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Why Is The Universe More Partial To Matter Than Antimatter?


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B factory experiments at the Stanford Linear Accelerator Center (SLAC) in the USA and at the High Energy Accelerator Research Organization (KEK) in Japan have reached a new milestone in the quest to understand the matter-antimatter imbalance in our universe. These experiments are used by scientists from around the world, including the UK, to probe such fundamental questions.

 

lefthttp://hypography.com/gallery/files/9/9/8/babar_thumb.jpg[/img]Experimenters have leaped from inference to direct knowledge of the proportions of the B unitarity triangle. Not just a simple geometric shape, this triangle summarizes knowledge of the rare processes that contribute to the universes partiality for matter over antimatter. Understanding the difference between matter and anti-matter is fundamental to understanding why our Universe looks the way it does.

 

The area of the triangle visually depicts the amount of difference, or asymmetry, between the decays of B particles and their antimatter counterparts, anti-B particles. The B meson is a sub-atomic particle that is short lived and particularly useful for studying the difference between matter and anti-matter.

 

Thanks to the accumulation of hundreds of millions of B and anti-B particles produced at the two laboratories, scientists have been able to measure all three angles of the triangle from measurements of matter-antimatter differences.

 

Based on these asymmetry measurements alone, we now know for the first time that the B unitarity triangle really does have finite area, said David MacFarlane, spokesperson for the BaBar experiment at SLAC.

 

This is an important jump forward because until now physicists have relied on measurements of the sides of the triangle. Proving that the sides really form a triangle requires the matter-antimatter measurements.

 

The direct measurement of the unitarity triangle's angles generates an area that is consistent with the area predicted by measurements of the sides.

 

"Such a confrontation between prediction and direct measurement is the very essence of science and has been a major goal for the two experiments, MacFarlane said. Once again, we have seen the power of precision measurements to peer into the future and infer solutions that could not have been experimentally determined at the time."

 

A number of measurements made over the past 50 years painted an increasingly precise picture of what the unitarity triangle should look like. Once the B factories had accumulated enough data, physicists could satisfy their hunger to know if the inferred size and shape of the triangle held up. In other words, did they really understand the unitarity triangle and what it said about the origin of the asymmetry between matter and antimatter?

 

The answer is yes: the new triangle matches the indirectly pieced-together knowledge of the triangle. Drawing the triangle directly, by using only measurements of matter-antimatter asymmetry in B decays, confirms the Standard Model, which predicts rates of particle decays.

 

"It's a real milestone and an elegant culmination of a 50-year investigation across an array of very different experiments," said Steve Olsen, co-spokesperson for the Belle experiment in Japan.

 

Taken together, the three angles of the triangle are now known with enough precision for physicists to confidently pin down the triangle's area. It's an outstanding feat: the asymmetry in B particle decays was discovered only five years ago and now physicists have made enough measurements to determine the angle called beta to better than 5 percent precision.

 

To measure the angle alpha with much greater accuracy than previously possible, the BaBar team found a way to use a particular decay mode that initially was thought to be too difficult to measure. The alpha angle is currently measured with a 15 percent precision.

 

"It was during a coffee break at the BABAR collaboration meeting at Imperial College in 2002 that we agreed with colleagues from Saclay to try this approach. We thought it was a very long shot, but it proved to be the best method. It has improved precision in alpha three-fold compared to the best previous results," said Christos Touramanis of the University of Liverpool.

 

An innovative analysis approach introduced by Belle experimenters opened up the possibility for measuring gamma as well, saving the B factory experiments from many years of additional data accumulation. Although gamma is the least-known angle, physicists have achieved enough precision to verify a closed triangle.

 

The outstanding agreement between the asymmetry measurements and the knowledge of the triangle's sides still leaves researchers with a real puzzle. The amount of asymmetry found experimentally is still far too small to explain why we live in a universe of matter rather than antimatter. It may take new kinds of physics to explain the missing antimatter. A much deeper understanding of nature and matter-antimatter asymmetry is expected with further studies of B mesons. The LHCb experiment at CERN in Geneva will start taking data in 2008 and scientists are looking into the possibility of an electron-positron Super B factory with 100 times higher performance than the current experiments.

