Charm and longitudinal structure functions with the Kharzeev-Levin-Nardi model

We use the Kharzeev-Levin-Nardi model of the low $x$ gluon distributions to fit recent HERA data on charm and longitudinal structure functions. Having checked that this model gives a good description of the data, we use it to predict $F^c_2$ and $F_L$ to be measured in a future electron-ion collider. The results interpolate between those obtained with the de Florian-Sassot and Eskola-Paukkunen-Salgado nuclear gluon distributions. The conclusion of this exercise is that the KLN model, simple as it is, may still be used as an auxiliary tool to make estimates both for heavy ion and electron-ion collisions.Comment: 6 pages, 7 figure

Nucleon Tensor Charge from Exclusive πo\pi^o Electroproduction

Exclusive $\pi^o$ electroproduction from nucleons is suggested for extracting the tensor charge and other quantities related to transversity from experimental data. This process isolates C-parity odd and chiral odd combinations of t-channel exchange quantum numbers. In a hadronic picture it connects the meson production amplitudes to C-odd Regge exchanges with final state interactions. In a description based on partonic degrees of freedom, the helicity structure for this C-odd process relates to the quark helicity flip, or chiral odd generalized parton distributions. This differs markedly from deeply virtual Compton scattering, and both vector meson and charged $\pi$ electroproduction, where the axial charge can enter the amplitudes. Contrarily the tensor charge enters the $\pi^o$ process. The connection through the helicity description of the process to both the partonic and hadronic perspectives is studied and exploited in model calculations to indicate how the tensor charge and other transversity parameters can be related to cross section and spin asymmetry measurements over a broad range of kinematics.Comment: 40 pages, 14 figures Revised text clarifying main points, fixing typos, adding reference

Bounds on R-parity Violation from Resonant Slepton Production at the LHC

We consider the ATLAS and CMS searches for dijet resonances, as well as the ATLAS search for like-sign dimuon pairs at the LHC with 7 TeV center of mass energy. We interpret their exclusions in terms of bounds on the supersymmetric R-parity violating parameter space. For this we focus on resonant slepton production followed by the corresponding decay.Comment: 17 pages, 11 figures, 3 table

On the dbar/ubar Asymmetry and Parton Distributions

We discuss the impact of different measurements of the dbar/ubar asymmetry in the extraction of parameterizations of parton distribution functions.Comment: Contributed paper to LP01, 13 pages, 4 figure

Phenomenological description of the gamma* p cross section at low Q2

Low Q2 photon-proton cross sections are analysed using a simple, QCD-motivated parametrisation $\sigma_{\gamma^\star p}\propto 1/(Q^2+Q_0^2)$, which gives a good description of the data. The Q2 dependence of the gamma* p cross section is discussed in terms of the partonic transverse momenta of the hadronic state the photon fluctuates into.Comment: 14 pages, revtex, epsfig, 2 figure

Design of Computer Experiments: a powerful tool for the numerical design of BAW filters

We apply Design of Computer Experiments methods to the simulation of piezoelectric stacks and the design of BAW resonators and filters. Through the example of DCS filters with two different technologies (Iridium and Molybdenum electrodes), we show that the definition and the exploitation of a metamodel can accurately replace acoustic simulations and allows therefore a much faster material stack desig

Spectroscopy at B-factories Using Hard Photon Emission

The process of hard photon emission by initial electrons (positrons) at B-factories is discussed. It is shown that studies of the bottomonium spectroscopy will be feasible for the planned integrated luminosity of the B-factory experiments.Comment: 9 pages, Latex, 1 fugure, Submitted to Int.Jour.Mod.Phys.

Dynamical QCD Predictions for Ultrahigh Energy Neutrino Cross Sections

Neutrino-nucleon total cross sections for neutrino energies up to ultrahigh energies (UHE), E_\nu=10^12 GeV, are evaluated within the framework of the dynamical (radiative) parton model. The expected uncertainties of these predictions do not exceed the level of about 20 % at the highest energies where contributions of parton distributions in the yet unmeasured region around x\simeq 10^-8 to 10^-9 are non-negligible. This is far more accurate than estimated uncertainties of about 2^+-1 due to ad hoc extrapolations of parton distributions to x<10^-5 required for calculating UHE cosmic neutrino event rates.Comment: 16 pages, LaTeX, 4 figures, uses epsfig and amssymb styl

Diffractive Phenomena and Shadowing in Deep-Inelastic Scattering

Shadowing effects in deep-inelastic lepton-nucleus scattering probe the mass spectrum of diffractive leptoproduction from individual nucleons. We explore this relationship using current experimental information on both processes. In recent data from the NMC and E665 collaboration, taken at small x << 0.1 and Q^2 < 1 GeV^2, shadowing is dominated by the diffractive excitation and coherent interaction of low mass vector mesons. If shadowing is explored at small x > 1 GeV^2 as discussed at HERA, the situation is different. Here dominant contributions come from the coherent interaction of diffractively produced heavy mass states. Furthermore we observe that the energy dependence of shadowing is directly related to the mass dependence of the diffractive production cross section for free nucleon targets.Comment: 12 pages Latex, 8 figure

Soft Photoproduction Physics

Several topics of interest in soft photoproduction physics are discussed. These include jet universality issues (particle flavour composition), the subdivision into event classes, the buildup of the total photoproduction cross section and the effects of multiple interactions.Comment: 10 pages, LaTeX2e, no figures, to appear in the proceedings of the Durham Workshop on HERA Physics, ``Proton, Photon and Pomeron Structure'', 17--23 September 1995, Durham, U.