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View Full Version : LHC and the upcomming 2.76TeV Heavy Ion Collisions (Nov. 2010)

malm1987
2010-Jul-19, 07:52 PM
I've heard a lot about the safety of Proton-Proton collisions, and that they should be completelly safe (with a wide margin for errors). But when it comes to this (HIC) I haven't heard all that much about the safety aspects. So I thought I would ask around here and see if someone have information on the safety aspect of these collisions? Does the LSAG-report cover the safety aspects of high energy heavy ion collisions, or is it only applicable to the Proton-proton collisions?

I'm not suggesting that Strangelets or mBH's could be created, but on a general level, isn't HIC more dangerous to the operators (within CERN's research grounds) and sensitive to failures such as the one that delayed the 7Tev collisions?

What are your thoughts on these collisions? Are they safe?

Jens
2010-Jul-20, 10:29 AM
What are your thoughts on these collisions? Are they safe?

I don't think the collisions themselves are dangerous, since obviously people will be out of danger zone before they start, but clearly there are dangers involved. They are working with very heavy magnets and high-voltage electricity and big pieces of construction, so I think there is a clear danger to workers involved in it. But I imagine they are also well aware of what these dangers are and are taking proper precautions. There have been a number of glitches but I'm not aware of any operators having been injured (though I could be wrong).

Eta C
2010-Jul-20, 12:54 PM
I don't think the collisions themselves are dangerous, since obviously people will be out of danger zone before they start, but clearly there are dangers involved. They are working with very heavy magnets and high-voltage electricity and big pieces of construction, so I think there is a clear danger to workers involved in it. But I imagine they are also well aware of what these dangers are and are taking proper precautions. There have been a number of glitches but I'm not aware of any operators having been injured (though I could be wrong).

If any of the operators or scientists are injured it won't occur while the LHC is operating. The beam tunnel is a very dangerous place while the machine has beam stored. Besides the high magnetic fields of the magnets and the high voltages of the various detctors there is a radiation hazard from the synchnotron radiation as the beams are bent. Now this is less of a problem in proton machines like the LHC as opposed to electron machines like its predecessor LEP or, on a smaller scale, SPEAR where I did my thesis work. Usual practice is for the beam tunnel and detector pit to be evacuated before bringing beam into the machine. The access doors are interlocked and the beam is dumped if one is opened.

As to issues with the P-P collisions themselves. Safe!

Nereid
2010-Jul-20, 01:51 PM
It can be quite a lot of fun to poke holes in the various depictions of the LHC (and similar) particle accelerators in movies. One of my faves is in one of the Terminator films ... those superconducting bending magnets are quite magical in their properties! :)

malm1987
2010-Jul-20, 08:55 PM
It can be quite a lot of fun to poke holes in the various depictions of the LHC (and similar) particle accelerators in movies. One of my faves is in one of the Terminator films ... those superconducting bending magnets are quite magical in their properties! :)

What, do you mean that Terminator wasn't based on a true story?=) Haha, nah... Just kidding, I can only second what you said... I think it's quite fun to see people like that Wagner-character proclaiming all the dangers of LHC (as he did with RHIC), yet doesn't even bother to make a reality check once in a while.

malm1987
2010-Jul-21, 08:55 AM
There was one thing however that I couldn't really figure out of the LSAG-report. They cover most aspects of possible disaster scenarios, but seem to have left out the theory of vacuum bubbles. Or at least I couldn't figure out how they were thinking concerning that, since they, as they do everywhere, refer to cosmic radiation and collisions that take place at much higher energies. But, I think I've read somewhere that the highest observed heavy ion collision in nature meassured up to 2,6 Tev, which I think that the RHIC safety assesment group claims to be the upper limit. But the upcomming heavy ion collision that is scheduled to november are going to collide particles in 2,76 Tev (above the observed upper limit). Isn't this at least a little risky? I don't think that vacuum bubbles are all that easy to create, but could there be any kind of danger with these high energy heavy ion collisions? Or are LSAG sure that there is no danger in pushing the limits?

