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.

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.

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.

scholarly journals A STUDY OF GLUON PROPAGATOR ON COARSE LATTICE

2000 ◽  
Vol 15 (04) ◽  
pp. 229-244 ◽  
Author(s):  
J. P. MA
Keyword(s):  
Lattice Qcd ◽  
Smooth Function ◽  
Qualitative Agreement ◽  
Lattice Spacing ◽  
Continuum Limit ◽  
Gluon Propagator ◽  
Landau Gauge ◽  
Lattice Action ◽  
Lattice Volume ◽  
The Continuum

We study gluon propagator in Landau gauge with lattice QCD, where we use an improved lattice action. The calculation of gluon propagator is performed on lattices with the lattice spacing from 0.40 fm to 0.24 fm and with the lattice volume from (2.40 fm )4 to (4.0 fm )4. We find that the rotation invariance is approximately restored in the q2-range, indicated by the fact that the propagator is a smooth function of the continuum momentum q2. We try to fit our results by two different ways, in the first one we interpret the calculated gluon propagators as a function of the continuum momentum, while in the second we interpret the propagators as a function of the lattice momentum. In both cases we use models which are the same in continuum limit. A qualitative agreement between two fittings is found.

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 Chiral Perturbation Theory for Three-Flavour Lattice QCD with Isospin Splitting

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
S. Engelnkemper ◽  
G. Münster
Keyword(s):  
Perturbation Theory ◽  
Lattice Qcd ◽  
Chiral Perturbation Theory ◽  
Lattice Spacing ◽  
Light Quark ◽  
Mass Difference ◽  
Finite Lattice ◽  
Chiral Perturbation ◽  
Isospin Splitting ◽  
The Masses

An important tool for the analysis of results of numerical simulations of lattice QCD is chiral perturbation theory. In the Wilson chiral perturbation theory the effects of the finite lattice spacingaare taken into account. In recent years the effects of isospin splitting on the masses of hadrons have been investigated in the Monte Carlo simulations. Correspondingly, in this paper we derive the expansions of the masses of the pseudoscalar mesons in chiral perturbation theory at next-to-leading order for twisted mass lattice QCD with three light quark flavours, taking the mass difference between the up- and downquarks into account. The results include terms up to ordersmq2in the quark masses,Δm2in the mass splitting between up- and downquarks, anda2in the lattice spacing, respectively.

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 EFFECTIVE RANGE EXPANSION FOR THE INTERACTION DEFINED ON THE LATTICE

2010 ◽  
Vol 19 (04) ◽  
pp. 781-786 ◽  
Author(s):  
GABRIEL WLAZŁOWSKI ◽  
PIOTR MAGIERSKI
Keyword(s):  
Range Expansion ◽  
Lattice Spacing ◽  
Finite Lattice ◽  
Computational Scheme ◽  
Effective Range ◽  
Interaction Parameters ◽  
Effective Range Expansion ◽  
Spatial Lattice ◽  
T Matrix

The relation between the interaction parameters for fermions on the spatial lattice and the two-body T matrix is discussed. The presented method allows determination of the interaction parameters through the relatively simple computational scheme which includes the effect of finite lattice spacing. In particular the relation between the interaction parameters and the effective range expansion parameters is derived in the limit of large lattices.

scholarly journals CLS 2+1 flavor simulations at physical light-and strange-quark masses

2018 ◽  
Vol 175 ◽  
pp. 02010 ◽  
Author(s):  
Daniel Mohler ◽  
Stefan Schaefer ◽  
Jakob Simeth
Keyword(s):  
Quark Mass ◽  
Strange Quark ◽  
Lattice Spacing ◽  
Current Status ◽  
Short Discussion ◽  
Lattice Volume ◽  
Quark Masses ◽  
Strange Quark Mass ◽  
First Results ◽  
Wilson Fermions

We report recent efforts by CLS to generate an ensemble with physical lightand strange-quark masses in a lattice volume of 192 × 963 at β = 3:55 corresponding to a lattice spacing of 0:064 fm. This ensemble is being generated as part of the CLS 2+1 flavor effort with improved Wilson fermions. Our simulations currently cover 5 lattice spacings ranging from 0:039 fm to 0:086 fm at various pion masses along chiral trajectories with either the sum of the quark masses kept fixed, or with the strange-quark mass at the physical value. The current status of simulations is briefly reviewed, including a short discussion of measured autocorrelation times and of the main features of the simulations. We then proceed to discuss the thermalization strategy employed for the generation of the physical quark-mass ensemble and present first results for some simple observables. Challenges encountered in the simulation are highlighted.

Testing pseudofermion lattice QCD with small quark masses and large volumes

1989 ◽  
Vol 67 (8) ◽  
pp. 792-797 ◽  
Author(s):  
M. Campostrini ◽  
K. J. M. Moriarty ◽  
J. Potvin ◽  
C. Rebbi
Keyword(s):  
Lattice Qcd ◽  
Quark Mass ◽  
Wilson Loop ◽  
Lattice Volume ◽  
Quark Masses

We report on extensive tests done on the pseudofermion algorithm in a simulation of lattice QCD with dynamical quarks. These tests are carried out in a more realistic context than many of the studies previously attempted as a lattice volume of 103 × 32 sites and quark mass of about 50 to 200 MeV are used throughout the calculation. Wilson loop factors of various sizes, as well as chiral condensates and pion propagators, are shown to change by less than 5% when the pseudofermion algorithm is tuned to simulate QCD more accurately.

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.

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