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.

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Proton decay - Kamiokande experiment

The Kamiokande experiments measure proton decay using water, i.e. probing the proton in an H-atom. The electron in the H-atom has a nonzero probability at the proton position. It is well known that ...
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Proton decay formulae

Some recent reviews of proton decay in higher dimensional models derive the estimate $$\tau_{proton}\sim\left(\dfrac{M_P}{M_{proton}}\right)^D\dfrac{1}{M_{proton}}$$ For $D=4$, it yields about $\tau\...
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Stability/decay, are they boolean or not, or does QM probabilities overrule this?

This is not a duplicate, I am not asking whether the proton is a stable particle, or why it is. I am asking about the definition of stability/decay whether it is boolean or not. I have read this ...
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The half-life of carbon-12

Let us denote the half-life of the proton by $Y_p$. (There is, of course, no experimental evidence that $Y_p<\infty$, but there are theories that assert it, so this is really a question about those ...
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Why does the conclusion that protons are monopoles has led us to believe that they specifically may have a half-life? [closed]

from Zeldovich, Ya. B.; Khlopov, M. Yu. (1978). "On the concentration of relic monopoles in the universe": "The majority of particles appearing in any quantum field theory are unstable, and they ...
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Why is a delta resonance decay not a radioactive decay

A delta resonance decays as given in http://hyperphysics.phy-astr.gsu.edu/hbase/Particles/delta.html . I wonder, why is it not a radioactive decay? In principle, most/all decays should be radioactive ...
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Why does a scintillator need to be fast decaying?

I have two scintillators, say, one with a decay time of 1 ns vs. one with 100 ns. All other parameters like light yield, size of crystal, electronics used, source emission rate, are the same for both. ...
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Scintillator decay time=1000 nsec,does that mean dead time is really high?

What I'm really confused about is, say my scintillator is really slow, and has a decay time of about 1000 nsec. Does that mean, if one neutron is being read by the electronics, for that particular ...
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Runaway Monopole Catalyzed Baryon Decay

I am a layman in the subject, but I have recently learned that magnetic monopoles could be used to induce baryon decay (Callan-Rubakov mechanism), according to some GUTs. I have also learned that ...
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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 ...
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What is the status of SUSY GUTs in 2018?

Grand unification theories (GUTs) generically predict proton decay, and many of them have been under pressure for decades as experiments have failed to see it. I don't think there have been recent ...
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SUSY and proton decay

If proton decays are NOT observed and we manage to push the lower bound to its lifetime at about 10³⁶ or 10³⁷ years...Can we prove SUSY is wrong or can we always build SUSY models for any proton ...
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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?
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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.
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Mean life of radioactive substance

While I was reading up about mean life I came across a common definition. It is the average time taken by an arbitrary radioactive nucleus to undergo decay (since different particles may take ...
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Proton's half life (Energy-dependent)

Proton's half life has a lower estimated bound in 10^33 years aprox. This is due to the enormous mass of the X boson, predicted by some GUTs. So my question is: if the free proton is in a high energy ...
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Confusion in proton decay

I read that a proton cannot decay because it is the least massive baryon. However, in positron emission, the proton converts to a neutron a releases a positron. Is that considered a proton decay?
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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 ...
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How to make Energy from radioactive material

I have seen where Tritium hitting phosphorus emits light, and a solar cell collects it to for a "battery" of a sort, but Are you able to extract (For Example) Americium from smoke detector and use it ...
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Decay of hydrogen nucleus?

Very naive question. Nuclear decay is associated to more complex nuclei and explained through radiation. What about hydrogen and less complex nuclei? Will these nuclei eventually break apart? Or is it ...
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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 ...
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Proton Decay; How long until this becomes a problem and are there ways to overcome it? [closed]

I've long wondered about the future of our species. Taking the long view, I find it very amusing to consider the challenges that humans will face and (hopefully) overcome on our journey to the end of ...
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Proton Decay Modes

May I know the proton decay mode predicted by Theoretical Physics? These are the decay mode I've found: 1: $p^+\rightarrow e^++\pi^0$ 2: $p^+\rightarrow \mu^++\pi^0$
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What is the maximum proton lifetime allowed by the standard model?

