We study the possibility of soft breaking effects of the generalized parity within the minimal Left-Right model. One aim of the paper is to elaborate on the potentiality, the limit, and the predictivity of a restored parity at high scale. While revisiting the issue of strong CP in the Left-Right theories, we motivate the possibility of explicit-parity-breaking, that we then parameterize in the right-handed quark mixing matrix. The strong CP parameter $\barθ$ is also parameterized in terms of the breaking. We discuss some possible phenomenological consequences in this scenario. In particular, the constraint provided by $\barθ$ enables us to quantify the maximal deviation of the right-handed quark mixings from the standard case with exact parity in term of a single parameter. This deviation has a direct impact on flavor physics.
We considered parity breaking in some left-right symmetric models. We studied spontaneous and explicit parity violation in two cases with doublet and triplet Higgs scalars. The minimization condition in these two cases differ significantly. A comparative study of these models is presented emphasizing their phenomenological consequences.
Domain wall formation is quite generic in spontaneous Left-Right parity (D-parity) breaking models. Since they are in conflict with cosmology, we need some mechanisms to remove them. Planck scale suppressed effects have been considered to be quite successful for this purpose. We study this possibility in Minimal Supersymmetric Left-Right (SUSYLR) model originally proposed by Kuchimanchi et al \cite{Kuchimanchi:1993jg} where both D-parity and R-parity $(R_p = (-1)^{3(B-L)+2s})$ are spontaneously broken. We find that Planck scale suppressed terms allowed for the specific particle content of this…
A fresh analysis of Left right symmetric supersymmetric models in the generic case where the scale of right handed symmetry breaking $M_R >> M_{SUSY}\sim M_W$ is presented. We conclude that the low energy effective theory for such models is essentially the MSSM with R parity (and therefore B,L symmetry) but the spectrum includes heavy conjugate neutrino supermultiplets that permit a seesaw mechanism and several characteristic charged supermultiplets over and above those of the MSSM.
The different scenarios of spontaneous breaking of D-parity have been studied in both non-supersymmetric and supersymmetric version of the left-right symmetric models(LRSM). We explore the possibility of a TeV scale $SU(2)_R$ breaking scale $M_R$ and hence TeV scale right handed neutrinos from both minimization of the scalar potential as well as the coupling constant unification point of view. We show that although minimization of the scalar potential allows the possibility of a TeV scale $M_R$ and tiny neutrino masses in LRSM with spontaneous D-parity breaking, the gauge coupling unification …
We propose a novel implementation of spontaneous parity breaking in supersymmetric left-right symmetric model, avoiding some of the problems encountered in previous studies. This implementation includes a bitriplet and a singlet, in addition to the bidoublets which extend the Higgs sector of the Minimal Supersymmetric Standard Model (MSSM). The supersymmetric vacua of this theory are shown to lead generically to spontaneous violation of parity, while preserving R parity. The model is shown to reproduce the see-saw relation for vacuum expectation values, $v_L v_R \approx m_{EW}^2$ relating the …
We study the baryogenesis via leptogenesis in a class of left-right symmetric models, in which $D$-parity is broken spontaneously. We first discuss the consequence of the spontaneous $D$-parity breaking on the neutrino masses. Than we study the lepton asymmetry in various cases, from the decay of right handed neutrino as well as the triplet Higgs, depending on their relative masses they acquire from the symmetry breaking pattern. The leptogenesis bound on their masses are discussed by taking into account the low energy neutrino oscillation data. It is shown that a TeV scale leptogenesis is via…
We construct the truly minimal left-right symmetric model by utilizing only the fields dictated by supersymmetry and automatic R-parity conservation. Allowing for non-renormalizable operators in the superpotential, we show that parity can be spontaneously broken while preserving electromagnetic gauge invariance. The scale of parity breakdown is predicted in the intermediate region: $M_R > 10^{10}- 10^{11} GeV$, and R-parity remains exact. The theory contains a number of charged and doubly charged Higgs scalars with a low mass of order $M_R^2/M_{Planck}$, accessible to experiment.
