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Chasing the Higgs boson with a worldwide distributed

trigger system

Sander Klous

NIKHEF

VENI proposal 2006

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Gary Stix, editor ofScientific American, January 2001

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High Energy Physics

atom

10-15 m

nucleus

quarks

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quarks

leptons

The Standard Model

Electromagnetism Weak nuclear force Strong force

Higgs Boson

Present predictions:

About 100 x heavier than proton

Very unstable Predominant decay

to bottom quarks

upcharm

down

top

strange

bottom

neutrinostau

muonelectronP

articles

Forces

CERN and ATLAS

ATLAS detector

LHC tunnel

Large Hadron Collider• 27km• High intensity• High energy

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Radiating top quarks

40 million events per second A few hundred signal events per year

PROTON

PROTON

COLLISIONHIGGS

TOP

TOP

with lepton

with b quarks

particle jets

particle jets

particle jets

Time

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Data processing: Triggers and Filters

• Standard ATLAS approach• Just a small signal expected

in 2009/2010• We can do much better…

Physics streams40 MHz

Level 1

Level 2

Accept 1 in 500

Accept 1 in 10

Level 3

Accept 1 in 50

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PROTON

PROTON

COLLISIONHIGGS

TOP

TOP

with lepton

with b quarks

particle jets

particle jets

particle jets

Fully hadronic decays

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Physics streams40 MHz

Level 1

Level 2

Accept 1 in 500

Amsterdam

NIKHEF/SARA

Accept 1 in 50

Data processing: Triggers and Filters

Accept 1 in 10

Level 3

Computing grid

Networkswitch

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Project requirements

Big network switch A few computers on site Technical assistance

Data-Analysis

And B-physics

Trigger experience

Funding

Distributed computing

PhD thesisPostdoc

Involved in VL-e and in Tier-1 activities.

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Timeline of Research

Phase 1: Preparation Deploy networking hardware Commission hardware and softwarePhase 2: Beam on Data collection and calibration Analysis and algorithm developmentPhase 3: Harvest Successful deployment of worldwide trigger Find the Higgs boson

2006

2007

2010

2008

2009