Related papers: Probing Leptogenesis with the Cosmological Collide…
We study the imprints of high scale non-thermal leptogenesis on cosmic microwave background (CMB) from the measurements of inflationary spectral index ($n_s$) and tensor-to-scalar ratio ($r$), which otherwise is inaccessible to the…
We present a new leptogenesis scenario, where the lepton asymmetry is generated by CP violating decays of heavy electroweak singlet neutrinos via electromagnetic dipole moment couplings to the ordinary light neutrinos. Akin to the usual…
Assuming a light Higgs boson is discovered, its nature may remain unknown in case that no supersymmetric particles are found. The detection and study of heavier Higgs particles is then of great interest. For this purpose the…
We study cosmological gravitational particle production (CGPP) in Higgs inflation, wherein the inflaton is a scalar field with quartic self-coupling $\lambda$ and a nonminimal coupling to gravity $\xi$, and which may, but need not be, the…
We find that the triplet Higgs of the Type II seesaw mechanism can simultaneously generate the neutrino masses and observed baryon asymmetry, while playing a role in inflation. We survey the allowed parameter space and determine that this…
We point out a new effect on the freeze-out process of heavy particles induced by density perturbations in the early universe, which we call ``acoustically driven freeze-out.'' This beyond-linear effect is caused by the exponential…
The Cosmological Collider (CC) provides a unique opportunity to probe the particle spectrum and fundamental interactions at extremely high energies. Massive particles, via their decay into inflaton quanta, can induce a non-analytic,…
We study a class of leptogenesis models where the light neutrinos acquire their observed small masses by a symmetry-motivated construction. This class of models may naturally include three nearly degenerate heavy Majorana neutrinos that can…
The anomalous conversion of leptons into baryons during leptogenesis is shown to produce a right-handed helical magnetic field; in contrast, the magnetic field produced during electroweak baryogenesis is known to be left-handed. If the…
Thermal leptogenesis induced by the CP-violating decay of a right-handed neutrino (RHN) is discussed in the background of quintessential kination, i.e., in a cosmological model where the energy density of the early Universe is assumed to be…
It was commonly thought that the observation of low energy leptonic CP-violating phases would not automatically imply the existence of a baryon asymmetry in the leptogenesis scenario. This conclusion does not generically hold when the issue…
Leptoquarks can be produced in substantial numbers for masses very close to the collider centre of mass energy in $e^+e^-$, $e\gamma$, and $\mu^+\mu^-$ collisions due to the quark content of the photon resulting in equivalently high…
A $\gamma\gamma$ collider, either in conjunction with an $e^+e^-$ linear collider or as a stand-alone facility, offers a very attractive Higgs physics programme at relatively low centre-of-mass (c.m.) energies. While the Higgs boson that…
Observed neutrino oscillations imply that the global lepton flavor symmetry of the Standard Model must be broken. Therefore, searches for lepton flavor violation (LFV) are promising probes of new physics beyond the Standard Model.…
Measuring a non-zero value for the cross section of any lepton number violating (LNV) process would put a strong lower limit on the washout factor for the effective lepton number density in the early universe at times close to the…
While leptogenesis is a very solid but hard to check contender for the generation of the observed excess of baryons over anti-baryons in the Universe, we show that the observation of gauge bosons associated with right-handed currents at…
If the masses of at least two generations of right-handed neutrinos (RHNs) are near-degenerate, the scale of leptogenesis can be as low as $\sim$ 100 GeV. In this work, we study probing such resonant leptogenesis in the $B-L$ model at the…
Seesaw models with a slightly broken lepton number symmetry can explain small neutrino masses, and allow for low-scale leptogenesis. We make a thorough analysis of leptogenesis within the simplest model with two right-handed (RH) neutrinos…
An extension of the Standard Model with three right-handed neutrinos and a simple invisible axion model can account for all experimentally confirmed signals of new physics (neutrino oscillations, dark matter and baryon asymmetry) in…
Primordial non-Gaussianity signatures of extremely heavy particles are re-examined within a simple alternative to the standard inflationary paradigm, in which the primordial fluctuations and the inflationary spacetime expansion are sourced…