Presymmetry, the hidden symmetry underlying the charge and generational patterns of quarks and leptons, is utilized for repairing the left-right asymmetry of the standard model with Dirac neutrinos. It is shown that the restoration of parity is consequent with an indispensable left-right symmetric residual presymmetry. Thus, presymmetry substantiates left-right symmetry and the experimental search for the latter is the test of the former, with the nature of neutrinos as a crucial feature that can distinguish the left-right symmetry alone and its combination with presymmetry. This phenomenologi…
Supersymmetric left-right models with the see-saw mechanism for the neutrino masses have the attractive property that they conserve baryon and lepton number exactly in the Lagrangian. In this talk, I review the recent results valid for a large class of minimal versions of the model that supersymmetry combined with the requirement that the ground state of the model conserve electric charge constrains the mass of the right handed $W_R$ boson to be in a certain range i.e. $M_{W_R}\leq$ 10 TeV or $\geq 10^{10}$ GeV. In the former case (low $M_{W_R}$), the vacuum breaks R-parity spontaneously and t…
We present the two-loop $β$-functions for non-standard soft supersymmetry-breaking couplings including non-standard R-parity violating soft terms in the Minimal Supersymmetric Standard Model
We revisit the Higgs sector of the left-right supersymmetric model. We study the scalar potential in a version of the model in which the minimum is the charge conserving vacuum state, without R-parity violation or additional non-renormalizable terms in the Lagrangian. We analyze the dependence of the potential and of the Higgs mass spectrum on the various parameters of the model, pinpointing the most sensitive ones. We also show that, contrary to previous expectations, the model can predict light neutral flavor-conserving Higgs bosons, while the flavor-violating ones are heavy, and within the …
We revisit the minimal supersymmetric left-right model with B-L=2 triplet Higgs fields and show that a self-consistent picture emerges with automatic R-parity conservation even in the absence of higher dimensional operators. By computing the effective potential for the Higgs system including heavy Majorana neutrino Yukawa couplings we show that the global minimum of the model can lie in the charge and R-parity conserving domain. The model provides natural solutions to the SUSY phase problem and the strong CP problem and makes several interesting predictions. Quark mixing angles arise only afte…
We propose a simple renormalizable left-right theory where R-parity is spontaneously broken and neutrino masses are generated through the Type I seesaw mechanism and R-parity violation. In this theory R-parity and the gauge symmetry are broken by the sneutrino vacuum expectation values and there is no Majoron problem. The SU(2)_R and R-parity violation scales are determined by the SUSY breaking scale making the model very predictive. We discuss the spectrum and possible tests of the theory through the neutralinos, charginos, Z^' and W_R decays at the Large Hadron Collider.
Here we propose models with $SU(2)_L\otimes SU(2)_R\otimes U(1)_{B-L}$ electroweak gauge symmetry in which parity (or charge conjugation) is broken explicitly and the interactions of left- and right-handed fermions are completely different from each other at any energy scale. In these sort of models there is no restoration of parity at high energies. However, as in all left-right symmetric models, the electroweak charged interactions of quarks and leptons appear to be only left-handed at low energies, because the right-handed interactions are suppressed by the mass of the respective charged ve…
We present full renormalisation group equations for the MSSM with R-parity violation, including all soft supersymmetry breaking terms. The inclusion of dimensionless R-parity violating couplings can generate many possible low energy effects through the generation of off-diagonal soft masses violating lepton and quark flavour, and through the generation of lepton-Higgs mixing. We discuss the relation between the weak and unification scale R-parity violation and study the effects on neutrino mass generation and $μ\to eγ$.
In a class of supersymmetric left-right models (SUSYLR) of weak interactions where R-parity is automatically conserved, we show that spontaneous breakdown of parity CANNOT occur without spontaneous breakdown of R-parity. This intriguing result connects two physically different scales in supersymmetric models.
