<div dir="auto">Reminder: happenings now.</div><div><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Sun, Mar 9, 2025 at 18:12 Pooyan Goodarzi <<a href="mailto:pooyan.goodarzi@email.ucr.edu">pooyan.goodarzi@email.ucr.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;padding-left:1ex;border-left-color:rgb(204,204,204)"><u></u>
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<p>Hi all, <br>
<br>
We will have our next <span>PASS</span> <span>talk</span> tomorrow by David. Please join us
at noon (from 12:00 pm to 1:00 pm) in the Nebula Room (PHYS
3027).<br>
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<div align="center"><strong>David Kapukchyan</strong><b>, PhD
student</b><br>
Monday, 12:00 pm, Nebula Room (PHYS 3027)<br>
<b>Measurement of the transverse single spin asymmetry in π0
production in polarized proton proton collisions</b></div>
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The Transverse Single Spin Asymmetry (TSSA) in polarized proton
proton collisions has proved to be a valuable tool in
understanding the internal structure of the proton.
Specifically, to understand the origin of the proton’s spin.
Initially, it was thought that the three quarks that make up the
proton solely contribute to the proton’s spin. However,
experiments showed that the spin contribution of the quarks is
insufficient to account for the total spin. Current theories
posit that the quarks and gluons (partons) inside a proton carry
transverse momentum that is coupled to the proton’s spin which
affects the production of the particles generated with respect
to the polarization. The TSSA measures this asymmetry of
particle production for a proton whose spin is polarized
transverse to its momentum. The measurement of the TSSA provides
input into those theoretical models to understand the different
contributions of the quarksand gluons to the overall spin. To
measure the π0 TSSA, polarized beams of protons are generated at
the Relativistic Heavy Ion Collider (RHIC). The detector at RHIC
utilized in this presentation is the Solenoidal Tracker At RHIC
(STAR) and a major part of this work was building, installing,
and commissioning an upgrade to the STAR detector system. The
upgrade expanded STAR’stracking and calorimetry capability for
2.5<pseudorapidity(η)<4.0. This presentation will describe
the calorimeter upgrade as well as the measurement of the π0
TSSA as a function of Feynman-x (xF ).<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>].<br>
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Best,<br>
Pooyan<br>
Physics and Astronomy Student Seminar (<span>PASS</span>)
<br>
<a href="https://ucrpass.arxiv.social/" target="_blank">https://ucrpass.arxiv.social</a></div>
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