Search results for "Subatomic particle"
showing 6 items of 6 documents
Precision studies in traps: Measurement of fundamental constants and tests of fundamental theories
2003
Experiments on single atomic particles confined in Penning ion traps have contributed significantly to the improvements of fundamental constants and to tests of the theory of Quantum Electrodynamics for free and bound electrons. The most precise value of the fine structure constant as well as the electron mass have been derived from trap experiments. Numerous atomic masses of interest for fundamental questions have been determined with precisions of 10 � 9 or below. Further progress is envisaged in the near future.
From subatomic to immense: About the possible influence of the Theory of Relativity and Quantum Mechanics in the fantastic
2015
The fantastic is based on three pillars: reality, the impossible and fear. Theoretical physics is a branch of science that has deeply studied reality, from the subatomic world to the immensity of outer space. In this article, we want to study how the Theory of Relativity and the Quantum Mechanics have influenced the configuration of the fantastic, and in addition, we want to verify if these branches of physics are capable of explaining certain fantastic phenomena.
Modeling epitaxial film growth of C$_{60}$ revisited
2020
Epitaxial films evolve on time and length scales that are inaccessible to atomistic computer simulation methods like molecular dynamics (MD). To numerically predict properties for such systems, a common strategy is to employ kinetic Monte Carlo simulations, for which one needs to know the transition rates of the involved elementary steps. The main challenge is thus to formulate a consistent model for the set of transition rates and to determine its parameters. Here, we revisit a well-studied model system, the epitaxial film growth of the fullerene ${\mathrm{C}}_{60}$ on an ordered ${\mathrm{C}}_{60}$ substrate (111). We implement a systematic multiscale approach in which we determine transi…
Quantum Mechanics of Point Particles
2013
In developing quantum mechanics of pointlike particles one is faced with a curious, almost paradoxical situation: One seeks a more general theory which takes proper account of Planck’s quantum of action \(h\) and which encompasses classical mechanics, in the limit \(h\rightarrow 0\), but for which initially one has no more than the formal framework of canonical mechanics. This is to say, slightly exaggerating, that one tries to guess a theory for the hydrogen atom and for scattering of electrons by extrapolation from the laws of celestial mechanics. That this adventure eventually is successful rests on both phenomenological and on theoretical grounds.
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…
Asymmetric balance in symmetry breaking
2020
Spontaneous symmetry breaking is central to our understanding of physics and explains many natural phenomena, from cosmic scales to subatomic particles. Its use for applications requires devices with a high level of symmetry, but engineered systems are always imperfect. Surprisingly, the impact of such imperfections has barely been studied, and restricted to a single asymmetry. Here, we experimentally study spontaneous symmetry breaking with two controllable asymmetries. We remarkably find that features typical of spontaneous symmetry breaking, while destroyed by one asymmetry, can be restored by introducing a second asymmetry. In essence, asymmetries are found to balance each other. Our st…