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The energy resolution of a highly granular 1 m 3 analogue scintillator-steel hadronic calorimeter is studied using charged pions with energies from 10 GeV to 80 GeV at the CERN SPS. The energy resolution for single hadrons is determined to be approximately 58%/ E/GeV. This resolution is improved to approximately 45%/ E/GeV with software compensation techniques. These techniques take advantage of the event-by-event information about the substructure of hadronic showers which is provided by the imaging capabilities of the calorimeter. The energy reconstruction is improved either with corrections based on the local energy density or by applying a single correction factor to the event energy sum derived from a global measure of the shower energy density. The application of the compensation algorithms to GEANT4 simulations yield resolution improvements comparable to those observed for real data.

Photonic packet switches offer high speed, data rate and format transparency, and flexihility required by future computer com munications and cell-based telecommunications networks. In this paper, we review experimental progress in state-of-the-art pho tonic packet switches with an emphasis on all-optical guided-wave systems. The term all-optical implies that the data portion of a packet remains in opticalformat from the source to the destination. While the data remain all-optical, both optical and optoelectronic techniques have been used to process packet routing functions based on extremely simple routing protocols. An overview of the design issues for all-optical photonic packet switching is given and contrasted with electronic packet switch implementations. Low-level functions that have heen experimentally implemented include routing, contention resolution, synchronization, and header regeneration. System level demonstrations. including centralized photonic switching and distributed all-optical multihop networks. will be reviewed. tonic switches provide both the high switching speeds and a transmission bandwidth compatible with the fiber-Manuscript

Four-wave mixing in wavelength-division-multiplexed soliton systems with damping and amplification is studied. An analytical model is introduced that explains the dramatic growth of the four-wave terms. The model yields a resonance condition relating the soliton frequency and the amplifier distance. It correctly predicts all essential features regarding the resonant growth of the four-wave contributions.

An analysis of an extensive sample of the world's data has been performed to test the hypothesis of radial scaling. We have studied the inclusive reactions p + p --+ (~* %~ or K * or p or 9) +anything to determine the behavior of the invariant cross section as a function of p,, x, = E*/E*,,,, the radial scaling variable, and s.The data cover a range in p, from 0.25 to -6.0 GeV/c and a range in d s from 3.0 to 63 GeV. For small x, and all available p, the single-particle inclusive cross sections for the reactions studied scale to a good approximation for all v ' s , even down to the kinematic threshold. For large x,, the single-particle inclusive cross sections for increasing d s show a rapid approach to the scaling limit from above. In these cases the scaling limit is always approached by v ' s z 10 GeV. Thus, data for all particles to a good approximation exhibit radial scaling at all available p, and x, over the CERN ISR energy range. A comparison of radial scaling with Feynman scaling is given. It is shown that in the Feynman case the cross sections for small xll ( x , , = p*,, /p*,.,) approach their scaling limit from below, and that the approach to the scaling limit is slower than is exhibited for the case of small x,. The systematic differences among the inclusive cross sections of various particles are discussed in the range of v ' s where radial scaling has been shown to be valid. In particular, the p, and x, distributions of E d v / d p 3 are examined.

Calorimeters with a high granularity are a fundamental requirement of the Particle Flow paradigm. This paper focuses on the prototype of a hadron calorimeter with analog readout, consisting of thirty-eight scintillator layers alternating with steel absorber planes. The scintillator plates are finely segmented into tiles individually read out via Silicon Photomultipliers. The presented results are based on data collected with pion beams in the energy range from 8 GeV to 100 GeV. The fine segmentation of the sensitive layers and the high sampling frequency allow for an excellent reconstruction of the spatial development of hadronic showers. A comparison between data and Monte Carlo simulations is presented, concerning both the longitudinal and lateral development of hadronic showers and the global response of the calorimeter. The performance of several GEANT4 physics lists with respect to these observables is evaluated.

We present density-matrix elements and single-spin correlations for the reaction p , p -p~+ n at 1.18, 1.47, 1.71, and 1.98 GeV/c, using both longitudinal and transverse beam polarizations. For the p , p -h + + n subprocess we find quite different energy dependence for the helicity-i and helicity-+ A+ + -production asymmetries. The helicity-f asymmetry has pi,, dependence similar to the polarization in p,p-.ntd, while the helicity-4 asymmetry changes sign between 1.18 and 1.47 GeV/c. By fitting the production angle dependence of the spin correlations, we obtain joint moments which are easily related to the partial-wave structure. We have carried out a partial-wave analysis with the moments data. We find that the production wave intensities are qualitatively consistent with the elastic phase-shift analyses, and the phases vary smoothly with plab. From the absence of Breit-Wigner phase behavior, we conclude that the dinucleon resonances seen in the pp elastic waves are not true coupled-channel Briet-Wigner states in N N and N A .

Multisoliton interactions are studied with an asymptotic expansion of the N-soliton solution in the limit of large frequency separation between the channels. In this limit the spectral distortion is small and the peak frequency shift of a channel is the sum of pairwise shifts as a result of interaction with other channels. These results, derived for collisions among an arbitrary number of channels, will be useful in estimating the limits on the minimum channel spacings and packet sizes for a wavelength-multiplexed optical communication system.