"I am among those who think that science has great beauty. A scientist in his laboratory is not only a technician: he is also a child placed before natural phenomena which impress him like a fairy tale."
- Marie Curie, Chemist and Physicist (1867 - 1934)
What is particle physics?
Particle physics is concerned with the building blocks of matter and the forces that they exert on each other.
Particle physicists are interested in questions like:
- What is dark matter and dark energy?
- What gives fundamental particles mass?
- Where does gravity fit into all of this?
What is The Standard Model?
The Standard Model of particle physics is a theory of three of the four known fundamental interactions and the elementary particles that take part in these interactions. These particles make up all visible matter in the universe. Every high energy physics experiment carried out since the mid-20th century has eventually yielded findings consistent with the Standard Model. Still, the Standard Model falls short of being a complete theory of fundamental interactions because it does not include gravitation, dark matter, or dark energy.
The Higgs Boson
The Higgs boson plays a unique role in the Standard Model, by explaining why the other elementary particles, the photon and gluon excepted, are massive. In particular, the Higgs boson would explain why the photon has no mass, while the W and Z bosons are very heavy. In fact, for a number of reasons the Standard Model could not exist as a standalone theory without the Higgs boson. At the same time, there are a number of theoretical difficulties with the SM Higgs boson which have led physicists to believe there may be some type of new physics about to be discovered that resolves these difficulties (Supersymmetry, extra hidden dimensions, technicolor etc...).On 4 July 2012, the ATLAS and CMSexperiments at CERN's Large Hadron Collider announced they had each observed a new particle in the mass region around 126 GeV, this was then confirmed to be the Higgs boson.
The knowledge of the 90 odd stable atoms was once easily summarised by the now familiar periodic table. The much smaller particles (now referred to as fundamental particles) and how they work together is summarised in this Standard Model diagram. This shows the particles that make up all matter, along with the particles that `carry' the four forces, gravity, elecromagnetism, the strong, and weak forces.
For a more detailed description of the Standard Model, its development and possible new physics visit these links:
What is terascale physics?
Terascale physics is concerned with the generation of mass and with theories that encompass extra dimensions, supersymmetry (SUSY) and new forces. The Large Hadron Collider (LHC) collides protons or ions at an energy in the ‘terascale’—so coined because of the scale of energies used in particle physics—one trillion or 1012 electron volts. Terascale experiments at the LHC are where physicists enter unchartered territory.