The Standard Model of particle physics is the most beautiful and complete theory we have so far describing the electromagnetic, the nuclear weak and the nuclear strong interactions. The matter particles interact by exchanging other particles associated with these interactions. The basic grains of matter are fermions and the force carriers are bosons. The names of these two classes refer to their spin. Fermions have half-integer values of spin whereas bosons have integer values as shown in the diagram below.
However, we know that there are several problems with the Standard Model and it's not the final ultimate theory. The problems are called "The Hierarchy Problem". Why there is a wide range in mass for the elementary particles. In the table shown, we see the electron is about 200 times lighter than the muon and 3500 times lighter than the tau. Same thing for the quarks: the top quark is 75 000 times heavier than the up quark. Other problem is the huge difference in the strength of fundamental forces, plus, the Standard Model doesn't describe gravity which seems to be very very weak compared to the other three interactions. The hierarchy problem is also related to the Higgs boson mass In the equations, the Higgs boson has a basic mass to which theorists add a correction for each particle that interact with it. The heavier the particle, the larger the correction. The top quark being the heaviest particle, it adds such a large correction to the theoretical Higgs boson mass that theorists wonder how the measured Higgs boson mass can be as small as it was found. What's more, why there are so many particles describing nature, we would like to have much simpler chart of elementary particles where we do not consider these elementary particles as elementary, like Superstring theory suggests, each particle contains a one dimensional string of energy vibrating in many modes in extradimensions and for each mode we obtain a specific particle. Finally, the Standard Model doesn't describe Dark Matter.Dark matter does not emit any light but manifests itself through its gravitational effects.
One of the most promising extensions of the Standard Model is Supersymmetry which I'm working on. In the Standard Model the vacuum is not stable. Vacuum could be stabilized by Supersymmetry. The three fundamental interactions are unified by supersymmetry. But the philosophical aspect of the theory is not satisfying, the theory predicts more particles (super-partners) and in the Next-to-The-Minimal-Supersymmetric-Standard-Model which I'm working on, there must be 7 different Higgs bosons.
The unification of gravity with the other three fundamental interactions could not be achieved if there is no Supersummetry because the most promising theories of quantum gravity are supergravity and superstring theories. There are some theorists who believe that we don't need to unify gravity because it's just a geometrical property of spacetime. But this point of view is excluded because there are cases in the universe where we need both General Relativity and Quantum Mechanics like the Black holes, because the Strength of gravity is so high thus we need General Relativity, and the matter is condensed is a very very small region of spacetime thus we need Quantum Mechanics. So we need to discover the gravitational waves and a Boson with spin 2 called Graviton. But unfortunately this is out of reach now because we need first to discover Supersymmetry.
The discovery of the Higgs Boson in 2012 was a great achievement, but as usual in science, new answers bring with them a new set of new questions.
The next run of the LHC at CERN will start in April 2015, and we will for sure either discover supersymmetry and the door will be open to the next unification, or we will discover other phenomena that our minds and mathematics couldn't find and it's cooler and more exciting because it will drive particle physics to a whole new area and physicists will face new challenges and will be forced to changed radically their views and models of the extensions of the Standard Model of Particle Physics.
-Amine Benaichouche
_M R S S Shourie
However, we know that there are several problems with the Standard Model and it's not the final ultimate theory. The problems are called "The Hierarchy Problem". Why there is a wide range in mass for the elementary particles. In the table shown, we see the electron is about 200 times lighter than the muon and 3500 times lighter than the tau. Same thing for the quarks: the top quark is 75 000 times heavier than the up quark. Other problem is the huge difference in the strength of fundamental forces, plus, the Standard Model doesn't describe gravity which seems to be very very weak compared to the other three interactions. The hierarchy problem is also related to the Higgs boson mass In the equations, the Higgs boson has a basic mass to which theorists add a correction for each particle that interact with it. The heavier the particle, the larger the correction. The top quark being the heaviest particle, it adds such a large correction to the theoretical Higgs boson mass that theorists wonder how the measured Higgs boson mass can be as small as it was found. What's more, why there are so many particles describing nature, we would like to have much simpler chart of elementary particles where we do not consider these elementary particles as elementary, like Superstring theory suggests, each particle contains a one dimensional string of energy vibrating in many modes in extradimensions and for each mode we obtain a specific particle. Finally, the Standard Model doesn't describe Dark Matter.Dark matter does not emit any light but manifests itself through its gravitational effects.
One of the most promising extensions of the Standard Model is Supersymmetry which I'm working on. In the Standard Model the vacuum is not stable. Vacuum could be stabilized by Supersymmetry. The three fundamental interactions are unified by supersymmetry. But the philosophical aspect of the theory is not satisfying, the theory predicts more particles (super-partners) and in the Next-to-The-Minimal-Supersymmetric-Standard-Model which I'm working on, there must be 7 different Higgs bosons.
The unification of gravity with the other three fundamental interactions could not be achieved if there is no Supersummetry because the most promising theories of quantum gravity are supergravity and superstring theories. There are some theorists who believe that we don't need to unify gravity because it's just a geometrical property of spacetime. But this point of view is excluded because there are cases in the universe where we need both General Relativity and Quantum Mechanics like the Black holes, because the Strength of gravity is so high thus we need General Relativity, and the matter is condensed is a very very small region of spacetime thus we need Quantum Mechanics. So we need to discover the gravitational waves and a Boson with spin 2 called Graviton. But unfortunately this is out of reach now because we need first to discover Supersymmetry.
The discovery of the Higgs Boson in 2012 was a great achievement, but as usual in science, new answers bring with them a new set of new questions.
The next run of the LHC at CERN will start in April 2015, and we will for sure either discover supersymmetry and the door will be open to the next unification, or we will discover other phenomena that our minds and mathematics couldn't find and it's cooler and more exciting because it will drive particle physics to a whole new area and physicists will face new challenges and will be forced to changed radically their views and models of the extensions of the Standard Model of Particle Physics.
-Amine Benaichouche
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