# Presentation: 499483

## TAUP 2001

- O. Palamara
- Sept. 10th, 2001

- The Atmospheric and Solar Neutrino Experiment
- with the ICARUS T600 Detector
- @ Gran Sasso Laboratory

- O. Palamara - LNGS

- Sept. 10th 2001

##  ICARUS T600: status of the detector 

-  1997- 2000: Realization completed (Pavia-INFN Exp. Hall)
-  **April-Aug. 2001:** Full Test in experimental conditions (Pavia)
-  2002: Transportation to LNGS (Underground Site)
-              re-mounting and start physics run

-  *The solar neutrino experiment:*
- Signal and Background event Rate Evaluation
-  Signal: Based on BP98 Solar **** Flux
-  Bckgd: based on neutron flux direct measurement performed by ICARUS
-   Collaboration at LNGS (Hall C)
- Signal to Background Discrimination: from full MC simulation

- OUTLINE:

-  *The atmospheric neutrino experiment: *
- Event Rate Evaluation
- Reconstruction capability with ICARUS

- O. Palamara - LNGS

- Sept. 10th 2001

## The ICARUS Collaboration

**INFN-Laboratori Nazionali del GranSasso, Italy**
**Inst. of Exp. Physics, Warsaw University, Warsaw-Poland**
**Inst. for Particle Physics, ETH, Zurich-Switzerland**
**Dip.to di Fisica e INFN, Padova-Italy**
**Dip.to di Fisica e INFN, Milano-Italy**
**Dip.to di Fisica e INFN, Pavia-Italy**
**Dip.to di Fisica e INFN, L’Aquila-Italy**
**CERN, Geneva-Switzerland**
**Dip.to Ing.Nucleare, Univ. di Milano, Milano-Italy**
**IHEP-Academia Sinica, Beijing-China**
**Dep.t of Physics, UCLA, LosAngeles-California, USA**
**H.Niewodniczanski Inst. of Nucl. Phys., Krakow-Poland**
**Inst. of Physics, Wroclaw Univ.,Wroclaw-Poland**
**Inst. of Physics, Silesia Univ.,Katowice-Poland**
**A. Soltan Inst. Of Nucl. Studies, Warsaw-Poland**
**Fac. of Phys. And Nucl. Tech., Krakow-Poland**
**ICFG-CNR and Dip.to di Fisica, Torino-Italy**
**INFN-Laboratori Nazionali di Frascati, Roma-Italy**
**Inst. of Physics, Jagellonian Univ., Krakow-Poland**
**INFN-Pisa, Italy**

- O. Palamara - LNGS

- Sept. 10th 2001

## The ICARUS technology

**Working principle****: **
**Ionization chamber filled with LAr, equipped with sophisticated electronic read-out system (TPC) for 3D imaging reconstruction, calorimetric measurement, particle ID. **
**Absolute timing definition and internal trigger from LAr scintillation light detection**
**T600 detector****:**
**Cryostat: 2 identical, adjacent half modules (3.6x3.9x19.9 m****3****)**
**Internal detector: **
**       ****- 2 TPC per half module (3 wire planes @ 60****o****: induction I,**
**         ****induction II, collection)**
**       ****- field shaping system (cathode, race track, HV feed-through)**
**       ****- array of PMT’s for scintillation light detection**
**       ****- monitors and probes**
**Electronics: analogue board + digital board**

- O. Palamara - LNGS

- Sept. 10th 2001

## LAr Cryostat (half-module)

- 20 m

- 4 m

- 4 m

- View of the inner detector

**The T600 Detector during construction**

- O. Palamara - LNGS

- Sept. 10th 2001

## Run @ Pv: full test in final experimental configuration (May-Aug 2001) 

- Collection of large
- statistics of cosmic
- ray data with various
- trigger configurations:
- from long **** tracks (up to
- 18 m length), to high multiplicity **** bundles,
- to large el.m.
- and hadronic showers

- O. Palamara - LNGS

- Sept. 10th 2001

##  T600 test @ Pv: Run 201 - Evt 12

- El.m. shower

- Full 2D View from the Collection Wire Plane

- 2

- 4

- 6

- 18

- 12

- Wire coord. (m)

- 2

**Drift coord. (m)**

*Zoom views*

- 1

- 3

- 2

- 2

- 3

**** stop and decay in *e*

- Detail of a long (14 m) **** track
- with ****-ray spots

- El.m. shower

** ****T600 test @ Pv: Run 201 - Evt 12**

- 1

- O. Palamara - LNGS

- Sept. 10th 2001

##  T600 test @ Pv: Run 308 - Evt 4 (July 2nd, 2001)

- Full 2D View from the Collection Wire Plane

- 2

- 4

- 12

- 6

- 18

- 2

- Wire coord. (m)

**Drift **
**Coord.**
**(m)**

- Zoom View

- Zoom View

- 3.1 m

- 0.9 m

- A spectacular event showing
- a dense Air Shower formed by
- hundreds of parallel tracks
- (muons and pions) and low energy
****’s converting into electrons.
- Also visible in the zoom views a
- hadr. shower, an el.m. shower and
- a muon bundle.

