We study in detail the mechanism of baryon and lepton asymmetry generation in the framework of the $ν$MSM (an extension of the Standard Model by three singlet fermions with masses smaller than the electroweak scale). We elucidate the issue of CP-violation in the model and define the phase relevant for baryogenesis. We clarify the question of quantum-mechanical coherence, essential for the lepton asymmetry generation in singlet fermion oscillations and compute the relevant damping rates. The range of masses and couplings of singlet leptons which can lead to successful baryogenesis is determined. The conditions which ensure survival of primordial (existing above the electroweak temperatures) asymmetries in different leptonic numbers are analysed. We address the question whether CP-violating reactions with lepton number non-conservation can produce leptonic asymmetry {\em below} the sphaleron freeze-out temperature. This asymmetry, if created, leads to resonant production of dark matter sterile neutrinos. We show that the requirement that a significant lepton asymmetry be produced puts stringent constraints on the properties of a pair of nearly degenerate singlet fermions, which can be tested in accelerator experiments. In this region of parameters the $ν$MSM provides a common mechanism for production of baryonic matter and dark matter in the universe. We analyse different fine-tunings of the model and discuss possible symmetries of the $ν$MSM Lagrangian that can lead to them.
We consider the leptonic asymmetry generation in the nuMSM via hadronic decays of sterile neutrinos at T<<T_{EW}, when the masses of two heavier sterile neutrinos are between pion mass and 2 GeV. The choice of upper mass bound is motivated by absence of direct experimental searches for singlet fermions with greater mass. We carried out computations at zero temperature and ignored the background effects. Combining constraints of sufficient value of the leptonic asymmetry for production of dark matter particles, condition for sterile neutrino to be out of thermal equilibrium and existing experim…
We study the forward-backward and the CP-violating asymmetries (both time-independent and time-dependent) in rare semileptonic and radiative leptonic B_{d,s}-decays and investigate the sensitivity of these asymmetries to the extensions of the Standard model.
A low-energy non-unitary leptonic mixing matrix is a generic effect of some theories of new physics accounting for neutrino masses. We show how the extra CP-phases of a general non-unitary matrix allow for sizeable CP-asymmetries in the $ν_μ\to ν_τ$ channel. This CP-asymmetries turns out to be an excellent probe of such new physics.
The non-leptonic two body decays of D mesons are studied in the framework of an improved factorization approximation. The final state interaction effects are taken into account assuming them dominated by nearby resonances. The agreement with experimental data is quite good. CP-violating asymmetries are predicted.
Leptonic flavor-changing $H^0$ decays with branching ratios of the order of $10^{-5}-10^{-6}$ may constitute an interesting framework when looking for large $CP$-violating effects. We show that leptonic $CP$~asymmetries of an intermediate $H^0$ boson can be fairly large in natural scenarios of the minimal Standard Model ($SM$) with right-handed neutrinos, at a level that may be probed at future $H^0$~factories.
We present a study of non-leptonic B-meson decays, partial widths and CP asymmetries, and discuss the possibilities of determining the penguin contributions through less model-dependent phenomenological analyses. In the last section we employ a specific model to give more definite numerical predictions.
