ATLAS Status Report Part II Fabiola Gianotti RRB

ATLAS Status Report (Part II) Fabiola Gianotti, RRB, 20/4/2010 CERN-RRB-2010 -009 �Collaboration and Management matters �First results from 900 Ge. V and 7 Te. V collision data (in particular: first observation of W eν, μν candidates at LHC) �Physics prospects for 2010 -2011 (a few examples …) F. Gianotti, ATLAS RRB, 20 -4 -2010 Detector status, consolidation and upgrade: see M. Nessi’s talk 1

Collaboration and Management matters F. Gianotti, ATLAS RRB, 20 -4 -2010 2

F. Gianotti, ATLAS RRB, 20 -4 -2010 3

~ 2988 Active physicists: -- ~ 1900 with a Ph. D, for M&O share -- ~ 1100 students 173 Institutions 37 Countries 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 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, Mc. Gill Montreal, RUPHE Morocco, FIAN Moscow, ITEP Moscow, MEPh. I 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 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 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 F. Gianotti, ATLAS RRB, 20 -4 -2010 4

ATLAS active physicists age distribution All 2690 Male 81. 8% Female 18. 2% (Status 1. 1. 2010) F. Gianotti, ATLAS RRB, 20 -4 -2010 (< 35 y 47. 2%) 44. 0%) 61. 3%) 5

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 years through 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 ATLAS has 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 2010 If positive, ATLAS will have a new country and a new FA (DST) F. Gianotti, ATLAS RRB, 20 -4 -2010 6

New since October RRB F. Gianotti, ATLAS RRB, 20 -4 -2010 7

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) g 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) g 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 Covered-expected FTE requirements and FA contributions reviewed and updated yearly Distribution per FA in 2009 (CERN-based shifts not included) Zero means ok, negative is bad F. Gianotti, ATLAS RRB, 20 -4 -2010 Funding Agency 8

First LHC data-taking and first performance and physics results at √s= 900 Ge. V and 7 Te. V F. Gianotti, ATLAS RRB, 20 -4 -2010 9

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 Ge. V � 8, 14, 16 December: few hours of collisions at √s = 2. 36 Te. V (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 Te. V � 30 March : first collisions at 3. 5+3. 5 Te. V � 1 st April : first W candidate F. Gianotti, ATLAS RRB, 20 -4 -2010 10

Data recorded by ATLAS √s=900 Ge. V Total number of events With stable beams (*) ~ 920 k ~ 540 k ~ 12 μb-1 Int. luminosity stable beams (~30% uncertainty) √s=2. 36 Te. V ~34 k ----- √s=7 Te. V ~ 22 M ~ 400 μb-1 (*) Full detector (including tracker) on 2009 run Max peak L in ATLAS: ~ 7 x 1026 cm-2 s-1 2010 run Max peak L in ATLAS : ~ 2 x 1027 cm-2 s-1 1 x 1 colliding bunches (~ 1010 p/bunch) ATLAS data-taking efficiency at 7 Te. V: > 95 % during stable beams Fraction non-operational F. Gianotti, of ATLAS RRB, 20 -4 -2010 detector: percent level see M. Nessi’s talk 11

Worldwide data distribution MB/s per day Total data throughput through the Grid: 1 st January to 15 th April 2010 Jan Feb MC reprocessing March 2009 data reprocessing April Start of 7 Te. V data-taking Typically 4 h between Data Acquisition at the pit and data arrival at Tier 2 (including reconstruction at Tier 0) F. Gianotti, ATLAS RRB, 20 -4 -2010 12

Increasing usage of the Grid for analysis activities Average number of concurrent analysis jobs vs time March 18 to April 18 Start of 7 Te. V data-taking 30 March-18 April: 1. 3 million successful jobs 11. 5 billion events processed 584 users �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 F. Gianotti, ATLAS RRB, 20 -4 -2010 13

Support for ATLAS activities at Tier-1 s and Tier-2 s Personnel supporting ATLAS activities at Tier-1 s and Tier-2 s 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 F. Gianotti, ATLAS RRB, 20 -4 -2010 14

