University of Michigan, Physics Department

High Energy Physics / Astrophysics Seminar Schedule

Fall 2011

Time: Mondays at 4:00 pm

Place: 335 West Hall

Organizers: Michael Schubnell, Junjie Zhu

Information about travel, hotel and seminar can be found here





September 2011


Karl Giboni (Shanghai Jiao Tong University)

“Panda-X – A New Detector for Dark Matter Search”

With the XENON100 and the XMAS experiments taking data, the Dark Matter Search field is preparing for the next generation of experiments. There will be an additional project, Panda-X. This project started last year to bring a sizeable LXe dual phase detector to work in the just finished Jin Ping laboratory in southern China, Szechuan province. In the initial implementation the mass will be about 25 kg of xenon after a 5 cm all around fiducial cut. The detector is housed in a passive lead/poly shield. The shield, but also the detector vessels are dimensioned sufficient for a future version.  The great depth (7500  m.w.e.) of the lab reduces the background to a level which does not require an external muon veto any longer. The TPC is optimized towards high light yield for a low trigger threshold, and a high drift field for enhanced gamma ray discrimination. The design is completed, and all major parts are ordered or have already been received. Presently we set up a full-scale test module in our lab in Shanghai.


Andre de Gouvea (Northwestern University), neutrino physics

"Looking for The Origin of Neutrinos Masses: from neV to YeV"


Reina Maruyama (U of Wisconsin), DM-Ice

DM-Ice: a direct detection experiment for dark matter at the South Pole

I will describe DM-Ice, a direct detection dark matter experiment at the South Pole.  The aim of the experiment is to test the claim for an observation of dark matter by the DAMA collaboration by carrying out an experiment with the same detector technology, but in the southern hemisphere.  By going to the opposite hemisphere, many of the suspected backgrounds would produce annual modulation with the opposite phase whereas the dark matter signature should stay the same. DMIce-17, a 17-kg detector was installed in the Antarctic ice at the South Pole in December 2010 at the depth of ~2200 m.w.e. and is currently taking data.  A 250-kg scale experiment that can test DAMA's claim is currently being designed.  I will report on the status of DMIce-17 and the plans for the 250 kg-scale experiment.


Jianming Qian (University of Michigan)

Higgs boson search at ATLAS

October 2011


Eva Halkiadakis (Rutgers University)

Searches for Hadronic Resonances at CDF and CMS

Most searches for new physics at high energy hadron colliders use signatures that require leptons, photons, or missing transverse energy in order to suppress backgrounds from QCD.  I will present two searches for new physics in an entirely hadronic channel with no MET signature using data collected with the CDF detector at Fermilab and the CMS detector at CERN. They represent the first dedicated model independent searches for three-jet hadronic resonances  in a multijet environment.  These searches utilizes a novel approach: an ensemble of all possible jet triplets within  an event consisting of at least six jets is used to extract a signal from the multijet QCD backgrounds.   In both analyses, the number  of expected standard model background events is found to be in good agreement with the observed events. Limits on the cross section times branching ratio are set in a model of gluino pair production with an R-parity-violating decay to three quarks.


Daniel Whiteson (UC Irvine)

A Year of Searching the Energy Frontier with ATLAS

The Large Hadron Collider's first year of proton collisions at 7 TeV has opened a virgin energy territory to exploration.  I will discuss a strategy for searching the new territory for unexpected new particles or interactions. I will present recent results from the ATLAS experiment, focussing on events with four or more charged leptons.


Lei Xia (Argonne Lab)

Imaging Calorimeter for the Future Lepton Collider

Particle Flow Algorithms (PFAs) have been applied to existing detectors to improve the measurement of hadronic jets in colliding beam experiments.  For future experiments, such as a TeV lepton collider, detector concepts optimized for the application of PFAs are being developed. These concepts require so-called imaging calorimeters, with unprecedented granularity. I will review the various recent developments of such highly granular calorimeters.


