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Sample records for cern axion solar

  1. Cern Axion Solar Telescope (CAST)

    CERN Multimedia

    2002-01-01

    The CERN Solar Axion Telescope, CAST, aims to shed light on a 30-year-old riddle of particle physics by detecting axions originating from the 15 million degree plasma in the Sun 's core. Axions were proposed as an extension to the Standard Model of particle physics to explain why CP violation is observed in weak but not strong interactions.

  2. CAST-CERN Axion Solar Telescope

    International Nuclear Information System (INIS)

    CAST (CERN Axion Solar Telescope) is a helioscope looking for axions coming from the solar core to the Earth. The experiment, located at CERN, is based on the Primakoff effect and uses a magnetic field of 9 T provided by a decommissioned LHC magnet. CAST is able to follow the Sun during sunrise and sunset and therefore three X-ray detectors are mounted on both ends of the magnet waiting for a photon from axion-to-photon conversion due to Primakoff effect. During its first phase, which concluded in 2004, CAST has been looking for axions with masses up to 0.02 eV. The second phase did already start and first data were taken in December 2005. CAST's second phase manages to reestablish the coherence needed to scan for axions with masses up to 0.83 eV by using a buffer gas. This enables the experiment to look into the theoretical regions for axions

  3. The CERN axion solar telescope (CAST)

    CERN Document Server

    Aalseth, C E; Autiero, D; Avignone, F T; Barth, K; Bowyer, S M; Bräuninger, H; Brodzinski, R L; Carmona, J M; Cebrián, S; Celebi, G; Cetin, S A; Collar, J I; Creswick, R; Delbart, A; Delattre, M; Di Lella, L; De Oliveira, R; Eleftheriadis, C; Erdutan, N; Fanourakis, G K; Farach, H A; Fiorini, C; Geralis, T; Giomataris, Ioanis; Girard, T A; Gninenko, S N; Golubev, N A; Hasinoff, M D; Hoffmann, D; Irastorza, I G; Jacoby, J; Jeanneau, F; Knopf, M A; Kovzelev, A; Kotthaus, R; Krcmar, M; Krecak, Z; Lakic, B; Liolios, A; Ljubicic, A; Lutz, Gerhard; Longoni, A; Luzón, G; Mailov, A; Matveev, V A; Miley, H S; Morales, A; Morales, J; Mutterer, M; Nikolaidis, A; Nussinov, S; Ortiz, A; Pitts, W K; Placci, A; Postoev, V E; Raffelt, G G; Riege, H; Sampietro, M; Sarsa, M; Savvidis, I; Stipcevic, M; Thomas, C W; Thompson, R C; Valco, P; Villar, J A; Villierme, B; Walckiers, L; Wilcox, W; Zachariadou, K; Zioutas, Konstantin

    2002-01-01

    A decommissioned LHC test magnet is being prepared as the CERN Axion Solar Telescope (CAST) experiment. The magnet has a field of 9.6 Tesla and length of 10 meters. It is being mounted on a platform to track the sun over +-8 deg. vertically and +-45 deg. , horizontally. A sensitivity in axion-photon coupling g alpha gamma gamma < 5 x 10 sup - sup 1 sup 1 GeV sup - sup 1 can be reached for m subalpha <= 10 sup - sup 2 eV, and with a gas filled tube-can reach g alpha gamma gamma <= 10 sup - sup 1 sup 0 GeV sup - sup 1 for axion masses m subalpha < 2eV.

  4. First results from the CERN axion solar telescope.

    Science.gov (United States)

    Zioutas, K; Andriamonje, S; Arsov, V; Aune, S; Autiero, D; Avignone, F T; Barth, K; Belov, A; Beltrán, B; Bräuninger, H; Carmona, J M; Cebrián, S; Chesi, E; Collar, J I; Creswick, R; Dafni, T; Davenport, M; Di Lella, L; Eleftheriadis, C; Englhauser, J; Fanourakis, G; Farach, H; Ferrer, E; Fischer, H; Franz, J; Friedrich, P; Geralis, T; Giomataris, I; Gninenko, S; Goloubev, N; Hasinoff, M D; Heinsius, F H; Hoffmann, D H H; Irastorza, I G; Jacoby, J; Kang, D; Königsmann, K; Kotthaus, R; Krcmar, M; Kousouris, K; Kuster, M; Lakić, B; Lasseur, C; Liolios, A; Ljubicić, A; Lutz, G; Luzón, G; Miller, D W; Morales, A; Morales, J; Mutterer, M; Nikolaidis, A; Ortiz, A; Papaevangelou, T; Placci, A; Raffelt, G; Ruz, J; Riege, H; Sarsa, M L; Savvidis, I; Serber, W; Serpico, P; Semertzidis, Y; Stewart, L; Vieira, J D; Villar, J; Walckiers, L; Zachariadou, K

