Publications (89)148.86 Total impact
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ABSTRACT: The PTOLEMY experiment (Princeton Tritium Observatory for Light, EarlyUniverse, MassiveNeutrino Yield) aims to achieve the sensitivity required to detect the relic neutrino background through a combination of a large area surfacedeposition tritium target, MACE filter methods, cryogenic calorimetry, and RF tracking and timeofflight systems. A smallscale prototype is in operation at the Princeton Plasma Physics Laboratory with the goal of validating the technologies that would enable the design of a 100 gram PTOLEMY. With precision calorimetry in the prototype setup, the limitations from quantum mechanical and Doppler broadening of the tritium target for different substrates will be measured, including graphene substrates. Beyond relic neutrino physics, sterile neutrinos contributing to the dark matter in the universe are allowed by current constraints on partial contributions to the number of active neutrino species in thermal equilibrium in the early universe. The current PTOLEMY prototype is expected to have unique sensitivity in the search for sterile neutrinos with electronflavor content for masses of 0.11keV, where less stringent, 10eV, energy resolution is required. The search for sterile neutrinos with electronflavor content with the 100g PTOLEMY is expected to reach the level $U_{e4}^2$ of $10^{4}$$10^{6}$, depending on the sterile neutrino mass.07/2013;  [Show abstract] [Hide abstract]
ABSTRACT: We study symmetry of spacetime in the presence of a minimally coupled scalar field interacting with a Kalb–Ramond tensor fields in a homogeneous but initially anisotropic universe. The analysis is performed for the two relevant cases of a pure cosmological constant and a minimal quadratic, renormalizable, interaction term. In both cases, due to expansion, a complete spatial symmetry restoration is dynamically obtained.Modern Physics Letters A 05/2012; 20(08). · 1.11 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: In the framework of a novel approach to the dynamics of nuclei and large collections of nucleons, which fully exploits the coherent interaction among π’s, nucleons and Δ’s, we derive a new equation of state for neutronic matter. By introducing it in the TolmanOppenheimerVolkof equations we derive the masses and radii of neutron stars as a function of the central density. We obtain a maximum mass Mmax≃2.7 Mʘ and a minimum period of rotation Tmin=0.8 msec.International Journal of Modern Physics D 01/2012; 04(04). · 1.03 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: In the framework of the ConnesLott model based on noncommutative geometry, the basic features of a gauge theory in the presence of gravity are reviewed, in order to show the possible physical relevance of this scheme for inflationary cosmology. These models naturally contain at least two scalar fields, interacting with each other whenever more than one fermion generation is assumed. In this paper we propose to investigate the behavior of these two fields (one of which represents the distance between the copies of a twosheeted spacetime) in the early stages of the universe evolution. In particular the simplest Abelian model, which preserves the main characteristics of more complicate gauge theories, is considered and the corresponding inflationary dynamics is studied. We find that a chaotic inflation is naturally favored, leading to a field configuration in which no symmetry breaking occurs and the final distance between the two sheets of spacetime is smaller the greater the number of e fold in each sheet.International Journal of Modern Physics A 01/2012; 11(16). · 1.13 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: We report on the status of primordial nucleosynthesis in light of recent results on CMB anisotropies from WMAP experiment. Theoretical estimates for nuclei abundances, along with the corresponding uncertainties, are evaluated using a new numerical code, where all nuclear rates usually considered have been updated using the most recent available data. Moreover, additional processes neglected in previous calculations have been included. The combined analysis of CMB and primordial nucleosynthesis prediction for Deuterium gives an effective number of relativistic degrees of freedom in good agreement with the simplest scenario of three nondegenerate neutrinos. Our findings seem to point out possible systematics affecting 4He mass fraction measurements, or the effect of exotic physics, like a slightly degenerate relic neutrino background.International Journal of Modern Physics A 01/2012; 19(26). · 1.13 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: A method to measure the low energy nuclear recoils induced by weakly interactive massive particles (WIMPs) has been achieved by means of an ultra pure Liquid Argon detector. The simultaneous observation of scintillation and ionization occurring in the liquid Argon allow to obtain a very high rejection power against background sources. The first preliminary upper bounds on WIMP parameters obtained with a small 2.3 liter test chamber with an accumulated fiducial exposure of about 100 kg⋅day at the Gran Sasso Underground Laboratory is reported. This supports the validity of this method for a larger detector presently under construction with correspondingly increased sensitivities.Nuclear Physics B  Proceedings Supplements 12/2011; 221:53–56. · 0.88 