We studied the question of parity breaking in a supersymmetric left-right model, in which the left-right symmetry is broken with Higgs doublets (carrying $B-L=\pm 1$). Unlike the left-right symmetric models with triplet Higgs scalars (carrying $B-L=\pm 2$), in this model it is possible to break parity spontaneously by adding a parity odd singlet. We then discussed how neutrino mass of type III seesaw can be invoked in this model by adding extra fermion singlets. We considered simple forms of the mass matrices that are consistent with the unification scheme and demonstrate how they can reproduc…
Probing Parity Manifest Minimal Left-Right Symmetric Model through $CP$ Violation & Anomalous Magnetic Moment of Charged Leptons Constrained by Lepton Flavor Violating $l_i \rightarrow l_jγ$ & $l_i \rightarrow 3l_j$ Channels
The magnitude of R-parity violating coupling constants depends on which direction in the space of weak doublets with hypercharge = -2 corresponds to the Higgs. To address this ``basis dependence'', one can construct combinations of coupling constants that are invariant under these basis transformations, and which parametrise how much R parity violation is present in the Lagrangian (analogous to Jarlskog invariants for CP violation). This has previously been done for the Higgs vev and the R parity violating couplings constants in the superpotential. In this letter, I build invariants that inclu…
We consider the most general class possible of soft supersymmetry breaking terms that can be added to the MSSM, with and without R-parity violation, consistent with the sole requirement that no quadratic divergences are induced. We renormalise the resulting theory through one loop and give an example of how a previously ignored term might affect the sparticle spectrum.
Supersymmetric standard model has a parity violation in QCD through chiral quark-squark-gluino interactions with non-degenerate masses between left-handed and right-handed squarks. Since experiments have not show any parity violations in QCD yet, a bound for the mass degeneracy between left-handed and right-handed squarks should exist. In this paper we try to obtain this bound for each squark. At first, we investigate a non-degeneracy bound between $m_{\tilde{c}_L}$ and $m_{\tilde{c}_R}$ from experimental data of charmonium decay. Next, we estimate the non-degeneracy bounds for $\tilde{u}$ and…
Left--right symmetry breaking in a model with composite Higgs scalars is discussed. It is assumed that the low--energy degrees of freedom are just fermions and gauge bosons and that the Higgs bosons are generated dynamically through a set of gauge-- and parity--invariant 4-fermion operators. It is shown that in a model with composite bi-doublet and two triplet scalars there is no parity breaking at low energies, whereas in the model with two doublets instead of two triplets parity is broken automatically regardless of the choice of the parameters of the model. For phenomenologically allowed va…
We construct a supersymmetric SU(2)_L X SU(2)_R X U(1)_B-L model in which a discrete symmetry (C-parity) implements strict left-right symmetry in the scalar (Higgs) sector. Although two electroweak bidoublets are introduced to accommodate the observed fermion masses and mixings, a natural missing partner mechanism insures that a single pair of MSSM Higgs doublets survives below the left-right symmetry breaking scale. If this scale happens to lie in the TeV range, several new particles potentially much lighter than the SU(2)_R charged gauge bosons W_R^+- will be accessible at the LHC.
We present a SU(2)_L * SU(2)_R * U(1) left-right symmetric model for elementary particles and their connection with the fermion mass spectrum. New mirror fermions and a minimal set of Higgs particles are proposed. The model can accommodate a consistent pattern for charged and neutral fermion masses as well as neutrino oscillations. The connection between the left and right sectors can be done by the neutral vector gauge boson Z and a new heavy Z'.
An unstable gravitino with lifetime longer than $10^{26}$ sec or so has been proposed as a possible dark matter candidate in supergravity models with R-parity breaking. We find a natural realization of this idea in the minimal supersymmetric left-right models where left-right symmetry breaking scale in the few TeV range. It is known that in these models, R-parity must break in order to have parity breaking as required by low energy weak interactions. The sub-eV neutrino masses imply that R-parity breaking effects in this model must be highly suppressed. This in turn makes the gravitino LSP lon…
We study the new physics contributions to neutrinoless double beta decay ($0νββ$) in a TeV scale left-right model with spontaneous D-parity breaking mechanism where the values of the $SU(2)_L$ and $SU(2)_R$ gauge couplings, $g_L$ and $g_R$ are unequal. Neutrino mass is generated in the model via gauge extended inverse seesaw mechanism. We embed the model in a non-supersymmetric $SO(10)$ GUT with a purpose of quantifying the results due to the condition $g_{L} \neq g_{R}$. We compare the predicted numerical values of half life of $0νββ$ decay, effective Majorana mass parameter and other lepton …
We present a simplest inflationary scenario in the minimal left-right symmetric model with spontaneous D-parity breaking, which is a well motivated particle physics model for neutrino masses. This leads us to connect the observed anisotropies in the cosmic microwave background to the sub-eV neutrino masses. The baryon asymmetry via the leptogenesis route is also discussed briefly.
