Ernest Ma, Jose Wudka
One-loop radiative Majorana neutrino masses through the exchange of scalars have been considered for many years. We show for the first time how such a one-loop mass is also possible through the exchange of vector gauge bosons. It is based on a simple variation of a recently proposed $SU(2)_N$ extension of the standard model, where a vector boson is a candidate for the dark matter of the Universe.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
继续探索
Comment on "Neutrino oscillations originate from virtual excitation of $Z$ bosons" and "Neutrinos produced from $β$ decays of neutrons cannot be in coherent superpositions of different mass eigenstates"
本文针对arxiv:2407.00954提出的“常规质量混合的中微子振荡受能量守恒禁止、振荡源于虚Z玻色子交换”及arxiv:2410.03133的重复论断，论证其均不正确。
In order to have massive neutrinos, the right-handed neutrino/sneutrino superfield ($N$) need to be introduced in supersymmetry. In the framework of NMSSM (the MSSM with a singlet $S$) such an extension will dynamically lead to a TeV-scale Majorana mass for the right-handed neutrino through the $SNN$ coupling when $S$ develops a vev (the free Majorana mass term is forbidden by the assumed $Z_3$ symmetry). Also, through the couplings $SNN$ and $SH_uH_d$, the SM-like Higgs boson (a mixture of $H_u$, $H_d$ and $S$) can naturally couple with the right-handed neutrino/sneutrino. As a result, the Te…
We consider a model of dynamical neutrino masses via the see-saw mechanism. Nambu-Goldstone bosons (majorons) arise associated with the formation of the heavy right-handed majorana masses. These bosons then acquire naturally soft masses (become pNGB's) at loop level via the Higgs-Yukawa mass terms. These models, like the original neutrino pNGB quintessence schemes of the 1980's that proceed through the Dirac masses, are natural, have cosmological implications through mass varying neutrinos, long range forces, and provide a soft potential for dark energy. We further argue that these models can …
In the simplest scheme for neutrino masses invoking a triplet of Higgs scalars there are two CP-even neutral Higgs bosons $H_i$ (i=1,2) and one massive pseudoscalar $A$. For some choices of parameters, the lightest $H_1$ may be lighter than the Standard Model Higgs boson. If the smallness of neutrino mass is due to the small value of the triplet expectation value, as expected in a seesaw scheme, the Higgs bosons may decay dominantly to the invisible neutrino channel. We derive limits on Higgs masses and couplings that follow from LEP I precision measurements of the invisible Z width.
The production of the three normal neutrinos via $e^-e+$ collision at $Z$-boson peak (neutrino production in a Z-factory) is investigated thoroughly. The differences of $ν_e$-pair production from $ν_μ$-pair and $ν_τ$-pair production are presented in various aspects. Namely the total cross sections, relevant differential cross sections and the forward-backward asymmetry etc for these neutrinos are presented in terms of figures as well as numerical tables. The restriction on the room for the mixing of the three species of light neutrinos with possible externals (heavy neutral leptons and/or ster…
We explore possible signatures for heavy neutrinos and neutral gauge boson, Z', in TeV scale B-L extension of the Standard Model (BLSM) with inverse seesaw mechanisms at the Large Hadron Collider. We show that due to new decay channels of Z' into heavy/inert neutrinos, the LHC stringent bounds imposed on Z' mass can be significantly relaxed. We analyze the pair production of heavy neutrinos decaying to four leptons plus two neutrinos, four jets plus two leptons, or three leptons plus two jets and one neutrino. We show that the 4l + 2 nu is the most promising decay channel for probing both Z' a…
We evaluate the LHC discovery potential for the fourth family Standard Model neutrinos in the process $pp\to Z/h\toν_{4}{\barν_{4}}\to WμWμ$. We show that, depending on their masses, the simultaneous discovery of both the Higgs boson and the heavy neutrinos is probable at early stages of LHC operation. Results are presented for both Majorana and Dirac type fourth family neutrinos.
