Lecturer: Prof. Murray Moinester
Affiliation: Tel Aviv University
Abstract:
The pion polarizability is of fundamental
interest in the low-energy sector of quantum
chromodynamics. It is directly linked to the
quark-gluon substructure and dynamics of
the pion, the lightest bound system of the
strong interaction. For more than a decade,
COMPASS has been tackling the
measurement of the electromagnetic
polarizability of the charged pion, which
describes the stiffness of the pion against
deformation in electromagnetic fields.
Previous experiments date back to the
1980's in Serpheukhov (Russia), where the
Primakoff method for realizing interactions
of charged pions with quasi-real photons
was first employed. Later, other
measurements based on photon-nucleon
and photon-photon collisions were also
carried out at different laboratories.
The COMPASS measurement
demonstrates that the charged-pion
polarizability is significantly smaller than the
previous results, roughly by a factor two,
with the smallest uncertainties realized so
far.
Additional details of the upcoming Israeli
Joint Nuclear Physics' Seminars can be
found on the following link.