home contact us site map

Lunchtime Seminars

Tuesdays ~ 12pm ~ Kolker Room, 26-414

 

Committee:
Joseph Formaggio, Chair ~ William Barletta ~ Gunther Roland


 

April 2, 2013

Lindley Winslow, UCLA

 

"Next Generation Scintillation Detectors: Neutrinos and Nanotechnology"

 

The last decade has seen a revolution in our understanding of the most mysterious of the Standard Model particles, the neutrino, and this last year has been no exception. In the last year, we have seen exciting results from both double beta decay experiments and experiments measuring the last mixing angle θ13. For the most part, the detectors responsible for these measurements use Cerenkov and scintillation light to detect neutrino interactions. The wavelength of this light is matched to the peak efficiency of photo-multiplier tubes. This technique has been finely tuned over the last decades, but no great leaps forward in efficiency have been achieved. Nanotechnology may hold the key to improving both scintillators and photo-detectors. In this talk, I will focus on one particular technology, semiconducting nanocrystals known as quantum dots, and their unique optical properties. I will discuss how their use could enhance the capabilities of new photo-detection technology, and address the needs of the next-generation neutrino experiments.

 

Time: 12:00 pm
Place: LNS Kolker Room, 26-414

April 9, 2013
Michael Peskin, SLAC

 

"Models of Electroweak Symmetry Breaking in the Harsh Light of LHC"

 

The ATLAS and CMS experiments have discovered a new particle similar to the Higgs Boson of the Standard Model. However, the other major results from the LHC have been exclusions of parameter regions for theories of physics beyond the Standard Model. In this lecture, I will review the motivations for new physics associated with electroweak symmetry breaking, discuss the implications of the LHC results for models of new physics such as supersymmetry, and project the possible avenues for discovery that remain.

Time: 12:00 pm
Place: LNS Kolker Room, 26-414

April 23, 2013

Matthew McCullough, MIT

 

"Modified Higgs Sectors and NLO Associated Production"

 

Many beyond the Standard Model (BSM) scenarios involve Higgs couplings to additional neutral or electroweak-charged fields. It is well established that in some scenarios these new fields may modify Higgs gamma-gamma and Higgs gamma-Z decays at one-loop. However, one unexplored aspect of such scenarios is that by electroweak symmetry one should also expect modifications to the Higgs Z-Z coupling at one-loop and, more generally, modifications to Higgs production and decay channels beyond tree-level. In this talk I will discuss the full BSM modified electroweak corrections to associated Higgs production at both the LHC and a future lepton collider in some simple SM extensions, and discuss prospects for their determination at the LHC and future lepton colliders.

 

Time: 12:00 pm
Place: LNS Kolker Room, 26-414

April 30, 2013
Emanuel Katz, Boston University

 

"Model Independent Direct Detection of Dark Matter"

 

I will describe a model-independent approach to parameterizing possible dark-matter (DM) interactions with nucleons. The idea is to require only terms consistent with Galilean invariance and the rules of quantum mechanics. This general framework leads to novel ways with which nuclei can interact with the DM. Besides the standard spin-dependent and spin-independent interactions, there are three more types of interaction, sensitive to nuclear properties of targets which were not considered previously. Moreover, interference effects between operators lead to a rich parameter space. I will report on the latest bounds on this parameter space, focusing on the complementarity of different experiments in placing bounds.

 

Time: 12:00 pm
Place: LNS Kolker Room, 26-414

May 7, 2013
Asher Kaboth, Imperial College London

 

"Recent Results from the T2K Experiment"

 

Abstract: Neutrino oscillation physics has entered a precision era with the determination of all three mixing angles in standard 3x3 mixing. The T2K (Tokai-to-Kamioka) Experiment is a long-baseline neutrino experiment using an off-axis, narrow-band beam suited for such precision. The experiment has two detectors: a multipurpose near-detector suite to characterize the beam, and the Super-Kamiokande detector, 295km away, used to investigate oscillations. This configuration opens the door to studying several oscillation parameters as well as determining neutrino cross sections. I will discuss recent T2K results on both of these fronts.