In the following: few examples from huge number of detector performance and physics results (obtained in only a few days in many cases …. ) F. Gianotti, ATLAS RRB, 20 -4 -2010 15

F. Gianotti, ATLAS RRB, 20 -4 -2010 16

First resonances popped up after a few days of collisions in November 2009 K 0 s π+π- Λ pπ- π0 γγ η γγ F. Gianotti, ATLAS RRB, 20 -4 -2010 17

First resonances popped up after a few days of collisions in November 2009 K 0 s π+π- Λ pπ- These and other early observations and measurements indicated immediately that the detector was in excellent shape π0 γγ η γγ F. Gianotti, ATLAS RRB, 20 -4 -2010 18

First data also showed remarkable agreement with the Geant 4 -based simulation in the (most difficult) soft regime. Two examples shown here. Pixels Years of efforts to model the detector details (material, imperfections, …) and validate the simulation against test-beam measurements paid off Missing transverse energy resolution ν or new particle (weakly-interacting) missing ET Measured over full calorimeter coverage 0 in φ, |η| < 5, ~ 200 k cells) (360 F. Gianotti, ATLAS RRB, 20 -4 -2010 Sensitive to calorimeter performance (noise, coherent noise, dead cells, mis-calibrations, cracks, etc. ), and cosmics and beam-related backgrounds 19

γ e+e- conversions 2009 data -- main source of electrons in the 900 Ge. V data p. T (e+) = 1. 75 Ge. V, 11 TRT high-threshold hits p. T (e-) = 0. 79 Ge. V, 3 TRT high-threshold hits ee+ F. Gianotti, ATLAS RRB, 20 -4 -2010 γ conversion point R ~ 30 cm (1 st Silicon strip layer) 20

γ e+e- conversions -- main source of electrons in the 900 Ge. V data -- useful to map the inner detector material Beam pipe e+ F. Gianotti, ATLAS RRB, 20 -4 -2010 Pixel 2 e- Pixel 1 p. T (e+) = 1. 75 Ge. V, 11 TRT high-threshold hits p. T (e-) = 0. 79 Ge. V, 3 TRT high-threshold hits γ conversion point R ~ 30 cm (1 st Silicon strip layer) Pixel 3 SCT 1 21

First 7 Te. V collisions disclose immediately a different regime … Beam spot size and location from prompt offline vertex reconstruction (available a few hours after first collisions) • 7 Te. V beam spot (30 March 2010) σx ~ 45 μm • 900 Ge. V beam spot (12 December 2009) σx ~ 200 μm F. Gianotti, ATLAS RRB, 20 -4 -2010 σy ~ 70 μm Note: equal scales σy ~ 279 μm

Hard di-jet event : un-calibrated jet transverse energies: ~ 300 Ge. V F. Gianotti, ATLAS RRB, 20 -4 -2010 23

A pileup event in ATLAS (prob. per triggered event 1. 8 x 10 -4 expect ~910 pileup events in run) Pile-up event : two pp interactions inside the same bunch-crossing F. Gianotti, ATLAS RRB, 20 -4 -2010 Probability of double interactions: ~ 10 -3

First ATLAS physics paper: “Charged-particle multiplicities in pp interactions at √s = 900 Ge. V measured with the ATLAS detector at the LHC”, published in Phys. Lett. B Recently: measurement updated to include the first fill taken at 7 Te. V on 30 March Inclusive, minimally model-dependent measurement: �made over a well-defined kinematic region: ≥ 1 charged particle p T> 500 Me. V, |η| <2. 5 �no subtraction for single/double diffractive components �distributions corrected back to hadron level easy to compare with MC models The very precise ATLAS measurements provide strong constraints on available models 7 Te. V results are under approval F. Gianotti, ATLAS RRB, 20 -4 -2010 25

