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11 results on '"Neff, S."'

1. New CAST Limit on the Axion-Photon Interaction

Author

CAST collaboration, Anastassopoulos, V., Aune, S., Barth, K., Belov, A., Brauninger, H., Cantatore, G., Carmona, J. M., Castel, J. F., Cetin, S. A., Christensen, F., Collar, J. I., Dafni, T., Davenport, M., Decker, T. A., Dermenev, A., Desch, K., Eleftheriadis, C., Fanourakis, G., Ferrer-Ribas, E., Fischer, H., Garcia, J. A., Gardikiotis, A., Garza, J. G., Gazis, E. N., Geralis, T., Giomataris, I., Gninenko, S., Hailey, C. J., Hasinoff, M. D., Hoffmann, D. H. H., Iguaz, F. J., Irastorza, I. G., Jakobsen, A., Jacoby, J., Jakovcic, K., Kaminski, J., Karuza, M., Kralj, N., Krcmar, M., Kostoglou, S., Krieger, Ch., Lakic, B., Laurent, J. M., Liolios, A., Ljubicic, A., Luzon, G., Maroudas, M., Miceli, L., Neff, S., Ortega, I., Papaevangelou, T., Paraschou, K., Pivovaroff, M. J., Raffelt, G., Rosu, M., Ruz, J., Choliz, E. Ruiz, Savvidis, I., Schmidt, S., Semertzidis, Y. K., Solanki, S. K., Stewart, L., Vafeiadis, T., Vogel, J. K., Yildiz, S. C., Zioutas, K., Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, CAST, Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, Anastassopoulos, V., Aune, S., Barth, K., Belov, A., Bräuninger, H., Cantatore, Giovanni, Carmona, J. M., Castel, J. F., Cetin, S. A., Christensen, F., Collar, J. I., Dafni, T., Davenport, M., Decker, T. A., Dermenev, A., Desch, K., Eleftheriadis, C., Fanourakis, G., Ferrer Ribas, E., Fischer, H., García, J. A., Gardikiotis, A., Garza, J. G., Gazis, E. N., Geralis, T., Giomataris, I., Gninenko, S., Hailey, C. J., Hasinoff, M. D., Hoffmann, D. H. H., Iguaz, F. J., Irastorza, I. G., Jakobsen, A., Jacoby, J., Jakovčić, K., Kaminski, J., Karuza, M., Kralj, N., Krčmar, M., Kostoglou, S., Krieger, C. h., Lakić, B., Laurent, J. . m., Liolios, A., Ljubičić, A., Luzón, G., Maroudas, M., Miceli, L., Neff, S., Ortega, I., Papaevangelou, T., Paraschou, K., Pivovaroff, M. J., Raffelt, G., Rosu, M., Ruz, J., Chóliz, E. Ruiz, Savvidis, I., Schmidt, S., Semertzidis, Y. . k., Solanki, S. K., Stewart, L., Vafeiadis, T., Vogel, J. K., Yildiz, S. C., and Zioutas, K.

Subjects
solar axion, Photon, Physics - Instrumentation and Detectors, Physics::Instrumentation and Detectors, General Physics and Astronomy, magnetic field, 01 natural sciences, 7. Clean energy, law.invention, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Axion, law, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Detectors and Experimental Techniques, physics.ins-det, [ PHYS.PHYS.PHYS-INS-DET ] Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Physics, Large Hadron Collider, Instrumentation and Detectors (physics.ins-det), Axions, solar axions, axion helioscope, dark matter, axion-like particles, CERN LHC Coll, S029IAG, CAST, axion: mass, Astrophysics::Earth and Planetary Astrophysics, CERN Axion Solar Telescope, Particle Physics - Experiment, Particle physics, CERN Lab, Dark matter, FOS: Physical sciences, Telescope, Nuclear physics, [ PHYS.HEXP ] Physics [physics]/High Energy Physics - Experiment [hep-ex], 0103 physical sciences, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], 010306 general physics, Coupling constant, Helioscope, hep-ex, 010308 nuclear & particles physics, background, coupling constant, axions, dark matter, axion helisocope, axion-photon coupling, sensitivity, magnet, coupling: (axion 2photon), High Energy Physics::Experiment, axion: solar, experimental results
Abstract

