Evidence of Higgs Boson Production through Vector Boson Fusion
dc.contributor.advisor | Kotwal, Ashutosh V | |
dc.contributor.author | Cerio, Benjamin C | |
dc.date.accessioned | 2015-05-12T20:44:08Z | |
dc.date.available | 2015-09-26T04:30:04Z | |
dc.date.issued | 2015 | |
dc.department | Physics | |
dc.description.abstract | The discovery of the Higgs boson in 2012 provided confirmation of the proposed mechanism for preserving the electroweak $SU(2) \times U(1)$ gauge symmetry of the Standard Model of particle physics. It also heralded in a new era of precision Higgs physics. This thesis presents a measurement of the rate at which the Higgs boson is produced by vector boson fusion in the $WW^{(\ast)}\rightarrow\,\ell\nu\ell\nu$ decay channel. With gauge boson couplings in both the production and decay vertices, a VBF measurement in this channel is a powerful probe of the $VVH$ vertex strength. Using $4.5$~fb$^{-1}$ and $20.3$~fb$^{-1}$ of $pp$ collision data collected at respective center-of-mass energies of 7 and $8 \tev$ in the ATLAS detector, measurements of the statistical significance and the signal strength are carried out in the Higgs mass range $100 \leq m_H \leq 200 \gev$. These measurements are enhanced with a boosted decision tree that exploits the correlations between eight kinematic inputs in order to separate signal and background processes. At the benchmark Higgs mass of $125.36 \gev$, the significance of the data assuming the background-only hypothesis to be true has been observed to be $3.2\sigma$ ($2.7\sigma$ expected), constituting evidence of VBF Higgs boson production. The measured signal strength (ratio of observed cross section times branching ratio to that predicted by the SM) is $1.27^{+0.53}_{-0.45}$. The inclusive cross section times branching ratio is found to be $0.51^{+0.22}_{-0.17}$~pb at $\sqrts = 8 \tev$, consistent with the SM prediction of $0.34$~pb. No significant deviations from the SM predictions for VBF Higgs boson production are observed. | |
dc.identifier.uri | ||
dc.subject | Physics | |
dc.subject | Particle physics | |
dc.subject | BDT | |
dc.subject | boson | |
dc.subject | Fusion | |
dc.subject | Higgs | |
dc.title | Evidence of Higgs Boson Production through Vector Boson Fusion | |
dc.type | Dissertation | |
duke.embargo.months | 4 |
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