Open Access. Powered by Scholars. Published by Universities.®
Elementary Particles and Fields and String Theory Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Institution
Articles 1 - 3 of 3
Full-Text Articles in Elementary Particles and Fields and String Theory
Scattering Amplitudes In Flat Space And Anti-De Sitter Space, Savan Kharel
Scattering Amplitudes In Flat Space And Anti-De Sitter Space, Savan Kharel
Doctoral Dissertations
We calculate gauge theory one-loop amplitudes with the aid of the complex shift used in the Britto- Cachazo-Feng-Witten (BCFW) recursion relations of tree amplitudes. We apply the shift to the integrand and show that the contribution from the limit of infinite shift vanishes after integrating over the loop momentum, with a judicious choice of basis for polarization vectors. This enables us to write the one-loop amplitude in terms of on-shell tree and lower-point one-loop amplitudes. Some of the tree amplitudes are forward amplitudes. We show that their potential singularities do not contribute and the BCFW recursion relations can be applied …
Studies Of Angular Correlations Of Jets With The Atlas Detector, Rajivalochan Subramaniam
Studies Of Angular Correlations Of Jets With The Atlas Detector, Rajivalochan Subramaniam
Doctoral Dissertations
The strong force is one of the four fundamental forces and its strength is given by the coupling constant αs. The theory that describes the strong interaction is Quantum Chromodynamics (QCD) and it explains the interactions between quarks and gluons. The strong coupling constant is the only free parameter in the QCD Lagrangian if the quark masses are fixed. Determinations of αs provide direct tests of perturbative QCD calculations. The collimated sprays of particles originating from the quark and gluon interactions are called jets. The ratio of jet cross sections are sensitive to α s and are …
Direct Measurement Of The Pp Solar Neutrino Interaction Rate In Borexino, Keith Otis
Direct Measurement Of The Pp Solar Neutrino Interaction Rate In Borexino, Keith Otis
Doctoral Dissertations
This dissertation presents the first direct detection of pp solar neutrinos within Borexino, the underground liquid-scintilator detector located at the Gran Sasso National Labratory(LNGS) in Italy, designed to measure the interaction of neutrinos through neutrino-electron elastic scattering. The rate of scattering in Borexino from the pp solar neutrino spectrum is measured to be 155 +/- 16(stat) +/- 13(sys) counts per day per 100 tonnes. With this measurement we are able to rule out the no oscillation hypothesis at the 2-sigma C.L. and the results agree with Standard Solar Model predictions within 1.1-sigma. These neutrinos are from the keystone proton-proton fusion …