TY  - JOUR
A1  - Giacosa, Francesco
T1  - QFT derivation of the decay law of an unstable particle with nonzero momentum
T2  - Advances in high energy physics
N2  - We present a quantum field theoretical derivation of the nondecay probability of an unstable particle with nonzero three-momentum p. To this end, we use the (fully resummed) propagator of the unstable particle, denoted as  Sto obtain the energy probability distribution, called dpS(E), as the imaginary part of the propagator. The nondecay probability amplitude of the particle S with momentum p turns out to be, as usual, its Fourier transform: ... (mth is the lowest energy threshold in the rest frame of S and corresponds to the sum of masses of the decay products). Upon a variable transformation, one can rewrite it as ... [here, ... is the usual spectral function (or mass distribution) in the rest frame]. Hence, the latter expression, previously obtained by different approaches, is here confirmed in an independent and, most importantly, covariant QFT-based approach. Its consequences are not yet fully explored but appear to be quite surprising (such as the fact that the usual time-dilatation formula does not apply); thus its firm understanding and investigation can be a fruitful subject of future research.
Y1  - 2018
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/50744
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-507444
SN  - 1687-7365
SN  - 1687-7357
N1  - Copyright © 2018 Francesco Giacosa. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The publication of this article was funded by SCOAP3.
VL  - 12
IS  - Art. 4672051
SP  - 1
EP  - 7
PB  - Hindawi
CY  - New York, NY
ER  -