DAMA/LIBRA–phase2 results and implications on several dark matter scenarios

2020 ◽  
Vol 35 (36) ◽  
pp. 2044023
Author(s):  
R. Bernabei ◽  
P. Belli ◽  
V. Caracciolo ◽  
R. Cerulli ◽  
V. Merlo ◽  
...  
Keyword(s):  
Dark Matter ◽  
Confidence Level ◽  
Nuclear Physics ◽  
Energy Threshold ◽  
High Confidence ◽  
Annual Modulation ◽  
Total Exposure ◽  
Model Independent ◽  
High Confidence Level

The first DAMA/LIBRA–phase2 model-independent results (exposure: [Formula: see text], and software energy threshold at 1 keV). They further confirm — with high confidence level — the evidence already observed by DAMA/NaI and DAMA/LIBRA–phase1 on the basis of the exploited model-independent dark matter (DM) annual modulation signature. The total exposure of the three experiments above the 2 keV software energy threshold is [Formula: see text]. Here, several DM candidate particles and related scenarios are analyzed including the latest results. Thanks to the increased exposure and to the lower software energy threshold, corollary model-dependent analyses permit to significantly restrict the allowed regions for the parameters spaces of various dark matter candidates and astrophysical, particle and nuclear physics scenarios.

scholarly journals PARTICLE DARK MATTER IN THE GALACTIC HALO: RESULTS FROM DAMA/LIBRA

2012 ◽  
Vol 12 ◽  
pp. 37-47
Author(s):  
R. BERNABEI ◽  
P. BELLI ◽  
F. MONTECCHIA ◽  
F. NOZZOLI ◽  
F. CAPPELLA ◽  
...  
Keyword(s):  
Dark Matter ◽  
First Generation ◽  
Galactic Halo ◽  
National Laboratory ◽  
Annual Modulation ◽  
Independent Evidence ◽  
Total Exposure ◽  
Annual Cycles ◽  
Model Independent ◽  
Particle Dark Matter

The DAMA/LIBRA experiment, running at the Gran Sasso National Laboratory of the I.N.F.N. in Italy, has a sensitive mass of about 250 kg highly radiopure NaI(Tl). It is mainly devoted to the investigation of Dark Matter (DM) particles in the Galactic halo by exploiting the model independent DM annual modulation signature. The present DAMA/LIBRA experiment and the former DAMA/NaI one (the first generation experiment having an exposed mass of about 100 kg) have cumulatively released so far the results obtained with the data collected over 13 annual cycles; the total exposure is 1.17 ton × yr. They give a model independent evidence of the presence of DM particles in the galactic halo at 8.9 σ C.L. on the basis of the investigated DM signature. Few aspects of the obtained results are summarized and some comments addressed.

PARTICLE DARK MATTER IN THE GALACTIC HALO: RESULTS AND PERSPECTIVES

2013 ◽  
Vol 22 (11) ◽  
pp. 1360001 ◽  
Author(s):  
R. BERNABEI ◽  
P. BELLI ◽  
A. DI MARCO ◽  
F. MONTECCHIA ◽  
F. CAPPELLA ◽  
...  
Keyword(s):  
Dark Matter ◽  
Galactic Halo ◽  
National Laboratory ◽  
Future Perspectives ◽  
Annual Modulation ◽  
Total Exposure ◽  
Annual Cycles ◽  
Deep Underground ◽  
Model Independent ◽  
Particle Dark Matter

The DAMA project is an observatory for rare processes operating deep underground at the Gran Sasso National Laboratory of the I.N.F.N. In particular, the main apparatus DAMA/LIBRA is mainly dedicated to the investigation of the presence of Dark Matter (DM) particles in the galactic halo by exploiting the model independent DM annual modulation signature. The present DAMA/LIBRA and the former DAMA/ NaI (exposed masses: ≃ 250 kg and ≃ 100 kg of highly radiopure NaI ( Tl ), respectively) experiments have released so far a total exposure of 1.17 ton × yr, collected over 13 annual cycles. They have obtained a positive model independent result for the presence of DM particles in the galactic halo at 8.9σ C.L. Some of the obtained results are shortly summarized and future perspectives mentioned.

