Can we understand the decay width of the Tcc+ state?

Inspired by the recent discovery of a doubly charmed tetraquark state T-cc(+) by the LHCb Collaboration, we employ the effective Lagrangian approach to investigate the decay width of T-cc(+)-> (D+D0)pi(0)/(DD0)-D-0 pi(+) and T-cc(+) -> (DD+)-D-0 gamma with the assumption that T-cc(+) is an isoscalar DD* molecule. We show that both the T-cc -> DD pi and T-cc -> DD gamma modes contribute to the decay width of T-cc, with the former being dominant. The resulting total decay width of about gamma = 63 keV is smaller than the experimental decay width obtained from the Breit-Wigner fit of the LHCb data, gamma = 410 +/- 165 +/- 43(-38)(+18) keV, while close to the number obtained from the alternative unitary analysis, gamma = 48 +/- 2(-14)(+0) keV, which supports the molecular nature of T-cc. (C)&2022 The Author(s). Published by Elsevier B.V.

Automated summary

Inspired by the recent discovery of a doubly charmed tetraquark state T-cc(+) by the LHCb Collaboration, this study investigates the decay width of T-cc(+) using the effective Lagrangian approach and assumes it to be an isoscalar DD* molecule. The results show that both T-cc -> DD pi and T-cc -> DD gamma contribute to the decay width, with the former being dominant.