Hello The textbooks about nuclear physics I have read don't explain too much about the Yukawa's model. For example, the textbook Structure of the Nucleus -by Preston and Bhaduri- finish the Yukawa's model with open questions about the "mesonic effects" by virtual pions. And my doubt: are the "mesonic effects" in the nucleus measurable? [directly or indirectly] If this question is already answered in this forum, just tell me, and I will delete this thread. Thank you for your time :) Greetings PS: My mother language is not English, so I'll be glad if you correct any mistake.