Cross Sections

DEPARTMENT OF PHYSICS AND ASTRONOMY UNIVERSITY OF ROCHESTER WINTER 2002

Diagram credit: Fermilab Physics and Astronomy • WINTER 2002 Message from the Chair

—Arie Bodek Over the years we have given high tradition that Len established at Roch- Because of the great success of last priority to the training of our under- ester in this area of physics. year’s sesquicentennial celebration, the graduate and graduate students. This We wish to take this opportunity to University has initiated a new tradition attention has not gone unnoticed and thank all our alumni who have contrib- of hosting a Meliora has just been recognized in a nation- uted generously to the support of the Weekend reunion every wide survey of U.S. graduate students department. By completing the form on year. The theme this conducted in 2001. The Department of the last page of our newsletter, or by past fall was Freedom. Physics and Astronomy at Rochester was responding to our recent appeal for Several of our alumni ranked second nationwide in overall assistance, you can continue (or begin) attended and visited the graduate-student satisfaction. that tradition of giving that will assure department during our After an exhaustive search, it is a the future excellence of the department. open-house festivities. pleasure to report our success in the Other ways to help our cause is to We encourage all our alumni and friends recent recruitment of Alice Quillen, our inform any promising students about to continue this tradition, come for the newest faculty member, who is an our summer undergraduate research weekend, and visit us during Meliora experimenter in astrophysics. She has program (REU), and to encourage stu- Weekend (or anytime!). just joined our astrophysics group as dents interested in careers in physics to Several of our faculty and students assistant professor of physics and as- apply for graduate study at Rochester. have received awards during this past tronomy and will be on campus starting All application material for these pro- academic year. Among the faculty, Kevin January 2002. grams is available on our Web pages McFarland was named a Cottrell Scholar The department suffered a major loss (www.pas.rochester.edu). If you know of by the Research Corporation of America, this past year with the passing of Len any exceptional undergraduates whom and five faculty were elected Fellows of Mandel, one of the world’s leading ex- we should consider either for our REU the American Physical Society. Among perts in the field of quantum optics. Len program or for graduate school, we our students, graduate student Un Ki was an admired teacher and a brilliant would appreciate it if you would please Yang received an award from the Amer- experimenter, and was elected posthu- send their names and e-mail addresses ican Korean Physics Association, Michael mously to the National Academy of Sci- to Barbara Warren ([email protected]. Fitch was awarded the 2001 URA/ ence. A search is currently under way edu), and we will contact them directly. Fermilab award for best Ph.D. thesis, and for a new faculty member in experimental Any help from our alumni along these undergraduate Albert Wang was named quantum optics to continue the strong lines would be welcomed. a finalist for the APS 2001 Apker award.

Cross Sections On the Cover

Editors: Eric Blackman and Ashok Das The diagram on the cover illustrates a The reason is that the Standard Model Published by the Department of Physics and As- remarkable recent result in high-energy of particle physics has been so successful tronomy of the University of Rochester, and distrib- particle physics from Fermilab’s NuTev in so many ways that any such “appar- uted to alumni and friends free of charge. Copies collaboration. The analysis, led by Roch- ent” disagreements are unusual. Is there may be obtained by writing to CROSS SECTIONS, ester’s Kevin McFarland, suggests that a previously unrecognized problem with Department of Physics and Astronomy, University Neutrinos simply do not behave as ex- our understanding of the theory, or per- of Rochester, P.O. Box 270171, Rochester, NY pected. The vertical axis gives the extent haps more likely, is there an as yet un- 14627-0171. to which the combined electroweak force seen particle? The story is discussed behaves as a mixture of the electromag- further on page 5. Important notices: Area code for Rochester netic force (parity conserving) and the The Department of Physics and has changed to 585. Department phone: (585) weak force (parity violating). The dis- Astronomy and its alumni continue to 275-4351 and fax: (585) 275-8527. crepancy between theory, results for lead cutting-edge research efforts across If you change your mailing address, please other particles, and the NuTev neutrino a broad range of fields. Other examples contact Bob Knox with your new whereabouts findings has surprised many in the of such endeavors are also presented in ([email protected]). Also let him know high-energy physics community and has the science highlights section. your current e-mail address. received widespread public attention.