During 2003--2015, the CERN Axion Solar Telescope (CAST) has searched for $a\to\gamma$ conversion in the 9 T magnetic field of a refurbished LHC test magnet that can be directed toward the Sun. In its final phase of solar axion searches (2013--2015), CAST has returned to evacuated magnet pipes, which is optimal for small axion masses. The absence of a significant signal above background provides a world leading limit of $g_{a\gamma} < 0.66 \times 10^{-10} {\rm GeV}^{-1}$ (95% C.L.) on the axion-photon coupling strength for $m_a \lesssim 0.02$ eV. Compared with the first vacuum phase (2003--2004), the sensitivity was vastly increased with low-background x-ray detectors and a new x-ray telescope. These innovations also serve as pathfinders for a possible next-generation axion helioscope., Comment: Second version after referees comments (post-print). Published version available Open Access at https://www.nature.com/articles/nphys4109

Published
2017
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2. Search for Solar Axions by the CERN Axion Solar Telescope with He3 Buffer Gas: Closing the Hot Dark Matter Gap

Author

Arik, M., Aune, S., Barth, K., Belov, A., Borghi, S., Brauninger, H., Cantatore, Giovanni, Carmona, J. M., Cetin, S. A., Da Riva, J. I. Collar E., Dafni, T., Davenport, M., Eleftheriadis, C., Elias, N., Fanourakis, G., Ferrer Ribas, E., Friedrich, P., Galan, J., Garcia, J. A., Gardikiotis, A., Garza, J. G., Gazis, E. N., Geralis, T., Georgiopoulou, E., Giomataris, I., Gninenko, S., Gomez, H., Gomez Marzoa, M., Gruber, E., Guthorl, T., Hartmann, R., Hauf, S., Haug, F., Hasinoff, M. D., Hoffmann, D. H. H., Iguaz, F. J., Irastorza, I. G., Jacoby, J., Jakovcic, K., Karuza, M., Konigsmann, K., Kotthaus, R., Krcmar, M., Kuster, M., Lakic, B., Lang, P. M., Laurent, J. M., Liolios, A., Ljubicic, A., Lozza, V., Luzon, G., Neff, S., Niinikoski, T., Nordt, A., Papaevangelou, T., Pivovaroff, M. J., Raffelt, G., Riege, H., Rodriguez, A., Rosu, M., Ruz, J., Savvidis, I., Shilon, I., Silva, P. S., Solanki, S. K., Stewart, L., Tomas, A., Tsagri, M., van Bibber, K., Vafeiadis, T., Villar, J., Vogel, J. K., Yildiz, S. C., Zioutas, K., M., Arik, S., Aune, K., Barth, A., Belov, S., Borghi, H., Brauninger, Cantatore, Giovanni, J. M., Carmona, S. A., Cetin, J. I. Collar E., Da Riva, T., Dafni, M., Davenport, C., Eleftheriadi, N., Elia, G., Fanouraki, E., Ferrer Riba, P., Friedrich, J., Galan, J. A., Garcia, A., Gardikioti, J. G., Garza, E. N., Gazi, T., Gerali, E., Georgiopoulou, I., Giomatari, S., Gninenko, H., Gomez, M., Gomez Marzoa, E., Gruber, T., Guthorl, R., Hartmann, S., Hauf, F., Haug, M. D., Hasinoff, D. H. H., Hoffmann, F. J., Iguaz, I. G., Irastorza, J., Jacoby, K., Jakovcic, M., Karuza, K., Konigsmann, R., Kotthau, M., Krcmar, M., Kuster, B., Lakic, P. M., Lang, J. M., Laurent, A., Liolio, A., Ljubicic, V., Lozza, G., Luzon, S., Neff, T., Niinikoski, A., Nordt, T., Papaevangelou, M. J., Pivovaroff, G., Raffelt, H., Riege, A., Rodriguez, M., Rosu, J., Ruz, I., Savvidi, I., Shilon, P. S., Silva, S. K., Solanki, L., Stewart, A., Toma, M., Tsagri, K., van Bibber, T., Vafeiadi, J., Villar, J. K., Vogel, S. C., Yildiz, and K., Zioutas

