3,915 research outputs found
The IceCube neutrino observatory: Status and initial results
The IceCube collaboration is building a cubic kilometer scale neutrino
telescope at a depth of 2 km at the geographic South Pole, utilizing the clear
Antarctic ice as a Cherenkov medium to detect cosmic neutrinos. The IceCube
observatory is complemented by IceTop, a square kilometer air shower array on
top of the in-ice detector. The construction of the detector is nearly finished
with 79 of a planned 86 strings and 73 of 80 IceTop stations deployed. Its
completion is expected in the winter 2010/11. Using data from the partially
built detector, we present initial results of searches for neutrinos from
astrophysical sources such as supernova remnants, active galactic nuclei, and
gamma ray bursts, for anisotropies in cosmic rays, and constraints on the dark
matter scattering cross section. Further, we discuss future plans and R&D
activities towards new neutrino detection techniques.Comment: Proceedings of ECRS 2010, Turku, Finland, August 201
NLO QCD corrections to the production of a weak boson pair associated by a hard jet
In this talk we discuss recent progress concerning precise predictions for
the LHC. We give a status report of an application of the GOLEM method to deal
with multi-leg one-loop amplitudes, namely the next-to-leading order QCD
corrections to the process pp to V V + jet, where V is a weak boson W,Z.Comment: Talk at 2008 Rencontres de Moriond, QCD session, La Thuile, March
2007. Four page
Drilling deep in South Pole Ice
To detect the tiny flux of ultra-high energy neutrinos from active galactic
nuclei or from interactions of highest energy cosmic rays with the microwave
background photons needs target masses of the order of several hundred cubic
kilometers. Clear Antarctic ice has been discussed as a favorable material for
hybrid detection of optical, radio and acoustic signals from ultra-high energy
neutrino interactions. To apply these technologies at the adequate scale
hundreds of holes have to be drilled in the ice down to depths of about 2500 m
to deploy the corresponding sensors. To do this on a reasonable time scale is
impossible with presently available tools. Remote drilling and deployment
schemes have to be developed to make such a detector design reality. After a
short discussion of the status of modern hot water drilling we present here a
design of an autonomous melting probe, tested 50 years ago to reach a depth of
about 1000 m in Greenland ice. A scenario how to build such a probe today with
modern technologies is sketched. A first application of such probes could be
the deployment of calibration equipment at any required position in the ice, to
study its optical, radio and acoustic transmission properties.Comment: 4 pages, 3 figures, contribution to the Workshop ARENA2014, June 9-12
2014, Annapoli
NLO QCD corrections to graviton production at hadron colliders
Models with large extra dimensions predict the existence of Kaluza-Klein
graviton resonances. We compute the next-to-leading order QCD corrections to
graviton plus jet hadro-production, which is an important channel for graviton
searches at the Tevatron and the LHC. The QCD corrections are sizable and lead
to a significant reduction of the scale dependence. We present numerical
results for cross sections and distributions, and discuss the uncertainty from
parton distribution functions and the ultraviolet sensitivity of the
theoretical prediction.Comment: 19 pages, 9 eps figures, v2: additional references and comments, new
Fig. 9. Matches published version in Physical Review
NLO QCD corrections to ZZ+jet production at hadron colliders
A fully differential calculation of the next-to-leading order QCD corrections
to the production of Z-boson pairs in association with a hard jet at the
Tevatron and LHC is presented. This process is an important background for
Higgs particle and new physics searches at hadron colliders. We find sizable
corrections for cross sections and differential distributions, particularly at
the LHC. Residual scale uncertainties are typically at the 10% level and can be
further reduced by applying a veto against the emission of a second hard jet.
Our results confirm that NLO corrections do not simply rescale LO predictions.Comment: 15 pages, 4 figures, 4 tables; added 1 reference, version to appear
in Phys. Lett.
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