down quark

Thân thiện

A scientist points to a diagram of a down quark in a physics textbook.

Definition

1. Noun:
   • A stable quark with an electric charge of -1/3 and a mass 607 times that of an electron: A "down quark" is a fundamental particle, a type of quark, and a basic constituent of matter. It is one of the six flavors of quarks in the Standard Model of particle physics.

Usage

• The "down quark" is a first-generation quark, along with the up quark.
• It is a component of protons and neutrons. For example, a proton contains two up quarks and one down quark.
• It is classified as a fermion and experiences all four fundamental forces: strong, weak, electromagnetic, and gravitational.

Examples

• Noun:
  • The neutron is composed of one up quark and two down quarks.
  • The down quark has a negative fractional electric charge.
  • In particle accelerators, scientists study the properties of the down quark.

Advanced Usage

• "Down quark content": Refers to the number or contribution of down quarks within a composite particle.
  • The down quark content of a neutron determines its overall charge.
• "Down quark sea": In quantum chromodynamics, this refers to the virtual down quarks and antiquarks that contribute to the internal structure of a hadron.
  • The proton's properties are influenced by its internal down quark sea.

Variants and Related Words

• Quark (n): A fundamental particle and a basic building block of matter.
  • There are six types, or "flavors," of quarks.
• Up quark (n): The other first-generation quark, with a charge of +2/3.
  • The up quark is the lightest of all quarks.
• Strange quark (n): A second-generation quark with a charge of -1/3, heavier than the down quark.
• Hadron (n): A composite particle made of quarks held together by the strong force (e.g., protons, neutrons).
• Baryon (n): A type of hadron made of three quarks (e.g., protons, neutrons).

Synonyms

• d quark: A common abbreviated form used in physics literature.
  • The symbol for the down quark is 'd'.

Related Terms and Concepts

• Standard Model: The theoretical framework describing the fundamental particles and forces (except gravity).
  • The down quark is an essential component of the Standard Model.
• Strong interaction / Strong force: The fundamental force that binds quarks together inside protons and neutrons.
  • Down quarks are bound by the strong force.
• Electric charge: A fundamental property of particles; the down quark has a charge of -1/3 of the elementary charge.
• Mass: A measure of inertia; the down quark's mass is approximately 4.8 MeV/c², which is about 607 times the mass of an electron.

Học thuật

Noun

1. a stable quark with an electric charge of -1/3 and a mass 607 times that of an electron