In this article, we study the two body gluino decays $\tilde{g} \rightarrow \tilde{u}_i \bar{u}_g$, $\tilde{g} \rightarrow \tilde{d}_i \bar{d}_g$ with $i=1,2,...6$ and $g=1,2,3$ in the Minimal Supersymmetric Standard Model (MSSM) with quark flavour violation (QFV). At the outset, constraints on QFV parameters $δ_{ij}^{U/D(LR)}$ and $δ_{ij}^{U/D(RL)}$ with $i,j=1,2,3$ and $(i\neq j) $ are calculated for a specific set of MSSM parameters using charge and color breaking minima (CCB) and unbounded from below minima (UFB) conditions. These constraints are more stringent compared to the constraints coming from B-physics observables (BPO), that are already available in literature. In the second step, we re-calculate the partial decay widths of $\tilde{g} \rightarrow \tilde{u}_i \bar{u}_g$, $\tilde{g} \rightarrow \tilde{d}_i \bar{d}_g$ for the allowed range of QFV parameters. The partial decay widths can reach upto 120 GeV in the RR sector of the squarks mass matrices while in the LL sector it can be $\approx 90$ GeV. The QFV in the LR/RL sector is usually ignored due to stringent CCB andd UFB constraints, however, our analysis reveals that this mixing can contribute upto $\approx 12 $ GeV for some parameter points and should not be ignored. We hope that these results will prove helpful for the experimental searches of gluinos at the current and future colliders.
Flavor mixing in the quark-squark-gluino coupling is studied for the minimal SU(5) SUGRA-GUT model and applied to evaluation of the nucleon lifetime. All off-diagonal (generation mixing) elements of Yukawa coupling matrices and of squark/slepton mass matrices are included in solving numerically one-loop renormalization group equations for MSSM parameters, and the parameter region consistent with the radiative electroweak symmetry breaking condition is searched. It is shown that the flavor mixing in the gluino coupling for a large $\tanβ$ is of the same order of magnitude as the corresponding K…
Implications of a 2 - 5.5 GeV sbottom and 12 - 16 GeV gluino masses for rare B decay phenomenology are discussed. An effective Hamiltonian is constructed in which the gluinos are integrated out and a \tilde{b} squark remains among the light flavor degrees of freedom. Restrictive constraints come from $b \to s γand b \to sg, but they allow a substantially enhanced inclusive b decay rate into charmless hadronic final states, and {\cal O}(10%) direct CP asymmetries in $B \to X_s γand B^\pm \to K^0 π^\pm decays, which are an order of magnitude larger than in the Standard Model. New contributions t…
The discovery of the Higgs boson with a mass of about 125 GeV intimates us a possibility of a high-scale supersymmetry (SUSY) breaking model, where a sfermion mass scale is much higher than the electroweak scale. Although a general SUSY standard model can contribute to the low-energy flavor and/or CP-violating processes, the high-scale SUSY breaking model provides smaller signatures and therefore are less constrained, even in the presence of large flavor/CP violations of sfermions. However, a manner of gluino decay directly reflects the squark flavor structure and provides us a clue for the sf…
We study constraints from LHC run I on squark and gluino masses in the presence of squark flavor violation. Inspired by the concept of `flavored naturalness', we focus on the impact of a non-zero stop-scharm mixing and mass splitting in the right-handed sector. To this end, we recast four searches of the ATLAS and CMS collaborations, dedicated either to third generation squarks, to gluino and squarks of the first two generations, or to charm-squarks. In the absence of extra structure, the mass of the gluino provides an additional source of fine tuning and is therefore important to consider wit…
Flavor changing interactions of the gluino allow the $b$ quark to decay into the strange quark plus a gluino pair if the gluino is in the ultra low mass window below 1 GeV. In this case the enhancement of the nonleptonic $b$ decay could explain the anomalous semileptonic branching ratio.
