Journal article

Observation of X(3872) -> J/psi gamma and Search for X(3872) -> psi 'gamma in B Decays

V Bhardwaj, K Trabelsi, JB Singh, S-K Choi, SL Olsen, I Adachi, K Adamczyk, DM Asner, V Aulchenko, T Aushev, T Aziz, AM Bakich, E Barberio, K Belous, B Bhuyan, M Bischofberger, A Bondar, M Bracko, J Brodzicka, TE Browder Show all

Physical Review Letters | AMER PHYSICAL SOC | Published : 2011


We report a study of B→(J/ψγ)K and B→(ψ'γ)K decay modes using 772×10⁶ B ̅B events collected at the Υ(4S) resonance with the Belle detector at the KEKB energy-asymmetric e(+)e(-) collider. We observe X(3872)→J/ψγ and report the first evidence for χ(c2)→J/ψγ in B→(X_{c ̅cγ)K decays, while in a search for X(3872)→ψ'γ no significant signal is found. We measure the branching fractions, B(B(±)→X(3872)K(±))B(X(3872)→J/ψγ)=(1.78(-0.44)(+0.48)±0.12)×10(-6), B(B(±)→χ(c2)K(±))=(1.11(-0.34)(+0.36)±0.09)×10(-5), B(B(±)→X(3872)K(±))B(X(3872)→ψ'γ)<3.45×10⁶ (upper limit at 90% C.L.), and also provide upper limits for other searches.

University of Melbourne Researchers


Awarded by Grants-in-Aid for Scientific Research

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 and the NII for valuable computing and SINET3 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 (U.S.).