Can baryon number be violated e.g. in baryogenesis, Hawking radiation ... neutron star?

[Duda Jarek]

For a few decades they have unsuccessfully searched for proton decay in room temperature water, what seems interpreted as disproof of this possibility ... but is it really?

The same way we could "disprove" nuclear fusion as it practically doesn't happen in room temperature water ... but happens in extreme conditions.

So maybe it didn't disprove baryon number violation, only it needs extreme conditions e.g. to get into some higher energy state before decay?

Baryon number violation is hypothesized in baryogenesis, Hawking radiation - which need quite extreme conditions. It is required in many models like supersymmetric, or now popular sphaleron.

How can we verify this possibility?

Talking with particle physicists, they say we just cannot know if it happens e.g. in LHC, checking baryon number is practically impossible there (?)

So maybe astrophysical objects to understand orders of magnitude higher energies than we can explain in standard way?

For example https://www.space.com/35846-brightest-farthest-neutron-star-discovered.html

Quote

Astronomers have discovered the brightest neutron star ever found. This extremely dense object is 1,000 times brighter than researchers previously thought was possible for neutron stars (...)
This is one of the questions the scientific community needs to answer in the next years

[joigus]

Thank goodness you've asked "can baryon number be violated?" and not "will we ever see baryon number violation?"

If you look at the relevant pieces of the standard model Lagrangian, it strongly suggests that baryon number can be violated. Otherwise, what's this continuous symmetry doing there not associated with a local conservation law, completely looking like a gauge symmetry but the local degrees of freedom being absent? It's very peculiar.

Plus it's the best way so far to explain baryogenesis and matter/antimatter asymmetry.

The directions I tend to look at when the lights go off and I think about this are mainly:

GUT extensions to the SM are not written in stone.

The role that the scalar field plays in Nature is kind of like a parametric all-purpose machinery, not something fundamentally understood.

[Duda Jarek]

"Can baryon number be violated" is one of the most fundamental questions of physics, it seems we still don't really know answer to (?)

Indeed it seems necessary for hypothesis that our Universe has started from a single point, but there is alternative of fixed baryon number of the Universe as kind of additional constant, in Big Crunch preceding our Big Bang.

So do we have any chance to answer this question in some future? - what could be accessible convincing experiment?

Could it already be happening in LHC? Be accessible in some future colliders? If so, could it be verified there?

If not, what about astrophysical possibilities like neutron stars, GRBs with orders of magnitudes higher energies than what we could imagine? ... or Hawking radiation which finally turns baryonic matter into massless radiation ...

[joigus]

1 hour ago, joigus said:

not associated with a local conservation law,

Sorry, just to correct myself. It is associated with a local conservation law, but not local DOF associated (gauge fields). I think you understood me.

24 minutes ago, Duda Jarek said:

Could it already be happening in LHC? Be accessible in some future colliders? If so, could it be verified there?

I sincerely doubt it. The LHC is being useful at the level of studying a lot of QCD background. But it's very difficult IMO to use it to detect such a small deviation from SM.

If one in 10³⁹ (or wherever the threshold is from Superkamiokande and such) protons decayed there, it would be very difficult to highlight it from the background, I surmise.

28 minutes ago, Duda Jarek said:

If not, what about astrophysical possibilities like neutron stars, GRBs with orders of magnitudes higher energies than what we could imagine? ... or Hawking radiation which finally turns baryonic matter into massless radiation ...

Very interesting possibility. +1 There is actually an argument in favour of baryon number violation that has to do with BHs. There may be exotica to be explored in the spectrum of primordial or supermassive BHs.

[Duda Jarek]

3 hours ago, joigus said:

I sincerely doubt it. The LHC is being useful at the level of studying a lot of QCD background. But it's very difficult IMO to use it to detect such a small deviation from SM.

If one in 10³⁹ (or wherever the threshold is from Superkamiokande and such) protons decayed there, it would be very difficult to highlight it from the background, I surmise.

While I agree that it might be practically impossible to verify it, I have asked if it might be already happening there - these are two separate questions, and I wouldn't be surprised if the answer to the latter was positive.

But maybe it could be tested through some Monte-Carlo by adding hypothesized Feynman diagrams into considered ensemble?

3 hours ago, joigus said:

There is actually an argument in favour of baryon number violation that has to do with BHs. There may be exotica to be explored in the spectrum of primordial or supermassive BHs.

