Last updated: 04/04/08

Tuesday, January 22nd, 10:30am

Location: ISB 310
Development of Radiation Hard Tracking Detectors
Speaker: Hartmut Sadrozinski (UCSC-SCIPP)

The Large Hadron Collider (LHC) at CERN has been designed to achieve the unprecedented luminosity of 10 34 cm -2 s -1 . Recently, a 10-fold luminosity upgrade has been proposed (SuperLHC). To exploit the physics potential of the upgraded LHC, an efficient tracking down to a few centimeters from the interaction point will be required, and Semiconductor detectors seem the best option as tracking sensors.

The CERN RD50 collaboration ''Development of Radiation Hard Semiconductor Devices for Very High Luminosity Colliders'' started in 2002 with the aim to develop new reliable detector technologies for the SuperLHC. Three main research lines have been identified: the understanding of the microscopic defects causing the degradation of the irradiated detectors, search for semiconductor materials with increased radiation-hardness, and variations in the sensor geometry.

The present plans for the ATLAS Upgrade are taken as an example how the work on radiation hardness is being applied.



Thursday, January 31st, 12:00pm

Location: ISB 431
Yossi Nir for pedestrians (discussion on flavor violation)
Speaker: Abe Seiden (UCSC-SCIPP)

This will be an informal discussion about what low energy
physics, including mixing measurements, hint at for the LHC.  We will follow the
lead of the work of Yossi Nir on this topic as a guide.


Tuesday, February 5th, 10:30am

Location: ISB 310
Searching for Ghosts: Looking for Dark Matter Axions using the ADMX experiment
Speaker: Gianpaolo Carosi (LLNL)

One of the major open questions in physics is the nature of the dark matter which makes up approximately 25% of the energy density of the universe. One potential candidate is the axion, an extremely light (micro-eV to meV) pseudoscalar boson postulated to exist as a solution to problems in strong nuclear physics. Large amounts of relic axions could have been generated after the Big Bang and would thus make a natural dark matter candidate. Since the mid-1990s the Axion Dark Matter eXperiment (ADMX) at Lawrence Livermore National Laboratory (LLNL) has been searching for these particles by utilizing their predicted interaction with photons via the Primakoff effect (two-photon coupling). Here we describe the ADMX detector and its results before going into detail on the progress of our current system upgrade, which will provide us with unprecedented sensitivity to these hypothetical particles.


Please Note Special Location: ISB 221

Tuesday, February 12th, 10:30am

Location: ISB 221
SDSS-III and the Baryon Oscillation Spectroscopic Survey (BOSS)
Speaker: Natalie Roe ( LBNL)

Building on the success of the Sloan Digital Sky Survey, SDSS-III
is a proposed third-generation, all-spectroscopic survey.  BOSS is
the flagship project of SDSS-III, awarded all the dark and grey
observing time for five years (2009- 2014).  BOSS will cover 10,000
square degrees and employ two different techniques to precisely
measure the standard ruler provided by baron acoustic oscillation
(BAO) 'ripples' in the large scale matter distribution.  I will give
an overview of SDSS-III, and describe the BOSS scientific goals and
project status.



Tuesday, February 19th, 10:30am

Location: ISB 310

"Astrophysical Probe of New Physics: Cosmological Dark Matter and Anisotropy"

Schin'ichiro Ando (Caltech)
I introduce results of a few attempts to probe new physics using
astrophysical and cosmological signatures. In this talk, I will focus
on particle dark matter and primordial anisotropy of the Universe.
These approaches include:

(1) Detection of charged massive particles produced by atmospheric and
astrophysical neutrinos at neutrino telescopes;
(2) Effect of nonlinear evolution of primordial anisotropy in the Universe.

All these are related to currently running or upcoming projects such as
(1) IceCube, (2) 2dF/SDSS galaxy surveys, respectively.

Wednesday, February 20th, 12:00pm
Location: ISB 310
"Charged cosmic rays and searches for dark matter "
Speaker: Pierre Brun
This seminar aims at showing the importance of the measurement of charged
particles and nuclei in the GeV-TeV region, from particle physics point of
view. In this energy range, the fine control of the theoretical
uncertainties is crucial and I will show how current and upcoming
experiments (PAMELA, AMS-02) will allow significant progress. Specific
experimental challenges will be presented, together with nowadays
technical solutions, widely inspired from high energy physics. I will eventually
present the prospects for indirect searches for dark matter, with a
particular emphasis on the computation of the expected signals and the
so-called boost factors.
Tuesday, February 26th, 10:30am
Location: ISB 310
"Latest results from Auger"
Speaker: Troy Porter (UCSC-SCIPP)
The first detection of cosmic rays with energies greater than 1020 eV was
over 40 years ago. However, their nature and origin remain elusive. The
measurement techniques at these energies rely upon the detection of the
products of the giant air shower induced by the primary cosmic ray as
it traverses the atmosphere: fluorescence light from atmospheric nitrogen,
or the secondary particles that reach the ground. The Pierre Auger
Observatory is a new generation of experiment utilising both techniques
to study cosmic rays with energies greater than 1018 eV and answer the
crucial questions of cosmic ray physics at these energies. The Southern
Observatory has been collecting data since 2004 and, while still under
construction, already has an exposure larger than all previous experiments.
With data collected over these past three years, a strong correlation has
been shown between the arrival directions of cosmic rays with energies
greater than 6x1019 eV and the positions of Active Galactic Nuclei lying
within 75 Mpc. This correlation is compatible for an origin for these
energetic particles from nearby extragalactic objects without significant
attenuation of the fluxes by interactions with the cosmic microwave
background radiation. I will give an overview of the observatory and
discuss this remarkable result.
Tuesday, March 4th, 10:30am
Location: ISB 310
"GRASP - Surveying Radioactivity in our Galaxy with modern Compton
Speaker: Trixi Wunderer (UCB)
Deep, uniform surveys of our galaxy in individual radioactive isotopes
could provide crucial clues for our understanding of the cycle of matter
in our universe. Continuous, sensitive, long-term monitoring of cosmic
accelerators in the MeV regime could greatly enhance our understanding
of the inner workings of these sources.
Ground-breaking technological advances during the 3 decades since the
conception of COMPTEL on CGRO now enable lighter, more compact, and
significantly more sensitive instruments. GRASP leverages these
developments, building heavily on UC Berkeley's experience from the NCT
Balloon, to promise a deep view of the whole radioactive sky.

Tuesday, March 11th, 10:30am

Location: ISB 310
"Search for the Last Neutrino Mixing Angle at Dayabay"
Speaker: Cheng-Ju Lin (LBNL)

Results from the solar, atmospheric, accelerator, and reactor neutrino
experiments have provided compelling evidence for neutrino mass and
oscillation.  Two of the three neutrino mixing angles have now been
measured.  The last mixing angle (Theta_13), which describes the coupling
of the electron neutrino flavor to the 3rd mass eigenstate, is still unknown.
This angle is a fundamental parameter of the Standard Model and it is
critical to future CP violation searches in the neutrino sector.  In this
talk, I will report on the status of the Dayabay neutrino oscillation
experiment currently under construction in southern China.  Dayabay is a
reactor based neutrino oscillation experiment designed to measure
sin 2 (2*Theta_13) to better than 0.01.  With the expected sensitivity of
Dayabay, the end to the quest for the last mixing angle may be within sight.