We explore generating the dimension five operator leading to neutrino masses by integrating out heavy SU(2)_L triplet fermions. We exhibit a model that has a neutrino mass matrix consistent with observations. In addition, the model is capable of producing the observed baryon asymmetry, and unification can be achieved without dangerous proton decay. Supersymmetry can be broken at the fundamental scale with no supersymmetric signal at low energies.
Probing Grand Unification Through Neutrino Oscillations, Leptogenesis, and Proton Decay
支持超对称大统一的证据包括基于观测到的族多重态结构、规范耦合统一、中微子振荡、重子生成以及夸克轻子质量和混合的某些有趣特征。有人认为，试图理解（a）微小的中微子质量（特别是Δ m^2（nu_2 -nu_3）），（b）宇宙的重子不对称性（c）观察到的费米子质量特征，如m_b/m_tau比值、V_c b的小值和theta_{nu_mu-nu_tau}的极大值，似乎选择了基于有效弦统一G（224）= SU（2）_L x SU（2）_R x SU（4）^c或SO（10）-对称性的更高统一的路线，在4D中操作，而不是其他替代方案。基于具有超对称性的有效SO（10）或G（224）对称性，提出了一个预测框架，成功地描述了包括中微子在内的所有费米子的质量和混合。它还通过利用瘦生过程解释了观察到的宇宙重子不对称性，这是这个框架的自然现象。有人认为，在SO（10）/G（224）框架内，质子寿命的保守上限是（1/3-2）× 10^34年，这是迄今为止最成功的。这反过来又有力地表明，电流灵敏度提高5到10倍（与SuperK相比）应该可以揭示质子衰变。这一预测的下一代核子衰变和中微子探测器的影响。
No-scale supergravity provides a successful framework for Starobinsky-like inflation models. Two classes of models can be distinguished depending on the identification of the inflaton with the volume modulus, $T$ (C-models), or a matter-like field, $ϕ$ (WZ-models). When supersymmetry is broken, the inflationary potential may be perturbed, placing restrictions on the form and scale of the supersymmetry breaking sector. We consider both types of inflationary models in the context of high-scale supersymmetry. We further distinguish between models in which the gravitino mass is below and above the…
We have shown a new scenario of successful leptogenesis with one $L$ violating coupling and a relative Majorana phase playing the role of $CP$ violation. This is in contrast to the usual consideration of Feynman diagram with at least two $L$ violating couplings. We have considered $R$-parity violating Minimal Supersymmetric Standard Model (MSSM) for leptogenesis at TeV scale. This scenario is also consistent with generating light neutrino mass if asymmetry is generated through semileptonic $λ^{\prime}$ coupling.
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 …
We investigate unification prospects of two heavy scalar triplet extension of the standard model where, in the absence of any right-handed neutrino (RHN), type-II seesaw accounts for current oscillation data with hierarchical neutrino masses consistent with cosmological bounds and the lighter triplet decay explains baryon asymmetry of the Universe via leptogenesis. We note that the absence of RHNs in the fundamental fermion representations of SU(5) delineates its outstanding position compared to SO(10) (or $E_6$). In addition, SU(5) needs smaller scalar representations ${15}_{H1}\oplus {15}_{H…
In this paper, we consider a lopsided flavor texture compatible with thermal leptogenesis in partially composite Pati--Salam unification. The Davidson--Ibarra bound $M_{νR1} \gtrsim 10^9$ GeV for the successful thermal leptogenesis can be recast to the Froggatt--Nielsen (FN) charge of the lopsided texture. We found the FN charge $n_{\nu1}$ of the lightest right-handed neutrino $ν_{R1}$ can not be larger than a upper bound, $n_{\nu1} \lesssim 4.5$. From the viewpoint of unification, the FN charges of the neutrinos $n_{νi}$ should be the same to that of other SM fermions. Then, two cases $n_{νi}…
Low scale leptogenesis scenarios are difficult to verify due to our inability to relate the parameters involved in the early universe processes with the low energy or collider observables. Here we show that one can in principle relate the parameters giving rise to the transient $CP$ violating phase involved in leptogenesis with those that can be deduced from the observation of electric dipole moment (EDM) of the electron. We work out the details of this in the context of the left right symmetric supersymmetric model (LRSUSY) which provides a strong connection between such parameters. In partic…
