Abstract:The gauged U (1)L µ−Lτ model can provide for additional contributions to the muon anomalous magnetic moment by means of a loop involving the Z gauge boson. However, the parameter space of such models is severely constrained if one combines the latest muon (g − 2) data with various neutrino experiments, such as neutrino trident production, ν − e and ν − q elastic scattering, etc. In a supersymmetric U (1)L µ−Lτ model, a larger region of parameter space opens up, thus enabling one to explore otherwise forbidden … Show more
“…A supersymmetric gauged U(1) Lµ−Lτ model requires at least two additional R-Parity even superfieldsη andη to be consistent with Z-boson decay observations and neutrino mixing texture [50]. Scalars corresponding to these U(1) Lµ−Lτ charged additional superfields, singlets under SM gauge symmetries and R-Parity even, acquire vacuum expectation values (VEVs) to break the additional gauge symmetry spontaneously.…”
Section: The Modelmentioning
confidence: 97%
“…The cancellation of chiral anomalies require these superfields to always have equal and opposite charge under the U(1) Lµ−Lτ symmetry. While R-Parity was not considered to be a global symmetry in [50], we work in a simplified scenario where R-Parity is conserved and the superpotential is given by…”
Minimal gauged $$ \mathrm{U}{(1)}_{L_{\mu }-{L}_{\tau }} $$
U
1
L
μ
−
L
τ
models can provide for an additional source for the muon anomalous magnetic moment however it is difficult to accommodate the discrepancy in the electron magnetic moment in tandem. Owing to the relative sign between the discrepancies in these quantities, it seems unlikely that they arise from the same source. We show that a supersymmetric (SUSY) gauged $$ \mathrm{U}{(1)}_{L_{\mu }-{L}_{\tau }} $$
U
1
L
μ
−
L
τ
model can accommodate both the muon and electron anomalous magnetic moments in a very simple and intuitive scenario, without utilizing lepton flavor violation. The currently allowed parameter space in this kind of a scenario is constrained from the latest LHC and various low energy experimental data,e.g., recent COHERENT data, CCFR, Borexino, BaBaR, supernova etc. These constraints, in conjunction with the requirement to explain both lepton magnetic moments, lead to an upper bound on the first generation slepton mass, a lower bound on the second generation slepton mass and constricts the allowed range for the new gauge boson mass and coupling. The scheme can be probed at the ongoing COHERENT and Coherent CAPTAIN-Mills experiments and at future experiments, e.g., DUNE, BELLE-II etc.
“…A supersymmetric gauged U(1) Lµ−Lτ model requires at least two additional R-Parity even superfieldsη andη to be consistent with Z-boson decay observations and neutrino mixing texture [50]. Scalars corresponding to these U(1) Lµ−Lτ charged additional superfields, singlets under SM gauge symmetries and R-Parity even, acquire vacuum expectation values (VEVs) to break the additional gauge symmetry spontaneously.…”
Section: The Modelmentioning
confidence: 97%
“…The cancellation of chiral anomalies require these superfields to always have equal and opposite charge under the U(1) Lµ−Lτ symmetry. While R-Parity was not considered to be a global symmetry in [50], we work in a simplified scenario where R-Parity is conserved and the superpotential is given by…”
Minimal gauged $$ \mathrm{U}{(1)}_{L_{\mu }-{L}_{\tau }} $$
U
1
L
μ
−
L
τ
models can provide for an additional source for the muon anomalous magnetic moment however it is difficult to accommodate the discrepancy in the electron magnetic moment in tandem. Owing to the relative sign between the discrepancies in these quantities, it seems unlikely that they arise from the same source. We show that a supersymmetric (SUSY) gauged $$ \mathrm{U}{(1)}_{L_{\mu }-{L}_{\tau }} $$
U
1
L
μ
−
L
τ
model can accommodate both the muon and electron anomalous magnetic moments in a very simple and intuitive scenario, without utilizing lepton flavor violation. The currently allowed parameter space in this kind of a scenario is constrained from the latest LHC and various low energy experimental data,e.g., recent COHERENT data, CCFR, Borexino, BaBaR, supernova etc. These constraints, in conjunction with the requirement to explain both lepton magnetic moments, lead to an upper bound on the first generation slepton mass, a lower bound on the second generation slepton mass and constricts the allowed range for the new gauge boson mass and coupling. The scheme can be probed at the ongoing COHERENT and Coherent CAPTAIN-Mills experiments and at future experiments, e.g., DUNE, BELLE-II etc.
