The leading-log QCD corrections to K-Kbar mixing in R-symmetric supersymmetric models are computed using effective field theory techniques. The spectrum topology where the gluino is significantly heavier than the squarks is motivated and focused on. It is found that, like in the MSSM, QCD corrections can tighten the kaon mass difference bound by roughly a factor of three. CP violation is also briefly considered, where QCD corrections can constrain phases to be as much as a factor of ten smaller than the uncorrected value.
We have recently shown that the large direct CP violation observed in the decay B^0 -> pi^+ pi^-, and the enhanced branching ratio for B^0 -> pi^0 pi^0, can be understood by invoking a small mixing of the pi pi system with the dominant D Dbar channel. We examine here the analogous effect of D Dbar <-> K Kbar mixing on the rare decays B^0 -> K^0 K^0bar, B^- -> K^- K^0 and B^0 -> K^+ K^-. We find (a) significant values for the asymmetry parameters C and S in B^0 / B^0bar -> K^0 K^0bar, (b) a possible enhancement of the suppressed mode B^0 -> K^+ K^-, (c) a correlation between the three decay cha…
We compute the 1-loop chiral corrections to the bag parameters which are needed for the discussion of the SUSY K-Kbar mixing problem in both finite and infinite volume. We then show how the bag parameters can be combined among themselves and with some auxiliary quantities and thus sensibly reduce the systematic errors due to chiral extrapolations as well as those due to finite volume artefacts present in the results obtained from lattice QCD. We also show that in some cases these advantages remain as such even after including the 2-loop chiral corrections. Similar discussion is also made for t…
We compute the leading QCD corrections to K-Kbar mixing in the supersymmetric standard model with general soft supersymmetry-breaking parameters. We construct the ΔS=2 effective Lagrangian for three hierarchies of supersymmetric particle masses, namely, when the gluino mass is comparable to, much greater than, or much less than the masses of the first two generation squarks. We find that the QCD corrections tighten the limits on squark mass splittings by more than a factor of two.
Structure of the $a_{0}(980)$ and $f_{0}(980)$ resonances is investigated with the $a_{0}(980)$-$f_{0}(980)$ mixing intensity from the viewpoint of compositeness, which corresponds to the amount of two-body states composing resonances as well as bound states. For this purpose we first formulate the $a_{0}(980)$-$f_{0}(980)$ mixing intensity as the ratio of two partial decay widths of a parent particle, in the same manner as the recent analysis in BES experiments. Calculating the $a_{0}(980)$-$f_{0}(980)$ mixing intensity with the existing Flatte parameters from experiments, we find that many c…
Starting from the Chiral Perturbation Theory Lagrangian, but keeping different masses for the charged and neutral mesons, and using a previously developed non-perturbative unitary scheme that generates the lightest meson-meson resonances, we construct K Kbar to K Kbar and K Kbar to pi+ pi- in the vector channel. This allows us to obtain the kaon-loop contribution to the phi-rho mixing and study the phi to pi+pi- decay. The dominant contribution to this decay comes from the phi to gamma to pi+pi- process. However, there can be large interferences with the subdominant contributions coming from p…
We present the most general supersymmetric amplitude for \kkb\/ and \bbb\/ mixing resulting from gluino box diagrams. We use this amplitude to place general constraints on the magnitude of flavor-changing squark mass mixings, and compare these constraints to theoretical predictions both in and beyond the Minimal Supersymmetric Standard Model.
This dissertation investigates the flavor mixing effects in supersymmetric models on electroweak precision observables, Higgs boson mass predictions, B-physics observables, quark flavor violating Higgs decays, lepton flavor violating charged lepton decays and lepton flavor violating Higgs decays. The flavor mixing effects are studied in model independent way i.e. by putting off-diagonal entries in the sfermion mass matrix by hand as well as in the minimal flavor violating constrained MSSM, where mixing can originate from CKM matrix in the case of squarks and from PMNS matrix in the case of sle…
We discuss potential to measure squark flavor mixings based on future data at super B factory and LHC. In particular we focus on the imaginary part of the mixings by investigating the CP violating observables. As a result, we find they are determined with the uncertainty about 10 % at best.
