Recently, it was pointed out that the mixing phase in the Bs-Bsbar system is large, contrary to the expectations in the Standard Model as well as in minimal flavour violation models. The leptonic decay widths of the D_s meson are also found to be larger than expected. We show how a minimal set of four R-parity violating lambda-prime type couplings can explain both these anomalies. We also point out other phenomenological implications of such new physics.
We use the precision electroweak data at LEP to place bounds on $B$-violating Yukawa couplings, two theoretically appealing examples being provided by $R$-parity--violating supersymmetry and diquarks. The couplings involving the third generation quarks are most severely constrained. These bounds are complementary to those obtained from low-energy processes.
We present the two-loop $β$-functions for non-standard soft supersymmetry-breaking couplings including non-standard R-parity violating soft terms in the Minimal Supersymmetric Standard Model
We investigate the possible role that baryon number violating Yukawa interactions may take in the inclusive decay $ B \to X_s γ$. The constraints, derived using the experimental results of the CLEO collaboration, turn out, in many cases, to be more stringent than the existing bounds.
Yukawa-like R-parity violating (RPV) couplings are generated as effective operators with a typical strength of ${\cal O}(10^{-3})$ through loops involving the scalars, the gauginos and the soft supersymmetry breaking RPV interactions. Neutrino masses and other phenomenological implications of such a scenario are discussed.
We summarized our report on leptonic flavor violating Higgs decay into mu + tau under the scheme of a generic supersymmetric standard model without R parity. With known experimental constraints imposed, important combinations of R-parity violating parameters which can give notable branching ratios are listed.
R-parity-violating supersymmetry (with a conserved baryon number B) provides a framework for particle physics with lepton number (L) violating interactions. We examine in detail the structure of the most general R-parity-violating (B-conserving) model of low-energy supersymmetry. We analyze the mixing of Higgs bosons with sleptons and the mixing of charginos and neutralinos with charged leptons and neutrinos, respectively. Implications for neutrino and sneutrino masses and mixing and CP-conserving sneutrino phenomena are considered. L-violating low-energy supersymmetry can be probed at future …
We consider the proton decay involving a light gravitino or axino in gauge-mediated supersymmetry breaking models to derive constraints on the $R$ parity and baryon number violating Yukawa couplings. Bounds on all nine coupling constants are obtained by considering the decay amplitudes at one-loop order.
We discuss the implications of the recent measurement of the $B_s-\bar{B_s}$ oscillation frequency $ΔM_s$ on the parameter space of R-parity violating supersymmetry. For completeness, we also discuss the bounds coming from leptonic, semileptonic, and nonleptonic B decay modes, and point out some possibly interesting channels at LHC.
We compute the supersymmetric (SUSY) corrections to the parity-violating, deep inelastic electron-deuteron asymmetry. Working with the Minimal Supersymmetric Standard Model (MSSM) we consider two cases: R parity conserving and R parity-violating. Under these scenarios, we compare the SUSY effects with those entering other parity-violating observables. For both cases of the MSSM, we find that the magnitude of the SUSY corrections can be as large as about 1% and that they are strongly correlated with the effects on other parity-violating observables. A comparison of various low-energy parity-vio…
I study the weak basis CP-violating invariants in supersymmetric models, in particular those which cannot be expressed in terms of the Jarlskog--type invariants, and find basis--independent conditions for CP conservation. With an example of the K-anti-K mixing, I clarify what are the combinations of supersymmetric parameters which are constrained by experiment.
We consider the neutrino oscillations within the minimal supersymmetric standard model with R-parity violation. The Super-Kamiokande atmospheric neutrino data are used to set limits on the bilinear R-parity violating terms. These very stringent limits are out of reach of the other experiments at present and in the near future.
The latest results from CMS on R-Parity violating Supersymmetry based on the 19.5/fb full dataset from the 8 TeV LHC run of 2012 are reviewed. The results are interpreted in the context of simplified models with multilepton and b-quark jets signatures that have low missing transverse energy arising from light top-squark pair with R-parity-violating decays of the lightest supersymmetric particle. In addition to simplified model, a new approach for phenomenological MSSM interpretation is shown which demonstrates that the obtained results from multilepton final states are valid for a wide range o…
We study one-loop contributions to the fermion electric dipole moments in the Minimal Supersymmetric Standard Model with explicit R-parity violating interactions. We obtain new individual bounds on R-parity violating Yukawa couplings and put more stringent limits on certain parameters than those obtained previously.
