相关论文: Understanding the first measurement of $\mathcal{B…

When looking for heavy ($\mathcal{O}$(few TeV)) New Physics, the most efficient way to benefit from both high and low-energy measurements simultaneously is the use of the Standard Model Effective Field Theory (SMEFT). In this talk I…

The recent Belle and BaBar measurements of the branching ratio of $B^+ \to \tau^+ \nu_\tau$ indicate a significant deviation from the Standard Model prediction. We demonstrate that this measurement has a serious impact on models with…

We report a measurement of ratio ${\cal R}(D^*) = {\cal B}(\bar{B}^0 \rightarrow D^{*+} \tau^- \bar{\nu}_{\tau})/{\cal B}(\bar{B}^0 \rightarrow D^{*+} \ell^- \bar{\nu}_{\ell})$, where $\ell$ denotes an electron or a muon. The results are…

Recently Belle II reported the first measurement of $B^+\to K^++{\rm invisible (inv)}$, which is $2.7\sigma$ above the standard model (SM) prediction. If confirmed, this calls for new physics beyond SM. In the SM, the invisible particles…

Deviations from the standard model prediction have been observed in several leptonic and semileptonic $B$ meson decays to $\tau\nu$ final states mediated via $b \to u$ and $b \to c$ charged current interactions. The measured value of ratio…

We study potential New Physics effects in the $\bar B \to D^{(*)} \tau \bar\nu$ decays. As a particular example of New Physics models we consider the class of leptoquark models and put the constraints on the leptoquark couplings using the…

The recently measured B -> tau nu branching ratio allows to test the Standard Model by probing virtual effects of new heavy particles, such as a charged Higgs boson. The accuracy of the test is currently limited by the experimental error on…

The first lattice result from the RBC and UKQCD Collaborations and improved perturbative calculations of $\varepsilon^{\prime}_K / \varepsilon_K$ have implied that the Standard-Model (SM) expectation deviates from measured values at the…

Indirect signs of new physics beyond the Standard Model may be appearing in $B \to K^{(*)}\mu^+\mu^-$ decays. If confirmed, the title question will be of paramount importance in determining the strategy for future colliders. We answer it by…

In this work we consider the implications of current $b \to s \ell^+ \ell^-$ ($\ell=e,\,\mu$) measurements on several $B \to K^* \tau^+ \tau^-$ observables under the assumption that the possible new physics can have both universal as well…

The Belle II experiment recently observed the decay $B^+ \to K^+ \nu \nu$ for the first time, with a measured value for the branching ratio of $ (2.3 \pm 0.7) \times 10^{-5}$. This result exhibits a $\sim 3\sigma$ deviation from the…

We present a model independent analysis of new-physics contributions to the decays K^+ \to \pi^+ \nu \bar \nu and K_L \to \pi^0 \nu \bar \nu. We parameterize the effects of new physics in these decays by two parameters: r_K and \theta_K,…

In 2023, Belle II collaboration announced the observarion of the $B^+ \to K^+ \nu\bar{\nu}$ decay channel for the first time. This decay channel provides a clean signal with high precision in theoretical calculation. However, we encounter…

Motivated by the anomalies present in $b \to u$ and $b \to c$ semileptonic decays, we study the corresponding $B_s \to (K,K^*) \tau \nu$ and $B \to \pi \tau \nu$ decays within an effective field theory formalism. Our analysis is based on a…

We report the first measurement of the $D^{\ast -}$ meson polarization in the decay $B^0 \to D^{*-} \tau^+\nu_{\tau}$ using the full data sample of 772$\times 10^6$ $B\bar{B}$ pairs recorded with the Belle detector at the KEKB…

Disentangling New Physics effects from the Standard Model requires a good understanding of all pieces that stem from the latter, especially the uncertainties that might plague the theoretical estimations within the Standard Model. In the…

Belle II has reported the first evidence for $B^+ \to K^+\nu\bar\nu$ with a branching ratio $2.7 \sigma$ higher than the standard model expectation. We explain this, and the MiniBooNE and muon anomalous magnetic moment anomalies in a model…

This paper reports a study of $B \to K^{*}\gamma$ decays using $62.8\pm 0.6$ fb$^{-1}$ of data collected during 2019--2020 by the Belle II experiment at the SuperKEKB $e^{+}e^{-}$ asymmetric-energy collider, corresponding to $(68.2 \pm 0.8)…

We review some selected rare B decays calculated in next-to-leading order accuracy in the Standard Model (SM). These include the radiative decays $B \to (X_s,K^*,\rho)\gamma$ and the semileptonic decays $B \to (X_s,K,K^*) \ell^+ \ell^-$,…

Precise measurement of the Electric Dipole Moment (EDM) and anomalous magnetic moment ($g$-2) of particles are important tests of Beyond Standard Model (BSM) physics. It is generally believed that the tau lepton couples more strongly to BSM…