Search

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]

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]

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]