We investigate a model of dark sector based on non-Abelian $SU(2)_D$ gauge symmetry. This dark gauge symmetry is broken into discrete $Z_2$ via vacuum expectation values of two real triplet scalars, and an $SU(2)_D$ doublet Dirac fermion becomes $Z_2-$odd particles whose lighter component makes stable dark matter candidate. The standard model and dark sector can be connected via the scalar mixing and the gauge kinetic mixing generated by higher dimensional operators. We then discuss relic density of dark matter and implications to collider physics in the model. The most unique signatures of this model at the LHC would be the dark scalar ($Φ_1^{(')}$) productions where it subsequently decays into : (1) a fermionic dark matter ($χ_l$) and a heavy dark fermion ($χ_h$) pair, $Φ_1^{(')} \to \bar χ_l χ_h(\bar χ_h χ_l) $, followed by $χ_h$ decays into $χ_l$ and non-Abelian dark gauge bosons ($X_i$'s) which decays into SM fermion pair $\bar f_{SM} f_{SM}$ resulting in the reaction $p p \rightarrow Φ_1^{(')} \rightarrow \bar χ_h χ_l (\bar χ_l χ_h) \to f_{SM} \bar f_{SM} χ_l \bar χ_l $, (2) a pair of $X_i$'s followed by $X_i$ decays into a DM pair or the SM fermions resulting in the reaction, $p p \rightarrow Φ_1^{(')} \rightarrow X_i X_i \rightarrow \bar χ_l χ_l f_{SM} \bar f_{SM}$ or even number of $f_{SM} \bar{f}_{SM}$ pairs.
We present a SUSY breaking scenario based on Abelian gaugino kinetic term mixings between hidden and observable sectors. If an extra U(1) gaugino in the observable sector obtains a large mass through this mixing effect based on SUSY breaking in the hidden sector, soft SUSY breaking parameters in the MSSM may be affected by radiative effects due to this gaugino mass. New phenomenological aspects are discussed in such a SUSY breaking scenario.
The experimental data on atmospheric and solar neutrinos suggest that there is near-maximal mixing between ν_μand ν_τbut that their masses are hierarchically separated. In models of Abelian horizontal symmetries, mixing of O(1) generically implies that the corresponding masses are of the same order of magnitude. We describe two new mechanisms by which a large hierarchy between strongly mixed neutrinos can be achieved in this framework. First, a discrete Abelian symmetry can give the desired result in three ways: mass enhancement, mixing enhancement and mass suppression. Second, holomorphic zer…
The observed neutrino mixing, having a near maximal atmospheric neutrino mixing angle and a large solar mixing angle, is close to tri-bi-maximal. We argue that this structure suggests a family symmetric origin in which the magnitude of the mixing angles are related to the existence of a discrete non-Abelian family symmetry. We construct a model in which the family symmetry is the non-Abelian discrete group $Δ(27)$, a subgroup of SU(3) in which the tri-bi-maximal mixing directly follows from the vacuum structure enforced by the discrete symmetry. In addition to the lepton mixing angles, the mod…
We investigate what can be learnt about the $η$ -$η'$ mixing by means of dispersive representation of axial anomaly. We show that our method leads to the strong bounds for the $η-η'$ mixing angle: $θ= -15.3^o \pm 1^o$. Moreover, our result manifests also a dramatic dependence of the width $Γ_{η\to 2γ}$ on the mixing angle $θ$. This property explains how the relatively small mixing strongly effects the decay width.
