Münster 2017 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
HK: Fachverband Physik der Hadronen und Kerne
HK 1: Hadron Structure and Spectroscopy I
HK 1.4: Vortrag
Montag, 27. März 2017, 18:00–18:15, F 5
Extraction of resonance poles with JPC = 2−+ from COMPASS data — •Mikhail Mikhasenko1, Andrew Jackura2, Bernhard Ketzer1, and Adam Szczepaniak2,3 — 1Universität Bonn, Helmholtz-Institut für Strahlen- und Kernphysik, 53115 Bonn, Germany — 2Indiana University, Bloomington IN, U.S.A. — 3Thomas Jefferson National Accelerator Facility, Newport News VA, U.S.A.
The COMPASS experiment at CERN has collected 5×106 events of diffractive scattering of 190 GeV pions to the three-pion final state. Since around one hundred resonances observed in light-quark sector are coupled to pionic systems, the spin-density matrices from a partial wave analysis are extremely valuable to extract ordinary and, possibly, exotic mesons.
The aim of the present analysis is to extract three-pion scattering amplitudes from the mass-dependence of the COMPASS spin-density matrices using analyticity and unitarity constraints.
The three-body unitarity problem is very difficult and has not been completely solved. In the approximation of the isobar model, it is reduced to quasi-two-body (ππ-subchannel resonance + pion) unitarity requirements. We invoke a unitarization procedure to incorporate non-resonant long-range production processes via pion exchange, i.e. “Deck”-like processes.
This theoretical framework is applied to the COMPASS data. We discuss resonant pole positions and scattering phase shifts for the mesonic JPC = 2−+ sector. The project is supported by BMBF.