    2005-04-01

    Hypothetical axionlike particles with a two-photon interaction would be produced in the sun by the Primakoff process. In a laboratory magnetic field ("axion helioscope"), they would be transformed into x-rays with energies of a few keV. Using a decommissioned Large Hadron Collider test magnet, the CERN Axion Solar Telescope ran for about 6 months during 2003. The first results from the analysis of these data are presented here. No signal above background was observed, implying an upper limit to the axion-photon coupling g(agamma)<1.16x10(-10) GeV-1 at 95% C.L. for m(a) less, similar 0.02 eV. This limit, assumption-free, is comparable to the limit from stellar energy-loss arguments and considerably more restrictive than any previous experiment over a broad range of axion masses.

  5. Latest results and prospects of the CERN Axion Solar Telescope

    OpenAIRE

    2011-01-01

    The CERN Axion Solar Telescope (CAST) experiment searches for axions from the Sun converted into few keV photons via the inverse Primakoff effect in the high magnetic field of a superconducting Large Hadron Collider (LHC) decommissioned test magnet. After results obtained with vacuum in the magnet pipes (phase I of the experiment) as well as with 4He the collaboration is now immersed in the data taking with 3He, to be finished in 2011. The status of the experiment will be presented, including...

  6. CrossRef The CERN Axion Solar Telescope

    CERN Document Server

    Hasinoff, M D; Arik, E; Autiero, D; Avignone, F; Barth, K; Bingol, E; Brauninger, H; Brodzinski, R; Carmona, J; Chesi, E; Cebrian, S; Cetin, S; Collar, J; Creswick, R; Dafni, T; De Oliveira, R; Dedoussis, S; Delbart, A; Di Lella, L; Eleftheriadis, C; Fanourakis, G; Farach, H; Fischer, H; Formenti, F; Geralis, T; Giomataris, I; Gninenko, S; Goloubev, N; Hartmann, R; Hoffmann, D; Irastorza, I G; Jacoby, J; Kang, D; Konigsmann, K; Kotthaus, R; Krcmar, M; Kuster, M; Lakic, B; Liolios, A; LJubicic, A; Lutz, G; Luzon, G; Miley, H; Morales, A; Morales, J; Mutterer, M; Nikolaidis, A; Ortiz, A; Papaevangelou, T; Placci, A; Raffelt, G; Riege, H; Sarsa, M; Savvidis, I; Schopper, R; Semertzidis, I; Spano, C; Villar, J; Vullierme, B; Walckiers, L; Zachariadou, K; Zioutas, K

    2003-01-01

    The CAST experiment at CERN is using a decommissioned LHC prototype magnet to search for solar axions through their Primakoff conversion into x-ray photons. The magnet (B = 9.0 Tesla, L = 10 m) can track the sun each day for a total exposure time of ~180 minutes (sunrise + sunset). We expect to reach a sensitivity in axion-photon coupling, gaγγ ≲ 5 × 10-11 GeV-1 for ma ≲ 10-2 eV after ˜1 year's running time. By filling the beam tube with 4He or 3He gas we should be able to extend the sensitive axion mass region into the eV mass range.

  7. Latest results and prospects of the CERN Axion Solar Telescope

    Energy Technology Data Exchange (ETDEWEB)

    Irastorza, I G; Carmona, J M; Dafni, T; Galan, J [Instituto de Fisica Nuclear y Altas EnergIas, Universidad de Zaragoza, Zaragoza (Spain); Aune, S; Ferrer-Ribas, E [IRFU, Centre d' Etudes Nucleaires de Saclay (CEA-Saclay), Gif-sur-Yvette (France); Barth, K; Borghi, S; Davenport, M; Elias, N [European Organization for Nuclear Research (CERN), Geneve (Switzerland); Belov, A [Institute for Nuclear Research (INR), Russian Academy of Sciences, Moscow (Russian Federation); Braeuninger, H; Friedrich, P [Max-Planck-Institut fuer extraterrestrische Physik, Garching (Germany); Cantatore, G [Instituto Nazionale di Fisica Nucleare (INFN), Sezione di Trieste and Universita di Trieste, Trieste (Italy); Cetin, S A; Ezer, C [Dogus University, Istanbul (Turkey); Collar, J I [Enrico Fermi Institute and KICP, University of Chicago, Chicago, IL (United States); Eleftheriadis, C [Aristotle University of Thessaloniki, Thessaloniki (Greece); Fanourakis, G [National Center for Scientific Research ' Demokritos' , Athens (Greece); Gardikiotis, A, E-mail: Igor.Irastorza@cern.ch [Physics Department, University of Patras, Patras (Greece)

