Nuclear seminar

Chiral dynamics of hadrons

Based on N_C expansion, dynamical chiral symmetry breaking, and explicit chiral symmetry

  the Lagrangian of chiral field theory of mesons is constructed. The formalism of the meson theory

  is presented. It shows that this theory reproduces all the successes of previous study and answers

  all the puzzles in meson physics. A new symmetry breaking mechanism is revealed from this theory.

Date:
-
Location:
CP179
Event Series:

Lattice Effective Field Theory applied to Nuclear Physics

Lattice effective field theory combines the framework of effective field theory with computational lattice methods.  I discuss several recent results by the Nuclear Lattice Effective Field Theory Collaboration.  Some of the topics I will cover are the quark mass dependence of carbon production in red giant stars, the structure of oxygen-16, and ab initio simulations of medium-mass nuclei.

Date:
-
Location:
CP179
Event Series:

Muon g-2 and The Big Move

An international collaboration of 140 scientists is constructing an experiment to perform the most precise measurement of the anomalous magnetic moment of the muon. The muon ‘g’ factor is predicted to be exactly 2 by relativistic quantum mechanics. Deviations from 2 are caused by quantum fluctuations of virtual particles in the vacuum. Quantum Field Theory predicts these deviations from 2 well below the part per million level motivating our experimental goal of 0.1 parts per million precision. The cornerstone of the experiment is a 50 foot superconducting electromagnet used to store the muons that was constructed for the last Muon g-2 experiment at Brookhaven National Lab in the 90’s. The ring is a marvel of engineering and it was decided to move the entire ring intact from Brookhaven to Fermilab rather than try to reproduce the masterpiece. In this talk, I will motivate the measurement, describe the experimental techniques, present the status of the new experiment, and show highlights from The Big Move that occurred last July.

Date:
-
Location:
CP179
Event Series:

A spooky peek in the mirror: probing the weak nuclear force

The Hallowe'en Interaction (HWI) is a ghoulish way of investigating nuclear

structure.  Although it is dominated by the unsinister strong interaction, it

howls out in full force in the enchanted mirror of parity violating (PV)

observables.  The HWI is classified by the spin and isospin dependence of

transition amplitudes involving S and P waves.  There is an active program to

determine these mysterious parameters by measuring hadronic PV in reactions

with spine-chilling neutron beams.  These unnerving experiments use only

few-body observables, for which nuclear wave functions are not so horribly

gruesome to calculate.  We report startling intermediate results from the

NPDGamma experiment, sensitive to the long-range weak pion exchange, and

currently haunting the SNS.  The n-3He experiment is lurking in the shaddows

to pin down isospin zero couplings frightfully soon afterwards.  A

complementary experiment to measure the ghastly neutron spin rotation in 4He

is being scared up for an improved precision run at the NCNR reactor at NIST.

We show how this wizardry will over-constrain the four dominant couplings of

the HWI and will lay skeletons to rest for the first time.

Date:
-
Location:
CP179
Event Series:

Beta decays as tests of Lorentz invariance

Lorentz symmetry is a cornerstone of modern physics. As the
spacetime symmetry of special relativity, Lorentz invariance is

a basic component of the standard model of particle physics

and general relativity, which to date constitute our most successful

descriptions of nature. Deviations from exact symmetry would

radically change our view of the universe and current experiments

allow us to test the validity of this assumption. In this talk, I will

describe how we can use current and future beta-decay experiments

to search for some key signals of the violation of Lorentz invariance.
Date:
-
Location:
CP179
Event Series:

Neutron-rich Nuclei at the Heavy Frontier

The focus of this talk will be on high-spin spectroscopy of neutron-rich
nuclei with 94<Z<98, accessed via inelastic and transfer reactions,

using heavy stable beams on radioactive targets. These complement

spectroscopic investigations of elements with 100<Z<104 using

fusion-evaporation reactions. The physics of the highest neutron

orbitals at and beyond N=150 will be discussed. Valence orbitals here

can originate from above the spherical shell gaps that are believed to

be responsible for the stability of superheavy elements. Thus, a precise

mapping of single particle states in this deformed region can provide

guidance and constraints for theories that attempt to predict the next

higher spherical magic numbers.

 

 

Date:
-
Location:
CP179
Event Series: