  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.