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: We analyze the possibility to extend the Connes and Lott reformulation of the standard model to larger unified gauge groups. Noncommutative geometry imposes very stringent constraints on the possible theories, and remarkably, the analysis seems to suggest that no larger gauge groups are compatible with the noncommutative structure, unless one enlarges the fermionic degrees of freedom, namely the number of particles.Modern Physics Letters A 11/2011; 11(32n33). · 1.11 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: We extend a previous analysis concerning cosmological fluids with generalized equations of state in order to study inflationary scenarios. In the framework of the slowroll approximation we find the expressions for the perturbation parameters ε, η and the density perturbation spectra in terms of the adiabatic index γ(a) as a function of the universe scale factor. This connection allows one to find straightforwardly γ(a) corresponding, for example, to the simplest chaotic model and to the HarrisonZeldovich potential and shows its capability to be applied to more complicated situations. Finally, we use this description to develop a new approach to the early universe dynamics, based on a 1/N expansion, where N is the efold number. To this end, we introduce a set of suitable dimensionless variables and show that at the zeroth order in /1N, an improved slowroll approximation is obtained.Modern Physics Letters A 11/2011; 10(27). · 1.11 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: In a recent paper we pointed out the presence of extra fermionic degrees of freedom in a chiral gauge theory based on Connes' noncommutative geometry. Here we propose a mechanism which provides a high mass to these mirror states, so that they decouple from low energy physics.Modern Physics Letters A 11/2011; 13(03). · 1.11 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: We consider radiative electromagnetic corrections, at order α, to the process at finite density and temperature. This process represents one of the main contributions to the cooling of stellar environments in the late stages of star evolution. We find that these corrections affect the energy loss rate by a factor (41)% with respect to the tree level estimate, in the temperature and density ranges where the neutrino pair production via e+e annihilation is the most efficient cooling mechanism.Modern Physics Letters A 11/2011; 17(08). · 1.11 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: We consider a model of interacting cosmological constant/quintessence, where dark matter and dark energy behave as, respectively, two coexisting phases of a fluid, a thermally excited Bose component and a condensate, respectively. In a simple phenomenological model for the dark components interaction we find that their energy density evolution is strongly coupled during the universe evolution. This feature provides a possible way out for the coincidence problem affecting many quintessence models.Modern Physics Letters A 11/2011; 18(12). · 1.11 Impact Factor 
Article: The WArP Experiment
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ABSTRACT: Cryogenic noble liquid detectors are presently considered one of the best options for WIMP Dark Matter searches, especially when extensions to multi ton scale sensitive masses are foreseen. The WArP experiment is the first one that exploits the unique characteristics of liquid Argon to make a highly sensitive search for WIMP Dark Matter candidates. In 2008, a double phase detector has been assembled in the Gran Sasso National Laboratory with 140 kg sensitive mass and a discovery potential in the range of 5 × 10−45 cm2 in the spinindependent WIMPnucleon crosssection. In addition to standard neutrons and gammarays passive shields, WArP implements an 8 ton liquid Argon active shield with 4π coverage. The detector was commissioned and put into operation during the first half of 2009 for a first technical run. This first run lasted about three months and then it was stopped for some detector repairs and modifications in the summer of 2009. A second run was started at the beginning of 2010. Detector design, construction and assembly are described, together with the results of the technical run and the very first results of the 2010 run.Journal of Physics Conference Series 07/2011; 308(1):012005.  [Show abstract] [Hide abstract]
ABSTRACT: We summarize the talks presented to the Absolute neutrino mass scale parallel session of NOW2010, mainly focused on neutrinoless double beta decay in its theoretical and experimental aspects and the role of the neutrino mass scale in cosmology.Nuclear Physics B  Proceedings Supplements 01/2011; 217(1):363366. · 0.88 Impact Factor 
Article: Constraining the cosmic radiation density due to lepton number with Big Bang Nucleosynthesis
