European Physical Journal C: Particles and Fields (Apr 2022)

$$b\rightarrow s\ell ^+\ell ^-$$ b → s ℓ + ℓ - global fits after $$R_{K_S}$$ R K S and $$R_{K^{*+}}$$ R K ∗ +

  • Marcel Algueró,
  • Bernat Capdevila,
  • Sébastien Descotes-Genon,
  • Joaquim Matias,
  • Martín Novoa-Brunet

DOI
https://doi.org/10.1140/epjc/s10052-022-10231-1
Journal volume & issue
Vol. 82, no. 4
pp. 1 – 16

Abstract

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Abstract We present an up-to-date complete model-independent global fit to $$b\rightarrow s\ell \ell $$ b → s ℓ ℓ observables that confirms patterns of New Physics able to explain the data. We include the recent LHCb measurements of $$R_K$$ R K , $$R_{K_S}$$ R K S , $$R_{K^{*+}}$$ R K ∗ + , $$B_s \rightarrow \phi \mu ^+\mu ^-$$ B s → ϕ μ + μ - and $$B_s\rightarrow \mu ^+\mu ^-$$ B s → μ + μ - in our analysis, which now includes 254 observables. This updates our previous analyses and strengthens their two main outcomes. First, the presence of right-handed couplings encoded in the Wilson coefficients $${{\mathcal {C}}}_{9'\mu }$$ C 9 ′ μ and $${{\mathcal {C}}}_{10'\mu }$$ C 10 ′ μ remains a viable possibility. Second, a lepton flavour universality violating (LFUV) left-handed lepton coupling ( $${{\mathcal {C}}}_{9\mu }^{\mathrm{V}}=-{{\mathcal {C}}}_{10\mu }^{\mathrm{V}}$$ C 9 μ V = - C 10 μ V ), often preferred from the model building point of view, accommodates the data better if lepton-flavour universal New Physics is allowed, in particular in $${{\mathcal {C}}}_{9}^{\mathrm{U}}$$ C 9 U . We observe that the LFUV observable $$Q_5$$ Q 5 offers a very interesting possibility to separate both types of scenarios.