The $μν$SSM is a supersymmetric standard model that solves the $μ$ problem of the MSSM using the R-parity breaking couplings between the right-handed neutrino superfields and the Higgses in the superpotential, $λ_{i} \hat ν^c_i \hat H_d \hat H_u$. The $μ$ term is generated spontaneously through sneutrino vacuum expectation values, $μ=λ_i < \tilde ν^c_i>$, once the electroweak symmetry is broken. In addition, the couplings $κ_{ijk} \hat ν^c_i\hat ν^c_j\hat ν^c_k$ forbid a global U(1) symmetry avoiding the existence of a Goldstone boson, and also contribute to spontaneously generate Majorana masses for neutrinos at the electroweak scale. Following this proposal, we have analysed in detail the parameter space of the $μν$SSM. In particular, we have studied viable regions avoiding false minima and tachyons, as well as fulfilling the Landau pole constraint. We have also computed the associated spectrum, paying special attention to the mass of the lightest Higgs. The presence of right and left-handed sneutrino vacuum expectation values leads to a peculiar structure for the mass matrices. The most important consequence is that neutralinos are mixed with neutrinos, and neutral Higgses with sneutrinos.
We perform an analysis of the vacuum stability of the neutral scalar potential of the $μ$-from-$ν$ Supersymmetric Standard Model ($μν$SSM). As an example scenario, we discuss the alignment-without-decoupling limit of the $μν$SSM, for which the required conditions on the Higgs sector are derived. We demonstrate that in this limit large parts of the parameter space feature unphysical minima that are deeper than the electroweak minimum. In order to estimate the lifetime of the electroweak vacuum, we calculate the rates for the tunneling process into each unphysical minimum. We find that in many c…
We analyze the anomalous magnetic moment of the muon $g-2$ in the $μν$SSM. This $R$-parity violating model solves the $μ$ problem reproducing simultaneously neutrino data, only with the addition of right-handed neutrinos. In the framework of the $μν$SSM, light left muon-sneutrino and wino masses can be naturally obtained driven by neutrino physics. This produces an increase of the dominant chargino-sneutrino loop contribution to muon $g-2$, solving the gap between the theoretical computation and the experimental data. To analyze the parameter space, we sample the $μν$SSM using a likelihood dat…
The minimal supersymmetric extension of the standard model (MSSM) is extended to the $U(1)_X$SSM, whose local gauge group is $SU(3)_C \times SU(2)_L \times U(1)_Y \times U(1)_X$. To obtain the $U(1)_X$SSM, we add the new superfields to the MSSM, namely: three Higgs singlets $\hatη,~\hat{\barη},~\hat{S}$ and right-handed neutrinos $\hatν_i$. The CP violating effects are considered to study the lepton electric dipole moment(EDM) in $U(1)_X$SSM. The CP violating phases in $U(1)_X$SSM are more than those in the standard model(SM). In this model, some new parameters $(θ_S, θ_{BB^{\prime}}, θ_{BL})$…
$U(1)_X$SSM is the extension of the minimal supersymmetric standard model(MSSM) and its local gauge group is $SU(3)_C\times SU(2)_L \times U(1)_Y \times U(1)_X$. To obtain this model, three singlet new Higgs superfields and right-handed neutrinos are added to MSSM. In the framework of $U(1)_X$SSM, we study lepton flavor violating decays $τ\rightarrow{Pl}(P=π,~η,~η^\prime;~l=μ,~e)$. According to the latest experimental data of $τ\rightarrow{Pe}$ and $τ\rightarrow{Pμ}$, the influence of different sensitive parameters on the results is analyzed to make a reasonable prediction for future experimen…
$U(1)_X$SSM is the extension of the minimal supersymmetric standard model(MSSM) and its local gauge group is $SU(3)_C\times SU(2)_L \times U(1)_Y \times U(1)_X$. To obtain this model, three singlet new Higgs superfields and right-handed neutrinos are added to MSSM. In the framework of $U(1)_X$SSM, we study the Higgs mass and take the lightest CP-even sneutrino as a cold dark matter candidate. For the lightest CP-even sneutrino, the relic density and the cross section for dark matter scattering off nucleon are both researched. In suitable parameter space of the model, the numerical results sati…
Three singlet new Higgs superfields and right-handed neutrinos are added to MSSM to obtain $U(1)_X$SSM model. Its local gauge group is $SU(3)_C\times SU(2)_L \times U(1)_Y \times U(1)_X$. In the framework of $U(1)_X$SSM, we study muon anomalous magnetic moment and lepton flavor violating decays $l_j\rightarrow{l_iγ}(j=2,3;i=1,2)$ within the Mass Insertion Approximation(MIA). Through the MIA method, we can find the parameters that directly affect the analytical result of the lepton flavor violating decays $l_j\rightarrow{l_iγ}$, which make our work more convenient. We want to provide a set of s…
