March 1, 2012 report

# Fermilab results add to confidence in explaining less antimatter amounts

(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 particles 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 standard model, 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 antimatter 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.

**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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**Citation**: Fermilab results add to confidence in explaining less antimatter amounts (2012, March 1) retrieved 18 October 2019 from https://phys.org/news/2012-03-fermilab-results-confidence-antimatter-amounts.html

## User comments

ovidrgfmfbrestel3.5 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_physorgfmfbrestelfmfbrestelModernmysticNot that the fact that there (apparently) is CP violation isn't an amazing discovery in and of itself.

axemasterIt does, it's called CPT symmetry.

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

thermodynamicsI 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.

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

Seeker2Seeker2rodgodNoumenonNoether'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.

ovidrgMaxwellsDemonCP 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.

Lurker2358Would 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".

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