The group's major activities and goals are to carry out first principles calculation of nucleon and vacuum structure. These calculations are based on the lattice version of the fundamental theory of the strong interaction of quarks and gluons, Quantum Chromodynamics (Lattice QCD). The quantities to be calculated for the nucleon structure include strangeness and charmness, quark and glue momenta and angular momenta, quark spin, strangeness electromagnetic form factors, axial form factor, electromagnetic form factors of proton and neutron, and neutron electric dipole moment from the theta term. The vacuum structure study entails the calculation of the chiral polarization properties of quarks in the context of thermal QCD transition and QCD with many light flavors (low energy conformality).

We use the overlap fermion, which has chiral symmetry, as the valence quarks on borrowed 2+1 flavor domain wall fermion gauge configurations. There are 5 lattices with different lattice spacing and sea quark masses to calculate the above observables in order to carry out continuum and physical pion extrapolations with finite volume corrections in order to make predictions for the quark orbital angular momentum and glue angular momentum for future experiments, as well as to facilitate and constrain dark matter search with precise calculation of the quark contents in the nucleon.

During the last few years, substantial effort has been spent on improving the inversion code which calculates the quark propagator. We have implemented smearing of the gauge field via the Hypercube Blocking (HYP)-smearing procedure which has been shown to map the gauge field closer to that of the continuum and with renormalization constants much closer to unity. This lifts up the smallest eigenvalues of the Wilson fermion in the inner do loop of the overlap fermion inversion and reduces the conjugate gradient steps by a factor of approximately 3. We have also developed eigenvalue and eigenvector code for the overlap fermion and have been able to calculate 400 complex conjugate pairs of eigenmodes in addition to the zero modes. We have done deflation for the outer loop of the overlap inversion with these eigenmodes by projecting these eigenmodes out from the source and solving the matrix equation which is orthogonal to this low-frequency part of the Hilbert space. After this is done, we can add back the low-frequency part of the propagator with the original source since we have both the eigenvalues and eigenvectors. This is done on the fly when the quark propagators are generated. The detailed study of our approach and its speedup with the overlap valence on DWF sea is published in Phys. Rev. D 82, 114501 (2010) arXiv:1005.5424.

Projects on DLX

Nucleon Structure and Hadron Spectroscopy

Over the past several years, we have initiated a long-term project to study nucleon form factors, hadron spectroscopy, and decay constants with valence overlap fermion on 2+1-flavor dynamical gauge configurations with domain-wall fermions produced by the the Riken-Brookhaven-Columbia (RBC) Collaboration, the UKQCD Collaboration of the United Kingdom, and the Lattice Hadron Physics Collaboration (LHPC). Both the overlap fermion and the domain-wall fermions satisfy chiral symmetry via the Ginsparg-Wilson relation. There are 5 sets of domain-wall fermion gauge lattices available with 3 lattice spacings and the physical size ranges from 2.8 fm to 5.5 fm. The lowest pion mass has reached the physical mass of 140 MeV for the two large lattices with 5.5 fm size. We have worked on the three smaller lattices with the physical size at 2.8 fm and 4.5 fm and the lowest pion mass at 170 MeV. There is a good deal of theoretical and experimental interest in strangeness and charmness which are related to dark matter searches. The composition of the proton spin in terms of quark spin, quark orbital angular momentum, and the glue spin are being actively pursued experimentally at JLab, STAR at Brookhaven, and COMPASS at CERN. The strangeness electric and magnetic form factors are studied by G0 and HAPPEX Collaborations at JLab. We are calculating these quantities on the above-mentioned lattices to carry out continuum and physical pion extrapolations with finite volume corrections so that we can compare with existing experiments and make predictions for future experiments and quantities which are not readily observable experimentally, such as strangeness and charmness.

