1,298 research outputs found
The MAJORANA 76Ge neutrino less double-beta decay project: A brief update
At present, MAJORANA is a research and development (R&D) project to
investigate the feasibility and cost of constructing and operating a one ton
decay experiment with ~1000 kg of Ge detectors fabricated from germanium
enriched to 86% in . The study will include three separate cryostats with
various types of detectors: un-segmented, un-segmented point-contact, minimally
segmented, and highly segmented. One cryostat will contain at least 30 kg of
enriched (preferably point-contact) detectors. The performance of the cryostats
and detectors as well as background levels will be investigated. The goal of
the demonstrator project is to reach a discovery sensitivity of ~ 1026 y.Comment: 3 pages, no figure
Calorimeter R&D for the SuperNEMO Double Beta Decay Experiment
SuperNEMO is a next-generation double beta decay experiment based on the
successful tracking plus calorimetry design approach of the NEMO3 experiment
currently running in the Laboratoire Souterrain de Modane (LSM). SuperNEMO can
study a range of isotopes, the baseline isotopes are 82Se and possibly 150Nd.
The total isotope mass will be 100-200 kg. A sensitivity to neutrinoless double
beta decay half-life greater than 10e26 years can be reached which gives access
to Majorana neutrino masses of 50-100 meV. One of the main challenges of the
SuperNEMO R&D is the development of the calorimeter with an unprecedented
energy resolution of 4% FWHM at 3 MeV (Qbb value of 82Se).Comment: Presented at 13th International Conference on Calorimetry in High
Energy Physics (CALOR08), Pavia, Italy, 26-30 May 200
Ge Detectors and : The Search for Double Beta Decay with Germanium Detectors: Past, Present and Future
High Purity Germanium Detectors have excellent energy resolution; the best
among the technologies used in double beta decay. Since neutrino-less double
beta decay hinges on the search for a rare peak upon a background continuum,
this strength has enabled the technology to consistently provide leading
results. The Ge crystals at the heart of these experiments are very pure; they
have no measurable U or Th contamination. The added efforts to reduce the
background associated with electronics, cryogenic cooling, and shielding have
been very successful, leading to the longevity of productivity. The first
experiment published in 1967 by the Milan group of Fiorini, established the
benchmark half-life limit yr. More recently, the \MJ\ and
GERDA collaborations have developed new detector technologies that optimize the
pulse waveform analysis. As a result, the GERDA collaboration refuted the claim
of observation with a revolutionary approach to shielding by immersing the
detectors directly in radio-pure liquid argon. In 2018, the \MJ\ collaboration,
using a classic vacuum cryostat and high-Z shielding, achieved a background
level near that of GERDA by developing very pure materials for use nearby the
detectors. Together, GERDA and \MJ\ have provided limits approaching
yr. In this article, we elaborate on the historical use of Ge detectors for
double beta decay addressing the strengths and weaknesses. We also summarize
the status and future as many \MJ\ and GERDA collaborators have joined with
scientists from other efforts to give birth to the LEGEND collaboration. LEGEND
will exploit the best features of both experiments to extend the half-life
limit beyond yr with a ton-scale experiment.Comment: Invited submission to Frontiers in Physic
Coherent Neutral Current Neutrino-Nucleus Scattering at a Spallation Source; a Valuable Experimental Probe
The coherent contribution of all neutrons in neutrino nucleus scattering due
to the neutral current is examined considering the Spallation Neutron Source
(SNS) as a source of neutrinos. SNS is a prolific pulsed source of electron and
muon neutrinos as well as muon antineutrinos.Comment: 15 LaTex pages, 14 figures, 3 Table
INTERNATIONAL LIQUIDITY, NEGATIVE INTEREST RATE POLICY AND BANKING SUPERVISION: EVIDENCE FROM A NATURAL EXPERIMENT
Chapter 2: Given the importance Swap lines played during the coronavirus-induced crisis, this paper analyses the impact of temporary U.S. dollar liquidity arrangements (swap lines) on international reserves (IR). Specifically, I investigate the effect that the Federal Reserve (FED) swap lines have had on the accumulation of IR of those countries involved compared to those countries that do not have any type of liquidity arrangements with the FED. By analysing a sample of 47 countries over the period 2002-2018 and a difference-in-differences methodology, I find that, overall, there is no difference in the accumulation process of IR between those countries that were involved in the global financial crisis (GFC) swap lines and those that were not. However, on close inspection, by analysing the emerging market economies (EME) sub-sample, I find empirical evidences that these countries - involved in swap lines by FED, when these GFC arrangements expired - started to accumulate reserves to a greater extent to the other considered EME. Furthermore, when I investigate whether these divergences are due to ultra-easy monetary policies or turbulence periods, I find this greater accumulation to be a phenomenon clearly wanted by the countries involved. This result suggests that swap lines involved countries that do not believe in the benevolence of Fed operations, and being more exposed to dollar shocks than other EME, they need a higher stockpile of IR. My contribution could suggest that EME will continue to follow their precautionary patterns, also after the last coronavirus swap lines.Chapter 1: This paper analyses the impact of the Banking Union on European bank credit risk. Specifically, we investigate the effect that the establishment of the Single Supervisory Mechanism has had on the credit risk of the banks it supervises in comparison to financial institutions that are still supervised by National Supervisory Authorities. We analyse a sample of 746 European banks over the period 2011-2018, by means of a difference-in-differences methodology. We provide empirical evidence that Single Supervisory Mechanism supervised banks reduced credit risk exposure compared to banks supervised by National Supervisory Authorities, suggesting that the Banking Union has successfully reduced the riskiness of the European banking sector. Our results passed a battery of robustness tests that support the reliability of our analysis. Our contribution sheds light on the benefits of centralised versus decentralised supervision, on the effectiveness of the current supervisory system in Europe, and on its impact on European bank risk.Chapter 3: This paper investigates to what extent the introduction of negative monetary policy rates altered competitive conditions in the euro area banking sector. Specifically, it analyses the effect that negative policy rates had on euro area banks\u2019 market power in comparison to banks that have not been subject to negative rates. The analysis, considering a sample of 4,223 banks over the period 2011\u20132018 and relying on a difference-in-differences methodology, finds that negative monetary policy rates led to an increase in euro area banks\u2019 market power. Furthermore, it shows that, during the negative interest rate policy period, increased market power hindered the transmission of monetary policy and discouraged banks from taking excessive risks
The experimental challenge of detecting solar axion-like particles to test cosmological ALP-photon oscillation hypothesis
We consider possible experimental tests of recent hypotheses suggesting that
TeV photons survive the pair production interaction with extragalactic
background light over cosmological distances by converting to axion-like
particles (ALPs) in galactic magnetic fields. We show that proposed giant
ultra-low background scintillation detectors will even have a difficult time
reaching the present CAST sensitivity, which is one to two orders of magnitude
less sensitive than necessary for a meaningful test of the ALP-photon
oscillation hypothesis. Potential alternative tests are briefly discussed.Comment: 4 pages, no figure
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