Related papers: An example of resonance saturation at one loop
We show how the unitarized description of pion nucleon scattering within Heavy Baryon Chiral Perturbation Theory can be considerably improved, by a suitable reordering of the expansion over the nucleon mass. Within this framework, the…
This is part two in a series of papers in which we investigate an approach based on Lagrangian perturbation theory (LPT) to study the non-linear evolution of the large-scale structure distribution in the universe. Firstly, we compute the…
The effective Lagrangian including one loop corrections is deduced for the couplings of the charged Higgs with quarks and leptons, and with charginos and neutralinos. The effect of the one loop corrections is found to be quite significant…
We present a dispersive method which allows to investigate the low-energy couplings of chiral perturbation theory at the next-to-leading order (NLO) in the 1/N(C) expansion, keeping full control of their renormalization scale dependence.…
We consider the Resonance Chiral Theory with one multiplet of scalar and pseudoscalar resonances, up to bilinear couplings in the resonance fields, and evaluate its beta-function at one-loop with the use of the background field method. Thus…
In these proceedings, I shall review the basic concepts of perturbative QCD in its high-energy limit, emphasising the approach to the unitarity limit, usually referred to as {\em saturation}. I shall explain the basic framework showing the…
Chiral lagrangians provide a model independent description of the strongly interacting symmetry breaking sector. In this work it is first reviewed the LHC sensitivity to the chiral parameters (in the hardest case of non-resonant low-energy…
I review some basic facts about the chiral limit of QCD. This allows to formulate an effective field theory below the chiral symmetry breaking scale, chiral perturbation theory (CHPT). I show that for threshold reactions, the spectrum of…
We derive the equation of state of symmetric nuclear matter in a relativistic theory with $\sigma$ and $\omega$ exchange. We take a chiral version of this model which insures all the chiral constraints. Going beyond the mean field approach…
Heavy baryon chiral perturbation theory is briefly reviewed, paying particular attention to the role of the spin 3/2 delta resonances. The concept of resonance saturation for the baryonic sector is critically discussed. Starting from a…
We calculate the divergences of the generating functional of quenched Chiral Perturbation Theory at one loop, and renormalize the theory by an appropriate definition of the counterterms. We show that the quenched chiral logarithms can be…
We analyze the quark mass dependence of the Roper mass to one-loop order in relativistic baryon chiral perturbation theory. The loop integrals are evaluated using infrared regularization which preserves chiral symmetry and establishes a…
Quantizing any model in which a Lagrange multiplier (LM) field is used to restrict field configurations to those that satisfy the classical equations of motion, leads to at most one-loop radiative corrections. This approach can be used with…
The 1/N_c expansion of QCD provides a valuable semiquantitative tool to study baryon scattering amplitudes and the short-lived baryon resonances embedded within them. A generalization of methods originally applied in chiral soliton models…
We construct an effective Lagrangian for the hadronic decays of a heavy excited $s$-wave-spin-one quarkonium into its ground state. We show that reasonable fits to the measured invariant mass spectra in the $J/\psi$ and $\Upsilon$ systems…
We formulate the expansion for the mass of the nucleon as a function of pion mass within chiral perturbation theory using a number of different ultra-violet regularisation schemes; including dimensional regularisation and various…
The Chiral Confining Lagrangian, based on the chiral theory with quark degrees of freedom, is used to study the spectroscopy of scalar mesons. The formalism does not contain arbitrary fitting parameters and takes into account infinite…
Parameters of the effective chiral lagrangian (EChL) of orders $O(p^4)$ and $O(p^6)$ are extracted from low--energy behaviour of dual resonance models for $ \pi\pi$ and $\pi K$ scattering amplitudes. Dual resonance models are considered to…
Using the large N_C approximation we have constructed the most general chiral resonance Lagrangian in the odd-intrinsic parity sector that can generate low energy chiral constants up to O(p^6). Integrating out the resonance fields these…
Explicit chiral symmetry breaking is a natural feature of many QCD inspired models with multi-quark interactions. To carry out the 1/N expansion of these theories, one integrates over the quark fields. In the process of calculating the…