scholarly journals Sequence of eruptive events in the Vesuvio area recorded in shallow-water Ionian Sea sediments

2008 ◽  
Vol 15 (1) ◽  
pp. 25-32 ◽  
Author(s):  
C. Taricco ◽  
S. Alessio ◽  
G. Vivaldo
Keyword(s):  
Spectral Analysis ◽  
Shallow Water ◽  
Confidence Level ◽  
Statistical Procedure ◽  
Ionian Sea ◽  
High Confidence ◽  
Volcanic Events ◽  
High Confidence Level

Abstract. The dating of the cores we drilled from the Gallipoli terrace in the Gulf of Taranto (Ionian Sea), previously obtained by tephroanalysis, is checked by applying a method to objectively recognize volcanic events. This automatic statistical procedure allows identifying pulse-like features in a series and evaluating quantitatively the confidence level at which the significant peaks are detected. We applied it to the 2000-years-long pyroxenes series of the GT89-3 core, on which the dating is based. The method confirms the dating previously performed by detecting at a high confidence level the peaks originally used and indicates a few possible undocumented eruptions. Moreover, a spectral analysis, focussed on the long-term variability of the pyroxenes series and performed by several advanced methods, reveals that the volcanic pulses are superimposed to a millennial trend and a 400 years oscillation.

scholarly journals DARK MATTER PARTICLES IN THE GALACTIC HALO: RESULTS AND IMPLICATIONS FROM DAMA/NaI

2004 ◽  
Vol 13 (10) ◽  
pp. 2127-2159 ◽  
Author(s):  
R. BERNABEI ◽  
P. BELLI ◽  
F. CAPPELLA ◽  
R. CERULLI ◽  
F. MONTECCHIA ◽  
...  
Keyword(s):  
Dark Matter ◽  
Galactic Halo ◽  
National Laboratory ◽  
Dark Matter Particle ◽  
Side Reactions ◽  
Annual Modulation ◽  
Annual Cycles ◽  
Systematic Effects ◽  
Deep Underground ◽  
Model Independent

The DAMA/NaI experiment (≃100 kg highly radiopure NaI(Tl)) was proposed, designed and realized to effectively investigate in a model-independent way the presence of a Dark Matter particle component in the galactic halo by exploiting the annual modulation signature. With a total exposure of 107731 kg · day, collected over seven annual cycles deep underground at the Gran Sasso National Laboratory of the I.N.F.N., it has pointed out — at 6.3σC.L. — an effect which satisfies all the peculiarities of the signature and neither systematic effects nor side reactions able to mimic the signature were found. Moreover, several (but still few with respect to the possibilities) corollary model dependent quests for the candidate particle have been carried out. In this paper the obtained results are summarized and some perspectives are discussed at some extent.

scholarly journals Quantized Redshifts - New Physics or Old Muddle?

1999 ◽  
Vol 194 ◽  
pp. 290-294
Author(s):  
W.M. Napier
Keyword(s):  
Energy Density ◽  
Gravitational Lensing ◽  
Confidence Level ◽  
Spiral Galaxies ◽  
New Physics ◽  
Frame Of Reference ◽  
High Confidence ◽  
Redshift Distribution ◽  
Massive Galaxies ◽  
High Confidence Level

The HI redshift distribution of nearby spiral galaxies has been studied to test long-running but generally ignored claims that extragalactic redshifts are periodic or ‘quantized’. The existence of the phenomenon is confirmed at an extremely high confidence level, the quantization appearing in the galactocentric frame of reference. It is proposed that the energy density of the vacuum is a local, oscillating quantity associated with large masses such as spiral galaxies. A variety of ‘anomalies’ should then be detectable in massive galaxies, associated with their redshifts, their ambient gravitational lensing and their dynamics.

