Electronic Theses and Dissertations

Date of Award


Document Type


Degree Name

Ph.D. in Physics


Physics and Astronomy

First Advisor

Alakabha Datta

Second Advisor

Micah B. Milinovich

Third Advisor

Luca Bombelli

Relational Format



This dissertation is a study of beyond standard model physics or new physics. The third generation charged lepton -the τ -is an excellent probe of new physics (NP) because of it being the heaviest lepton. As the heaviest lepton, it has the largest coupling ( among the leptons) to the Higgs boson in the Standard Model (SM). New physics contributions to the tau-neutrino nucleon scattering were considered. Charged Higgs and W' effects to the deep inelastic scattering ντ ( [special character omitted]τ) + N → τ− (τ+) + X in the neutrino-nucleon interactions has been studied. The neutrino detection process at neutrino oscillation experiments modify the measured atmospheric and reactor mixing angles &thetas;23 and &thetas; 13, respectively. A significant deviation from the standard model was observed in terms of the neutrino mixing angles. The semileptonic decays of B meson to the τ lepton is mediated by a W boson in the SM. In many models of NP this decay gets contributions from additional states like new vector bosons, leptoquarks or new scalar particles. These new states affect the semileptonic b → c and b → u transitions and gave rise to new physics beyond the standard model. We have presented the angular B¯ → D*+ τ − [special character omitted]τ with the most general new physics structure including tensor op- distribution for B erators. We have then discussed the effects of the tensor operators on various observables that can be constructed out of the angular distribution. Our focus was on the azimuthal observables which include the important CP violating triple product asymmetries. We found that these azimuthal asymmetries, have different sensitivities to different new physics structures and hence they are powerful probes of the nature of the NP.



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