New Limits on the Polarized Anisotropy of the Cosmic Microwave   Background at Subdegree Angular Scales
  We update the limit from the 90 GHz PIQUE ground-based polarimeter on the magnitude of any polarized anisotropy of the cosmic microwave radiation. With a second year of data, we have now limited both Q and U on a ring of 1 degree radius. The window functions are broad: for E-mode polarization, the effective l is <l> = 191 +143 -132. We find that the E-mode signal can be no greater than 8.4 microK (95% CL), assuming no B-mode polarization. Limits on a possible B-mode signal are also presented. 
M. M. Hedman, D. Barkats, J. O. Gundersen, J. J. McMahon, S. T.   Staggs, B. Winstein