Dark photons γ¯ mediating long-range forces in a dark sector are predicted by various new physics scenarios, and are being intensively searched for in experiments. We extend a previous study of a new discovery process for dark photons proceedings via Higgs-boson production at the LHC. Thanks to the non-decoupling properties of the Higgs boson, BR(H→γγ¯) values up to a few percent are possible for a massless dark photon, even for heavy dark-sector scenarios. The corresponding signature consists (for a Higgs boson at rest) of a striking monochromatic photon with energy Eγ=mH/2, and similar amount of missing energy. We perform a model independent analysis at the LHC of both the gluon-fusion and VBF Higgs production mechanisms at 14 TeV, including parton-shower effects, and updating our previous parton-level analysis at 8 TeV in the gluon-fusion channel by a more realistic background modeling. We find that a 5σ sensitivity can be reached in the gluon-fusion channel for BR(H→γγ¯)≃0.1% with an integrated luminosity of L≃300fb−1. The corresponding VBF reach is instead restricted to 1%. Such decay rates can be naturally obtained in dark-photon scenarios arising from unbroken U(1)F models explaining the origin and hierarchy of the Yukawa couplings, strongly motivating the search for this exotic Higgs decay at the LHC.
Titolo: | Dark-photon searches via Higgs-boson production at the LHC |
Autori: | |
Data di pubblicazione: | 2016 |
Rivista: | |
Abstract: | Dark photons γ¯ mediating long-range forces in a dark sector are predicted by various new physics scenarios, and are being intensively searched for in experiments. We extend a previous study of a new discovery process for dark photons proceedings via Higgs-boson production at the LHC. Thanks to the non-decoupling properties of the Higgs boson, BR(H→γγ¯) values up to a few percent are possible for a massless dark photon, even for heavy dark-sector scenarios. The corresponding signature consists (for a Higgs boson at rest) of a striking monochromatic photon with energy Eγ=mH/2, and similar amount of missing energy. We perform a model independent analysis at the LHC of both the gluon-fusion and VBF Higgs production mechanisms at 14 TeV, including parton-shower effects, and updating our previous parton-level analysis at 8 TeV in the gluon-fusion channel by a more realistic background modeling. We find that a 5σ sensitivity can be reached in the gluon-fusion channel for BR(H→γγ¯)≃0.1% with an integrated luminosity of L≃300fb−1. The corresponding VBF reach is instead restricted to 1%. Such decay rates can be naturally obtained in dark-photon scenarios arising from unbroken U(1)F models explaining the origin and hierarchy of the Yukawa couplings, strongly motivating the search for this exotic Higgs decay at the LHC. |
Handle: | http://hdl.handle.net/11368/2886123 |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1103/PhysRevD.93.093011 |
URL: | http://journals.aps.org/prd/abstract/10.1103/PhysRevD.93.093011 |
Appare nelle tipologie: | 1.1 Articolo in Rivista |
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