Phys. Rev. Lett. 78, 424–427 (1997)Measurement of the Electromagnetic Coupling at Large Momentum TransferReceived 20 March 1996; revised 15 October 1996; published in the issue dated 20 January 1997 We report the first purely electroweak measurement of the strengthening of the electromagnetic coupling, αQED with increasing momentum transfer Q2, by comparing the process e+e-→μ+μ- with the process e+e-→e+e-μ+μ-. The data were accumulated at an average center-of-mass energy 〈√s〉 = 57.77GeV using the TOPAZ detector at the TRISTAN e+e- collider. We measure αQED-1(Q2) to change from its known value of αQED-1≅137.0 at Q2 = 0to128.5±1.8(stat)±0.7(syst) at Q2 = (57.77GeV/c)2. This result agrees with electroweak predictions. © 1997 The American Physical Society URL:
http://link.aps.org/doi/10.1103/PhysRevLett.78.424
DOI:
10.1103/PhysRevLett.78.424
PACS:
13.10.+q, 12.20.Fv
|
|
About | Terms and Conditions | Subscriptions | Search | Help
Use of the American Physical Society websites and journals implies that the user has read and agrees to our Terms and Conditions and any applicable Subscription Agreement. Physical Review®, Physical Review Letters®, Reviews of Modern Physics®, and Physical Review Special Topics® are trademarks of the American Physical Society.