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<p>Reminder: happening in ~2 hours. <br>
</p>
<div class="moz-cite-prefix">On 4/6/25 5:13 PM, Pooyan Goodarzi
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:271dc281-acb3-41af-95e0-e8e96f679d6e@email.ucr.edu">
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<p>Hi all, <br>
<br>
We will have a PASS talk tomorrow by Ananya. Please join us
at noon (from 12:00 pm to 1:00 pm) in the Nebula Room (PHYS
3027). <br>
<br>
<br>
</p>
<div align="center"><strong>Ananya Paul</strong><b>, PhD student</b><br>
Monday, 12:00 pm, Nebula Room (PHYS 3027)</div>
<div align="center"><b>Measurement of the Transverse Single Spin
Asymmetry (TSSA) of Neutral pions using transversely
polarised proton-proton collisions (COM 200 Gev) detected at
the Endcap Electromagnetic Calorimeter (EEMC) at STAR,
Brookhaven National Laboratory</b><br>
</div>
<div align="center"><br>
In recent years, endeavours have been made towards extending
the 1D Feynman parton picture to a 3D tomography of the
partons inside the nucleon. The transverse nucleon spin i.e.
the spin component perpendicular to the nucleon momentum
direction correlates naturally with the Transverse
Momentum-Dependant (TMD) parton distributions as well as the
Generalised Parton Distributions (GPD), hence providing a deep
insight into the internal structure and parton correlations of
the nucleon. The Transverse Single Spin Asymmetry (SSA) is
defined as an asymmetry between counting rates for a given
reaction for either the probe or the target transversely
polarised. High Energy Experiments show that the charged
pions are produced asymmetrically to the left or the right of
the plane spanned by the momentum and spin directions of the
initial polarized protons: <br>
<br>
AN = dσ(S⊥) - dσ(-S⊥)/dσ(S⊥) + dσ(-S⊥)<br>
<br>
<br>
Therefore, this asymmetry is also called left-right asymmetry.
AN is quantified by the TMD quark Sivers function and the GPD
function in the transverse direction by asserting that the
spin-averaged quark distributions are symmetric in the
transverse plane. Moreover, if the nucleon (or the quark) is
transversely polarised, the quark distribution is azimuthally
asymmetric in the transverse plane. Therefore, transverse spin
phenomena enables the exploration of QCD dynamics of quarks
and gluons in hadron structure, to test advanced concepts of
QCD factorization and to test the universality of parton
distribution functions between different high-energy
scattering processes. The goal of this study is to measure
the Transverse Single Spin Asymmetry (AN ) of neutral pions
(π⁰) with the STAR Endcap Electromagnetic Calorimeter. In the
past, measurements for AN have been made at forward rapidity
(3.3 < η < 5.5) and mid-rapidity with asymmetries
consistent with zero for the latter. With the STAR Endcap
Electromagnetic Calorimeter providing an azimuthal coverage
over the pseudorapidity range 1.086 ≤ η ≤ 2.00, the
determination of AN at intermediate rapidities will be
achieved. <br>
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If you’re interested in sharing your work as a speaker, please
feel free to add your name to this spreadsheet [<a
href="https://docs.google.com/spreadsheets/d/1N3ncf43jdB6aHYHhyWmyHMycxDg4_phHZXLkQvviO0o/edit?usp=sharing"
target="_blank" moz-do-not-send="true">Google Sheet</a>].
Recordings of all the previous talks are available at our
website: <a href="https://ucrpass.arxiv.social/"
target="_blank" class="moz-txt-link-freetext"
moz-do-not-send="true">https://ucrpass.arxiv.social</a>
<div><br>
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<div><br>
</div>
Best,<br>
Pooyan<br>
Physics and Astronomy Student Seminar (<span class="gmail-il">PASS</span>)
<br>
<a href="https://ucrpass.arxiv.social/" target="_blank"
class="moz-txt-link-freetext" moz-do-not-send="true">https://ucrpass.arxiv.social</a></div>
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