Search for exotic mesons at SLAC
The theoretical justification and results from recent experimental searches for backward-produced exotic mesons including two experiments carried out by the collaboration at SLAC are reviewed. The first experiment put upper limits of about 1 to 2 $mu$b for X$sup ++$ $Yields$ (2$pi$, 4$pi$, 6$pi$)$sup ++$ and anti pp$pi$$sup +$$pi$$sup +$ in the reaction $pi$$sup +$ + p $Yields$ X$sup ++$ + n/sub forward/ at 8.4 GeV/c studied with the SLAC 14 inch rapid cycling bubble chamber triggered by a downstream neutron detector. Also the important features of the recently completed second experiment with the SLAC streamer chamber to study the reaction $pi$$sup -$ + p $Yields$ X$sup --$ + p/sub forward/ at 14 GeV/c are discussed. (auth)
Search for exotics produced opposite a forward Λ in 15 GeV/c π+p interactions
We have carried out a search for exotic meson resonances produced in the reaction π+p→K++ + Λ (forward) at 15 GeV/c. We have found no evidence for the existence of resonance-like states in the K++ system, and have obtained 95% confidence level upper limits of 1.7 μb on their production with masses <2.8 GeV, and 2.6 μb with masses between 2.8 GeV and 4 GeV.
The Invariance of the Vacuum is the Invariance of the World
The following theorem is demonstrated: If the vacuum is invariant under the group generated by the space integral of the time component of a local vector current, then the Hamiltonian is invariant also. A similar theorem holds for the group generated by the space integral of a space component of a local axial-vector current.