Harvard University Department of Physics

EPB Annual Symposium

On Saturday, April 26, the annual Engineering and Physical Biology (EPB) Symposium will be held in Room B103 of the Northwest Building, 52 Oxford St. Speakers from constituent fields - Physics, Engineering, Chemistry and Molecular Biology - will present significant recent findings ranging from the physics of protein conformation to DNA knotting.

Reunion and Symposium for Graduate Alumni

On Friday, April 4, 2014, Harvard celebrated the venerable history of one of the country’s great physics programs.

François Englert: "The Brout-Englert-Higgs Mechanism And Its Scalar Bosons"

"A consistent approach to short range interactions through massive gauge vector fields was proposed by Robert Brout and me, and independently by Peter Higgs..."

Fall 2013 Certificate of Distinction in Teaching Awards

Graduate students Prahar Mitra, Elliot Schneider, Elizabeth Petrik, Nicholas Schade, Alexandru Lupsasca, Chi-Ming Chang, and Timothy Koby have been awarded the Harvard University Certificate of Distinction in Teaching for the Fall 2013 term by the Derek Bok Center.

First Direct Evidence of Cosmic Inflation

The BICEP2 Collaboration, led by Professor John Kovac, has announced the discovery of first direct evidence of cosmic inflation, the expansion of space first proposed in 1981 by Alan Guth of MIT. Watch the VIDEO.

EPiQS Funding to Boost Quantum Materials Theory Research

Harvard has been chosen one of the six receipients of Gordon and Betty Mooore Foundation's Emergent Phenomena in Quantum Systems (EPiQS) grants...

SPOTLIGHT ON...

Professor Eric Mazur has published a groundbreaking, modern introductory physics textbook that builds up physics from conservation principles: Principles & Practice of Physics (Pearson, 2014).

"When students focus just on the equations they do not necessarily understand the concepts… What I found out was that, if you focus on solid conceptual understanding, students will not only get a better understanding of physics as a whole and appreciation of physics as a whole, they will actually perform better on traditional textbook problems…"
Watch Prof. Mazur's presentation and learn more about the book on the Publisher's website.

UPCOMING EVENTS

Today

LPPC Seminar: Kinematic Variables for Weakly Interacting Particle Final State Reconstruction at the LHC - Chris Rogan (Harvard)
- At the Large Hadron Collider (LHC), many new physics signatures feature pair-production of massive particles with subsequent direct or cascading decays to weakly interacting particles, such as SUSY scenarios with conserved R-parity or Higgs decaying to two leptons and two neutrinos through W bosons, often motivated by models of new physics which attempt to mitigate the hierarchy problem in the Standard Model. While final states containing multiple weakly interacting particles represent an opportunity for discovery of new physics phenomena, they also present a unique experimental challenge; the kinematic information lost through particles escaping detection makes fully reconstructing these collision events impossible. In order to address this shortcoming special kinematic variables are used to partially reconstruct these events, providing sensitivity to properties of the particles appearing in them, including masses and even their spin correlations.
  
  We discuss a collection kinematic variables developed to study final states with weakly interacting particles at the LHC, focusing on the super-razor variables. Using the examples of slepton pair-production at the LHC, the motivation and derivation of these observables are described along with comparisons to previously existing approaches. Generalizations of the super-razor variables to more complicated decay topologies are also discussed, using fully leptonic top quark pair production as an example, along with its supersymmetric analogue of stop pair-production with subsequent decays to b-quarks and charginos.
- View in Google Calendar
Wonho Jhe; Seoul National University
- Water at the nanoscale: physics and applications
  
  Liquid exhibits unique peculiarities at the nanoscale compared with bulk liquid, similarly to the case of solid. I will discuss abnormal dynamic as well as mechanical properties of both nanofilm and nanobridge of water.
- View in Google Calendar

Tomorrow

CMP Seminar: Norman Yao (Harvard)
- Title: Many-body Localization with Dipoles
  
  Abstract: Statistical mechanics is the framework that connects thermodynamics to the microscopic world. It hinges on the assumption of equilibration. In isolated quantum systems, the failure of equilibration is captured by the phenomenon known as many-body localization (MBL). I will begin by briefly reviewing the theoretical status of many-body localization. To date, none of the phenomena associated with MBL have been observed in an experimental system, in part because of the isolation required to avoid thermalization. I will consider several dipolar systems, which we believe to be ideal platforms for the realization of MBL phases and for investigating the associated delocalization phase transition. The presence of strong interactions in these systems underlies their potential for exploring physics beyond that of single particle Anderson localization. However, the power law of the dipolar interaction immediately raises the question: can localization in real space persist in the presence of such long-range interactions? I will review and extend several arguments producing criteria for localization in the presence of power laws and present small-scale numerics regarding the MBL transition in several of the proposed dipolar systems. Time permitting, I will discuss recent work on understanding the possibility of many-body localization in translation invariant systems.
- View in Google Calendar
Liam McAllister (Cornell) "Quantum Gravity in the Sky? Inflation and String Theory after BICEP2"
- View in Google Calendar
François Englert, "The Brout-Englert-Higgs Mechanism and Its Scalar Bosons"
- Lee Historical Lecture
  
  "A consistent approach to short range interactions through massive gauge vector fields was proposed by Robert Brout and me, and independently by Peter Higgs. I shall explain our motivations for constructing this BEH mechanism which also gives information on the origin of elementary particle masses. I shall discuss its content and its use. I will comment on the ATLAS and CMS discovery at CERN of the scalar boson predicted by the mechanism: I will show how it confirms its validity and how it may have implications on structures at yet unexplored energies."
  
  ---------------------------------------------------
  François Englert is a co-recipients of the 2013 Nobel Prize in Physics “for the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles, and which recently was confirmed through the discovery of the predicted fundamental particle, by the ATLAS and CMS experiments at CERN’s Large Hadron Collider”
- View in Google Calendar

Friday, April 18th

Alessandro Tomasiello (Università di Milano-Bicocca)
- View in Google Calendar

Monday, April 21st

Physics Colloquium Tea
- View in Google Calendar
"Föppl, Fluctuations, and Feynman: Nonlinear Mechanics with Graphene and Nanotubes", Paul McEuen, Cornell University
- A carbon nanotube or graphene sheet can easily be many millions of times longer in one direction than another. This, combined with their diminutive size, makes them very interesting mechanical objects. Thin 2D structures, first studied in detail by August Föppl over a hundred years ago, are notoriously difficult to understand. The problem gets more interesting with graphene and nanotubes, as they undergo thermal fluctuations in their low energy modes that completely alter their emergent “macro” properties.
  
  In this talk, we will discuss experiments to probe these effects. First, individual nanotubes are picked up and strained with micron-sized tweezers, allowing us to simultaneously study the optical, electronic, and vibrational properties of these molecular rods. Similar tricks are performed with graphene. These experiments allow us to test decades-old predictions of the effects of fluctuations on Föpply structures and also create nanoscale optomechanical systems with record low masses. Finally, we discuss how the Japanese paper art of Kirigami (combined with 2D materials) offers a route to meeting Feynman’s last, as yet unmet, challenge: the construction of nanoscale machines.
- View in Google Calendar

Tuesday, April 22nd

Michael Ramsey-Musolf (UMass-Amherst) "Electroweak baryogenesis: Searching for new scalars and new CPV"
- View in Google Calendar