STUDY OF HYPERON-NUCLEON POTENTIAL FROM LATTICE QCD

2010 ◽  
Vol 19 (12) ◽  
pp. 2442-2447
Author(s):  
H. Nemura ◽  
N. Ishii ◽  
S. Aoki ◽  
T. Hatsuda
Keyword(s):  
Numerical Calculation ◽  
Lattice Qcd ◽  
Quark Mass ◽  
Lattice Spacing ◽  
Nucleon Potential ◽  
Scattering State ◽  
Scattering Lengths

We study pΞ0 and pΛ forces by using quenched lattice QCD. The Bethe-Salpeter amplitude is calculated for the lowest scattering state of the systems. The numerical calculation is twofold: (i) For the pΞ0, the potentials and scattering lengths are obtained by using 323 × 32 lattice with β = 5.7, the lattice spacing of a = 0.1416(9) fm , and two kinds of ud quark mass corresponding to mπ ≃ 0.37 GeV and 0.51 GeV. The present results indicate that the pΞ0 interactions are both attractive at 1S0 and 3S1 channels, and the interaction in the 3S1 is more attractive than in the 1S0. These attractive forces become stronger as the u, d quark mass decreases. (ii) For the pΛ, the potentials are calculated by using the 323 × 48 lattice, and two kinds of ud quark mass corresponding to mπ ≃ 0.47 GeV and 0.51 GeV. The present preliminary result shows that the pΛ interactions are both attractive at 1S0 and 3S1 channels.

HYPERON-NUCLEON FORCES CALCULATED FROM LATTICE QCD

2009 ◽  
Vol 24 (11) ◽  
pp. 2110-2117
Author(s):  
H. NEMURA ◽  
N. ISHII ◽  
S. AOKI ◽  
T. HATSUDA
Keyword(s):  
Numerical Calculation ◽  
Lattice Qcd ◽  
Quark Mass ◽  
Lattice Spacing ◽  
Finite Lattice ◽  
Temporal Part ◽  
Lattice Volume ◽  
Scattering State ◽  
Spatial Lattice ◽  
Scattering Lengths

We study the hyperon-nucleon (YN) forces by using quenched lattice QCD. The Bethe-Salpeter amplitudes are calculated for the lowest scattering state of the systems so as to obtain the YN potentials. The numerical calculation is twofold: (i) The pΞ0 potentials and scattering lengths are obtained by using lattice QCD with β = 5.7, the lattice spacing of a = 0.1416(9) fm , on the 323 × 32 lattice. Two kinds of ud quark mass are used, corresponding to mπ ≃ 0.37 GeV and 0.51 GeV. The spatial lattice volume is (4.5 fm)3. The scattering lengths obtained from Lüscher's formula show that the pΞ0 interactions are both attractive at 1S0 and 3S1 channels, and the interaction in the 3S1 is more attractive than in the 1S0. These attractive forces become stronger as the u, d quark mass decreases. (ii) The pΛ potentials are calculated. The lattice setup is almost same as the former calculation except for the temporal part. The calculation is performed on 323 × 48 lattice. Two kinds of ud quark mass are used, corresponding to mπ ≃ 0.47 GeV and 0.51 GeV. The lowest scattering energies in the finite lattice volume are calculated.

scholarly journals Heavy light tetraquarks from Lattice QCD

2018 ◽  
Vol 175 ◽  
pp. 05014 ◽  
Author(s):  
Parikshit Junnarkar ◽  
M Padmanath ◽  
Nilmani Mathur
Keyword(s):  
Lattice Qcd ◽  
Lattice Spacing ◽  
Energy Levels ◽  
Clear Indication ◽  
Lattice Calculation ◽  
Charm Quarks ◽  
Preliminary Results ◽  
Scattering State

We present preliminary results from a lattice calculation of tetraquark states in the charm and bottom sector of the type udbb, usbb, udcc and scbb. These calculations are performed on Nf = 2 + 1 + 1 MILC ensembles with lattice spacing of a = 0:12 fm and a = 0:06 fm. A relativistic action with overlap fermions is employed for the light and charm quarks while a non-relativistic action with non-perturbatively improved coefficients is used in the bottom sector. Preliminary results provide a clear indication of presence of energy levels below the relevant thresholds of different tetraquark states in the double bottom sector while a scattering state is observed in the charm sector.

