We study the neutralino radiative decay into the lightest supersymmetric particle (LSP) in the framework of a minimal anomalous U(1)' extension of the MSSM. It turns out that in a suitable decoupling limit the axino, which is present in the Stückelberg multiplet, is the LSP. We compute the branching ratio (BR) for the decay of a neutralino into an axino and a photon. We find that in a wide region of the parameter space, the BR is higher than 93% in contrast with the typical value (<=1%) in the CMSSM.
Starting from the previously constructed effective supergravity theory below the scale of U(1) breaking in orbifold compactifications of the weakly coupled heterotic string, we study the effective theory below the scale of supersymmetry breaking by gaugino and matter condensation in a hidden sector. Issues we address include vacuum stability, soft supersymmetry-breaking masses in the observable sector, and the masses of the various moduli fields, including those associated with flat directions at the U(1)-breaking scale, and of their fermionic superpartners. The consistent treatment of U(1) br…
The interplay between gaugino condensation and an anomalous Fayet-Iliopoulos term in string theories is not trivial and has important consequences concerning the size and type of the soft SUSY breaking terms. In this paper we examine this issue, generalizing previous work to the supergravity context. This allows, in particular, to properly implement the cancellation of the cosmological constant, which is crucial for a correct treatment of the soft breaking terms. We obtain that the D-term contribution to the soft masses is expected to be larger than the F-term one. Moreover gaugino masses must…
We determine the radiative corrections to the masses of the gauginos and Higgsinos in the MSSM, including all sectors of the theory in a one-loop calculation in the on-mass-shell renormalization scheme. We find that a gluino which is massless at tree level receives a mass of between 0 and 3 GeV, primarily due to the top/stop contribution. This radiatively generated mass depends directly on the off-diagonal element of the squark mass matrix. In the case of a massive gluino, its mass receives typically large corrections, as large as 40\% for a 125 GeV gluino. We find that the contributions to th…
We investigate the possibility that gauginos are massless at tree level and that the U(1) R-invariance is broken spontaneously by Higgs vevs, like the chiral symmetry of quarks in the standard model, or else explicitly by dimension 2 or 3 SUSY-breaking terms in the low energy effective Lagrangian. Gluino and lightest neutralino masses then depend on only a few parameters. For a SUSY-breaking scale <~ 400 GeV, the gluino and lightest neutralino have masses typically in the range 1/10 ~ 2 1/2 GeV. On the other hand, for a SUSY-breaking scale several TeV or larger, radiative contributions can yie…
In the MSSM, the assumptions of a common sfermion mass parameter m_0 and a common gaugino mass parameter m_1/2, along with the requirements from radiative electroweak symmetry breaking, lead to relatively large values of the Higgs mixing parameter mu, and consequently to a gaugino-like lightest neutralino. Lifting the requirement that the Higgs mass parameters unify with the sfermion masses is known to allow for smaller mu. We show that a mu parameter sufficiently small to yield a Higgsino-like neutralino requires a precise adjustment of the Higgs mass parameter m_Hu. Consequently a gaugino-ty…
Supersymmetric contribution to the muon anomalous magnetic moment a_μis discussed in the no-scale-type supersymmetry breaking scenarios. Taking the correlation between the supersymmetric contributions to a_μand Br(b\to sγ), it is shown that the precise measurements of these quantities serve an important constraint on the relative sign of the gaugino masses; combining the 2.6-σdeviation in a_μfrom the standard-model prediction measured by the E821 experiment and Br(b\to sγ) measured by CLEO, the sign of the product M_2M_3 is strongly preferred to be positive, where M_2 and M_3 are SU(2)_L and S…
We attempt to reconcile seemingly conflicting experimental results on the Higgs boson mass, the anomalous magnetic moment of the muon, null results in search for supersymmetry at the LHC within the 8\TeV data and results from $B$-physics, all within the context of supersymmetric grand unified theories. Specifically, we consider a supergravity grand unification model with non-universal gaugino masses where we take the $\mathrm{SU}(3)_C$ gaugino field to be much heavier than the other gaugino and sfermion fields at the unification scale. This construction naturally leads to a large mass splittin…