Given the increasing number of experimental data, together with the precise measurement of the properties of the Higgs boson at the LHC, the parameter space of supersymmetric models starts to be constrained. We carry out a detailed analysis of this issue in the framework of the $μν$SSM. In this model, three families of right-handed neutrino superfields are present in order to solve the $μ$ problem and simultaneously reproduce neutrino physics. The new couplings and sneutrino vacuum expectation values in the $μν$SSM induce new mixing of states, and, in particular, the three right sneutrinos can…
The $μν$SSM is a simple supersymmetric extension of the Standard Model (SM) capable of predicting neutrino physics in agreement with experiment. In this paper we perform the complete one-loop renormalization of the neutral scalar sector of the $μν$SSM with one generation of right-handed neutrinos in a mixed on-shell/$\overline{\mathrm{DR}}$ scheme. The renormalization procedure is discussed in detail, emphasizing conceptual differences to the minimal (MSSM) and next-to-minimal (NMSSM) supersymmetric standard model regarding the field renormalization and the treatment of non-flavor-diagonal sof…
The $μν$SSM is a simple supersymmetric extension of the Standard Model (SM) capable of describing neutrino physics in agreement with experiments. We perform the complete one-loop renormalization of the neutral scalar sector of the $μν$SSM with three generation of right-handed neutrinos in a mixed on-shell/$\overline{\mathrm{DR}}$ scheme. We calculate the full one-loop corrections to the neutral scalar masses of the $μν$SSM. The one-loop contributions are supplemented by available MSSM higher-order corrections. We obtain numerical results for a SM-like Higgs-boson mass consistent with experimen…
In $R$-parity violating supersymmetry, the gravitino as the lightest supersymmetric particle (LSP) is a good candidate for dark matter, with the interesting characteristic to be detectable through $γ$-ray telescopes. We extend this analysis considering an axino next-to-LSP (NLSP) as a coexisting dark matter particle contributing with a detectable signal in the $γ$-ray spectrum. The analysis is carried out in the framework of the $μν$SSM, which solves the $μ$ problem reproducing simultaneously neutrino data only with the addition of right-handed neutrinos. We find that important regions of the …
In the $μν$SSM, the presence of $R$-parity violating couplings involving right-handed (RH) neutrinos solves simultaneously the $μ$- and $ν$-problems. We explore extensions of the $μν$SSM adding a $U(1)'$ gauge group, which provides the RH neutrinos with a non-vanishing charge. In these models, dubbed U$μν$SSM, the anomaly cancellation conditions impose the presence of exotic quarks in the spectrum that are vector-like under the standard model (SM) gauge group: either three pairs $SU(2)$ quark singlets, or a pair of quark singlets together with a pair of quark doublets. Several extra singlets u…
Within the framework of the $μν$SSM, a displaced dilepton signal is expected at the LHC from the decay of a tau left sneutrino as the lightest supersymmetric particle (LSP) with a mass in the range $45 - 100$ GeV. We compare the predictions of this scenario with the ATLAS search for long-lived particles using displaced lepton pairs in $pp$ collisions, considering an optimization of the trigger requirements by means of a high level trigger that exploits tracker information. The analysis is carried out in the general case of three families of right-handed neutrino superfields, where all the neut…
We study the upper limits on the mass of the lightest and second lightest CP even Higgs bosons in the (M+1)SSM, the MSSM extended by a gauge singlet. The dominant two loop contributions to the effective potential are included, which reduce the Higgs masses by 10 GeV. Since the coupling R of the lightest Higgs scalar to gauge bosons can be small, we study in detail the relations between the masses and couplings of both lightest scalars. We present upper bounds on the mass of a 'strongly' coupled Higgs (R > 1/2) as a function of lower experimental limits on the mass of a 'weakly' coupled Higgs (…
Axino and gravitino are promising candidates to solve the dark matter (DM) problem in the framework of supersymmetry. In this work, we assume that the axino is the lightest supersymmetric particle (LSP), and therefore contributes to DM. In the case of R-parity violating models, the axino can decay into a neutrino-photon pair with a lifetime much longer than the age of the Universe, yielding a potentially detectable signal. Interestingly, a gravitino next-to-LSP (NLSP) can live enough as to contribute to the relic density. We study both scenarios, only axino LSP as DM, and axino LSP with gravit…