Research

Computing (2001 – Now)

  • 2018 - Now: Working at Cray, as part of the CERL group, in several EU projects (Plan4res, SODALITE).
  • 2017 – Now: Leading the development of the DBCSR library for the Sparse matrix-matrix multiplication.
  • 2018: Organizer of the mini-symposium Tensor Algebra Computation: Implementations and Applications, PASC18 conference, July 3, 2018, Basel (CH).
  • 2017: Porting DBCSR library to ARM architecture, participation at the 1st Isambard hackathon (November 2-3) in Bristol.
  • 2015 – 2016: Improving the MPI communication part of the DBCSR library for the Sparse matrix-matrix multiplication. Work presented at PASC17 conference, Lugano (CH).
  • 2014: Energy measurements of the Cray XC30 Piz Daint at CSCS by using CP2K. Results presented at CUG14, Lugano (CH).
  • 2014: Support of the OpenACC porting of the ICON code at CSCS.
  • 2014: Testing of the Fortran Cray Compiler (CCE) using the CP2K regression test.
  • 2014: Development of an autotuning framework, written in Ruby, within the EU project CRESTA (http://www.cresta-project.eu/).
  • 2013 – 2014: Collaborating to the improve the CRAY Math library libsci (CPU) and libsci_acc (GPU), following the requests by CSCS users. Organizing regular meetings between Cray Math team and CSCS.
  • 2012 – 2014: Support to CSCS users and developers.
  • 2012 – 2014: Improved the library for small matrix multiplication (libsmm), used by CP2K, and porting to Intel Xeon Phi (in collaboration with Intel).
  • 2012 – 2014: Porting of the CP2K application to Intel Xeon Phi (native and offload mode), in collaboration with Intel and CSCS.
  • 2013: Porting of the CP2K application to GPU, in collaboration with CP2K developers, NVIDIA and CSCS.
  • 2013: Contribution to the activities for the preparation to the installation of the hybrid XC30 system Piz Daint at CSCS.
  • 2013: MPI communication analysis of the CP2K-DBCSR code.
  • 2011 – 2013: Porting of the application for likelihood functions evaluation on a memory-distributed system using MPI. Hybrid evaluation with OpenMP and CUDA. Evaluation of the Intel microserver and Intel Single-Chip Cloud (SCC) research chip. Supervised the CERN openlab summer student Ruggero Caravita.
  • 2010 – 2013: Evaluation of the Intel Many Integrated Core (MIC) solution under the collaboration between CERN openlab and Intel. Work presented at CHEP13, Amsterdam (NL).
  • 2010 – 2013: Optimization and parallelization of an application for likelihood functions evaluation used in data analysis. The goal of the project is to develop a benchmark to be used by the CERN openlab group as part of its collaboration with Intel for the evaluation of the new Intel platforms. The parallelization is based on shared memory paradigms (OpenMP, TBB, Cilk Plus). The benchmark was used for the evaluation of the platforms Westmere-EP, Nehalem-EX, Westmere-EX, and Sandy Bridge-EP with good performance and scalability.
  • 2011 – 2012: Work on numerical accuracy of algorithm with floating point operations based on transcendental functions.
  • 2009 – 2012: Collaboration with RooStats project. RooStats is a project to create statistical tools for ROOT built on top of RooFit and distributed in ROOT. It is a joint project between the LHC experiments and the ROOT team. Presented at ACAT10 Conference, Jaipur (India).
  • 2011: Porting of the application for likelihood functions evaluation on GPUs using OpenCL and implementation of the heterogeneous evaluation on CPU/GPU. Work presented at ParCO2011 conference, Ghent (Belgium), and ACAT2011, Uxbridge (UK). Supervised the CERN openlab technical student Yngve Sneen Lindal.
  • 2010: Porting of the application for likelihood functions evaluation on GPUs using CUDA. Work presented at CHEP2010 conference, Taipei (Taiwan), and 12th IEEE International Workshop on Parallel and Distributed Scientific and Engineering Computing, Anchorage (USA). Supervised the CERN openlab summer student Felice Pantaleo. This work is also part of the activity of the MultiCore R&D group at CERN.
  • 2010: Work on parallelization of random number generation using shared memory paradigm. The work was part of the HPC-Europa2 activity based at SARA supercomputing center, Amsterdam (Netherlands). Presented at ACAT10 Conference, Jaipur (India). This work is also part of the activity of the MultiCore R&D group at CERN.
  • 2008 – 2010: Work on Massive Parallelization of data analysis programs using non-standard architectures based on FPGAs. Supervised University of Milan students Matteo Provenzano (Bachelor Thesis) and Lorenzo Dini (Master Thesis).
  • 2009: Configuration of a PROOF cluster (Parallel ROOT Facility) at Milan Atlas Tier3.
  • 2008 – 2009: Work on parallelization of data analysis programs using Message Passing Interface (MPI). This work is particularly interesting for CPU-time consuming fitting programs (based on minimization functions algorithm, such as MINUIT) and it aims to be as general as possible for different purposes. I started this work during my training period at the CINECA HPC group, in collaboration with Lorenzo Moneta (ROOT team, CERN). I presented the results at ACAT08 Conference, Erice (Italy), and an update at CHEP09, Prague (Czech Republic). The last implementation of the code is part of the ROOT release (since release 5.24). This work was also part of the activity of the MultiCore R&D group at CERN.
  • 2001 – 2009: Development of an unbinned maximum likelihood fit program, written in C++ language and based on ROOT and RooFit classes from CERN. The program is an advanced tool used in all published Babar Milan group analyses. It provides a user-friendly interface for general data analysis of B decay measurements. The development of the program was an important part of my activity during the Master Thesis and PhD.
  • 2007: Work as Physics Software Coordinator at Babar experiment (activity based at SLAC). The work consisted on maintenance and optimization of tools for data analysis and data reconstruction. Organized a mini-workshop on RooFit (http://www.slac.stanford.edu/BFROOT/www/doc/Workshops/2007/BaBar_RooFit/Agenda.html).
  • 2003: Activity as coordinator of the BaBar Italian Computing Farm for data reprocessing (at Padua, Italy).

