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<p class="MsoPlainText"><b>PHYSICS SEMINAR</b><br>
Tuesday, May 13, 2014<br>
2:00 PM <br>
Small Hall, Room 122</p>
<b>Boris Ermolaev </b>[Host: André Walker-Loud]<br>
Ioffe Physical Technical Institute, St. Petersburg, Russia
<p class="MsoPlainText">Title of Talk:<br>
<b><i>“Description of the Spin Structure Function g1 at Arbitrary
x and Q2”</i></b> <br>
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<b>Abstract:</b><br>
The standard theoretical description of polarized DIS is based on
the use of the DGLAP evolution equations. This approach is
theoretically grounded for the hard kinematics of large x and large
Q2. It controls the Q2 -evolution but cannot account for the x
-evolution. Instead, it mimics the x -evolution by ad hoc inserting
singular factors x^-a in parton distributions without any
theoretical grounds. Resummation of the leading logarithmic
contributions and merging it with DGLAPP allowed us to describe g1
at arbitrary x and drop the singular factors at the same time. Then,
independently of values of x, the region of small Q2 is also out of
the reach of DGLAP. We suggest a simple way to extrapolate DGLAP
into the small-Q2 region at any x, arriving thereby at description
of g1 at arbitrary x and Q2.
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