Light-flavor sea-quark distributions in the nucleon in the SU(3) chiral quark soliton model. II. Theoretical formalism

Wakamatsu, M.

doi:10.1103/physrevd.67.034006

Cited by 32 publications

(10 citation statements)

References 26 publications

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“…• The chiral soliton models of Wakamatsu [339] and Weigel et al [340] in which the quark degrees of freedom explicitly generate the hadronic chiral soliton properties of the Skyrme nucleon model.…”

Section: Quark Models and Other Predictions Ofmentioning

confidence: 99%

“…They predict A n 1 (x Bj = 1) values two to five times smaller than the pQCD expectation[173];• The bag model of Boros and Thomas, in which three free quarks are confined in a sphere of nucleon diameter. Confinement is provided by the boundary conditions requiring that the quark vector current cancels on the sphere surface[337].• The quark model of Kochelev[338] in which the quark polarization is affected by instantons representing non-perturbative fluctuations of gluons.• The chiral soliton models of Wakamatsu[339] and Weigel et al[340] in which the quark degrees of freedom explicitly generate the hadronic chiral soliton properties of the Skyrme nucleon model.• The quark-diquark model of Cloet et al[341].…”

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confidence: 99%

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The spin structure of the nucleon

2019

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We review the present understanding of the spin structure of protons and neutrons, the fundamental building blocks of nuclei collectively known as nucleons. The field of nucleon spin provides a critical window for testing Quantum Chromodynamics (QCD), the gauge theory of the strong interactions, since it involves fundamental aspects of hadron structure which can be probed in detail in experiments, particularly deep inelastic lepton scattering on polarized targets.QCD was initially probed in high energy deep inelastic lepton scattering with unpolarized beams and targets. With time, interest shifted from testing perturbative QCD to illuminating the nucleon structure itself. In fact, the spin degrees of freedom of hadrons provide an essential and detailed verification of both perturbative and nonperturbative QCD dynamics.Nucleon spin was initially thought of coming mostly from the spin of its quark constituents, based on intuition from the parton model. However, the first experiments showed that this expectation was incorrect. It is now clear that nucleon physics is much more complex, involving quark orbital angular momenta as well as gluonic and sea quark contributions. Thus, the nucleon spin structure remains a most active aspect of QCD research, involving important advances such as the developments of generalized parton distributions (GPD) and transverse momentum distributions (TMD).Elastic and inelastic lepton-proton scattering, as well as photoabsorption experiments provide various ways to investigate non-perturbative QCD. Fundamental sum rules -such as the Bjorken sum rule for polarized photoabsorption on polarized nucleons -are also in the non-perturbative domain. This realization triggered a vigorous program to link the low energy effective hadronic description of the strong interactions to fundamental quarks and gluon degrees of freedom of QCD. This has also led to advances in lattice gauge theory simulations of QCD and to the development of holographic QCD ideas based on the AdS/CFT or gauge/gravity correspondence, a novel approach providing a well-founded semiclassical approximation to QCD. Any QCD-based model of the nucleon's spin and dynamics must also successfully account for the observed spectroscopy of hadrons. Analytic calculations of the hadron spectrum, a long sought goal of QCD research, has now being realized using light-front holography and superconformal quantum mechanics, a formalism consistent with the results from nucleon spin studies.We begin this review with a phenomenological description of nucleon structure in general and of its spin structure in particular, aimed to engage non-specialist readers. Next, we discuss the nucleon spin structure at high energy, including topics such as 2

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Section: Quark Models and Other Predictions Ofmentioning

confidence: 99%

mentioning

confidence: 99%

The spin structure of the nucleon

2019

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“…• The quark model of Kochelev [339] in which the quark polarization is affected by instantons representing non-perturbative fluctuations of gluons. • The chiral soliton models of Wakamatsu [340] and Weigel et al [341] in which the quark degrees of freedom explicitly generate the hadronic chiral soliton properties of the Skyrme nucleon model.…”

