INFN-scheda presentazione progetti europei

A INFN CRUE 
Daniela Ferrucci – LNF – Frascati

•	TITOLO DEL PROGETTO: Strategies for the Commissioning of the Muon Spectrometer of the ATLAS experiment with LHC data 

•	CALL EUROPEA E SUA SCADENZA: IDEAS - ERC Starting Independent Researcher Grant  scheme; 
              VII Framework Program – deadline for applications: 25 April 2007

•	DESCRIZIONE ATTIVITA'
The ATLAS experiment at the LHC pp collider has a wide potential for discovery of new physics and for precise measurements of known processes. Since final states with muons are of great interest, a Muon Spectrometer with high resolution in a range of transverse momentum extending from 6GeV/c up to 1 TeV/c has been designed and is in the processes of being installed these days. The achievement of the design performance of the muon trigger and reconstruction system in ATLAS depends not only on the spatial resolution of carefully calibrated detectors,  but also on the constant monitoring of run time dependent conditions, like relative alignment and chamber distortions induced by mechanical stress and thermal gradients. In addition, the final resolution in the muon reconstruction will depend on the relative alignment of Inner Tracker and Muon Spectrometer. Furthermore, the ATLAS Muon Trigger has to cope with various challenges: namely, the high background from meson decays in flight, at low transverse momentum, and the high rate of uncorrelated background hits at high luminosity. As a consequence, the muon High Level Trigger algorithms deserve a long term optimization and tuning with physics data,  depending on the specific run conditions.  
Therefore, we propose to address the following items, aiming at achieving the ultimate performance of the Muon Spectrometer,  in order to fully meet the goals of the ATLAS scientific program: 
-	deploy software tools for detector description that fulfill the system requirements (run time correction of realistic effects)  in such a way that any muon identification algorithm, in the offline as well as in the online trigger environment,  can account for them;
-	introduce realism in the simulation of the Muon Spectrometer as much as the comparison with real data will require; 
-	add flexibility to the implementation of the HLT muon selection, in order to ensure efficiency and robustness  according to the run conditions; 
-	study how critically  the muon HLT depends upon detector misalignments and other run-time conditions and ensure robustness against these effects; 
-	define strategies for an overall calibration of the Muon Spectrometer using well known physics processes: the most useful being Z decaying to two muons;  in this respect, in the long term,  it is necessary a procedure for the determination from data of the absolute muon momentum scale (essential for improving the precision on the measurement of the W boson mass with the ATLAS data).
Along side these activities,  we propose to take part to the early physics search program of ATLAS,  with particular involvement in the search for SUSY processes with muonic signatures. 

•	PARTECIPANTI PRESENTI: Molte Sezioni INFN, tra cui Lecce,  hanno partecipato alla realizzazione dello spettrometro a muoni di ATLAS e sono attualmente coinvolte in attivita` legate a ricostruzione e trigger di muoni. La proposta qui avanzata consentirebbe di definire un nucleo di lavoro dedicato ai temi del commissioning dello spettrometro, oltre che alla fisica, che lavorerebbe in naturale collaborazione con sezioni INFN o ricercatori italiani e stranieri impegnati in attivita` attinenti. 

•	PARTECIPANTI DA ACQUISIRE: 2/3 post-docs

•	INFRASTRUTTURE NECESSARIE E CONTRIBUTO INFN: Si suppone l’utilizzo delle infrastrutture di calcolo di ATLAS Italia (in particolare i Tier2)  genericamente disponibili per le attivita` della collaborazione anche in ambito di “calibrazioni e tuning di algoritmi di trigger/ricostruzione” .

•	SETTORE SCIENTIFICO DI PERTINENZA: Fisica agli acceleratori di particelle

•	COLLABORAZIONE INTERNAZIONALE: ATLAS 

•	PROPONENTE E SUO RUOLO: Stefania Spagnolo, ricercatrice universitaria della Facolta` di Scienze, Università` del Salento e incaricata di ricerca presso la Sezione INFN di LECCE