We compute, for $t \bar t$ production at the LHC and at the Tevatron, several charge asymmetries to NLO QCD, including also the electromagnetic and weak-interaction corrections. We calculate these asymmetries both inclusively and with additional kinematic cuts and compare our results, where possible, with recent experimental results and with SM predictions. The $t \bar t$ asymmetries induce also corresponding asymmetries for the charged leptons from semileptonic top-quark decay. Although these asymmetries are, in the SM, smaller than the corresponding ones for top quarks, they are expected to …
Motivated by recent indications that the rates of colour-allowed non-leptonic channels are not in agreement with their Standard Model expectations based on QCD factorisation, we investigate the potential to study CP asymmetries with these decays. In the Standard Model, these flavour-specific decays are sensitive to CP violation in $B^0_{(s)}$--$\bar{B}^0_{(s)}$ mixing, which is predicted with low uncertainties and can be measured precisely with semileptonic decays. If there are beyond Standard Model contributions to the non-leptonic decay amplitudes, there could be significant enhancements to …
We study the contribution of the squark flavor mixing from the $LR(RL)$ component of the squark mass matrices to the direct CP violation of the $b\to sγ$ decay and the CP-violating asymmetry in the non-leptonic decays of $B$ mesons. The magnitude of the $LR(RL)$ component is constrained by the branching ratio and the direct CP violation of $b\to sγ$. We predict the correlation of the CP asymmetries among $A_{\text{CP}}^{b \to s γ}$, $\mathcal{S}_{ϕK_S}$ and $\mathcal{S}_{η'K^0}$ of the B decays. The precise data of these CP violations will give us the crucial test for our framework of the squa…
Semi-leptonic and leptonic decays of B-mesons are important probes for testing SM and theories beyond it because of their relative cleanliness and far less theoretical uncertainties. In semi-leptonic decays based on quark level transition $b \to s τ^+ τ^-$ apart from branching ratio one can study many other (possible) observables associated with final state leptons like, lepton pair Forward Backward asymmetry, lepton polarization asymmetries etc. But as proposed recently if we can tag the B-meson than one can measure the polarization asymmetries of both the leptons. Here we will study the pola…
We consider charmless weak decays of beauty-baryons into decuplet baryons and pseudoscalar mesons in a general framework based on $SU(3)$-flavor decomposition of the decay amplitudes. The dynamical assumption independent $SU(3)$ analysis accounts for the effects of an arbitrarily broken $SU(3)$ symmetry in these decays. An alternative approach in terms of quark diagrams is also provided and compared with the $SU(3)$ decomposition in the limit of exact $SU(3)$-flavor symmetry. Furthermore, the symmetries of the effective Hamiltonian is used to relate or neglect reduced $SU(3)$ amplitudes to der…
We examine the effects of the R parity odd renormalizable interactions on flavor changing rates and CP violation asymmetries in the production of fermion-antifermion pairs at $e^-- e^+$ leptonic colliders. The produced fermions may be leptons, down-quarks or up-quarks, and the center of mass energies may range from the Z-boson pole up to $ 1000$ GeV. Off the Z-boson pole, the flavor changing rates are controlled by tree level amplitudes and the CP asymmetries by interference terms between tree and loop level amplitudes. At the Z-boson pole, both observables involve loop amplitudes. The lepton …
Using existing experimental information from K, B and D decays as well as electroweak precision tests and oblique parameters, we provide constraints and correlations on the parameters of the 4X4 mixing matrix for the Standard Model with four generations (SM4). We emphasize that some correlations amongst the parameters have important repercussions for key observables. We work with a particular representation of this matrix which is highly suited for extracting information from B-decays. Implications of the resulting constraints for time dependent and semileptonic CP asymmetries for $D^0$, $B^0$…
