arXiv subjects

Carolina Bolognani

Publications and source records attributed to Carolina Bolognani.

6 recordsLinked to original sources

arXiv2026

EOS version 1.1: A Software for Flavor Physics Phenomenology

EOS is an open-source software package for a variety of computational tasks in flavor physics. In this article, we describe new developments for version 1.1 of this software and discuss changes with respect to version 1.0. These developments and changes include theory predictions for additional decay and scattering processes, such as semileptonic charm decays, hadronic tau decays, and $e^+e^- \to$ hadrons scattering. Overall, these changes have contributed 1063 additional (pseudo-)observables. Beyond the physics capabilities of the software, the changes include improving the quality and reducing the computational costs of posterior sampling; providing a more versatile and testable figure framework; and improving the overall user experience.

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arXiv2026

CP Violation in Charmed Meson Decays into Final States with $η'$

We derive Standard Model predictions for the CP asymmetries of singly-Cabibbo suppressed $D\rightarrow Pη'$ decays, where $P=K,π,η$. Our predictions are based on the approximate SU(3)$_F$ symmetry of QCD and include first-order symmetry-breaking effects in a systematic way. The underlying symmetry leads to correlations between different decay modes. To this end we predict the correlations between $ a_{\rm CP}^{\rm dir}(D^+\to π^+ η')$ and $a_{\rm CP}^{\rm dir}(D_s^+ \to K^+ η')$ as well as $a_{\rm CP}^{\rm dir}(D^0\to π^0 η')$ and $ a_{\rm CP}^{\rm dir}(D^0\to ηη')$. Our results can be used to probe the Standard Model with future measurements by LHCb, Belle II and BESIII. At the same time, such future measurements permit the extraction of the key theory parameter related to the ratio of color-suppressed to color-favoured contributions to the decay amplitudes. Future data on both branching ratios and CP asymmetries will automatically improve our predictions and thereby also their sensitivity to physics beyond the Standard Model.

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arXiv2026

Extracting production fractions of $b$ hadrons from exclusive semi-leptonic decays

Ratios of production fractions of $b$ hadrons are a dominant source of uncertainty in many LHC analyses, in particular in measurements with $B_s$ mesons. The currently used value for $f_s/f_d$ is based on a combination of hadronic and semi-inclusive semi-leptonic decays, and relies in part on assumptions about the underlying decays that are hard to quantify. We propose an independent alternative method to obtain this quantity by measuring ratios of the exclusive semi-leptonic decays $\bar B_{(s)} \to D_{(s)}^{(*)} \ell \barν$. This method benefits from significant cancellations of both experimental and theoretical uncertainties, as well as robustness against potential contamination from heavy physics beyond the Standard Model. As a proof of principle, we show that current measurements constrain $f_s/f_d$ with an uncertainty of $7\%$, dominated by present experimental uncertainties. This method can also be applied to other ratios of production fractions involving heavier $b$ hadrons, such as $B_c$ or $Λ_b$.

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arXiv2025

Anatomy of Non-Leptonic Two-Body Decays of Charmed Mesons into Final States with $η'$

We show that $D\rightarrow Pη^\prime$ decay amplitudes, where $P=K,π,η$, cannot be simply related to their $D\rightarrow Pη$ counterparts with a single $η_0$--$η_8$ mixing angle. We propose a novel, consistent treatment of $η_0$--$η_8$ mixing for application in $D\to Pη$ and $D\to Pη^\prime$ decays. Using this framework, we perform a global analysis of $D\rightarrow Pη^\prime$ decays employing SU(3)$_F$ symmetry including linear SU(3)$_F$ breaking. We find that the assumption of 30\% SU(3)$_F$ breaking is in slight tension ($2.5σ$) with the data when compared to a fit that allows for 50\% SU(3)$_F$ breaking, the latter giving a perfect description of the data. In order to allow for further scrutinization of SU(3)$_F$-breaking effects in the future, we give branching ratio predictions for all $D\rightarrow Pη'$ modes. Our predictions deviate from the current data in case of the branching ratios $\mathcal{B}(D_s^+\rightarrow K^+η^\prime)$ and $\mathcal{B}(D^+\rightarrow K^+η')$. Future more precise measurements of these channels are therefore highly important in order to clarify the quality of the SU(3)$_F$ expansion in nonleptonic $D\rightarrow Pη^\prime$ decays.

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arXiv2024

Constraining $|V_{cs}|$ and physics beyond the Standard Model from exclusive (semi)leptonic charm decays

We study the available data on exclusive leptonic and semileptonic $c\to s\ell^+ν$ decays within the Standard Model and beyond. Our analysis accounts for theory correlations between the relevant hadronic matrix elements through application of dispersive bounds. We find that, within a global analysis, the dispersive bounds are generally well respected and only mildly affect the extraction of the Cabibbo-Kobayashi-Maskawa (CKM) matrix element $|V_{cs}|$. Assuming Standard Model dynamics, we obtain $$ |V_{cs}| = 0.957 \pm 0.003\,, $$ which is compatible with the HFLAV/PDG reference value $|V_{cs}| = 0.975 \pm 0.006$ at the $2.7\,σ$ level. Our findings lead to significant deficits in the second-row and second-column unitarity relations of the CKM matrix. Allowing for beyond the SM contributions in the Weak Effective Theory, we find very strong constraints on potential (pseudo)scalar and tensor effects. However, the data still permits sizeable CP-violating right-handed currents.

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arXiv2023

New determination of $|V_{ub}/V_{cb}|$ from $B_s^0\to \lbrace K^-, D_s^- \rbrace μ^+ν$

We update the full set of $\bar{B}_s\rightarrow K$ form factors using light-cone sum rules with an on-shell kaon. Our approach determines the relevant sum rule parameters -- the duality thresholds -- from a Bayesian fit for the first time. Using a modified version of the Boyd-Grinstein-Lebed parametrisation, we combine our sum rule results at low momentum transfer $q^2$ with more precise lattice QCD results at large $q^2$. We obtain a consistent description of the form factors in the full $q^2$ range. Applying these results to a recent LHCb measurement of branching ratios for the decays $B_s^0 \to \lbrace K^-, D_s^-\rbrace μ^+ν_μ$, we determine the ratio of Cabibbo-Kobayashi-Maskawa elements $$ \notag \left|\frac{V_{ub}}{V_{cb}}\right|_{q^2<7\; \textrm{GeV}^2} = 0.0681\pm 0.0040 \quad \text{and} \quad \left|\frac{V_{ub}}{V_{cb}}\right|_{q^2>7 \;\textrm{GeV}^2} = 0.0801\pm 0.0047 \ , $$ which are mutually compatible at the $1.9σ$ level. We further comment on the sensitivity to Beyond the Standard Model effects through measurements of the shape of $B_s^0 \to K^- μ^+ν_μ$ decays, in light of recent limits on such effects from other exclusive $b\to u\ellν$ processes.

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