SkyDreamer
2010-Jul-22, 05:09 AM
There was one thing however that I couldn't really figure out of the LSAG-report. They cover most aspects of possible disaster scenarios, but seem to have left out the theory of vacuum bubbles. Or at least I couldn't figure out how they were thinking concerning that, since they, as they do everywhere, refer to cosmic radiation and collisions that take place at much higher energies. But, I think I've read somewhere that the highest observed heavy ion collision in nature meassured up to 2,6 Tev, which I think that the RHIC safety assesment group claims to be the upper limit. But the upcomming heavy ion collision that is scheduled to november are going to collide particles in 2,76 Tev (above the observed upper limit). Isn't this at least a little risky? I don't think that vacuum bubbles are all that easy to create, but could there be any kind of danger with these high energy heavy ion collisions? Or are LSAG sure that there is no danger in pushing the limits?

The same question has been bothering me for the past few weeks. The RHIC safety report says we have no possibility of knowing which type of collision is more likely to create a vacuum bubble, so we have to look at both types individually. I'm referring to the "Vacuum Instability" section.
http://www.bnl.gov/rhic/docs/rhicreport.pdf

Do we have any measurements of heavy ion cosmic rays suppressing 2.76 TeV? Because this is the only way of guaranteeing there to be no danger. More specifically, the LHC is going to collide Pb + Pb. Do we have any information concerning lead ions in cosmic rays?

I agree with you when saying the LSAG report fails to discuss this issue in length (as opposed to black holes etc.) which makes me very uneasy, considering the fact that this is the scariest scenario out of them all.

Jens
2010-Jul-22, 09:15 AM
I agree with you when saying the LSAG report fails to discuss this issue in length (as opposed to black holes etc.) which makes me very uneasy, considering the fact that this is the scariest scenario out of them all.

Actually, it seems a fairly unscary scenario. The instability would apparently propagate at the speed of light, so we would simply be instantly obliterated. It's much less uneasy to me than a heart attack or stroke or cancer.

Strange
2010-Jul-22, 09:22 AM
http://www.bnl.gov/rhic/docs/rhicreport.pdf

Do we have any measurements of heavy ion cosmic rays suppressing 2.76 TeV? Because this is the only way of guaranteeing there to be no danger. More specifically, the LHC is going to collide Pb + Pb. Do we have any information concerning lead ions in cosmic rays?

I only skimmed through it, but appendix B of that document seems to look at the effects of collisions, at the relevant energy levels, as a function of atomic number. This would include Pb even though it isn't mentioned explicitly. They point out that the mixture of ions in cosmic ray collisions roughly matches the proportions on Earth (and lead is fairly common) with, if anything, a greater proportion of heavy ions.

Actually, it seems a fairly unscary scenario. The instability would apparently propagate at the speed of light, so we would simply be instantly obliterated. It's much less uneasy to me than a heart attack or stroke or cancer.

Exactly what I was thinking.

SkyDreamer
2010-Jul-22, 11:01 AM
But the proportion isn't the issue here (to my knowledge), but rather the energy of the collision. Do you have any idea what is the highest Pb + Pb collision detected?

Recently UHECR were found to be made of protons, so the idea of them being consisted of heavy ions seems a bit unreasonable now.

malm1987
2010-Jul-28, 10:32 PM
But the proportion isn't the issue here (to my knowledge), but rather the energy of the collision. Do you have any idea what is the highest Pb + Pb collision detected?

Recently UHECR were found to be made of protons, so the idea of them being consisted of heavy ions seems a bit unreasonable now.

I came across that article too, and that is perhaps the only part of the LHC that makes me uneasy. If this article is accurate, and the vast majority of high energy collisions of cosmic rays are more or less exclusively between proton - proton, then that disproves the analogy of cosmic rays used in the LSAG-report regarding heavy ion collisions. But I hope that LSAG has made calculations on plausible scenarios (as with mbh's) that goes beyond just saying: hey, look at the cosmic rays! They don't produce any harmful objects, thus we wont either. Do anyone know if additional studies on heavy ion collisions has been carried out by LSAG, or others?

Sorry to rant on about this. Normally I have confidence in the scientists at CERN, but this new article was kind of bad news since their main argument lost all validity (reg. these heavy ion collisions).

Jerry
2010-Jul-29, 03:42 PM
Blog:

http://ichep2010.blogspot.com/

http://ichep2010.blogspot.com/2010/07/day-4-higgs-is-not-there-yet.html

Now we know, the Higgs boson did not show up at Tevatron. Yet.

But we also know that, if it exists, we would not find it in the 158-175 GeV mass range.

