Scalar resonance effects on the B_s - \bar B_s mixing angle

TL;DR

This paper investigates how scalar resonance effects, particularly from the $f_0(980)$, influence the extraction of the $B_s-ar{B}_s$ mixing angle from decay processes, highlighting the importance of S-wave contributions.

Contribution

It introduces a detailed analysis of scalar resonance effects on $B_s$ decay channels, emphasizing their impact on mixing angle measurements, which was previously underestimated.

Findings

S-wave effects in $f_0(980)$ decays are significant for $B_s$ mixing angle extraction.

The ratio of decay widths indicates non-negligible scalar resonance contributions.

Ignoring these effects could lead to inaccurate determination of the mixing angle.

Abstract

The $B_s^0 \to J/\psi \phi$ and $B_s^0 \to J/\psi f_0(980)$ decays are analyzed within generalized QCD factorization including all leading-order corrections in $\alphas$. We point out that the ratio of our calculated widths, $\Gamma (B_s^0\to J/\psi f_0(980), f_0(980)\to \pi^+\pi^-)/ \Gamma(B_s^0 \to J/\psi \phi,\phi\to K^+K^-)$, strongly indicates that $S$-wave effects in the $f_0(980)$'s daughter pions or kaons cannot be ignored in the extraction of the $B_s-\bar{B}_s$ mixing angle, $-2\beta_s$, from the $B_s^0 \to \phi J/\psi$ decay amplitudes.