Description
I will discuss recent developments in the theory of small-$x$ resummation. These include the matching of resummation to fixed NNLO (and even N$^3$LO), the construction of a variable flavour number scheme at small $x$, the resummation of the heavy-flvour matching conditions, a new formalism for the resummation of physical observables, and a variety of technical improvements. All these results have been implemented in a public code, HELL, which made possible the determination of PDFs with small-$x$ resummation, showing a significantly better agreement with HERA data at low $x$. The impact of resummation at present and future colliders will be discussed.
Author
Marco Bonvini
(INFN Rome)