We show that simple extensions of two Higgs doublet models consisting of new heavy neutrinos and a singly charged Higgs boson singlet can successfully explain the experimental data on muon and electron anomalous magnetic moments thanks to large chirally-enhanced one-loop level contributions. These contributions arise from the large couplings of inverse seesaw neutrinos with singly charged Higgs bosons and right-handed charged leptons. The regions of parameter space satisfying the experimental data on $(g-2)_{e,μ}$ anomalies allow heavy singly charged Higgs boson masses above the TeV scale, pro…
We show that conventional Higgs compositeness conditions can be achieved by the running of large Higgs-Yukawa couplings involving right-handed neutrinos that become active at $\sim 10^{13}- 10^{14}$ GeV. Together with a somewhat enhanced quartic coupling, arising by a Higgs portal interaction to a dark matter sector, we can obtain a Higgs boson composed of neutrinos. This is a "next-to-minimal" dynamical electroweak symmetry breaking scheme.
Comments related to reading the paper "Static quantities of the $W$ boson in the $SU_L(3)\times U_X(1)$ model with right-handed neutrinos", hep-ph/0312308 (by J. L. Garcia-Luna et al) are given. They do not concern the main results of the paper but a statement there about the Higgs sector of the 331 model with right-handed neutrinos. The scalar sextet introduced here may help us to generate neutrino masses in an acceptable range.
We discuss W and Z production through the deep inelastic neutrino-nucleon scattering in the context of the standard model SU(3)x SU(2)x U(1) of the strong and electroweak interactions. We find the cross section rates for the process neutrino + nucleon --> lepton(-) + W(+) + X for the case of ultrahigh-energy neutrinos colliding on a target nucleon.
It has been recently suggested in hep-ph/9911535 and hep-ph/0006324 that the fourth generation of leptons and quarks is not excluded by the precision Z-boson measurements, provided that the mass of the fourth neutrino is around 50 GeV and that its mixing with the neutrinos of the first three generations is negligibly small. We would like to note that in this case the decay rate of the Standard Model Higgs boson into the pair of such neutrinos would be about two orders of magnitude higher than than the Higgs to b-bbar rate. Thus, the predominant decay mode of the Higgs would be invisible, which…
We consider a model of neutrino oscillations with three additional sterile neutrinos and a gauged B-L interaction. We find allowed values of the model parameters which can reconcile the results of the evidence for antimuon neutrino to antielectron neutrino conversion seen at the LSND neutrino oscillation experiment with the null results of the MiniBooNE experiment. A portion of the low energy excess of electron neutrino events seen at MiniBooNE can arise naturally, and we make a quantitative prediction for the forthcoming anti-neutrino oscillation results at MiniBooNE.
Low-energy high-resolution neutrino-electron scattering experiments may play an important role in testing the gauge structure of the electroweak interaction. We discuss the use of strong radioactive neutrino sources (e.g. $^{51}$Cr) in underground experiments such as BOREXINO, HELLAZ and LAMA. We display the sensitivity of these detectors in testing the possible existence of extra neutral $E_6$ gauge bosons.
The existence of neutrino masses strongly suggests that right-handed neutrinos exist, but the data do not favor any particular scale for the Majorana mass parameters. Here I explore the possibility that these particles exist at the electroweak scale along with additional new physics at the TeV scale . Higher dimension operators involving right-handed neutrinos and the Higgs boson can introduce new decay modes of the Higgs boson, significantly modifying its phenomenology if it is light. With minimal flavor violation the Higgs boson cascade decays to 6 particles containing two highly displaced v…
In this work, we study the lepton number violating W boson and top quark decays via intermediate on-shell Majorana neutrinos Nj into three charged leptons and a light neutrino. We discuss the neutrino oscillation effects present in the decay due to the small mass gap between the heavy neutrino states. We focus on a scenario that contains at least two heavy Majorana neutrinos in the mass range 2-80 GeV. The results indicate that the modulation of the branching ratios as a function of the distance between the vertices may be detected in a future experiment such as High-Luminosity Large Hadron Co…
The models based on ${SU}(3)_C\otimes {SU}(3)_L \otimes {U}(1)_X$ gauge group (3-3-1) contain new Higgs bosons and one of them is the SM-like Higgs boson $h$. Production of this Higgs boson at $p p$ colliders in the framework of 3-3-1 model with right-handed neutrinos is calculated. We found that the contribution of the real $Z^\prime$ to the process $pp\to hZ$ is nearly 60 fb if $M_{Z^\prime}$ is about 1 TeV. The decay width and the branching ratios of the $Z'$ extra neutral gauge boson are systematically discussed.
