Pions are fantastic tools to look for new physics. The PIENU experiment at TRIUMF (data completion in 2012) has provided, to date, the most precise experimental determination
of $R^{\pi}_{e/\mu}$ , the ratio of pions decaying to positrons relative to muons. While more than an order of magnitude less precise that the Standard Model (SM) calculation, the PIENU result is a precise test of the...
PIONEER is a next-generation pion decay experiment that will run at the Paul Scherrer Institute in Switzerland. The initial goal of PIONEER is to improve the precision of the pion branching ratio measurement $R_{e/\mu} = \frac{\Gamma \left(\pi^{+}\rightarrow e^{+} \nu_{e} (\gamma)\right)}{\Gamma \left(\pi^{+} \rightarrow \mu^{+} \nu_{\mu} (\gamma) \right)}$, a stringent, direct test of lepton...
The Chiral Belle upgrade aims to introduce polarized electron beams to the SuperKEKB e+e− collider to enable a vast set of unique precision measurements using the Belle II detector. This includes the ability for Belle II to perform multiple high precision measurements of $\sin^2 \theta_W$ with left-right asymmetry measurements of pairs of electrons, muons, taus, charm and b-quarks...
The SuperKEKB collider, operating at the $\Upsilon$(4S) resonance energy, delivers e$^+$e$^-$ collisions at the world's highest instantaneous luminosity for the Belle II experiment. A proposed long-term Chiral Belle upgrade aims to introduce a polarized electron beam in the High Energy Ring (HER), enabling a new and unique program of precision physics. This upgrade will facilitate precision...
