Fermilab results add to confidence in explaining less antimatter amounts

Mar 01, 2012 by Bob Yirka report
Mass distribution of the 13 502 reconstructed candidates. Image from arXiv:1103.5762v1

(PhysOrg.com) -- The Standard Model of Physics suggests that shortly after the Big Bang there should have been the same amount of antimatter in existence as there was matter. As time passed, both should have decayed roughly equally, leaving roughly the same amounts of each today. But that is not the case of course as most everything today is matter and there is hardly any antimatter to be found.

To explain this, researchers theorize that antimatter must decay down to other at a different rate than does matter, but it can’t yet be proven positively. Researchers have come close though. Last November scientists working at the Large Hadron Collider found a difference of 0.8% in the decay rates of the subatomic particles known as D-mesons as they occur with matter and their associated antimatter particles.

Now, researchers working at the Collider Detector at Fermilab (CDF) have found a difference of 0.6% in the decay rates of the same particles adding considerable confidence to the theory. They have posted a paper describing their results on the preprint server arXiv and have also given a recent presentation outlining their findings at a particle physics meeting in Italy.

At the heart of the research is the idea of charge particle (CP) parity between matter and antimatter, or more specifically, CP violations, which occur when differences between the two are found. To find CP violations, researchers try to measure differences in decay rates between particles of each. If it can be proven that CP violations exist beyond statistical anomalies, then changes or addendums will have to be made to the , which is of course a pretty big deal in physics.

To find CP violations in a real experiment, scientists turn to colliders which can produce among other things, D0 meson particles and their associated particles. In so doing they can then measure their decay rates. According to the standard model, the decay rates for one should not differ from the other by more than 0.1%. In the real world experiments, however, they did just that; first by 0.8% at the LHC, and then by 0.6% at the CDF.

This doesn’t prove anything conclusively though, because physicists have come up with a measurement system for providing a level of confidence in findings or discoveries. To be declared a discovery, an experiment would have to produce a 5 sigma. This latest experiment is only about 3.7 sigma, meaning the odds of the results being due to random chance are 1 in 10,000. To get to 5 sigma, those odds have to rise to one in a million.

Explore further: Neutron tomography technique reveals phase fractions of crystalline materials in 3-dimensions

More information: Measurements of Direct CP Violating Asymmetries in Charmless Decays of Strange Bottom Mesons and Bottom Baryons, arXiv:1103.5762v1 [hep-ex] xxx.lanl.gov/abs/1103.5762

Abstract
We report measurements of direct CP-violating asymmetries in charmless decays of neutral bottom hadrons to pairs of charged hadrons with the upgraded Collider Detector at the Fermilab Tevatron. Using a data sample corresponding to 1 fb-1 of integrated luminosity, we obtain the first measurements of direct CP violation in bottom strange mesons, A_CP(BsKpi) = +0.39 +- 0.15 stat +- 0.08 syst, and bottom baryons, A_CP(Lb->ppi) = +0.03 +- 0.17 stat +- 0.05 syst and A_CP(Lb->pK) = +0.37 +- 0.17 +- 0.03 syst. In addition, we measure CP violation in Bd-->Kpi decays with 3.5sigma significance, A_CP(B->Kpi) = -0.086 +- 0.023 stat +- 0.009 syst, in agreement with the current world average. Measurements of branching fractions of Bs-->K+K- and B0-->pi+pi- decays are also updated.

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User comments : 18

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ovidrg
1.8 / 5 (5) Mar 01, 2012
because collider reactions occur in the gravitational field of matter (antimatter produce antigravity). http://www.physor...rgy.html
fmfbrestel
2 / 5 (4) Mar 01, 2012
Lets see, LHC experiment was a 3.5 sigma result, and this one was a 3.7 sigma result studying the same thing. The odds that both experiments were due to random chance then is....

3.5 sigma = .0005 3.7 sigma = .0002

.0002*.0005 = .0000001

5 sigma = .0000005733

The chances of both experiments both being due to random chance has about a 5.3 sigma.
antialias_physorg
5 / 5 (11) Mar 01, 2012
By your 'logic' I could make six test runs. If each one shows significance with 1 sigma then I have just shown 6 sigma. See how that makes no sense?
fmfbrestel
5 / 5 (3) Mar 01, 2012
antimatter CANNOT be said to produce antigravity. It can only be said that IF antimatter produces antigravity it would explain ONE observation.
fmfbrestel
5 / 5 (1) Mar 01, 2012
not scientifically valid, i get that, there is a significant portion of error that is not pure statistical, but systematic in the experiment. That said, it is still amazingly unlikely that they both have the same systematic error factors.
Modernmystic
5 / 5 (4) Mar 01, 2012
What's a more interesting question is WHY is there CP violation. If we answer that it might point to a deeper principle or something previously not considered.

Not that the fact that there (apparently) is CP violation isn't an amazing discovery in and of itself.
axemaster
not rated yet Mar 01, 2012
What's a more interesting question is WHY is there CP violation. If we answer that it might point to a deeper principle or something previously not considered.

It does, it's called CPT symmetry.
typicalguy
5 / 5 (3) Mar 01, 2012
What's a more interesting question is WHY is there CP violation. If we answer that it might point to a deeper principle or something previously not considered.

It does, it's called CPT symmetry.


