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Particle physics is standing
within reach of new discoveries. The undiscovered symmetries
of nature which unify the fundamental forces and particles,
the puzzle of dark matter and energy, and the apparent lack
of antimatter in our Universe, all these mysteries are about
to be uncovered at an unprecedented energy scale with the
Large Hadron Collider. The discovery of new particles at the
LHC will depend on the ability to distinguish their decay
products from random particles produced in the high-energy
collisions. An essential element of this is the alignment of
thousands of silicon detectors that track the particles'
paths which must be understood to micron precision. I am
developing new procedures for alignment analysis of the CMS
detector silicon tracking system and I am leading a group
of physicists to perform alignment of more than 15000
silicon sensors. Later in 2008
we expect first highest-energy beam collisions at LHC and I
preparing a program to search for new fundamental particles
that would resolve the nature puzzles.
In the last several years while direct access to new
fundamental particles was beyond the energy reach of
operating accelerators, I have developed new ways to search
for them via rare virtual loop decays. On the BABAR
experiment, I targeted spin-correlation measurements in its
decays to mesons with non-zero spin where new particles in
virtual loops might cause different spin alignments. Prior to
that on the CLEO experiment I discovered the first gluonic
penguin loop decays via the observation of flavor changing
neutral current process B->η'K. On BABAR, I
discovered the B meson loop decays to two spin-one particles,
such as B->φ K*, and developed techniques for their
angular analysis. The result was a surprisingly large
transverse polarization fraction, which contradicted all
expectations and may become evidence for new particles and
interactions. We are making a number of measurements that
would resolve the puzzle.
An alternative indirect way to search for new effects is
to constrain the Unitarity Triangle, which describes the only
known source of CP violation but is believed to be
insufficient to produce our matter-dominated Universe. One of
the unconstrained angles of the Unitarity Triangle α was
expected to be measured with B->ππ decays. However, I
led a discovery of a new, more complicated decay B->ρρ
and demonstrated that it gives the smallest uncertainty for
the measurement of α. This discovery provided a
determination of α with a precision that many believed
could not be achieved. Recently we achieved a new
breakthrough with the evidence for the all-neutral
B->ρOρO
decay and performed time-evolution measurements,
which provide new insight to
disentangle quantum effect ambiguities.
The above scientific questions shape the directions of my
group. To read more about my CMS or BABAR activities, click on
the CMS or
BABAR links.
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