Notre Dame High Energy Physics Theory Group

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Notre DameHigh Energy Physics Theory Group

• The Group
• 5 graduate students (details later)
• 1 postdoc
• David Diego
• 3 teaching and research faculty
• Ikaros Bigi, Antonio Delgado, Chris Kolda
• Kolya Uraltsev (visitor)
• Student Openings Delgado yes, Kolda possibly
• 
  

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Current Students
Brian Dudley - U.S.
Joel Griffith U.S.
Pokie Olson U.S.
Ayan Paul India
Dipajan Ray U.S.
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Notre DameHigh Energy Physics Experimental Group

• The Group
• 7 graduate students (details later)
• 7 research faculty/postdocs
• Leo Chan, Dan Karmgard, Jeff Kolb, Nancy
  Maranelli, Dmitri Smirnov, Wenfang Wang, Jadzia
  Warchol, new hire
• 3 technicians plus 1 engineer
• Jeff Marchant, Mike McKenna, Mark Vigneault,
  Barry Baumbaugh
• 6 teaching and research faculty
• Mike Hildreth, Colin Jessop, Kevin Lannon, John
  LoSecco
• Randy Ruchti, Mitch Wayne
• 
  

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Current Students
BaBar
? Kyle Knoepfel - U.S.

? Jyotsna Osta - India

Ted Kolberg - U.S.
Jamie Antonelli Sean Lynch U.S. U.S.
Doug Berry U.S.
David Morse U.S.
DØ
CMS
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• Now (15 billion years)

Stars form (1 billion years)
Atoms form (300,000 years)
Nuclei form (180 seconds)
Protons and neutrons form (10-10 seconds)
Quarks differentiate (10-34 seconds?)
??? (Before that)
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What is the Universe Made of?

• A very old question, answered many ways during
  the eons
• The only way to answer this question is by
  directly confronting Nature by experiments that
  can lead to definite conclusions
• Experiments have told us
• complexity often arises from simple building
  blocks
• Periodic Table of the Elements, Nuclear Structure
• fundamental constituents are small particles
• diverse phenomena can be manifestations of the
  same underlying physics
• the moons orbit, a falling apple
• intuition may not necessarily be trustworthy
• our world is really Quantum Mechanical, even
  though we dont see this in everyday life

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Fundamental Forces of Nature
Relative Strengths 10-40 10-2 10-6 1

• Gravity
• Electromagnetism
• Weak Nuclear Force
• Strong Nuclear Force

The ElectroWeak and Strong forces combine to form
the Standard Model of Particle Physics
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Open Questions in the Standard Model

• Without getting into the Structure of the
  Universe, there are some obvious questions here
• Why are there three families?
• Why are there pairs of particles in each family?
• Why are the masses so different?
• How is the Strong Force related to the
  Electroweak Force?
• Why are the forces such different strengths?
• What about Gravity?
• This is some of what we are trying to answer...

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On to Big Questions

• Particle Physics experiments may be able to
  answer
• What IS mass?
• Why is there matter at all?
• What is Dark Matter?
• What is the space-time structure of the Universe?
• ? Growing synergy between particle and
  astrophysics
• both fields working together on these questions

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• To answer these, we use the language of Quantum
  Field Theory, the theory that results when
  Quantum Mechanics and Special Relativity are
  merged

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• Although very successful from the experimental
  point of view and some predictions have been
  tested to great accuracy, it is far from being a
  complete theory
• the higgs is still to be discovered
• the rôle of the higgs itself introduces certain
  problems into the theory
• Therefore theorists go beyond the SM in order to
  address questions of physics at TeV scales

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• Let me summarize the research interests of the
  other two senior members of the group
• Professor Bigi is interested in flavour physics,
  i.e., the physics that deals with the interaction
  between the different families of quarks and
  leptons. These processes are rare in the SM and
  evidence for new physics can come in an excess of
  some of this effects. He is also a susy fan.
• Professor Kolda is interested in supersymmetry as
  a direction for physics BSM. Supersymmetry
  predicts the existence of new particles to be
  discovered at the LHC and provides us with a nice
  explanation for the EW scale.

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• In my case I am interested in the EW sector and
  studying models that may provide us with an
  explanation of what the higgs is and why it is
  much lighter than the Planck mass
• There are models where the higgs is a fundamental
  particle and the scale is protected by a
  symmetry susy, little higgs
• There are even models without a higgs
• My work is on the study of different models,
  their viability both on the theoretical side,
  i.e. no inconsistencies, and on the experimental
  side, i.e. they do not contradict any measurement
  we have already done.

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• It is a great opportunity that LHC will start to
  collect data next years and to probe the TeV
  scale so it will be a challenging time for
  particle physics .
• Because of that we have to take advantage of our
  experimental colleagues that have a major rôle in
  CMS
• As a last word I should say that the group is
  also interested on any interplay of particle
  physics and cosmology taking into account that
  there is a very good astro group here in ND.

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(some of) The people that built DØ
670 physicists 80 institutions 19
countries 120 grad students gt50 non-US
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Experimental Projects

• DØ/CDF at the Fermilab Tevatron
• proton-antiproton collisions at 2.0 TeV
• widespread current effort in Run II
  (soft/hardware, physics)
• BaBar at Stanford Linear Accelerator Center
• ee- collisions at 10 GeV
• Studies of CP Violation, potential effects of new
  physics
• CMS at the CERN LHC
• proton-proton collisions at 14.0 TeV
• detector development, construction, testing,
  commissioning
• Quarknet program for H.S. students, teachers
• International Linear Collider
• RD on Muon System, Beam Instrumentation

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Chicago
FERMILAB Accelerator Complex
Booster
p
Tevatron
?p
?p source
Main Injector Recycler
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SLAC ACCELERATOR FACILITIES
Hildreth, Wayne
Jessop, LoSecco
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World Travel
CERN The Large Hadron Collider
Hildreth, Lannon, Jessop, Ruchti, Wayne
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Chooz, France
LoSecco
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LHC Physics Center at Fermilab

• Center for US involvement in CMS
• local center of software/analysis expertise
• preparing to be very active in commissioning CMS
• Close!
• Easy way to get involved part time
• developing tutorials, example analysis packages,
  etc.
• nucleus of consultants for newcomers
• Senior ND personnel involved

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International Linear Collider

• Future ee- Linear Collider
• Center of Mass energy from 0.5 1.5 TeV
• Precision Measurements to complement LHC
• Same questions, different approach

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ILC RD
test beam at SLAC
Beam Energy Spectrometer
Prototype Muon Detector
test beam at FNAL
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Conclusions

• Not an easy game, but the payoff could be HUGE
• Origin of mass?
• Understanding Energy Scales for the Fundamental
  Forces?
• New forms of matter (Supersymmetry)?
• Structure of Spacetime
• Tevatron will be collecting up to 2x the current
  dataset over the next 2 years or so, CMS coming
  very fast
• lots of scope for new phenomena to appear
• Double Chooz starting very soon
• Fascinating time to be a particle physicist
• If we dont find new things at the Tevatron, the
  LHC will
• huge jump in energy and data quantity
• Within the coming years, we will have answers!
• (and more questions, of course)