We analyze the effect of flavor changing neutral currents within 331 models. In particular, we concentrate in the so-called "economical" models, which have a minimal scalar sector. Taking into account the experimental measurements of observables related to neutral K and B meson mixing, we study the resulting bounds for angles and phases in the mixing matrix for the down quark sector, and the mass and mixing parameters related to the new Z' gauge boson.
We investigate Lepton-Flavor Violating (LFV) decays of Higgs to muon-tau in the supersymmetric economical 3-3-1 (SUSYE331) model. In the presence of flavor mixing in sleptons {mu,tau} and large values of v/v', the ratio of Br(H -->tau^+mu^-)/Br(H -->tau^+tau^-) can reach to non-negligible values O(10^{-3}), as in many known SUSY models. We predict that for the Standard Model Higgs boson, the LHC may detect its decay to muon and tauon. We also investigate the asymmetry between left and right LFV values of corrections and prove that the LFV effects are dominated by the left FLV term, which is O(…
Interactions among the standard model gauge bosons and scalar fields in the framework of SU(3)_C X SU(3)_L X U(1)_X gauge model with minimal (economical) Higgs content are presented. From these couplings, all scalar fields including the neutral scalar $h$ and the Goldstone bosons can be identified and their couplings with the usual gauge bosons such as the photon, the charged $W^\pm$ and the neutral $Z$, without any additional condition, are recovered. In the effective approximation, full content of scalar sector can be recognized. The CP-odd part of Goldstone associated with the neutral non-H…
In this work we compute all relevant contributions stemming from the economical 3-3-1 model to the muon magnetic moment and the lepton flavor violation decay $μ\rightarrow eγ$. Using the current bounds on these phenomena, we derive lower limits on the scale of symmetry breaking of the model. Moreover, taking into account existing limits from meson and collider studies we show that there is still room for a possible signal in $μ\rightarrow eγ$ in the near future.
The supersymmetric extension of the economical 3-3-1 model is presented. The constraint equations and the gauge boson identification establish a relation between the vacuum expectation values (VEVs) at the top and bottom elements of the Higgs triplet $χ$ and its supersymmetric counterpart $χ^\prime$. Because of this relation, the exact diagonalization of neutral gauge boson sector has been performed. The gauge bosons and their associated Goldstone ones mix in the same way as in non-supersymmetric version. This is also correct in the case of gauginos. The eigenvalues and eigenstates in the Higg…
In this report the SU(3)_C X SU(3)_L X U(1)_X gauge model with minimal scalar sector, two Higgs triplets, is presented in detail. One of the vacuum expectation values $u$ is a source of lepton-number violations and a reason for mixing among charged gauge bosons--the standard model W^\pm and the bilepton gauge bosons Y^\pm as well as among the neutral non-Hermitian bilepton X^0 and neutral gauge bosons--the Z and the new Z'. An exact diagonalization of the neutral gauge boson sector is derived and bilepton mass splitting is also given. Because of these mixings, the lepton-number violating inter…
The deviation $\de Q_{\mathrm{W}}$ of the weak charge from its standard model prediction due to the mixing of the $W$ boson with the charged bilepton $Y$ as well as of the $Z$ boson with the neutral $Z'$ and the real part of the non-Hermitian neutral bilepton $X$ in the economical 3-3-1 model is established. Additional contributions to the usual $\de Q_\mathrm{W}$ expression in the extra $\mathrm{U}(1)$ models and the left-right models are obtained. Our calculations are quite different from previous analyzes in this kind of the 3-3-1 models and give the limit on mass of the $Z'$ boson, the $Z-…
We show that the economical 3-3-1 model poses a very high new physics scale of the order of 1000~TeV due to the constraint on the flavor-changing neutral current. The implications of the model for neutrino masses, inflation, leptogenesis, and superheavy dark matter are newly recognized. Alternatively, we modify the model by rearranging the third quark generation differently from the first two quark generations, as well as changing the scalar sector. The resultant model now predicts a consistent new physics at TeV scale unlike the previous case and may be fully probed at the current colliders. …
CP asymmetries for neutral charmed meson decays to CP eigenstates are carefully studied. The formulas and numerical results are presented. The impact on experiments is briefly discussed.
