UCL logo

UCL Discovery

UCL home » Library Services » Electronic resources » UCL Discovery

Search for Higgs boson pair production in the bƃbƃ final state at the Large Hadron Collider

Falla, RJ; (2016) Search for Higgs boson pair production in the bƃbƃ final state at the Large Hadron Collider. Doctoral thesis , UCL (University College London). Green open access

[img]
Preview
Text
Falla_Rebecca_Falla_Thesis_compressed.pdf

Download (21MB) | Preview

Abstract

The work presented in this thesis focuses on the search for resonant and non-resonant Higgs boson pair production in the bƃbƃ final state at the LHC. All of the searches require the use of high transverse momentum b-tagged jet systems. The first search presented is performed using a dataset of proton- proton collisions at √s = 8 TeV, collected in 2012 with the ATLAS detector, corresponding to an integrated luminosity of 19.5 fb^{-1}. The Higgs boson decay products are reconstructed as a pair of close- by small radius b-tagged jets with a high transverse momentum, known as “dijets”. The resonant signals looked for are a Randall- Sundrum Kaluza-Klein graviton, G^*, and a heavy neutral scalar boson in the 2HDM model, H. A non-resonant search is also performed. No evidence for resonant or non-resonant Higgs boson pair production is observed. An upper limit on the cross-section for σ(pp → G^* →hh→bƃbƃ) of 3.2 fb is set for a G^* mass of 1.0 TeV, at the 95% confidence level. The search for non-resonant Standard Model hh production sets an observed 95% confidence level upper limit on the production cross-section σ(pp → hh → bƃbƃ) of 202 fb, compared to a SM prediction of σ(pp → hh → bƃbƃ) = 3.6 ± 0.5 fb. In preparation for Run 2 and the HL-LHC simulation studies based on √s = 14 TeV are made. A non-resonant search using the dijet method used in Run 1 is presented. A resonant study is also presented which shows a new method for reconstructing pp → X →hh→bƃbƃ events. It uses the combination of many Higgs boson reconstruction techniques which vary with the Higgs boson transverse momentum and is shown to be excellent at providing a high signal efficiency.

Type: Thesis (Doctoral)
Title: Search for Higgs boson pair production in the bƃbƃ final state at the Large Hadron Collider
Event: UCL (University College London)
Open access status: An open access version is available from UCL Discovery
Language: English
UCL classification: UCL > Provost and Vice Provost Offices
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy
URI: http://discovery.ucl.ac.uk/id/eprint/1482160
Downloads since deposit
120Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item