We present a MSSM study of the b -> s gamma decay in a Minimal Flavor Violating (MFV) framework, where the form of the soft SUSY breaking terms is determined by the Standard Model Yukawa couplings. In particular, we address the role of gluino contributions, which are set to zero in most studies of the MFV MSSM. Gluino contributions can play an important role in the MFV MSSM whenever mu * tan(beta) is large. In fact, similarly to chargino contributions, gluino contributions are tan(beta) enhanced and can easily dominate charged Higgs contributions for large values of tan(beta). Even though each…
In light of a discrepancy of the direct $CP$ violation in $K\toππ$ decays, $\varepsilon'/\varepsilon_K$, we investigate gluino contributions to the electroweak penguin, where flavor violations are induced by squark trilinear couplings. Top-Yukawa contributions to $ΔS = 2$ observables are taken into account, and vacuum stability conditions are evaluated in detail. It is found that this scenario can explain the discrepancy of $\varepsilon'/\varepsilon_K$ for the squark mass smaller than 5.6 TeV. We also show that the gluino contributions can amplify $\mathcal{B}(K \to πν\overlineν)$, $\mathcal{B…
We examine the process $B \to X_s γ$ in minimal supersymmetry (SUSY) with general squark flavor mixings. We include all relevant next--to--leading order (NLO) QCD corrections and dominant NLO SUSY effects from the gluino. We find that gluino--squark corrections to down--type quark masses induce large NLO corrections to the dominant Wilson coefficients whose size is often similar to those at LO, especially at large $\tanβ$. For $μ>0$, destructive interference, and suppression by the renormalization group running lead to a ``focusing effect'' of reducing the size of gluino corrections to the bra…
Metastable charged particles produced at the LHC can decay in the quiescent period between beam crossing in the detector leading to spectacular signals. In this paper we consider augmenting the Standard Model with gluino, Higgsino and wino-like particles without invoking supersymmetry. Proton stability is ensured by imposing a discrete $Z_6$ parity that fixes their possible interaction and makes them metastable in a large portion of the parameter space. We investigate the possibility of employing these fields to improve gauge coupling unification, explain dark matter, generate neutrino mass an…
A variety of experimental searches and theoretical efforts have constrained gluinos that undergo an all-hadronic decay with no missing energy, as can arise in R-parity violating or stealth supersymmetry. Although the gluino->jj decay is robustly excluded, there is gap in current experimental coverage for gluinos with masses between 51-76 GeV that decay into three light-flavor quarks. In this work, we probe this gap with published multi-jet data from the UA2 experiment. Despite setting the strongest current limit on this region, we find that UA2 data is unable to close this gap for gluino->jjj …
We compute gluino decay widths in supersymmetric theories with arbitrary flavor and CP violation angles. Our emphasis is on theories with scalar superpartner masses heavier than the gluino such that tree-level two-body decays are not allowed, which is relevant, for example, in split supersymmetry. We compute gluino decay branching fractions in several specific examples and show that it is plausible that the only accessible signal of supersymmetry at the LHC could be four top quarks plus missing energy. We show another example where the only accessible signal for supersymmetry is two gluon jets…
We investigate two-loop gluino corrections to the effective Lagrangian for $b\to s+γ(g)$ in the minimal supersymmetric extension of the standard model (MSSM) at large $\tanβ$, including the contributions in which quark flavor change is mediated by charginos. Using the translation invariant of loop momenta and the Ward-Takahashi identities (WTIs) that are required by the $SU(3)_c\times U(1)_{_{em}}$ gauge invariance, we simplify our expressions to concise forms. As an example, we discuss two-loop gluino corrections to the CP asymmetry of inclusive $B\to X_{_s}γ$ decay in CP violating MSSM.
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 study a scenario in which light bottom squarks and light gluinos with masses in the range $2-5.5$ GeV and 12-16 GeV, respectively, can coexist in the MSSM, without being in conflict with flavor-conserving low-energy observables. We find that in such a scenario, the anomalous magnetic moment of a muon could be as large as $10^{-9}$, if the theory conserves CP. However, if the theory violates CP, we conclude that not both, the gluino and bottom squark, can be light at the same time, after the neutron electric dipole moment constraint on Weinberg's 3-gluon operator has been taken into account.
