[Seminar] Samuel D. Lane

by Dr Lane Samuel D (Kaist, Taejon)

Wednesday 28 Jun 2023, 16:00 → 17:30 Asia/Seoul

1424 in building 1 (KIAS)

Title : Multi-photon decays of the Higgs boson at the LHC

Speaker : Dr. Samuel D. Lane  (Kaist, Taejon)

Abstract : Many new physics scenarios predict multi-photon Higgs resonances. One such scenario is the dark axion portal model. The primary decay chain that we study is  h →γD γD → 2 γ2 a → 6γ. However, depending on the relevant kinematics, the photons can become well-collimated and appear as photon-jets (multiple photons that appear as a single photon in the detector) or ξ-jets (non-isolated multi-photon signals that do not pass the isolation criterion). These
effects cause the true six-photon resonance to appear as other multi-photon signals, such as two and four photons. We classify the mass regions where two, four, and six-photon resonances dominate. The four-photon signal is particularly interesting. These events mainly occur when the photons from the axion-like particles are collimated into photon-jets. The decay of the dark photon is then γD → γa → γ + γ-jet, which is an apparent violation of the Landau-Yang theorem. We show that current measurements of h → 2γ and searches for h → 4γ at the Large Hadron Collider (LHC) can limit BR(h → γD γD ) ≲ 10−3. This model also motivates new searches for Higgs decays into six isolated photons or ξ-jets at the LHC. While there are currently no dedicated searches, we show that many of the Higgs to six isolated photons or ξ-jet events could pass two or three-photon triggers. That is, new physics could be found by reanalyzing existing data. These multi-photon signals provide excellent footing to explore new physics at the LHC and beyond

 

Lane_Seminar_KIAS_2023.pdf

Video