J. Ruz

ORCID: 0000-0002-3253-7027
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About
Contact & Profiles
Research Areas
  • Dark Matter and Cosmic Phenomena
  • Particle Detector Development and Performance
  • Particle physics theoretical and experimental studies
  • Atomic and Subatomic Physics Research
  • Astrophysics and Cosmic Phenomena
  • Radiation Detection and Scintillator Technologies
  • Cosmology and Gravitation Theories
  • Nuclear Physics and Applications
  • Solar and Space Plasma Dynamics
  • Nuclear reactor physics and engineering
  • Neutrino Physics Research
  • Photocathodes and Microchannel Plates
  • Astronomy and Astrophysical Research
  • CCD and CMOS Imaging Sensors
  • Superconducting Materials and Applications
  • Scientific Research and Discoveries
  • Particle Accelerators and Free-Electron Lasers
  • Nuclear Materials and Properties
  • Particle accelerators and beam dynamics
  • Fault Detection and Control Systems
  • Geophysics and Gravity Measurements
  • Radioactive Decay and Measurement Techniques
  • Age of Information Optimization
  • Radio Astronomy Observations and Technology
  • Computational Physics and Python Applications

Universidad de Zaragoza
2009-2024

Lawrence Livermore National Laboratory
2015-2024

University of Bonn
2022

Barry University
2017

Universidad Nacional Autónoma de México
2016

Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2015

Lawrence Livermore National Security
2013-2015

Institut de Recherche sur les Lois Fondamentales de l'Univers
2015

CEA Paris-Saclay
2015

European Organization for Nuclear Research
2010-2014

Hypothetical low-mass particles, such as axions, provide a compelling explanation for the dark matter in universe. Such particles are expected to emerge abundantly from hot interior of stars. To test this prediction, CERN Axion Solar Telescope (CAST) uses 9 T refurbished Large Hadron Collider magnet directed towards Sun. In strong magnetic field, solar axions can be converted X-ray photons which recorded by detectors. 2013–2015 run, thanks low-background detectors and new telescope,...

10.1038/nphys4109 article EN cc-by Nature Physics 2017-05-01

We have searched for solar axions or similar particles that couple to two photons by using the CERN Axion Solar Telescope (CAST) setup with improved conditions in all detectors. From absence of excess X-rays when magnet was pointing Sun, we set an upper limit on axion-photon coupling 8.8 x 10^{-11} GeV^{-1} at 95% CL m_a <~ 0.02 eV. This result is best experimental over a broad range axion masses and eV also supersedes previous derived from energy-loss arguments globular-cluster stars.

10.1088/1475-7516/2007/04/010 article EN Journal of Cosmology and Astroparticle Physics 2007-04-17

The International Axion Observatory (IAXO) will be a forth generation axion helioscope. As its primary physics goal, IAXO look for axions or axion-like particles (ALPs) originating in the Sun via Primakoff conversion of solar plasma photons. In terms signal-to-noise ratio, about 4–5 orders magnitude more sensitive than CAST, currently most powerful helioscope, reaching sensitivity to axion-photon couplings down few × 10−12 GeV−1 and thus probing large fraction unexplored ALP parameter space....

10.1088/1748-0221/9/05/t05002 article EN cc-by Journal of Instrumentation 2014-05-12

Hypothetical axionlike particles with a two-photon interaction would be produced in the sun by Primakoff process. In laboratory magnetic field ("axion helioscope"), they transformed into x-rays energies of few keV. Using decommissioned Large Hadron Collider test magnet, CERN Axion Solar Telescope ran for about 6 months during 2003. The first results from analysis these data are presented here. No signal above background was observed, implying an upper limit to axion-photon coupling...

10.1103/physrevlett.94.121301 article EN Physical Review Letters 2005-04-01

We have searched for solar axions or other pseudoscalar particles that couple to two photons by using the CERN Axion Solar Telescope (CAST) setup. Whereas we previously reported results from CAST with evacuated magnet bores (Phase I), setting limits on lower mass axions, here report where were filled 4He gas II) of variable pressure. The introduction generates a refractive photon mγ, thereby achieving maximum possible conversion rate those axion masses ma match mγ. With 160 different...

10.1088/1475-7516/2009/02/008 article EN Journal of Cosmology and Astroparticle Physics 2009-02-09

Dark sectors, consisting of new, light, weakly-coupled particles that do not interact with the known strong, weak, or electromagnetic forces, are a particularly compelling possibility for new physics. Nature may contain numerous dark each their own beautiful structure, distinct particles, and forces. This review summarizes physics motivation sectors exciting opportunities experimental exploration. It is summary Intensity Frontier subgroup "New, Light, Weakly-coupled Particles" Community...

