Interactions The Newsletter of the UB Department of Physics Volume 6, Fall 2013 Our enrollment has also been growing steadily. UB enrolled 14 intended physics majors in 2011, 24 in 2012 and 33 this year. The most impressive number is the ratio of students enrolled to the number of offers made. It grew from 21% in 2011 to 32% in 2012, and to 38% this year. More and more students receiving our offers joined the Department. This again stands out in CAS, and is a testament to the qual- ity of our undergraduate programs and the efforts from the faculty, especially the Undergraduate Studies Committee under the leadership of Prof. Bernard Weinstein. Based on our record, the Department is one of a few used by CAS to establish model procedures for undergraduate recruitment. Dear alumni and friends, Once again, there are quite a few well-deserved promo- tions, important awards and recognitions this year. Con- It has been an exciting year since I last wrote to you. In gratulations to Prof. Francis Gasparini for becoming a January this year, the American Physical Society (APS) SUNY Distinguished Professor, Prof. Igor Zutic for promo- started what they called APS TV, highlighting some tion to Full Professor, Profs. Arnd Pralle and Wenjun Zheng departments to the physics community in the country. to Associate Professor, Prof. Doreen Wackeroth for being APS kicked this off by selecting 15 departments across elected as a Fellow of APS, Prof. Surajit Sen a Fellow of the country and ours was among them. They produced a the American Association for the Advancement of Science 6-minute film featuring our extraordinary growth in recent and Prof. Bruce McCombe for the Presidential Award for years. The film was shown at the biggest physics meeting Faculty Excellence. During my first term as the Chair, I wit- in the country, the APS March Meeting in Baltimore, MD, nessed first-hand 15 promotions to all ranks, among them and posted at the APS homepage and Youtube (a link is many early promotions, in addition to important awards. As posted at the homepage of our Department). It was played a group, their records/accomplishments have become the throughout the week-long meeting. We have been very envy in CAS and the University. proud of this growth seeing it first hand, and it is great to see it recognized by APS. There have been several successful workshops, public lectures and events. In May, Prof. Jong Han successfully As many of you may know, this year’s Nobel Prize in phys- organized the second workshop in the Physics at the Falls ics went to two theorists who predicted the Higgs boson. series on Recent Progress in Nonequilibrium Quantum Ma- It is very exciting and special to us, because three of our ny-Body Theory. The high-energy physics group organized faculty members, Profs. Avto Kharchilava, Ia Iashvili, and a public event celebrating the discovery of the Higgs boson. Salvatore Rappoccio, made contributions to the CMS Col- Prof. Peihong Zhang organized the inaugural lecture for the laboration at CERN, for the discovery of the Higgs boson. Ta-You Wu Memorial Lecture series, featuring Prof. Mar- In addition, 3 postdocs and about a dozen graduate and vin Cohen from UC Berkeley as the speaker. This year’s undergraduate students participated in various parts of the speaker for our Rustgi Lecture was Prof. Anthony Leggett, experiment, and two faculty members, Profs. Ulrich Baur a Nobel laureate from UIUC. (†2010) and Doreen Wackeroth, contributed with theoreti- cal work. Stay in touch! One of the signs of our growth is dear to our hearts, namely, Best regards, the number and quality of our incoming majors. This year’s class includes fourteen recipients of university scholarships, three of them Presidential Scholarships. This is about 50% of the incoming class, which is by far the highest in the Hong Luo, Chair College of Arts and Sciences (CAS). Professor of Physics Banner: Professor Francis Gasparini with President Sathish Tripathi, Provost Charles Zukoski and CAS Dean Bruce Pitman at the UB Celebration of Faculty & Staff Academic Excellence. Professor Gasparini was named SUNY Distinguished Profes- sor in recognition of his national and international prominence in his research field. Read more in www.buffalo.edu/news/ releases/2013/01/003.html. Photo: Nancy J. Parisi UB Physics and the Higgs Boson Discovery Interactions Volume 6 UB Physics Plays a Role in force (which manifests on the scale of tor such as the Tevatron (Fermilab) the Discovery of the Higgs atomic nuclei). Physicists have long and the Large Hadron Collider with Boson been trying to unify these forces under its record high energy and luminosity. By Drs. Avto Kharchilava, Ia Iashvili a single theory. A major breakthrough Next – general-purpose detectors that and Salvatore Rappoccio came nearly five decades ago when can handle proton-proton