Are There Diquarks in the Nucleon?

Abstract

This work is devoted to the study of diquark correlations inside the nucleon. We analyze some matrix elements which encode information about the non-perturbative forces, in different color anti-triplet diquark channels. We suggest a lattice calculation to check the quark-diquark picture and clarify the role of instanton-mediated interactions. We study in detail the physical properties of the 0+ diquark, using the Random Instanton Liquid Model. We find that instanton forces are sufficiently strong to form a diquark bound-state, with a mass of ~500 MeV, which is compatible with earlier estimates. We also compute its electro-magnetic form factor and find that the diquark is a broad object, with a size comparable with that of the proton.

Final version, accepted for publication on Phys. Rev. D

References in corpus (33)

• Instantons in QCD
• Evidence for Narrow S=+1 Baryon Resonance in Photo-production from Neutron
• Diquarks and Exotic Spectroscopy
• Exotic Anti-Decuplet of Baryons: Prediction from Chiral Solitons
• Observation of an Exotic $S=+1$ Baryon in Exclusive Photoproduction from the Deuteron
• Observation of a baryon resonance with positive strangeness in K+ collisions with Xe nuclei
• Evidence for the positive-strangeness pentaquark ${\Theta }^{+}$ in photoproduction with the SAPHIR detector at ELSA
• Observation of an Exotic Baryon with S=+1 in Photoproduction from the Proton
• Evidence for a narrow |S|=1 baryon state at a mass of 1528 MeV in quasi-real photoproduction
• Evidence for a narrow baryonic state decaying to K0s-p and K0s-pbar in deep inelastic scattering at HERA
• Evidence for a narrow resonance at 1530 MeV/c2 in the K0 p - system of the reaction pp --> Sigma+ K0 p from the COSY-TOF experiment
• Evidence for formation of a narrow pKshort resonance with mass near 1533 MeV in neutrino interactions
• Baryonic Correlation Functions in the Random Instanton Vacuum
• Light Quarks in the Instanton Vacuum at Finite Baryon Density
• Lattice study of exotic S=+1 baryon
• A schematic model for pentaquarks based on diquarks
• Electromagnetic form factors of the nucleon in the chiral quark soliton model
• Systematic Study of the Single Instanton Approximation in QCD
• Pentaquark and diquark-diquark clustering: a QCD sum rule approach
• Instanton Contribution to the Pion Electro-Magnetic Formfactor at Q^2 > 1 GeV^2
• Dynamical Higgs Mechanism without Elementary Scalars: A Lesson from Instantons
• Width of the J^P=1/2^+ pentaquark in the quark-diquark model
• Instanton induced quark dynamics and the pentaquark
• Decay of Theta+ in a quark model
• Light-Front Approach for Pentaquark Strong Decays
• Instantons, diquarks and non-leptonic weak decays of hyperons
• Proton Electro-Magnetic Form-Factors in the Instanton Liquid Model
• Pentaquarks: Status and Perspectives for Lattice Calculations
• Instanton Contribution to the Electro-Magnetic Form Factors of the Nucleon
• Parameter free calculation of hadronic masses from instantons
• Baryons as Fock states of 3,5,... quarks
• Pentaquarks in the Chiral Symmetry Limit
• Diquarks, Pentaquarks and Dibaryons

Cited by in corpus (21)

• Wounded quarks and diquarks in heavy ion collisions
• Time- and Spacelike Nucleon Electromagnetic Form Factors beyond Relativistic Constituent Quark Models
• Analysis of the light-flavor scalar and axial-vector diquark states with QCD sum rules
• QCD Topology at Finite Temperature: Statistical Mechanics of Selfdual Dyons
• Mesons and diquarks in the color neutral 2SC phase of dense cold quark matter
• Diquark effects in light baryon correlators from lattice QCD
• Isoscalar short-range current in the deuteron induced by an intermediate dibaryon
• Transient field fluctuations effects in d+Au and Au+Au collisions at \sqrt{s_nn} = 200 GeV
• Strong Color Field Baryonic Remnants in Nucleus-Nucleus Collisions at 200A GeV
• Exploring the Chiral Regime of QCD in the Interacting Instanton Liquid Model
• Strong longitudinal color field effects in pp collisions at energies available at the Large Hadron Collider
• Hyperon/meson ratios in rare high-multiplicity $pp$ collisions at energies available at the Large Hadron Collider, and potential signatures for mini-quark-gluon plasma formation
• Leading twist moments of the neutron structure function F2n
• Instantons, Chiral Dynamics and Hadronic Resonances
• Computing the Effective Hamiltonian of Low-Energy Vacuum Gauge Fields
• Open Charm Production in $p+p$ and Pb + Pb collisions at the CERN Large Hadron Collider
• Theoretical Overview: The New Mesons
• Multiplicity dependent $p_T$ distributions of identified particles in pp collisions at 7 TeV within HIJING/$B\bar{B}$ v2.0 model
• Instanton fermionic zero mode at finite temperature and chemical potential
• Radial Scaling in Inclusive Jet Production at Hadron Colliders
• Single-spin asymmetries in SIDIS induced by anomalous gluon-quark and photon-quark couplings