- el.m. shower

- had. shower

**** bundle

** ****T600 test @ Pv: Run 308 - Evt 4 (July 2nd, 2001)**

- O. Palamara - LNGS

- Sept. 10th 2001

## T600 test @ Pv: Run 308 - Evt 7 

- 2

- 6

- 4

- 18

- 12

- 2

**Wire coord. (m)**

**Drift**
**Coord.**
**(m)**

- Full 2D view from the Collection Wire Plane

- Zoom View

**3.9 m**

**1.3 m**

- Large el.m. shower

**T600 test @ Pv: Run 308 - Evt 7 **

- O. Palamara - LNGS

- Sept. 10th 2001

## Atmospheric neutrino Physics 

- Atmospheric neutrino Physics

- with ICARUS T600

-  Observation of atmospheric neutrino interactions  with unique
-   experimental features
-  Capability to observe electron and muon neutrino CC events and
-   NC events without detector biases and down to the kinematical
-   threshold

-  Improvements with respect to previous observations:
-         - complicated final states with multi-pion production will be
-           completely analyzed and reconstructed
-         - better reconstruction of the incoming neutrino variables
-           (i.e. incidence angle, energy) by using the information coming
-           from all particles produced in the final state

- O. Palamara - LNGS

- Sept. 10th 2001

## Difference between real and reconstructed

**Difference between real and reconstructed**
**neutrino angle for events with E********>1 GeV**

**Zenith angle resolution as a function **
**of the incoming neutrino energy **

** ****E********<500 MeV: the resolution is dominated by **
**  ****the smearing introduced by the Fermi motion **
**  ****of the initial state nucleon and re-interaction **
**  ****of hadrons inside the nucleus      **
** ****E********>500 MeV: the improvement in resolution **
**  ****when all particles are detected is significant**

- O. Palamara - LNGS

- Sept. 10th 2001

## Expected atmospheric neutrino rates for an exposure of 2 Kton year (in case of no oscill. and  oscill. with maximal mixing)

**Expected atmospheric neutrino rates for an exposure of ****2 Kton year** **(in case of no oscill. and**** ******************** ****oscill. with maximal mixing****)**

- Statistics comparable to those obtained with the first generation of water Cerenkov detectors (Kamiokande and IMB)

**Given the clean event reconstruction, **
**the ratio R of “muon like” to “electron **
**like” events can be determined free of **
**large experimental errors**

-  About 60% of CC events contain a
-   proton with kinetic energy >50 MeV
-   in final state
-  Detection of single recoil proton or
-   multi-prong final state will provide
-   a precise determination of the
-   incoming **** energy and direction

-  Almost 50% of the atm. events lies
-   below the Super-Kamiokande thr.
-   (plepton=400 MeV)
-             ICARUS can really contribute
-             to the understanding of the
-             low energy part of the atm.
-             **** spectrum

## Difference in the rates of upward and downward going atm. neutrino events

**Difference in the rates of upward and downward going atm. neutrino events**
**for a 2 Kton year exposure**

** ****Quite evident deficit of upward going “muon like” events,**
** ****for the range of osc. parameters allowed by SK  measurements**

## Atmospheric  events

**E******** = 370 MeV**

**P******** = 250 MeV**

**T****p**** = 90 MeV**

**** quasi-elastic interaction

**E******** = 450 MeV**

**P****e**** = 200 MeV**

**T****p**** = 240 MeV**

****e quasi-elastic interaction

- 90 cm

- 90 cm

- 

- p

- e

- (simulated  event)

- 100 cm

- 90 cm

- p

- e

- (simulated e event)

- O. Palamara - LNGS

- Sept. 10th 2001

## Cosmic ray event containing a hadronic interaction vertex

- providing an “Atmospheric neutrino”-_**like**_ topology

** ****10 m****3**** test @ LNGS: Run 641 - Evt 14 (Apr. 14th, 2000)**

**1**

**5**

**3**

**2**

**4**

**4**

**3**

**5**

**2**

**1**

- vertex

- vertex

-  Trk. 1 - m.i.p.
- 	E**dep**= 31 MeV
- 	L**trk**~ 18 cm
-  Trk. 2 – heavily i.p.
- 	E**dep**=  191 MeV
- 	L**trk**~ 53 cm
-  Trk. 3 - m.i.p.
- 	E**dep**= 105 MeV
- 	L**trk**~ 60 cm
-  Trk. 4 -  heavily i.p.
- 	E**dep**= 42 MeV
- 	L**trk**~ 16 cm
-  Trk. 5 - m.i.p.
- 	E**dep**= 111 MeV
- 	L**trk**~ 60 cm

