Braun, V. M. and Collins, S. and Glaessle, B. and Goeckeler, M. and Schaefer, A. and Schiel, R. W. and Soeldner, W. and Sternbeck, A. and Wein, P. (2014) Light-cone distribution amplitudes of the nucleon and negative parity nucleon resonances from lattice QCD. PHYSICAL REVIEW D, 89 (9): 094511. ISSN 1550-7998, 1550-2368
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We present the results of a lattice study of light-cone distribution amplitudes (DAs) of the nucleon and negative parity nucleon resonances using two flavors of dynamical (clover) fermions on lattices of different volumes and pion masses down to m(pi) similar or equal to 150 MeV. We find that the three valence quarks in the proton share their momentum in the proportion 37%:31%:31%, where the larger fraction corresponds to the u quark that carries proton helicity, and determine the value of the wave function at the origin in position space, which turns out to be small compared to the existing estimates based on QCD sum rules. Higher-order moments are constrained by our data and are all compatible with zero within our uncertainties. We also calculate the normalization constants of the higher-twist DAs that are related to the distribution of quark angular momentum. Furthermore, we use the variational method and customized parity projection operators to study the states with negative parity. In this way we are able to separate the contributions of the two lowest states that, as we argue, possibly correspond to N*(1535) and a mixture of N*(1650) and the pion-nucleon continuum, respectively. It turns out that the state that we identify with N*(1535) has a very different DA as compared to both the second observed negative parity state and the nucleon, which implies different electroproduction cross sections at large transferred momenta and may be related to the difference in the decay patterns observed in experiment.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | EXCLUSIVE PROCESSES; WAVE-FUNCTION; ASYMPTOTIC-BEHAVIOR; 3-QUARK OPERATORS; HIGHER TWIST; SUM-RULES; OCTET; RENORMALIZATION; BARYONS; PROTON; |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Theroretical Physics > Chair Professor Braun > Group Vladimir Braun |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 06 Nov 2019 14:21 |
| Last Modified: | 06 Nov 2019 14:21 |
| URI: | https://pred.uni-regensburg.de/id/eprint/10157 |
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