We investigate the effect of the dimuon CP asymmetry from the B decay modes, recently observed at 3.2 sigma deviation from the Standard Model (SM) by the D0 collaboration, in the context of SU(5) and SO(10) GUT models. We exhibit that a large amount of flavor violation between the second and the third generation is generated due to the large neutrino atmospheric mixing angle and this flavor violation can be responsible for the observed large CP asymmetry due to the presence of new phases (not present in the CKM matrix) in the Yukawa couplings. We also study the implication of the parameter space in these GUT models with large CP violating lepton asymmetry for different phenomenologies, e.g., Br(tau -> mu + gamma), Br(B_s -> mu + mu) at the Fermilab, direct detection of dark matter (DM) in the ongoing detectors and measurement of muon flux from solar neutrinos at the IceCube experiment.
We investigate the role that baryon number violating interactions may play in $B$ phenomenology. Present in various grand unified theories, supersymmetric theories with R-parity violation and composite models, a diquark state could be quite light. Using the data on B decays as well as $B - {\bar B}$ mixing, we find strong constraints on the couplings that such a light diquark state may have with the Standard Model quarks.
Motivated from the recent results of neutrino oscillation experiment, we investigated lepton flavor violating (LFV) processes in a SU(5) supersymmetric grand unified theory with right-handed neutrino. The current experimental upper bound for $μ\to eγ$ process gives already some constraint on the model. Correlation between $μ\to e γ$ and the SUSY contribution to the muon anomalous magnetic moment is also discussed. Future LFV experiments will give considerable impacts on this type of SUSY GUT models equipped with seesaw neutrino mass generation.
We consider a possibility that $R$-parity violating interactions of particles which do not involve the first generation have large (up to 1) coupling constants, $Λ$. Such couplings, if exist, could have a number of phenomenological consequences: renormalization of $b-τ$ mass ratio, generation of $ν_τ$ mass in MeV region, {\em etc.}. In Grand Unified models, where $B$- and $L$-violating couplings appear simultaneously, the proton decay can be forbidden in virtue of hierarchical flavor structure of $Λ.$ However, due to Cabibbo-Kobayashi-Maskawa mixing this decay is induced already in one-loop. P…
The question of CP violating phases in supersymmetry and electric dipole moments (EDMs) is considered within the framework of supergravity grand unification (GUT) models with a light ($\stackrel{<}{\sim}$1 TeV) mass spectrum. In the minimal model, the nearness of the t-quark Landau pole automatically suppresses the t-quark cubic soft breaking phase at the electroweak scale. However, current EDM data require the quadratic soft breaking phase to be small at the electroweak scale unless tan$β$ is small (tan$β\stackrel{<}{\sim}$3), and the EDM data combined with the requirement of electroweak symm…
We study the CP-violating asymmetry in nonleptonic decay $Λ\to pπ$. By employing the Skyrme model to calculate this decay amplitude contributed by the gluonic diploe operator, we find a possible large CP-violating asymmetry could be expected, which is consistent with the previous study.
We update the theoretical analysis of the CP-violating asymmetry in the decay K_L -> pi+ pi- e+ e-, relying on chiral perturbation theory and on the most recent phenomenological information. With the experimentally determined magnetic amplitude and branching ratio as input, the asymmetry can be calculated with good accuracy. The theoretical interpretation of the sign of the asymmetry is discussed.
In the context of Supersymmetric Grand Unified theories with soft breaking terms arising at the Planck scale, it is generally possible to link flavor changing neutral current and CP violating processes occurring in the leptonic and hadronic sectors. We study the correlation between flavor changing squark and slepton mass insertions in models à la SU(5). We show that the constraints coming from lepton flavor violation exhibit a strong impact on CP-violating B decays.
The CP violating asymmetry from the decay rates $H^\pm\to W^\pm h_1$ of charged Higgs bosons into the lightest neutral Higgs boson and a $W^\pm$ boson is calculated and discussed in the complex MSSM. The contributions from all complex phases are considered, especially from the top-squark trilinear coupling, which induces a large contribution to the CP asymmetry.
