochner, M. Bertemes, M. Bessner, S. Bettarini, V. Bhardwaj, B. Bhuyan, F. Bianchi, T. Bilka, S. Bilokin, D. Biswas, A. Bobrov, A. Bondar, G. Bonvicini, A. Bozek, M. Bračko, P. Branchini, N. Braun, R. A. Briere, T. E. Browder, D. N. Brown, A. Budano, L. Burmistrov, S. Bussino, M. Campajola, L. Cao, G. Caria, G. Casarosa, C. Cecchi, D. Červenkov, M.-C. Chang, P. Chang, R. Cheaib, V. Chekelian, C. Chen, Y. Q. Chen, Y.-T. Chen, B. G. Cheon, K. Chilikin, K. Chirapatpimol, H.-E. Cho, K. Cho, S.-J. Cho, S.-K. Choi, S. Choudhury, D. Cinabro, L. Corona, L. M. Cremaldi, D. Cuesta, S. Cunliffe, T. Czank, N. Dash, F. Dattola, E. De La Cruz-Burelo, G. De Nardo, M. De Nuccio, G. De Pietro, R. de Sangro, B. Deschamps, M. Destefanis, S. Dey, A. De Yta-Hernandez, A. Di Canto, F. Di Capua, S. Di Carlo, et al. (443 additional authors not shown)
BBelle
BELLE2-CONF-PH-2020-005August 18, 2020
A calibration of the Belle II hadronic tag-side reconstructionalgorithm with B → X (cid:96)ν decays
F. Abudin´en, I. Adachi,
24, 21
R. Adak, K. Adamczyk, P. Ahlburg,
J. K. Ahn, H. Aihara,
N. Akopov,
A. Aloisio,
97, 40
F. Ameli, L. Andricek, N. Anh Ky,
37, 14
D. M. Asner, H. Atmacan,
V. Aulchenko,
4, 74
T. Aushev, V. Aushev, T. Aziz, V. Babu, S. Bacher, S. Baehr, S. Bahinipati, A. M. Bakich,
P. Bambade,
Sw. Banerjee,
S. Bansal, M. Barrett, G. Batignani,
J. Baudot,
A. Beaulieu,
J. Becker, P. K. Behera, M. Bender, J. V. Bennett,
E. Bernieri, F. U. Bernlochner,
M. Bertemes, M. Bessner,
S. Bettarini,
V. Bhardwaj, B. Bhuyan, F. Bianchi,
T. Bilka, S. Bilokin, D. Biswas,
A. Bobrov,
4, 74
A. Bondar,
4, 74
G. Bonvicini,
A. Bozek, M. Braˇcko,
P. Branchini, N. Braun, R. A. Briere, T. E. Browder,
D. N. Brown,
A. Budano, L. Burmistrov,
S. Bussino,
M. Campajola,
97, 40
L. Cao,
G. Caria,
G. Casarosa,
C. Cecchi,
99, 42
D. ˇCervenkov, M.-C. Chang, P. Chang, R. Cheaib,
V. Chekelian, Y. Q. Chen,
Y.-T. Chen, B. G. Cheon, K. Chilikin, K. Chirapatpimol, H.-E. Cho, K. Cho, S.-J. Cho,
S.-K. Choi, S. Choudhury, D. Cinabro,
L. Corona,
L. M. Cremaldi,
D. Cuesta,
S. Cunliffe, T. Czank,
N. Dash, F. Dattola, E. De La Cruz-Burelo, G. De Nardo,
97, 40
M. De Nuccio, G. De Pietro, R. de Sangro, B. Deschamps,
M. Destefanis,
S. Dey, A. De Yta-Hernandez, A. Di Canto, F. Di Capua,
97, 40
S. Di Carlo,
J. Dingfelder,
Z. Doleˇzal, I. Dom´ınguez Jim´enez, T. V. Dong, K. Dort, D. Dossett,
S. Dubey,
S. Duell,
G. Dujany,
S. Eidelman,
4, 57, 74
M. Eliachevitch,
D. Epifanov,
4, 74
J. E. Fast, T. Ferber, D. Ferlewicz,
G. Finocchiaro, S. Fiore, P. Fischer,
A. Fodor, F. Forti,
A. Frey, M. Friedl, B. G. Fulsom, M. Gabriel, N. Gabyshev,
4, 74
E. Ganiev,
M. Garcia-Hernandez, R. Garg, A. Garmash,
4, 74
V. Gaur,
A. Gaz,
66, 67
U. Gebauer, M. Gelb, A. Gellrich, J. Gemmler, T. Geßler, D. Getzkow, R. Giordano,
97, 40
A. Giri, A. Glazov, B. Gobbo, R. Godang,
P. Goldenzweig, B. Golob,
P. Gomis, P. Grace,
W. Gradl, E. Graziani, D. Greenwald, Y. Guan,
C. Hadjivasiliou, S. Halder, K. Hara,
24, 21
T. Hara,
24, 21
O. Hartbrich,
T. Hauth, K. Hayasaka, H. Hayashii, C. Hearty,
M. Heck, M. T. Hedges,
I. Heredia de la Cruz,
6, 11
M. Hern´andez Villanueva,
A. Hershenhorn,
T. Higuchi,
E. C. Hill,
H. Hirata, M. Hoek, M. Hohmann,
S. Hollitt,
T. Hotta, C.-L. Hsu,
Y. Hu, K. Huang, T. Iijima,
66, 67
K. Inami, G. Inguglia, J. Irakkathil Jabbar, A. Ishikawa,
24, 21
R. Itoh,
24, 21
M. Iwasaki, Y. Iwasaki, S. Iwata, P. Jackson,
W. W. Jacobs, I. Jaegle,
D. E. Jaffe, E.-J. Jang, M. Jeandron,
H. B. Jeon, S. Jia, Y. Jin, C. Joo,
K. K. Joo, I. Kadenko, J. Kahn, H. Kakuno, A. B. Kaliyar, J. Kandra, K. H. Kang, P. Kapusta, a r X i v : . [ h e p - e x ] A ug . Karl, G. Karyan,
Y. Kato,
66, 67
H. Kawai, T. Kawasaki, T. Keck, C. Ketter,
H. Kichimi, C. Kiesling, B. H. Kim, C.-H. Kim, D. Y. Kim, H. J. Kim, J. B. Kim, K.-H. Kim,
K. Kim, S.-H. Kim, Y.-K. Kim,
Y. Kim, T. D. Kimmel,
H. Kindo,
24, 21
K. Kinoshita,
B. Kirby, C. Kleinwort, B. Knysh,
P. Kodyˇs, T. Koga, S. Kohani,
I. Komarov, T. Konno, S. Korpar,
N. Kovalchuk, T. M. G. Kraetzschmar, P. Kriˇzan,
R. Kroeger,
J. F. Krohn,
P. Krokovny,
4, 74
H. Kr¨uger,
W. Kuehn, T. Kuhr, J. Kumar, M. Kumar, R. Kumar, K. Kumara,
T. Kumita, T. Kunigo, M. K¨unzel,
12, 59
S. Kurz, A. Kuzmin,
4, 74
P. Kvasniˇcka, Y.-J. Kwon,
S. Lacaprara, Y.-T. Lai,
C. La Licata,
K. Lalwani, L. Lanceri, J. S. Lange, K. Lautenbach, P. J. Laycock, F. R. Le Diberder,
I.-S. Lee, S. C. Lee, P. Leitl, D. Levit, P. M. Lewis,
C. Li, L. K. Li,
S. X. Li, Y. M. Li, Y. B. Li, J. Libby, K. Lieret, L. Li Gioi, J. Lin, Z. Liptak,
Q. Y. Liu, Z. A. Liu, D. Liventsev,
S. Longo, A. Loos,
P. Lu, M. Lubej, T. Lueck, F. Luetticke,
T. Luo, C. MacQueen,
Y. Maeda,
66, 67
M. Maggiora,
S. Maity, R. Manfredi,
E. Manoni, S. Marcello,
C. Marinas, A. Martini,
M. Masuda,
15, 77
T. Matsuda,
K. Matsuoka,
66, 67
D. Matvienko,
4, 57, 74
J. McNeil,
F. Meggendorfer, J. C. Mei, F. Meier, M. Merola,
97, 40
F. Metzner, M. Milesi,
C. Miller,
K. Miyabayashi, H. Miyake,
24, 21
H. Miyata, R. Mizuk,
57, 26
K. Azmi,
G. B. Mohanty, H. Moon, T. Moon, J. A. Mora Grimaldo,
A. Morda, T. Morii,
H.-G. Moser, M. Mrvar, F. Mueller, F. J. M¨uller, Th. Muller, G. Muroyama, C. Murphy,
