[en] A review is given of the signals observed in the J/ψ radiative decays in the 1100/1500 MeV energy range from the DM2 analysis of the γKantiKπ and γηππ channels. The Partial Wave Analyses of these modes give evidence of a rich spectroscopy which suggests an exotic activity in this mass interval. The contradiction between a pseudoscalar state decaying into KantiKπ via a₀π dynamics and not into ηππ is still present

[en] Preliminary results from Partial Wave Analysis on the D/f₁(1285) mass region in the J/Ψ → γ4 π^± decay and on the ι/η(1440) region in the J/Ψ γK antiK π decays are presented. In the first channel the PWA excludes a η(1275) contribution, so supporting the f₁ identification for the observed peak. A clear pseudoscalar signal is evidenced in the K anti K π mass spectrum decaying via δ/a₀(980) as well as K* (892) dynamics. Its width is smaller than in the total spectrum, two other contributions, a narrow (less than 30 MeV/c²) 1⁺⁺ peak at 1395 MeV/c² which decays into δ π and a shoulder at 1515 MeV/c² observed in the direct 3-body decay K anti K π, being present. This last state might have a spin-parity 1⁺⁺ even if within large statistical limitations

[en] Preliminary results from Partial Wave Analysis on the D/f₁(1285) region in the J/ψ → γ4π^± decay, and the ι/η(1440) seen in the J/ψ → γ K bar Kπ decays are presented. In the first channel the PWA excludes a η(1275) contribution, so supporting the f₁ identification for the observed peak. A clear pseudoscalar signal is evidenced in the K bar Kπ mass spectrum decaying via δ/a₀ (980) as well as K*(892) dynamics. Its width is smaller than in the total spectrum, two other contributions, a narrow (less than 30 MeV/c²) 1⁺⁺ peak at 1395 MeV/c² which decays into δπ and a shoulder at 1515 MeV/c² observed in the direct 3-body decay K bar Kπ, being present. The shoulder might have a spin-parity 1⁺⁺ even if within strong statistical limitations. 18 references, 8 figures

[en] A review is given of the signals observed in the J/ψ radiative decays in the 1100/ 1500 MeV energy range from the DM2 analysis of the γKanti Kπ and Υηππ channels. The Partial Wave Analyses of these modes give evidence of a rich spectroscopy which suggests an exotic activity in this mass interval. The contradiction between a pseudoscalar state decaying into Kanti Kπ via a₀ π dynamics and not into ηππ is still present. (orig.)

[en] A discussion is given of a new method to isolate supersymmetric signals. As the presence of missing mass in the supersymmetric reactions is one of the biggest problems, the principal advantage of the new method proposed is its ability to offer an estimate of the mass of the produced superpartners. The technique has been successfully applied to the HERA environment, where errors of 10% on the mass values have been obtained, even starting from very few detected events. (orig.)

[en] Searches for squarks produced via R-parity violating interactions in e⁺p collisions at a center-of-mass energy of 300 GeV have been performed at HERA using the two detectors, H1 and ZEUS, and an integrated luminosity of 37 and 48 pb^-1, respectively. Squarks produced in e⁺ -quark fusion could decay either to e⁺ -quark or via a supersymmetric gauge decay, resulting in many possible final states. The signal has been searched for in most of R-parity violating decays and gauge decays of the squarks. No evidence for squark production was found and limits were set on the R-parity violating coupling as a function of the squark mass and the SUSY parameters, extending to domains unexplored in other direct or indirect searches. For a fixed value of the coupling, HERA results are interpreted for the first time in terms of constraints on the parameters of the mSUGRA model. (author)

[en] The relatively recent use in HEP of the Kalman filtering and smoothing technique for the reconstruction of single tracks through gaseous detectors interspaced by heavy materials, is shown to work and to give even better results than other more classic techniques. However, fine tuning of the computer implementation has to be done carefully as well as respecting the mathematical constraints. The feasibility of the Kalman method in heavy materials here demonstrated may lead to the development of a general software package for the reconstruction of single tracks in HEP detectors. (orig.)

[en] Preliminary results are reported from a search for the top quark in the dilepton channel using data collected by CDF during the 1992-93 Fermilab Collider Run. The dilepton analysis implies a lower limit on the top quark mass of 113 GeV/c² at the 95% confidence level, assuming Standard Model decays. (author). 3 refs., 2 figs., 2 tabs

[en] We present new results from the DM2 experiment on the η_c-state and the pseudoscalar production seen at the threshold of the vector-vector radiative decays at J/ψ. The η_c shows a vector-vector dominance in its decays and has a decay pattern which follows the SU(3)_F symmetry prediction, this being in contradiction with previous measurements. New pseudoscalar states are clearly present in the invariant mass spectrum of ρ⁰ρ⁰. There are at least three different resonances, here named L₁, L₂, L₃ to underline a supposed common origin. These states have no direct interpretation in the usual qanti q model and they are believed to have an isoscalar nature. An interesting new upper limit on the g_T's (2000/2500 MeV/c²) production at J/ψ is given as a by-product of the ρ⁰ρ⁰ analysis. (orig.)

[en] Preliminary results from the DM2 experiment at DCI on the pion form factor are presented. Almost 200 events have been selected, 7 times the previous world statistics in the time like region 1,38 to 2,28 GeV. The events exhibit a clear interference effect of the rho tail with a rho' (1600)