Search for a doubly charged DDK bound state in ? (1S, 2S) inclusive decays and via direct production in e+e- collisions at s =10.520, 10.580, and 10.867 GeV SEARCH for A DOUBLY CHARGED DDK BOUND STATE in ... LI Y. et al.

Abstract

We report the results of a first search for a doubly charged DDK bound state, denoted the R++, in ?(1S) and ?(2S) inclusive decays and via direct production in e+e- collisions at s=10.520, 10.580, and 10.867 GeV. The search uses data accumulated with the Belle detector at the KEKB asymmetric-energy e+e- collider. No significant signals are observed in the D+Ds?+ invariant-mass spectra of all studied modes. The 90% credibility level upper limits on their product branching fractions in ?(1S) and ?(2S) inclusive decays (B(?(1S, 2S)?R+++anything)�B(R++?D+Ds?+)), the product values of Born cross section and branching fraction in e+e- collisions (?(e+e-?R+++anything)�B(R++?D+Ds?+)) at s=10.520, 10.580, and 10.867 GeV under different assumptions of R++ masses varying from 4.13 to 4.17 GeV/c2 and widths varying from 0 to 5 MeV are obtained. � 2020 authors. Published by the American Physical Society.