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ABSTRACT: The cosmic energy density in the form of radiation before and during Big Bang Nucleosynthesis (BBN) is typically parameterized in terms of the effective number of neutrinos N_eff. This quantity, in case of no extra degrees of freedom, depends upon the chemical potential and the temperature characterizing the three active neutrino distributions, as well as by their possible nonthermal features. In the present analysis we determine the upper bounds that BBN places on N_eff from primordial neutrinoantineutrino asymmetries, with a careful treatment of the dynamics of neutrino oscillations. We consider quite a wide range for the total lepton number in the neutrino sector, eta_nu= eta_{nu_e}+eta_{nu_mu}+eta_{nu_tau} and the initial electron neutrino asymmetry eta_{nu_e}^in, solving the corresponding kinetic equations which rule the dynamics of neutrino (antineutrino) distributions in phase space due to collisions, pair processes and flavor oscillations. New bounds on both the total lepton number in the neutrino sector and the nu_e bar{nu}_e asymmetry at the onset of BBN are obtained fully exploiting the time evolution of neutrino distributions, as well as the most recent determinations of primordial 2H/H density ratio and 4He mass fraction. Note that taking the baryon fraction as measured by WMAP, the 2H/H abundance plays a relevant role in constraining the allowed regions in the eta_nu eta_{nu_e}^in plane. These bounds fix the maximum contribution of neutrinos with primordial asymmetries to N_eff as a function of the mixing parameter theta_13, and point out the upper bound N_eff < 3.4. Comparing these results with the forthcoming measurement of N_eff by the Planck satellite will likely provide insight on the nature of the radiation content of the universe.Journal of Cosmology and Astroparticle Physics 11/2010; 3(03). · 6.04 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: Annihilation of Dark Matter usually produces together with gamma rays comparable amounts of electrons and positrons. The e+e− gyrating in the galactic magnetic field then produce secondary synchrotron radiation which thus provides an indirect mean to constrain the DM signal itself. To this purpose, we calculate the radio emission from the galactic halo as well as from its expected substructures and we then compare it with the measured diffuse radio background. We employ a multi‐frequency approach using data in the relevant frequency range 100 MHz–100 GHz, as well as the WMAP Haze data at 23 GHz. The derived constraints are of the order 〈σAv〉 = 10−24 cm3s−1 for a DM mass mϰ = 100 GeV even though sensibly depending on the astrophysical uncertainties.AIP Conference Proceedings. 06/2010; 1241(1):418425. 
Article: The WArP experiment
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ABSTRACT: Cryogenic noble liquid detectors are presently considered one of the best options for WIMP Dark Matter searches, especially when extensions to multi ton scale sensitive masses are foreseen. The WArP experiment is the first one that exploits the unique characteristics of liquid Argon to make a highly sensitive search for WIMP Dark Matter candidates. In 2008, a double phase detector has been assembled in the Gran Sasso National Laboratory with 140 kg sensitive mass and a discovery potential in the range of 5 × 1045 cm2 in the spinindependent WIMPnucleon crosssection. In addition to standard neutrons and gammarays passive shields, WArP implements an 8 ton liquid Argon active shield with 4p coverage. The detector was commissioned and put into operation during the first half of 2009 for a first technical run. Detector design, construction and assembly are described, together with the very first results of this technical run.Journal of Physics Conference Series 02/2010; 203(1):012006.  [Show abstract] [Hide abstract]
ABSTRACT: The new chances offered by elementary particles as probes of the internal structure of our planet are briefly reviewed, by paying particular attention to the case of high energy neutrinos. In particular, the new results concerning the shadow of mountains on nutau flux at Pierre Auger Observatory is briefly discussed, and moreover the possibility to use the tail of atmospheric neutrinos to probe the core/mantle transition region is just sketched.Earth Planets and Space 01/2010; 62(2):205209. · 2.92 Impact Factor 
Article: Simulations of neutrino and muon interaction in matter for geological structures radiography
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ABSTRACT: Neutrino and muon radiography seems to provide a method complementary to the more conventional seismic studies for getting information on the very deep geological structures. Here we describe the status of the simulations of neutrino and muon interaction in matter.Earth Planets and Space 01/2010; 62(2):187193. · 2.92 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: Neutrino Earth radiography seems to provide an alternative tool to study the very deep geological structures. Even if the level of precision of such measurements might not be very high, nevertheless the information which can be obtained are absolutely independent and complementary to the more conventional seismic studies.Earth Planets and Space 01/2010; 62(2):211214. · 2.92 Impact Factor  Physical Review Letters 10/2009; 103(15). · 7.73 Impact Factor
Publication Stats
2k  Citations  
148.86  Total Impact Points  
Top Journals
Institutions

1991–2012

University of Naples Federico II
 Department of Physical Sciences
Napoli, Campania, Italy


1992–2011

INFN  Istituto Nazionale di Fisica Nucleare
Frascati, Latium, Italy


2006

Università degli Studi dell'Aquila
 Department of Chemistry, Chemical Engineering and Materials
Aquila, Abruzzo, Italy


2005–2006

Syracuse University
Syracuse, New York, United States


1997–2005

Policlinico Federico II di Napoli
Napoli, Campania, Italy


2004

University of Pavia
 Department of Physics
Pavia, Lombardy, Italy


2000

University of Oxford
 Department of Physics
Oxford, ENG, United Kingdom