Atlas Particle Physics Experiment (2008 – 2010)

  • 2009 – 2010: Extraction of resolutions of vertex reconstructions in data and MC. Use these values to extract the corrections to apply to MC for systematic studies. Vertex reconstruction is a key factor for the b-tagging.
  • 2008 – 2009: Work on Tool for MC Corrections, inside the Physics Analysis Tools (PAT) group.

BaBar Particle Physics Experiment (2001 – 2012)

  • 2001 – 2002 (Master Thesis): Measurement of branching fractions, direct CP asymmetry, and first measurement of Time Dependent CP violation in the B meson decay to η′K. Presented by F. Palombo, on behalf of the BaBar Collaboration, at PASCOS03, January 3 – 8, 2003, Mumbai (India), and published in Physical Review Letters (Phys. Rev. Lett. 91, 161801 (2003)).
  • 2003: Measurement of branching fractions and direct CP asymmetry of B decays to ηK and ηπ. Presented at XXXVIII Rencontres de Moriond on QCD and High Energy Hadronic Interactions, March 22 – 29, 2003, Les Arcs, Savoie (France), and published in Physical Review Letters (Phys. Rev. Lett. 92, 061801 (2004)).
  • 2003: Measurement of the upper limit of B meson decay to η′ϕ. Presented at XXI International Symposium on Lepton and Photon Interactions at High Energies, August 11 – 16, 2003, Fermilab, Illinois (USA) (arXiv:hep-ex/0309038).
  • 2004: Measurement of branching fractions, direct CP asymmetry, and Time Dependent CP violation of the B meson decay to η′K. Presented at ICHEP 2004, August 16 – 22, 2004, Beijing (China), and published in Physical Review Letters (Phys. Rev. Lett. 94, 191802 (2005)). Improved the Time Dependent measurement reconstructing more modes and improving the selection efficiency. Supervised the BaBar Milan student Giordano Cerizza (Master Thesis).
  • 2005: Measurement of Time Dependent CP violation of B meson decay to η′K0L. Presented at International Europhysics Conference On High-Energy Physics (HEP 2005), July 21 – 27, 2005, Lisbon (Portugal) (arXiv:hep-ex/0507087).
  • 2006: Measurement of branching fractions in radiative B decays to ηKγ and search for B decays to η'Kγ. Published in Physical Review D (Phys. Rev. D74 (2006) 031102). Supervised the BaBar Milan student Simone Stracka (Bachelor Thesis).
  • 2006: Search for B meson decays to η'η'K. Published in Physical Review D (Phys. Rev. D74 (2006) 031105). Supervised the BaBar Milan student Riccardo Pellegrini (Master Thesis).
  • 2006: Searches for B decays to ηK0, ηη, ηϕ, and η'ϕ. Published in Physical Review D (Phys.Rev. D74 (2006) 051106).
  • 2006 (PhD Thesis): Observation of CP violation in B0 to η' K0 decay. Presented by myself at ICHEP 2006, July 26 – August 2, 2006, Moscow (Russia), and published in Physical Review Letters (Phys. Rev. Lett. 98 (2007) 031801, Editors' Suggestion). This measurement is the first observation of CP violation asymmetry in b→s decay modes (loop dominated decays) and puts important constraints on New Physics effects.
  • 2008: Measurement of branching fraction and first measurement of Time Dependent CP violation of the radiative B meson decay to ηKγ (published on Phys. Rev. D79 (2009) 011102).
  • 2008: Update of measurement of the Time Dependent CP violation in B0 to η' K0 decay, presented at ICHEP 2008, July 29 – August 5, 2008, Philadelphia (USA), and published on Phys. Rev. D (Phys. Rev. D79 (2009) 052003). Supervised the BaBar Milan student Pietro Biassoni (Master Thesis).
  • 2008 – 2009: Update of the search for B0 to ηK0, ηη , ηf , η'ϕ, ηω , η'ω decays and update of measurements of branching fractions and direct CP asymmetry violation of B meson decays to ηK, η′K, ηπ, η′π decays. Results have been presented at EPS2009 Conference, July 16 – 22, 2009, Krakow (Poland), and published on Phys. Rev. D (Phys. Rev. D80 (2009) 112002).
  • 2008 – 2009: Search for B neutral 3-body decays to modes with 2 K0S in the final states: π0 K0S K0S, η K0S K0S, η' K0S K0S. Results have been published on Phys. Rev. D (Phys. Rev. D80 (2009) 011101). Supervised the BaBar Milan student Francesco Cerutti (Master Thesis).
  • 2010 – 2012: Section writer of the section “sinϕ1 from Charmless Two-body and Quasi-Two body decays” of the Physics of the B Factories, published in 2014 (arXiv:1406.6311).