Pseudo-scalar Higgs boson production at threshold N $$^3$$ 3 LO and N $$^3$$ 3 LL QCD

Abstract

We present the first results on the production of pseudo-scalar through gluon fusion at the LHC to N 3 LO in QCD taking into account only soft gluon effects. We have used the effective Lagrangian that describes the coupling of pseudo-scalar with the gluons in the large top quark mass limit. We have used recently available quantities namely the three loop pseudo-scalar form factor and the third order universal soft function in QCD to achieve this. Along with the fixed order results, we also present the process dependent resummation coefficient for threshold resummation to N 3 LL in QCD. Phenomenological impact of these threshold N 3 LO corrections to pseudo-scalar production at the LHC is presented and their role to reduce the renormalisation scale dependence is demonstrated.

Universal properties of pseudoscalar mediators in dark matter extensions of 2HDMs

“…The applied cuts are collected in the left column of table 2. We assume a systematic error of 5% and account for higher order corrections by applying a the mass-dependent N 2 LO K-factor at √ s = 13 TeV ranging from 2.1 for M A = 150 GeV to 2.37 for M A = 430 GeV [74].…”

“…The implementation of the cuts is validated against the dominant irreducible background process pp → ZZ → νν + − . In producing the exclusion limits, we assume a systematic error of 10% and account for higher order corrections by applying an N 2 LO K-factor of 2.3 for M H = 500 GeV at √ s = 13 TeV [74,78].…”

Isolating top contributions in the production of the 750 GeV diphoton excess

“…The inclusive production cross section is 565fb for φ H . For φ A , the NLO QCD production cross section at 13TeV LHC is roughly 705fb [166]. The top-pair associated production cross section of the SM Higgs-like scalar is calculated using MCFM7.0 to leading order (LO) with MSTW2008LO PDF [167] and µ R = µ F = (2m t + m φ ) /2 = 548.2GeV, which is shown to have a K-factor ∼ 1 [168].…”

Post-Higgs THDM scenarios associated with the new diphoton resonance data

“…More precise calculation containing a combination of fixed order at exact NNLO plus approximate N 3 LO and threshold resummation at N 3 LL [14] does not change the picture significantly [15]. As a rule the cross section value σ(gg → H(A) → γγ) is too small (∼ 0.015 fb for tan β = 1 in the alignment limit), however the appropriate ranges are still viable for tan β 1 and α −0.01, see Fig.2.…”