uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Searching for the charged Higgs boson in the tau nu analysis using Boosted Decision Trees
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
2016 (English)Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Abstract [en]

his thesis implements a multivariate analysis in the current cut- based search for the charged Higgs bosons, which are new scalar particles predicted by several extensions to the Standard Model. Heavy charged Higgs bosons (mH± mtop) produced in association with a top quark de- caying via H± → τν are considered. The final state contains a hadronic τ decay, missing transverse energy and a hadronically decaying top quark.

This study is based on Monte Carlo samples simulated at CM-energy

s = 13 TeV for signal and backgrounds. The figure of merit to measure the improvement of the new method with respect to the old analysis is the separation between the signal and background distributions. Four mass points (mH± = 200, 400, 600, 1000 GeV) are considered, and an increase of the separation ranging from 2.6% (1000 GeV) to 29.2% (200 GeV) com- pared to the current cut-based analysis is found. 

Abstract [sv]

Denna studie implementerar en flervariabel-analys till den befintliga

snitt-baserade analysen av laddade Higgs-bosoner, nya skal ̈arpartiklar fo ̈rutsagda

av flertalet fo ̈rl ̈angningar av Standardmodellen. Studien antar tunga lad-

dade Higgs-bosoner (mH± mtop) producerade tillsammans med en top-

kvark som fo ̈rfaller via H± → τν. Sluttillst ̊andet best ̊ar av ett hadroniskt

τ-so ̈nderfall, f ̈orlorad transversell energi och en hadroniskt so ̈nderfallande

toppkvark. Studien a ̈r baserad p ̊a data f ̈or signal och bakgrund. Fo ̈r att ma ̈ta fo ̈rba ̈ttringen av analysens ka ̈nslighet anva ̈nds avst ̊and mellan bakgrundens och signalens distribu- tioner som godhetstal. Fyra masspunkter (mH± = 200, 400, 600, 1000 GeV) anva ̈nds, och en o ̈kning av avst ̊and fr ̊an 2.6% (1000 GeV) till 29.2% (200 GeV) hittades. 

Place, publisher, year, edition, pages
Keyword [en]
Higgs, charged higgs, atlas, machine learning, ML, BDT, boosted decision trees, LHC, BSM, BSM physics, standard model, MSSM
National Category
Subatomic Physics
URN: urn:nbn:se:uu:diva-301351OAI: oai:DiVA.org:uu-301351DiVA: diva2:954187
Educational program
Master Programme in Physics
Available from: 2016-09-16 Created: 2016-08-21 Last updated: 2016-09-16Bibliographically approved

Open Access in DiVA

fulltext(5135 kB)25 downloads
File information
File name FULLTEXT01.pdfFile size 5135 kBChecksum SHA-512
Type fulltextMimetype application/pdf

By organisation
High Energy Physics
Subatomic Physics

Search outside of DiVA

GoogleGoogle Scholar
Total: 25 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 67 hits
ReferencesLink to record
Permanent link

Direct link