Search for a $D \bar{D}$ bound state in the $\Lambda_b \rightarrow \Lambda D\bar{D}$ process

TL;DR

This paper investigates the potential existence of a $D\bar{D}$ bound state in the decay process $\Lambda_b \to \Lambda D\bar{D}$, using a coupled-channel approach and resonance contributions, predicting an enhancement near the $D\bar{D}$ threshold.

Contribution

It introduces a combined analysis of $D\bar{D}$ interactions and resonance effects to predict a possible bound state in heavy-hadron interactions.

Findings

An enhancement near the $D\bar{D}$ threshold in the invariant mass distribution.

Identification of a reflection of the $D\bar{D}$ bound state.

Encouragement for experimental measurement of the $D\bar{D}$ invariant mass.

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.