We analyze the phenomenological implications for new electroweak physics in the Higgs sector in the framework of SU(2)_L x U(1)_Y theories that naturally predict heavy Majorana neutrinos. We calculate the one-loop Majorana-neutrino contributions to the decay rates of the Higgs boson into pairs of quarks and intermediate bosons and to its production cross section via bremsstrahlung in e^+e^- collisions. It turns out that these are extremely small in three- generation models. On the other hand, the sizeable quantum corrections generated by a conventional fourth generation with a Dirac neutrino m…
It is shown that a new light gauge boson $X$ which might be produced in the decays of pseudoscalar mesons $π^{0}(η)\toγ+ X$ could be effectively searched for in neutrino experiments via the Primakoff effect, in the process of $X + Z\to π^{0}(η) + Z$ conversion in the external Coulomb field of a nucleus. An estimate of the $X\to π^{0}$ conversion rate for the NOMAD neutrino detector at CERN is given.
We investigate the possibility that dark matter could be made from CP-even and CP- odd Higgs bosons in the SU(3)_C X SU(3)_L X U(1)_N (3-3-1) model with right-handed neutrinos. This self-interacting dark matters are stable without imposing of new symmetry and should be weak-interacting.
We present a realization of the idea that the Higgs boson is mainly a bound state of neutrinos induced by strong four-fermion interactions. The conflicts of this idea with the measured values of the top quark and Higgs boson masses are overcome by introducing, in addition to the right-handed neutrino, a new fermion singlet, which, at low energies, implements the inverse see-saw mechanism. The singlet fermions also develop a scalar bound state which mixes with the Higgs boson. This allows us to obtain a small Higgs boson mass even if the couplings are large, as required in composite scalar scen…
We propose a new mechanism to explain neutrino masses with lepton number conservation, in which the Dirac neutrino masses are generated at the two-loop level involving a dark matter candidate. In this model, branching ratios of lepton flavor violating decays of the Higgs boson can be much larger than those of lepton flavor violating decays of charged leptons. If lepton flavor violating decays of the Higgs boson are observed at future collider experiments without detecting lepton flavor violating decays of charged leptons, most of the models previously proposed for tiny neutrino masses are excl…
We calculate the CP-violating rate asymmetry of H^\pm decays into tau and neutrino at one loop in the MSSM with complex parameters. We find that the asymmetry is typically of the order of 10^-3, depending mainly on the phases of the trilinear coupling A_τand of the gaugino mass M_1.
We study the thermal leptogenesis in the scenario where the standard model is extended to include one $SU(2)_{L}$ triplet Higgs boson, in addition to three generations of the right-handed neutrinos. And in the model we introduce the coupling between the Quintessence and the right-handed neutrinos, the triplet Higgs boson, so that the light neutrino masses vary during the evolution of the universe. Assuming that the lepton number asymmetry is generated by the decays of the lightest right-handed neutrino $N_{1}$, we find the thermal leptogenesis can be characterized by four model independent par…
We propose an $SU(3)_C\times SU(2)_L \times SU(2)_N \times U(1)_Y$ model arising from $E_6$ grand unified theory. We show that the tiny neutrino masses in this model can be generated at the three-loop involving the $SU(2)_N$ gauge bosons. With Yukawa couplings around 0.01 or larger and TeV-scale $SU(2)_N$ gauge bosons, we show that the neutrino oscillation data can be explained naturally by presenting a concrete benchmark set of input parameters. All new particles are around the TeV scale. Thus our model can be tested at the ongoing/future collider experiments.
The potential for probing extra neutral gauge boson mediators ($Z^\prime$) from low-energy measurements is comprehensively explored. Our study mainly focuses on $Z^\prime$ mediators present in string-inspired $E_6$ models and left-right symmetry. We estimate the sensitivities of coherent-elastic neutrino-nucleus scattering (CE$ν$NS) and neutrino-electron scattering experiments. Our results indicate that such low-energy high-intensity measurements can provide a valuable probe, complementary to high-energy collider searches and electroweak precision measurements.