10.48550/arxiv.1311.0029 preprint EN other-oa arXiv (Cornell University) 2013-01-01

The CERN Axion Solar Telescope (CAST) has extended its search for solar axions by using 3He as a buffer gas. At T=1.8 K this allows larger pressure settings and hence sensitivity to higher axion masses than our previous measurements with 4He. With about 1 h of data taking at each 252 different we have scanned the mass range 0.39 eV < m_a 0.64 eV. From absence excess X-rays when magnet was pointing Sun set typical upper limit on axion-photon coupling g_ag 2.3 x 10^{-10} GeV^{-1} 95% CL, exact...

10.1103/physrevlett.107.261302 article EN cc-by Physical Review Letters 2011-12-23

We study the feasibility of a new generation axion helioscope, most ambitious and promising detector solar axions to date. show that large improvements in magnetic field volume, x-ray focusing optics backgrounds are possible beyond those achieved CERN Axion Solar Telescope (CAST). For hadronic models, sensitivity axion-photon coupling gaγ ≳ few × 10−12 GeV−1 is conceivable, 1–1.5 orders magnitude CAST sensitivity. If also couple electrons, Sun produces larger flux for same value Peccei-Quinn...

10.1088/1475-7516/2011/06/013 article EN Journal of Cosmology and Astroparticle Physics 2011-06-10

A new Micromegas manufacturing technique, based on kapton etching technology, has been developed recently, resulting in further improvement of the characteristics detector, such as uniformity and stability. Excellent energy resolution obtained, reaching 11% FWHM for 5.9 keV photon peak the55Fe X-ray source 1.8% (with possible evidence less than 1%) 5.5 MeV alpha 241Am source. The Microbulk detector shows several advantages like flexible structure, low material high radio-purity, opening thus...

10.1088/1748-0221/5/02/p02001 article EN Journal of Instrumentation 2010-02-01

The CERN Axion Solar Telescope has finished its search for solar axions with (3)He buffer gas, covering the range 0.64 eV ≲ ma 1.17 eV. This closes gap to cosmological hot dark matter limit and actually overlaps it. From absence of excess x rays when magnet was pointing Sun we set a typical upper on axion-photon coupling gaγ 3.3 × 10(-10) GeV(-1) at 95% C.L., exact value depending pressure setting. Future direct axion searches will focus increasing sensitivity smaller values gaγ, example by...

10.1103/physrevlett.112.091302 article EN cc-by Physical Review Letters 2014-03-04

We review the physics potential of a next generation search for solar axions: International Axion Observatory (IAXO) . Endowed with sensitivity to discover axion-like particles (ALPs) coupling photons as small gaγ∼ 10−12 GeV−1, or electrons gae∼10−13, IAXO has find QCD axion in 1 meV∼1 eV mass range where it solves strong CP problem, can account cold dark matter Universe and be responsible anomalous cooling observed number stellar systems. At same time, will have enough detect lower axions...

10.1088/1475-7516/2019/06/047 article EN Journal of Cosmology and Astroparticle Physics 2019-06-24

A bstract We present results of the Relic Axion Dark-Matter Exploratory Setup (RADES), a detector which is part CERN Solar Telescope (CAST), searching for axion dark matter in 34.67 μ eV mass range. radio frequency cavity consisting 5 sub-cavities coupled by inductive irises took physics data inside CAST dipole magnet first time using this filter-like haloscope geometry. An exclusion limit with 95% credibility level on axion-photon coupling constant g aγ ≳ 4 × 10 − 13 GeV 1 over range 34 ....

10.1007/jhep10(2021)075 article EN cc-by Journal of High Energy Physics 2021-10-01

The CAST-CAPP axion haloscope, operating at CERN inside the CAST dipole magnet, has searched for axions in 19.74 $\mu$eV to 22.47 mass range. detection concept follows Sikivie haloscope principle, where Dark Matter convert into photons within a resonator immersed magnetic field. is an array of four individual rectangular cavities inserted strong phase-matched maximize sensitivity. Here we report on data acquired 4124 h from 2019 2021. Each cavity equipped with fast frequency tuning mechanism...

10.1038/s41467-022-33913-6 article EN cc-by Nature Communications 2022-10-19

In non-hadronic axion models, which have a tree-level axion-electron interaction, the Sun produces strong flux by bremsstrahlung, Compton scattering, and axio-recombination, ``BCA processes.'' Based on new calculation of this flux, including for first time we derive limits Yukawa coupling gae axion-photon interaction strength gaγ using CAST phase-I data (vacuum phase). For ma≲10 meV/c2 find < 8.1 × 10−23 GeV−1 at 95% CL. We stress that next-generation helioscope such as proposed IAXO could...

