Collinear approach for top quark production at ep colliders

Abstract

An analysis study of the collinear approach for tt production at the Future Circular Collider hadron-electron (FCC-he) is performed. To study the heavy quark production processes, the collinear generalized double asymptotic scaling (DAS) approach at the next-to-next-to-leading order (NNLO) approximation at small Bjorken x values is used. Bounds on the top reduced cross section at the FCC-he center-of-mass energy and at the high inelasticity are derived. Expanding the method to high-values of Q 2 , Q 2 ≥m 2 t , can be considered in the process analysis of new colliders. A nonlinear modification of the evolution of the gluon density for heavy-quark production in DIS is obtained at small x from the parametrization of the proton structure function to include the effects of heavy-quark masses.

On x-independence of RQ = FLQ/F2Q ratio at low x

“…In the case of t quark, this flat behavior was recently discussed in the second paper of Ref. [8]. Very large NNLO contribution to R t (x, Q 2 ) for Q 2 4m 2 t indicates a strong need for resummation for small x (see, for example, [13,14,28,29] and discussions therein), but that is beyond the scope of this short paper.…”

“…An additional important result of the evaluations [6] is that the compact analytical expressions for these DIS coefficient functions have been presented up to next-to-next-to-leading order (NNLO) accuracy. These expressions were used very recently to investigate the top quark production in the FCC-he kinematical regime [8]. Here we continue our study [5,6].…”