2 SCIENCE HIGHLIGHTS Physics and Astronomy • WINTER 2002 New Power from Fractal Mathematics: Predicting Extremes

Graduate student Subhadip Raychaud- is by measuring the height of a roomful huri, undergraduate Corry Przybyla, pro- of people. Although the tallest person in fessor Yonathan Shapir, and mathematics the world probably isn’t in the room, professor Michael Cranston continue to extreme-value statistics offers a way to demonstrate the power of fractal math estimate how tall that tallest person is for modeling physical systems. Most re- likely to be. Again the key is the idea of cently, the group has been able to formu- fractal scaling, across both space and late a prediction for when a single point time. A pattern that can be scaled is one on a surface will erode to a critical depth. that has the same shape no matter how [Raychaudhuri, Cranston, Przybyla, close you may “zoom in” on it. The basic Shapir, PRL 87, 136101 (2001)]. Predict- pattern repeats on any scale at which The next step in the research was to ing when the lowest point in a surface you view. Fractals display infinite scal- model the growth or erosion process will erode to a critical depth or when the ing. Likewise, when a surface grows or backward in time to determine what a highest point will build up to a critical is eroded, its overall pattern repeats small section of the surface originally height is challenging. The group has used with time. Consequently, a magnified looked like, by studying the way the “extreme-value statistics” to determine piece of the surface will look just like whole surface wound up. With input the probability of extreme events, such the whole surface after a long period of from Michael Cranston, the team was as to forecast severe weather conditions erosion or accumulation. able to generalize the way the extreme or predict floods. “This is the first time The team visualized how the roughness points wound up by solving a mathemat- we’ve had a way to predict how these of a surface changed as it wore away— ical model that should work for other extreme points grow based on nothing by an acid, for instance—or accumulated, fractal surfaces. more than the roughness of the surface such as inside a battery. They concluded Subhadip and Corry then ran com- they’re on,” says Yonathan. An extreme that the extreme point of a section puter simulations of different growth point could be the deepest point of rust changed in a nonlinear way with the and erosion processes thousands of in a steel girder or the highest point of roughness. The section could then be times to gather enough statistics for the metal accumulation inside a battery that scaled to the whole of the surface af- extreme points. Their results confirmed leads to a short. Understanding such fected by the corrosion or accumulation. the fractal-based predictions. issues can lead to better designs of In essence, the height of the tallest per- Yonathan emphasizes that the power material and more reliable devices. son in the world could be extrapolated of the widely applicable technique is its The process is akin to trying to find by scaling up the relationship between ability to determine when an extreme how tall the tallest person in the world the average and the tallest to account point will hit a critical height with much for the world’s population. more accuracy than just trial and error.

Evidence Found for Spinning Black Hole

University alumnus Todd Strohmayer J1655-40. During x-ray flares in 1996, (Ph.D. ’92) has found that a blinking x- a small percentage of the x-ray light, ray source near the center of the Milky within a narrow frequency range, turned Way has given the best evidence to date on and off about 450 times per second. that black holes spin [Strohmayer, ApJ Given that the mass of the presumed 552, L49 (2001)]. black hole is known from properties of Theorists are almost certain that black the binary system, the extremely rapid holes of stellar mass rotate because they variability could only come from ma- form during the collapse of a rotating terial orbiting very close to the black heavy star and conserve angular momen- hole. A maximally spinning black hole tum. But measuring the actual spin of a provides the smallest radius for the last

black hole is tricky. stable orbit of material, and this is the Image credit: NASA Todd’s evidence comes from a phe- only consistent interpretation of the Drawing of inner region of accretion nomenon observed during two blasts of data. If confirmed, this would provide disk around spinning black hole x-rays from a binary system called GRO the first definitive detection of a spin- ning black hole.

3 SCIENCE HIGHLIGHTS Physics and Astronomy • WINTER 2002 Origin of Force That Shapes Planetary Nebulae

The cosmic “paintbrush” that creates The idea that magnetic fields play a some of the most dazzling images in the role in shaping the material thrown off night sky may have been found by Roch- by dying stars has been considered be- ester astrophysicists [Blackman, Frank, fore, but previous work looked only at Markiel (Ph.D. ’98), Thomas, and Van the activity of the outer shell rather Horn, Nature 409, 485 (2001)]. The than the crucial interplay with the inner team realized that a magnetic dynamo, core, which leads to much stronger

similar to the kind operating in the sun, fields than previously realized. Image credit: NASA also appears to operate in the stellar The new model is supported by another Hubble Telescope image of planetary phases that immediately precede plane- well-known phenomenon. The typical Nebula M2-9 tary nebulae—the colorful, wispy clouds leftover core of such stars, called a white of light that radiate from many dying dwarf, is known to spin more slowly is the kind of unifying concept that one stars. The forces of the magnetic fields than astrophysicists expect. The Nature seeks in science.” The implications of can twist the radiating material into article suggests that the core is slowed the research reach beyond nebulae. The beautiful and distinctive shapes. down by “magnetic braking”—a sort of same processes that generate the magnetic The model thrives on the properties of drag produced by the magnetic fields fields in dying stars are also at work in a typical low-mass star as it approaches that twist up like a wrung towel that our own sun. the last years of its life. The core of such gets harder and harder to twist. As this Sunspots, solar storms, and coronal a star decouples from the outer shell of is happening, the material resting on mass ejections that endanger power grids the star like a yolk spinning inside an the surface of the white dwarf is pro- and satellites are all directly caused by egg. Since the magnetic fields act as pelled into space along the magnetic magnetic fields generated in the present elastic bands with endpoints on the shell lines, slowing the rotation further by sun. But when our sun runs out of fuel and yolk, respectively, the differential carrying off angular momentum. in a scant four or five billion years, it rotation between the two strengthens “The dynamo-generated magnetic too will become a planetary nebula. The the tension and energy in the magnetic field that we’ve proposed may explain role of magnetic fields will likely be as field by stretching. The strong fields can many other phenomena of planetary important then, as it is now, in powering then be used to propel and collimate ma- nebulae, such as the launching of the the solar corona. terial, as the fields uncoil like a spring. stellar wind,” says Jack Thomas. “This

