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An anomaly observed in the 8Be nuclear transition by the Atomki collaboration hints at a light, neutral boson decaying into an e + e − pair with a mass of about 17 MeV. In this paper, we study the Atomki anomaly in the framework of axial (ABJ) anomaly. Some theoretical results indicate that the X17 particle is the color singlet pseudoscalar. We take the X17 particle as a pseudoscalar meson (u ū) system which has the axial (ABJ) anomaly, where u denotes the up quark. Besides this, we also give an interpretation for E38 particle with a mass of about 38 MeV as a pseudoscalar meson (d d ̄) system. We obtain the correct masses of the two pseudoscalars by a non-perturbative mass formula. [ABSTRACT FROM AUTHOR]

Recently, some small hints of lepton flavor violating (LFV) decays have been probed in different colliders and accelerators. Although these processes are forbidden in the Standard Model (SM), observation of LFV decays are considered as good probes to test theory beyond the SM. In this paper, we study some LFV decays, e.g. three-body decay channels of μ lepton like μ → 3 e , μ → e ν ν ̄ and two-body decays of B meson and τ lepton like B s , d → μ ± e ∓ and τ → e ϕ in Z ′ model. We calculate the branching ratio of the above decays considering the effect of both Z and Z ′ -mediated flavor-changing neutral-current (FCNC). [ABSTRACT FROM AUTHOR]

Like the two-photon and two-gluon decays of the P -wave χ c 0 , 2 and χ b 0 , 2 charmonium state for which the Born term produces a very simple decays amplitude in terms of an effective Lagrangian with two-quark local operator, the Born term for the processes c d ̄ → (π , K) ℓ ν and b d ̄ → (π , K) ℓ ν , could also produce the D and B meson semileptonic decays with the light meson π , K in the final state. In this approach to heavy-light meson form factors with the π , K meson treated as Goldstone boson, a simple expression is found for the decays form factors, given as: f + (0) / 1 − q 2 / m H 2 + m π 2 , with H = D , B for D , B → π form factors, and f + (0) / 1 − q 2 / m H 2 + m K 2 for B , D → K form factor. The purpose of this paper is to show that this expression for the form factors could describe rather well the q 2 -behavior observed in the BaBar, Belle and BESIII measurements and lattice simulation. In particular, the D → K form factors are in good agreement with the measured values in the whole range of q 2 showing evidence for S U (3) breaking with the presence of m K 2 term in the quark propagator, but some corrections to the Born term are needed at large q 2 for D , B → π form factors. [ABSTRACT FROM AUTHOR]

Meson-baryon potentials are proposed as an extension of baryon-baryon one-boson-exchange potentials. All coupling constants satisfy the SU(3) symmetry and all mesons and baryons are assumed to have physical masses and widths and to behave as gaussian sources of meson fields. Assuming the parameters determined so as to reproduce the πN and K N scattering, our model inevitably predicts a strongly attractive S-wave $\bar K N$ interaction both in isospin 0 and 1 states. [ABSTRACT FROM AUTHOR]

The chiral effective Lagrangian for pseudoscalar meson nonet including eight Goldstone bosons and a SU(3) singlet η0 is constructed with the breaking effect of chiral symmetry in both quark condensate and quark mass differences taken into account. The $\tilde{\pi}^0-\eta-\eta^\prime$ mixing is discussed. By solving the mass equations of pseudoscalar mesons, the quark mass ratios are obtained and the quark condensate ratios are constrained in ranges. The mass split of π0-π± is discussed. [ABSTRACT FROM AUTHOR]

We discuss a left-right symmetric model with two Higgs bi-doublet and spontaneous P and CP violation. The flavor changing neutral currents is suppressed by assuming approximate global U(1) family symmetry. We calculate the constraints from neural K meson mass difference ΔmK and demonstrate that a right-handed gauge boson W2 contribution in box-diagrams with mass around 600 GeV is allowed due to a negative interference with a light charged Higgs boson around 150 ~ 300 GeV. The W2 contribution to ɛK is suppressed from appropriate choice of additional CP phases appearing in the right-handed Cabbibo-Kobayashi-Maskawa(CKM) matrix. The model is found fully consistent with B0 mass difference and the mixing-induced CP asymmetry measurements. [ABSTRACT FROM AUTHOR]

A current algebra based effective chiral theory of pseudoscalar, vector, axial-vector mesons is reviewed. A new mechanism generating the masses and guage fixing terms of gauge boson is revealed from this effective theory. A EW theory without Higgs is proposed. The masses and gauge fixing terms of W and Z are dynamically generated. Three heavy scalar fields are dynamically generated too. They are ghosts. [ABSTRACT FROM AUTHOR]

Positive baryon numbers (A>0) and positive lepton numbers (L>0) characterize matter particles while negative baryon numbers and negative lepton numbers characterize antimatter particles. Matter particles and antimatter particles belong to two distinct classes of particles. Matter neutral particles are particles characterized by both zero baryon number and zero lepton number. This third class of particles includes mesons formed by a quark and an antiquark pair (a pair of matter particle and antimatter particle) and bosons which are messengers of known interactions (photons for electromagnetism, W and Z bosons for the weak interaction, gluons for the strong interaction). The antiparticle of a matter particle belongs to the class of antimatter particles, the antiparticle of an antimatter particle belongs to the class of matter particles. The antiparticle of a matter neutral particle belongs to the same class of matter neutral particles. A truly neutral particle is a particle identical with its antiparticle; it belongs necessarily to the class of matter neutral particles. All known interactions of the Standard Model conserve baryon number and lepton number; matter cannot be created or destroyed via a reaction governed by these interactions. Conservation of baryon and lepton number parallels conservation of atoms in chemistry; the number of atoms of a particular species in the reactants must equal the number of those atoms in the products. These laws of conservation valid for interaction involving matter particles are indeed valid for any particles (matter particles characterized by positive numbers, antimatter particles characterized by negative numbers, and matter neutral particles characterized by zero). Interactions within the framework of the Standard Model which conserve both matter and charge at the microscopic level cannot explain the observed asymmetry of our Universe. The strong interaction was introduced to explain the stability of nuclei: there must exist a powerful force to compensate the electromagnetic force which tends to cause protons to fly apart. The weak interaction with laws of conservation different from electromagnetism and the strong interaction was postulated to explain beta decay. Our observed material and neutral universe would signify the existence of another interaction that did conserve charge but did not conserve matter. [ABSTRACT FROM AUTHOR]

It is shown that the difference between the magnetic moment results in the quark model with null instantons and semibosonized Nambu–Jona-Lasinio model lies in the symmetry properties of the meson cloud contributions. [ABSTRACT FROM AUTHOR]

K → ππ decays are investigated in the framework of the SU(2)[sub L] × U(1) gauge theory of J = 0 mesons proposed in Ref. 1, to which is added an interaction between mesons respecting the two symmetries generally attributed to strong interactions, flavor symmetry and parity conservation. It is shown that the damping of the K[sup +] → π[sup +]π[sup 0] amplitude with respect to the ones of K[sub s] → ππ results from a cancellation between the W and g gauge bosons. The ratio of the two types of amplitudes is sensitive to the spectrum of electroweak (pseudoscalar and scalar) mass eigenstates, and in particular to the mass of the Higgs boson. In the case where scalars and pseudoscalars are degenerate, I demonstrate for the amplitudes the lower bound |K[sub s] → π[sup +]π[sup -]/K[sup +] → π[sup +]π[sup 0] ≥ 1/tan² θ[sub W], where θ[sub W] is the Weinberg angle. [ABSTRACT FROM AUTHOR]