ترغب بنشر مسار تعليمي؟ اضغط هنا

Nucleon and dinucleon decays to leptonic final states in a left-right symmetric model with large extra dimensions

173   0   0.0 ( 0 )
 نشر من قبل Sudhakantha Girmohanta
 تاريخ النشر 2020
  مجال البحث
والبحث باللغة English




اسأل ChatGPT حول البحث

We consider baryon-number-violating nucleon and dinucleon decays to leptonic final states in the context of a left-right symmetric (LRS) model with large extra dimensions. Specifically, we study (a) nucleon to trilepton decays with $Delta B=-1$ and $Delta L=-3$, and (b) dinucleon to dilepton decays with $Delta B=-2$ and $Delta L=-2$. In the LRS model, $B-L$ is gauged and is spontaneously broken by a Higgs vacuum expectation value $v_R$, which characterizes the scale at which processes violating $B-L$ occur. We show that together with the lower bound on $v_R$ from experimental limits on $n$-$bar n$ oscillations, constraints from searches for other nucleon decay modes imply sufficient suppression of these nucleon to trilepton and dinucleon to dilepton decay modes in this model to agree with experimental bounds.



قيم البحث

اقرأ أيضاً

It is known that limits on baryon-violating nucleon decays do not, in general, imply corresponding suppression of $n - bar n$ transitions. In the context of a model with fermions propagating in higher dimensions, we investigate a related question, na mely the implications of limits on $Delta L=-1$ proton and bound neutron decays mediated by four-fermion operators for rates of nucleon decays mediated by $k$-fermion operators with $k =6$ and $k=8$. These include a variety of nucleon and dinucleon decays to dilepton and trilepton final states with $Delta L=-3, -2, 1$, and $2$. We carry out a low-energy effective field theory analysis of relevant operators for these decays and show that, in this extra-dimensional model, the rates for these decays are strongly suppressed and hence are in accord with experimental limits.
We study baryon-number-violating processes, including proton and bound neutron decays and $n-bar n$ oscillations, in a left-right-symmetric (LRS) model in which quarks and leptons have localized wavefunctions in extra dimensions. In this model we sho w that, while one can easily suppress baryon-number-violating nucleon decays well below experimental bounds, this does not suppress $n-bar n$ transitions, which may occur at levels comparable to current limits. This is qualitatively similar to what was found in an extra-dimensional model with a Standard-Model low-energy effective field theory (SMEFT). We show that experimental data imply a lower limit on the mass scale $M_{n bar n}$ characterizing the physics responsible for $n-bar n$ oscillations in the LRS model that is significantly higher than in the extra-dimensional model using a SMEFT and explain the reason for this. Our results provide further motivation for new experiments to search for $n - bar n$ oscillations.
We study the effect of interference on the lepton number violating~(LNV) and lepton number conserving~(LNC) three-body meson decays $M_1^{+}to l_i^{+} l_j^{pm}pi^{mp}$, that arise in a TeV scale Left Right Symmetric model~(LRSM) with degenerate or ne arly degenerate right handed~(RH) neutrinos. LRSM contains three RH neutrinos and a RH gauge boson. The RH neutrinos with masses in the range of $M_N sim$ (MeV - few GeV) can give resonant enhancement in the semi-leptonic LNV and LNC meson decays. In the case, where only one RH neutrino contributes to these decays, the predicted new physics branching ratio of semi-leptonic LNV and LNC meson decays $M_1^{+}to l_i^{+} l_j^{+}pi^{-}$ and $M_1^{+}to l_i^{+} l_j^{-}pi^{+}$ are equal. We find that with at least two RH neutrinos contributing to the process, the LNV and LNC decay rates can differ. Depending on the neutrino mixing angles and $CP$ violating phases, the branching ratios of LNV and LNC decay channels mediated by the heavy neutrinos can be either enhanced or suppressed, and the ratio of these two rates can differ from unity.
In this paper we take B-L supersymmetric standard model (B-LSSM) and TeV scale left-right symmetric model (LRSM) as two types of typical ones beyond SM to study the nuclear neutrinoless double beta decays ($0 u2beta$) and to see the senses for the pr esent data and the expected data in the near future of the decays. In the study we pay much attention onto the QCD corrections in the energy-scale region from $mu=M_W$ to $musimeq 1.0;$GeV, but we treat the nuclear effects in the decays as done in the relevant literatures. For these two models the decay half-life of the nuclei, $^{76}$Ge and $^{136}$Xe, $T^{0 u}_{1/2}$($^{76}$Ge, $^{136}$Xe), are precisely estimated with the model parameters allowed by experiments and the results are presented properly. Results show that the concerned QCD corrections to the half-life of the $0 u2beta$ decays for the two models are quite sizable. The interference effects between the different contributions happened only in the model LRSM are specially analyzed. According to the numerical results, an optimistic conclusion is obtained that the $0 u2beta$ decays for the models may be observed in the next generation of the underground observations.
We investigate the potential collider signatures of singly-charged and doubly-charged Higgs bosons such as those arising in minimal left-right symmetric models. Focusing on multileptonic probes in the context of the high-luminosity run of the Large H adron Collider, we separately assess the advantages of the four-leptonic and trileptonic final states for a representative benchmark setup designed by considering a large set of experimental constraints. Our study establishes possibilities of identifying singly-charged and doubly-charged scalars at the Large Hadron Collider with a large significance, for luminosity goals expected to be reached during the high-luminosity phase of the Large Hadron Collider. We generalise our results and demonstrate that existing limits can in principle be pushed much further in the heavy mass regime.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا