Journal article
First observation of the P-wave spin-singlet bottomonium states h b(1P) and h b(2P)
I Adachi, H Aihara, K Arinstein, DM Asner, T Aushev, T Aziz, AM Bakich, E Barberio, K Belous, V Bhardwaj, B Bhuyan, A Bondar, M Bračko, J Brodzicka, TE Browder, P Chang, A Chen, P Chen, BG Cheon, K Chilikin Show all
Physical Review Letters | Published : 2012
Abstract
We report the first observations of the spin-singlet bottomonium states h b(1P) and h b(2P). The states are produced in the reaction e +e -→h b(nP)π +π - using a 121.4fb -1 data sample collected at energies near the Υ(5S) resonance with the Belle detector at the KEKB asymmetric-energy e +e - collider. We determine M[h b(1P)]=(9898.2- 1.0-1.1+1.1+1.0)MeV/c2 and M[h b(2P)]=(10259.8±0.6-1.0+1.4)MeV/ c2, which correspond to P-wave hyperfine splittings ΔM HF=(+1. 7±1.5) and (+0.5-1.2+1.6)MeV/c2, respectively. The significances of the h b(1P) and h b(2P) are 5.5σ and 11.2σ, respectively. We find that the production of the h b(1P) and h b(2P) is not suppressed relative to the production of the Υ(1S..
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Awarded by National Science Foundation
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); NSFC (China); MSMT (Czechia); DST (India); MEST, NRF, NSDC of KISTI, and WCU (Korea); MNiSW (Poland); MES and RFAAE (Russia); ARRS (Slovenia); SNSF (Switzerland); NSC and MOE (Taiwan); and DOE and NSF (USA).