Photon vetoes status report WG on photon vetoes

Photon vetoes status report – WG on photon vetoes active since November • First meeting on December 14 th • ~2 meetings/ month during the proposal preparation • Scope: large angle vetoes, LKr calorimeter, small angle vetoes September 7 th, 2005 Photon vetoes status report

September 7 th, 2005 Photon vetoes status report 2

Large angle vetoes • Definition of the layout – Optimization of the layout wrt p 0 detection inefficiency • Identify distribution of g energy vs angular sector • Compute p 0 inefficiency with different inefficiency tables • Spot angular/energy region where a better inefficiency is a must • Take into account LKr calorimeter and small angle vetoes • Inefficiency quoted in the proposal: – Between 3 · 10 -9 and 3. 3 · 10 -8 with 8<Pp+<40 Gev/c and depending on the variation of the inefficiency tables wrt to realistic choices September 7 th, 2005 Photon vetoes status report

Parametrizations of inefficiencies September 7 th, 2005 Photon vetoes status report 4

Large angle vetoes – Start to think of a mechanical design • • Counters in vacuum Ways of insulating from the main vacuum Support Dimensions • Simple conceptual design for the proposal • Now start to think to a detailed design • Useful to meet together with engineers i. e. at one of the next WG meetings September 7 th, 2005 Photon vetoes status report

Large angle vetoes – Focus on counter technology • Tiles a la CKM • Spaghetti a la KLOE • Extensive Geant 4 simulation started to study both solutions (see report from P. Valente) – Punchtrough – Inefficiency dependence from the hitting angle, energy and position • But also to be compared for – Costs – Mechanical design of the support September 7 th, 2005 Photon vetoes status report

Large angle vetoes – From now on • Do extensive simulation studies • Build and test a prototype – Existing Kloe prototype under test (see report) – Electrons and gamma beams in Frascati • Study electrical signal features – To define the readout electronics – To define the way of getting time and amplitude information • Define in detail the mechanical design • Assign building jobs … September 7 th, 2005 Photon vetoes status report

Large angle vetoes – Former CKM physicist interested in joining us • A lot of R/D done for CKM vetoes • A prototype (2 sectors, 80 layers, 1 mm/5 mm) exists at FNAL – Tested in an electron beam. Results are published » Inefficiency for electrons @ 1. 2 Gev/c 3*10 -6 – Available for inspection and tests (not easy to bring it to Europe) • CKM private documentation open to P 326 – Notes on electronics/mechanics – Mechanical drawings – Photo of the prototype (useful to learn about the mess in fiber handling) September 7 th, 2005 Photon vetoes status report

The CKM prototype at FNAL September 7 th, 2005 Photon vetoes status report 9

Examples from CKM September 7 th, 2005 Photon vetoes status report 10

Large angle vetoes – CKM prototype built with cast Bicron scintillator • Too expensive for the final detectors • They had plans to build in Protvino complete tiles – Scintillator, fibers, wrapping, fiber connections, holes – Ready to test and install – Light yield of this russian scintillator ok for them • A prototype (1 sector, 20 layers) exists in Protvino – Made with russian scintillator – 20 layers 1 mm/5 mm – 20 WLS Kuraray Y-11 fibers/layer – Trapezoidal shape (28, 12) 39 cm 2 – Total thickness 4. 5 X 0 – Available for transport at CERN – Could be tested in Frascati September 7 th, 2005 Photon vetoes status report

The CKM prototype in Protvino September 7 th, 2005 Photon vetoes status report 12

Large angle vetoes – Protvino has the know-how for scintillator production • They have bought all the manufacturing equipment for scintillator from Uniplast (Vladimir) – Extruded scintillator – Molded scintillator – Intended to be used for CKM (Kplus) and KOPIO • Interested to collaborate even for prototype studies • Opportunity to use this facility for P 326 • Need discussion, inspection, agreement, control, etc. . September 7 th, 2005 Photon vetoes status report

Liquid krypton calorimeter – Work in progress to evaluate the photon detection inefficiency of the calorimeter • Study from Ruggiero using p+p 0 from the special run in 2004 – Measured inefficiency <1. 7*10 -4 per E>12 Gev – Still not conclusive: need a factor 10 • Work started by me using p+p 0 p 0 from 2003 and 2004 asymmetry runs – High statistics could help – Additional analysis possible with p+p 0 D • Beam time will be requested in 2006 – To have more statistics for p+p 0 – Spot possible readout inefficiencies: read with NZS, exploit peak finder readout September 7 th, 2005 Photon vetoes status report

Liquid krypton calorimeter – Still to be done • Evaluate the effect on the inefficiency of the material in front of the calorimeter (RICH, hodoscope, windows, etc) – to be added to the study by Marchetto on the effect of the Stesalit plate: found to be less than 3*10 -6 • Start to define the new readout electronics – CPDs are obsolete – Same functionality as the old one – Integration with the new scheme for the readout – CERN will likely take care of it September 7 th, 2005 Photon vetoes status report

Small angle vetoes – Two technologies in the proposal • Shashlik (lead/scintillator) • Crystals – Sofia/INR will build a shashlik prototype • Requests for financing in Bulgaria submitted in June • People are restarting now to work on this – Still missing • Detailed mechanical design • Details on the readout electronics • Layout of the electrical connections for the IRCs, to minimize the crossing of the sensitive area of the RICH and of the LKr September 7 th, 2005 Photon vetoes status report

Ottimizzazione del design dell’esperimento Monte Carlo esperimento e fisica Ottimizzazione design del veto Monte Carlo dettagliato veto Richieste per 1 -e Soluzioni per il veto (layout, tecnologia, readout) Costruzione/Riutilizzo prototipi Test-beam Monte Carlo prototipi e fascio Misura di 1 -e Stima errori sistematici (mistag, alone del fascio, ecc. ) Test/caratterizzazione materiali Ottimizzazione costi Stima di 1 -e Validazione Monte Carlo September 7 th, 2005 Finalizzazione design Photon vetoes status report 17

Milestones e tasks • 31/1/2006: Definizione della tecnologia e del layout – – – • • Simulazione dettagliata dei veti Tools produzione MC, framework software Simulazione dei testbeam Tools di analisi dati dei testbeam Test a BTF di strutture esistenti Roma & Napoli & Pisa Roma Frascati & Roma Frascati Napoli & Roma & Frascati &Pisa 15/7/2006: Costruzione prototipo – – – Studi sul vuoto/degassing Ottimizzazione readout ottico Studio/caratterizzazione dei materiali Progettazione meccanica Prototipo(i) Napoli & Roma & Frascati Pisa & Roma Napoli & Roma & Frascati &Pisa 31/12/2006: Risultati test prototipo – – Test a BTF prototipo(i) Analisi dati September 7 th, 2005 Napoli & Roma & Frascati &Pisa Photon vetoes status report