New Results on Superluminal Propagation of Light

Two graduates of the department’s clarify some subtle misunderstood im- usual region of “anomalous dispersion” quantum optics group, Lijun Wang (Ph.D. plications of relativity.” in the six centimeters of cesium gas, ’92, advisor L. Mandel) and Alexander Physicists agree that the speed of where the velocity of light is higher for Kuzmich (Ph.D. ’99, advisors L. Mandel light does not provide an upper limit to higher frequencies of light. Raymond and N. Bigelow), have published impor- the group velocity, contrary to what is Chiao of the University of California at tant new experimental results [Wang, stated in most textbooks. Instead it ap- Berkeley describes the effect of a pulse Kuzmich, Dogariu, Nature 406, 227, plies to a more idealized quantity called reshaping akin to squeezing a long bal- (2000)] on Gain-Assisted Superluminal the “front velocity”—the speed of the loon filled with water. The cesium atoms Light Propagation. edge of a light pulse that is abruptly amplify the front parts of the pulse by The experiment involved the “super- and instantaneously switched on. stimulated emission of radiation (the luminal” propagation of a light pulse Past experiments of superluminal quantum process that creates laser through a cell of cesium gas: the group group velocity in an opaque material, beams), whereas later parts are deam- velocity (the velocity of a pulse undis- including those in 1982 by Nobel laure- plified by stimulated absorption. In other torted in shape) is negative, a counter- ate Steven Chu (B.S. ’70) of Stanford words, the system recreates the entire intuitive situation, which means that University, have suggested the presence pulse based on the front part of the pulse. the pulse peak arrives at the end of the of the faster-than-light phenomenon, Lijun plans to investigate several other cell in a time less than that of an equiv- first predicted in 1970. The new work aspects of superluminal group velocity, alent pulse traveling through a vacuum. by Wang and his colleagues may be the including the measurement of the veloc- In fact, because the group velocity is most impressive so far: More than 40 ity of energy transport (he suspects it negative, it exits the cell even before it percent of the pulse gets through the will be bounded by the vacuum speed of enters. “This is not at odds with special cesium gas medium, as opposed to light) by creating a pulse that allows the relativity,” maintains Lijun, now at the previous experiments that largely in- front velocity to be measured, and ex- NEC Research Institute in Princeton, N.J. volved quantum mechanical tunneling, ploration of the few-photon case. “In fact, we hope our experiment can in which very little incident light got through. The researchers used a com- bination of laser beams to create an un- 4 SCIENCE HIGHLIGHTS Physics and Astronomy • WINTER 2002 New Neutrino Measurement Surprises Particle Physicists

A team of scientists at the Department model. As yet, we don’t of Energy’s Fermi National Accelerator know the explanation, but Laboratory has found a surprising dis- we believe it may fore- crepancy between predictions for the be- shadow discoveries just havior of neutrinos and the way they ahead at accelerator lab- actually behave. oratories.” The NuTeV (Neutrinos at the Tevatron) Kevin emphasized that collaboration, whose analysis team is led the NuTeV measurement by Rochester’s Kevin McFarland, meas- would not be so striking if ured the ratio of two types of particles— the experiment had not neutrinos and muons—emerging from achieved an extraordinary high-energy collisions of neutrinos with level of precision, unprece- target nuclei. The results of generations dented for a neutrino ex- of particle experiments with other part- periment of its kind. “Be-

icles have yielded precise predictions for cause we examined the Photo credit: Fermilab the value of this ratio, which character- interactions of millions of Kevin McFarland (center) points out results to collaborators. izes the interactions of particles with the neutrinos and antineutrinos, weak force, one of the four fundamental their antimatter counterparts, we deter- cleus break up, they knew a neutrino forces of nature. For other elementary mined that there is only a one in four had interacted. If they saw a particle particles, including the quarks and elec- hundred chance that our measurement leaving the scene of the collision, they trons of ordinary matter, the predictions is consistent with the prediction. Unless knew it was a muon. If they saw nothing seem to hold true. But, to the NuTeV ex- this is a statistical fluke, it looks as if leaving, they knew a neutrino (invisible perimenters’ surprise, when they looked neutrinos may really behave differently to the detector’s “eye”) had come and at neutrinos with comparable precision, from other fundamental particles. Fur- gone. The NuTeV scientists measured the neutrinos did not appear to fall into line ther, experimenters using the Large ratio of muons to neutrinos and com- with expectations. Electron Positron at CERN, the European pared it with the predicted values, which “We measured a quantity called ‘sine Particle Physics Laboratory, recently other experiments have verified to a part squared theta W,’” said NuTeV physicist measured this same neutrino interaction per thousand accuracy for other particles. Sam Zeller, a graduate student from in a different particle reaction. They A painstaking yearlong analysis of the Northwestern University. “It tells us the saw the same discrepancy we found, NuTeV data revealed the unexpected dis- strength of the interaction of neutrinos although with less precision.” crepancy. with the Z boson, one of the carriers of Neutrinos carry no electric charge The 45-member, multi-institutional the weak force. The predicted value was and “feel” only the weak force, which is NuTeV collaboration (which is small on 0.2227. The value we found was 0.2277, a hundred times weaker than the elec- the scale of today’s particle physics ex- a difference of 0.0050. It might not sound tromagnetic force. As a result, neutrinos periments) collected data for 15 months like much, but the room full of physicists rarely interact with each other or with in 1996 and 1997. Kevin presented the fell silent when we first revealed the other particles, making them extremely analyzed results at an October 26 sem- result.” hard to detect. Physicists designed the inar at Fermilab. The collaboration has The NuTeV result gets physicists’ atten- NuTeV experiment in order to observe submitted the results to Physical Review tion because it doesn’t quite fit the Stan- interactions of millions of the highest- Letters. dard Model (see cover diagram), the very energy, highest-intensity neutrinos ever The collaboration included physicists precise theoretical picture that physicists produced. Starting with a proton beam from the University of Cincinnati, Colum- have developed to explain fundamental from Fermilab’s Tevatron, the world’s bia University, Fermilab, Kansas State particles and forces and their interactions. highest-energy particle accelerator, ex- University, Northwestern University, the In particle physics, such “misfit” results perimenters created a beam of neutrinos University of Oregon, the University of are often the harbinger of new particles, directed at a giant particle detector. The Pittsburgh, and the University of Roch- new forces and new ways of seeing na- detector itself was a 700-ton sandwich ester. The Rochester group included ture. The experimenters reported a three- of alternating slices of steel and detector. faculty members Arie Bodek and Kevin sigma discrepancy, which translates to As the beam passed from the first to McFarland; senior research associates a 99.75 percent probability that the neu- the last slice, one in a billion neutrinos Howard Budd, Pawel de Barbaro, and trinos are not behaving like other particles. collided with a target nucleus, breaking Willis Sakumoto; postdoctoral researcher “Our picture of matter has held true it apart. Deborah Harris, and students Sergey for 30 years of experimental results,” After the collision with a nucleus, Avvakumov and Un Ki Yang. said Fermilab Associate Director Michael the neutrino could either remain a neu- Shaevitz, a NuTeV cospokesperson. “With trino or turn into a muon, a particle the NuTeV result, it’s possible we may that is a heavier cousin of the electron. have stumbled across a crack in the When NuTeV experimenters saw a nu-

