Year: 2019
Type: article
Abstract: All existing experimental evidence for the bound state nature of <?CDATA $X(3872)$ ?> relies on observing its decay products, which are measured with a finite experimental mass resolution that is typically <?CDATA $\Delta m \geqslant 2 $ ?> MeV , and much larger than its alleged binding energy, <?CDATA $B_X=0.00\,(18)$ ?> MeV. On the other hand, we have found recently that there is a clear cancellation in the <?CDATA $1^{++}$ ?> channel of the invariant <?CDATA $D {\bar D}^*$ ?> mass around the threshold between continuum and the bound state. This is very much like a similar cancellation in the proton-neutron continuum with the deuteron in the <?CDATA $1^{++}$ ?> channel. Based on comparative fits with a common Tsallis distribution of the experimental cross-sections for prompt production of deuterons and <?CDATA $X(3872)$ ?> in pp collisions with a finite <?CDATA $p_T$ ?> , we find a strong argument for questioning the bound state nature of this state, which also suggests that the large observed production rate could be consistent with a half-bound state.
Source: Chinese Physics C
Authors: Pablo G. Ortega, Enrique Ruiz Arriola
Institutions: Universidad de Salamanca, Universidad de Granada
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid:
OpenAlex ID: W2954081901