arXiv subjects

Peter Matak

Publications and source records attributed to Peter Matak.

4 recordsLinked to original sources

arXiv2025

Unitarity, the optical theorem, and the Pauli exclusion principle

We show that the fermionic exclusion principle in scattering problems manifests itself through constraints implied by unitarity and the optical theorem. Configurations that formally allow identical fermions to appear in the same quantum state at the level of intermediate amplitudes are not pathological. Instead, they turn out to be essential for implementing the Pauli principle in scattering processes. Making this connection explicit resolves an apparent tension between the exclusion principle and unitarity and provides a clarified view of how fermionic statistics manifests itself within the $S$-matrix framework.

hep-ph↗

arXiv2025

Minimal effective theory for leptogenesis, dark matter, and neutrino masses

We study the phenomenology of choosing a minimal set of effective operators simultaneously generating the dark matter relic density and matter-antimatter asymmetry of the universe. Neutrino masses are obtained in a specific case of baryogenesis via leptogenesis. We find that only two new particles -- a heavy unstable fermion and a light dark matter scalar -- need to be included in addition to the Standard Model particle content.

hep-ph↗

arXiv2024

Axion Dark Matter from Heavy Quarks

We propose simple scenarios where the observed dark matter abundance arises from decays and scatterings of heavy quarks through freeze-in of an axion-like particle with mass in the $10 {\rm \, keV} - 1 {\rm \, MeV}$ range. These models can be tested by future X-ray telescopes, and in some cases will be almost entirely probed by searches for two-body decays $K \to \pi + {\rm invis.}$ at NA62. As a byproduct, we discuss the cancellation of IR divergencies in flavor-violating scattering processes relevant for thermal axion production, and derive the general contribution to axion-photon couplings from all three light quarks.

hep-ph↗

arXiv2022

Modifying the Dyson Series for Unstable Particles and Resonances

In this work, we introduce a modification of the Dyson series based on the perturbative unitarity as a starting point. The presented approach systematically avoids singularities and double-counting related to the presence of unstable particles as intermediate states and, at the same time, it does not rely on a specific choice of the renormalization scheme.

hep-ph↗