In quantum mechanics, mass is not generally considered an emergent property resulting from the confinement of energy. In both classical physics and quantum mechanics, mass is treated as an intrinsic property of particles. It is a fundamental quantity that characterizes the inertia of an object and its response to applied forces.
In classical physics, mass is considered a fundamental property, independent of energy confinement. The classical understanding of mass arises from observations and experiments that led to the formulation of Newton's laws of motion. Mass is a fundamental parameter in these laws, and it is not tied to the confinement of energy or any other emergent phenomena.
Quantum mechanics, on the other hand, describes the behavior of particles on a microscopic scale and introduces new principles and phenomena that are not present in classical physics. In quantum field theory, which is the framework that combines quantum mechanics with special relativity, particles and their properties, including mass, are described in terms of fields and their excitations called particles. The mass of a particle in quantum field theory is considered an intrinsic property, which is not solely a result of energy confinement.
While there are some concepts in physics where emergent properties arise from the collective behavior of many particles or interactions, such as in condensed matter physics, the notion that mass in quantum mechanics is an emergent property resulting from the confinement of energy is not a widely accepted interpretation. It is important to note that our understanding of quantum mechanics and its relationship with classical physics is an ongoing area of research, and different interpretations exist.