Feebly-interacting particles: FIPs 2020 workshop report

With the establishment and maturation of the experimental programs searching for new physics with sizeable couplings at the LHC, there is an increasing interest in the broader particle and astrophysics community for exploring the physics of light and feebly-interacting particles as a paradigm complementary to a New Physics sector at the TeV scale and beyond. FIPs 2020 has been the first workshop fully dedicated to the physics of feebly-interacting particles and was held virtually from 31 August to 4 September 2020. The workshop has gathered together experts from collider, beam dump, fixed target experiments, as well as from astrophysics, axions/ALPs searches, current/future neutrino experiments, and dark matter direct detection communities to discuss progress in experimental searches and underlying theory models for FIPs physics, and to enhance the cross-fertilisation across different fields. FIPs 2020 has been complemented by the topical workshop Physics Beyond Colliders meets theory, held at CERN from 7 June to 9 June 2020. This document presents the summary of the talks presented at the workshops and the outcome of the subsequent discussions held immediately after. It aims to provide a clear picture of this blooming field and proposes a few recommendations for the next round of experimental results

New CUORICINO Results On the Way to CUORE

CUORE is a 0.75 ton experiment to search for neutrinoless double beta decay of Te130 using 988 TeO2 bolometers. It aims at reaching a sensitivity on the effective neutrino mass of the order of few tens of meV. CUORICINO, a single CUORE tower running since 2003, plays an important role as a stand alone experiment and for developing the future CUORE setup. Present results already achieved and studies that are underway are here presented and discussed

Results from CUORICINO experiment and prospects for CUORE

Cuoricino is a taking data bolometric experiment searching for neutrinoless double beta decay (0νDBD) of 130Te. The detector consists of an array of large cubic TeO2 crystal bolometers. Cuoricino works at about 10 mK in the Gran Sasso Underground Laboratory. Good energy resolutions were obtained (2.1 keV at 911 keV and 3.9 keV at 2615 keV at best). The counting rate in the region of 0νDBD is 0.18±0.02 c/keV/kg/y. The limit for the 0νDBD half lifetime is 2.0 × 1024 years at the 90% of C.L. This results correspond to a limit for the effective neutrino mass between 0.2 and 1.0 eV, depending on the nuclear matrix elements used. A large international collaboration is working on CUORE project, a future experiment with a mass of 741 kg of TeO2 crystal bolometers. The experiment aims to probe the neutrino absolute mass down to 50 meV and to understand if the inverted hierarchy holds in the neutrino mass pattern

CUORE: An experiment to investigate for neutrinoless double beta decay by cooling 750 kg of TeO\u3csub\u3e2\u3c/sub\u3e crystals at 10 mK

CUORE (Cryogenic Underground Observatory for Rare Events) is an experiment proposed to infer the effective Majorana mass of the electron neutrino from measurements on neutrinoless double beta decay (0νDBD). The goal of CUORE is to achieve a background rate in the range 0.001 to 0.01 counts/keV/kg/y at the 0νDBD transition energy of 130Te (2528 keV). The proposed experiment, to be mounted in the underground Gran Sasso INFN National Laboratory, Italy, is realized by cooling about 1000 TeO2 bolometers, of 750 g each, at a temperature of 10mK. We will describe the experiment, to be cooled by an extremely powerful dilution refrigerator, operating with no liquid helium, and the main experimental features designed to assure the predicted sensitivity. We present moreover the last results of a small scale (40.7 kg) 0νDBD experiment carried on in the Gran Sasso Laboratory (CUORICINO)

An active-shield method for the reduction of surface contamination in CUORE

The main goal of the CUORE experiment is to search for the neutrinoless double beta decay of 130Te. As it is a rare nuclear decay, the sensitivity of the experiment strongly depends on the background level in the transition energy region. In this paper we describe the R&D work performed to develop an active method for the reduction of radioactive background in CUORE. The idea is to reject events originated by surface contamination in large mass bolometric detectors by using bolometers sensitive to surface events. Results obtained with the first prototypes and tests made with large mass surface sensitive bolometers will be reported

Experimental Searches for the Axion and Axion-Like Particles

Four decades after its prediction, the axion remains the most compelling solution to the strong-CP problem and a well-motivated dark matter candidate, inspiring a host of elegant and ultrasensitive experiments based on axion-photon mixing. This article reviews the experimental situation on several fronts. The microwave cavity experiment is making excellent progress in the search for dark matter axions in the µeV range and may plausibly be extended up to 100 µeV. Within the past several years, however, researchers have realized that axions are pervasive throughout string theories, but with masses that fall naturally in the neV range, for which an NMR-based search is under development. Both searches for axions emitted from the Sun's burning core and purely laboratory experiments based on photon regeneration have recently made great progress, with ambitious projects proposed for the coming decade. Each of these campaigns has pushed the state of the art in technology, enabling large gains in sensitivity and mass reach. Furthermore, each modality has been exploited in order to search for more generalized axion-like particles, which we also discuss in this review. We are hopeful, even optimistic, that the next review of the subject will concern the discovery of the axion, its properties, and its exploitation as a probe of early universe cosmology and structure formation