English

Can $X(5568)$ be described as a $B_s\pi$, $B\bar{K}$ resonant state?

High Energy Physics - Phenomenology 2016-11-28 v1 Nuclear Theory

Abstract

The D0 Collaboration has recently seen a resonant-like peak in the BsπB_s\pi invariant mass spectrum, claimed to be a new state called X(5568)X(5568). Using a BsπB_s\pi--BKˉB\bar{K} coupled channel analysis, implementing unitarity, and with the interaction derived from Heavy Meson Chiral Perturbation Theory, we are able to reproduce the reported spectrum, with a pole that can be associated to the claimed X(5568)X(5568) state, and with mass and width in agreement with the ones reported in the experimental analysis. However, if the TT-matrix regularization is performed by means of a momentum cutoff, the value for the latter needed to reproduce the spectrum is Λ=2.80±0.04 GeV\Lambda = 2.80 \pm 0.04\ \text{GeV}, much larger than a "natural" value Λ1 GeV\Lambda \simeq 1\ \text{GeV}. In view of this, it is difficult to interpret the nature of this new state. This state would not qualify as a resonance dynamically generated by the unitarity loops. Assuming the observed peak to correspond to a physical state, we make predictions for partners in the DD, DD^\ast, and BB^\ast sectors. Their observation (or lack thereof) would shed light into this issue.

Keywords

Cite

@article{arxiv.1603.09230,
  title  = {Can $X(5568)$ be described as a $B_s\pi$, $B\bar{K}$ resonant state?},
  author = {Miguel Albaladejo and Juan Nieves and Eulogio Oset and Zhi-Feng Sun and Xiang Liu},
  journal= {arXiv preprint arXiv:1603.09230},
  year   = {2016}
}