E. L. Martín
A5011776660- Stellar, planetary, and galactic studies
- Neutrino Physics Research
- Astronomy and Astrophysical Research
- Particle physics theoretical and experimental studies
- Astrophysics and Star Formation Studies
- Dark Matter and Cosmic Phenomena
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- Particle Detector Development and Performance
- Radiation Detection and Scintillator Technologies
- Orthopaedic implants and arthroplasty
- Atomic and Subatomic Physics Research
- Astro and Planetary Science
- Total Knee Arthroplasty Outcomes
- Hip disorders and treatments
- Orthopedic Infections and Treatments
- Nuclear Physics and Applications
- Astrophysical Phenomena and Observations
- Particle accelerators and beam dynamics
- X-ray Spectroscopy and Fluorescence Analysis
- Nuclear physics research studies
- Spectroscopy and Laser Applications
- Atmospheric Ozone and Climate
- Adaptive optics and wavefront sensing
- Electron and X-Ray Spectroscopy Techniques
University of North Carolina at Chapel Hill
2019-2024
Triangle Universities Nuclear Laboratory
2019-2024
Instituto de Astrofísica de Canarias
1994-2022
Consejo Superior de Investigaciones Científicas
1995-2022
Unidades Centrales Científico-Técnicas
2014-2022
Universidad de La Laguna
2020-2022
Campbell Collaboration
2022
University of Washington
2013-2021
University of Liverpool
2018
Centro de Astrobiología
2009-2018
Abstract Since the discovery of neutrino oscillations, we know that neutrinos have non-zero mass. However, absolute neutrino-mass scale remains unknown. Here report upper limits on effective electron anti-neutrino mass, m ν , from second physics run Karlsruhe Tritium Neutrino experiment. In this experiment, is probed via a high-precision measurement tritium β -decay spectrum close to its endpoint. This method independent any cosmological model and does not rely assumptions whether Dirac or...
The Majorana Demonstrator searched for neutrinoless double-β decay (0νββ) of ^{76}Ge using modular arrays high-purity Ge detectors operated in vacuum cryostats a low-background shield. with up to 40.4 kg (27.2 enriched ∼88% ^{76}Ge). From these measurements, the has accumulated 64.5 yr active exposure. With world-leading energy resolution 2.52 keV FWHM at 2039 Q_{ββ} (0.12%), we set half-life limit 0νββ T_{1/2}>8.3×10^{25} (90% C.L.). This provides range upper limits on m_{ββ} (113-269) meV...
We combine results from imaging searches for substellar objects in the σ Orionis cluster and follow-up photometric spectroscopic observations to derive a census of brown dwarf population region 847 arcmin2. identify 64 very low mass member candidates this region. have available three-color (I, Z, J) photometry all them, spectra 24 objects, K 27% our sample. These data provide well-defined sequence I versus I-J I-K color-magnitude diagrams indicate that exhibits little reddening despite its...
We report on the data set, handling, and detailed analysis techniques of first neutrino-mass measurement by Karlsruhe Tritium Neutrino (KATRIN) experiment, which probes absolute scale via $\beta$-decay kinematics molecular tritium. The source is highly pure, cryogenic T$_2$ gas. $\beta$ electrons are guided along magnetic field lines toward a high-resolution, integrating spectrometer for energy analysis. A silicon detector counts above threshold spectrometer, so that scan thresholds produces...
We report on the light sterile neutrino search from first four-week science run of KATRIN experiment in 2019. Beta-decay electrons a high-purity gaseous molecular tritium source are analyzed by high-resolution MAC-E filter down to 40 eV below endpoint at 18.57 keV. consider framework with three active neutrinos and one neutrino. The analysis is sensitive mass, ${m}_{4}$, fourth mass state for ${m}_{4}^{2}\ensuremath{\lesssim}1000\text{ }\text{ }{\mathrm{eV}}^{2}$ active-to-sterile mixing...
We present the results of light sterile neutrino search from second KATRIN measurement campaign in 2019. Approaching nominal activity, $3.76 \times 10^6$ tritium $\beta$-electrons are analyzed an energy window extending down to $40\,$eV below endpoint at $E_0 = 18.57\,$keV. consider $3\nu+1$ framework with three active and one flavor. The analysis is sensitive a fourth mass eigenstate $m_4^2\lesssim1600\,$eV$^2$ active-to-sterile mixing $|U_{e4}|^2 \gtrsim 6 10^{-3}$. As no sterile-neutrino...
Abstract The Karlsruhe Tritium Neutrino (KATRIN) experiment is designed to measure a high-precision integral spectrum of the endpoint region T 2 β decay, with primary goal probing absolute mass scale neutrino. After first tritium commissioning campaign in 2018, has been regularly running since 2019, and its two measurement campaigns already achieved sub-eV sensitivity. 1000 days data-taking, KATRIN’s design sensitivity 0.2 eV at 90% confidence level. In this white paper we describe current...
We present eight new T4.5-T7.5 dwarfs identified in the UKIRT Infrared Deep Sky Survey (UKIDSS) Large Area (LAS) Data Release 1 (DR1). In addition we have recovered T4.5 dwarf SDSS J020742.91+000056.2 and T8.5 ULAS J003402.77-005206.7. Photometric candidates were picked up two-colour diagrams over 190 square degrees (DR1) selected at least two filters. All exhibit near-infrared spectra with strong methane water absorption bands characteristic of T derived spectral types follow unified scheme...
