121339748
MOMENTUM TRANSFER DEPENDENCE IN DIFFRACTION DISSOCIATION.
Abstract The mechanism of kinematic coupling between momentum transfers in producing a low mass two particle system with double-peripheral dynamics is studied theoretically and model calculations. A method of data analysis which eliminates the effects of this kinematic reflection is presented. The data of the reaction pp → pnπ + at 19 GeV/ c have been analyzed using this method. It is seen that the high production slope of the low mass ηπ + system observed in this process is not a cosequences of double-peripheral dynamics plus kinematics but must be explicitly present in the invariant matrix element.
121110858
BACKWARD-SCATTERING EXTRAPOLATIONS AND BARYON COUPLINGS.
Extrapolation of an asymptotic cross section to a baryon pole cannot uniquely determine the coupling constant. The only asymptotic quantities capable of doing this are the R and A parameters. The notorious discrepancy between extrapolation of dσ(πp)/du and the known Δ width is shown to be purely illusory.
120502863
Hadronic Production with a Drell-Yan Trigger
The ratio of cross sections for producing fast ${\ensuremath{\pi}}^{+}'\mathrm{s}$ and ${\ensuremath{\pi}}^{\ensuremath{-}}'\mathrm{s}$ in association with a massive dilepton should be a strongly varying function of the mass of the pair, reducing at small mass to its value in the absence of a pair. For $\frac{{{M}_{\ensuremath{\mu}\ensuremath{\mu}}}^{2}}{s}g0.1$, the $\frac{{\ensuremath{\pi}}^{+}}{{\ensuremath{\pi}}^{\ensuremath{-}}}$ ratio should fall by a factor of 1.7 in the reactions $p+\overline{p}\ensuremath{\rightarrow}\ensuremath{\pi}+({\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}})+X$ and $p+{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\rightarrow}\ensuremath{\pi}+({\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}})+X$, rise by a factor of 2.6 in $p+{\ensuremath{\pi}}^{+}\ensuremath{\rightarrow}\ensuremath{\pi}+({\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}})+X$, and fall by about 25% in $p+p\ensuremath{\rightarrow}\ensuremath{\pi}+({\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}})+X$.
118941079
Regge phenomenology of inclusive reactions
124906083
Geometrical description of hadronic collisions
123478569
Coherent production on nuclei does not measure total cross sections for unstable particles
We calculate diffractive production in nucleon-nucleus collisions using a parton model. We fit the result by the standard optical-model formula, and obtain estimates of 12--30 mb for the cross section of the diffractively produced system on a nucleon. The actual value of that cross section in the model is 65 mb. Estimates for the total cross section of an unstable hadron which are based on the A dependence of coherent production should therefore not be trusted.
121132984
Hadron-nucleus scattering as a function of nuclear size☆
Abstract High-energy hadron-nucleus collisions, when viewed in terms of nuclear size, exhibit a remarkable simplicity. The data suggest that nuclear matter is extremely opaque to hadrons, and that fast-forward hadrons ( x ≳0.3) arise solely from peripheral collisions. This picture naturally explains why the production ratios of different hadron species are target independent at large x .
59333281
Evidence for multiple scattering of high energy partons in nuclei
Abstract New experimental information is presented about the effect of a nucleus on partons which have undergone a hard scatter. We have observed clear dijet events from 400 GeV / c p-nucleus interactions and compared them to dijets from pp interactions. Our results show that the angular width of the individual jets is only slightly affected by the presence of the nucleus, but the acoplanarity of the jet pairs is sharply increased.
120544624
Triggering on high-transverse-momentum jets
We compare the characteristics of events selected by ''global'' and ''two-high'' triggers in large-transverse-energy hadron-hadron collisions. Using a QCD-based Monte Carlo model of Fox and collaborators, we find that the former is effectively a high-multiplicity trigger, the latter a high-planarity trigger favoring unusually clean jet events. Predictions of the model for both triggers are in good qualitative agreement with recent data.
120365910
Modular TPCs for relativistic heavy-ion experiments☆
Abstract A description is given of a TPC system that operates in a relativistic heavy-ion beam and yields good track reconstruction efficiency in very-high-multiplicity events. The mechanical construction of the chamber is discussed. A set of custom hybrid circuits are used to build a very compact, cost-effective electronics system mounted directly on the chamber. Results from running in test beams and from preliminary experimental runs are given.
118155642
Development and tests of an anode readout TPC with high track separability for large solid angle relativistic ion experiments
We have developed, constructed and tested an anode readout TPC with high track separability which is suitable for large solid angle relativistic ion experiments. The readout via rows of short anode wires parallel to the beam has been found in tests to allow two-track separability of approx.2-3 mm. The efficiency of track reconstruction for events from a target, detected inside the MPS 5 KG magnet, is estimated to be >90% for events made by incident protons and pions. 15 GeV/c x A Si ion beams at a rate of approx.25 K per AGS pulse were permitted to course through the chamber and did not lead to any problems. When the gain was reduced to simulate the total output of a minimum ionizing particle, many Si ion tracks were also detected simultaneously with high efficiency. The resolution along the drift direction (parallel to the MPS magnetic field and perpendicular to the beam direction) was <1 mm and the resolution along the other direction /perpendicular/ to the beam direction was <1 mm also. 3 refs., 5 figs.