Related papers: Vector Meson Contributions in epsilon'/epsilon
Historically vector-meson physics arose along two different paths to be reviewed in Sections 1 and 2. In Section 3, the phenomenological consequences will be discussed with an emphasis on those aspects of the subject matter relevant in…
We present a comprehensive analysis of form factors for two light pseudoscalar mesons induced by scalar, vector, and tensor quark operators. The theoretical framework is based on a combination of unitarized chiral perturbation theory and…
The diffractive production of vector mesons in ep interactions at low x is a subject of heated debates. This chapter consists of four contributions written by the original authors and expresses the possible scenarios which are to be…
A momentum dependent quark mass may be incorporated into a quark model in a manner consistent with dynamically broken chiral symmetry. We use this to study the high $Q^2$ behavior of the vector, axialvector, scalar and pseudoscalar…
Theoretical approaches to assess modifications of vector mesons in the medium, as well as their experimental identification via electromagnetic probes, are discussed. Implications for the nature of chiral symmetry restoration in hot/dense…
We have performed a systematical calculation of the pion ($\pi, K, \eta$) and heavy pseudoscalar meson S-wave scattering lengths up to ${\cal O}(p^3)$ in the chiral perturbation theory in the heavy quark symmetry limit. With the three…
The production of soft dileptons in a thermal mesonic medium is discussed in the context of recent CERN experimental data reported by the CERES Collaboration. We do not intend to give a general and critical review, but instead concentrate…
First full next-to-leading order analytical results in Chiral Perturbation Theory for the charged Kaon K -> 3 pi slope g and decay rates CP-violating asymmetries are presented. We discuss the constraints that a measurement of these…
In this short review, I present the recent lattice computations of kaon weak matrix elements relevant to $K \to \pi\pi$ decays and neutral kaon mixing. These matrix elements are key to the theoretical determination of the CP violation…
We consider two body decays of B meson into a light vector (V) and a pseudoscalar (P) meson. The constraint obtained from the $B\to P P$ modes on the parameter space of the input parameters is imposed also on $B\to V P$ modes. In particular…
The low-energy $\pi\pi$ amplitude is computed explicitly to two-loop accuracy in the chiral expansion. It depends only on six independent (combinations of) low-energy constants which are not fixed by chiral symmetry. Four of these constants…
We consider constraints on the isoscalar S-wave pi-N scattering length a+ from pi-deuteron scattering, to third order in small momenta and pion masses in chiral perturbation theory. To this order, the pi-deuteron scattering length is…
We consider finite volume effects on the electro-magnetic pion form factor near the chiral limit, in the so-called $\epsilon$ regime. The pseudoscalar-vector-pseudoscalar three-point function is calculated in the $\epsilon$ expansion of…
This PhD thesis is a first step towards the control of the quantum corrections in the Resonance Chiral Theory, the suggested framework to handle QCD in the resonance region. After a theoretical introduction, Chapter 3 is devoted to…
We discuss $\pi^0$ -$\eta$ mixing and its implication for $\epsilon'/ \epsilon$ to next-to-leading order in the low-energy expansion. The big effect due to $\eta$-$\eta'$ mixing is shown to be largely cancelled by other contributions…
Dispersive approaches provide model independent description of meson-meson scattering. We first review here the use of dispersion relations to obtain a model independent unitarization of Chiral Perturbation Theory amplitudes, that establish…
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…
We present a new analysis of the ratio \epsilon'/\epsilon which measures the direct CP violation in K\to\pi\pi decays. We use the 1/N_c expansion within the framework of the effective chiral lagrangian for pseudoscalar mesons. The 1/N_c…
Vector Meson Dominance ideas together with a Finite Energy QCD sum rule allows for the determination of the $q^{2}$- and the $T$- dependence of the effective hadronic coupling constant $g_{\rho \pi \pi}$ in the space-like region. It turns…
The hypothesis is scrutinized that the weak interaction of hadronic systems at low energies is dominated by the coupling of the pseudoscalar, vector, and axial-vector mesons to the weak gauge bosons. The strength of the weak coupling of the…