Nuclear Physics (CSN3)

BGO-OD (BGO-Open Dipole)

The international BGO-OD collaboration is made of about 60 physicists, from Italy, Germany, Russia, UK, Switzerland.

The BGO-OD experiment is focused on the study of the excited states of the nucleon (proton and neutron) and in particular on the search of those nucleon resonances, which have not been observed so far.

It is installed at the ELSA accelerator in Bonn: a polarized photon beam, of energies up to 3 GeV, impinges on a H2 or D2 target and produces photonuclear reactions on the nucleon, whose final products are detected in a large solid angle detector. Example of studied photoreaction are:

1.     Pseudoscalar meson (eta and eta’)photoproduction

2.     Vector mesons(omega and phi) photoproduction

3.     Associated strangeness photoproduction K+ Lambda photoproduction

4.     K0 Lambda photoproduction

5.     K0 Sigma+ photoproduction

6.     Excited hyperon photoproduction

7.     K photoproduction

More details on the physics can be found  in the BGO-OD site 

The central part of this detector, made of a high energy resolution BGO electromagnetic calorimeter, a barrel of scintillator bars and two cylindrical MWPCs, the cryogenic target and the forward MRPC detector, are entirely under the responsibility of the Italian collaboration (Roma Tor Vergata, Pavia, Roma1-ISS, LNF, Messina, Torino).

Some Italian members of the collaboration are also involved in the A2 experiment at the MAMI accelerator in Mainz, which is focused on the same physics at energies up to 1.6 GeV with the use of a polarized beam and a polarized target.

Both the two experiments are part of the CSNIII project MAMBO.




JLAB12 is an INFN experiment in the CSNIII that includes all Italian activities at Thomas Jefferson National Accelerator Facility (USA).

Jefferson Lab is a  laboratory for nuclear physics hosting CEBAF (Continuous Electron Beam Accelerator Facility), a 12 GeV  electron accelerator, and four experimental halls, A to D, equipped with advanced particle detectors.

The goal of the experiment is the study of the structure and dynamics of hadrons and nuclei through the scattering of (longitudinally polarized) 12 GeV electrons on (polarized) fixed nuclear targets.

More than 50 Italian physicists and engineers collaborate with the 1300 researchers of the JLab community to run experiments and carry out a broad program in hadronic physics.

The JLAB12 main research areas are: nucleon and nuclei form factors; nucleon structure functions; electromagnetic and weak electron-hadron interactions; meson spectroscopy; baryon spectroscopy and search for hybrid configurations; physics beyond the Standard Model.
JLAB12 experimental activity is supported by the Italian theoretical physics community that participates with more than 30 researchers in the study of QCD (Quantum Chromo Dynamics), that governs the structure of hadrons, and to the interpretation of experimental results.

The Roma Tor Vergata group is involved in the

1 - Realization and usage of polarized frozen-spin HD targets (HDice)

2 - Purity measurements of HD gas using Raman scattering trachnique

3 - Contribution to the construction of a Forward Tagger for Clas12

4 - Study of photo-production experiments on polarized nucleons

5 - Search for hybrid baryons in kaon electro-production

6 - Search for dark photons in the HPS experiment