https://doi.org/10.1140/epjc/s10052-023-12107-4
Regular Article – Theoretical Physics
P-wave Sommerfeld enhancement near threshold: a simplified approach
1
Ottawa-Carleton Institute for Physics, Carleton University, K1S 5B6, Ottawa, ON, Canada
2
Centre for Cosmology, Particle Physics and Phenomenology (CP3), Université Catholique de Louvain, 1348, Louvain-la-Neuve, Belgium
3
ICTP South American Institute for Fundamental Research and Instituto de Física Teórica, Universidade Estadual Paulista, Rua Dr. Bento T. Ferraz 271, 01140-070, São Paulo, SP, Brazil
a
CarlosHenriquedeLima@cmail.carleton.ca
Received:
25
April
2023
Accepted:
4
October
2023
Published online:
18
October
2023
The calculation of P-wave Sommerfeld enhancement in processes with unstable particles in the final state is known to be divergent. In a complete description, where resonant (on-shell unstable particles) and non-resonant contributions are included, it has been shown that results are finite. For most beyond the Standard Model applications, these complete calculations are not readily available. In this work, we are interested in the near-threshold region and we consider only the resonant contribution. In this case, we provide a simplified prescription to compute the P-wave Sommerfeld enhancement in the narrow-width approximation of the unstable particle that directly eliminates divergences. We show that we can define a finite resonant contribution without the inclusion of the non-resonant processes in a way similar to the usual S-wave Sommerfeld enhancement.
© The Author(s) 2023
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