TY - JOUR AU - Coppola, M. AU - Gomez Dumm, D. AU - Noguera, S. AU - Scoccola, N. N. PY - 2020 DA - 2020// TI - Weak decays of magnetized charged pions in the symmetric gauge T2 - Phys. Rev. D JO - Physical Review D SP - 034003 EP - 13pp VL - 101 IS - 3 PB - Amer Physical Soc AB - We consider the decay pi(-) -> l (nu) over bar (l) (l = e(-) , mu(-)) in the presence of an arbitrary large uniform magnetic field, using the symmetric gauge. The consequences of the axial symmetry of the problem and the issue of angular momentum conservation arc discussed in detail. In particular, we analyze the projection of both the canonical and the mechanical total angular momenta along the direction of the magnetic field. It is found that while the former is conserved in the symmetric gauge, the latter is not conserved in both the symmetric and Landau gauges. We derive an expression for the integrated pi(-) -> l (nu) over bar (l) width that coincides exactly with the one we previously found using the Landau gauge, providing an explicit test of the gauge independence of that result. Such an expression implies that for nonzero magnetic fields the decay width does not vanish in the limit in which the outgoing charged leptons can be considered as massless, i.e., it does not exhibit the helicity suppression found in the case of no external field. SN - 2470-0010 UR - https://arxiv.org/abs/1910.10814 UR - https://doi.org/10.1103/PhysRevD.101.034003 DO - 10.1103/PhysRevD.101.034003 LA - English N1 - WOS:000511198700005 ID - Coppola_etal2020 ER -