"(Jester?)Tevatron now excludes the standard model Higgs for masses between 156 and 175 GeV. The exclusion window widened considerably since the last combination. Together with the input from direct Higgs searches at LEP and from electroweak precision observables it means that Higgs is most likely hiding somewhere between 115 and 155 GeV (assuming Higgs exists and has standard model properties). We'll get you *******, sooner or later."

I check the LHC site at regular intervals - they are still making progress, but there are a lot of problems stearing the beams - it might settle down now that the world cup and the tour are over.

Even at its peak, the LHC will produce less energetic events than cosmic rays striking the surface of the moon. So if we are going to all disappear into a Black Hole; watch for the moon to disappear first. (That gives us about six seconds to duck and cover)

More Jester:

Another potentially interesting detail: there is some excess of events in the $b \bar b$ channel where a light Higgs could possibly show up. The distribution of the s/b likelihood variable (which is some inexplicably complicated function that mortals cannot interpret) has 5 events in one of the higher s/b bins, whereas only 0.8 expected. This cannot be readily interpreted as the standard model Higgs signal, as then one would also expect events at higher s/b where there is none. Most likely the excess is a fluke, or maybe some problem with background modeling. But it could also be an indication that something weird is going on that does not fit the standard model Higgs paradigm.

malm1987
2010-Jul-29, 03:59 PM
Blog:

http://ichep2010.blogspot.com/

http://ichep2010.blogspot.com/2010/07/day-4-higgs-is-not-there-yet.html

I check the LHC site at regular intervals - they are still making progress, but there are a lot of problems stearing the beams - it might settle down now that the world cup and the tour are over.

Even at its peak, the LHC will produce less energetic events than cosmic rays striking the surface of the moon. So if we are going to all disappear into a Black Hole; watch for the moon to disappear first. (That gives us about six seconds to duck and cover)

I don't want to sound rude now, but you didn't really address any of the points made in the article. Much more energetic collisions take place every second in the universe, but... Those are found to be p-p collisions, not heavy ion collisions. Since heavy ion collisions haven't been observed there's no way to know what effect they can have, or how likelly they are to produce a false vacuum. To clarify, what I want to know is if heavy ion collisions are more dangerous than proton - proton collisions?

trinitree88
2010-Jul-29, 04:26 PM
I don't want to sound rude now, but you didn't really address any of the points made in the article. Much more energetic collisions take place every second in the universe, but... Those are found to be p-p collisions, not heavy ion collisions. Since heavy ion collisions haven't been observed there's no way to know what effect they can have, or how likelly they are to produce a false vacuum. To clarify, what I want to know is if heavy ion collisions are more dangerous than proton - proton collisions?

malm. I'm pretty sure the early cosmic ray detectors included blocks of silver bromide photographic emulsion. Instead of thin photsensitive coatings, the gelatins containing the silver nitrate and the potassium bromide were mixed and cast warm in large blocks like food Jell-O molds. They were then washed to remove the KBr, and the silver bromide grains were ripened using Ostwald ripening, to increase grain size. They were sent aloft using balloons and sounding rockets and the interactions occurred between heavy silver nuclei and incoming cosmic rays which were at least partially heavy elements. So, I think we've seen those collisions, historically. (No black holes, no mini black holes, no vacuum instabilities, no dark matter, no dark energy, no Bigfoot, no Ogopogo, no Polywater, no Greys, no trolls, no Gremlins, no Wimps, no supersymmetric particles or sparticles....just straight forward Standard Model particle physics tracks in the emulsions. You might try gathering some friends and making a cosmic ray block yourself for a ~ thousand bucks, or you can gather at your local tavern and have a cold beer, with a very remote chance of a Higgs showing up in the bubbles in your glass ( I've seen at least one background cosmic ray in a nice cold Molson Golden many years ago....still searching....pete)

SEE:http://science.nasa.gov/media/medialibrary/2009/09/29/29sep_cosmicrays_resources/data_imf_cap.jpg

SEE:http://en.wikipedia.org/wiki/Cosmic_ray

and note that this is CERN a decade ago :http://cerncourier.com/cws/article/cern/27944

SEE:http://blog.modernmechanix.com/mags/qf/c/PopularScience/2-1933/med_cosmic_rays_trapped.jpg

Jens
2010-Jul-30, 02:31 AM
To clarify, what I want to know is if heavy ion collisions are more dangerous than proton - proton collisions?