We analyze a contribution of the finite-width (mass-smearing) effects to the mixing of neutral mesons. It was shown, that this contribution is dominant in the D-meson system and large in the K-meson one. An account of the mass-smearing effects allows to explain some discrepancy between standard predictions and experimental data in these cases.
In this talk, the status of CPT tests with neutral mesons is reviewed in the context of quantum field theory and the Lorentz- and CPT-violating standard-model extension.
A sketch of our results on CPT and strings is given. A mechanism for spontaneous CPT violation in string theory is briefly reviewed, and recent theoretical progress is summarized. Possible CPT-violating contributions to a four-dimensional low-energy effective theory could produce effects at levels testable in neutral-meson systems. Likely experimental signatures and attainable bounds are outlined in candidate experiments with correlated and uncorrelated neutral mesons.
A mechanism for spontaneous CPT breaking appears in string theory. Possible implications for present-energy particle models are discussed. A realistic string theory might exhibit CPT violation at levels detectable in current or future experiments. Bounds on CPT from neutral-meson oscillations are considered.
We consider the experimental data on neutral Kstar-meson production on nucleon and nuclear targets. The Quark-Gluon String Model quantitatively describes the inclusive density in the midrapidity region, as well as the initial energy and A dependences of the produced Kstar-mesons.
Minimal CPT violation has been constrained using observations of neutral-meson oscillations. Violation of CPT symmetry arising from nonminimal operators in the Lagrange density can also occur. A general approach using scalar effective field theory is presented and used to infer the effects of nonminimal CPT violation on neutral-meson oscillations.
A general technique is presented for treating CPT violation in neutral-meson oscillations. The effective field theory for a complex scalar with CPT-violating operators of arbitrary mass dimension is incorporated in the formalism for the propagation and mixing of neutral mesons. Observable effects are discussed, and first measurements of CPT-violating operators of dimension five are extracted from existing experimental results.
Certain types of asymmetries in neutral meson physics have not been treated properly, ignoring the difference of normalization factors with an assumption of the equality of total decay width. Since the corrected asymmetries in $B^0$ meson are different from known asymmetries by a shift in the first order of CP- and CPT-violation parameters, experimental data should be analyzed with the consideration of this effect as in $K^0$ meson physics.
This talk provides an overview of a string-based mechanism for spontaneous CPT violation. A summary is given of theoretical developments. The mechanism could generate CPT-violating contributions to a four-dimensional low-energy effective theory and thereby produce detectable consequences for candidate experiments with neutral-meson systems.
This work gives a general overview of phenomenology developed for neutral-meson searches for CPT violation in the framework of the Standard-Model Extension with focus on meson factories. It gives a comparison of notations and fundamental approach in the formalism used by the different experiments. Asymmetries and possible experimental investigations are presented for tests of the momentum-dependent phenomenological parameter of CPT violation in neutral-meson oscillations. The general results apply to any mesons produced as correlated meson pairs and addresses the issue of decoherence as a cons…
The sensitivity of experiments with neutral mesons to possible indirect CPT violation is examined. It is shown that experiments conventionally regarded as equivalent can have CPT reaches differing by orders of magnitude within the framework of a minimal CPT- and Lorentz-violating extension of the standard model.
We re-investigate the scalar potential and the Higgs sector of the supersymmetric economical 3-3-1 model (SUSYE331) in the presence of the B/μtype terms which has many important consequences. First, the model contains no massless Higgs fields. Second, we prove that the soft mass parameters of Higgses must be at the SU(3)_L scale. As a result, the masses of the Higgses drift toward this scale except one light real neutral Higgs with the mass of m_Z|cos(2γ)| at the tree level. We also show that there are some Higgses containing many properties of the Higgses in the minimal supersymmetric standar…
Neutral pseudoscalar mesons in an entangled or Einstein-Podolsky-Rosen state are routinely produced in phi and B factories. Based on the peculiar properties of an entangled state, we present some general exact theorems about parameters characterizing CP and CPT violations, by using various asymmetries defined for the correlated decays of the two entangled mesons, which are rigorously calculated.