Is some amount proton decay necessary in the standard model or is it possible for the proton lifetime to be infinite?
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Estimate mass of exchange boson by decay time

I have made a rough estimate that the minimum lifetime $\tau$ of the proton must be $10^{23} \, \mathrm{s}$. From this I would like to estimate the mass of the X boson which would mediate this decay ...
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Why positron emission is unlikely to occur for nuclei with an excess of neutrons?

Is it because a neutron decays into a proton and electron rather than a positron. Which type of nucleus emits positron and which emits electrons . Is it something to do with beta plus and beta minus ...
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Time and frequency extremes

I wonder if there exists a table of which physical events have the shortest time scale (like matter/antimatter annihilation) and which have the longest (like proton decay). The same question applies ...
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Does electrons revolve around a Neutron Star similar to an atom? [closed]

Is a neutron star's residual light come from the electrons similar to an atom? Is the stars gravity holding in the electrons similar to protons in atoms? Is the light we see from a neutron star not ...
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Is there any stable hadron?

Neutron can decay into proton and I think some hypothesis claim that proton can also undergoes decay into subatomic particles... Is there any hadron that never decays?
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Why do protons not break into quarks?

I know that free a neutron breaks into a proton because a proton has less mass and energy. Then, why do protons not break into quarks, since they have even less energy? Or why do gluons join quarks?
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Why is this nuclear reaction $p\to n+e^++\nu$ forbidden for a free proton? [closed]

Why is this nuclear reaction forbiden for a free proton? $$p\to n+e^++\nu$$ Where $p$ is the proton, $n$ is a neutron, $e^+$ is a positron, and $\nu$ is a neutrino. What i´ve been thinking is because ...
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Can photons decay without interaction?

Can photons decay like other particles without interacting with other particles or fields, i.e. by just "being"? In case the answer is "no" - does this have anything to do with them travelling at c, ...
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What happens to the nucleus energy when it decays?

When an atom decays into another atom, what happens to the potential energy of the nucleus ? I think it will get more negative because, in general, through fission and fusion an atom tries to get a ...
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Why is energy released during decay?

Why is energy released when an atom decays into another atom, even though no energy is added? What does the mass defect mean? Is it because a nucleus which decays is unstable (proton/neutron = 1)? ...
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are protons in proton decay allowing theories stable inside nuclei?

It is known that isolated neutrons are unstable, but that neutrons inside nuclei can be stable. I know there are candidate theories that allow proton decay but I wonder whether in these theories ...
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If neutron would be lighter by 1 MeV, how stability of Hydrogen could be changed?

In current Universe proton is stable and the following reaction does not go $ p + e \rightarrow n + \overline{\nu_e}$ Currently proton is lighter than neutron by 1.293 MeV. If neutron would be ...
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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 ...
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Can we observe proton decay?

I know that the half life of a proton is more than $6.6\cdot 10^{33}$ years (antimuon decay). I have found this data on Wikipedia proton decay but I do not know the probability distribution that leads ...
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Color-charge conservation in proton decay

In some extensions of the Standard Model of particle physics (Supersymmetry with R-parity violation being a prominent example), the proton is allowed to decay, e.g. via $p\to e^+\pi^0$: While this ...
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Questions on beta-decay

According to my textbook, for all the beta decays, it is required that the mass of the original atom to be heavier than the mass of the final atom. Is this due to the fact that all the beta decays ...
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It's possible to create a proton colliding a positron with enough energetic photons?

If a proton is supposed to decay in a positron and gamma ray photons is possible to obtain the opposite process colliding enough energetic photons with a positron and create a proton ?
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The life of proton [closed]

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 ...
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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 ...
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Relation between decay probability and the energy of particle

Is there any way to find the energy of a particle through its decay probability?
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Do atoms have lifespans?

From A Short History of Nearly Everything by Bill Bryson: Atoms, however, go on practically forever. Nobody actually knows how long an atom can survive, but according to Martin Rees it is ...
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Does the strong (nuclear) force ever contribute to decay?

Does the strong (nuclear) force ever contribute to decay ? Or is the weak nuclear force the only decaying force ?
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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 ...