We have succeeded in completing the world's first calculation (M. Deka et al., arXiv:1312:4816 hep-lat, submitted to Physical Review D) of the quark and glue momentum and angular momentum in the nucleon in the so called quenched approximation. We find the quark spin, the quark orbital angular momentum, and the glue angular momentum contribute 25%, 50%, and 25% to the proton spin respectively. Since we have demonstrated that we can do the complete calculation with this approximation, we have moved aggressively ahead to carry out the realistic calculation with the physical quark mass, large volume and with extrapolation to the continuum limit.

We have calculated the strangeness and charmness contents in the nucleon which are needed for estimating the cross section for the dark matter search with the neutralino as the popular candidate which couples to the target nuclei via Higgs exchange. The improvement of the nucleon correlator with low-mode substitution and of the loop with low-mode averaging and the application to our calculation of strangeness and charmness in the nucleon has been published in Phys. Rev. D88, 014503 (2013).

Yibo Yang has led the project to decompose the hadron masses (meson and nucleon) into their components - quark mass, quark kinetic and potential energy, glue field energy, and glue anomaly contribution (Y.-B. Yang et al., arXiv: 1405:4440 hep-ph). This has been submitted for publication in Physical Review D.

Yibo Yang and our chi-QCD Collaboration have finished a multi-year project to find the strange and charm quark masses with two lattice spacings and 3 sets of sea quark masses each to extrapolate to the continuum and physical pion mass limits. The preliminary results were published in the lattice proceedings (Y. Yang at al., PoS LATTICE 2013, 500 (2013)) and the full-length manuscript is being written up for publication. The quark masses, the charmonium hyperfine splitting, the charmonium P-wave states and the Ds decay constant all agree with experiments. This is an ab initio calculation which has only the quark masses as parameters.

The bulk part of this project is being carried out with resources provided by ALCC (ASCR on OLCF), NERSC, NICS, and USQCD. However, we do some of our extensive data analysis and code testing on DLX.

Participants

PI: Keh-Fei Liu
Co-PI: Terrence Draper
Postdocs: Michael Glatzmaier, Yibo Yang
Staff: Shao-Jing Dong
Students: Raza Sufian, Mingyang Sun, Gen Wang

Non-UK collaborators:

Faculty: Andrei Alexandru (George Washington University), Ying Chen (Institute of High Energy Physics, China), Takumi Doi (RIKEN, Japan), Ming Gong (IHEP, China) Postdocs: Mridupawan Deka (Dubna, Russia)

Computation method:

Linear algebra for eigenvalue problems and large sparse matrix inversion with Krylov space algorithms, Monte Carlo simulations.

Software:

No commercial software are needed.

Dynamical Chirality: Novel Characterization of Strongly Coupled Dynamics

The main goal of this project is to investigate chiral polarization properties of quarks using dynamical chiral polarization methods. This is studied in the context of thermal QCD transition and in the context of QCD with many light flavors (low energy conformality). The study is expected to provide a non-trivial new insight into the dynamics of strongly coupled theories. Additional non-linear correlations, characterizing QCD vacuum in a similar manner, are planned to be investigated in the upcoming year.

Participant:

Faculty: Dr.Ivan Horvath

Non-UK collaborator:

Faculty: Prof. Andrei Alexandru (George Washington University)

Computation method:

The computational tools employed are the Krylov space methods applied to various versions of lattice Dirac operator. These methods are currently available at UK (our own implementation).

Software:

No external software will be used.

Testing of GPU

DLX is used for debugging and testing GPU codes, like QUDA. QUDA is an generic inverter for various fermion actions. It is an open source software. GPU? is used to do most of the calculation and to exchange data through MPI on CPU. Most of the fermion actions are done and currently, the project is working on the overlap fermion action.

Participant:

Postdoc: Yibo Yang

Non-UK collaborator:

Faculty: Ming Gong (Institute of High Energy Physics, China)

Computation method:

Large matrix inversion with GPUs.

Software:

QUDA and MPI are both available on DLX.

