Extra Higgs Boson and Z′Z' as Portals to Signatures of Heavy Neutrinos at the LHC

In this paper, we discuss the potential of observing heavy neutrino ($\nu_h$) signatures of a $U(1)_{B-L}$ enlarged Standard Model (SM) encompassing three heavy Majorana neutrinos alongside the known light neutrino states at the Large Hadron Collider (LHC). We exploit the theoretical decay via a pair of heavy (non-SM-like) Higgs boson and $Z'$ production followed by $\nu_h \rightarrow l^\pm W^{\mp (*)}$ and $\nu_h \rightarrow \nu_l Z^{(*)}$ decays, ultimately yielding a $3l+2j+E_{T}^{\rm{miss}}$ signature and, depending upon how boosted the final state objects are, we define different possible selections aimed at improving the signal to background ratio in LHC Run 2 data for a wide range of heavy neutrino masses.Comment: 31 pages, 10 figures. arXiv admin note: text overlap with arXiv:1612.0597

Sum-frequency generation of 589 nm light with near-unit efficiency

We report on a laser source at 589 nm based on sum-frequency generation of two infrared laser at 1064 nm and 1319 nm. Output power as high as 800 mW are achieved starting from 370 mW at 1319 nm and 770 mW at 1064 nm, corresponding to converting roughly 90% of the 1319 nm photons entering the cavity. The power and frequency stability of this source are ideally suited for cooling and trapping of sodium atoms

Modeling risk contagion in the Italian zonal electricity market

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Ensuring the security of stable, efficient, and reliable energy supplies has intensified the interconnections between energy markets. Imbalances between supply and demand due to operational failures, congestion, and other sources of risk faced by market connections can lead to a system that is vulnerable to the spread of risk and its spillover. The main contribution of this paper is the development and estimation of a Bayesian Graphical Vector-AutoRegression and a Bayesian Graphical Structural Equation Modelling with external regressors - BG-VARX and BG-SEMX, respectively - enhancing the proper analysis of market connections. The Italian electricity market has been chosen because it is a clear example of a zonal market where risk can spread over connected zones. We estimate, for the first time, within-day and across-day zonal market interconnections with a multivariate time series of hourly prices, actual and forecast power demand, and forecast wind generation over the period 2014-2019 and evaluate the dynamics and persistence of zonal market connections, examining the spread of risk in the zones of the Italian electricity market. Our findings provide an improved, accurate explanation of risk contagion, identifying the zones that are most influential in terms of hub centrality (major transmitters) and authority centrality (major recipients), respectively, for intra-day and inter-day risk propagation in the Italian electricity market. In addition, the policy implications in terms of market monitoring are discussed

Analysis of olive grove destruction by xylella fastidiosa bacterium on the land surface temperature in Salento detected using satellite images

Agricultural activity replaces natural vegetation with cultivated land and it is a major cause of local and global climate change. Highly specialized agricultural production leads to extensive monoculture farming with a low biodiversity that may cause low landscape resilience. This is the case on the Salento peninsula, in the Apulia Region of Italy, where the Xylella fastidiosa bacterium has caused the mass destruction of olive trees, many of them in monumental groves. The historical land cover that characterized the landscape is currently in a transition phase and can strongly affect climate conditions. This study aims to analyze how the destruction of olive groves by X. fastidiosa affects local climate change. Land surface temperature (LST) data detected by Landsat 8 and MODIS satellites are used as a proxies for microclimate mitigation ecosystem services linked to the evolution of the land cover. Moreover, recurrence quantification analysis was applied to the study of LST evolution. The results showed that olive groves are the least capable forest type for mitigating LST, but they are more capable than farmland, above all in the summer when the air temperature is the highest. The differences in the average LST from 2014 to 2020 between olive groves and farmland ranges from 2.8 °C to 0.8 °C. Furthermore, the recurrence analysis showed that X. fastidiosa was rapidly changing the LST of the olive groves into values to those of farmland, with a difference in LST reduced to less than a third from the time when the bacterium was identified in Apulia six years ago. The change generated by X. fastidiosa started in 2009 and showed more or less constant behavior after 2010 without substantial variation; therefore, this can serve as the index of a static situation, which can indicate non-recovery or non-transformation of the dying olive groves. Failure to restore the initial environmental conditions can be connected with the slow progress of the uprooting and replacing infected plants, probably due to attempts to save the historic aspect of the landscape by looking for solutions that avoid uprooting the diseased plants. This suggests that social-ecological systems have to be more responsive to phytosanitary epidemics and adapt to ecological processes, which cannot always be easily controlled, to produce more resilient landscapes and avoid unwanted transformations

Tracking and Structure from Motion

Dense three-dimensional reconstruction of a scene from images is a very challenging task. In the structure from motion approach one of the key points is to compute depth maps which contain the distance of objects in the scene to a moving camera. Usually, this is achieved by finding correspondences in successive images and computing the distance by means of epipolar geometry. In this Master's thesis, a variational framework to solve the depth from motion problem for planar image sequences is proposed. Camera ego-motion estimation equations are derived and combined with the depth from motion estimation in a single algorithm. The method is successfully tested on synthetic images for general camera translation. Since it does not depend on the correspondance problem and because it is highly parallelizable, it is well adapted for real-time implementation. Further work in this thesis include a review of general variational methods in image processing, and in particular TV-L1 optical flow as well as its real-time implementation on the graphics processing unit

Amateur Observers Witness the Return of Venus’ Cloud Discontinuity

Firstly identified in images from JAXA’s orbiter Akatsuki, the cloud discontinuity of Venus is a planetary-scale phenomenon known to be recurrent since, at least, the 1980s. Interpreted as a new type of Kelvin wave, this disruption is associated to dramatic changes in the clouds’ opacity and distribution of aerosols, and it may constitute a critical piece for our understanding of the thermal balance and atmospheric circulation of Venus. Here, we report its reappearance on the dayside middle clouds four years after its last detection with Akatsuki/IR1, and for the first time, we characterize its main properties using exclusively near-infrared images from amateur observations. In agreement with previous reports, the discontinuity exhibited temporal variations in its zonal speed, orientation, length, and its effect over the clouds’ albedo during the 2019/2020 eastern elongation. Finally, a comparison with simultaneous observations by Akatsuki UVI and LIR confirmed that the discontinuity is not visible on the upper clouds’ albedo or thermal emission, while zonal speeds are slower than winds at the clouds’ top and faster than at the middle clouds, evidencing that this Kelvin wave might be transporting momentum up to upper clouds.Junta de Andalucía EMERGIA20_00414European Research Council (ERC) 772086Japan Society for the Promotion of Science (JSPS) JP21J0035

Neuroanatomical dysmorphology of the medial superior olivary nucleus in sudden fetal and infant death

doi: 10.3389/fnhum.2012.00322 Neuroanatomical dysmorphology of the medial superior olivary nucleus in sudden fetal and infant deat