The Higgs - Theory The Higgs Martin Bauer Arthur H. Compton Lecture th Martin Oct. 26 2013Bauer Arthur H. Compton Lectures Oct 26th 2013 Theory
Outline The Higgs: A new interaction How the Higgs field gives particles their masses How the Higgs mechanism breaks symmetries
What are the fundamental forces? The most well known fundamental force is gravity. Newton 1686 Gravity acts on all masses!
What are the fundamental forces? The most well known fundamental force is gravity. Einstein 1916 Gravity acts on all masses! Forms of energy!
What are the fundamental forces? Electromagnetism acts on charges. It is the force that holds atoms together. It is much stronger than gravity take a guess!
- +..about a million times large than the visible universe
What are the fundamental forces? Electromagnetism acts on charges. It is the force that holds atoms together. It is 1 000 000 000 000 000 000 000 000 000 000 000 000 000 times stronger than gravity!
What are the fundamental forces? The strong nuclear Force acts on different charges (aca color charges). It holds the nucleus together It also holds the quarks in the Proton and Neutrons together It is 100 times stronger than the electromagnetic force
And we make use of this... Fermi 1942
Why are there no macroscopic objects bound by the strong force? Politzer, Gross, Wilczek 1973 it is short ranged.
What are the fundamental forces? The weak nuclear Force acts on the weak charge It is hard to picture, because there are no bound systems
What are the fundamental forces? The Higgs Force acts on masses In contrast to gravity its really only couples to masses and not to other kinds of energy
What are the fundamental forces? Name Acts on... Strength Range Spin Character Gravity Energy Extremely weak infinite 2 Always attractive Electromagnetic Force Electric charge strong infinite 1 Strong Nuclear Force Color charge Very strong 10 ¹⁵ m 1 Weak Nuclear Force Weak charge weak 10 ¹⁸ m 1 depends 10 ¹⁸ m 0! Higgs Interaction Masses Attractive or repulsive Always attractive
What is a Field? Everything is a field! The best description of nature we have today is Quantum Field Theory. particle
What is a Quantum Field? Quantum field theory tells us that there is a smallest possible excitation of a field, the quanta of this field or a particle.
What is a Quantum Field? Quantum field theory tells us that there is a smallest possible excitation of a field, the quanta of this field or a particle. When we say particles interact, what we really mean is: One field quantum excites another field. B A B
The Spin of a Field A good example for a scalar field (spin 0) is temperature
The Spin of a Field A good example for a vector field (spin 1) is a wind map
The Spin of a Field Every fundamental field In nature... 0
The Spin of a Field vev 0 The Higgs
Masses from the Higgs Field For some particles the Higgs field is transparent. They are massless and move with the speed of light. Other particles slow down in the Higgs field, for example matter fields (quarks and leptons), but also the weak force carriers. This is the reason why the weak force is short-ranged!
The Higgs Mechanism The process of generating masses for the elementary particles and clouding the weak force is called Higgs Mechanism.
The Phase of the Universe The underlying physics are the same as in phase transitions in thermodynamic systems. H2O The Universe
Symmetry Breaking When water freezes it looses its spherical symmetry. In the same way breaks the Higgs mechanism the electroweak symmetry.
Dictionary Higgs Mechanism Higgs Field Higgs Boson
Thank you for your attention!