Magnetic Polarizability of Hadrons from Dynamical Configurations Scott Moerschbacher The George Washington University Lattice 2008, July 14

Outline of Talk Magnetic Polarizability Physics Lattice Calculation Results of Simulations Future Possibilities

Classical Polarizability The polarizability is the proportionality constant between the induced dipole moment and the field.

Simulation Parameters Lattice Approach CP-PACS Dynamical Configurations: Simulation Parameters

Lattice Approach Nucleon interpolating fields Correlation Functions

Background Field Method Introduce the magnetic field as a phase onto the lattice links Covariant Derivative:

Linear vs. exponential Do we linear-ize??

Extraction of Polarizability Expand the mass shift as a polynomial in the field:

Lat 16—EMass Shifts—Linear

Lat 16—EMass Shifts—Linear

Lat 16—EMass Shifts—Exp

Lat 16—EMass Shifts—Exp

Lat 12—Polarizabilty—Exp

Lat 12—Polarizabilty—Linear

Lat 16—Polarizabilty—Linear

Lat 16—Polarizabilty—Exp

Conclusions… What have we learned?? a=0.2 is too coarse Perhaps the field should be introduced as an exponential phase…

What next?? Better statistics Introduce the field at the point of configuration generation And of coarse.. Smaller spacings and quark masses..

Extra Slides… Extra Slides…

Lat 16—Polarizabilty—Exp

Proton Polarizability--Linear

Mass Shifts--Exponential