R. Mussa, K. Nakagiri, I. Nakamura,
24, 21
K. R. Nakamura,
24, 21
E. Nakano, M. Nakao,
24, 21
H. Nakayama,
24, 21
H. Nakazawa, T. Nanut, Z. Natkaniec, A. Natochii,
M. Nayak, G. Nazaryan,
D. Neverov, C. Niebuhr, M. Niiyama, J. Ninkovic, N. K. Nisar, S. Nishida,
24, 21
K. Nishimura,
M. Nishimura, M. H. A. Nouxman,
B. Oberhof, K. Ogawa, S. Ogawa, S. L. Olsen, Y. Onishchuk, H. Ono, Y. Onuki,
P. Oskin, E. R. Oxford, H. Ozaki,
24, 21
P. Pakhlov,
57, 65
G. Pakhlova,
26, 57
A. Paladino,
T. Pang,
A. Panta,
E. Paoloni,
S. Pardi, C. Park,
H. Park, S.-H. Park,
B. Paschen,
A. Passeri, A. Pathak,
S. Patra, S. Paul, T. K. Pedlar, I. Peruzzi, R. Peschke,
R. Pestotnik, M. Piccolo, L. E. Piilonen,
P. L. M. Podesta-Lerma, G. Polat, V. Popov, C. Praz, E. Prencipe, M. T. Prim,
M. V. Purohit, N. Rad, P. Rados, R. Rasheed,
M. Reif, S. Reiter, M. Remnev,
4, 74
P. K. Resmi, I. Ripp-Baudot,
M. Ritter, M. Ritzert,
G. Rizzo,
L. B. Rizzuto, S. H. Robertson,
64, 36
D. Rodr´ıguez P´erez, J. M. Roney,
C. Rosenfeld,
A. Rostomyan, N. Rout, M. Rozanska, G. Russo,
97, 40
D. Sahoo, Y. Sakai,
24, 21
D. A. Sanders,
S. Sandilya,
A. Sangal,
L. Santelj,
P. Sartori,
98, 41
J. Sasaki,
Y. Sato, V. Savinov,
B. Scavino, M. Schram, H. Schreeck, J. Schueler,
C. Schwanda, A. J. Schwartz,
B. Schwenker, R. M. Seddon, Y. Seino, A. Selce,
K. Senyo,
I. S. Seong,
J. Serrano, M. E. Sevior,
C. Sfienti, V. Shebalin,
C. P. Shen, H. Shibuya, J.-G. Shiu, B. Shwartz,
4, 74
A. Sibidanov,
F. Simon, J. B. Singh, S. Skambraks, K. Smith,
R. J. Sobie,
A. Soffer, A. Sokolov, Y. Soloviev, E. Solovieva, S. Spataro,
B. Spruck, M. Stariˇc, S. Stefkova, Z. S. Stottler,
R. Stroili,
98, 41
J. Strube, J. Stypula, M. Sumihama,
20, 77
K. Sumisawa,
24, 21
T. Sumiyoshi,
2. J. Summers,
W. Sutcliffe,
K. Suzuki, S. Y. Suzuki,
24, 21
H. Svidras, M. Tabata, M. Takahashi, M. Takizawa,
82, 25, 84
U. Tamponi, S. Tanaka,
24, 21
K. Tanida, H. Tanigawa,
N. Taniguchi, Y. Tao,
P. Taras,
F. Tenchini, D. Tonelli, E. Torassa, K. Trabelsi,
T. Tsuboyama,
24, 21
N. Tsuzuki, M. Uchida, I. Ueda,
24, 21
S. Uehara,
24, 21
T. Ueno, T. Uglov,
57, 26
K. Unger, Y. Unno, S. Uno,
24, 21
P. Urquijo,
Y. Ushiroda,
24, 21, 127
Y. Usov,
4, 74
S. E. Vahsen,
R. van Tonder,
G. S. Varner,
K. E. Varvell,
A. Vinokurova,
4, 74
L. Vitale,
V. Vorobyev,
4, 57, 74
A. Vossen, E. Waheed, H. M. Wakeling, K. Wan,
W. Wan Abdullah,
B. Wang, C. H. Wang, M.-Z. Wang, X. L. Wang, A. Warburton, M. Watanabe, S. Watanuki,
I. Watson,
J. Webb,
S. Wehle, M. Welsch,
C. Wessel,
J. Wiechczynski, P. Wieduwilt, H. Windel, E. Won, L. J. Wu, X. P. Xu, B. Yabsley,
S. Yamada, W. Yan,
S. B. Yang, H. Ye, J. Yelton,
I. Yeo, J. H. Yin, M. Yonenaga, Y. M. Yook, T. Yoshinobu, C. Z. Yuan, G. Yuan,
W. Yuan, Y. Yusa, L. Zani, J. Z. Zhang, Y. Zhang,
Z. Zhang,
V. Zhilich,
4, 74
Q. D. Zhou,
66, 68
X. Y. Zhou, V. I. Zhukova, V. Zhulanov,
4, 74 and A. Zupanc (Belle II Collaboration)(The Belle II Collaboration) Aix Marseille Universit´e, CNRS/IN2P3, CPPM, 13288 Marseille, France Beihang University, Beijing 100191, China Brookhaven National Laboratory, Upton, New York 11973, U.S.A. Budker Institute of Nuclear Physics SB RAS, Novosibirsk 630090, Russian Federation Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, U.S.A. Centro de Investigacion y de Estudios Avanzados delInstituto Politecnico Nacional, Mexico City 07360, Mexico Faculty of Mathematics and Physics, Charles University, 121 16 Prague, Czech Republic Chiang Mai University, Chiang Mai 50202, Thailand Chiba University, Chiba 263-8522, Japan Chonnam National University, Gwangju 61186, South Korea Consejo Nacional de Ciencia y Tecnolog´ıa, Mexico City 03940, Mexico Deutsches Elektronen–Synchrotron, 22607 Hamburg, Germany Duke University, Durham, North Carolina 27708, U.S.A. Institute of Theoretical and Applied Research(ITAR), Duy Tan University, Hanoi 100000, Vietnam Earthquake Research Institute, University of Tokyo, Tokyo 113-0032, Japan Forschungszentrum J¨ulich, 52425 J¨ulich, Germany Department of Physics, Fu Jen Catholic University, Taipei 24205, Taiwan Key Laboratory of Nuclear Physics and Ion-beam Application (MOE) and nstitute of Modern Physics, Fudan University, Shanghai 200443, China II. Physikalisches Institut, Georg-August-Universit¨atG¨ottingen, 37073 G¨ottingen, Germany Gifu University, Gifu 501-1193, Japan The Graduate University for Advanced Studies (SOKENDAI), Hayama 240-0193, Japan Gyeongsang National University, Jinju 52828, South Korea Department of Physics and Institute of NaturalSciences, Hanyang University, Seoul 04763, South Korea High Energy Accelerator Research Organization (KEK), Tsukuba 305-0801, Japan J-PARC Branch, KEK Theory Center, High Energy AcceleratorResearch Organization (KEK), Tsukuba 305-0801, Japan Higher School of Economics (HSE), Moscow 101000, Russian Federation Indian Institute of Science Education and Research Mohali, SAS Nagar, 140306, India Indian Institute of Technology Bhubaneswar, Satya Nagar 751007, India Indian Institute of Technology Guwahati, Assam 781039, India Indian Institute of Technology