Pentaquark baryon in anisotropic lattice QCD

Ishii, Noriyoshi; Doi, Takumi; Iida, Hidehiro; Oka, M.; Okiharu, Fumiko; Suganuma, Hideo

doi:10.1103/physrevd.71.034001

Cited by 57 publications

(70 citation statements)

References 66 publications

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“…By now there are several groups who performed simulations, but their results do not always agree with each other and the issue is still controversial [41,42,43]. In drawing conclusions, one must know the limitation due to the approximations such as quenched approximation or finite quark mass.…”

Section: Lattice Qcdmentioning

confidence: 99%

Structure and reactions of pentaquark baryons

Hosaka

2006

Pramana - J Phys

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We review the current status of the exotic pentaquark baryons. After a brief look at experiments of both positive and negative results, we discuss theoretical methods to study the structure and reactions for the pentaquarks. First we introduce the quark model and the chiral soliton model, where we discuss the relation of mass spectrum and parity with some emphasis on the role of chiral symmetry. It is always useful to picture the structure of the pentaquarks in terms of quarks. As for other methods, we discuss a model independent method, and briefly mention the results from the lattice and QCD sum rule. Decay properties are then studied in some detail, which is one of the important properties of Θ + . We investigate the relation between the decay width and the quark structure having certain spin-parity quantum numbers. Through these analyses, we consider as plausible quantum numbers of Θ + , J P = 3/2 − . In the last part of this note, we discuss production reactions of Θ + which provide links between the theoretical models and experimental information. We discuss photoproductions and hadron-induced reactions which are useful to explore the nature of Θ + .

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Section: Lattice Qcdmentioning

confidence: 99%

Structure and reactions of pentaquark baryons

Hosaka

2006

Pramana - J Phys

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“…To resolve this problem, we use two distinct spatial boundary conditions(BC), i.e., the periodic BC (PBC) and the hybrid BC (HBC), which is recently proposed in Ref. [10]. In PBC, we impose the spatially periodic BC on u,d and s-quarks.…”

Section: Pos(lat2005)064mentioning

confidence: 99%

“…Under these circumstances, we present anisotropic lattice QCD results on 5Q states in J P = 3/2 ± channels. Note that while there have been several lattice QCD calculations of 5Q states [6,7,8,9,10,11,12,13,14,15,16], these studies are restricted to J P = 1/2 ± channels except for a very recent one [16].…”

Section: Introductionmentioning

confidence: 99%

Anisotropic lattice QCD study of pentaquark baryons in spin 3/2 channel

Doi¹,

Ishii²,

Nemoto³

et al. 2005

Proceedings of XXIIIrd International Symposium on Lattice Field Theory — PoS(LAT2005)

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We perform the comprehensive analysis of the pentaquark (5Q) in J P = 3/2 ± channel using anisotropic quenched lattice QCD. We employ the standard Wilson gauge action at β = 5.75 and the O(a) improved Wilson (clover) quark action on a 12 3 × 96 lattice with the renormalized anisotropy as a s /a t = 4. A large number of gauge configurations as N conf = 1000 is analyzed, which is found to be essential to achieve a reliable measurement. We study three types of the Rarita-Schwinger intepolationg fields with I = 0: (a) the NK * -type, (b) the (color-)twisted NK * -type, (c) a diquark-type. As a result, we find only massive states as m 5Q ≃ 2.1 − 2.2 GeV in J P = 3/2 − channel, and m 5Q = 2.4 − 2.6 GeV in J P = 3/2 + channel in the chiral limit. The analysis with the hybrid boundary condition (HBC) is performed to distinguish whether these resonances are compact 5Q resonances or two-particle scattering states. No low-lying compact 5Q resonance states are found below 2.1GeV. XXIIIrd International Symposium on Lattice Field Theory

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“…We use the hybrid boundary condition(HBC) [4] as well as the conventional periodic BC(PBC) to discriminate a compact resonance state from two-hadron scattering states. HBC is a flavor-dependent spatial BC, where we impose PBC on s quark, and anti-PBC on u and d quarks.…”

