Hard hadron spectroscopy

We study the coupled πN system (negative parity, isospin 1 2 ) based on a lattice QCD simulation for n f =2 mass degenerate light quarks. Both, standard 3-quarks baryon operators as well as mesonbaryon (4+1)-quark operators are included. This is an exploratory study for just one lattice size and lattice spacing and at a pion mass of 266 MeV. Using the distillation method and variational analysis we determine energy levels of the lowest eigenstates. Comparison with the results of simple 3-quark correlation studies exhibits drastic differences and a new level appears. A clearer picture of the negative parity nucleon spectrum emerges. For the parameters of the simulation we may assume elastic s-wave scattering and can derive values of the phase shift.

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“…In our case (n f = 2) there is just one pseudoscalar meson η called η 2 , with a mass larger than 800 MeV [41,42]. With our parameters (see Sect.…”

Section: Interpolatorsmentioning

confidence: 98%

Scattering in theπNnegative parity channel in lattice QCD

2013

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“…Because naive constituent quark models with theqq description for the scalar mesons have difficulties in reproducing the light mass of the σ and the mass spectrum of scalar nonets, various internal structures beyond the simpleqq have been proposed: the four-quark state with strong diquark correlation [18][19][20][21], the collectiveqq excitation [7,[22][23][24][25][26], the dynamically generated mesonic molecule [6,[12][13][14] and the glueball [27]. Although several approaches based on QCD have been performed [28][29][30][31], the understanding of the structure of the lowest scalar-isoscalar meson has not been settled yet.…”

Section: Introductionmentioning

confidence: 99%

Nature of the σ meson as revealed by its softening process

Hyodo

Kunihiro

2010

Nuclear Physics A

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The ππ scattering is studied in two-flavor chiral models with a finite pion mass to investigate the nature of the σ meson which is observed as the lowest scalar-isoscalar resonance. We compare several models with different origins of the σ meson, such as the chiral partner of the pion and the dynamically generated ππ molecule. We find that the dynamically generated σ meson exhibits a novel pattern of the threshold enhancement reflecting the s-wave nature of the resonance, which is qualitatively different from the softening of the chiral partner introduced as a bare field. This behavior around the threshold energy region is universal as far as the bare σ pole stays away from the threshold throughout the symmetry restoration process. On the other hand, for m π = 0, the dynamically generated σ behaves similarly to the chiral partner in the symmetry restoration limit, implying the possibility of the dynamically generated chiral partner.

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“…In the present work we will present preliminary results on: (i) the vector meson mass m K * , (ii) its decay constant f K * , (iii) the ratio of tensor to vector decay constants f T / f V , computed at the K * physical mass and (iv) the B K parameter for neutral Kaon oscillations. Other subgroups of the collaboration are working on decay constants in the light and strange quark sector [1,2].…”

Section: Introduction: Theory and Computational Setupmentioning

confidence: 99%

K-meson vector and tensor decay constants and B-parameter from Nf = 2 tmQCD

Vladikas¹,

Dimopoulos²,

Frezzotti³

et al. 2009

Proceedings of the XXVI International Symposium on Lattice Field Theory — PoS(LATTICE 2008)

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We present work in progress on the computation of the K-meson vector and tensor decay constants, as well as the B-parameter in Kaon oscillations. Our simulations are performed in a partially quenched setup, with two dynamical (sea) Wilson quark flavours, having a maximally twisted mass term. Valence quarks are either of the standard or the Osterwalder-Seiler maximally twisted variety. These two regularizations can be suitably combined in order to obtain a B K parameter which is both multiplicatively renormalizable and O(a) improved.The XXVI International Symposium on Lattice Field Theory

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Hard hadron spectroscopy

Cited by 16 publications

References 74 publications

Scattering in theπNnegative parity channel in lattice QCD

Scattering in theπNnegative parity channel in lattice QCD

Nature of the σ meson as revealed by its softening process

K-meson vector and tensor decay constants and B-parameter from Nf = 2 tmQCD

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