We construct and present a model for leptonic mixing based on higher-dimensional operators, using the Froggatt-Nielsen mechanism, and Abelian horizontal symmetries (flavor symmetries) of continuous and discrete type. Our model naturally yields bilarge leptonic mixing, coming from both the charged leptons and the neutrinos, and an inverted neutrino mass hierarchy spectrum. The obtained values of the parameters, i.e., the leptonic mixing parameters and the neutrino mass squared differences, are all consistent with the atmospheric neutrino data and the Mikheyev-Smirnov-Wolfenstein large mixing an…
I construct predictive models of neutrino mass and mixing that have fewer parameters, both in the lepton sector and overall, than the default seesaw model. The predictions are theta13=0 and one massless neutrino, with the models having a Z4 or Z2 symmetry and just one extra degree of freedom: one real singlet Higgs field. It has been shown that models with an unbroken family symmetry, and with no Higgs fields other than the Standard Model Higgs doublet produce masses and mixing matrices that have been ruled out by experiment. Therefore, this article investigates the predictions of models with …
Kinetic mixing is a fundamental property of models with a gauge symmetry involving several $\mathrm{U}(1)$ group factors. In this paper, we perform a numerical study of the impact of kinetic mixing on beta functions at two-loop. To do so, we use the recently published PyR@TE 2 software to derive the complete set of RGEs of the SM B-L model at two-loop including kinetic mixing. We show that it is important to properly account for kinetic mixing as the evolution of the parameters with the energy scale can change drastically. In some cases, these modifications can even lead to a different conclus…
We present the possible mixing effects associated with the low-energy limit of a Standard-Model extension by two abelian gauge groups U(1)_1 x U(1)_2. We derive general formulae and approximate expressions that connect the gauge eigenstates to the mass eigenstates. Applications using the well-studied groups U(1)_B, U(1)_(B-L), U(1)_(L_alpha - L_beta) (L_alpha being lepton flavor numbers), and U(1)_DM (a symmetry acting only on the dark matter sector) are discussed briefly.
We consider non-abelian kinetic mixing between the Standard Model SU(2$)_L$ and a dark sector U(1$)^\prime$ gauge group associated with the presence of a scalar SU(2$)_L$ triplet. The magnitude of the resulting dark photon coupling $ε$ is determined by the ratio of the triplet vacuum expectation value, constrained to by $\lsim 4$ GeV by electroweak precision tests, to the scale $Λ$ of the effective theory. The corresponding effective operator Wilson coefficient can be $\mathcal{O}(1)$ while accommodating null results for dark photon searches, allowing for a distinctive LHC dark photon phenomen…
We suggest a rigorous generalization of the pseudoscalar mesons mixing description in SU(3) basis. It is shown that the appearance of extra massive state nicknamed in the paper as glueball is unavoidable in any scheme with more than one angle. In this framework we develop the dispersive approach to Abelian axial anomaly of isoscalar non-singlet current. Combining it with the analysis of experimental data of charmonium radiative decays ratio we get the number of quite strict constraints for mixing parameters. Our analysis favors the equal values of axial currents coupling constants which may be…
We propose that the radiative generation of the neutrino mass can be achieved by incorporating the kinetic mixing of fermion fields which arises radiatively at one-loop level. As a demonstrative example of the application of the mechanism, we present the particular case of the Standard Model extension by $U(1)_D$ symmetry. As a result, we show how neutrino masses can be generated via a kinetic mixing portal instead of a mass matrix with residual symmetries responsible for the stability of multicomponent dark matter.
Atmospheric neutrino data strongly suggests a near-maximal ν_μ-ν_τ mixing and also solar neutrino data can be nicely explained by another near-maximal ν_e-ν_μ or ν_e-ν_τ mixing. We examine the possibility that this bi-maximal mixing of atmospheric and solar neutrinos arises naturally, while keeping U_{e3} and Δm^2_{sol}/Δm^2_{atm} small enough, as a consequence of Abelian flavor symmetry. Two simple scenarios of Abelian flavor symmetry within supersymmetric framework are considered to obtain the desired form of the neutrino mass matrix and the charged lepton mass matrix parameterized by the Ca…
We consider both "bottom-up" and "top-down" approaches to the origin of gauge kinetic mixing. We focus on the possibilities for obtaining kinetic mixings $ε$ which are consistent with experimental constraints and are much smaller than the naive estimates ($ε\sim 10^{-2} - 10^{-1}$) at the one-loop level. In the bottom-up approach, we consider the possible suppression from multi-loop processes. Indeed we argue that kinetic mixing through gravity alone, requires at least six loops and could be as large as $\sim 10^{-13}$. In the top-down approach we consider embedding the Standard Model and a $U…
We have studied the large mixing angle MSW solution for the solar neutrinos in the non-abelian flavor symmetry. We predict the MNS mixing matrix taking account of the symmetry breakings.
