According to our current understanding of particle physics, protons are considered stable particles, meaning they do not decay into other particles, including neutrons. The proton is the lightest and most stable baryon (a type of particle composed of three quarks) and is not known to decay under normal circumstances.
However, it is important to note that there are theories beyond the Standard Model, such as Grand Unified Theories (GUTs) and some extensions of the Standard Model, that predict proton decay. In these theories, protons can potentially decay into other particles, including combinations of neutrons, positrons, mesons, and other particles.
For example, in certain GUT models, protons can decay via a process called baryon number violation. One such hypothetical decay mode is the decay of a proton into a positron (an antielectron) and a neutral pion, which would subsequently decay into two neutrons.
It's crucial to emphasize that these theories predicting proton decay are still speculative and have not been experimentally confirmed. To date, no experimental evidence of proton decay has been observed, despite extensive searches conducted in underground detectors such as Super-Kamiokande and the Sudbury Neutrino Observatory.
Therefore, while proton decay is an intriguing possibility in certain theoretical frameworks, it remains an open question in particle physics, and further experimental investigations are needed to provide conclusive evidence or constraints on such decay processes.