We show that the gaugino and higgsino sectors of supersymmetric theories can naturally acquire observable CP violation through radiative effects which originate from large CP-violating trilinear couplings of the Higgs bosons to the third-generation scalar quarks. These CP-violating loop effects are not attainable by evolving the supersymmetric renormalization-group equations from a higher unification scale down to the electroweak one. We briefly discuss the phenomenological consequences of such a scenario, and as an example, calculate the two-loop contribution to the neutron electric dipole mo…
Realizing that couplings related by supersymmetry (SUSY) can be disentangled when SUSY is broken, it is suggested that unwanted flavor and CP violating SUSY couplings may be suppressed via quenched gaugino-flavor interactions, which may be accomplished by power-law running of sfermion anomalous dimensions. A simple theoretical framework to accomplish this is exemplified and the defeated constraints are tallied. One key implication of the scenario is the expectation of enhanced top, bottom and tau production at the LHC, accompanied by large missing energy. Also, direct detection signals of dark…
We study the neutralino decay in the supersymmetric extra U(1) models which can solve the $μ$-problem. In these models the neutralino sector is extended at least into six components by an extra U(1) gaugino and a superpartner of a singlet Higgs. Focussing on its two lower mass eigenstates $\tildeχ_2^0$ and $\tildeχ_1^0$, decay processes such as a tree level three body decay $\tildeχ_2^0\to \tildeχ_1^0 f\bar f$ and a one-loop radiative decay $\tildeχ_2^0\to \tildeχ_1^0γ$ are estimated. We investigate the condition under which the radiative decay becomes the dominant mode and also numerically se…
The radiative decay Z2-> Z1 gamma proceeds at the one-loop level in the MSSM. It can be the dominant decay mode for the second lightest neutralino Z2 in certain regions of parameter space of supersymmetric models, where either a dynamical and/or kinematic enhancement of the branching fraction occurs. We perform an updated numerical study of this decay mode in both the minimal supergravity model (mSUGRA) and in the more general MSSM framework. In mSUGRA, the largest rates are found in the ``focus point'' region, where the mu parameter becomes small, and the lightest neutralinos become higgsino-…
We present the full $\mathcal{O}(α_s)$ supersymmetric QCD corrections for gaugino annihilation and co-annihilation into light and heavy quarks in the Minimal Supersymmetric Standard Model (MSSM). We demonstrate that these channels are phenomenologically relevant within the so-called phenomenological MSSM. We discuss selected technical details such as the dipole subtraction method in the case of light quarks and the treatment of the bottom quark mass and Yukawa coupling. Numerical results for the (co-)annihilation cross sections and the predicted neutralino relic density are presented. We show …
The recent measurement of a_μ=\frac{g_μ-2}{2} by the E821 Collaboration at Brookhaven deviates from the quoted Standard Model (SM) central value prediction by 2.6σ. The difference between SM theory and experiment may be easily accounted for in a variety of particle physics models employing weak scale supersymmetry (SUSY). Other supersymmetric models are distinctly disfavored. We evaluate a_μfor various supersymmetric models, including minimal supergravity (mSUGRA), Yukawa unified SO(10) SUSY GUTs, models with inverted mass hierarchies (IMH), models with non-universal gaugino masses, gauge medi…
We study a variation to the SUSY Left-Right symmetric model based on the gauge group $SU(3)_c\times SU(2)_L\times SU(2)_R\times U(1)_{BL}$. Beyond the quark and lepton superfields we only introduce a second Higgs bidoublet to produce realistic fermion mass matrices. This model does not include any $SU(2)_R$ triplets. We calculate renormalization group evolutions of soft SUSY parameters at the one-loop level down to low energy. We find that an $SU(2)_R$ slepton doublet acquires a negative mass squared at low energies, so that the breaking of $SU(2)_R\times U(1)_{BL}\rightarrow U(1)_Y$ is realiz…
We investigate the neutralino dark matter in the focus point gaugino mediation model with the O(100) GeV gravitino. The thermal relic abundance of the neutralino with a sizable Higgsino fraction can explain the dark matter density at the present universe. The spin-independent cross section is marginally consistent with the current upper limit from the XENON 100 experiment, and the whole parameter region can be covered at the XENON1T experiment. We also discuss the origin of the gluino mass to wino mass ratio at around 3/8, which is crucial for the mild fine-tuning in the electroweak symmetry b…
