Search for Second Neutral Pion.pdfVIP

Search for Second Neutral Pion W. A. Perkins Perkins Advanced Computing Systems, 12303 Hidden Meadows Circle, Auburn, CA 95603, USA E-mail: wperkins@ There is evidence of a second neutral pion from: (1) the anomalous branching ratios in the reactions p p → ππ and p d → ππN , and (2) the 1960’s results of Tsai-Ch¨u et al. for antinucleon annihilation stars in emulsions. The anomaly of (1) is eliminated if the two neutral pions in the reactions p p → 1 0 0 0 0 0 π π and p d → π π n are not identical. Tsai-Ch¨u et al. observed a second 0 neutral pion that “decays more rapidly into electron pairs with larger opening 2 angles and more frequently into double pairs.” One antineutron annihilation t c event produced three neutral particles (each with a mass of 135±14 MeV), and O each decayed into four electrons with much wider opening angles than those 4 of the internal conversion electrons seen in π0 decays. The larger opening angles and much more frequent double pair production could be caused by 1 v neutral pions with a lifetime so short that they sometimes decay into photon 3 pairs before they can leave the annihilation nucleus (e.g., Ag) of the emulsion. 5 0 We discuss several methods of searching for this second neutral pion. 0 1 PACS numbers: 14.40.Aq, 13.75.Cs, 11.30.Er 1 0 / h p