F.Gianotti, ATLAS RRB, 20-4-2010 1 Collaboration and Management matters First results from 900 GeV...

F.Gianotti, ATLAS RRB, 20-4-2010 1

◼ Collaboration and Management matters◼ First results from 900 GeV and 7 TeV collision data (in particular: first observation of W eν, μν candidates at LHC)◼ Physics prospects for 2010-2011 (a few examples …)Detector status, consolidation and upgrade: see M.Nessi’s talk

ATLAS Status Report (Part II)Fabiola Gianotti, RRB, 20/4/2010CERN-RRB-2010-009


Collaboration and Management matters



Albany, Alberta, NIKHEF Amsterdam, Ankara, LAPP Annecy, Argonne NL, Arizona, UT Arlington, Athens, NTU Athens, Baku, IFAE Barcelona, Belgrade, Bergen, Berkeley LBL and UC, HU Berlin, Bern, Birmingham, UAN Bogota, Bologna, Bonn, Boston, Brandeis, Brasil Cluster, Bratislava/SAS Kosice, Brookhaven NL, Buenos Aires, Bucharest, Cambridge, Carleton, CERN, Chinese Cluster, Chicago, Chile, Clermont-Ferrand, Columbia, NBI Copenhagen, Cosenza, AGH UST Cracow, IFJ PAN Cracow, SMU Dallas, UT Dallas, DESY, Dortmund, TU Dresden, JINR Dubna, Duke, Edinburgh, Frascati, Freiburg, Geneva, Genoa, Giessen, Glasgow, Göttingen, LPSC Grenoble, Technion Haifa, Hampton, Harvard, Heidelberg, Hiroshima IT, Indiana, Innsbruck, Iowa SU, Iowa, UC Irvine, Istanbul Bogazici, KEK, Kobe, Kyoto, Kyoto UE, Lancaster, UN La Plata, Lecce, Lisbon LIP, Liverpool, Ljubljana, QMW London, RHBNC London, UC London, Lund, UA Madrid, Mainz, Manchester, CPPM Marseille, Massachusetts, MIT, Melbourne, Michigan, Michigan SU, Milano, Minsk NAS, Minsk NCPHEP, Montreal, McGill Montreal, RUPHE Morocco, FIAN Moscow, ITEP Moscow, MEPhI Moscow, MSU Moscow, Munich LMU, MPI Munich, Nagasaki IAS, Nagoya, Naples, New Mexico, New York, Nijmegen, Northern Illinois University, BINP Novosibirsk, Ohio SU, Okayama, Oklahoma, Oklahoma SU, Olomouc, Oregon, LAL Orsay, Osaka, Oslo, Oxford, Paris VI and VII, Pavia, Pennsylvania, Pisa, Pittsburgh, CAS Prague, CU Prague, TU Prague, IHEP Protvino, Regina, Rome I, Rome II, Rome III, Rutherford Appleton Laboratory, DAPNIA Saclay, Santa Cruz UC, Sheffield, Shinshu, Siegen, Simon Fraser Burnaby, SLAC, NPI Petersburg, Stockholm, KTH Stockholm, Stony Brook, Sydney, Sussex, AS Taipei, Tbilisi, Tel Aviv, Thessaloniki, Tokyo ICEPP, Tokyo MU, Tokyo Tech, Toronto, TRIUMF, Tsukuba, Tufts, Udine/ICTP, Uppsala, UI Urbana, Valencia, UBC Vancouver, Victoria, Waseda, Washington, Weizmann Rehovot, FH Wiener Neustadt, Wisconsin, Wuppertal, Würzburg, Yale, Yerevan

~ 2988 Active physicists: -- ~ 1900 with a PhD, for M&O share -- ~ 1100 students173 Institutions37 Countries


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Male

Female

ATLAS active physicists age distribution

All 2690 (< 35 y 47.2%)Male 81.8% (< 35 y 44.0%)Female 18.2% (< 35 y 61.3%)(Status 1.1.2010)


Collaboration composition since the last RRB

At the Collaboration Board (CB) meeting on 26 February 2010, the Collaboration unanimously admitted one new Institution:

Northern Illinois University, USA(Tile calorimeter, Data Quality, Core software, Computing, Simulations for Upgrade)

An Expression of Interest had been presented at the October 2009 CB.Members of the above Institution have been active in ATLAS for several yearsthrough affiliation to another Institution, contributing successfully to high-priority tasks for the experiment.