Funding:

1. Lattice QCD Calculation of Nucleon Structure and Excited States, U.S. Department of Energy, DE-FG05-84ER40154, 02/13-01/15, $391K, K.F. Liu (PI), T. Draper (co-PI)
2. Lattice QCD Calculation of Hadronic Spectrum, Nucleon Structure, and Finite Density, U.S. Department of Energy, DE-FG05-84ER40154, 02/10-01/13, $579K, K.F. Liu (PI), T. Draper (co-PI)
3. Research in Theoretical Nuclear Physics, U.S. Department of Energy, DE-FG05-84ER40154, 02/07-1/10, $540K, K.F. Liu (PI), T. Draper (co-PI)

ASCR Award:

We have been awarded 69 million processor-hours from the 2014 ASCR Leadership Computing Challenge (ALCC) which is a competitive award from DOE to perform Advanced Scientific Computing Research (ASCR) on Oak Ridge Leadership Computing Facility (OLCF). In 2013, 39 awards were made with a total of 1.8 billion processor hours for an average of 46 million processor hours per award.

According to the ASCR website (http://science.energy.gov/ascr/facilities/alcc/), ``The mission of the ASCR Leadership Computing Challenge (ALCC) is to provide an allocation program for projects of interest to the Department of Energy (DOE) with an emphasis on high-risk, high-payoff simulations in areas directly related to the DOE mission and for broadening the community of researchers capable of using leadership computing resources.''

Protons and neutrons (collectively known as nucleons) found in the nuclei of atoms are made of quarks and gluons. Therefore, studying and understanding the quark-gluon structure of the nucleons and their interactions are of fundamental importance to understanding the building blocks of our universe and life. Quantum Chromodynamics (QCD) is the fundamental theory of quarks and gluons. The aim of this project is to determine how a basic property of a proton, namely its spin, is made up from its constituent quarks and gluons. It will investigate the quark and gluon compositions of the proton spin with a numerical approach called ``Lattice QCD.'' The outcome of this work will be an improved and first-principle-based understanding of the quark-gluon structure of the nucleon which can be compared with experiments being conducted in high energy and nuclear physics laboratories around the world.

This proposal was submitted by K.F. Liu as PI with co-PI's T. Draper of UK, and A. Alexandru and F.X. Lee of George Washington University on behalf the `chi QCD' Collaboration which consists of 23 members from institutions based in the US, China, India, and Japan.

chi QCD Collaboration Membership:

Senior Researchers:
Keh-Fei Liu, Terrence Draper, Shao-Jing Dong, Ivan Horvath (University of Kentucky)
Andrei Alexandru, Frank Lee (George Washington University)
Ying Chen, Ming Gong, Zhaofeng Liu (Inst. of High Energy Physics, Beijing)
Takumi Doi (RIKEN, Japan)
Huey-Wen Lin (University of Washington)
Nilmani Mathur (Tata Institute, Mumbai)
Hank Thacker (University of Virginia)
Jianbo Zhang (Zhejiang University)

Postdocs:
Mridupawan Deka (JINR, Dubna, Russia)
Walter Freeman (George Washington University)
Michael Glatzmaier, Yibo Yang (University of Kentucky)
Anyi Li (INT, University of Washington)

Graduate Students:
Michael Lujan (George Washington University)
Raza Sufian, Mingyang Sun, Geng Wang (University of Kentucky)

Publications:

