Past activities

MACRO

MACRO was a large area experiment located in the Gran Sasso National Laboratories near L'Aquila (central Italy). Its main goals were the search for magnetic monopoles in the cosmic radiation, the study of the cosmic rays by measuring the underground muons, the detection of neutrinos produced in a gravitational collapse of a star, the search for astronomical sources of high energy neutrinos, the study of the neutrino oscillations, the search for exotic particles (Strange Quark Matter, fractional charges).

During my degree thesis, in 1990-1991, I was interested in the study of the underground muons and in the primary cosmic ray composition models. In particular I developed simulation programs allowing the comparison of the predictions of various composition models with the real data.

During my PhD Thesis, from 1992 to 1994, and later on till the shutdown of the experiment (in December 2000) I worked instead in the search for magnetic monopoles predicted by the Grand Unification Theories, and in particular about a possible interaction mechanism with matter able to produce the nucleon decay. Also in this case my research work consisted mainly in the development of simulation programs of both the physical process, by means of a detailed description of the decay process, and the detector and in particular of the limited streamer tubes and their acquisition electronics. I devoted also to the real data analysis, developing a dedicated analysis technique aimed to the detection of a nucleon decay event determined by the passage of a magnetic monopole. The upper limits to the monopole flux obtained in this way are the result of my PhD thesis, and the following updates and improvements were presented in many international conferences on behalf of the MACRO Collaboration.

NA50

NA50 was an experiment hosted in the European Organization for Particle Research (CERN) near Geneva, Switzerland, and dedicated to the study of the heavy ion interactions. Its main goal was the measure of the number and the characteristics of the J/Psi particles produced in the Lead-Lead interactions. It was a "fixed target" experiment: a beam of Pb ions produced by the SPS accelerator collided with a thin Pb sheet placed immediately before the detector. Although the detector finished taking data in 2001, the data analysis was in progress for a certain time later.

I began my research activity in the NA50 Collaboration in 1996 with the Torino group, which was involved in the Multiplicity Detector. The first work was the development of a Linux driver to pilot a CAEN A303 card. This card allowed to interface a low- and high-voltage power supply, located near the detector about 80 meters deep, with a PC in the control room at surface. With a working Linux driver I was then able to develop a monitoring program to be used also remotely: in this way the control of the Multiplicity Detector power voltages was possible also to users connected from Torino and not physically present in the control room (as it was before with the old DOS program).

I then participated to the analysis of the real data collected with the Multiplicity Detector, in order to detect the peculiar state of matter know as Quark-Gluon Plasma, by means of the measure of the J/Psi suppression (here there is an introduction to this argument). In particular I worked in the development of simulation programs of the Multiplicity Detector, to adapt them to the different data taking configurations. Moreover I was involved in the simulation of the Electromagnetic Calorimeter located after the Multiplicity Detector, whose data were essential in the study of supposed asymmetries in the particle flow.

GPCALMA and MAGIC5

The GPCALMA (Grid Platform for CALMA) project was aimed to develop a software to analyse a distributed database of digital mammographic images minimizing the data transfer thanks to the use of the technology developed by the great particle physics experiments. The previous project CALMA (Computer Assisted Library in MAmmography) finalised a workstation to digitise, report and archive mammographic images, implementing also a software for an automated analysis based on neural networks which was able to detect massive damages and microcalcifications. In this case the data collection is intrinsically distributed, and the current computer networks available between different hospitals cannot afford a centralised approach. The development of distributed computing infrastructures by the great high energy physics experiments finds here a very interesting application.

Inside this project I cooperated with researchers of Alessandria, Torino and Cuba to apply the software developed inside the Alice experiment, in particular ROOT, PROOF e AliEn. The goal was to realize a meta-catalog of mammographic images and to analyse them remotely both to allow a physician to obtain a "consultation-at-a-distance" with a colleague, and to make available a vast "library" of mammographic images to students and researchers.

Present activities

ALICE

ALICE is a heavy ion detector at the LHC, the Large Hadron Collider CERN at CERN in Geneva.

In this Collaboration at present I am involved in different topics. One is the study of cosmic ray muons with the Alice detectors, to determine with a great precision their properties (like momentum, positive to negative muon ratio, and so on). At present some colleagues from Torino and the University of Puebla (Mexico) and me developed analyses and simulations which allowed us to analyze the data collected during Run 1 (2009-2012). The results of this analysis were published in an international physics review. A second article with the data fo Run 2 (2015-2018) is in preparation.

The second argument is in the area of the GRID project, which has the aim of creating networks of computers to deal with the huge amount of data the LHC experiments will collect. Similar problems are present also in other research fields, such as Meteorology (and in general the Earth observation by satellite), Biomedicine, and other areas where it is necessary to store and analyse great amounts of data. No single research centre is or will be able to do that by itself, so innovative computing tools are needed. In particular I managed a computing farm (which included four servers, about 40 clients and some disk servers) used to produce simulated events. Since 2017 this physical farm was gradually dismantled and replaced with a virtual farm dynamically employing resources from the Torino cluster, Since the very beginning I contributed to the configuration of this new farm, and to this day I follow its maintenance. Moreover since October 2023 I was appointed as National Manager of the Computing Resources for the Italian part of the ALICE Collaboration.

I was also the person in charge of handling the geometry description of the previous Inner Tracking System (ITS) in the Offline group (dealing with the development of the experiment simulation and analysis software). I organized the working group developing the ITS description, and I personally took care of the code for the Silicon Drift Detector (SDD).

As an extension of this activity, since 2011 I am also a member of the working group which designed an Upgrade of the ITS. Besides developing software myself, I organized the activities of a working group devoted to the geometry description of the new ITS. Currently I take care of the geometry code and organize the work of those members who actually develop it.

Lastly, I was also in charge of the data acquisition for the SDD subdetector as Subsystem Run Coordinator. For this reason in 2008 and 2009 I spent two 6-month leave of absence periods at CERN to organize the detector's revision and the test of its acquisition and online control systems during the data taking, even as on-call shifter for urgent operations in case of SDD hardware problems. In the following years I spent other more or less long periods at CERN (the last leave from July 2018 to September 2019). During the last one I also dealt with monitoring and quality assurance of the modules later mounted on the new ITS. I also take central shifts in the experiment control room during the data taking periods.

Last Update: 09 May 2024 - (C) Mario Sitta, Alessandria, Italy