Analysis Tools for Next-Generation Hadron Spectroscopy Experiments

The series of workshops on {\it New Partial-Wave Analysis Tools for Next-Generation Hadron Spectroscopy Experiments} was initiated with the\break ATHOS 2012 meeting, which took place in Camogli, Italy, June 20--22, 2012. It was followed by ATHOS~2013 in Kloster Seeon near Munich, Germany, May 21--24, 2013. The third, ATHOS3, meeting is planned for April 13--17, 2015 at The George Washington University Virginia Science and Technology Campus, USA. The workshops focus on the development of amplitude analysis tools for meson and baryon spectroscopy, and complement other programs in hadron spectroscopy organized in the recent past including the INT-JLab Workshop on Hadron Spectroscopy in Seattle in 2009, the International Workshop on Amplitude Analysis in Hadron Spectroscopy at the ECT*-Trento in 2011, the School on Amplitude Analysis in Modern Physics in Bad Honnef in 2011, the Jefferson Lab Advanced Study Institute Summer School in 2012, and the School on Concepts of Modern Amplitude Analysis Techniques in Flecken-Zechlin near Berlin in September 2013. The aim of this document is to summarize the discussions that took place at the ATHOS~2012 and ATHOS~2013 meetings. We do not attempt a comprehensive review of the field of amplitude analysis, but offer a collection of thoughts that we hope may lay the ground for such a document. The material presented in the article was edited by the following Editorial Board: Marco Battaglieri, Bill J.~Briscoe, Su-Urk Chung, Michael D\"oring, JĂłzef Dudek, Geoffrey Fox, Christoph Hanhart, Martin Hoferichter, David G.~Ireland, Bernhard Ketzer, Bastian Kubis, Vincent Mathieu, Ryan Mitchell, Jos\'e R.~Pel\'aez, Elena Santopinto, Adam Szczepaniak

<math altimg="si1.gif" xmlns="http://www.w3.org/1998/Math/MathML"><msup><mrow><mi>K</mi></mrow><mrow><mo>+</mo></mrow></msup><mi>Λ</mi></math> and <math altimg="si2.gif" xmlns="http://www.w3.org/1998/Math/MathML"><msup><mrow><mi>K</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>Σ</mi></mrow><mrow><mn>0</mn></mrow></msup></math> photoproduction with fine center-of-mass energy resolution

Measurements of <math altimg="si3.gif" xmlns="http://www.w3.org/1998/Math/MathML"><mi>γ</mi><mi>p</mi><mo stretchy="false">→</mo><msup><mrow><mi>K</mi></mrow><mrow><mo>+</mo></mrow></msup><mi>Λ</mi></math> and <math altimg="si4.gif" xmlns="http://www.w3.org/1998/Math/MathML"><mi>γ</mi><mi>p</mi><mo stretchy="false">→</mo><msup><mrow><mi>K</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>Σ</mi></mrow><mrow><mn>0</mn></mrow></msup></math> cross-sections have been obtained with the photon tagging facility and the Crystal Ball calorimeter at MAMI-C. The measurement uses a novel <math altimg="si5.gif" xmlns="http://www.w3.org/1998/Math/MathML"><msup><mrow><mi>K</mi></mrow><mrow><mo>+</mo></mrow></msup></math> meson identification technique in which the weak decay products are characterized using the energy and timing characteristics of the energy deposit in the calorimeter, a method that has the potential to be applied at many other facilities. The fine center-of-mass energy ( W ) resolution and statistical accuracy of the new data results in a significant impact on partial wave analyses aiming to better establish the excitation spectrum of the nucleon. The new analyses disfavor a strong role for quark–diquark dynamics in the nucleon