Taking into account the mixing effects between left- and right-handed top-squarks, we calculate the genuine supersymmetric eletroweak correction to top quark production at the Tevatron in the minimal supersymmetric model. The analytic expressions of the corrections to both the parton level cross section and the total hadronic cross section are presented. Some numerical examples are also given to show the size of the corrections.
For large masses, the two heavy neutral Higgs bosons are nearly degenerate in many 2--Higgs doublet models, and particularly in supersymmetric models. In such a scenario the mixing between the states can be very large if the theory is CP-noninvariant. We analyze the formalism describing this configuration, and we point to some interesting experimental consequences.
In the supersymmetric seesaw model of neutrino masses, augmented by the non-Abelian discrete tetrahedral symmetry A_4, a specific pattern of neutrino mixing is automatically generated if one of the three heavy singlet neutrino superfields acquires a nonzero vacuum expectation value. This pattern turns out to be exactly that of tribimaximal mixing, i.e. sin^2 theta_23 = 1/2, sin^2 theta_12 = 1/3, and sin^2 theta_13 = 0, in good agreement with data.
Using renormalization group techniques, we examine several interesting relations among masses and mixing angles of quarks and leptons in the Standard Model. We extend the analysis to the minimal supersymmetric extension to determine its effect on these mass relations. Remarkably Supersymmetry allows for these relations to be satisfied at a single grand unified scale.
We present a predictive scheme for fermion masses and mixings based on supersymmetric SO(10) which provides an understanding of the observed hierarchies in the charged fermion sector including CKM mixings. In the neutrino sector bi-large mixing can be realized, while the third leptonic mixing angle $θ_{13}\simeq 0.01 - 0.2$.
A simple extension of the minimal renormalizable supersymmetric SO(10) grand unified theory by adding a 120-dimensional Higgs representation is examined. This brings new antisymmetric contributions to the relevant quark and lepton mass sum rules and leads to a better fit of the measured values of lepton masses and mixings together with a natural completion of the renormalizable Higgs sector within the SUSY SO(10) framework.
Supersymmetric contribution to the CP asymmetry of B_d \to ϕK_S is re-examined. It is emphasized that our analysis takes into account the recently found constraint from the mercury electric dipole moment, in addition to the well-known constraint from the branching ratio of b \to s γ. We show that, despite these constraints, the CP asymmetry can considerably deviate from the Standard Model prediction, if the CP-odd flavor mixing comes from left-handed squarks. Alignment mechanism of sfermion masses and mixing may imprint the required flavor mixing at high energy scale.
We analyze the chargino contributions to B_d - B-bar_d mixing and CP asymmetry of the B_d --> J/psi K_S decay, in the framework of the mass insertion approximation. We derive model independent bounds on the relevant mass insertions. Moreover, we study these contributions in supersymmetric models with minimal flavor violation, Hermitian flavor structure, and small CP violating phases and universal strength Yukawa couplings. We show that in supersymmetric models with large flavor mixing, the observed values of sin(2 beta) may be entirely due to the chargino-up-squark loops.
We analyze in detail the constraints on SUSY-model parameters obtained from K-Kbar mixing in the hypothesis of a splitted SUSY spectrum. FCNC contributions from gluino-squark-quark interactions are studied in the so-called mass insertion approximation. We present boundaries on mass insertions and on SUSY mass scales. We improve previous results by including the NLO-QCD corrections to Delta S=2 effective Hamiltonian and the complete set of B-parameters for the evaluation of hadronic matrix elements. A full set of magic-numbers, that can be used for further analyses of these models, is also give…
We discuss how θ_{13} \neq 0 is accommodated in a recently proposed renormalizable model of neutrino mixing using the non-Abelian discrete symmetry T_7 in the context of a supersymmetric extension of the Standard Model with gauged U(1)_{B-L}. We predict a correlation between θ_{13} and θ_{23}, as well as the effective neutrino mass m_{ee} in neutrinoless double beta decay.
