First Observation of the Hadronic Transition Γ (4S) →ηhb (1P) and New Measurement of the hb (1P) and ηb (1S) Parameters

U Tamponi; R Mussa; A Abdesselam; H Aihara; K Arinstein; DM Asner; H Atmacan; T Aushev; R Ayad; I Badhrees; AM Bakich; E Barberio; V Bhardwaj; B Bhuyan; J Biswal; A Bondar; G Bonvicini; A Bozek; M Bračko; TE Browder; D Červenkov; A Chen; BG Cheon; K Cho; V Chobanova; SK Choi; Y Choi; D Cinabro; M Danilov; Z DoleŽal; Z Drásal; A Drutskoy; S Eidelman; D Epifanov; H Farhat; JE Fast; T Ferber; BG Fulsom; V Gaur; N Gabyshev; A Garmash; D Getzkow; R Gillard; YM Goh; B Golob; J Haba; K Hayasaka; H Hayashii; XH He; MT Hedges; WS Hou; T Iijima; K Inami; A Ishikawa; I Jaegle; D Joffe; T Julius; E Kato; P Katrenko; H Kichimi; C Kiesling; DY Kim; HJ Kim; JH Kim; KT Kim; SH Kim; K Kinoshita; P Kodyš; S Korpar; P KriŽan; P Krokovny; T Kumita; A Kuzmin; JS Lange; P Lewis; J Libby; P Lukin; D Matvienko; K Miyabayashi; H Miyata; R Mizuk; GB Mohanty; A Moll; T Mori; E Nakano; M Nakao; T Nanut; Z Natkaniec; M Nayak; NK Nisar; S Nishida; S Ogawa; S Okuno; SL Olsen; W Ostrowicz; C Oswald; G Pakhlova; B Pal; H Park; TK Pedlar

Journal article

First Observation of the Hadronic Transition Γ (4S) →ηhb (1P) and New Measurement of the hb (1P) and ηb (1S) Parameters

U Tamponi, R Mussa, A Abdesselam, H Aihara, K Arinstein, DM Asner, H Atmacan, T Aushev, R Ayad, I Badhrees, AM Bakich, E Barberio, V Bhardwaj, B Bhuyan, J Biswal, A Bondar, G Bonvicini, A Bozek, M Bračko, TE Browder Show all

Physical Review Letters | Published : 2015

DOI: 10.1103/PhysRevLett.115.142001

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Abstract

Using a sample of 771.6×106 ΓΓ(4S) decays collected by the Belle experiment at the KEKB e+e- collider, we observe, for the first time, the transition Γ(4S)→ηhb(1P) with the branching fraction B[Γ(4S)→ηhb(1P)]=(2.18±0.11±0.18)×10-3 and we measure the hb(1P) mass Mhb(1P)=(9899.3±0.4±1.0)MeV/c2, corresponding to the hyperfine (HF) splitting ΔMHF(1P)=(0.6±0.4±1.0)MeV/c2. Using the transition hb(1P)→γηb(1S), we measure the ηb(1S) mass Mηb(1S)=(9400.7±1.7±1.6)MeV/c2, corresponding to ΔMHF(1S)=(59.6±1.7±1.6)MeV/c2, the ηb(1S) width Γηb(1S)=(8-5+6±5)MeV/c2 and the branching fraction B[hb(1P)→γηb(1S)]=(56±8±4)%.

University of Melbourne Researchers

Elisabetta Barberio Author

Martin Sevior Author

Phillip Urquijo Author

Grants

Funding Acknowledgements

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 PNNL/EMSL for valuable computing and SINET4 network support. We acknowledge support from MEXT, JSPS, and Nagoya's TLPRC (Japan); ARC and DIISR (Australia); FWF (Austria); NSFC (China); MSMT (Czechia); CZF, DFG, and VS (Germany); DST (India); INFN (Italy); MOE, MSIP, NRF, GSDC of KISTI, and BK21Plus (Korea); MNiSW and NCN (Poland); MES (particularly under Contract No. 14.A12.31.0006), RFAAE and RFBR under Grant No. 14-02-01220 (Russia); ARRS (Slovenia); IKERBASQUE and UPV/EHU (Spain); SNSF (Switzerland); NSC and MOE (Taiwan); and DOE and NSF (USA).