An explanation of Belle states Zb(10610) and Zb(10650)
Queen Mary, University of London - London E1 4NS, UK, EU
Accepted: 19 August 2011
Belle report data on ϒ(5S)→ϒ(1S, 2S, 3S)π+π− and χb(1P, 2P)π+π−; they observe peaks in ϒπ± and χbπ± consistent with JP=1+. They interpret the peaks as molecular states Zb(10608) and Zb(10653). Their masses are just above and thresholds at 10604.6 and 10650.2 MeV. An explanation in terms of cusps at these thresholds is presented here. The product of the rising phase space for and with the cusps creates peaks a few MeV higher in and , and these peaks can de-excite to π+π−ϒ(1S, 2S, 3S) and π+π−χb(1P, 2P).
PACS: 13.25.Hw – Decays of bottom mesons / 14.40.Pq – Heavy quarkonia / 12.39.Ki – Relativistic quark model
© EPLA, 2011