5 HONORS AND AWARDS Physics and Astronomy • WINTER 2002 Physicists Elected McFarland Recognized by Research APS Fellows Corporation and by Peers

Five University of Rochester physicists In May of 2001, Kevin McFarland re- third calendar year of their first appoint- were honored in early 2001 by the Amer- ceived a $75,000 Cottrell Scholars Award. ment. Designed to recognize teaching and ican Physics Society (APS) for their ac- McFarland is the first faculty member research, the awards aim to help the hold- complishments. Less than 1/2 of 1 per- from Rochester to re- ers become outstanding scientists and cent of the membership of the society is ceive this award since educators. Kevin’s area of research is elected to fellowship. its inception in 1994. high-energy experimental particle physics. Priscilla Auchincloss, About 15 awards are Kevin was also recently “given the nod” senior lecturer in phys- given yearly (to faculty by his peers, being appointed to a DOE/ ics, was recognized for in astronomy, chemistry, NSF panel to chart a 20-Year Future for her exemplary record or physics) nationwide. High-Energy Physics. The appointments of service to the APS The Cottrell Scholars to the panel were made after a request and for her ongoing ef- Awards are given by the Research Corpor- for nominations was sent to the high- fective work to improve ation to junior tenure-track faculty in the energy physics community. the climate for women physicists and to ensure gender equity. Stephen Craxton, senior scientist at the Laboratory for Laser Energetics, was Albert Wang Named Apker Award Finalist recognized for original contributions to laser-driven inertial confinement fusion Albert Wang, University of Rochester Wang is the third stu- (ICF) including two-dimensional hydro- undergraduate physics and mathematics dent from the University dynamic simulations, uniformity model- double major from the class of 2001, was to be named as a final- ing in tetrahedral hohlraums, and the one of three finalists for the 2001 Apker ist for the Apker Award, ubiquitously used third harmonic con- Award. This award is given by the Amer- which coincidentally is version of ICF glass laser systems. ican Physical Society to an undergrad- named for a University Stephen Teitel, pro- uate who has demonstrated exceptional of Rochester physics fessor of physics, was potential for scientific research through and astronomy 1941 recognized for contribu- an original contribution to physics. alumnus. In 1999, Govind Krishnaswami tions toward the under- Albert’s nomination was based on his (B.S. ’99), now a graduate student with standing and numerical senior thesis in condensed matter theory, Sarada Rajeev, went on to win the award modeling of critical “Simulation of the Driven Lattice Two for his undergraduate research also with phenomena in Josephson Dimensional Coulomb Gas,” which was Rajeev. In 1983, Bob Kowalewski, cur- junction arrays and supervised by Steve Teitel. As a finalist, rently a professor at the University of high-temperature superconductors. Wang traveled to Washington, D.C., to Victoria in Canada, was an Apker final- Jack Thomas, professor speak at the September 2001 APS meet- ist, and was supervised by Tom Ferbel. of mechanical and aero- ing. He also received a $2,000 award. space sciences and of as- tronomy, was cited for contributions to solar magnetohydrodynamics, David Birnbaum Honored at Xerox the study of the interac- tion between gas motions David Birnbaum (Ph.D. ’69) was re- is outstanding considering there are and magnetic fields in the sun. cently named the first Xerox Fellow from only about 15 fellows in the corporation Ian Walmsley, professor of optics, was the company’s Office Systems Group, of nearly 90,000 employees. David was recognized for developing methods of and the first Xerox Fellow from the en- recognized for leadership in establishing measuring quantum states of matter, and gineering groups in over 20 years. This color digital reproduction devices. for the characterization of wave fields.

Un Ki Yang Honored by American Korean Physics Association

Un Ki Yang (Ph.D. ’00), who received the committee to select the Outstanding “. . . his truly outstanding scholarly and his Ph.D. in experimental high-energy Young Researcher Award (ORYA) of the pioneering research on high-energy physics from Rochester in 2000 (advisor AKPA (American Korean Physics Asso- physics” by the Awards Committee on A. Bodek), won honorable mention by ciation) in 2001. He was cited for March 14, 2001, in Seattle, Washington.