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) 300 μb-1 of analysed data Expected signal Observed candidates Sign of candidates W eν ~ 1. 5 2 +, + W μν ~ 1. 5 2 +, - Note: -- pp collisions: σ (W+) > σ (W-) -- expected background : ~ 0. 15 events -- leptons pass tight e/μ cuts ν W μ Missing ET p. T (μ, ν) ~ 40 Ge. V (~ m. W/2) 1 st observed candidate: 1 st April F. Gianotti, ATLAS RRB, 20 -4 -2010 26

2 nd observed candidate: 5 April Electron: 3 Pixel hits, 9 SCT hits, 37 TRT hits (20% with transition radiation), E/p~1. 3 F. Gianotti, ATLAS RRB, 20 -4 -2010 27

3 rd observed candidate: 10 April Electron: 3 Pixel hits, 8 SCT hits, 34 TRT hits (35% with transition radiation), E/p~1 F. Gianotti, ATLAS RRB, 20 -4 -2010 28

4 th observed candidate: 12 April Muon: 3 Pixel hits, 8 SCT hits, 17 TRT hits, 14 MDT hits, Z~3 mm from vertex, good tracker-spectrometer F. Gianotti, ATLAS RRB, 20 -4 -2010 momentum match, E(calo) ~ 4 Ge. V (as expected) 29

Results produced so far: �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 3 main messages from the first periods of data-taking: �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 G 4 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 F. Gianotti, ATLAS RRB, 20 -4 -2010 30

What’s next ? Prospects for the 2010 -2011 run Machine plan: √s = 7 Te. V 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 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 Te. V have just started F. Gianotti, ATLAS RRB, 20 -4 -2010 31

Expected number of events in ATLAS for 100 pb-1 after cuts for some representative processes J/ψ μμ W μν Z μμ tt μν+X inside peak (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 D 0 -1 expected “analyzable” luminosity at Tevatron by end 2011 with 10 fb F. Gianotti, ATLAS RRB, 20 -4 -2010 32

New Physics : approximate LHC reach √s = 7 Te. V (one experiment) for some benchmark scenarios Z’ (SSM): Tevatron limit ~ 1 Te. V (95% C. L) 50 pb-1 : exclusion up to ~ 1 Te. V (95% C. L. ) 500 pb-1 : discovery up to ~ 1. 3 Te. V exclusion up to ~ 1. 5 Te. V 1 fb-1 : discovery up to ~ 1. 5 Te. V SUSY ( W’ : Tevatron limit ~ 1 Te. V (95% C. L) 10 pb-1 : exclusion up to 1 Te. V 100 pb-1 : discovery up to ~ 1. 3 Te. V 1 fb-1 : discovery up to ~ 1. 9 Te. V exclusion up to ~ 2. 2 Te. V ) : Tevatron limit ~ 400 Ge. V (95% C. L) 100 pb-1 : discovery up to ~ 400 Ge. V 1 fb-1 : discovery up to ~ 700 Ge. V LHC will start to compete with the Tevatron in 2010, and should take over in 2011 in most cases. F. Gianotti, ATLAS RRB, 20 -4 -2010 33

Very preliminary estimates �Exclusion of the full mass range down to m. H~115 Ge. V requires ~1. 5 fb-1 per experiment at 14 Te. V �Discovery for m. H ~ 115 Ge. V requires ~ 10 fb-1 per experiment at 14 Te. V A long way to go if the Higgs is just above the LEP 2 limit: 2014 ? F. Gianotti, ATLAS RRB, 20 -4 -2010 34

Conclusions ■ ATLAS has successfully collected first LHC pp data at √s = 900 Ge. V and √s =7 Te. V 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 F. Gianotti, ATLAS RRB, 20 -4 -2010 35

Conclusions ■ ATLAS has successfully collected first LHC pp data at √s = 900 Ge. V and √s =7 Te. V 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 ATLAS is very grateful to the Funding Agencies for their software tools (simulation, reconstruction, understanding of material, control contributions tobetter the experiment ofhuge instrumental effects, …) is than expected atand this continuous (initial) stage ofsupport the experiment, in aalmost (soft) energy regime ATLAS was not optimized for. during 20 years. ■ 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 F. Gianotti, ATLAS RRB, 20 -4 -2010 36