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Questions tagged [proton-decay]

Proton decay is a hypothetical form of radioactive decay in which the proton decays into lighter subatomic particles. There is currently no experimental evidence that proton decay.

Proton decay is a hypothetical form of radioactive decay in which the proton decays into lighter subatomic particles. There is currently no experimental evidence that proton decay. Experimental physicists search for proton decay as it is one of the few observable effects of the various proposed GUTs models. See the PDG entry for protons and this wikipedia page for more details.

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Dark matter and $SO(10)$ grand unification

$SO(10)$ grand unified theories nicely accommodate a massive $\sim 10^{14-15}\; GeV$ sterile neutrino. Would this be a viable dark matter candidate? I haven't found any specific material regarding this possibility and I was wondering if there is…
Sebby
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Standard Model Proton Decay Rate

The electro-weak force is known to contain a chiral anomaly that breaks $B+L$ conservation. In other words, it allows for the sum of baryons and leptons to change, but still conserves the difference between the two. This means that the standard…
Sean E. Lake
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The life of proton

I have two questions regarding protons 1) Wikipedia says Mean lifetime of a proton $>2.1×10^{29}$ years (stable) Obviously this means practically nothing happens to a proton, but what does this mean lifetime signify ? What does the proton…
Rijul Gupta
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Can proton disintegrate into fundamental particles on its own when its speed approaches that of light?

In the Large Hadron Collider (LHC) the particles move close to the speed of light. The LHC accelerates beams of particles, usually protons, around and around a 17-mile ring until they reach 99.9999991 percent the speed of light. (Source) Mass of…
PG1995
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Why should proton decay into positron rather than antimuon?

Grand unification theories, such as $SU(5)$/$SO(10)$/SUSY variants, suggest proton decay. The lack of observational evidence for proton decay rules out simple GUTs. But wait a minute! The GUT's prediction of proton half-life is based on the…
MadMax
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Spontaneous decay of mass?

Do all masses, small (quantum particles) or large (classical, stars) spontaneously (without an external cause) decay in time sooner or later?
user192263
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Is proton decay considered in neutron star models (and LHC)?

Although it is definitely not simple, there are many reasons to consider that baryon number can be violated, for example: during baryogenesis (just after Big Bang) there was created more matter than antimatter, hypothetical Hawking radiation (black…
Jarek Duda
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Why do gauge bosons/leptoquarks not mediate proton decay in the Pati-Salam model?

In the Pati-Salam $\mathrm{SU}(4)_c\times\mathrm{SU}(2)_L\times\mathrm{SU}(2)_R$ model, I see Wikipedia and some slides mention this model doesn't predict gauge mediated proton decay without giving any reasoning. Why do leptoquarks not mediate…
Curio
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Why is the proton the only stable hadron?

The title pretty much explains the question, but I've always thought that it'd be a neutron because of its 0 charge.
radial9174
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Can colliders detect B violation?

I think there is some theoretical uncertainty whether high-energy collisions can violate B. It is known that at high temperature (higher than the Higgs scale) you violate B by SU(2) instantons. But in a situation where you have a very energetic…
Ron Maimon
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Supressing proton and neutron decay?

I was wondering whether the decay of neutrons and protons (if they happen to be able to decay, as it is predicted by some GUTs) could be avoided in some cases. Let's begin with neutrons: In principle neutrons have a very short time when they are…
vengaq
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What is the half-life of isotopes that decay via electron capture, if they are stripped of their electrons?

If an isotope that undergoes decay via electron capture, like 7Be, loses ONE electron, how will its radioactive half life change? What about 2 electrons? And so on and so forth for heavier elements? How do you calculate the change in half lives…
RadiationPhysicsGirl
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Does the lack of evidence for proton decay really rule out the basic grand unification theories?

Grand unification theories (GUT), such as $SU(5)$/$SO(10)$/SUSY variants, suggest proton decay. The lack of observational evidence for proton decay is supposed to rule out basic GUTs, at least for the basic $SU(5)$ GUT. But does the lack of evidence…
MadMax
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Adjusting the rate of proton decay in the standard $\rm SU(5)$ grand unified theory

The proton decay rate in the standard $SU(5)$ grand unified theory is given by $$ \Gamma \sim \left(\frac{g^2}{M_x^2}\right)^2 m_p^5 =\frac{g^4}{M_x^4}m_p^5 $$ Naively we could push up the bound for the decay rate $\Gamma$ arbitrarily high by…
ann marie cœur
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Can protons and neutrons be completely converted into Leptons?

In beta decay, a neutron releases an electron and turns into a proton. The inverse happens, though usually not naturally, in positron emission, where a proton emits a positron and becomes a neutron. As the electron has mass, approximately 1/1836th…
Mat NX
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