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Vincent, A. C., Scott, P., & Trampedach, R. (2013). Light bosons in the photosphere and the solar abundance problem. Mon. Not. Roy. Astron. Soc., 432(4), 3332–3339.
Abstract: Spectroscopy is used to measure the elemental abundances in the outer layers of the Sun, whereas helioseismology probes the interior. It is well known that current spectroscopic determinations of the chemical composition are starkly at odds with the metallicity implied by helioseismology. We investigate whether the discrepancy may be due to conversion of photons to a new light boson in the solar photosphere. We examine the impact of particles with axion-like interactions with the photon on the inferred photospheric abundances, showing that resonant axion-photon conversion is not possible in the region of the solar atmosphere in which line formation occurs. Although non-resonant conversion in the line-forming regions can in principle impact derived abundances, constraints from axion-photon conversion experiments rule out the couplings necessary for these effects to be detectable. We show that this extends to hidden photons and chameleons (which would exhibit similar phenomenological behaviour), ruling out known theories of new light bosons as photospheric solutions to the solar abundance problem.
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Verdu-Andres, S., Amaldi, U., & Faus-Golfe, A. (2013). CABOTO, a high-gradient linac for hadrontherapy. J. Radiat. Res., 54, 155–161.
Abstract: The field of hadrontherapy has grown rapidly in recent years. At present the therapeutic beam is provided by a cyclotron or a synchrotron, but neither cyclotrons nor synchrotrons present the best performances for hadrontherapy. The new generation of accelerators for hadrontherapy should allow fast active energy modulation and have a high repetition rate, so that moving organs can be appropriately treated in a reasonable time. In addition, a reduction of the dimensions and cost of the accelerators for hadrontherapy would make the acquisition and operation of a hadrontherapy facility more affordable, which would translate into great benefits for the potential hadrontherapy patients. The 'cyclinac', an accelerator concept that combines a cyclotron with a high-frequency linear accelerator (linac), is a fast-cycling machine specifically conceived to allow for fast active energy modulation. The present paper focuses on CABOTO (CArbon BOoster for Therapy in Oncology), a compact, efficient high-frequency linac that can accelerate C6+ ions and H-2 molecules from 150-410 MeV/u in similar to 24 m. The paper presents the latest design of CABOTO and discusses its performances.
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Roman, F. L., Abler, D., Kanellopoulos, V., Amoros, G., Davies, J., Dosanjh, M., et al. (2013). Hadron therapy information sharing prototype. J. Radiat. Res., 54, 56–60.
Abstract: The European PARTNER project developed a prototypical system for sharing hadron therapy data. This system allows doctors and patients to record and report treatment-related events during and after hadron therapy. It presents doctors and statisticians with an integrated view of adverse events across institutions, using open-source components for data federation, semantics, and analysis. There is a particular emphasis upon semantic consistency, achieved through intelligent, annotated form designs. The system as presented is ready for use in a clinical setting, and amenable to further customization. The essential contribution of the work reported here lies in the novel data integration and reporting methods, as well as the approach to software sustainability achieved through the use of community-supported open-source components.
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Davesne, D., Pastore, A., & Navarro, J. (2013). Skyrme effective pseudopotential up to the next-to-next-to-leading order. J. Phys. G, 40(9), 095104–8pp.
Abstract: The explicit form of the next-to-next-to-leading order ((NLO)-L-2) of the Skyrme effective pseudopotential compatible with all required symmetries and especially with gauge invariance is presented in a Cartesian basis. It is shown in particular that for such a pseudopotential there is no spin-orbit contribution and that the D-wave term suggested in the original Skyrme formulation does not satisfy the invariance properties. The six new (NLO)-L-2 terms contribute to both the equation of state and the Landau parameters. These contributions to symmetric nuclear matter are given explicitly and discussed.
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XENON100 Collaboration(Aprile, E. et al), & Orrigo, S. E. A. (2013). The neutron background of the XENON100 dark matter search experiment. J. Phys. G, 40(11), 115201–17pp.
Abstract: TheXENON100 experiment, installed underground at the LaboratoriNazionali del Gran Sasso, aims to directly detect dark matter in the form of weakly interacting massive particles (WIMPs) via their elastic scattering off xenon nuclei. This paper presents a study on the nuclear recoil background of the experiment, taking into account neutron backgrounds from (alpha, n) reactions and spontaneous fission due to natural radioactivity in the detector and shield materials, as well as muon-induced neutrons. Based on MonteCarlo simulations and using measured radioactive contaminations of all detector components, we predict the nuclear recoil backgrounds for the WIMP search results published by theXENON100 experiment in 2011 and 2012, 0.11(-0.04)(+0.08) events and 0.17(-0.07)(+0.12) events, respectively, and conclude that they do not limit the sensitivity of the experiment.
