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Posts related to particle and nuclear physics research

UConn PhD student Daniel Horning receives Dept. of Energy fellowship

Daniel Hoying
Daniel Hoying on April 13, 2017. (Peter Morenus/UConn Photo)

As a theoretical physicist studying the fundamental elements of matter, UConn graduate student Daniel Hoying creates calculations so large and complex they require supercomputers to perform them.

So Hoying is obviously excited that he will soon have regular access to one of the world’s most powerful supercomputers at the U.S. Department of Energy’s Brookhaven National Laboratory in Long Island, N.Y. The system is outfitted with Intel’s powerful new Knights Landing Xeon Phi chip. The chip’s 8 billion transistors and other cutting-edge technologies can carry the heavy processing loads that scientists like Hoying need to do their work.

“This represents an enormous opportunity for me,” says Hoying, who is headed to Brookhaven as a recipient of a U.S. Department of Energy (DOE) Office of Science Graduate Student Research (SCGSR) Award. “The level of precision offered by these processors allows us to make calculations that we would never have conceived of a few years ago. The on-site expertise can’t be discounted either. There are a lot of people there who know a lot of things I don’t know. It’s very exciting to have an opportunity to learn from them.”

Starting in July, Hoying will spend 12 consecutive months conducting part of his dissertation research at Brookhaven. Only 53 graduate students around the country received SCGSR awards this year. Other winners included students from Yale, Princeton, MIT, Duke, Cornell, CalTech, and Michigan State.

“The SCGSR program prepares graduate students for science, technology, engineering, or mathematics (STEM) careers critically important to the DOE Office of Science’s mission,” says Steve Binkley, acting director of DOE’s Office of Science. “We are proud of the accomplishments these outstanding students already have made, and look forward to following their achievements in years to come.”

Hoying’s research focuses on the Standard Model of particle physics. The Standard Model explains how the basic building blocks of matter interact and are governed by fundamental forces such as gravity and electromagnetism. It is the most fundamental theory of nature.

Hoying specifically studies the strong force in the Standard Model, otherwise known as Quantum Chromodynamics or QCD. The strong force binds fundamental particles of matter together to form larger particles. For example, the strong force helps quarks and gluons combine to make protons and neutrons, which in turn combine to make atoms, which in turn combine to make molecules and so on.

He is currently looking at the decaying cycle of particles known as kaons, which decay into two other particles called pions. These extremely small particles, first discovered in cosmic rays, only exist for fractions of a second and have been identified in experiments run in large particle accelerators. They are an essential part of the Standard Model of particle physics.

Previous calculations have shown that theory and experiments involving the decay of kaons have differed by small amounts. Hoying’s research aims to reduce those uncertainties, to help scientists learn more about what these particles are and how they behave.

Besides increasing understanding and advancing basic science, ultimately the information gathered through Hoying’s research could have a variety of applications in advanced computing and various energy fields.

“Dan is a talented young physicist who works hard,” says Professor Thomas Blum, Hoying’s advisor in the Department of Physics. “I’m fortunate to have him working for me.”


This article by Colin Poitras (UConn Communications) appeared in UConn Today on April 17, 2016.

Landmark g-2 experiment begins second phase in long career of testing the Standard Model

Instead of directly searching for new particles as the LHC experiments are doing in Geneva, the muon g-2 experiment at Fermilab measures a well-known physical property of the muon to ever greater precision, looking for deviations from the value it should have based on the Standard Model of particle physics, assuming that no new forces or particles are in play. UConn theorists Tom Blum and Luchang Jin are contributing to this effort by reducing the theoretical uncertainty on the Standard Model prediction to match the anticipated experimental precision.

The Muon g-2 experiment has begun its search for phantom particles with its world-famous and well-traveled electromagnet.

The Muon g-2 ring with instrumentationThe Muon g-2 ring with instrumentation, awaiting muons at Fermi National Accelerator Laboratory. Credit: Fermilab

What do you get when you revive a beautiful 20-year-old physics machine, carefully transport it 3,200 miles over land and sea to its new home, and then use it to probe strange happenings in a magnetic field? Hopefully you get new insights into the elementary particles that make up everything. The Muon g-2 experiment, located at the U.S. Department of Energy’s (DOE) Fermi National Accelerator Laboratory, has begun its quest for those insights. On May 31, the 50-foot-wide superconducting electromagnet at the center of the experiment saw its first beam of muon particles from Fermilab’s accelerators, kicking off a three-year effort to measure just what happens to those particles when placed in a stunningly precise magnetic field. The answer could rewrite scientists’ picture of the universe and how it works.

“The Muon g-2 experiment’s first beam truly signals the start of an important new research program at Fermilab, one that uses muon particles to look for rare and fascinating anomalies in nature,” said Fermilab Director Nigel Lockyer. “After years of preparation, I’m excited to see this experiment begin its search in earnest.”

Getting to this point was a long road for Muon g-2, both figuratively and literally. The first generation of this experiment took place at the U.S. DOE’s Brookhaven National Laboratory in New York State in the late 1990s and early 2000s. The goal of the experiment was to precisely measure one property of the muon – the particles’ precession, or wobble, in a magnetic field. The final results were surprising, hinting at the presence of previously unknown phantom particles or forces affecting the muon’s properties.

