[Theory-seminars] Seminar tomorrow

[Raza Sufian]

Dear All,

Here is a reminder for the seminar tomorrow. The summer students will be giving 15 minute talks.

Cake seminar:
Monday, July 29, 1:00PM, Room F113

Marston Copeland, "Self-energies in a relativistic chiral effective theory"
Abstract: We calculate the self-energies of the flavor SU(3) octet and decuplet baryons, using a relativistic chiral effective theory framework consistent with Lorentz and gauge invariance. The results are compared using several different regularization prescriptions, including finite-range regularization, Pauli-Villars, and dimensional regularization, which are shown to yield the same leading nonanalytic behaviors in the chiral limit, as expected in QCD. Using the same chiral effective theory, the self-energy corrections to the baryon masses can also be computed.

Luisa Velasco, “Improving the Particle Multiplicity Generator Model for the Empirically Trained Hadronic Event Regenerator"
Abstract:
Particle collision event generators are extremely useful, providing synthetic data quickly and to the user’s specifications. At present, all such event generators function via underlying theory that provides rules by which particle multiplicities and momenta are generated. To remove theory dependence, the Empirically Trained Hadronic Event Regenerator (ETHER) at Jefferson Lab implements machine learning models to be trained on experimental data.  The focus of this study is to improve the performance of the particle multiplicity generator and develop the implementation of a non-trivial conditional feature. An ensemble learning meta-algorithm is implemented to refine the model’s learning ability. The base model is altered to accept a conditional label and is trained on continuous and discrete encoded labels. We find that the model's ability to learn rare events can be augmented through ensemble training, but it struggles to learn the shifts in the underlying data distribution necessary for the successful implementation of a conditional feature. Preliminary results suggest that many more training steps are required to implement a conditional feature in the generator model.


Jake Bringewatt, “Confronting lattice parton densities with global QCD analysis"
Abstract:
Recent progress in lattice QCD simulations of parton quasi-distributions is paving the way towards the study of the
momentum dependence of PDFs from first principles. We are working on a combined global QCD analysis of inclusive deep-inelastic scattering, Drell-Yan and other high-energy scattering data with recent results from lattice calculations of the u − d PDFs in the proton. In this talk I present our initial fits for unpolarized and polarized PDFs anddiscuss how the lattice results match with phenomenological determinations of PDF parameters. I also analyze how these results may indicate which regions of parton fraction in the lattice data induce constraints on the  anti-down − anti-up PDF difference in the proton.

Thank you.
-Carlota, Miguel & Raza
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mailman.jlab.org/pipermail/theory-seminars/attachments/20190729/1a2fc7cf/attachment.html>