6,163 research outputs found
Searches for Supersymmetry at the Tevatron
Both Tevatron experiments, D0 and CDF, have searched for signs of
Supersymmetry in the present Run II data sample, using integrated luminosities
of up to 260/pb collected in ppbar collisions at a center-of-mass energy of
1.96TeV. In these proceedings, new results are presented in the search for
squarks and gluinos in the jets and missing transverse energy final state,
associated production of charginos and neutralinos with multilepton final
states, search for the rare decay B_s->mumu, searches allowing R-parity
violation (muons+jets, multileptons), and searches in the gauge mediated
supersymmetry breaking framework with the final state of two photons and
missing transverse energy. In the absence of any significant deviation from
Standard Model expectations, limits on the presence of new physics are set,
which in many cases are the most stringent to date.Comment: To appear in the proceedings of 32nd International Conference on
High-Energy Physics (ICHEP 04), Beijing, China, 16-22 Aug 200
False seedbeds in organic grown winter wheat
The false or stale seedbed technique is known as an effective tool of integrated weed control espe-cially in winter crops. However, only little data are available on the additional false seedbed effect compared to the only effect of late sowing
New Charm(onium) Results from CDF
After many upgrades to the CDF detector and to the accelerator complex, Run
II began in April 2001. The new detector has improved capabilities for charm
physics, and first results from the analysis of early Tevatron Run II data are
reported here.Comment: 6 pages, 4 figures, contribution to the DIS2003 workshop, St.
Petersbur
Reducing weed infestation in winter wheat by sowing technique
Hoeing can improve weed control in cereals but this requires wider row spacing of the crop. A spe-cific band row design may also ensure high crop yield and quality, especially at the conditions of organic farming. In order to study those effects two field experiments with winter wheat were con-ducted in 2005 and 2006 at the organic farming research area of the BBA. Three different row de-signs have been investigated: narrow (100 mm spacing), wide (400 mm) and band sowing (alternat-ing of crop band of 400 mm and a crop-free band of 300 mm width). All plots were harrowed whereas the wide and band sown plots have additionally been hoed. Also two cultivars differing in growth habit and competitiveness were tested (Ludwig, Pegassos).
Neither harrowing nor the combination of harrowing and hoeing could reduce weed density (by analysing data before and after treatments). Also the different row spacing had no effect on weed density at late spring (257 weeds m-2). However, weed growth at the same time was clearly influenced by the row spacing: Weed biomass was significantly higher in the plots with wide rows (23.1 g m-2) compared to normal (8.3 g m-2 ) and band sowing (10.5 g m-2 ). Crop yield was highest at band sowing (7.09 t ha-1) whereas the wide sown crop stand was of significant lower yield (6.18 t ha-1) but highest protein content (10%). Regarding cultivar effects Pegassos was more competitive against weeds and provided also a higher yield than cultivar Ludwig.
So far, band sowing has been proved as an easily applicable sowing technique which enables the use of hoes in cereals and ensure high crop yield especially at conditions of organic farming
Organic broilers in floorless pens on pasture
This thesis investigates different aspects of rearing broilers organically in floorless pens on pasture. The birds and pens were moved daily to fresh pasture. The interdisciplinary studies comprise the birds' growth performance and carcass quality, health, behaviour, leg condition and the birds’ effect on pasture. In the final study, on-farm diets were tested in a feeding experiment indoors. The data are based on four experiments carried out during 2000 to 2003. In 2000 and 2002, restricted-fed conventional broilers (ROSS 208) were reared in floorless pens on pasture and in control groups outdoors on straw. In 2001, two genotypes, ROSS 208 and the slow-growing ISA 657 were reared on three ground types, pasture, outdoors on straw and indoors on wood shavings with either an ad libitum or restricted feeding level. In 2003, a feeding experiment with slow-growing broilers fed on-farm diets in a choice feeding system was conducted indoors. Most birds were reared to 12 weeks of age, but ad libitum-fed ROSS birds were reared to 6 weeks. The experimental phase was from ca. 3 weeks to slaughter. The experiments indicate that under the given conditions - access to pasture does not offer sufficient protein and metabolizable energy to allow considerable feed savings in the farm enterprise (Paper I) - moving the floorless pens daily provides favourable conditions to prevent infections with Campylobacter and Eimeria in outdoor broilers (Paper II) - access to pasture as such appears to play no major role for the broilers' physical activity (Paper III) or leg condition (Paper IV) - broiler chickens on pasture can sustain white clover in a mixed grass/white clover pasture (Paper V) - with access to high-quality protein during the first three weeks there is a good potential to produce organic broiler meat with feed produced on-farm in northwestern Europe (Paper VI)
Spin Physics with Top Quarks at Hadron Colliders
We discuss the prospects to observe effects of transverse polarization and
spin-spin correlations of top quark pairs produced at hadron colliders.Comment: 3 pages, Latex, Talk presented at the 12th International Symposium on
High-Energy Spin Physics, Amsterdam, The Netherlands, September 10th-14th
199
Searches for New Phenomena at the Tevatron and at HERA
Recent results on searches for new physics at Run II of the Tevatron and
highlights from HERA are reported. The searches cover many different final
states and a wide range of models. All analyses have at this point led to
negative results, but some interesting anomalies have been found.Comment: Invited talk at the XXVI Physics in Collisions Conference (PIC06),
Buzios, Brasil, July 2006, 20 pages. PSN THUPL0
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