STRINGY SPHALERONS AND GAUSS-BONNET TERM

The effect of the Gauss-Bonnet term on the SU(2) non-Abelian regular stringy sphaleron solutions is studied within the non-perturbative treatment. It is found that the existence of regular solutions depends crucially on the value of the numerical factor beta in front of the Gauss-Bonnet term in the four-dimensional effective action. Numerical solutions are constructed in the N = 1,2, 3 cases for different beta below certain critical values beta(N) which decrease with growing N (N being the number of nodes of the Yang-Mills function). It is proved that for any static spherically symmetric asymptotically flat regular solution the ADM mass is exactly equal to the dilaton charge. No solutions were found for beta above critical values, in particular, for beta=1.