Explicit parity violation in $SU(2)_L\otimes SU(2)_R\otimes U(1)_{B-L}$ models
Henry Diaz, E. Castillo-Ruiz, O. P. Ravinez, V. Pleitez
备注：
20 pages, 4 figures, we are replacing the previous version of our article Explicit parity violation in $SU(2)_L\otimes SU(2)_R\otimes U(1)_{B-L}$ models. This new version has already been published in the Journal of Physics G: Nuclear and Particle Physics
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 vector bosons and/or because these interactions may be much weaker than the left-handed ones.
We explore the idea that dark matter stability results from the presence of a matter-parity symmetry, arising naturally as a consequence of the spontaneous breaking of an extended $\mathrm{SU(3) \otimes SU(3)_L \otimes U(1)_X \otimes U(1)_{N}}$ electroweak gauge symmetry with fully gauged B-L. Using this framework we construct a theory for scotogenic dark matter and analyze its main features.
Lepton mass generation and family number violation mechanism in the $SU(6)\otimes U(1)$ model
在$SU(6)_L \otimes U(1)_Y$模型中，由于存在一个额外的中性规范玻色子Z $'$，且该玻色子具有族变耦合，以及由于该模型要求存在重奇异轻子，轻子族数违反过程出现。标准Z与Z的混合以及普通轻子与奇异轻子的混合共同诱导了Z上的族变耦合，从而导致了轻子族数破坏过程的非零速率，如$Z \to e \barμ$、$μ\to ee\bar{e}$和$μ\to eγ$。对过程$μ\to e γ$和$μ\to ee \bar{e}$的额外贡献由质量生成机制诱导。这最后一种贡献可能会与上面的一种竞争，这取决于参与辐射产生带电轻子质量的图的标量的质量。利用实验数据，我们计算的混合参数和标量的质量的一些界限。
We overview the dark parity violation, which means the parity violation induced by a dark gauge boson of very small mass and coupling. When a dark gauge boson has an axial coupling, as in dark Z model, it can change the effective Weinberg angle in the low-energy experiments such as the atomic parity violation and the low-Q^2 polarized electron scatterings. Such low-energy parity tests are an excellent probe of the dark force.
In this lectures, we give a review about the Minimal Supersymmetric Standard Model (MSSM) with $R$-Parity Violation because it provides an attractive way to generate neutrino masses, lepton mixing angles in acconcordance to present neutrino data.
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 discuss possible constraints on R-parity violation from recently announced Belle/Babar results on the B\toτνbranching fraction, and the bounds on τ^-\to\ell^- K_S^0 (\ell=e or μ) from Babar.
We propose a new method, using the Andreev reflection at superconductors, to measure parity violation induced by the standard electroweak theory, which in turn constrains the possible parity-violating effects of new physics. The weak neutral currents induce parity-violating, marginal effective operators, though quite tiny, in superconductors. We estimate their effects on superconducting gaps and propose a method to measure the parity-violation from the spin polarization effect, when electrons or holes get Andreev-reflected at the interface between normal metal and a superconductor. Such polari…
Effects of R-parity violation on CP asymmetries in $Λ_b \to p π$ decay
我们研究了在具有R宇称破坏的最小超对称标准模型中，在$Λ_b \to p π$衰变模中产生的新的CP破坏效应。我们已经估计了R-宇称破坏在多大程度上改变了标准模型对CP不对称性的预测。我们发现，在R-奇偶破坏模型中，速率不对称性（$a_{cp}$）被抑制（约10倍）和不对称性参数$A(α)$增强（约$10^2$倍）相对于SM预测。
Supersymmetric scenarios with R-parity conservation are becoming very constrained due to the lack of missing energy signals, thus motivating those scenarios with R-parity violation. In view of this, we consider a supersymmetric model with R-parity violation and extended by an anomalous horizontal $U(1)_H$ symmetry, where a self-consistent framework with baryon-number violation is achieved along with a proper supression for lepton number violating dimension-5 operators in order to keep a proton decay safe. With the introduction of right-handed neutrinos both Dirac and Majorana masses can be acc…
The presence of R-parity violating interactions may relieve the tension between existing LHC constraints and natural supersymmetry. In this paper we lay down the theoretical framework and explore models of dynamical R-parity violation in which the breaking of R-parity is communicated to the visible sector by heavy messenger fields. We find that R-parity violation is often dominated by non-holomorphic operators that have so far been largely ignored, and might require a modification of the existing searches at the LHC. The dynamical origin implies that the effects of such operators are suppresse…
Non-Standard-Model parity violation may be occurring in LHC collisions. Any such violation would go unseen, however, as searches are for it are not currently performed. One barrier to searches for parity violation is the lack of model-independent methods sensitive to all of its forms. We remove this barrier by demonstrating an effective and model-independent way to search for parity-violating physics at the LHC. The method is data-driven and makes no reference to any particular parity-violating model. Instead, it inspects data to construct sensitive parity-odd event variables (using machine le…
We explore the consequences of promoting bilinear R-parity violation, usually formulated in the minimal supersymmetric standard model framework, to a supersymmetric SU(5) grand unified theory. We observe that the limits on proton decay and neutrino mass place tight constraints on the bilinear SU(5) R-parity violating parameters creating a different doublet-triplet issue which cannot be resolved by an extension of the usual fine-tuning in the symmetry breaking scalar sector. If the parameters are made to satisfy the constraints, albeit unnaturally, there remains no room for the possibility to c…
Lepton number violation and its relation to neutrino masses is investigated in several versions of the $SU(3)_c\otimes SU(3)_L\otimes U(1)_x$ model. Spontaneous and explicit violation and conservation of the lepton number are considered. In one of the models (the so-called economical one), the lepton number is spontaneously violated and it is found that the would be Majoron is not present because it is gauged away, poviding in this way the longitudinal polarization component to a now massive gauge field.
The minimum supersymmetric standard model without R-parity through various lepton-number violations
系统地研究了无R宇称的最小超对称标准模型在各种轻子数破坏下的性质。模型中所有可能的混合都精确地公式化。保留了树层次上最轻的“Higgs”$H_1^0$可能比弱玻色子$Z$重的显著问题，作为只允许轻子数双线性破坏的特殊R-宇称破坏MSSM。本文还明确地指出，在重新定义轻子和Higgs超场时，存在一个自由度$U(n+1)$（$n$是破缺轻子数的个数）.在$'$ t Hooft-Feynman规范中精确地给出了与R宇称破坏有关的Feynman规则。进一步的假设和考虑所有可用的实验约束，频谱感兴趣的部门进行了数值计算。
Here, we give a broad overview of the more natural spectra allowed by the LHC when UDD R-parity violation is allowed. Because R-parity violation removes the missing energy signals in colliders, the experimental constraints on the gluino, stops, sbottoms and higgsinos are relatively mild. We also show that UDD R-parity violation and lepton number conservation can be made consistent with grand unification. This feat is achieved through the product unification, SU(5) X U(3). In this model, mixing of the SM quarks with additional quark like particles charged under the U(3) generate a UDD R-parity …