A Vibration and Wave Propagation Based Methodology for Near Real-Time Damage Monitoring of Composite Structures

2007 ◽  
Author(s):  
Sauvik Banerjee ◽  
Fabrizio Ricci ◽  
Ajit Mal
Keyword(s):  
Wave Propagation ◽  
Real Time ◽  
Confidence Level ◽  
Damage Index ◽  
Damage Parameter ◽  
High Confidence ◽  
Index Approach ◽  
Damage Monitoring ◽  
High Confidence Level ◽  
Statistical Damage

This paper presents a novel approach to achieve near real-time damage monitoring whereby ultrasonic wave propagation and vibration data are analyzed to determine the location and degree of damage, requiring minimal operator intervention. An improved test setup, consisting of high fidelity sensor arrays, laser scanning vibrometer, data acquisition boards, signal conditioning and dedicated software has been implemented. The collected data are analyzed using a statistical damage index approach to determine the degree of damage to the structure as a function of time with a high confidence level. The statistical damage index approach is designed to overcome the complexity and variability of the signals in the presence of damage as well as the geometric complexity of the structure. It relies on the fact that the dynamical properties of a structure change with the initiation of new damage or growth of existing damage. Using measurements performed on an undamaged or partially damaged structure as baseline, the damage index is evaluated by comparing the changes in the frequency response of the monitored structure as a new damage occurs or an existing damage grows. The proposed algorithm does not require extensive rigorous signal processing, but it computes a single statistical damage parameter (statistic t) with a high confidence level (> 95%), which makes it very fast and automatic. The damage parameter vanishes if there is no change in the structure and its value increases with the severity and proximity of damage to the sensor locations. Thus if damage is initiated at a location within or near the sensor array, then its location and severity can be determined in real-time by the autonomous scheme. The method is applied to identify low velocity impact damage in stiffened composite panels for different arrangements of the source and the receivers.

scholarly journals Cosmic Ray Anisotropy above 1015 eV

1987 ◽  
Vol 40 (3) ◽  
pp. 423 ◽  
Author(s):  
RW Clay
Keyword(s):  
Internal Consistency ◽  
Confidence Level ◽  
Cosmic Ray ◽  
Published Data ◽  
High Confidence ◽  
Real Effect ◽  
Confidence Levels ◽  
High Confidence Level

An examination is made of published data on cosmic ray anisotropy at energies above about 1015 eV. Both amplitude and phase results are examined in an attempt to assess the confidence which can be placed in the observations as a whole. It is found that whilst many published results individually may suggest quite high confidence levels of real measured anisotropy, the data taken as a whole are less convincing. Some internal consistency in the phase results suggests that a real effect may have been measured but, again, this is not at a high confidence level.

scholarly journals A SEGMENT-BASED APPROACH FOR DTM DERIVATION OF AIRBORNE LIDAR DATA

2016 ◽  
Vol XLI-B1 ◽  
pp. 115-120
Author(s):  
Dejin Tang ◽  
Xiaoming Zhou ◽  
Jie Jiang ◽  
Caiping Li
Keyword(s):  
Confidence Level ◽  
Spatial Location ◽  
Point Clouds ◽  
Airborne Lidar ◽  
High Confidence ◽  
Confidence Levels ◽  
Segment Distribution ◽  
Adjacent Segments ◽  
Airborne Lidar Data ◽  
High Confidence Level

With the characteristics of LIDAR system, raw point clouds represent both terrain and non-terrain surface. In order to generate DTM, the paper introduces one improved filtering method based on the segment-based algorithms. The method generates segments by clustering points based on surface fitting and uses topological and geometric properties for classification. In the process, three major steps are involved. First, the whole datasets is split into several small overlapping tiles. For each tile, by removing wall and vegetation points, accurate segments are found. The segments from all tiles are assigned unique segment number. In the following step, topological descriptions for the segment distribution pattern and height jump between adjacent segments are identified in each tile. Based on the topology and geometry, segment-based filtering algorithm is performed for classification in each tile. Then, based on the spatial location of the segment in one tile, two confidence levels are assigned to the classified segments. The segments with low confidence level are because of losing geometric or topological information in one tile. Thus, a combination algorithm is generated to detect corresponding parts of incomplete segment from multiple tiles. Then another classification algorithm is performed for these segments. The result of these segments will have high confidence level. After that, all the segments in one tile have high confidence level of classification result. The final DTM will add all the terrain segments and avoid duplicate points. At the last of the paper, the experiment show the filtering result and be compared with the other classical filtering methods, the analysis proves the method has advantage in the precision of DTM. But because of the complicated algorithms, the processing speed is little slower, that is the future improvement which should been researched.

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