In Addition to Charge and Baryon Number, Another Conserved Quantity

question 50

Multiple Choice

In addition to charge and baryon number, another conserved quantity in particle interactions is lepton number. The six leptons have lepton number +1, and their antiparticles have lepton number −1. The lepton numbers for each generation (electron, muon, tau) are separately conserved. For example, an electron has electron-lepton number +1, while the electron antineutrino has electron-lepton number −1. What is the missing particle X in the following decay? π⁺ → X + ν_μ

• A) μ⁻
• B) μ⁰
• C) π⁻
• D) π⁰
• E) μ⁺

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Definitions:

Repression

A defense mechanism whereby the ego prevents unacceptable impulses from reaching consciousness.

Critical Incident Stress Debriefing

A process aimed at preventing post-traumatic stress disorder among individuals exposed to traumatic events, involving immediate emotional support and psychological counseling.

Stress Management

Techniques and strategies aimed at controlling a person's levels of stress, for the purpose of improving everyday functioning.

Exposure Treatment

A therapeutic technique used to treat anxiety disorders by gradually exposing patients to their feared objects or situations in a controlled way to reduce fear.