$\Upsilon(1s)\to\gamma f_2(1270)$ Decay

TL;DR

This paper investigates the decay of $
$ into a photon and $f_2(1270)$, revealing a d-wave dominance and providing decay rates and amplitude ratios consistent with experimental data.

Contribution

It introduces a gluon-coupling approach to analyze $
$ decay, highlighting d-wave dominance and calculating decay rates aligned with observations.

Findings

Decay rate matches experimental data

D-wave dominance enhances decay amplitude

Helicity amplitude ratios are consistent with measurements

Abstract

Decay $\Upsilon(1s)\to\gamma f_2(1270)$ is studied by an approach in which the tensor meson, $f_2(1270)$, is strongly coupled to gluons. Besides the strong suppression of the amplitude $\Upsilon(1s)\to\gamma gg, gg\to f_2$ by the mass of b-quark, d-wave dominance in $\Upsilon(1s)\to\gamma f_2(1270)$ is revealed from this approach, which provides a large enhancement. The combination of these two factors leads to larger $B(\Upsilon(1s)\to\gamma f_2(1270))$. The decay rate of $\Upsilon(1s)\to\gamma f_2(1270)$ and the ratios of the helicity amplitudes are obtained and they are in agreement with data.