Isospin analysis of [formula omitted] and the absence of the Zc(3900) in B decays

Zhi Yang,Qian Wang,Ulf-G Meißner

doi:10.1016/j.physletb.2017.10.049

Abstract

We study the isospin amplitudes in the exclusive B to D⁎D¯K decay process and fit the available D⁎0D¯0 invariant mass distributions near threshold. The analysis demonstrates that the production of the isospin triplet D⁎D¯ state is highly suppressed compared to the isospin singlet one. That explains why the Zc(3900) has not been found in B decays. In addition, the production of the negative charge-parity state might be further suppressed in the heavy quark limit. These two reasons which are based on the molecular assumption offer the first explanation why the Zc(3900) is absent in B decays. Further studies of the absence from both the experimental and the theoretical side is extremely important for understanding the nature of the X(3872) and the Zc(3900).

Highlights

We study the isospin amplitudes in the exclusive B to D∗D K decay process and fit the available D∗0D 0 invariant mass distributions near threshold
The production of the X(3872) in the process B → D∗D K has already been studied in Ref. [29], where it occurs through the isospin conserved weak transition (∆I = 0) b → ccs current
It is the prerequisite that one can analyse the isospin amplitudes of the B → D∗D K process

Summary

Introduction

We study the isospin amplitudes in the exclusive B to D∗D K decay process and fit the available D∗0D 0 invariant mass distributions near threshold. The production of the X(3872) in the process B → D∗D K has already been studied in Ref. We derive the isospin relations for the B → D∗D K process through the quark-level Feynman diagrams, c.f. Fig. 1.

Results

Conclusion