Hyderabad, Telangana 502285, India Indian Institute of Technology Madras, Chennai 600036, India Indiana University, Bloomington, Indiana 47408, U.S.A. Institute for High Energy Physics, Protvino 142281, Russian Federation Institute of High Energy Physics, Vienna 1050, Austria Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China Institute of Particle Physics (Canada), Victoria, British Columbia V8W 2Y2, Canada Institute of Physics, Vietnam Academy ofScience and Technology (VAST), Hanoi, Vietnam Instituto de Fisica Corpuscular, Paterna 46980, Spain INFN Laboratori Nazionali di Frascati, I-00044 Frascati, Italy INFN Sezione di Napoli, I-80126 Napoli, Italy INFN Sezione di Padova, I-35131 Padova, Italy INFN Sezione di Perugia, I-06123 Perugia, Italy INFN Sezione di Pisa, I-56127 Pisa, Italy INFN Sezione di Roma, I-00185 Roma, Italy INFN Sezione di Roma Tre, I-00146 Roma, Italy INFN Sezione di Torino, I-10125 Torino, Italy INFN Sezione di Trieste, I-34127 Trieste, Italy Advanced Science Research Center, Japan Atomic Energy Agency, Naka 319-1195, Japan Johannes Gutenberg-Universit¨at Mainz, Institutf¨ur Kernphysik, D-55099 Mainz, Germany Justus-Liebig-Universit¨at Gießen, 35392 Gießen, Germany Institut f¨ur Experimentelle Teilchenphysik, KarlsruherInstitut f¨ur Technologie, 76131 Karlsruhe, Germany Kitasato University, Sagamihara 252-0373, Japan Korea Institute of Science and Technology Information, Daejeon 34141, South Korea Korea University, Seoul 02841, South Korea Kyoto Sangyo University, Kyoto 603-8555, Japan Kyungpook National University, Daegu 41566, South Korea P.N. Lebedev Physical Institute of the Russian Academyof Sciences, Moscow 119991, Russian Federation Liaoning Normal University, Dalian 116029, China Ludwig Maximilians University, 80539 Munich, Germany Luther College, Decorah, Iowa 52101, U.S.A. Malaviya National Institute of Technology Jaipur, Jaipur 302017, India Max-Planck-Institut f¨ur Physik, 80805 M¨unchen, Germany Semiconductor Laboratory of the Max Planck Society, 81739 M¨unchen, Germany McGill University, Montr´eal, Qu´ebec, H3A 2T8, Canada Moscow Physical Engineering Institute, Moscow 115409, Russian Federation Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan Kobayashi-Maskawa Institute, Nagoya University, Nagoya 464-8602, Japan Institute for Advanced Research, Nagoya University, Nagoya 464-8602, Japan Nara Women’s University, Nara 630-8506, Japan Department of Physics, National Taiwan University, Taipei 10617, Taiwan National United University, Miao Li 36003, Taiwan H. Niewodniczanski Institute of Nuclear Physics, Krakow 31-342, Poland Niigata University, Niigata 950-2181, Japan Novosibirsk State University, Novosibirsk 630090, Russian Federation Okinawa Institute of Science and Technology, Okinawa 904-0495, Japan Osaka City University, Osaka 558-8585, Japan Research Center for Nuclear Physics, Osaka University, Osaka 567-0047, Japan Pacific Northwest National Laboratory, Richland, Washington 99352, U.S.A. Panjab University, Chandigarh 160014, India Peking University, Beijing 100871, China Punjab Agricultural University, Ludhiana 141004, India Meson Science Laboratory, Cluster for PioneeringResearch, RIKEN, Saitama 351-0198, Japan Seoul National University, Seoul 08826, South Korea Showa Pharmaceutical University, Tokyo 194-8543, Japan Soochow University, Suzhou 215006, China Soongsil University, Seoul 06978, South Korea J. Stefan Institute, 1000 Ljubljana, Slovenia Taras Shevchenko National Univ. of Kiev, Kiev, Ukraine Tata Institute of Fundamental Research, Mumbai 400005, India Department of Physics, Technische Universit¨at M¨unchen, 85748 Garching, Germany Tel Aviv University, School of Physics and Astronomy, Tel Aviv, 69978, Israel Toho University, Funabashi 274-8510, Japan Department of Physics, Tohoku University, Sendai 980-8578, Japan Tokyo Institute of Technology, Tokyo 152-8550, Japan Tokyo Metropolitan University, Tokyo 192-0397, Japan Universidad Autonoma de Sinaloa, Sinaloa 80000, Mexico Dipartimento di Scienze Fisiche, Universit`a di Napoli Federico II, I-80126 Napoli, Italy Dipartimento di Fisica e Astronomia, Universit`a di Padova, I-35131 Padova, Italy Dipartimento di Fisica, Universit`a di Perugia, I-06123 Perugia, Italy
Dipartimento di Fisica, Universit`a di Pisa, I-56127 Pisa, Italy
Universit`a di Roma “La Sapienza,” I-00185 Roma, Italy
Dipartimento di Matematica e Fisica, Universit`a di Roma Tre, I-00146 Roma, Italy
Dipartimento di Fisica, Universit`a di Torino, I-10125 Torino, Italy
Dipartimento di Fisica, Universit`a di Trieste, I-34127 Trieste, Italy
Universit´e de Montr´eal, Physique des Particules, Montr´eal, Qu´ebec, H3C 3J7, Canada
Universit´e Paris-Saclay, CNRS/IN2P3, IJCLab, 91405 Orsay, France
Universit´e de Strasbourg, CNRS, IPHC, UMR 7178, 67037 Strasbourg, France
Department of Physics, University of Adelaide, Adelaide, South Australia 5005, Australia
University of Bonn, 53115 Bonn, Germany
University of British Columbia, Vancouver, British Columbia, V6T 1Z1, Canada
University of Cincinnati, Cincinnati, Ohio 45221, U.S.A.
