The Dark Sequential Z' Portal: Collider and Direct Detection Experiments

We revisit the status of a Majorana fermion as a dark matter candidate when a sequential Z' gauge boson dictates the dark matter phenomenology. Direct dark matter detection signatures rise from dark matter-nucleus scatterings at bubble chamber and liquid xenon detectors, and from the flux of neutrinos from the Sun measured by the IceCube experiment, which is governed by the spin-dependent dark matter-nucleus scattering. On the collider side, LHC searches for dilepton and mono-jet + missing energy signals play an important role. The relic density and perturbativity requirements are also addressed. By exploiting the dark matter complementarity we outline the region of parameter space where one can successfully have a Majorana dark matter particle in light of current and planned experimental sensitivities.Comment: 22 pages, 6 figure

Thermal Relics in Modified Cosmologies: Bounds on Evolution Histories of the Early Universe and Cosmological Boosts for PAMELA

Alternative cosmologies, based on extensions of General Relativity, predict modified thermal histories in the Early Universe during the pre Big Bang Nucleosynthesis (BBN) era, epoch which is not directly constrained by cosmological observations. When the expansion rate is enhanced with respect to the standard case, thermal relics typically decouple with larger relic abundances. The correct value of the relic abundance is therefore obtained for larger annihilation cross--sections, as compared to standard cosmology. A direct consequence is that indirect detection rates are enhanced. Extending previous analyses of ours, we derive updated astrophysical bounds on the dark matter annihilation cross sections and use them to constrain alternative cosmologies in the pre--BBN era. We also determine the characteristics of these alternative cosmologies in order to provide the correct value of relic abundance for a thermal relic for the (large) annihilation cross--section required to explain the PAMELA results on the positron fraction, therefore providing a "cosmological boost" solution to the dark matter interpretation of the PAMELA data.Comment: 19 pages, 27 figures, matches published versio

Orchestrating Forest Policy in Italy: Mission Impossible?

In the Italian political and economic agenda the forest sector occupies a marginal role. The forest sector in Italy is characterized by a high institutional fragmentation and centralized decision-making processes dominated by Public Forest Administrations. Public participation in forest policy processes has been implemented since the 1990s at national, regional and local levels in several cases. However, today no significant changes have been observed in the overall governance of the forest sector and stakeholders' involvement in Italian forest policy decision-making is still rather limited. The aims of this paper are to describe the state of forest-related participatory processes in Italy at various levels (national, regional and local) and identify which factors and actors hinder or support the establishment and implementation of participatory forest-related processes in the country. The forest-related participatory processes are analyzed adopting a qualitative-based approach and interpreting interactive, complex and non-linear participatory processes through the lens of panarchy theory

Can unstable relics save pure Cold Dark Matter?

The standard CDM model fails to describe the power spectrum of fluctuations since it gives too much power at small scales. Among other possible improvements, it has been suggested that an agreement with observations can be achieved with the addition of a late decaying particle, through the injection of non-thermal radiation and the consequent increase of the horizon length at the equivalence time. We analyze the possibility of implementing this idea in extensions of the electroweak standard model, with particular attention to supersymmetry with and without R-parity. After considering cosmological and astrophysical bounds, only few candidate models survive as viable solutions

CP conserving constraints on Supersymmetric CP violation in the MSSM

We address the following question. Take the Constrained Minimal Supersymmetric Standard Model (CMSSM) with the two CP violating SUSY phases different from zero, and neglect the bound coming from the electric dipole moment of the neutron (EDM): is it possible to fully account for CP violation in the kaon and B systems using only the SUSY contributions with vanishing CKM phase? We show that the ${BR}(B\to X_{s} \gamma)$ constraint, though CP conserving, forces a negative answer to the above question. This implies that, even in the regions of the CMSSM where a cancellation of different contributions to the EDM allows for large SUSY phases, it is not possible to exploit the SUSY phases to fully account for observable CP violation. Hence to have sizeable SUSY contributions to CP violation, one needs new flavor structures in the sfermion mass matrices beyond the usual CKM matrix

Neutrino mixing and large CP violation in B physics

We show that in see-saw models of neutrino mass a la SUSY SO(10), the observed large mixing in atmospheric neutrinos naturally leads to large b-s transitions. If the associated new CP phase turns out to be large, this SUSY contributions can drastically affect the CP violation in some of the B decay channels yielding the beta and gamma angles of the unitarity triangle. They can even produce sizeable CP asymmetries in some decay modes which are not CP violating in the standard model context. Hence the observed large neutrino mixing makes observations of low energy SUSY effect in some CP violating decay channels potentially promising in spite of the agreement between the Standard Model and data in K and B physics so far.Comment: References adde

Hamilton Jacobi Bellman equations in infinite dimensions with quadratic and superquadratic Hamiltonian

We consider Hamilton Jacobi Bellman equations in an inifinite dimensional Hilbert space, with quadratic (respectively superquadratic) hamiltonian and with continuous (respectively lipschitz continuous) final conditions. This allows to study stochastic optimal control problems for suitable controlled Ornstein Uhlenbeck process with unbounded control processes

Numerical study of SU(2) Yang-Mills theory with gluinos

We report on a numerical investigation of the SU(2) gauge theory with gluinos. The low-lying spectrum in bosonic and fermionic channels is determined. Improvements of the multi-bosonic algorithm are discussed.Comment: latex, 3 pages, 4 figures; Poster presented by K. Spanderen at LATTICE9