We investigate the muon anomalous magnetic moment in the context of the supersymmetric version of the economical 3-3-1 model. We compute the 1-loop contribution of super-partner particles. We show that contribution of superparticle loop becomes significant when \tan γis large. We investigate for both small and large values of $\tan γ$. We find the region of the parameter space where the slepton masses are of a few hundreds GeV is favour by the muon g-2 for small \tan γ(\tan γ\sim 5 ). Numerical estimation gives the mass of supersymmetric particle, the mass of gauginos m_G \sim 700 GeV and ligh…
The radiative decay width of a heavy Higgs boson $H \rightarrow W^+W^-γ$ for a {\it hard} photon is calculated in the Standard Model and its extension with anomalous $γWW$ couplings. Its dependence on the Higgs mass, the two unknown anomalous couplings, and the photon energy cutoff are studied in detail. We show that this radiative decay of a heavy Higgs is not very sensitive to a wide range of the anomalous couplings compared to the Standard Model result.
We analyze the LEP constraints from searches for charginos $χ^{\pm}$ and neutralinos $χ_i$, taking into account radiative corrections to the relations between their masses and the underlying Higgs-mixing and gaugino-mass parameters $μ, m_{1/2}$ and the trilinear mass parameter $A_t$. Whilst radiative corrections do not alter the excluded domain in $m_{χ^{\pm}}$ as a function of $m_{χ^{\pm}} - m_χ$, its mapping into the $μ, m_{1/2}$ plane is altered. We update our previous lower limits on the mass of gaugino dark matter and on tan$β$, the ratio of Higgs vacuum expectation values, in the light o…
The leptons are viewed as composite objects, exhibiting anomalous magnetic moments and anomalous flavor-changing transition moments. The decay $μ\to e γ$ is expected to occur with a branching ratio of the same order as the present experimental limit.
We investigate supersymmetric models in which an anomalous $U(1)_{X}$ symmetry explains the Yukawa hierarchy, and the related $D_{X}$-term plays a role in supersymmetry breaking. We use a bottom-up approach to model building. Phenomenological viability leads to a scenario with degenerate squark and slepton spectra and with heavy gauginos. Features of a Kähler potential that allows for such a scenario are described.
An extension of the Standard Model by at least one extra U(1) gauge symmetry has been investigated by many authors. In this paper we explore the possibility that this extra U(1) is anomalous. One of the possible signatures of this model could be given by the photons produced in the decays of the NLSP into the LSP.
We study how two moduli can be stabilized in a Minkowski/de Sitter vacuum for a wide class of string-inspired Supergravity models with an effective Fayet-like Supersymmetry breaking. It is shown under which conditions this mechanism can be made natural and how it can give rise to an interesting spectrum of soft masses, with a relatively small mass difference between scalar and gaugino masses. In absence of a constant superpotential term, the above mechanism becomes completely natural and gives rise to a dynamical supersymmetry breaking mechanism. Some specific type IIB and heterotic string ins…
Inspired by recent studies of high-scale decay constant or flavorful QCD axions, we review and clarify their existence in effective string models with anomalous $U(1)$ gauge groups. We find that such models, when coupled to charged scalars getting vacuum expectation values, always have one light axion, whose mass can only come from nonperturbative effects. If the main nonperturbative effect is from QCD, then it becomes a Peccei-Quinn axion candidate for solving the strong CP problem. We then study simple models with universal Green-Schwarz mechanism and only one charged scalar field: in the mi…
In many strongly-coupled systems, the infrared dynamics is described by different degrees of freedom from the ultraviolet. It is then natural to ask how operators written in terms of the microscopic variables are mapped to operators composed of the macroscopic ones. Certain types of operators, like conserved currents, are simple to map, and in supersymmetric theories one can also follow the chiral ring. In this note, we consider supersymmetric theories and extend the mapping to anomalous currents (and gaugino bilinears). Our technique is completely independent of subtleties associated with the…
In this work, we introduce the hadronic loop contribution to explain the anomalous radiative transitions between $h_b(nP)$ and $η_b(mS)$, which was recently observed by the Belle Collaboration. Our calculation shows that the hadronic loop mechanism associated with these known decay mechanisms can explain why there exist anomalous radiative transitions between $h_b(nP)$ and $η_b(mS)$. This study deepens our understanding of the decay mechanism of higher bottomonium radiative decays.