University of Florida, Gainesville, Florida 32611, U.S.A.
University of Hawaii, Honolulu, Hawaii 96822, U.S.A. University of Heidelberg, 68131 Mannheim, Germany
Faculty of Mathematics and Physics, University of Ljubljana, 1000 Ljubljana, Slovenia
University of Louisville, Louisville, Kentucky 40292, U.S.A.
National Centre for Particle Physics, University Malaya, 50603 Kuala Lumpur, Malaysia
University of Maribor, 2000 Maribor, Slovenia
School of Physics, University of Melbourne, Victoria 3010, Australia
University of Mississippi, University, Mississippi 38677, U.S.A.
University of Miyazaki, Miyazaki 889-2192, Japan
University of Pittsburgh, Pittsburgh, Pennsylvania 15260, U.S.A.
University of Science and Technology of China, Hefei 230026, China
University of South Alabama, Mobile, Alabama 36688, U.S.A.
University of South Carolina, Columbia, South Carolina 29208, U.S.A.
School of Physics, University of Sydney, New South Wales 2006, Australia
Department of Physics, University of Tokyo, Tokyo 113-0033, Japan
Kavli Institute for the Physics and Mathematics of theUniverse (WPI), University of Tokyo, Kashiwa 277-8583, Japan
University of Victoria, Victoria, British Columbia, V8W 3P6, Canada
Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, U.S.A.
Wayne State University, Detroit, Michigan 48202, U.S.A.
Yamagata University, Yamagata 990-8560, Japan
Alikhanyan National Science Laboratory, Yerevan 0036, Armenia
Yonsei University, Seoul 03722, South Korea
Abstract
Tag-side reconstruction is an important method for reconstructing B meson decays with missingenergy. The Belle II tag-side reconstruction algorithm, Full Event Interpretation, relies on a hier-archical reconstruction of B meson decays with multivariate classification employed at each stageof reconstruction. Given the large numbers of classifiers employed and decay chains reconstructed,the performance of the algorithm on data and simulation differs significantly. Here, calibrationfactors are derived for hadronic tag-side B decays by measuring a signal side decay, B → X(cid:96)ν , in34 . − of Belle II data. For a very loose selection on the tag-side B multivariate classifier, thecalibration factors are 0 . ± .
02 and 0 . ± .
03 for tag-side B + and B mesons, respectively. . INTRODUCTION The Belle II experiment [1] is an e + e − collider experiment in Japan, which began itsmain physics runs in early 2019 and has collected 74 fb − of data at a centre-of-mass (CM)energy, √ s , corresponding to the mass of the Υ (4 S ) resonance. The clean environmentof e + e − collisions together with the unique event topology of Belle II, in which an Υ (4 S )meson is produced and subsequently decays in a pair of B mesons, allows a wide range ofphysics measurements to be performed that are difficult or impossible at hadron colliders.In particular, measurements in which there is missing energy, which includes semileptonicdecays with missing neutrinos, can benefit substantially from the additional constraintsprovided by the collision environment of Belle II. This includes the measurement of the ratioof branching fractions, R ( D ∗ ) = B ( B → D ( ∗ ) τ ν ) / B ( B → D ( ∗ ) (cid:96)ν ), inclusive determinationsof the CKM matrix elements | V ub | and | V cb | from B → X u/c (cid:96)ν decays and searches for therare decay B → K ∗ ν ¯ ν .Full Event Interpretation [2] is an algorithm for tag-side B meson reconstruction at BelleII. The algorithm utilises a hierarchical reconstruction of exclusive decay chains of B mesons,with multivariate classifiers utilised to identify each unique sub-decay channel. Given thelarge number of decay chains reconstructed and multivariate classifiers employed, there canbe significant differences between the tag-side reconstruction efficiency in simulation anddata. In order to correct for this, a calibration can be performed by measuring a decaywith a well known branching fraction and sufficient available statistics after selection. Asuitable choice, given the current Belle II dataset, is inclusive B → X(cid:96)ν decays due to theirsubstantial branching fraction of ∼
2. DETECTOR AND SIMULATION
The Belle II detector [1, 3] operates at the SuperKEKB asymmetric-energy electron-positron collider [4], located at the KEK laboratory in Tsukuba, Japan. The detectorconsists of several nested detector subsystems arranged around the beam pipe in a cylindricalgeometry.The innermost subsystem is the vertex detector, which includes two layers of silicon pixeldetectors and four outer layers of silicon strip detectors. Currently, the second pixel layer isinstalled in only a small part of the solid angle, while the remaining vertex detector layersare fully installed. Most of the tracking volume consists of a helium- and ethane-basedsmall-cell drift chamber.Outside the drift chamber, a Cherenkov-light imaging and time-of-propagation detec-tor provides charged-particle identification in the barrel region. In the forward endcap,this function is provided by a proximity-focusing, ring-imaging Cherenkov detector with anaerogel radiator. Further out is an electromagnetic calorimeter, consisting of a barrel andtwo endcap sections made of CsI(Tl) crystals. A uniform 1.5 T magnetic field is providedby a superconducting solenoid situated outside the calorimeter. Multiple layers of scintil-lators and resistive plate chambers, located between the magnetic flux-return iron plates,constitute the K L and muon identification system.The data used in this analysis were collected at a CM energy, √ s , of 10.58 GeV, cor-8esponding to the mass of the Υ (4S) resonance. The energies of the electron and positronbeams are 7 GeV and 4 GeV, respectively, resulting in a boost of βγ = 0 .
28 of the CM framerelative to the lab frame. The integrated luminosity of the data is 34 . − . In addition, asmaller sample of 3 .
23 fb − off-resonance data was collected at a CM energy of 10 .
52 GeV.The analysis utilises several samples of simulated events. These include a sample of e + e − → ( Υ (4 S ) → B ¯ B ) with generic B -meson decays, generated with EvtGen [5], andcorresponding to an integrated luminosity of 100 fb − . A 100 fb − sample of continuum e + e − → q ¯ q ( q = u, d, s, c ) is simulated with KKMC [6] interfaced with PYTHIA [7]. Alldata samples were analyzed (and, for Monte Carlo (MC) events, generated and simulated)in the basf2 [8] framework.
