Three Brookhaven Lab Scientists Named Fellows of American Physical Society

Newswise — UPTON, NY—The American Physical Society (APS), the world’s largest physics organization, has elected three scientists from the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory as 2018 APS fellows. With more than 53,000 members from academia, government, and industry, APS seeks to advance and share physics knowledge through research journals, scientific meetings, and activities in education, outreach, and advocacy. Each year, a very small percentage of APS members are elevated to the status of fellow through a peer nomination process. Fellows are recognized for their exceptional contributions to physics, including in research, applications, leadership and service, and education. 

Taku Izubuchi, APS Division of Particles and Fields

Taku Izubuchi, a theorist in Brookhaven Lab's Physics Department, has been honored for “developing numerical methods and algorithms in lattice QCD allowing precision tests of the standard model, from CP violation in heavy quark and kaon decays to hadronic corrections to the muon g-2.”

Izubuchi has made seminal contributions in the study of quantum chromodynamics (QCD), the theory describing the strong-force interactions of subatomic particles, particularly the quarks and gluons that make up most of the visible matter in the universe, advancing our understanding of how those interactions affect other particles in the Standard Model.

He is an internationally recognized expert and leader in the field of “lattice gauge theory,” a method for breaking complex physics problems into pieces that can be solved by running calculation-based simulations on powerful supercomputers. This approach models particle interactions on a four-dimensional lattice that includes three spatial dimensions plus time.

While Izubuchi’s interests and expertise are very broad, ranging from quantum gravity to lattice QCD, his overriding focus has been developing lattice computational methods that are directly related to experimental measurements in particle physics. One such method, known as “All Mode Averaging” (AMA), is having a tremendous impact on the drive toward ever-more precise results while significantly decreasing the computing cost required to solve a problem—often by an order of magnitude or more.

Many of these precision calculations provide quantities for comparison with results from important experimental programs that test the limits of the Standard Model to explain our world. These include precision calculations predicting the rate of rare particle decay processes showing evidence of charge-parity (CP) symmetry violation; the anomalous magnetic moment of the muon (muon g-2); the electric dipole moment of the neutron; the proton lifetime; and calculations for determining quark masses.

Through his continued connections with the RIKEN Brookhaven Lab Research Center (RBRC, founded by RIKEN Japan), where he now serves as the Leader for the Computing Group, Izubuchi has played a crucial role in the development of the RIKEN/Brookhaven/Columbia lattice gauge collaboration. This has become among the world’s leading groups working in large scale lattice gauge simulations.

“It is a great honor to receive this fellowship,” Izubuchi said. “I am very grateful for the illuminating interactions I have had with many excellent collaborators and colleagues whom I have had the pleasure to work with in my career. I am also grateful for the generous support that makes my research possible, including the computing resources provided at Brookhaven and RIKEN, as well as many other places in the U.S. and Japan. I am looking forward to continuing to contribute to exciting research in computing and particle physics.”

Izubuchi received his Ph.D. in 1997 from the University of Tokyo. He held a postdoctoral position at the University of Tsukuba for two years before becoming a tenured assistant professor at Kanazawa University. In 2008, he joined Brookhaven Lab with a joint position as an RBRC Fellow and a member of the High Energy Theory group in the Physics Department. In 2011, he became a founding group leader of the RBRC Computing Group and is now a full-time member of the Physics Department, granted tenure in 2013. Highly sought for invited talks at international physics conferences, Izubuchi also helps to train future physicists through his guidance of postdoctoral fellows and graduate students.

Igor Zaliznyak, APS Division of Condensed Matter Physics

Igor Zaliznyak, a physicist in the Condensed Matter & Materials Science Department, received his fellowship in recognition of his “innovative use of neutron scattering to probe quantum materials and [his] leadership in development of the corresponding instrumentation.”

Zaliznyak is an expert in using beams of neutrons to probe the structure and dynamics of atomic lattices. An advantage of neutron scattering is that it is very sensitive to magnetic atoms and the relative orientations of magnetic moments on neighboring atoms. One area in which Zaliznyak has exploited this capability is in the study of high-temperature superconductors, materials that allow the loss-free flow of electric current. For example, he has combined careful measurements with clever analysis to arrive at elegant models that describe the local magnetic correlations in a particular family of iron-based superconductors.

Another recent example of Zalizynak’s accomplishments involves a study of the magnetic excitations in an electrical conductor containing large magnetic moments on an array of rare-earth atoms. From neutron scattering measurements, he was able to identify the signature of quantum fluctuations associated with chains of magnetic atoms coupled together only in one direction, along the chain. Surprisingly, deep analysis demonstrated that the magnetic coupling is achieved by an electron hopping from one atom to its neighbor. This exotic example established a new type of electronic behavior.

In addition to performing groundbreaking experiments, Zaliznyak has also made important contributions to the development of unique neutron instrumentation. In particular, he led a team that developed the conceptual design and obtained the funding for a $15 million hybrid spectrometer that was built and commissioned at the Spallation Neutron Source, a DOE Office of Science user facility at Oak Ridge National Laboratory. That instrument is now capable of uniquely distinguishing magnetic excitations from lattice vibrations, a capability that Zaliznyak is currently applying to iron-based superconductors.