Video depicting the first leg of the g-2 electromagnet’s 3,200-mile journey from Brookhaven to Fermilab

The new experiment at Fermilab will make use of the laboratory’s intense beam of muons to definitively answer the questions the Brookhaven experiment raised. And since it would have cost 10 times more to build a completely new machine at Brookhaven rather than move the magnet to Fermilab, the Muon g-2 team transported that large, fragile superconducting magnet in one piece from Long Island to the suburbs of Chicago in the summer of 2013.

The magnet took a barge south around Florida, up the Tennessee-Tombigbee waterway and the Illinois River, and was then driven on a specially designed truck over three nights to Fermilab. And thanks to a GPS-powered map online, it collected thousands of fans over its journey, making it one of the most well-known electromagnets in the world.

“Getting the magnet here was only half the battle,” said Chris Polly, project manager of the Muon g-2 experiment. “Since it arrived, the team here at Fermilab has been working around the clock installing detectors, building a control room and, for the past year, adjusting the uniformity of the magnetic field, which must be precisely known to an unprecedented level to obtain any new physics. It’s been a lot of work, but we’re ready now to really get started.”

That work has included the creation of a new beamline to deliver a pure beam of muons to the ring, the installation of a host of instrumentation to measure both the magnetic field and the muons as they circulate within it, and a year-long process of “shimming” the magnet, inserting tiny pieces of metal by hand to shape the magnetic field. The field created by the magnet is now three times more uniform than the one it created at Brookhaven.

The Muon g-2 electromagnet arriving at Fermilab

The Muon g-2 electromagnet arriving at Fermilab in July 2013 after a 3,200-mile journey from Brookhaven National Laboratory. Credit: Fermilab

Over the next few weeks the Muon g-2 team will test the equipment installed around the magnet, which will be storing and measuring muons for the first time in 16 years. Later this year, they will start taking science-quality data, and if their results confirm the anomaly first seen at Brookhaven, it will mean that the elegant picture of the universe that scientists have been working on for decades is incomplete, and that new particles or forces may be out there, waiting to be discovered.

“It’s an exciting time for the whole team, and for physics,” said David Hertzog of the University of Washington, co-spokesperson of the Muon g-2 collaboration. “The magnet has been working, and working fantastically well. It won’t be long until we have our first results, and a better view through the window that the Brookhaven experiment opened for us.”

The Muon g-2 collaboration includes more than 150 scientists and engineers from more than 30 institutions in nine countries.

Learn more about the Muon g-2 experiment. Take a 360-degree tour of the Muon g-2 experiment hall.

The Muon g-2 experiment is supported by DOE’s Office of Science and the National Science Foundation.

Fermilab Media Contact

  • Andre Salles, Fermilab Office of Communication, 630-840-6733, media@fnal.gov

Science contacts

  • David Hertzog, Muon g-2 collaboration co-spokesperson, University of Washington, 206-543-0839, hertzog@uw.edu
  • Chris Polly, Muon g-2 project manager, Fermilab, 630-840-2552, polly@fnal.gov
  • B. Lee Roberts, Muon g-2 collaboration co-spokesperson, Boston University, 791-799-7483, roberts@bu.edu

Fermilab is America’s premier national laboratory for particle physics research. A U.S. Department of Energy Office of Science laboratory, Fermilab is located near Chicago, Illinois, and operated under contract by the Fermi Research Alliance LLC. Visit Fermilab’s website and follow us on Twitter @Fermilab.

Brookhaven National Laboratory and Fermilab are 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 the Office of Science of the U.S. Department of Energy’s website.

GlueX experiment publishes first scientific results following accelerator upgrade

Scientists are one step closer to understanding the strong force that binds quarks together forever. Researchers working with the Continuous Electron Beam Accelerator Facility (CEBAF) at the U.S. Department of Energy’s Jefferson National Accelerator Facility (J-Lab) have published their first scientific results since the accelerator energy was increased from six billion electron volts (GeV) to 12  GeV. The upgrade was commissioned to enable the next generation of physics experiments that will allow scientists to see smaller bits of matter than have ever been seen before. The first publication from the upgraded CEBAF was published by the Gluonic Excitation Project (GlueX) in the April issue of Physical Review C, available online through the APS web site.

University of Connecticut Associate Professor of Physics Richard Jones and students have played a leading role in the GlueX experiment since its inception in a series of scientific workshops nearly 20 years ago. The goal of GlueX is to discover whether or not a new class of subatomic particle known as “hybrid mesons” actually exists, and if they do, to measure their masses and other properties. While their existence is widely accepted on the basis of general theoretical arguments, definitive experimental evidence is still lacking. If they exist, hybrid mesons should be much more massive than ordinary mesons, so they should decay into ordinary mesons before they can travel any further than a few femtometers from where they were formed. Hence, the GlueX experiment is equipped with a multi-particle tracking spectrometer with nearly full angular coverage and sensitivity to both charged particles and neutrals.

In this new paper, the GlueX team describes how they produced two ordinary mesons, the neutral pion and eta. While creating these two particles is fairly simple for an accelerator of the CEBAF’s magnitude, what was interesting to the researchers is that they were able to show that the linear polarization of the accelerator’s photon beam can provide enough information about how the meson was formed. They can use that information to narrow down theories about how the mesons were produced. The research team plans to continue to analyze the data the accelerator has produced since it was commissioned a year ago, and they will begin to collect new data this fall.

-based on a news article by Jocelyn Duffy