Broemmel, Dirk and Crompton, Peter and Gattringer, Christof and Glozman, Leonid Ya. and Lang, C. B. and Schaefer, Stefan and Schaefer, Andreas (2004) Excited nucleons with chirally improved fermions. PHYSICAL REVIEW D, 69 (9): 094513. ISSN 0556-2821
Full text not available from this repository.Abstract
We study positive and negative parity nucleons on the lattice using the chirally improved lattice Dirac operator. Our analysis is based on a set of three operators chi(i) with the nucleon quantum numbers but in different representations of the chiral group and with different diquark content. We use a variational method to separate the ground state and excited states and determine the mixing coefficients for the optimal nucleon operators in terms of the chi(i). We clearly identify the negative parity resonances N(1535) and N(1650) and their masses agree well with experimental data. The mass of the observed excited positive parity state is too high to be interpreted as the Roper state. Our results for the mixing coefficients indicate that chiral symmetry is important for N(1535) and N(1650) states. We confront our data for the mixing coefficients with quark models and provide insights into the physics of the nucleon system and the nature of strong decays.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | GINSPARG-WILSON FERMIONS; LATTICE GAUGE-THEORY; BARYON MASSES; FIXED-POINT; QCD; SYMMETRY; SPECTROSCOPY; RESONANCE; SPECTRUM; MODEL; |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Theroretical Physics > Chair Professor Schäfer > Group Andreas Schäfer |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 21 Jul 2021 06:10 |
| Last Modified: | 21 Jul 2021 06:10 |
| URI: | https://pred.uni-regensburg.de/id/eprint/37722 |
Actions (login required)
 |
View Item |
