We study the pi N --> phi N reaction close to the phi N threshold within the chiral unitary approach, by combining the pi^- p --> K^+ Sigma^-, pi^- p --> K^0 Sigma^0 and pi^- p --> K^0 Lambda amplitudes with the coupling of the phi to the K component
s of the final states of these reactions via quantum loops. We obtain a good agreement with experiment when the dominant pi^- p --> K^0 Lambda amplitude is constrained with its experimental cross section. We also evaluate the coupling of the N*(1535) to phi N and find a moderate coupling as a consequence of partial cancellation of the large KY components of the N*(1535). We also show that the N*(1535) pole approximation is too small to reproduce the measured cross section for the pi N --> phi N reaction.
We calculate the radiative decay width of the $psi(3770)$ into the dynamically generated scalar resonance X(3700) which is predicted in a previous paper. The results show that it is possible that the upgraded BEPC-II facility will generate enough sta
tistics in order to observe this decay and thus confirm the existence of the X(3700).
The $s$-$bar{s}$ asymmetry in nucleon sea is an important observable for understanding nucleon structure and strong interaction. There have been many theoretical attempts on this subject and recently on its relation to the NuTeV anomaly. Calculations
with different theoretical frameworks lead to different conclusions. Here assuming a newly proposed penta-quark configuration for the $s$-$bar{s}$ asymmetry in nucleon, we examine its contribution to the NuTeV anomaly, with a result of about $10-20%$.
