1997/01/20 by I. Levine, D. Koltick, Bryan Lad Howell +54 · 2 citations
Physics and Astronomy · #Particle physics theoretical and experimental studies #Dark Matter and Cosmic Phenomena #Quantum Chromodynamics and Particle Interactions
paper · doi:10.1103/physrevlett.78.424
openalex publication_date 1997/01/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/11
We report the first purely electroweak measurement of the strengthening of the electromagnetic coupling, \ensuremathαQED with increasing momentum transfer Q2, by comparing the process e+e^\ensuremath-\ensuremath→\ensuremathμ+\ensuremathμ^\ensuremath- with the process e+e^\ensuremath-\ensuremath→e+e^\ensuremath-\ensuremathμ+\ensuremathμ^\ensuremath-. The data were accumulated at an average center-of-mass energy 〈√(s)〉\phantom\rule0ex0ex=\phantom\rule0ex0ex57.77GeV using the TOPAZ detector at the TRISTAN e+e^\ensuremath- collider. We measure \ensuremathαQED^\ensuremath-1(Q2) to change from its known value of \ensuremathαQED^\ensuremath-1\ensuremath≅137.0 at Q2\phantom\rule0ex0ex=\phantom\rule0ex0ex0to128.5\ifmmode±\else\textpm\fi1.8(stat)\ifmmode±\else\textpm\fi0.7(syst) at Q2\phantom\rule0ex0ex=\phantom\rule0ex0ex(57.77GeV/c)2. This result agrees with electroweak predictions.