Statements - Presence at CERN for 60% of the time, taking into account the lower presence rate correlated with the 2.5 month teaching. - Availability to work for COMPASS 100%. - Short term goals: The past years were devoted to the data taking of a larger sample of Primakoff data in 2012 and to prepare for the other measurements on which the Collaboration was and is committed (DY, DVCS and SIDIS). This was perused by bringing the MoU to signature in early 2013 and by including in this MoU common projects for tasks that couldn t be assigned to specific institutes. In the next two years the focus will be devoted to carry on successfully the planned measurements and to prepare prepare for extra data taking time, if needed to complete the approved program. - Long term goals: In 2013 the Collaboration sent to the European Preparatory Strategy Groups ideas for physics topics that constituted a natural continuation of our mainstream physics, both for structure and for spectroscopy. It will be crucial to check if we will be able to bring these ideas (as well as others that may arrive) forward as a new proposal, and have the needed strength to update a large part of our experiment. The development of this long term strategy, that by far don t concerns only spokesperson, is also the only way in our hands to attract new collaborators. 1
Curriculum Vitæ Name: Andrea Bressan Date and place of birth: July 19, 1964 Gorizia, Italy Nationality: Italian Marital Status Married Education: University degree at the University of Trieste, a.y. 1989/90. Title of the thesis: Study of the reaction pp nn at the CERN LEAR: problems connected with the detection of two neutral particles in the final state. PhD degree discussing a thesis with the title Measurement of the cross-section of the pp nn reaction at LEAR, Rome, a.y. 1993/94. Working positions and responsibilities: Assistant Post Doctorat at the Département de Physique Nucláire et Corpuscolaire (DPNC), University of Geneve, from May 1, 1995 to June 30, 1996. Research Fellow at CERN from May 1, 1997 to August 31 1999, working on GEM development within the Gas Detector Development team lead by F. Sauli. Post Doctoral at the Max Plank Institute of Heidelberg from September 1999 till August 2000. Position left at the start of the contract with the University of Trieste. University Researcher at the University of Trieste from January 2000. CERN Associate from February 1 st 2007, till January 31, 2008. Analysis Coordinator of the COMPASS experiment from the 1 st of January 2007 to the 31 of January 2008. Member of the COMPASS Publication Committee from December 2007 till April 2011. 2
Convener of the Spin Physics working group with Elke Aschenauer (Jlab), Andreas Metz (Temple), and Bernd Surrow (MIT)) for the XVI International Workshop on Deep- Inelastic Scattering and Related Subjects, DIS 2008, 7-11 April 2008, University College London. Spokesperson of the COMPASS experiment together with Fabienne Kunne since April 2011. Member of the International Program Committee of the 3 rd Workshop on the QCD structure of the nucleon (QCD-N 12), 22-26 October, Bilbao, Spain. Member of the International Advisory Committed of the 10 th European Research Conference on Electromagnetic Interactions with Nucleons and Nuclei (EINN2013). Convener of the session Spin Structure of Nucleon (transverse) with Alexei Prokudin and Zuo-Tang Liang for the Conference Spin2014 The 21 st International Symposium on Spin Physics October 20-24, 2014, Beijing, China. Member of the International Advisory Committed of 11 th European Research Conference on Electromagnetic Interactions with Nucleons and Nuclei (EINN2015). Research Activities: The Research Activities are organised according to the arguments. Study of the pp nn reaction at LEAR (1991-1996) Experiment PS199: The main purpose of this experiment was the measurement of the analysing power A 0n of the charge-exchange reaction pp nn at different energies (8) of the incident antiproton beam, between 600 and 1300 MeV/c. Together with A 0n, results have also been obtained for the depolarisation D 0n0n and for the spin transfer K n00n parameters for respectively 2 and 1 energy only, given the needs of a much larger statistics connected with these two measurements. The measurements of quantities connected with the spin dependent part of the cross-section are mandatory in order to fix the large number of parameters needed in the potential models used to describe the NN interaction. Simulation of the neutral particle veto system. Measurement of the efficiency of the neutron detectors. In charge of the Monte Carlo simulation of the anti-neutron detectors. Experiment PS206: The main objective of the PS206 experiment was the measurement of the pp nn chargeexchange differential cross-section, with a point-to-point precision of better than 1% and and overall absolute normalisation of 3%. The reached precision has allowed to extract the pion-nucleon coupling constant f πnn for the first time by using this reaction only. In charge of the tracking of the beam by MWPC. Measurements of the efficiencies of the neutron and anti-neutron detectors. Systematics and stability checks. Data analysis to extract of the pp nn differential cross-section. 3