Motivated by the recent experimental data of the E787, E949 and E865 collaborations and by the difference between the standard model (SM) prediction and data, we consider in detail R-parity violating (RPV) supersymmetric contributions to K -> pi nu nubar. The theoretical cleaness of this decay constitutes a useful way to provide constraints, independent of long distance effects. Including the possiblity of interferences between one-loop R-parity conserving (RPC) supersymmetry and tree-level RPV supersymmetric contributions, our results allow to improve the limits on R-parity violating coupling…
We discuss a model for neutrino masses and mixings based on R parity violating Yukawa couplings. The model requires no right-handed neutrinos. It accommodates the SuperKamiokande data on atmospheric neutrinos and successfully relates this data to the mass difference for solar neutrinos in the small-angle MSW solution. We obtain an unexpected testable pattern for the three neutrino flavors.
We update the single-coupling bounds on R-parity violating supersymmetry using the most up to date data as of October 2009. In addition to the data listed in the 2009 Review of Particle Properties, we utilize a new determination of the weak charge of cesium-133, and preliminary tau-decay branching fractions from Babar. Analysis of semileptonic D-decay is improved by the inclusion of experimentally measured form-factors into the calculation of the Standard Model predictions.
We have developed an efficient formulation for the study of the generic supersymmetric standard model, which admits all kind of R-parity violating terms. Using the formulation, we discuss all sources of fermion dipole moment contributions from R-parity violating, or rather lepton number violating, parametersand the constraints obtained. Stringent constraints comparable to those from neutrino masses are resulted in some cases.
The phenomenology and prospects for a discovery of R-parity violating Supersymmetry at HERA are analysed. Emphasis is put on the direct resonant production of squarks by electron-quark fusion and all possible subsequent decay modes of the squarks are considered. In particular, the full consequences of the mixing in the supersymmetric gaugino-higgsino sector are taken into account. A rich phenomenology emerges for HERA which offers a unique sensitivity to new R-parity violating couplings and good discriminating power against free parameters of the theory.
We calculate the radiative decay amplitude for Majorana neutrinos in trilinear R-parity violating supersymmetric framework. Our results make no assumption regarding the masses and mixings of fermions and sfermions. The results obtained are exemplary for generic models with loop-generated neutrino masses. Comparison of this amplitude with the neutrino mass matrix shows that the two provide independent probes of CP-violating phases.
We study $t \bar t$ production in R-parity violating supersymmetry. The annihilation channel $q \bar q \rightarrow t \bar t$ gets new contributions from $t$-channel exchange of squarks or sleptons. With the data from Tevatron on $t \bar t$ production, we find that the squark- or slepton-exchange processes constrain the $B$-violating $λ''$ couplings or the $L$-violating $λ'$ couplings, respectively. Our bounds are already comparable to the few existing constraints on third-generation $R$-parity violating couplings, and will improve when more precise measurements of the $t \bar t$ production cro…
We study CP violating B decays in the minimal supersymmetric standard model with R-parity violation. We estimate how much R-parity violation modifies the SM predictions for CP asymmetries in B decays within the present bounds. The effects of R-parity- and lepton-number-violating couplings on the ratio of the decay amplitude due to R-parity violation to that of the SM can differ by one or two orders of magnitudes depending on the models of the left-handed quark mixing. It is possible to disentangle the R-parity violating effects from those of the SM and R-parity- conserving supersymmetric model…
The contribution of the R-parity violating minimal supersymmetric standard model to the neutron beta decay at the one-loop level is investigated. It is found that the baryon number and R-parity violating interactions contribute to the D correlation through one-loop corrections, while the tree level prediction is vanishing. The Fierz interference term is also investigated at the one-loop level by considering the lepton number and R-parity violating interactions. We show that future experimental progress can provide us with better constraints on some of the combinations of R-parity violating cou…
Phenomenological analysis to the R-parity violating supersymmetry with a vector-like extra generation is performed in detail. It is found that, via the trilinear couplings, the correct neutrino spectrum can be obtained. The Higgs mass rises to 125 GeV by new up-type Yukawa couplings of vector-like quarks with no need of very heavy superpartners. Phenomena of new heavy fermions at LHC are predicted.