2014

1. Meson Mass Decomposition from Lattice QCD. By Yi-Bo Yang, Ying Chen, Terrence Draper, Ming Gong, Keh-Fei Liu, Zhaofeng Liu, Jian-Ping Ma. [arXiv:1405.4440 hep-ph].
2. Chiral Symmetry Breaking and Chiral Polarization: Tests for Finite Temperature and Many Flavors. By Andrei Alexandru, Ivan Horváth. [arXiv:1405.2968 hep-lat].
3. From Nuclear Structure to Nucleon Structure. By Keh-Fei Liu. [arXiv:1404.3754 hep-ph].
4. Perturbative Renormalization and Mixing of Quark and Glue Energy-Momentum Tensors on the Lattice. By Michael Glatzmaier, Keh-Fei Liu. [arXiv:1403.7211 hep-lat].
5. The Roper Puzzle. By Keh-Fei Liu, Ying Chen, Ming Gong, Raza Sufian, Mingyang Sun, Anyi Li. [arXiv:1403.6847 hep-ph]. PoS LATTICE2013 (2014) 507.
6. The Flavor Structure of the Nucleon Sea. By J.C. Peng, W.C. Chang, H.Y. Cheng, K.F. Liu. [arXiv:1402.1236 hep-ph].
7. On the Momentum Dependence of the Flavor Structure of the Nucleon Sea. By Jen-Chieh Peng, Wen-Chen Chang, Hai-Yang Cheng, Tie-Jiun Hou, Keh-Fei Liu, Jian-Wei Qiu. [arXiv:1401.1705 hep-ph].
8. Charmonium, from overlap fermion on DWF configurations. By Y.B. Yang, Y. Chen, A. Alexandru, S.J. Dong, T. Draper, M. Gong, F.X. Lee, A. Li et al.. [arXiv:1401.1487 hep-lat].
9. Non-perturbative renormalization of overlap quark bilinears on 2+1-flavor domain wall fermion configurations. By chiQCD Collaboration (Zhaofeng Liu et al.). [arXiv:1312.7628 hep-lat].
10. A Lattice Study of Quark and Glue Momenta and Angular Momenta in the Nucleon. By M. Deka, T. Doi, Y.B. Yang, B. Chakraborty, S.J. Dong, T. Draper, M. Glatzmaier, M. Gong et al.. [arXiv:1312.4816 hep-lat].
11. Oscillatory behavior of the domain wall fermions revisited. By Jian Liang, Ying Chen, Ming Gong, Long-Cheng Gui, Keh-Fei Liu, Zhaofeng Liu, Yi-Bo Yang. [arXiv:1310.3532 hep-lat]. 10.1103/PhysRevD.89.094507. Phys.Rev. D89 (2014) 094507.
12. Study of the scalar charmed-strange meson with chiral fermions. By M. Gong, A. Li, A. Alexandru, Y. Chen, T. Draper, K.F. Liu. [arXiv:1103.0589 hep-lat]. PoS Lattice2010 (2014) 106.

2013

1. Non-perturbative renormalization of overlap quark bilinears on domain wall fermion configurations. By chiQCD Collaboration (Zhaofeng Liu et al.). [arXiv:1312.0375 hep-lat]. PoS LATTICE2013 (2013) 307.
2. Chiral polarization scale of QCD vacuum and spontaneous chiral symmetry breaking. By Andrei Alexandru, Ivan Horvath. 10.1088/1742-6596/432/1/012034. J.Phys.Conf.Ser. 432 (2013) 012034.
3. Proceedings, Extreme QCD 2012 (XQCD12) : Washington, USA, August 21-23, 2012. By Andrei Alexandru, Alexei Bazavov, Keh-Fei Liu. J.Phys.Conf.Ser. 432 (2013).
4. Strangeness and charmness content of the nucleon from overlap fermions on 2+1-flavor domain-wall fermion configurations. By XQCD Collaboration (M. Gong et al.). [arXiv:1304.1194 hep-ph]. 10.1103/PhysRevD.88.014503. Phys.Rev. D88 (2013) 1, 014503.
5. Spontaneous Chiral Symmetry Breaking as Condensation of Dynamical Chirality. By Andrei Alexandru, Ivan Horvath. [arXiv:1210.7849 hep-lat]. 10.1016/j.physletb.2013.03.041. Phys.Lett. B722 (2013) 160-166.