NΩ interaction from two approaches in lattice QCD

2014 ◽  
Vol 29 (33) ◽  
pp. 1450177 ◽  
Author(s):  
Faisal Etminan ◽  
Mohammad Mehdi Firoozabadi
Keyword(s):  
Lattice Qcd ◽  
Finite Volume Method ◽  
Ground State ◽  
Quark Mass ◽  
Lattice Spacing ◽  
State Energy ◽  
Potential Method ◽  
Bound State ◽  
Omega System ◽  
Volume Method

We compare the standard finite volume method by Lüscher with the potential method by HAL QCD collaboration, by calculating the ground state energy of N(nucleon)-Ω(Omega) system in 5 S2 channel. We employ 2+1 flavor full QCD configurations on a (1.9 fm )3×3.8 fm lattice at the lattice spacing a≃0.12 fm , whose ud(s) quark mass corresponds to mπ = 875(1) (mK = 916(1)) MeV . We have found that both methods give reasonably consistent results that there is one NΩ bound state at this parameter.

scholarly journals PRESENT CONSTRAINTS ON THE H-DIBARYON AT THE PHYSICAL POINT FROM LATTICE QCD

2011 ◽  
Vol 26 (34) ◽  
pp. 2587-2595 ◽  
Author(s):  
◽  
S. R. BEANE ◽  
E. CHANG ◽  
W. DETMOLD ◽  
B. JOÓ ◽  
...  
Keyword(s):  
Binding Energy ◽  
Lattice Qcd ◽  
Lattice Spacing ◽  
Pion Mass ◽  
Physical Point ◽  
Physical Pion ◽  
Scattering State ◽  
H Dibaryon ◽  
Near Threshold

The current constraints from lattice QCD on the existence of the H-dibaryon are discussed. With only two significant lattice QCD calculations of the H-dibaryon binding energy at approximately the same lattice spacing, the forms of the chiral and continuum extrapolations to the physical point are not determined. In this brief report, we consider the constraints on the H-dibaryon imposed by two simple chiral extrapolations. In both instances, the extrapolation to the physical pion mass allows for a bound H-dibaryon or a near-threshold scattering state. Further lattice QCD calculations are required to clarify this situation.

scholarly journals Double parton distributions in the pion from lattice QCD

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Gunnar S. Bali ◽  
Luca Castagnini ◽  
Markus Diehl ◽  
Jonathan R. Gaunt ◽  
Benjamin Gläßle ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Lattice Qcd ◽  
Quark Mass ◽  
Matrix Elements ◽  
Parton Distributions ◽  
Almost All ◽  
The Relationship

Abstract We perform a lattice study of double parton distributions in the pion, using the relationship between their Mellin moments and pion matrix elements of two local currents. A good statistical signal is obtained for almost all relevant Wick contractions. We investigate correlations in the spatial distribution of two partons in the pion, as well as correlations involving the parton polarisation. The patterns we observe depend significantly on the quark mass. We investigate the assumption that double parton distributions approximately factorise into a convolution of single parton distributions.

scholarly journals Isospin-1/2 Dπ scattering and the lightest $$ {D}_0^{\ast } $$ resonance from lattice QCD

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Luke Gayer ◽  
Nicolas Lang ◽  
Sinéad M. Ryan ◽  
David Tims ◽  
Christopher E. Thomas ◽  
...  
Keyword(s):  
Scattering Amplitudes ◽  
Lattice Qcd ◽  
Quark Mass ◽  
Light Quark ◽  
Energy Levels ◽  
Experimental Result ◽  
Infinite Volume ◽  
Resonance Pole ◽  
Strongly Coupled ◽  
Light Quark Mass

Abstract Isospin-1/2 Dπ scattering amplitudes are computed using lattice QCD, working in a single volume of approximately (3.6 fm)3 and with a light quark mass corresponding to mπ ≈ 239 MeV. The spectrum of the elastic Dπ energy region is computed yielding 20 energy levels. Using the Lüscher finite-volume quantisation condition, these energies are translated into constraints on the infinite-volume scattering amplitudes and hence enable us to map out the energy dependence of elastic Dπ scattering. By analytically continuing a range of scattering amplitudes, a $$ {D}_0^{\ast } $$ D 0 ∗ resonance pole is consistently found strongly coupled to the S-wave Dπ channel, with a mass m ≈ 2200 MeV and a width Γ ≈ 400 MeV. Combined with earlier work investigating the $$ {D}_{s0}^{\ast } $$ D s 0 ∗ , and $$ {D}_0^{\ast } $$ D 0 ∗ with heavier light quarks, similar couplings between each of these scalar states and their relevant meson-meson scattering channels are determined. The mass of the $$ {D}_0^{\ast } $$ D 0 ∗ is consistently found well below that of the $$ {D}_{s0}^{\ast } $$ D s 0 ∗ , in contrast to the currently reported experimental result.

scholarly journals Bs → Kℓv form factors with 2+1 flavors

2018 ◽  
Vol 175 ◽  
pp. 13008 ◽  
Author(s):  
Yuzhi Liu ◽  
Jon A. Bailey ◽  
A. Bazavov ◽  
C. Bernard ◽  
C. M. Bouchard ◽  
...  
Keyword(s):  
Quark Mass ◽  
Strange Quark ◽  
Lattice Spacing ◽  
Light Quark ◽  
Form Factors ◽  
Ckm Matrix ◽  
Strange Quark Mass ◽  
Light Quark Mass ◽  
B Quark

