Browsing by Author "Moore, Robert Christopher"

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    Event reconstruction using the linear correlation probability for fixed targets at 400 GEV
    (1985) Moore, Robert Christopher; Corcoran, Marjorie D.; Miettinen, Hannu E.; Mutchler, Gordon S.
    Adaptations of the Fermilab E69 event reconstruction program were made to increase its speed and versatility. An attempt to increase the number of chambers utilized per track prompted the examination of a new track selection criterion, the linear correlation probability. A comparative study of the merits of the probability of linear correlation, as opposed to the reduced chi square, for determination of tracks shows that, for a limited set of track parameters, the linear correlation probability works better than the x2/v. For optimized parameters the x2/v selection criterion has a slightly finer resolution. However, the linear correlation can achieve nearly the same resolution involving less computer time. In general the x2/v should remain the preferred choice for accurate tracking while the linear correlation probability should be used for rapid track reconstruction suffering a 1% loss in resolution.
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    Production of jets from proton-nucleus collisions at 400 GeV/c
    (1989) Moore, Robert Christopher; Corcoran, Marjorie D.
    Jets produced in high transverse energy proton-nucleus collisions at 400 GeV/c were recorded in a calorimeter study at Fermilab. The jets were identified with two different jet-finding algorithms; the results from the two algorithms agree. For the eight nuclear targets with atomic number, A, ranging from 1 to 207 (H$\sb2$, He, Be, C, Al, Cu, Sn and Pb), the cross section increases as A$\sp{1.35\pm0.01}$ over mean jet pair transverse momentum of 4 to 8 GeV/c. The enhancement, however, depends on the class of jets selected; for example the cross section increases as A$\sp1$ for highly planar high-transverse-momentum jet events and as A$\sp{1.65}$ for non-planar high-transverse-momentum events. Jet properties were studied as a function of jet transverse momentum and A. In general as A increases, the number of particles in the jets increases while their collimation and coplanarity decrease. Also with increasing A, the proton transfers more of its energy into the target fragmentation region instead of the forward or central regions. Multiple scattering models describe nuclear enhancement, however fits to our data require negative coefficients in the higher order terms of the expansion, presenting a challenge to simple multiple scattering models.