2025/12/24 by Qi Wu, Wu, Qi, Zhong-Quan Sun +7
Physics and Astronomy · #Quantum Chromodynamics and Particle Interactions #High-Energy Particle Collisions Research #Nuclear physics research studies
paper · doi:10.48550/arxiv.2512.21161
In this work, we investigate the dipion transition processes X(3872)→ ππχcJ (J=0,1,2) within the framework of heavy hadron chiral perturbation theory, treating X(3872) as a molecular state composed of DD^*+ H.c. components. By analyzing the box and triangle loop diagrams with the nonrelativistic effective field theory power-counting rule, we demonstrate that box diagrams dominate these dipion transition processes. Branching ratios are calculated as functions of the mixing angle θ, which parametrizes the neutral and charged meson compositions of the X(3872). Our results indicate that the branching fractions for X(3872)→ππχc0, X(3872)→ ππχc1, and X(3872)→ ππχc2 are of the orders of 10-4, 10-3, and 10-5, respectively. We also predict the ratios B[X(3872)→ ππχc0/2]/B[X(3872)→ ππχc1] and B[X(3872)→ π+π-χcJ]/B[X(3872)→ π0π0χcJ]. The latter deviates from isospin-symmetry expectations, revealing various degrees of isospin violation. By studying the π+π- and π+χcJ invariant mass spectra, we find a double-bump structure in the π^ + π- invariant mass distributions of the process X(3872)→ π+π-χc1 and π+χc0 invariant mass distribution of the process X(3872)→ π+π-χc0, which could be tested by future experimental measurements.