We analyze the possibility of $CP$ violation induced by heavy Majorana neutrinos in the decays of the Higgs particle into top-quark, $W$- and $Z$-boson pairs. In the framework of various ``see-saw" models with interfamily mixings, we find that Majorana neutrinos may give rise to sizable $CP$-odd observables at the one-loop electroweak order. Numerical estimates of these $CP$-violating effects that may be detected in high-energy colliders are presented.
We present a detailed calculation of the rare decay Z --> neutrino antineutrino photon photon via the quartic neutral gauge boson coupling Z-Z-photon-photon in the framework of the effective Lagrangian approach. The current experimental bound on this decay mode is then used to constrain the coefficients of this coupling. It is found that the bounds obtained in this way, of the order of $10^{-1}$, are weaker than the ones obtained from the analysis of triple-boson production at LEP-2
A natural scenario for the generation of neutrino masses is the see-saw mechanism, in which a large right-handed neutrino mass makes the left-handed neutrinos light. We review a special case when the Majorana masses originate from spontaneous breaking of a global U(1)XU(1) symmetry. The interactions of the right-handed with the left-handed neutrinos at the electorweak scale further break the global symmetry giving mass to one pseudo Nambu-Goldstone boson (pNGB). The pNGB can then generate a long-range force. Leptogenesis occurs through decays of heavy neutrinos into the light ones and Higgs pa…
Within the model based on the $SU (2)_L\times SU (2)_R\times U (1)_{B-L} $ gauge group and having the bidoublet and two triplets of the Higgs fields (left-right model) the Higgs sector impact on the value of the muon anomalous magnetic moment is considered. The contributions coming from the doubly charged Higgs bosons, the singly charged Higgs bosons and the lightest neutral Higgs boson are taken into account. The obtained value of the muon anomalous magnetic moment is the function of the Higgs boson masses and the Higgs boson couplings constants (CC's). We express the most of part of the CC's…
In gauge models with bigger number of Higgs particles their couplings to fermions are more complicated then in the standard model (SM). The influence of the Higgs bosons exchange on the neutrino production cross section in $e^-e^+$ collision ($e^-e^+ \rightarrow νN$) is investigated. The study has been done in the framework of the left-right symmetric model with the rich Higgs sector containing bidoublet and two triplets. The couplings of the Higgs particles even to light leptons can be as large as the gauge bosons couplings. The total effect of the Higgs bosons is small as a result of the big…
We consider the contributions to the neutrinoless double beta decays in a $SU(3)_L\otimes U(1)_N$ electroweak model. We show that for a range of the parameters in the model there are diagrams involving vector-vector-scalar and trilinear scalar couplings which can be potentially as contributing as the light massive Majorana neutrino exchange one. We use these contributions to obtain constraints upon some mass scales of the model, like the masses of the new charged vector and scalar bosons. We also consider briefly the decay in which besides the two electrons a Majoron-like boson is emitted.
A wide range of models beyond the Standard Model predict charged and neutral resonances, generically called $W'$- and $Z'$-bosons, respectively. In this paper we study the impact of such resonances on the deep inelastic scattering of ultra-high energy neutrinos as well as on the resonant charged current $\barν_e e^-$ scattering (Glashow resonance). We find that the effects of such resonances can not be observed with the Pierre Auger Observatory or any foreseeable upgrade of it.
The existence of certain TeV suppressed higher-dimension operators may open up new decay channels for the Higgs boson to decay into lighter right-handed neutrinos. These channels may dominate over all other channels if the Higgs boson is light. For a Higgs boson mass larger than $2 m_W$ the new decays are subdominant yet still of interest. The right-handed neutrinos have macroscopic decay lengths and decay mostly into final states containing leptons and quarks. A distinguishing collider signature of this scenario is a pair of displaced vertices violating lepton number. A general operator analy…
We present analytic expressions corresponding to a set of one loop Feynman diagrams, built within R-parity violating (RpV) minimal supersymmetric standard model (MSSM). Diagrams involve both bilinear and trilinear RpV couplings and represent Majorana neutrino masses and magnetic moments.