Quantum field theories containing scalar fields with equal quantum numbers allow for a mixed kinetic term in the Lagrangian. It has been argued that this mixing must be taken into consideration when performing renormalization group (RG) analyses of such a theory. However, from the fact that scalar kinetic mixing does not correspond to a physical observable, we show that no extra parameters need to be introduced. Using a toy model, we explicitly derive the 1-loop RG equations (RGEs) in three different renormalization schemes to demonstrate how this issue can be dealt with. In schemes without ki…
The hypothetical dark photon portal connecting the visible and dark sectors of the Universe has received considerable attention in recent years, with a focus on CP-conserving kinetic mixing between the Standard Model (SM) hypercharge gauge boson and a new U(1)$_X$ gauge boson. In the effective field theory context, one may write down non-renormalizable CP-violating kinetic mixing interactions involving the $X$ and SU(2)$_L$ gauge bosons. We construct for the first time a renormalizable model for CP-violating kinetic mixing that induces CP-violating non-Abelian kinetic mixing at mass dimension …
A lepton flavor violating process $μ\to eγ$ is investigated in the supersymmetric extra U(1) models, which often appear as the low energy effective models of superstring and can potentially solve the $μ$-problem. The branching ratio of this process is calculated. It is numerically estimated and compared with that of the MSSM. In this study we take account of an abelian gaugino kinetic term mixing and discuss its influence on this process. The possibility to find the extra gauge structure through this process is discussed.
We examine spontaneous symmetry breaking of a renormalisable U(1) x U(1) gauge theory coupled to fermions when kinetic mixing is present. We do not assume that the kinetic mixing parameter is small. A rotation plus scaling is used to remove the mixing and put the gauge kinetic terms in the canonical form. Fermion currents are also rotated in a non-orthogonal way by this basis transformation. Through suitable redefinitions the interaction is cast into a diagonal form. This framework, where mixing is absent, is used for subsequent analysis. The symmetry breaking determines the fermionic current …
A new $U(1)_X$ gauge boson $X$ primarily interacting with a dark sector can have renormalizable kinetic mixing with the standard model (SM) $U(1)_Y$ gauge boson $Y$. This mixing besides introduces interactions of dark photon and dark sector with SM particles, it also modifies interactions among SM particles. The modified interactions can be casted into the oblique $S$, $T$ and $U$ parameters. We find that with the dark photon mass larger than the $Z$ boson mass, the kinetic mixing effects can reduce the tension of the W mass excess problem reported recently by CDF from $7σ$ deviation to within…
We analyze a minimal flavored gauge mediation model in which the electroweak Higgs and messenger doublets are embedded in multiplets of a discrete non-Abelian symmetry. In this scenario, the minimal Higgs-messenger sector that is consistent with the 125 GeV Higgs mass has two vectorlike pairs of messenger fields. This scenario is obtained in a specific limit of the superpotential interactions of the Higgs-messenger fields and the matter fields. Due to the structure of the messenger-matter Yukawa couplings in this limit, sizable stop mixing and flavor-diagonal soft supersymmetry breaking parame…
We show that the mixing effect of the neutral gauge bosons in the 3-3-1-1 model comes from two sources. The first one is due to the 3-3-1-1 gauge symmetry breaking as usual, whereas the second one results from the kinetic mixing between the gauge bosons of U(1)_X and U(1)_N groups, which are used to determine the electric charge and baryon minus lepton numbers, respectively. Such mixings modify the ρ-parameter and the known couplings of Z with fermions. The constraints that arise from flavor-changing neutral currents due to the gauge boson mixings and non-universal fermion generations are also…
The Abelian decomposition of QCD which decomposes the gluons to the color neutral binding gluons (the neurons) and the colored valence gluons (the chromons) gauge independently naturally generalizes the quark model to the quark and chromon model which could play the central role in hadron spectroscopy. We discuss the color reflection symmetry, the fundamental symmetry of the quark and chromon model, and explain how it describes the glueballs and the glueball-quarkonium mixing in QCD. We present the numerical analysis of glueball-quarkonium mixing in $0^{++}$, $2^{++}$, and $0^{-+}$ sectors bel…
The addition of an Abelian family symmetry to the Minimal Supersymmetric Standard Model reproduces the observed hierarchies of quark and lepton masses and quark mixing angles, only if it is anomalous. Green-Schwarz compensation of its anomalies requires the electroweak mixing angle to be $\sin^2θ_w=3/8$ at the string scale, without any assumed GUT structure, suggesting a superstring origin for the standard model. The analysis is extended to neutrino masses and the lepton mixing matrix.