2012

1. Dynamical Local Chirality and Chiral Symmetry Breaking. By Andrei Alexandru, Ivan Horvath. [arXiv:1302.0905 hep-lat]. PoS ConfinementX (2012) 079.
2. Chiral polarization scale of QCD vacuum and spontaneous chiral symmetry breaking. By Andrei Alexandru, Ivan Horvath. [arXiv:1211.3728 hep-lat]. Chiral Polarization Scale at Finite Temperature. By Andrei Alexandru, Ivan Horvath. [arXiv:1211.2601 hep-lat]. PoS LATTICE2012 (2012) 210.
3. Connected-Sea Partons. By Keh-Fei Liu, Wen-Chen Chang, Hai-Yang Cheng, Jen-Chieh Peng. [arXiv:1206.4339 hep-ph]. 10.1103/PhysRevLett.109.252002. Phys.Rev.Lett. 109 (2012) 252002.
4. The $\Delta_{mix}$ parameter in the overlap on domain-wall mixed action. By M. Lujan, A. Alexandru, Y. Chen, T. Draper, W. Freeman, M. Gong, F.X. Lee, A. Li et al.. [arXiv:1204.6256 hep-lat]. 10.1103/PhysRevD.86.014501. Phys.Rev. D86 (2012) 14501.
5. By Huey-Wen Lin, Keh-Fei Liu. [arXiv:1111.0678 hep-ph]. 10.1103/PhysRevD.85.058901. Phys.Rev. D85 (2012) 058901.
6. How Self-Dual is QCD?. By Andrei Alexandru, Ivan Horvath. [arXiv:1110.2762 hep-lat]. 10.1016/j.physletb.2011.11.034. Phys.Lett. B706 (2012) 436-441.
7. Charge-dependent Azimuthal Correlations in Relativistic Heavy-ion Collisions and Electromagnetic Effects. By K.F. Liu. [arXiv:1109.4883 nucl-th]. 10.1103/PhysRevC.85.014909. Phys.Rev. C85 (2012) 014909.

2011

1. The Strangeness and Charmness of Nucleon from Overlap Fermions. By xQCD Collaboration (M. Gong et al.). [arXiv:1204.0685 hep-lat]. PoS LATTICE2011 (2011) 156.
2. Quark and Glue Momenta and Angular Momenta in the Proton --- a Lattice Calculation. By K.F. Liu, M. Deka, T. Doi, Y.B. Yang, B. Chakraborty, Y. Chen, S.J. Dong, T. Draper et al.. [arXiv:1203.6388 hep-ph]. PoS LATTICE2011 (2011) 164.
3. Is $1^-+$ Meson a Hybrid?. By Yi-Bo Yang, Yin Chen, Gang Li, Keh-Fei Liu. [arXiv:1202.2205 hep-ph]. 10.1103/PhysRevD.86.094511. Phys.Rev. D86 (2012) 094511.
4. Comment on `Controversy concerning the definition of quark and gluon angular momentum' by Elliot Leader (PRD 83, 096012 (2011)).
5. Absolute X-distribution and self-duality. By Andrei Alexandru, Ivan Horvath. [arXiv:1111.3897 hep-lat]. PoS LATTICE2011 (2011) 268.
6. Critical point of $N_f = 3$ QCD from lattice simulations in the canonical ensemble. By Anyi Li, Andrei Alexandru, Keh-Fei Liu. [arXiv:1103.3045 hep-ph]. 10.1103/PhysRevD.84.071503. Phys.Rev. D84 (2011) 071503.
7. Chiral extrapolation beyond the power-counting regime. By J.M.M. Hall, F.X. Lee, D.B. Leinweber, K.F. Liu, N. Mathur, R.D. Young, J.B. Zhang. [arXiv:1101.4411 hep-lat]. 10.1103/PhysRevD.84.114011. Phys.Rev. D84 (2011) 114011.
8. Nucleon strangeness form factors and moments of PDF. By Takumi Doi, Mridupawan Deka, Shao-Jing Dong, Terrence Draper, Keh-Fei Liu, Devdatta Mankame, Nilmani Mathur, Thomas Streuer. [arXiv:1010.2834 hep-lat]. 10.1063/1.3647212. AIP Conf.Proc. 1374 (2011) 598-601.
9. The Analysis of Space-Time Structure in QCD Vacuum II: Dynamics of Polarization and Absolute X-Distribution. By Andrei Alexandru, Terrence Draper, Ivan Horvath, Thomas Streuer. [arXiv:1009.4451 hep-lat]. 10.1016/j.aop.2011.04.007. Annals Phys. 326 (2011) 1941-1971.

