Soft-gluon corrections for $tW$ production at N$^3$LO

Abstract: I present approximate results that include third-order soft-gluon corrections for the associated production of a single top quark with a $W$ boson. The calculation uses expressions from soft-gluon resummation at next-to-next-to-leading-logarithm (NNLL) accuracy. From the NNLL resummed cross section I derive approximate next-to-next-to-next-to-leading order (aN$^3$LO) cross sections for the process $bg \rightarrow tW^-$ at LHC and Tevatron energies. The aN$^3$LO top-quark transverse-momentum and rapidity distributions in $tW$ production are also presented.