“…Apart from being an anomaly free gauged U(1) extension, the L µ − L τ symmetry naturally violets the LFU between e and µ because the L µ − L τ charge of leptons are such that the corresponding new non-standard gauge boson couples only to µ(τ ) but not to e. This scenario was originally formulated by Volkas et al [77,78]. Thereafter, several variants of U(1) Lµ−Lτ model have been studied in the context of different phenomenological purposes: e.g., contribution of the U(1) Lµ−Lτ gauge boson to explain the (g − 2) µ anomaly [79][80][81][82][83][84][85][86], dark matter phenomenology [84,85,[87][88][89][90][91], generation of neutrino masses and mixing parameters [79,84,86,[92][93][94][95] etc.…”
We propose an anomaly free unified scenario by invocation of an extra local U(1) Lµ−Lτ gauge symmetry. This scenario simultaneously resolves the R K (*) anomalies, the dark matter puzzle and the long-standing discrepancy in muon's anomalous magnetic moment. A complex scalar (η) having nonzero L µ − L τ charge has been introduced to break this new U(1) symmetry spontaneously. Moreover, for the purpose of studying dark matter phenomenology and R K (*) anomalies in a correlated manner, we introduce an inert SU(2) L scalar doublet (Φ), a Z 2-odd real singlet scalar (S) and a Z 2-odd coloured fermion (χ) which transforms vectorially under the U(1) Lµ−Lτ symmetry. This extra gauge symmetry provides a new gauge boson Z µτ which not only gives additional contribution to both b → s transition and (g − 2) µ but also provides a crucial annihilation channel for dark matter candidate ρ 1 of the present scenario. This ρ 1 is an admixture of CPeven neutral component of Φ and S. Our analysis shows that the low mass dark matter regime (M ρ 1 60 GeV) is still allowed by the experiments like XENON1T, LHC (via Higgs invisible branching) and Fermi-LAT, making the dark matter phenomenology drastically different from the standard Inert Doublet and the Scalar Singlet models. Furthermore, the present model is also fairly consistent with the observed branching ratio of B → X s γ in 3σ range and is quite capable of explaining neutrino masses and mixings via Type-I seesaw mechanism if we add three right handed neutrinos in the particle spectrum. Finally, we use the latest ATLAS data of non-observation of a resonant + − signal at the 13 TeV LHC to constrain the mass-coupling plane of Z µτ .
“…This symmetry is anomaly-free within the SM, and all of our new fermions are Dirac, so it can be gauged. A gauge symmetry of this form has been used to explain the structure of neutrino masses and mixings [79][80][81][82][83] and also has been invoked in other attempts to explain the positron excess [33,79,84].…”
Semi-annihilation is a generic feature of particle dark matter that is most easily probed by cosmic ray experiments. We explore models where the semi-annihilation cross section is enhanced at late times and low temperatures by the presence of an s-channel resonance near threshold. The relic density is then sensitive to the evolution of the dark matter temperature, and we compute expressions for the associated Boltzmann equation valid in general semi-annihilating models. At late times, a self-heating effect warms the dark matter, allowing number-changing processes to remain effective long after kinetic decoupling of the dark and visible sectors. This allows the semi-annihilation signal today to be enhanced by up to five orders of magnitude over the thermal relic cross section. As a case study, we apply this to a dark matter explanation of the positron excess seen by AMS-02. We see that unlike annihilating dark matter, our model has no difficulty fitting the data while also giving the correct relic density. However, constraints from the CMB and γ-rays from the galactic centre do restrict the preferred regions of parameter space.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.