Headlines

Reports on recent events within the larger scientific world, with a member of the department explaining the science and commenting on its significance.

Daniel McCarron wins NSF Early Career Award

Daniel McCarron, assistant professor of physics, the College of Liberal Arts and Sciences, will receive $645,000 over five years for his work on the development of techniques to trap large groups of molecules and cool them to temperatures near absolute zero. The possible control of molecules at this low temperature provides access to new research applications, such as quantum computers that can leverage the laws of quantum mechanics to outperform classical computers.

The NSF Faculty Early Career Development (CAREER) Program supports early-career faculty who have the potential to serve as academic role models in research and education, and to lead advances in the mission of their department or organization. Activities pursued by early-career faculty build a firm foundation for a lifetime of leadership in integrating education and research.

McCarron was one of 8 junior faculty at the University of Connecticut to receive the prestigious Early Career awards from NSF in 2019. For a description of all 8 awards, see this recent article published in UConn Today.

UConn Astronomers React to First Photo of a Black Hole

credit: Event Horizon Telescope collaboration

This image is the first ever taken of a black hole, captured by the Event Horizon Telescope (EHT) project. The black center is a direct view of the event horizon of a supermassive black hole with a mass of 6.5 billion times the Sun, lying at the center of the Virgo cluster of galaxies. The bright ring is emission from hot gas just above the event horizon, with an asymmetric shape caused by gravitational lensing of light in the strong gravity of the black hole. The EHT collaboration captured the image using a network of 8 radio telescopes that spanned the Earth, effectively creating a planet-sized interferometer.

For more information, see the full NSF press release:

This result directly impacts research in galaxy evolution and cosmology that is being carried out at UConn. The following comments from UConn Astrophysics researchers indicate the level of interest that this result has generated within the international Astrophysics community.

This is a stunning technical achievement. Supermassive black holes are the most extreme objects in the Universe, bizarre rips in spacetime that lie in the center of every massive galaxy. But despite their extreme properties, black holes have a remarkably simple mathematical description, with just a few numbers describing all of their vital properties: mass, size, and spin. Until now, the only way to measure black holes was through indirect methods, like my own research program that uses the timing of light echoes in the surrounding gas. The Event Horizon Telescope black hole image is a tremendous first step in a new understanding of extreme gravity and the detailed astrophysics of black holes. – Jonathan Trump, Assistant Professor
I am fascinated by this result and how we can actually see a direct image of a black hole that is a trillion times our distance to the Sun. This is truly an amazing result for human beings achieved within the limitation of our observational instruments. As an observational astronomer who works with black holes, this result also opens up new possibilities to learn about their unknown features such as black hole spin that could revolutionize our understanding of black hole physics. – Yasaman Homayouni, Graduate Student
This result is a beautiful demonstration of what is possible when the global community works in concert towards a scientific goal. Sometimes the greatest discoveries are not found by the biggest new telescopes in space, but through creative thinking, years of dedicated effort, and big data techniques, building upon what we have here on Earth. – Cara Battersby, Assistant Professor
It is truly extraordinary to be able to provide this new evidence for Einstein’s ideas on space and time through observations made no less than one hundred years since he first proposed them. As to the discovery itself, there are two aspects to black holes, one is that they pull everything in, and the other is that they do not let anything out. With nothing being able to get out, they thus look black to an observer on the outside, to thereby give them their black hole name. Now for many years we have had evidence of things falling into black holes, but had never previously had any evidence that things cannot get out. These new data show a fireball ring of things falling in, with the ring surrounding a black space in the center where nothing can get out. We thus confirm that indeed nothing can escape a black hole. – Philip Mannheim, Professor

For more about this topic, see this recent article in the Daily Campus, UConn Astronomy Community Responds Joyously to M87 Black Hole Image.

2 for the price of 1: UConn researcher finds new mechanism making double ionization an efficient process

Schematic of dICD

An international research team headed by Dr. Aaron LaForge from the research group of Prof. Nora Berrah in the Physics department at UConn has recently discovered a new type of decay mechanism leading to highly efficient double ionization in weakly-bound systems. The team has published its results in the science journal “Nature Physics”.

Ionization is a fundamental process where energetic photons or particles strip an electron from an atom or molecule. Normally, a much weaker process is double ionization, where two electrons are simultaneously emitted, since it requires higher-order interactions such as electron correlation. However, these new results show that double ionization doesn’t necessarily need to be a minor effect and can even be the primary ionization mechanism thereby getting two electrons for the price of one.

