Complete one-loop analysis of the nucleon's spin polarizabilities

We present a complete one-loop analysis of the four nucleon spin polarizabi lities in the framework of heavy baryon chiral-perturbation theory. The fir st nonvanishing contributions to the isovector and first corrections to the isoscalar spin polarizabilities an calculated. No unknown parameters enter these predictions. We compare our results to various dispersive analyses. We also discuss the convergence of the chiral expansion and the role of the delta isobar.