54890
This particle was discovered in 1932 by Carl Anderson , who proposed calling standard electrons " negatons " and using " electron " as a generic term to describe both the positively and negatively charged variants .
 Carl Anderson
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 Carl Anderson