TY  - JOUR
A1  - Biedermann, B.
A1  - Billoni, M.
A1  - Denner, A.
A1  - Dittmaier, S.
A1  - Hofer, L.
A1  - Jäger, B.
A1  - Salfelder, L.
T1  - Next-to-leading-order electroweak corrections to pp -> W\(^{+}\)W\(^{-}\) -> 4 leptons at the LHC
JF  - JOURNAL OF HIGH ENERGY PHYSICS
N2  - We present results of the first calculation of next-to-leading-order electroweak corrections to W-boson pair production at the LHC that fully takes into account leptonic W-boson decays and off-shell effects. Employing realistic event selections, we discuss the corrections in situations that are typical for the study of W-boson pairs as a signal process or of Higgs-boson decays H → WW∗, to which W-boson pair production represents an irreducible background. In particular, we compare the full off-shell results, obtained treating the W-boson resonances in the complex-mass scheme, to previous results in the so-called double-pole approximation, which is based on an expansion of the loop amplitudes about the W resonance poles. At small and intermediate scales, i.e. in particular in angular and rapidity distributions, the two approaches show the expected agreement at the level of fractions of a percent, but larger differences appear in the TeV range. For transverse-momentum distributions, the differences can even exceed the 10% level in the TeV range where “background diagrams” with one instead of two resonant W bosons gain in importance because of recoil effects.
KW  - NLO Computations
KW  - W-boson
KW  - LHC
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-167790
VL  - 06
IS  - 065
ER  - 
TY  - JOUR
A1  - Ranger, Christopher M.
A1  - Biedermann, Peter HW
A1  - Phuntumart, Vipaporn
A1  - Beligala, Gayathri U.
A1  - Ghosh, Satyaki
A1  - Palmquist, Debra E.
A1  - Mueller, Robert
A1  - Barnett, Jenny
A1  - Schultz, Peter B.
A1  - Reding, Michael E.
A1  - Benz, J. Philipp
T1  - Symbiont selection via alcohol benefits fungus farming by ambrosia beetles
JF  - Proceedings of the National Academy of Sciences
N2  - Animal-microbe mutualisms are typically maintained by vertical symbiont transmission or partner choice. A third mechanism, screening of high-quality symbionts, has been predicted in theory, but empirical examples are rare. Here we demonstrate that ambrosia beetles rely on ethanol within host trees for promoting gardens of their fungal symbiont and producing offspring. Ethanol has long been known as the main attractant for many of these fungus-farming beetles as they select host trees in which they excavate tunnels and cultivate fungal gardens. More than 300 attacks by Xylosandrus germanus and other species were triggered by baiting trees with ethanol lures, but none of the foundresses established fungal gardens or produced broods unless tree tissues contained in vivo ethanol resulting from irrigation with ethanol solutions. More X. germanus brood were also produced in a rearing substrate containing ethanol. These benefits are a result of increased food supply via the positive effects of ethanol on food-fungus biomass. Selected Ambrosiella and Raffaelea fungal isolates from ethanol-responsive ambrosia beetles profited directly and indirectly by (i) a higher biomass on medium containing ethanol, (ii) strong alcohol dehydrogenase enzymatic activity, and (iii) a competitive advantage over weedy fungal garden competitors (Aspergillus, Penicillium) that are inhibited by ethanol. As ambrosia fungi both detoxify and produce ethanol, they may maintain the selectivity of their alcohol-rich habitat for their own purpose and that of other ethanol-resistant/producing microbes. This resembles biological screening of beneficial symbionts and a potentially widespread, unstudied benefit of alcohol-producing symbionts (e.g., yeasts) in other microbial symbioses.
KW  - fungus-farming insects
KW  - plant-insect-microbe interactions
KW  - symbiosis
KW  - insect-fungus mutualism
KW  - host screening
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-224953
VL  - 115
IS  - 17
ER  -