Parameters of track structure

Linear energy transfer (or collision stopping power) and energy straggling along the tracks of charged particles are both relevant to the effectiveness of ionizing radiation. Energy straggling is the dominant aspect whenever one is concerned with small energy depositions ( < 1 keV) and a correction to L E T is necessary in these cases. The correction term and its relation to the spectrum of energy transfers in primary collisions is derived. Other parameters of track structure are discussed, and an analysis is mentioned which can substitute the Landau- and Vavilov-theory in the analysis of the collision spectrum

All-particle cosmic ray energy spectrum measured with 26 IceTop stations

We report on a measurement of the cosmic ray energy spectrum with the IceTop air shower array, the surface component of the IceCube Neutrino Observatory at the South Pole. The data used in this analysis were taken between June and October, 2007, with 26 surface stations operational at that time, corresponding to about one third of the final array. The fiducial area used in this analysis was 0.122 km^2. The analysis investigated the energy spectrum from 1 to 100 PeV measured for three different zenith angle ranges between 0{\deg} and 46{\deg}. Because of the isotropy of cosmic rays in this energy range the spectra from all zenith angle intervals have to agree. The cosmic-ray energy spectrum was determined under different assumptions on the primary mass composition. Good agreement of spectra in the three zenith angle ranges was found for the assumption of pure proton and a simple two-component model. For zenith angles {\theta} < 30{\deg}, where the mass dependence is smallest, the knee in the cosmic ray energy spectrum was observed between 3.5 and 4.32 PeV, depending on composition assumption. Spectral indices above the knee range from -3.08 to -3.11 depending on primary mass composition assumption. Moreover, an indication of a flattening of the spectrum above 22 PeV were observed.Comment: 38 pages, 17 figure

Tunnelling Studies of Two-Dimensional States in Semiconductors with Inverted Band Structure: Spin-orbit Splitting, Resonant Broadening

The results of tunnelling studies of the energy spectrum of two-dimensional (2D) states in a surface quantum well in a semiconductor with inverted band structure are presented. The energy dependence of quasimomentum of the 2D states over a wide energy range is obtained from the analysis of tunnelling conductivity oscillations in a quantizing magnetic field. The spin-orbit splitting of the energy spectrum of 2D states, due to inversion asymmetry of the surface quantum well, and the broadening of 2D states at the energies, when they are in resonance with the heavy hole valence band, are investigated in structures with different strength of the surface quantum well. A quantitative analysis is carried out within the framework of the Kane model of the energy spectrum. The theoretical results are in good agreement with the tunnelling spectroscopy data.Comment: 29 pages, RevTeX, submitted in Phys.Rev.B. Figures available on request from [email protected]

Inclusive B→XclνB \to X_c l \nu decay spectra at Belle and the determination of ∣Vcb∣|V_{cb}|

We report measurements of the inclusive electron energy spectrum and hadron invariant mass spectrum for charmed semileptonic decays of B mesons in a 140 fb^-1 data sample collected with the Belle detector at the KEKB e+e- collider. We determine the first four central moments and partial branching fraction of the electron energy spectrum for electron energy thresholds from 0.4 to 2.0 GeV, and the first two central and second non-central moments of the hadron invariant mass spectrum for lepton energy thresholds from 0.7 to 1.9 GeV. Using these measurements and Belle measurements of the photon energy moments in B -> X_s gamma decays, we determine the CKM matrix element |Vcb|, the b quark mass and higher order non-perturbative parameters that appear in the Heavy Quark Expansion by performing a global fit analysis in the kinetic mass and 1S schemes.Comment: 4 pages, 4 figures, Contribution to the Proceedings of the XXXIII International Conference of High Energy Physics (ICHEP'06), Moscow, 200

Possible structure in the cosmic ray electron spectrum measured by the ATIC-2 and ATIC-4 experiments

A strong excess in a form of a wide peak in the energy range of 300-800 GeV was discovered in the first measurements of the electron spectrum in the energy range from 20 GeV to 3 TeV by the balloon-borne experiment ATIC (J. Chang et al. Nature, 2008). The experimental data processing and analysis of the electron spectrum with different criteria for selection of electrons, completely independent of the results reported in (J. Chang et al. Nature, 2008) is employed in the present paper. The new independent analysis generally confirms the results of (J. Chang et al. Nature, 2008), but shows that the spectrum in the region of the excess is represented by a number of narrow peaks. The measured spectrum is compared to the spectrum of (J. Chang et al. Nature, 2008) and to the spectrum of the Fermi/LAT experiment.Comment: LaTeX2e, 10 pages, 4 figures, a paper for ECRS 2010 (Turku, Finland); http://www.astrophys-space-sci-trans.net/7/119/2011

Derivation of the Blackbody Radiation Spectrum from a Natural Maximum-Entropy Principle Involving Casimir Energies and Zero-Point Radiation

By numerical calculation, the Planck spectrum with zero-point radiation is shown to satisfy a natural maximum-entropy principle whereas alternative choices of spectra do not. Specifically, if we consider a set of conducting-walled boxes, each with a partition placed at a different location in the box, so that across the collection of boxes the partitions are uniformly spaced across the volume, then the Planck spectrum correspond to that spectrum of random radiation (having constant energy kT per normal mode at low frequencies and zero-point energy (1/2)hw per normal mode at high frequencies) which gives maximum uniformity across the collection of boxes for the radiation energy per box. The analysis involves Casimir energies and zero-point radiation which do not usually appear in thermodynamic analyses. For simplicity, the analysis is presented for waves in one space dimension.Comment: 11 page

Periodic systems in time: double-well potential

Time analysis of oscillations of a particle between wells in the one-dimensional double-well potential with infinite high outside walls, based on wave packet use and energy spectrum analysis, is presented. For the double-well potential of the form $x^{2}+1/x^{2}$ in the external regions, an exact analytical solution of the energy spectrum is found (by standard QM approach), an analysis of oscillation periodicity is fulfilled, an approach for exact analitical calculation of the oscillation period is proposed (for the first time for the double-well potential).Comment: 11 pages, no figures. LaTeX 2e, class `elsart' (Elsevier Science) is used. Reference correctio