[en] Experimental tests are proposed to examine the origin of the average < psub(T)> dependence on hadron-hadron events multiplicity and to verify some possible implications of the existence of high-temperature phase transition to quark-gluon plasma. It is suggested that evidences may already exist of this transition in SPS collider and ISR events with central rapidity density dn/dy within an interval of one or two units around 6

[en] High p_T proton and antiproton production has been measured for three different production angles at √s = 63 GeV using the SFM detector at the CERN ISR. The ratio of baryon production to meson production exhibits a characteristic dependence on θ and p_T. Diquark scattering as one source of high p_T baryons is discussed. The observation of a short range baryon number correlation on the other hand indicates that production of baryons/antibaryons in the fragmentation chain of a scattered quark or gluon may be particularly important for high p_T antiproton production. (author)

[en] In the first part of the report the author presents preliminary results on the multiplicity dependence of the transverse momentum and of the particle source dimensions obtained by the Ames-Bologna-CERN-Dortmund-Heidelberg-Warsaw (ABCDHW) collaboration in p-p interactions at √s=63,44 and 31 Gev. Then he comments on results obtained by the UA1 collaboration on the multiplicity dependence of the transverse momentum in p-bar-p collisions at √s=200, 540,900 Gev. Finally he presents some considerations on the significance of the presented results for the search of the phase transition from hadronic matter to quark-gluon plasma

No abstract available

[en] We describe here a preliminary upper limit of the cross-section for the production of particles with masses around 2 GeV and lifetimes of the order of 10^-13 seconds, obtained by using nuclear emulsions exposed to 300 and 400 GeV protons at the Fermilab accelerator. (orig.)

[en] A prototype for Positron Emission Mammography, the YAP-PEM, is under development within a collaboration of the Italian Universities of Pisa, Ferrara, and Bologna. The aim is to detect breast lesions, with dimensions of 5 mm in diameter, and with a specific activity ratio of 10:1 between the cancer and breast tissue. The YAP-PEM is composed of two stationary detection heads of 6x6 cm², composed of a matrix of 30x30 YAP:Ce finger crystals of 2x2x30 mm³ each. The EGSnrc Monte Carlo code has been used to simulate several characteristics of the prototype. A fast EM algorithm has been adapted to reconstruct all of the collected lines of flight, also at large incidence angles, by achieving 3D positioning capability of the lesion in the FOV. The role of the breast compression has been studied. The performed study shows that a 5 mm diameter tumor of 37 kBq/cm³ (1 μCi/cm³), embedded in active breast tissue with 10:1 tumor/background specific activity ratio, is detected in 10 min with a Signal-to-Noise Ratio of 8.7±1.0. Two hot lesions in the active breast phantom are clearly visible in the reconstructed image

[en] In a search for charmed particles produced by 300 and 400 GeV/c protons in nuclear emulsions, no reliable candidate was found among 16.000 interactions. This implies an upper limit of 7μb(90% confidence level) for the associated production of charmed particles with lifetime between 3.10^-15 and 3.10^-13sec

[en] The multiplicities of charged secondaries in proton-proton collisions were determined using the split-field-magnet detector at the CERN Intersecting Storage Rings (ISR). Measurements are presented on multiplicity distributions both for inelastic and non-single-diffractive events at four different energies √s = 30.4, 44.5, 52.6, and 62.2 GeV. The results reported here represent the first high-statistics measurement of charged multiplicity distributions at ISR energies with a magnetic detector covering nearly the full solid angle

[en] Compact gamma cameras based on arrays of compact Position Sensitive Photomultipliers (PSPMTs) (Hamamatsu R7600-C8/12) were recently developed by several research groups. The previous generation of dedicated gamma cameras (5 in. PSPMT) demonstrated the clinical benefit and general diagnostic value for functional breast imaging in comparison with conventional nuclear medicine technique (Anger Camera prone scintimammography and ^99mTc Sestamibi administration). The aim of this paper is to investigate how scintillation material and pixel size of crystal arrays can improve image contrast and tumor SNR values. In this paper we compare tumor Signal-to-Noise Ratio (SNR) results obtained by imagers based on CsI(Tl) and NaI(Tl) array, respectively, by means of a liquid and solid breast phantom. The data collected by NaI(Tl) array show a improvement of SNR values for small tumor size (less than 8 mm). The improvement is also evident in small camera, even though for tumor size less than 6 mm the results are near visibility limit

[en] In pp collisions at √ s=62.3 GeV where each proton fragments into at least one low p/sub T/, high-x pion, no significant correlations for π⁺π⁺, π⁺π^- and π^-π^- are found, thus excluding quark exchange with Brodsky-Gunion counting rules as the dominant interaction mechanism. This, together with the experimental x dependence of single-particle spectra, suggests the introduction of a new counting rule, which is discussed