I really think it's good to have some perspective here (Ken G mentioned this too, perhaps in another thread). We live in a big universe, and there is a very, very good chance that there are other civilizations who can do similar experiments. So if the universe was so fragile that it could be destroyed by an experiment like this, the chances are nearly certain that we wouldn't be here.

trinitree88
2010-Jul-30, 01:30 PM
I really think it's good to have some perspective here (Ken G mentioned this too, perhaps in another thread). We live in a big universe, and there is a very, very good chance that there are other civilizations who can do similar experiments. So if the universe was so fragile that it could be destroyed by an experiment like this, the chances are nearly certain that we wouldn't be here.

Jens. Yep. It's needless worrying. People ought to stretch out and find faces in the clouds more often and worry less about nitwit mania from the media mogols. pete

SkyDreamer
2010-Aug-02, 12:02 AM
I don't want to sound rude now, but you didn't really address any of the points made in the article. Much more energetic collisions take place every second in the universe, but... Those are found to be p-p collisions, not heavy ion collisions. Since heavy ion collisions haven't been observed there's no way to know what effect they can have, or how likelly they are to produce a false vacuum. To clarify, what I want to know is if heavy ion collisions are more dangerous than proton - proton collisions?

I private messaged you the following comment, but I'm not sure whether you pay attention to your inbox or not -

The same question came to my head a few weeks ago. Most of the responses you got on this board seem to be avoiding the point you made, and completely unrelated.

There is no way to know which type of collision (protons or heavy ions) is more likely to cause the decay of our false vacuum. The RHIC safety report authors therefore concluded we need to look at both types individually in order to exclude the possibility of a vacuum instability event.

Iron cosmic rays were directly measured up to more than 1000 TeV. The cosmic rays review (a 67 page document) contains this information. However, the LHC is mainly going to collide lead ions so we have to focus on that. Lead cosmic rays are much rarer and harder to observe, so we need to rely on a certain formula, and on something called "abundance" rather than observed events.

Someone who studied theoretical physics explained it to me on the chat. My suggestion would be to come there and discuss the issue yourself.
http://chat.mibbit.com/
The IRC you need to choose is Gimp and the channel you need to write is #lhc

mugaliens
2010-Aug-02, 05:37 AM
I really think it's good to have some perspective here (Ken G mentioned this too, perhaps in another thread). We live in a big universe, and there is a very, very good chance that there are other civilizations who can do similar experiments. So if the universe was so fragile that it could be destroyed by an experiment like this, the chances are nearly certain that we wouldn't be here.

Piggybacking on your logic and stats, if such a thing were possible, it's almost certainly happened, but the effect simply hasn't reached us yet. :)

Nereid
2010-Aug-02, 06:35 AM
I don't want to sound rude now, but you didn't really address any of the points made in the article. Much more energetic collisions take place every second in the universe, but... Those are found to be p-p collisions, not heavy ion collisions. Since heavy ion collisions haven't been observed there's no way to know what effect they can have, or how likelly they are to produce a false vacuum. To clarify, what I want to know is if heavy ion collisions are more dangerous than proton - proton collisions?
IIRC, there is quite a lot of published material on the composition of cosmic rays, by energy (i.e. what proportion are protons, He nuclei, ... up to Pb ones), and that it has been known - for more than a decade? - that while protons are certainly in the (big?) majority, there are nuclei of (almost) every element, at least up to Pb. In fact, the elemental composition has been used, in at least some papers, to hypotheses on possible sites of origin of cosmic rays (different types of supernovae will produce different element abundances, for example).

Also, again IIRC, some other work suggests that at the highest energies - ~10^18 eV and above - the composition may change, from predominantly protons to predominantly Fe nuclei.

Would you be interested in some of these papers, malm1987?

malm1987
2010-Aug-04, 04:53 PM
IIRC, there is quite a lot of published material on the composition of cosmic rays, by energy (i.e. what proportion are protons, He nuclei, ... up to Pb ones), and that it has been known - for more than a decade? - that while protons are certainly in the (big?) majority, there are nuclei of (almost) every element, at least up to Pb. In fact, the elemental composition has been used, in at least some papers, to hypotheses on possible sites of origin of cosmic rays (different types of supernovae will produce different element abundances, for example).

Also, again IIRC, some other work suggests that at the highest energies - ~10^18 eV and above - the composition may change, from predominantly protons to predominantly Fe nuclei.

