Role of diquark correlations and the pion cloud in nucleon elastic form factors

被引：62

作者：

Cloet, Ian C. ^{[1
]}

Bentz, Wolfgang ^{[2
]}

Thomas, Anthony W. ^{[3
,4
]}

机构：

[1] Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA

[2] Tokai Univ, Sch Sci, Dept Phys, Hiratsuka, Kanagawa 2591292, Japan

[3] Univ Adelaide, CSSM, Adelaide, SA 5005, Australia

[4] Univ Adelaide, ARC Ctr Excellence Particle Phys Terascale, Sch Chem & Phys, Adelaide, SA 5005, Australia

来源：

PHYSICAL REVIEW C | 2014年 / 90卷 / 04期

基金：

澳大利亚研究理事会;

关键词：

QUARK DISTRIBUTIONS; NJL-MODEL; MAGNETIC-MOMENTS; DYNAMICAL MODEL; SCALING LAWS; BAG MODEL; SCATTERING; SPIN; CONFINEMENT; EQUATIONS;

D O I：

10.1103/PhysRevC.90.045202

中图分类号：

O57 [原子核物理学、高能物理学];

学科分类号：

070202 ;

摘要：

Electromagnetic form factors of the nucleon in the spacelike region are investigated within the framework of a covariant and confining Nambu-Jona-Lasinio model. The bound-state amplitude of the nucleon is obtained as the solution of a relativistic Faddeev equation, where diquark correlations appear naturally as a consequence of the strong coupling in the color (3) over bar qq channel. Pion degrees of freedom are included as a perturbation to the "quark-core'' contribution obtained using the Poincare covariant Faddeev amplitude. While no model parameters are fit to form-factor data, excellent agreement is obtained with the empirical nucleon form factors (including the magnetic moments and radii) where pion loop corrections play a critical role for Q(2) less than or similar to 1 GeV2. Using charge symmetry, the nucleon form factors can be expressed as proton quark sector form factors. The latter are studied in detail, leading, for example, to the conclusion that the d-quark sector of the Dirac form factor is much softer than the u-quark sector, a consequence of the dominance of scalar diquark correlations in the proton wave function. On the other hand, for the proton quark sector Pauli form factors we find that the effect of the pion cloud and axial-vector diquark correlations overcomes the effect of scalar diquark dominance, leading to a larger d-quark anomalous magnetic moment and a form factor in the u-quark sector that is slightly softer than in the d-quark sector.

引用

页数：29

共 94 条

[11] Goldstone theorem and diquark confinement beyond rainbow-ladder approximation [J].

Bender, A ;

Roberts, CD ;

vonSmekal, L .

PHYSICS LETTERS B, 1996, 380 (1-2) :7-12

[12] The stability of nuclear matter in the Nambu-Jona-Lasinio model [J].

Bentz, W ;

Thomas, AW .

NUCLEAR PHYSICS A, 2001, 696 (1-2) :138-172

[13] REVIEW OF PARTICLE PHYSICS Particle Data Group [J].

Beringer, J. ;

Arguin, J. -F. ;

Barnett, R. M. ;

Copic, K. ;

Dahl, O. ;

Groom, D. E. ;

Lin, C. -J. ;

Lys, J. ;

Murayama, H. ;

Wohl, C. G. ;

Yao, W. -M. ;

Zyla, P. A. ;

Amsler, C. ;

Antonelli, M. ;

Asner, D. M. ;

Baer, H. ;

Band, H. R. ;

Basaglia, T. ;

Bauer, C. W. ;

Beatty, J. J. ;

Belousov, V. I. ;

Bergren, E. ;

Bernardi, G. ;

Bertl, W. ;

Bethke, S. ;

Bichsel, H. ;

Biebel, O. ;

Blucher, E. ;

Blusk, S. ;

Brooijmans, G. ;

Buchmueller, O. ;

Cahn, R. N. ;

Carena, M. ;

Ceccucci, A. ;

Chakraborty, D. ;

Chen, M. -C. ;

Chivukula, R. S. ;

Cowan, G. ;

D'Ambrosio, G. ;

Damour, T. ;

de Florian, D. ;

de Gouvea, A. ;

DeGrand, T. ;

de Jong, P. ;

Dissertori, G. ;

Dobrescu, B. ;

Doser, M. ;

Drees, M. ;

Edwards, D. A. ;

Eidelman, S. .

