FINUDA TRIGGER FINUDA Collaboration Meeting Trieste, May Simonetta Marcello - Torino Paola Gianotti - LNF Fulvio Pompili - LNF Aldo Zenoni (MC) - Brescia Francesca De Mori (OA) - Torino ….

FINUDA TRIGGER Strategy n SELECTIVE TRIGGER based on fast detector (TOF) and electronics n MODULAR and PROGRAMMABLE STRUCTURE to have a flexible configuration n CARE of TRIGGER DESIGN from the beginning to cope with high rates (up to 30 MHz) n Dedicated MC SIMULATION physical events, background (Touschek) [2000: G.Gomez- 2003: A. Zenoni] n Latency ~ 200 ns at First Level RF signal not used at all in the Logic (due to old FEE on detectors) RF: 380 MHz (interbunch time 2.6 ns) rate ~ 400 Hz, interaction time 2 ms HYP rate < 1Hz Bhabha < 200 Hz n Asynchronous Trigger (continous source of events) FINUDA TRIGGER - Simonetta Marcello - TS 6/5/04 L = cm -2 s -1 Accurate TIMING is CRUCIAL to select events from background For more details: ISEO 2002

Level 0 u selection is made using TOFINO signals u here trigger is asynchronous Level 1 u selection includes TOFONE signals u synchronization is given by level 0 TRIGGER STRATEGY Selections energy loss topology multiplicity tof (In-Ext barrels) Mean Timing signals to identifiy hit slabs FINUDA TRIGGER - Simonetta Marcello - TS 6/5/04 ISEO 2002

TIMING alignment Reference: photodiode Gated OR TOFONE TOFINO LThr MTTOFINO HThr MT MLU Exclusive BTB 1-1 BTB (Bhabha, not used for triggering) PAL Exclusive BTB 1-3 BTB (Bhabha + KsKl) OR-MB PAL NOT Excl BTB 1-3 K+K- OR-EL PCoin narrow window OR-TOFONE Prompt Coincidence (less +) Slow Coincidence (only +) MULT SEL HYP 2-7 HYP Mult MULT SEL BHABHA 2-7 BHABHA Mult MALU Gate from OR Tofino DISC MULT TOFONE > 1 TOFONE MT FINUDA TRIGGER - Simonetta Marcello - TS 6/5/04 LASERLASER TRIGGER LOGIC

COSM HYP BHABHA LASER OR TOFONE MULT TOFONE > 1 OR TOFINO BASIC TRIGGERS TRIGGER LOGIC FINUDA TRIGGER - Simonetta Marcello - TS 6/5/04 BTB Bhabha MULT Bhabha BTB K+K- MULT HYP OR MB MULT TOFONE > 1 OR TOFONE LASER PhDiode PLU System + PRESC

Moduli VME (Heart of Trigger Logic) progettati e realizzati da Silvano Gallian Electronic Lab - Torino INFN) n Pattern Recognition LE297 BtB Topologies OK n Multiplicity Selector LE308 HYP, BHA multiplicities OK n Prescaler LE312 prescaling triggers OK Prompt Coincidence LE301 tof Tofino-Tofone Not working in CRoom! Already repaired, it still gives problems of noise. New tests and/or design needed Estimated time 6 m.u. FINUDA TRIGGER - Simonetta Marcello - TS 6/5/04

Rate TOFINO ~ 400 kHz ! SELECTION OF HYP EVENTS Background rejection for HYP Trigger L = cm -2 s -1 High rejection power MC ISEO 2002 FINUDA TRIGGER - Simonetta Marcello - TS 6/5/04 Real HYP TRIG Rate ~ 7 L ~ 4x10 31 cm -2 s -1 RUN

SELECTION OF BHABHA EVENTS Background rejection for Bhabha Trigger L = cm -2 s -1 MC ISEO 2002 FINUDA TRIGGER - Simonetta Marcello - TS 6/5/04 Real BHABHA TRIG Rate ~ 15 L ~ 4x10 31 cm -2 s -1 RUN Maybe Tofino efficiency for mip ?

TRIGGER Efficiency for BHABHA selection FINUDA TRIGGER - Simonetta Marcello - TS 6/5/04 Pattern Recognition exclusive BTB 1-3 Topologies 95% evaluated on TDC hits 98% evaluated on MT hits Multiplicity Selector * BTB1-3 Mult 2-7 on Tofone 90% evaluated on TDC hits 99% evaluated on MT hits ? evaluated on MT hits inside Tofino gate Need of TOF Calibration Beam Runs Dec 2003 with Trigger ORTofino*ORTofone TRIGGER EFFICIENCY

What about Trigger Efficiency for HYP selection ? Maybe not enough statistics on Beam Runs with Trigger ORTofino*ORTofone We have to check including last runs FINUDA TRIGGER - Simonetta Marcello - TS 6/5/04 TRIGGER EFFICIENCY

Trigger Timing FINUDA TRIGGER - Simonetta Marcello - TS 6/5/04 MT Tofino (jitter/jump ~ 10 ns) MT Tofone (jitter < 2ns) Timing Alignment with LASER Maybe due to CFD ? Between Tofino and Tofone (Basic Trigger signals) FINAL Timing Alignment with with beam collisions Due to not safe calibrated optical fibers Loose Timing Need of TOF Calibration to measure real length of fibers

SELECTION OF HYP EVENTS prompt - Fast coincidence ( tof) custom VME module Multiplicity >= 1 (Ext TOF) custom VME module + from K + decayprompt - tof Inner-Outer Barrels K + mean lifetime = 12.4 ns MC ISEO 2002 Trigger Timing

Common STOP FINUDA TRIGGER - Simonetta Marcello - TS 6/5/04 Programmable Choice using Output Register CES ST03 OR Tofino (Physics, Cosmics) OR Tofone (Cosmics) Photodiode (LASER) RF (not used, but read out on dedicated TDC) 8 double ANDs, 1 gate Progettato e realizzato da Fulvio Pompili (INFN-LNF) Safe Timing > 10 ns

TO BE or NOT TO BE FINUDA TRIGGER - Simonetta Marcello - TS 6/5/04 RF for Physics (on all TDCs) OR RF not used, but read out on dedicated TDC Times with Physics Meaning TOF (particle time of flight between Tofino and Tofone) Computing differences RF expires NO advantage Resolution still depends on Tofino and Tofone ones

Higher Levels of Trigger FINUDA TRIGGER - Simonetta Marcello - TS 6/5/04 Maybe useful at 3 rd Level TOF used at 1 st Level LMD and STB not useful alone at 2 nd Level SIL most interesting information to be manage at 2 nd Level, BUT unfortunately too slow (> 15 ms) TOF again at 2 nd Level ? Filippini/Panzarasa TALK Do we need a strict selection ?