Search results for "theoretical physics"
showing 10 items of 751 documents
Electromagnetic Processes and Interactions
2011
The electron, the muon, and their neutrinos are important tools in testing the structure of the fundamental electromagnetic and weak interactions. On the other hand, if these interactions are known, they serve as ideal probes for the internal structure of complex hadronic targets such as nucleons and nuclei. Although electroweak interactions should in fact be discussed as a whole and on the same footing, purely electromagnetic interactions play a distinctive role, for obvious experimental reasons: At low and intermediate energies the effective electromagnetic coupling is larger by many orders of magnitude than the weak couplings, so that electromagnetic processes are measurable to much high…
The Nonlinear σ Model
1989
The nonlinear (principal) σ model has been for a long time a theoretical laboratory to test different approaches for quantizing classical field theories. Here we shall discuss as an application of the current algebra representation theory a construction of the quantized σ model.
Electroweak penguins in isospin-violating Bs decays
2011
¯Bs ! φ π 0 and ¯ Bs ! φ ρ 0 , which are dominated by EW penguins. Our results extend the analysis in [1] and have recently been published in [2]. Here we give a brief overview of the outcome. We show that in presence of a new EW penguin amplitude the two Bs branching ratios can be enhanced by an order of magnitude without violating any constraints from other hadronic B decays. This makes them very interesting modes for LHCb and Super B factories. We perform both a model-independent analysis and a study within realistic New Physics (NP) models such as a modified- Z 0 -penguin scenario, a model with an additional Z 0 boson and the MSSM, including a fit to B ! πK data and the relevant experim…
Chiral Perturbation Theory
1995
47 páginas, 4 figuras, 4 tablas.-- arXiv:hep-ph/9502366v1
Basic Physical Concepts
2010
Mossbauer spectroscopy is based on recoilless emission and resonant absorption of γ-radiation by atomic nuclei. The aim of this chapter is to familiarize the reader with the concepts of nuclear γ-resonance and the Mossbauer effect, before we describe the experiments and relevant electric and magnetic hyperfine interactions in Chaps. 3 and 4. We prefer doing this by collecting formulae without deriving them; comprehensive and instructive descriptions have already been given at length in a number of introductory books ([7–39] in Chap. 1). Readers who are primarily interested in understanding their Mossbauer spectra without too much physical ballast may skip this chapter at first reading and p…
A Graph-Theoretical Approach to Calculate Vibrational Energies of Atomic and Subatomic Systems
2012
One of the challenges still pending in string theory and other particle physics related fields is the accurate prediction of the masses of the elementary particles defined in the standard model. In this paper an original algorithm to assign graphs to each of these particles is proposed. Based on this mapping, we demonstrate that certain indices associated with the topology of the graph (graph theoretical indices) are very effective in predicting the masses of the particles. Specifically, the spectral moments of the graph adjacency matrix weighted by edge degrees play a key role in the excellent correlations found. Moreover, the same topological pattern is found in other well known quantum s…
η and η′ transition form factors from Padé approximants
2014
We employ a systematic and model-independent method to extract, from space- and time-like data, the η and η′ transition form factors (TFFs) obtaining the most precise determination for their low-energy parameters and discuss the Γη→γγ impact on them. Using TFF data alone, we also extract the η − η′ mixing parameters, which are compatible to those obtained from more sophisticated and input-demanding procedures.
QUANTUM MODELING OF LOVE AFFAIRS
2010
We adopt the so-called number representation, originally used in quantum me- chanics and recently considered in the description of stock markets, in the analysis of the dynamics of love relation. We present a simple model, involv- ing two actors (Alice and Bob), and we consider either a linear model or a nonlinear model.
A critical analysis of the advanced generalized theory: Applicability and applications
2006
Abstract A recent series of theoretical works (“advanced generalized theory”) has been proposed and applied to the analysis of hydrogen lines, particularly H α in plasmas. The “advanced generalized theory” (AGT) [JQSRT 1994;51:129, Phys Rev E 1999;60:R2480, JQSRT 2000; 65:405] is critically examined, both theoretically and in applications to the analysis of experimental data. A number of serious flaws are exposed and discussed. The major flaws include using an inconsistent perturbation theory and erroneous Weisskopf radius-type arguments to access dynamic behavior. Further, the results derived from calculations using the theory are in disagreement with both exact analytic results and benchm…
Quantum gases in optical lattices
2004
IMAGINE having an artificial substance in which you can control almost all aspects of the underlying periodic structure and the interactions between the atoms that make up this dream material. Such a substance would allow us to explore a whole range of fundamental phenomena that are extremely difficult – or impossible – to study in real materials. It may sound too good to be true, but over the last two years physicists have come extremely close to achieving this goal.