Condensed Matter Theory Lecture Set for September 24 at UMD

COLLEGE PARK, Md. -- Nobel laureate David Gross of the University of California, Santa Barbara and the Kavli Institute for Theoretical Physics has been named the 2013 recipient of the Richard E. Prange Prize and Lectureship in Condensed Matter Theory and Related Areas. Dr. Gross will deliver a public lecture entitled "Frontiers of Fundamental Physics” at the University of Maryland, College Park, on September 24, 2013. He will also present a Condensed Matter Theory Center seminar entitled “Quantum Field theory: Past, Present, Future” on Monday, September 23, 2013.

The Prange Prize, established by the UMD Department of Physics and Condensed Matter Theory Center (CMTC), honors the late Professor Richard E. Prange, whose distinguished professorial career at Maryland spanned four decades (1961-2000). The Prange Prize is made possible by a gift from Dr. Prange's wife, Dr. Madeleine Joullié, a Professor of Chemistry at the University of Pennsylvania.

Gross received his bachelor's degree in physics and mathematics from the Hebrew University of Jerusalem, and his Ph.D. in physics from the University of California, Berkeley. He was appointed a Harvard Junior Fellow, and thereafter served for 27 years on the faculty at Princeton University. From 1997-2012, he directed the Kavli Institute for Theoretical Physics at UCSB, where he remains a Permanent Member. Gross holds the Frederick W. Gluck Chair in Theoretical Physics at UCSB.

Working at Princeton in 1973, Gross and his PhD student Frank Wilczek discovered asymptotic freedom, which holds that the closer quarks are to each other, the weaker the interaction (color charge) between them; in extreme proximity, quarks behave almost as free particles. This insight helped lead to the Standard Model of particle physics. Gross and Wilczek shared the 2004 Nobel Prize in physics with David Politzer for this breakthrough. Another of Gross’ Princeton PhD students, Edward Witten, won the Fields Medal in 1990. Gross is also well known for the Gross–Neveu field theory model devised with André Neveu and for heterotic string theory (with Jeffrey Harvey, Emil Martinec and Ryan Rohm). Like the late Richard Prange himself, Gross has been keenly interested in the physics of quantum Hall effects, writing several important papers, notably with Édouard Brézin.

In addition to being one of the most influential theoretical physicists of the last 50 years, David Gross has been unstinting in his national and international service to the cause of theoretical physics, not only in his role as the Director of the prestigious KITP, but also as the chair of various advisory boards for theory centers all over the world such the Solvay Institute in Belgium, the KITPC in China, and the ICTS in India.

Gross’ Prange Prize lecture will be delivered at the University of Maryland's John S. Toll Physics Building at 4:00 p.m. on Tuesday, Sept. 24 in the lecture hall, Room 1412. The event is open to the public. Dr. Gross will also present a seminar entitled “Quantum Field Theory: Past, Present, Future” on Monday, September 23 at 11:00 am in Room 2324 of the Computer and Space Sciences Building, in conjunction with the Joint Quantum Institute.

At the University of Chicago, Richard Prange received his PhD under Nobelist Yoichiro Nambu and also worked with Murray Gell-Mann and Marvin Goldberger. At the University of Maryland, he edited a highly-respected book on the quantum Hall effect and made important theoretical contributions to the subject. His interests extended into all aspects of theoretical physics, and continued after his retirement. Dr. Prange was a member of the Maryland condensed matter theory group for more than 40 years and was an affiliate of CMTC since its inception in 2002.

"Richard enjoyed a fascinating and fulfilling career at the University of Maryland exploring condensed matter physics, and even after retirement was active in the department," said Dr. Joullié. "He spent the very last afternoon of his life in the lecture hall for a colloquium on graphene, followed by a vigorous discussion. And so I was happy to institute the Prange Prize, to generate its own robust discussions in condensed matter theory."

"The Prange Prize provides a unique opportunity to acknowledge transformative work in condensed-matter theory, a field that has proven to be an inexhaustible source of insights and discoveries in both fundamental and applied physics,” said Dr. Sankar Das Sarma, who holds the Richard E. Prange Chair in Physics at UMD and is also a Distinguished University Professor and Director of the CMTC.

Since its initiation in 2009, the Prange Prize has been awarded to Nobelists Philip W. Anderson (2009), Walter Kohn (2010), Daniel Tsui (2011) and Andre Geim (2012).

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Parking is available in the Regents Drive Garage, across the street from the Physics lecture hall; an attendant will direct visitors within the garage. A free ShuttleUM bus runs to and from the College Park Metro station at about eight-minute intervals.

