Zoekresultaten

Zoekopdracht: faculteit: "FNWI" en publicatiejaar: "2012"

AuteurBouwe Andela
TitelMassive neutrinos and Z′. Extending the Standard Model gauge group with U(1)B−L
BegeleiderJ.W. van Holten
Jaar2012
FaculteitFaculteit der Natuurwetenschappen, Wiskunde en Informatica
Instituut/afd.FNWI: Instituut voor Hoge Energie Fysica
OpleidingFNWI MSc Physics
SamenvattingIn this master’s thesis an interesting extension of the Standard Model (SM) is reviewed. This extension consists of adding three right-handed neutrinos to the SM, which leads to an extra global anomaly free U(1) symmetry with baryon minus lepton number (B − L) as the charges of the fermions. This symmetry is then promoted to a local symmetry by adding an extra abelian gauge field, that mixes with the SM Z boson into a Z and a Z′ boson. A Majorana mass term for the right-handed neutrinos is forbidden by the newly added U(1) symmetry, so in order to retain the seesaw mechanism, it is added to the model as a Yukawa coupling to an extra scalar singlet with B − L = 2, that has large (compared to the SM Higgs) vacuum expectation value. Since the masses of all the new particles in the model are determined by this vacuum expectation value, the effects caused by the presence of this new physics is expected to start appearing at similar energy scales, which could be low enough to be accessible at the Large Hadron Collider in the near future. The new parameters in the extended model are explored and the thesis ends with a review of current experimental and theoretical limits on these parameters.
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