- 2D view

- 2D view

- Preliminary analysis

- O. Palamara - LNGS

- Sept. 10th 2001

## 3D reconstruction

** ****10 m****3**** test @ LNGS: Run 641 - Evt 14 (Apr. 14th, 2000)**

- O. Palamara - LNGS

- Sept. 10th 2001

## x + e --> x + e 

-  Sensitive to **8****B **component of the
-    Solar ****Spectrum

******Elastic Scattering on **
**   ****Atomic Electrons:**
******x**** + e --> ********x**** + e**** **

-  Two reactions can be exploited
-     for Solar model
- independent studies

**GT: Gamow-Teller**
**F  : Fermi**

- One primary e-track (above threshold)
- +
- M secondary e-tracks from Compton conversion
- of K* de-excitation gamma’s

- One isolated e-track (above threshold)
- with high angular correlation to the Sun
- direction

**&**

- Solar neutrino Physics

- with ICARUS T600

- _Inputs:_
-  BP98 **** Flux (**8****B**)
-  Ar nuclear shell
-   model calculation
-   and measures
-   on mirror nucleus
-  **n** meas. @ LNGS
-  ****** **meas. @LNGS

***T******thr******(e) = 5 MeV******   ***
- (limited by background)

- (Relatively) High Statistics available and reduced background,
-  depending on the actual energy threshold:

- Event rates for an exposure of
- 1 Kton year

- No oscillation hypothesis

- O. Palamara - LNGS

- Sept. 10th 2001

## Full MC simulation for determination of:

-  Signal (ES, F and GT reactions)
-    detection efficiency
-  Background rejection power
-  Sample contamination

- _Full MC simulation for determination of:_

- ES Channel              453
- Background               14
- F+GT Contamination  11

- F+GT Channel          1616
- Background                55
- ES Contamination       17

- 1 Kton X year
- Exposure

**The off-line selection between elastic and absorption events is based on **_**the energy of the main electron (primary track, above 5 MeV) **_**and on the **_**total associated energy **_**and **_**multiplicity **_**of **_**secondary tracks **_**(Compton)**

-  **all cuts imposed**

## Real Event recorded with 50lt ICARUS Prototype

- 5.6 MeV e-Track

- End-point

- (Gamma source)

- O. Palamara - LNGS

- Sept. 10th 2001

## the primary vertex 

**A *****Montecarlo event (Absorption***** reaction)**

**E ****primary electron track**** ****= ****6700 keV**
**Associated Compton energy= ****2140 KeV**
**Multiplicity of secondary tracks= ****3**

- Compton activity
- limited to volume of
- about 50 cm radius
- around
- the primary vertex

**Assumed threshold for single Compton electron  150 KeV**

- O. Palamara - LNGS

- Sept. 10th 2001

## 1 m

**1 m**

**0.5 m**

-  e-like track
- ~6.5 MeV

- End-point

-  2 e-like spots
- from Compton
- conversion

** ****T600 test @ Pv: Run 785 - Evt 4 (July 22nd, 2001)**

- 2

- 4

- 6

- 12

- 18

**Drift Coord. (m)**

- Zoom view

- ~800KeV

- ~800KeV

-  Cosmic ray event containing a “Solar neutrino”-_**like**_ signature
-        “inverse **** reaction” type with:

**Wire Coord. (m)**

- Preliminary analysis

- O. Palamara - LNGS

- Sept. 10th 2001

## Conclusions

-  The ICARUS Technology is now fully operational at experimental
-    scale _(T600 detector has been tested on surface over 100 days)_
-  After many years of technological development, it may start acting
-   as a new, high resolution, real-time  “player” in the Solar and
-   Atmospheric **** “games” (after installation in the GranSasso
-   underground site)
-  Detection of atmospheric ********, ******e** (********) – CC+NC – interactions down
-   to the production threshold
-  Two solar-****reactions in LAr are available, well separated in
-   signature and  available at rather large statistics for SSM model
-   independent  study
-  Possibility of enlarging the LAr mass at GS are under evaluation

-  to find more about the physics programme of the T600: LNGS-P28/2001 and
-     LNGS-EXP 13/89 add. 1/01 (March 2001)
-  to find more about solar neutrino physics with Icarus: **N.I.M.** A455 (2000), 376.
-  to find more about ICARUS: *www.aquila.infn.it/icarus* or *www.cern.ch/icarus*

- O. Palamara - LNGS

- Sept. 10th 2001