Estimation of all the corrections and systematic effects needed in the extraction of the cross section. Experiment SMC The CERN SMC experiment has studied the spin structure of the nucleon. It has performed measurements of g 1 and its first moment Γ 1 both with a longitudinally polarised proton and longitudinally polarised deuteron target, using a naturally longitudinally polarised 190 GeV µ + beam, allowing the first experimental verification of the Bjorken sum rule, confirming the early EMC founding of the smallness of the Σ the quark contribution to the nucleon spin. Also g 2 has been measured, together with semi-inclusive measurements. management of the MWPC telescope of the beam polarimeter. Experiment COMPASS (1997...) On this experiment I ve work both on the hardware (GEM and RICH detectors) and on the data analysis; in the following a very short description of the main activities is given. GEM based detectors: In charge of the development design and start of the construction of GEM based detectors, with double x y coordinates read-out for the small area tracking system of the experiment. Optimisation of the GEM active part geometry. Optimisation of the drift electric field, and the field between consecutive GEM and the GEM foil and the collective PCB, in order to increase the efficiency and the total signal visible by the read-out strips. Study of the aging for high integrated charge values. Study of the discharge limits of the detector for x-ray photons, minimum ionising particles and highly ionising particles. Test beams with hadrons both at low and high intensity, with also the responsibility of the data analysis. Optimisation of the pitch and strip width for a bidimentional read out with a 50% charge sharing between x and y strips. Study of the energy correlation between the two signals to reduce the ambiguities at high occupancy. RICH-1 detector: In charge of the C 4 F 10 radiator, and radiator gas system for the RICH-1 detector of COMPASS from 1997 till 2006. The radiator gas C 4 F 10 is 10 times heavier than air, allowing to separate pions, kaons and protons in a momentum interval between 2 and 50GeV/c. Moreover, since the CsI used as photon-converter as a threshold for the photoelectric effect of 250 nm, the transparency of the radiator is an important issue; both the water and the oxygen contaminations have to be kept below 5ppm. The responsibility includes also the pre-cleaning of the gas in order to reach the needed transparency, the constant monitoring during the run and the overall filling/recovery of the gas before and after the run. 4
Refurbishing and installations of the MWPC with CsI photocadodes used as photon detectors in the RICH-1 detector. Monte Carlo studies by using the Garfield and Maxwell packages of the gain performances of these MWPCs used for the Cherenkov photon detection. Data analysis for the characterisation of the RICH-1 detector, mainly concerning the PID efficiency and the average number of detected photons per ring. Development of the event display for the RICH-1 detector. Extraction of the radiator refractive index from the data and creation of relative database of this value needed for the event reconstruction in the DST production. Participation to the design, test-beams and analysis of the collected data (in these test-beams) in view of the upgrade with MAPMT of the central area of the RICH-1 photons detectors. The central 4 out of 16 photocathodes, the one which see the higher rates have been replaced during the 2005 technical stop of all the CERN accelerator complex with a system of lenses and multi-anodes photomultipliers (MAPMT). Participation to the RD51, CERN R&D for the study of fast micro-pattern gaseous detectors for PID applications. The main objective to the participations at this R&D is the development of a thickgem detector with CsI as photocathode to replace the 12 remaining photocathodes. This new technology would allow to reach higher gains a to cope with higher rates. Analysis: Two hadron Collins asymmetries for unidentified hadrons from transversely polarised deuteron target data. Single hadron Collins and Sivers asymmetries for unidentified hadrons from transversely polarised deuteron target data. Preliminary studies for Collins and Sivers asymmetries for identified hadrons on deuteron. Appointed Analysis Coordinator of the COMPASS experiment from January 1 st, 2007. Monte Carlo simulation for the proposal of an extension of the COMPASS experiment to be submitted at the beginning of 2009. Side data analysis for the measurement of the asymmetry of the 2 unidentified hadrons on the transversely polarised proton target. Teaching Activities: Assistant of Prof. X. Artru for the course Polarization longitudinale et transversale dans le réactions inélastiques profondes, given for the 1996 Troisième Cycle de la Physique en Suisse Romande. Assistant of the course Introduction to Nuclear and Sub-Nuclear Physics for the 1 st level Master in Physics of the University of Trieste, from January 2000. Assistant of the course Experimental Nuclear and Subnuclear Physics for the 2 nd level degree in Physics ( Laurea Magistralis in Physics with training tracks in Nuclear and Sub-nuclear Physics) from the academic year 2001/2002. 5
Assistan of the course Fisica I for the 1 st level Master in Physics of the University of Trieste, academic years 1999/2000, 2000/2001 and 2001/2002. Professor of the course of Accelerator Physics for the 2 nd level degree in Physics ( Laurea Magistralis in Physics with training tracks in Nuclear and Sub-nuclear Physics) from the academic year 2001/2002 till the academic year 2005/2006. Professor of the course Laboratorio I for the 1 st level degree in Physics of the University of Trieste, from the academic year 2008 untill now. Miscellaneous: Editor of Spin Physics. Polarised Electron Sources And Polarimeters. Proceedings, 16th International Symposium, Spin 2004, Trieste, Italy, October 10-16, 2004, And Workshop, Pesp 2004, Mainz, Germany, October 7-9, 2004 K. Aulenbacher, F. Bradamante, A. Bressan and A. Martin. Editor of 6th International Workshop on Ring Imaging Cherenkov Counters (RICH2007) Stazione Marittima, Trieste, Italy 15-20 October 2007 Special Issue of Nucl. Instr. Meth. A595, 2008. A. Bressan, S. dalla Torre, B. Gobbo and F. Tessarotto. 6