23 research outputs found
Predictions on the transverse momentum spectra for charged particle production at LHC-energies from a two component model
Transverse momentum spectra, , of charged hadron
production in -collisions are considered in terms of a recently introduced
two component model. The shapes of the particle distributions vary as a
function of c.m.s. energy in the collision and the measured pseudorapidity
interval. In order to extract predictions on the double-differential
cross-sections of hadron production for future
LHC-measurements the different sets of available experimental data have been
used in this study.Comment: 5 pages, 7 plot
Strong Viscosity Increase in Aqueous Solutions of Cationic C22-Tailed Surfactant Wormlike Micelles
The viscoelastic properties and structure parameters have been investigated for aqueous solutions of wormlike micelles of cationic surfactant erucyl bis(hydroxyethyl) methylammonium chloride with long C22 tail in the presence inorganic salt KCl. The salt content has been varied to estimate linear to branched transition conditions due to screening of the electrostatic interaction in the networks. The local cylindrical structure and low electrostatic repulsion was obtained by SANS data. The drastic power law dependencies of rheological properties on surfactant concentrations were obtained at intermediate salt content. Two power law regions of viscosity dependence were detected in semi-dilute solutions related to “unbreakable” and “living” micellar chains. The fast contour length growth with surfactant concentration demonstrated that is in good agreement with theoretical predictions
Measurement of Jet Production Cross Sections in Deep-inelastic ep Scattering at HERA
A precision measurement of jet cross sections in neutral current deep-inelastic scattering for photon virtualities and inelasticities is presented, using data taken with the H1 detector at HERA, corresponding to an integrated luminosity of . Double-differential inclusive jet, dijet and trijet cross sections are measured simultaneously and are presented as a function of jet transverse momentum observables and as a function of . Jet cross sections normalised to the inclusive neutral current DIS cross section in the respective -interval are also determined. Previous results of inclusive jet cross sections in the range are extended to low transverse jet momenta . The data are compared to predictions from perturbative QCD in next-to-leading order in the strong coupling, in approximate next-to-next-to-leading order and in full next-to-next-to-leading order. Using also the recently published H1 jet data at high values of , the strong coupling constant is determined in next-to-leading order.A precision measurement of jet cross sections in neutral current deep-inelastic scattering for photon virtualities and inelasticities is presented, using data taken with the H1 detector at HERA, corresponding to an integrated luminosity of . Double-differential inclusive jet, dijet and trijet cross sections are measured simultaneously and are presented as a function of jet transverse momentum observables and as a function of . Jet cross sections normalised to the inclusive neutral current DIS cross section in the respective -interval are also determined. Previous results of inclusive jet cross sections in the range are extended to low transverse jet momenta . The data are compared to predictions from perturbative QCD in next-to-leading order in the strong coupling, in approximate next-to-next-to-leading order and in full next-to-next-to-leading order. Using also the recently published H1 jet data at high values of , the strong coupling constant is determined in next-to-leading order.A precision measurement of jet cross sections in neutral current deep-inelastic scattering for photon virtualities and inelasticities is presented, using data taken with the H1 detector at HERA, corresponding to an integrated luminosity of . Double-differential inclusive jet, dijet and trijet cross sections are measured simultaneously and are presented as a function of jet transverse momentum observables and as a function of . Jet cross sections normalised to the inclusive neutral current DIS cross section in the respective -interval are also determined. Previous results of inclusive jet cross sections in the range are extended to low transverse jet momenta . The data are compared to predictions from perturbative QCD in next-to-leading order in the strong coupling, in approximate next-to-next-to-leading order and in full next-to-next-to-leading order. Using also the recently published H1 jet data at high values of , the strong coupling constant is determined in next-to-leading order
Colombeau generalized functions on manifolds
Eduard NigschZsfassung in dt. SpracheWien, Techn. Univ. u. Univ., Dipl.-Arb., 2006OeBB(VLID)161012
Exclusive Meson Photoproduction with a Leading Neutron at HERA
A first measurement is presented of exclusive photoproduction of mesons associated with leading neutrons at HERA. The data were taken with the H1 detector in the years and at a centre-of-mass energy of GeV and correspond to an integrated luminosity of pb. The mesons with transverse momenta , are detected in the Forward Neutron Calorimeter. The phase space of the measurement is defined by the photon virtuality GeV, the total energy of the photon-proton system GeV and the polar angle of the leading neutron mrad. The cross section of the reaction is measured as a function of several variables. The data are interpreted in terms of a double peripheral process, involving pion exchange at the proton vertex followed by elastic photoproduction of a meson on the virtual pion. In the framework of one-pion-exchange dominance the elastic cross section of photon-pion scattering, , is extracted. The value of this cross section indicates significant absorptive corrections for the exclusive reaction