Meson loop singularity, exotic states' productions and decays near threshold

2013/11/11 by Qian Wang, Christoph Hanhart, C. Hanhart +4
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph

paper · pdf · doi:10.48550/arxiv.1311.2401

to appear in the proceedings of The 6th International Workshop on Charm Physics (CHARM 2013)

arxiv created 2013/11/11 · openalex publication_date 2013/11/11 · arxiv updated 2013/11/12 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28

Abstract

We investigate in detail the "triangle singularity" regions of meson loops where the corresponding intermediate mesons are nearly-on-shell and have relatively small momenta, and the two heavy mesons strongly interact with each other in an S wave. This S-wave interaction will make such kind of meson loops always enhanced and can explain experimental observations of threshold enhancements. We show that the production of the Y(4260) and the recently observed Z_c(3900) can be related to each other by this mechanism which will allow for a possible understanding of the nature of these threshold enhancements.

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