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The Process of B-meson Decays Gives the Reason of Having More Matter than Antimatter in the Universe

A new physics discovery explores why there is more matter than antimatter in the universe.

The latest research findings, which involved significant contributions from physicists at the University of Melbourne, have been recently published in the journal Nature. The paper reveals that investigation into the process of B-meson decays has given insight into why there is more matter than antimatter in the universe.

“B-mesons are a new frontier of investigation for us and have proved very exciting in the formation of new thought in the field of particle physics.” said Associate Professor Martin Sevior of the University’s School of Physics who led the research.

Sevior says that B-mesons contain heavy quarks that can only be created in very high energy particle accelerators. Their decays provide a powerful means of probing the exotic conditions that occurred in the first fraction of a second after the Big Bang created the Universe.

“Our universe is made up almost completely of matter. While we’re entirely used to this idea, this does not agree with our ideas of how mass and energy interact. According to these theories there should not be enough mass to enable the formation of stars and hence life.”

“In our standard model of particle physics, matter and antimatter are almost identical. Accordingly as they mix in the early universe they annihilate one another leaving very little to form stars and galaxies. The model does not come close to explaining the difference between matter and antimatter we see in the nature. The imbalance is a trillion times bigger than the model predicts.”

Sevior says that this inconsistency between the model and the universe implies there is a new principle of physics that we haven’t yet discovered.

“Together with our colleagues in the Belle experiment, based at KEK in Japan, we have produced vast numbers of B mesons with the world’s most intense particle collider.”

“We then looked at how the B-mesons decay as opposed to how the anti-B-mesons decay. What we find is that there are small differences in these processes. While most of our measurements confirm predictions of the Standard Model of Particle Physics, this new result appears to be in disagreement.”

“It is a very exciting discovery because our paper provides a hint as to what the new principle of physics is that led to our Universe being able to support life.”

Note for Antimatter
In particle physics and quantum chemistry, antimatter is the extension of the concept of the antiparticle to matter, whereby antimatter is composed of antiparticles in the same way that normal matter is composed of particles. For example an antielectron (a positron, an electron with a positive charge) and an antiproton (a proton with a negative charge) could form an antihydrogen atom in the same way that an electron and a proton form a normal matter hydrogen atom. Furthermore, mixing of matter and antimatter would lead to the annihilation of both in the same way that mixing of antiparticles and particles does, thus giving rise to high-energy photons (gamma rays) or other particle–antiparticle pairs. The particles resulting from matter-antimatter annihilation are endowed with energy equal to the difference between the rest mass of the products of the annihilation and the rest mass of the original matter-antimatter pair, which is often quite large.

There is considerable speculation both in science and science fiction as to why the observable universe is apparently almost entirely matter, whether other places are almost entirely antimatter instead, and what might be possible if antimatter could be harnessed, but at this time the apparent asymmetry of matter and antimatter in the visible universe is one of the greatest unsolved problems in physics. The process developing particles and antiparticles is called baryogenesis.

In December 1928 Paul Dirac developed a relativistic equation for the electron, now known as the Dirac equation. Curiously, the equation was found to have negative-energy solutions in addition to the normal positive ones. This presented a problem, as electrons tend toward the lowest possible energy level; energies of negative infinity are nonsensical. As a way of getting around this, Dirac proposed that the vacuum is filled with a "sea" of negative-energy electrons, the Dirac sea. Any real electrons would therefore have to sit on top of the sea, having positive energy.

Thinking further, Dirac found that a "hole" in the sea would have a positive charge. At first he thought that this was the proton, but Hermann Weyl pointed out that the hole should have the same mass as the electron. The existence of this particle, the positron, was confirmed experimentally in 1932 by Carl D. Anderson. During this period, antimatter was sometimes also known as "contraterrene matter".

Today's Standard Model shows that every particle has an antiparticle, for which each additive quantum number has the negative of the value it has for the normal matter particle. The sign reversal applies only to quantum numbers (properties) which are additive, such as charge, but not to mass, for example. The positron has the opposite charge but the same mass as the electron. For particles whose additive quantum numbers are all zero, the particle may be its own antiparticle; such particles include the photon and the neutral pion.