CP violation can be observed in B decays when a given process depends upon interference between two weak amplitudes which have different $CP$-violating phases. Since most weak decay diagrams have quark lines where each has a definite flavor label, neutral mesons which are flavor mixtures are particularly interesting. Different diagrams can contribute to the different flavor components of the meson, and the wave function itself provides interference.
The proof of the Khalfin Theorem for neutral meson complex is analyzed. It is shown that the unitarity of the time evolution operator for the total system under considerations assures that the Khalfin's Theorem holds. The consequences of this Theorem for the neutral mesons system are discussed: it is shown, eg., that diagonal matrix elements of the exact effective Hamiltonian for the neutral meson complex can not be equal if CPT symmetry holds and CP symmetry is violated. Properties of time evolution governed by a time--independent effective Hamiltonian acting in the neutral mesons subspace of…
A brief review of checking the factorization hypothesis for matrix element of $B^0 - \bar B^0$ mixing within operator product expansion and QCD sum rules is given. Both perturbative and power corrections are considered.
Antiproton--proton annihilation into light neutral mesons in the few GeV energy domain is investigated in view of a global description of the existing data and predictions for future experiments at PANDA, FAIR. An effective meson model earlier developed, with mesonic and baryonic degrees of freedom in $s$, $t$, and $u$ channels, is applied here to $π^0π^0$ production. Form factors with logarithmic $s$ and $t(u)$ dependencies are applied. A fair agreement with the existing angular distributions is obtained. Applying SU(3) symmetry, it is straightforward to recover the angular distributions for …
We consider the decays of a correlated neutral-meson--antimeson state with C-parity +1. We show that there is CPT noninvariance in the mixing of the neutral mesons if, for any two decay modes f and g, the decay rate has a component R_A which is antisymmetric under the interchange of the decay times t_1 and t_2. In particular, one may cleanly extract the CPT-noninvariance parameter with the help of R_A by using opposite-sign dilepton events.
Phenomenological CP-violating parameters in decays of neutral B-mesons are discussed. Special attention is given to the degree of their measurability. We emphasize important role of the sign of $Δm_B$ and suggest how it could be determined experimentally.
Present and planned experiments motivate new theoretical study of properties of light unflavoured pseudoscalar meson decays. An overview including details on two-loop calculation in SU(3) limit is given.
We point out a significance of ultraperipheral photoproduction of vector mesons in the Coulomb field of nuclei as a means of measuring the radius of the neutral vector meson. This new contribution to the production amplitude is very small compared to the conventional diffractive amplitude, but because of large impact parameters inherent to the ultraperipheral Coulomb mechanism its impact on the diffraction slope is substantial. We predict appreciable and strongly energy dependent increase of the diffraction slope towards very small momentum transfer.The magnitude of the effect is proportional …
Tests of CPT and Lorentz symmetry using neutral-meson oscillations are studied within a formalism that allows for indirect CPT and T violation of arbitrary size and is independent of phase conventions. The analysis is particularly appropriate for studies of CPT and T violation in oscillations of the heavy neutral mesons D, B_d, and B_s. The general Lorentz- and CPT-breaking standard-model extension is used to derive an expression for the parameter for CPT violation. It varies in a prescribed way with the magnitude and orientation of the meson momentum and consequently also with sidereal time. …
We estimate the isospin-violating QED radiative corrections to the charged-to-neutral ratios of the decay rates for B^+ and B^0 in non-leptonic B meson decays. In particular, these corrections are potentially important for precision measurement of the charged-to-neutral production ratio of B meson in e^+e^- annihilation. We calculate explicitly the QED corrections to the ratios of two different types of decay rates Γ(B^+ \to J/ψK^+)/Γ(B^0 \to J/ψK^0) and Γ(B^+ \to D^+_S \bar{D^0})/Γ(B^0 \to D^+_S D^-) taking into account the form factors of the mesons based on the vector meson dominance model,…
Using supersymmetric grand unified theories, we have recently invented a framework which allows the prediction of three quark masses, two of the parameters of the Kobayashi-Maskawa matrix and tan $β$, the ratio of the two vevs. These predictions are used to calculate $ε$ and $ε'$ in the kaon system, B meson mass mixing and the size of CP asymmetries in the decays of neutral B mesons to explicit final states of given CP.