We study the constraint arising from the recently observed D - anti-D mixing in the context of supersymmetric models with left-right symmetry. In these models, the supersymmetric contributions in the mixing amplitudes of D - anti-D, K - anti-K and B - anti-B are all correlated. We compare the constraint from the D - anti-D mixing with the K - anti-K mixing and find that the D - anti-D mixing constrains the maximal supersymmetric contribution to the B_s - anti-B_s mixing amplitude. The maximal supersymmetric contribution can allow a large CP phase of B_s - anti-B_s mixing which agrees with the …
In the minimal supersymmetric standard model, we have studied the evolution of the neutrino flavor mixing by using the renormalization group equation(RGE) with the Georgi-Jarlskog texture for the Yukawa coupling matrices.For the large Yukawa coupling of the charged lepton, i.e.,$\tan\b \gg 1$, the neutrino flavor mixing increases significantly with running down to the electroweak scale by the RGE. If one wishes to get the large neutrino flavor mixing $\sin þ_{23}$ at the electroweak scale, which is suggested by the muon neutrino deficit in the atomospheric neutrino flux, the initial condition …
A supersymmetric model based on a left-right symmetric gauge group is proposed where hybrid inflation, baryogenesis and neutrino oscillations are linked.This scheme, supplemented by a familiar ansatz for the neutrino Dirac masses and mixing of the two heaviest families and with the MSW resolution of the solar neutrino puzzle, implies that $m_{ν_τ}$ lies between 1 and 9 eV. The mixing angle $θ_{μτ}$ is predicted to lie in a narrow range which will be partially tested by the Chorus/Nomad experiment.
A supersymmetric extension of the Standard Model, with maximal s_R-b_R mixing and a new source of CP violation, contains all the necessary ingredients to account for a possible anomaly in the measured CP asymmetry in B->phi K_s decay. In the same framework we study the decay B->J/psi K*, paying particular attention to observables that can be extracted by performing a time dependent angular analysis, and become nonzero because of new physics effects.
We consider neutrino mixings in supersymmetric SU(5) supplemented by a U(1) flavor symmetry. In particular, we show how bi-maximal neutrino mixings can be realized. Two scenarios for implementing the small mixing angle MSW solution, with one involving a sterile state $ν_s$ and maximal $ν_μ-ν_s$ mixing to resolve the atmospheric anomaly, are also discussed. Finally, a new mechanism for eliminating the asymptotic relations $m^{(0)}_μ =m^{(0)}_s$ and $m^{(0)}_e=m^{(0)}_d$, while retaining $m^{(0)}_τ=m^{(0)}_b$, is presented. It employs `matter' multiplets in the $15+\bar{15}$ of SU(5), and is con…
We provide, in the R-parity violating supersymmetric standard model, a comprehensive analysis for sneutrino minimization from the one-loop effective scalar potential, and also for one-loop renormalized neutrino masses and mixing by calculating the effective neutrino mass matrix in the weak basis. Applying our results to theories with gauge mediated supersymmetry breaking, we show how atmospheric and solar neutrino oscillations can be accommodated simultaneously in this framework. It is observed that the one-loop correction to sneutrino vacuum expectation values leads to a significant effect on…
In the context of the minimal supersymmetric standard model, nonzero neutrino masses and mixing can be generated through renormalizable lepton number (and thus R-parity) violating operators. It is examined whether neutrino mass matrices from tree and one-loop contributions can account for two mass-squared differences and mixing angles that explain current experimental data. By accommodating, in particular, the solar and atmospheric neutrino data, we find interesting restrictions not only on the free parameters of the theory, such as lepton number violating couplings and soft-parameters, but al…
Recent results from Belle and BaBar Collaborations hint at a small $\sin2ϕ_1$, while the measured $B\toππ$ rate also seems to be on the low side. Supersymmetric (SUSY) models with down squark mixings can account for the deficits in both cases. By studying the origin of SUSY contributions that could impact on $B^0_d$--$\bar B^0_d$ mixing and $B\toππ$ decay, we find that the former would most likely arise from left-left or right-right squark mixings, while the latter would come from left-right squark mixings. These two processes in general are not much correlated in the Minimum Supersymmetric St…
We inspect consequences of the latest B_s mixing phase measurements on lepton flavor violation in a supersymmetric SU(5) theory. The O(1) phase, preferring a non-vanishing squark mixing, generically implies tau -> (e + mu) gamma and mu -> e gamma. Depending on the gaugino and the scalar mass parameters as well as tan beta, the rates turn out to be detectable or even already excessive, if the RR mass insertion of down-type squarks is nonzero. We find that it becomes easy to reconcile B_s mixing phase with lepton flavor violation given: gaugino to scalar squared mass ratio around 1/12, both LL a…
Following the anomalous like-sign dimuon charge asymmetry measured by the D0 collaboration at the Tevatron collider we discuss the implications of large CP violation in $B_{d,s}$ mixing for Supersymmetric (SUSY) Standard Models, focussing on those models which allow a family symmetry and unification. For the Minimal Supersymmetric Standard Model (MSSM) we show that it is only possible to account for $B_{s}$ mixing and CP violation at the expense of large squark mixing which would require a new approach to family symmetry models. In order to describe both $B_{s}$ and $B_{d}$ mixing and CP viola…
The connection between B_s mixing phase and lepton flavor violation is studied in SU(5) GUT. The O(1) phase, preferring a non-vanishing squark mixing, generically implies tau -> (e + mu) gamma and mu -> e gamma. In addition to the facts already well-known, stresses are put on the role of gaugino to scalar mass ratio at the GUT scale and the possible modifications due to Planck-suppressed non-renormalizable operators.