We consider hadronic weak decays of beauty-baryons into charmless baryons and pseudoscalar mesons in a general framework based on $SU(3)$ decomposition of the decay amplitudes. The advantage of the approach lies in the ability to perform an $SU(3)$ analysis of these decays without any particular set of dynamical assumptions while accounting for the effects of an arbitrarily broken $SU(3)$ flavor symmetry. Dictated by the symmetries of the effective Hamiltonian that allow us to relate or neglect reduced $SU(3)$ amplitudes, we derive several sum rule relations between amplitudes and relations be…
We examine the effect of the R parity odd renormalizable interactions on flavor non-diagonal rates and CP violation asymmetries in the production of slepton pairs at $e^- - e^+$ leptonic colliders, for center of mass energies spanning the interval from the Z-boson pole up to 1000 GeV. The lepton number violating interactions, associated with the lepton number violating coupling constants, are assumed to incorporate CP odd complex phases. The flavor changing rates are controlled by tree level amplitudes and quadratic products of different R parity violating coupling constants and the CP asymmet…
The relatively clean theoretical probes of the Standard Model (SM), and the various theories beyond the SM, provided by radiative, semi-leptonic and (purely) leptonic decays of B-mesons have become increasingly important. Due to the large number of possible distributions in the semi-leptonic decays based on the quark level transition $b \to s \ell^+ \ell^-$ (not just the branching ratio), these transitions have become very useful. A study of the Forward-Backward asymmetries for the inclusive decay ($B \to X_s \ell^+ \ell^-$) is carried out in this paper. This study shall be performed in the SM…
We consider the possibility of violations of the selection rule $ΔS=ΔQ$ at an appreciable level in {\it exclusive} semi-leptonic decays of Kaons. At $Φ$-Factories, intense Kaon beams will be available and will probe among others, the semi-leptonic decays $K_{l4}$ and $K_{l3γ}$ in addition to $K_{l3}$ and could provide novel testing grounds for the $ΔS=ΔQ$ rule. In particular, the branching ratio of $K_{l3γ}$ is non-negligible and could be used to probe new phenomena associated with the violation of this selection rule. Furthermore, we modify certain di-lepton event rate ratios and asymmetries …
In this work we shall derive expressions for the single and double lepton polarization asymmetries for the exclusive decay $B \to K^* \ell^+ \ell^-$, using the most general model independent effective Hamiltonian. We have conducted this study with this particular channel as it has the highest branching ratio among the various purely leptonic and semi-leptonic decay modes, making this mode particularly useful for studying physics beyond the SM. We have also analyzed the effects on these polarization asymmetries, and hence the physics underlying it, when complex phases are included in some of th…
The computation of direct CP asymmetries in charmless B decays at next-to-next-to-leading order (NNLO) in QCD is of interest to ascertain the short-distance contribution. Here we compute the two-loop penguin contractions of the current-current operators Q_{1,2} and provide a first estimate of NNLO CP asymmetries in penguin-dominated b -> s transitions.
Among the various "rare" semi-leptonic decays of $B$-mesons the $B \to K^* \ell^+ \ell^-$ mode is of special interest. This is because it has the highest branching ratio among all the semi-leptonic B decays within the SM. This channel also provides us with a very large number of possible observables, such as the Forward Backward (FB) asymmetry, lepton polarization asymmetry etc. Of special interest is the zero which the FB asymmetry has in this decay mode. In this work we have studied this zero in the most general model independent framework.
The vertex corrections to the leptonic partial widths of the $Z$ induced by leptoquarks that couple leptons to the top quark are considered. We obtain stringent bounds on the parameter space of the masses and Yukawa couplings of these leptoquarks, using the latest information on the $Z \rightarrow l^+l^-$ decay widths measured at LEP. Leptoquarks coupling with electroweak strength to top quarks are constrained to be heavier than several hundred GeV, at 95$\%$ C.L. As a consequence, such leptoquarks cannot make a significant contribution to lepton asymmetries, $τ$ polarisation asymmetries or $A…