We present a detailed and complete calculation of the gluino and scalar quarks contribution to the flavour-changing top quark decay into a charm quark and a photon, gluon, or a Z boson within the minimal supersymmetric standard model including flavour changing gluino-quarks-scalar quarks couplings in the right-handed sector. We compare the results with the ones presented in an earlier paper where we considered flavour changing couplings only in the left-handed sector. We show that these new couplings have important consequences leading to a large enhancement when the mixing of the scalar partn…
We examine squark--gluino loop effects on the process $b \to s γ$ in minimal supersymmetry with general flavor mixing in the squark sector. In the regime of heavy squarks and gluino, we derive analytic expressions for the beyond--LO corrections to the Wilson coefficients and find them to be often large, especially at large $\tanβ$ and $μ>0$. The ensuing ranges of values of the Wilson coefficients are typically smaller than in the LO approximation, and sometimes even change sign. This has the effect of often reducing, relative to the LO, the magnitude of supersymmetric contributions to $BR(B \t…
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 show that in supersymmetric extensions of the Standard Model gluino box diagrams can yield a large CP-violating Delta(I)=3/2 contribution to s->d+q(bar)+q flavor-changing neutral current processes, which feeds into the I=2 isospin amplitude in K->pi+pi decays. This contribution only requires moderate mass splitting between the right-handed squarks u(tilde)_R and d(tilde)_R, and persists for squark masses of order 1 TeV. Taking into account current bounds on Im(delta_{sd}^{LL}) from K-K(bar) mixing, the resulting contribution to epsilon'/epsilon could naturally be an order of magnitude large…
The presence of a light b-squark (with mass about 4 GeV) and gluino (with mass about 15 GeV) might explain the observed excess in b-quark production at the Tevatron. Though provocative, this model is not excluded by present data. The light supersymmetric particles can induce large flavor-changing effects in radiative decays of B mesons. We analyse the decays B->X_s gamma and B->X_{sg} in this scenario and derive restrictive bounds on the flavor-changing quark-squark-gluino couplings.
We study the effect of squark-generation mixing on gluino decays in the Minimal Supersymmetric Standard Model (MSSM). We show that due to the effect the quark-flavor violating (QFV) gluino decay branching ratio B(gluino -> c bar{t} (t bar{c}) + neutralino_1) can be very large (up to ~50%) in a significant part of the MSSM parameter space despite the very strong experimental constraints on QFV from B meson observables. This could have an important impact on the search for gluinos and the determination of the MSSM parameters at LHC.
The current measurement of the Higgs mass, the ubiquitous nature of loop-suppressed gaugino masses in gravity-mediated supersymmetry breaking, relic dark matter density from $\sim$ TeV mass gauginos, together with the success of supersymmetric gauge coupling unification, suggest that scalar superpartner masses are roughly $m_{sc} \sim$ 100-1000 TeV. Higgsino masses, if not at the Planck scale, should generically appear at the same scale. The gaugino mass contributions from anomaly mediation, with the heavy Higgsino threshold, generally leads to a more compressed spectrum than standard anomaly …
The values of quark condensate and tensor susceptibility of QCD vacuum are calculated with different number of flavors. It is shown that, the values of tensor susceptibility are obviously dependent on the flavor numbers while the flavor-number dependence of quark condensate is undetermined.