In this paper, we study the effects of the unparticles on the parity-violating asymmetry for the low energy electron-electron scattering, $e^-e^-\to e^-e^-$. Using the data from the E158 experiment at SLAC we extract the limits on the unparticle coupling $λ_{AV}$, and on the the energy scale $Λ$ at 95% C.L. for various values of the scaling dimension $d$.
We consider the embedding of the supersymmetric Standard Model with broken R-parity in the minimal supergravity (mSUGRA) model. We restrict ourselves to the case of broken lepton number, the B3 mSUGRA model. We first study in detail how the tree-level neutrino mass depends on the mSUGRA parameters. We find in particular a strong dependence on the trilinear supersymmetry breaking A-parameter, even in the vicinity of the mSUGRA SPS1a point. We then reinvestigate the bounds on the trilinear R-parity violating couplings at the unification scale from the low-energy neutrino masses including dominan…
We will study some possible non universal corrections that could affect single measurements of the Weinberg angle sin^2(theta) (leaving the full average essentially unchanged). We will concentrate on the class of the models that introduces a new light gauge boson and an extended Higgs sector, but we restrict the Higgs charges choice in order to automatically achieve zero mixing at the tree level between the Z_0 and the Z'. This will more naturally keep small the universal effects with a relatively light Z', but it will imply only vector-like coupling between this boson and the standard fermion…
We study the implication of R-parity violating Rp Minimal Supersymmetric Standard Model (MSSM) model in lepton polarization asymmetry ALP in B l l(bar) decays . The analysis show that the ALP is significant in a certain phenomenological parametric region of Yukawa couplings. We have also placed indirect bounds on Lambda' lambda couplings as obtained from B t t(bar).
Discovery of neutrino mass has put the spotlight on supersymmetric SO(10) as a natural candidate for grand unification of forces and matter. However, the suppression of proton decay is a major problem in any supersymmetric grand unified models. In this paper we show how to alleviate this problem by simple threshold effect which raises the colored Higgsino masses and the grand unification scale to \gtrsim 10^{17} GeV. There exist only four types of fields arising from different SO(10) representations which can generate this kind of threshold effects. Some of these fields also generate a sizable…
The likelihood of a sizable, direct CP-violating asymmetry in the decays $B^\mp\to K^\mpη$, is calculated within the framework of the model which originally predicted a sizeable asymmetry in $π^\mpη(η')$. It is shown in a transparent manner that these decays are the best places for providing the first clear evidence for direct CP violation in the decays of a charged particle. These decays contain two amplitudes of comparable magnitude, with different weak-interaction phase, and with different strong-interaction phase which is explicitly calculated in a model of three coupled channels of physic…
We compute a full set of the first order QED corrections to the parity-violating observables in polarized Moller scattering. We employ a covariant method of removing infrared divergences, computing corrections without introducing any unphysical parameters. When applied to the kinematics of the SLAC E158 experiment, the QED corrections reduce the parity violating asymmetry by 4.5%. We combine our results with the previous calculations of the first-order electroweak corrections and obtain the complete O(alpha) prescription for relating the experimental asymmetry A_LR to the low-energy value of t…
We investigate the possible measurement of parity-violating spin asymmetries in jet pair production in proton-proton collisions at the Brookhaven Relativistic Heavy Ion Collider (RHIC), with the goal to constrain longitudinally polarized quark and antiquark distribution functions. A measurable asymmetry could be observed in the vicinity of the massive weak W boson resonance, where the parity-violating signal appears above the parity-conserving background and is enhanced by interference of the strong and electroweak production amplitudes. We discuss the potential for such measurements, perhaps …
In this paper, forward-backward asymmetry and differential cross section of top quark in flavor violating $Z'$ model up to $\mathscr{O}(α_s^2 α_X)$ at Tevatron are calculated. In order to account for the top observed large forward-backward asymmetry, the new coupling $g_X$ among $Z'$ and quarks will be not much less than strong coupling constant $g_s$. After including the new higher order correction, the differential cross section can fit the data better than those only including the leading contributions from $Z'$, while the forward-backward asymmetry is still in agreement with the measuremen…
In a model of supersymmetric SU(5) Grand Unification with a spatial dimension described by the orbifold $S^1/(Z_2 \times Z_2')$, proton decay is naturally suppressed at all orders. This is achieved by a suitable implementation of the discrete symmetries on the brane. But baryon number violating interactions are present in this model. We propose a few possible experimental tests of this model which exploit the effect of the baryon number violating couplings on low-energy observables like neutron-antineutron oscillations, double nucleon decay into two kaons, hadronic decay widths of the $Z$ boso…
We compute a net electric current during a first order EWPT arising from the asymmetric propagation of fermion chiral modes due to a CP-violating interaction with the Higgs. The interaction is quantified in terms of a CP-violating phase in the bubble wall that separate both false and true vacuum phases. We comment on the possibility of this current to generate a seed magnetic field and its implications for primordial magne- togenesis in the early Universe.
