English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

With few open channels and uncomplicated theoretical description, chargedpion decays are uniquely sensitive to certain standard model (SM) symmetries,the universality of weak fermion couplings, and to aspects of pion structureand chiral dynamics. We review the current knowledge of the pion electronicdecay $\pi^+ \to e^+ \nu_e({\gamma})$, or $\pi_{e2({\gamma})}$, and theresulting limits on non-SM processes. Focusing on the PEN experiment at thePaul Scherrer Institute (PSI), Switzerland, we examine the prospects forfurther improvement in the near term.

PEN experiment: a precise test of lepton universality