[Theory-seminars] Lecture series and seminars next week

[Christopher Thomas]

Dear all,

Next week, as well as the usual seminars, we have the start of a *mini 
lecture series on "The transverse spin and momentum structure of 
hadrons" (Wednesday and Friday)*:

* Mon, Mar 22, 1pm (L104): Theory Seminar -- Daniel Mohler (TRIUMF) 
"Properties of ground and excited state hadrons from lattice QCD"

* Weds, Mar 24, 3pm (L104): Cake Seminar -- Diana Nicmorus (Univ. Graz, 
Austria) "A Dyson-Schwinger equation study of the nucleon-photon vertex"

Mini lecture series by Leonard Gamberg (Penn State) on "The transverse 
spin and momentum structure of hadrons":
* Weds, Mar 24, 11am (F113)
* Fri, Mar 26, 11am (F113)
* Mon, Mar 29, 11am (F113)

More details and abstracts below:


-----
Monday, March 22nd
1pm (coffee at 12:45pm)
Room L104

*Properties of ground and excited state hadrons from lattice QCD*

Daniel Mohler
TRIUMF, Canada

Over the years the determination of ground state hadron masses from
lattice QCD has continuously improved. While these states are a good
benchmark for lattice calculations, a large number of hadron excitations
are known and it would be desirable to calculate their properties from
first principles. This turns out to be a highly non-trivial task, as
excited states only contribute as sub-leading exponentials to Euclidean
correlation functions. In this talk I will briefly describe one possible
method for the calculation of excited state properties and present
results for light-quark mesons from simulations with Chirally Improved
fermions. For scalar mesons, both conventional quark-antiquark states as
well as a tetraquark interpretation will be considered. In addition, I
will present some (preliminary) results for baryon axial charges.


-----
Wednesday, March 24th
3pm
Room L104

*A Dyson-Schwinger equation study of the nucleon-photon vertex*

Diana Nicmorus
Univ. Graz, Austria

I present a Dyson-Schwinger equation motivated study of the physics
that governs the nucleon. In particular I focus on the quark-core
contributions to the nucleon mass and form factors. The calculations
are performed within in a Poincare-covariant Faddeev framework
describing the quark-core of the nucleon via a quark-diquark picture.
A consistent setup for the dressed-quark propagator, the quark-quark
and the quark-diquark interactions is used, where all the ingredients
are solutions of their respective Dyson-Schwinger or Bethe-Salpeter
equations and obtained in the rainbow-ladder truncation. In the
quark-diquark picture a nucleon-photon vertex that fulfills the
electromagnetic Ward-Takahashi identity is resolved by specifying
the quark-photon and diquark-photon vertices, and by using a
consistent ansatz for the seagull terms. I discuss the evolution of
the nucleon properties with the current quark mass, as well as the
role of the pion cloud in this approach. I also present a comparison
of the results to a collection of experimental and lattice data.

Cake Sponsor: Rocco


-----
*Mini lecture series on "The transverse spin and momentum structure of 
hadrons"*

Wednesday 24th, Friday 26th and Monday 29th March
11am
Room F113

Leonard Gamberg
Penn State

Theoretical  and experimental research on hard scattering processes has 
resulted in a great deal of knowledge on the partonic content of hadron 
structure. These talks focus on the role that transverse spin and 
momentum correlations play in our understanding of the partonic 
sub-structure of the  hadrons in the context of QCD scattering
reactions such as semi-inclusive deep inelastic scattering.  An emphasis 
is placed on the emerging role of so call naive time reversal odd 
("T-odd") effects in describing these correlations in terms of parton 
distribution and fragmentation functions.  I will  summarize the key 
theoretical issues and discuss some experimental results that have led 
us to the present understanding.


-----


A complete list of upcoming theory seminars and talks from previous
seminars are available from:
http://www.jlab.org/~thomasc/seminars/index.html

Thanks,
Christopher


-- 
Christopher Thomas

Jefferson Laboratory
12000 Jefferson Avenue
Suite #1
Newport News
VA 23606
USA

Tel: +1 (757) 269 7453
Email: thomasc at jlab.org