Scientists at Fermilab close in on fifth force of nature

It would also seem that colliders are not the only tool in the search for dark matter
I came across this article in my reading on the topic and appears to give some insight into my question as to why they use titanium.

An Experiment Buried Deep Inside an Abandoned Gold Mine Could Solve a Huge Physics Mystery

Scientists, therefore, build dark matter detectors using the most “radiopure” materials — that is, free of radioactive contaminants — they can find both inside and outside the detector.

For example, by working with metal foundries, LZ was able to use the cleanest titanium on Earth to build the central cylinder — or cryostat — that holds the liquid xenon. Using this special titanium reduces the radioactivity in LZ, creating a clear space to see any dark matter interactions.

Here is a link to the study results so far if anyone is inclined
First Dark Matter Search Results from the LUX-ZEPLIN (LZ) Experiment

And a video on how they built it, almost 1 mile underground

a reply to: datguy

You do have a point on what is that we observe and how do we interpret it. In this case muons appear to wobble at a faster rate than expected and this could be down to a new force or a new subatomic particle or even something else. If we assume the experiments have eliminated completely the possibility of a mistake.

a reply to: AlienBorg

I feel like this would also presume that any dark matter reaction would leave a radioactive trace.
As much as I love the theoretical sciences, and as much as I (we/humans) don't understand about them, I sometimes find myself at odds with the professionals in the field with the methods and efforts used to pretty much resolve nothing.

I wonder if they have considered some of the ideas of string theory in relation to the wobble, it could reasonably be interpreted as a "vibration" given the scale of the observation.

What is String Theory

Instead of treating subatomic particles as the fundamental building blacks of matter, string theory says that everything is made of unbelievably tiny strings, whose vibrations produce effects that we interpret as atoms, electrons and quarks.

originally posted by: datguy
a reply to: AlienBorg

I feel like this would also presume that any dark matter reaction would leave a radioactive trace.
As much as I love the theoretical sciences, and as much as I (we/humans) don't understand about them, I sometimes find myself at odds with the professionals in the field with the methods and efforts used to pretty much resolve nothing.

I wonder if they have considered some of the ideas of string theory in relation to the wobble, it could reasonably be interpreted as a "vibration" given the scale of the observation.

What is String Theory

Instead of treating subatomic particles as the fundamental building blacks of matter, string theory says that everything is made of unbelievably tiny strings, whose vibrations produce effects that we interpret as atoms, electrons and quarks.

Dark matter doesn't interact with light or any other part of the electromagnetic spectrum so we can't see it. But at the same time the only effect it has is through gravity and it's a type of matter that passes through ordinary matter, photons, and itself leaving no traces.

originally posted by: interupt42
a reply to: AlienBorg

The unknown is what makes science fun and exciting, but tell those mofos to put us back in the right time line

Hells yea. Skip the fugging clowns this time.

originally posted by: datguy
a reply to: AlienBorg

I feel like this would also presume that any dark matter reaction would leave a radioactive trace.
As much as I love the theoretical sciences, and as much as I (we/humans) don't understand about them, I sometimes find myself at odds with the professionals in the field with the methods and efforts used to pretty much resolve nothing.

I wonder if they have considered some of the ideas of string theory in relation to the wobble, it could reasonably be interpreted as a "vibration" given the scale of the observation.

What is String Theory

Instead of treating subatomic particles as the fundamental building blacks of matter, string theory says that everything is made of unbelievably tiny strings, whose vibrations produce effects that we interpret as atoms, electrons and quarks.

The point about string theory is good but I don't think it's related to the wobbling effect. A certain vibration produces a unique particle and having a faster rate at which a particle wobbles indicates something very different going on.

a reply to: datguy

nd the PDF below is just ODD, while i cannot say i read it fully, browsing some of the sections they talk about experiment results from tests in 2025, 2026, 2030 ect...
Is this Doc brown working here?
Stanford PDF

Read the first line of page 1.

a reply to: erbdds

LOL
oh my... I am laughing at myself here, glad you pointed that out

originally posted by: surfer_soul
a reply to: gortex

Ahh yes the so call “god particle” such a massive undertaking for that. I would have thought they might have been able to achieve something more substantial with all the time and money plowed into it.

Perhaps there is something they aren’t telling us about though?

You're complaining because the most advanced thing mankind has ever built or achieved surpassed all expectations and discovered several new exotic particles and proved theoretical Physics models correct to a degree of over 15SD making it singlehandedly responsible for the biggest discovery era in Physics the last 100 years?

It cost less than $5bn which is inredible value for money and likely to lead the next 100 years of science and tech.

a reply to: AlienBorg

They are fundamental according to our thresholds of perception. Who really knows the definition of fundamental.

