Search for a $D\bar{D}$ bound state in the ${\Lambda }_b\to \Lambda D\bar{D}$ process

Abstract

We have investigated the process of ${\Lambda }_b\to \Lambda D\bar{D}$, by taking into account the contributions from the $s$-wave $D\bar{D}$ interaction within the coupled-channel unitary approach, and the intermediate $\psi (3770)$ resonance. In addition to the peak of the $\psi (3770)$, an enhancement near the $D\bar{D}$ mass threshold is found in the $D\bar{D}$ invariant mass distributions, which should be the reflection of the $D\bar{D}$ bound state. We would like to encourage our experimental colleagues to measure the $D\bar{D}$ invariant mass distribution of the ${\Lambda }_b\to \Lambda D\bar{D}$ process, which is crucial to search for the $D\bar{D}$ bound state and to understand the heavy-hadron heavy-hadron interactions.

Comments: 7 pages, 9 figures, comments are welcome