Subjects
solar axions, dark matter, Photon detection, solar axion, Physics::Instrumentation and Detectors, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics
Abstract

The CERN Axion Solar Telescope (CAST) has finished its search for solar axions with 3^He buffer gas, covering the search range 0.64 eV < m_a

Published
2014

3. Search for solar axions by the CERN axion solar telescope with He 3 buffer gas: Closing the hot dark matter gap

Author

Arik, M., Aune, S., Barth, K., Belov, A., Borghi, S., Bräuninger, H., Cantatore, G., Carmona, J.M., Cetin, S.A., Collar, J.I., Da Riva, E., Dafni, T., Davenport, M., Eleftheriadis, C., Elias, N., Fanourakis, G., Ferrer-Ribas, E., Friedrich, P., Galán, J., García, J.A., Gardikiotis, A., Garza, J.G., Gazis, E.N., Geralis, T., Georgiopoulou, E., Giomataris, I., Gninenko, S., Gómez, H., Gómez Marzoa, M., Gruber, E., Guthörl, T., Hartmann, R., Hauf, S., Haug, F., Hasinoff, M.D., Hoffmann, D.H.H., Iguaz, F.J., Irastorza, I.G., Jacoby, J., Jakovcic, K., Karuza, M., Königsmann, K., Kotthaus, R., Krcmar, M., Kuster, M., Lakic, B., Lang, P.M., Laurent, J.M., Liolios, A., Ljubicic, A., Luzón, G., Neff, S., Niinikoski, T., Nordt, A., Papaevangelou, T., Pivovaroff, M.J., Raffelt, G., Riege, H., Rodríguez, A., Rosu, M., Ruz, J., Savvidis, I., Shilon, I., Silva, P.S., Solanki, S.K., Stewart, L., Tomás, A., Tsagri, M., Van Bibber, K., Vafeiadis, T., Villar, J., Vogel, J.K., Yildiz, S.C., and Zioutas, K.

Subjects
Physics::Instrumentation and Detectors, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics
Abstract

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

Published
2014

4. Search for solar axions by the CERN axion solar telescope with 3He buffer gas: closing the hot dark matter gap

Author

Arik, M., Aune, S., Barth, K., Belov, A., Borghi, S., Bräuninger, H., Cantatore, G., Carmona, J.M., Cetin, S.A., Collar, J.I., Da Riva, E., Dafni, T., Davenport, M., Eleftheriadis, C., Elias, N., Fanourakis, G., Ferrer-Ribas, E., Friedrich, P., Galán, J., García, J.A., Gardikiotis, A., Garza, J.G., Gazis, E.N., Geralis, T., Georgiopoulou, E., Giomataris, I., Gninenko, S., Gómez, H., Gómez Marzoa, M., Gruber, E., Guthörl, T., Hartmann, R., Hauf, S., Haug, F., Hasinoff, M.D., Hoffmann, D.H.H., Iguaz, F.J., Irastorza, I.G., Jacoby, J., Jakovčić, Krešimir, Karuza, Marin, Königsmann, K., Kotthaus, R., Krčmar, Milica, Kuster, M., Lakić, Biljana, Lang, P.M., Laurent, J.M., Liolios, A., Ljubičić, Ante, Luzón, G., Neff, S., Niinikoski, T., Nordt, A., Papaevangelou, T., Pivovaroff, M.J., Raffelt, G., Riege, H., Rodríguez, A., Rosu, M., Ruz, J., Savvidis, I., Shilon, I., Silva, P.S., Solanki, S.K., Stewart, L., Tomás, A., Tsagri, M., van Bibber, K., Vafeiadis, T., Villar, J., Vogel, J.K., Yildiz, S.C., and Zioutas, K.

