2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/37743We determine the b-quark shape function parameters, Lambda^SF and lambda_1^SF using the Belle B->X_s gamma photon energy spectrum. We assume three models for the form of the shape function; Exponential, Gaussian and Roman.of the Belle Collaboration for the Heavy Flavor Averaging GroupHigh Energy Physics - Experimenttext