We argue that given the experimental constraints on the Higgs mass the least fine tuned parameter space of minimal supersymmetric standard model is with negative stop masses squared at the grand unification scale. While stop mass squared is typically driven to positive values at the weak scale, the contribution to the Higgs mass squared parameter from the running can be arbitrarily small, which reduces fine tuning of electroweak symmetry breaking. At the same time the stop mixing is necessarily enhanced and the maximal mixing scenario for the Higgs mass can be generated radiatively even when s…
We study flavor violation in a supersymmetric SU(5) grand unification scenario in a model-independent way employing mass insertions. We examine how the quark and the lepton sector observables restrict sfermion mixings. In many cases, a lepton flavor violating process provides a stringent constraint on the flavor structure of right-handed down-type squarks. In particular, mu -> e gamma turns out to be highly susceptible to the 1-3 and 2-3 mixings thereof, due to the radiative correction from the top Yukawa coupling to the scalar mass terms of 10. We also discuss projected sensitivity of forthco…
The most general QCD-NLO Anomalous-Dimension Matrix of all four-fermion dimension six Delta F=2 operators is presented. Two applications of this Anomalous-Dimension Matrix to the study of SUSY contribution to K- Kbar mixing are also discussed.
We discussed neutrino masses and mixings in SUSY SO(10) model where quarks and leptons have Yukawa couplings to at least two 10 and one $\bar{126}$ Higgs scalars. In this model, the Dirac and the right-handed Majorana mass terms are expressed by linear combinations of quark and charged lepton mass matrices, which then determine the neutrino mass matrix by the see-saw mechanism. We show that there are various solutions to reproduce a large mixing angle for $ν_μ-ν_τ$ and a small mixing angle for $ν_e-ν_μ$, as well as the hierarchical mass spectrum of neutrinos.