We evaluate the complete four-loop anomalous dimension matrix that is necessary for determining the effective flavour-changing neutral current couplings qbar-q'-gamma and qbar-q'-g at the next-to-next-to-leading order in QCD. The resulting O(alpha_s^2(mu_b)) correction to the B -> X_s gamma branching ratio amounts to around -2.9% for mu_b = 5 GeV, and -4.4% for mu_b = 2.5 GeV
In the context of a SUSY GUT inspired MSSM version, the low energy consequences of the asymptotic $b-τ$ Yukawa coupling Unification are examined, under the assumption of universal or non-universal boundary conditions for the gaugino and sfermion masses. Gaugino non-universality is applied, so that the SUSY corrections to $b$-quark mass can be reconciled with the present experimental data on muon anomalous magnetic moment. Restrictions on the parameter space, originating from the Cold Dark Matter abundance in the universe, the inclusive branching ratio of $b\to sγ$ and the accelerator data are,…
Using the Ritus eingenfunction method we compute corrections to the electron mass m_{0} in the presence of a moderate magnetic field eB ~ m_0^2. From this we obtain an expression for the anomalous magnetic moment near the critic field. For this we solved numerically the Schwinger-Dyson equations in the rainbow approximation including all Landau levels without make any assumption respect to the field strength.
The evidence for dark matter signals a new class of particles at the TeV scale, which may manifest themselves indirectly through loop effects. In a simple model we show that these loop effects may be responsible for the enhanced muon anomalous magnetic moment, for the neutrino mass, as well as for leptogenesis in a novel way. This scenario can be verified at LHC experiments.
Evaluation of anomalous couplings in the $γγ\to W^+W^-$ process needs to calculate the cross section $σ(W^+W^-)$ with a high precision. Therefore one has to consider the main contribution of high order effects. In this paper contributions of anomalous quartic boson interaction given by ${\cal L}_0$, ${\cal L}_c$, $\tilde{\cal L}_0$ are analyzed in high-energy region. Influence of high order effects is studed in dependences of $σ(W^+W^-)$ on anomalous constants and contour plots with statistical error $2δ$.
As one of the extensions of the Standard Model, we investigate the anomalous four-point $τ-W-ν_τ-γ$ scalar- and tensor-type interactions, which originate from the gauge invariant dimension-five operators. The coupling constants are constrained by the measured branching ratio of the $τ^- \rightarrow μ^- ν_τ \bar{ν_μ} γ$ decay: $-4.9<κ_τ^S<9.4$ and $-1.4<κ_τ^T<2.8$ at the 95% confidence level for the scalar and tensor interactions, respectively.
We calculate the squared matrix element for the process e+ e- --> tau+ tau- gamma allowing for anomalous magnetic and electric dipole moments at the tau tau gamma vertex. No interferences are neglected and no approximations of light fermion masses are made. We show that anomalous moments affect not only the cross section, but also the shape of the photon energy and angular distributions. We also demonstrate that in the case of the anomalous magnetic dipole moment, the contribution from interference involving Standard Model and anomalous amplitudes is significant compared to the contribution fr…
We compute the complete O(alphas^2) anomalous dimension matrix relevant for the b to s gamma, b to s gluon and b to s l+l- transitions in the standard model and some of its extensions. For radiative decays we confirm the results of Misiak and Munz, and of Chetyrkin, Misiak and Munz. The O(alphas^2) mixing of four-quark into semileptonic operators is instead a new result and represents one of the last missing ingredients of the next-to-next-to-leading-order analysis of rare semileptonic B meson decays.