“I am truly delighted to be elected an APS fellow and have my work be recognized by my peers,” Zaliznyak said. “Throughout my scientific career I was extremely fortunate to be able to work on the most interesting scientific problems and collaborate with amazing scientists who lead the field. I am especially indebted to my mentors, Lous-Pierre Regnault and Collin Broholm, whose profound knowledge of experimental condensed matter physics and appreciation for neutron scattering instrumentation have been an inspiration for me. This honor strongly reflects on the important role that neutron scattering research has for understanding quantum materials and on the leading role that Brookhaven Lab continues to play in this area.”

Zaliznyak earned his Ph.D. in Physics in 1993 from the P.L. Kapitza Institute for Physical Problems in Moscow, Russia. He held a joint graduate appointment there and at the Laboratoire de Magnetisme et Diffraction des Neutrons in Grenoble, France, where from 1991 to 1993 he carried out neutron studies that contributed to the experimental verification of the Haldane theory of quantum spin chains. He joined P.L. Kapitza Institute as a junior scientist upon completion of his studies and was promoted to scientist in 1995. He continued to work as a visiting researcher at the Laboratoire de Magnetisme et Diffraction des Neutrons in Grenoble from 1994 to 1996 and was a postdoctoral research fellow at Johns Hopkins University from 1996 to 1999. He joined Brookhaven Lab’s Neutron Scattering Group as an assistant physicist in 1999 and was promoted to assistant physicist (2001) and physicist (2004). He has served as a member of many scientific review committees, including for the Department of Energy and the National Science Foundation, and is a member of the American Physical Society and the Neutron Scattering Society of America.

Anatoli Zelenski, APS Division of Physics of Beams

Anatoli Zelenski, a senior physicist in the Collider-Accelerator Department (C-AD) at Brookhaven Lab, was selected for his “groundbreaking work in developing high-intensity high-brightness polarized ion beam sources, in particular, optically-pumped polarized sources.”

The optically-pumped polarized ion source Zelenski developed for the Relativistic Heavy Ion Collider (RHIC) at Brookhaven Lab is a critical component of the “spin physics” program at this DOE Office of Science user facility for nuclear physics research. Delivering beams with high levels of polarization—where the protons are aligned with their individual spin axes pointing in a particular direction—enables studies of how the protons’ internal building blocks (quarks, antiquarks, and gluons) contribute to the overall spin property.

Solving the mystery of how spin is derived from the proton’s components has been a driving force in physics since the discovery that the three main building blocks, known as valence quarks, contribute only about 20 percent to the overall proton spin. Experiments using the polarized beams at RHIC have revealed that gluons also make a significant contribution to proton spin.

The generation of the polarized proton beam is a complex multi-step process where each step requires a thorough understanding of the physical process involved, and careful optimization of all parameters. The beam source developed by Zelenski and other innovative contributions he designed to improve measurements of RHIC’s beam polarizations have produced high-current, high-intensity, highly polarized beams and ever-increasing polarized-proton collision rates at RHIC.

These successes build on Zelenski’s prior experience developing innovative accelerator technologies for experiments around the world—including at the Institute for Nuclear Research (INR) in Moscow and TRIUMF, Canada’s National Lab for nuclear and particle physics—and will be equally important to the success of the spin physics program of a future Electron-Ion Collider, a proposed facility that could solve the proton spin mystery.

“I am honored to be named an APS fellow and have my work recognized by my peers,” said Zelenski. “The success of our project at RHIC is based on international collaboration with many contributions of physicists from KEK Japan, TRIUMF Canada, INR Moscow, and BINP Novosibirsk, in addition to Brookhaven Lab in the USA. I believe, that international scientific collaboration is one of the strongest parts of our community of physicists and I hope it will continue this way in the future.”

Zelenski earned a Ph.D. in 1986 from INR for his work in developing the first optically pumped polarized ion sources, and a second Ph.D. from INR in 2003 for work on spin-exchange methods of proton and H- minus ion beam polarization for high-energy accelerators and colliders. He worked at TRIUMF from 1992-99, before joining Brookhaven Lab as a physicist in 2000. He won the Lab’s “Science and Technology Award” in 2003, and in 2006, he and a colleague won the prestigious Veksler Award, granted once every three years by the Russian Academy of Sciences, for “outstanding achievements in accelerator physics.” He was granted tenure at Brookhaven Lab in 2010.

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Two other scientists with connections to Brookhaven Lab were also named APS Fellows this year. They are:

Helen Caines of Yale University, who serves as a co-spokesperson for the STAR collaboration at the Relativistic Heavy Ion Collider (RHIC), Brookhaven Lab’s premiere nuclear physics research facility. She was recognized for “her pivotal role in promoting the beam energy scan at RHIC and measurement of the energy dependence of jet quenching through development of techniques for full jet reconstruction in relativistic heavy ion collisions.”

Grazyna Odyniec of Lawrence Berkeley National Laboratory, who was recognized for “leadership and contributions to the understanding of strangeness production in high-energy nuclear collisions and to the RHIC beam energy scan program.”

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The work of the three Brookhaven Lab scientists was supported in large part by the DOE Office of Science.

Brookhaven National Laboratory is supported by the Office of Science of the U.S. Department of Energy. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

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