 

Source: Particle Physics and Astronomy Research Council

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They're really the same, right? Its just when they meet up that things get....messy.

Yes. They're the same like your left hand and your right hand are the same. Or like you and your image in a mirror are the same, only there's no way to tell which is the original and which the reflection.

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One thing I could never wrap my head around, if matter and antimatter's supposed to be identical in all respects except charge, how could they give off energy when they annihilate? Shouldn't they simply 'disappear'? Where's the mass difference between a hydrogen atom and an antihydrogen atom that could account for the released energy? :hihi: If not mass, there must be some sort of difference between the two that can be given off as energy...

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One thing I could never wrap my head around, if matter and antimatter's supposed to be identical in all respects except charge, how could they give off energy when they annihilate? ...

I am not an authority on this, but I will try.

Nuclear matter is not elemental, but is itself, made of more primitive things. We call these things quarks and gluons, but those are just names and we should never make the mistake that we understand something simply because we have named it. So much for protons and neutrons in the nucleus.

 

Electrons have mass, but they are elemental. They do not appear to be made of quarks or anything like them.

 

At some level below that of quarks and electrons, it is posited that there IS the ultimate primitive building blocks of all matter. If these building blocks are just a million times bigger than the Planck distance (smallest unit of length at the sub-quantum level) then a building block would still be millions of times smaller than an electron or quark.

 

This is where the true difference between matter and antimatter would reside: localblox and contrablox. Larger structures can be build of blox, but only if they have the same "bloxity" (local or contra). Mass itself is an emergent property of large structures built of blox in a specific way; mass represents the total "energy" of the blox that are required to build this massive thing, like an electron. Or perhaps even the number of blox required. Maybe electrons are so light because it takes only a few million blox to make one and quarks require a few billion. The Fermion and Boson families may represent the ONLY two distinct ways (geometries) that blox can be assembled into stable structures. Like tetrahedral and icosahedral.

 

We only have a few stable particles because there are so few ways of assembling millions of blox into a self-repeating structure. It's not that an electron is "stable"--it's that its structure evolves through a huge number of configurations until it returns to the starting blox configuration. Other arbitrary structures quickly evolve into configurations that result in blox speeding off in all directions--the structures disassociate or disintegrate. They are not repeating structures.

 

When a structure of blox disintegrates, the blox do not have mass but they have energy. When a large structure does exhibit mass, it does so because the individual blox are "bound" in their behavior (like bricks in a wall) and cannot fully exhibit their energy. But if a massive structure disintegrates, the mass "disappears" (because it was an emergent phenomenon of the structure) and the equivalent energy "appears" (because it is no longer bound into the structure).

 

One critical thing must be added to make a structure stable: it must be stable in the presence of other structures! Anything that isn't has long since gone. So localblox only construct with localblox; contrablox only construct with contrablox. That is because only structures assembled of just one bloxity can be a repeating structure. Only two or more structures ALL of the same bloxity can attache to each other to form super-structures like nuclei, atoms, molecules, lima beans.

 

A structure of localblox (matter) contacting a structure of contrablox (antimatter) would not "attach" or "collide" as would structures of like bloxity. Their individual blox are mirror images of each other! Their "handedness" (right = local, left = contra) would cause the structures to immediately disassociate! The mass would be converted to energy! Things would go boom!

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Interesting, Pyro - first time in my life I've heard of 'blox'. Although, it has been said before that atoms themselves are elemental particles - so, give it another few years and I guess some propellerhead somewhere would split a 'blox' and then there goes the argument of them being elemental. Cute name, however.

 

I like idea of string theory, hoever, with an elemental particle being a string vibrating at a certain frequency. And the antimatter particle would be vibrating at the same frequency, just a different phase. So when they collide, they 'cancel' each other out perfectly via destructive interference. It still doesn't explain the resultant energy!