In the supersymmetry (SUSY) models, because of the mass difference between the left- and right-top squarks, the supersymmetric QCD interactions can generate parity violating effects in the production of $ t \bar t$ pairs. We show that SUSY QCD radiative corrections to the parity violating asymmetry in the production rates of the left- and right-handed top quarks via the $q \bar q \ra t \bar t$ process can reach about 3% at the Fermilab Tevatron with $\sqrt{s}=2$ TeV. This could be observable with an integrated luminosity larger than $2 fb^{-1}$. We also show that in these models the SUSY QCD r…
We study left-right symmetric models which contain only fermion and gauge boson fields and no elementary scalars. The Higgs bosons are generated dynamically through a set of gauge- and parity-invariant 4-fermion operators. It is shown that in a model with a composite bi-doublet and two triplet scalars there is no parity breaking at low energies, whereas in the model with two doublets instead of two triplets parity is broken automatically regardless of the choice of the parameters of the model. For phenomenologically allowed values of the right-handed scale a tumbling symmetry breaking mechanis…
The simplest minimal left-right symmetric extension of the standard model is studied in the high energy limit, and some consequences of the grand unification hypothesis are explored assuming that the parity breaking scale is the only relevant energy between the electro-weak scale and the unification point. While the model is shown to be compatible with the observed neutrino phenomenology, the parity breaking scale and the heavy boson masses are predicted to be above 10^7 TeV, quite far from the reach of nowadays experiments. Below that scale only an almost sterile right handed neutrino is allo…
I consider parity violation of the chiral symmetry broken vacuum. It is shown that the parity of the true vacuum in the chiral symmetry breaking model is violated. I propose new mechanism of massive neutrino, which the neutrinos have mass in terms of the chiral symmetry breaking. In this mechanism, it may give us new understanding why almost neutrinos have left chirality. Further, NJL model is proposed as alternative phenomenological model of neutrinos.
Parity violating left-right scattering asymmetries at future high energy e+e- and e-e- colliders are examined. The utility of two polarized beams for precision measurements is pointed out. Sensitivity to ``new'' short-distance physics is briefly discussed. Electroweak radiative corrections due to the running of sin^2(theta_W)(q^2) are exhibited.
A novel gauge model which has a spontaneously broken parity symmetry is constructed. The model has only 2 parameters beyond those of the standard model. Some of the unusual implications of the model are discussed.
The muon transverse polarization in the $K^+ \leftarrow π^0 μ^+ ν_μ$ decay will be measured at the $10^{-4}$ level in forthcoming experiments. We compare the phenomenological perspectives with the theoretical predictions in supersymmetric extensions of the standard model. In the minimal extension, CP-violating phases lead to a non-zero transverse polarization, that however is too small to account for a positive experimental signal. The problems that one encounters when departing from minimal assumptions are discussed. An observable effect is possible if the hypothesis of R-parity conservation …
We examine the leptonic forward-backward and polarization (left-right) asymmetries in the dileptonic B -> X_s l^+ l^- decay when the momentum dependence of $ψ$ and $ψ'-γ$ conversion strength is taken into account. The results indicate only a small shift in the asymmetry distributions.
We show that the low energy limit of the minimal supersymmetric Left-Right models is the supersymmetric standard model with an exact R-parity. The theory predicts a number of light Higgs scalars and fermions with masses much below the $B-L$ and $SU(2)_R$ breaking scales. The non-renormalizable version of the theory has a striking prediction of light doubly charged supermultiplets which may be accessible to experiment. Whereas in the renormalizable case the scale of parity breaking is undetermined, in the non-renormalizable one it must be bigger than about $10^{10} - 10^{12}$ GeV. The precise n…
In this paper we discuss a left-right symmetric model for elementary particles and their connection with the mass spectrum of elementary fermions. The model is based on the group $SU(2)_L\otimes SU(2)_R\otimes U(1)$. New mirror fermions and a minimal set of Higgs particles that breaks the symmetry down to $U(1)_{em}$ are proposed. The model can accommodate a consistent pattern for charged and neutral fermion masses as well as neutrino oscillations. An important consequence of the model is that the connection between the left and right sectors can be done by the neutral vector gauge bosons Z an…
We suggest simple models of spontaneous parity violation in supersymmetric strong gauge theory. We focus on left-right symmetric model and investigate vacuum with spontaneous parity violation. Non-perturbative effects are calculable in supersymmetric gauge theory, and we suggest two new models. The first model shows confinement, and the second model has a dual description of the theory. The left-right symmetry breaking and electroweak symmetry breaking are simultaneously occurred with the suitable energy scale hierarchy. The second model also induces spontaneous supersymmetry breaking.