In the MSSM with complex parameters, loop corrections to the decay of a stop into a bottom quark and a chargino can lead to a CP violating decay rate asymmetry. We calculate this asymmetry at full one-loop level and perform a detailed numerical study, analyzing the dependence on the parameters and complex phases involved. If the stop can decay into a gluino, the self-energy and the vertex correction dominate due to the strong coupling. It is shown that the vertex contribution is always suppressed. We therefore give a simple approximate formula for the asymmetry. We account for the constraints …
The paper investigates contributions of $Z$, $W$ and $γ$ intermediate states to the parity-violating Moller scattering asymmetry up to two-loop level. Using the Yennie--Frautschi--Suura factorization form for amplitudes, we demonstrate that QED corrections, with an exception of vacuum-polarization effects, cancel at the asymmetry level. We obtain chiral amplitudes at Born, one-loop and partially at two-loop level: boxes with lepton self-energies, ladder boxes and decorated boxes. Our calculations are relevant for the ultra-precise 11 GeV MOLLER experiment planned at Jefferson Laboratory and fu…
In the context of texture 4 - zero and texture 5 - zero hierarchical quark mass matrices, CP violating asymmetry in $B^o_d({\bar B}^o_d) \to ψK_S$ (sin2$β$) has been evaluated by considering quark masses at $m_Z$ scale. For a particular viable texture 4 - zero mass matrix the range of sin2βis: 0.27 - 0.60 and for the corresponding texture 5 - zero case it is 0.31 - 0.59. Further our calculations reveal a crucial dependence of sin2$β$ on light quark masses as well as the phase in this sector.
In the MSSM with complex parameters, loop corrections to the decay of a stop into a bottom quark and a chargino can lead to a CP violating decay rate asymmetry. We calculate this asymmetry at full one-loop level and perform a detailed numerical study, analyzing the dependence on the parameters and complex phases involved. In addition, we take the Yukawa couplings of the top and bottom quark running. We account for the constraints on the parameters coming from several experimental limits. Asymmetries of several percent are obtained. We also comment on the feasibility of measuring this asymmetry…
We study the Lorentz and CPT violating effects on the branching ratio and the CP violating asymmetry of the lepton flavor violating interactions μ\to eγand τ\to μγ, in the model III version of the two Higgs doublet model. Here we consider that the Lorentz and CPT violating effects exist in the QED part of the interactions and enter into expressions in the lepton propagators and in the lepton-photon vertex. We observe that there exists a non-zero CP asymmetry. However, the Lorentz and CPT violating effects on the braching ratio and the CP asymmetry are negligibly small.
In the MSSM with complex parameters, loop corrections to $\cha_i^\pm \to \neu_j^0 W^\pm$ lead to a CP violating asymmetry $\ACP = (Γ(\cha_i^+ \to \neu_j^0 W^+) - Γ(\cha_i^- \to \neu_j^0 W^-))/ (Γ(\cha_i^+ \to \neu_j^0 W^+) + Γ(\cha_i^- \to \neu_j^0 W^-))$. We calculate this asymmetry at full one-loop level. We perform a detailed numerical analysis for $\cha_1^\pm \to \neu_1^0 W^\pm$ and $\cha_2^\pm \to \neu_1^0 W^\pm$ analyzing the dependence on the parameters and phases involved. Asymmetries of several percent are obtained. We also discuss the feasability of measuring these asymmtries at LHC.