The RRB is kindly requested to endorse the admission of this new Institution in the ATLAS Collaboration.The total number of Institutions (with voting rights in the CB)increases from 172 to 173

Furthermore, at the February CB meeting an Expression of Interest to join ATLAShas been submitted by a joint team (a “cluster” : 1 vote in the CB) from South-Africa: University of Johannesburg and University of Witwatersrand.Members of these teams are already active through affiliation to other Institutions

Admission will be considered at the CB on 2 July 2010If positive, ATLAS will have a new country and a new FA (DST)


New since October RRB


Operation Task sharing

ATLAS operation [detector, data quality and calibration, software, world-wide computing, including all kinds of shifts ...] requires ~ 800 FTE (physics is not an OT) OT are distributed in a fair way across Institutions: proportional to the number of authors -- students get favorable treatment as they are weighted 0.75 -- new Institutions contribute more the first two years (weight factors 1.5, 1.25) 200 FTE (out of 800 total) are for shifts: ~ 50000 shifts in 2010 (~20 per author) -- 70% CERN-based (Control Room or on-call); 30% remote shifts -- we have recently reduced the number of Control Room shifts by 15% -- as we gain experience less shifts in general, in particular less CERN-based shifts

Funding Agency

Covered-expected expected

Distribution per FA in 2009 (CERN-based shifts not included)Zero means ok, negative is bad

FTE requirements and FA contributions reviewed and updated yearly


First LHC data-taking and first performance and physics results at √s= 900 GeV and 7 TeV


Since the last RRB meeting (12 October 2009)

Chronology of a fantastic escalation of events:

◼ 20 November: first beams circulating in the LHC◼ 23 November: first collisions at √s = 900 GeV◼ 8, 14, 16 December: few hours of collisions at √s = 2.36 TeV (the world record !)◼ 16 December: end of first run◼ 16 December- 28 February: Winter technical stop

◼ 27 February : machine operation started again◼ 19 March : first (single) beams ramped up to 3.5 TeV◼ 30 March : first collisions at 3.5+3.5 TeV◼ 1st April : first W candidate


Data recorded by ATLAS √s=900 GeV √s=2.36 TeV √s=7 TeV

Total number of events ~ 920k ~34k With stable beams (*) ~ 540k --- ~ 22M Int. luminosity stable beams (~30% uncertainty) ~ 12 μb-1 --- ~ 400 μb-1

Max peak L in ATLAS: ~ 7 x 1026 cm-2 s-1

(*) Full detector (including tracker) on

ATLAS data-taking efficiency at 7 TeV: > 95 % during stable beamsFraction of non-operational detector: percent level see M.Nessi’s talk

2009 run 2010 run

Max peak L in ATLAS : ~ 2 x 1027 cm-2 s-1

1x1 colliding bunches (~ 1010 p/bunch)


Worldwide data distribution

Typically 4h between Data Acquisition at the pit and data arrival at Tier2 (including reconstruction at Tier0)

MB/sper day

Total data throughput through the Grid: 1st January to 15th April 2010

MC reprocessing2009 datareprocessing Start of

7 TeVdata-taking

Jan Feb March April


◼ Most of available Tier-1/Tier-2 resources used in 2009 (e.g. ~ 97% of Tier-1 CPU)◼ Continuous efforts to reduce resources requests without affecting physics and worldwide analysis capabilities, for instance: -- simulation CPU/event reduced by 25% at zero cost for physics -- amount of legacy data (e.g. cosmics) reduced significantly

March 18 to April 18

Average number of concurrent analysis jobs vs time

Start of 7 TeVdata-taking

30 March-18 April: 1.3 million successful jobs11.5 billion events processed 584 users

Increasing usage of the Grid for analysis activities


Support for ATLAS activities at Tier-1s and Tier-2s

Personnel supporting ATLAS activities at Tier-1s and Tier-2s is given in the Table below (in FTE). These are not ATLAS members.

We are grateful to FA for their support to such a crucial component in the working of a worldwide Collaboration




First resonances popped up after a few days of collisions in November 2009

K0s π+π-

Λ pπ-

π0 γγ

η γγ


First resonances popped up after a few days of collisions in November 2009

K0s π+π-

Λ pπ-

π0 γγ

η γγ

These and other early observations and measurements indicated immediately that the detector was in excellent shape


PixelsFirst data also showed remarkable agreement with the Geant4-based simulation in the (most difficult) soft regime. Two examples shown here.