But if considered for BH, they are created by collapse of neutron stars, many of which have extreme rotation (with some fluxes, shockwaves etc.), with orders of magnitudes higher brightness than what we can explain ... but baryon decay possibility seems completely neglected for neutron stars - should we be so certain about it?

[joigus]

4 hours ago, Duda Jarek said:

While I agree that it might be practically impossible to verify it, I have asked if it might be already happening there - these are two separate questions, and I wouldn't be surprised if the answer to the latter was positive.

But maybe it could be tested through some Monte-Carlo by adding hypothesized Feynman diagrams into considered ensemble?

I can't think of any reason why that would be impossible. My intuition, though, is that trying to study this process in dirty jets of QCD is perhaps not the best way. But the more accurately the QCD background is known, I suppose the easier it will become to subtract it from whatever's happening and detect cross sections of new physics. I would suggest to contact people who know about luminosities, etc. in the LHC.

4 hours ago, Duda Jarek said:

But if considered for BH, they are created by collapse of neutron stars, many of which have extreme rotation (with some fluxes, shockwaves etc.), with orders of magnitudes higher brightness than what we can explain ... but baryon decay possibility seems completely neglected for neutron stars - should we be so certain about it?

I'm not sure that people neglect it because they feel certain about it. Maybe it's just about difficulties in measuring it.

In the last years, some colossal BHs have been argued to be just too big to have accreted from stellar matter. Perhaps they are more primeval objects than anybody had thought thus far. I don't think we have a complete picture of how all BHs arise. Collapse from neutron stars may just be one way for a stellar object to become a BH. For all I know, BHs could be violating baryon conservation like crazy. And then there's the possibility of primordial BHs...

If you take a look at the SM Lagrangian, it just looks as if baryon number were the remains of an honest-to-goodness gauge theory, but some extreme process had stripped the baryons completely clean of their baryonic gauge "dressing". The space of possible ideas that are still reasonable is richer than we sometimes dare to think.

I have just looked up "baryon number violation and black holes" and there seem to be lots of papers. And even one that proposes something very similar to what I was trying to suggest (that they have something to do in baryogenesis):

https://cds.cern.ch/record/355696/files/9805455.pdf

It's from 1998.

Keep in mind that it's usually called "baryogenesis", but what people really mean is both baryogenesis and leptogenesis.

[Duda Jarek]

16 hours ago, joigus said:

Maybe it's just about difficulties in measuring it.

If baryon decay would happen inside some neutron star, the basic observed consequence would be larger energy outcome ... like "This extremely dense object is 1,000 times brighter than researchers previously thought was possible for neutron stars (...)" from https://www.space.com/35846-brightest-farthest-neutron-star-discovered.html

So the question is if astrophysicists should have baryon dacay in "bag of possibilities to consider" - and it seems currently it is completely neglected, I would say that due to general belief that it was disproven by unsuccessful search of proton decay in water tanks ... which is misunderstand as the same way it "disprove" nuclear fusion.

We rather don't have doubts that electric charge has to be ultimately conserved - due to Gauss law making all field guards its conservation, analogously to topological charge. But for baryon number we don't have anything like this.

[Strange]

2 hours ago, Duda Jarek said:

So the question is if astrophysicists should have baryon dacay in "bag of possibilities to consider" - and it seems currently it is completely neglected, I would say that due to general belief that it was disproven by unsuccessful search of proton decay in water tanks ... which is misunderstand as the same way it "disprove" nuclear fusion.

Physicists always have everything in the possibilities to consider. One of the explanations explored when the energy gap in beta decay was noticed (eventually explained by neutrinos) was that energy might not always be conserved. You don't get more fundamental than that.

And proton decay has not been "disproved". That would be pretty much impossible.

[joigus]

1 hour ago, Duda Jarek said:

We rather don't have doubts that electric charge has to be ultimately conserved - due to Gauss law making all field guards its conservation, analogously to topological charge. But for baryon number we don't have anything like this.

It's not the same. You would have to change physics completely to have U(1) charge violation. But violation of baryon and lepton number could be easily accommodated. I think everybody is aware of that.

