Rotation curves & lensing. Cosmic acceleration. Stars, planets, Human life. Nuclear Science: The Mission. Understand the origin, evolution, and structure of the baryonic matter of the Universe. from M. Ramsey-Musolf, Caltech. FUNDAMENTAL PARTICLES+INTERACTIONS redux.
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Hot Dense Matter and Phase Transitions
(What are the phases, how did the early universe behave?)
QCD and the Structure of Matter
(How are nucleons constructed from quarks and gluons, what about nuclei? )
(n’s, neutron beams, radioactive ion traps)
Origins of the Elements
(How are elements formed in stars, how do stars burn, what are the limits of stability?)
Modern Tools of Nuclear Physics
From W. Nazarewicz, ORNL
KS 1731-260What is the Origin of the Elements?
from MSU Phys 983 web site
Search for evidence of transition from nucleons to “free” quarks + gluons at very high energy density.
compare d-Au collisions with Au-Au collisions
Nuclear Physics is a Tool
atomic trapping of radioactive atoms
a trapped 21Na atom at Berkeley
test time reversal invariance
unitarity of quark mixing
neutron lifetime -> He abundance
solar neutrino mixing showed that neutrinos have mass
what are the masses?
Are there more than 3 types?
A 6 GeV continuous
electron beam accelerator
superconducting RF cavities
First beam in 1995
3 experimental halls
50-100 people per
properties of light nuclei
strangeness in nuclei
Strong interaction QCD
do not exist in QED!
e.g. Proton: u + u + d Qp = 2(2/3) + (-1/3) = 1
Neutron: u+ d + d Qn = (2/3) + 2(-1/3) = 0
BUT:quarks are very light and relativistic
gluons carry angular momentum
interaction is STRONG and INCREASING with distance
Example 1: Hydrogen atom
MH = 1.00794(7) amu = 938.89(6) MeV
Mp = 938.27231(28) MeV
me = 0.51099906(15) MeV
Ionization energy = 13.6 eV = 10-8 MH
Example 2: pion
Example 3: proton
Mp = 938.27231(28) MeV
(2mu+md) 0.015 Mp
De Broglie Wavelength:l ~ h/p (~ hc/E)
visible:l ~ 500 nm, E ~ few eV atomic structure
X-rays:l ~ 0.01-1 nm, E ~ few keV crystallography
gamma rays:l < 0.1 nm
E ~ MeV (106 eV) nucleons inside nuclei
E ~ GeV (109 eV) quark structure of nucleons
(1 electron-Volt = 1.602 x 10-19 Joules)
find “effective” degrees of freedom to relate observation to measurement. Works well for 2 nucleons, not so well for > 2.
quarks + gluons
are weakly interacting
at high energy. Can
“brute force”: large scale computing
Put quarks on a grid in (x,y,z,t), compute interactions, build nucleon
Why is there more matter than anti-matter ?
How do the properties of baryons, leptons and their interactions reflect the symmetries of the early Universe?
What is the nature of baryonic matter at the highest temperatures and densities ?
How do the properties of the vacuum evolve with temperature?
How is the nucleon assembled from the quarks and gluons of the Standard Model?
How do the interactions between quarks and gluons give rise to the properties of light nuclei?
How do the properties of complex nuclei arise from the elementary NN interaction?
What are the limits of nuclei and atoms?
How does the physics of nuclei impact the physical Universe (origin of heavy elements)?
How does the physics of nuclei impact the physical Universe (neutron stars, supernovae, neutrinos…)?