According to our current understanding of quantum mechanics, the spin of a particle is an intrinsic property that is conserved. Once a particle is generated with a certain spin, its spin will generally remain unchanged over time. However, there are a few important points to consider:
Conservation of spin: In the absence of any external influences, the total spin of an isolated system is conserved. This means that the sum of the individual spins of the particles within the system remains constant. However, individual particle spins can change through interactions with other particles or fields.
Measurement and superposition: The spin of a particle is described by quantum superposition until it is measured or interacts with its environment. When a measurement is made, the spin state "collapses" into one of the possible outcomes, and subsequent measurements will yield the same spin value. So, once the spin is measured, it remains the same until another measurement is performed.
External influences: External fields or interactions can affect the spin of a particle. For example, in the presence of a magnetic field, the spin of a charged particle can precess or change its orientation. These external influences can modify the spin of a particle over time.
In summary, while the spin of a particle is generally conserved, it can be influenced by interactions with other particles, measurements, or external fields. It is crucial to consider the specific conditions and context in which the particle is being studied to determine if and how its spin might change.