 

I know - when it comes down to this I'm a dunce. But it is immensely interesting, nonetheless!

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Interesting, Pyro - first time in my life I've heard of 'blox'.

 

Same, thanks also - I'm still getting my head around bosons, fermions, etc. Now someone just has to explain to me what a B meson is and why they are so useful for studying the matter/antimatter asymmetry! :hihi:

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Same, thanks also - I'm still getting my head around bosons, fermions, etc. Now someone just has to explain to me what a B meson is and why they are so useful for studying the matter/antimatter asymmetry! :hihi:

The standard definitions of Bosons & Fermions have to do with spin and the fact that only 2 Fermions can dance on the head of a pin at one time. I think.

 

Anyhow, I used to play with Conway's "Game of Life" which is really a cellular automaton.

http://www.bitstorm.org/gameoflife/

My "blox" description above comes from the idea (I'm sure I'm not the first to have it) that Real/Space/Time is a cellular automaton. The GOL "cell" corresponds to the Planck Distance. The only reason that there are "permanent" objects in the GOL is that there exist patterns of cell/states that repeat every 2 or 4 or 6 or 7 or whatever generations. Like the "Glider" in the link above, which repeats itself every 4 generations, but does so 1 cell removed from its original position. So, it appears to MOVE. Hence its name.

 

In my theory (?) above, a blox would be like a Glider, only it must be constructed of millions of cell/states. Likely it is something like a photon, that recreates itself on average of 1 Planck Distance every Planck Time (generation) which would the be speed of light. Or perhaps the blox is made up of several "photons" which have no handedness--photons and their anti-photons are identical.

 

So, maybe there is no MOTION in Real/Space/Time. Maybe Time clicks from generation to generation, and cellular "laws" (string frequencies?) cause neighboring cells to change state giving the appearance of motion when a pattern of bloxes repeats with an offset.

 

Anyway, I'm not sure this analogy can be carried any further, but I like it.

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...what a B meson is and why they are so useful for studying the matter/antimatter asymmetry! :hihi:

Woops! Forgot the B meson.

 

B mesons are Fermions, in the same family as electrons. In fact, mesons can be considered to be extra heavy ('fat') electrons. Other than the electron itself, all the mesons are unstable.

 

The B meson has several mirror-image ways of disintegrating, all of which which involve production of one or more anti-something particles.

 

After many many many collisions in giant accellerators, producing billions of B mesons, and watching their disintegrations, it is now clear that the B mesons FAVOR modes of disintegration that produce more regular matter and less antimatter. This is called 'assymetry' or 'symetry breaking'. And it means that during the Big Bang, there was at least ONE process that produced more matter than antimatter.

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And it means that during the Big Bang, there was at least ONE process that produced more matter than antimatter.

...or, maybe, there's some function of normal matter that forces that preference. And the accellerators are all made of normal matter, the surrounding area, the planet, everything that might have any bearing on the accellerated particle's eventual demise is made of normal matter. Including the particle itself.

So maybe, at the other end of the universe, there are a bunch of propellerheads doing the same experiment, but they live in an antimatter world. And they would then reach the conclusion through their experiments that something at the Big Bang favoured antimatter...

 

Who knows...?

 

Arrogantly flaunting my ignorance

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Why should one assume that the universe started symmetric in the first place. If there was a difference in count between positively and negatively charged particles, this assymetry will prevail through all of the future and influence even symmetrical processes to appear assymmetric. The same can be for matter/antimatter.

 

About particle annihilation and energy: elementary particles like electrons and positrons might behave like waves in some experiments, but they aren't, so no one can honestly suggest that the wave analogy is proper. I think the wavy theories are dangerous because everything in the universe seems to be limited and discrete whereas any wave formulation ignores that fact by nature of the underlying mathematics.

 

In order to return to the electrons and positrons: because collisions of this kind disappear in our 3d coordinate system this doesn't mean they are really gone. Obviously they are not gone because they seem to be doing something. I think the 3 dimensions are emergent phenomenons of the universe but not it's true geometry. Therefore humanity is doing so poor on describing the patterns by laws based on orthogonal space.

