121701561
Unitarity bounds for inelastic diffraction
Unitarity in the s-channel is invoked to derive an upper bound for the inelastic diffractive cross-section as a func- tion of impact parameter. The application of this bound to high-energy proton-proton scattering strongly suggests that inelastic diffraction should be peripheral in the impact parameter space. Introduction. Recent observation of a structure around t = -0.2 GeV 2 in the differential cross-section of the process pp ~ p(n,r +) at the CERN ISR (1 ) sup- ports the assumption that inelastic diffraction, unlike elastic diffraction, is peripheral in the impact param- eter space. This assumption has been made very plaus- ible in the past by many authors (2-6), partially on intuitive grounds, partially on the basis of phenome- nological analyses of experimental data. In this letter we suggest that the previous conclu- sion is in fact a very natural consequence of s-channel unitarity and of the assumption that inelastic, as well as elastic diffraction, is the shadow of non-diffractive particle production. Using these assumptions, Pumplin has recently derived the following bound (7) :
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.
124906083
Geometrical description of hadronic collisions
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
12119345
Event Selection Using Adaptive Gaussian Kernels
The invention relates to polymorphic markers (two tetranucleotide, one dinucleotide repeat polymorphisms, 27 markers characterized by primer pairs 1A-27A, and eleven markers characterized by primer pairs 1B-11B that are useful for human individualization. Applications are in forensic medicine and for paternity and prenatal screening as well as genetic mapping. These markers are characterized by sets of oligonucleotide primers according to the invention useful in PCR amplification and DNA segment resolution. The invention further relates to an assay for measuring the subtle differences in genetic material regarding an added or omitted set of dinucleotide or tetranucleotide repeat polymorphisms which comprises obtaining an amount of nucleotide segments effective for testing, amplifying the segments by the PCR procedure using at least one primer nucleotide sequence according to the present invention, resolving the amplified segments using gel electrophoresis, and comparing the resolved segments by autoradiography to observe the differences in migration patterns due to structural differences. The assay according to the invention is easy to perform and results can be obtained within 24 hours. It is not uncommon for results to be available within 3-4 hours. Accordingly, the invention also relates to an improved PCR procedure and a PCR assay kit which comprise nucleotides according to the invention.
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.
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.
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.
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 .