Section: Introductionmentioning

confidence: 99%

“…We use 504 gauge configurations for J P = 1/2 ± penta-quarks, 1000 gauge configurations for J P = 3/2 ± penta-quarks, and 1872 gauge configurations for tetra-quarks. A smeared source with gaussian size ρ ≃ 0.4 fm is adopted after Coulomb gauge fixing to suppress the contamination of excited states.We use the hybrid boundary condition(HBC) [4] as well as the conventional periodic BC(PBC) to discriminate a compact resonance state from two-hadron scattering states. HBC is a flavor-dependent spatial BC, where we impose PBC on s quark, and anti-PBC on u and d quarks.…”

mentioning

confidence: 99%

Anisotropic lattice QCD studies of penta-quarks and tetra-quarks

Ishii

Doi

Iida

et al. 2006

AIP Conference Proceedings

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Abstract.Anisotropic lattice QCD studies of penta-quarks(5Q) with J P = 1/2 ± and 3/2 ± are presented at the quenched level together with tetra-quarks(4Q). The standard gauge action at β = 5.75 and O(a) improved quark (clover) action with κ = 0.1410(0.010)0.1440 are employed on the anisotropic lattice with the renormalized anisotropy a s /a t = 4. The "hybrid boundary condition(HBC)" is adopted to discriminate a compact resonance state from scattering states. Only massive 5Q states are found for J P = 1/2 + and 3/2 ± , which cannot be identified as Θ + (1540). A low-lying 5Q state is found for J P = 1/2 − at m 5Q ≃ 1.75 GeV, which however turns out to be an NK scattering state through the HBC analysis. A preliminary result for 4Q states is presented suggesting an existence of a compact 4Q resonance at m 4Q ≃ 1.1 GeV in the idealized SU(4) f chiral limit.Keywords: Exotic hadron, lattice QCD PACS: 12.38. Gc, 12.39.Mk, 14.20.Jn Multi-quark states attract an increasing interest from wide range of high energy physics. Enormous number of experimental as well as theoretical contributions have been devoted to the penta-quarks(5Q) [1,2,3,4,5,6], and series of tetra-quark(4Q) candidates have been discovered recently as D + s0 (2317) [7,8] and Y (4260). In this paper, we are interested in 5Q Θ + (1540) and 4Q D + s0 (2317). We adopt 12 3 × 96 anisotropic lattice QCD for high precision measurements, where the temporal lattice spacing is 4 times finer than the spatial ones as a s /a t = 4. We employ standard gauge action at β = 5.75 and O(a) improved Wilson (Clover) action with κ = 0.1410(0.010)0.1440, which roughly covers the quark mass region of m s ≤ m q ≤ 2m s . κ s = 0.1440 is fixed for s quark, and the chiral extrapolation is performed by varying κ = 0.1410 − 0.1440 for u and d quarks. The lattice spacing is determined with the Sommer parameter r −1 0 = 395 MeV leading to the spatial lattice spacing as a −1 s = 1.10 GeV (a s ≃ 0.18 fm). We use 504 gauge configurations for J P = 1/2 ± penta-quarks, 1000 gauge configurations for J P = 3/2 ± penta-quarks, and 1872 gauge configurations for tetra-quarks. A smeared source with gaussian size ρ ≃ 0.4 fm is adopted after Coulomb gauge fixing to suppress the contamination of excited states.We use the hybrid boundary condition(HBC) [4] as well as the conventional periodic BC(PBC) to discriminate a compact resonance state from two-hadron scattering states. HBC is a flavor-dependent spatial BC, where we impose PBC on s quark, and anti-PBC on u and d quarks. Since Θ + (uudds) contains even number of u and d quarks, it obeys

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Pentaquark baryon in anisotropic lattice QCD

Cited by 57 publications

References 66 publications

Structure and reactions of pentaquark baryons

Structure and reactions of pentaquark baryons

Anisotropic lattice QCD study of pentaquark baryons in spin 3/2 channel

Anisotropic lattice QCD studies of penta-quarks and tetra-quarks

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