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On new physics in non-leptonic tree level b-quark decays and hadron-quark duality violations.

Tetlalmatzi Xolocotzi, Gilberto (2017) On new physics in non-leptonic tree level b-quark decays and hadron-quark duality violations. Doctoral thesis, Durham University.

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Abstract

We review the validity of the assumption of having no new physics in tree level b quark transitions $b\rightarrow q q' d$ and $b\rightarrow q q' s$ ( $q, q'= u,c$ ).
In particular we test for possible deviations on the Wilson coefficients of the corresponding effective current-current operators with respect to their Standard Model values.
The allowed
new physics regions are determined using a global fit. We take into account constraints from different flavour observables calculated from the hadronic decays $B^0_d\rightarrow \pi\pi$ , $B^0_d\rightarrow \rho\pi$ , $B^0_d\rightarrow \rho\rho$ , $B\rightarrow X_s \gamma$ and $B\rightarrow X_d \gamma$ . We also include observables from neutral B meson mixing such as $\Delta \Gamma_s$ and the semileptonic asymmetries $a^{s,d}_{sl}$ .
We show that deviations in the tree level Wilson coefficients of the order $\mathcal{O}(10\%)$ are consistent with state of the art experimental measurements. We study the implications of these deviations over the decay width $\Delta \Gamma_d$ of $B^0_d$ meson mixing, not measured yet by experiments, and over the precision of the CKM phase $\gamma$ .
Our results
show that enhancements on $\Delta \Gamma_d$ by up to a factor of 3.6 with respect to the Standard Model value are allowed by data.
Moreover the effects on $\gamma$
can compete with the corresponding experimental precision $\mathcal{O}(6^{\circ})$ .
Finally we explore for possible hadron-quark duality violations in the neutral $B$ and $D$ meson sectors.
This analysis includes constraints from
mixing observables and from the lifetimes of $B^0_d$ and $B^0_s$ mesons. We find that duality violations of $\mathcal{O}(20\%)$ can provide an explanation to the tension of several orders of magnitude between the Heavy Quark Expansion and experimental data in the observable $\Delta \Gamma_D$ of neutral $D$ meson mixing.

Item Type:	Thesis (Doctoral)
Award:	Doctor of Philosophy
Keywords:	High Energy Physics, quark-flavour physics, new physics, B-meson physics.
Faculty and Department:	Faculty of Science > Physics, Department of
Thesis Date:	2017
Copyright:	Copyright of this thesis is held by the author
Deposited On:	16 Jan 2017 12:09

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On new physics in non-leptonic tree level b-quark decays and hadron-quark duality violations.

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