"Obtaining Parton Distribution Functions from Self-Organizing Maps"

Dr. Heli Honkanen

University of Virginia

Abstract

Neural nerwork algorithms have been recently applied to construct Parton Distribution Function (PDF) parametrizations which provide an alternative to standard global fitting procedures. We propose a technique based on an interactive neural network algorithm using Self-Organizing Maps (SOMs). SOMs are a class of clustering algorithms based on competitive learning among spatially-ordered neurons. Our SOMs are trained on progressively narrower selections of stochastically generated PDF samples. The selection criterion is that of convergence towards a neighbourhood of the experimental data. Our main goal is to provide a fitting procedure that, at variance with the standard neural network approaches, allows for an increased control of the systematic bias by enabling user interaction in the various stages of the process.