 

Best regards.

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Woops! Forgot the B meson.

 

B mesons are Fermions, in the same family as electrons. In fact, mesons can be considered to be extra heavy ('fat') electrons. Other than the electron itself, all the mesons are unstable.

 

The B meson has several mirror-image ways of disintegrating, all of which which involve production of one or more anti-something particles.

 

After many many many collisions in giant accellerators, producing billions of B mesons, and watching their disintegrations, it is now clear that the B mesons FAVOR modes of disintegration that produce more regular matter and less antimatter. This is called 'assymetry' or 'symetry breaking'. And it means that during the Big Bang, there was at least ONE process that produced more matter than antimatter.

 

Thanks, that answered my question perfectly. In fact, after reading your reply the whole article makes a lot more sense! :)

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...or, maybe, there's some function of normal matter that forces that preference. ...at the other end of the universe ...they live in an antimatter world. And they would then reach the conclusion through their experiments that something at the Big Bang favoured antimatter......

Actually, this is very clever!

 

What it says is this: You may assume the Big Bang was equal M and AM if you wish, BUT-- if in any region, however small, there was the slightest imbalance of M and AM, then subsequent condensation of matter out of the Big Bang super-plasma would FAVOR increasing that imbalance.

 

Voila!! Boerseun, you just SOLVED the mystery of why our universe is Matter!!! Somewhere, in the first few seconds, a quantum imbalance spread, favoring the production of MORE Matter, increasing the imbalance even more, and so on and on, until when the residual AM had all annihilated with M, we had a universe full of Matter!

 

I will contact the Nobel Prize committee in Sweden.

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Voila!! Boerseun, you just SOLVED the mystery of why our universe is Matter!!! Somewhere, in the first few seconds, a quantum imbalance spread, favoring the production of MORE Matter, increasing the imbalance even more, and so on and on, until when the residual AM had all annihilated with M, we had a universe full of Matter!

 

I will contact the Nobel Prize committee in Sweden.

 

I don't know whether you're serious about it or whether that's an irony of you. Any local instability with preference to matter results in some local preference of antimatter elsewhere. In the end when large number of particles are involved you can use statistics and you will find out that no preference of matter above antimatter exists. This means that everything would be annihilated again OR that islands of matter and antimatter will be created. Now, according to my knowledge so far, no antimatter galaxies were discovered. Production of matter and antimatter cannot be symmetric in the first place.

 

Best regards.

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I don't know whether you're serious about it or whether that's an irony of you. ...Production of matter and antimatter cannot be symmetric in the first place...

I am sometimes the expressing of irony and humor, but I am under therapy for this problem. It will be getting better I hope.

 

I also have read quite a bit on this subject as you have. Yes, currently, there is a tendency to believe that M & AM production were probably not symmetrical. However, if the production of any particle "seeded" the creation of more like particles (as Boerseun suggested) then the problem seems to go away. It does not matter if the initial production favored either one or was symetrical. The first kind of particle that was produced in even the tiniest excess would have led to run-away dominance of that kind.

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Electrons have mass, but they are elemental. They do not appear to be made of quarks or anything like them.

 

This misses a keen point. Electrons are elemental, in that they seemingly do not split into smaller pieces, however.

 

Electrons have mass

Mass is equivilant to energy. When an Electron meets it's anti, the Positron, they annihilate into two new bodies. Two gamma rays with the kinetic Energy of the Electron and the Positron.

 

Note: In this Annihilation, Conservation of Charge, Energy, and Spin must be observed.

 

So. Questions: What is the Charge of a Gamma ray? In this case, what is the beginning and ending charge?

 

How would this differ in terms of Quantum Charge?

 

If mass, is made of smaller portions of mass, but the electron isn't and the Electron can be "split" charge wise, so that it produces a net Neutral particle. Then can the Electron be said to be fundmental?

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