We discuss the existence of a non-abelian gauge structure associated with flavor mixing. In the specific case of two flavor mixing of Dirac neutrino fields, we show that this reformulation allows to define flavor neutrino states which preserve the Poincaré structure. Phenomenological consequences of our analysis are explored.
Extra dimensions provide a unique tool for building new physics models. Here we extend the kinetic mixing/dark photon mediator scenario for the case of complex scalar dark matter interacting with the Standard Model to 5-D. We assume that the inverse size of the new, flat extra dimension is $\sim 10 - 1000$ MeV, the mass range of interest in numerous current experiments, and discuss the resulting phenomenology. Here we see that 5-D constructions can be used to soften some of the possible tuning issues which are sometimes encountered in the corresponding 4-D models.
We propose a model for the mass matrices of quarks and leptons based on two Abelian flavor symmetries. One is assumed to be broken at a high energy region near the Planck scale. It is used for the Froggatt-Nielsen mechanism in both quark and charged lepton sectors. Another one remains unbroken to a multi-TeV region. The mixings among neutrinos and gauginos including the one of the new Abelian symmetry generate non-zero masses and mixings among neutrinos. A bi-maximal scheme for the neutrino oscillation can be realized together with suitable masses and CKM-mixings in the quark sector. FCNC cons…
We explore two bilarge neutrino mixing anz$\ddot{a}$tze within the context of Abelian flavor symmetry theories: ($\mathrm{\tt BL_1}$) $\sinθ_{12}\simλ$, $\sinθ_{13}\simλ$, $\sinθ_{23}\simλ$, and ($\mathrm{\tt BL_2}$) $\sinθ_{12}\simλ$, $\sinθ_{13}\simλ$, $\sinθ_{23}\sim 1-λ$. The first pattern is proposed by two of us and is favored if the atmospheric mixing angle $θ_{23}$ lies in the first octant, while the second one is preferred for the second octant of $θ_{23}$. In order to reproduce the second texture, we find that the flavor symmetry should be $U(1)\times Z_m$, while for the first patter…
The experimental data on atmospheric and solar neutrinos are used to test the framework of non-anomalous Abelian horizontal gauge symmetries with only three light active neutrinos. We assume that the hierarchy in mass-squared splittings is not accidental and that the small breaking parameters are not considerably larger than 0.2. We find that the small angle MSW solution of the solar neutrino problem can only be accommodated if the $ν_μ-ν_τ$ mass hierarchy depends on the charges of at least three sterile neutrinos. The large angle MSW solution can be accommodated in simpler models if $ν_e$ and…
We explore the Dirac fermionic and complex scalar dark matter in the framework of a hidden $\mathrm{U}(1)_\mathrm{X}$ gauge theory with kinetic mixing between the $\mathrm{U}(1)_\mathrm{X}$ and $\mathrm{U}(1)_\mathrm{Y}$ gauge fields. The $\mathrm{U}(1)_\mathrm{X}$ gauge symmetry is spontaneously broken due to a hidden Higgs field. The kinetic mixing provides a portal between dark matter and standard model particles. Besides, an additional Higgs portal can be realized in the complex scalar case. Dark matter interactions with nucleons are typically isospin violating, and direct detection constr…
We investigate the dark matter phenomenology of a Dirac fermion together with kinetic mixing in the context of an $L_μ- L_τ$ model. We analyze which part of the parameter space can provide a viable dark matter candidate and explain the B-decay anomaly, while obeying current data. Although the allowed region of parameter space, satisfying these requirements, is still large at the moment, future direct detection experiments like XENONnT and DARWIN will, in case of null results, significantly strengthen the limits and push the model to a corner of the parameter space.
