Welcome

• Stefano Ragazzi (LNGS)

An Introduction to Dark Matter

• Zurab Berezhiani (L'Aquila University)

I shall discuss, in a very simple way, cosmological and astrophysical indications for dark matter in the Universe, particle candidates for dark matter and experimental ways for their detection, direct and indirect.

DAMA

• Vincenzo Caracciolo (LNGS)

The DAMA project is an observatory for rare processes that develops and uses highly radiopure crystal scintillators. It consists of various low-background apparata located in Gran Sasso laboratory. DAMA has a pioneer activity in the direct investigation of Dark Matter. In particular, its main experiment, DAMA/LIBRA, gave evidence for the presence of Dark Matter particles in the galactic halo by exploiting the model-independent annual modulation signature. This result confirms the evidence obtained by the former DAMA/NaI experiment. DAMA/LIBRA is now running in a new phase of measurement with an increased sensitivity. Other searches for rare events, such as double beta decay in various isotopes, axions, etc., are carried out with the other set-ups. In the seminar the main results obtained by DAMA in all its field of activity will be presented as well as the present measurements and advanced perspectives.

DARKSIDE

• Stefano Davini (GSSI)

There is a wide range of astronomical evidence that the visible stars and gas in all galaxies are immersed in a much larger cloud of non-luminous 'dark matter'. The nature of this dark matter is still totally unknown. Dark matter may be comprised of as yet undiscovered Weakly Interacting Massive Particles (WIMPs). WIMPs could in principle be detected in terrestrial experiments through their collisions with ordinary nuclei, giving observable low-energy (<100 keV) nuclear recoils. DarkSide-50 is a liquid argon detector for WIMP detection. In the seminar, I will review the features of DarkSide-50.

Exploring low wimp masses with CRESST

• Paolo Gorla (LNGS)

In recent years the hunt for the direct detection of Dark Matter has become one of the most challenging physic searches. While the presence of dark matter in the universe was verified by observations on various astronomical scales, the nature of dark matter still remains a puzzling question. CRESST-II (Cryogenic Rare Event Search with Superconducting Thermometers), located at the Gran Sasso underground laboratory, is a direct dark matter search experiment aiming to detect WIMPs scattering off nuclei in CaWO4 target crystals. Using cryogenic detectors the CRESST-II setup was able to reach extremely low energy threshold (~600 eV). Recent results from 29 kg-days of exposure acquired by a single 249 g CaWO4 detector are presented. A leading limit on the spin-independent IMP-nucleon cross section in the low-mass WIMPs region is reported together with the probe of a new region of parameter space for WIMP masses below 3GeV/c2. Plans and status of the CRESST-III phase 1 with new upgraded detectors optimized towards the detection of low-mass WIMPs are also reported.

XENON

• Marcello Messina (Columbia University)

The XENON Project aims at directly detecting dark matter particles through their interaction in a liquid xenon target. The XENON100 detector, a double phase Time Projection Chamber employing 161 kg of liquid xenon, started the first science run at INFN Gran Sasso National Laboratories (LNGS), Italy, in 2010. It provided limits on the spin-independent and spin-dependent interaction cross sections of Weakly Interacting Massive Particles (WIMPs) with xenon nuclei, and on the couplings of solar axions and galactic xions-like particles. A new data taking run is currently ongoing, mainly focused on additional calibration for the low energy response of the detector. While still taking data with XENON100 the collaboration is also committed to build the third generation detector, XENON1T. This new detector, currently under construction at LNGS and starting data taking by the end of 2015, will exploit a liquid xenon target of tonnes scale, reaching a sensitivity to spin-independent WIMP-nucleon cross section of the order of 10-47 cm^2 in a 2 yr data taking.

The neutrinoless double beta-decay: a brief overview

• Karoline Schaeffner (LNGS)

More than 80 years after the postulation of the neutrino important properties of this particleare still unknown. In case neutrinos are Majorana particles [1], which implies the presence of physics beyond the Standard Model of particle physics, an extremely rare process should be observable, namely the so-called Neutrinoless Double-Beta Decay (0vDBD) [2]. Its experimental observation would prove that neutrinos are their own anti-particles, that lepton number is not conserved and, more importantly, it would set constraints on the mass scale of the neutrinos at the level of a few tens of meV, important answers to outstanding questions in present-day physics. The present contribution reviews the different experimental approaches and results which have been performed and achieved in the past. Furthermore, next generation experiments using different isotopes and experimental techniques in order to explore the inverted hierarchy region will be discussed. An overview on the expected sensitivities of future experiments will be given. [1] E. Majorana, Il Nuovo Cimento 14, 171 (1937). [2] F. T. Avignone, S. R. Elliott and J. Engel, Rev. Mod. Phys. 80, 481 (2008).

CUORE

• Lucia Canonica (LNGS)

The Cryogenic Underground Observatory for Rare Events (CUORE) is a large-scale double beta decay experiment based on cryogenic bolometers. Its primary goal is to observe neutrino-less double beta decay and measure Majorana neutrino masses with a projected sensitivity reaching the so-called inverted mass hierarchy region. A single CUORE-like tower, CUORE-0, assembled with 52 CUORE-like bolometers has started taking data in spring 2013. In the talk, the results from CUORE-0 will be discussed and the status and the physics potential of CUORE will be presented.