We consider corrections to the unification of down-quark and charged-lepton Yukawa couplings in supersymmetric GUTs, which links the large nu_tau-nu_mu mixing angle to b -> s transitions. These corrections generically occur in simple grand-unified models with small Higgs representations and affect s -> d and b -> d transitions via the mixing of the corresponding right-handed superpartners. On the basis of a specific SUSY-SO(10) model, we analyze the constraints from K-Kbar and B-Bbar mixing on the additional \tilde{d}_R-\tilde{s}_R rotation angle theta. We find that epsilon_K already sets a st…
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 present the results of our analysis on $b \to s γ$ in the minimal supersymmetric standard model with a general flavor mixing in the squark sector. We identify the next--to--leading order focusing effect, which considerably reduces the gluino contribution to $b \to s γ$ relative to the leading order calculation. We illustrate that $BR(B \to X_s γ)$ is still very sensitive to the flavor mixing parameters, $δ^d_{ll}$ and $δ^d_{lr}$ so that the lower bound for $m_{1/2}$ obtained in the minimal flavor violation can be easily removed even at $μ<0$, while it is rather stable against $δ^d_{rr}$ and…
We study B_s-\bar{B}_s mixing in grand unified SO(10), SU(5) models where the mixings among the second and third generation squarks arise due to the existence of flavor violating sources in the Dirac and Majorana couplings which are responsible for neutrino mixings. We find that when the branching ratio of tau->mu gamma decay is enhanced to be around the current experimental bound, B_s-\bar{B}_s mixing may also contain large contribution from supersymmetry in the SO(10) boundary condition. Consequently, the phase of B_s-\bar{B}_s mixing is large (especially for small tan beta and large scalar …
We study flavor violation in a supersymmetric SU(5) grand unification scenario in a model-independent way employing mass insertions. We examine how the quark and the lepton sector observables restrict sfermion mixings. With a low soft scalar mass, a lepton flavor violating process provides a stringent constraint on the flavor structure of right-handed down-type squarks. In particular, mu -> e gamma turns out to be highly susceptible to the 1-3 and 2-3 mixings thereof, due to the radiative correction from the top Yukawa coupling to the scalar mass terms of 10. With a higher scalar mass around t…
In a large class of supersymmetric SO(10) and left-right models, requiring that the effective theory below the scale of $SU(2)_R$ breaking be the MSSM implies partial Yukawa unification with $Y_u=Y_d$ and $Y_e=Y_{ν^D}$. The same result also emerges in models with a horizontal $SU(3)_H$ symmetry. As a result, at the tree level, these models lead to vanishing quark mixing angles. We show that the correct mixing pattern can be generated in these models at the loop level from the flavor structure associated with the supersymmetry breaking terms. We generalize the constraints on supersymmetric para…
We discuss how the experimental neutrino oscillation data can be realized in the framework of the baryon triality ($B_3$) constrained supersymmetric Standard Model (cSSM). We show how to obtain phenomenologically viable solutions, which are compatible with the recent WMAP observations. We present results for the hierarchical, inverted and degenerate cases which illustrate the possible size and structure of the lepton number violating couplings. We work with a new, as yet unpublished version of SOFTSUSY, where we implemented full one--loop neutrino masses. Finally, we shortly discuss some pheno…
The baryon asymmetry of the universe can be explained by the out-of-equilibrium decays of heavy right-handed neutrinos. We analyse this mechanism in the framework of a supersymmetric extension of the Standard Model and show that lepton number violating scatterings are indispensable for baryogenesis, even though they may wash-out a generated asymmetry. By assuming a similar pattern of mixings and masses for neutrinos and up-type quarks, as suggested by SO(10) unification, we can generate the observed baryon asymmetry without any fine tuning, if (B-L) is broken at the unification scale Λ_{GUT}\s…
we study fermion masses and flavor mixing in a supersymmetric SO(10) model, where $\mathbf{10}$, $\mathbf{120}$ and $\mathbf{\bar{126}}$ Higgs multiplets have Yukawa couplings with matter multiplets and give masses to quarks and leptons through the breaking chain of a Pati-Salam group. This brings about that, at the GUT energy scale, the lepton mass matrices are related to the quark ones via several breaking parameters, and the small neutrino masses arise from a Type II see-saw mechanism. When evolving renormalization group equations for the fermion mass matrices from the GUT scale to the elec…
We present a complete next-to-leading-order calculation of the QCD corrections to $B^0-\bar{B}^0$ ($K^0-\bar{K}^0$) mixing in the framework of the minimal flavor violating (MFV) supersymmetry. We take into account the contributions from the gluino and find that the gluino-mediated corrections modify the LO result obviously even when the mass of gluino $m_{\tilde{g}} \gg m_{\rm w}$. In general, one cannot neglect gluino contributions.
We analyze all possible extensions of the recently proposed minimal renormalizable SUSY SU(5) grand unified model with the inclusion of an additional A4 flavor symmetry. We find that there are five possible cases but only one of them is phenomenologically interesting. We develop in detail such case and we show how the fermion masses and mixing angles come out. As a prediction we obtain the neutrino masses of order of 0.1 eV with an inverted hierarchy.