3. THE ALGORITHM
The Full Event Interpretation employs a hierarchical reconstruction of exclusive B mesondecay chains, in which each unique decay channel of a particle has its own designatedmultivariate classifier. The algorithm utilises several stages of reconstruction, which areshown in Fig. 1. The algorithm starts by selecting candidates for stable particles, whichinclude muons, electrons, pions, kaons, protons and photons, from tracks and EM clustersin the event. Subsequently, the algorithm carries out several stages of reconstruction ofintermediate particles such as π , K S , J/ψ , D and D ∗ mesons and, in addition, Σ , Λ and Λ c baryons. The addition of baryonic modes is a recent extension of the algorithm. Intermediateparticles are reconstructed in specific decay modes from a combination of stable and otherintermediate particle candidates. The final stage of the algorithm reconstructs the B + and B mesons in 36 (8) and 31 (8) hadronic (semileptonic) modes. Tracks DisplacedVertices NeutralClusters π K K π + e + µ + K + p Σ + γ D ∗ D ∗ + D ∗ s B B + D D + D s Λ c J /ψ Λ K FIG. 1. The stages of reconstruction employed by Full Event Interpretation.
Each stage consists of pre-reconstruction and post-reconstruction steps. In the pre-reconstruction step, candidates for particles are reconstructed, an inital pre-selection is ap-9 .00.20.40.60.81.01.2 C a n d i d a t e s / ( . ) ×10 B +tag dt = 34.6 fb Belle II preliminary (4 S ) BB ContinuumMC stat. unc.Data1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0 log( tag ) ( D a t a - M C ) / M C (a) M bc (GeV/ c ) E v e n t s / ( . G e V / c ) ×10 N B +tag =84907 ± 734 tag >0.1 dt =34.6fb Belle II preliminary
Correctly reconstructedContinuum & mis-reconstructedData (b) M bc (GeV/ c ) E v e n t s / ( . G e V / c ) ×10 N B =65855 ± 590 tag >0.1 dt =34.6fb Belle II preliminary
Correctly reconstructedContinuum & mis-reconstructedData 5.250 5.255 5.260 5.265 5.270 5.275 5.280 5.285 M bc (GeV/ c ) E v e n t s / ( . G e V / c ) ×10 N B +tag =38545 ± 1161 tag >0.5 dt =34.6fb Belle II preliminary
Correctly reconstructedContinuum & mis-reconstructedData5.250 5.255 5.260 5.265 5.270 5.275 5.280 5.285 M bc (GeV/ c ) E v e n t s / ( . G e V / c ) N B =35401 ± 297 tag >0.5 dt =34.6fb Belle II preliminary
Correctly reconstructedContinuum & mis-reconstructedData
FIG. 2. (a) Comparison of the distribution of log P tag in early Belle II data to the shape expectationfrom simulation. Here, log P tag is the logarithm of the tag-side B + meson classifier output, P tag .Reference selection criteria of P tag > . P tag > . M bc , distribution of reconstructed B + (top) and B (bottom) tag-side B mesonsin data. A looser selection criteria of P tag > . P tag > . B meson classifier P tag to select samples with different levels of purity. plied and a best candidate selection is made on a discriminating variable. Subsequently, inthe post-reconstruction step, vertex fits are performed where applicable, pre-trained classi-fiers are applied and a best-candidate selection is made on the classifier output. Classifiersfor stable particles utilise kinematic and particle identification information as features; mean-while, intermediate and B classifiers utilise the kinematic information from all daughters,daughter classifier outputs and information from vertex fits as features.The algorithm requires a training procedure, in which all of the particle classifiers aretrained. For the calibration studies performed here, the training was performed on simulated Υ (4 S ) → B ¯ B events corresponding to an integrated luminosity of 100 fb − . The training ofthe algorithm utilises an equivalent reconstruction procedure to produce training datasetsfor each particle decay channel classifier.Subsequently, the tag-side B classifier, P tag , can be used to select a pure sample ofcorrectly reconstructed tag-side B mesons. This is demonstrated in Fig. 2, which showsfits to the beam constrained mass distribution, M bc = (cid:113) E − ( p CMtag ) , for reconstructedtag-side B and B + mesons, for selections requiring P tag to be greater than 0.1 and 0.5. Thecontribution from correctly reconstructed tag-side B mesons is parametrised by a CrystalBall function [9]; backgrounds from e + e − → q ¯ q and incorrectly reconstructed B mesonsare modelled with an Argus function [10]. By applying a tighter selection on the classifieroutput, a higher purity sample of tag-side B mesons can be selected with the sacrifice of alower tag-side efficiency, which is proportional to the yield of correctly reconstructed tag-side B mesons. 10 . SELECTION The selection process begins by requiring that there is at most one tag-side B mesoncandidate in each event. This is achieved by selecting the tag-side candidate with the high-est tag-side B classifier output, P tag . For correctly reconstructed tags, the beam energydifference, ∆ E , should peak around 0 with some mode-dependent resolution, which is asym-metric with a skew towards lower values for modes containing π → γγ decays. Therefore, anasymmetric requirement of − . < ∆ E < . e + e − → q ¯ q events, a requirement on the event-level-normalisedsecond Fox-Wolfram moment to be less than 0.3 is made. Fig. 3 shows a breakdown ofthe M bc distribution in data into several categories of tag-side decay mode after the aboveselection and the loose purity requirement that P tag > .
01. The dominant tag-side decaymode categories are Dπ , D ∗ π , Dnπ and D ∗ nπ . The recently added baryonic modes resultin a small increase in the tag-side efficiency, boosting the number of correctly reconstructedtag-side B mesons by roughly 3% (2%) for tag-side B + ( B ) mesons. The final selectionapplied to the tag-side candidate, is a requirement that M bc is greater than 5.27 GeV/ c ,which selects the region containing correctly reconstructed tag-side B mesons as can be seenin Fig. 2. M bc (GeV/ c ) C a n d i d a t e s / ( . G e V / c ) ×10 B +tag dt = 34.6 fb Belle II preliminary
Baryonic D K + J / XD (*) D (*) XD (*)+ s D (*)0 D *0 nD *0 + D nD nD M bc (GeV/ c ) C a n d i d a t e s / ( . G e V / c ) ×10 B dt = 34.6 fb Belle II preliminary
Baryonic J / XD (*) D (*) XD +(*) s D (*) D * nD * + D nD nD + FIG. 3. Contribution of different tag-side decay modes to the M bc distribution in data for B + (left) and B (right) parents for P tag > .
01. Contributions from the newly added baryonic modescan also be seen.
After the tag-side selection, the signal-side selection is applied. In particular, a leptonis selected with p ∗ (cid:96) > c , where p ∗ (cid:96) refers to the momentum of the lepton in the restframe of the signal-side B meson, which can be determined using the four-momentum ofthe recoiling tag-side B meson. The distance of closest approach between each track andthe interaction point is required to be less than 2 cm along the z direction (parallel to thebeams) and less than 0.5 cm in the transverse r − φ plane. Particle identification informationfrom several sub-detectors, including Cherenkov time of propagation (TOP), Aerogel ring11maging Cherenkov and dedicated muon detectors, is combined into a likelihood for each ofelectron and muon hypotheses in order to select each lepton species. The selection on p ∗ (cid:96) tobe greater than 1 GeV/ c was motivated by the fact that lepton identification performanceis found to degrade significantly below 1 GeV/ c .
