3,563 research outputs found
Matter and Interactions: a particle physics perspective
In classical mechanics matter and fields are completely separated. Matter
interacts with fields. For particle physicists this is not the case. Both
matter and fields are represented by particles. Fundamental interactions are
mediated by particles exchanged between matter particles. In this paper we
explain why particle physicists believe in such a picture, introducing the
technique of Feynman diagrams starting from very basic and popular analogies
with classical mechanics, making the physics of elementary particles
comprehensible even to high school students, the only prerequisite being the
knowledge of the conservation of mechanical energy.Comment: 14 pages, 6 figures, Lecture given to degree students other than
physicists during outreach seminars. Vers. 2 has better figure placement and
an acknowledge section, as well as corrections in the bibliograh
Unveiling the Higgs mechanism to students
In this paper we give the outline of a lecture given to undergraduate
students aiming at understanding why physicists are so much interested in the
Higgs boson. The lecture has been conceived for students not yet familiar with
advanced physics and is suitable for several disciplines, other than physics.
The Higgs mechanism is introduced by semi-classical arguments mimicking the
basic field theory concepts, assuming the validity of a symmetry principle in
the expression of the energy of particles in a classical field. The lecture is
divided in two parts: the first, suitable even to high--school students, shows
how the mass of a particle results as a dynamical effect due to the interaction
between a massless particle and a field (as in the Higgs mechanism). The
audience of the second part, much more technical, consists mainly of teachers
and university students of disciplines other than physics.Comment: mistake corrected in equation (2) and below thanks to Loic Turba
Effectiveness of a laboratory course with Arduino and smartphones
Arduino and Smartphones have been used since 2021 in a class of practicals held at Sapienza Università di Roma, to train physics undergraduates in laboratory activities. This paper briefly describes the organisation of the activities and report about the results of questionnaires administered to participating students before and after the course
A modern, rapid and simple investigation of Ampère’s law
Classical physics results are often taught purely from the theoretical side.
Key results, especially in electromagnetism, are typically not explored
experimentally, and in applications students are then expected to leap straight
into more complex scenarios that make use of these principles in electronics,
sensors and instrumentation. This is unfortunate because not all individuals
are equally able to learn well purely from the mathematical angle, and even
those who do are not exposed to exploring the magnitude of competing
effects, for example isolating a particular magnetic field signal from the
background of the Earth's field. An experiment is presented here to test
Ampère’s law with a setup that can be assembled out of everyday materials
with minimal components - a smartphone, a DC power supply, wires - in a
procedure that can be completed in just a few hours. The data from the three
magnetic field sensors of the phones, together with the gyroscope sensors
providing position, are recorded and numerically integrated. The experiment
is also demonstrated using sensors collected by an Arduino board instead of
a smartphone. The experiment allows to measure the net current carried by
wires inside the closed path over which the magnetic field is integrated, i.e.
Ampere's law. This experimental approach to exploring Ampere's Law can
be adapted towards high school or university demonstrations, depending on
the level of accuracy and detail that one aims to pursue
Magnetic fields produced by electric railways
We propose a simple experiment to explore magnetic fields created by electric
railways and compare them with a simple model and parameters estimated using
easily available information. A pedestrian walking on an overpass above train
tracks registers the components of the magnetic field with the built-in
magnetometer of a smartphone. The experimental results are successfully
compared with a model of the magnetic field of the transmission lines and the
local Earth's magnetic field. This experiment, suitable for a field trip,
involves several abilities, such as modeling the magnetic field of power lines,
looking up reliable information and estimating non-easily accessible
quantities.Comment: 5 pages, 3 figures, some typos correcte
ECAL Front-End Monitoring in the CMS experiment
The CMS detector at LHC is equipped with a high precision lead tungstate crystal electromagnetic calorimeter (ECAL). The front-end boards and the photodetectors are monitored using a network of DCU (Detector Control Unit) chips located on the detector electronics. The DCU data are accessible through token rings controlled by an XDAQ based software component. Relevant parameters are transferred to DCS (Detector Control System) and stored into the Condition DataBase. The operational experience from the ECAL commissioning at the CMS experimental cavern is discussed and summarized
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