In compressed supersymmetry, a light top squark naturally mediates efficient neutralino pair annihilation to govern the thermal relic abundance of dark matter. I study the LHC signal of same-sign leptonic top-quark decays from gluino and squark production, which follows from gluino decays to top plus stop followed by the stop decaying to a charm quark and the LSP in these models. Measurements of the numbers of jets with heavy-flavor tags in the same-sign lepton events can be used to confirm the origin of the signal. Summed transverse momentum observables provide an estimate of an effective sup…
By means of the functional integral method we show that in the case of the quark-antiquark pairing at zero temperature and zero chemical potential (in the vacuum) the singlet pairing is more preferable than that with the color-flavor locking (CFL)
We study the constraints on the mass-splitting of the first two generations of left-handed squarks obtained from Delta M_K, epsilon_K and D mixing. The different contributions from gluino, neutralino and chargino diagrams are examined in detail, concluding that it is not justified to neglect electroweak gaugino diagrams if the squark mass matrices contain flavor non-diagonal LL elements. We find that the constraints on the mass-splitting are very strong for light gluino masses. However, if the gluino is heavier than the squarks the constraints on the mass-splitting are much weaker. There are e…
We study the prospect of determining the decay properties of the gluino in the supersymmetric (SUSY) standard model at a 100 TeV future hadron collider. We consider the case where the neutral Wino is the lightest superparticle. In this case, the long-lived charged Wino can be used to eliminate standard model backgrounds, which enables us to study the details of superparticles. We show that, based on the analysis of the numbers of high $p_T$ leptons, boosted $W$-jets, and $b$-tagged jets, we may determine the gaugino species and the quark flavors in the gluino decay. With such determinations, w…
I advocate the virtues of a very economical version of the minimal supersymmetric standard model which avoids cosmological problems often encountered in dynamical SUSY-breaking and solves the SUSY-CP problem. Imposing $m_Z=91$ GeV and $m_t \sim 175$ GeV implies that scalar masses are generally $100-200$ GeV. The gluino and photino are massless at tree level. At 1-loop, the gluino mass is predicted to be in the range $m_{\gluino}: 100 - 600$ MeV and the photino mass can be estimated to be $m_{\photino}: 100 - 1400$ MeV. New hadrons with mass $\sim 1 \frac{1}{2}$ GeV are predicted and described.…
The mass matrix forms of quarks and leptons are discussed in theory with permutation flavor symmetry. The structure of scalar potential is analyzed in case that electroweak doublet Higgs fields have non-trivial flavor symmetry charges. We find that realistic forms of mass matrices are obtained dynamically in the vacuum of the theory, where some of Higgs bosons have vanishing expectation values which lead to vanishing elements in quark and lepton mass matrices. Mass textures are realized in the true vacuum and their positions are controlled by flavor symmetry. An interesting point is that, due …
We show that the study of neutrino capture on tritium, for non-relativistic neutrinos, can allow to distinguish among the various neutrino models, eventually prove the quantum field theory condensation effects and permit to test the hypothesis according to which the flavor vacuum energy gives a contribution to the dark matter of the universe. Indeed, we show that the capture rate depends on the neutrino model considered, and that it brings an imprint of the flavor vacuum condensate. Experiments like PTOLEMY, designed to reveal the cosmic neutrino background, then can give an indication of the …
Exploring hints of New Physics in the decay modes B -> pi K^* and B -> rho K can shed light on the B -> K pi puzzle. In this talk we discuss supersymmetric contributions to the direct CP asymmetries of the decays B -> pi K^* and B -> rho K within Soft Collinear Effective Theory. We consider non-minimal flavor SUSY contributions mediated by gluino exchange and apply the Mass Insertion Approximation in the analysis. We show that gluino contributions can enhance the CP asymmetries and accommodate the experimental results.
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 CP violations in the B_s-> K+K- and Bs->K0K0 decays in order to find the contribution of the supersymmetry, which comes from the gluino-squark mediated flavor changing current. We obtain the allowed region of the squark flavor mixing parameters by putting the experimental data, the mass difference Delta M_Bs, the CP violating phase phi_s in Bs to J/psi phi decay and the b to s gamma branching ratio. In addition to these data, we take into account the constraint from the asymmetry of B0->K+pi because the Bs->K+K- decay is related with the B0->K+pi- decay by replacing the spectator s wi…
Results are presented for a variety of SUSY Simplified Models at the 14 TeV LHC as well as a 33 and 100 TeV proton collider. Our focus is on models whose signals are driven by colored production. We present projections of the upper limit and discovery reach in the gluino-neutralino (for both light and heavy flavor decays), squark-neutralino, and gluino-squark Simplified Model planes. Depending on the model a jets + MET, mono-jet, or same-sign di-lepton search is applied. The impact of pileup is explored. This study utilizes the Snowmass backgrounds and combined detector. Assuming 3000 fb^{-1} …
