QCD Corrections to Decay Distributions of Neutral Higgs Bosons with (In)definite CP Parity
Abstract
We compute the order
α
s
QCD corrections to the density matrix for the decay of a neutral Higgs boson
ϕ
with (in)definite CP parity into a quark antiquark pair, respectively the QED corrections for the decay into a pair of charged leptons. We classify and calculate single spin asymmetries and spin-spin correlations which are generated by the scalar and pseudoscalar Yukawa couplings. These spin effects can be traced in
ϕ→
τ
−
τ
+
and, for heavy Higgs bosons, in
ϕ→t
t
¯
. We also calculate resulting correlations among the final states and estimate, for the respective decay modes, the number of events needed to measure the Yukawa couplings with these correlations at the 3 sigma level.