2007/03/31 by Hidehiro Iida, H. Iida, Hideo Suganuma +3 · 7 citations
Physics and Astronomy · #Baryon #Geometry #Hadron #High-Energy Particle Collisions Research #Meson #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quark #Quark model #Quarkonium #Scalar (mathematics) #hep-lat
paper · pdf · doi:10.1103/physrevd.75.114503
published in Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields 75(11) (American Physical Society) · 9 pages, 9 figures
arxiv created 2007/05/28 · openalex publication_date 2007/06/22 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
In terms of mass generation in the strong interaction without chiral symmetry breaking, we perform the first study for light scalar-quarks \ensuremathφ (colored scalar particles with 3c or idealized diquarks) and their color-singlet hadronic states using quenched SU(3)c lattice QCD with \ensuremathβ=5.70 (i.e., a\ensuremath≃0.18 fm) and lattice size 163\ifmmode×\else\texttimes\fi32. We investigate ``scalar-quark mesons'' \ensuremathφ^\ifmmode†\else\textdagger\fi\ensuremathφ and ``scalar-quark baryons'' \ensuremathφ\ensuremathφ\ensuremathφ as the bound states of scalar-quarks \ensuremathφ. We also investigate the color-singlet bound states of scalar-quarks \ensuremathφ and quarks \ensuremathψ, i.e., \ensuremathφ^\ifmmode†\else\textdagger\fi\ensuremathψ, \ensuremathψ\ensuremathψ\ensuremathφ, and \ensuremathφ\ensuremathφ\ensuremathψ, which we name ``chimera hadrons.'' All the new-type hadrons including \ensuremathφ are found to have a large mass even for zero bare scalar-quark mass m_\ensuremathφ=0 at a^\ensuremath-1\ensuremath≃1 GeV. We find a ``constituent scalar-quark/quark picture'' for both scalar-quark hadrons and chimera hadrons. Namely, the mass of the new-type hadron composed of m \ensuremathφ's and n \ensuremathψ's, M_m\ensuremathφ+n\ensuremathψ, approximately satisfies M_m\ensuremathφ+n\ensuremathψ\ensuremath≃mM_\ensuremathφ+nM_\ensuremathψ, where M_\ensuremathφ and M_\ensuremathψ are the constituent scalar-quark and quark masses, respectively. We estimate the constituent scalar-quark mass M_\ensuremathφ for m_\ensuremathφ=0 at a^\ensuremath-1\ensuremath≃1 GeV as M_\ensuremathφ\ensuremath≃1.5--1.6 GeV, which is much larger than the constituent quark mass M_\ensuremathψ\ensuremath≃400 MeV in the chiral limit. Thus, scalar quarks acquire a large mass due to large quantum corrections by gluons in the systems including scalar quarks. Together with other evidences of mass generation of glueballs and charmonia, we conjecture that all colored particles generally acquire a large effective mass due to dressed gluon effects. In addition, the large mass generation of pointlike colored scalar particles indicates that plausible diquarks used in effective hadron models cannot be described as the pointlike particles and should have a much larger size than a\ensuremath≃0.2 fm.