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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">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">https://ucrpass.arxiv.social</a>
<div><br>
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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">https://ucrpass.arxiv.social</a></div>
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