NNLL resummation for squark-antisquark pair production at the LHC

Abstract

Abstract:We consider the resummation of soft gluon emission for squark-antisquark pair-production at the LHC at next-to-next-to-leading-logarithmic (NNLL) accuracy in the framework of the minimal supersymmetric standard model. We present the analytical ingredients needed for the calculation and provide numerical predictions for the LHC at centre-of-mass energies of 7 and 14 TeV. We find a significant reduction in the scale uncertainty and a considerable increase in the prediction of the total cross section. Compared to the next-to-leading order prediction, the corrections increase the cross section by up to 30% for 1.5 TeV squarks at a centre-of-mass energy of 7 TeV.

Soft gluon resummation for associated t t ¯ H $$ \mathrm{t}\overline{\mathrm{t}}\mathrm{H} $$ production at the LHC

“…In our calculations we follow the methodology of [52,53], where the case of two massive coloured particle in the final state was considered. We have explicitly checked that adding a massive colour singlet particle in the final state does not introduce any extra terms dependent on the mass of the added particle.…”

Supersymmetric type-III seesaw mechanism: Lepton flavor violation and LHC phenomenology

“…We have not pursued this further, as this is at most of the order of the expected theoretical uncertainty on the SUSY cross section, which is about 10%-20% (see e.g., Refs. [84][85][86][87] and references therein). In the following examples we have checked that the bounds on SUSY particles are fulfilled [88][89][90][91].…”

NNLL resummation for squark-antisquark production

“…(2.2) and comparing it to figure 1. The g 3 term can be found in [15,[22][23][24] and the ingredients for C will be discussed in section 3. The hadronic cross section σ h 1 h 2 →qq can be recovered by taking the inverse Mellin transform.…”

“…The complete expressions for the hard matching coefficients of the squark-antisquark production processes can be found in Ref. [15]. Their behaviour for varying gluino mass is shown in Fig.…”

“…Recently, resummation at NNLL accuracy for squark-antisquark pair production was presented [15]. Compared to the NLL calculation the new ingredients are the one-loop matching coefficients, which contain the NLO cross section near threshold, and the two-loop soft anomalous dimensions.…”