6 HONORS AND AWARDS Physics and Astronomy • WINTER 2002 Talat Rahman Honored at KSU APS Prize Named

Talat Rahman (Ph.D. ’77, advisor Bob and corrosion. Before joining the K-State for Alumnus Knox) is one of five faculty honored as faculty, she was a postdoctoral physicist University Distinguished Professors at at the University of California at Irvine. The APS has established a new prize Kansas State University in 2001 in rec- Her awards include the UNDP Fellowship to recognize physicists under the age of ognition of outstanding contributions to and the CNR-Italy Research Fellowship, 30. Named the George E. Valley, Jr. Prize teaching, research, and service. the William L. Stamey Teaching Award, in honor of a generous bequest from the Talat is a solid-state theorist who in- the K-State University Distinguished estate of George E. Valley, Jr. (Ph.D. ’39), vestigates the physics of metal surfaces, Graduate Faculty Member Award, and the prize will be given every two years which is important for solving techno- the Alexander von Humboldt prize in and will carry a cash award of $20,000, logical issues such as thin-film growth, 2000. She is also a Fellow of the Amer- making it the largest single prize that the new materials development, catalysis, ican Physical Society. society gives. Recipients will be chosen by the president and two immediate past-presidents of the APS, as well as a chairperson to be elected by the APS Michael Fitch Receives Award Council. The prize is open to candidates in any field of physics. for Best Ph.D. Thesis at Fermilab George received his Ph.D. in physics from Rochester in 1939. He was named a Na- Michael J. Fitch (Ph.D. ’00) was awarded beam positions in accelerators. The tech- tional Research Fellow in nuclear physics the Universities Research Association nique will be used for future linear col- in 1940 and was project supervisor and (URA) thesis prize for the best Ph.D. liders, and may also be useful in other senior staff member of the Radiation thesis done on work at Fermilab. The accelerators in which nonintercepting Laboratory at MIT from 1941 to 1945. award was presented by Fred Bernthal, diagnostics are needed. During his stay He was on the faculty at MIT from 1946 president of the URA, at the Fermilab at Fermilab, Fitch was supported by our to 1974, was one of the founders of MIT User’s Meeting, June 12, 2001. Department of Energy (DOE) High-Energy Lincoln Laboratory, and was chief sci- Michael’s thesis, titled “Electro-Optic Physics grant and by a Fermilab Graduate entist of the Air Force in 1957–58. His Sampling of Transient Electric Fields from Fellowship in the Beams Division. areas of research included artificial Charged Particle Beams,” was advised by Michael has taken a one-year postdoc- radioactivity, mass spectroscopy, cosmic Adrian Melissinos. In the thesis, a new toral position with Ian Walmsley’s group rays, design of radar systems, and in- technique was developed for measuring at The Institute of Optics. vention of the SAGE Air Defense System. George passed away in 1999.

Alumnus Receives Canadian National Teaching Medal

The Canadian Association of Physicists teaching, which has been manifest in Calvin has been a full professor of (CAP) awarded its 1999 National Teach- both the classroom, where he has been a physics at Concordia since 1984 and was ing Medal to Professor Calvin Kalman pioneer in employing innovative coopera- chair from 1983 to 1989. He specializes (Ph.D. ’71, advisor C. Hagen) of Concor- tive teaching techniques, and in the edu- in high-energy particle research and dia University for his dedication to the cational community, where he has dissem- physics education. improvement of undergraduate physics inated his expertise in numerous papers on student-centered learning.

Herbert York Wins Fermi Award in 2000

Herbert F. York (B.S./M.S. ’43) won Herbert was born in Rochester in 1921 Award (2000), and Honorary Doctorate the Enrico Fermi Award in 2000 “for his and earned his B.S. and M.S. degrees in degrees from Case Western Reserve Uni- contributions to formulating and imple- physics at Rochester in 1943 and his Ph.D. versity, Claremont Graduate University, menting arms control policy under four degree at the University of California in and the University of San Diego. Presidents; for his founding direction of 1949. Among his awards are the Ernest The full text of the Enrico Fermi Award the Lawrence Livermore National Lab- Orlando Lawrence Award of the Depart- Citation can be found at www.pnl.gov/fermi/ oratory and his leadership in Research ment of Energy (1964), Guggenheim Fel- citations/york-cit.htm. Herbert was also and Engineering at the Department of lowship (1972–73), Szilard Award (1994), awarded the University of Rochester Defense; and for his publications analyz- the National Science Board’s Vannevar Hutchison Medal, see www.rochester. ing and explaining these complex issues Bush Award (2000), and the University edu/pr/Review/V60N1/alumni.html. with clarity and simplicity.” of California at Berkeley’s Clark Kerr 7 OTHER DEPARTMENT NEWS Physics and Astronomy • WINTER 2002 Rochester Leads Rochester Physics and Astronomy Domestic Univer- Ranks 2nd Nationally in Graduate- sities at Fermilab Student Satisfaction

The June 2001 survey of Fermilab users The National Association of Graduate- 1st place; Preparation for a Broad Range (www.fnal.gov/pub/ferminews/ferminews Professional Students (NAGPS) has an- of Careers: 2nd place; Teaching and TA 01-06-08/p1.html) shows the Rochester nounced the results of its 2000 survey Preparation: 4th place; Professional group at Fermilab leads all U.S. institutions of graduate students (http://survey.nagps. Development: 3rd place; Career Guidance with 57 users, followed by Lawrence org/), funded by the Alfred P. Sloan and Placement Services: 1st place; Berkeley National Laboratory with 56 Foundation. Our department did ex- Controlling Time to Degree: 8th place; users. tremely well. The full list follows. Mentoring: 3rd place; Program Climate: Overall Satisfaction: 2nd place; Infor- 2nd place. mation for Prospective Graduate Students: Selected Works of Emil Wolf Alice Quillen Joins the Department Published as Assistant Professor of Physics

