Searching for the Higgs The Sheffield High Energy Physics group is an active participant in the ATLAS experiment, one of the general purpose detectors being built to exploit the exciting physics potential of the Large Hadron Collider (LHC) at CERN. The group plays a leading role in the search for the Higgs boson in the golden decay channels to 4 leptons (electrons/muons) and to two photons. The decay to 4 leptons is shown in the figure where a proton-proton collision produces a Jet and the Higgs which decays to a pair of Z bosons. ATLAS measures the products of the two Z bosons: an electron/positron pair trapped in the EM calorimeter detector (blue lines/wedges going upwards), and a pair of muons (red lines). ATLAS can also identify a Jet of particles produced in the collision (blue-red wedge going downwards).

Higgs related Sheffield Group Activities

• Higgs to ZZ(*) to 4 leptons Analysis
  
• Higgs to 2 photons Analysis
  
• Electron based calibration of the EM LAr Calorimeter (with the LAr and egamma groups)
  Calorimeter calibration constants in ATLAS offline software extracted by S.Paganis and N.Kerschen.
• Photon Conversion Reconstruction
  
• Coverage Studies for Higgs Analyses
  

Link to ATLAS Presentations.

Publications and Proceedings

• "Bacgkround and signal estimation for a low mass Higgs boson at the LHC", S.Paganis D.Tovey, Eur.Phys.J.C, Vol.56 1 153-159, July 2008.
• "Search for the Standard Model Higgs boson decays to four leptons (e,mu) final state with the ATLAS experiment at the LHC", B.Lenzi, Hadron Collider Physics Symposium (HCP08), Galena, Illinois USA, 2008.
• "Search for the Standard Model Higgs boson decaying to four lepton final states at the ATLAS experiment", N.Kerschen S.Paganis, Acta Phys. Polon.B Proc Supp. Vol. 1, No 2 (2008)
• "Searches for the Standard Model Higgs boson in the H->ZZ*->4l decay with the ATLAS detector at the LHC",K.Prokofiev (Sheffield), Advanced Studies Institute "symmetries And Spin" (spin-praha-2008), Prague, Czech Republic, 20 July - 26 July 2008.
• "ATLAS Sensitivity to Standard Model and SUSY Higgs Bosons", S.Paganis, 13th International Conference on Supersymmetry (SUSY2005).

Older ATLAS Notes and Papers

• "Higgs to ZZ(*) to 4leptons Analysis with DC1 Full ATLAS Simulation and Reconstruction"
  CERN Server, PS, PDF . S.Paganis, ATL-COM-PHYS-2005-043.
• "Coverage Studies for Higgs to 2 photons"
  CERN Server, PDF . K.Cranmer S.Paganis, ATL-COM-PHYS-2005-006.
• "Prospects for the Search of a Standard Model Higgs Boson in ATLAS using Vector Boson Fusion"
  CERN Server, PS, PDF . S.Asai et al, Eur. Phys. J., C 32 (2004) 19-54.
• "The Higgs working group: Summary report 2003"
  Spires Server, Higgs working group collaboration (K. Assamagan et al), Proceedings 3rd Les Houches Workshop.

Higgs Physics Analysis work presented in ATLAS meetings and Conferences.

2006

• "Update on Higgs->4 leptons"
  CERN server , PPT , PDF . N.Benekos, R.Nikolaidou, S. Paganis, K. Prokofiev, Higgs Working Group, CERN, 19-Jul-2006.
• "First Look at H->2photons with EventView",
  CERN server , PPT , PDF . Hongbo Zhu, S. Paganis, Higgs Working Group, CERN, 28-Jun-2006.
• "Progress in Higgs->4leptons with EventView in 11.0.41",
  PPT , PDF . N.Benekos, R.Nikolaidou, S. Paganis, Physics Week, CERN, 21-Mar-2006.
• "Higgs->4lepton Analysis Plans with the CSC samples",
  PPT , PDF . N.Benekos, R.Nikolaidou, S. Paganis, Higgs Working Group Meeting, CERN, 19-Jan-2005.

2005

• "Higgs Analyses with EventViews",
  PPT , PDF . S. Paganis, Physics Analysis Model Meeting, CERN, 1-Nov-2005.
• "Higgs to 4leptons with EventView",
  PPT , PDF . S. Paganis, Atlas Physics Week, CERN, 28-Oct-2005.
• "Higgs to 4leptons with EventView",
  PPT , PDF . S. Paganis, Atlas Higgs UK meeting, UCL, 19-Sep-2005.
• "ATLAS sensitivity to Standard Model and SUSY Higgs Bosons",
  PPT , PDF . S. Paganis, for the ATLAS Collaboration, SUSY-05, Durham, UK, July 2005.

2004

• Higgs to muons and electrons (talk at Higgs WG 3/Nov/04)
• e/mu/Z Higgs reconstruction with 8.x.0 (talk at Higgs WG 1/Sep/04)
• Progress in Higgs->2e2mu analysis with Full ATLAS Simulation and Reconstruction (talk at Higgs WG 12/May/04)
• Higgs->4l analysis with Full ATLAS Simulation and Reconstruction (talk at Higgs WG 25/Feb/04)
• Higgs->4l and EM reconstruction in ATLAS (talk at LAr week 28/Jan/04)
• Higgs->4e and 2e2mu in ATLAS (talk at Higgs WG Jan/04)
• Higgs->4e in ATLAS (talk at Higgs WG Dec/01/03)