Double-transverse spin asymmetries at NLO

We report on a next-to-leading order QCD calculation of the cross section and the spin asymmetry for isolated large-p_T prompt photon production in collisions of transversely polarized protons. Corresponding measurements may be used at RHIC to determine the transversity parton distributions of the proton.Comment: 3 pages, LaTeX, 1 figure as eps file. Invited talk presented by W. Vogelsang at the "Conference on the Intersections of Particle and Nuclear Physics (CIPANP 2003)", New York City, May 19-24, 200

Next-to-leading Order QCD Corrections to A_TT for Single-Inclusive Hadron Production

We report on a calculation of the next-to-leading order QCD corrections to the partonic cross sections contributing to single-inclusive high-p_T hadron production in collisions of transversely polarized hadrons. We give some predictions for the double spin asymmetry A_TT^\pi for the proposed experiments at RHIC and at the GSI.Comment: Presented at DIS 2005, Madison, Wisconsin, USA, April 27-May 1, 200

Next-to-leading order QCD corrections to single-inclusive hadron production in transversely polarized p-p and pbar-p collisions

We present a calculation of the next-to-leading order QCD corrections to the partonic cross sections contributing to single-inclusive high-p_T hadron production in collisions of transversely polarized hadrons. We use a recently developed projection technique for treating the phase space integrals in the presence of the cos(2Phi) azimuthal-angular dependence associated with transverse polarization. Our phenomenological results show that the double-spin asymmetry A_TT^pi for neutral-pion production is expected to be very small for polarized pp scattering at RHIC and could be much larger for the proposed experiments with an asymmetric pbar-p collider at the GSIComment: 7 pages, 5 figure

Providing ramps in rearing aviaries affects laying pullet distribution, behavior and bone properties

To ensure that laying hens can make full use of the various resources within an aviary barn and develop optimum bone health while minimizing keel bone fractures, appropriate cognitive and bone development during rearing is critical. Given previous work documenting the benefit of ramps that could be used by hens to transition between tiers and reduced incidence of keel bone fractures, the project examined the provision of ramps during the rearing period, which birds could use voluntarily from 10 d of age. We hypothesized that the provision of ramps would influence how pullets distribute within the aviary and how birds vertically move between the aviary tiers leading to greater bone strength in birds with access to ramps. The study used 2 flocks of laying hen chicks (Lohmann Selected Leghorn; 4,800 chicks/flock) that were reared in one of 2 commercial rearing facilities with each divided into 4 pens (600 chicks/pen) to allow for treatment assignments. In 2 pens of each facility, ramps were installed from each of the 3 tiers providing a walking path that birds could access from 10 d of age. Video recordings were made at 4 times per day at 3, 4, 5, 8, 11, and 14 wk of age to determine the relative distribution of birds and the number of transitions between each tier. At 16 wk of age, 10 birds per pen per flock were killed and the tibia and humerus collected for biomechanical assessment; the keel was also collected for bone mineral density via computed tomography. Chicks/pullets within pens provided ramps demonstrated a rapid use of the upper tiers of the aviary paralleling greater usage of ramps between all aviary levels. Despite the ramp and tier usage following the predicted pattern, differences in bone strength were opposite than expected for tibiae and may reflect the different behaviors pens with ramps and without ramps would allow. Results support the position that provision of ramps within a commercial system will lead to voluntary usage of the ramps with long term effects on the distribution of birds in the system throughout the rearing period.Egg Industry Cente

Global analysis of fragmentation functions for pions and kaons and their uncertainties

We present new sets of pion and kaon fragmentation functions obtained in NLO combined analyses of single-inclusive hadron production in electron-positron annihilation, proton-proton collisions, and deep-inelastic lepton-proton scattering with either pions or kaons identified in the final state. At variance with all previous fits, the present analyses take into account data where hadrons of different electrical charge are identified, which allow to discriminate quark from anti-quark fragmentation functions without the need of non trivial flavor symmetry assumptions. The resulting sets are in good agreement with all data analyzed, which cover a much wider kinematical range than in previous fits. An extensive use of the Lagrange multiplier technique is made in order to assess the uncertainties in the extraction of the fragmentation functions and the synergy from the complementary data sets in our global analysis.Comment: 28 pages, 25 figure

The potential of a light spot, heat area, and novel object to attract laying hens and induce piling behaviour.