 

Time: 12:00 pm
Place: LNS Kolker Room, 26-414

May 14, 2013
"TBA"

 

Time: 12:00 pm
Place: LNS Kolker Room, 26-414

Early 2013 Spring Semester Talks

 

February 12, 2013

William Barletta and Markus Klute, MIT

 

Informal Seminar and Open Discussion: Circular Machines on the Energy Frontier

 

The Director of the Office of Science has asked each of his scientific advisory panels to evaluate possibilities for future facilities. A few of us have been asked to provide input to the High Energy Physics Advisory Panel regarding circular e+e- machines and very large proton colliders. We will show some background material, and open the floor for discussion of the questions being asked by the DOE.

 

Time: 12:30 pm
Place: LNS Kolker Room, 26-414

February 19, 2013
No Seminar

 

Time: 12:00 pm
Place: LNS Kolker Room, 26-414

February 26, 2013
Shep Doeleman, Haystack

 

"The Event Horizon Telescope: Observing Black Holes with Schwarzschild Radius Resolution"

 

It is now almost certain that at the center of our Milky Way Galaxy lies a super massive black hole - 4 million times more massive than our Sun. Because of its proximity to Earth, this object, known as Sagittarius A*, presents astronomers with the best opportunity in the Universe to spatially resolve and image a black hole Event Horizon. To do this requires using Very Long Baseline Interferometry (VLBI), the technique whereby radio telescopes around the world are linked together in a Global phased array. Very short wavelength VLBI observations have now confirmed structure on ~4 Schwarzschild radius scales within SgrA*, and have revealed time variability in this source on the same spatial scales. For the much more massive (6 billion solar mass) black hole powering the relativistic jet in M87, similarly compact structures have been detected. I will describe the instrumentation efforts that enable these observations, discuss what current and future VLBI observations can tell us about these super-massive black holes, and describe plans for assembling a Global submm-VLBI Event Horizon Telescope.

 

Time: 12:00 pm
Place: LNS Kolker Room, 26-414

March 5, 2013
June Matthews, MIT

 

"Big Bang Nucleosynthesis in the Laboratory"

 

By around a microsecond after the Big Bang, the cosmos had cooled sufficiently so that quarks and gluons could coalesce into protons and neutrons. During the next few minutes, deuterium, helium, and a small amount of lithium nuclei were formed. One can use nuclear reaction cross sections obtained in the laboratory to predict the abundances of these elements which can be compared with astronomical observations. However, the most basic cross section, that for the formation of deuterium, has not yet been well-measured.

 

Time: 12:00 pm
Place: LNS Kolker Room, 26-414

March 12, 2013

Tetsuo Matsui, Kinki University

 

"Effective Theory for Quark-Hadron Phase Transition"

 

I will discuss pros and cons of the PNJL model which has been proposed for describing the quark-hadron phase transition. I will show that the model has nice features of describing the change of the degrees of freedom from those of quarks and gluons at high temperatures to hadrons at low temperatures, incorporating quark confinement as well as spontaneous breakdown of (approximate) chiral symmetry. Yet, the model still requires some amendments when one wish to see its physical consequences in the exploration of the QCD phase diagram and heavy-ion collisions.

 

Time: 12:00 pm
Place: LNS Kolker Room, 26-414

March 19, 2013
Julien Billard, MIT

 

"Directional Detection of Dark Matter with MIMAC"

 

A substantial body of cosmological evidence and astrophysical measurements supports the fact that our galaxy should be immersed in a halo of non-baryonic dark matter. Directional detection aims at measuring the direction of recoiling nuclei following an elastic scattering with a Dark Matter particle. This should allow us to show the expected strong angular dependence of the recoil distribution due to the rotation of the Solar System around the galactic center. In this talk, I will describe what directionality could bring to the field of direct Dark Matter searches in terms of exclusion limits, discovery potential and identification of Dark Matter both from particle and galactic halo physics. I will then introduce the MIMAC project which is a low pressure gaseous TPC dedicated to directional detection enabling the measurement of 3D tracks down to few keVs. I will describe both its detection and data analysis strategy to show some expected and measured performances. Eventually, I will also present an original measurement of the drift velocity of electron in gas that is a key point for the 3D track reconstruction within the MIMAC project

 

Time: 12:00 pm
Place: LNS Kolker Room, 26-414