Lecture

The Higgs Mechanism

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In course

PHYS-416: Particle physics II

This course aims to make students familiar and comfortable with the main concepts of particle physics, providing a clear connection between the theory and relevant experimental results, including the most recent ones from modern particle physics experiment ...

Description

This lecture delves into the formal aspects of the Higgs mechanism, explaining the origin of the Higgs bosons' properties. It covers the appearance of mass terms for scalar and gauge fields, the full Higgs mechanism by breaking local gauge symmetry, and the symmetry breaking for a complex scalar field. The lecture also explores interacting scalar fields, the vacuum state, and the interactions of scalar particles. It concludes with an overview of the standard model Higgs boson, discussing the extension to local gauge symmetry, the masses of gauge bosons, and the interactions of the Higgs boson with gauge bosons.

Instructor

Lesya Shchutska

Current Work Our research is focused on testing the boundaries of the Standard Model of particle physics and on looking for new phenomena which might explain unanswered puzzles in the fundamental description of the Universe. The examples of such puzzles would be dark matter nature, matter-antimatter asymmetry of the Universe or very small but non-zero neutrino masses.The main instrument for these tasks is the LHCb detector at CERN, where the analyses of the data collected in the LHC proton-proton collisions

Official source

Ontological neighbourhood

Physics

Quantum field theory: Topics in quantum field theory

Particle physics: Standard Model

Related concepts (32)

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.

Spontaneous symmetry breaking

Spontaneous symmetry breaking is a spontaneous process of symmetry breaking, by which a physical system in a symmetric state spontaneously ends up in an asymmetric state. In particular, it can describe systems where the equations of motion or the Lagrangian obey symmetries, but the lowest-energy vacuum solutions do not exhibit that same symmetry. When the system goes to one of those vacuum solutions, the symmetry is broken for perturbations around that vacuum even though the entire Lagrangian retains that symmetry.

Symmetry breaking

In physics, symmetry breaking is a phenomenon where a disordered but symmetric state collapses into an ordered, but less symmetric state. This collapse is often one of many possible bifurcations that a particle can take as it approaches a lower energy state. Due to the many possibilities, an observer may assume the result of the collapse to be arbitrary. This phenomenon is fundamental to quantum field theory (QFT), and further, contemporary understandings of physics.

Gauge boson

In particle physics, a gauge boson is a bosonic elementary particle that acts as the force carrier for elementary fermions. Elementary particles, whose interactions are described by a gauge theory, interact with each other by the exchange of gauge bosons, usually as virtual particles. Photons, W and Z bosons, and gluons are gauge bosons. All known gauge bosons have a spin of 1; for comparison, the Higgs boson has spin zero and the hypothetical graviton has a spin of 2. Therefore, all known gauge bosons are vector bosons.

Higgs mechanism

In the Standard Model of particle physics, the Higgs mechanism is essential to explain the generation mechanism of the property "mass" for gauge bosons. Without the Higgs mechanism, all bosons (one of the two classes of particles, the other being fermions) would be considered massless, but measurements show that the W+, W−, and Z0 bosons actually have relatively large masses of around 80 GeV/c2. The Higgs field resolves this conundrum. The simplest description of the mechanism adds a quantum field (the Higgs field) which permeates all of space to the Standard Model.

Related lectures (64)

The Higgs Mechanism: Formal Aspects

Covers the formal aspects of the Higgs mechanism, explaining mass terms for scalar and gauge bosons through symmetry breaking.

The Higgs Mechanism: Unveiling Mass Generation

Explores the Higgs mechanism, solving the issue of massless gauge bosons and predicting masses of gauge bosons.

Overview of Particle Physics and Rutherford Scattering

Covers the constituents of matter, fundamental forces, the Standard Model, natural units, and particle interaction experiments.

Higgs boson; Dark matter

Explores the properties of the Higgs boson and the concept of dark matter, including detection strategies and challenges.

Gauge Theories And Modern Particle Physics