1 hour ago, Duda Jarek said:

So the question is if astrophysicists should have baryon dacay in "bag of possibilities to consider" - and it seems currently it is completely neglected, I would say that due to general belief that it was disproven by unsuccessful search of proton decay in water tanks ... which is misunderstand as the same way it "disprove" nuclear fusion.

I'm having difficulties understanding this paragraph. Could you break it down into simpler sentences? Which is "misunderstand as the same way it disprove nuclear fusion"? What is misunderstood, and what disproves what the same way as what?

------

The thing about taking any excess radiance of stellar objects as a watertight proof that baryon number violation (or CP violation, which combined would account for baryo/lepto genesis) is going on there is that you would have to have a clean prediction of what such spectrum would look like in neutron stars (or BHs, for that matter) to compare against. Do you know of any such clean prediction?

That's what I meant when I said "difficult to prove", rather than being a question of incredulity or neglect. I find it very difficult to believe it's just a matter of neglect.

[Duda Jarek]

Indeed charge conservation is quite different from baryon/lepton number conservation.

Regarding "the same way it disprove nuclear fusion", I have only meant that fusion also don't happen in room temperature water, but we shouldn't conclude that it disproves fusion - which requires much more extreme conditions.

However, unobservation of proton decay in room temperature water is often seen as disproof, made it an exotic concept not worth considering.

Regarding hypothetical confirmation for astronomical objects, if it would happen in one of the most extreme places: core of neutron star, we wouldn't have a chance to see some additional spectral lines, only excessive energy, like this "1,000 times brighter than researchers previously thought was possible for neutron stars " of NGC 5907 X-1.

[swansont]

Why would we see excessive energy?

If the process were massively exothermic, as you are implying with "1,000 times brighter than researchers previously thought was possible for neutron stars" then perhaps it would be more common. But I can see no reason to think that violation of baryon number requires the process to be exothermic.

BTW, a fusion reaction can happen at room temperature. Reaction ≠ chain reaction (i.e. sustained fusion doesn't happen at room temperature) But proton decay must be something that happens spontaneously, if it's a decay. If it requires a system to be at some temperature, then it's an induced reaction, not a decay. So if we observe for some period of time and don't see evidence of a decay, we can place a lower limit on the lifetime of the process. 

 

[Duda Jarek]

Because baryon decay would be nearly complete mc^2 matter -> energy conversion.

If happening in core of neutron star, it could greatly increase energy production - above what we can explain without it, and there are observed such unexplained examples.

How many nuclear fusion events should they expect in all these proton decay experiments?

Edited August 17, 2020 by Duda Jarek

[Strange]

4 minutes ago, Duda Jarek said:

Because baryon decay would be nearly complete mc^2 matter -> energy conversion.

What do you base that on?

There are several hypothetical decay modes. None of them correspond to that description.

5 hours ago, Duda Jarek said:

So the question is if astrophysicists should have baryon dacay in "bag of possibilities to consider" - and it seems currently it is completely neglected

Completely neglected?

Quote

Proton decay [has] been the focus of major experimental physics efforts since the early 1980s. To date, all attempts to observe these events have failed; however, these experiments have been able to establish lower bounds on the half-life of the proton. Currently the most precise results come from the Super-Kamiokandewater Cherenkov radiation detector in Japan: a 2015 analysis placed a lower bound on the proton's half-life of 1.67×10³⁴ years via positron decay,^[2] and similarly, a 2012 analysis gave a lower bound to the proton's half-life of 1.08×10³⁴ years via antimuon decay,^[4] close to a supersymmetry (SUSY) prediction of 10³⁴–10³⁶ years.^[5]An upgraded version, Hyper-Kamiokande, probably will have sensitivity 5–10 times better than Super-Kamiokande.^[2]

https://en.wikipedia.org/wiki/Proton_decay

[swansont]

14 minutes ago, Duda Jarek said:

Because baryon decay would be nearly complete mc^2 matter -> energy conversion.

That also requires that to be a common event

Baryon decay happens all the time. You are, I assume, referring to free proton decay, in the context of baryon number non-conservation (per the title) These are not interchangeable descriptions.

 

Quote

If happening in core of neutron star, it could greatly increase energy production - above what we can explain without it, and there are observed such unexplained examples.

If it happens in the core of a neutron star but not outside of it, that implies it is not a decay process that is occurring. 

You seem to be once again referring to baryon number non-conservation, rather than any particular decay.

And, as above, this would require the process to be fairly common.

