Jethalal S. Zaveri
Prof. Muni Mahendra Kumar
Subatomic particles do not just sit around being subatomic particles. They are beehives of activity. An electron, for example, is constantly emitting and absorbing photons. These photons, again, are not 'real' photons but now-you-see-it-now-you-don't variety - virtual photons (virtual means being so in effect or essence, although not in actual fact). They are exactly like real photons except that they don't fly off on their own. They are reabsorbed almost as soon as they are emitted by electrons. In other words, first there is an electron, then there is an electron and a photon and then there is an electron again. Lifetime of a virtual photon is 10-15 of a second.
Protons and neutrons, like electrons, interact with themselves in more ways than one. The simplest proton self-interaction is the emission and reabsorption of a virtual neutral pion. In addition, a proton can emit a positive pion and transforms itself into a neutron. So there is a neutron plus a positive pion. Reabsorption of the positive pion transforms the neutron again into a proton. In other words proton continually changes into a neutron and back into a proton again. In a similar manner, neutrons emit and reabsorb neutral pions or negative pions and momentarily transform into protons and back again into neutrons.
Particle self-interaction becomes quite intricate when virtual particles themselves emit virtual particles, which again emit virtual particles in a diminishing sequence. For instance, a negative pion transforms itself into two virtual particles - a neutron and an anti-proton (anti-protons were discovered at Berkeley in 1955). This is the simplest example of self-interaction.
Thus, a proton never remains a simple proton and a neutron never remains a simple neutron. A negative pion never remains a simple negative pion. A proton alternates between being a proton and a neutral pion on the one hand and being a neutron and a positive pion on the other hand. A neutron alternates between being a neutron and a neutral pion on the one hand and being a proton and a negative pion on the other hand. A negative pion alternates between being a neutron and an anti-proton on the one hand and etc. etc. Eleven particles make their transient appearance between the time the original proton transforms itself into a neutron and a pion and the time it becomes a single proton again. (Compare the arthaparyaya of pudgala as per Jain Physics in Section III of Chapter II.)
