The main objective of CNNP2017 is to promote a collaborative framework of researchers from the fields of nuclear, neutrino, astro and dark-matter physics to discuss experiments and theories in which nuclear physics aspects are particularly relevant. The overlap between different communities is an unavoidable, despite demanding, feature in order to face several challenges of modern fundamental physics. The sharing of different experimental and theoretical techniques, the exchange of technical experiences and know-how is perhaps the best resource to build a unified view of the afore mentioned scientific problems.
A preliminary list of the topics to be developed during the Conference is below:
At present nuclear structure plays an ever growing role in the mentioned fields of fundamental physics, but still a lot needs to be done. In this context, it is of utmost importance to allow people working at the intersections of these fields to meet regularly to exchange ideas and results. For this reason, the CNNP2017 aims at evolving in the long term into a periodic meeting.
The CNNP2017 conference is hosted jointly by the Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, and the University of Catania.
In this presentation, after a brief historical introduction, I will review the progress made in the last few years in theoretical approaches to the open questions of 1. What is the absolute mass scale of neutrinos 2. Are neutrinos Dirac or Majorana particles  3. How many neutrino species are there After briefly discussing single beta decay and single electron capture as a way to determine the neutrino mass , I will concentrate my attention to neutrinoless double beta decay (DBD). Here, I will first discuss the standard mass mechanism and the associated phase space factors (PSF), G0ν, and nuclear matrix elements (NME), M0ν, appearing in the expression for the inverse half-life showing the current limits on the average neutrino mass, <mν>, obtained with the free value of the axial vector coupling constant, gA=1.269. I will then discuss the present situation for the quenching of the axial vector coupling constant in heavy nuclei, indicating the impact that this quenching may have on experiments and showing results for three scenarios, free value gA=1.269, quark value gA=1.0, and maximal quenching gA=1.269 A-0.18. In the final part of the presentation, I will discuss current work on contributions to neutrinoless DBD of 1. (Hypothetical) sterile neutrinos , light and heavy 2. (Hypothetical) non-standard mechanisms, short-range and long-range In the concluding remarks, and in light of the part of the presentation dealing with sterile neutrino and non-standard mechanisms, I will strengthen the argument for continuing experimental work of neutrinoless DBD.  E. Majorana, Nuovo Cimento 14, 171 (1937)  E. Fermi, Z. Phys. 88, 161 (1934)  B. Pontecorvo, Sov. Phys. JETP 26, 984 (1968)