collisions at physicists realized that the weak 10-100 MHz rates. One also needs On July 4th, 2012, the CMS and AT- and electromagnetic forces can to design and implement unique and LAS collaborations at the CERN Large be described by a single, “unified” sophisticated event simulation, recon- Hadron Collider (LHC) announced the electroweak theory based on a struction and analysis software that discovery of the Higgs boson, to much fundamental symmetry between them. can process petabytes of data daily. worldwide attention and fanfare. The theory of electroweak interactions Past years – and the Higgs boson dis- and Quantum Chromodynamics (the covery in particular – have shown that theory of the strong force) form the basis all is possible through the concerted of the Standard Model. The Standard efforts of world-wide collaboration of Model successfully describes all of the thousands of physicists and engineers, elementary particles we know and how which is a miracle on its own and prob- they interact with one another. But our ably a thesis topic for a student in so- understanding of Nature is incomplete. ciology. In particular, the Standard Model as originally conceived could not answer “I think we have it!” proclaims Rolf Heuer, one basic question: Why do most director of CERN, announcing the discovery of of these elementary particles have the Higgs boson. Photo: CERN masses? The symmetry responsible This remarkable discovery is the cap- for electroweak unification requires the stone of a model that explains known force-carrying particles be massless. interactions of matter to 12 decimals The carrier of the electromagnetic force, of precision. As such, this model, the the photon, is an example. However, so-called “Standard Model” of particle the W and Z bosons, carriers of the physics, is the best theory there is. As weak force, have non-zero masses, the Higgs boson was predicted in 1964, A candidate Higgs boson event, decaying into and this fact breaks the electroweak two photons, as recorded by the CMS detector. its discovery was long-anticipated, with symmetry. It also leads to nonsensical Photo: CERN a search that took many decades, predictions such as interactions with the combined efforts of thousands of probabilities greater than one. As a UB physicist Avto Kharchilava and Ia scientists and engineers across the way out, Higgs, Brout and Englert Iashvili, joined the race in the early globe, and tireless commitment from have proposed a mechanism that 90’s, when they became members governments worldwide. It is a true explains the broken symmetry. Once of the CMS Collaboration – one of achievement of the human species, incorporated into the equations of the the two CERN experiments that have and a model for the wondrous things Standard Model, this electroweak- announced this discovery. They spent that can be achieved with global co- symmetry breaking mechanism would almost 10 years at CERN, until 2000, operation and a sustained investment not only allow W and Z bosons to be and contributed to the successful hunt in science by all of us. As members of massive, but all elementary matter for the Higgs boson in many ways, the CMS collaboration, UB physicists particles to have mass, as a bonus! ranging from CMS detector design played a role in the discovery of the Peter Higgs et al. pointed out that the optimization studies, tracking detector Higgs boson. mechanism required the existence of a R&D, construction and commissioning new particle with specific properties: it through software validation and Science on an Epic Scale is massive and carries neither electric physics potential of the CMS/LHC. charge nor spin. And the race for this Here we briefly mention two projects; Our Universe seems to be governed elusive particle had begun! tracking R&D and searches for a Higgs by four fundamental forces: gravity, boson in four lepton final states via electromagnetism, the weak force Well, many components are vital for the production of two Z bosons. This (which regulates nuclear phenomena the race of these proportions! First, process is one of the many ways the like fusion within stars) and the strong one needs a high energy accelera- unstable Higgs boson leaves a trace in 2 UB Physics and the Higgs Boson Discovery CONTINUED the ATLAS and CMS detectors. of the Higgs boson signal from the non- the CMS detector in 2013-2015. While Higgs background can be improved by the Higgs boson discovery is a cap- Until the late 90’s, the CMS Collabora- ~20% compared to traditional search stone of the Standard Model of particle tion was considering the MSGC detec- methods, which is a crucial improve- physics, many questions remain unan- tor – a gaseous tracking device – as a ment in view of the difficulty to detect swered, such as why the mass of the baseline detector for particle tracking.