2010

1. Meson spectra from overlap fermion on domain wall gauge configurations. By xQCD Collaboration (N. Mathur et al.). [arXiv:1011.4378 hep-lat]. PoS LATTICE2010 (2010) 114.
2. Absolute Measure of Local Chirality and the Chiral Polarization Scale of the QCD Vacuum. By Andrei Alexandru, Terrence Draper, Ivan Horvath, Thomas Streuer. [arXiv:1010.5474 hep-lat]. PoS LATTICE2010 (2010) 082.
3. Overlap Valence on 2+1 Flavor Domain Wall Fermion Configurations with Deflation and Low-mode Substitution. By xQCD Collaboration (A. Li et al.). [arXiv:1005.5424 hep-lat]. 10.1103/PhysRevD.82.114501. Phys.Rev. D82 (2010) 114501.
4. Finite density phase transition of QCD with $N_f=4$ and $N_f=2$ using canonical ensemble method. By Anyi Li, Andrei Alexandru, Keh-Fei Liu, Xiangfei Meng. [arXiv:1005.4158 hep-lat]. 10.1103/PhysRevD.82.054502. Phys.Rev. D82 (2010) 054502.
5. Lattice study of light scalar tetraquarks with I=0,2,1/2,3/2: Are \sigma and \kappa tetraquarks?. By Sasa Prelovsek, Terrence Draper, Christian B. Lang, Markus Limmer, Keh-Fei Liu, Nilmani Mathur, Daniel Mohler. [arXiv:1005.0948 hep-lat]. 10.1103/PhysRevD.82.094507. Phys.Rev. D82 (2010) 094507.

2009

1. Searching for tetraquarks on the lattice. By Sasa Prelovsek, T. Draper, C.B. Lang, M. Limmer, K.F. Liu, N. Mathur, D. Mohler. [arXiv:1002.0193 hep-ph]. 10.3204/DESY-PROC-2010-04/P37. Conf.Proc. C0908171 (2009) 508-510.
2. The Charmed-strange meson spectrum from overlap fermions on domain wall dynamical fermion configurations. By QCD Collaboration (S.J. Dong et al.). [arXiv:0911.0868 hep-ph]. PoS LAT2009 (2009) 090.
3. Spectroscopy of light tetraquark states. By Sasa Prelovsek, Christian B. Lang, Markus Limmer, Daniel Mohler, Terrence Draper, Keh-Fei Liu, Nilmani Mathur. [arXiv:0910.2749 hep-lat]. PoS LAT2009 (2009) 103.
4. The Calculation of nucleon strangeness form factors from N(f) = 2+1 clover fermion lattice QCD. By Takumi Doi, Mridupawan Deka, Shao-Jing Dong, Terrence Draper, Keh-Fei Liu, Devdatta Mankame, Nilmani Mathur, Thomas Streuer. [arXiv:0910.2687 hep-lat]. PoS LAT2009 (2009) 134.
5. Study of QCD critical point using canonical ensemble method. By chi QCD Collaboration (Anyi Li et al.). [arXiv:0908.1155 hep-lat]. 10.1016/j.nuclphysa.2009.10.113. Nucl.Phys. A830 (2009) 633C-635C.
6. Nucleon strangeness form factors from N(f) = 2+1 clover fermion lattice QCD. By Takumi Doi, Mridupawan Deka, Shao-Jing Dong, Terrence Draper, Keh-Fei Liu, Devdatta Mankame, Nilmani Mathur, Thomas Streuer. [arXiv:0903.3232 hep-ph]. 10.1103/PhysRevD.80.094503. Phys.Rev. D80 (2009) 094503.
7. Moments of Nucleon's Parton Distribution for the Sea and Valence Quarks from Lattice QCD. By M. Deka, T. Streuer, T. Doi, S.J. Dong, T. Draper, K.F. Liu, N. Mathur, A.W. Thomas. [arXiv:0811.1779 hep-ph]. 10.1103/PhysRevD.79.094502. Phys.Rev. D79 (2009) 094502.
8. Panel discussion on scalar mesons: Plenary session. By F. Buccella, D.V. Bugg, Yu.S. Kalashnikova, K.F. Liu, F. Llanes-Estrada, T. Matsuki, J.A. Oller, J.L. Rosner et al.. 10.1063/1.2973536. AIP Conf.Proc. 1030 (2008) 387-391.
9. Panel discussion on scalar mesons. By Keh-Fei Liu. 10.1063/1.2973534. AIP Conf.Proc. 1030 (2008) 383-384.
10. Pseudoscalar glueball mass from eta - eta-prime - G mixing. By Hai-Yang Cheng, Hsiang-nan Li, Keh-Fei Liu. [arXiv:0811.2577 hep-ph]. 10.1103/PhysRevD.79.014024. Phys.Rev. D79 (2009) 014024.
11. Neutron Electric Dipole Moment at Fixed Topology. By Keh-Fei Liu. [arXiv:0807.1365 hep-ph]. 10.1142/S0217732309031375. Mod.Phys.Lett. A24 (2009) 1971-1982.

