Nevio Grion- – LNF Scientific Committee, Frascati, May 29 th, 2003

Table of contents 1.From the Beam Pipe to FINUDA at DA  NE: the story of an assembly. 2.Debugging FINUDA with the cosmic rays (field OFF). 3.Alignment of the vertex detector (VDET): goal and preliminary event reconstruction. 4. A reminder of the initial FINUDA physics. 5. Next steps toward data taking.

Beam pipe ready

People at work

Inserting TOFINO

Beam Pipe & TOFINO TOFINO One halve of TOFINO

Wiring TOFINO First half of a physicist

VDET getting ready

VDET getting there

VDET go it!

VDET getting wired second half of a physicist

Installing the He-bag

Preparing FINUDA for the roll-in

FINUDA starts rolling in

Roll-in completed !

and finally FINUDA … saw the light!

FINUDA at DA  NE

VDET region Typical event: Reconstructed cosmic ray

The VDET region enlarged Beam Line TOFINO Target VDE T Cosmic ray pattern recognition Side viewFront view

Expected results:  int : pitch/  12 =  =  int +  MS +  sag average efficiency of a module > 97% Alignment of VDET with straight cosmics ISIM 7 -  ISIM 7 - Z z ~ 30 µm  ~ 15 µm 2222 Assessed time scale: ~ good cosmics required ~ 3 Hz of cosmics crossing TOFINO  ~3 weeks of cosmic rays data taking Results after 1 st order correction

momentum The VDET PID p KK -- Measured PID for hyp. event Simulated PID for hyp. event

VDET expected results : 15 µm  int   15 µm  int z  30 µm VDET in ASTRA, early results: 22 µm    22 µm  z  34 µm µmµm  2 O   14 µm  2 O z  23 µm µmµm  int   18 µm  int z  25 µm VDET in FINUDA, field OFF: 12 µm  int   12 µm  int z  24 µm 1. better modules; 2. selective trigger; 3. improved analysis VDET in FINUDA, field ON: evaluation of Lorentz drift evaluation of Lorentz drift VDET spatial resolution, results OSIM 9 OSIM 9 in FINUDA, field OFF (1/2 statistics analysed) 10 µm  int   10 µm

Hypernuclear physics with FINUDA Production of  -hyp. K - stop + A   A +   prompt : –spectroscopy of hyp. via the   prompt momentum Decay of  -hypernuclei: –mesonic decay (   p  - ;   n  0 ) –non-mesonic decay (  p  n p;  n  n n) Lifetime of  -hypernuclei

Expected results Segmented target: 2x 6 Li + 1x 7 Li + 3x 12 C + 1x 27 Al + 1x 51 V Integrated luminosity: 250 pb -1 6 Li: Source of 4  He and 5  He ( 6  Li unstable), expected yield ; Study of the decay of light hypernuclei (~ never examined) 5  He  3 He + n + p 5  He  3 H + n + n 6  He  4 He + n + n (T = 1/2 still valid ???) 4  He  d + d 4  He  p + 3 He 4  He   + + n + 3 H 7 Li: Comparison with the 6 Li target, available data of poor quality; More than 10 5 events in the excitation spectrum.

12 C: Reference target for spectroscopy and weak decays studies, expected over 10 5 events in the excitation spectrum; Search for weakly excited states,  /K stop (present limit /K stop ) Weak decays:  p ~ 2%  n ~ 3%  pn ~ 5% New  nn ~ 10% New  - ~ 3% The results will greatly improve the previous results, expected factor Al: Never studied before; Measurement of the capture rate in the medium hypernuclei; Excitation spectrum with  10 5 events, useful for weak decay studies. 51 V: No measurements available with K - at rest, useful for weak decay studies; Important to assess the capture rate for the medium and heavy hypernuclei (  10 5 events in spectrum).

A glance over new hypernuclear physics Rare two body decays ( 4  He  p + t  d + d ) Neutron-rich hypernuclei (NRH) Sigma hypernuclei …it comes for free

Further steps toward data taking 1.FINUDA: DAQ with cosmics field OFF 6-7/06 a. VDET alignment b. determination of T 0 for STB 2. Cooling down & closing end-caps + AD operations ~10/06 3.FINUDA: power ON & debugging detectors 11-12/06 4.DAQ with cosmics & field ON  till DA  NE ready a. alignment of the whole FINUDA

End of the presentation