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Botella-Soler, V., Oteo, J. A., Ros, J., & Glendinning, P. (2013). Lyapunov exponent and topological entropy plateaus in piecewise linear maps. J. Phys. A, 46(12), 125101–26pp.
Abstract: We consider a two-parameter family of piecewise linear maps in which the moduli of the two slopes take different values. We provide numerical evidence of the existence of some parameter regions in which the Lyapunov exponent and the topological entropy remain constant. Analytical proof of this phenomenon is also given for certain cases. Surprisingly however, the systems with that property are not conjugate as we prove by using kneading theory.
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Caroca, R., Kondrashuk, I., Merino, N., & Nadal, F. (2013). Bianchi spaces and their three-dimensional isometries as S-expansions of two-dimensional isometries. J. Phys. A, 46(22), 225201–24pp.
Abstract: In this paper we show that certain three-dimensional isometry algebras, specifically those of type I, II, III and V (according to Bianchi's classification), can be obtained as expansions of the isometries in two dimensions. In particular, we use the so-called S-expansionmethod, which makes use of the finite Abelian semigroups, because it is the most general procedure known until now. Also, it is explicitly shown why it is impossible to obtain the algebras of type IV, VI-IX as expansions from the isometry algebras in two dimensions. All the results are checked with computer programs. This procedure shows that the problem of how to relate, by an expansion, two Lie algebras of different dimensions can be entirely solved. In particular, the procedure can be generalized to higher dimensions, which could be useful for diverse physical applications, as we discuss in our conclusions.
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Andrianopoli, L., Merino, N., Nadal, F., & Trigiante, M. (2013). General properties of the expansion methods of Lie algebras. J. Phys. A, 46(36), 365204–33pp.
Abstract: The study of the relation between Lie algebras and groups, and especially the derivation of new algebras from them, is a problem of great interest in mathematics and physics, because finding a new Lie group from an already known one also means that a new physical theory can be obtained from a known one. One of the procedures that allow us to do so is called expansion of Lie algebras, and has been recently used in different physical applications-particularly in gauge theories of gravity. Here we report on further developments of this method, required to understand in a deeper way their consequences in physical theories. We have found theorems related to the preservation of some properties of the algebras under expansions that can be used as criteria and, more specifically, as necessary conditions to know if two arbitrary Lie algebras can be related by some expansion mechanism. Formal aspects, such as the Cartan decomposition of the expanded algebras, are also discussed. Finally, an instructive example that allows us to check explicitly all our theoretical results is also provided.
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de Azcarraga, J. A., & Izquierdo, J. M. (2013). k-Leibniz algebras from lower order ones: From Lie triple to Lie l-ple systems. J. Math. Phys., 54(9), 093510–14pp.
Abstract: Two types of higher order Lie l-ple systems are introduced in this paper. They are defined by brackets with l > 3 arguments satisfying certain conditions, and generalize the well-known Lie triple systems. One of the generalizations uses a construction that allows us to associate a (2n – 3)-Leibniz algebra pound with a metric n-Leibniz algebra () pound over tilde by using a 2(n – 1)-linear Kasymov trace form for () pound over tilde. Some specific types of k-Leibniz algebras, relevant in the construction, are introduced as well. Both higher order Lie l-ple generalizations reduce to the standard Lie triple systems for l = 3.
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KM3NeT Collaboration(Adrian-Martinez, S. et al), Aguilar, J. A., Bigongiari, C., Calvo Diaz-Aldagalan, D., Emanuele, U., Gomez-Gonzalez, J. P., et al. (2013). Expansion cone for the 3-inch PMTs of the KM3NeT optical modules. J. Instrum., 8, T03006–20pp.
Abstract: Detection of high-energy neutrinos from distant astrophysical sources will open a new window on the Universe. The detection principle exploits the measurement of Cherenkov light emitted by charged particles resulting from neutrino interactions in the matter containing the telescope. A novel multi-PMT digital optical module (DOM) was developed to contain 31 3-inch photomultiplier tubes (PMTs). In order to maximize the detector sensitivity, each PMT will be surrounded by an expansion cone which collects photons that would otherwise miss the photocathode. Results for various angles of incidence with respect to the PMT surface indicate an increase in collection efficiency by 30% on average for angles up to 45 degrees with respect to the perpendicular. Ray-tracing calculations could reproduce the measurements, allowing to estimate an increase in the overall photocathode sensitivity, integrated over all angles of incidence, by 27% (for a single PMT). Prototype DOMs, being built by the KM3NeT consortium, will be equipped with these expansion cones.
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