Observation of ϒ(4S)→η′ϒ(1S)

We thank the KEKB group for excellent operation of the accelerator; the KEK cryogenics group for efficient solenoid operations; and the KEK computer group, the NII, and Pacific Northwest National Laboratory (PNNL)/Environmental Molecular Sciences Laboratory (EMSL) for valuable computing and Science Information NETwork 5 (SINET5) network support. We acknowledge support from Ministry of Education, Culture, Sports, Science, and Technology (MEXT), Japan Society for the Promotion of Science (JSPS), and Nagoya's TLPRC (Japan); Australian Research Council (ARC) (Australia); FWF (Austria); National Natural Science Foundation of China (NSFC) and CAS Center for Excellence in Particle Physics (CCEPP) (China); MSMT (Czechia); CZF, Deutsche Forschungsgemeinschaft (DFG), EXC153, and VS (Germany); DST (India); Instituto Nazionale di Fisica Nucleare (INFN) (Italy); Ministry of Education (MOE), Ministry of Science, ICT and Future Planning (MSIP), National Research Foundation (NRF), RSRI, FLRFAS project, and GSDC of Korea Institute of Science and Technology Information (KISTI) (Korea); Ministerstwo Nauki i Szkolnictwa Wyzszego (MNiSW) and Narodowe Centrum Nauki (NCN) (Poland); MES under Contract No. 14.W03.31.0026 (Russia); ARRS (Slovenia); IKERBASQUE and Ministry of Economy and Competitiveness (MINECO) (Spain); SNSF (Switzerland); Ministry of Education (MOE) and Ministry of Science and Technology, Taiwan (MOST) (Taiwan); and U.S. Department of Energy (DOE) and National Science Foundation (NSF) (USA).