Uncovering neutrinos from cosmic ray factories: the Multi Point Source method

We present a novel method for the search of high energy extraterrestrial neutrinos in extended regions. The method is based on the study of the spatial correlations between the events recorded by neutrino telescopes. Extended regions radiating neutrinos may exist in the Galaxy due to the hierarchical clustering of massive stars, the progenitors of all the Galactic accelerators known so far. The neutrino emission associated to such extended regions might be faint and complex due to both the escape of cosmic rays and the intricate distribution of gas in the environment of the accelerators. We have simulated extended neutrino emission over an area of 10deg x 10deg, where the intensity fluctuations across the region are modelled as a Gaussian random field with a given correlation structure. We tested our proposed method over realizations of this intensity field plus a uniform random field representative of the spatial distribution of the atmospheric neutrino background. Our results indicate that the method proposed here can detect significant event patterns that would be missed by standard search methods, mostly focused in the detection of individual hot spots.Comment: 8 pages, 16 figures, accepted for publication in Astroparticle Physic

Are both BL Lacs and pulsar wind nebulae the astrophysical counterparts of IceCube neutrino events?

IceCube has recently reported the discovery of high-energy neutrinos of astrophysical origin, opening up the PeV (10^15 eV) sky. Because of their large positional uncertainties, these events have not yet been associated to any astrophysical source. We have found plausible astronomical counterparts in the GeV -- TeV bands by looking for sources in the available large area high-energy gamma-ray catalogues within the error circles of the IceCube events. We then built the spectral energy distribution of these sources and compared it with the energy and flux of the corresponding neutrino. Likely counterparts include mostly BL Lacs and two Galactic pulsar wind nebulae. On the one hand many objects, including the starburst galaxy NGC 253 and Centaurus A, despite being spatially coincident with neutrino events, are too weak to be reconciled with the neutrino flux. On the other hand, various GeV powerful objects cannot be assessed as possible counterparts due to their lack of TeV data. The definitive association between high-energy astrophysical neutrinos and our candidates will be significantly helped by new TeV observations but will be confirmed or disproved only by further IceCube data. Either way, this will have momentous implications for blazar jets, high-energy astrophysics, and cosmic-ray and neutrino astronomy.Comment: 13 pages, 8 figures, accepted for publication in the Monthly Notices of the Royal Astronomical Society. Abstract shortened to comply with journal limit, no other change mad

Meat consumption: Trends and quality matters

peer-reviewedThis paper uses quality theory to identify opportunities for the meat sector that are consistent with trends in meat consumption. Meat consumption has increased and is likely to continue into the future. Growth is largely driven by white meats, with poultry in particular of increasing importance globally. The influence of factors such as income and price is likely decline over time so that other factors, such as quality, will become more important. Quality is complex and consumers' quality expectations may not align with experienced quality due to misconception of certain intrinsic cues. Establishing relevant and effective cues, based on extrinsic and credence attributes, could offer advantage on the marketplace. The use of extrinsic cues can help convey quality characteristics for eating quality, but also for more abstract attributes that reflect individual consumer concerns e.g. health/nutrition, and collective concerns, e.g. sustainability. However, attributes are not of equal value to all consumers. Thus consumer segmentation and production differentiation is needed.The authors acknowledge the financial support of the Irish Department of Agriculture Food and Marine for funding through their Stimulus Fund for the project entitled “Genetic selection for improved milk and meat product quality in dairy, beef and sheep”: project reference no: 11/SF/311

Two particle states, lepton mixing and oscillations

Discussions of lepton mixing and oscillations consider generally only flavor oscillations of neutrinos and neglect the accompanying charged leptons. In cases of experimental interest like pion or nuclear beta decay an oscillation pattern is expected indeed only for neutrinos if only one of the two produced particles is observed. We argue that flavor oscillations of neutrinos without detecting the accompanying lepton is a peculiarity of the two-particle states $|l\nu>$ produced in pion or nuclear beta decay. Generally, an oscillation pattern is only found if both particles are detected. We discuss in a pedagogical way how this distinction of the neutrinos arises, although on the level of the Lagrangian lepton mixing does not single them out against charged leptons. As examples, we discuss the difference between the state $|l\nu>$ produced by the decay of real $W$ boson and a $W$ originating from pion decay

Gravity with torsion in non-conservative Maxwell-like gauge approach

In this work we take into consideration a generalization of Gauge Theories based on the analysis of the structural characteristics of Maxwell theory, which can be considered as the prototype of such kind of theories (Maxwell-like). Such class of theories is based on few principles related to different orders of commutators between covariant derivatives. Their physical meaning is very simple, and lies in stating that the local transformations of a suitable substratum (the space-time or a particular phase space) and the imposed constraints define a "compensative mechanism" or the "interaction" we want to characterize. After a mathematical introduction, we apply this approach to a modified theory of gravity, in which the algebra of operators of covariant derivatives leads to an additional term in the equation of motion associated with the non-conservation of the energy-moment tensor. This offers the possibility to include, without ad hoc physical assumptions and directly from the formalism, new forms of coupling between matter and energy and the expression of the mixing between gravity and torsion.Comment: 13 pages, accepted for publication in International Journal of Geometric Methods in Modern Physic