We consider the cosmology and phenomenology of a dark photon portal to a simple dark sector consisting of a single, light, fermionic dark matter particle species with mass in the MeV range. We entertain three possible kinetic mixing structures of a new Abelian gauge group U(1)$_{\text{dark}}$ with the visible sector through U(1)$_{\text{e.m.}}$, U(1)$_{\text{Y}}$ and T[SU(2)$_{\text{L}}$]. We assume the dark photon to be massive and around the MeV scale, thus close to the mass scale of the dark matter candidate. We compute the dark matter relic density via freeze-out and freeze-in, entertainin…
A popular class of extensions of the Standard Model (SM) are models of a new Abelian gauge boson $X$, called $dark$ or $hidden\ photon$, that kinetically mixes with the SM photon. We revisit the matching procedure of kinetic mixing terms in the electroweak symmetric phase to the ones in the broken phase. Our central finding is that in order to obtain the correct matching prescription one has to take into account mixing of the hidden photon with the neutral component of the weak $SU(2)_L$ bosons. This mixing is generated by a dimension-six operator and, in theories where $SU(2)_L$ multiplets ar…
In the superstring models we have not only the complete {\bf 27} multiplets of $E_6$ but also extra incomplete $({\bf 27}+{\overline {\bf 27}})$ chiral supermultiplets being alive at low energies. Associated with these additional multiplets, when the gauge symmetry contains more than one $U(1)$ gauge group, there may exist gauge kinetic mixings among these $U(1)$ gauge groups. In such cases the effect of gauge kinetic mixings should be incorporated into the study of unification of gauge couplings. We study these interesting effects systematically in these models. The string threshold effect is…
An extension to the original dark photon model is proposed, by a generalization of matrix transformation with any angle θ of orthogonal rotation. Not only all the results presented by the dark photon model have been accurately reproduced, but new horizons have been opened by exploring new fields induced by this generalization, with new possibilities in the investigation and research of dark photon in particular and dark matter in general.
We revisit the $L_μ- L_τ$ extension of the Standard Model that can simultaneously address anomalies in semileptonic $B$ meson decays and the nature of dark matter (DM). In the region favored by the $B$ anomalies, this scenario is excluded by a combination of low-energy flavor constraints and stringent DM direct detection constraints if the kinetic mixing between $Z^\prime$ gauge boson and the photon vanishes at high energy scales, since this leads to a sizable coupling between DM and the SM in low-momentum scattering processes. However, this is no longer the case if the kinetic mixing vanishes…
The observed hierarchy of quark and lepton masses and mixings may be obtained by adding an abelian family symmetry to the Minimal Supersymmetric Model and coupling quarks and leptons to an electroweak singlet scalar field. In a large class of such models, this symmetry suffers from anomalies which must be compensated by the Green-Schwarz mechanism; this in turn fixes the electroweak mixing angle to be $\sin^2 θ_W = 3/8$ at the string scale, without any assumed GUT structure. The analysis is extended to two distinct generalisations of the Standard Model: neutrino masses and mixings and R-parity…
The structure of the neutrino mixing matrix is indicative of an underlying family symmetry that interrelates the three generations of fermions in the Standard Model. We systematically scan the parameter space of 76 discrete non-Abelian family symmetries and construct all models with the Standard Model particle content and up to three flavon fields where we include non-renormalizable interactions of mass dimension five and six. We find that of the 76 groups that we considered, 44 groups can accommodate models that are consistent with experiment at 3sigma, and 38 groups can have models that are …
We re-analyse the effect of corrections from canonical normalisation of kinetic terms on the quark and lepton mixing angles. This type of corrections emerges, for example, from effective higher-dimensional Kahler potential operators in the context of locally supersymmetric models of flavour. In contrast to previous studies we find that the necessary procedure of redefining the fields in order to restore canonically normalised kinetic terms, i.e. canonical normalisation, can lead to significant corrections to the fermion mixing angles (as determined from the superpotential). Such potentially la…
If dark matter is composed of new fundamental particles, Earth's orbital motion around the Sun may induce an annual modulation in the rate at which these particles interact in a terrestrial detector. The DAMA collaboration has identified at a 12$σ$ confidence level such an annual modulation in their event rate. One previously proposed explanation is `plasma dark matter' (e.g. mirror dark matter) which would have electron recoils in the detector from interactions via kinetic mixing. We perform a chi-squared goodness of fit test of this plasma dark matter model to DAMA/LIBRA modulation amplitude…
Based on the kinetic theory, the non-Abelian medium property of hot Quark-Gluon Plasma is investigated. The nonlinearity of the plasma comes from two aspects: The nonlinear wave-wave interaction and self-interaction of color field. The non-Abelian color permittivity is obtained by expanding the kinetic equations to third order. As an application, the nonlinear Landau damping rate and the nonlinear eigenfrequency shift are calculated in the longwave length limit.