Furthermore, i had a science question hoping maybe sombody can answer:

IF the nucleus of an atom is smaller compared to a human than a human is compared to the sun, by proportion, is it not therefore correct to assume that there is more distance between an atom and a human than between a human and the sun? Just we cannot measure that distance in a perceptive way??

It has led me to conclude that distance does not exist, only volume, but we have created a perceptive measure construct called distance, to more easily perceive volume? i could be wrong, im not a theoretical phycisist.
I dunno just random thought!

PLease i would be grateful for some gifted people who know science!

a reply to: AlienBorg

Totally made up story by the News Media, the Fermi Lab press release in no way implied a new 5th force may have been found. All this latest data press release did is narrow the uncertainty bar (variance) around the experimental data for -> Measurement of the Positive Muon Anomalous Magnetic Moment by about 1/2 and shifted it slightly closer to the Standard-Model prediction from a 2020 paper on the subject.

Basically, the predicted value of the Muon Mag Moment Anomaly is very-very slightly offset from the latest experimental data by only -> 0.000214 %. That is in no way proves there is a new unknown force, but that only the 2020 prediction analyses needs a tiny refinement. Even the 2020 paper admitted to the need for calculation improvement of some of the 7 muon-anomaly terms that were summed up to create the final number.

That analyses paper is -> T. Aoyama et al., The anomalous magnetic moment of the muon in the Standard Model, Phys. Rep. 887, 1 (2020).

a reply to: combatmaster

It's a good question but it doesn't work like that. Subatomic scale is measured down to planck length (1.612 x 10 ^ -34 metres) which is the smallest possible unit of scale (at least in 3D/4D) and things act very differently at this scale than the everyday reality we see around us. There's similar scales of Planck Mass, Time and Temperature that mark the smallest possible units in 3d/4d universe. While they can be measures in units other than metres or kelvin, the same core equations and fundamental constants and boundaries of the physical universe still apply.

If you imagine a nucleus to be the size of a soccerball then the distance to the nucleus to the outer electron shell would be 2,500km at human sccale it would be almost equal to the circumference of Earth (straight line distance).

Distance and volume still exist and are part of both euclidean and non-eucidean space/dimensions - i.e if you differentiate the equation for the volume of an object (x^3) it will give you the equation for surface area of a cube (6x^2) which is a 2D representation of a 3D object. The dimensions exist regardless of which units they are measured in.

Going 4D and higher gets ridiculously confusing - the maths of it arem't that difficult; just trying to understand what it meams or the implications of it in real life is nigh on impossible as it goes against all intuition/logic learnt as it's so far removed from the reality we experience.

a reply to: bastion

It makes no sense....Unless... distance is relative to mass and volume. If there is greater difference between the size of an atoms nucleaus and the human, than that of human to earth then there is a greater distance, relatively speaking.
But if you were the size of a star system you wouldnt be able to see earth or the sun, doesnt mean there isnt a greater distance between them relatively speaking, than between you and the sun.

It will mean that even plank length if constantly folding in on itself (so to speak) and thats why our perception is not able to find a fundamental constant to measure as length, because it dosnt stand in time. IS that why we see the universe as expanding?

i wish i had a friend who was a theoretical physicist, its actually quite fascinating!

just an afterthought, so if you remove whatever gives planks their mass/energy, you can remove entropy, no?

Ahhhh sorry its all most probably giberish!

originally posted by: FWGuy
a reply to: AlienBorg

Totally made up story by the News Media, the Fermi Lab press release in no way implied a new 5th force may have been found. All this latest data press release did is narrow the uncertainty bar (variance) around the experimental data for -> Measurement of the Positive Muon Anomalous Magnetic Moment by about 1/2 and shifted it slightly closer to the Standard-Model prediction from a 2020 paper on the subject.

Basically, the predicted value of the Muon Mag Moment Anomaly is very-very slightly offset from the latest experimental data by only -> 0.000214 %. That is in no way proves there is a new unknown force, but that only the 2020 prediction analyses needs a tiny refinement. Even the 2020 paper admitted to the need for calculation improvement of some of the 7 muon-anomaly terms that were summed up to create the final number.

That analyses paper is -> T. Aoyama et al., The anomalous magnetic moment of the muon in the Standard Model, Phys. Rep. 887, 1 (2020).

The newspapers didn't fabricate this story but have added to the already known hypothesis about the anomalous rate of precession of the muon when placed in a magnetic field.

Here is the page of University College London back from 2021

www.ucl.ac.uk...