Years of efforts to model the detector details (material, imperfections, …) and validate the simulation against test-beam measurements paid off

Sensitive to calorimeter performance (noise, coherent noise, dead cells, mis-calibrations, cracks, etc.), and cosmics and beam-related backgroundsMeasured over full calorimeter coverage

(3600 in φ, |η| < 5, ~ 200k cells)

Missing transverse energy resolution

ν or new particle (weakly-interacting) missing ET


γ e+e- conversions

e+

e-γ conversion pointR ~ 30 cm (1st Silicon strip layer)

pT (e+) = 1.75 GeV, 11 TRT high-threshold hitspT (e-) = 0.79 GeV, 3 TRT high-threshold hits

2009 data

-- main source of electrons in the 900 GeV data


γ e+e- conversions

e+

e-γ conversion pointR ~ 30 cm (1st Silicon strip layer)

pT (e+) = 1.75 GeV, 11 TRT high-threshold hitspT (e-) = 0.79 GeV, 3 TRT high-threshold hits

Beam

pip

ePix

el 1

Pix

el 2

Pixel 3SCT 1

-- main source of electrons in the 900 GeV data-- useful to map the inner detector material

F.Gianotti, ATLAS RRB, 20-4-2010

First 7 TeV collisions disclose immediately a different regime …

• 7 TeV beam spot (30 March 2010)

• 900 GeV beam spot (12 December 2009)Note: equal scales

σx ~ 45 μmσy ~ 70 μm

σx ~ 200 μm σy ~ 279 μm

Beam spot size and location from prompt offline vertex reconstruction(available a few hours after first collisions)


Hard di-jet event : un-calibrated jet transverse energies: ~ 300 GeV


A pileup event in ATLAS (prob. per triggered event 1.8 x 104 expect ~910 pileup events in run)Pile-up event : two pp interactions inside the same bunch-crossing

Probability of double interactions: ~ 10-3


First ATLAS physics paper: “Charged-particle multiplicities in pp interactions at √s = 900 GeV measured with the ATLAS detector at the LHC”, published in Phys.Lett.BRecently: measurement updated to include the first fill taken at 7 TeV on 30 March

Inclusive, minimally model-dependent measurement:◼ made over a well-defined kinematic region: ≥ 1 charged particle pT> 500 MeV, |η| <2.5◼ no subtraction for single/double diffractive components ◼ distributions corrected back to hadron level easy to compare with MC models

7 TeV results are under approval

The very precise ATLAS measurements provide strong constraints on available models


First observation of W eν, μν candidates at the LHC

W is the first milestone in the “rediscovery” of the Standard Model Other “candles”: J/ψ (see later), Z (requires ~ 10 more data), top (requires ~ 10 pb-1)

μν W

Missing ET

300 μb-1 of analysed data W eν W μνExpected signal ~ 1.5 ~ 1.5Observed candidates 2 2Sign of candidates +, + +, -

Note:-- pp collisions: σ (W+) > σ (W-)-- expected background : ~ 0.15 events-- leptons pass tight e/μ cuts

pT (μ,ν) ~ 40 GeV (~ mW/2)

1st observed candidate: 1st April


2nd observed candidate: 5 April

Electron: 3 Pixel hits, 9 SCT hits, 37 TRT hits (20% with transition radiation), E/p~1.3


3rd observed candidate: 10 April

Electron: 3 Pixel hits, 8 SCT hits, 34 TRT hits (35% with transition radiation), E/p~1


4th observed candidate: 12 April

Muon: 3 Pixel hits, 8 SCT hits, 17 TRT hits, 14 MDT hits, Z~3mm from vertex, good tracker-spectrometer momentum match, E(calo) ~ 4 GeV (as expected)


◼ More than 200 plots approved◼ A physics paper published in Phys. Lett. B◼ 19 approved and 11 soon-to-be-approved CONF-notes for Winter/Spring conferences◼ A “Detector performance paper” on 2009 data undergoing internal review◼ ~ 40 CONF-notes and papers planned for Summer conferences

Results produced so far:

◼ Detector works very well: -- ~ 1% of non-operational channels; data-taking efficiency larger than 95% -- performance is better than expected at this early stage (close to nominal)◼ Very good agreement data-simulation in the (most difficult) soft regime tested so far (years of test-beam activities, material scrutiny, tune of G4 physics lists paid off ..)◼ Ability of the Collaboration to extract results very quickly (few hours after data-taking in some cases) the whole experiment from detector operation at the pit to laptop analysis works efficiently Excellent basis to produce more and more good physics results soon

3 main messages from the first periods of data-taking:


What’s next ?Prospects for the 2010-2011 run

Machine plan:

2010: L = ~1027 1032 cm-2 s-1 total of 100-200 pb-1

2011: L = 1 few 1032 cm-2 s-1 ≥ 100 pb-1 per month total of ~ 1 fb-1 2012: shut-down

