Search for B( ns) via the B( ns) → B( ms) π π transition at LHCb and Z factory.

It is interesting to study the characteristics of the whole family of B which contains two different heavy flavors. LHC and the proposed Z factory provide an opportunity because a large database of the B family will be achieved. B and its excited states can be identified via their decay modes. As suggested by experimentalists, B* ( ns) → B + γ is not easy to be clearly measured, instead, the trajectories of π and π occurring in the decay of B( ns) → B( ms) + π π ( n > m) can be unambiguously identified, thus the measurement seems easier and more reliable; therefore this mode is more favorable at the early running stage of LHCb and the proposed Z factory. In this work, we calculate the rate of B( ns) → B( ms) + π π in terms of the QCD multipole-expansion and the numerical results indicate that the experimental measurements with the luminosity of LHC and Z factory are feasible. [ABSTRACT FROM AUTHOR]