由气泡产生的右手中微子引发的宇宙对撞机引力波：检验跷跷板、轻子生成和暗物质

Testing Seesaw and Leptogenesis with Gravitational Waves

We present the possibility that the seesaw mechanism with thermal leptogenesis can be tested using the stochastic gravitational background. Achieving neutrino masses consistent with atmospheric and solar neutrino data, while avoiding non-perturbative couplings, requires right-neutrinos lighter than the typical scale of grand unification. This scale separation suggests a symmetry protecting the right handed neutrinos from getting a mass. Thermal leptogenesis would then require that such a symmetry be broken below the reheating temperature. We enumerate all such possible symmetries consistent wi…

The reheating era leptogenesis in models with seesaw mechanism

Observed baryon asymmetry can be achieved not only by the decay of right-handed neutrinos but also by the scattering processes in the reheating era. In the latter scenario, new physics in high energy scale does not need to be specified, but only two types of the higher dimensional operator of the standard model particles are assumed in the previous work. In this paper, we examine the origin of the higher dimensional operators assuming models with a certain seesaw mechanism at the high energy scale. The seesaw mechanism seems to be a simple realization of the reheating era leptogenesis because …

II型和III型跷跷板模型中的微扰轻子生成

Leptogenesis with perturbations in type-II and type-III seesaw models

本研究将声学驱动冻结效应扩展到II型和III型跷跷板模型，发现其能在弱冲洗区域增强重子不对称性，区别于I型轻子生成。

Leptogenesis Constraints on $B-L$ breaking Higgs Boson in TeV Scale Seesaw Models

In the type-I seesaw mechanism for neutrino masses, there exists a $B-L$ symmetry, whose breaking leads to the lepton number violating mass of the heavy Majorana neutrinos. This would imply the existence of a new neutral scalar associated with the $B-L$ symmetry breaking, analogous to the Higgs boson of the Standard Model. If in such models, the heavy neutrino decays are also responsible for the observed baryon asymmetry of the universe via the leptogenesis mechanism, the new seesaw scalar interactions with the heavy neutrinos will induce additional dilution terms for the heavy neutrino and le…

当反锯齿与反电弱相变相遇：产生轻子不对称性的新路径

When inverse seesaw meets inverse electroweak phase transition: a novel path to leptogenesis

本文提出一种通过反电弱相变和反锯齿机制产生轻子不对称性的新非热机制，通过TeV尺度向量状轻子的相互作用实现质子不对称性。

Leptogenesis and low-energy CP violation in a type-II-dominated left-right seesaw model

We consider leptogenesis in a left-right-symmetric seesaw scenario in which neutrino mass generation and leptogenesis are dominated by the type-II seesaw term. Motivated by grand unification, we assume that the neutrino Dirac mass matrix is dominated by a single entry of the order of the top-quark mass, which leaves the low-energy phases of the lepton mixing matrix as the only sources of CP violation. Working in a regime where the triplet scalar predominantly decays into leptons, this results in a predictive scenario based on a minimal number of parameters. We perform a detailed analysis of th…

Triplet seesaw model: from inflation to asymmetric dark matter and leptogenesis

The nature of dark matter (DM) particles and the mechanism that provides their measured relic abundance are currently unknown. Likewise, the nature of the inflaton is unknown as well. We investigate the triplet seesaw model in an unified picture. At high energy scale, we consider Higgs inflation driven by an admixture of standard model and triplet Higgs fields, both coupled non-minimally to gravity. At intermediate and low energies we investigate vector like fermion doublet DM candidates with a charge asymmetry in the dark sector, which is generated by the same mechanism that provides the bary…

原初非高斯性作为跷跷板机制与轻子生成的探针

Primordial non-Gaussianity as a probe of seesaw and leptogenesis

本文提出在majoron曲率子模型中，通过原初非高斯性探测高尺度跷跷板机制与非热轻子生成，并指出未来CMB-S4、LSST等实验可全面检验相关参数空间。

Probing the Seesaw Mechanism and Leptogenesis with the International Linear Collider

We investigate the potential of the International Linear Collider (ILC) to probe the mechanisms of neutrino mass generation and leptogenesis within the minimal seesaw model. Our results can also be used as an estimate for the potential of a Compact Linear Collider (CLIC). We find that heavy sterile neutrinos that simultaneously explain both, the observed light neutrino oscillations and the baryon asymmetry of the universe, can be found in displaced vertex searches at ILC. We further study the precision at which the flavour-dependent active-sterile mixing angles can be measured. The measurement…

高标度Seesaw机制与轻子生成对作为可探测引力波的暴胀张量扰动的影响

Impact of high-scale Seesaw and Leptogenesis on inflationary tensor perturbations as detectable gravitational waves

本文研究高标度Seesaw与轻子生成中右手中微子主导及熵释放对暴胀引力波的阻尼，并通过SNR评估多种干涉仪的探测前景。

MeV-scale Seesaw and Leptogenesis

We study the type-I seesaw model with three right-handed neutrinos and Majorana masses below the pion mass. In this mass range, the model parameter space is not only strongly constrained by the requirement to explain the light neutrino masses, but also by experimental searches and cosmological considerations. In the existing literature, three disjoint regions of potentially viable parameter space have been identified. In one of them, all heavy neutrinos decay shortly before big bang nucleosynthesis. In the other two regions, one of the heavy neutrinos either decays between BBN and the CMB deco…

通过暗物质共湮灭实现轻子生成

Leptogenesis from Dark Matter Coannihilation

本文提出通过暗物质共湮灭实现轻子生成，结合I型锯齿模型扩展，提供对暗物质丰度的直接解释。

TeV Scale Neutrino Mass Generation, Minimal Inelastic Dark Matter, and High Scale Leptogenesis

The seesaw and leptogenesis commonly depend on the masses of same particles, and thus are both realized at the same scale. In this work, we demonstrate a new possibility to realize a TeV-scale neutrino seesaw and a natural high-scale leptogenesis. We extend the standard model by two gauge-singlet scalars, a vector-like iso-doublet fermion and one iso-triplet Higgs scalar. Our model respects a softly broken lepton number and an exactly conserved $Z_2$ discrete symmetry. It can achieve three things altogether: (i) realizing a testable type-II seesaw at TeV scale with two nonzero neutrino mass-ei…

Inflation, reheating, leptogenesis and bounds on soft supersymmetry breaking parameters

In the no-scale supergravity with Type-I Seesaw model of Non-minimal supersymmetric standard model (NMSSM), we have analysed inflation, reheating and leptogenesis. A no-scale supergravity realization of Starobinsky model of inflation in simple Wess-Zumino model have been shown earlier by Ellis et al. Here we show a no-scale supergravity realization of Starobinsky model of inflation in Type-I Seesaw framework of NMSSM. In this framework an appropriate choice of no-scale Kähler potential results in Starobinsky like plateau inflation along a Higgs-sneutrino $D$-flat direction consistent with the …

Testing the low scale seesaw and leptogenesis

Heavy neutrinos with masses below the electroweak scale can simultaneously generate the light neutrino masses via the seesaw mechanism and the baryon asymmetry of the universe via leptogenesis. The requirement to explain these phenomena imposes constraints on the mass spectrum of the heavy neutrinos, their flavour mixing pattern and their $CP$ properties. We first combine bounds from different experiments in the past to map the viable parameter regions in which the minimal low scale seesaw model can explain the observed neutrino oscillations, while being consistent with the negative results of…