Lepton-flavor-violating decays of the type L->l gamma gamma (mu->e gamma gamma, tau->e gamma gamma, and tau->mu gamma gamma) are proposed as new probes of R-parity-violating supersymmetry. Non-penguin diagrams with a sneutrino that decays into two photons via a triangle graph might trigger such decays even in the absence of the corresponding radiative decays into one photon only, e.g. mu->e gamma. Thus, processes of the type L->l gamma gamma may provide an independent probe of new flavor physics.
Recent measurements of CP asymmetry in B --> phi K_S appear to be inconsistent with Standard Model expectations. We explore the effect of R-parity-violating SUSY to understand the data.
Upper bounds at the weak scale are put on all $λ'_{ijk}λ'_{imn}$ type products of R-parity violating supersymmetry that may affect K-Kbar and B-Bbar mixing. We constrain all possible products, including some not considered before, using next-to-leading order QCD corrections to the mixing amplitudes. Constraints are obtained for both real and imaginary parts of the couplings. We also discuss briefly some correlated decay channels which should be investigated in future experiments.
The lepton number violating process $μ\rightarrow eγ$ is used to study the lepton number violating couplings in MSSM extended by terms violating $R$-parity explicitly. Bounds are obtained for the products of $λ$- or $λ'$-type couplings. It is found that many of these limits are more stringent than the ones obtained previously.
We prove a general low-energy theorem establishing a generic relation between the neutrino Majorana mass and the superpartner sneutrino B-L-violating "Majorana"-like mass term. The theorem states that, if one of these two quantities is non-zero the other one is also non-zero and, vice versa, if one of them vanishes the other vanishes, too. The theorem is a consequence of the underlying supersymmetry (SUSY) and valid for any realistic gauge model with weak scale softly broken SUSY.
The effective Hamiltonian for the R-parity violating couplings induced nonleptonic decay $B^-\to K^-K^0$ is calculated including leading log QCD corrections running from $m_{\tilde q}$, the mass of the up-type squark, to $m_b$. Experimental upper limit of this decay is used to give the bound on the R-parity violating couplings $λ''$.
Parity-violating asymmetries in polarized electron scattering have been interpreted as the asymmetries between opposite helicities of incoming fermion based on the approximation of the spin polarization operator. Here exact calculations of cross sections for parity-violating asymmetries in SLAC E158 and SLD have been performed using spin projection operators. And the parity-violating factor incorporating with spin polarization and momentum has been identified and shown that its sign depends on the spin polarization of incoming particle and the relative velocity of incoming and target particles…
We present the full two-loop beta-functions for the MSSM including R-parity violating couplings. We analyse the effect of two-loop running on the bounds on R-parity violating couplings, on the nature of the LSP and on the stop masses.
Parity-violating nuclear force, as may be accessed from parity violation studies in nuclear systems, represents an area of nonleptonic weak interactions which has been the subject of experimental investigations for several decades. In the simple meson-exchange picture, parity-violating nuclear force may be parameterized as arising from exchange of π, ρ, ω, or other meson(s) with strong meson-nucleon coupling at one vertex and weak parity-violating meson-nucleon coupling at the other vertex. The QCD sum rule method allows for a fairly complicated, but nevertheless straightforward, leading-order…
$D$- and $τ$-decays are used to place bounds on some $R$-parity--violating $λ'$-type Yukawa interactions. Some of these bounds are competitive with the existing ones, some are improved while some are new.
We study in the framework of R-parity violating supersymmetric theories the effect of R-parity violation due to the operator L_i L_j \bar{E_k} on the (V-A) structure of the muon decay. The precisely measured muon decay parameters can constrain a product of R-parity violating couplings: |λ_{232}λ_{131}| < 0.022 at the 90% CL, which is complementary to the previous limits obtained by the e-μuniversality in τdecay.