The Majorana nature of neutrinos can be detected by the precise measurement of muon decay. This possibility comes from the presence of charged Higgs boson interaction for Majorana neutrinos. We study the effects of the neutrino Yukawa interaction via charged Higgs bosons in muon decay processes such as $μ\to eν\barν$ and $μ\to eγ$. The Higgs triplet model with small vacuum expectation value is of special importance whose neutrino Yukawa coupling can affect significantly muon decays. External neutrino lines in the Feynman diagrams of $μ\to eν\barν$ can be crossed because of its Majorana nature.…
In this paper, we discuss the potential of observing heavy neutrino ($ν_h$) signatures of a $U(1)_{B-L}$ enlarged Standard Model (SM) encompassing three heavy Majorana neutrinos alongside the known light neutrino states at the Large Hadron Collider (LHC). We exploit the theoretical decay via a pair of heavy (non-SM-like) Higgs boson and $Z'$ production followed by $ν_h \rightarrow l^\pm W^{\mp (*)}$ and $ν_h \rightarrow ν_l Z^{(*)}$ decays, ultimately yielding a $3l+2j+E_{T}^{\rm{miss}}$ signature and, depending upon how boosted the final state objects are, we define different possible selecti…
Two boson exchange (TBE) correction to the cross section for the quasi-elastic charged current $νn$ and $\barν p$ scattering is evaluated. The TBE is given by $Wγ$ box diagrams. The calculations are performed for 1 GeV neutrinos. The averaged TBE correction is of the order of $2\div4 %$ (with respect to Born contribution) in the case of $ν_e$ and $\barν_e$ and $1\div2 %$ in the case of $ν_μ$ and $\barν_μ$. The impact of the TBE effect on the systematic discrepancy between the $ν_e$ and $ν_μ$ cross sections is discussed.
A wide range of models beyond the Standard Model predict charged and neutral resonances, generically called $W'$- and $Z'$-bosons, respectively. We present a study of the impact of such resonances on the deep inelastic scattering of ultra-high energy neutrinos as well as on the resonant charged current $\barν_e e^-$ scattering (Glashow resonance). We find that the effects of such resonances can not be observed with the Pierre Auger Observatory or any foreseeable upgrade of it.
We examine the charged boson and right-handed neutrino contribution to the muon g-2 anomaly in the twin Higgs models with the joint constraints of the Higgs global fit data, the precision electroweak data, the leptonic flavor changing decay μ\to eγ, and the mass requirement of the heavy gauge bosons. It comes out with the conclusion that some parameters such as the coupling of charged Higgs to the lepton y_μ, the top Yukawa y_t, and the heavy gauge boson coupling to the lepton V_μare constrained roughly in the range of 0.12\lesssim y_μ\lesssim 0.4, 0.4\lesssim y_t\lesssim 0.9, and 0.47\lesssim…
We investigate how observations of the lepton flavor violating decay of the Higgs boson ($h \to \ell\ell^\prime$) can narrow down models of neutrino mass generation mechanisms, which were systematically studied in Refs. [1,2] by focusing on the combination of new Yukawa coupling matrices with leptons. We find that a wide class of models for neutrino masses can be excluded if evidence for $h \to \ell\ell^\prime$ is really obtained in the current or future collider experiments. In particular, simple models of Majorana neutrino masses cannot be compatible with the observation of $h \to \ell\ell^\…
Forward Searches for Heavy Neutrinos and $Z'$ Bosons at FCC-hh
研究在FCC-hh的前向物理设施中，通过长寿命粒子信号探测重中微子和$Z'$玻色子，评估事件率并推导灵敏度，扩展了对轻长寿命重中微子和轻$Z'$玻色子的发现能力。
We study the impact of light gauge bosons on neutrino physics. We show that they can explain the NuTeV anomaly and also escape the constraints from neutrino experiments if they are very weakly coupled and have a mass of a few GeV. Lighter gauge bosons with stronger couplings could explain both the NuTeV anomaly and the positive anomalous magnetic moment of the muon. However, in the simple model we consider in this paper (say a purely vectorial extra U(1) current), they appear to be in conflict with the precise measurements of ν-e elastic scattering cross sections. The surprising agreement that…
Motivated by the observation of neutrino oscillations, we extend the Higgs boson exempt no-scale supersymmetry model (HENS) by adding three heavy right-handed neutrino chiral supermultiplets to generate the light neutrino masses and mixings. The neutrino Yukawa couplings can induce new lepton flavor violating couplings among the soft terms in the course of renormalization group running down from the boundary scale. We study the effects this has on the predictions for low-energy probes of lepton flavor violation(LFV). Heavy right-handed neutrinos also provide a way to generate the baryon asymme…
The process $e^- γ\to e^+ W_R^- W_R^-$ is studied in the framework of the Left-Right symmetric model. It is shown that this reaction and $e^- γ\to l^+ W_R^- W_R^-$ for the arbitrary final lepton are likely to be discovered for CLIC collider option. For relatively light doubly charged Higgs boson its mass does not have much influence on the discovery potential, while for heavier values the probability of the reaction increases.