Assuming one nonzero product of two $λ'$-type couplings and working in two different bases for the left-handed quark superfields, the neutral meson mixings are used to bound these products. We emphasize the strong basis dependence of the bounds: in one basis many products contribute to neutral meson mixings at tree level, while in the other these products except one contribute at 1-loop level only and the GIM mechanism takes place. Correspondingly, these bounds differ between bases by orders of magnitudes.
A model is developed for electromagnetic form factors of the charged and neutral K-mesons. The formalism is based on ChPT Lagrangians with vector mesons. The form factors, calculated without fitting parameters, are in a good agreement with experiment for space-like and time-like photon momenta. Contribution of the two-kaon channels to the muon anomalous magnetic moment a_μis calculated.
The process of a light neutral vector meson electroproduction is studied in the framework of QCD factorization in which the amplitude factorizes in a convolution of the nonperturbative meson distribution amplitude and the generalized parton densities with the perturbatively calculable hard-scattering amplitudes. We derive a complete set of hard-scattering amplitudes at next-to-leading order (NLO) for the production of vector mesons, $V=ρ^0, ω, ϕ$.
Phenomenological CP-violating parameters in decays of neutral B-mesons are discussed with special attention to the degree of their measurability. Important role of the sign of Δm_B is emphasized. We briefly describe how it could be determined experimentally.
Flavour changing neutral scalar interactions are a standard feature of generic multi Higgs models. These are constrained by mixing in the neutral meson systems. We consider situations where there are natural cancellations in such contributions. In particular, when the spin 0 particle has both scalar and pseudoscalar couplings, one may have a self-cancellation. We illustrate one such partial cancellation with BGL models. We also inquire whether the flavour changing quark interactions can lead to new production mechanisms for a neutral scalar at LHC.
We analyze the proof of the Khalfin Theorem for neutral meson complex. The consequences of this Theorem are discussed: using this Theorem we find, eg., that diagonal matrix elements of the exact effective Hamiltonian for the neutral meson complex can not be equal if CPT symmetry holds and CP symmetry is violated. The Properties of time evolution governed by a time--independent effective Hamiltonian acting in the neutral mesons subspace of states are considered. By means of the Khalfin's Theorem we show that if such Hamiltonian is time--independent then the evolution operator for the total syst…
Classic tests of CPT symmetry have been done in the neutral-meson system. These have been continued with new results in the framework of the Standard-Model Extension, where the coefficient for CPT violation is both boost and direction dependent. Recent contributions and new phenomenological improvements are discussed with possible new contributions for $b$ and $d$ specific correlated decays at the Belle II asymmetric energy collider.
Analogue models for CP violation in neutral-meson systems are studied in a general framework. No-go results are obtained for models in classical mechanics that are nondissipative or that involve one-dimensional oscillators. A complete emulation is shown to be possible for a two-dimensional oscillator with rheonomic constraints, and an explicit example with spontaneous T and CPT violation is presented. The results have implications for analogue models with electrical circuits.
Experimental signals for indirect CPT violation in the neutral-meson systems are studied in the context of a general CPT- and Lorentz-violating standard-model extension. In this explicit theory, some CPT observables depend on the meson momentum and exhibit diurnal variations. The consequences for CPT tests vary significantly with the specific experimental scenario. The wide range of possible effects is illustrated for two types of CPT experiment presently underway, one involving boosted uncorrelated kaons and the other involving unboosted correlated kaon pairs.