The “wobble”, or rate of precession, of the muon particle in a magnetic field is different from what our best theoretical model of the subatomic world would predict, according to an experiment involving UCL researchers that strengthens evidence for new, unknown physics.

When placed in a magnetic field, the particle acts like a tiny magnetic compass and, like the axis of a spinning top, it precesses, or rotates, as its spins. This rotation was faster than is predicted by the Standard Model of particle physics.

Dr Gavin Hesketh (UCL Physics & Astronomy), g-2 lead at UCL, said: “The new result gives strong evidence that there may be a previously unknown particle or force of nature influencing the muon’s behaviour. This measurement could mark the start of a new leap in our understanding of the universe.”

The current experiments that are more precise have verified the anomalous behaviour of the muon which could mean the existence of a fifth natural force, or the existence of another unknown subatomic particle, or even an unknown mechanism. Nobody has yet concluded anything about the phenomenon.

The thing about experimental measurements is that the most important outcome is typically the error bar more than the absolute value. The new measurement claims 'Evidence...' which in particle physics and other areas for that matter means... ~3 sigma

3 sigma basically says the measurement has an accuracy that is at a 99.7% confidence level. Or that the true value of the measurement you are making is 99.7% likely to be within the uncertainty band.

However this is not counted as a discovery... only evidence, as, believe it or not, statistical fluctuations can easily make this evidence 'go away' so to speak. This is what happened with many measurements of new particles and decay modes of particles at the LHC when they were searching for the higgs.

In the case of the higgs there were several energies at which it might have existed depending on which models/theories you are using... there were more than one occasion when a 3 sigma level peak developed in the datasets, only to later dissapear with more statistics.

For a discovery you are looking at 5 sigma or better... which is 99.998% confidence. 5 sigma accuracy hardly ever just goes away with more stats... if its real, the sigma confidence typically just gets better and better.


So... new force? TBD


on other questions of particle physics... if there are any questions about the standard model, dark matter, and or neutrino physics... my PhD and profession is in exactly that...

On the idea that a muon has to contain an electron, electron neutrino and a muon neutrino as its constituent parts and not be fundamental, you are actually fundamentally not understanding the standard model, or the evidence.

Example, the mass of the electron is - 0.511MeV/c2
the mass of the muon is 105.7MeV/c2

It would mean that the electron neutrino and muon neutrino mass needs to be... fairly enormous coming in at some kind of split in the 30-70MeV/c2 range. This is simply not what is observed. The electron neutrino as best as measurements have it so far (its not been conclusively measured) is less than 0.2 eV so the muon neutrino by this definition needs to have an enormous mass... again... something we don't see just based on kinematics in detectors.

You might say... oh but maybe they have some kind of binding energy that takes up that mass. and the answer to that is... no evidence for that at all either, since if there was near 100MeV of binding energy available when muons decay... we would see that, probably as a gamma, or some kind of jet of leptons when a muon decays. We dont see that. Plus its a ridiculous amount of energy that if was present, we could totally exploit to generate power. Our oceans are not boiling because of cosmic rays, and yet the water absorbs a lot of them... a very very very lot of them

Simple conclusion, the muon is a fundamental particle rather than having constituent parts.

originally posted by: AlienBorg
There is good possibility we have come across a fifth unknown force that has just been observed, it has been proposed sometime ago and the first results announced back in 2021.

It's only one of several candidates for a Fifth Force so I would just say it's possible. If one of the other candidates is confirmed first, then if this muon thing is really is a force, it might end up being the 6th force rather than the 5th force. Some other candidates are described here, which are not related to the muon observations:

The search for a fifth force has increased in recent decades due to two discoveries in cosmology which are not explained by current theories. It has been discovered that most of the mass of the universe is accounted for by an unknown form of matter called dark matter. Most physicists believe that dark matter consists of new, undiscovered subatomic particles,[1] but some believe that it could be related to an unknown fundamental force. Second, it has also recently been discovered that the expansion of the universe is accelerating, which has been attributed to a form of energy called dark energy. Some physicists speculate that a form of dark energy called quintessence could be a fifth force.

A fifth force may not be the only way to resolve the discrepancy, see below.

originally posted by: datguy
And the PDF below is just ODD, while i cannot say i read it fully, browsing some of the sections they talk about experiment results from tests in 2025, 2026, 2030 ect...
Is this Doc brown working here?
Stanford PDF

You only had to read the first sentence to see it had nothing to do with Doc Brown:
"This is an imaginary story that could come to pass..."

here is a good video that explains what cern has or hasnt accomplished.
They point out that gravity isnt a known force and is fairly well unexplained
They also talk about this new Z Prime force towards the end

There are much better sources, like PBS spacetime for example. That video was very muddled, and I didn't think it was a good video at all. Probably the best source for a video about the potential new force related to muons at Fermi lab would be Don Lincoln at Fermilab:

What does the Muon g-2 experiment tell us?