We study the alignment of the vacuum in gauge theories with $N_f$ Dirac fermions transforming according to a complex representation of the gauge group. The alignment of the vacuum is produced by adding a small mass perturbation to the theory. We study in detail the $N_f=2,3$ and $4$ case. For $N_f=2$ and $N_f=3$ we reproduce earlier known results including the Dashen phase with spontaneous violation of the combined charge conjugation and parity symmetry, CP. For $N_f=4$ we find regions with and without spontaneous CP violation. We then generalize to an arbitrary number of flavors. Here it is s…
The null results of the LHC searches have put strong bounds on new physics scenario such as supersymmetry (SUSY). With the latest values of top quark mass and strong coupling, we study the upper bounds on the sfermion masses in Split-SUSY from the observed Higgs boson mass and electroweak (EW) vacuum stability. To be consistent with the observed Higgs mass, we find that the largest value of supersymmetry breaking scales $M_{S}$ for $\tanβ=2$ and $\tanβ=4$ are $\mathcal{O} (10^{3}\, {\rm TeV})$ and $\mathcal{O} (10^{1.5}\, {\rm TeV})$ respectively, thus putting an upper bound on the sfermion ma…
We estimate the twist-4 spin-1 nucleon matrix element f_2 in an instanton-based description of the QCD vacuum. In addition to the flavor-nonsinglet we compute also the flavor-singlet matrix element, which appears in next-to-leading order of the (1/N_c)-expansion. The corresponding twist-3 spin-2 matrix elements d_2 are suppressed in the packing fraction of the instanton medium, (\bar ρ)/(\bar R) << 1. We use our results to estimate the leading (1/Q^2) power corrections to the first moment of the proton and neutron spin structure functions G_1, as well as the intrinsic charm contribution to the…
We analyze the decays of charginos, neutralinos, gluinos and the first/second generation squarks in the Minimal Supersymmetric extension of the Standard Model, focusing on the three-body decays in scenarios where the ratio $\tan β$ of vacuum expectation values of the two Higgs doublet fields is large. We show that the three-body decays of the next-to-lightest neutralinos (lightest charginos) into $b\bar{b},τ^+τ^-$ ($τν$) final states, where third generation sfermion and Higgs boson exchange diagrams play an important role, are dominant. Furthermore, we show that decays of gluinos into $b\bar{b…
Extensions of GMSB models were explored to explain the recent reports of the Higgs boson mass around 124-126 GeV. Some models predict a large mu term, which can spoil the vacuum stability of the universe. We study two GMSB extensions: i) the model with a large trilinear coupling of the top squark, and ii) that with extra vector-like matters. In both models, the vacuum stability condition provides upper bounds on the gluino mass if combined with the muon g-2. The whole parameter region is expected to be covered by LHC at sqrt{s} = 14 TeV. The analysis is also applied to the mSUGRA models with t…
We study the minimal type-III seesaw model in which we extend the SM by adding two $SU(2)_L$ triplet fermions with zero hypercharge to explain the origin of the non-zero neutrino masses. We show that the naturalness conditions and the limits from lepton flavor violating decays provide very stringent bounds on the model parameters along with the constraints from the stability/metastability of the electroweak vacuum. We perform a detailed analysis of the model parameter space including all the constraints for both normal as well as inverted hierarchies of the light neutrino masses. We find that …
We examine the phenomenological consequences of quadratically divergent contributions to the scalar potential in supergravity effective Lagrangians. We focus specifically on the effect of these corrections on the vacuum configuration of scalar fields in softly-broken supersymmetric theories and the role these corrections play in generating non-diagonal soft scalar masses. Both effects can only be properly studied when the divergences are regulated in a manifestly supersymmetric manner -- something which has thus far been neglected in past treatments. We show how a supersymmetric regularization…
In this article we present the complete resummation of the leading chirally-enhanced corrections stemming from gluino-squark, chargino-sfermion and neutralino-sfermion loops in the MSSM with non-minimal sources of flavor-violation. We compute the finite renormalization of fermion masses and the CKM matrix induced by chirality-flipping self-energies. In the decoupling limit Msusy>>v, which is an excellent approximation to the full theory, we give analytic results for the effective gaugino(higgsino)-fermion-sfermion and the Higgs-fermion-fermion vertices. Using these vertices as effective Feynma…
Zero temperature properties of an (axial-) vector meson extended linear sigma model are discussed, concerning on the possible different realizations of the axial anomaly term. The different anomaly terms are compared with each other on the basis of a chi^2 minimalization process. It is found that there is no essential difference among the different realizations. This means that any of them can be equally used from phenomenological point of view.