Using the MILC 2+1 flavor asqtad quark action ensembles, we are calculating the form factors f0 and f+ for the semileptonic Bs → Kℓv decay. A total of six ensembles with lattice spacing from ≈ 0.12 to 0.06 fm are being used. At the coarsest and finest lattice spacings, the light quark mass m’l is one-tenth the strange quark mass m’s. At the intermediate lattice spacing, the ratio m’l/m’s ranges from 0.05 to 0.2. The valence b quark is treated using the Sheikholeslami-Wohlert Wilson-clover action with the Fermilab interpretation. The other valence quarks use the asqtad action. When combined with (future) measurements from the LHCb and Belle II experiments, these calculations will provide an alternate determination of the CKM matrix element |Vub|.

scholarly journals Chiral Fermions Algorithms In Lattice QCD

2019 ◽  
Keyword(s):  
Lattice Qcd ◽  
Quark Mass ◽  
Optimal Algorithm ◽  
Quark Propagator ◽  
Critical Slowing Down ◽  
Group Symmetry ◽  
Inversion Algorithm ◽  
Four Dimensions ◽  
Slowing Down ◽  
Lattice Gauge

The theory that explains the strong interactions of the elementary particles, as part of the standard model, it is the so-called Quantum Chromodynamics (QCD) theory. In regimes of low energy this theory it is formulated and solved in a lattice with four dimensions using numerical simulations. This method it is called the lattice QCD theory. Quark propagator it the most important element that is calculated because it contains the physical information of lattice QCD. Computing quark propagator of chiral fermions in lattice means that we should invert the chiral Dirac operator, which has high complexity. In the standard inversion algorithms of the Krylov subspace methods, that are used in these kinds of simulations, the time of inversion is scaled with the inverse of the quark mass. In lattice QCD simulations with chiral fermions, this phenomenon it is knowing as the critical slowing-down problem. The purpose of this work is to show that the preconditioned GMRESR algorithm, developed in our previous work, solves this problem. The preconditioned GMRESR algorithm it is developed in U(1) group symmetry using QCDLAB 1.0 package, as good “environment” for testing new algorithms. In this paper we study the escalation of the time of inversion with the quark mass for this algorithm. It turned out that it is a fast inversion algorithm for lattice QCD simulations with chiral fermions, that “soothes” the critical slowing-down of standard algorithms. The results are compared with SHUMR algorithm that is optimal algorithm used in these kinds of simulations. The calculations are made for 100 statistically independent configurations on 64 x 64 lattice gauge U(1) field for three coupling constant and for some quark masses. The results showed that for the preconditioned GMRESR algorithm the coefficient k, related to the critical slowing down phenomena, it is approximately - 0.3 compared to the inverse proportional standard law (k = -1) that it is scaled SHUMR algorithm, even for dense lattices. These results make more stable and confirm the efficiency of our algorithm as an algorithm that avoid the critical slowing down phenomenon in lattice QCD simulations. In our future studies we have to develop the preconditioned GMRESR algorithm in four dimensions, in SU (3) lattice gauge theory.

scholarly journals Kaon-Nucleon potential from lattice QCD

2010 ◽  
Vol 3 ◽  
pp. 03007 ◽  
Author(s):  
Y. Ikeda ◽  
S. Aoki ◽  
T. Doi ◽  
T. Hatsuda ◽  
T. Inoue ◽  
...  
Keyword(s):  
Lattice Qcd ◽  
Nucleon Potential

scholarly journals The Leutwyler–Smilga relation on the lattice

2019 ◽  
Vol 35 (01) ◽  
pp. 1950346 ◽  
Author(s):  
Gernot Münster ◽  
Raimar Wulkenhaar
Keyword(s):  
Perturbation Theory ◽  
Quantum Chromodynamics ◽  
Lattice Qcd ◽  
Chiral Perturbation Theory ◽  
Effective Action ◽  
Lattice Spacing ◽  
Chiral Perturbation ◽  
Quark Masses

According to the Leutwyler–Smilga relation, in Quantum Chromodynamics (QCD), the topological susceptibility vanishes linearly with the quark masses. Calculations of the topological susceptibility in the context of lattice QCD, extrapolated to zero quark masses, show a remnant nonzero value as a lattice artefact. Employing the Atiyah–Singer theorem in the framework of Symanzik’s effective action and chiral perturbation theory, we show the validity of the Leutwyler–Smilga relation in lattice QCD with lattice artefacts of order a2 in the lattice spacing a.

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