Discovery of the chib(3p) particle

The Large Hadron Collide (LHC) has proved its value once again.  This time by confirming the existence of an up till now hypothetical particle.  Known as the Chib(3p) particle, it is a boson, the same class of particle the Higgs is in.  Bosons are any particle with an integral spin (0, 1, 2, etc).  The existence of Chib had been expected for quite a while, but the energies required to detect it had yet to be attained.  However thanks to the LHC, teams of physicists working with the ATLAS (A Toroidal LHC ApparatuS ) detector were able to do just this.

Unlike the Higgs Boson, the chip particle is not an Elementary Boson, but composed out of other particles, namely a pairing of a Bottom and an antiBottom quark.  Sometimes still refereed to as the Beauty quark (it all depends on where the team you are working with hails from), interactions between this kind of pairing had been beyond the abilities of particle accelerators until now.

For a little more explanation into what this means, let me first explain what a meson is.  A meson is a pairing of a quark and an anti-quark.  While quarks are technically fermions (particles that have fractional spins, such as 1/2, 2/3, etc) and have a mass, when a quark and its anti-quark join up, their spins combine to form an integral spin (1/2 + 1/2 = 1), making them actually a Boson.  As I said, this puts them in a different class from elementery Bosons such as the photon, W and Z Bosons, gluon, and potentially the Higgs and Graviton.  Instead, they are called Composite Bosons, due to their being constructed of multiple parts.  This allows them to have mass and, because of this, does not allow them to have a trait shared by Elementary Bosons such as the ability for multiple to be in the same place at the same time.  Known as the Pauli Exclusion Principle, particles with mass cannot exist in the same place at the same time.  But Bosons do have an effect on the Pauli Exclusion principle, being that, for a short range, particles are attracted to one another if they are of the right type.

To elucidate this, think of a simple atom, say Helium.  A neutral atom of Helium is made of two protons, two neutrons (though this varies in isotopes) and two electrons.  Each Proton is composed of a series of Quarks, namely two Down and an Up Quark (while a Neutron is made up of one Down and two Up Quarks).  These are held together by the exchange of the Elementary Bosons called Gluons, which mediate the Strong Nuclear Force.  At very close distances, the interaction of these Quarks through their Gluons emit short lived Mesons, which, as we said, are Composite Bosons, usually made of an Up and an antiDown Quark (or vice versa) that radiates away and quickly decays.  But before it can decay, it extends the Strong Nuclear Force (mediated by the Gluons) to the nucleaus and holds the protons and neutrons together despite being of the same charge and wanting to be apart (remeber how like charges such as with a magnet repel?).  This is what I was meaning as the short range of the Pauli Exclusion principle where Fermions (in this case, the protons) can be held together.  The Composite Bosons (if you wish to know, the up and antidown pair is known as a Pion) keep them together, elaborating upon the Strong Nuclear Force.

Now that this is in place, we can understand what the Chib particle really is.  It is a Composite Meson that is made up of, and in turn, holds together a Bottom and and antiBottom pair.  Through this process, many ordinary bits of matter get much of their mass.  Their mass is an effect of the Strong Nuclear Force emiting these Mesons and holding things together.  The Higgs field is still needed to determin what that mass will be, but it cannot do it without the Strong Force. 

While this new particle is very short lived, it shows that the underlying physics that we have developed is still displayed in nature which is good news for researchers looking for this Higgs Boson.  It doesn't mean the Higgs does exist, it just means that there is a bit more evidence to suggests that it does based on what we have observed.

CERN announces possible evidence for the Higgs Boson

On Tuesday, December 13th, the European Center for Nuclear Research (CERN) announced that two competing teams have possibly detected the hypothetical Higgs Boson, the last of the elementary particles predicted by the Standard Model remaining to be uncovered. The possible new discovery was made at the Large Hadron Collider (LHC), the largest particle accelerator in existence. With a circumference of 27km (17 miles), the LHC is able to accelerate twin proton beams up to a speed of 99.999 the speed of light, creating an impact energy of 14.7 TeV (Terra Electron Volts). One of the prime reasons for the construction of the LHC was to look for the Higgs Boson, which until the construction of the LHC, had a predicted energy limit above the capability of the largest particle colliders of the time.