Selected works of Professor Emil Wolf, and Astronomy Wilson Professor of Physics and Optics, have been published as Vol. 29 of the In January 2002, the department will bus postdoctoral fellow at Ohio State World Scientific Series in 20th Century welcome Alice C. Quillen, its newest fac- University before moving to Arizona. Physics (2001). The 661-page volume ulty member in obser- Her research takes her to the forefront presents many of Emil’s seminal papers vational astrophysics. of a broad range of areas of astronomy, over the past 50 years. Currently assistant including the structure of active, barred, Main topics include dif- astronomer at the Uni- and star-forming galaxies, the nature of fraction theory, the the- versity of Arizona’s active galactic nuclei, and the dynamics ory of direct and inverse Steward Observatory, and evolution of planet formation and scattering, phase-space Alice earned her degrees protoplanetary systems. Alice’s work is methods in quantum from Harvard (A.B., Phys- characterized by her ability to use both mechanics, the founda- ics) and the California Institute of Tech- theoretical and observational techniques tion of radiometry, phase nology (Ph.D., Physics). She was a Colum- in her research. We look forward to her conjugation and coherence theory. Emil’s continued success. classic papers on a rigorous formulation of the theory of partial coherence and par- tial polarization, the introduction of dif- fraction tomography, and his discovery New Opportunity for Rochester of correlation-induced shifts of spectral lines (the “Wolf effect”) are included, as Undergraduates to Accelerate into are papers discussing the historical de- Graduate Program velopment of optics and review articles and commentary on the selections. A new opportunity has been established of graduate study. The program aims for our undergraduates to continue on to for the smoothest possible transition graduate school in physics and astronomy between undergraduate and graduate at Rochester. Our students can apply in school and early completion of a Ph.D. their junior year for early admission into While the value of attending graduate graduate school. The program is designed school at a student’s undergraduate in- for top undergraduates who have estab- stitution is often debated, this program lished strong research ties with one or operates under the philosophy that there more of our faculty members. Highlights is no single answer that applies to every of the program include additional finan- student. The program therefore provides cial compensation for students, and a an option for students to consider, and significantly shortened completion time can also bring superb graduate students for the course and teaching requirements to the department.

8 OTHER DEPARTMENT NEWS Physics and Astronomy • WINTER 2002 Florencia Canelli Wins Multiple Accolades

Florencia Canelli, a graduate student of her accomplishments and hard work, Nino Zichichi. Her presentation was working with Tom Ferbel on the DZero this past August, Michael Witherell, the based on a new approach to extracting antiproton-proton Tevatron Collider ex- Director of Fermilab, offered Florencia parameters of the top quark, a method periment at Fermilab, has over the years the opportunity to attend the prestigious she has developed in collaboration with made many important contributions to Erice Summer School in Sicily. Once again, her colleague Juan Estrada (who just her experiment and to the Laboratory. she impressed the organizers, who received his Ph.D. from Rochester) and Last year, she represented the Labora- awarded her a Chien Shiung Wu scholar- Gaston Gutierrez from Fermilab. Floren- tory in Dallas, Texas, at a Department ship (named after legendary physicist cia plans to apply the new ideas in her of Energy exhibition promoting science Mme. Wu of Columbia University), and own Ph.D. analysis to check whether the and technology. She has also been in- a “New Talents” Prize for Original Work. top quark decays as expected in the volved with the Fermilab Users Organ- Both affidavits were signed by no lesser Standard Model (V–A theory) of electro- ization, and has been a leader of the luminaries than Gerard’t Hooft, Gabriele weak interactions. Young Physicists Association. Because Veneziano, and the Director of the School,

Remembering Leonard Mandel

Professor Leonard Mandel died Friday, ics, whose many implications even the says Ian Walmsley, professor and director February 9, 2001, at the age of 73. The most experienced scientists have difficulty of the University’s Institute of Optics. DuBridge Professor Emeritus of Physics accepting. Nevertheless, the theory has “Len was always able to put his finger and Optics, he was one of the founders held up whenever experimenters have precisely where the boundary lay be- of quantum optics—the study of the phys- been clever enough to find a way to tween classical and quantum physics. ics of light at its most fundamental level. test it. His experiments were models of simplic- He was known for his groundbreaking “Len systematically tested the foun- ity and elegance. It was the way you experiments on the nature of light and dations of quantum theory with the fin- would do the experiment if you were as was first to observe a variety of remark- est experiments in the world,” says Emil smart as someone like Len Mandel.” able phenomena predicted by quantum Wolf, longtime colleague and friend, who Len’s work helped form the basis for theory. persuaded Len to join him in Rochester a growing field of knowledge that today Len’s career spanned an era when the in 1964. “He was an excellent teacher includes quantum encryption, quantum influence of quantum and a first-class researcher, and he was computing, and quantum communications theory, which describes truly one of the founders of quantum —radically new ways to process, transmit, the behavior of matter optics. He was also a kind and incred- and retrieve information that offer super- at the subatomic level, ibly generous man.” secure protocols and extraordinary powers expanded to touch every Len laid claim to several achievements of deciphering. Several research centers area of physics. He was through a series of experiments from around the world owe their existence to at the forefront, putting the 1950s through the 1990s. He and his initial work by Len, including the Uni- quantum theory through students were the first to demonstrate versity’s Center for Quantum Information. its paces, and demonstrating in the lab- the self-interference of single photons; Typically, his experiments employed oratory some of the bizarre outcomes first to demonstrate nonclassical inter- laser beams and simple equipment to predicted by quantum mechanics. ference between two photons; and first split the beams and bounce them in var- It was he who most elegantly demon- to design and carry out an experiment ious directions in the laboratory, and strated what Einstein once called “spooky to observe “photon anti-bunching,” dem- sensitive equipment to measure the action at a distance,” the idea that any onstrating that a single atom illuminated results. His experiments with photons action can affect another seemingly by a laser beam emits photons uniformly even earned a nickname: “quantum unrelated action elsewhere—an idea spaced in time like soldiers marching pinball.” Using such a set-up 10 years physicists call “quantum entanglement.” past in a column. His measurements of ago, Len showed that the Heisenberg With a laboratory set-up as simple and the statistical properties of light gave Uncertainty Principle is more subtle disarming as his smile, Len showed that rise to the “Mandel formula,” which than had previously been thought. By a change to one laser beam in his lab- addresses the topic of photon detection. checking interference patterns of photons, oratory affected another, unrelated beam In one experiment, his team measured he showed that just the possibility of elsewhere in the laboratory. The experi- the time interval between the arrival making a measurement is enough to ment was one of the clearest demonstra- of two photons more accurately than change the outcome of an experiment, tions of the validity of quantum mechan- anyone had ever done before. The team worked constantly at the boundary be- Continued on page 10 tween classical and quantum physics,

