The angular distributions of muons from gamma(1S, 2S, 3S) -> mu(+)mu(-) decays are measured using data from p (p) over bar collisions at root s = 1.96 TeV corresponding to an integrated luminosity of 6.7 fb(-1) and collected with the CDF II detector at the Fermilab Tevatron. This analysis is the first to report the full angular distributions as functions of transverse momentum p(T) for gamma mesons in both the Collins-Soper and s-channel helicity frames. This is also the first measurement of the spin alignment of gamma(3S) mesons. Within the kinematic range of gamma rapidity vertical bar y vertical bar < 0.6 and p(T) up to 40 GeV/c, the angular distributions are found to be nearly isotropic. RI Prokoshin, Fedor/E-2795-2012; maestro, paolo/E-3280-2010; song, hao/I-2782-2012
File in questo prodotto:
Non ci sono file associati a questo prodotto.