Tuesday 25 March 1:30pm
Dr. Vadim Rusu
Wilson Fellow at Fermi National Accelerator Laboratory
From Collisions to Publication: A Higgs Story (Slides pdf)
For more than 30 years the Standard Model of Particle Physics
provided a solid framework for explaining the experimental
observations of the last decades. A fundamental piece is missing and
that is the origin of mass. Within the Standard Model, the mass of
fundamental particles is given by their interaction with the Higgs
field. The quanta of this field is the Higgs boson. The experimental
observation of the Higgs particle is an essential part of our
particle physics program and may provide us with clues about new
physics beyond the realm of the Standard Model. I will show the
experimental progress towards this goal at CDF, one of the two
experiments at Tevatron, the world's largest collider currently in
operation. The presentation will overview all aspects of this
progress, from detector and data collection improvements to new
analysis strategies.
Tuesday 1 April 1:30pm
Dr. Chris Neu
University of Pennsylvania
Measurement of W+b-jets at CDF (pdf)
Tuesday 15 April 1:30pm
Dr. Anadi Canepa
University of Pennsylvania
Tau leptons at CDF (pdf)
Tau leptons are unique in the Standard Model.
Thanks to a large coupling to the Higgs boson, they might shed light on
the electroweak symmetry breaking. Tau leptons are also an exciting window
into New Physics. SUSY predicts abundance of taus in charged
Higgs decays. Taus processes are enriched in Right-Left Symmetric Models with double charged Higgs,
while new massive gauge bosons can undergo lepton flavor violating decays.
CDF established its tau reconstruction technique measuring the W → τ ν and Z → τ+ τ-
cross sections and it is now exploring the pp collisions at Tevatron looking for new phenomena.
The challenge of reconstructing taus at hadron colliders and the
latest results of tau physics at CDF are reported.
Thursday 17 April 4pm Room A8
Emeritus Professor James Cronin
University of Chicago
Study of the Highest Energy Cosmic Rays with the Pierre Auger Observatory
Tuesday 22 April 1:30pm
Professor Joe Boudreau
University of Pittsburgh
sin 2 βs at CDF
While CP violation in B0 and B+ decays has been extensively
investigated at B-factories over the last decade, corresponding
knowlege in the B0s system has been lacking. B0s mesons, which
are not produced in B factories at the Upsilon(4S) are produced
with large cross section at the Tevatron collider. Following the
measurement of the B0s to B0s oscillation frequency in 2006,
the CDF experiment has now investigated CP asymmetries in B0s
meson decays. We report on the very first flavor-tagged analysis of
about 2,000 B0s decays to J/ψ φ, reconstructed in
1.35/fb of data. This channel is sensitive not only to the
width difference Delta Γ in the B0s system but also to to
βs, the angle of the "squashed" (bs) unitarity triangle. We
report a confidence region in the two dimensional space of 2βs
and Delta Γ. The data is consistent with the standard model
prediction at the 15% confidence level, corresponding to 1.5 Gaussian
standard deviations.
Fall 2007
Tuesday 18 September A5 3:15pm
Dr. Bernd Stelzer
University of California, Los Angeles
Search for Single Top Quark Production at CDF
Slides (ppt) and pdf (no animations)
In 1995, the CDF and D0 collaborations at the Tevatron collider at Fermilab
discovered top quarks that were produced in pairs via the strong
interaction.
The top quark was measured to be the heaviest elementary particle of the
Standard Model. Ten years after the top quark discovery, many things remain
unknown about its properties. In this talk, I will present recent evidence
for electroweak single top quark production. This alternative mechanism of
producing top quarks at the Tevatron is experimentally very challenging to
measure but allows the direct determination of the CKM matrix element
|Vtb|.
Wednesday 17 October A2 3:30pm
Dr. Ulrich Husemann
Yale University
Search for Flavor-Changing Neutral Currents in Top Quark Decay at CDF
Slides (pdf)
Flavor changing neutral current (FCNC) interactions are heavily
suppressed in the standard model of particle physics, but are expected
to be enhanced in the presence of new physics. Searches for FCNC
interactions are therefore excellent probes of physics beyond the
standard model. The suppression of FCNC interactions is especially
strong in the top quark sector. The standard model predicts branching
fractions for top quark FCNC decays far below the reach of experiments
at the Fermilab Tevatron and even at the Large Hadron Collider
currently under construction at CERN. I will present the first search
for the FCNC decay t→ Zq during Tevatron Run II using data recorded
with the CDF II detector between March 2002 and September 2006.