Would you be interested in some of these papers, malm1987?

I would absolutelly be interrested in reading some of those papers.

I know most people are under the impression that I think that CERN is about to make the whole universe vanish in a *poff*. That couldn't be further from the truth. I have great confidence in the scientists at CERN, and I'm constantly fascinated by their progress (and sometimes set-backs). But I'm also that kind of person that at times obsess over matters most don't even think about, and when it comes to heavy ion collisions I find the LSAG (both old and revised ver.) to be inconclusive thus not that comforting. And with all the Wagners, Goreliks and JTankers screaming doom out there I would like to see for myself that everything is safe.

Nereid
2010-Aug-04, 05:02 PM
I would absolutelly be interrested in reading some of those papers.

I know most people are under the impression that I think that CERN is about to make the whole universe vanish in a *poff*. That couldn't be further from the truth. I have great confidence in the scientists at CERN, and I'm constantly fascinated by their progress (and sometimes set-backs). But I'm also that kind of person that at times obsess over matters most don't even think about, and when it comes to heavy ion collisions I find the LSAG (both old and revised ver.) to be inconclusive thus not that comforting. And with all the Wagners, Goreliks and JTankers screaming doom out there I would like to see for myself that everything is safe.
I'll see what I can find.

BTW, I made a mistake in my earlier post - the Fly Eye result concerns only the highest energy cosmic rays, those near the 'ankle', of energy ~10^18 eV and above. Their conclusion - that the CRs are (mostly) protons - is inconsistent with an earlier result, published by the Auger team IIRC.

These UHECRs (ultra-high energy cosmic rays) are thought to have come from beyond our galaxy (many reasons for this conclusion); note that they are ~a million times more energetic than what the LHC will research, so a more realistic comparison is with much less energetic CRs, which do (we think) come from galactic sources (such as supernovae remnants); these lower energy CRs certainly are composed of a variety of atomic nuclei (there are also, IIRC, some electrons and positrons).

Nereid
2010-Aug-04, 05:16 PM
It was the Auger team I remembered; here (http://blogs.physicstoday.org/update/2010/04/cosmic-ray-composition.html) is a link with a summary, and a reference to their paper.

Nereid
2010-Aug-04, 05:30 PM
Try this paper: Composition of Primary Cosmic-Ray Nuclei at High Energies (http://arxiv.org/abs/0801.0582)

Two of the recent investigations into cosmic ray composition go by the names TRACER and CREAM (!); googling those terms (plus 'cosmic rays'!) will give you many more papers ....

malm1987
2010-Aug-06, 12:04 AM
Try this paper: Composition of Primary Cosmic-Ray Nuclei at High Energies (http://arxiv.org/abs/0801.0582)

Two of the recent investigations into cosmic ray composition go by the names TRACER and CREAM (!); googling those terms (plus 'cosmic rays'!) will give you many more papers ....

Thank you very much Nereid, those articles helped me to see things from a different perspective. Just a question on the same subject though. If false vacuum decay even was possible wouldn't higher energy collisions (derived from neutron stars collapsing or such) be more likelly to trigger such a phenomena than those measly energies RHIC/LHC can produce?

Could the fact that the collisions at LHC take place much much more frequent than between CR be a possible danger? I've heard some discussion that claimed that the frequency could be dangerous due to excess particles interaction in the oncomming collisions (like cake on cake). Wouldn't the excess particles alter the outcome of collisions? Just a thought though, perhaps particles "disappear" more or less instantaneous?

malm1987
2010-Aug-15, 09:53 PM
Thought it could be a good addition to this thread to add some responses I got from LSAG during a short correspondence:
My mail (excluded less vital parts)
"...That being said, I have to ask you one thing though. In what manner are you going to start the pb-collisions? I mean, are you going to ramp up the beam energies as you did with the first p-p collisions or are you going to try to achieve full beam energy from the beginning?

And finally, are you sure that vacuum bubbles can't be created in the comming pb-collisions? Is the conclusion in the LSAG-report based on previous experiments as well as cosmic rays, or are they solely based on the latter? My apologies for the really stupid questions, just got a little spooked by the whole "false vacuum decay" claims."