We compute the net electric current generated during a first order electroweak phase transition when fermions transit from the false to the true vacuum. This current is generated by the CP-violating fermion interaction with the Higgs during the phase transition and is quantified in terms of a CP-violating phase in the bubble wall separating the symmetric from the symmetry-broken phases. We comment on the seed magnetic field that this current is able to generate and it is possible implications for magnetogenesis in the early universe during the electroweak phase transition.
We consider generation of baryon asymmetry of the universe through $R-$parity violation in a scenario in which out-of-equilibrium condition is satisfied by making the electroweak phase transition to be first order. We study all the $R-$parity violating interaction which can generate $(B-L)$ asymmetry which then converts to baryon asymmetry of the universe. We demonstrate that CP--violating sfermion deudy all the $R-$parity violating interaction which can generate $(B-L)$ asymmetry which then converts to baryon asymmetry of the universe. We demonstrate that CP--violating sfermion decays contrib…
A triple vector correlation in the $μ^{+} \to e^{+} e^{+} e^{-}$ decay with polarized muons is investigated as a probe to CP violating coupling constants in supersymmetric models. A sizable triple correlation can be induced due to a complex phase in the supersymmetric soft-breaking terms in the SU(5) grand unified theory. Correlation with the electric dipole moments of electron and neutron are investigated and it is shown that these quantities give independent information on possible CP violating sources.
We analyze the asymmetry in the partial widths for the decays $B^{\pm} \to M {\bar M} π^{\pm}$ ($ M = π^+, K ^+, π^0, η$), which results from the interference of the nonresonant decay amplitude with the resonant amplitude for $B^{\pm} \to χ_{c0} π^{\pm} $ followed by the decay $χ_{c0} \to M {\bar M} $. The CP violating phase $γ$ can be extracted from the measured asymmetry. We find that the partial width asymmetry for $B^\pm \to π^+ π^- π^\pm$ is about $0.33~sin γ$, and about $0.45~ sin γ$ for $B^\pm \to K^+ K^-π^\pm$, while it is somewhat smaller for $B^\pm \to π^0 π^0 π^\pm$ and $B^\pm \to η…
The experimental results on the t bar t production cross section at the Tevatron are well described by the QCD contributions within the standard model, while the recent measurement of the forward-backward asymmetry cannot be accounted for within this framework. We consider light colored scalars appearing in a particular SU(5) GUT model within the 45-dimensional Higgs representation. A virtue of the model is that it connects the presence of a light colored SU(2) singlet (Delta_6) and a color octet weak doublet (Delta_1) with bounds on the proton lifetime, which constrain the parameter space of …
Recent measurements of time dependent CP asymmetry in B --> phi K_S, if confirmed, would indicate a new source of CP violation. We examine flavor violating tree-level Z currents in models with extra down-type quark singlets that arise naturally in string compactified gauge groups like E_6. We evaluate the new operators at the scale mu = m_b in NLO, and using QCD improved factorization to describe B --> phi K_S, find the allowed range of parameters for rho and psi, the magnitude and phase of the flavor violating parameter U_{bs}. This allowed range does satisfy the constraint from flavor changi…
We study the decay width and CP-asymmetry of the inclusive process b--> s g g (g denotes gluon) in the three and two Higgs doublet models with complex Yukawa couplings. We analyse the dependencies of the differential decay width and CP-asymmetry to the s- quark energy E_s and CP violating parameter θ. We observe that there exist a considerable enhancement in the decay width and CP asymmetry is at the order of 10^{-2}. Further, it is possible to predict the sign of C_7^{eff} using the CP asymmetry.
We systematically analyze the correlations between the various leptonic and hadronic flavor violating processes arising in SUSY Grand Unified Theories. Using the GUT-symmetric relations between the soft SUSY breaking parameters, we assess the impact of hadronic and leptonic flavor observables on the SUSY sources of flavor violation.