The design and construction of CARMENES has been presented at previous SPIE conferences. It is a next-generation radial-velocity instrument the 3.5m telescope Calar Alto Observatory, which was built by consortium eleven Spanish German institutions. consists two separate échelle spectrographs covering wavelength range from 0.52 to 1.71μm spec-tral resolution R < 80,000, fed fibers Cassegrain focus telescope. saw "First Light" on Nov 9, 2015. During commissioning initial operation phases, we...
Abstract The determination of the neutrino mass is one major challenges in astroparticle physics today. Direct experiments, based solely on kinematics $$\upbeta $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>β</mml:mi></mml:math> -decay, provide a largely model-independent probe to scale. Karlsruhe Tritium Neutrino (KATRIN) experiment designed directly measure effective electron antineutrino with sensitivity $$0.2\hbox { eV}$$...
Background: The MAJORANA DEMONSTRATOR , a modular array of isotopically enriched high-purity germanium (HPGe) detectors, was constructed to demonstrate backgrounds low enough justify building tonne-scale experiment search for the neutrinoless double-beta decay ($\beta\beta(0\nu)$) $^{76}\mathrm{Ge}$. Purpose: This paper presents description instrument, its commissioning, and operations. It covers electroforming, underground infrastructure, enrichment, detector fabrication, low-background...
Abstract Neutrinoless double-beta decay (0νββ) is a rare nuclear process that, if observed, will provide insight into the nature of neutrinos and help explain matter-antimatter asymmetry in universe. The Large Enriched Germanium Experiment for Double-Beta Decay (LEGEND) operate two phases to search 0νββ. first (second) stage employ 200 (1000) kg High-Purity (HPGe) enriched 76 Ge achieve half-life sensitivity 10 27 (10 28 ) years. In this study, we present semi-supervised data-driven approach...
We report the discovery of a transiting brown dwarf orbiting low-mass star, TOI-6508,b. Today, only ∼50 dwarfs have been discovered. TOI-6508,b was first detected with data from Transiting Exoplanet Survey Satellite ( TESS ) in Sectors 10, 37 and 63. Ground-based follow-up photometric were collected SPECULOOS-South (Search for habitable Planets EClipsing ULtra-cOOl Stars) LCOGT-1m telescopes, RV measurements obtained Near InfraRed Planet Searcher (NIRPS) spectrograph. find that has mass M_p...
Substellar objects, including brown dwarfs and free-floating planetary-mass are a significant product of star formation. Their sensitivity to initial conditions early dynamical evolution makes them especially valuable for studying planetary stellar formation processes. We search isolated mass objects in young star-forming region better constrain their mechanisms. took advantage the unprecedented sensitivity, spatial resolution wide field view LDN 1495 Taurus molecular clouds. combined recent...
Context. Extrasolar-planet searches that target very low-mass stars and brown dwarfs are hampered by intrinsic or instrumental limitations. Time series of astrometric measurements with precisions better than one milli-arcsecond can yield new evidence on the planet occurrence around these objects.
The Karlsruhe Tritium Neutrino (KATRIN) experiment is a large-scale effort to probe the absolute neutrino mass scale with sensitivity of 0.2 eV (90% confidence level), via precise measurement endpoint spectrum tritium β-decay. This work documents several KATRIN commissioning milestones: complete assembly experimental beamline, successful transmission electrons from three sources through beamline primary detector, and tests ion transport retention. In First Light campaign autumn 2016,...
The KATRIN experiment will probe the neutrino mass by measuring β-electron energy spectrum near endpoint of tritium β-decay. An integral analysis be performed an electro-static spectrometer (``Main Spectrometer''), ultra-high vacuum vessel with a length 23.2 m, volume 1240 m3, and complex inner electrode system about 120 000 individual parts. strong magnetic field that guides β-electrons is provided super-conducting solenoids at both ends spectrometer. Its influence on turbo-molecular pumps...
With excellent energy resolution and ultralow-level radiogenic backgrounds, the high-purity germanium detectors in Majorana Demonstrator enable searches for several classes of exotic dark matter (DM) models. In this work, we report new experimental limits on keV-scale sterile neutrino DM via transition magnetic moment from conversion to active neutrinos νs→νa. We fermionic absorption (χ+A→ν+A) sub-GeV DM-nucleus 3→2 scattering (χ+χ+A→ϕ+A), exclusion bosonic (axionlike particles photons)....
We observed VB 10 in August and September 2009 using the FORS2 camera of VLT with aim measuring its astrometric motion probing presence announced planet 10b. used published STEPS positions over a time-span 9 years, which allowed us to compare expected due parallax proper compute precise deviations. The achieved single-epoch precisions our observations are about 0.1 mas data showed no significant residual trend, while should have induced an apparent larger than mas/yr. Subtraction predicted...
The KATRIN experiment aims for the determination of effective electron anti-neutrino mass from tritium beta-decay with an unprecedented sub-eV sensitivity. strong magnetic fields, designed up to 6~T, adiabatically guide $\beta$-electrons source detector within a flux 191~Tcm$^2$. A chain ten single solenoid magnets and two larger superconducting magnet systems have been designed, constructed, installed in 70-m-long beam line. diameter varies 0.064~m 9~m, depending on density along Two...
The neutrino mass experiment KATRIN requires a stability of 3 ppm for the retarding potential at − 18.6 kV main spectrometer. To monitor stability, two custom-made ultra-precise high-voltage dividers were developed and built in cooperation with German national metrology institute Physikalisch-Technische Bundesanstalt (PTB). Until now, regular absolute calibration voltage required bringing equipment to specialised laboratory. Here we present new method based on measuring energy difference...