We investigate quantitatively the extent to which having a primordial leptonic asymmetry (n_nu \neq n_nubar) relaxes the bounds on light sterile neutrinos imposed by BBN and LSS. We adopt a few assumptions that allow us to solve the neutrino evolution equations over a broad range of mixing parameters and asymmetries. For the general cases of sterile mixing with the electron or muon neutrino, we identify the regions that can be reopened. For the particular case of a LSND-like sterile neutrino, soon to be rejected or confirmed by MiniBooNE, we find that an asymmetry of the order of 10^-4 is need…
We propose CP asymmetries based on triple product correlations in the decays sbottom_m -> top chargino_j with subsequent decays of top and chargino_j. For the subsequent chargino_j decay into a leptonic final state l^- νneutralino_1 we consider the three possible decay chains chargino_j -> l^- sneutrino -> l^- νneutralino_1, chargino_j -> slepton_n ν-> l^- νneutralino_1 and chargino_j -> W^- neutralino_1 -> l^- νneutralino_1. We consider two classes of CP asymmetries. In the first class it must be possible to distinguish between different leptonic chargino_j decay chains, whereas in the second…
Leptonic and semi-leptonic rare decays of B-mesons are very clean (both theoretically and experimentally) signatures of any new physics beyond the Standard Model (SM). More specifically the decay \btokll has been theoretically observed to be very sensitive to new physics as the Forward Backward (FB) asymmetry in this decay mode vanishes in the SM. Supersymmetry, however, predicts a non-vanishing value of this asymmetry. In this work we will study the polarized lepton pair FB asymmetry, i.e. the FB asymmetry of the lepton when one (or both) final state lepton(s) are polarized. We will study the…
We present estimates of the direct (in decay amplitudes) and indirect (mixing- induced) CP-violating asymmetries in the non-leptonic charmless two-body decay rates for $B \to PP$, $B \to PV$ and $B \to VV$ decays and their charged conjugates, where P(V) is a light pseudoscalar (vector) meson. These estimates are based on a generalized factorization approach making use of next-to-leading order perturbative QCD contributions which generate the required strong phases. No soft final state interactions are included. We study the dependence of the asymmetries on a number of input parameters and show…
The semi-leptonic baryonic $b\to s$ decay, $Λ_b\rightarrow Λ\ell^+\ell^-$, has been studied and new angular observables and asymmetries have been proposed which can test the presence of new physics beyond the standard model.
We investigate hard-thermal-loop (HTL) corrections to the CP-asymmetries in neutrino and, at high temperature, Higgs boson decays in leptogenesis. We pay special attention to the two leptonic quasiparticles that arise at non-zero temperature and find that there are four contributions to the CP-asymmetries, which correspond to the four combinations of the two leptonic quasiparticles in the loop and in the final states. In two additional cases, we approximate the full HTL-lepton propagator with a zero-temperature propagator that employs the thermal lepton mass m_l(T), or the asymptotic thermal l…
In this paper we study the polarization asymmetries of the final state lepton in the radiative dileptonic decay of B meson (\bsllg) in the framework of Minimal Supersymmetric Standard Model (MSSM) and various other unified models within the framework of MSSM e.g. mSUGRA, SUGRA (where condition of universality of scalar masses is relaxed) etc. Lepton polarization, in addition of having a longitudinal component (\pl), can have two other components, \pt and \pn, lying in and perpendicular to the decay plane, which are proportional to \ml and hence are significant for final state being $μ^+ ~ μ^-$…
We study the lepton polarization asymmetries in the radiative leptonic B decays of $B^+\to l^+ν_{l}γ$ and $B^+_{c}\to l^+ν_{l}γ$. We concentrate on the transverse component of the $τ$ lepton asymmetries in the tau decay modes due to CP violation in theories beyond the standard model to search T violating effect.
In this work we calculate the branching ratios of semi-leptonic and non-leptonic decays of $Λ_b$ into light baryons ($p$ and $Λ$), as well as the measurable asymmetries which appear in the processes, in the light front quark model (LFQM). In the calculation, we adopt the diquark picture and discuss the justifiability of applying the picture in our case. Our result on the branching ratio of $Λ_b\toΛ+J/ψ$ is in good agreement with data. More predictions are made in the same model and the results will be tested in the future experiments which will be conducted at LHCb and even ILC.
