We calculate the parity-violating nucleon-nucleon potential in heavy-baryon chiral perturbation theory up to the next-to-next-to-leading order. The one-pion exchange comes in the leading order and the next-to-next-to-leading order consists of two-pion-exchange and the two-nucleon contact terms. In order to investigate the effect of the higher order contributions, we calculate the parity-violati...

The pion form factor at very large Q2 is obtained by using a new pion wave function. It shows that when Q2 >> (1.8GeV )2 the pion form factor reaches the asymptotic limit αs(Q) Q .

The behavior of the pion dispersion relation in a pion medium is strongly modified by the introduction of a finite chemical potential associated to the finite pion number density. Such behavior is particularly important during the hadronic phase of a relativistic heavy-ion collision, between chemical and thermal freeze-out, where the pion number changing processes, driven by the strong interact...

Absorptive corrections to the one pion exchange and measurability of the small-x pion structure function at HERA Abstract We compare the absorptive corrections to the one pion exchange in pp → Xn and ep → e ′ Xn reactions. It is shown that the absorption is stronger in the case of pp collision. The difference in strength of the absorption for the pp → Xn and ep → e ′ Xn reactions breaks the fac...

Due to the large resonance πN scattering cross section a pion with momentum ∼ 0.3 GeV/c acquires a width in nuclear matter. The pion spectral function in nuclear matter is, therefore, different from the vacuum one. The present work is the first attempt to include the pion spectral function into the BUU transport theory. We have calculated the pion polarization function Πc(k) in isospin symmetri...

Within the framework of massive $\mathrm{O}(N)$ nonlinear sigma model extended to next-to-leading order in chiral counting [for $N=3$ corresponding two(-quark)-flavor Chiral Perturbation Theory], we calculate relativistic six-pion scattering amplitude at low energy up and including terms $\mathcal{O}({p}^{4})$. Results for pion mass, decay constant, four-pion case $N$ (meson) flavors $\mathcal{...

The vector pion form factor is used as an example to analyze this question. Given the experimental radius of the pion, the crucial question is whether perturbative methods could be used for the effective chiral lagrangian to calculate the pion form factor. Our analysis shows that the pion rms radius is far too large (or the related ρ resonant mass is too low) for the perturbation theory to be v...