The well-known leptonic U(1) symmetry of the standard model of quarks and leptons is extended to include a number of new fermions and scalars. The resulting theory has an invisible QCD axion (thereby solving the strong CP problem), a candidate for weak-scale dark matter, as well as radiative neutrino masses. A possible key connection is a color-triplet scalar, which may be produced and detected at the Large Hadron Collider.
We discuss the feasibility of spontaneous CP violation being induced by radiative corrections in 2HDM's, emphasizing on a consistent treatment at 1-loop level. Specifically, we analyze the cases of gaugino/higgsino effect on MSSM, and a new model proposed here with an extra, exotic, quark doublet. The latter model is phenomenologically interesting. One conclusion is that some fine tuning is in general needed for the scenario to work. The case for the new model requires a tree level mass mixing between the two Higgses, which fits in the standard SUSY picture. The fine tuning requires is then ve…
Recently it has been realized that the production and decay processes of charginos, neutralinos, and sleptons receive corrections which grow like log m_squark for large m_squark. In this paper we calculate the chargino pair production cross section at e+e- colliders with quark/squark loop corrections. We introduce a novel formulation, where the one-loop amplitude is reorganized into two parts. One part is expressed in terms of the ``effective'' chargino coupling gbar and mixing matrices U^P, V^P, and includes all O(log m_squark) corrections, while the other decouples for large m_squark. The fo…
We present a new contribution to the $K_L\rightarrow γγ$ amplitude, which is ${\cal{O}}(p^4)$ within the counting rules of chiral perturbation theory. This direct (non-pole) amplitude, obtained from short-distance $s \rightarrow d γ$ quark diagrams of order $e G_F α_s/π$, and similar $s \rightarrow d γγ$ diagrams, can account for about half of the experimental amplitude. Closely following the description of the $π^0\rightarrow γγ$ and $K_L\rightarrow γγ$ processes in the variants of the same low-energy QCD, we find that both of these processes are anomalous in the same sense. Then, by the anom…
We propose a leptoquark model simultaneously to explain anomalies of muon anomalous magnetic dipole moment and $b\to s μ\barμ$ in light of experimental reports very recently. Here, we satisfy several stringent constraints such as $μ\to eγ$ and meson mixings. In addition, we find these leptoquarks also play an role in generating tiny neutrino masses at one-loop level without introducing any additional symmetries. We have numerical analysis and show how degrees our parameter space is restricted.
We study the effect of anomalous Wtb couplings on the B -> Xs gamma branching ratio. The considered couplings are introduced as parts of gauge-invariant dimension-six operators that are built out of the Standard Model fields only. One-loop contributions from the charged-current vertices are assumed to be of the same order as the tree-level flavour-changing neutral current ones. Bounds on the corresponding Wilson coefficients are derived.
The coupling between the spin of a massive Dirac fermion and the angular momentum of the medium, i.e. the gravitomagnetic moment, is shown here to be renormalized by QED interactions at finite temperature. This means that the anomalous gravitomagnetic moment (AGM) does not vanish, and implies that thermal effects can break the Einstein equivalence principle in quantum field theory, as argued previously. We also show that the AGM causes radiative corrections to the axial current of massive fermions induced by vorticity in quantum relativistic fluids, similarly to the previous findings for massl…
We demonstrate that charged particles in a sufficiently intense standing wave are compressed toward, and oscillate synchronously at, the maxima of the electric field. This unusual trapping behaviour, which we call 'anomalous radiative trapping' (ART), opens up new possibilities for the generation of radiation and particle beams, both of which are high-energy, directed and collimated. ART also provides a mechanism for particle control in high-intensity QED experiments.