Neutrinoless double beta decay, lepton number violating collider processes and the Baryon Asymmetry of the Universe (BAU) are intimately related. In particular lepton number violating processes at low energies in combination with sphaleron transitions will typically erase any pre-existing baryon asymmetry of the Universe. In this contribution we briefly review the tight connection between neutrinoless double beta decay, lepton number violating processes at the LHC and constraints from successful baryogenesis. We argue that far-reaching conclusions can be drawn unless the baryon asymmetry is st…
We study the branching ratio, CP-violating asymmetry, forward-backward asymmetry and the CP-violating asymmetry in the forward-backward asymmetry for the exclusive decay B--> K l^+ l^-$ in the two Higgs doublet model with tree level flavor changing neutral currents (model III). We analyse the dependencies of these quantities on the neutral Higgs boson contributions and the CP parameter sinθin the model III. We observe that to determine the neutral Higgs boson effects, the measurements of the forward-backward asymmetry and the CP-violating asymmetry in the forward-backward asymmetry for the dec…
We propose a new mechanism for late cosmological baryon asymmetry in models with first order electroweak phase transition. Lepton asymmetry arises through the decay of particles produced out of equilbrium in bubble collisions and is converted into baryon asymmetry by sphalerons. Supersymmetric models with explicitly broken R-parity may provide a suiatble framework for the implementation of this mechanism.
In the Minimal Supersymmetric Standard Model (MSSM) with complex parameters, one-loop corrections to the decay of a stop into a bottom-quark and a chargino can lead to a CP violating decay rate asymmetry. We perform a detailed numerical analysis of this asymmetry and also of the branching ratio of the decay, analyzing the dependence on the parameters and complex phases involved. In addition, we take the Yukawa couplings of the top- and bottom-quark running. We account for the constraints on the parameters coming from the experimental limit of the electric dipole moment of the electron by calcu…
We study the decay rate of process B->K l+ l- (l=e,mu) and some of its other related observables, like forward backward asymmetry (A_{FB}), polarization asymmetry (PA) and CP-asymmetry (A_{CP}) in R-parity violating (R_{p}) Minimal Supersymmetric Standard Model (MSSM). The analysis shows that R_{p}Yukawa coupling products contribute significantly to the branching fraction of B->K l+ l- within 1 sigma and 2 sigma. Study shows that PA and A_{FB} are sensitive enough to R_{p}Yukawa coupling products and turn out to be good predictions for measurement in future experiments.The CP-asymmetry calcula…
We explore possible asymmetric dark matter models using CP violating scatterings to generate an asymmetry. In particular, we introduce a new model, based on DM fields coupling to the SM Higgs and lepton doublets, a neutrino portal, and explore its UV completions. We study the CP violation and asymmetry formation of this model, to demonstrate that it is capable of producing the correct abundance of dark matter and the observed matter-antimatter asymmetry. Crucial to achieving this is the introduction of interactions which violate CP with a $T^{2}$ dependence.
