My current neutrino research activities: OPERA and NOMAD


Within the group of prof. Ante Ljubicic at Rudjer Boskovic Institute, I am leading the neutrino oscillation reearch activity.


I am the deputy leader of the Zagreb group (A. Ljubicic, M. Stipcevic, K. Jakovcic, B. Klicek) of the OPERA experiment which takes place in the Gran Sasso Underground Laboratory (LNGS) and at CERN.


Immediately after joining OPERA, our group has been closely involved in prototyping, testing and mounting of full-scale bakelyte RPC's. Testing of the RPC's included work on mechanical testing, determining of U-I characteristics of each RPC module, measuring of efficiency of each channel and low background testing. It was mainly done by Kreso Jakovcic.


During 2005 to 2007 our young members Branimir Zauner, Sasa Micanovic and Ivana Zamboni have worked on development, testing and instalment of glass RPC's (GRPC) intended for VETO of OPERA. In particular they were engaged in building of GRPC prototypes, testing in cosmic rays, measurement of current-voltage characteristics and efficiencies of different GRPC configurations (geometries, gas mixtures...) thus contributing in finding the optimum GRPC construction. After recieving of the first indrustrially made batch of 18 GRPC's, our young scientists have suggested improvements which were implemented in the final version. Finally at the begining of 2007 they have helped installing of the GRPC's in the VETO system and testing of the associated in situ hygrometers.


Later in 2007 and 2008 we have engaged in writing of parts of slow control software and in the ELEDET group. In 2008 our young student Budimir Klicek has started developping his theoretical calculation of CC/NC ratio in OPERA-like target, which resulted in his diploma work at the very beginning of 2009. His prediction for the CC/NC ratio has been sucessfully reproduced by the first 600 events from OPERA. Alternatively, using the CC/NC ratio as derived from OPERA data, it was possible to contribute to the world's average for sin2(.W). Budimir is going to pursue this matter further under the supervision of Mario Stipcevic. He is also preparing an internal note on this topic.


The contribution of Zagreb group in OPERA so far has resulted in co-authoring of 7 scientific papers and one conference poster:

  1. Design and prototype tests of the RPC system for the OPERA spectrometers, NIM A 508(2003)175-180
  2. The OPERA cosmic ray test facility at the Gran Sasso, NIM A 533(2004)221-224
  3. The quality control tests for the RPCs of the OPERA experiment , NIM A 533(2004)203-207
  4. Tests of OPERA RPC detectors, IEEE Transactions on Nuclear Science. 52(2005)2963-2970
  5. First events from the CNGS neutrino bean detected in the OPERA experiment, New J. Phys. 8 (2006) 303(1-17)
  6. Glass Resistive Plate Chambers in the OPERA experiment, POSTER at the XIth Vienna Conference on Instrumentation, Vienna 2007.
  7. Emulsion sheet doublets as interface trackers for the OPERA experiment, Journal of Instrumentation 3(2008) P07005
  8. Study of the effects induced by lead on the emulsion films of the OPERA experiment, Journal of Instrumentation 3(2008) P07002

Plans for 2009 are the following. Budimir will finishing his 3 months long work in ELEDET group in Frascati by May 2009. After that we plan to take part in 16 weeks of various shifts: 8 weeks of ELEDET shifts and 8 weeks of CS shifts. We would like to have the shifs split as follows: 4 ELEDET shifts and 4 CS shifts would be undertaken simultaneously by Budimir Klicek (ELEDET) and Kreso Jakovcic (CS) as soon as CNGS beam is available. The other 4+4 shifts (again simultaneously by Budimir and Kreso) would be taken after summer. We will also continue our CC/NC analysis.



I am the leader of the Zagreb group (...) in the NOMAD experiment at CERN. NOMAD has ended its data-taking phase in 1999. and the final results regarding its main tasks, that is nu_mu -> nu_tau and nu_mu -> nu_e oscillations have been published. However, we are still doing analisys of NOMAD data in search for interesting physics not necesarrily connected to neutrino oscillations.