Analytic calculation are presented of the contribution to the anomalous magnetic moment of a muon from the channels of annihilation of an electron-positron pair to a pair of charged pi-mesons with radiative correction connected with the final state, as well as corrections to the lowest order kernel. The result with point-like pi-meson assumptions is $a_{point}=a_{point}^{(1)}+Δa_{point}$, $a_{point}^{(1)}=7.0866 \cdot 10^{-9}; Δa_{point}= -2.4 \cdot 10^{-10} .$ Taking into account the pion form factor in the frames of the Nambu-Jona-Lasinio (NJL) approach leads to $a_{NJL}=a_{NJL}^{(1)}+Δa_{NJ…
In the minimal supersymmetric extension of the Standard Model (MSSM), if the two Higgs doublets are lighter than some subset of the superpartners of the Standard Model particles, then it is possible to integrate out the heavy states to obtain an effective broken-supersymmetric low-energy Lagrangian. This Lagrangian can contain dimension-four gauge invariant Higgs interactions that violate supersymmetry (SUSY). The "wrong-Higgs" Yukawa couplings generated by one-loop radiative corrections are a well known example of this phenomenon. In this paper, we examine gauge invariant gaugino--higgsino--H…
We demonstrate that for a finite-size quark-gluon plasma the induced gluon radiation from heavy quarks is stronger than that for light quarks when the gluon formation length becomes comparable with (or exceeds) the size of the plasma. The effect is due to oscillations of the light-cone wave function for the in-medium $q\to gq$ transition. The dead cone model by Dokshitzer and Kharzeev neglecting quantum finite-size effects is not valid in this regime. The finite-size effects also enhance the photon emission from heavy quarks.
The leptons are viewed as composite objects, exhibiting anomalous magnetic moments and anomalous flavor-changing transition moments. The decay μ\to e γis expected to occur with a branching ratio of the same order as the present experimental limit. The first order QED radiative correction is considered.
The existence of an anomalous U(1) symmetry is shown to play a crucial role in the supersymmetric radiative seesaw model for neutrino masses. It explains the smallness of some couplings related to neutrino mass generation in a favorable way in addition to cause the hierarchical structure of Yukawa couplings of quarks and leptons. If it is spontaneously broken to a $Z_2$ subgroup, this $Z_2$ symmetry can make a lifetime of the lightest field with its odd parity extremely long. Thus, the model has an additional dark matter candidate other than the lightest neutralino, which appears in the $R$-pa…
In an R-parity violating supersymmetric scenario, the lightest neutralino $\tilde χ^0_1$ is no longer a stable particle. We calculate the branching ratio for the decay mode $\tilde χ^0_1 \longrightarrow νγ$ which occurs at the one-loop level. Taking into account bilinear as well as trilinear lepton number violating interactions as the sources of R-parity violation, we make a detailed scan of the parameter space, both with and without gaugino mass unification and including the constraints on the neutrino sector from the recent Superkamiokande results. This study enables one to suggest interesti…
The preliminary results of PIBETA experiment strongly suggest the presence of non V-A anomalous interactions in the radiative pion decay. Without a guiding idea about the nature of these new interactions it is very difficult to interpret and fit experimental data. We assume that they arise as a result of the exchange of new intermediate chiral bosons which interact anomalously with matter. Their mixing with W-bosons leads effectively to a small anomalous weak moment for W. Based on these assumptions, we show that the most general form of the radiative pion decay rate can be parametrized by thr…
Radiative charmonium decays in a contact-interaction model with dynamical quark anomalous magnetic moment
School of Physics, Nankai University（南开大学物理学院）；Department of Integrated Sciences and Center for Advanced Studies in Physics, Mathematics and Computation, University of Huelva（韦尔瓦大学综合科学与物理、数学和计算高级研究中心）
The rare radiative $B$-meson decay $B^-\toγ\ell^-\barν$ and the radiative Higgs-boson decay $h\toγγ$ mediated by light-quark loops both receive large logarithmic corrections in QCD, which can be resummed using factorization theorems derived in soft-collinear effective theory. In these factorization theorems the same radiative jet function appears, which is a central object in the study of factorization beyond the leading order in scale ratios. We calculate this function at two-loop order both in momentum space and in a dual space, where its renormalization-group evolution takes on a simpler fo…
While radiative corrections of infrared origin normally depress high energy amplitudes (Sudakov form factors), we find that in some cases resummation of leading effects produces exponentials with positive exponents, giving rise to amplitudes that grow indefinitely with energy. The effect happens in broken gauge theories like the electroweak sector of the Standard Model, and is related to the existence of amplitudes that do not respect the gauge symmetry, and that contrary to expectations do not vanish in the very high energy limit, but rather become dominant. As a working example we consider a…