2008

1. Winding number expansion for the canonical approach to finite density simulations. By Xiang-fei Meng, Anyi Li, Andrei Alexandru, Keh-Fei Liu. [arXiv:0811.2112 hep-lat]. PoS LATTICE2008 (2008) 032.
2. Light scalar mesons in 2+1 flavor full QCD. By Terrence Draper, Takumi Doi, Keh-Fei Liu, Devdatta Mankame, Nilmani Mathur, Xiang-fei Meng. [arXiv:0810.5512 hep-lat]. PoS LATTICE2008 (2008) 108.
3. 2+1 flavor QCD calculation of and . By Devdatta Mankame, Takumi Doi, Terrence Draper, Keh-Fei Liu, Thomas Streuer. [arXiv:0810.3241 hep-lat]. PoS LATTICE2008 (2008) 142.
4. Charmed Strange mesons from Lattice QCD with Overlap Fermions. By chi QCD Collaboration (S.J. Dong et al.). [arXiv:0810.2993 hep-lat]. PoS LATTICE2008 (2008) 117.
5. Strangeness and glue in the nucleon from lattice QCD. By QCD Collaboration (Takumi Doi et al.). [arXiv:0810.2482 hep-lat]. PoS LATTICE2008 (2008) 163.
6. Finite Density Simulations with Canonical Ensemble. By Anyi Li, Xiangfei Meng, Andrei Alexandru, Keh-Fei Liu. [arXiv:0810.2349 hep-lat]. PoS LATTICE2008 (2008) 178.
7. Dominance of Sign Geometry and the Homogeneity of the Fundamental Topological Structure. By Ivan Horvath, Andrei Alexandru, Thomas Streuer. [arXiv:0809.2834 hep-lat]. PoS LATTICE2008 (2008) 261.
8. Challenges of Lattice Calculation of Scalar Mesons. By Keh-Fei Liu. [arXiv:0805.3364 hep-lat].
9. Classical Limits of Scalar and Tensor Gauge Operators Based on the Overlap Dirac Matrix. By Andrei Alexandru, Ivan Horvath, Keh-Fei Liu. [arXiv:0803.2744 hep-lat]. 10.1103/PhysRevD.78.085002. Phys.Rev. D78 (2008) 085002.