Note for B mesons
B mesons comprise a bottom antiquark and an up (B+), down (B0), strange (Bs0) or charm (Bc+) quark. Their respective antiparticles comprise a bottom quark and an up (B−), down (B0), strange (Bs0) or charm quark (Bc−). The neutral B mesons, B0 and Bs0, spontaniously transform into their own antiparticles and back. This fenomenon is called flavor oscillation and has been measured in the B0/B0 system to be about 0.496ps-1 but remains to be observed in the Bs0/Bs0 system. On of the mayor goals of the DØ experiment[2] is to measure the oscillation frequency of the later system. It is predicted to be between 16.7ps-1 and 25.4ps-1.

Note for Big Bang
The Big Bang is a cosmological model of the universe that has become well supported by several independent observations. After Edwin Hubble discovered that galactic distances were generally proportional to their redshifts in 1929, this observation was taken to indicate that the universe is expanding. If the universe is seen to be expanding today, then it must have been smaller, denser, and hotter in the past. This idea has been considered in detail all the way back to extreme densities and temperatures, and the resulting conclusions have been found to conform very closely to what is observed.

Ironically, the term 'Big Bang' was first coined by Fred Hoyle in a derisory statement seeking to belittle the credibility of the theory that he did not believe to be true. However, the discovery of the cosmic microwave background in 1964 was taken as almost undeniable support for the Big Bang.

Analysis of the spectrum of light from distant galaxies reveals a shift towards longer wavelengths proportional to each galaxy's distance in a relationship described by Hubble's law, which is taken to indicate that the universe is undergoing a continuous expansion. Furthermore, the cosmic microwave background radiation discovered in 1964 provides strong evidence that due to the expansion, the universe has naturally cooled from an extremely hot, dense initial state. The discovery of the cosmic microwave background led to almost universal acceptance among physicists, astronomers, and astrophysicists that the Big Bang describes the evolution of the universe quite well, at least in its broad outline.

Further evidence supporting the Big Bang model comes from the relative proportion of light elements in the universe. The observed abundances of hydrogen and helium throughout the cosmos closely match the calculated predictions for the formation of these elements from nuclear processes in the rapidly expanding and cooling first minutes of the universe, as logically and quantitatively detailed according to Big Bang nucleosynthesis.

However, there are mysteries of the universe that are not explained by the Big Bang model alone. For example, a region of the universe 12 billion lightyears distant in one direction appears little different than a region 12 billion lightyears distant in the opposite direction. But since the universe is 'only' around 13.7 billion years old, it would appear these regions could never have been causally connected. How, then, can they be so similar? Alan Guth's 1981 theory of cosmic inflation, a short, sudden burst of extreme exponential expansion in the very early universe, provided an explanation for this horizon problem and several of the features unaccounted for by the original Big Bang model. The successor to Guth's original theory has found some circumstantial support, but it is not yet nearly as well supported as the Big Bang model.

The Big Bang theory developed from observations of the structure of the universe and from theoretical considerations. In 1912 Vesto Slipher measured the first Doppler shift of a "spiral nebula" (spiral nebula is the obsolete term for spiral galaxies), and soon discovered that almost all such nebulae were receding from Earth. He did not grasp the cosmological implications of this fact, and indeed at the time it was highly controversial whether or not these nebulae were "island universes" outside our Milky Way. Ten years later, Alexander Friedmann, a Russian cosmologist and mathematician, derived the Friedmann equations from Albert Einstein's equations of general relativity, showing that the universe might be expanding in contrast to the static universe model advocated by Einstein. In 1924, Edwin Hubble's measurement of the great distance to the nearest spiral nebulae showed that these systems were indeed other galaxies. Independently deriving Friedmann's equations in 1927, Georges Lemaître, a Belgian physicist and Roman Catholic priest, predicted that the recession of the nebulae was due to the expansion of the universe.