To obtain natural inflation with large tensor-to-scalar ratio in string framework, we need a special moduli stabilization mechanism which can separate the masses of real and imaginary components of Kähler moduli at different scales, and achieve a trans-Planckian axion decay constant from sub-Planckian axion decay constants. In this work, we stabilize the matter fields by F-terms and the real components of Kähler moduli by D-terms of two anomalous $U(1)_X\times U(1)_A$ symmetries strongly at high scales, while the corresponding axions remain light due to their independence on the Fayet-Iliopoul…
We study the SUSY flavor problem in the MSSM, we are namely interested in estimating the size of the SUSY flavor problem and its dependence on the MSSM parameters. For that, we made a numerical analysis randomly generating the entries of the sfermion mass matrices and then determinated which percentage of the points are consistent with current bounds on the flavor violating transitions on lepton flavor violating (LFV) decays $l_i \to l_j γ$. We applied two methods, mass-insertion approximation method (MIAM) and full diagonalization method (FDM). Furthermore, we determined which fermion masses …
We perform a comprehensive analysis of the Minimal Supersymmetric Standard Model (MSSM) in the scenario where the scalar partners of the fermions and the Higgs particles (except for the Standard-Model-like one) are assumed to be very heavy and are removed from the low-energy spectrum. We first summarize our determination of the mass spectrum, in which we include the one-loop radiative corrections and resum to all orders the leading logarithms of the large scalar masses, and describe the implementation of these features in the FORTRAN code SuSpect which calculates the masses and couplings of th…
We establish a correspondence between those Feynman diagrams in the MSSM which give supersymmetric contributions to the muon anomalous magnetic moment and those which contribute to the flavor violating processes $μ--> eγ$ and $τ--> μγ$. Using current experimental limits on the branching ratios of these decay modes, combined with the assumption of a supersymmetric contribution to the muon anomalous magnetic moment, we establish bounds on the size of the lepton flavor violating soft masses in the MSSM largely independent of assumptions about other supersymmetric parameters. If the deviation meas…
Anomalous transitions involving photons derived by many-body interaction of the form, $\partial_μ G^μ$, in the standard model are studied. This does not affect the equation of motion in the bulk, but makes wave functions modified, and causes the unusual transition characterized by the time-independent probability. In the transition probability at a time-interval $T$ expressed generally in the form $P=T Γ_0 +P^{(d)}$, now with $ P^{(d)} \neq 0 $. The diffractive term $P^{(d)}$ has the origin in the overlap of waves of the initial and final states, and reveals the characteristics of waves. In pa…
We address the question of how light can be the lightest supersymmetric particle neutralino to be a reliable cold dark matter (CDM) particle candidate. To this end we have performed a combined analysis of the parameter space of the Minimal Supersymmetric Standard Model (MSSM) taking into account cosmological and accelerator constraints including those from the radiative $b\rightarrow sγ$ decay. Appropriate grand unification (GUT) scenarios were considered. We have found that the relaxation of gaugino mass unification is sufficient to obtain a phenomenologically and cosmologically viable soluti…
We study a possibility to measure the anomalous magnetic moment of vector leptoquarks in reactions with single leptoquark production associated with hard photon emission in ep collisions. For this purpose we propose to use the radiative amplitude zero effect. We find that an exact radiative zero in the angular distribution of the emitted photon is present only for pure Yang-Mills coupling of photons to leptoquarks. As a result the cross section is sensitive to the anomalous magnetic moment kappa of the leptoquark. This effect offers a possibility to measure kappa with rather high accuracy. For…
We demonstrate that electroweak baryogenesis can occur in a supersymmetric model with an exact R-symmetry. The minimal R-symmetric supersymmetric model contains chiral superfields in the adjoint representation, giving Dirac gaugino masses, and an additional set of "R-partner" Higgs superfields, giving R-symmetric μ-terms. New superpotential couplings between the adjoints and the Higgs fields can simultaneously increase the strength of the electroweak phase transition and provide additional tree-level contributions to the lightest Higgs mass. Notably, no light stop is present in this framework,…