We analyze $B^0_d-{\bar B}^0_d$ mixing in a fully left-right supersymmetric model. We give explicit expressions for all the chargino, gluino, gluino-neutralino and neutralino amplitudes involved in the process. We calculate the mass difference $Δm_d$ and CP asymmetry $a_{J/ψK_s}$ in both the constrained case (where the only flavor violation comes from the Cabibbo-Kobayashi-Maskawa matrix) and the unconstrained case (including soft supersymmetry breaking terms). The constrained case does not contain any new information beyond the supergravity-inspired MSSM. In the unconstrained case, the main c…
We consider the possibility of a large phase of B_s-\bar B_s mixing in supersymmetric SU(5) and SO(10) models. We find that in the SU(5) model, the magnitude of this phase is correlated with the branching ratio of τ-> μγand the phase can be within 2σof the recent UTfit analysis. In the case of SO(10) models, this correlation can be relaxed and a large phase can be obtained. In this scenario, a non-zero value of CP asymmetry for B -> X_sγwill be predicted. We predict the sparticle mass ranges for the LHC for these models once the UTfit result is accommodated and discuss the dark matter and the …
We consider the problem of neutrino masses and mixing angles in a supersymmetric model based on the gauge group SU(4)$\otimes$SU(2)$_L\otimes$SU(2)$_R$ broken at the scale $M_X\approx 10^{16}$ GeV. We extend a previous operator analysis of the charged lepton and quark masses and mixing angles in this model to include the neutrino sector, assuming a universal Majorana mass $M$ for the right-handed neutrinos. The Dirac part of the neutrino matrix is then fixed and the physical neutrino masses and magnitudes of all of the elements of the leptonic mixing matrix are then predicted in terms of the s…
The gauge interactions of any supersymmetric extension of the standard model involve new flavor mixing matrices. The assumptions involved in the construction of minimal supersymmetric models, both $SU(3) \times SU(2) \times U(1)$ and grand unified theories, force a large degree of triviality on these matrices. However, the requirement of realistic quark and lepton masses in supersymmetric grand unified theories forces these matrices to be non-trivial. This leads to important new dominant contributions to the neutron electric dipole moment and to the decay mode $p \to K^oμ^+$, and suggests that…
We show that in the supersymmetric standard model (SSM) box diagrams mediated by charginos and up-type squarks may give large contributions to $\BB$ and $\KK$ mixings. This is due to the fact that a heavy top quark mass allows large mass differences among the up-type squarks, which leads to a less efficient cancellation among the different squark diagrams. If the ratio of the vacuum expectation values of the Higgs bosons is of order of unity, box diagrams mediated by charged Higgs bosons also contribute appreciably. For sizable regions of the SSM parameter space, the SSM contributions could be…
In an improved application of the tetrahedral symmetry A_4 first introduced by Ma and Rajasekaran, supplemented by the discrete symmetry Z_3 as well as supersymmetry, a two-parameter form of the neutrino mass matrix is derived which exhibits the tribimaximal mixing of Harrison, Perkins, and Scott. This form is the same one obtained previously by Altarelli and Feruglio, and the inverse of that obtained by Babu and He. If only A_4 is used, then corrections appear, making tan^2(theta_{12}) differenet from 0.5, without changing significantly sin^2(2 theta_{23}) from one or theta_{13} from zero.
