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Title: Model selection for pion photoproduction

Partial-wave analysis of meson and photon-induced reactions is needed to enable the comparison of many theoretical approaches to data. In both energy-dependent and independent parametrizations of partial waves, the selection of the model amplitude is crucial. Principles of the S matrix are implemented to a different degree in different approaches; but a many times overlooked aspect concerns the selection of undetermined coefficients and functional forms for fitting, leading to a minimal yet sufficient parametrization. We present an analysis of low-energy neutral pion photoproduction using the least absolute shrinkage and selection operator (LASSO) in combination with criteria from information theory and K-fold cross validation. These methods are not yet widely known in the analysis of excited hadrons but will become relevant in the era of precision spectroscopy. As a result, the principle is first illustrated with synthetic data; then, its feasibility for real data is demonstrated by analyzing the latest available measurements of differential cross sections (dσ/dΩ), photon-beam asymmetries (Σ), and target asymmetry differential cross sections (dσ T/d≡Tdσ/dΩ) in the low-energy regime.
Authors:
 [1] ;  [2] ;  [3] ;  [1] ;  [1]
  1. The George Washington Univ., Washington, D.C. (United States)
  2. The George Washington Univ., Washington, D.C. (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
  3. Univ. Nacional Autonoma de Mexico, Ciudad de Mexico (Mexico)
Publication Date:
Report Number(s):
JLAB-THY-16-2364; DOE/OR/23177-3972; arXiv:1610.07547
Journal ID: ISSN 2469-9985; PRVCAN; TRN: US1701000
Grant/Contract Number:
1415459; AC05-06OR23177; SC0016582; 251817; IA101717
Type:
Accepted Manuscript
Journal Name:
Physical Review C
Additional Journal Information:
Journal Volume: 95; Journal Issue: 1; Journal ID: ISSN 2469-9985
Publisher:
APS
Research Org:
Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
OSTI Identifier:
1342390
Alternate Identifier(s):
OSTI ID: 1339185