Production of the Y(4260) state in B meson decay

R.M Albuquerque,M Nielsen,C.M Zanetti

doi:10.1016/j.physletb.2015.05.022

Abstract

We calculate the branching ratio for the production of the meson Y(4260) in the decay B−→Y(4260)K−. We use QCD sum rules approach and we consider the Y(4260) to be a mixture between charmonium and exotic tetraquark, [c¯q¯][qc], states with JPC=1−−. Using the value of the mixing angle determined previously as: θ=(53.0±0.5)∘, we get the branching ratio B(B→Y(4260)K)=(1.34±0.47)×10−6, which allows us to estimate an interval on the branching fraction 3.0×10−8<BY<1.8×10−6 in agreement with the experimental upper limit reported by BaBar Collaboration.

Highlights

The Y (4260) state was first observed by BaBar Collaboration in the e+e− annihilation through initial state radiation [1], and it was confirmed by CLEO and Belle Collaborations [2]
The Zc+(3900) was first observed by the BESIII Collaboration in the (π ± J /ψ) mass spectrum of the Y (4260) → J /ψπ +π − decay channel [8]. This structure was observed at the same time by the Belle Collaboration [9] and was confirmed by the authors of Ref. [10] using CLEO-c data
Some theoretical interpretations for the Y (4260) are: tetraquark state with scalar diquarks in P -wave with sslight quark components [11], tetraquark state with one scalar and one axial diquarks (same as the X(3872)) in P -wave with qqlight quark components [12], hadronic D1 D, D0 D∗ molecule [13], χc1ω molecule [14], χc1ρ molecule [15], J /ψ f0(980) molecule [16], a hybrid charmonium [17], a charm-baryonium [18], a cusp [19,20,21], etc

Summary

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[29] with good agreement with data, considering it as a mixing between the J /ψ charmonium and a tetraquark state with one scalar and one vector diquarks in S-wave and qqlight quark components. The same approach was applied to the X(3872) state and good agreement with the data was obtained for its mass and the decay width into J /ψπ π [30], its radiative decay [31], and in the X(3872) production rate in. The Y meson as a mixed state of tetraquark and charmonium interacts via cc component of the weak current. For the decay width calculation, we need the value of the form factor at Q 2 = −m2Y , where mY is the mass of the Y (4260) meson. Inserting the currents (3) and (14) in the correlator we have in the OPE side of the sum rule

OPE μν

For the