9 OTHER DEPARTMENT NEWS Physics and Astronomy • WINTER 2002

Continued from page 9 Len earned his doctorate in nuclear for his gift of explaining the most com- physics in 1951 from the University of plex topics in the simplest terms. whether or not anyone actually makes London, where he also earned under- Len wrote more than 300 scientific a measurement. graduate degrees in mathematics and papers, including one with Emil on the Subsequently, Len demonstrated, un- physics. As a graduate student, he stud- coherence properties of optical fields equivocally, a central tenet of quantum ied cosmic rays, and as part of his work that became one of the most-cited arti- mechanics, that an event is not real he climbed high into the Alps to make cles in physics. Emil, Len, and others until it has been measured. In other his measurements. It wasn’t long before also wrote the seminal textbook Optical words, no matter how much is known, he began to wonder how his cosmic ray Coherence and Quantum Optics, a 1,166- what will happen next can never be detectors actually worked; that curiosity page volume on the nature of light. The known with certainty. His experiment led him to a career asking fundamental pair and others also organized an on- had its roots in a 1935 paper by Einstein, questions about photon detection and going series of Rochester Conferences Podolsky, and Rosen, which implied that measurement. He was senior lecturer in on Coherence and Quantum Optics, con- if an event can be predicted with certainty, physics at Imperial College of the Uni- sidered one of the world’s premier con- the event is real, even if it is not specif- versity of London for nine years before ferences in the field since the first one ically measured. Backers of quantum joining the University of Rochester in in 1960. theory demurred, with Niels Bohr, Werner 1964. Len was recognized with many top Heisenberg, and Max Born insisting that At the University, he was known as honors, including the Frederic Ives Medal there is no reality until a measurement an outstanding teacher, training 39 doc- and Max Born Award of the Optical Soci- is made. Sixty years later, with careful toral students who permeate physics ety of America, the Italian National Re- study of photons in the laboratory, Man- programs around the world. In 1992 search Council’s Marconi Medal, and the del demonstrated with dramatic clarity Len was awarded the University’s Fac- Thomas Young Medal from the British that the quantum theory of Bohr, Heisen- ulty Award for Graduate Teaching. Institute of Physics. He was a fellow of berg, and Born is correct. In addition to his work at the highest the American Physical Society, the Op- “Len took what seemed like an intel- level of physics, Len also had a special tical Society of America, and the Amer- lectual exercise and demonstrated that interest in neophyte science students. ican Academy of Arts and Sciences. In it corresponded to physically observable He developed the University’s first phys- 2001 he was elected posthumously to consequences,” says Nick Bigelow, who ics course geared specifically for non- the National Academy of Sciences. succeeded Len as the DuBridge Profes- science majors and taught that course sor of Physics and Optics. regularly for 20 years, and was known

ALUMNI NOTES

Vi-En Choong (Ph.D. ’97) is currently this year. Very few experimental papers Faculty at the University of Freiburg working at BioChip Systems of Motorola reach this magic number. since 1999 and continues to work in Inc. He is involved in making high- nuclear and particle physics at the DESY density biochips. Biochips are thin wafers John Harvey (Ph.D. ’78) finished serv- and CERN accelerators. of glass or plastic with thousands of ing with the Clinton administration De- microscopic bits of DNA arrayed on their fense Department as Deputy Assistant Jim Scholl (B.S. ’80) is currently a senior surfaces. Scientists are already using Defense Secretary for Nuclear Forces and multi-disciplined engineer at Raytheon them to identify disease genes and to Missile Defense Policy. He was brought Missile Systems in Tucson. Before that help speed drug discovery. They may ul- to Washington by Bill Perry, for whom he had spent 10 years at the Rockwell timately do for biology what microproc- he worked at the Stanford University Science Center in Thousand Oaks, Ca. essors did for computers. The biggest Center for International Security and After being out of school over 12 years, market for DNA chips is expected in the Arms Control, and who later became he is now enrolled in the Ph.D. program diagnosis of disease. Secretary of Defense. Though planning at the Optical Sciences Center at the Uni- to leave government in January 2001, versity of Arizona. Sameer Datar (Ph.D. ’94) is currently Harvey was convinced to stay in govern- a development engineer with PDF Solu- ment by General John Gordon, who heads Tim Tredwell (Ph.D. ’75) is still at Kodak, tions, Inc., a semiconductor fabrication the DOE National Nuclear Security Ad- and was just appointed Executive Chair- consulting company in San Jose, Ca., ministration, a semi-autonomous or- man of the IEEE International Solid State and works out of the Dallas office. ganization responsible for stewardship Circuits Conference (ISSCC). He has served of U.S. nuclear weapons capabilities on ISSCC for the past 12 years, including Jesse Ernst (Ph.D. ’95) is to be congra- and nonproliferation programs with the program chair in 1995, and has served tulated. His thesis, “First Measurement former Soviet Union. on the ADCOM of the IEEE Solid-State of the Rate for the Inclusive Radiative Circuits Society for the past five years. Penguin Decay b -> s gamma” PRL 74, Kay Koeningsmann (M.S. ’73) has 2885 (1995) received its 500th citation been serving as the Dean of the Physics

