[Theory-seminars] Seminars next week

[Carlota Andres Casas]

Dear all,

Here is a reminder for seminars next week:

Theory seminar:
Monday, Dec 9, 1:00PM, Room L102
Sergey Syritsyn (Stony Brook University), "Calculations of nucleon EDM on a lattice"

Abstract:
Electric dipole moments of the nucleons would be evidence of CP violation due to the QCD theta term or effective quark-gluon interactions induced by symmetry-breaking physics beyond the Standard Model. Upcoming experiments will improve precision of neutron EDM measurements by 1-2 orders of magnitude within the next decade. Corresponding improved constraints on (and eventual observation of) nucleon EDMs will have to be traced back to the quark-gluon level to be used as constraints on new particles and interactions. While low-energy theories and nucleon models provide ballpark estimates of nEDMs that can be produced by different kinds of CP violation in quark-gluon interactions, nonperturbative QCD calculations on a lattice are necessary to find precise and model-independent relations between them. Lattice QCD has reached a respectable level of statistical and systematic precision for hadron spectrum and simple nucleon structure observables with physical quark masses, and on the verge of producing reliable results for nucleon EDMs induced by quark-gluon operators starting from the lowest-order operators. In this talk, I will overview the current status of such calculations as well as discuss some recent results and outlook.



Theory seminar:
Wednesday, Dec 11, 1:00PM, Room F224-225
Michael Paolone (Temple University), "Coulomb Corrections and the Coulomb Sum Rule at JLab"

Abstract:
In order to determine the Coulomb sum in nuclei, a precision measurement of inclusive electron scattering cross sections in the quasi-elastic region was performed at Jefferson Lab. Incident electrons with energies ranging from 0.4 GeV to 4 GeV scattered from 4He,12C, 56Fe and 208Pb nuclei at four scattering angles (15, 60, 90,120 deg) and scattered energies ranging from 0.1 GeV to 4 GeV. The Rosenbluth separation method is used to extract the transverse and longitudinal response functions at three-momentum transfers in the range 0.55 GeV/c < q < 1.0 GeV/c.  The coulomb distortion of the incident and scattered electron wave-functions due to the electro-static potential of the nucleus is typically accounted for in experimental analysis with an effective momentum approximation (EMA).  The documented effectiveness and limitations of this approximation for specific nuclei and kinematics will be discussed.  For heavier nuclei, the need for alternative corrections specific to the kinematics of data collected at Jefferson Lab will also be discussed.

Bluejeans connection: https://bluejeans.com/610445877

Raza, Miguel, Carlota



--

Postdoctoral researcher
Theory Center - Jefferson Lab
12000 Jefferson Avenue,
Newport News, VA 23606 USA
CEBAF center, office A206

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