Physical Sciences and Mathematics Commons^™

Early Universe Cosmology As A Probe Of Fundamental Physics, Ogan Ozsoy

Dissertations - ALL

Cosmology, together with cosmological and astrophysical observations of ever increasing precision, represents a unique opportunity to study physics at energies far beyond the reach of terrestrial laboratories. In particular, observations of the cosmic microwave background radiation supports the idea for an early phase of accelerated expansion called inflation. While the simplest inflationary models provide a consistent theoretical framework in explaining observational data, we are yet to understand the microscopic

details of the inflationary dynamics, the process of how the inflation ends and how the evolution in the post-inflationary era proceeds. In this dissertation, we will explore observational consequences of well-motivated …

Measurement Of The Cp Violating Asymmetry A^S_Sl Using Bs0->(Ds->Phi Pi) Mu Nu, Alessandra Borgia

Dissertations - ALL

The time-integrated measurement of the semileptonic CP violating asymmetry, as_sl, with data acquired at the Large Hadron Collider with the LHCb experiment is presented. This measurement can help physicists understand some peculiarities in the Standard Model, which is the fundamental framework of knowledge of the universe. Should this asymmetry diverge from zero, new physics may be a main motivator. Using 1 fb-1 of collected data in 2011 with proton-proton collisions at a center-of-mass energy of 7 TeV, the measured value of as_sl presented is (-0.06 ± 0.50 ± 0.36)%, where the first uncertainty is statistical and the …

Covariant Quantum Fields On Noncommutative Spacetimes, A. P. Balachandran, A. Ibort, G. Marmo, M. Martone

Physics - All Scholarship

A spinless covariant field $\phi$ on Minkowski spacetime $\M^{d+1}$ obeys the relation $U(a,\Lambda)\phi(x)U(a,\Lambda)^{-1}=\phi(\Lambda x+a)$ where $(a,\Lambda)$ is an element of the Poincar\'e group $\Pg$ and $U:(a,\Lambda)\to U(a,\Lambda)$ is its unitary representation on quantum vector states. It expresses the fact that Poincar\'e transformations are being unitary implemented. It has a classical analogy where field covariance shows that Poincar\'e transformations are canonically implemented. Covariance is self-reproducing: products of covariant fields are covariant. We recall these properties and use them to formulate the notion of covariant quantum fields on noncommutative spacetimes. In this way all our earlier results on dressing, statistics, etc. for …

Quantum Geons And Noncommutative Spacetimes, A. P. Balachandran, A. Ibort, G. Marmo, M. Martone

Physics - All Scholarship

Physical considerations strongly indicate that spacetime at Planck scales is noncommutative. A popular model for such a spacetime is the Moyal plane. The Poincare group algebra acts on it with a Drinfel'd-twisted coproduct. But the latter is not appropriate for more complicated spacetimes such as those containing the Friedman-Sorkin (topological) geons. They have rich diffeomorphism groups and in particular mapping class groups, so that the statistics groups for N identical geons is strikingly different from the permutation group SN. We generalise the Drinfel'd twist to (essentially) generic groups including to finite and discrete ones and use it to modify the …

S-Waves And The Extraction Of Beta_S, Sheldon Stone

Physics - All Scholarship

The CP Violating asymmetry in Bs mixing (beta_s) is one of the most promising measurements where physics beyond the Standard Model could be revealed. As such, analyses need to be subjected to great scrutiny. The mode Bs -> J/psi\phi has been used, and the mode Bs -> \phi \phi proposed for future measurements. These modes both have two vector particles in the final state and thus angular analyses must be used to disentangle the contributions from CP+ and CP- configurations. The angular distributions, however, could be distorted by the presence of S-waves masquerading as low mass K+K- pairs, that could …

Nonperturbative Results For Yang-Mills Theories, Francesco Sannino, Joseph Schechter

Physics - All Scholarship

Some non perturbative aspects of the pure SU(3) Yang-Mills theory are investigated assuming a specific form of the beta function, based on a recent modification by Ryttov and Sannino of the known one for supersymmetric gauge theories. The characteristic feature is a pole at a particular value of the coupling constant, g. First it is noted, using dimensional analysis, that physical quantities behave smoothly as one travels from one side of the pole to the other. Then it is argued that the form of the integrated beta function g(m), where m is the mass scale, determines the mass gap of …

Supersymmetric Lattices - A Brief Introduction, Simon Catterall

Physics - All Scholarship

Recently, new theoretical ideas have allowed the construction of lattice actions which are explicitly invariant under one or more supersymmetries. These theories are local and free of doublers and in the case of Yang-Mills theories also possess exact gauge invariance. In this talk these ideas are reviewed with particular emphasis being placed on ${\cal N}=4$ super Yang-Mills theory.