RIKEN Nishina Center for AcceleratorBased Science Computing Group
Group Leader: Taku Izubuchi (D.Sc.)
Research Summary
The computing group founded in 2011 as a part of of the RIKEN BNL Research Center established at Brookhaven National Laboratory in New York, USA, and dedicated to conduct researches and devlopements for large scale physics computations important for particle and nuclear theory. The main subjects include the lattice gauge theory, such as lattice QCD describing the subatomic structures of hadrons, which allow us the abinitio investigation for strongly interacting quantum field theories beyond pertrubative analysis. The three of the major activities are R&D for high performance computers, developments for computing algorithms, and researches of particle, nuclear, and lattice theories.
In 1997, the group pioneered the use of the domainwall fermions, which preserve chiral symmetry, a key symmetry for understainding nature of paritcle nuclear physics, and investigate various hadron physics including an important calculation of quark flavor mixing and CPviolations or hadronic contributions to muon's anomalous magnetic moment (g2) that are relevant for checking the standard model of particle nuclear physics utilizing the CabibboKobayashiMaskawa theory. In JFY2004, the numerical lattice QCD group built a 10 TFlops QCDOC parallel supercomputer dedicated for the firstprinciple nonperturbative calculations of QCD. A total 600 teraflop (peak) successor to the QCDOC computer, three racks of QCDCQ (QCD with Chiral Quarks), is installed and starts to run new physics programs.
Main Research Fields
 Mathematical & Physical Sciences
Keywords
 Particle physics
 Nuclear physics
 High Performance Computing
 Quantum field theory
 Lattice field theory
Selected Publications
 1.T. Blum, N. Christ, M. Hayakawa, T. Izubuchi, L. Jin, C. Jung and C. Lehner.:
"Connected and leading disconnected hadronic lightbylight contribution to the muon anomalous magnetic moment with phys ical pion mass"
Physical Review Letteters Volume 118, Article 022005, (2017)  2.T. Blum, P. A. Boyle, T. Izubuchi, L. Jin, A. Jüttner, C. Lehner, K. Maltman, M. Marinkovic, A. Portelli, and M. Spraggs (RBC and UKQCD Collaborations).:
"Calculation of the Hadronic Vacuum Polarization Disconnected Contribution to the Muon Anomalous Magnetic Moment"
Physical Review Letters Volume 116, Article 232002, (2016)  3.Z.Bai,T.Blum,P.A.Boyle,N.H.Christ,J.Frison,N.Garron,T.Izubuchi,C.Jung,C.Kelly,C.Lehner, R. D. Mawhinney, C. T. Sachrajda, A. Soni, and D. Zhang (RBC and UKQCD Collaborations).:
"Standard Model Prediction for Direct CP Violation in K → ππ Decay"
Physical Review Letters Volume 115, Article 212001 (2015) [ Editors' suggestion ]  4.Michael G. Endres, Andrea Shindler, Brian C. Tiburzi, Andre WalkerLoud.:
"Massive photons: an infrared regularization scheme for lattice QCD + QED"
Physical Review Letters, Volume 117  5.T. DeGrand, M. Golterman, W. I. Jay, E. T. Neil, Y. Shamir and B. Svetitsky.:
"Radiative contribution to the effective potential in composite Higgs models from lattice gauge theory"
Phys. Rev. D94:5, 054501 (2016)  6.Thomas Blum, Saumitra Chowdhury, Masashi Hayakawa, Taku Izubuchi.:
"Hadronic lightbylight scattering contribution to the muon anomalous magnetic moment from lattice QCD"
Phys.Rev.Lett. 114 (2015) 1, 012001, arXiv:1407.2923.  7.Thomas Blum, Taku Izubuchi, Eigo Shintani.:
"A new class of variance reduction techniques using lattice symmetries"
Phys.Rev.D88 (2013) 094503 (6 pages)  8.Tomomi Ishikawa, Thomas Blum, Masashi Hayakawa, Taku Izubuchi, Chulwoo Jung, Ran Zhou.:
"Full QED+QCD LowEnergy Constants through Reweighting"
Phys.Rev.Lett. 109 (2012) 072002 (5 pages).  9.S. Meinel.:
"Λc → Λl+νl form factors and decay rates from lattice QCD with physical quark masses"
Phys. Rev. Lett. 118, no. 8, 082001 (2017)  10.Yasumichi Aoki, Taku Izubuchi, Eigo Shintani, Amarjit Soni.:
"Improved lattice computation of proton decay matrix elements"
arXiv:1705.01338
Recent Research Results

Mar. 20, 2015
Narrowing the gap between theory and experiment
Related Links
Lab Members
Principal investigator
 Taku Izubuchi
 Group Leader
Core members
 Stefan Meinel
 RBRC Researcher
 Akio Tomiya
 Special Postdoctoral Researcher
 Hiroshi Oki
 Visiting Scientist
Contact Information
21 Hirosawa,
Wako, Saitama
3510198, Japan
Email: izubuchi [at] bnl.gov