We investigate low energy implications of string loop corrections to supergravity couplings which break a possible flavor universality of the tree level. If Supersymmetry is broken by the dilaton $F$-term, universal soft scalar masses arise at the leading order but string loop corrections generically induce flavor-non-diagonal soft terms. Constraints from flavor changing neutral currents (FCNC) and CP violation then require a large supersymmtery breaking scale and thus heavy gluinos and squarks. If Supersymmetry is broken by moduli $F$-terms, universality at the string tree level can only be g…
A texture-zeros is an approach to reduce the number of free parameters in Yukawa couplings and it is one of the most attractive ones. In our paper, we discuss the origin of zero-structure in texture-zeros by S_3 flavor symmetry approach. Some of electroweak doublet Higgs fields have vanishing vacuum expectation value(VEV) which leads to vanishing elements in quark and lepton mass matrices. Then, the structure of supersymmetric scalar potential is analyzed and Higgs fields have non-trivial S_3 charges. As a prediction of our paper, a lower bound of a MNS matrix element, U_{e3} \geq 0.04, is obt…
The decay $b\to sν\barν$ is discussed in the minimal supersymmetric standard model with general flavor mixing for squarks, at large $\tanβ$. In this case, in addition to the chargino loop contributions which were analyzed in previously studies, $\tanβ$-enhanced contributions from the gluino and charged Higgs boson loops might become sizable compared with the standard model contribution, at least in principle. However, it is demonstrated that the experimental bounds on the new physics contributions to the radiative decay $b\to sγ$ should strongly constrain these contributions to $b\to sν\barν$,…
In this article, we study the light-flavor scalar and axial-vector diquark states in the vacuum and in the nuclear matter using the QCD sum rules in an systematic way, and make reasonable predictions for their masses in the vacuum and in the nuclear matter.
Supersymmetric theories which can allow for a 125 GeV Higgs mass and also solve the naturalness and susy flavor problems now require a fair degree of complexity. Here we consider the simplest possibility for supersymmetry near the weak scale, but with the requirement of naturalness dropped. In "pure gravity mediation", all supersymmetric particles except for the gauginos lie at tens to thousands of TeV, with the gauginos obtaining loop suppressed masses automatically by anomaly mediation and higgsino threshold corrections. The gauginos are the lightest superpartners, and we investigate the cur…
We provide a short account of the effects one expects on meson-antimeson oscillations in the context of the Minimal Supersymmetric Standard Model (MSSM). This issue is largely dependent on the assumptions made on the MSSM parameter space. In this respect, we consider in closer detail the cases of the general MSSM, with completely free soft terms, and the Minimal Flavor Violating limit of the MSSM, providing a natural mechanism of near-flavor-conservation. For the case of meson oscillations in the Delta B = 2 sector, we show that this approach leads to a striking increase of the predictivity of…
Lattice results are available for Delta S=2 matrix elements for the first time in full QCD, which improve considerably the status of hadronic uncertainties in K-Kbar mixing with respect to earlier phenomenological studies. Using an average of the ETMC and RBC results, we analyze epsilonK in Natural SUSY. This scenario arises as a consistent BSM framework after the latest results from the LHC. The analysis is improved with respect to previous studies including next-to-leading order matching conditions of order (alpha_s)^3. We derive new bounds for SUSY mass insertions in the scenario with a lig…
Pure leptonic and semileptonic rare B decays, $B_s \to μ^+ μ^-$ and $B \to X_s μ^+ μ^-$ in the minimal supersymmetric Standard Model (MSSM), in particular, gluino and neutralino contributions to the decays, are discussed under Br($B \to X_s γ$) and other experimental constraints . The general scalar quark mass matrices as the new sources of flavor violation are considered. We present Wilson coefficients of $bs$ transitions from $γ$, $Z$, and neutral Higgs boson penguin diagrams by using vertex mixing method to deal with scalar down-type quark flavor changing and also give their expressions in …
