Search results for "General Physics and Astronomy"
showing 6 items of 6576 documents
Does using a visual-representation tool foster students’ ability to identify forces and construct free-body diagrams?
2013
Earlier research has shown that after physics instruction, many students have difficulties with the force concept, and with constructing free-body diagrams (FBDs). It has been suggested that treating forces as interactions could help students to identify forces as well as to construct the correct FBDs. While there is evidence that identifying interactions helps students in quantitative problem solving, there is no previous research investigating the effect of a visual-representation tool—an interaction diagram (ID)—on students’ ability to identify forces, and to construct the correct FBDs.We present an empirical study conducted in 11 Finnish high schools on students (n ¼ 335, aged 16) takin…
The mechanically based non-local elasticity: an overview of main results and future challenges
2013
The mechanically based non-local elasticity has been used, recently, in wider and wider engineering applications involving small-size devices and/or materials with marked microstructures. The key feature of the model involves the presence of non-local effects as additional body forces acting on material masses and depending on their relative displacements. An overview of the main results of the theory is reported in this paper.
Search for Light Dark Matter Interactions Enhanced by the Migdal Effect or Bremsstrahlung in XENON1T.
2019
Direct dark matter detection experiments based on a liquid xenon target are leading the search for dark matter particles with masses above ∼5 GeV/c2, but have limited sensitivity to lighter masses because of the small momentum transfer in dark matter-nucleus elastic scattering. However, there is an irreducible contribution from inelastic processes accompanying the elastic scattering, which leads to the excitation and ionization of the recoiling atom (the Migdal effect) or the emission of a bremsstrahlung photon. In this Letter, we report on a probe of low-mass dark matter with masses down to about 85 MeV/c2 by looking for electronic recoils induced by the Migdal effect and bremsstrahlung us…
Interplay between the Belousov-Zhabotinsky reaction-diffusion system and biomimetic matrices
2007
Abstract Interactions between reaction–diffusion systems and restricted host environments are a subject of widespread interest. In this work the behaviour of the Belousov–Zhabotinsky reaction was investigated in lamellar phases formed by phospholipid bilayers with relevance for biological systems. The influence of the reactive medium on the structure of the lipid matrix and, in turn, the influence of the matrix on the dynamical evolution of chemical patterns, were studied by small angle scattering.
Search for scalar leptoquarks in pp collisions at $\sqrt{s}$=13 TeV with the ATLAS experiment
2016
An inclusive search for a new-physics signature of lepton-jet resonances has been performed by the ATLAS experiment. Scalar leptoquarks, pair-produced in pp collisions at s √s = 13 TeV at the large hadron collider, have been considered. An integrated luminosity of 3.2 fb-1, corresponding to the full 2015 dataset was used. First (second) generation leptoquarks were sought in events with two electrons (muons) and two or more jets. The observed event yield in each channel is consistent with Standard Model background expectations. The observed (expected) lower limits on the leptoquark mass at 95% confidence level are 1100 and 1050 GeV (1160 and 1040 GeV) for first and second generation leptoqua…
Search for the Decay of the Higgs Boson to Charm Quarks with the ATLAS Experiment
2018
A direct search for the standard model Higgs boson decaying to a pair of charm quarks is presented. Associated production of the Higgs and Z bosons, in the decay mode ZH→ℓ+ℓ−c¯c is studied. A data set with an integrated luminosity of 36.1 fb−1 of pp collisions at √s=13TeV recorded by the ATLAS experiment at the LHC is used. The H→c¯c signature is identified using charm-tagging algorithms. The observed (expected) upper limit on σ(pp→ZH)×B(H→c¯c) is 2.7 (3.9+2.1−1.1) pb at the 95% confidence level for a Higgs boson mass of 125 GeV, while the standard model value is 26 fb.