We perform a comprehensive SU(3)-flavor analysis of charmed mesons decaying to two pseudoscalar SU(3)-octet mesons. Taking into account SU(3)-breaking effects induced by the splitting of the quark masses, m_s != m_{u,d}, we find that existing data can be described by SU(3)-breaking of the order 30%. The requisite penguin enhancement to accomodate all data on CP violation tends to be even larger than the one extracted from Delta a_{CP}^{dir}(K^+K^-,pi^+pi^-) alone, strengthening explanations beyond the standard model. Despite the large number of matrix elements, correlations between CP asymmetr…
We study the effects on the leptonic asymmetries A_{FB}, A_{pol} and A_{LR} coming from a model of compositeness. We consider the effects coming from the self-energies and the vertex correction to $Z l^+ l^-$. Thus we use the Altarelli parametrization of the oblique corrections. We get the asymptotic limits of these corrections in terms of the parameters $(m^*, Λ, f, f')$ and we get bounds for the quotient $m^*/Λ$ with different values of $(f, f')$. We conclude that both asymmetries produce bounds for such quotient when $f'$ overweigth to $f$, and this fact is related with the breakdown of the…
Precision measurements of branching fractions and CP asymmetries in non-leptonic b -> s decays reveal certain "puzzles" when compared with Standard Model expectations based on a global fit of the CKM triangle and general theoretical expectations. Without reference to a particular model, we investigate to what extent the (small) discrepancies observed in (B -> J/psi K), (B -> phi K) and (B -> K pi) may constrain new physics in (b -> s q qbar) operators. In particular, we compare on a quantitative level the relative impact of different quark flavours q=c,s,u,d.
We present the NLO QCD corrections to the processes p p and p anti-p to W+ W- b anti-b including leptonic decays of the W bosons. Non-resonant contributions as well as diagrams with doubly resonant and singly resonant top quark propagators are fully taken into account. We employ the narrow width approximation to perform the decays of the W bosons; spin correlations are however preserved. We also calculate observables relevant for top quark mass measurements, and study the impact of kinematical requirements and different scale choices on t anti-t asymmetries.
A novel contribution to the leptonic CP asymmetries in type II seesaw leptogenesis scenarios is obtained for the cases in which flavor effects are relevant for the dynamics of leptogenesis. In the so-called flavoured leptogenesis regime, the interference between the tree-level amplitude of the scalar triplet decaying into two leptons and the one-loop wave-function correction with leptons in the loop, leads to a new nonvanishing CP asymmetry contribution. The latter conserves total lepton number but violates lepton flavour. Cases in which this novel contribution may be dominant in the generatio…
In the presence of an electric dipole coupling of t-tbar to a photon, and an analogous "weak" dipole coupling to the Z, CP violation in the process e+e- --> t tbar results in modified polarization of the top and anti-top. This polarization can be analyzed by studying the angular distributions of decay charged leptons when the top or anti-top decays leptonically. Analytic expressions are presented for these distributions when either t or tbar decays leptonically, including O(alpha_s) QCD corrections in the soft-gluon approximation. The angular distributions are insensitive to anomalous interact…
We define a lepton-based asymmetry in semi-leptonic ttbar production at the LHC. We show that the ratio of this lepton-based asymmetry and the ttbar charge asymmetry, measured as a function of the lepton transverse momentum or the ttbar invariant mass is a robust observable in the Standard Model. It is stable against higher order corrections and mis-modeling effects. We show that this ratio can also be a powerful discriminant among different new physics models and between them and the Standard Model. Finally, we show that a related ratio defined at the Tevatron is also robust as a function of …
In the presence of an electric dipole coupling of the top quark to a photon, and an analogous "weak" dipole coupling to the Z, CP violation in the process e+e- -> t tbar leads to the polarization of the top and anti-top. This polarization can be analyzed by studying the angular distributions of decay charged leptons when the top or anti-top decays leptonically. We have obtained analytic expressions for these distributions when either t or tbar decays leptonically, including O(alpha_s) QCD corrections in the soft-gluon approximation. The angular distributions are insensitive to anomalous intera…