We show that for any effective field theory of colorless meson fields, the mixing schemes of particle states and decay constants are not only related but also determined exclusively by the kinetic and mass Lagrangian densities. In the general case, these are bilinear in terms of the intrinsic fields and involve non-diagonal kinetic and mass matrices. By applying three consecutive steps this Lagrangian can be reduced into the standard quadratic form in terms of the physical fields. These steps are : (i) the diagonalization of the kinetic matrix, (ii) rescaling of the fields, and (iii) the diago…
We show that models with an abelian family symmetry which accounts for the observed hierarchies of masses and mixings in the quark sector may also accomodate quasi-degeneracies in the neutrino mass spectrum. Such approximate degeneracies are, in this context, associated with large mixing angles. The parameters of this class of models are constrained. We discuss their phenomenological implications for present and foreseen neutrino experiments.
We consider particle oscillations and their damping in second-quantized form. We find that the damping or "decoherence" may be described by a Boltzmann-like collision integral with "non-abelian blocking factors" (fermions). Earlier results are generalized in that the momentum degrees of freedom are included and that the mixing equations become intrinsically non-linear at high densities.
Extensions of the standard model with a $U(1)$ gauge symmetry contain gauge invariant kinetic mixing, $\sinχ$, and gauge non-invariant mass mixing, $δM^2$, between the hypercharge and the new gauge boson $Z'$. These represent a priori incalculable but phenomenologically important parameters of the theory. They become calculable if there exist spontaneously or softly broken symmetries which forbid them at tree level but allow their generation at the loop level. We discuss various symmetries falling in this category in the context of the gauged $L_μ-L_τ$ models and their interplay with lepton mi…
Extensions beyond the Standard Model allow for a gauge singlet scalar to be kinetically coupled with the Higgs. We consider kinetic mixing between a Dark scalar gauge singlet \emph{nearly degenerate} with the Higgs, focusing on the \emph{dynamical} aspects of the mixing phenomena. The renormalization program is carried out by obtaining the one-loop effective action which yields an effective non-hermitian Hamiltonian to study the dynamics of mixing. The scalar Higgs becomes a coherent superposition of the mass eigenstates, thus kinetic mixing leads to oscillations and common decay channels in s…
An analysis is given of the Stueckelberg extension of the Standard Model with a hidden sector gauge group $U(1)_X$ where the mass growth for the extra gauge boson occurs via the Stueckelberg mechanism, and where the kinetic mixing in the $U(1)_X\times U(1)_Y$ sector is included. Such a kinetic mixing is generic in a broad class of supergravity and string models. We carry out a detailed global fit of the model with the precision LEP data on and off the $Z$ pole, with $χ^2$ within 1% of the $χ^2$ of the Standard Model fit. Further, it is shown that in the absence of matter in the hidden sector, …
A double perturbation idea is presented in framework of the quark-gluon plasma kinetic theory. A solvable set of equations from the 'double perturbation' is derived and the equations are showed to be gauge-independent. The formalism of Landau damping rate for the plasmon at zero momentum is given and discussed.
