scholarly journals Covariant nucleon wave function withS-,D-, andP-state components

2012 ◽  
Vol 85 (9) ◽  
Author(s):  
Franz Gross ◽  
G. Ramalho ◽  
M. T. Peña
Keyword(s):  
Wave Function ◽  
Nucleon Wave Function

Nucleon-antinucleon interaction in the new Tamm-Dancoff approximation

1960 ◽  
Vol 257 (1288) ◽  
pp. 59-73
Keyword(s):  
Integral Equation ◽  
Wave Function ◽  
Cross Sections ◽  
Nucleon Nucleon ◽  
Phase Shifts ◽  
Exchange Term ◽  
Total Cross Sections ◽  
Nucleon Wave Function ◽  
Usual Manner ◽  
Order Of Magnitude

The nucleon-antinucleon ( N-N ) problem is formulated in the new Tamm-Dancoff (NTD) approximation in the lowest order, and the integral equation for N-N̅ scattering derived, taking account of both the exchange and annihilation interactions. It is found convenient to represent the N-N̅ wave-function as a 4 x 4 matrix, rather than the usual 16 x 1 matrix for the nucleon-nucleon wave-function, and a complete correspondence is established between these two representations. The divergences associated with the annihilation interaction and their renormalization are discussed in detail in the following paper (Mitra & Saxena 1960; referred to as II). The integral equation with the exchange interaction alone, is then separated into eigenstates of T, J, L and S in the usual manner and the various phase shifts obtained. The results of II for the contribution of the annihilation term are then used to calculate the complete phase shifts from which the various cross-sections (scattering and charge exchange) are derived. The results indicate that while the exchange term alone gives too small values for the total cross-sections versus energy, inclusion of the annihilation interaction without renormalization effects makes the cross-sections nearly three times larger than those observed. On the other hand, inclusion of the finite effects of renormalization (which manifest themselves essentially as a suppression of the virtual meson propagator) brings down these cross-sections to the order of magnitude of the observed ones.

scholarly journals Structure of the Nucleon and its Excitations

2018 ◽  
Vol 175 ◽  
pp. 06019 ◽  
Author(s):  
Waseem Kamleh ◽  
Derek Leinweber ◽  
Zhan-wei Liu ◽  
Finn Stokes ◽  
Anthony Thomas ◽  
...  
Keyword(s):  
Wave Function ◽  
Finite Volume ◽  
Form Factors ◽  
Effective Field ◽  
Radial Excitation ◽  
Nucleon Wave Function ◽  
Scattering State ◽  
Nucleon Spectrum ◽  
Magnetic Form Factors ◽  
Channel Interactions

The structure of the ground state nucleon and its finite-volume excitations are examined from three different perspectives. Using new techniques to extract the relativistic components of the nucleon wave function, the node structure of both the upper and lower components of the nucleon wave function are illustrated. A non-trivial role for gluonic components is manifest. In the second approach, the parity-expanded variational analysis (PEVA) technique is utilised to isolate states at finite momenta, enabling a novel examination of the electric and magnetic form factors of nucleon excitations. Here the magnetic form factors of low-lying odd-parity nucleons are particularly interesting. Finally, the structure of the nucleon spectrum is examined in a Hamiltonian effective field theory analysis incorporating recent lattice-QCD determinations of low-lying two-particle scattering-state energies in the finite volume. The Roper resonance of Nature is observed to originate from multi-particle coupled-channel interactions while the first radial excitation of the nucleon sits much higher at approximately 1.9 GeV.

Quasi-potential approach to the three-quark nucleon wave function

2004 ◽  
Vol 47 (12) ◽  
pp. 1242-1249 ◽  
Author(s):  
S. G. Shul’ga ◽  
T. P. Il’icheva
Keyword(s):  
Wave Function ◽  
Potential Approach ◽  
Nucleon Wave Function

Nucleon wave function and nucleon form factors in QCD

1984 ◽  
Vol 246 (1) ◽  
pp. 52-74 ◽  
Author(s):  
V.L. Chernyak ◽  
I.R. Zhitnitsky
Keyword(s):  
Wave Function ◽  
Form Factors ◽  
Nucleon Wave Function ◽  
Nucleon Form Factors

THE ROLE OF FERMI MOTION ON THE STRUCTURE FUNCTIONS OF 3He AND 3H NUCLEI IN THE QUARK EXCHANGE FRAMEWORK

2013 ◽  
Vol 22 (06) ◽  
pp. 1350037 ◽  
Author(s):  
M. MODARRES ◽  
M. RASTI
Keyword(s):  
Experimental Data ◽  
Wave Function ◽  
Three Dimensional ◽  
Structure Functions ◽  
Exchange Model ◽  
Coordinate Space ◽  
Nuclear Wave Function ◽  
Fermi Motion ◽  
Nucleon Wave Function

The quark exchange model and the full three-nucleon wave function in the configuration space are used to evaluate the role of Fermi motion on the structure functions (SFs) of helium-3 and tritium nuclei. The three-nucleon wave function is obtained from the solution of the Faddeev equations with the Malfliet–Tjon-type potential, by using the three-dimensional approach as a function of the magnitudes of the Jacobi momenta vectors and the angle between them. In this calculation, the initial valence quarks inputs are taken from the GRV's (Glück, Reya and Vogt) fitting procedure and the next-to-leading order (NLO) QCD calculation on [Formula: see text], which give a very good fit to the available experimental data in the (x, Q2)-plane. The role of Fermi motion on the EMC ratio of the SFs of 3 He and 3 H nuclei are analyzed through the NLO expansion of the nuclear wave function in the coordinate space. A good agreement between the calculated EMC ratios, the corresponding experimental data and the theoretical results is found. Finally, the ratios of the SFs of the neutron to the proton (with the isospin symmetry assumption) with and without the Fermi motion effect, are also calculated, and they are compared with the available experimental data. Our results show that the roles of the Fermi motion in the framework of the quark exchange model for the calculations of the nuclear SFs are important.

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