Final answer:
Particles being considered in exercises 61-64 are likely subatomic particles in the field of particle physics, which studies the substructures of atoms and nuclei.
Step-by-step explanation:
In exercises 61-64, the particle being considered is most likely a subatomic particle in the field of particle physics. Particle physics deals with the substructures of atoms and nuclei and focuses on finding fundamental particles that have no further substructure. It studies particles like fermions (e.g., electrons, protons, and neutrons) and bosons (e.g., photons) and their interactions. The study of particles in exercises 61-64 may involve classifying them by spin or understanding their characteristics and substructures.