We discuss resonant leptogenesis arising from the decays of two nearly-degenerate right-handed neutrinos, identified as the inflaton and stabiliser superfields in a model of chaotic sneutrino inflation. We compare an analytical estimate of the baryon asymmetry $ η_B $ in the Boltzmann approximation to a numerical solution of the full density matrix equations, and find that the analytical result fails to capture the correct physics in certain regions of parameter space. The observed baryon asymmetry can be realised for a breaking of the mass degeneracy as small as $ \mathcal{O}(10^{-8}) $. The …
We discuss gauge coupling unification of the SM descending directly from SO(10) while providing solutions to the three outstanding problems: neutrino masses, dark matter, and the baryon asymmetry of the universe. Conservation of matter parity as gauged discrete symmetry in the model calls for high-scale spontaneous symmetry breaking through ${126}_H$ Higgs representation. This naturally leads to the hybrid seesaw formula for neutrino masses mediated by heavy scalar triplet and right-handed neutrinos. The seesaw formula predicts two distinct patterns of RH$ν$ masses, one hierarchical and anothe…
Flavour violation in supersymmetric SO(10) unification with a type II seesaw mechanism
我们研究味道违反超对称SO（10）实现的第二类跷跷板机制，这提供了一个预测实现三重leptogenesis。轻子味违反过程的实验上界有显着的影响leptogenesis动力学，特别是他们排除了强冲洗制度。要求成功的leptogenesis然后约束，否则很大程度上未知的整体大小的味道违反可观的，从而产生可检验的预测。特别是，如果在大型强子对撞机上可以获得超伴子光谱，那么μ-> e γ的分支比就在MEG实验的范围内，并且超对称对μ_K的贡献可以解释实验值的很大一部分。我们证明了这种情况可以在一个一致的SO（10）模型中实现，该模型实现了与质子衰变边界一致的规范对称性破缺和双重-三重态分裂，改进了MSSM对α_3（m_Z）的预测，并再现了测量的夸克和轻子质量。
We review the current status of baryogenesis with emphasis on electroweak baryogenesis and leptogenesis. The first detailed studies were carried out for SU(5) GUT models where CP-violating decays of leptoquarks generate a baryon asymmetry. These GUT models were excluded by the discovery of B+L violating sphaleron processes at high temperatures. Yet a new possibility emerged, electroweak baryogenesis. Here sphaleron processes generate a baryon asymmetry during a strongly first-order phase transition. This mechanism has been studied in many extensions of the Standard Model. However, constraints …
Suppressing naturalness concerns, we discuss the compatibility requirements of high-scale supersymmetry breaking with the Higgs boson mass constraint and gauge coupling unification. We find that to accommodate superpartner masses significantly greater than the electroweak scale, one must introduce large non-degeneracy factors. These factors are enumerated, and implications for the allowed forms of supersymmetry breaking are discussed. We find that superpartner masses of arbitrarily high values are allowed for suitable values of $\tanβ$ and the non-degeneracy factors. We also compute the large,…
Affleck-Dine leptogenesis after thermal inflation along the $LH_u$ direction requires $m_L^2+m_{H_u}^2 < 0$ up to the AD scale ($|L|\simeq |H_u|\sim 10^9$ GeV). We renormalised this condition from the AD scale to the soft supersymmetry breaking scale by solving the renormalisation group equations perturbatively in the Yukawa couplings to obtain a semi-analytic constraint on the soft supersymmetry breaking parameters. We also used a fully numerical method to renormalise the baryogenesis condition and constrained the Minimal Supersymmetric Cosmological Model using the resulting baryogenesis cond…