5. CALIBRATION PROCEDURE
The calibration factor is defined as (cid:15) = N Data
X(cid:96)ν /N MC X(cid:96)ν , where the yield of B → X(cid:96)ν decaysin data, N Data
X(cid:96)ν , is determined by fitting the p ∗ (cid:96) distribution and the expected yield, N MC X(cid:96)ν , isdetermined using MC simulation.The fitting procedure maximises a binned likelihood, L , defined by the following equation, − L = − (cid:89) i P( ν obs i | ν exp i ) + θ T Σ − θ θ T + ( k − k constraints ) T Σ − ( k − k constraints ) , (1)where the probability to observe ν obs i events in bin i of p ∗ (cid:96) given that ν exp i events were expectedis P( ν obs i | ν exp i ) and is governed by a Poisson distribution. Here, ν exp i , is given by ν exp i = (cid:88) j ν j p ji (1 + θ ji ) (cid:80) k p jk (1 + θ jk ) , (2)where p ji defines the probability for an event of process type j to have a reconstructed valueof p ∗ (cid:96) in bin i . The nuisance parameters, θ ji , account for both MC template statistics andadditional systematic effects. The associated bin-to-bin correlations arising from systematicuncertainties are accounted for in the covariance matrix, Σ θ .The fit has three yields associated with three probability density functions (pdfs), whichdescribe the B → X(cid:96)ν signal decays, background from e + e − → q ¯ q events, and background inwhich the lepton is fake or secondary. “Secondary” here refers to the situation in which thelepton is not produced directly in the decay of the B meson but rather through a secondarycascade decay of a charmed meson. Meanwhile, “Fake” refers to the case in which a hadronis mis-reconstructed as a lepton. The B → X(cid:96)ν signal pdf has four sub-components, whichinclude B → D ∗ (cid:96)ν , B → D(cid:96)ν , B → X u (cid:96)ν and any remaining B → X c (cid:96)ν decays ( B → D ∗∗ (cid:96)ν and B → D ( ∗ ) nπ(cid:96)ν ). The relative contributions of these four components are parametrisedby three fractions ( f D , f D ∗ and f X u ).The last term, ( k − k constraints ) T Σ − ( k − k constraints ), in Equation 1 allows for con-straints on parameters in the fit. The parameter vector k = ( N ( e + e − → q ¯ q ) , f D , f D ∗ , f X u )contains the subset of fit parameters, which are subject to constraints. The vector k constraints contains the corresponding nominal values to which these parameters are constrained. Thecontinuum yield, N ( e + e − → q ¯ q ), is constrained to its expectation based on counting off-resonance events and scaling up to account for luminosity. The constraints on the threefractions are obtained from MC expectation after all branching fraction corrections aremade.Fit results for the channels B + e − , B + µ − , B e − and B µ − with a selection of P > . dt = 34.6 fb B +tag e Belle II preliminary D ** , gap B X u B D * B D
Fake or Secondary e + e qq MC UncertaintyData p * (GeV/ c )2.50.02.5 01000200030004000 dt = 34.6 fb B +tag Belle II preliminary D ** , gap B X u B D * B D
Fake or Secondary e + e qq MC UncertaintyData p * (GeV/ c )2.50.02.5050010001500 dt = 34.6 fb B e Belle II preliminary D ** , gap B X u B D * B D
Fake or Secondary e + e qq MC UncertaintyData p * (GeV/ c )2.50.02.5 0500100015002000 dt = 34.6 fb B Belle II preliminary D ** , gap B X u B D * B D
Fake or Secondary e + e qq MC UncertaintyData p * (GeV/ c )2.50.02.5 FIG. 4. Fits to p ∗ (cid:96) in data for charged (top) and neutral (bottom) tag-side B mesons combinedeither with electron (left) or muon (right) signal-side B → X(cid:96)ν decays. across all channels. Fig. 5 shows the B + (cid:96) − fit channels in the region where p ∗ (cid:96) > c .In this region, the contribution from B → X u (cid:96)ν decays becomes evident due to the lowerkinematic endpoint of B → X c (cid:96)ν decays. This allows one to better constrain the albeitsmall contribution from B → X u (cid:96)ν decays.
6. SOURCES OF SYSTEMATIC UNCERTAINTY
The calibration procedure is affected by a number of sources of systematic uncertainty.These can influence the determination of the MC expected yield (normalisation uncertain-ties) or the shapes of pdfs in the fitting procedure (shape uncertainties).We first discuss the estimation of systematic uncertainties for the MC expected yield,13 dt = 34.6 fb B +tag e Belle II preliminary D ** , gap B X u B D * B D
Fake or Secondary e + e qq MC UncertaintyData p * (GeV/ c )2.50.02.5 050100150200 dt = 34.6 fb B +tag Belle II preliminary D ** , gap B X u B D * B D
Fake or Secondary e + e qq MC UncertaintyData p * (GeV/ c )2.50.02.5 FIG. 5. Fits to p ∗ (cid:96) in data in the region p ∗ (cid:96) > c . This region is enhanced in B → X u (cid:96)ν decays relative to B → X c (cid:96)ν decays due to the lower kinematic endpoint for B → X c (cid:96)ν decays. N MC X(cid:96)ν . The first source of systematic uncertainty considered is that arising from the knowl-edge of the B → X(cid:96)ν branching fractions. Several branching fractions of the B → X(cid:96)ν decay modes, including B → D(cid:96)ν , B → D ∗ (cid:96)ν and B → X u (cid:96)ν , were first corrected to theirlatest PDG values. After having applied these corrections, the overall charged and neutral B → X(cid:96)ν branching fractions were scaled to match those in the PDG: B ( B + → X(cid:96)ν ) =10 . ± .
28 and B ( B → X(cid:96)ν ) = 10 . ± .
