相关论文: Probing unknown nonperturbative effects in $b \to …
The rare $B \to K^{(*)} \bar{\ell} \ell$ decays exhibit a long-standing tension with Standard Model (SM) predictions, which can be attributed to a lepton-universal short-distance $b \to s \bar{\ell} \ell$ interaction. We present two novel…
Rare semileptonic $b \to s \ell^+ \ell^-$ transitions provide some of the most promising frameworks to search for new physics effects. Recent analyses of these decays have indicated an anomalous behaviour in measurements of angular…
Motivated by a recent Belle~II measurement that suggests an excess in the rare decay $B \to K\, E_{\rm miss}$, and building upon our recent differential decay rate likelihood analysis of the existing experimental information, we investigate…
The recent LHCb angular analysis of the exclusive decay B->K^*mu+mu- has indicated significant deviations from the Standard Model expectations. Accurate predictions can be achieved at large K*-meson recoil for an optimised set of…
We discuss the implications of $b \to s \ell^+\ell^-$ measurements and their deviations with respect to the Standard Model predictions in a model-independent framework. We highlight in particular the impact of the recent updated…
In this work we study the effects of New Physics (NP) operators on the inclusive $\bar{B} \to X_c \tau^- \bar{\nu}_\tau$ decay including power $(\mathcal{O}(1/m_b^2))$ corrections in the NP operators. In analogy with $R(D^{(*)})$…
We consider the exclusive decays $B \to D^{(*)}\,\ell \bar\nu$ and study the effect of non $V-A$ structures on the observables. We extend the standard model hadronic current by additional right-handed vector as well as left- and…
The recent measurements on $R_D$, $R_{D^*}$ and $R_{J/\psi}$ by three pioneering experiments, BaBar, Belle and LHCb, indicate that the notion of lepton flavour universality is violated in the weak charged-current processes, mediated through…
Recently, the LHCb Collaboration provided updated measurements for the lepton flavour ratios $R_K$ and $R_{K^*}$. The currently observed values align with the predictions of the standard model. In light of these recent updates, our…
One of the most pragmatic ways to look for the effects of New Physics at low energy scales is to study a detailed angular distribution of various decay modes, and in particular those based on $b\to c\ell\bar \nu_\ell$. In this paper we…
We study the differential decay rate for the rare $\Lambda_b \to \Lambda (\to N \pi)\ell^+\ell^-$ transition, including a determination of the complete angular distribution, assuming unpolarized $\Lambda_b$ baryons. On the basis of a…
The most recent measurements of the observables $R_{D^{(*)}}$ are in tension with the Standard Model offering hints of New Physics in $b\rightarrow c \ell \bar{\nu}_{\ell}$ transitions. Motivated by these results, in this work we present an…
We present a model-independent study of spectator effects, which are responsible for the lifetime differences between beauty hadrons. These effects can be parametrized in terms of hadronic matrix elements of four four-quark operators. For…
Hadron spectra and hadronic moments in the decay $B \to X_s \ell^+ \ell^-$ are calculated taking into account both the short-distance and long-distance contributions in the decay amplitude using a Fermi motion (FM) model to incorporate the…
We discuss nonperturbative contributions to the inclusive rare $B$ decays $B\to X_s\gamma$ and $B\to X_s\ell^+\ell^-$. We employ an operator product expansion and the heavy quark effective theory to compute the leading corrections to the…
We identify the correct power counting of all the variables in the low-$q^2$ window of the inclusive decay $\bar B \to X_s \ell^+\ell^-$ within the effective theory SCET if a hadronic mass cut is imposed. Furthermore we analyse the resolved…
We present a critical assessment of the present $B$ anomalies in the exclusive $b \to s \ell\ell$ mode based on the QCD factorisation (QCDf) approach. In particular, we analyse the impact of different local form factor calculations and of…
Inclusive semileptonic $B\to X_c \ell \bar{\nu}_\ell$ decays, where $\ell = \mu,e$, are by now standard candles in the determination of the CKM element $|V_{cb}|$. These determinations rely on the heavy-quark expansion and use moments of…
We conduct a systematic study of the impact of new physics in quark-level $b \to c \bar{c} s$ transitions on $B$-physics, in particular rare $B$-decays and $B$-meson lifetime observables. We find viable scenarios where a sizable effect in…
We study the exclusive decays of $B\to K^{(*)}\ell^+ \ell^-$ by the results in the perturbative QCD with the heavy quark effective theory and lattice calculations. We obtain the form factors for the $B\to K^{(*)}$ transitions in the whole…