The baryon asymmetry of the universe can be explained by the out-of-equilibrium decays of heavy right-handed neutrinos. We analyse this mechanism in the framework of a supersymmetric extension of the Standard Model and show that lepton number violating scatterings are indispensable for baryogenesis, even though they may wash-out a generated asymmetry. By assuming a similar pattern of mixings and masses for neutrinos and up-type quarks, as suggested by SO(10) unification, we can generate the observed baryon asymmetry without any fine tuning, if $(B-L)$ is broken at the unification scale $Λ_{GUT…
Supersymmetric (SUSY) Grand Unified theories (GUTs) generally predict FCNC and CP violating processes to occur both in the leptonic and hadronic sectors. Assuming an underlying SU(5) group plus right-handed neutrinos (RN), we perform an extensive study of FCNC and CP violation, analyzing the correlations between leptonic and hadronic processes like mu-> e gamma and K-Kbar mixing, tau->mu gamma and b -> s transitions such as B_d -> phi K_s and Bs-Bsbar mixing. Moreover, we examine the impact of the considered scenario on the UT analyses, monitoring the low energy consequences implied by possibl…
We study neutrino masses and mixing in Supersymmetric Models without $R$ parity and with generic soft Supersymmetry breaking terms. Neutrinos acquire mass from various sources: tree level neutrino--neutralino mixing, loop effects and non--renormalizable operators. Abelian horizontal symmetries (invoked to explain the smallness and hierarchy in quark parameters) replace $R$ parity in suppressing neutrino masses. We find lower bounds on the mixing angles: $\sinθ_{ij} \gsim m(\ell_i^-)/m(\ell_j^-)$ ($i<j$) and unusual order of magnitude predictions for neutrino mass ratios: $m(ν_e)/m(ν_μ)\sim\sin…
We analyse the CP asymmetry of the B -> phi K_S process in general supersymmetric models. In the framework of the mass insertion approximation, we derive model independent limits for the mixing CP asymmetry. We show that chromomagnetic type of operator may play an important role in accounting for the deviation of the mixing CP asymmetry between B -> phi K_S and B -> J/psi K_S processes observed by Belle and BaBar experiments. A possible correlation between the direct and mixing CP asymmetry is also discussed. Finally, we apply our result in minimal supergravity model and supersymmetric models …
We study the contribution to flavor changing neutral current processes from box diagrams with light higgsinos and squarks. Starting with just the Cabbibo Kobayashi Maskawa (CKM) phase, we find contributions to the $K^0$ and $B^0$ meson mass matrices that are out of phase with the Standard Model contributions in the case of substantial mixing between the up-type squarks. This difference in phase could be large enough to be detected at the proposed $B$ factories, with interesting implications for the unitarity triangle of CKM matrix elements.
We analyze the possibility of probing the supersymmetric flavor structure through the constraints of the K and B meson systems and those of the electric dipole moments. We show that combining these constraints would favor SUSY models with large flavor mixing either in LR(RL) or LL but with a very small RR and intermediate/large tan beta. Large LR mixing requires specific patterns for trilinear A-terms, while LL mixing seems quite natural and easier to obtain. We present an example for this class of models and show how it can accommodate the current CP asymmetries experimental results.
Motivated by the possibility of ${\cal S}_{ϕK_S}<0$, we study the implications for $B_s$ meson system. In a specific model that realizes ${\cal S}_{ϕK_S}<0$ with large $s$-$b$ mixing, right-handed dynamics and a new CP phase, we present predictions for CP asymmetries in $B_s\to J/ψϕ$, $K^+K^-$ and $ϕγ$ decays. Even if the measurement of time-dependent CP asymmetry becomes hampered by very fast $B_s$ oscillation, a finite difference between the decay rates of $B_s$ mass eigenstates may enable the studies of CP violations with untagged data samples. Thus, studies of CP violation in the $B_s$ sys…
We analyse supersymmetric contributions to B_s mixing and their impact on mixing-induced CP asymmetries, using the mass insertion approximation. We discuss in particular the correlation of SUSY effects in the CP asymmetries of B_s -> J/psi phi and B_d -> phi K_S and find that the mass insertions dominant in B_s mixing and B_d -> phi K_S are (delta_{23}^d)_{LL, RR} and (delta_{23}^d)_{LR, RL}, respectively. We show that models with dominant (delta_{23}^d)_{LR, RL} can accomodate a negative value of S_{phi K_S}, in agreement with the BELLE measurement of that observable, but yield a B_s mixing p…
We introduce a momentum dependent mixing angle $α(p^2)$ which allow us to diagonalize at any external momentum $p$ the one-loop corrected inverse propagator matrix of two coupled scalar fields while keeping the full momentum dependence in the self energies. We compare this method with more traditional techniques applied to the diagonalization of coupled scalars at the one-loop level. This method is applied to the CP-even Higgs sector of the Minimal Supersymmetric Model, defining the momentum dependent mixing angle $α(p^2)$, and calculating the two CP-even Higgs masses and the mixing angle at t…
A mechanism to have the quark mass hierarchy in the supersymmetric composite model is proposed. The source of the hierarchy is the kinetic-term mixing between composite quarks. Such mixing can be expected, if quarks are composite particles. A model in which the mechanism works is constructed, although it is not perfectly realistic because of some assumptions and unnaturalness.
