Eur. Phys. J. C (2020) 80: 935
https://doi.org/10.1140/epjc/s10052-020-08447-0

Regular Article - Experimental Physics

Measurement of the absolute branching fraction of the inclusive decay

(BESIII Collaboration)

¹ Institute of High Energy Physics, Beijing, 100049, People’s Republic of China
² Beihang University, Beijing, 100191, People’s Republic of China
³ Beijing Institute of Petrochemical Technology, Beijing, 102617, People’s Republic of China
⁴ Bochum Ruhr-University, 44780, Bochum, Germany
⁵ Carnegie Mellon University, Pittsburgh, PA, 15213, USA
⁶ Central China Normal University, Wuhan, 430079, People’s Republic of China
⁷ China Center of Advanced Science and Technology, Beijing, 100190, People’s Republic of China
⁸ COMSATS University Islamabad, Lahore Campus, Defence Road, Off Raiwind Road, Lahore, 54000, Pakistan
⁹ Fudan University, Shanghai, 200443, People’s Republic of China
¹⁰ G.I. Budker Institute of Nuclear Physics SB RAS (BINP), Novosibirsk, 630090, Russia
¹¹ GSI Helmholtz Centre for Heavy Ion Research GmbH, 64291, Darmstadt, Germany
¹² Guangxi Normal University, Guilin, 541004, People’s Republic of China
¹³ Guangxi University, Nanning, 530004, People’s Republic of China
¹⁴ Hangzhou Normal University, Hangzhou, 310036, People’s Republic of China
¹⁵ Helmholtz Institute Mainz, Johann-Joachim-Becher-Weg 45, 55099, Mainz, Germany
¹⁶ Henan Normal University, Xinxiang, 453007, People’s Republic of China
¹⁷ Henan University of Science and Technology, Luoyang, 471003, People’s Republic of China
¹⁸ Huangshan College, Huangshan, 245000, People’s Republic of China
¹⁹ Hunan Normal University, Changsha, 410081, People’s Republic of China
²⁰ Hunan University, Changsha, 410082, People’s Republic of China
²¹ Indian Institute of Technology Madras, Chennai, 600036, India
²² Indiana University, Bloomington, IN, 47405, USA
²³ INFN Laboratori Nazionali di Frascati, 00044 Frascati, Italy; INFN and University of Perugia, 06100, Perugia, Italy
²⁴ INFN Sezione di Ferrara, 44122 Ferrara, Italy; University of Ferrara, 44122, Ferrara, Italy
²⁵ Institute of Modern Physics, Lanzhou, 730000, People’s Republic of China
²⁶ Institute of Physics and Technology, Peace Ave. 54B, Ulaanbaatar, 13330, Mongolia
²⁷ Jilin University, Changchun, 130012, People’s Republic of China
²⁸ Johannes Gutenberg University of Mainz, Johann-Joachim-Becher-Weg 45, 55099, Mainz, Germany
²⁹ Joint Institute for Nuclear Research, 141980, Dubna, Moscow Region, Russia
³⁰ Justus-Liebig-Universitaet Giessen, II. Physikalisches Institut, Heinrich-Buff-Ring 16, 35392, Giessen, Germany
³¹ KVI-CART, University of Groningen, 9747 AA, Groningen, The Netherlands
³² Lanzhou University, Lanzhou, 730000, People’s Republic of China
³³ Liaoning Normal University, Dalian, 116029, People’s Republic of China
³⁴ Liaoning University, Shenyang, 110036, People’s Republic of China
³⁵ Nanjing Normal University, Nanjing, 210023, People’s Republic of China
³⁶ Nanjing University, Nanjing, 210093, People’s Republic of China
³⁷ Nankai University, Tianjin, 300071, People’s Republic of China
³⁸ Peking University, Beijing, 100871, People’s Republic of China
³⁹ Qufu Normal University, Qufu, 273165, People’s Republic of China
⁴⁰ Shandong Normal University, Jinan, 250014, People’s Republic of China
⁴¹ Shandong University, Jinan, 250100, People’s Republic of China
⁴² Shanghai Jiao Tong University, Shanghai, 200240, People’s Republic of China
⁴³ Shanxi Normal University, Linfen, 041004, People’s Republic of China
⁴⁴ Shanxi University, Taiyuan, 030006, People’s Republic of China
⁴⁵ Sichuan University, Chengdu, 610064, People’s Republic of China
⁴⁶ Soochow University, Suzhou, 215006, People’s Republic of China
⁴⁷ Southeast University, Nanjing, 211100, People’s Republic of China
⁴⁸ State Key Laboratory of Particle Detection and Electronics, Beijing 100049, Hefei, 230026, People’s Republic of China
⁴⁹ Sun Yat-Sen University, Guangzhou, 510275, People’s Republic of China
⁵⁰ Tsinghua University, Beijing, 100084, People’s Republic of China
⁵¹ Ankara University, Tandogan, 06100 Ankara, Turkey; Istanbul Bilgi University, 34060 Eyup, Istanbul, Turkey; Uludag University, 16059 Bursa, Turkey; Near East University, Mersin 10, Nicosia, North Cyprus, Turkey
⁵² University of Chinese Academy of Sciences, Beijing, 100049, People’s Republic of China
⁵³ University of Hawaii, Honolulu, HI, 96822, USA
⁵⁴ University of Jinan, Jinan, 250022, People’s Republic of China
⁵⁵ University of Manchester, Oxford Road, Manchester, M13 9PL, UK
⁵⁶ University of Minnesota, Minneapolis, MN, 55455, USA
⁵⁷ University of Muenster, Wilhelm-Klemm-Str. 9, 48149, Münster, Germany
⁵⁸ University of Oxford, Keble Rd, Oxford, OX13RH, UK
⁵⁹ University of Science and Technology Liaoning, Anshan, 114051, People’s Republic of China
⁶⁰ University of Science and Technology of China, Hefei, 230026, People’s Republic of China
⁶¹ University of South China, Hengyang, 421001, People’s Republic of China
⁶² University of the Punjab, Lahore, 54590, Pakistan
⁶³ University of Turin, 10125 Turin, Italy; University of Eastern Piedmont, 15121 Alessandria, Italy; INFN, 10125, Turin, Italy
⁶⁴ Uppsala University, Box 516, 75120, Uppsala, Sweden
⁶⁵ Wuhan University, Wuhan, 430072, People’s Republic of China
⁶⁶ Xinyang Normal University, Xinyang, 464000, People’s Republic of China
⁶⁷ Zhejiang University, Hangzhou, 310027, People’s Republic of China
⁶⁸ Zhengzhou University, Zhengzhou, 450001, People’s Republic of China

^* e-mail: wangbin@ihep.ac.cn

Received: 22 May 2020
Accepted: 8 September 2020
Published online: 10 October 2020

Abstract

We report the first measurement of the absolute branching fraction of the inclusive decay . The analysis is performed using an collision data sample corresponding to an integrated luminosity of 567  taken at = 4.6 GeV with the BESIII detector. Using eleven Cabibbo-favored decay modes and the double-tag technique, this absolute branching fraction is measured to be , where the first uncertainty is statistical and the second systematic. The relative deviation between the branching fractions for the inclusive decay and the observed exclusive decays is , which indicates that there may be some unobserved decay modes with a neutron or excited baryons in the final state.