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1. The I = 1 pion–pion scattering amplitude and timelike pion form factor from Nf = 2 + 1 lattice QCD

   https://doi.org/10.1016/j.nuclphysb.2018.12.018  

   Andersen, Christian; Bulava, John; Hörz, Ben; Morningstar, Colin (February 2019, Nuclear Physics B)
2. The long-distance behaviour of the vector-vector correlator from pion-pion scattering

   https://doi.org/10.22323/1.430.0073  

   Paul, Srijit; Hanlon, Andrew D.; Hoerz, Ben; Mohler, Daniel; Morningstar, Colin; Wittig, Hartmut (April 2023, 39th International Symposium on Lattice Field Theory)

   We present the estimation of the long distance behaviour of the vector-vector correlator computed on a lattice QCD ensemble generated with 2 + 1 flavour physical Wilson clover quarks. The long distance regime of the correlator is dominated by multi-hadronic scattering states. We reconstruct the correlator in this regime using the pion-pion scattering states in the 𝐼 = 1 channel. The vector-vector correlator appears in the integrand to estimate the hadronic vacuum polarization contributions to the anomalous magnetic moment of the muon. Therefore, an improved estimation of the correlator will help resolve the tension between (𝑔 − 2)𝜇 experiment and theory. 

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3. Probing pion valence quark distribution with beam-charge asymmetry of pion-induced J/ψ production

   https://doi.org/10.1016/j.physletb.2025.139582  

   Chang, Wen-Chen; Meyer-Conde, Marco; Peng, Jen-Chieh; Platchkov, Stephane; Sawada, Takahiro (July 2025, Physics Letters B)
4. Electric conductivity of hot pion matter

   https://doi.org/10.1016/j.nuclphysa.2023.122704  

   Atchison, Joseph; Rapp, Ralf (September 2023, Nuclear Physics A)
5. Pion electronic decay and lepton universality

   https://doi.org/10.21468/SciPostPhysProc.5.025  

   Pocanic, Dinko (January 2021, SciPost Physics Proceedings)

   In common with a number of simple processes involving elementaryparticles, charged pion decays are profoundly shaped by applicableStandard Model (SM) symmetries and properties. Given the highly preciseSM theoretical description, pion decays are used as selective probes ofSM parameters, and of possible SM extensions. The PEN experiment at PSIis studying the \pi^+ \to e^+\nu_e(\gamma) π + → e + ν e ( γ ) ,or \pi_{e2(\gamma)} π e 2 ( γ ) decay. The primary goal is to reach the relative precision of 5 \times 10^{-4} 5 × 10 − 4 in R_{e/\mu}^\pi R e / μ π ,the branching ratio for \pi_{e2(\gamma)} π e 2 ( γ ) decay. We review the PEN research program, its present status, andprospects. 

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