Tuesday 30 October A5 3:15pm
Prof. Daniel McKinsey
Yale University
New results from the XENON10 dark matter search
Slides (pdf)
The XENON10 experiment is a search for dark matter in the form
of Weakly Interacting Massive Particles (WIMPs). The XENON10 detector
uses the simultaneous measurement of ionization and scintillation in
liquid xenon to distinguish between nuclear recoils (due to WIMPs or
fast neutrons) and electron recoils (due to gamma rays). Ionization
electrons are extracted into the xenon vapor where they produce a large
proportional scintillation signal in a grid assembly. Both prompt and
proportional scintillation light are detected by PMT arrays on the top
and bottom of the active liquid xenon volume. The distribution of
proportional scintillation light in the top PMT array can be used to
achieve xy position resolution, while the ionization drift time gives
position resolution in the z direction. This allows the definition of a
low-background fiducial volume. XENON10 was installed in the underground
Gran Sasso National Laboratory in Italy in March 2006, and a blind
analysis was performed on data acquired between November 2006 and
February 2007. I will present the results of that analysis, which has
resulted in the most sensitive limit to date on the spin-independent
WIMP-nucleon scattering cross-section. I will also describe LUX, a new
dark matter experiment using the same technology, planned for
2008-2009.
Tuesday 13 November A5 3:15pm
Dr. Conor Henderson
Massachusetts Institute of Technology
Global Search for New Physics at CDF
Slides (pdf)
The Standard Model of particle physics is widely believed to
be incomplete, but as yet there are no clear indications as
to what form the new electroweak scale physics might take.
Rather than focusing on particular new physics scenarios,
we present a new approach where the entire high transverse
momentum data collected by the CDF detector at the
Fermilab Tevatron are searched for discrepancies relative
to the Standard Model prediction.
A model-independent approach (Vista) considers the bulk
features of the data, and a quasi-model-independent technique
(Sleuth) focuses on the high-pT tails. Results of this global
search for beyond Standard Model physics will be presented.
Tuesday 27 November A5 3:15pm
Prof. B. Lee Roberts
Boston University
Proposal for a new muon g-2 experiment
Slides (pdf)
The muon (g-2) experiment at the BNL AGS reached a relative precision of
0.5 parts per million on the muon anomalous magnetic moment.
Thanks to recent data from electron-positron
annihilation to hadrons, the standard-model prediction has reached
the same level of precision. When compared, the two differ by
3.4 standard deviations. Since the muon anomaly is sensitive to
a wide range of physics beyond the standard model, agreement or
difference with the standard-model will be important in
constraining interpretations of discoveries that will be
made at the LHC. The experiment and theory will be reviewed,
and possibilities for improving both values will
be discussed, along with the implications for LHC data.
A recent review of theory and experiment can be found in
hep-ph/0703049, published in Reports on Progress in Physics, {\bf 70},
(2007) 795-881
The non-standard model reach is discussed in arXiv:0705.4617 [hep-ph]
Tuesday 11 December 2N36 1:30pm
Prof. Gregorio Bernardi
LPNHE, Universities Paris VI and VII, France
Search for the Higgs boson at D0
Slides (pdf)
The Higgs boson is the only particle of the standard model which has not
been discovered yet, but it might be the most important one. Indeed, it is
through the Higgs mechanism that all massive fundamental particles are expected to
acquire their mass. Hence the search for the Higgs boson has been one
of the major activities of Elementary Particle Physicists during this
last decade. In this seminar, we will introduce the physics of the Higgs
boson and report on the experimental searches which are currently being
done at the Tevatron by the D0 experiment, and on the combined results
obtained by CDF and D0. We will conclude on the prospects of Higgs discovery
in the coming years.
Early spring 2008 seminars this link
points to a password-protected web page.
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