Influence of intense laser fields on measurable quantities in $W^{-}$-boson decay

TL;DR

This paper explores how intense laser fields can influence the decay properties of the W-boson, including decay rates and branching ratios, through theoretical calculations of leptonic and hadronic decay channels.

Contribution

It extends previous work by calculating the laser effects on W-boson hadronic decay and combines results to analyze changes in decay rate, lifetime, and branching ratios under strong electromagnetic fields.

Findings

Laser significantly reduces the total decay rate, increasing the W-boson's lifetime.

Branching ratios for leptonic and hadronic decays are notably affected by the laser field.

The study provides theoretical insights for potential experimental investigations of laser-controlled particle decay.

Abstract

In principle, this paper suggests powerful laser technology as a promising instrument that can be experimentally useful to control the lifetime and branching ratio for an unstable particle decay. In a recent paper [arXiv:2101.00224], we calculated theoretically the $W^{-}$-boson leptonic decay $(W^{-}\rightarrow \ell^{-} \bar{\nu}_{\ell})$ in the presence of a circularly polarized laser and we showed that the laser significantly contributed to the diminution of the leptonic decay rate. In this paper, as a continuation of the previous one, we mainly deal with the theoretical calculation of the $W^{-}$-boson hadronic decay $(W^{-}\rightarrow q \bar{q}')$ and we combine the analytical results obtained in both papers to examine the effect of an intense laser, in terms of its field strength and frequency, on the three measurable quantities in $W^{-}$-boson decay (total decay rate, lifetime and branching ratios). It was found that the laser has notably contributed to the reduction of the total decay rate leading to a longer lifetime. Most importantly, the two branching ratios (one for leptons and the other for hadrons) are affected (increased or decreased) by the presence of a strong external electromagnetic field. Combined together, these two complementary works may provide an in-depth and comprehensive study that would be useful for any experimental investigation in the future.