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000615859 005__ 20241015213442.0
000615859 037__ $$aPUBDB-2024-06300
000615859 041__ $$aEnglish
000615859 1001_ $$0P:(DE-H253)PIP1110338$$aSulimann, Sen$$b0$$eCorresponding author$$gmale
000615859 245__ $$aSuppression of Light $q\bar{q}$ Backgrounds with Multivariate Techniques in the Measurement of Radiative B-Meson Decays$$f2024-04-22 - 2024-09-30
000615859 260__ $$aHamburg$$c2024
000615859 300__ $$a66
000615859 3367_ $$2DRIVER$$abachelorThesis
000615859 3367_ $$02$$2EndNote$$aThesis
000615859 3367_ $$2DataCite$$aOutput Types/Supervised Student Publication
000615859 3367_ $$0PUB:(DE-HGF)2$$2PUB:(DE-HGF)$$aBachelor Thesis$$bbachelor$$mbachelor$$s1728992728_1708574
000615859 3367_ $$2BibTeX$$aMASTERSTHESIS
000615859 3367_ $$2ORCID$$aSUPERVISED_STUDENT_PUBLICATION
000615859 502__ $$aBachelorarbeit, University of Hamburg, 2024$$bBachelorarbeit$$cUniversity of Hamburg$$d2024$$o2024-09-30
000615859 520__ $$aThe Standard Model of particle physics has been highly successful in describing fundamental particles and their interactions, but potential extensions are needed to address itslimitations. Precise measurements of rare decays, such as the radiative B → Xsγ decay, provide an opportunity to test Beyond Standard Model (BSM) theories, due to them being suppressed by the Standard Model. This thesis focuses on the suppression of lightquark-antiquark ($q\bar{q}$) continuum backgrounds, a dominant source of noise in the analysis of the B → $X_sγ$ decay, using multivariate classification techniques to improve the signal to -background ratio. Furthermore, an attempt is made to suppress $B\bar{B}$-backgrounds. In particular, Boosted Decision Trees (BDTs) are trained to differentiate the rare B → $X_sγ$ signal from continuum and $B\bar{B}$-backgrounds. Specifically, two approaches are employed: multi-class classifiers and the consecutive application of binary classifiers. The data analyzed were collected by the Belle II detector from $e^+e^−$ -collisions at the SuperKEKB collider in Japan. The work presented in this thesis includes the selection and analysis of discriminating variables, the development and training of BDTs, and the evaluation of their performance. The trained models demonstrate promising results in suppressing background noise, especially continuum events. The analysis provides valuable insights into the variable importance and limitations of the single approaches, as well as the potential for future refinement. 
000615859 536__ $$0G:(DE-HGF)POF4-611$$a611 - Fundamental Particles and Forces (POF4-611)$$cPOF4-611$$fPOF IV$$x0
000615859 693__ $$0EXP:(DE-H253)BELLE-20150101$$1EXP:(DE-H253)KEK-20150101$$5EXP:(DE-H253)BELLE-20150101$$aKEK$$eKEK: BELLE I/II$$x0
000615859 7001_ $$0P:(DE-H253)PIP1013754$$aTackmann, Kerstin$$b1$$eThesis advisor
000615859 7001_ $$0P:(DE-H253)PIP1099444$$aMoreira de Carvalho, Ana Luisa$$b2$$eThesis advisor
000615859 8564_ $$uhttps://bib-pubdb1.desy.de/record/615859/files/Bachelor_Thesis_Sen_Sulimann.pdf$$yRestricted
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000615859 9101_ $$0I:(DE-HGF)0$$6P:(DE-H253)PIP1110338$$aExternal Institute$$b0$$kExtern
000615859 9101_ $$0I:(DE-588b)2008985-5$$6P:(DE-H253)PIP1013754$$aDeutsches Elektronen-Synchrotron$$b1$$kDESY
000615859 9101_ $$0I:(DE-588b)2008985-5$$6P:(DE-H253)PIP1099444$$aDeutsches Elektronen-Synchrotron$$b2$$kDESY
000615859 9131_ $$0G:(DE-HGF)POF4-611$$1G:(DE-HGF)POF4-610$$2G:(DE-HGF)POF4-600$$3G:(DE-HGF)POF4$$4G:(DE-HGF)POF$$aDE-HGF$$bForschungsbereich Materie$$lMatter and the Universe$$vFundamental Particles and Forces$$x0
000615859 9141_ $$y2024
000615859 920__ $$lyes
000615859 9201_ $$0I:(DE-H253)BELLE-20210408$$kBELLE$$lBELLE II Experiment$$x0
000615859 980__ $$abachelor
000615859 980__ $$aVDB
000615859 980__ $$aI:(DE-H253)BELLE-20210408
000615859 980__ $$aUNRESTRICTED