Nuclear Physics

1
Nuclear Physics

• UConn Mentor Connection
• Mariel Tader

2
The Standard Model

• Describes three of the four fundamental forces
• Electromagnetism, weak and strong interactions
• There are 12 different kinds of elementary
  particles

3
The Forces

• Electromagnetism why opposites attract
• Biology/ Chemistry
• Strong Force holds quarks together
• Weak Force mediates fundamental particle decay
• (Gravity) not included in Standard Model

4
Electroweak Theory

• Electromagnetism and weak force are two different
  aspects of the same force electroweak
• The two merge into the same force at high
  energies and close distance

5
The particles

• 6 Quarks make up protons, neutrons, etc.
• 6 Leptons electrons,
• neutrinos, etc.
• Force carriers
• gluons for strong
• force, etc.
• Weak forces range
• The three generations

6
Antimatter

• Each type of particle has a comparable
  anti-particle
• The same properties, except charge
• The mystery why so much more matter?
• Annihilation matter and antimatter collide a
  Z boson/gluon/photon form decay into new
• matter/ antimatter pair

7
The Nucleus

• Quarks come in threes (protons/ neutrons/ etc.)
  or twos (mesons)
• Gluons hold quarks together, force carrier
  particle for strong force

8
Quantum Numbers

• Electric Charge all particles except quarks have
  integer charge, quark charges add to whole
  numbers
• Flavor different kinds of quarks/ leptons
• Spin goes by 1/2s, particles/ nuclei
• Lepton/baryon numbers, etc.
• Color Charge gets its own slide
• Angular momentum/ momentum location
• Weak Charge strength of weak force

9
Color Charge

• Why quarks come in threes or twos neutral charge
• Why quarks stay together color force field
• Quark 1 of 3 colors
• Anti-quark 1 of 3 anti-colors
• Gluon color charges 1 color and 1 anti-color
  combination

10
Bosons and Fermions

• Pauli Exclusion Principle
• two particles cant have identical sets of
  quantum numbers
• Fermions obey Pauli
• Bosons violate Pauli

11
Radiation

• Unstable nuclei decay
• Alpha release of 2 protons/2 neutrons (helium
  nucleus)
• Beta release of an electron
• Gamma release of photons (as gamma rays)
• Neutron radiation like it sounds

12
Fundamental Particle Decay

• Unlike atoms, fundamentals can not break into
  constituents
• To become a less massive particle
• Emit a force carrier (W boson) virtual
• W boson immediately decays into lighter particles

13
Virtual Particles

• Can not be detected directly
• Can break conservation of energy for a very
  short time

You can not see virtual particles, but you can
see the before and after
14
The Project

• Thomas Jefferson National Accelerator
• The collaboration
• Will be the first to observe and study exotic
  mesons
• Will begin 2014

15
gluex

• GlueX hopes to learn about quarks, gluons, and
  confinement by creating exotic mesons
• How we see the gluons
• Polarized beam liquid hydrogen target
  exotic mesons final particles and radiation
  data deciphered

16
Bremsstrahlung

• German for braking radiation
• A radiation particle interacts with atoms and
  creates more radiation, while
• losing the
• corresponding
• energy

Atom
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Coherent Bremsstrahlung

• Must be in a crystal
• Particle/crystal must be in correct
  alignment
• A few specific wavelengths are prevalent,
  peaks

18
Reciprocal Lattice Vectors

• Bravais Lattice repeating crystalline
  arrangements of points
• Reciprocal Lattice
• made from the vectors
• perpendicular to three
• of the vectors of the original
• Used as a simple geometric model that can
  interpret diffraction in crystals

19
Framing the Crystal

• A frame would produce too much unwanted bremms.
• diamond is mounted
• on tiny carbon fibers
• The resonant frequency of
• the fibers should be known,
• to minimize rotation

20
Vibration

• Interference two or more superimposed waves
  create a new wave pattern need coherent bremss.
• Resonant frequency An objects natural frequency
  of vibration
• Gluonic flux tube vibration is like a string

21
The Carbon Wire

• The theoretical model vs. the experimental data
• How we modeled it
• The glue ball equation
• How we measured it
• Uncertainty bars

22
Polarization

• The orientation of the waves electric/ magnetic
  fields
• Transverse wave polarization is perpendicular to
  waves direction
• Linear Polarization
• the electric or magnetic
• field is oriented in
• one direction, i.e. no
• rotation (chirality)

23
Putting it all together

• The process Electron beam diamond wafer
  polarized photons hit mesons detectors