# What happens when we constantly observe a neutron?

The mechanism which we think neutrons decay is by the weak force. The interaction between the quarks of a neutron cause one of them to change their flavor to "up". Thus the neutron decays into a proton, an electron and an electron neutrino. And it is known that the boson of the weak force, the W boson acts against the law of conservation of energy(thats why we can not see it). So suppose that we observe the neutron all the time, constantly sending photons. Would it decay or not?

• Note that any neutron interacting with photons will behave the same way. There's nothing special about humans "observing" it. – Asher May 27 '17 at 16:12
• The problem is related with the W boson and it acting against the law of conservation of energy. That is why we can not observe it. – user147133 May 27 '17 at 16:13
• This question seems to be constructed on a jumble of pop-sci understandings that don't quite hit the mark. Presumably the question in the title is related to the quantum Zeno effect, and the bit in the body seems to assume that there is a relationship between that and the "borrowing energy" explanation of how vacuum fluctuations work. Maybe. Perhaps you could clarify. – dmckee May 27 '17 at 17:01
• this is interesting , which shows the degree of control needed news.cornell.edu/stories/2015/10/… .Neutrons are very hard to manipulate experimentally. – anna v May 27 '17 at 17:15

In this interaction, the pion field is constantly "checking" whether the neutron has turned into a proton or not, and the neutron lifetime is dramatically different inside of a nucleus than outside. That's not a great example of the quantum Zeno effect, however, because there are nuclei whose lifetime against $\beta^-$ decay is shorter than the free neutron lifetime, as well as nuclei which are $\beta^+$-unstable even though free protons do not decay.