$B\to K^* M_X$ vs $B\to K M_X$ as a probe of a scalar-mediator dark matter scenario

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Berezhnoy, Alexander, Melikhov, Dmitri
Format: Preprint
Published: 2023
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917584468705280
author Berezhnoy, Alexander
Melikhov, Dmitri
author_facet Berezhnoy, Alexander
Melikhov, Dmitri
contents Recently, Belle II reported the observation of the decay $B\to K M_X$, $M_X$ the missing mass, with the branching ratio much exceeding ${\cal B}(B\to K ν\barν)$ which is the only Standard Model (SM) process contributing to this reaction. If confirmed, this might be an indication of new nonSM particles produced in this decay. One of the possible explanations of the observed effect could be light dark-matter (DM) particles produced via a scalar mediator field. We give simple arguments, that a combined analysis of the $B\to K M_X$ and $B\to K^* M_X$ reactions would be a clean probe of the scalar mediator scenario: (i) making use of an observed value ${\cal B}(B\to K M_X)\simeq 5.4\, {\cal B}(B\to K ν\barν)_{\rm SM}$ and (ii) assuming that the effect is due to the light dark matter coupling to the top quark via a {\it scalar} mediator field, one finds an upper limit ${\cal B}(B\to K^* M_X) < 2.8 \, {\cal B}(B\to K^* ν\barν)_{\rm SM}$. Within the discussed scenario, this upper limit does not depend on the mass of the scalar mediator nor on the specific details of the unobserved dark-matter particles in the final state.
format Preprint
id arxiv_https___arxiv_org_abs_2309_17191
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle $B\to K^* M_X$ vs $B\to K M_X$ as a probe of a scalar-mediator dark matter scenario
Berezhnoy, Alexander
Melikhov, Dmitri
High Energy Physics - Phenomenology
Recently, Belle II reported the observation of the decay $B\to K M_X$, $M_X$ the missing mass, with the branching ratio much exceeding ${\cal B}(B\to K ν\barν)$ which is the only Standard Model (SM) process contributing to this reaction. If confirmed, this might be an indication of new nonSM particles produced in this decay. One of the possible explanations of the observed effect could be light dark-matter (DM) particles produced via a scalar mediator field. We give simple arguments, that a combined analysis of the $B\to K M_X$ and $B\to K^* M_X$ reactions would be a clean probe of the scalar mediator scenario: (i) making use of an observed value ${\cal B}(B\to K M_X)\simeq 5.4\, {\cal B}(B\to K ν\barν)_{\rm SM}$ and (ii) assuming that the effect is due to the light dark matter coupling to the top quark via a {\it scalar} mediator field, one finds an upper limit ${\cal B}(B\to K^* M_X) < 2.8 \, {\cal B}(B\to K^* ν\barν)_{\rm SM}$. Within the discussed scenario, this upper limit does not depend on the mass of the scalar mediator nor on the specific details of the unobserved dark-matter particles in the final state.
title $B\to K^* M_X$ vs $B\to K M_X$ as a probe of a scalar-mediator dark matter scenario
topic High Energy Physics - Phenomenology
url https://arxiv.org/abs/2309.17191