PT Journal
AU Jantzen, B
   Ruiz-Femenia, P
TI Next-to-next-to-leading order nonresonant corrections to threshold top-pair production from e(+)e(-) collisions: Endpoint-singular terms
SO Physical Review D
JI Phys. Rev. D
PY 2013
BP 054011
EP 20pp
VL 88
IS 5
DI 10.1103/PhysRevD.88.054011
LA English
AB We analyze the subleading nonresonant contributions to the e(+)e(-) -> W(+)W(-)b (b) over bar cross section at energies near the top-antitop threshold. These correspond to next-to-next-to-leading-order (NNLO) corrections with respect to the leading-order resonant result. We show that these corrections produce 1/epsilon endpoint singularities which precisely cancel the finite-width divergences arising in the resonant production of the W(+)W(-)b (b) over bar final state from on-shell decays of the top and antitop quarks at the same order. We also provide analytic results for the (m(t)/Lambda)(2), (m(t)/Lambda) and (m(t)/Lambda)(0) log Lambda terms that dominate the expansion in powers of (Lambda/m(t)) of the complete set of NNLO nonresonant corrections, where Lambda is a cut imposed on the invariant masses of the bW pairs that is neither too tight nor too loose (m(t)Gamma(t) << Lambda(2) << m(t)(2)).
ER