10.1088/1475-7516/2013/05/010 article EN cc-by Journal of Cosmology and Astroparticle Physics 2013-05-09

Abstract A finite axion–nucleon coupling, nearly unavoidable for QCD axions, leads to the production of axions via thermal excitation and subsequent de-excitation $$^{57}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mrow /> <mml:mn>57</mml:mn> </mml:msup> </mml:math> Fe isotopes in sun. We revise solar bound on this flux adopting up date emission rate, investigate sensitivity proposed International Axion Observatory IAXO its intermediate stage BabyIAXO detect...

10.1140/epjc/s10052-022-10061-1 article EN cc-by The European Physical Journal C 2022-02-01

Abstract Dark (hidden) photons are widely recognised as well motivated candidates for physics beyond the standard model, and have been invoked solution of several outstanding problems, including to account dark matter in universe. In this paper, we consider a simple model photons, which is coupled ordinary only through kinetic mixing with photons. Within framework, calculate flux solar on Earth revise potential detect it next generation axion helioscopes, particularly International AXion...

10.1088/1475-7516/2024/06/070 article EN Journal of Cosmology and Astroparticle Physics 2024-06-01

The CERN Axion Solar Telescope (CAST) searches for $a\ensuremath{\rightarrow}\ensuremath{\gamma}$ conversion in the 9 T magnetic field of a refurbished LHC test magnet that can be directed toward Sun. Two parallel bores filled with helium adjustable pressure to match x-ray refractive mass ${m}_{\ensuremath{\gamma}}$ axion search ${m}_{a}$. After vacuum phase (2003--2004), which is optimal ${m}_{a}\ensuremath{\lesssim}0.02\text{ }\text{ }\mathrm{eV}$, we used $^{4}\mathrm{He}$ 2005--2007...

10.1103/physrevd.92.021101 article EN cc-by Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D, Particles, fields, gravitation, and cosmology 2015-07-28

10.1016/j.net.2025.103462 article EN cc-by-nc-nd Nuclear Engineering and Technology 2025-01-01

A low-background Micromegas detector has been operating in the CAST experiment at CERN for search solar axions during first phase of (2002–2004). The detector, made out low radioactivity materials, operated efficiently and achieved a very high level background rejection (5 × 10−5 counts keV−1 cm−2 s−1) without shielding.

10.1088/1367-2630/9/6/170 article EN cc-by New Journal of Physics 2007-06-22

We have searched for 14.4 keV solar axions or more general axion-like particles (ALPs), that may be emitted in the M1 nuclear transition of 57Fe, by using axion-to-photon conversion CERN Axion Solar Telescope (CAST) with evacuated magnet bores (Phase I). From absence excess monoenergetic X-rays when was pointing to Sun, we set model-independent constraints on coupling constants pseudoscalar couple two photons and a nucleon gaγ|−1.19gaN0+gaN3| < 1.36 × 10−16 GeV−1 ma 0.03 eV at 95% confidence level.

10.1088/1475-7516/2009/12/002 article EN Journal of Cosmology and Astroparticle Physics 2009-12-02

In this work we present a search for (solar) chameleons with the CERN Axion Solar Telescope (CAST). This novel experimental technique, in field of dark energy research, exploits both chameleon coupling to matter (βm) and photons (βγ) via Primakoff effect. By reducing X-ray detection threshold used axions from 1 keV 400 eV CAST became sensitive converted solar spectrum which peaks around 600 eV. Even though have not observed any excess above background, can provide 95% C.L. limit strength...

10.1016/j.physletb.2015.07.049 article EN cc-by Physics Letters B 2015-07-28

We report on the design, construction and operation of a low background x-ray detection line composed shielded Micromegas detector microbulk technology. The is made from radiopure materials placed at focal point ∼ 5 cm diameter, 1.5 m focal-length, cone-approximation Wolter I telescope (XRT) assembled thermally-formed (or "slumped") glass substrates deposited with multilayer coatings. system has been conceived as technological pathfinder for future International Axion Observatory (IAXO), it...

10.1088/1475-7516/2015/12/008 article EN Journal of Cosmology and Astroparticle Physics 2015-12-03

We propose a novel detection concept for neutrinoless double-beta decay searches. This is based on Time Projection Chamber (TPC) filled with high-pressure gaseous xenon, and separated-function capabilities calorimetry tracking. Thanks to its excellent energy resolution, together powerful background rejection provided by the distinct topological signature, design discussed in this Letter Of Intent promises be competitive possibly out-perform existing proposals next-generation experiments....

10.48550/arxiv.0907.4054 preprint EN other-oa arXiv (Cornell University) 2009-01-01
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