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Elementary Particle Physics Experiment:The ATLAS experiment at the LHC

University of Massachusetts, AmherstGraduate Research Orientation

1 Feb 2010

QuickTime™ and aSorenson Video 3 decompressorare needed to see this picture.

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The UMass ATLAS Group

Faculty– Ben Brau - LGRT 1032

– Carlo Dallapiccola - LGRT 1038

– Stephane Willocq - LGRT 1042

Postdoctoral Researchers– Ed Moyse, Elisa Pueschel, Niels Van Eldik,

Martin Woudstra - CERN

Graduate Students– Andrew Meade, Emily Thompson - CERN

– German Colon, Preema Pais, Tulin Verol - LGRT 1036

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Experiments can address long standing puzzles / questions:

What are the fundamental constituents of matter?

What are the fundamental forces between elementary

particles?

Can the forces of nature be unified? Including

gravity?

What is the origin of mass?

What is the origin of the matter-antimatter asymmetry

of the Universe?

What is dark matter?

Are there extra dimensions? + many

more…

What is Particle Physics About?

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How can we answer these Fundamental Questions?

Particle Accelerators– Reach very high collision energies to probe

extremely small distance scales (< 10-18 m)

– Research at the energy frontier (a few TeV) with theATLAS experiment at the Large Hadron Collider (LHC) 10 x higher energy than previous colliders search for

Higgs boson (origin of mass?)

SuperSymmetric particles (dark matter candidate?)

New interactions (heavy gauge bosons, extra dimensions?)

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The Large Hadron Collider (LHC)Proton-proton collider circumference = 27 km

Energy = 7 TeV / beam√s = 14 TeV

Stored energy / beam = 350 MJ (!)

Bunch spacing = 25 ns 40 MHz crossing rate

Design luminosity= 1034 cm-2 s-1

Number of interactionsper crossing ~23

Collisions expected

in late 2009

Run for ~10-15 years

Lake Geneva

14 TeV

CMSATLAS

CERN Main Site

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Inner Tracker

EM Calorimeter

Hadronic Calorimeter

Muon Detectors

Diameter 25 mBarrel toroid length 26 mEnd-cap end-wall chamber span 46 mOverall weight 7000 Tons

The ATLAS Detector @ LHC

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November 2005

September 2006August 2006

February 2008

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ATLAS Data Event

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UMass Work on ATLAS

Software development for Muon Spectrometer– Leading muon reconstruction effort

(SW co-coordinator, EM event data model leader)

– Validation of detector description, performance improvements

Physics analysis = Search for new physics– Search for new heavy gauge bosons (new interactions)

– Alternatives to Higgs mechanism (origin of mass)

– Signs of extra (large) dimensions: micro black holes

– Model-Independent: Hints of things we haven’t thought of yet

More information at http://people.umass.edu/eppex/

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LHC ScheduleLHC Schedule

First Physics Run at 3.5 GeV on 3.5 GeV begins First Physics Run at 3.5 GeV on 3.5 GeV begins now.now.

Run will continue through 2010 and 2011, with a Run will continue through 2010 and 2011, with a goal luminosity of 1 fbgoal luminosity of 1 fb-1.-1.

All splices will be repaired in a long (~year) All splices will be repaired in a long (~year) shutdown.shutdown.

High-energy 7GeV on 7GeV will begin ~2013.High-energy 7GeV on 7GeV will begin ~2013.