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.
120158411
Structure of two-body correlations in high energy hadron production
Abstract Experimental information on diffraction is used to estimate long range effects in multiparticle production. Diffractively produced secondaries are found to produce a plateau in the central region. Diffraction accounts for 30% of the observed correlations and the remainder, consistent with being short range, corresponds to a cluster size of 2.4 charged particles.
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.
118941079
Regge phenomenology of inclusive reactions
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 $p+p\ensuremath{\rightarrow}\ensuremath{\pi}+({\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}})+X$.
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.
119722876
Measurement of the dijet cross section in 400-GeV pp collisions
The invariant cross section for production of jet pairs in 400-GeV/c pp interactions has been measured as a function of p{tau} in the p{tau} range 4 to 9 GeV/c. The results are in good agreement with predictions of perturbative QCD models. 20 refs., 3 figs., 1 tab.
125525593
HADRON JETS IN 400-GeV p p COLLISIONS
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.
120282404
A new multivariate technique for top quark search
Abstract We present a new multivariate event classifier, the PDE classifier, which can be used to identify rare signals in the presence of large backgrounds. The classifier is based on a discriminant function which uses kernel density estimates of the signal and background event densities. The PDE method offers the flexibility of a neural network but is conceptually simpler, theoretically better understood, and easier to optimize in practice. The technique is tested on Monte Carlo data using processes t t → e + E t + jets as signal and W + jets → e + Et + jets as background. The performance of the PDE classifier is similar to that of a neural network. Both methods outperform conventional analysis.