A method is proposed for tagging the flavor of neutral $B$ mesons in the study of CP-violating decay asymmetries. The method makes use of a possible difference in interactions in $B π$ or $B^* π$ systems with isospins 1/2 and 3/2, and would be particularly clean if the $I = 1/2$ systems can be detected as ``$B^{**}$'' resonances.
By means of the universal unitary and analytic model of electromagnetic structure of hadrons the two-photon decay rates of P=pi^0, eta, eta' mesons are determined in an alternative way from data on their transition form factors.
A density-matrix method for the study of tagged states of neutral B mesons with arbitrary coherence properties is applied to several examples, including $e^+ e^-$ production both at and above the $Υ(4S)$ resonance, and hadronic production. In the absence of coherence the only term modulating the exponential decay of a neutral B meson behaves as $\cos Δm t$, while a $\sin Δm t$ modulation is a signal of partial or full coherence. Decays to CP eigenstates are needed to fully specify the density matrix. We relate these results to more familiar expressions for the cases of the $Υ(4S)$ and incohere…
The subject of the charged-to-neutral yield ratio for B{\bar B} and D{\bar D}pairs near their respective thresholds in e^+e^- annihilation is revisited. As previously argued for the B mesons, this ratio should exhibit a substantial variation across the Upsilon(4S) resonance due to interference of the resonance scattering phase with the Coulomb interaction between the charged mesons. A simple alternative derivation of the expression describing this effect is presented here, and the analysis is extended to include the D meson production in the region of the psi(3770) resonance. The available dat…
Two particle vacuum transitions (oscillations) are studied in the general case. We found that: 1) a nondiagonal mass term characterising oscillations is the width of two particle transitions into each other (this width can be computed by the standard method); 2) two types of oscillations take place: real and virtual. Solution of the problem of origin of mixing angle in the theory of vacuum oscillations is given. It is shown that neutral K meson and neutrino oscillations must proceed via two stages. First, neutral K^{o}, antineutral K-eigenstates of strong interaction (or nu(e), nu(mu), nu(tau)…
We review the application of the Wigner-Weisskopf model to the two-channel decay problem for the neutral $K$ meson system in the resolvent formalism. The residues in the pole approximation are not orthogonal, leading to additional interference terms in the $K_S-K_L 2π$ channel. We show that these terms lead to non-trivial changes in the exit beam in comparison to the result calculated with the assumptions of Lee, Oehme and Yang, and Wu and Yang, corresponding to semigroup evolution for which the pole residues are orthogonal, and hence appear to rule out the applicability of the Wigner-Weisskop…
We revisit various results, which have been obtained by the BABAR and Belle Collaborations over the last twelve years, concerning symmetry properties of the Hamiltonian, which governs the time evolution and the decay of neutral B mesons.We find that those measurements, which established CP violation in B meson decay, 12 years ago, had as well established T (time-reversal) symmetry violation. They also confirmed CPT symmetry in the decay (T_CPT = 0) and symmetry with respect to time-reversal (epsilon? = 0) and to CPT (delta? = 0) in the B0 ?B0bar oscillation.
A quantum wave packet treatment of neutrino and neutral K and B meson oscillations is presented which incorporates the recoil particle in the production process, and includes the effect of the localization and lifetime of the source assumed to be a resonance or unstable particle. This approach removes the ambiguities in the conventional single particle treatment of these oscillations with the recoil particle. A fundamental connection between the stochastic decay time of the source and the space-time coordinates of the correlated final state particles is derived.
This talk summarizes some theoretical features and experimental implications of a general Lorentz-violating extension of the minimal SU(3) x SU(2) x U(1) standard model that allows for both CPT-even and CPT-odd effects. The theory would arise as the low-energy limit of a fundamental theory that is Lorentz and CPT covariant but in which spontaneous Lorentz breaking occurs. The use of neutral-meson oscillations and various QED systems to bound the apparent CPT and Lorentz violations is described.