Piling behaviour of laying hens often results in smothering or death due to suffocation. Mechanisms leading to piling are not yet understood though various potential factors have been suggested. In this experimental study, we predicted that the presence of a light spot, a novel object (metal foil), or a heat area within animal pens would increase animal numbers around the stimulus leading to piling behaviour. We presented the cues in a 4 × 2 Latin-square design in eight identical experimental pens including each 55 Lohmann Selected Leghorn hens. The cues were presented in two test areas per pen, at two bouts per day in the morning, consecutively for 5 days, over four periods (age: 20, 22, 24, 26 weeks). Each pen received a cue and control condition simultaneously (test areas without cue presentation) once. For a bout, each cue was presented for 35 min except for the light spot where the duration was 10 min. Birds' responses to the cues during bout and non-bout times were video recorded and analysed for the first bout of each period. To assess the cues' attractiveness, the number of hens during bout times was counted at predefined times within the test and control areas. To assess the cues' effects on piling, we described piling behaviour (pile number, duration, animal numbers, trigger) in control and test areas during bout times. Furthermore, we described piling behaviour during bout times and non-bout times on the first day of the first period and fourth period. The best model explaining the number of hens included the interactions of treatment and bout time, and treatment and area. Over the bout's time course, more hens were attracted to the light spot compared to the control condition, and more to test areas compared to control areas. In the novel object condition, more hens were drawn to the test areas compared to the control areas. Hens were not attracted to the heat area. Piling in bout times was observed twice when hens pecked at the novel object. During non-bout times, piling behaviour occurred frequently at midday and in the late morning compared to the afternoon, mostly in corners and mainly preceded by the mutual attraction of hens. Overall, hens were attracted to light spots and less so to the novel object though neither reliably induced piling behaviour. The occurrence of piling behaviour in non-bout times shows that more work is needed to understand mechanisms eliciting piling behaviour

Global Analysis of Fragmentation Functions for Eta Mesons

Fragmentation functions for eta mesons are extracted at next-to-leading order accuracy of QCD in a global analysis of data taken in electron-positron annihilation and proton-proton scattering experiments. The obtained parametrization is in good agreement with all data sets analyzed and can be utilized, for instance, in future studies of double-spin asymmetries for single-inclusive eta production. The Lagrange multiplier technique is used to estimate the uncertainties of the fragmentation functions and to assess the role of the different data sets in constraining them.Comment: 11 pages, 8 figures, updated reference

Calibration of LACIS as a CCN detector and its use in measuring activation and hygroscopic growth of atmospheric aerosol particles

A calibration for LACIS (Leipzig Aerosol Cloud Interaction Simulator) for its use as a CCN (cloud condensation nuclei) detector has been developed. For this purpose, sodium chloride and ammonium sulfate particles of known sizes were generated and their grown sizes were detected at the LACIS outlet. From these signals, the effective critical super-saturation was derived as a function of the LACIS wall temperature. With this, LACIS is calibrated for its use as a CCN detector. The applicability of LACIS for measurements of the droplet activation, and also of the hygroscopic growth of atmospheric aerosol particles was tested. The activation of the urban aerosol particles used in the measurements was found to occur at a critical super-saturation of 0.46% for particles with a dry diameter of 75 nm, and at 0.42% for 85 nm, respectively. Hygroscopic growth was measured for atmospheric aerosol particles with dry diameters of 150, 300 and 350 nm at relative humidities of 98 and 99%, and it was found that the larger dry particles contained a larger soluble volume fraction of about 0.85, compared to about 0.6 for the 150 nm particles