Scalar form factors in SU(3) chiral perturbation theory

The scalar form factors for the pions and kaons are calculated in SU(3)Chiral Perturbation Theory at order $p^6$, in the isospin limit$m_u=m_d=\hat{m}$. We find in general sizable corrections of$\mathcal{O}(p^6)$. We use our results to obtain results on the $1/N_c$suppressed low energy constants $L_4^r$ and $L_6^r$ as well as on two$\mathcal{O}(p^6)$ low energy constants. We present some numerical results formasses and decay constants as well. We derive a relation for the scalar form factors analogous to Sirlin'srelation for vector form factors.Comment: 35 pages, references added, discussion of numerical results extende