0000000000490219
AUTHOR
Nils-erik Bomark
Textbook myths about early atomic models
Most physics textbooks at college and university level introduce quantum physics in a historical context. However, the textbook version of this history does not match the actual history. In this article, the first in a series of articles looking at the textbook description of the quantum history, we follow an exceptional student through her endeavors to understand the early atomic models that led up to the work of Niels Bohr. We experience her disappointment when she discovers that the description of the famous atomic model by Thomson, is a mere caricature with almost no trace of Thomson's work and that the supposedly important radiative instability of Rutherford's atoms, is not there at al…
LHC phenomenology of light pseudoscalars in the NMSSM
After the discovery of the 125 GeV Higgs boson, the Next-to-Minimal Supersymmetric Standard Model (NMSSM) has become more interesting as a model for new physics since new tree-level contributions to the Higgs mass makes it easier to accommodate the relatively high measured value, as compared to the MSSM. One very distinctive feature of the NMSSM is the possible existence of a light singlet-like pseudoscalar. As this pseudoscalar may be lighter than the discovered Higgs boson without conflict with data, it may lead to LHC signatures rather different to what is usually searched for in terms of new physics. In these proceedings we will discuss studies concerning the discoverability of such lig…
How can the nucleus be lighter than its constituents?
Abstract The fact that the nucleus is lighter than its constituents, seems rather strange. How can the whole have a smaller mass than its components? To get some intuition about how this is possible, one can look at a simpler more familiar system exhibiting the same phenomena; the hydrogen atom. It turns out that the same is true here; the hydrogen atom is a little bit lighter than the sum of its constituents. This difference corresponds to the ionisation energy of hydrogen. This observation allows a simple explanation for how this is possible; the destructive interference between the electric fields of the proton and electron causes a reduction in the energy of the electric field and hence…
Modeller i kjemiundervisning - et eksempel på hvordan de kan bidra til læring og feillæring
We discuss the use of analogical models in science education using examples from online learning resources. We have conducted a teaching program for a group of 7th grade pupils and a group of science teacher students, and the main theme of this program is the use of models in chemistry. Specifically, we study the effect of an analogical model that is designed to promote understanding of the properties of molecules, related to a paper chromatography experiment. Our research indicates that analogical models can be a useful tool to convey understanding of abstract concepts and non-visible phenomena, but they hold serious pitfalls that can lead to misunderstandings amongst students if not used…
Review of LHC experimental results on low mass bosons in multi Higgs models
A number of searches at the LHC looking for low mass ($2m_{\mu} - 62\ \mathrm{GeV}$) bosons in $\sqrt{s} = 8\ \mathrm{TeV}$ data have recently been published. We summarise the most pertinent ones, and look at how their limits affect a variety of supersymmetric and non-supersymmetric models which can give rise to such light bosons: the 2HDM (Types I and II), the NMSSM, and the nMSSM.
Detection prospects of light NMSSM Higgs pseudoscalar via cascades of heavier scalars from vector boson fusion and Higgs-strahlung
A detection at the Large Hadron Collider of a light Higgs pseudoscalar would, if interpreted in a supersymmetric framework, be a smoking gun signature of non-minimal supersymmetry. In this work in the framework of the Next-to-Minimal Supersymmetric Standard Model we focus on vector boson fusion and Higgs-strahlung production of heavier scalars that subsequently decay into pairs of light pseudoscalars. We demonstrate that although these channels have in general very limited reach, they are viable for the detection of light pseudoscalars in some parts of parameter space and can serve as an important complementary probe to the dominant gluon-fusion production mode. We also demonstrate that in …
Teaching gauge theory to first year students
One of the biggest revelations of 20th century physics, is virtually unheard of outside the inner circles of particle physics. This is the gauge theory, the foundation for how all physical interactions are described and a guiding principle for almost all work on new physics theories. Is it not our duty as physicists to try and spread this knowledge to a wider audience? Here, two simple gauge theory models are presented that should be understandable without any advanced mathematics or physics and it is demonstrated how they can be used to show how gauge symmetries are used to construct the standard model of particle physics. This is also used to describe the real reason we need the Higgs fie…
Teaching particle physics to high school teachers
In Norway, particle physics is part of the high school curriculum in physics which introduces the need for good university teaching in particle physics without the usual technical approach. Given how much conflicting information and inaccurate explanations there are on the subject; how should we teach this to people without much knowledge in mathematics? By carefully explaining the fundamental consepts of the theory it is fully possible to achieve an appreciation of particle physics without much mathematics. Through the use of analogies, such as an analogy between the freedom in choosing timezone and the freedom in choosing phase angle, one can introduce gauge theory and hence show the unde…