The first response
"Hello,
the startup scenario will be similar to the one of the proton-proton run, with collisions at the injection energy first (about 400 gev in the nucleon-nucleon center of mass), and then ramping up to the maximum energy available this year (about 2.8 TeV in the nucleon-nucleon COM). The creation of vacuum bubbles would be governed by the energy density. This can be achieved also in proton-proton, as well as in proton-nucleous, collisions, and therefore the cosmic-ray argument provides by far the strongest empirical evidence that such a phenomenon cannot take place, as discussed in our report. Of course, today, you may also add the negative evidence from the collisions at the LHC at 7 TeV....
best regards,

LSAG,
LHC Safety Assessment Group"

2nd mail from me
"Thank you so much for taking the time to answer my questions, as silly as they may be. I do however have some followup questions on the response (no more after these).

Do you have any estimate of roughly how high energies (per beam) is possible to achieve before bubble nucleition can become a problem, i.e. how high energies has been observed in CR collisions? Are you absolutelly certain that LHC can't trigger a phase transition? Finally, I've read your report several times but can't seem to find any conclusive discussion on vacuum metastability disaster events. I don't doubt that the CR argument is valid, I just wonder why it isn't as thouroghly covered as microscopic black holes and strangelets (which were very conclusive)? An answer to these questions would be deeply appreciated"

2nd response
"hello, the reason why it's not discussed in much detail is that this is a topic that has been covered in detail in the past (see refs in the report), and we had nothing to add to previous discussions, except to report their conclusions. The argument based on CR collisions holds for energies up to over 100 times the maximum LHC energy (since CR energies reach out to about 10^21eV). If I remember correctly (we have this number anyway in teh report), the total number of collisions which the LHC will generate, at its maximum energy, during its expected operational lifetime, is happening 10^13 times per second throughout the universe. This has been going on for several billion years now. Any bubble of false vacuum would have obliterated the universe since long!
best regards,

LSAG,
LHC Safety Assessment Group"

CJSF
2010-Aug-16, 08:06 AM
What an extraordinarily restrained and patient pair of replies. This is why I never want to work in any customer service field.

CJSF

malm1987
2010-Aug-16, 12:58 PM
What an extraordinarily restrained and patient pair of replies. This is why I never want to work in any customer service field.

CJSF

I am well aware that people like me are nothing short of a severe nuisance to people that actually do know what they are talking about, but LSAG was put together solely to adress fears of the LHC. Ofcourse, Those who know enough about particle physics/quantum mechanics/string theory to see through all the claims made by anti-LHC lunatics never have to turn to such desperate meassures such as contacting CERN/LSAG directly. Those on the other that doesn't know enough about these things and why they can't happen (like myself from time to time), need to get things clarified from those that are directly responsible for the security, and know what they are talking about.

This mail correspondence was published here for a specific reason, and took place before Nereid answered my questions. There are people, even if you don't acknowledge this, that actually looses sleep and get anxious thanks to these experiments. I can happily admit that I am one of those. And that is exactly the reason to why I choose to publish such a silly correspondence as this, so that others can see that LSAG actually has thought through the vacuum metastability disaster event even though it's hardly mentioned in the LSAG-report (neither v.2003 nor v.2008).

Don't get me wrong, the LSAG-report IS excellent. It covers all speculative disaster scenarios, but to different extents. For example, compare the mbh or strangelet section to the vacuum bubble section. One is more conclusive than the other, don't you agree?

Both LSAG-report refers back to the old report on RHIC safety (Review of speculative disaster scenarios at RHIC) regarding the vacuum bubbles. The RHIC safety report furthermore acknowledge observations of heavy ion collisions at up to 2TeV at COM. See where I'm going with this?

The LSAG report states that they found no reason as to why they would need to revise the previous conclusions of the RHIC safety report even though their report only governs heavy ion collisions of energies up to 2TeV at COM, even though LHC is going to collide heavy ions at energies of up to aprox. 2.80TeV/COM this year and up to 5.5TeV/COM after the long shutdown (perhaps 2013-2014?). Since they base their conclusions on inadequate studies, at least in order to prove it's safe by analogy to CR that according to the previous report have only been meassured up to 2TeV/COM, I choosed to contact LSAG directly to get an straight answer to why they seem to have overlooked this.

Since then Nereid have shown me that different research point to heavy ion CR of energies way above anything LHC can produce, which then obviously proves that LSAG was right even though they didn't account for neither Auger nor HiRes research in their report. And I'm now more than convinced that heavy ion collisions at LHC isn't going to cause a catastrophic disaster event.