Related papers: ALPy Cogenesis
We propose a new method to search for axion-like particles (ALPs) based on the gamma-rays produced concomitant with high-energy astrophysical neutrinos. The existence of high-energy neutrinos implies production of gamma-rays in the same…
Upper bounds on the CP asymmetry relevant for leptogenesis are reexamined and found weaker than in previous literature, both for hierarchical and for quasi-degenerate right-handed neutrinos. Successful leptogenesis implies the usual lower…
We revisit the generation of a matter-antimatter asymmetry in the minimal extension of the Standard Model with two singlet heavy neutral leptons (HNL) that can explain neutrino masses. We derive an accurate analytical approximation to the…
In an unconventional realization of left-right symmetry, the particle corresponding to the left-handed neutrino nu_L (with SU(2)_L interactions) in the right-handed sector, call it n_R (with SU(2)_R interactions), is not its Dirac mass…
We analyze the interplay between leptogenesis and residual symmetry in the framework of two right-handed neutrino model. Working in the flavor basis, we show that all the leptogenesis CP asymmetries are vanishing for the case of two…
We consider the generation of a baryon asymmetry in an extension of the Standard Model with two singlet Majorana fermions that are degenerate above the electroweak phase transition. The model can explain neutrino masses as well as the…
We present a covariant framework for analyzing the interactions and decay rates of axion-like particles (ALPs) that couple to both gluons and quarks. We identify combinations of couplings that are invariant under quark-field redefinitions,…
The possibility of searching for long-lived axion-like particles (ALPs) decaying into photons is investigated in ultraperipheral $PbPb$ collisions at the Large Hadron Collider (LHC). We propose a search strategy for low mass ALPs using the…
A simple model is constructed based on the gauge symmetry $SU(3)_c \times SU(2)_L \times U(1)_Y \times SU(2)_\ell$, with only the leptons transforming nontrivially under $SU(2)_\ell$. The extended symmetry is broken down to the Standard…
We study the scenario of thermal leptogenesis in which the leptonic asymmetries are resonantly enhanced through the mixing of nearly degenerate heavy Majorana neutrinos that have mass differences comparable to their decay widths.…
Axion-like particles (ALP) can in principle be produced in very hot and dense astrophysical environments, escape from the extreme object where such conditions are met, and then be converted in gamma--rays in the magnetic fields intervening…
We perform a thermal unflavored leptogenesis analysis on minimal left-right symmetric models with discrete left-right symmetry identified as generalized parity or charge conjugation. When left-right symmetry is unbroken in the lepton Yukawa…
In the left-right symmetric models without bi-doublet Higgs scalars, the standard model fermions can obtain masses by integrating out heavy charged singlet fermions. We find the decays of heavy neutral singlet fermions, responsible for…
We introduce a CP violating coupling between the Ricci curvature and the heavy right handed neutrinos. This splits the Majorana masses of the left and the right handed heavy neutrinos. When the heavy neutrinos decay, their decay rates are…
The main mechanism responsible for Axion-Like-Particle (ALP) production in the early universe is the so-called misalignment mechanism. Three regimes have been investigated in this context: standard misalignment, large misalignment and…
Leptogenesis is studied within the seesaw neutrino mass model in a regime where all sterile neutrinos have prompt rather than delayed decays. It is shown that during neutrino thermal production lepton asymmetries are generated in both…
It is known that the radiative neutrino mass model proposed by Ma could be a consistent framework for dark matter, leptogenesis and suppressed lepton flavor violation if a neutral component of the inert doublet is identified as dark matter…
Leptogenesis is an attractive scenario for the generation of the baryon asymmetry of the Universe that relies on the dynamics of right-handed neutrinos (RHNs) in the seesaw extension of the Standard Model. In standard thermal leptogenesis,…
A non-supersymmetric renormalizable $SO(10)$ model is investigated for its viability in explaining the observed fermion masses and mixing parameters along with the baryon asymmetry produced via thermal leptogenesis. The Yukawa sector of the…
We derive updated cosmological bounds on light axion-like particles (ALPs) coupled to leptons or photons, using a full phase-space treatment of their production from the primordial thermal plasma. The ALP phase-space distribution, obtained…