Charged lepton transverse momenta in the Drell-Yan processes play an important role at the LHC in precision measurements of the Standard Model parameters, such as the W-boson mass and width, their charge asymmetries and sin^2(theta_W). Therefore, their distributions should be described as accurate as possible by the Monte Carlo event generators. In this paper we discuss the problem of matching the hard-process kinematics of the Monte Carlo generator WINHAC with the parton-shower kinematics of the PYTHIA 6.4 generator while interfacing these two programs. We show that improper assignment of the…
We discuss lepton charge asymmetries in $t \bar t$ and $t \bar t γ$ production at the LHC, which can be measured in the semileptonic decay channel $t \bar t \to W^+ b \, W^- \bar b \to \ell^+ νb \, q \bar q' \bar b$ (or the charge conjugate). Considering several variants of a new physics scenario with a light colour octet, it is seen that for $t \bar t$ these asymmetries may have a sensitivity competitive with the dilepton asymmetry already measured. For $t \bar t γ$ the new leptonic asymmetries, as well as the $t \bar t$ charge asymmetry, will reach their full potential with the high luminosi…
Tensor operators are often invoked as specific new physics operators beyond the standard model in an effort to explain anomalies in rare B-decays and CP asymmetries. Specifically, $b \to s μ^+μ^-$ tensor operators are invoked in the study of semi-leptonic decays, both inclusive and exclusive. In this note we use the data on $b \to s$ radiative decay modes and CP asymmetries to tightly constrain the tensor operators. It is found that constraints thus obtained are tighter than those from semi-leptonic modes. We also comment on $b \to ss\bar{s}$ tensor operators that help in explaining the $B \to…
We study implications of a recent observation of non-leptonic $B^+_c\to D^0 K^+$ decay and a bound on $B^+_c\to D^0 π^+$ transition on CP-violating asymmetries in $B_c$ decays. In the U-spin symmetry limit, we derive a relation between the CP-asymmetries in the $B^+_c\to D^0 K^+$ and $B^+_c\to D^0 π^+$ channels and the corresponding branching ratios. We also derive several relations between non-leptonic $B_c$ decays into the final states with $D$ mesons in the flavor $SU(3)_F$ limit. We point out that a combined study of $SU(3)_F$ amplitudes in these decays can be used to constrain the angle $…
In this paper, we examine the leptonic flavor invariants in the minimal seesaw model (MSM), in which only two right-handed neutrino singlets are added into the Standard Model in order to accommodate tiny neutrino masses and explain cosmological matter-antimatter asymmetry via leptogenesis mechanism. For the first time, we calculate the Hilbert series (HS) for the leptonic flavor invariants in the MSM. With the HS we demonstrate that there are totally 38 basic flavor invariants, among which 18 invariants are CP-odd and the others are CP-even. Moreover, we explicitly construct these basic invari…
Rates and CP asymmetries of the non-leptonic two-body decay of $B_c$ are calculated based on the low energy effective Hamiltonian. We concentrate on such $b$ quark decays of the processes with $0^-$ and $1^-$ S-wave particles and/or $0^+$ and $1^+$ P-wave particles in the final states. The Salpeter method, which is the relativistic instantaneous approximation of the original Bethe-Salpeter equation, is used to derive hadron transition matrix elements. Based on the calculation, it is found that the best decay channels to observe CP violation are $B_c^-\rightarrow η_c +D^-(D^{*-}_0)$, which need…
In inclusive deep-inelastic lepton-hadron scattering multi-photon exchange between the leptonic and the hadronic part of the process causes single spin asymmetries. The asymmetries exist for a polarized target as well as a polarized incoming or outgoing lepton, if the polarization vector has a component transverse with respect to the reaction plane. The spin dependent parts of the single polarized cross sections are suppressed like $α_{em} m_{pol}/Q$ - where $m_{pol}$ denotes the mass of the polarized particle - compared to the leading terms of the cross section for unpolarized or double-polar…
We revisit the production of leptonic asymmetries in minimal extensions of the Standard Model that can explain neutrino masses, involving extra singlets with Majorana masses in the GeV scale. We study the quantum kinetic equations both analytically, via a perturbative expansion up to third order in the mixing angles, and numerically. The analytical solution allows us to identify the relevant CP invariants, and simplifies the exploration of the parameter space. We find that sizeable lepton asymmetries are compatible with non-degenerate neutrino masses and measurable active-sterile mixings.