The Muon g-2 experiment announced one of the most tantalizing physics measurements in over a decade. It is possible that the measurement tells us that our theoretical calculation is missing some new physical phenomena. It is also possible that a new theoretical prediction points to the possibility that measurement and prediction basically agree. In this exciting video, Fermilab’s Dr. Don Lincoln gives you an insider’s perspective.

Here's the other source I mentioned, PBS spacetime

Why the Muon g-2 Results Are So Exciting!

When a theory makes a prediction that disagrees with an experimental test, sometimes it means we should throw the theory away. But what if that theory has otherwise produced the most successful predictions in all of physics? Then, that little glitch may be pointing the way to layers of physics deeper than we've yet imagined. Well, FermiLabs Muon G-2 experiment has been chasing the most promising glitch of all, and they've just announced their results.

Those are both about 2 years old, but the recent announcement is basically confirming they recently confirmed the discrepancy mentioned in those 2 year old videos. The next step is to figure out a resolution to the discrepancy. A fifth force isn't the only possibility, there could be some nuance to the theoretical calculation they missed, but either way, it will be interesting to see how the discrepancy is resolved.

I can't recommend this video for anybody who isn't a scientist because it's so technical, but for the scientists here, it discusses what steps they are taking to resolve the discrepancy on both the experimental side and on the theoretical side:

Scientific Seminar: 2023 results from the Muon g-2 experiment at Fermilab

originally posted by: ErosA433
The thing about experimental measurements is that the most important outcome is typically the error bar more than the absolute value. The new measurement claims 'Evidence...' which in particle physics and other areas for that matter means... ~3 sigma

3 sigma basically says the measurement has an accuracy that is at a 99.7% confidence level. Or that the true value of the measurement you are making is 99.7% likely to be within the uncertainty band.

However this is not counted as a discovery... only evidence, as, believe it or not, statistical fluctuations can easily make this evidence 'go away' so to speak. This is what happened with many measurements of new particles and decay modes of particles at the LHC when they were searching for the higgs.

In the case of the higgs there were several energies at which it might have existed depending on which models/theories you are using... there were more than one occasion when a 3 sigma level peak developed in the datasets, only to later dissapear with more statistics.

For a discovery you are looking at 5 sigma or better... which is 99.998% confidence. 5 sigma accuracy hardly ever just goes away with more stats... if its real, the sigma confidence typically just gets better and better.


So... new force? TBD


on other questions of particle physics... if there are any questions about the standard model, dark matter, and or neutrino physics... my PhD and profession is in exactly that...

On the idea that a muon has to contain an electron, electron neutrino and a muon neutrino as its constituent parts and not be fundamental, you are actually fundamentally not understanding the standard model, or the evidence.

Example, the mass of the electron is - 0.511MeV/c2
the mass of the muon is 105.7MeV/c2

It would mean that the electron neutrino and muon neutrino mass needs to be... fairly enormous coming in at some kind of split in the 30-70MeV/c2 range. This is simply not what is observed. The electron neutrino as best as measurements have it so far (its not been conclusively measured) is less than 0.2 eV so the muon neutrino by this definition needs to have an enormous mass... again... something we don't see just based on kinematics in detectors.

You might say... oh but maybe they have some kind of binding energy that takes up that mass. and the answer to that is... no evidence for that at all either, since if there was near 100MeV of binding energy available when muons decay... we would see that, probably as a gamma, or some kind of jet of leptons when a muon decays. We dont see that. Plus its a ridiculous amount of energy that if was present, we could totally exploit to generate power. Our oceans are not boiling because of cosmic rays, and yet the water absorbs a lot of them... a very very very lot of them

Simple conclusion, the muon is a fundamental particle rather than having constituent parts.

You're on the theoretical or experimental side?

The member asking questions on why the muon isn't made up of electrons and neutrinos implies they're not familiar with particle physics. Their question is legitimate if one doesn't know about particles and the standard model. But it has already been explained.

I don't think the newspapers have claimed there is a new discovery. I ve mentioned a few times earlier that there could be a fifth force associated with this phenomenon, or a new and unknown subatomic particle, or even a new mechanism we don't know of. What about a hole in the standard model?

This is from UCL website two years ago.
Mentioned it earlier and gave the link.