In the following work we consider the possibility of explaining the observed baryon number asymmetry in the universe from simple baryon number violating modifications, involving massive scalar bosons, to the Standard Model. In these cases baryon number violation is mediated through a combination of Yukawa and scalar self-coupling interactions. Starting with a previously compiled catalogue of baryon-number violating extensions of the Standard Model, we identify the minimal subsets which can induce a $B-L$ asymmetry and thus be immune to sphaleron washout. For each of these models, we identify t…
The measurement of CP asymmetries in charged B meson decays might provide the first demonstration of CP violation outside the K system. Among the usual three CP-odd phases $α$, $β$ and $γ$, the phase $γ$ seems to be the most difficult to explore experimentally. In this talk I would like to report on a recent analysis of the CP asymmetry in the partial widths for the non-leptonic decays $B^{\pm} \to M {\bar M} π^{\pm}$ ($ M = π^+, K ^+, π^0, η$), which results from the interference of the non-resonant decay amplitude with the resonant amplitude for $B^{\pm} \to χ_{c0} π^{\pm} $ followed by the …
We calculate CP-violating rate asymmetries in the rare radiative decays $B^\pm\rightarrow K^{\ast\pm} γ$ and $B^\pm\rightarrow ρ^\pm γ$. They arise because of the interference between leading-order penguin amplitudes and one-gluon corrections with absorptive phases, and provide unambiguous evidence for direct CP violation. Complementing earlier studies, we also investigate gluon exchange with the `spectator' quark. The bound state effects in the exclusive matrix elements are taken into account by a covariant model, which yields a branching ratio $BR(B\rightarrow K^\ast γ) = (4-5)\times 10^{-5}…
The existence of baryon asymmetry and dark matter in the Universe may be related to CP-violating reactions of three heavy neutral leptons (HNLs) with masses well below the Fermi scale. The dynamical description of the lepton asymmetry generation, which is the key ingredient of baryogenesis and of dark matter production, is quite complicated due to the presence of many different relaxation time scales and the necessity to include quantum-mechanical coherent effects in HNL oscillations. We derive kinetic equations accounting for fermion number violating effects missed so far and identify one of …
We study baryogenesis through lepton number violation in left-right symmetric models. In these models the lepton number and CP violating interactions of the triplet higgs scalars can give rise to lepton number asymmetry through non-equilibrium decays of the $SU(2)_L$ triplet higgs and the right handed neutrinos. This in turn generates baryon asymmetry during the electroweak anomalous processes.
The interaction of bottom squark-mediated top quark pair production, occurring in the R-parity violating minimal supersymmetric standard model (MSSM), is proposed as an explanation of the anomalously large $t\bar{t}$ forward-backward asymmetry (FBA) observed at the Tevatron. We find that this model can give a good fit to top quark data, both the inclusive and invariant mass-dependent asymmetries, while remaining consistent (at the 2-$σ$ level) with the total and differential production cross-sections. The scenario is challenged by strong constraints from atomic parity violation (APV), but we p…
Weak interactions are expected to induce a parity violating pion-nucleon coupling, h_{πNN}^{(1)}. This coupling should be measurable in a proposed experiment to study the parity violating asymmetry A_γin the process \vec n + p \to d+γ. We compute the leading dependence of A_γon the coupling h_{πNN}^{(1)} using recently developed effective field theory techniques and find an asymmetry of A_γ= +0.17 h_{πNN}^{(1)} at leading order. This asymmetry has the opposite sign to that given by Desplanques, Donoghue and Holstein.
We consider a minimal grand unified model where the dark matter arises from non-thermal decays of a messenger particle in the TeV range. The messenger particle compensates for the baryon asymmetry in the standard model and gives similar number densities to both the baryon and the dark matter. The non-thermal dark matter, if massive in the GeV range, could have a free-streaming scale in the order of 0.1 Mpc and potentially resolve the discrepancies between observations and the LCDM model on the small scale structure of the Universe. Moreover, a GeV scale dark matter naturally leads to the obser…
We study the differential branching ratio, forward-backward asymmetry, CP-violating asymmetry, CP-violating asymmetry in the forward-backward asymmetry and polarization asymmetries of the final lepton in the B-> X_d \ell^+\ell^- decays in the context of a CP softly broken two Higgs doublet model. We analyze the dependencies of these observables on the model parameters by paying a special attention to the effects of neutral Higgs boson (NHB) exchanges and possible CP violating effects. We find that NHB effects are quite significant for the τmode. The above-mentioned observables seems to be prom…
We investigate the possibility of obtaining sizeable R-parity breaking interactions violating baryon number but not lepton number within supersymmetric grand unified theories. Such a possibility allows to ameliorate the naturalness status of supersymmetry while maintaining successful gauge coupling unification, one of its main phenomenological motivations. We show that this can be achieved without fine-tuning or the need of large representations in simple SO(10) models.
