Diquark effects in light baryon correlators from lattice QCD

Abstract

We study the role of diquarks in light baryons through point to point baryon correlators. We contrast results from quenched simulations with ones with two flavors of dynamical overlap fermions. The scalar, pseudoscalar and axial vector diquarks are combined with light quarks to form color singlets. The quenched simulation shows large zero mode effects in correlators containing the scalar and pseudoscalar diquark. The two scalar diquarks created by γ5 and γ0γ5 lead to different behavior in baryon correlators, showing that the interaction of diquarks with the third light quark matters: we do not see an isolated diquark. In our quark mass range, the scalar diquark created by γ5 seems to play a greater role than the others.

Wave functions of the proton ground state in the presence of a uniform background magnetic field in lattice QCD

“…Earlier lattice studies that have paired two light quarks with a static quark [18,19] have shown a large diquark (Oð1Þ fm) can form inside of a baryon, though with limited effect on the structure of the particle. More recently, light quarks have been paired with various diquark correlators [20] which suggest that diquarks are not a significant factor in light baryons. To the best of our knowledge, this is the first time that such a diquark configuration has been shown in a baryon composed of three light quarks.…”

Strange and nonstrange baryon spectra in the relativistic interacting quark-diquark model with a Gürsey and Radicati-inspired exchange interaction

“…Many articles have been written on this subject since its introduction (for a review, see Ref. [23]) and more recently the diquark concept has been used in several studies, ranging from one-gluon exchange to lattice QCD calculations [24][25][26][27][28][29][30][31][32][33][34]. Important phenomenological indications for diquark-like correlations [28][29][30]35,36] and for diquark confinement [37] have also been provided.…”

Relativistic quark-diquark model of baryons with a spin-isospin transition interaction: Non-strange baryon spectrum and nucleon magnetic moments

“…Since then, many papers have been written on this topic (for a review see Ref. [16]) and, more recently, the diquark concept has been applied to various calculations [17][18][19][20][21][22][23][24][25][26][28][29][30][31][32][33][34][35][36][37]. Important phenomenological indications for diquark-like correlations have been collected [17,19,38,39] and indications for diquark confinement have also been provided [40].…”