# strong CP problem

> the observation that the θ angle in quantum chromodynamics that would violate CP symmetry seems fine-tuned to 0

**Wikidata**: [Q7624462](https://www.wikidata.org/wiki/Q7624462)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Strong_CP_problem)  
**Source**: https://4ort.xyz/entity/strong-cp-problem


## References

1. [OpenAlex](https://docs.openalex.org/download-snapshot/snapshot-data-format)