Measurement of total cross sections on hydrogen and deuterium

Total cross sections of {pi}{sup {+-}}, K{sup {+-}}, p and {bar p} on hydrogen and deuterium are to be measured at about eight energies between 20 GeV and the maximum available energy. An accuracy of about one part in one thousand will yield the energy dependence of cross sections, comparisons of cross sections within SU(3) supermultiplets, and stringent tests of high energy limiting theorems

Search for the decay K+→π+ννˉK^+\to \pi^+ \nu \bar\nu in the momentum region Pπ<195 MeV/cP_\pi < 195 {\rm ~MeV/c}

We have searched for the decay $K^+ \to \pi^+ \nu \bar\nu$ in the kinematic region with pion momentum below the $K^+ \to \pi^+ \pi^0$ peak. One event was observed, consistent with the background estimate of $0.73\pm 0.18$. This implies an upper limit on $B(K^+ \to \pi^+ \nu \bar\nu)< 4.2\times 10^{-9}$ (90% C.L.), consistent with the recently measured branching ratio of $(1.57^{+1.75}_{-0.82}) \times 10^{-10}$, obtained using the standard model spectrum and the kinematic region above the $K^+ \to \pi^+ \pi^0$ peak. The same data were used to search for $K^+ \to \pi^+ X^0$, where $X^0$ is a weakly interacting neutral particle or system of particles with $150 < M_{X^0} < 250 {\rm ~MeV/c^2}$.Comment: 4 pages, 2 figure

Further search for the decay K+→π+ννˉK^+ \to \pi^+ \nu \bar \nu in the momentum region P < 195 MeV/c

We report the results of a search for the decay $K^+ \to \pi^+ \nu \bar \nu$ in the kinematic region with $\pi^+$ momentum $140 < P < 195$ MeV/c using the data collected by the E787 experiment at BNL. No events were observed. When combined with our previous search in this region, one candidate event with an expected background of $1.22 \pm 0.24$ events results in a 90% C.L. upper limit of $2.2 \times 10^{-9}$ on the branching ratio of $K^+ \to \pi^+ \nu \bar \nu$. We also report improved limits on the rates of $K^+ \to \pi^+ X^0$ and $K^+ \to \pi^+ X^1 X^2$ where $X^0, X^1, X^2$ are hypothetical, massless, long-lived neutral particles.Comment: 5 pages, 3 figures, Accepted for publication in Phys. Rev.

A high resolution detector for H{sup 0} {yields} {gamma}{gamma}

SSC detectors represent a challenging departure, both in size and precision, from currently operating detectors. In this note we enumerate some of the benefits of using high magnetic fields both to simplify the detector and improve its resolution and sensitivity. We have chosen an arrangement optimized to search for the reaction H{sup 0} {yields} {gamma}{gamma}. The arrangement also has the excellent momentum resolution for muons and electrons considered critical for the discovery of such processes as H{sup 0} {yields} Z{sup 0}Z{sup 0} {yields} {ell}{sup +}{ell}{sup {minus}}{ell}{sup +}{ell}{sup {minus}}, H{sup 0} {yields} Z{sup 0}Z{sup 0} {yields} {ell}{sup +}{ell}{sup {minus}}{ell}{sup +}{ell}{sup {minus}}, new and narrow vector bosons, and bound states of extra generational quarks. This detection scheme represents an improvement in the H{sup 0} {yields} {gamma}{gamma} mass resolution of at least a factor of 7 beyond the best currently proposed detectors. In addition, we have a significantly improved rejection of common H{sup 0} {yields} {gamma}{gamma} backgrounds. As indeed most experiments do not exceed their initial projections, this extra factor could insure the unambiguous discovery of this decay should it indeed occur. As no reasonably realistic detector can achieve excellent detection for all physics signatures we chose to give tip on excellent hadron calorimetry. For Higgs masses between 80 and 150 GeV/c{sup 2} the Higgs decay into two photons is an excellent signature. To date, all attempts to search for this decay mode have centered on the use of electromagnetic calorimetry. We are proposing a different approach. We will convert the two photons close to the production point and measure the momenta of the electron pairs