10 Physics and Astronomy • WINTER 2002 Departmental Funds

The department has established several young nuclear and particle physicists The Physics and Astronomy Alumni funds that greatly benefit departmental to Rochester to continue their research Fund. Established in 1968, this fund is activities. They are: in the department. for the discretionary use of the chair of the Department of Physics and Astron- The David L. Dexter Memorial Fund. The C. E. Kenneth Mees Observatory omy in support of departmental activities. Established in 1981 to honor the memory Fund. Established in 1977, this fund is of the late Professor Dexter, this fund for the discretionary use of the director Contributions from alumni and friends supports an annual lecture by an out- of the University’s Mees Observatory in are the dominant source of income to standing scientist. support of observatory activities, such these funds. If you would like to support as the recent upgrade to the facility. the Department of Physics and Astron- The Robert E. Marshak Memorial Fund. omy, please mark the appropriate box on This fund will be used to support the The Elliott W. Montroll Memorial Fund. the form below and send it with your newly created postdoctoral Robert E. Established in 1984 in memory of the contribution. Donations may be tax- Marshak Research Fellowships, in- late Professor Montroll, this fund sup- deductible, and donations of appreciated tended to attract the most talented ports the Montroll Memorial Lectures securities may also carry significant tax in Physics. advantages. The department is grateful for any help you may wish to give.

I wish to contribute to the following fund: ❑ The David L. Dexter Memorial Fund ❑ The Robert E. Marshak Memorial Fund ❑ The C. E. Kenneth Mees Observatory Fund ❑ The Elliott W. Montroll Memorial Fund ❑ The Physics and Astronomy Alumni Fund

My contribution: $

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If donating by check, please make your check payable to the “University of Rochester,” and indicate that it is for the “Department of Physics and Astronomy.” Be sure to check the specific fund to which your donation should be applied. Gifts of appreciated securities are also gratefully accepted. Please send this form to:

Chair, Department of Physics and Astronomy University of Rochester P.O. Box 270171 Rochester, NY 14627-0171 USA

11 Physics and Astronomy • WINTER 2002

Thank You! Norman C. Francis (Ph.D. ’52) Stefano Migliuolo (Ph.D. ’78) R. J. M. Fry Owen H. Gailar (B.S. ’46) David T. Nelson (M ’55) We gratefully acknowledge the following Charles Gaumond (Ph.D. ’79) Jaewoo Noh (Ph.D. ’93) for their donations to the department James D. Greenfield (B.A. ’57) John F. O’Brien (Ph.D. ’67) during this past year. Edith Halbert (Ph.D. ’56) Susumu (Ph.D. ’58) and Mary Okubo Melvyn Halbert (Ph.D. ’55) John H. Osborn (B.S. ’82) Rexford E. Adelberger (Ph.D. ’68) John C. Heurtley (Ph.D. ’66) C. Diehl Ott (B.S. ’52) Theodore Auerbach (B.S. ’55) J. P. Hsu (Ph.D. ’69) Donald M. Packer (Ph.D. ’38) Peter Avakian (B.S. ’55) Joshua Kaminstein (M ’75) Paul E. Parris (Ph.D. ’84) Masayoshi Azuma Yutaka Kano (Ph.D. ’63) Theodore Pella (B.A. ’50) Hattie Bradlow (M ’48) David E. Knapp (Ph.D. ’62) Steven C. Pieper (B.S. ’65) William C. Broeffle (B.S. ’53) R. S. Knox (Ph.D. ’58) Robert J. Potter (Ph.D. ’60) Christine Caccamise (B.S. ’92) Thomas Koffas (Ph.D. ’98) Esther Conwell Rothberg (M.S. ’54) Randolph Bake Capone (B.S. ’90) Masatoshi Koshiba (Ph.D. ’55) Lewis Rothberg (B.S. ’77) Warren Cheston (B.S. ’51) Don Q. Lamb (Ph.D. ’74) Bunji Sakita (Ph.D. ’60) Vi-En Choong (Ph.D. ’97) Barbara Lasinski (Ph.D. ’68) Frederick Seward (Ph.D. ’59) Roland W. Cobb (Ph.D. ’67) Daniel H. Lichtin (B.S. ’77) Roger W. Shaw (B.S. ’55) Ernest D. Courant (Ph.D. ’43) Harold H. Lichtin (B.A. ’73) Steven L. Solomon (Ph.D. ’98) Fred W. Craver (Ph.D. ’71) Eugene Y. Liu (Ph.D. ’70) Robert L. Sproull Mario Dagenais (Ph.D. ’79) Ming T. Lu (Ph.D. ’70) Steven G. Steadman (B.S. ’64) Scott K. Dunfield (B.S. ’89) George Luckey (Ph.D. ’50) Motoomi Yamanoi (Ph.D. ’86) Charles W. Engelbracht (B.S. ’92) Bruce McAvoy (B.S. ’54)

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