R-parity-violating supersymmetry with a conserved baryon number B provides a framework for particle physics with lepton number (L) violating interactions. Two important probes of the L-violating physics are neutrino masses and sneutrino-antisneutrino mass-splittings. We evaluate these quantities in the context of the most general CP-conserving, R-parity-violating B-conserving extension of the minimal supersymmetric standard model. In generic three-generation models, three sneutrino-antisneutrino mass splittings are generated at tree-level. In contrast, only one neutrino mass is generated at tr…
It is shown that in R-parity violating models of supersymmetry, the CP violation observed in the kaon system could arise purely from the R-parity violating scalar interactions (A-terms), with no CP violation in the CKM matrix. The direct CP violating parameter, epsilon', could be as large or larger than that expected in the Standard Model. CP violation in the B system however is expected to be negligible.
We perform a systematic reevaluation of the constraints on the flavor-changing neutral current (FCNC) parameters in R-parity conserving and R-parity violating supersymmetric models. As a typical process, we study the constraints coming from the measurements on the B0-\bar{B0} system on the supersymmetric $δ^d_{13}$ parameters, as well as on the products of the lambda' type R-parity violating couplings. Present data allows us to put constraints on both the real and the imaginary parts of the relevant parameters.
We update the bounds on $R$-parity violating supersymmetry originating from meson oscillations in the $B^0_{d/s}$ and $K^0$ systems. To this end, we explicitly calculate all corresponding contributions from $R$-parity violating operators at the one-loop level, thereby completing and correcting existing calculations. We apply our results to the derivation of bounds on $R$-parity violating couplings, based on up-to-date experimental measurements. In addition, we consider the possibility of cancellations among flavor-changing contributions of various origins, e.g. from multiple $R$-parity violati…
In an R-parity-violating supersymmetric theory, we derive upper bounds on all the λ''_{ijk}λ_{i'j'k'}-type combinations from the consideration of proton stability, where λ''_{ijk} are baryon-number-violating couplings involving three baryonic fields and λ_{i'j'k'} are lepton-number-violating couplings involving three leptonic fields.
Motivated by the recent SuperKamiokande results on atmospheric neutrinos, we incorporate massive neutrinos, with large angle oscillation between the second and third generations, in a theory with R-parity violating supersymmetry. The general features of such a theory are briefly reviewed. We emphasize its testability through the observation of comparable numbers of muons and taus, produced together with the W-boson, in decays of the lightest neutralino. A distinctly measurable decay gap is another remarkable feature of such a scenario.
We present a reanalysis of nucleon decay in the context of the R-parity violating MSSM, updating bounds on R-parity violating parameters against recent experimental and lattice results. We pay particular attention to the derivation of these constraints and specifically to the hadronic matrix elements, which usually stand as the limiting factor in order to derive reliable bounds, except for these few channels that have been studied on the lattice.
In this talk I discuss the motivations for supersymmetry, focussing on models with broken R-parity and lepton number. After describing the main theoretical features of these models, I discuss some of the signals expected at colliders such as Tevatron, LEP II, NLC and LHC.
In lepton-number-violating supersymmetric models, there is no natural choice of basis to distinguish the down-type Higgs and lepton superfields. We employ basis-independent techniques to identify the massless majoron and associated light scalar in the case of spontaneously-broken lepton number (L). When explicit L-violation is added, these two scalars can acquire masses of order the electroweak scale and can be identified as massive sneutrinos.
Motivated by the recent Super-Kamiokande results on atmospheric neutrinos, we incorporate massive neutrinos, with large angle oscillation between the second and third generations, in a scenario with R-parity violating supersymmetry. We emphasize the testability of such models through the observation of comparable numbers of muons and taus, produced together with the W-boson, in decays of the lightest neutralino. A distinctly measurable decay gap is another remarkable feature of such a scenario.
