A new scheme for heavy flavors in DIS

Abstract : This talk will present an heavy quark masses dependent extension of the DGLAP equations fully to six flavors. It satisfy heavy quark kinematical constraints W>2M_h, momentum sumrule and quark counting sumrules. For Q^2 << 4 M^2_h the corresponding heavy quark gets decoupled (with a quasi null x domain) and for Q^2 >> 4 M^2_h the two corresponding DGLAP equations get their usual appearance. Coefficient functions are modified accordingly. This is mainly done by making the flavor number a continous function of the scale Q^2 in a specific way. As a consequence all observables (CN and CC strucure functions),are also continous and no further scheme additions are needed. The name of continous flavor number scheme has been given to this work although scheme is here not used with the usual meaning. Programing of this cfns has started and is at the middle of January at the LO level. A comparaison of massless scheme and cfns will be presented. Some theoretical justification will be also approached.