Heavy Flavour production in Deep-Inelastic Scattering

por Isabella Bierenbaum (IFIC Valencia)

jueves 4 mar. 2010 12:00 → 13:00 Europe/Madrid

Sala Seminarios IFIC (Edf. Institutos de Investigación)

Deep-inelastic scattering of charged or neutral leptons off proton and deuteron targets allows to measure the leading twist parton densities of the nucleon, the QCD-scale Lambda_QCD, and the strong coupling constant to high precision. For unpolarized DIS via single photon exchange, the cross section can be expressed in terms of two inclusive structure functions F2(x,Q^2), FL(x,Q^2). Of particular interest are the c(cbar)-contributions to these structure functions, which, especially in the region of smaller values of Bjorken-x, provide contributions of up to 20-40%. In the limit of large momentum transfer, these contributions are very well described by asymptotic expressions, where the mass dependence, up to polynomial terms in m^2/Q^2, is described by massive Operator Matrix Elements (OMEs). I will report on the calculation of these OMEs up to 3-loop order for fixed even moments of the Mellin variable N and the calculation of the OMEs which are required to define heavy quark parton densities in the variable flavor number scheme.