Related papers: Precritical Chiral Fluctuations in Nuclei
We present a study of the $\pi\pi$ scattering amplitude in the $\sigma$ and $\rho$ channels at finite temperature and nuclear density within a chiral unitary framework. Meson resonances are dynamically generated in our approach, which…
It should be a typical subject in this workshop to explore possible change of hadron properties in association with that of QCD vacuum due to an environmental change. In this report, we first summarize what hadrons are expected to show such…
This paper is devoted to the interplay between p-wave, s-wave pion-nucleon/ nucleus interaction and in-medium pion-pion interaction with special emphasis on the role of the nuclear pionic scalar density driving a large amount of chiral…
We consider the form of the chiral symmetry breaking piece of the effective potential in the linear sigma model. Surprisingly, it allows for a second local minimum at both zero and finite temperature. Even though chiral symmetry is not…
Since the prediction of nuclear chirality in 1997, tremendous progresses both theoretically and experimentally have been achieved. Experimentally, 59 chiral doublet bands in 47 chiral nuclei (including 8 nuclei with multiple chiral…
We set up a general framework to describe $\pi\pi$ scattering below 1 GeV based on chiral low-energy expansion with possible spin-0 and 1 resonances. Partial wave amplitudes are obtained with the $N/D$ method, which satisfy unitarity,…
We present a new rearrangement of short-range interactions in the $^1S_0$ nucleon-nucleon channel within Chiral Effective Field Theory. This is intended to reproduce the amplitude zero (scattering momentum $\simeq$ 340 MeV) at leading…
Complex poles of the unitarized pi-pi scattering amplitude in nuclear matter are studied. Partial restoration of chiral symmetry is modeled by the decrease of in-medium pion decay constant f*_{pi}. For large chiral restoration…
We argue that a decrease of the chiral scalar meson mass is responsible for re-creation of $\Psi'$ from $J/\Psi$ in ultrarelativistic nucleus-nucleus collisions. This causes the charmonium yields to freeze out at temperatures close to the…
The pion-production $\pi^+ A \to \pi^+\pi^{\pm} A'$ reactions were studied on nuclei $^{2}H$, $^{12}C$, $^{40}Ca$ and $^{208}Pb$ at a pion energy of $T_{\pi^{+}}$=283 MeV using the CHAOS spectrometer. The experimental results are reduced to…
Weak interactions cause small parity-violating energy differences between left- and right-handed chiral systems. Although normally tiny, these effects may be significantly enhanced during collective phenomena such as phase transitions. We…
We examine several types of symmetries which are relevant to quantum phase transitions in nuclei. These include: critical-point, quasidynamical, and partial dynamical symmetries.
The QCD vacuum shows the dynamical breaking of chiral symmetry. In the hot/dense QCD medium, the chiral order parameter such as $ < \bar q q > $ is expected to change as function of temperature $T$ and density $\rho$ of the medium, and its…
The inclusive A(gamma,pi+ pi-)X reaction is studied theoretically. A sizeable enhancement of the cross section is found, in comparison with the scaling of the deuteron cross section (sigma_deuteron * A/2). This enhancement is due to the…
We study the nuclear modification of the scalar QCD susceptibility, calculated as the derivative of the quark condensate with respect to the quark mass. We show that it has two origins. One is the low lying nuclear excitations. At normal…
In this article we study restoration of chiral symmetry at finite temperature for quark matter with a chiral chemical potential, $\mu_5$, by means of a quark-meson model with vacuum fluctuations included. Vacuum fluctuations give a…
A general prescription for the construction of $\pi \pi$ interaction potentials which preserve scattering length constraints from chiral symmetry when iterated in scattering equations is derived. The prescription involves only minor…
We investigate the possible restoration of chiral and axial symmetries across the phase transition at finite temperature and chemical potential, by analyzing the behavior of several physics quantities, such as the quark condensates and the…
A chiral model based on nucleons interacting via boson exchange is investigated. Fluctuation effects are included consistently beyond the mean-field approximation in the framework of the functional renormalization group. The liquid-gas…
The pion-production reactions $\pi^+ A \to \pi^+\pi^{\pm} A'$ were studied on $^{2}H$, $^{12}C$, $^{40}Ca$, and $^{208}Pb$ nuclei at an incident pion energy of $T_{\pi^{+}}$=283 MeV. Pions were detected in coincidence using the CHAOS…