Sensitivity of $W$-boson measurements to low-mass right-handed neutrinos
本文通过有效场论研究低质量右-handed中微子与$W$-玻色子的相互作用，利用CDF和LHC的测量结果发现参数不一致，并提出通过测量$W$玻色子的余弦旋角来提高敏感性。
A new era in particle physics is being spurred on by new data from the Large Hadron Collider. Non-vanishing neutrino masses represent firm observational evidence of new physics beyond the Standard Model. An extension of the latter, based on a SU(3)_C x SU(2)_L x U(1)_Y x U(1)_{B-L} symmetry, incorporating an established Baryon minus Lepton number invariance, is proposed as a viable and testable solution to the neutrino mass problem. We argue that LHC data will probe all the new content of this model: heavy neutrinos, an extra gauge boson emerging from spontaneous breaking of the additional gau…
We examine the contributions of Majorana neutrinos to CP-violating WWZ and ZZZ self-couplings, using a model in which sterile neutrinos couple to the W and Z by mixing with a fourth-generation heavy lepton. We find that the induced form factors can be as large as 0.5%. The model satisfies all phenomenological bounds in a natural way, including those due to the strong limits on the neutron and electron electric dipole moments. Anomalous CP-odd couplings of this size are unlikely to be observed at LEP200, but might be detectable at NLC.
The tau neutrino is probably the least studied particle in the SM, with only a handful of interaction events being identified so far. This can in part be attributed to their small production rate in the SM, which occurs mainly through D_s meson decay. However, this also makes the tau neutrino flux measurement an interesting laboratory for additional new physics production modes. In this study, we investigate the possibility of tau neutrino production in the decay of light vector bosons. We consider four scenarios of anomaly-free U(1) gauge groups corresponding to the B-L, B-L_mu-2L_tau, B-L_e-…
The triplet scalars $(Δ=Δ^{++},Δ^{+},Δ^{0})$, utilized in the so-called Type-II seesaw model to explain the lightness of neutrinos, would generate nonstandard interactions (NSI) for neutrino propagating in matter. We investigate the prospects to probe these interactions in long baseline neutrino oscillation experiments. We analyze the upper bounds that the proposed DUNE experiment might set on the nonstandard parameters and numerically derive upper bounds, as function of the lightest neutrino mass, on the ratio the mass $M_Δ$ of the triplet scalars and strength $|λ_ϕ|$ of the coupling $ϕϕΔ$ of…
We explore the possibility to explain a bosonic dark matter candidate with a gauge singlet inside the loop to generate the neutrino mass matrix at two-loop level. The mass matrix is suppressed by a small mixing that comes from the bound on {direct detection experiments of the dark matter, and equivalent of the three-loop neutrino model due to the small mixing between neutral inert bosons. Here, our setup is} the Zee-Babu type scenario with $Z_3$ discrete symmetry, in which we consider the neutrino oscillation data, lepton flavor violations, muon $g-2$, $μ-e$ conversion rate, lepton flavor-chan…
It is demonstrated that the light Higgs boson scenario, which the lightest Higgs mass is less than the LEP bound, mh > 114.4 GeV, is consistent with the SUSY seesaw model. With the assumptions of the universal right-handed neutrino mass and the hierarchical mass spectrum of the ordinary neutrinos, the bounds for the right-handed neutrino mass is investigated in terms of lepton flavor violating charged lepton decays. We also discuss the effect of the modification of renormalization group equations by the right-handed neutrinos on the b to s gamma process and the relic abundance of dark matter i…
We present a full diagrammatic computation of the one-loop corrections from the neutrino/sneutrino sector to the renormalized neutral CP-even Higgs boson self-energies and the lightest Higgs boson mass, Mh, within the context of the so-called MSSM-seesaw scenario. This consists of the Minimal Supersymmetric Standard Model with the addition of massive right handed Majorana neutrinos and their supersymmetric partners, and where the seesaw mechanism is used for the lightest neutrino mass generation. We explore the dependence on all the parameters involved, with particular emphasis in the role pla…
It is suggested that Goldstone bosons may be masquerading as fractional cosmic neutrinos, contributing about 0.39 to what is reported as the effective number of neutrino types in the era before recombination. The broken symmetry associated with these Goldstone bosons is further speculated to be the conservation of the particles of dark matter.
