Technical University of Dortmund

About: Technical University of Dortmund is a education organization based out in Dortmund, Nordrhein-Westfalen, Germany. It is known for research contribution in the topics: Large Hadron Collider & Neutrino. The organization has 13028 authors who have published 27666 publications receiving 615557 citations. The organization is also known as: Dortmund University & University of Dortmund.

Tunable isolated attosecond X-ray pulses with gigawatt peak power from a free-electron laser

Abstract: The quantum-mechanical motion of electrons in molecules and solids occurs on the sub-femtosecond timescale. Consequently, the study of ultrafast electronic phenomena requires the generation of laser pulses shorter than 1 fs and of sufficient intensity to interact with their target with high probability. Probing these dynamics with atomic-site specificity requires the extension of sub-femtosecond pulses to the soft X-ray spectral region. Here, we report the generation of isolated soft X-ray attosecond pulses with an X-ray free-electron laser. Our source has a pulse energy that is millions of times larger than any other source of isolated attosecond pulses in the soft X-ray spectral region, with a peak power exceeding 100 GW. This unique combination of high intensity, high photon energy and short pulse duration enables the investigation of electron dynamics with X-ray nonlinear spectroscopy and single-particle imaging, unlocking a path towards a new era of attosecond science. The generation of ultrashort X-ray pulses with a peak power exceeding 100 GW offers new opportunities for studying electron dynamics with nonlinear spectroscopy and single-particle imaging.

Next-to-leading-order radiative parton model analysis of polarized deep inelastic lepton-nucleon scattering

Abstract: A next-to-leading-order QCD analysis of spin asymmetries and structure functions in polarized deep inelastic lepton-nucleon scattering is presented within the framework of the radiative parton model. A consistent NLO formulation of the ${\mathit{Q}}^{2}$ evolution of polarized parton distributions yields two sets of plausible NLO spin-dependent parton distributions in the conventional MS factorization scheme. They respect the fundamental positivity constraints down to the low resolution scale ${\mathit{Q}}^{2}$=${\mathrm{\ensuremath{\mu}}}_{\mathrm{NLO}}^{2}$=0.34 ${\mathrm{GeV}}^{2}$. The ${\mathit{Q}}^{2}$ dependence of the spin asymmetries ${\mathit{A}}_{1}^{\mathit{p},\mathit{n},\mathit{d}}$(x,${\mathit{Q}}^{2}$) is similar to the leading-order (LO) one in the range 1\ensuremath{\le}${\mathit{Q}}^{2}$\ensuremath{\le}20 ${\mathrm{GeV}}^{2}$ and is shown to be non-negligible for x values relevant for the analysis of the present data and possibly forthcoming data at DESY HERA. \textcopyright{} 1996 The American Physical Society.

Flavor Ratio of Astrophysical Neutrinos above 35 TeV in IceCube

Abstract: A diffuse flux of astrophysical neutrinos above 100 TeV has been observed at the IceCube Neutrino Observatory. Here we extend this analysis to probe the astrophysical flux down to 35 TeV and analyze its flavor composition by classifying events as showers or tracks. Taking advantage of lower atmospheric backgrounds for showerlike events, we obtain a shower-biased sample containing 129 showers and 8 tracks collected in three years from 2010 to 2013. We demonstrate consistency with the (f(e) : f(mu) : f(tau))(circle plus) approximate to (1 : 1 : 1)(circle plus) flavor ratio at Earth commonly expected from the averaged oscillations of neutrinos produced by pion decay in distant astrophysical sources. Limits are placed on nonstandard flavor compositions that cannot be produced by averaged neutrino oscillations but could arise in exotic physics scenarios. A maximally tracklike composition of (0 : 1 : 0)(circle plus) is excluded at 3.3 sigma, and a purely showerlike composition of (1 : 0 : 0)(circle plus) is excluded at 2.3 sigma.

Search for high-mass diboson resonances with boson-tagged jets in proton-proton collisions at √s=8 TeV with the ATLAS detector

Abstract: A search is performed for narrow resonances decaying into WW, WZ, or ZZ boson pairs using 20.3 fb(-1) of proton-proton collision data at a centre-of-mass energy of root s = TeV recorded with the AT ...