We investigate several quantities, defined in the decays of top quark pairs, which can be used to explore non-standard Wtb interactions. Two new angular asymmetries are introduced in the leptonic decay of top (anti)quarks. Both are very sensitive to anomalous Wtb couplings, and their measurement allows for a precise determination of the W helicity fractions. We also examine other angular and energy asymmetries, the W helicity fractions and their ratios, as well as spin correlation asymmetries, analysing their dependence on anomalous Wtb couplings and identifing the quantities which are most se…
We examine the leptonic forward-backward and polarization (left-right) asymmetries in the dileptonic B -> X_s l^+ l^- decay when the momentum dependence of $ψ$ and $ψ'-γ$ conversion strength is taken into account. The results indicate only a small shift in the asymmetry distributions.
We consider a simple extension of the Standard Model by adding two Higgs triplets and a complex scalar singlet to its particle content. In this framework, the CP symmetry is spontaneously broken at high energies by the complex vacuum expectation value of the scalar singlet. Such a breaking leads to leptonic CP violation at low energies. The model also exhibits an $A_4\times Z_4$ flavour symmetry which, after being spontaneously broken at a high-energy scale, yields a tribimaximal pattern in the lepton sector. We consider small perturbations around the tribimaximal vacuum alignment condition in…
Isosinglet fermions naturally arise in a variety of extensions of the Standard Model, in particular in models with extra dimensions. In this paper, we study the effect of the addition of a new isosinglet charged lepton to the standard spectrum, with special emphasis on implications for neutrino asymmetries to be measured at future neutrino factories. Lepton flavour violation in neutral current and lepton universality constraints are extensively discussed. We show that new physics effects in $ν_e-ν_μ$ CP asymmetries are significantly enhanced due to leptonic maximal mixings but still too small …
We calculate the CP-averaged branching ratios and CP-violating asymmetries of a number of two-body charmless hadronic decays $\bar{B_s^0} \to PP, PV, VV$ in the perturbative QCD (pQCD) approach to leading order in $α_s$ (here $P$ and $V$ denote light pseudoscalar and vector mesons, respectively). The mixing-induced CP violation parameters are also calculated for these decays. We also predict the polarization fractions of $B_s \to VV$ decays and find that the transverse polarizations are enhanced in some penguin dominated decays such as $\bar{B_s^0} \to K ^{*}\bar{K^{*}}$, $K ^{*}ρ$. Some of th…
Finding \cp~violation (\CPV ) in 1964 produced a real revolution in the fundamental dynamics, although the community did not understand it right away. The paper by Kobayashi \& Maskawa \cite{KM} appeared in 1973 to describe \CPV~in classes of three (or more) families of quarks, non-minimal Higgs' dynamics and/or charged right-handed currents. The Standard Model is defined now with three families of quarks. It can describe the measured \cp~ \& \ot~violation in kaon and $B$ mesons at least as the leading source. None has been found in baryons, charm mesons, top quarks and EDMs -- except from `ho…
The extension of the standard model with new high-scale weakly coupled physics involving right-handed neutrinos in an effective field theory framework (SMNEFT) allows for a systematic study of heavy neutrinos phenomenology in current and future experiments. We exploit the outstanding angular resolution in future lepton colliders to study the sensitivity of forward-backward asymmetries to discover the possible single production of heavy Majorana neutrinos via $e^{+}e^{-} \to N ν$, followed by a purely leptonic decay $N \to μ^{-} μ^{+} ν$ or a semi-leptonic decay $N \to μ^{-} \mathrm{j} \mathrm{…
