English

Understanding the first measurement of $\mathcal{B}(B\to K \nu \bar{\nu})$

High Energy Physics - Phenomenology 2024-01-03 v3

Abstract

Recently, Belle II reported on the first measurement of B(B±K±ννˉ)\mathcal{B}(B^\pm\to K^\pm \nu\bar{\nu}) which appears to be almost 3σ3\sigma larger than predicted in the Standard Model. We point out the important correlation with B(BKννˉ)\mathcal{B}(B\to K^{\ast} \nu\bar{\nu}) so that the measurement of that decay mode could help restraining the possible options for building the model of New Physics. We then try to interpret this new experimental result in terms of physics beyond the Standard Model by using SMEFT and find that a scenario with coupling only to τ\tau can accommodate the current experimental constraints but fails in getting a desired RD()exp/RD()SMR_{D^{(\ast )}}^\mathrm{exp}/R_{D^{(\ast )}}^\mathrm{SM}, unless one turns the other SMEFT operators that are not related to bsb\to s\ell\ell or/and bsννb\to s\nu\nu.

Keywords

Cite

@article{arxiv.2309.02246,
  title  = {Understanding the first measurement of $\mathcal{B}(B\to K \nu \bar{\nu})$},
  author = {Lukas Allwicher and Damir Becirevic and Gioacchino Piazza and Salvador Rosauro-Alcaraz and Olcyr Sumensari},
  journal= {arXiv preprint arXiv:2309.02246},
  year   = {2024}
}

Comments

9 pages, 6 figures. Corrected some typos and improved the discussion