Strong CP problem
label: 強いCP問題 @ja
subject: Category:Particle physics
subject: Category:Unsolved problems in physics
hypernym: Question
description: the observation that the θ angle in quantum chromodynamics that would violate CP symmetry seems fine-tuned to 0
description: la cuestión de por qué la cromodinámica cuántica no parece romper la simetría CP @es
label: Problema CP fort @ca
label: Problema CP fuerte @es
label: Problema della CP forte @it