Sökning: "Strålning"

Visar resultat 1 - 5 av 234 avhandlingar innehållade ordet Strålning.

1. 1. Om strålning och molekyler i mörka moln

   Författare :Claes Bernes; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : This thesis, which consists of five articles in English and a summary in Swedish, deals with observations and theoretical studies of dark interstellar clouds, and with a method for calculations of radiative transfer. Article 1 is a catalogue of bright nebulosities in dark clouds, based on a survey of photographic sky atlases. LÄS MER

3. 2. 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. 3. 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

5. 4. Nonlinear Evolution in High Energy QCD

   Författare :Emil Avsar; Teoretisk partikelfysik - Geonomgår omorganisation; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Elementarpartikelfysik; quantum field theory; DIS; Elementary particle physics; Saturation; QCD; Small-x Physics; kvantfältteori; High energy interactions; cosmic rays; Kosmisk strålning; högenergi;

   Sammanfattning : QCD at very high energies is still not very well understood. Difficulties arise from a strong non-linear dynamics and also from nonperturbative physics. Detailed analytic calculations are often only possible either for simple toy models, or for asymptotically high energies. LÄS MER

7. 5. Isospin Breaking in Kaon Decays to Pions

   Författare :Fredrik Borg; Teoretisk partikelfysik - Geonomgår omorganisation; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Elementary particle physics; termodynamik; statistisk fysik; gravitation; relativitet; kvantmekanik; thermodynamics; Matematisk och allmän teoretisk fysik; Pseudo-scalar meson; Isospin Breaking; Chiral Perturbation Theory; Mathematical and general theoretical physics; classical mechanics; quantum mechanics; relativity; statistical physics; Weak Interaction; Strong Interaction; kvantfältteori; High energy interactions; Kärnfysik; Nuclear physics; klassisk mekanik; quantum field theory; cosmic rays; Kosmisk strålning; högenergi; Elementarpartikelfysik;

   Sammanfattning : The five different K -> 3 Pi and the three K -> 2 Pi decays are calculated in Chiral Perturbation Theory. The calculation is done using different approximations, to study whether this changes the result significantly. First the isospin approximation is used. Discrepancies are then found between theory and experiment. LÄS MER