Section: Quark Models and Other Predictions Ofmentioning

confidence: 99%

The Spin Structure of the Nucleon

Deur,

Brodsky,

de Teramond

2018

Preprint

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We review the present understanding of the spin structure of protons and neutrons, the fundamental building blocks of nuclei collectively known as nucleons. The field of nucleon spin provides a critical window for testing Quantum Chromodynamics (QCD), the gauge theory of the strong interactions, since it involves fundamental aspects of hadron structure which can be probed in detail in experiments, particularly deep inelastic lepton scattering on polarized targets.QCD was initially probed in high energy deep inelastic lepton scattering with unpolarized beams and targets. With time, interest shifted from testing perturbative QCD to illuminating the nucleon structure itself. In fact, the spin degrees of freedom of hadrons provide an essential and detailed verification of both perturbative and nonperturbative QCD dynamics.Nucleon spin was initially thought of coming mostly from the spin of its quark constituents, based on intuition from the parton model. However, the first experiments showed that this expectation was incorrect.It is now clear that nucleon physics is much more complex, involving quark orbital angular momenta as well as gluonic and sea quark contributions. Thus, the nucleon spin structure remains a most active aspect of QCD research, involving important advances such as the developments of generalized parton distributions (GPD) and transverse momentum distributions (TMD).Elastic and inelastic lepton-proton scattering, as well as photoabsorption experiments provide various ways to investigate non-perturbative QCD. Fundamental sum rules -such as the Bjorken sum rule for polarized photoabsorption on polarized nucleons -are also in the non-perturbative domain. This realization triggered a vigorous program to link the low energy effective hadronic description of the strong interactions to fundamental quarks and gluon degrees of freedom of QCD. This has also led to advances in lattice gauge theory simulations of QCD and to the development of holographic QCD ideas based on the AdS/CFT or gauge/gravity correspondence, a novel approach providing a well-founded semiclassical approximation to QCD. Any QCD-based model of the nucleon's spin and dynamics must also successfully account for the observed spectroscopy of hadrons. Analytic calculations of the hadron spectrum, a long sought goal of QCD research, have now being realized using light-front holography and superconformal quantum mechanics, a formalism consistent with the results from nucleon spin studies.We begin this review with a phenomenological description of nucleon structure in general and of its spin structure in particular, aimed to engage non-specialist readers. Next, we discuss the nucleon spin structure at high energy, including topics such as Dirac's front form and light-front quantization which provide a frame-independent, relativistic description of hadron structure and dynamics, the derivation of spin sum rules, and a direct connection to the QCD Lagrangian. We then discuss experimental and theoretical advances in the nonperturbative domain -in ...

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“…The Nambu-JonaLasinio (NJL) model [99,100], based on a local four-fermion interaction with U(1)×SU(2) L ×SU(2) R chiral symmetry, is a popular choice for studies of nucleon structure functions [101,102,103] [101,102]; the blue solid line is a prediction from an SU(3)-based model [104,105]. We have made use of parameterizations compiled by X. Zheng [71].…”

Section: Chiral Soliton Modelmentioning

confidence: 99%

“…This approach has the advantage that the model preserves the original SU L (N f )× SU R (N f ) symmetry of the QCD Lagrangian (although it does explicitly break the axial U A (1) symmetry). This second approach has recently been extended to three quark flavors and used to make predictions about nucleon structure functions [104,105]. Figure 2.15 shows the ratio g n 1 /F n 1 as predicted by these two approaches to the chiral soliton model.…”

Section: Chiral Soliton Modelmentioning

confidence: 99%

Measurements of the Double-Spin Asymmetry A<sub>1</sub> on Helium-3: Toward a Precise Measurement of the Neutron A<sub>1</sub>

Parno

2011

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The spin structure of protons and neutrons has been an open question for nearly twenty-five years, after surprising experimental results disproved the simple model in which valence quarks were responsible for nearly 100% of the nucleon spin. Diverse theoretical approaches have been brought to bear on the problem, but a shortage of precise data -especially on neutron spin structure -has prevented a thorough understanding.Experiment E06-014, conducted in Hall A of Jefferson Laboratory in 2009, presented an opportunity to add to the world data set for the neutron in the poorly covered valence-quark region. Jefferson Laboratory's highly polarized electron beam, combined with Hall A's facilities for a high-density, highly polarized 3 He target, allowed a high-luminosity double-polarized experiment, while the large acceptance of the BigBite spectrometer gave coverage over a wide kinematic range: 0.15 < x < 0.95. In this work, we present the analysis of a portion of the E06-014 data, measured with an incident beam energy of 4.74 GeV and spanning 1.5 < Q 2 < 5.5 (GeV/c) 2 . From these data, we extract the longitudinal asymmetry in virtual photon-nucleon scattering, A 1 , on the 3 He nucleus. Combined with the remaining E06-014 data, this will form the basis of a measurement of the neutron asymmetry A n 1 that will extend the kinematic range of the data available to test models of spin-dependent parton distributions in the nucleon. AcknowledgmentsNo one in this age can earn a physics PhD based solely on her own work and study; the making of a doctor, like the making of a modern particle-physics experiment, requires the goodwill and support of many. In my own life and studies, I have been profoundly blessed by the presence of my family, friends, and colleagues. It is traditional to thank these wonderful people in these pages, as though words were enough. They aren't, but they are a start.My parents, Christine Marwick and Richard Seymour, brought me up to have both a deep curiosity about the world and the work ethic I needed to answer my own questions. The love of language my mother gave me made writing this dissertation far less painful than it might have been; my father urged me to take my first voluntary science course and then kindly refrained from saying "I told you so" at the sudden fascination with physics that resulted. My not-so-little brother, Matthew, kept me honest with everything I did.The love and support of my extended family has been invaluable. My grandparents, Bob and Dolores Marwick, generously funded my undergraduate education. They and my aunts, uncles, and assorted cousins, scattered around the continent, taught me that I could find something of home wherever I am. To Rob and Ann Marwick, Mike and Monica Marwick, Lorrie Marwick and Guy Marsh, Nancy and Don DeMuth, and Josephine Marwick, thank you for the delicious meals, the fascinating conversations and your willingness to talk physics. To my beloved cousins, thank you for everything. Growing up, I was also lucky to enjoy the love of many peo...

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Light-flavor sea-quark distributions in the nucleon in the SU(3) chiral quark soliton model. II. Theoretical formalism

Cited by 32 publications

References 26 publications

The spin structure of the nucleon

The spin structure of the nucleon

The Spin Structure of the Nucleon

Measurements of the Double-Spin Asymmetry A<sub>1</sub> on Helium-3: Toward a Precise Measurement of the Neutron A<sub>1</sub>

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