In some class of supersymmetric models, small neutrino mass is given as a consequence of the supersymmetry (SUSY) breaking. Phenomenologically interesting features of this scenario are as follows: (i) the right-handed sneutrino mass could be as low as TeV scale due to the Giudice-Masiero mechanism, and (ii) a scalar trilinear interaction of Higgs-slepton-(right-handed) sneutrino could be sizable without suppression by the small neutrino Yukawa coupling. We study some phenomenological aspects of this scenario focusing on the scalar trilinear interaction. We show that the 1-loop correction by sn…
Majorana neutrinos in the seesaw model can have sizable mixings through which they can be produced at the Large Hadron Collider (LHC) and show a remarkable Lepton Number Violating (LNV) signature. In this article we study the LNV decay of the W boson via two almost degenerate heavy on-shell Majorana neutrinos $N_j$, into three charged leptons and a light neutrino. We consider the scenario where the heavy neutrino masses are within $1$ GeV $\leq M_N \leq 10$ GeV. We evaluated the possibility to measure a LNV oscillation process in such a scenario, namely, the modulation of the quantity $d Γ/d L…
Lepton flavor violating Higgs boson decays are studied within the context of seesaw models with Majorana massive neutrinos. Two models are considered: The SM-seesaw, with the Standard Model Particle content plus three right handed neutrinos, and the MSSM-seesaw, with the Minimal Supersymmetric Standard Model particle content plus three right handed neutrinos and their supersymmetric partners. The widths for these decays are derived from a full one-loop diagrammatic computation in both models, and they are analyzed numerically in terms of the seesaw parameters, namely, the Dirac and Majorana ma…
We propose a new mechanism for generating small neutrino masses which predicts the relation m_ν~ v^4/M^3, where v is the electroweak scale, rather than the conventional seesaw formula m_ν~ v^2/M. Such a mass relation is obtained via effective dimension seven operators LLHH(H*H)/M^3, which arise when an isospin 3/2 Higgs multiplet Φis introduced along with iso-triplet leptons. The masses of these particles are naturally in the TeV scale. The neutral member of Φacquires an induced vacuum expectation value and generates neutrino masses, while its triply charged partner provides the smoking gun si…
We present the full tree-order calculation of the process $e^+e^-\to\ell\barν_\ell\; q \bqp$ including the width effects in a way which is consistent with gauge invariance and high energy unitarity and which has a natural interpretation within standard perturbation theory. We also include C- and P-preserving deviations from Standard Model trilinear vector boson couplings. An analysis of the sensitivity of these channels on the trilinear couplings, using well measured angular variables of the four fermion final state, is also presented.
If annihilating MeV-scale dark matter particles are responsible for the observed 511 keV emission from the Galactic bulge, then new light gauge bosons which mediate the dark matter annihilations may have other observable consequences. In particular, if such a gauge boson exists and has even very small couplings to Standard Model neutrinos, cosmic neutrinos with ~TeV energies will scatter with the cosmic neutrino background through resonant exchange, resulting in a distinctive spectral absorption line in the high-energy neutrino spectrum. Such a feature could potentially be detected by future h…
扫码添加微信好友，提出您的宝贵建议 👇
💡 备注请填写：网站反馈
发表机构由 AI 从论文文本抽取，如发现错误，欢迎反馈修正建议。