The rare decays $B \to X_{s,d} \nu \bar \nu$ and $B_{s,d} \to l^+l^- $ in the Multiscale Walking Technicolor Model

TL;DR

This paper investigates how technipions in the Multiscale Walking Technicolor Model can significantly enhance rare B-decay rates and derives experimental mass bounds from existing collider data.

Contribution

It provides the first detailed calculation of technipion effects on rare B-decays within this model, revealing potential large enhancements and setting experimental mass constraints.

Findings

Branching ratios can increase by up to three orders of magnitude.

ALEPH data impose strong lower bounds on technipion masses.

CDF data set weaker but still relevant mass limits.

Abstract

We calculate the contributions to the rare B-decays, $B \to X_{s,d} \nu \bar \nu$, $B_{s,d} \to l^+l^- $ from the unit-charged technipions. Within the considered parameter space we find that: (a) the enhancements to the branching ratios in question can be as large as three orders of magnitude; (b) the ALEPH data of $B \to X_s \nu \bar \nu$ lead to strong mass bounds on $m_{p1}$ and $m_{p8}$: $m_{p8} \geq 620, 475 GeV$ for $F_Q=40GeV$ and $m_{p1}=100, 400 GeV$ respectively. (c) the CDF data of $B_s \to \mu \bar \mu$ lead to a relatively weak limit: $m_{p8} \geq 320 GeV$ for $F_Q=40GeV$ and $m_{p1}=200 GeV$.