The contribution of the R-parity violating trilinear couplings in the supersymmetric model to the fermion electric dipole moment is analyzed at the two-loop level. We show that in general, the Barr-Zee type contribution to the fermion electric dipole moment with the exchange of W and Z bosons is not small compared to the currently known photon exchange one with R-parity violating interactions. We will then give new upper bounds on the imaginary parts of R-parity violating couplings from the experimental data of the electric dipole moments of the electron and of the neutron. The effect due to b…
This article provides a brief overview of some of the theoretical aspects of R-parity violation (RPV) in the minimal supersymmetric standard model (MSSM) and its extensions. Both spontaneous and explicit RPV models are discussed and some consequences are outlined. In particular, it is emphasized that the simplest supersymmetric theories based on local B-L predict that R-parity must be a broken symmetry, a fact which makes a compelling case for taking R-parity breaking seriously in discussions of supersymmetry phenomenology.
The recent measurements of the $B_s$ mass difference $ΔM_s$ by the CDF and DØ collaborations are roughly consistent with the Standard Model predictions, therefore, these measurements will afford an opportunity to constrain new physics scenarios beyond the Standard Model. We consider the impact of the R-parity violating supersymmetry in the $B^0_s-\bar{B}^0_s$ mixing, and use the latest experimental results of $ΔM_s$ to constrain the size of the R-parity violating tree level couplings in the $B^0_s-\bar{B}^0_s$ mixing. Then, using the constrained R-parity violating parameter space from $ΔM_s$, …
The contribution of the R-parity violating minimal supersymmetric Standard model (RPVMSSM) at the one-loop level to the 199Hg atomic electric dipole moment (EDM) through P, CP-odd electron-nucleon (e-N) interaction is calculated. We show that the current experimental data of the 199Hg EDM give tighter constraints on some of the imaginary parts of R-parity violating (RPV) coupling than those currently known. We add also the analysis of the P, CP-odd 4-quark interaction generated by R-parity violating interactions at the one-loop level, and discuss the possibility to constrain them in future exp…
We show how the renormalizable see-saw mechanism in the context of supersymmetry and spontaneously broken B-L symmetry implies exact R-parity at all energies. We argue that supersymmetry plays an important role in providing a "canonical" form for the see-saw, in particular in grand unified theories that solve the doublet-triplet splitting problem via the Dimopoulos-Wilczek mechanism.
Assuming the lightest supersymmetric particle is the gluino, we treat the decays gluino->quark-antiquark-neutrino and gluino->gluon-neutrino. Such couplings can be induced by the R parity violating quark-squark-lepton interaction which can also be responsible for neutrino masses and mixings. These R parity violating gluino decays have the same final state structure (jets plus missing energy) as previously considered decays into quark-antiquark-photino and gluon-gravitino but with significantly different gluino lifetimes.
We investigate the ability of single top quark production via qq'-> squark->tb and q \bar q'->slepton->t\bar b at the LHC and Tevatron to probe the strength of R-parity violating couplings in the minimal supersymmetric model. We found that given the existing bounds on R-parity violating couplings, single top quark production may be greatly enhanced over that predicted by the standard model, and that both colliders can either discover R-parity violating SUSY or set strong constraints on the relevant R-parity violating couplings. We further found that the LHC is much more powerful than the Tevat…
The nontrivial structure of the neutrino mass matrix, suggested by the recent Super-Kamiokande results and data from other neutrino experiments, can be reproduced in R-parity-violating supersymmetric theories. This requires sets of products of R-parity-violating trilinear couplings to take appropriately chosen values. It is shown that the existing constraints on these couplings are satisfied by these choices.
We derive the upper bounds on certain products of R-parity- and lepton-flavor-violating couplings from $B^\pm \to l^\pm ν$ decays. These modes of B-meson decays can constrain the product combinations of the couplings with one or more heavy generation indices which are comparable with or stronger than the present bounds. And we investigate the possible effects of R-parity violating interactions on $B_c \to l ν$ decays. These decay modes can be largely affected by R-parity violation.
We present a study of charged lepton mass matrix diagonalization in R-parity violating SUSY. The case in which the bilinear couplings $μ_i$ have large values is given special attention.
Bounds on R-parity violating couplings in the supersymmetric standard model are reviewed, and some new bounds arising from non-observation of certain rare B-decays (such as $B \rightarrow K^+K^-$) are presented. The focus is on baryon-number violating couplings, but it is also noted that many products of lepton- number violating and baryon-number violating couplings are not significantly constrained by proton decay bounds. The talk reviewed the work in a recent paper by Carlson, Roy and Sher (Phys. Letters, in press).
