Related papers: New physics in $b\rightarrow se^+e^-$: A model ind…
The recent LHCb measurement of $R_{K^*}$ in two $q^2$ bins, when combined with the earlier measurement of $R_K$, strongly suggests lepton flavour non-universal new physics in semi-leptonic $B$ meson decays. Motivated by these intriguing…
We construct an expression for a general lepton flavour universality (LFU) ratio, $R_{X}$, in $b\to s l^+ l^-$ decays in terms of a series of hadronic quantities which can be treated as nuisance parameters. This expression allows to include…
The experimental information on b --> s l^+ l^- decays has grown enormously during the last couple of years due to BaBar, Belle, CDF and LHCb. Especially, exclusive modes B --> K^(*) l^+ l^-, which have the largest rate and are easily…
We consider the most general new physics effective Lagrangian for b --> s l+ l-. We derive the upper limit on the branching ratio for the processes B_s --> l+ l- where l=e, mu, subject to the current experimental bounds on related…
The flavor changing rare decay $B\to K^{*}(\to K\pi)\ell^+\ell^-$ is one of the most studied modes due to its sensitivity to physics beyond the standard model and several discrepancies have come to light among the plethora of observables…
Recent experimental data on several observables in semileptonic $B$-meson decays are found to be in tension with the corresponding Standard Model predictions. Most of these deviations are related to $b \to c$ and $b \to s$ flavour changing…
Rare decays mediated by $b \to s \nu \bar \nu$ transitions have been reported by the Belle II experiment. The branching ratio of the decay $B^+ \to K^+ \nu \bar \nu$ is found to be enhanced with respect to the standard model value. If taken…
The persisting anomalous data in semileptonic B-decays point towards New Physics models exhibiting large sources of Lepton Flavour Universality Violation. In this work we generalise previous studies by considering frameworks which include…
Motivated by the anomalies present in $b \to s\,l^+\,l^-$ neutral current decays, we study the corresponding $B_c \to (D_s,\,D^{\ast}_s)\mu^+\mu^-$ decays within the standard model and beyond. We use a model independent effective theory…
We study the rare $\Lambda_b\to\Lambda\mu^+\mu^-$ decay in the Standard Model and beyond. Beyond the Standard Model we include new vector and axial-vector operators, scalar and pseudo-scalar operators, and tensor operators in the effective…
Phenomenological aspects of flavor changing processes are considered in the context of the supergravity model.Various flavor changing neutral current processes in B and K decays are calculated in such models. For lepton flavor violating…
We investigate new-physics contributions to $b\to s \ell\ell$ transitions in the context of an effective field theory extension of the Standard Model, including operator mixing at one loop. We identify the few scenarios where a single…
Inspired by the discrepancies observed in the $b\to s\ell^+\ell^-$ neutral current decays, we study the decay channel $B_c\to D_s^{(\ast)} \,\ell^+\ell^-$ ($\ell=\mu,\tau$), which is based on the same flavor changing neutral current (FCNC)…
Non-leptonic $B^0_s \rightarrow D_s^{\pm} K^{\mp}$ transitions are particularly interesting processes to test the Standard Model. As these decays occur via pure tree diagrams, they allow a theoretically clean determination of the angle…
We analyse the new physics implications of theoretically clean $b \to s$ observables in a model-independent approach and compare their coherence with the implications of other rare $B$-decays. A statistical comparison is done between the…
In this letter we propose a strategy for discerning if new physics in the Wilson coefficient ${\cal C}_{9\mu}$ is dominantly lepton flavour universality violating or if it contains a sizable lepton flavour universal component (${\cal…
We revisit the status of the new-physics interpretations of the anomalies in semileptonic $B$ decays in light of the new data reported by Belle on the lepton-universality ratios $R_{D^{(*)}}$ using the semileptonic tag and on the…
In a recent paper arXiv:1706.08437, we have advanced a minimal resolution of some of the persistent anomalies in semileptonic $B$-decays. These include the neutral-current observables $R_K$ and $R_{K^*}$, as well as the charged-current…
This Thesis presents my personal contributions to two distinct fields, namely the recent experimental anomalies in B-meson decays, and the longstanding quest for a theoretical explanation of lepton masses and mixings, under a unifying…
The exclusive (B -> K_2 l^+ l^-) decay is studied using the most general, model independent four-fermion interaction. The sensitivity of the ratio of the decay widths when K_2 meson is longitudinally and transversally polarized, the…