[Hallc_sidis_analysis] [EXTERNAL] SIDIS Analysis Meeting Cancelled

[Dipangkar Dutta]

Hi All,
We will have to cancel the regular CSV analysis meeting tomorrow (Friday)
to be able to attend the Marathon session of MARATHON talks.

I am sure all of you will want to attend these talks (see announcement
below).

Date: Wed, 28 Apr 2021 13:09:05 +0000
From: Stephanie Tysor <stysor at jlab.org>
To: "jlab-seminars at jlab.org" <jlab-seminars at jlab.org>
Subject: [Jlab-seminars] Virtual Physics Division Seminar: The
        MARATHON Marathon; Hanjie Liu, Christopher Cocuzza, Efrain Segarra
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Virtual Physics Division Seminar

The MARATHON Marathon
Hanjie Liu, Christopher Cocuzza, Efrain Segarra
University of Massachusetts Amherst, Temple University, Massachusetts
Institute of Technology


The recently released MARATHON results have generated considerable interest
with two derivative papers already on the arXiv. This Friday we will have a
MARATHON Marathon with Hanjie Li (Univ. of Mass. Amherst), Christopher
Cocuzza (Temple), and Efrain Segarra (MIT) presenting these new results. We
will loosely follow an APS invited session format with each presenter
having thirty minutes to present though we have allow considerably more
time for questions and discussions.

Friday, April 30, 2021
12:00 pm ? 2:30 pm
https://urldefense.proofpoint.com/v2/url?u=https-3A__bluejeans.com_245615984&d=DwIBaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=6UVi9h7XDe4YpNVl1Pr7kJfw2N_A9rNcjJ8jEvLZw2M&m=QfNcmedh3v49Fjs9panIiJdq1q4VX6MtC0n31uaj0jk&s=dunkNhN3VV47ZQz0gTMRoHfWs4h2od5fz__yQOJhuyo&e= 



Abstracts:

The Measurement of the Nucleon F2n/F2p Structure Function Ratio from the
MARATHON Experiment



Hanjie Liu (Univ. of Mass. Amherst)



The ratio of neutron structure function to that of proton F2n/F2p is one of
the best methods to extract d/u quark ratio.  While the F2n/F2p extracted
from deuteron deep inelastic scattering data has large systematic
uncertainty at high x (x>0.7) from model dependent nuclear corrections, the
MARATHON experiment, which ran in spring 2018, uses a novel method. It
performed deep inelastic electron scattering off tritium and helium-3
mirror nuclei to measure F2n/F2p over the range x=0.195 to x=0.825. Since
tritium and helium-3 are mirror nuclei, theoretical uncertainties are
expected to be largely canceled out in the ratio. The results of F2n/F2p
from the MARATHON experiment was recently posted in arxiv. An overview of
the MARATHON experiments and the results will be presented.




First Evidence of Isovector EMC effect from Global QCD Analysis with
MARATHON Data


Christopher Cocuzza (Temple)


I will report the results of a Monte Carlo global QCD analysis of
unpolarized parton distribution functions (PDFs), including for the first
time constraints from ratios of 3He to 3H structure functions recently
obtained by the MARATHON experiment at Jefferson Lab.  This simultaneous
analysis of nucleon PDFs and nuclear effects in A=2 and A=3 nuclei reveals
the first indication for an isovector nuclear EMC effect in light nuclei.
Thus, while the MARATHON data yield relatively weak constraints on the
F2n/F2p neutron to proton structure function ratio and the d/u PDF ratio,
the data suggest a strongly enhanced nuclear effect on the d-quark PDF in
the bound proton.




Nucleon Off-shell Structure and the Free Neutron Valence Structure from A=3
Inclusive Electron Scattering


Efrain Segarra (MIT)


While there are large amounts of proton structure measurements, data on the
structure of the neutron is much more spars as experiments typically
extract the structure of neutrons from measurements of light atomic nuclei
using model-dependent corrections for nuclear effects.   Here we evaluate
the model dependence of this extraction by examining a wide range of models
including the effect of using instant-form and light-cone nuclear wave
functions and several different parameterizations of nucleon modification
effects, including those with and without isospin dependence. We find that,
while the data cannot differentiate among the different models of nuclear
structure and nucleon modification, they consistently prefer a
neutron-to-proton structure function ratio of at xB?1 of ?0.4 with a
typical uncertainty (1?) of ?0.05 and ?0.10 for isospin-independent and
isospin-dependent modification models, respectively. While strongly
favoring SU(6) symmetry breaking models based on per!
 turbative QCD and the Schwinger-Dyson equation calculation, the MARATHON
data do not completely rule out the scalar di-quark models if an
isospin-dependent modification exist.


Friday, April 30, 2021
12:00 pm ? 2:30 pm
https://urldefense.proofpoint.com/v2/url?u=https-3A__bluejeans.com_245615984&d=DwIBaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=6UVi9h7XDe4YpNVl1Pr7kJfw2N_A9rNcjJ8jEvLZw2M&m=QfNcmedh3v49Fjs9panIiJdq1q4VX6MtC0n31uaj0jk&s=dunkNhN3VV47ZQz0gTMRoHfWs4h2od5fz__yQOJhuyo&e= 




Cheers
Dipangkar
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