Last Update: October 2000

MONOLITH-RD

Collaboration
Berlin, Bonn, Hamburg, Muenster, Bologna, LNF, LNGS, Milano, Napoli, Torino,INR (Moscow), MEPhI
(Moscow), Frescati (Stockholm), Columbia University
Laboratory and beam: Laboratori Nazionali del Gran Sasso and atmospheric neutrino beam
1. Goal of the experiment
MONOLITH is a proposed experiment on atmospheric neutrinos at the Gran Sasso laboratory in Italy. The detector would consist in a massive (34 kt) magnetized tracking calorimeter, optimized for the detection of atmospheric muon neutrinos. The main goal is to establish (or reject) the neutrino oscillation hypothesis through an explicit observation of the full first oscillation swing. Oscillations will be discriminated against alternative hypothesis like decay or decoherence The sensitivity range for this measurement comfortably covers the full Dm2 (square of the mass difference of the two neutrinos involved in the oscillation) region allowed by the Super-Kamiokande experiment. Other measurements include studies of matter effects, the neutral currents up/down ratio, the neutrino/antineutrino ratio, the study of cosmic ray muons in the multi-TeV range, and auxiliary measurements from the CERN to Gran Sasso neutrino beam. Depending on approval, data taking with part of the detector could start towards the end of 2004.
2. Physics achievements during 2000
In the year 2000 the principles of the MONOLITH experiment have been proven. It was shown that a detector with the proposed design will be able to observe the first oscillation period and discriminate the oscillation from alternative hypothesis: decay or decoherence. The time resolution of the proposed detector components (glass RPCs) was also measured in a dedicated run; it was shown that the resulting up/down discrimination is sufficient to reduce the cosmic ray background to a negligible level. The proof of the principles and the demonstration of the existence of a suitable technique led the collaboration to submit an Experiment Proposal to the Scientific Committee of the LNGS.
3. INFN contribution to the experiment in terms of manpower and financial support
- 9 full-time equivalent physicists and 5 technicians from INFN groups were involved in MONOLITH R&D in the year 2000.
- In the year 2000 MONOLITH was funded by INFN as R&D. Total financial support was 330 MLit
4. Number of publications in refereed journals: 0
5. Number of talks to conferences: 5
6. Number of undergraduate and doctoral thesis on the experiment:
- n.1 Ph.D.;
- n.4 graduates (Laurea thesis)
7. Leadership of the experiment
The spokesman of the experiment is Stefano Ragazzi of the Milano group. Four out of five members of the Executive Committee are from Italian INFN groups.
8. Innovative instruments:
In the R&D phase the collaboration is developing glass RPCs. Glass RPCs cannot withstand a high particle rate per unit area,but in a low rate environment –as a cosmic ray experiment- they represent a very promising detector technique: high space resolution, down to 1 mm, depending on read-out pitch, time response better than 1 ns, and low cost per unit area(MONOLITH aims to large-scale industrial production at a cost around 200 kLit, 100 $, per square meter).
9.Competing experiments
Competing experiments are Super-Kamiokande in Japan, running since 1996, and MINOS on the NUMI long baseline neutrino beam from Fermilab, which is foreseen to start data taking in fall 2003. Concerning the main goal of MONOLITH –detection of the oscillation pattern- Super-Kamiokande is most likely limited by resolution, while MINOS will not cover the lower Dm2 values allowed by Super-Kamiokande.
10.International committee that has reviewed the experiment
The experiment proposal has been submitted and reported to the Scientific Committee of Laboratori Nazionali del Gran Sasso (LNGS).