Comments on "Which is the Quantum Decay Law of Relativistic Particles?"

TL;DR

This paper critically analyzes a recent study on quantum decay laws for relativistic particles, showing that their approximations are only valid for particles nearly at rest, thus questioning the generality of their main formula.

Contribution

The paper demonstrates that the approximations used in the recent decay law derivation are only valid for particles with negligible velocity, highlighting limitations in the previous work.

Findings

The derived decay formula is only valid for particles with gamma approximately 1.

Approximations force the particle to almost stop moving.

Main formula's validity is limited to near-zero velocities.

Abstract

Results presented in a recent paper "Which is the Quantum Decay Law of Relativistic particles?", arXiv: 1412.3346v2 [quant--ph]], are analyzed. We show that approximations used therein to derive the main final formula for the survival probability of finding a moving unstable particle to be undecayed at time $t$ force this particle to almost stop moving, that is that, in fact, the derived formula is approximately valid only for $\gamma \cong 1$, where $\gamma = 1/\sqrt{1-\beta^{2}}$ and $\beta = v/c$, or in other words, for the velocity $v \simeq 0$.