118915062
Dark matter search with innovative techniques
121131430
Advances in the detection of neutrinoless double beta decay
This paper introduces briefly neutrinoless Double Beta Decay and discusses its implications for neutrino physics. After a presentation of general experimental concepts, such as the various proposed methodological approaches and the sensitivity, the current experimental situation is concisely reviewed.
203744172
How to improve the sensitivity of future neutrino mass experiments with thermal calorimeters
In this paper we discuss the perspectives for a new generation of neutrino mass experiments using thermal detectors to reach interesting sensitivities before and after the KATRIN experiment. By scaling the performance of the present Milano neutrino mass experiment with Monte Carlo simulations, we show how a new experiment can validate the present limit of few eV set by spectrometers before the KATRIN experiment starts. We also show how such a result can be used to design a very large thermal detector experiment to reach sensitivities beyond the KATRIN expected one. r 2003 Elsevier B.V. All rights reserved. PACS: 14.60.Pq; 23.40.Bw; 29.90.þr; 02.70.Uu
118866996
Review of Neutrino Mass Measurements
After a brief summary of the recent achievements of neutrino physics, the concept of neutrino mass scale is clarified. The methods for the determination of the neutrino mass values are summarized and critically compared, in particular in the different and complementary contexts of cosmology, double and single beta decay. The attention is then focussed on the laboratory approaches to investigate neutrino mass. The role of neutrinoless double beta decay is explained and a short review of the present and most promising future experiments in this field is given. Single beta decay sensitivity is discussed, with brief descriptions of the KATRIN tritium experiment and of the recently proposed MARE rhenium project.
121148985
Neutrinoless Double-Beta Decay
This paper introduces the neutrinoless double-beta decay (the rarest nuclear weak process) and 
describes the status of the research for this transition, both from the point of view of theoretical 
nuclear physics and in terms of the present and future experimental scenarios. Implications of this 
phenomenon on crucial aspects of particle physics are briefly discussed. The calculations of the nuclear 
matrix elements in case of mass mechanisms are reviewed, and a range for these quantities is proposed 
for the most appealing candidates. After introducing general experimental concepts—such as the 
choice of the best candidates, the different proposed technological approaches, and the sensitivity—we make the point on the experimental situation. Searches running or in preparation are described, providing an organic presentation which picks up similarities and differences. A critical comparison of 
the adopted technologies and of their physics reach (in terms of sensitivity to the effective Majorana 
neutrino mass) is performed. As a conclusion, we try to envisage what we expect round the corner 
and at a longer time scale.
125019184
Lucifer: An experimental breakthrough in the search for neutrinoless double beta decay
LUCIFER (Low-background Underground Cryogenic Installation For Elusive Rates) is a new project for the study of neutrinoless Double Beta Decay, based on the technology of the scintillating bolometers. These devices promise a very efficient rejection of the α background, opening the way to a virtually background-free experiment if candidates with a transition energy higher than 2615 keV are investigated. The baseline candidate for LUCIFER is Se. This isotope will be embedded in ZnSe crystals grown with enriched selenium and operated as scintillating bolometers in a low-radioactivity underground dilution refrigerator. In this paper, the LUCIFER concept will be introduced and the sensitivity and the prospects related to this project will be discussed.
119295233
The ground state construction of the two-dimensional Hubbard model on the honeycomb lattice
In these lectures I consider the half-filled two-dimensional (2D) Hubbard model on the honeycomb lattice and I review the rigorous construction of its ground state properties by making use of constructive fermionic Renormalization Group methods.
55458894
Lattice quantum electrodynamics for graphene
Abstract The effects of gauge interactions in graphene have been analyzed up until now in terms of effective models of Dirac fermions. However, in several cases lattice effects play an important role and need to be taken consistently into account. In this paper, we introduce and analyze a lattice gauge theory model for graphene, which describes tight binding electrons hopping on the honeycomb lattice and interacting with a three-dimensional quantum U ( 1 ) gauge field. We perform an exact renormalization group analysis, which leads to a renormalized expansion that is finite at all orders. The flow of the effective parameters is controlled thanks to Ward identities and a careful analysis of the discrete lattice symmetry properties of the model. We show that the Fermi velocity increases up to the speed of light and Lorentz invariance spontaneously emerges in the infrared. The interaction produces critical exponents in the response functions; this removes the degeneracy present in the non interacting case and allows us to identify the dominant excitations. Finally, we add mass terms to the Hamiltonian and derive by a variational argument the correspondent gap equations, which have an anomalous non-BCS form, due to the non trivial effects of the interaction.
29885643
Anomalous Behavior in an Effective Model of Graphene with Coulomb Interactions
We analyze by exact Renormalization Group (RG) methods the infrared properties of an effective model of graphene, in which two-dimensional (2D) massless Dirac fermions propagating with a velocity smaller than the speed of light interact with a 3D quantum electromagnetic field. The fermionic correlation functions are written as series in the running coupling constants, with finite coefficients that admit explicit bounds at all orders. The implementation of Ward Identities in the RG scheme implies that the effective charges tend to a line of fixed points. At small momenta, the quasi-particle weight tends to zero and the effective Fermi velocity tends to a finite value. These limits are approached with a power law behavior characterized by non-universal critical exponents.