Contact Manifolds, Contact Instantons, and Twistor Geometry

Recently, Kallen and Zabzine computed the partition function of a twisted supersymmetric Yang-Mills theory on the five-dimensional sphere using localisation techniques. Key to their construction is a five-dimensional generalisation of the instanton equation to which they refer as the contact instanton equation. Subject of this article is the twistor construction of this equation when formulated on K-contact manifolds and the discussion of its integrability properties. We also present certain extensions to higher dimensions and supersymmetric generalisations.Comment: v3: 28 pages, clarifications and references added, version to appear in JHE

The neutron irradiation module at the European Spallation Source ESS

The neutron Irradiation Module at the European Spallation Source will make use of the high intensity fast neutron spectrum to study the behaviour of the materials used in the facility, set within the ESS research and development program for the target station. By studying how these materials are affected by radiation, estimates of the material degradation in irrradiated bespoke samples will allow to optimise of the design and lifetime of regularly replaced target components. The general design and a set of results from the neutronics calculations, aimed at estimating proton and neutron flux distributions, displacement damage, heat deposition and activation for the radiological hazard analysis of the Irradiation Module, set within the Italian contributions to the ESS construction phase, are reported. © Published under licence by IOP Publishing Ltd

Development of a High Intensity Neutron Source at the European Spallation Source: The HighNESS project

The European Spallation Source (ESS), presently under construction in Lund, Sweden, is a multidisciplinary international laboratory that will operate the world's most powerful pulsed neutron source. Supported by a 3M Euro Research and Innovation Action within the EU Horizon 2020 program, a design study (HighNESS) is now underway to develop a second neutron source below the spallation target. Compared to the first source, located above the spallation target and designed for high cold and thermal brightness, the new source will provide higher intensity, and a shift to longer wavelengths in the spectral regions of cold (2 /- 20 {\AA}), very cold (VCN, 10 /- 120 {\AA}), and ultra cold (UCN, > 500 {\AA}) neutrons. The core of the second source will consist of a large liquid deuterium moderator to deliver a high flux of cold neutrons and to serve secondary VCN and UCN sources, for which different options are under study. The features of these new sources will boost several areas of condensed matter research and will provide unique opportunities in fundamental physics. Part of the HighNESS project is also dedicated to the development of future instruments that will make use of the new source and will complement the initial suite of instruments in construction at ESS. The HighNESS project started in October 2020. In this paper, the ongoing developments and the results obtained in the first year are described.Comment: 10 pages, 10 figures, 14th International Topical Meeting on Nuclear Applications of Accelerators, November 30 to December 4, 2021, Washington, D

One-loop effective actions and higher spins. Part II

In this paper we continue and improve the analysis of the effective actions obtained by integrating out a scalar and a fermion field coupled to external symmetric sources, started in the previous paper. The first subject we study is the geometrization of the results obtained there, that is we express them in terms of covariant Jacobi tensors. The second subject concerns the treatment of tadpoles and seagull terms in order to implement off-shell covariance in the initial model. The last and by far largest part of the paper is a repository of results concerning all two point correlators (including mixed ones) of symmetric currents of any spin up to 5 and in any dimensions between 3 and 6. In the massless case we also provide formulas for any spin in any dimension

M-Branes:Lessons from M2's and Hopes for M5's: LMS/EPSRC Durham Symposium on Higher Structures in M-Theory

In this talk we will review the construction of M2-brane SCFT's highlighting some novelties and the role of 3-algebras. Parts of our discussion will closely follow parts of arXiv:1203.3546. Next we will discuss M5-branes: the basics, the obstacles as well as various attempts to construct the associated SCFT and potential relations between M2-branes and M5-branes.Comment: 16 pages, Contribution to Proceedings of LMS/EPSRC Durham Symposium Higher Structures in M-Theory, August 201