The general properties of the effective Hamiltonian for neutral meson system improved by L.A. Khalfin in 1980 are studied. It is shown that contrary to the standard result of the Lee--Oehme--Yang (LOY) theory, the diagonal matrix elements of this effective Hamiltonian can not be equal in a CPT invariant system. It is also shown that the scalar product of short, $|K_{S}>$, and long, $|K_{L}>$, living superpositions of neutral kaons can not be real when CPT symmetry is conserved in the system under considerations whereas within the LOY theory such a scalar product is real.
New very precise KLOE data on $\m{e}^+\m{e}^-\toπ^+π^-$ obtained by radiative return method in Frascati are unified with corrected CMD-2 and SND Novosibirsk $\m{e}^+\m{e}^-\toπ^+π^-$ data and supplemented below and beyond by older data in order to be described by the unitary and analytic pion electromagnetic form factor model, which provides the most precise neutral $ρ$-meson family parameters. Then the recently appeared accurate Belle (KEK) data of the weak pion form factor are described by the same unitary and analytic model, as it follows from the CVC hypothesis, providing the charged $ρ$-m…
In the presence of CP violation, the effective Hamiltonian matrix describing a neutral meson anti-meson system does not commute with its hermitian conjugate. As a result, this matrix cannot be diagonalized by a unitary transformation and one needs to introduce a reciprocal basis. Although known, this fact is seldom discussed and almost never used. Here, we use this concept to highlight a parametrization of the Hamiltonian matrix in terms of physical observables, and we show that using it reduces a number of long and tedious derivations into simple matrix multiplications. These results have a s…
A simple, but fully-covariant model for describing neutral Vector Mesons, in both light and heavy sectors, is briefly illustrated. The main ingredients of our relativistic constituent model are i) an Ansatz for the Bethe-Salpeter vertex for Vector Mesons, and ii) a Mandelstam-like formula for the electromagnetic decay widths. The free parameters of our approach are fixed through a comparison with the valence transverse-momentum distribution, $n(k_\perp)$, obtained within phenomenological Light-Front Hamiltonian Dynamics models reproducing the mass spectra. Preliminary results for the transvers…
We consider neutral pseudoscalar mesons in an entangled or Einstein-Podolsky-Rosen state with $C=-1$. Due to quantum entanglement and antisymmetry of this state, the rates of the joint decays of the meson pair display various interesting features, as is well known. As functions of CP and CPT violating parameters, here we obtain some exact results about the joint decay rates and their asymmetries for a given time difference defined for joint decays to flavor eigenstates, as well as those for joint decays to CP eigenstates. The entanglement allows a meaningful and useful definition of the transi…
It is known that the existing experimental limit for$ CPT $ violation is rather poor; the 10 \% level at best. The $ \DSDQ $ rule is tested only up to 2 \%. In this note, we discuss the possibility of measuring $ T, CP, CPT $ and $ \DSDQ $ rule violations in the neutral $ K $ meson system. It is shown that not all the symmetry breaking parameters can be determined at a symmetric $ ϕ$ factory. Experiments with $ K^0 $ and $ \bar{K}^0 $ beams are needed to test all the symmetries.
In this work we show that the existence of a complete biorthonormal set of eigenvectors of the effective Hamiltonian governing the time evolution of neutral meson system is a necessary condition for diagonalizability of such a Hamiltonian. We also study the possibility of probing the $CPT$ invariance by observing the time dependence of cascade decays of type $P^{\circ}(\bar{P^{\circ}})\to \{M_a,M_b\}X\to fX$ by employing such basis and exactly determine the $CPT$ violation parameter by comparing the time dependence of the cascade decays of tagged $P^{\circ}$ and tagged $\bar{P^{\circ}}$.
We study the behavior of neutral meson properties in the presence of a static uniform external magnetic field in the context of nonlocal chiral quark models. The formalism is worked out introducing Ritus transforms of Dirac fields, which allow to obtain closed analytical expressions for $π^0$ and $σ$ meson masses and for the $π^0$ decay constant. Numerical results for these observables are quoted for various parameterizations. In particular, the behavior of the $π^0$ meson mass with the magnetic field is found to be in good agreement with lattice QCD results. It is also seen that the Goldberge…