The enhancement is likely due to double ionization proceeding through a new type of energy transfer process termed double intermolecular Coulombic decay, or dICD, for short. The experiments were performed at the synchrotron, Elettra, in Trieste, Italy. There, electrons are accelerated to near the speed of light and then rapidly undulated through an alternating magnet field. In this way, the electrons emit short wavelength light which is needed to trigger dICD. The researchers produced superfluid helium droplets, which are cryogenic, nanometer-sized matrices capable of attaching various atomic and molecular species in order to perform precise spectroscopic measurements. In this case, dimers consisting of two alkali metal atoms were attached to the surface of helium droplets. The dICD process, schematically shown in Fig. 1, occurs through an electronically excited helium atom (red), produced by the synchrotron radiation, interacting with the neighboring alkali dimer (blue and white) resulting in energy transfer and double ionization. Although an alkali dimer attached to a helium nanodroplet is a model case, dICD is potentially relevant for any system where it is energetically allowed.

dICD belongs to a special class of decay mechanisms where energy is exchanged between neighboring atoms or molecules leading to enhanced ionization rates. Seemingly ubiquitous in weakly-bound, condensed phase systems such as van der Waals clusters or hydrogen-bonded networks like water, these processes can contribute to radiation damage of biological systems by producing particularly harmful low-energy electrons. dICD could strongly enhance such effects through the production of two low-energy electrons for each intermolecular decay.

Original publication:

A. C. LaForge, M. Shcherbinin, F. Stienkemeier, R. Richter, R. Moshammer, T. Pfeifer & M. Mudrich, “Highly efficient double ionization of mixed alkali dimers by intermolecular Coulombic decay”, Nature Physics (2019) DOI: 10.1038/s41567-018-0376-5

Kate Whitaker wins the Sloan Fellowship!

Original UConn Today article here

Rising Star in Astrophysics Receives Sloan Foundation Fellowship

Kate Whitaker, assistant professor of physics, stands next to a telescope inside the observatory on top of the Gant Complex on Feb. 14, 2019. (Peter Morenus/UConn Photo)
Kate Whitaker, assistant professor of physics, stands next to a telescope inside the observatory on top of the Gant Complex on Feb. 14, 2019. (Peter Morenus/UConn Photo)

As an assistant professor of astrophysics, Kate Whitaker spends a lot of her time thinking about stars. Hundreds of billions of stars that comprise galaxies, to be more precise. But with a recent fellowship from the Alfred P. Sloan Foundation, it is Whitaker’s star that is shining brightly.

Whitaker is one of 126 outstanding U.S. and Canadian researchers selected by the Alfred P. Sloan Foundation to receive 2019 Sloan Research Fellowships. The fellowships, awarded yearly since 1955, honor early-career scholars whose achievements mark them as among the most promising researchers in their fields.

Valued not only for their prestige, Sloan Research Fellowships are a highly flexible source of research support. Funds may be spent in any way a Fellow deems will best advance his or her work.

“Sloan Research Fellows are the best young scientists working today,” says Adam F. Falk, president of the Alfred P. Sloan Foundation. “Sloan Fellows stand out for their creativity, for their hard work, for the importance of the issues they tackle, and the energy and innovation with which they tackle them. To be a Sloan Fellow is to be in the vanguard of twenty-first century science.”

According to colleagues, Whitaker certainly fits the bill as one of the brightest young minds at UConn and beyond.

“Kate’s record so far is truly impressive and speaks to her potential as a leader in her field,” explains Barry Wells, head of UConn’s Department of Physics. “It was my great pleasure to nominate her for a Sloan Foundation Research Fellowship, and I am thrilled they felt she was worthy of the prize.”

An observational extragalactic astronomer, Whitaker’s research tries to reveal how galaxies are evolving from the earliest times to the present day.

In addition to her position at UConn, Whitaker is also an associate faculty at the new Cosmic Dawn Center in Copenhagen, Denmark. Whitaker and her students actively collaborate with DAWN, working towards pushing our detection of quiescent “red and dead” galaxies even earlier in time.

She will be among the world’s first scientists to explore the universe using the new James Webb Space Telescope when it is launched in 2019, which she says will allow her to push into new frontiers of research.

Apart from that exciting work, Whitaker and colleagues Cara Battersby and Jonathan Trump were tasked with building a full-fledged astronomy program from scratch at UConn. Not only has their work exceeded expectations, the fruits of their labor are already beginning to emerge. Whitaker and colleagues have so far created five new astrophysics courses with two more slated for next year, established an official astronomy minor, and are operating a thriving research program that involves doctoral students, undergrads, and even local high school students.

“I am both thrilled at this opportunity and humbled to be named amongst such a prestigious cohort of scientists,” says Whitaker. “With the Sloan Foundation’s generous support, I aspire to continue to lead ground-breaking studies of the distant universe, the mystery of which will no doubt captivate our imaginations.”

The Alfred P. Sloan Foundation is a philanthropic, not-for-profit grant making institution based in New York City. Established in 1934 by Alfred Pritchard Sloan Jr., then-President and Chief Executive Officer of the General Motors Corporation, the Foundation makes grants in support of original research and education in science, technology, engineering, mathematics, and economics. A full list of the 2019 Fellows is available at the Sloan Foundation website at https://sloan.org/fellowships/2019-Fellows.

