Decay ofψ(3684)intoψ(3095)

Abstract

We observe $(3684) to decay into $(3095) with a branching ratio of 0.57±0 .08. The branching ratio for the particular decay mode $(3095) +ir + + 7r" is measured to be 0.32 ±0.04. Remaining decays leading to $(3095) are largely, but not entirely, accounted for by the mode $(3095) + 7r° + 7r° if the two pions in this decay are in a state of zero isospin.

The Role of Spin-Flipping Terms in Hadronic Transitions of $${\Upsilon (4S)}$$ Υ ( 4 S )

“…QCD couples color singlets to octet QQ states. Therefore, the hadronic transitions between eigenstates |Φ I and |Φ F of H order in H (2) QCD and the leading term is given by…”

“…Hadronic transitions are important decay modes for low-lying heavy quarkonium states. For instance, the first observed hadronic transition ψ(2S) → J/ψππ [2] has a branching fraction reported by the Particle Data Group (PDG) of (52.58 ± 0.43)% [3]. Moreover, during the last years, hadronic transitions between heavy quarkonia have led to a remarkable series of discoveries helping either to establish new conventional heavy quarkonium states, like the h b (1P ) and h b (2P ) observed in the twopion decay of the Υ(5S) [4] state, or to extract relevant information of the so-called "XYZ" states, like in the cases of X(3872) [5][6][7] and X(4260) [8].…”

Mesons with beauty and charm: Spectroscopy

“…The normalized invariant-mass distribution for the transition 2 3 S 1 → 1 3 S 1 + ππ is shown in Figure 2 for the cc, cb, and bb families. The soft-pion expression (3.7) describes the depletion of the dipion spectrum at low invariant masses observed in the transitions ψ(2S) → ψ(1S)ππ [42] and Υ(2S) → Υ(1S)ππ [43], but fails to account for the Υ(3S) → Υ(1S)ππ and Υ(3S) → Υ(2S)ππ spectra [44]. We expect the 3S levels to lie above flavor threshold in the cb system.…”

Hadronic decays of excited heavy quarkonia

“…where m ππ = (p π + + p π − ), p π + = (E π + , p π + ) and ǫ Ψ , ǫ Ψ ′ are the polarization vectors of the heavy spin-one quarkonia. First we observe that the term proportional to g 2 describes the d-wave part of the pion system, which is found to be suppressed experimentally in the charmonium decay [8] as well as in the bottomonium decay [9] to a few percent. This observation is supported in addition by theoretical arguments, see next section.…”