PHYSICAL REVIEW D, 2012, 86 (01)

[14] High-Precision Determination of the Electric and Magnetic Form Factors of the Proton [J].

Bernauer, J. C. ;

Achenbach, P. ;

Gayoso, C. Ayerbe ;

Boehm, R. ;

Bosnar, D. ;

Debenjak, L. ;

Distler, M. O. ;

Doria, L. ;

Esser, A. ;

Fonvieille, H. ;

Friedrich, J. M. ;

Friedrich, J. ;

de la Paz, M. Goez Rodriguez ;

Makek, M. ;

Merkel, H. ;

Middleton, D. G. ;

Mueller, U. ;

Nungesser, L. ;

Pochodzalla, J. ;

Potokar, M. ;

Majos, S. Sanchez ;

Schlimme, B. S. ;

Sirca, S. ;

Walcher, Th. ;

Weinriefer, M. .

PHYSICAL REVIEW LETTERS, 2010, 105 (24)

[15] Charged pion form factor between Q2=0.60 and 2.45 GeV2. I. Measurements of the cross section for the 1H(e,e'π+)n reaction [J].

Blok, H. P. ;

Horn, T. ;

Huber, G. M. ;

Beise, E. J. ;

Gaskell, D. ;

Mack, D. J. ;

Tadevosyan, V. ;

Volmer, J. ;

Abbott, D. ;

Aniol, K. ;

Anklin, H. ;

Armstrong, C. ;

Arrington, J. ;

Assamagan, K. ;

Avery, S. ;

Baker, O. K. ;

Barrett, B. ;

Bochna, C. ;

Boeglin, W. ;

Brash, E. J. ;

Breuer, H. ;

Chang, C. C. ;

Chant, N. ;

Christy, M. E. ;

Dunne, J. ;

Eden, T. ;

Ent, R. ;

Fenker, H. ;

Gibson, E. ;

Gilman, R. ;

Gustafsson, K. ;

Hinton, W. ;

Holt, R. J. ;

Jackson, H. ;

Jin, S. ;

Jones, M. K. ;

Keppel, C. E. ;

Kim, P. H. ;

Kim, W. ;

King, P. M. ;

Klein, A. ;

Koltenuk, D. ;

Kovaltchouk, V. ;

Liang, M. ;

Liu, J. ;

Lolos, G. J. ;

Lung, A. ;

Margaziotis, D. J. ;

Markowitz, P. ;

Matsumura, A. .

PHYSICAL REVIEW C, 2008, 78 (04)

[16] UNIVERSAL PROPERTIES OF THE ELECTROMAGNETIC-INTERACTIONS OF SPIN-ONE SYSTEMS [J].

BRODSKY, SJ ;

HILLER, JR .

PHYSICAL REVIEW D, 1992, 46 (05) :2141-2149

[17] SCALING LAWS FOR LARGE-MOMENTUM-TRANSFER PROCESSES [J].

BRODSKY, SJ ;

FARRAR, GR .

PHYSICAL REVIEW D, 1975, 11 (05) :1309-1330

[18] SCALING LAWS AT LARGE TRANSVERSE MOMENTUM [J].

BRODSKY, SJ ;

FARRAR, GR .

PHYSICAL REVIEW LETTERS, 1973, 31 (18) :1153-1156

[19] NJL-model analysis of dense quark matter [J].

Buballa, M .

PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS, 2005, 407 (4-6) :205-376

[20] BARYONS AS BOUND-STATES OF DIQUARKS AND QUARKS IN THE NAMBU-JONA-LASINIO MODEL [J].

BUCK, A ;

ALKOFER, R ;

REINHARDT, H .

PHYSICS LETTERS B, 1992, 286 (1-2) :29-35

← 1 2 3 4 5 6 7 8 9 10 →