In this paper we present a model for the spontaneous breaking of parity with two Higgs doublets and two neutral Higgs singlets which are even and odd under D-parity. The condition $ v_R >>v_L $ can be satisfied without introducing bidoublets and it is induced by the breaking of D-parity through the vacuum expectation value of the odd Higgs singlet. Examples of left-right symmetric and mirror fermions models in grand unified theories are presented.
A right-right-left extension of the standard model is proposed. In this model, the standard model gauge group $SU(2)_L \otimes U(1)_Y $ is extended to $SU(2)_L \otimes SU(2)_R \otimes SU(2)^{\prime}_R \otimes SU(2)^{\prime}_L \otimes U(1)_{Y}$. The gauge symmetries $SU(2)^{\prime}_R$, $SU(2)^{\prime}_L$ are the mirror counter-parts of the $SU(2)_L$ and $SU(2)_R$ respectively. Parity is spontaneously broken when the scalar Higgs fields acquire vacuum-expectation values in a certain pattern. Parity is restored at the scale of $SU(2)^{\prime}_L$. The gauge sector has a unique pattern. The scalar …
We evaluate the predictions of the left-right symmetry model based on $SU(2)\otimes U(1)$ gauge group with one bidoublet and one doublet Higgs fields on the parity violation, charged leptons and neutrinos masses. Parity violation in the weak interaction is due to the very large $M_{W_{R}}$ mass compare to the $M_{W_{L}}$ mass. The charged leptons acquire a Dirac mass via ordinary Higgs mechanism, meanwhile the neutrinos acquire a very small Dirac masses via seesaw-like mechanism with values $m_{1}=0.000043$ eV, $m_{2}=0.008888$ eV, $m_{3}=0.014948$ eV when $ρ=8.4\times 10^{-11}$, or m_{1}=0.00…
We propose a class of left-right symmetric models (LRSMs) with spontaneous D parity breaking, where SU(2)_R breaks at the TeV scale while discrete left-right symmetry breaks around 10^9 GeV. By embedding this framework in a non-supersymmetric SO(10) Grand Unified Theory (GUT) with Pati-Salam symmetry as the highest intermediate breaking step, we obtain g_R / g_L ~ 0.6 between the right- and left-handed gauge couplings at the TeV scale. This leads to a suppression of beyond the Standard Model phenomena induced by the right-handed gauge coupling. Here we focus specifically on the consequences fo…
The Standard Model of particle interactions is extended to include fermion doublets (n,e)_R transforming under the gauge group SU(2)_R such that n is a scotino (dark-matter fermion), with odd R parity. This dark left-right model (DLRM) treats neutrinos and scotinos in parallel, and has interesting phenomenology at the Large Hadron Collider (LHC).
We present twin Higgs models based on the extension of the Standard Model to left-right symmetry that protect the weak scale against radiative corrections up to scales of order 5 TeV. In the ultra-violet the Higgs sector of these theories respects an approximate global symmetry, in addition to the discrete parity symmetry characteristic of left-right symmetric models. The Standard Model Higgs field emerges as the pseudo-Goldstone boson associated with the breaking of the global symmetry. The parity symmetry tightly constrains the form of radiative corrections to the Higgs potential, allowing n…
In the framework of the left-right symmetric model the CP-parity violation has been studied in heavy Majorana neutrino decays $N\rightarrow e^{\mp} μ^{\pm} n$. The numerical estimates of CP-asymmetry for different masses of neutrino and $W_{R}^{\pm}$-boson were obtained. The possibility to detect this phenomenon at high energy colliders is mentioned.
A left-right symmetric mirror model restoring parity at a high scale in a way such that the mirror fermions and mirror gauge sector simultaneously could exist at TeV scale is discussed. We also provide an ultraviolet completion of the model with vector-like fermions, and discuss some theoretical and phenomenological implications of this model.
