How small is the proton?

Olivia Meyer-Streng writes at IDW Online: ''The proton – one of the universal building-blocks of all matter – is even smaller than had previously been assumed (Nature, 8 July 2010). This is the result obtained at the Paul-Scherrer-Institut (PSI) in Villigen (Switzerland) by an international research team, including scientists from the Max Planck Institute of Quantum Optics (MPQ) in Garching, the Ludwig-Maximilians-Universität (LMU) Munich and the Institut für Strahlwerkzeuge (IFWS) of the Universität Stuttgart (both from Germany).'' See also https://muhy.web.psi.ch/wiki/ for more information.