28. The corresponding uncertainties are treatedas a source of systematic uncertainty. In addition to correcting several branching fractions,the form factors of
D(cid:96)ν and D ∗ (cid:96)ν decays are updated to the BGL parametrisations ofRef. [11, 12], with the central parameter values in Ref. [13]. The associated uncertaintieson the form factor parameters of these parameterisations are propagated in the analysisusing one-sigma variations in an uncorrelated eigenbasis of form factor parameters of thecorresponding BGL parametrisations. The form factor uncertainties can influence N MC X(cid:96)ν dueto the selection of p ∗ (cid:96) > c .The next sources of uncertainty relate to tracking and particle identification. Due tomismatches in the reconstruction of tracks between simulation and data, a systematic errorof 0.91% is assigned for the single signal-side track. The performance of lepton identifi-cation also differs between data and MC. Consequently, the lepton identifcation rates and π → (cid:96) and K → (cid:96) fake rates are corrected in bins of lepton momentum and polar angleusing corrections derived from data samples of J/ψ → (cid:96) + (cid:96) − , D ∗ + → ( D → K − π + ) π + and K S → π + π − decays. The systematic uncertainty associated with these corrections isdetermined by generating gaussian variations on these weights according to their systematicand statistical uncertainties, while assuming that the systematic uncertainties across binsare 100% correlated. The final considered source of systematic uncertainty on N MC X(cid:96)ν is thestatistical size of the MC sample used to estimate N MC X(cid:96)ν .A number of systematic effects can impact the expected p ∗ (cid:96) distribution from simulation.These include the Monte Carlo statistics, the B → D ( ∗ ) (cid:96)ν form factors, lepton identificationand the composition of B → X(cid:96)ν decays. The uncertainty associated with the composition14f B → X(cid:96)ν is propagated into the fit through the freedom of the B → X(cid:96)ν pdf to changeaccording to aforementioned sub-pdf fractions. A multivariate Gaussian constraint on thesefractions is estimated, which accounts for the PDG uncertainty on several branching fractionupdates and Monte Carlo statistics. Given that the contribution from B → D ∗∗ (cid:96)ν and B → D ( ∗ ) nπ(cid:96)ν is not very well known, the overall branching fraction of these transitions isassigned a 20% uncertainty.The shape impact for the remaining systematic sources of uncertainty are accountedfor by using the nuisance parameters associated with each bin of a sub-pdf. For eachsystematic source of uncertainty, s , a N dim × N dim covariance matrix, Σ s , is estimated,where N dim = N bins × N pdfs . For lepton identification, Σ LID , is estimated by filling histogramswith each independent weight variation. Meanwhile, for the D ( ∗ ) form factors, Σ D ( ∗ ) FF isestimated by combining covariance matrices associated with one-sigma eigen-variations ofBGL form factor parameters. Lastly, for MC statistics, Σ MC is determined using Poissonstatistics and is purely diagonal. The total covariance matrix Σ θ = (cid:80) s Σ s is used in thenuisance parameter constraint term of Equation 1.
7. RESULTS
Final results for the calibration factors as determined from the fitted yields are shownin Fig. 6. The corresponding numerical results are itemised in Appendix A along with thesimulated and fitted yields of B → X(cid:96)ν decays. Calibration factors for tag-side B and B + mesons are found to agree well for both lepton channels with the B + and B calibrationfactors ranging from 0 . .
63 and 0 . .
83, respectively. For tag-side B mesons, thecalibration factors with a looser selection on the tag-side B classifier output, P B , aregenerally observed to be higher. This appears to be due to the fact that a looser cut increasesthe contribution of certain modes in the lower purity region. The sources uncertainties forthe calibration factors are shown in Table I for the threshold of P > . B ( B + / → X(cid:96)ν ) (2 . . B ( B + / → X(cid:96)ν ), and the D ( ∗ ) (cid:96)ν form factors are deemed to be 100%correlated. Channel MC Stat. B ( B / + → X(cid:96)ν ) Tracking
D(cid:96)ν
FF Lepton ID D ∗ (cid:96)ν FF Fit Stat. Fit Model B + e − B + µ − B e − B µ − P tag > . + e B + B + B e B B Channel c a l = ( N D a t a X / N M C X ) dt = 34.6 fb Belle II preliminary tag > 0.001 tag > 0.01 tag > 0.1 (a)
20 30 40 50 60
Purity (%) M C t a g × c a l ( % ) dt = 34.6 fb Belle II preliminary B + B (b)FIG. 6. (a) Calibration factors for each of the different channels and different signal probability, P tag , selection choices. Good agreement is seen between the muon and electron channels for thesignal-side B → X(cid:96)ν decay. (b) (cid:15)
MCtag × (cid:15) cal against purity for P tag > . .
01 and 0 . B and B + mesons. B + P tag > (cid:15) uncertainty [%]0.001 0 . ± .
02 3.00.01 0 . ± .
02 3.10.1 0 . ± .
02 3.3 B P tag > (cid:15) uncertainty [%]0.001 0 . ± .
03 3.40.01 0 . ± .
03 3.50.1 0 . ± .
03 3.9TABLE II. Final calibration factors averaged over lepton type. A weighted average taking intoaccount the uncertainties and correlated systematics is used.
The final calibration factors, (cid:15) cal , in Table II can be applied in order to correct the tag-side efficiency in simulation, (cid:15)
MCtag . In Fig. 6 the corrected tag-side efficiency from simulation, (cid:15)
MCtag × (cid:15) cal , is shown against purity, for the P tag thresholds of 0 . .
01 and 0 .
1. Here,the tag-side efficiency, (cid:15)
MCtag , refers to ratio of the number of events containing a correctlyreconstructed tag-side B meson in the region M bc > .
27 GeV/ c to the total number ofsimulated Υ (4 S ) → B ¯ B events. Meanwhile the purity is the ratio of the number of eventscontaining a correctly reconstructed tag-side B meson in this region to the number of eventscontaining a reconstructed tag-side B meson.16 . CONCLUSIONS At Belle II, hadronic tag-side reconstruction will be a critical part of the physics program,allowing a number of challenging final states with missing energy to be measured. Thisincludes measurements of R ( D ( ∗ ) ) with B → D ( ∗ ) τ ν decays, measurements of the CKMmatrix elements | V ub | and | V cb | using inclusive B → X c/u (cid:96)ν transitions and searches for therare decay B → K ∗ ν ¯ ν .The Belle II experiment’s tag-side reconstruction algorithm, Full Event Interpretation,relies on a hierarchical reconstruction of around 10000 B meson decays with over 200 mul-tivariate classifiers. In order to employ the algorithm in a physics analysis, it is necessaryto account for differences in the performance of the algorithm between data and simulation.Here, first calibration factors were derived in order to correct for these effects by measuringa well-known signal side of B → X(cid:96)ν decays. Calibration factors are determined for both B and B + mesons for a range of selections on the tag-side B multivariate classifier. For avery loose selection, the calibration factors are 0 . ± .
020 and 0 . ± .
029 for tag-side B + and B mesons, respectively.