The point he's making is that we have no explanation as to why symmetry is broken. We knew it had to be broken for things to work right In a bunch of areas. Then they looked at it and the symmetry was indeed broken. The answer to the question, "Why is symmetry broken?" isn't "because it has to be for things to work". We know it is broken and we know that's why things work but WHY is it broken and why does it work that way?
vacuum-mechanics
1.8 / 5 (5) Mar 01, 2012


The point he's making is that we have no explanation as to why symmetry is broken. We knew it had to be broken for things to work right In a bunch of areas. Then they looked at it and the symmetry was indeed broken. The answer to the question, "Why is symmetry broken?" isn't "because it has to be for things to work". We know it is broken and we know that's why things work but WHY is it broken and why does it work that way?


This is the weak point in conventional modern physics, they use mathematical trick to describe natural phenomena, instead of explaining its physical mechanism.
thermodynamics
5 / 5 (1) Mar 01, 2012
Lets see, LHC experiment was a 3.5 sigma result, and this one was a 3.7 sigma result studying the same thing. The odds that both experiments were due to random chance then is....

3.5 sigma = .0005 3.7 sigma = .0002

.0002*.0005 = .0000001

5 sigma = .0000005733

The chances of both experiments both being due to random chance has about a 5.3 sigma.

I think you have to take a look at how standard deviations are combined.

http://en.wikiped...atistics

Once you do that you can go back and make the appropriate corrections.
axemaster
5 / 5 (1) Mar 01, 2012
This is the weak point in conventional modern physics, they use mathematical trick to describe natural phenomena, instead of explaining its physical mechanism.

There is no difference between mathematics and reality, provided proper constraints are observed (like causality in relativistic mechanics).
Seeker2
5 / 5 (1) Mar 01, 2012
Lets see, LHC experiment was a 3.5 sigma result, and this one was a 3.7 sigma result studying the same thing. The odds that both experiments were due to random chance then is....

3.5 sigma = .0005 3.7 sigma = .0002

.0002*.0005 = .0000001

5 sigma = .0000005733

The chances of both experiments both being due to random chance has about a 5.3 sigma.

I think you have to take a look at how standard deviations are combined.

http://en.wikiped...atistics

Once you do that you can go back and make the appropriate corrections.
If you assume the covariance (whatever that is) between the data sets is 0, then roughly you take the square root of the sum of squares to get a pooled standard deviation which would likely be 3.6 sigma.
Seeker2
3 / 5 (2) Mar 01, 2012
antimatter CANNOT be said to produce antigravity. It can only be said that IF antimatter produces antigravity it would explain ONE observation.
I don't think antimatter produces antigravity. Rather, per Feynman, antimatter travels backwards in time, meaning, to me at least, it backs off away from gravitational fields. This would be why most of the evidence for antimatter just floats away, except when it gets magnetically trapped. So antimatter would decay while retreating from gravity instead of being attracted by gravity. This could answer some of the CP violation problems.
rodgod
1 / 5 (1) Mar 02, 2012
Bingo! You see, I think Black Holes are "clumps" of antimatter. Deep space "winds" are caused by these "clumps" as it interacts with matter. Symmetry is everywhere. How could it not also be in the case of matter/antimatter. Oh, but we call it ... "Dark Energy."
Noumenon
2.3 / 5 (3) Mar 02, 2012


The point he's making is that we have no explanation as to why symmetry is broken. We knew it had to be broken for things to work right In a bunch of areas. Then they looked at it and the symmetry was indeed broken. The answer to the question, "Why is symmetry broken?" isn't "because it has to be for things to work". We know it is broken and we know that's why things work but WHY is it broken and why does it work that way?


This is the weak point in conventional modern physics, they use mathematical trick to describe natural phenomena, instead of explaining its physical mechanism.


Noether's theorem is a proof of physical conservation laws derived from continuous symmetries in mathematical theory (Lagrangians in classical mechanics). I don't know if there is an analogous proof for descrete symmetries, but certainly there is analogous use in qm.
ovidrg
1 / 5 (2) Mar 02, 2012
so .. IF antimatter produce antigravity, this would explain the above problem. also there could be lots of antimatter galaxies that are rejected by mater galaxies. this may explain why we believe that the universe is composed only of matter. could also be possible that for antimatter time flow backwards. (around antimatter space is curved in the opposite way than matter , through ....time)
MaxwellsDemon
5 / 5 (1) Mar 03, 2012
Chardin has published a couple of papers that explore the idea that the influence of the gravitational field may explain CP violation in neutral kaon decay:

CP violation: a matter of (anti)gravity? G. Chardin, 1992.
http://irfu.cea.f...2-07.pdf

CP violation and antigravity (revisited), G. Chardin, 1993.
http://www.scienc...9390415T

His hypothesis is based on the notion that antimatter and matter gravitationally repel, which is a philosophically-unpopular concept (probably because the term "antigravity" smacks of ufos and such). Nevertheless, the gravitational interaction between matter and antimatter remains experimentally unproven. The claim that all galactic superclusters are made of matter also remains an unproven assumption. Dr. Ting's AMS-02, currently operating aboard the ISS, may help us answer both questions.
Lurker2358
2.3 / 5 (3) Mar 04, 2012
This is the weak point in conventional modern physics, they use mathematical trick to describe natural phenomena, instead of explaining its physical mechanism.

There is no difference between mathematics and reality, provided proper constraints are observed (like causality in relativistic mechanics).


Would have to disagree there partner.

The inverse squared relationship is a prime example. It works perfect, in theory, except when r = 0, or when r equals an event horizon or other similar phenomenon.

In fact, the lorentz equation is undefined when V = C, yet not undefined when V > C.

"Zero" is one of the most problematic and glaring mathematical absurdities when trying to describe reality.

Also, there are abstract forms of math that have not even been proven to correspond to reality, such as higher dimensions and non-euclidean spaces,etc.

So there certainly is a difference between "math" and "reality".