New Physics without bias: Charming Penguins and Lepton Universality Violation in $b \to s \ell^+ \ell^-$ decays
| Popis: | The LHCb experiment has very recently presented new results on Lepton Universality Violation (LUV) in $B \to K^{(*)} \ell^+ \ell^-$ decays involving $K_S$ in the final state, which strengthen the recent evidence of LUV obtained in $B^+ \to K^{+} \ell^+ \ell^-$ decays and the previous measurements of $B \to K^{*0} \ell^+ \ell^-$. While LUV observables in the Standard Model are theoretically clean, their predictions in New Physics scenarios are sensitive to the details of the hadronic dynamics, and in particular of the charming penguin contribution. In this work, we show how a conservative treatment of hadronic uncertainties is crucial not only to assess the significance of deviations from the Standard Model but also to obtain an unbiased picture of the New Physics responsible for LUV. Adopting a very general parameterization of charming penguins, we find that: i) current data hint at a sizable $q^2$ and helicity dependence of charm loop amplitudes; ii) unbiased NP solutions to $B$ anomalies favour a left-handed or an axial lepton coupling rather than a vector one. |
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| Jazyk: | English |
| DOI: | 10.3204/PUBDB-2021-04136 |
| Přístupová URL adresa: | https://explore.openaire.eu/search/publication?articleId=od______1108::a2186bc6aec5b677f7e7b85e83929698 https://bib-pubdb1.desy.de/record/470285 |
| Rights: | OPEN |
| Přírůstkové číslo: | edsair.od......1108..a2186bc6aec5b677f7e7b85e83929698 |
| Autor: | Ciuchini, Marco, Fedele, Marco, Franco, Enrico, Paul, Ayan, Silvestrini, Luca, Valli, Mauro |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
penguin [Feynman graph]
new physics penguin [amplitude analysis] amplitude analysis [helicity] High Energy Physics::Phenomenology universality: violation [lepton] dependence [helicity] B0 --> K*(892)0 lepton antilepton flavor: universality [lepton] B+ --> K+ lepton antilepton branching ratio: ratio [B] flavor changing [decay] High Energy Physics::Experiment semileptonic decay [B] B0 --> K0(S) lepton antilepton |
| DOI: | 10.3204/PUBDB-2021-04136 |
| Popis: | The LHCb experiment has very recently presented new results on Lepton Universality Violation (LUV) in $B \to K^{(*)} \ell^+ \ell^-$ decays involving $K_S$ in the final state, which strengthen the recent evidence of LUV obtained in $B^+ \to K^{+} \ell^+ \ell^-$ decays and the previous measurements of $B \to K^{*0} \ell^+ \ell^-$. While LUV observables in the Standard Model are theoretically clean, their predictions in New Physics scenarios are sensitive to the details of the hadronic dynamics, and in particular of the charming penguin contribution. In this work, we show how a conservative treatment of hadronic uncertainties is crucial not only to assess the significance of deviations from the Standard Model but also to obtain an unbiased picture of the New Physics responsible for LUV. Adopting a very general parameterization of charming penguins, we find that: i) current data hint at a sizable $q^2$ and helicity dependence of charm loop amplitudes; ii) unbiased NP solutions to $B$ anomalies favour a left-handed or an axial lepton coupling rather than a vector one. |
| Databáze: | OpenAIRE |
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