Subjects
Physics::Instrumentation and Detectors, High Energy Physics::Phenomenology, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, solar axions, photons, dark matter
Abstract

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

Published
2013

5. CAST solar axion search with 3^He buffer gas: Closing the hot dark matter gap

Author

Arik, M., Aune, S., Barth, K., Belov, A., Borghi, S., Brauninger, H., Cantatore, G., Carmona, J. M., Cetin, S. A., Collar, J. I., Da Riva, E., Dafni, T., Davenport, M., Eleftheriadis, C., Elias, N., Fanourakis, G., Ferrer-Ribas, E., Friedrich, P., Galan, J., Garcia, J. A., Gardikiotis, A., Garza, J. G., Gazis, E. N., Geralis, T., Georgiopoulou, E., Giomataris, I., Gninenko, S., Gomez, H., Marzoa, M. Gomez, Gruber, E., Guthorl, T., Hartmann, R., Hauf, S., Haug, F., Hasinoff, M. D., Hoffmann, D. H. H., Iguaz, F. J., Irastorza, I. G., Jacoby, J., Jakovcic, K., Karuza, M., Konigsmann, K., Kotthaus, R., Krcmar, M., Kuster, M., Lakic, B., Lang, P. M., Laurent, J. M., Liolios, A., Ljubicic, A., Lozza, V., Luzon, G., Neff, S., Niinikoski, T., Nordt, A., Papaevangelou, T., Pivovaroff, M. J., Raffelt, G., Riege, H., Rodriguez, A., Rosu, M., Ruz, J., Savvidis, I., Shilon, I., Silva, P. S., Solanki, S. K., Stewart, L., Tomas, A., Tsagri, M., van Bibber, K., Vafeiadis, T., Villar, J., Vogel, J. K., Yildiz, S. C., and Zioutas, K.

Subjects
High Energy Physics - Experiment (hep-ex), Physics - Instrumentation and Detectors, Physics::Instrumentation and Detectors, High Energy Physics::Phenomenology, Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Earth and Planetary Astrophysics, Instrumentation and Detectors (physics.ins-det), Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), High Energy Physics - Experiment
Abstract

The CERN Axion Solar Telescope (CAST) has finished its search for solar axions with 3^He buffer gas, covering the search range 0.64 eV < m_a, 5 pages, 2 figures. Last version uploaded

Published
2013
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6. The GALEX Time Domain Survey I. Selection and Classification of Over a Thousand UV Variable Sources

Author

Gezari, S., Martin, D. C., Forster, K., Neill, J. D., Huber, M., Heckman, T., Bianchi, L., Morrissey, P., Neff, S. G., Seibert, M., Schiminovich, D., Wyder, T. K., Burgett, W. S., Chambers, K. C., Kaiser, N., Magnier, E. A., Price, P. A., and Tonry, J. L.

Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO), Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present the selection and classification of over a thousand ultraviolet (UV) variable sources discovered in ~ 40 deg^2 of GALEX Time Domain Survey (TDS) NUV images observed with a cadence of 2 days and a baseline of observations of ~ 3 years. The GALEX TDS fields were designed to be in spatial and temporal coordination with the Pan-STARRS1 Medium Deep Survey, which provides deep optical imaging and simultaneous optical transient detections via image differencing. We characterize the GALEX photometric errors empirically as a function of mean magnitude, and select sources that vary at the 5\sigma level in at least one epoch. We measure the statistical properties of the UV variability, including the structure function on timescales of days and years. We report classifications for the GALEX TDS sample using a combination of optical host colors and morphology, UV light curve characteristics, and matches to archival X-ray, and spectroscopy catalogs. We classify 62% of the sources as active galaxies (358 quasars and 305 active galactic nuclei), and 10% as variable stars (including 37 RR Lyrae, 53 M dwarf flare stars, and 2 cataclysmic variables). The remaining unclassified sources include UV-bright extragalactic transients, two of which have been spectroscopically confirmed to be a young core-collapse supernova and a flare from the tidal disruption of a star by dormant supermassive black hole. We calculate a surface density for variable sources in the UV with NUV < 23 mag and |\Delta m| > 0.2 mag of ~ 8.0, 7.7, and 1.8 deg^-2 for quasars, AGNs, and RR Lyrae stars, respectively. We also calculate a surface density rate in the UV for transient sources, using the effective survey time at the cadence appropriate to each class, of ~ 15 and 52 deg^-2 yr^-1 for M dwarfs and extragalactic transients, respectively. (Abridged.), Comment: Accepted for publication in ApJ, 14 pages, 19 figures, 4 tables

