A joint explanation of the $B\to πK$ puzzle and the $B \to K ν\barν$ excess

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Altmannshofer, Wolfgang, Roy, Shibasis
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915012862279680
author Altmannshofer, Wolfgang
Roy, Shibasis
author_facet Altmannshofer, Wolfgang
Roy, Shibasis
contents In light of the recent branching fraction measurement of the $B^{+}\to K^{+} ν\barν$ decay by Belle II and its poor agreement with the SM expectation, we analyze the effects of an axion-like particle (ALP) in $B$ meson decays. We assume a long-lived ALP with a mass of the order of the pion mass that decays to two photons. We focus on a scenario where the ALP decay length is of the order of meters such that the ALP has a non-negligible probability to decay outside the detector volume of Belle II, mimicking the $B^{+}\to K^{+} ν\barν$ signal. Remarkably, such an arrangement is also relevant for the long-standing $B\to πK$ puzzle by noting that the measured $B^{0}\to π^{0}K^{0}$ and $B^{+}\to π^{0}K^{+}$ decays could have a $B^{0}\to a K^{0}$ and $B^{+}\to a K^{+}$ component, respectively. We also argue based on our results that the required ALP-photon effective coupling belongs to a region of parameter space that can be extensively probed in future beam dump experiments like SHiP.
format Preprint
id arxiv_https___arxiv_org_abs_2411_06592
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle A joint explanation of the $B\to πK$ puzzle and the $B \to K ν\barν$ excess
Altmannshofer, Wolfgang
Roy, Shibasis
High Energy Physics - Phenomenology
High Energy Physics - Experiment
In light of the recent branching fraction measurement of the $B^{+}\to K^{+} ν\barν$ decay by Belle II and its poor agreement with the SM expectation, we analyze the effects of an axion-like particle (ALP) in $B$ meson decays. We assume a long-lived ALP with a mass of the order of the pion mass that decays to two photons. We focus on a scenario where the ALP decay length is of the order of meters such that the ALP has a non-negligible probability to decay outside the detector volume of Belle II, mimicking the $B^{+}\to K^{+} ν\barν$ signal. Remarkably, such an arrangement is also relevant for the long-standing $B\to πK$ puzzle by noting that the measured $B^{0}\to π^{0}K^{0}$ and $B^{+}\to π^{0}K^{+}$ decays could have a $B^{0}\to a K^{0}$ and $B^{+}\to a K^{+}$ component, respectively. We also argue based on our results that the required ALP-photon effective coupling belongs to a region of parameter space that can be extensively probed in future beam dump experiments like SHiP.
title A joint explanation of the $B\to πK$ puzzle and the $B \to K ν\barν$ excess
topic High Energy Physics - Phenomenology
High Energy Physics - Experiment
url https://arxiv.org/abs/2411.06592