New QCD results from LEP

I review recent QCD results from LEP. The emphasis is on results that represent new studies and on puzzling disagreements of theory and experiment. Further results are nevertheless mentioned by reference. The new studies discussed in more detail are the most precise measurement of unbiased gluon jets to date, strong evidence of color coherence in 3-jet events, and an, albeit unsuccessful, search for penta-quarks. As yet unexplained disagreements are observed in photon-photon collisions for high momentum charged particle and single jet production, and for the total cross section of b-quark production.Comment: To appear in the proceedings of the 39th Rencontres De Moriond On QCD And High Energy Hadronic Interactions 28 March - 4 April 2004, La Thuile, Ital

Jet production in two-photon collisions at LEP

Jet and di-jet production are studied in collisions of quasi-real photons collected during the LEP2 program at e+e- center-of-mass energies from 189 to 209 GeV. OPAL reports good agreement of NLO perturbative QCD with the measured differential di-jet cross sections, which reach a mean transverse energy of the di-jet system of 25 GeV. L3, on the other hand, finds drastic disagreement of the same calculation with single jet production for transverse jet momenta larger than about 25 GeV.Comment: 3 pages, 4 figures, Talk presented at the EPS'03 conference in Aachen, Germany, to be published in the proceedings (EPJ direct

Highlights from ATLAS

The ATLAS experiment has been taking data efficiently since LHC collisions started, first at the injection energy of 450 GeV/beam and at 1.18 TeV/beam in 2009, then at 3.5 TeV/beam in 2010. Many results have already been obtained based on this data demonstrating the performance of the detector, as well as first physics measurements. Only a selection of highlights will be presented here.Comment: 12 pages, 9 figures, proceedings of talk presented at XVIII International Workshop on Deep-Inelastic Scattering and Related Subjects, April 19 -23, 2010, Convitto della Calza, Firenze, Ital

High momentum particle and jet production in photon-photon collisions

Jet and particle production have been studied in collisions of quasi-real photons collected during the LEP2 program. OPAL and DELPHI report good agreement of NLO perturbative QCD with the measured differential di-jet cross sections, which reach a mean transverse energy of the di-jet system of 25 GeV. L3, on the other hand, finds drastic disagreement of the same calculation with single jet production for transverse jet momenta larger than about 25 GeV. L3 observes similar disagreement between data and NLO QCD in their measurements of charged and neutral particle production at high transverse momenta of the particles. A recent measurement performed by DELPHI of the same quantities does not confirm this observation.Comment: 7 pages, 3 figures, to appear in the proceedings of PHOTON200

The Hadronic Picture of the Photon

The hadronic interactions of the photon are studied in terms of new measurements of the total hadronic cross section and di-jet production in photon-photon collisions at LEP2.Comment: 3 pages, 3 figures, 1 table, to be published in proceedings ICHEP2000, Osaka, Japa

The gluon content of the photon from di-jet production at the photon-photon collider

A study of di-jet measurements at a future photon collider is reported. The sensitivity to extract the gluon distribution is discussed. The results are compared with calculations for a linear e+e- collider.Comment: revised version with minor text changes and one figure replace

Erste Ergebnisse eines Artenvergleichs von Erbsen und Ackerbohnen

Organic farmers have to take the decision which grain legume specie is the best for their site. The existing recommendations are based on variety tests and studies on cropping systems. The best grain leg¬ume specie on one site has not been investigated. The aim of this work is to test field pea and faba bean on one and the same site. In 2011/2012 these two species were sown in autumn and in spring, as well as in pure stand and in mixture with cereals (for the field pea) in a field trial. Hardiness of the winter crops and yield were assessed. Winter field pea in mixture with triticale had the highest hardiness and was significantly different from field pea in pure stand and from faba bean. Spring faba bean was the crop with the highest yield and had no significant difference from the winter form and the spring field pea. Results show that it is important to test different grain legume species on one and the same site

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements