<html>
<head>
<meta http-equiv="content-type" content="text/html;
charset=ISO-8859-1">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<font color="#cc0000"><b>Physics Seminar<br>
Friday, Sept. 27, 2013<br>
F224/225<br>
11:00AM<br>
Cookies and coffee at 10:45AM</b></font><br>
<br>
<small><b><font color="#000066"><big><font face="Times New Roman">Dr.
Barbara Pasquini</font></big></font></b></small><br>
<font color="#000066"><b>Universita di Pavia</b></font><br>
<br>
<pre wrap=""><big><font face="Times New Roman"><b><font color="#000099"> "Wigner Functions and Parton Distributions in Light-cone Quark
Models</font></b></font></big>"
<font face="Times New Roman">I will discuss the Wigner functions of the nucleon which provide multidimensional images of the quark distributions in phase space. They depend on both the transverse position and the three-momentum of the quark relative to the nucleon, and therefore combine in a single picture all the information contained in the generalized parton distributions and the transverse-momentum dependent parton distributions. We consider a few example of Wigner functions within light-cone quark models, discussing the role of the quark orbital angular momentum in shaping the nucleon and its correlations with the quark and nucleon polarizations. The quark orbital angular momentum is also calculated from the phase-space average of the orbital angular momentum operator weighted with the Wigner distribution of unpolarized quarks in a longitudinally polarized nucleon. The corresponding results obtained within different light-cone quark models are compared with
alternative definitions of the quark orbital angular momentum, as given in terms of generalized parton distributions and transverse-momentum dependent parton distributions.</font>
</pre>
<br>
<br>
<br>
<br>
<br>
</body>
</html>