Under the assumption of classical conformal invariance, we study the Coleman-Weinberg symmetry breaking mechanism in the minimal left-right symmetric model. This model is attractive as it provides a natural framework for small neutrino masses and the restoration of parity as a good symmetry of nature. We find that, in a large fraction of the parameter space, the parity symmetry is maximally broken by quantum corrections in the Coleman-Weinberg potential, which are a consequence of the conformal anomaly. As the left-right symmetry breaking scale is connected to the Planck scale through the loga…
We point out that in a large class of supersymmetric left-right models with automatic R-parity conservation there are a pair of light doubly charged Higgs bosons and Higgsinos. Requiring the mass of these particles to satisfy the LEP Z-width bound implies that $W_R$ mass must be above $10^{9}$ GeV.
While Left-Right symmetry (space parity) breaking historically appeared as a surprise, we argue that the real wonder is its restoration in long-distance interactions (at least until we find electric dipole moments!).
Within the minimal Left-Right (LR) symmetric model we revisit the predictions for the kaon CP violating observables $\varepsilon$ and $\varepsilon'$ in correlation with the neutron electric dipole moment. We perform a complete study of the cross constraints on the model parameters, phases and the $M_{W_R}$ scale, considering the two cases of extended parity or charge conjugation as LR discrete symmetries, together with the possible presence of a Peccei-Quinn symmetry. We discuss in particular two scenarios: whether the Standard Model saturates the experimental value of $\varepsilon'/\varepsilo…
The conventional derivation of neutrino oscillation treats neutrino mass eigenstate as plane wave with an overall evolution phase. Nevertheless, due to the intrinsic parity-violating nature of weak interactions, only the left-chiral neutrino can be produced as initial condition. On the other hand, the neutrino mass term connects the left-chiral component to the right-chiral one and unavoidably leads to generation of the later through oscillation. This chiral oscillation has significant consequences on the detection of the cosmological relic neutrinos. The event rate is reduced by a factor of 2…
We construct supersymmetric SU(4)_C X SU(2)_L X SU(2)_R models with spontaneously broken left-right symmetry (C-parity). The minimal supersymmetric standard model (MSSM) can be recovered at low scales by exploiting the missing partner mechanism. The field content is compatible with realistic fermion masses and mixings, proton lifetime is close to or exceeds the current experimental bounds, and supersymmetric hybrid inflation can be implemented to take care of C-parity domain walls as well as magnetic monopoles, and to realize the observed baryon asymmetry via non-thermal leptogenesis.
We systematically study the connection between P, C and strong CP in the context of both non-supersymmetric and supersymmetric left-right theories. We find that the solution to the strong CP problem requires both supersymmetry and parity breaking scales to be around the weak scale.
We investigated thermal leptogenesis scenarios in the left-right symmetric extension of the standard model. In the SO(10) GUT framework, we impose the D-parity realization below GUT scale. These two conditions makes our model more restrictive and predictive. In such a case, a D-parity odd singlet in the 4-index antisymmetric tensor representation of SO(10) have a critical role. This singlet have prospects of causing a very large mass hierarchy between SU(2)L and SU(2)R triplet scalars. We test our model by computing baryogenesis via leptogenesis. The heavy right-handed neutrinos N's and the SU…
The $\Zbb$ excess, $\Zcc$ deficit, and low left-right asymmetry $A_b$ may be explained by a single term $\lam C^c B^c B^{\prime c}$ in the superpotential. This operator violates R-parity and requires a sequential 4th generation. 1-loop diagrams involving squark exchange interfere with the tree-level processes to give an excess of right-handed $b$ quarks, and a deficit of right-handed $c$ quarks. Though the coupling must be large ($\lam\approx 2$ or $3$), the model is phenomenologically and cosmologically acceptable.
We investigate a mechanism for spontaneous R-parity breaking in a class of extensions of the minimal supersymmetric standard model with an extra Abelian gauge symmetry which is a linear combination of B-L and weak hypercharge. Both U(1)_X and R-parity are broken by the vacuum expectation value of the right-handed sneutrinos which is proportional to the soft SUSY masses. In these models the mechanism for spontaneous R-parity violation can be realized even with positive soft masses. In this context one has a realistic mechanism for generating neutrino masses as well as a realistic spectrum. We b…
