Fiducial cross sections for the lepton-pair-plus-photon decay mode in Higgs production up to NNLO QCD

Abstract

The rare three-body decay of a Higgs boson to a lepton-antilepton pair and a photon is starting to become experimentally accessible at the LHC. We investigate how higher-order QCD corrections to the dominant gluon-fusion production process impact on the fiducial cross sections in this specific Higgs decay mode for electrons and muons. Corrections up to NNLO QCD are found to be sizeable. They are generally uniform in kinematical variables related to the Higgs boson, but display several distinctive features in the kinematics of its individual decay products.

Higgs boson decay into a lepton pair and a photon revisited

“…These experimental pursuits align with recent theoretical analyses of the process H → ℓ + ℓ − γ given in several articles [4][5][6][7][8][9][10], building upon earlier studies [11][12][13][14][15]. Furthermore, the analogous decay of the Higgs boson, involving a photon and a neutrino pair in the final state has received relatively less attention [16][17][18].…”

“…The corresponding rates are loop-suppressed in the standard model, providing opportunities to detect signals of physics beyond the standard model, particularly if new particles appear with sufficiently low masses and large enough couplings to produce discernible signatures. In addition to H → Zγ, there is an ongoing effort to search for a decay channel to a photon and a pair of light charged leptons in the region of low lepton-pair invariant mass [3].These experimental pursuits align with recent theoretical analyses of the process H → ℓ + ℓ − γ given in several articles [4][5][6][7][8][9][10], building upon earlier studies [11][12][13][14][15]. Furthermore, the analogous decay of the Higgs boson, involving a photon and a neutrino pair in the final state has received relatively less attention [16][17][18].…”

Event Generators for High-Energy Physics Experiments

“…Moreover, the interplay between fiducial cuts and radiative corrections can also impact the perturbative stability of the prediction. This has been observed for the case of H → 4 decays [586] in the different treatment of the lepton isolation (rejecting leptons as opposed to jets), as well as in the Higgs Dalitz decay [587] in the almost degenerate low-mass region. Fiducial cuts close to back-to-back kinematics were found to potentially induce large power corrections [588] that were also identified in [76] through large higher-order corrections.…”

Event generators for high-energy physics experiments

“…Moreover, the interplay between fiducial cuts and radiative corrections can also impact the perturbative stability of the prediction. This has been observed for the case of H → 4ℓ decays [669] in the different treatment of the lepton isolation (rejecting leptons as opposed to jets), as well as in the Higgs Dalitz decay [670] in the almost degenerate low-mass region. Fiducial cuts close to back-to-back kinematics were found to potentially induce large power corrections [671] that were also identified in [80] through large higher-order corrections.…”