1-5 July 2019
The University of Manchester
Europe/London timezone
- pascos2019@manchester.ac.uk
- +44 (0)161 275 4171
The Local Organising Committee
Resonant dark matter annihilation in a gauge-independent manner
Presented by Mateusz DUCH
on
2 Jul 2019
from
15:10
to
15:30
Type: oral presentation
Track: Particle Physics Models of New Physics
Content
Transition amplitudes describing dark-matter annihilation processes through a resonance may become highly inaccurate close to a production threshold if a Breit-Wigner propagator with a constant width is used. To partially overcome this problem, the BW propagator needs to be modified by including a momentum dependent decay width. However, such an approach to resonant transition amplitudes generically suffers from gauge artefacts that may also give rise to a bad or ambiguous high-energy behaviour of the amplitudes. We address the two problems of gauge dependence and high-energy unitarity within a gauge-independent framework of resummation implemented by the so-called e Technique. We study DM annihilation via scalar resonances in a gauged U(1)_X complex-scalar extension of the Standard Model that features a massive stable gauge field which can play the role of the DM. We find that the predictions for the DM abundance may vary significantly from previous studies using Breit-Wigner ansatz and propose an alternative simple approximation which leads to the correct DM phenomenology.
Place
Location: Schuster
Room: Bragg Lecture Theatre
Co-authors
- Prof. Bohdan GRZADKOWSKI University of Warsaw
- Prof. Apostolos PILAFTSIS University of Manchester