Goodwin School 3rd grade visits the Physics Learning Labs

About one mile from the Gant plaza, Goodwin Elementary School teaches some really bright kids. On January 15, 2019, science teacher Nancy Titchen and Goodwin teachers brought the entire 3rd grade class on a field trip to the Physics Learning Labs mock-up studio for some science fun. Students enjoyed a liquid nitrogen show, witnessed quantum effects in superconducting magnetic levitation, experienced mechanics concepts such as angular momentum, and learned about vibrations and the phenomenon mechanical of resonance. The expert hands of a star team of PhD students (Erin Curry and Donal Sheets) and new laboratory technicians (James Jaconetta and Zac Transport) ensured students had a great time and learned some interesting science. Big thanks to the staff and the Goodwin School!

Nora Berrah Named 2018 AAAS Fellow

Physics professor Nora Berrah has been named a 2018 Fellow of the American Association for the Advancement of Science (AAAS). Prof. Berrah has been recognized for her distinguished contributions to the field of molecular dynamics, particularly for pioneering non-linear science using x-ray lasers and spectroscopy using synchrotron light sources.

Prof. Berrah

View full story on CLAS website.

Welcoming Barrett Wells as new department head

 

In August 2018, Professor Barrett Wells entered as the new head of the Physics department, following Professor Nora Berrah.  Barrett is an experimental condensed matter physicists with a robust research program involved in both synthesis and advanced experimentation around novel phases of quantum materials. Barrett brings to the department strong administrative talent, having served a long term as the associate department head for undergraduate affairs as well as chairing many important committees since his arrival at UConn.

Learn more about Professor Wells and the physics department from a recent interview produced by the College of Liberal Arts and Sciences.

UConn Physics major wins national recognition for research

Connor Occhialini – Finalist 2018 LeRoy Apker Undergraduate Achievements Award

by Jason Hancock

One of our star undergraduates, Connor Occhialini, has won national recognition as a finalist in the 2018 LeRoy Apker Undergraduate Achievements Award competition for his research in the UConn Physics department. The honor and distinction is awarded not only for the excellent research achievements of the student, but also for the department that provides the supportive environment and opportunities for students to excel in research. Connor is in fact the second Apker finalist in three years’ time (Michael Cantara was a 2016 Apker finalist). Connor graduated with a BS in Physics from UConn in May 2018 and stayed on as a researcher during summer 2018. During his time here, he developed theoretical models, helped build a pump-probe laser system, and carried out advanced analysis of X-ray scattering data which revealed a new context for an unusual phenomenon – negative thermal expansion. With these outstanding achievements, the department presented Connor’s nomination to the 2018 LeRoy Apker award committee of the American Physical Society. Connor was selected to be one of only four Apker finalists from all PhD-granting institutions in the US. With this prestigious honor, the department receives a plaque and a $1000 award to support undergraduate research. Connor is now a PhD student in the Physics Department at MIT.

New gravity wave detection signals collision of two dead stars

For the first time, scientists have directly detected gravitational waves — ripples in space-time — in addition to light from the spectacular collision of two neutron stars. This marks the first time that a cosmic event has been viewed in both gravitational waves and light.

The discovery was made using the U.S.-based Laser Interferometer Gravitational-Wave Observatory (LIGO); the Europe-based Virgo detector; and some 70 ground- and space-based observatories.

Neutron stars are the smallest, densest stars known to exist and are formed when massive stars explode in supernovas. As these neutron stars spiraled together, they emitted gravitational waves that were detectable for about 100 seconds; when they collided, a flash of light in the form of gamma rays was emitted and seen on Earth about two seconds after the gravitational waves. In the days and weeks following the smashup, other forms of light, or electromagnetic radiation — including X-ray, ultraviolet, optical, infrared, and radio waves — were detected.

GW+EM Observatories Map

GW170817: A Global Astronomy Event

The observations have given astronomers an unprecedented opportunity to probe a collision of two neutron stars. For example, observations made by the U.S. Gemini Observatory, the European Very Large Telescope, and the Hubble Space Telescope reveal signatures of recently synthesized material, including gold and platinum, solving a decades-long mystery of where about half of all elements heavier than iron are produced.

The LIGO-Virgo results are published today in the journal Physical Review Letters; additional papers from the LIGO and Virgo collaborations and the astronomical community have been either submitted or accepted for publication in various journals.

“It is tremendously exciting to experience a rare event that transforms our understanding of the workings of the universe,” says France A. Córdova, director of the National Science Foundation (NSF), which funds LIGO. “This discovery realizes a long-standing goal many of us have had, that is, to simultaneously observe rare cosmic events using both traditional as well as gravitational-wave observatories. Only through NSF’s four-decade investment in gravitational-wave observatories, coupled with telescopes that observe from radio to gamma-ray wavelengths, are we able to expand our opportunities to detect new cosmic phenomena and piece together a fresh narrative of the physics of stars in their death throes.”


Written by Jennifer Chu, MIT News Office, full text of original article available here on the LIGO web site.

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.