Are you an EPFL student looking for a semester project?
Work with us on data science and visualisation projects, and deploy your project as an app on top of Graph Search.
Concept
Top quark
Summary
The top quark, sometimes also referred to as the truth quark, (symbol: t) is the most massive of all observed elementary particles. It derives its mass from its coupling to the Higgs Boson. This coupling is very close to unity; in the Standard Model of particle physics, it is the largest (strongest) coupling at the scale of the weak interactions and above. The top quark was discovered in 1995 by the CDF and DØ experiments at Fermilab.
Like all other quarks, the top quark is a fermion with spin 1 /2 and participates in all four fundamental interactions: gravitation, electromagnetism, weak interactions, and strong interactions. It has an electric charge of + 2 /3 e. It has a mass of 172.76GeV/c2, which is close to the rhenium atom mass. The antiparticle of the top quark is the top antiquark (symbol: , sometimes called antitop quark or simply antitop), which differs from it only in that some of its properties have equal magnitude but opposite sign.
The top quark interacts with gluons of the strong interaction and is typically produced in hadron colliders via this interaction. However, once produced, the top (or antitop) can decay only through the weak force. It decays to a W boson and either a bottom quark (most frequently), a strange quark, or, on the rarest of occasions, a down quark.
The Standard Model determines the top quark's mean lifetime to be roughly 5e-25s. This is about a twentieth of the timescale for strong interactions, and therefore it does not form hadrons, giving physicists a unique opportunity to study a "bare" quark (all other quarks hadronize, meaning that they combine with other quarks to form hadrons and can only be observed as such).
Because the top quark is so massive, its properties allowed indirect determination of the mass of the Higgs boson (see below). As such, the top quark's properties are extensively studied as a means to discriminate between competing theories of new physics beyond the Standard Model. The top quark is the only quark that has been directly observed due to its decay time being shorter than the hadronization time.
Official source
About this result
This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.
Ontological neighbourhood
Related courses (13)
PHYS-741: Gauge Theories and the Standard Model
The goal of this course is to explain the conceptual and mathematical bases of the Standard Model of fundamental interactions and to illustrate in detail its phenomenological consequences.
PHYS-416: Particle physics II
Presentation of the electroweak and strong interaction theories that constitute the Standard Model of particle physics. The course also discusses the new theories proposed to solve the problems of the
PHYS-415: Particle physics I
Presentation of particle properties, their symmetries and interactions.
Introduction to quantum electrodynamics and to the Feynman rules.
Related lectures (40)
Probability and Statistics for Physics
Introduces probability and statistics concepts in physics, exploring the Standard Model and practical applications.
Overview of Particle Physics and Rutherford Scattering
Covers the constituents of matter, fundamental forces, the Standard Model, natural units, and particle interaction experiments.
Probability and Statistics
Introduces key concepts in probability and statistics, covering event likelihood, data analysis, and particle detection.
Related publications (479)
Related people (236)
Related units (33)
Related concepts (26)
Higgs boson
The Higgs boson, sometimes called the Higgs particle, is an elementary particle in the Standard Model of particle physics produced by the quantum excitation of the Higgs field, one of the fields in particle physics theory. In the Standard Model, the Higgs particle is a massive scalar boson with zero spin, even (positive) parity, no electric charge, and no colour charge that couples to (interacts with) mass. It is also very unstable, decaying into other particles almost immediately upon generation.
Large Hadron Collider
The Large Hadron Collider (LHC) is the world's largest and highest-energy particle collider. It was built by the European Organization for Nuclear Research (CERN) between 1998 and 2008 in collaboration with over 10,000 scientists and hundreds of universities and laboratories, as well as more than 100 countries. It lies in a tunnel in circumference and as deep as beneath the France–Switzerland border near Geneva. The first collisions were achieved in 2010 at an energy of 3.
Flavour (particle physics)
In particle physics, flavour or flavor refers to the species of an elementary particle. The Standard Model counts six flavours of quarks and six flavours of leptons. They are conventionally parameterized with flavour quantum numbers that are assigned to all subatomic particles. They can also be described by some of the family symmetries proposed for the quark-lepton generations. In classical mechanics, a force acting on a point-like particle can only alter the particle's dynamical state, i.e.
Related MOOCs (8)
Global Arctic
The Global Arctic MOOC introduces you the dynamics between global changes and changes in the Arctic. This course aims to highlight the effects of climate change in the Polar region. In turn, it will u
Smart Cities, Management of Smart Urban Infrastructures
Learn about the principles of management of urban infrastructures in the era of Smart Cities. The introduction of Smart urban technologies into legacy infrastructures has already resulted and will con
Smart Cities, Management of Smart Urban Infrastructures
Learn about the principles of management of urban infrastructures in the era of Smart Cities. The introduction of Smart urban technologies into legacy infrastructures has already resulted and will con