The current status of LUCIFER experiment

• Serge Nagorny (LNGS)

The registration of elusive particles requires the use of new high quality detectors with enhanced characteristics. The production of such materials often depends up on the application of dedicated methods for the entire production process from synthesis of raw materials up to the storage and transport of the finished product ready for use for the construction of the particle detector. Scintillating bolometers are among the most promising detectors used in rare event physics, what have clearly demonstrated by the excellent background rejection capabilities that arise from the simultaneous, independent, double readout of heat and scintillation light. Moreover, the bolometric technique allows an extremely good energy resolution. The main goal of LUCIFER experiment is to build a “background-free” small-scale experiment in order to directly prove the potentiality of this technique for Neutrinoless Double Beta Decay (0νDBD) searches. The current report reviews scientific and technological aspects related to the Zn82Se enriched scintillating crystal production, and progress in bolometric technique in framework of LUCIFER experiment.

GERDA

• Valerio D'Andrea (GSSI)

Round table Chair: Carlo Bucci (LNGS) & Paolo Gorla (LNGS)

Neutrinos

• Natalia Di Marco (LNGS)

The study of neutrino properties is one of the main topics of the researches carried out at the LNGS. Several experiments have been or are currently devoted to the study of neutrinos exploiting different sources both natural or artificial. In this talk a general introduction about neutrino oscillation properties together with an overview about present and future LNGS experimental activities, will be presented.

BOREXINO

• Nicola Rossi (LNGS)

The Borexino experiment (located at Laboratori Nazionali del Gran Sasso) is the most radiopure liquid scintillator neutrino detector all over the world. Starting from 2007, the Borexino experiment provided a precision measurement of "Be7" solar neutrino flux (including also a detailed day/night modulation analysis), and gave the first detection of pep neutrinos, a detection of the B8 neutrinos at low energy threshold (3 MeV) and an important contribution to the geo-neutrino physics. In 2014, we presented the first direct observation of the low energy neutrinos coming from the "pp" fusion in the core of the Sun. The forthcoming program includes an improvement of the solar neutrino and geo-neutrino detection and an important project focused on the sterile neutrino search (SOX).

LVD

• Andrea Molinario (LNGS)

The Large Volume Detector (LVD), located in Hall A at LNGS, is an underground neutrino observatory mainly designed to study neutrinos from core-collapse supernovae. It is in operation since 1992, under different larger configurations. LVD currently consists of an array of 840 scintillator counters, arranged in a compact and modular geometry, for a total active mass of M=1000 t. Since July 2005 LVD has taken part to the Supernovae Early Warning System (SNEWS), the network of supernova neutrino observatories whose main goal is to provide the astronomical community with a prompt alert for the next galactic core-collapse supernova.

Round table Chair: Riccardo Cerulli (LNGS)

GSSI Presentation

• Eugenio Coccia

Nuclear Astrophysics at Gran Sasso

• Andreas Best (LNGS)

The understanding of the processes that power stars and that produce and continue to produce (almost) all elements in the universe is the subject matter of the field of Nuclear Astrophysics. In part this involves measuring in a laboratory the extremely small cross sections of stellar nuclear reactions. Due to the very low expected event rate reduction of the natural background level is of major importance. For over 20 years, the experiments LUNA and LUNA-II at the LNGS have exploited the background reduction provided by the underground location to measure critical reactions at energies directly inside the relevant stellar energy range. I will present an overview over nuclear astrophysics and connect the general subject to the past, present and future activities of LUNA at LNGS.

STELLA

• Matthias Laubenstein (LNGS)

The LNGS ultra low background counting facility STELLA (SubTErranean Low Level Assay) is a service infrastructure located in the underground laboratories of the Laboratori Nazionali del Gran Sasso (LNGS), devoted to highly sensitive radiopurity measurements and material screening for the experiments installed at the LNGS. The lab is working at the frontier of ultra low-level radioactivity measurements. Its main core is the pool of about 10 high purity Germanium (HPGe) detectors used for gamma spectroscopy. The installations and experimental set-ups using ultra low background techniques will be described shortly. Gamma spectroscopy is a very powerful tool that can be applied to many physics fields. Moreover, performing this technique in a deep underground laboratory using ultra low background equipment gives the unique opportunity of having almost background free measurements. This is very helpful for example when measuring tiny objects with small amounts of radioactivity. The most stunning examples that have been measured recently are on the one hand small meteorite specimens, and on the other hand activated materials that were exposed to neutrons and charged particles under extreme conditions close to the plasma in the JET facility. These examples will show how useful this application can be to physics fields other than Astroparticle physics.

Theory Group scientific activity

• Francesco Lorenzo Villante (L'Aquila University)
• Giulia Pagliaroli (LNGS)

The main theoretical research activity of INFN is organized in 5 groups. The research topics concern five main areas: i) Astroparticle physics; ii) Compact stellar objects and dense hadronic matter; iii) Cosmology, large scale structures and dark matter; iv) Computer simulations of gauge theories; v) Particle physics phenomenology. We will briefly outline the topics of interest.

Search for Second Laws and Landauer’s principle: connecting information and physics

• Umut Kaya (ETH Zurich)
• Alessandro Georgoudis (ETH Zurich)

Development of a prototype for a fluorescence detector array of single-pixel telescopes

• Ariel Matalon (KICP, University of Chicago)

Searching for WIMPs at the EDELWEISS experiment by optimization of the background reduction

• Tobias Messer (Karlsruhe Institute of Technology)

Evaluating input parameter uncertainty affecting the Global Braginskii Solver

• Lucio Milanese (Imperial College London)

Calibration of the CMS Pixel Detector at the Large Hadron Collider

• Tamas Almos Vami (Wigner Research Centre for Physics, Budapest)

On the Stability of Fundamental Couplings in the Galaxy

• Pedro Vianez (Universidade do Porto)

Poster prize-giving ceremony