W. Di Nicolantonio

Searching for WIMPs by the annual modulation signature

Abstract A set of preliminary test data, collected with large mass highly radiopure NaI(Tl) detectors, has been analysed by a maximum likelihood method to search for the WIMP annual modulation signature.

On a further search for a yearly modulation of the rate in particle Dark Matter direct search

The results achieved with a statistics of 14962 kg . day, collected with the large mass highly radiopure DAMA NaI(TI) set-up, are described and investigated in terms of WIMP annual modulation signature. A maximum likelihood analysis of these data, combined with the statistics of 4549 kg day previously published (total statistics of 19511 kg . day), favours the hypothesis of presence of an annual modulation at 99.6% C.L

Performances of the ≃ 100 kg NaI(Tl) set-up of the DAMA experiment at Gran Sasso

SummaryThe main features of the highly radiopure ≃ 100 kg NaI(Tl) set-up, searching for particle dark matter deep underground at the Gran Sasso National Laboratory of INFN, are described in some details.

Search for non-paulian transitions in Na-23 and I-127

Abstract A new search of non-paulian nuclear processes, i.e. processes normally forbidden by the Pauli exclusion principle, was carried out by determining an improved upper limit for the spontaneous emission rate of protons in 23 Na and 127 I. A large set-up of highly radiopure NaI(Tl) crystals was employed; it was placed deeply underground at the Gran Sasso National Laboratory of I.N.F.N. The upper limit on the unit time probability of non-paulian emission of protons with energy E p ⩾ 10 MeV is λ ⩽ 4.6 · 10 −33 s −1 . The corresponding limit on the relative strength ( δ 2 ) for the searched non-paulian transitions has been estimated to be δ 2 ≲ 1.0 · 10 −54 .

Improved limits on WIMP-F-19 elastic scattering and first limit on the 2EC2 nu Ca-40 decay by using a low radioactive CaF2(Eu) scintillator

Improved limits on WIMP-F-19 elastic scattering and first experimental limit on the 2EC2 nu Ca-40 decay have been obtained by using a low radioactive CaF2(Eu) scintillator at the Gran Sasso National Laboratory (LNGS)

Charge conservation and electron lifetime: Limits from a liquid xenon scintillator

New limits on the mean lifetime of the electron for decay into non-ionizing particles have been achieved by using a low activity liquid xenon scintillator at the Gran Sasso National Laboratory.

Dark matter search with calcium fluoride crystals

Abstract A first result on dark matter direct search with calcium fluoride scintillators is presented. The low and high energy spectra are discussed together with the measurements of the fluorine and calcium recoil scintillation efficiencies. Exclusion plots for axial vector coupled WIMPs are derived and compared with previous measurements with NaI and Ge detectors.

Limits on WIMP-129Xe inelastic scattering

Abstract Limits on WIMP- 129 Xe nucleus inelastic scattering have been achieved by using a low activity liquid xenon scintillator at the Gran Sasso National Laboratory. Signigicant improvements have been reached.

Search for WIMPs with enriched xenon at Gran Sasso

SummaryA low-activity liquid-xenon scintillator is running at the Gran Sasso National Laboratory of INFN using liquid Kr-free xenon enriched at 99.5% in129Xe. The result of adark matter direct search—looking also for the annual modulation effect—is presented. Preliminary exclusion plots both for coherent and spin-dependent coupled WIMPs are evaluated.

A MULTITON LOW ACTIVITY NAI(TL) DETECTOR FOR UNDERGROUND PHYSICS

This paper presents the main physical goals reachable with a large mass and extremely radiopure NaI(Tl) set-up such as the detection of very low interacting rate Dark Matter candidates and of solar neutrinos.