We derive transport equations for fermionic systems with a space-time dependent mass matrix in flavor space allowing for complex elements leading to CP violation required for electroweak baryogenesis. By constructing appropriate projectors in flavor space of the relevant tree level Kadanoff-Baym equations, we split the constraint equations into "diagonal" and "transversal" parts in flavor space, and show that they decouple. While the diagonal densities exhibit standard dispersion relations at leading order in gradients, the transverse densities exhibit a novel on-shell structure. Next, the kin…
Extensions of the Standard Model of particle physics with new Abelian gauge groups allow for kinetic mixing between the new gauge bosons and the hypercharge gauge boson, resulting in mixing with the photon. In many models the mixing with the hypercharge gauge boson captures only part of the kinetic mixing term with the photon, since the new gauge bosons can also mix with the neutral component of the $SU(2)_L$ gauge bosons. We take these contributions into account and present a consistent description of kinetic mixing for general Abelian gauge groups both in the electroweak symmetric and the br…
Mirror dark matter is a dissipative and self-interacting multiparticle dark matter candidate which can explain the DAMA, CoGeNT and CRESST-II direct detection experiments. This explanation requires photon-mirror photon kinetic mixing of strength $ε\sim 10^{-9}$. Mirror dark matter with such kinetic mixing can potentially leave distinctive signatures on the CMB anisotropy spectrum. We show that the most important effect of kinetic mixing on the CMB anisotropies is the suppression of the height of the third and higher odd peaks. If $ε\stackrel{>}{\sim} 10^{-9}$ then this feature can be observed …
We propose a model in which supersymmetric weak scale dark matter is charged under a U(1)_d dark gauge symmetry. Kinetic mixing between U(1)_d and hypercharge generates the appropriate hierarchy of scales needed to explain PAMELA and ATIC with a GeV scale force carrier and DAMA (or INTEGRAL) using the proposals of inelastic (or, respectively, exciting) dark matter. Because of the extreme simplicity of this setup, observational constraints lead to unambiguous determination of the model parameters. In particular, the DAMA scattering cross section is directly related to the size of the hypercharg…
We derive the chiral kinetic equation in 8 dimensional phase space in non-Abelian $SU(N)$ gauge field within the Wigner function formalism. By using the "covariant gradient expansion", we disentangle the Wigner equations in four-vector space up to the first order and find that only the time-like component of the chiral Wigner function is independent while other components can be explicit derivative. After further decomposing the Wigner function or equations in color space, we present the non-Abelian covariant chiral kinetic equation for the color singlet and multiplet phase-space distribution …
The observed neutrino mixing, having a near maximal atmospheric neutrino mixing angle and a large solar mixing angle, is close to tri-bi-maximal. This structure may be related to the existence of a discrete non-Abelian family symmetry. In this paper the family symmetry is the non-Abelian discrete group $Δ(27)$, a subgroup of $SU(3)$ with triplet and anti-triplet representations. Different frameworks are constructed in which the mixing follows from combining fermion mass terms with the vacuum structure enforced by the discrete symmetry. Mass terms for the fermions originate from familon triplet…
It is known that non-Abelian classical kinetic theory reproduces the Hard Thermal/Dense Loop (HTL/HDL) effective action of QCD, obtained after integrating out the hardest momentum scales from the system, as well as the first higher dimensional operator beyond the HTL/HDL level. We discuss here its applicability at still higher orders, by comparing the exact classical effective action obtained in the static limit, with the 1-loop quantum effective potential. We remark that while correct types of operators arise, the classical colour algebra reproduces correctly the prefactor of the 4-point func…
We study an anisotropic inflation model with a gauge kinetic function for a non-abelian gauge field. We find that, in contrast to abelian models, the anisotropy can be either a prolate or an oblate type, which could lead to a different prediction from abelian models for the statistical anisotropy in the power spectrum of cosmological fluctuations. During a reheating phase, we find chaotic behaviour of the non-abelian gauge field which is caused by the nonlinear self-coupling of the gauge field. We compute a Lyapunov exponent of the chaos which turns out to be uncorrelated with the anisotropy.
