English

Is the X(3872) a bound state ?

High Energy Physics - Phenomenology 2020-01-08 v2 Nuclear Theory

Abstract

All existing experimental evidence of the bound state nature of the X(3872)X(3872) relies on considering its decay products with a finite experimental spectral mass resolution which is typically Δm2\Delta m \ge 2 MeV and much larger than its alleged binding energy, BX=0.00(18)B_X=0.00(18)MeV. On the other hand, we have found recently that there is a neat cancellation in the 1++1^{++} channel for the invariant DDˉD \bar D^* mass around the threshold between the continuum and bound state contribution. This is very much alike a similar cancellation in the proton-neutron continuum with the deuteron in the 1++1^{++} channel. Based on comparative fits of experimental cross section deuteron and X(3872)X(3872) prompt production in pp collisions data with a finite pTp_T to a common Tsallis distribution we find a strong argument questioning the bound state nature of the state but also explaining the large observed production rate likely consistent with a half-bound state.

Keywords

Cite

@article{arxiv.1907.01441,
  title  = {Is the X(3872) a bound state ?},
  author = {Pablo G. Ortega and Enrique Ruiz Arriola},
  journal= {arXiv preprint arXiv:1907.01441},
  year   = {2020}
}

Comments

6 pages, 4 figures, 1 table

R2 v1 2026-06-23T10:10:06.463Z