# Scalar-quark systems and chimera hadrons in SU(3){sub c} lattice QCD

## Abstract

In terms of mass generation in the strong interaction without chiral symmetry breaking, we perform the first study for light scalar-quarks {phi} (colored scalar particles with 3{sub c} or idealized diquarks) and their color-singlet hadronic states using quenched SU(3){sub c} lattice QCD with {beta}=5.70 (i.e., a{approx_equal}0.18 fm) and lattice size 16{sup 3}x32. We investigate ''scalar-quark mesons'' {phi}{sup {dagger}}{phi} and ''scalar-quark baryons'' {phi}{phi}{phi} as the bound states of scalar-quarks {phi}. We also investigate the color-singlet bound states of scalar-quarks {phi} and quarks {psi}, i.e., {phi}{sup {dagger}}{psi}, {psi}{psi}{phi}, and {phi}{phi}{psi}, which we name ''chimera hadrons.'' All the new-type hadrons including {phi} are found to have a large mass even for zero bare scalar-quark mass m{sub {phi}}=0 at a{sup -1}{approx_equal}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 {phi}'s and n {psi}'s, M{sub m{phi}}{sub +n{psi}}, approximately satisfies M{sub m{phi}}{sub +n{psi}}{approx_equal}mM{sub {phi}}+nM{sub {psi}}, where M{sub {phi}} and M{sub {psi}} are the constituent scalar-quark and quark masses, respectively. We estimate the constituent scalar-quark mass M{sub {phi}} for m{sub {phi}}=0 at a{sup -1}{approx_equal}1 GeV as M{sub {phi}}{approx_equal}1.5-1.6 GeV, which is much larger than the constituent quark mass M{sub {psi}}{approx_equal}400 MeVmore »

- Authors:

- Yukawa Institute for Theoretical Physics, Kyoto University, Sakyo, Kyoto 606-8502 (Japan)
- Department of Physics, Kyoto University, Graduate School of Science, Sakyo, Kyoto 606-8502 (Japan)

- Publication Date:

- OSTI Identifier:
- 20929560

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Physical Review. D, Particles Fields; Journal Volume: 75; Journal Issue: 11; Other Information: DOI: 10.1103/PhysRevD.75.114503; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; BOUND STATE; CHIRAL SYMMETRY; CHIRALITY; COLOR MODEL; EFFECTIVE MASS; GEV RANGE 01-10; GLUEBALLS; GLUONS; LATTICE FIELD THEORY; MEV RANGE 100-1000; PHI MESONS; QUANTUM CHROMODYNAMICS; QUARKS; STRONG INTERACTIONS; SU-3 GROUPS; SYMMETRY BREAKING

### Citation Formats

```
Iida, H., Takahashi, T. T., and Suganuma, H.
```*Scalar-quark systems and chimera hadrons in SU(3){sub c} lattice QCD*. United States: N. p., 2007.
Web. doi:10.1103/PHYSREVD.75.114503.

```
Iida, H., Takahashi, T. T., & Suganuma, H.
```*Scalar-quark systems and chimera hadrons in SU(3){sub c} lattice QCD*. United States. doi:10.1103/PHYSREVD.75.114503.

```
Iida, H., Takahashi, T. T., and Suganuma, H. Fri .
"Scalar-quark systems and chimera hadrons in SU(3){sub c} lattice QCD". United States.
doi:10.1103/PHYSREVD.75.114503.
```

```
@article{osti_20929560,
```

title = {Scalar-quark systems and chimera hadrons in SU(3){sub c} lattice QCD},

author = {Iida, H. and Takahashi, T. T. and Suganuma, H.},

abstractNote = {In terms of mass generation in the strong interaction without chiral symmetry breaking, we perform the first study for light scalar-quarks {phi} (colored scalar particles with 3{sub c} or idealized diquarks) and their color-singlet hadronic states using quenched SU(3){sub c} lattice QCD with {beta}=5.70 (i.e., a{approx_equal}0.18 fm) and lattice size 16{sup 3}x32. We investigate ''scalar-quark mesons'' {phi}{sup {dagger}}{phi} and ''scalar-quark baryons'' {phi}{phi}{phi} as the bound states of scalar-quarks {phi}. We also investigate the color-singlet bound states of scalar-quarks {phi} and quarks {psi}, i.e., {phi}{sup {dagger}}{psi}, {psi}{psi}{phi}, and {phi}{phi}{psi}, which we name ''chimera hadrons.'' All the new-type hadrons including {phi} are found to have a large mass even for zero bare scalar-quark mass m{sub {phi}}=0 at a{sup -1}{approx_equal}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 {phi}'s and n {psi}'s, M{sub m{phi}}{sub +n{psi}}, approximately satisfies M{sub m{phi}}{sub +n{psi}}{approx_equal}mM{sub {phi}}+nM{sub {psi}}, where M{sub {phi}} and M{sub {psi}} are the constituent scalar-quark and quark masses, respectively. We estimate the constituent scalar-quark mass M{sub {phi}} for m{sub {phi}}=0 at a{sup -1}{approx_equal}1 GeV as M{sub {phi}}{approx_equal}1.5-1.6 GeV, which is much larger than the constituent quark mass M{sub {psi}}{approx_equal}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{approx_equal}0.2 fm.},

doi = {10.1103/PHYSREVD.75.114503},

journal = {Physical Review. D, Particles Fields},

number = 11,

volume = 75,

place = {United States},

year = {Fri Jun 01 00:00:00 EDT 2007},

month = {Fri Jun 01 00:00:00 EDT 2007}

}