Sökning: "cosmic radiation"

Visar resultat 16 - 20 av 44 avhandlingar innehållade orden cosmic radiation.

  1. 16. Multi-messenger emission from gamma-ray bursts

    Författare :Filip Samuelsson; Felix Ryde; Peter Mészáros; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; astrophysics; gamma-ray bursts; cosmic rays; Atomic; Subatomic and Astrophysics; Atomär fysik; subatomär fysik och astrofysik;

    Sammanfattning : Multi-messenger astronomy is a very hot topic in the astrophysical community. A messenger is something that carries information. Different astrophysical messenger types are photons, cosmic rays, neutrinos, and gravitational waves. They all carry unique and complementary information to one another. LÄS MER

  3. 17. QCD Phenomenology of Heavy Particle Dynamics

    Författare :Emanuel Norrbin; Teoretisk partikelfysik - Geonomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; High energy interactions; heavy quarks; QCD; charm asymmetry; hadronization; string fragmentation; colour reconnection; leptoquarks; parton shower; cosmic rays; Kosmisk strålning; högenergi; Fysicumarkivet A:2000:Norrbin;

    Sammanfattning : In this thesis the phenomenology of Quantum Chromo Dynamics (QCD) is studied in a variety of circumstances from both perturbative and non-perturbative perspectives. The main emphasis is on the production and hadronization of heavy particles, specifically heavy quarks, gauge bosons, leptoquarks and supersymmetric particles. LÄS MER

  4. 18. NOx Production by Ionisation Processes in Air

    Författare :Mahbubur Rahman; Vernon Cooray; Pierre Laroche; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Engineering physics; Nitrogen oxides; Lightning; Electrical Discharges; Cosmic Rays; Troposphere; Teknisk fysik; Engineering physics; Teknisk fysik;

    Sammanfattning : The study presented in this thesis was motivated by the large uncertainty on the concentration of atmospheric electrical discharges to the global nitrogen budget. This uncertainty is partly due to the fact that information concerning the NOx production efficiency of electrical discharges having current signatures similar to those of lightning flashes is not available in the literature. LÄS MER

  5. 19. Aspects of QCD and the Photon Structure

    Författare :Christer Friberg; Teoretisk partikelfysik - Geonomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; High energy interactions; QCD; Photons; Monte Carlo Event Generator; Leptoquarks; Colour Connections; cosmic rays; Kosmisk strålning; högenergi; Fysicumarkivet A:2000:Friberg;

    Sammanfattning : In a single theoretical framework, real and virtual photon interactions are modeled for gamma-p and gamma-gamma collisions. The description covers aspects from the production of jets to total cross sections, where special emphasis is put on the range of uncertainty in the modeling of a resolved photon component. LÄS MER

  7. 20. Study of Two-Photon processes at low Q2 using the VSAT calorimeter in the DELPHI experiment

    Författare :Pavel Tyapkin; Partikel- och kärnfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; högenergi; QCD; STIC; VSAT; DELPHI; LEP; antitag; double tag; single tag; photon structure function; hadronic cross-section; virtual photons; two-photon; gamma-gamma; Kosmisk strålning; cosmic rays; High energy interactions; PHOJET; TWOGAM; PYTHIA; VDM; GSP; Fysicumarkivet A:2004:Tyapkin;

    Sammanfattning : The study is based on data collected at the LEP II accelerator during the second period of the Large Electron-Positron collider operations (1996-2000). During that time the DELPHI (DEtector with Lepton, Photon and Hadron Identification) experiment collected about 90 Gb of data on tape corresponding to 687-691 pb-1 of luminosity. LÄS MER