A bstract This work presents an asymmetric dark matter model with relic density determined by the freeze-out of semi-annihilations into long-lived particles slowly decaying Standard Model states. We carefully consider CPT symmetry and unitarity constraints to asymmetries entering Boltzmann equation. The main idea paper is point out a critical inconsistency in previous literature, where these are violated. present systematic approach avoid inconsistency.

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

Abstract In this work, a diagrammatic representation of thermal mass effects is derived from the S -matrix unitarity both in classical and quantum Boltzmann equations. Within example seesaw type-I leptogenesis, we discuss connection Higgs cancelations infrared divergences zero- finite-temperature calculations right-handed neutrino decay scattering processes.

The main focus of this paper is to introduce a new method control perturbative calculations $CP$ asymmetric reaction rates in Boltzmann equation. asymmetries particle reactions are traditionally calculated terms complex couplings, Feynman integrals, and Cutkosky rules. We use an expansion the $S$-matrix unitarity condition instead, obtaining general expression for without reference imaginary part loops. Asymmetry cancelations implied by $CPT$ manifested diagrammatic way easy track at any...

We analyze the role of left-left squark mixing in rare $K^+ \rightarrow \pi^+\nu\bar{\nu}$ decay within minimal supersymmetry with a large $\tan\beta$. A Higgs boson mass 125 GeV has been taken into account leading to correlation between stop masses and trilinear soft breaking coupling $A_{\tilde{t}}$. find that measurable effects, similar well known $LR$ terms, are possible for $A_{\tilde{t}}$ combined off-diagonal $LL$-insertions. Precise measurements rate expected from ongoing NA62...

Abstract Nonequilibrium quantum field theory is often used to derive an approximation for the evolution of number densities and asymmetries in astroparticle models when a more precise treatment thermal effects required. This work presents alternative framework using zero-temperature theory, S -matrix unitarity, classical Boltzmann equation as starting points leading set rules calculations corrections reaction rates. Statistical factors due on-shell intermediate states are obtained from cuts...

We study the role of perturbative unitarity in resonant annihilation two dark matter particles into standard model bath. Systematically including all kinematically allowed holomorphic cuts corresponding forward-scattering diagram, cancellation singularities occurs, resulting a fixed-order correction to narrow-width approximation for cross section. Unlike approach based on finite width mediator, no double counting intermediate states occurs. Published by American Physical Society 2024

Abstract Within the seesaw type-I leptogenesis, we formulate CPT and unitarity constraints for equilibrium reaction rate CP asymmetries consider thermal mass quantum statistics. We demonstrate that including higher-order perturbative corrections in classical Boltzmann equation remarkably induces effects into kinetic theory.

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

We use an unconventional diagrammatic approach to formulate $CPT$ and unitarity constraints for higher-order $CP$ asymmetries entering the source term in Boltzmann equation. Usually, reaction rate these are computed within classical kinetic theory, using zero-temperature quantum field theory describe particles' interactions. approximate rates, otherwise obtained closed-time-path formalism, terms of diagrams drawn on a cylindrical surface their holomorphic cuts. The resulting equilibrium...

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

Leptogenesis typically requires the introduction of heavy particles whose out-of-equilibrium decays are essential for generating a matter-antimatter asymmetry, according to one Sakharov's conditions. We demonstrate that in Dirac leptogenesis, scatterings between light degrees freedom - Standard Model plus neutrinos sufficient generate asymmetry. Due its vanishing source term Boltzmann equations, asymmetry right-handed solely arises through wash-in processes. conditions satisfied because...

Leptogenesis typically requires the introduction of heavy particles whose out-of-equilibrium decays are essential for generating a matter-antimatter asymmetry, according to one Sakharov’s conditions. We demonstrate that in Dirac leptogenesis, scatterings between light degrees freedom—Standard Model plus neutrinos—are sufficient generate asymmetry. The generation at least two effective charges conserved by fast Standard interactions. Due its vanishing source term Boltzmann equations,...

This work presents an asymmetric dark matter model with relic density determined by the freeze-out of semi-annihilations into long-lived particles slowly decaying standard model. We carefully consider $CPT$ symmetry and unitarity constraints to asymmetries entering Boltzmann equation, pointing out a critical inconsistency in previous literature.

Unitarity and CPT symmetry constrain the CP asymmetries entering Boltzmann equation for net particle number generation. These constraints often manifest as cancelations of leading-order in decays scatterings. This contribution considers seesaw type-I leptogenesis with top-Yukawa corrections. Even when starting Maxwell-Boltzmann phase-space densities, some contributions required by unitarity are interpreted approximations quantum statistics thermal-mass effects. The work is based on JCAP10 (2022) 042.

We use an unconventional diagrammatic approach to formulate $CPT$ and unitarity constraints for higher-order $CP$ asymmetries entering the source term in Boltzmann equation. Usually, reaction rate these are computed within classical kinetic theory, using zero-temperature quantum field theory describe particles' interactions. approximate rates, otherwise obtained closed-time-path formalism, terms of diagrams drawn on a cylindrical surface their holomorphic cuts. The resulting equilibrium...

We study the role of perturbative unitarity in resonant annihilation two dark matter particles into standard model bath. Systematically including all kinematically allowed holomorphic cuts corresponding forward-scattering diagram, cancelation singularities occurs, resulting a fixed-order correction to narrow-width approximation for cross section. Unlike approach based on finite width mediator, no double counting intermediate states occurs.

In their recent letter, Heeck et al. [Phys. Rev. D 108, L031703] introduced a simple model of leptogenesis, in which the asymmetry originates from scattering processes only. Here we argue that calculation violates some basic principles perturbative quantum field theory.

We briefly explain a novel diagrammatic method for including thermal corrections in $CP$ asymmetric reaction rates entering the quantum Boltzmann equation. In equilibrium, asymmetries have to cancel precisely due $S$-matrix unitarity and $CPT$ invariance. Such cancelations are easy track zero-temperature leading-order calculations. However, accounting medium effects requires modification of on-shell part propagators and, consequently, violating rates. literature, correct form statistical...

Within the seesaw type-I leptogenesis, we formulate $CPT$ and unitarity constraints for equilibrium reaction rate $CP$ asymmetries consider thermal mass quantum statistics. We demonstrate that including higher-order perturbative corrections in classical Boltzmann equation remarkably induces effects into kinetic theory.