相关论文: The scalar-isoscalar spectral function of strong m…
The scalar-isoscalar propagator of the effective linear $\sigma$ model of meson dynamics is investigated with the help of an expansion in the number of the Goldstone bosons. A generic scenario is suggested for the temperature and density…
We calculate the imaginary parts of the isoscalar scalar and isovector electromagnetic form factors of the nucleon up to two-loop order in chiral perturbation theory. Particular attention is paid on the correct behavior of Im $\sigma_N(t)$…
An important role of the scalar isoscalar sigma-meson in the low-energy physics is discussed. The behavior of the sigma-meson in the hot and dense medium is studied. It is shown that in the vicinity of critical values of temperature(T) and…
By assuming certain analytic properties of the propagator, it is shown that universal features of the spectral function including threshold enhancement arise if a pole describing a particle at high temperature approaches in the complex…
The thermal evolution of the spectral densities derivable from the two-point functions of the elementary and the quadratic composite fields of the O(N) model is studied in the isosinglet channel and in the broken symmetry phase at infinite…
We study the properties of the Resonance-Spectrum Expansion near threshold in I=0 S-wave pion-pion scattering. The real part of the amplitude, when extrapolated from above threshold to below threshold, is found to vanish at a positive…
We discuss the effective field theory of large scale structure in terms of a single scalar degree of freedom, corresponding to the velocity potential of the matter fluid in a $\Lambda$CDM universe. This cosmic ``pion'' field is nonlinearly…
We apply the Effective Field Theory of Inflation to study the case where the continuous shift symmetry of the Goldstone boson \pi is softly broken to a discrete subgroup. This case includes and generalizes recently proposed String Theory…
The properties of the pion quasiparticle in hot and dense isospin medium, including the temperature and isospin chemical potential dependence of their screening mass, pole mass and thermal width, as well as their relationships with the pion…
Properties of scalar-isoscalar mesons are analysed using separable interactions in three decay channels: pion-pion, kaon-antikaon and an effective 2pion-2pion. We obtain different solutions by fitting various data on the pion-pion and…
A separable potential model of three coupled channels (pion-pion, kaon-antikaon and an effective four pion) has been constructed and applied in the analysis of the isoscalar S-wave pion-pion and kaon-antikaon phase shifts and inelasticities…
From recent analysis of the $\pi\pi$ scattering amplitude, it has been claimed that there exists a broad and light $\sigma$ meson. However, if this meson really exists, it must also appear in other observables such as the pion scalar form…
In a dimensionless multi-scalar extension of the Standard Model, Gildener and Weinberg assumed that along a flat direction, there is only one classically massless scalar, known as the {\it scalon}, which acquires mass through radiative…
Threshold biasing of a Gaussian random field gives a linear amplification of the reduced two point correlation function at large distances. We show that for standard cosmological models this does not translate into a linear amplification of…
We analyse available data on the quark pseudoscalar vertex and extract the contribution og the Goldstone boson pole. The strength of the pole is found to be quite large at presently accessible scales. We draw the important consequences of…
Spectra of pions, which are known as the pseudo-Goldstone bosons of spontaneous chiral symmetry breaking, as well as their relationship with chiral phase transition and pion superfluidity phase transition, have been investigated in the…
We consider light scalar fields during inflation and show how the stochastic spectral expansion method can be used to calculate two-point correlation functions of an arbitrary local function of the field in de Sitter space. In particular,…
We study the imprints of massive particles with spin on cosmological correlators. Using the framework of the effective field theory of inflation, we classify the couplings of these particles to the Goldstone boson of broken time…
We present an extension to the Poisson-Boltzmann model where the dipolar features of solvent molecules are taken explicitly into account. The formulation is derived at mean-field level and can be extended to any order in a systematic…
The effective potential of the $O(N)$ model at large $N$ limit is reinvestigated with varying pion mass and temperature. For large pion masses and high temperatures, we find the phenomenologically favored vacuum, located on the upper branch…