current status of lhc and atlas and prospects for 2010 - 2011 andy

Andy Haas - 5/21/2010 Slide 1

LHC DATA!LHC DATA!Current status of LHC and ATLAS Current status of LHC and ATLAS

and prospects for 2010 - 2011and prospects for 2010 - 2011

Andy HaasAndy HaasSLACSLAC

West Coast LHC Theory MeetingWest Coast LHC Theory MeetingSCIPP, UC Santa CruzSCIPP, UC Santa Cruz

May 21, 2010May 21, 2010

Andy Haas - 5/21/2010 Slide 2

Overview

LHC commissioning progress at 7 TeV– I'm not an accelerator physicist!

Observing from ATLAS...

ATLAS commissioning at 7 TeV

LHC plans for the rest of 2010LHC plans for 2011– (or ask the Farmers Almanac !)

My comments and conclusions

* A lot stolen from LHCC meetings:http://indico.cern.ch/conferenceDisplay.py?confId=92525

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Collision xs ~ 80 mb

Collision rate ~ 100 Hz

Record every collision to tape!

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Squeeze

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Collision rate ~ 1 kHz

Prescale collision trigger!

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Overview

LHC commissioning progress at 7 TeV– I'm not an accelerator physicist!

Observing from ATLAS...

ATLAS commissioning at 7 TeV

LHC plans for the rest of 2010LHC plans for 2011– (or ask the Farmers Almanac !)

My comments and conclusions

* A lot stolen from LHCC meetings:http://indico.cern.ch/conferenceDisplay.py?confId=92525

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~1 cm!

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Overview

LHC commissioning progress at 7 TeV– I'm not an accelerator physicist!

Observing from ATLAS...

ATLAS commissioning at 7 TeV

LHC plans for the rest of 2010LHC plans for 2011– (or ask the Farmers Almanac !)

My comments and conclusions

* A lot stolen from LHCC meetings:http://indico.cern.ch/conferenceDisplay.py?confId=92525

Andy Haas - 5/21/2010 Slide 25

Beyond the First 1/nb

In the last 2 weeks:Up to 6 filled bunches/beam

→ 3 colliding bunches/turnUp to 2e10 protons/bunch

~10/nb delivered!

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Rest of 2010 Plan● Increase number of bunches, and slowly the bunch charge● Constraints: total current (safety), beam stability

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Rest of 2010 Plan

Bunch charge of 1e11already very stable!

Reconsider plan...

● Increase number of bunches, and slowly the bunch charge● Constraints: total current (safety), beam stability

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A somewhat pleasant surprise

● Go to “nominal” (that means high, 1e11) bunch charge now ?!

L ~ (bi1*bi2)*nbI ~ (bi1+bi2)*nb

● If you want low I and high L, increase bi, keep nb low!Of course, there's a limit to how high you can make bi, so eventually you have to increase nb

● Just 2 colliding bunches / turn : <0.1% of bunches filled!– But big bunches !

● Upside: more luminosity in the short term (this summer)● Downside: multiple interactions, ~2 per (filled) crossing!

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As I'm writing this talk...

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And the Farmer's Almanac...

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ConclusionsLHC is performing great at 7 TeV !Now on track, steady improvementsGood machine availability / uptime

~50/nb by the end of May– That's a Z peak

~1/pb by end of June– Start to see top

~100/pb by end of October– Discover SUSY !

~1/fb in 2011– Measure SUSY masses !

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Conclusions● ATLAS (and CMS) working as designed

– Years of delays not wasted time...– ATLAS data is well understood

after just ~6 months of data !

● Incredible data/MC agreement– Testbeam, G4, detector description– Puts pressure on accurate calculations !

● Not just “Tevatron at 3.5x the energy”– Granularity, improved particle ID– Much lower fake rates– Much larger detector acceptance– Timing, timing, timing !

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Conclusions● ATLAS (and CMS) working as designed

– Years of delays not wasted time...– ATLAS data is well understood

after just ~6 months of data !

● Incredible data/MC agreement– Testbeam, G4, detector description– Puts pressure on accurate calculations !

● Not just “Tevatron at 3.5x the energy”– Granularity, improved particle ID– Much lower fake rates– Much larger detector acceptance– Timing, timing, timing !

Thank you!

Enjoy the data!!

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Backup...

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Trigger

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