√s = 7 TeV

Note: ◼ A few examples for illustration only …◼ Very preliminary estimates using fast simulations in most cases, as studies of the ATLAS potential at √s = 7 TeV have just started


Expected number of events in ATLAS for 100 pb-1 after cutsfor some representative processes

J/ψμμ

Wμν

Zμμ

ttμν+X

ttμν+Xinside peak

€

450 GeV ˜ q , ˜ g

(strong cuts)

Note: with 1 fb-1 (end 2011): expected number of tt l+jets events in ATLAS is ~ 2 times larger than CDF or D0with 10 fb-1 expected “analyzable” luminosity at Tevatron by end 2011


New Physics : approximate LHC reach √s = 7 TeV (one experiment) for some benchmark scenarios

Z’ (SSM): Tevatron limit ~ 1 TeV (95% C.L)

50 pb-1 : exclusion up to ~ 1 TeV (95% C.L.)500 pb-1 : discovery up to ~ 1.3 TeV exclusion up to ~ 1.5 TeV1 fb-1 : discovery up to ~ 1.5 TeV

W’ : Tevatron limit ~ 1 TeV (95% C.L)

10 pb-1 : exclusion up to 1 TeV100 pb-1 : discovery up to ~ 1.3 TeV1 fb-1 : discovery up to ~ 1.9 TeV exclusion up to ~ 2.2 TeV

SUSY ( ) : Tevatron limit ~ 400 GeV (95% C.L)

100 pb-1 : discovery up to ~ 400 GeV1 fb-1 : discovery up to ~ 700 GeV

€

˜ q , ˜ g

LHC will start to compete with the Tevatron in 2010, and should take over in 2011 in most cases.


◼ Exclusion of the full mass range down to mH~115 GeV requires ~1.5 fb-1 per experiment at 14 TeV◼ Discovery for mH ~ 115 GeV requires ~ 10 fb-1 per experiment at 14 TeV

A long way to go if the Higgs is just abovethe LEP2 limit: 2014 ?

34

Very preliminaryestimates


Conclusions■ ATLAS has successfully collected first LHC pp data at √s = 900 GeV and √s =7 TeV We are grateful to the LHC team for the excellent performance of the machine !

■ The whole experiment has worked efficiently and fast, from data taking at the pit, to data processing and transfer worldwide, to fast delivery of results. We are making efforts (as we gain experience) to reduce the number of shifts and CERN-based tasks.

■ The first data demonstrate that the performance of the detector and software tools (simulation, reconstruction, understanding of material, control of instrumental effects, …) is better than expected at this (initial) stage of the experiment, in a (soft) energy regime ATLAS was not optimized for.

■ Years of test beam activities, increasingly realistic simulations, and commissioning with cosmics were fundamental to achieve these nice results so quickly.

■ A first physics paper has been published, many more physics results are expected soon. This is only the beginning of an exciting physics phase, but already a major achievement of the worldwide ATLAS Collaboration.

■ Looking further ahead: activities to consolidate and upgrade the detector continue with vigor, in order to mitigate ageing, cope with increasing luminosity, enhance the performance maximize the physics potential throughout ATLAS lifetime


Conclusions■ ATLAS has successfully collected first LHC pp data at √s = 900 GeV and √s =7 TeV We are grateful to the LHC team for the excellent performance of the machine !

■ The whole experiment has worked efficiently and fast, from data taking at the pit, to data processing and transfer worldwide, to fast delivery of results. We are making efforts (as we gain experience) to reduce the number of shifts and CERN-based tasks.

■ The first data demonstrate that the performance of the detector and software tools (simulation, reconstruction, understanding of material, control of instrumental effects, …) is better than expected at this (initial) stage of the experiment, in a (soft) energy regime ATLAS was not optimized for.

■ Years of test beam activities, increasingly realistic simulations, and commissioning with cosmics were fundamental to achieve these nice results so quickly.

■ A first physics paper has been published, many more physics results are expected soon. This is only the beginning of an exciting physics phase, but already a major achievement of the worldwide ATLAS Collaboration.

■ Looking further ahead: activities to consolidate and upgrade the detector continue with vigor, in order to mitigate ageing, cope with increasing luminosity, enhance the performance maximize the physics potential throughout ATLAS lifetime

ATLAS is very grateful to the Funding Agencies for their huge contributions to the experiment and continuous support during almost 20 years.

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F.Gianotti, ATLAS RRB, 20-4-2010 1 Collaboration and Management matters First results from 900 GeV...

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