Hunting for the X_b via Radiative Decays

Understand

In this paper, we study radiative decays of X_b, the counterpart of the famous X(3872) in the bottomonium-sector as a candidate for meson-meson molecule, into the \gamma \Upsilon(nS) (n=1, 2, 3).

• Since it is likely that the X_b is below the B\bar B^* threshold and the mass difference between the neutral and charged bottom meson is small compared to the binding energy of the X_b, the isospin violating decay mode X_b\to \Upsilon (nS)\pi^+\pi^- would be greatly suppressed.
• This will promote the importance of the radiative decays.
• We use the effective Lagrangian based on the heavy quark symmetry to explore the rescattering mechanism and calculate the partial widths.