Published
2013
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7. Imaging of z~2 QSO host galaxies with the Hubble Space Telescope

Author

Hutchings, J. B., Frenette, D., Hanisch, R., Mo, J., Dumont, P. J., Redding, D. C., and Neff, S. G.

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

We report on deep imaging in 2 filters with the PC2 camera of HST, of five QSOs at redshift ~2, with a range of optical and radio luminosity. The observations included a suite of PSF observations which were used to construct new PSF models, described elsewhere by Dumont et al. The new PSF models were used to remove the QSO nucleus from the images. We find that the host galaxies have resolved flux of order 10% of the QSO nuclei, and are generally luminous and blue, indicating active star-formation. While most have clearly irregular morphologies, the bulk of the flux can be modelled approximately by an r**1/4 law. However, all host galaxies also have an additional approximately exponential luminosity profile beyond a radius about 0.8 arcsec, as also seen in ground-based data with larger telescopes. The QSOs all have a number of nearby faint blue companions which may be young galaxies at the QSO redshift. We discuss implications for evolution of the host galaxies, their spheroidal populations, and central black holes., Comment: 18 pages including 2 tables; to appear in AJ

Published
2002
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8. The Emergence of the Modern Universe: Tracing the Cosmic Web

Author

Shull, J. M., Savage, B. D., Morse, J. A., Neff, S. G., Clarke, J. T., Heckman, T., Kinney, A. L., Jenkins, E. B., Dupree, A. K., Baum, S. A., and Hasan, H.

Subjects
Astrophysics (astro-ph), Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

This is the report of the Ultraviolet-Optical Working Group (UVOWG) commissioned by NASA to study the scientific rationale for new missions in ultraviolet/optical space astronomy approximately ten years from now, when the Hubble Space Telescope (HST) is de-orbited. The UVOWG focused on a scientific theme, The Emergence of the Modern Universe, the period from redshifts z = 3 to 0, occupying over 80% of cosmic time and beginning after the first galaxies, quasars, and stars emerged into their present form. We considered high-throughput UV spectroscopy (10-50x throughput of HST/COS) and wide-field optical imaging (at least 10 arcmin square). The exciting science to be addressed in the post-HST era includes studies of dark matter and baryons, the origin and evolution of the elements, and the major construction phase of galaxies and quasars. Key unanswered questions include: Where is the rest of the unseen universe? What is the interplay of the dark and luminous universe? How did the IGM collapse to form the galaxies and clusters? When were galaxies, clusters, and stellar populations assembled into their current form? What is the history of star formation and chemical evolution? Are massive black holes a natural part of most galaxies? A large-aperture UV/O telescope in space (ST-2010) will provide a major facility in the 21st century for solving these scientific problems. The UVOWG recommends that the first mission be a 4m aperture, SIRTF-class mission that focuses on UV spectroscopy and wide-field imaging. In the coming decade, NASA should investigate the feasibility of an 8m telescope, by 2010, with deployable optics similar to NGST. No high-throughput UV/Optical mission will be possible without significant NASA investments in technology, including UV detectors, gratings, mirrors, and imagers., Report of UV/O Working Group to NASA, 72 pages, 13 figures, Full document with postscript figures available at http://casa.colorado.edu/~uvconf/UVOWG.html

Published
1999

9. Star Formation Triggering Mechanisms in Dwarf Galaxies: The Far-Ultraviolet, H-alpha, and HI Morphology of Holmberg II

Author

Stewart, S. G., Fanelli, M. N., Byrd, G. G., Hill, J. K., Westpfahl, D. J., Cheng, K. P., O'Connell, R. W., Roberts, M. S., Neff, S. G., Smith, A. M., and Stecher, T. P.