 

Quote

How many nuclear fusion events should they expect in all these proton decay experiments?

I don't know, but I would imagine that the circumstances that make fusion more likely would not be part of a design of a proton decay experiment.

[Duda Jarek]

14 minutes ago, Strange said:

22 minutes ago, Duda Jarek said:

Because baryon decay would be nearly complete mc^2 matter -> energy conversion.

What do you base that on?

https://en.wikipedia.org/wiki/Proton_decay says

proton -> positron + pi0

and pion further decaying to gammas, which from energy conservation need to carry ~1GeV energy in this nearly complete matter->energy conversion.

I am saying saying "baryon decay" because such matter->energy conversion would also concern especially neutrons.

22 minutes ago, Strange said:

Completely neglected?

There are many astronomical objects they say with orders of magnitudes higher energy production than can be explained, but I didn't see hypothesizing baryon decay (?)

24 minutes ago, swansont said:

You seem to be once again referring to baryon number non-conservation, rather than any particular decay.

Yes, I am referring to baryon number non-conservation: as proton/neutron decay into non-baryons.

 

 

[Strange]

Just now, Duda Jarek said:

There are many astronomical objects they say with orders of magnitudes higher energy production than can be explained, but I didn't see hypothesizing baryon decay (?)

Maybe because, despite your guesses, it isn't actually a useful explanation. You know, when you actually model what is happening.

[Duda Jarek]

To know whether a possibility is useful, it needs first to be considered - the problem is that it seems this didn't happen (?).

[Strange]

3 minutes ago, Duda Jarek said:

To know whether a possibility is useful, it needs first to be considered - the problem is that it seems this didn't happen (?).

Citation needed.

[Duda Jarek]

Indeed - for papers discussing proton/neutron decay possibility to understand energy sources we cannot explain in standard way.

I couldn't find any (?)

[Strange]

14 minutes ago, Duda Jarek said:

Indeed - for papers discussing proton/neutron decay possibility to understand energy sources we cannot explain in standard way.

I couldn't find any (?)

So maybe people have thought: "Oh I wonder if this could be explained by proton decays ..." [spends 2 minutes doing some calculations] "No, that doesn't work"

I find that more plausible than your unsupported guesswork.

[Duda Jarek]

Sounds like "neglected possibility" as I am writing - one question is why? (I would say that due to proton decay nonobservation in water).

Second question is if it really should be neglected without real consideration?

[Strange]

18 minutes ago, Duda Jarek said:

Sounds like "neglected possibility"

Maybe you should stop ignoring what people write. I explained one scenario in which it is NOT neglected.

18 minutes ago, Duda Jarek said:

as I am writing - one question is why?

I am suggesting that the reason may be that it doesn't work to explain the observations.

As you have zero evidence for your claims, they are not worth considering.

18 minutes ago, Duda Jarek said:

Second question is if it really should be neglected without real consideration?

Please provide some evidence that this is the case.

Soapboxing like this is against the rules.

 

It is very sad that science has not found some magic way of making your desired mechanism come true, but we will just have to live with the disappointment.

 

"No one has proved it isn't invisible pink unicorns."

[Duda Jarek]

But the claim "it doesn't work to explain the observations. " needs doing some analysis of this possibility - where is this analysis?

If there is none, means this possibility was neglected - excluded without even trying.

[Strange]

6 minutes ago, Duda Jarek said:

But the claim "it doesn't work to explain the observations. " needs doing some analysis of this possibility - where is this analysis?

I am assuming it took an expert in the subject about 30 seconds to dismiss the idea, when they thought of it. So the analysis is on a scrap of paper in the trash.

People (including scientists) think of hundreds of possible solutions to problems. They are not going to publish a paper saying "I thought of this, but obviously it doesn't work. Then I thought if this, it took a bit longer but obviously that doesn't work either. ..."

6 minutes ago, Duda Jarek said:

If there is none, means this possibility was neglected - excluded without even trying.

Of course it doesn't. 

There is a saying "absence of evidence is not evidence of absence". While it sounds clever, it is not always true.

However, your claim that "absence of evidence proves I am right" is just nonsensical.

If you think proton decay is a plausible mechanism, then it is up to YOU to demonstrate that.

[Duda Jarek]

I don't know what is the difference between "neglected" and "dismissed in 30 second" ... only asking why is it so?