Download or read book The Decay Tau. --]. Rho Nu (and Rho. --]. Pi. Eta Nu.). written by and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Motivated by the question of missing exclusive branching fractions in tau decays, mostly suspected to be in one prong decays with neutrals, we have studied the decay tau .-->. rho nu in tau pair production by ee− annihilation at .sqrt.s = 3.77 GeV. The branching fraction is measured to be B(tau .-->. rho nu) = (23.0 +- 1.3 +- 1.7)% consistent with known measurements and not offering a solution to the branching ratio question. No eta signal in the .gamma gamma. mass spectrum pointing to a decay tau .-->. eta .pi. nu is obvious. An upper limit on this branching fraction is given.