Subjects
Astrophysics (astro-ph), Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

Far-UV (FUV), H-alpha, and HI observations of dwarf galaxy Holmberg II are used to trace the interaction between sites of massive star formation and the neutral and ionized components of the surrounding ISM. The data emphasize the importance of local conditions in regulating star formation from evidence such as massive stars inside ionized shells, compact HII regions surrounding aging clusters, and stars formed in chains of progressing age. Large-scale triggering by HI shells is supported by observations of progenitor populations as well as secondary sites of star formation associated with their dense rims. Analysis of the energy available from massive stars inside HI shells indicates energy deposited into the ISM from supernovae and stellar winds is sufficient to account for the HI morphology. Ages of individual star forming regions are derived using B, H-alpha, and FUV photometry. The distribution of ages is reconciled with the HI morphology, showing a clear preference of young regions for areas of dense HI and old regions for HI voids. Global kinematical properties may also play a role in the star formation process since differences in the rotation characteristics of the neutral gas disk correlate with differences in triggering mechanisms., Comment: 24 Pages, 20 Figures, to appear in ApJ

Published
1999
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10. Search for Solar Axions by the CERN Axion Solar Telescope with He-3 Buffer Gas: Closing the Hot Dark Matter Gap

Author

Arik, M., Aune, S., Barth, K., Belov, A., Borghi, S., Braeuninger, H., Cantatore, G., Carmona, J. M., Cetin, S. A., Collar, J. I., Da Riva, E., Dafni, T., Davenport, M., Eleftheriadis, C., Elias, N., Fanourakis, G., Ferrer-Ribas, E., Friedrich, P., Galan, J., Garcia, J. A., Gardikiotis, A., Garza, J. G., Gazis, E. N., Geralis, T., Georgiopoulou, E., Giomataris, I., Gninenko, S., Gomez, H., Marzoa, M. Gomez, Gruber, E., Guthoerl, T., Hartmann, R., Hauf, S., Haug, F., Hasinoff, M. D., Hoffmann, D. H. H., Iguaz, F. J., Irastorza, I. G., Jacoby, J., Jakovcic, K., Karuza, M., Koenigsmann, K., Kotthaus, R., Krcmar, M., Kuster, M., Lakic, B., Lang, P. M., Laurent, J. M., Liolios, A., Ljubicic, A., Luzon, G., Neff, S., Niinikoski, T., Nordt, A., Papaevangelou, T., Pivovaroff, M. J., Raffelt, G., Riege, H., Rodriguez, A., Rosu, M., Ruz, J., Savvidis, I., Shilon, I., Silva, P. S., Solanki, S. K., Stewart, L., Tomas, A., Tsagri, M., Van Bibber, K., Vafeiadis, T., Villar, J., Vogel, J. K., and CAST Collaboration

Subjects
Physics::Instrumentation and Detectors, Astrophysics::Earth and Planetary Astrophysics
Abstract