Dr Gavin Hesketh (UCL Physics & Astronomy), g-2 lead at UCL, said: “The new result gives strong evidence that there may be a previously unknown particle or force of nature influencing the muon’s behaviour. This measurement could mark the start of a new leap in our understanding of the universe.”

originally posted by: AlienBorg

You're on the theoretical or experimental side?

experimental side, though as a requirement I did have theoretical background training regarding the workings of the standard model of particle physics... kind of more of a rights of passage more than anything else.

The member asking questions on why the muon isn't made up of electrons and neutrinos implies they're not familiar with particle physics. Their question is legitimate if one doesn't know about particles and the standard model. But it has already been explained.

It is a legitimate question, however, making a follow up statement or suggestion based on the supposed question being correct is not super helpful to follow. Its great to speculate but too often than not iv seen speculation and questioning being used in order to suggest that science as we know it is wrong.

What i'd say is that, the evidence we have from the last 50 or so years of experimentation (and around 80 or so years of us knowing about muons and radiation) are that leptons are fundamental particles. It is clear they are not made of constituent parts that contain their own momentum and quantum properties.

Hadrons on the other hand, its clear they are bound states of particles that are held together in a configuration that contains constituent particles with momentum and quantum properties.

I don't think the newspapers have claimed there is a new discovery. I ve mentioned a few times earlier that there could be a fifth force associated with this phenomenon, or a new and unknown subatomic particle, or even a new mechanism we don't know of. What about a hole in the standard model?

Well the statement at the end is part and parcel of the earlier statements. The g-2 measurement is showing that the standard model is very accurate in describing things down to a high degree of accuracy. HOWEVER the experiment is looking at a deviation in the experimental observation from the prediction. What discrepancy that may... or may not be present is extremely slight. So calling it a hole in the standard model is maybe a bit of an extreme statement.

Iv seen all kinds of statements from the media, which part of the issue with science reporting by any media outlet. iv experienced it myself where you talk to a media person, they take notes and no matter how careful you are with language and how much you try to be sure they understand what you are saying... some will walk away from
"We have evidence for" as being "We have measured that there is definitely is"

Those two statements are obviously in tension with each other, but you can see my point.

This is from UCL website two years ago.
Mentioned it earlier and gave the link.

Dr Gavin Hesketh (UCL Physics & Astronomy), g-2 lead at UCL, said: “The new result gives strong evidence that there may be a previously unknown particle or force of nature influencing the muon’s behaviour. This measurement could mark the start of a new leap in our understanding of the universe.”

Indeed and the reason why its interesting is because science always does change, we have never drawn a line under anything and said "Done" so we do measurements because we have areas in the model that could give us interesting avenues for new physics. Interestingly the discovery of charm was a similar thing. Basically the 'evidence' for it was made when physcists looked at their model, and created a accelerator and detector to make particles with strange quarks in them.

They looked for all the decay modes the strange quark undergoes according to theory and calculated, according to the theory of the time, how much they should see of each type.

The experimental observation did not match the theory... and more so it didnt match at higher energies. So one way to 'fix' or one possibility was that, quarks, when interacting, exist as a quantum mechanical superposition of states. So a 'strange' is not really a pure strange, but its actually a super position, or a mixed state of strange and this other unknown, as yet unobserved quark, (it could not be created in the lab, as machines that could achieve the centre of mass energy had not been built yet.)

BUT the theory, if it was modified or this idea of superpositions added... actually made the theory match the data extremely well, not only that, but it didn't break current observations or previous observations either. The model naturally just works at lower energy, but it also does predict a few things and expain a few slight oddities too.

So what happened? well bigger machine to search for that new particle... it was found... the charm, and it came in at a mass close to the prediction of the model.

Basically the super position with a higher mass state, meant that the class of decays they did not observe, turned out to be energetically and quantum mechanically forbidden should the charm particle exist.

The same could be said for g-2 if we do see evidence for oddities, and can prove it beyond doubt... it points down a few avenues... particles... forces... something else? im sure the theories are legion

a reply to: AlienBorg

"may be"

So nothing has been found. Nice way for Fermilab to try and stay relevant.

a reply to: AlienBorg

When cosmic rays collide with molecules in the upper atmosphere they produce pi mesons that quickly decay to produce muons which in turn decay after 2.2 microseconds to produce electrons/positrons and two types of neutrinos.

If Muons decay after 2.2 microseconds, then at relativistic speed, they can only travel about 235 feet before they decay.
Since they form in the upper atmosphere, how can these muons possibly hit the surface of the earth?

Relativistic speed for muons is 57% of the speed of light. so 186,000 miles per second becomes a relativistic 98,022 miles per second which is 517,556,160 feet per seconds divided by 2,200,000 (which is 2.2 microseconds) = 235 feet