Many baryogenesis scenarios invoke the charge parity (CP) violating out-of-equilibrium decay of a heavy particle in order to explain the baryon asymmetry. Such scenarios will in general also allow CP violating scatterings. We study the effect of these CP violating scatterings on the final asymmetry in a neutron portal scenario. We solve the Boltzmann equations governing the evolution of the baryon number numerically and show that the CP violating scatterings play a dominant role in a significant portion of the parameter space.
We show that a cosmological baryon asymmetry generated at the GUT scale, which would be destroyed at lower temperatures by sphalerons and possible new B- or L-violating effects, can naturally be preserved by an asymmetry in the number of right-handed electrons. This results in a significant softening of previously derived baryogenesis-based constraints on the strength of exotic B- or L-violating interactions.
If the present baryon-asymmetry is due to a Planck or GUT-scale matter asymmetry then baryon- or lepton-number violating processes are constrained by the condition that they do not subsequently erase this asymmetry. We present a revision of the analysis of sphaleron baryon-number violating processes in the standard model including lepton-mass effects. We find the surprising result that a GUT-scale matter-asymmetry can survive the $B$ and $L$ violating sphaleron interactions even though ($B- L$) is conserved and equals zero for all temperatures. We extend the analysis to cover the minimal super…
We reexamine the idea that bilinear R-parity violating couplings can be responsible for leptogenesis. We prove that, to have lepton number violation before the electroweak phase transition, misalignment between the lepton-Higgsino and slepton-Higgs sectors must be involved. The processes that generate a lepton asymmetry are bino or wino decays into a lepton-Higgs and slepton-Higgsino final states. Since these decays occur mainly while the gauginos are still in thermal equilibrium, they quantitatively fail to produce the observed baryon asymmetry of the universe.
We revisit the results of recent electroweak baryogenesis calculations and include all allowed large CP-violating supersymmetric phases. If the phases are large, the resulting baryon asymmetry can be considerably larger than the observed value $n_B/s \sim 4 \times 10^{-11}$. Much of the asymmetry must therefore be washed out, and we argue that the upper bound on the light Higgs mass is larger than the value reported in previous work.
We show that an anomalous CP-violating gamma-gamma-Z vertex gives rise to a novel asymmetry with transversely polarized electron and positron beams in the process e+e- -> gamma Z. This asymmetry, which is odd under naive time reversal, is proportional to the real part of the gamma-gamma-Z CP-violating coupling. This is in contrast to the simple forward-backward asymmetry of the gamma (or Z) with unpolarized or longitudinally polarized beams studied earlier, which is even under naive time reversal, and is proportional to the imaginary part. We estimate the sensitivity of future experiments to t…
QED radiative corrections have been calculated for leptonic and hadronic variables in parity-violating elastic ep scattering. For the first time, the calculation of the asymmetry in the elastic radiative tail is performed without the peaking-approximation assumption in hadronic variables configuration. A comparison with the PV-A4 data validates our approach. This method has been also used to evaluate the radiative corrections to the parity-violating asymmetry measured in the G0 experiment. The results obtained are here presented.
Lepton flavor violating processes $μ\to e γ$ and $μ\to 3e$ with polarized muons are studied in the supersymmetric grand unified theory (SUSY GUT). As a result of a detailed numerical calculation, it is shown that the P- and T-odd asymmetries defined with the help of the muon polarization and the ratio of two branching fractions make a good contrast between the SU(5) and SO(10) SUSY GUT. These observables are useful to extract differences of the two theories. In particular, the P-odd asymmetry of $μ\to e γ$ varies 100%--100% in SO(10) whereas it is 100% in SU(5) and the T-odd asymmetry of $μ\to…
We study the differential branching ratio, forward-backward asymmetry, CP-violating asymmetry, CP-violating asymmetry in the forward-backward asymmetry and polarization asymmetries in the $B -> K \ell^+ \ell^-$ and $B -> K^* \ell^+ \ell^-$ decays in the context of a CP softly broken two Higgs doublet model. We analyze the dependencies of these observables on the model parameters by paying a special attention to the effects of neutral Higgs boson (NHB) exchanges and possible CP violating effects. We find that NHB effects are quite significant for both decays. A combined analysis of above-mentio…
