Search for microwave emission from ultrahigh energy cosmic rays
  We present a search for microwave emission from air showers induced by ultrahigh energy cosmic rays with the microwave detection of air showers experiment. No events were found, ruling out a wide range of power flux and coherence of the putative emission, including those suggested by recent laboratory measurements. 
J. Alvarez-Mu\~niz, A. Berlin, M. Bogdan, M. Boh\'a\v{c}ov\'a, C.   Bonifazi, W. R. Carvalho Jr, J. R. T. de Mello Neto, P. ...
astro-ph.HE