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Communication Dans Un Congrès Année : 2023

The hadronic running of the electromagnetic coupling and electroweak mixing angle

Teseo San José
  • Fonction : Auteur
Hartmut Wittig
  • Fonction : Auteur
Marco Cè
  • Fonction : Auteur
Georg von Hippel
  • Fonction : Auteur
Harvey B. Meyer
  • Fonction : Auteur
Kohtaroh Miura
  • Fonction : Auteur
Konstantin Ottnad
  • Fonction : Auteur
Andreas Risch
  • Fonction : Auteur
Jonas Wilhelm
  • Fonction : Auteur

Résumé

We present results for the hadronic running of the electromagnetic coupling and the weak mixing angle from simulations of lattice QCD with $N_f=2+1$ flavours of $O(a)$-improved Wilson fermions. Using two different discretisations of the vector current, we compute the quark-connected and -disconnected contributions to the hadronic vacuum polarisation (HVP) functions $\bar{\Pi}^{\gamma\gamma}$ and $\bar{\Pi}^{Z\gamma}$ for spacelike squared momenta $Q^2\leq 7$$\mathrm{GeV}^2$. Our results are extrapolated to the physical point using ensembles at four lattice spacings, with pion masses ranging from 130 to 420 MeV. We observe a tension of up to 3.5 standard deviations between our lattice results for $\Delta\alpha_{\rm had}^{(5)}(-Q^2)$ and estimates based on the $\textit{R}$-ratio for space-like momenta in the range $Q^2=3-7\,\rm GeV^2$. To obtain an estimate for $\Delta\alpha_\mathrm{had}^{(5)}(M_Z^2)$, we employ the Euclidean split technique. The implications for comparison with global electroweak fits are assessed.

Dates et versions

hal-03958504 , version 1 (26-01-2023)

Identifiants

Citer

Teseo San José, Hartmut Wittig, Marco Cè, Antoine Gérardin, Georg von Hippel, et al.. The hadronic running of the electromagnetic coupling and electroweak mixing angle. 39th International Symposium on Lattice Field Theory, Aug 2022, Bonn, Germany. pp.220, ⟨10.22323/1.430.0328⟩. ⟨hal-03958504⟩
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