baryon number

Thân thiện

A scientist writes the baryon number on a whiteboard during a lecture.

Definition

1. Noun:
   • A conserved quantum number in particle physics: The baryon number is a fundamental property assigned to particles in subatomic physics. It is defined as the difference between the number of baryons (like protons and neutrons) and the number of antibaryons (like antiprotons and antineutrons) within a given system. This number remains constant in all known types of particle interactions, such as those governed by the strong and electromagnetic forces.

Usage Examples

• Noun:
  • The conservation of baryon number explains why a proton, the lightest baryon, is stable and does not decay.
  • In this reaction, you must check that the total baryon number on the left side equals the total baryon number on the right side.

Advanced Usage

• "Violation of baryon number": A theoretical concept in some grand unified theories or discussions of baryogenesis, where the strict conservation law might not hold under certain extreme conditions.
  • Processes in the early universe may have involved a slight violation of baryon number, leading to the matter-antimatter asymmetry we observe today.

Variants and Related Words

• Baryon (n): A type of subatomic particle, such as a proton or neutron, that is made of three quarks and has a baryon number of +1.
• Antibaryon (n): The antiparticle of a baryon, such as an antiproton, with a baryon number of -1.
• Baryonic (adj): Relating to or consisting of baryons.
  • Most of the mass in galaxies is thought to be baryonic matter.

Synonyms

• Baryonic charge: A less common but technically accurate synonym, emphasizing its role as a conserved quantum number similar to electric charge.

Related Concepts

• Conservation law: A fundamental principle in physics stating that the total value of a specific measurable property (like baryon number, electric charge, or energy) of an isolated system remains constant over time.
• Lepton number: A similar conserved quantum number assigned to leptons (like electrons and neutrinos).

Học thuật

Noun

1. a number equal to the difference between the number of baryons and the number of antibaryons in any subatomic structure; it is conserved in all types of particle interactions