3rd Year Special Projects in 2013

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Particle Theory: Klein "paradox" with an accelerated potential barrier

Supervisor: Dr Archil Kobakhidze
Contact: Dr Archil Kobakhidze
Email: archil.kobakhidze AT coepp.org.au
Phone: (03) 8344 5439

The famous Klein paradox of relativistic quantum mechanics finds a natural resolution within quantum field theory due to particle production from the vacuum by the potential barrier. We will study this phenomenon for the barrier moving with a constant acceleration. Besides the pedagogical significance of gaining an understanding of advanced topics in relativistic quantum mechanics, this investigation will contribute to uncovering previously unaccounted for effects in the dynamics of the electroweak phase transition in relation to the generation of the observed dominance of matter over anti-matter in our Universe.


Here you will find a list of the 3rd year special projects on offer for Semester 2, 2013.

Particle Theory/Cosmology: Quantum-mechanical oscillations in accelerated reference frames

Supervisor: Dr Archil Kobakhidze
Contact: Dr Archil Kobakhidze
Email: archil.kobakhidze AT coepp.org.au
Phone: (03) 8344 5439

Particle oscillations, such as K-anti-K or neutrino oscillations, are important quantum mechanical processes for studying new physical phenomena. In this project we study oscillation phenomenon as seen from non-inertial reference frames. This consideration is relevant, e.g., for studies of neutrino oscillations in cosmological spacetimes or near strongly gravitating objects, such as black holes.


Belle Experiment: Study of the Decay B to rho lepton neutrino at Belle

Supervisors: Dr Alexei Sibidanov and A/Prof. Kevin Varvell
Contact: Dr Alexei Sibidanov
Room: 364
Email: a.sibidanov AT physics.usyd.edu.au
Phone: 9351 2712

The rate of the charmless semileptonic decay of a B meson, via the weak force, to a rho meson, lepton and neutrino allows us to determine a fundamental parameter of the Standard Model of Particle Physics known as |Vub|. The measurement is complicated by the presence of the strong force, which binds quarks together to form the B and rho mesons. Using around 1000 examples of this decay reconstructed with the Belle detector at KEK in Japan, we will test various theoretical models which describe the decay, to see which performs best in taking into account these strong interaction effects.


ATLAS Experiment: How sensitive is our analysis to new physics?

Supervisors: Dr Aldo Saavedra & A/Prof. Kevin Varvell
Contact: Dr Aldo Saavedra
Room: 366
Email: a.saavedra AT physics.usyd.edu.au
Phone: 9351 5970

AIDA (An inclusive Dilepton Analysis) is a tool used to determine the production rate of a number of particle physics processes simultaneously, and to compare them to the predictions of the Standard Model of Particle Physics . In this project we would like to explore the possibility of expanding the capabilities of AIDA so that it becomes a tool of discovery. We will aim to determine the smallest production rate AIDA is sensitive to, and what level of associated uncertainty is tolerable, and hence explore its sensitivity to new physics. A natural starting point will be to see if the analysis is sensitive to processes associated with the Higgs boson.

Currently, AIDA is applied to 7 TeV proton-proton collisions that took place within the ATLAS detector at the Large Hadron Collider, located at the European Particle Physics Laboratory (CERN). The analysis focuses on well known processes produced in the proton-proton collisions such as top quark pairs, di-bosons (WW) and single Z, using decays which include an electron and a muon (dilepton). The advantage of the inclusive AIDA analysis is that limited selections are made on the collision products except for the electron and muon requirements. Any process, with an origin known or unknown, will in principle be amenable to a study of this kind.



Particle Phenomenology: How to choose a Particle Physics model?

Supervisors: Dr Aldo Saavedra
Contact: Dr Aldo Saavedra
Room: 366
Email: a.saavedra AT physics.usyd.edu.au
Phone: 9351 5970

In the last two years the data from the Large Hadron Collider (LHC) has produced a spectacular number of measurements with which to test the Standard Model of Particle Physics, and any upcoming models featuring new physics. In this project we will think about the big picture. We will ask the question: What level of agreement is there between a popular new physics model with the current collider-based measurements and/or astro-particle physics measurements, such as the dark matter density in the universe?

To achieve this aim, we will use a framework developed by a small international collaboration, called GAMBIT which the Sydney Particle Physics group is part of. In this project we will deal with questions such as how sensitive are current experiments to particle physics processes featured in the new physics model, how are particle physics processes generated and simulated in software, and how can we quantify the level of compatibility between experimental measurements and theory.