The announcement was made based on the works of two competing teams working at two separate detectors located at the LHC. One at the ATLAS (A Toroidal LHC ApparatuS) and the other at the CMS (Compact Muon Solenoid), both of which are considered the general purpose detectors of the LHC, with the ATLAS fittingly being the larger of the two. The team at ATLAS found an excess of reactions stemming from the range of 125-6 GeV (Giga Electron Volts) while the CMS team found a similar excess at 124 GeV. When combined with other data from previous experiments, this gives us a certainty of 95% of the Higgs Boson being limited to the range of 115-130 Gev. To give you an example of what these numbers mean, 125 GeV is 133 times the mass of a proton, one of the two particles that make up the nucleus of an atom.

The Higgs Boson itself is far to short lived to be detected directly. Instead, it can be infered based on particles formed from its decay inside the detectors at the LHC. Because of this and the mess of other particles formed during these intense collisions, it takes both large amounts of computing power as well as huge numbers of collisions. In the case of the Higgs, an excess of two muons and two neutrinos, which come from, in turn, two W bosons. Because these kinds of reactions can be formed by random background noise, physicists must be careful to rule out all possible causes before settling upon the Higgs Boson as the source.

A simulated computer model for the reaction caused by a Higgs Boson.

It should be noted that CERN did not confirm that the Higgs Boson had been discovered, but that further evidence must be uncovered before it can be safely said that the Higgs Boson exists. Until then, this new data only makes the existence of the particle much more likely while reducing the energy ranges that are likely to harbor the particle. If the Higgs does exist, it is expected to be confirmed sometime in 2012 if current predictions are accurate.

The importance of the discovery of the Higgs Boson is hard to understate. It has often been referred to as the "God Particle" in the media, much to the chagrin of many physicists. This is due to the book of the same name written by physicist Leon Lederman who has been quoted as stating that the Higgs Boson is:

so central to the state of physics today, so crucial to our understanding of the structure of matter, yet so elusive

As well as jokingly following this with:

the publisher wouldn't let us call it the Goddamn Particle, though that might be a more appropriate title, given its villainous nature and the expense it is causing.

The Higgs Boson was predicted by three independent groups at nearly the same time in 1964. Eventually the particle was named after one of these individuals who has been given the credit for fleshing out the concept the most, Scottish physicist Peter Higgs. The Higgs Boson is the quanta (smallest unit of energy) for the Higgs Field, which would grant mass to other particles. One of the simplest ways to describe the Higgs Field was written by David J. Miller. He described the process as:

Imagine that a room full of physicists chattering quietly is like space filled with the Higgs field. A well-known scientist walks in, creating a disturbance as he moves across the room and attracting a group of admirers with every step.

This increases his resistance to movement. In other words, he acquires mass, just like a particle moving through the Higgs field. Now imagine if, instead of a well-known scientist entering, somebody started a rumour.

As the rumour spreads throughout the room, it creates the same kind of grouping, but this time it’s the scientists grouping together.

In this analogy, these groups are the Higgs bosons. If we find these groups, we can prove the Higgs field exists and thus explain the origin of mass.

The Higgs Boson also would be responsible for the symmetry breaking of the ElectroWeak Force, which is a combination of the Electromagnetic and Weak Nuclear forces and would explain why the mediating particle of the Electromagnetic (the Photon) is mass-less while the ones for the Weak Nuclear (the W and Z bosons) has a mass. It has also been hypothesized as one possible cause for the Inflationary period of the universe, when the young and hot cosmos expanded in volume by a factor of 10 to the 78th power between the times of 10 to the -36th seconds and either 10 to the -33rd or -32nd seconds. Though the Higgs Boson's part in Inflation is still hotly debated.