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

11. Improved search for solar chameleons with a GridPix detector at CAST

Author

Wolfgang Funk, Milica Krčmar, T. Geralis, M. Maroudas, S. C. Yildiz, I. G. Irastorza, Joachim Jacoby, Sofia Kostoglou, Babette Döbrich, Sergei Gninenko, Giovanni Cantatore, C. Krieger, Søren Schmidt, M. Davenport, Marin Karuza, I. Ortega, M. J. Pivovaroff, Konstantin Zioutas, C. J. Hailey, J. Ruz, S. Neff, L. Miceli, T. Papaevangelou, S. Aune, Georg G. Raffelt, T. Dafni, I. Savvidis, M. Vretenar, Klaus Kurt Desch, Biljana Lakić, A. Liolios, Georgios Fanourakis, Nenad Kralj, Alexander Dermenev, J. F. Castel, A. Belov, Krešimir Jakovčić, L. Stewart, Dieter Hoffmann, Sami K. Solanki, Heinrich Bräuninger, Serkant Ali Cetin, E. Ruiz Chóliz, F.J. Iguaz, Vassilis Anastassopoulos, H. Fischer, A. Gardikiotis, Yannis K. Semertzidis, M. D. Hasinoff, C. Eleftheriadis, Jochen Kaminski, Anders Clemen Jakobsen, K. Paraschou, E. Ferrer-Ribas, J. M. Carmona, Julia Vogel, Theodoros Vafeiadis, J. G. Garza, K. Barth, G. Luzón, Walter Wuensch, I. Giomataris, M. Rosu, P. Brax, Ante Ljubičić, J. M. Laurent, J. A. Garcia, Evangelos Gazis, Finn Erland Christensen, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Théorique - UMR CNRS 3681 (IPHT), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), CAST, Anastassopoulos, V., Aune, S., Barth, K., Belov, A., Bräuninger, H., Cantatore, G., Carmona, J. M., Castel, J. F., Cetin, S. A., Christensen, F., Dafni, T., Davenport, M., Dermenev, A., Desch, K., Döbrich, B., Eleftheriadis, C., Fanourakis, G., Ferrer-Ribas, E., Fischer, H., Funk, W., García, J. A., Gardikiotis, A., Garza, J. G., Gazis, E. N., Geralis, T., Giomataris, I., Gninenko, S., Hailey, C. J., Hasinoff, M. D., Hoffmann, D. H. H., Iguaz, F. J., Irastorza, I. G., Jakobsen, A., Jacoby, J., Jakovčić, K., Kaminski, J., Karuza, M., Kostoglou, S., Kralj, N., Krčmar, M., Krieger, C., Lakić, B., Laurent, J. M., Liolios, A., Ljubičić, A., Luzón, G., Maroudas, M., Miceli, L., Neff, S., Ortega, I., Papaevangelou, T., Paraschou, K., Pivovaroff, M. J., Raffelt, G., Rosu, M., Ruz, J., Chóliz, E. Ruiz, Savvidis, I., Schmidt, S., Semertzidis, Y. K., Solanki, S. K., Stewart, L., Vafeiadis, T., Vogel, J. K., Vretenar, M., Wuensch, W., Yildiz, S. C., Zioutas, K., and Brax, P.

Subjects
Physics - Instrumentation and Detectors, Photon, Physics::Instrumentation and Detectors, Solar luminosity, magnetic field, Astrophysics, 01 natural sciences, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), photon: coupling, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Astrophysics::Solar and Stellar Astrophysics, Detectors and Experimental Techniques, GridPix, dark energy, modified gravity, physics.ins-det, Solar physics, Physics, dark energy experiments, particle physics - cosmology connection, solar physics, Astronomy and Astrophysics, chameleon: solar, solar physic, Instrumentation and Detectors (physics.ins-det), Coupling (probability), transition: (axion photon), dark energy experiment, Beta (plasma physics), Physics::Space Physics, CAST, Astrophysics::Earth and Planetary Astrophysics, CERN Axion Solar Telescope, Particle Physics - Experiment, chameleon, Modified gravity, Particle physics, CERN Lab, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, photon: spectrum, coupling constant: upper limit, Tachocline, Astrophysics::Cosmology and Extragalactic Astrophysics, X-ray, Dark energy experiments, 0103 physical sciences, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Sensitivity (control systems), hep-ex, background, 010308 nuclear & particles physics, magnet, coupling: (axion 2photon), Particle physics - cosmology connection, axion: solar, tachocline, Energy (signal processing), experimental results
Abstract

We report on a new search for solar chameleons with the CERN Axion Solar Telescope (CAST). A GridPix detector was used to search for soft X-ray photons in the energy range from 200 eV to 10 keV from converted solar chameleons. No signiffcant excess over the expected background has been observed in the data taken in 2014 and 2015. We set an improved limit on the chameleon photon coupling, $\beta_\gamma < 5.7\times10^{10}$ for $1, Comment: 19 pages, 12 figures, 3 tables

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