P-wave excited baryons from pion- and photo-induced hyperon production

We report evidence for $N(1710)P_{11}$, $N(1875)P_{11}$, $N(1900)P_{13}$, $\Delta(1600)P_{33}$, $\Delta(1910)P_{31}$, and $\Delta(1920)P_{33}$, and find indications that $N(1900)P_{13}$ might have a companion state at 1970\,MeV. The controversial $\Delta(1750)P_{31}$ is not seen. The evidence is derived from a study of data on pion- and photo-induced hyperon production, but other data are included as well. Most of the resonances reported here were found in the Karlsruhe-Helsinki (KH84) and the Carnegie-Mellon (CM) analyses but were challenged recently by the Data Analysis Center at GWU. Our analysis is constrained by the energy independent $\pi N$ scattering amplitudes from either KH84 or GWU. The two $\pi N$ amplitudes from KH84 or GWU, respectively, lead to slightly different $\pi N$ branching ratios of contributing resonances but the debated resonances are required in both series of fits.Comment: 22 pages, 28 figures. Some additional sets of data are adde

Observation of exclusive DVCS in polarized electron beam asymmetry measurements

We report the first results of the beam spin asymmetry measured in the reaction e + p -> e + p + gamma at a beam energy of 4.25 GeV. A large asymmetry with a sin(phi) modulation is observed, as predicted for the interference term of Deeply Virtual Compton Scattering and the Bethe-Heitler process. The amplitude of this modulation is alpha = 0.202 +/- 0.028. In leading-order and leading-twist pQCD, the alpha is directly proportional to the imaginary part of the DVCS amplitude.Comment: 6 pages, 5 figure

A Kinematically Complete Measurement of the Proton Structure Function F2 in the Resonance Region and Evaluation of Its Moments

We measured the inclusive electron-proton cross section in the nucleon resonance region (W < 2.5 GeV) at momentum transfers Q**2 below 4.5 (GeV/c)**2 with the CLAS detector. The large acceptance of CLAS allowed for the first time the measurement of the cross section in a large, contiguous two-dimensional range of Q**2 and x, making it possible to perform an integration of the data at fixed Q**2 over the whole significant x-interval. From these data we extracted the structure function F2 and, by including other world data, we studied the Q**2 evolution of its moments, Mn(Q**2), in order to estimate higher twist contributions. The small statistical and systematic uncertainties of the CLAS data allow a precise extraction of the higher twists and demand significant improvements in theoretical predictions for a meaningful comparison with new experimental results.Comment: revtex4 18 pp., 12 figure

Nucleon resonances in the fourth resonance region

Nucleon and $\Delta$ resonances in the fourth resonance region are studied in a multichannel partial-wave analysis which includes nearly all available data on pion- and photo-induced reactions off protons. In the high-mass range, above 1850\,MeV, several alternative solutions yield a good description of the data. For these solutions, masses, widths, pole residues and photo-couplings are given. In particular, we find evidence for nucleon resonances with spin-parities $J^P=1/2^+...7/2^+$. For one set of solutions, there are four resonances forming naturally a spin-quartet of resonances with orbital angular momentum L=2 and spin S=3/2 coupling to $J=1/2,...,7/2$. Just below 1.9\,GeV we find a spin doublet of resonances with $J^P=1/2^-$ and $3/2^-$. Since a spin partner with $J^P=5/2^-$ is missing at this mass, the two resonances form a spin doublet which must have a symmetric orbital-angular-momentum wave function with L=1. For another set of solutions, the four positive-parity resonances are accompanied by mass-degenerate negative-parity partners -- as suggested by the conjecture of chiral symmetry restoration. The possibility of a $J^P=1/2^+, 3/2^+$ spin doublet at 1900\,MeV belonging to a 20-plet is discussed.Comment: 16 page

Tillage of compacted haul roads and landings in the boreal forests of Alberta, Canada

Ten temporary haul roads and landings in west-central Alberta were tilled with a winged subsoiler specifically designed for tilling compacted forest soils. Surface soil had been removed from all sites during construction, and spread over three of the four landings prior to tillage. Soil bulk density at the 0–10, 10–20, and 20–30 cm depths, and clod size distribution at the 0–30 cm depth were measured immediately after tillage. Bulk density of undisturbed and compacted (untilled) soil was also measured. Mean bulk density of compacted soil in haul roads was significantly greater than the bulk density of undisturbed soil, but not for landings. Tillage significantly reduced mean bulk density on three haul roads and two landings; subsurface soil was relatively dry at these sites. Most soils were difficult to fracture into small clods because these weakly aggregated soils were severely remoulded and compacted by equipment, particularly logging trucks operating on the haul roads. The degraded soil was massive and the strenght of the surface soil layers was generally much higher than was the strength of lower soil layers; this resulted in the subsoil deforming around the wings of the subsoiler rather than fracturing the surface soil. Fracturing of compacted soil into small clods was apparently enhanced by at least 2 years of frost action. The winged subsoiler was only moderately effective at fracturing recently compacted soil because of an often high soil water content, but it was observed that sites where soil was broken into large clods was loosened by frost action the following winter. Alternative methods of tilling compacted soil that insure soil fracturing over a wider range of soil water contents are needed for loosening compacted soil in northern boreal forests

Soil Biological Activity in Recent Clearcuts in West-Central Alberta

Soil biota response to changes in the soil physical environment following forest harvesting is relatively unknown in boreal forests. Soil biological activity was measured at four sites with Luvisolic soil following clear-cut forest har- vesting. Aerobic respiration rate and cellulose decomposition in flooded soils were measured on soil samples collected from treat- ment plots subjected to tree removal only and tree removal associated with three levels of skidding activity immediately after clear-cut harvesting and after 1 and 2 yr. More than half of variation in respiration and cellulose decomposition rates was related to soil properties. Soil respiration rate increased significantly after 1 yr but was not affected by skidder traffic. Cellulose decom- position was highest in soil with air-filled porosity \u3c0.10 m3 m–3, and increased significantly with skidder traffic. Air-filled porosity measured in the field at the time of harvest indicated a poorly aerated environment that becomes wetter in subsequent years. The results imply that soil had biota well adapted to poor soil aeration. The development of a fully anaerobic soil environment fol- lowing forest harvesting only occurred on compacted soil after heavy precipitation, but partial anaerobiosis of these boreal forest soils was common. Although partial anaerobiosis increased decomposition rate, it is considered sufficient to adversely affect the growth of plant roots and change the availability and mobility of nutrients

The strategic process of a cultural change to implement total quality management: a case study

The implementation of a total quality management (TQM) culture, with its implicit orientation towards the customer, is a complex matter and requires a long-term approach. Consequently, the firms that try to change from a bureaucratic culture to one oriented towards quality will have to design an appropriate strategy in order to succeed. This type of modification can only be achieved through an evolutionary process and not a reactionary or a revolutionary one, since we are dealing with individual and collective behaviours that can obtain customer satisfaction through continuous improvement. In this respect, we present the case of a transformation towards a TQM culture in the Division of Alicante (Alicante is a province in the East of Spain) of Telefonica Group (a Spanish telecommunications company which, in 1999, provided jobs for over 100000 people and had profits of more than 1780 million euros). Thus, we are going to study the stages the Division went through in the process and the problems they had to face, finally reflecting the results obtained after implementing a strategy that was formulated to achieve this purpose in the long run