Mark Devlin (University of Pennsylvania)

Where Did Half the Starlight in the Universe Go?  

We believe that approximately half of all the light from stars is absorbed and reprocessed by dust. The resulting emission is grey body with a temperature near 30 Kelvin. The COBE satellite made the first measurements of the resulting Far Infrared Background (FIRB), but since that time, we have been unable to resolve the background into individual galaxies. The Balloon-borne Large Aperture Submillimeter Telescope (BLAST) was designed to do this job. Its three bands at 250, 350, and 500 microns span the peak in emission for galaxies at z=1. I will discuss the BLAST experiment and present results from our measurements of resolved and unresolved galaxies.


November 2011


Elke-Cariline Aschenauer (Brookhaven Lab)

Spin physics - results from RHIC and future research


Christian Reichardt (UC Berkeley)

Probing reionization and large-scale structure with the South Pole Telescope
The South Pole Telescope (SPT) is a 10-meter telescope designed to survey the millimeter-wave sky, taking advantage of the exceptional observing conditions at the Amundsen-Scott South Pole Station. The telescope and its ground-breaking 960-element bolometric camera were successfully installed at the South Pole in 2007. Since then, SPT has embarked upon a large, three-frequency survey covering 6% of the entire sky. I will report on the multi-frequency power spectrum results for this survey, including a detection of the thermal Sunyaev-Zel'dovich (SZ) power and improved upper limits on the kinetic SZ power. I will discuss how we can use the kinetic SZ power and CMB polarization data to determine when the epoch of reionization began, when it ended and how long it lasted.


Tanya Rindler-Daller (U of Texas)


Natalia Panikashvili (U of Michigan)

December 2011


Aurelio Juste (IFAE)

Searches for the Higgs boson at the Tevatron
Unraveling the secret of electroweak symmetry breaking remains one of the highest priorities in particle physics research, with the elusive Higgs boson being a center piece of many theoretical constructions. A comprehensive program of searches for the Higgs boson is underway at the Fermilab Tevatron Collider, which has started to sensitively probe the most interesting mass range. We will present the latest results on the Higgs boson search from the CDF and D0 experiments using up to 8.6/fb of integrated luminosity, including a recent combined result with improved sensitivity. We will also discuss the future prospects for Higgs boson searches at the Tevatron using the full Run II dataset.


Jim Buckley (Washington University)

Detector Technology for Indirect and Direct Detection of Dark Matter

A comprehensive program for detecting and identifying dark matter should include both direct and indirect detection experiments. Direct detection techniques can provide important upper limits, but very clean discrimination of nuclear recoil events and good statistics are required to distinguish dark matter from background and to constrain the dark matter properties. If dark matter is a thermal relic like the neutralino, future gamma-ray searches could perform particle identification through measurements of the annihilation spectrum, and measurements of the halo distribution by imaging the central halos of nearby galaxies.  I will discuss some of the technical drivers for both approaches, and how these are shaping the design of next generation experiments.  For indirect detection, I will describe the design requirements for a next-generation gamma-ray observatory (e.g., CTA or a future space-based pair telescope).  UV-blue sensitive photon-counting detectors are a key enabling technology for both ground-based gamma-ray experiments as well as liquid-nobel direct detection experiments.  I will describe work by the Washington University group on the development of crystalline and amorphous AlGaN-InGaN photocathodes and solid state detectors as well as the design of very low background PMTs.  


Jadranka Sekaric (U of Kansas)

The measurement of WW and WZ production in W + jets final states and study of the dijet invariant mass distribution at D0 experiment

I will present a study of the dijet invariant mass spectrum in events with two jets produced in association with a W boson that decays leptonically, searching for an evidence for anomalous
resonant dijet production in data collected at the D0 experiment. In futher efforts to measure the WW and WZ production cross sections we apply a b-tagging to separate the WZ contribution from the dominant WW production in lepton+jets final states directly relevant to searches for a low mass Higgs boson.