Measurement of the Radiative Decay Width of the Positive Rho Meson
Joey Walter Huston, USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25) · 1982
We have investigated the coherent reaction $\pi^+ + (A,Z) \to \pi^+ \pi^0 + (A,Z)$ on three nuclear targets (carbon, copper and lead) at an incident momentum of 200 GeV. The mass spectrum was found to be dominated by $p^+$ production. A fit was performed on the line shape of the $p^+$ and the values of 770 MeV for the mass and 150 MeV for the total width were found. The t distributions were analyzed allowing a small amount of hadronic production to interfere with the dominant electromagnetic production of the $p^+$. A new value for the radiative width , $\Gamma(p^+ \to \pi^+ \gamma$), of 60 ± 4 KeV was extracted. This value is in reasonable agreement with that expected from VDM, SU(3) and non-relativistic quark model arguments. -