We investigate the effects of flavor SU(3)-symmetry breaking on the quark, gluon, and mixed quark-gluon condensates, based on the nonlocal effective chiral action from the instanton vacuum. We employ two different parameterizations for the dependence of the momentum-dependent dynamical quark mass on the strange current quark mass. With a proper choice of the current-quark mass dependence of the dynamical quark mass, we show that the gluon condensate is independent of the current quark mass. We obtain the ratios of the quark and mixed condensates, respectively: $[<\bar{s}s>/< \bar{u}u>]^{1/3}=0…
We consider the question of vacuum alignment in the recently proposed "composite technicolor" (CTC) models. In order for these models to work, an "ultrafermion" condensate must align in a particular way, driven by the competition between ultrafermion masses and "flavor" gauge boson exchange. We show that for ultrafermion masses large enough to explain the top quark mass, order-of-magnitude estimates are sufficient to establish that the required vacuum alignment cannot occur for perturbative values of the flavor gauge couplings. If the top quark gets its mass from some other mechanism, a detail…
The discovery of a Higgs boson near 125 GeV, together with the absence of LHC signals for supersymmetry or direct detection signals of dark matter, motivate further study of a particular theory of split supersymmetry. In arguably the theoretically simplest implementation of split, the superpartner spectrum is spread over several decades. The squarks and sleptons are heavier than the gravitino and Higgsinos by a factor M_Pl/M_*, where M_* is the mediation scale of supersymmetry breaking and is high, between unified and Planck scales. On the other hand the gaugino masses are 1-loop smaller than …
We investigate the prospects to extract supersymmetric couplings from a decay length measurement at the LHC. Specifically, we exploit the opportunity of a light and long-lived stop which is pair-produced through gluinos in association with like-sign top quarks. Any observed finite value of the stop decay length strongly supports models in which flavor is broken in a minimal way solely by the Standard Model Yukawa couplings. We find that a 1 picosecond stop lifetime, dominated by t~ -> c chi^0 decays, yields macroscopic transverse impact parameters of about 180 microns. If the lightest neutrali…
Three interesting scenarios for neutrino mixing, i.e., (i) small-large mixing scenario, (ii) nearly bi-maximal mixing scenario and (iii) three-flavor oscillation scenario, are analyzed in connection with three possible assignments of the maximal CP-violating phase after spontaneous symmetry breaking of SO(3) in a model with gauged SO(3) lepton flavor symmetry. As a consequence, it is found that the scenario (ii) is more reliable to be resulted in reconciling both solar and atmospheric neutrino data. Though three Majorana neutrino masses in all scenarios can be nearly degenerate, in the scenari…
We investigate the twist-3 pion and kaon distribution amplitudes of the pseudoscalar (phi^p_{pi,K}) and pseudotensor (phi^{sigma}_{pi,K}) types, based on the effective chiral action from the instanton vacuum. Effects of flavor SU(3) symmetry breaking are explicitly taken into account. The Gegenbauer moments and the moments of the distribution amplitudes (<xi^m>) are also computed. Our results are summarized as follows: a^p_{2,pi} ~ 0.4, a^p_{1,K} ~ 0.02 and a^p_{2,K} ~ 0.14, and a^{sigma}_{2,pi} ~ 0.02 and a^{sigma}_{1,K} ~ a^{sigma}_{2,K} ~ 0; <xi^2>^p_π ~ <xi^2>^p_K ~ 0.37 and <xi>^p_K ~ 0, …
Vacuum free energy, quark condensate shifts and magnetization in three-flavor chiral perturbation theory to $\mathcal{O}(p^6)$ in a uniform magnetic field
Production of (electrically neutral) heavy-quark pairs, such as t{\bar c} and {\bar t}c, is extremely suppressed in the SM. In supersymmetric (SUSY) theories, such as the MSSM, the number of these events can be significantly enhanced thanks (mainly) to the FCNC couplings of gluinos. We compute the efficiency of this mechanism for FCNC production of heavy quarks at the LHC. We find that σ(pp\to t\bar{c}+\bar{t}c) can reach 1 pb, and therefore one can expect up to 10^{5} events per 100 fb^{-1} of integrated luminosity (with no counterpart in the SM). Their detection would be instant evidence of …
I describe a technicolor model (without walking) of all interactions up to energies of the order of 1000~TeV. The low energy extended technicolor model has the CTSM form. But at intermediate energy scales, additional interactions are required to give the KM mixing. I discuss the characteristic flavor changing neutral current interactions arising from this flavor physics below 1000~TeV.