9. ACKNOWLEDGEMENTS
We thank the SuperKEKB group for the excellent operation of the accelerator; the KEKcryogenics group for the efficient operation of the solenoid; and the KEK computer groupfor on-site computing support. This work was supported by the following funding sources:Science Committee of the Republic of Armenia Grant No. 18T-1C180; Australian ResearchCouncil and research grant Nos. DP180102629, DP170102389, DP170102204, DP150103061,FT130100303, and FT130100018; Austrian Federal Ministry of Education, Science and Re-search, and Austrian Science Fund No. P 31361-N36; Natural Sciences and EngineeringResearch Council of Canada, Compute Canada and CANARIE; Chinese Academy of Sci-ences and research grant No. QYZDJ-SSW-SLH011, National Natural Science Foundationof China and research grant Nos. 11521505, 11575017, 11675166, 11761141009, 11705209,and 11975076, LiaoNing Revitalization Talents Program under contract No. XLYC1807135,Shanghai Municipal Science and Technology Committee under contract No. 19ZR1403000,Shanghai Pujiang Program under Grant No. 18PJ1401000, and the CAS Center for Excel-lence in Particle Physics (CCEPP); the Ministry of Education, Youth and Sports of the CzechRepublic under Contract No. LTT17020 and Charles University grants SVV 260448 andGAUK 404316; European Research Council, 7th Framework PIEF-GA-2013-622527, Hori-zon 2020 Marie Sklodowska-Curie grant agreement No. 700525 ‘NIOBE,’ and Horizon 2020Marie Sklodowska-Curie RISE project JENNIFER2 grant agreement No. 822070 (Europeangrants); L’Institut National de Physique Nucl´eaire et de Physique des Particules (IN2P3) duCNRS (France); BMBF, DFG, HGF, MPG, AvH Foundation, and Deutsche Forschungsge-meinschaft (DFG) under Germany’s Excellence Strategy – EXC2121 “Quantum Universe”’– 390833306 (Germany); Department of Atomic Energy and Department of Science andTechnology (India); Israel Science Foundation grant No. 2476/17 and United States-IsraelBinational Science Foundation grant No. 2016113; Istituto Nazionale di Fisica Nucleareand the research grants BELLE2; Japan Society for the Promotion of Science, Grant-in-Aidfor Scientific Research grant Nos. 16H03968, 16H03993, 16H06492, 16K05323, 17H01133,177H05405, 18K03621, 18H03710, 18H05226, 19H00682, 26220706, and 26400255, the Na-tional Institute of Informatics, and Science Information NETwork 5 (SINET5), and the Min-istry of Education, Culture, Sports, Science, and Technology (MEXT) of Japan; NationalResearch Foundation (NRF) of Korea Grant Nos. 2016R1D1A1B01010135, 2016R1D1A1B-02012900, 2018R1A2B3003643, 2018R1A6A1A06024970, 2018R1D1A1B07047294, 2019K1-A3A7A09033840, and 2019R1I1A3A01058933, Radiation Science Research Institute, For-eign Large-size Research Facility Application Supporting project, the Global Science Ex-perimental Data Hub Center of the Korea Institute of Science and Technology Informa-tion and KREONET/GLORIAD; Universiti Malaya RU grant, Akademi Sains Malaysiaand Ministry of Education Malaysia; Frontiers of Science Program contracts FOINS-296,CB-221329, CB-236394, CB-254409, and CB-180023, and SEP-CINVESTAV research grant237 (Mexico); the Polish Ministry of Science and Higher Education and the National Sci-ence Center; the Ministry of Science and Higher Education of the Russian Federation,Agreement 14.W03.31.0026; University of Tabuk research grants S-1440-0321, S-0256-1438,and S-0280-1439 (Saudi Arabia); Slovenian Research Agency and research grant Nos. J1-9124 and P1-0135; Agencia Estatal de Investigacion, Spain grant Nos. FPA2014-55613-P and FPA2017-84445-P, and CIDEGENT/2018/020 of Generalitat Valenciana; Ministryof Science and Technology and research grant Nos. MOST106-2112-M-002-005-MY3 andMOST107-2119-M-002-035-MY3, and the Ministry of Education (Taiwan); Thailand Cen-ter of Excellence in Physics; TUBITAK ULAKBIM (Turkey); Ministry of Education andScience of Ukraine; the US National Science Foundation and research grant Nos. PHY-1807007 and PHY-1913789, and the US Department of Energy and research grant Nos. DE-AC06-76RLO1830, DE-SC0007983, DE-SC0009824, DE-SC0009973, DE-SC0010073, DE-SC0010118, DE-SC0010504, DE-SC0011784, DE-SC0012704; and the National Foundationfor Science and Technology Development (NAFOSTED) of Vietnam under contract No103.99-2018.45. [1] E. Kou et al.,
The Belle II Physics Book , PTEP (2019) no. 12, 123C01.[2] T. Keck et al.,
The Full Event Interpretation – An exclusive tagging algorithm for the BelleII experiment , Comput Softw Big Sci (2019) 6.[3] T. Abe et al., Belle II Collaboration, Belle II Technical Design Report , arXiv:1011.0352[physics.ins-det] .[4] K. Akai, K. Furukawa, and H. Koiso, SuperKEKB Collaboration, SuperKEKB Collider ,Nucl. Instrum. Meth.
A907 (2018) 188–199.[5] D. Lange,
The EvtGen particle decay simulation package , Nucl. Instrum. Meth. A (2001) 152–155.[6] S. Jadach, B. F. L. Ward, and Z. Was,
The Precision Monte Carlo event generator K K fortwo fermion final states in e + e − collisions , Comput. Phys. Commun. (2000) 260–325.[7] T. Sjostrand, S. Mrenna, and P. Z. Skands, A Brief Introduction to PYTHIA 8.1 , Comput.Phys. Commun. (2008) 852–867, arXiv:0710.3820 [hep-ph] .[8] T. Kuhr, C. Pulvermacher, M. Ritter, T. Hauth, and N. Braun, Belle-II Framework SoftwareGroup,
The Belle II Core Software , Comput. Softw. Big Sci. (2019) no. 1, 1, arXiv:1809.04299 [physics.comp-ph] .
9] T. Skwarnicki,
A study of the radiative CASCADE transitions between the Upsilon-Primeand Upsilon resonances . PhD thesis, Cracow, INP, 1986.[10] H. Albrecht et al., ARGUS,
Search for Hadronic b → u Decays , Phys. Lett. B (1990)278–282.[11] B. Grinstein and A. Kobach,
Model-Independent Extraction of | V cb | from ¯ B → D ∗ (cid:96)ν , Phys.Lett. B (2017) 359–364, arXiv:1703.08170 [hep-ph] .[12] D. Bigi, P. Gambino, and S. Schacht, A fresh look at the determination of | V cb | from B → D ∗ (cid:96)ν , Phys. Lett. B (2017) 441–445, arXiv:1703.06124 [hep-ph] .[13] A. Abdesselam et al., Belle II Collaboration, A fresh look at the determination of | V cb | from B → D ∗ (cid:96)ν , arXiv:1702.01521 [hep-ph] . Appendix A
A summary of all fitted yields, N Data
X(cid:96)ν , MC expected yields, N MC X(cid:96)ν and the correspondingcalibration factors are provided in Table III.
Sig. Prob. > . N MC X(cid:96)ν N Data
X(cid:96)ν (cid:15)B + e − (4 . ± . × (2 . ± . × . ± . B + µ − (4 . ± . × (3 . ± . × . ± . B e − (1 . ± . × (1 . ± . × . ± . B µ − (1 . ± . × (1 . ± . × . ± . > . N MC X(cid:96)ν N Data
X(cid:96)ν (cid:15)B + e − (2 . ± . × (1 . ± . × . ± . B + µ − (2 . ± . × (1 . ± . × . ± . B e − (1 . ± . × (0 . ± . × . ± . B µ − (1 . ± . × (0 . ± . × . ± . > . N MC X(cid:96)ν N Data
X(cid:96)ν (cid:15)B + e − (1 . ± . × (0 . ± . × . ± . B + µ − (1 . ± . × (0 . ± . × . ± . B e − (0 . ± . × (0 . ± . × . ± . B µ − (0 . ± . × (0 . ± . × . ± . N X(cid:96)ν as determined from the fits to data and simulation together withtotal uncertainties. The corresponding calibration factors computed from the ratio of these yieldsare also shown for each channel.as determined from the fits to data and simulation together withtotal uncertainties. The corresponding calibration factors computed from the ratio of these yieldsare also shown for each channel.