Related Experiment Video
Updated: May 1, 2026
10:42
Infrared Degenerate Four-wave Mixing with Upconversion Detection for Quantitative Gas Sensing
Published on: March 22, 2019
8.0K
Two-color gauge theory with novel infrared behavior
T Appelquist1, R C Brower2, M I Buchoff3
1Department of Physics, Sloane Laboratory, Yale University, New Haven, Connecticut 06520, USA.
Physical Review Letters
|April 8, 2014
Summary
This study of SU(2) gauge theory found no evidence for an infrared fixed point. The theory may exhibit novel behavior through a strong fixed point or chiral symmetry breaking with many Nambu-Goldstone bosons.
Area of Science:
- High Energy Physics
- Quantum Field Theory
- Lattice Gauge Theory
Background:
- SU(2) gauge theory with six massless Dirac fermions is a key model for studying fundamental interactions.
- Understanding the infrared (long-distance) behavior of quantum field theories is crucial for describing phenomena like confinement and chiral symmetry breaking.
Purpose of the Study:
- Investigate the infrared dynamics of SU(2) gauge theory with six massless fermions.
- Determine if the theory possesses an infrared fixed point using nonperturbative methods.
Main Methods:
- Utilized lattice simulations to model the quantum field theory.
- Computed the running gauge coupling via the nonperturbative Schrödinger functional method.
Main Results:
- No evidence for an infrared fixed point was found for gauge couplings up to g(2) ~ 20.
- The results suggest either a very strong, currently unobserved fixed point or chiral symmetry breaking.
Conclusions:
- The SU(2) gauge theory with six massless fermions exhibits novel infrared behavior.
- Possible scenarios include a strong infrared fixed point or chiral symmetry breaking leading to numerous Nambu-Goldstone bosons.
Related Concept Videos
01:09Infrared (IR) Spectroscopy: Overview
6.8K
When electromagnetic radiation passes through a material, atoms or molecules transition from a lower to a higher energy state by absorbing radiation corresponding to the energy difference between the two states. The absorption of infrared (IR) radiation causes transitions between vibrational energy levels in a molecule. Therefore, IR spectroscopy is a useful analytical tool for determining the molecular structure of molecules.
Different compounds display unique properties due to their...
Different compounds display unique properties due to their...
6.8K
01:04IR Absorption Frequency: Delocalization
1.7K
Electron delocalization refers to the distribution of electrons across multiple atoms within a molecule rather than being confined to a single atom or bond. This phenomenon is common in systems with conjugated bonds—structures where alternating single and double bonds allow π-electrons to move freely across the network. The movement of electrons stabilizes the molecule and can affect various chemical properties, including vibrational frequencies observed in IR spectroscopy.
In IR...
In IR...
1.7K
01:17Theory of Metallic Conduction
2.0K
The conduction of free electrons inside a conductor is best described by quantum mechanics. However, a classical model makes predictions close to the results of quantum mechanics. It is called the theory of metallic conduction.
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...
2.0K
01:21IR Absorption Frequency: Hybridization
1.5K
Hydrocarbons such as alkanes, alkenes, and alkynes show characteristic C–H stretching absorption bands. These IR stretching frequencies depend on the hybridization of the involved carbon atom and can be explained in terms of the s character of each hybridized atomic orbital.
Among the sp, sp2, and sp3 hybridized orbitals, sp orbitals have the maximum s character (50%). Consequently, the electrons are held more closely to the nucleus, resulting in stronger and shorter C–H bonds that...
Among the sp, sp2, and sp3 hybridized orbitals, sp orbitals have the maximum s character (50%). Consequently, the electrons are held more closely to the nucleus, resulting in stronger and shorter C–H bonds that...
1.5K
01:24IR Spectroscopy: Molecular Vibration Overview
5.8K
When Infrared (IR) radiation passes through a covalently bonded molecule, the bonds transition from lower to higher vibrational levels. The fundamental vibrational motions that result in infrared absorption can be classified as stretching or bending vibrations.
Stretching vibrations are vibrational motions that occur along the bond line, changing the bond length or distance between two bonded atoms. They are further distinguished as symmetric or asymmetric. In symmetric stretching, the...
Stretching vibrations are vibrational motions that occur along the bond line, changing the bond length or distance between two bonded atoms. They are further distinguished as symmetric or asymmetric. In symmetric stretching, the...
5.8K
01:28Debye–Huckel–Onsager Conductance Equation
291
The Debye-Hückel-Onsager equation is a cornerstone of physical chemistry, providing a method to determine the molar conductance (Λm) and molar conductance at infinite dilution (Λ°m) for uni-univalent electrolytes.Uni-univalent electrolytes are electrolytes that dissociate in solution to produce one cation with a +1 charge and one anion with a –1 charge per formula unit.This equation addresses two crucial phenomena: the asymmetry effect and the electrophoretic effect.
291