Directions to the College Park campus can be found here: http://www.cvs.umd.edu/visitors/maps.html

To locate the Physics Building, see the campus map at: http://www.cvs.umd.edu/downloads/campus%20map%20012309.pdf .

University of Maryland Physics: http://umdphysics.umd.edu/ Weekly colloquia: http://www.umdphysics.umd.edu/events/physicscolloquia.html

College of Computer, Mathematical and Natural Sciences: http://www.cmns.umd.edu/

Condensed Matter Theory Center: http://www.physics.umd.edu/cmtc/

UMD Physics colloquia: http://umdphysics.umd.edu/index.php/events/32-events/701-physicscolloquia.html

Click image for information.

The High-Altitude Water Cherenkov (HAWC) Gamma Ray Observatory formally began operations on August 1. This is the culmination of four years of work by a persevering team of scientists and technicians from Mexico and the United States. Researchers from the University of Maryland, including Jordan Goodman, Andrew Smith, Brian Baughman, Jim Braun and Josh Wood, are playing a very prominent role in the construction of HAWC and will help lead in the analysis of data from the observatory.

“HAWC will be the world’s premier wide-field TeV gamma-ray observatory with between 10 and 15 times the sensitivity of previous generation wide-field detectors,” said Goodman, UMD professor and principal investigator for the project.

HAWC is located at an altitude of 4100 meters (13,500’) on the slope of the volcanoes Sierra Negra and Pico de Orizaba at the border between the states of Puebla and Veracruz. The observatory, which is still under construction, uses an array of Cherenkov detectors to observe high-energy cosmic rays and gamma rays. Currently 111 out of 300 Cherenkov detectors are deployed and taking data. Each Cherenkov detector consists of 180,000 liters (40,000 gallons) of extra-pure water stored inside an enormous tank (5 meters high and 7.3 meters in diameter) with four highly sensitive light sensors fixed to the bottom of the tank.

The HAWC array, operating with 111 Cherenkov detectors since August 1 and growing each week, will be sensitive to of high-energy particles and radiation between 100 GeV and 100 TeV, energy equivalent to billion times the energy of visible light.

Click image for information.

In 2009, HAWC was identified as the Mexican astronomical project with the highest expected impact on high-energy astrophysics and in the US was endorsed by a joint NSF – DOE panel. Shortly thereafter a test array with three Cherenkov detectors was installed at the volcano Sierra Negra and successfully observed cosmic rays and gamma rays. Following these early tests, a prototype array of seven Cherenkov detectors was built in 2009 to test the tank design, simulate real data-taking, and study the logistics of deploying a large-scale observatory in this remote location. In 2012, the first 30 of 300 HAWC detectors were deployed, and since that time have been operated nearly continuously. The 30-detector stage of HAWC permitted calibration of the observatory via the observation of the shadow of the moon as it blocked cosmic rays.

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The Most Energetic Particles in the Known Universe

Gamma rays (electromagnetic radiation of very-high frequency) and cosmic rays (subatomic particles of very-high energy) are products of the most energetic and cataclysmic events in the known universe. These phenomena include the collisions of two neutron stars, the explosions of supernovae, binary systems of stars with stellar accretion, and active galactic nuclei which host black holes millions of times more massive than the Sun.

When high-energy cosmic rays and gamma rays reach the Earth, they interact with air molecules in the upper atmosphere. Gamma rays, for example, are converted into pairs of charged matter and anti-matter particles (mainly electrons and positrons). These particles rapidly interact with other air molecules, producing additional gamma rays of reduced energy which then create further charged particle pairs. This chain reaction proceeds until a large cascade of particles and radiation reaches ground level, where it can be recorded in the HAWC detectors.

When the charged particle cascade from an extra-terrestrial gamma ray passes through a Cherenkov detector, its particles are traveling faster than the speed of light in water. The resulting effect is similar to the shock wave produced in the atmosphere by a supersonic airplane (a "sonic boom"), but instead of producing sound the particles produce a visible cone of blue light. The flash of light, called Cherenkov radiation, is measured by the light sensor fixed to the bottom of each detector in HAWC. By combining the light signal observed in many tanks with fast electronics and high precision computing equipment, it is possible for scientists to determine the time of arrival, energy, and direction of the original extraterrestrial gamma ray or cosmic ray."

For more information see http://www.hawc-observatory.org/

http://www.aneki.com/entry.php?id=top_20_living_physicists

Dan Lathrop was featured in an episode of the Weather Channel series, Secrets of the Earth. The magnetic shield episode aired on June 27th at 8:30p.m.