    2011-08-10

    The CERN Axion Solar Telescope (CAST) experiment searches for axions from the Sun converted into few keV photons via the inverse Primakoff effect in the high magnetic field of a superconducting Large Hadron Collider (LHC) decommissioned test magnet. After results obtained with vacuum in the magnet pipes (phase I of the experiment) as well as with {sup 4}He the collaboration is now immersed in the data taking with {sup 3}He, to be finished in 2011. The status of the experiment will be presented, including a preliminary exclusion plot of the first {sup 3}He data. CAST is currently sensitive to realistic QCD axion models at the sub-eV scale, and with axion-photon couplings down to the {approx} 2 x 10{sup -10} GeV{sup -1}, compatible with solar life limits. Future plans include revisiting vaccuum and {sup 4}He configurations with improved sensitivity, as well as possible additional search for non-standard signals from chamaleons, paraphotons or other WISPs. For the longer term, we study the feasibility of an altogether improved version of the axion helioscope concept, with a jump in sensitivity of about one order of magnitude in g{sub a}{gamma} beyond CAST.

  8. Search for sub-eV mass solar axions by the CERN Axion Solar Telescope with 3He buffer gas.

    Science.gov (United States)

    Arik, M; Aune, S; Barth, K; Belov, A; Borghi, S; Bräuninger, H; Cantatore, G; Carmona, J M; Cetin, S A; Collar, J I; Dafni, T; Davenport, M; Eleftheriadis, C; Elias, N; Ezer, C; Fanourakis, G; Ferrer-Ribas, E; Friedrich, P; Galán, J; García, J A; Gardikiotis, A; Gazis, E N; Geralis, T; Giomataris, I; Gninenko, S; Gómez, H; Gruber, E; Guthörl, T; Hartmann, R; Haug, F; Hasinoff, M D; Hoffmann, D H H; Iguaz, F J; Irastorza, I G; Jacoby, J; Jakovčić, K; Karuza, M; Königsmann, K; Kotthaus, R; Krčmar, M; Kuster, M; Lakić, B; Laurent, J M; Liolios, A; Ljubičić, A; Lozza, V; Lutz, G; Luzón, G; Morales, J; Niinikoski, T; Nordt, A; Papaevangelou, T; Pivovaroff, M J; Raffelt, G; Rashba, T; Riege, H; Rodríguez, A; Rosu, M; Ruz, J; Savvidis, I; Silva, P S; Solanki, S K; Stewart, L; Tomás, A; Tsagri, M; van Bibber, K; Vafeiadis, T; Villar, J A; Vogel, J K; Yildiz, S C; Zioutas, K

    2011-12-23

    The CERN Axion Solar Telescope (CAST) has extended its search for solar axions by using (3)He as a buffer gas. At T=1.8 K this allows for larger pressure settings and hence sensitivity to higher axion masses than our previous measurements with (4)He. With about 1 h of data taking at each of 252 different pressure settings we have scanned the axion mass range 0.39 eV≲m(a)≲0.64 eV. 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)≲2.3×10(-10) GeV(-1) at 95% C.L., the exact value depending on the pressure setting. Kim-Shifman-Vainshtein-Zakharov axions are excluded at the upper end of our mass range, the first time ever for any solar axion search. In the future we will extend our search to m(a)≲1.15 eV, comfortably overlapping with cosmological hot dark matter bounds. PMID:22243149

  9. Search for sub-eV mass solar axions by the CERN Axion Solar Telescope with 3He buffer gas.

    Science.gov (United States)

    Arik, M; Aune, S; Barth, K; Belov, A; Borghi, S; Bräuninger, H; Cantatore, G; Carmona, J M; Cetin, S A; Collar, J I; Dafni, T; Davenport, M; Eleftheriadis, C; Elias, N; Ezer, C; Fanourakis, G; Ferrer-Ribas, E; Friedrich, P; Galán, J; García, J A; Gardikiotis, A; Gazis, E N; Geralis, T; Giomataris, I; Gninenko, S; Gómez, H; Gruber, E; Guthörl, T; Hartmann, R; Haug, F; Hasinoff, M D; Hoffmann, D H H; Iguaz, F J; Irastorza, I G; Jacoby, J; Jakovčić, K; Karuza, M; Königsmann, K; Kotthaus, R; Krčmar, M; Kuster, M; Lakić, B; Laurent, J M; Liolios, A; Ljubičić, A; Lozza, V; Lutz, G; Luzón, G; Morales, J; Niinikoski, T; Nordt, A; Papaevangelou, T; Pivovaroff, M J; Raffelt, G; Rashba, T; Riege, H; Rodríguez, A; Rosu, M; Ruz, J; Savvidis, I; Silva, P S; Solanki, S K; Stewart, L; Tomás, A; Tsagri, M; van Bibber, K; Vafeiadis, T; Villar, J A; Vogel, J K; Yildiz, S C; Zioutas, K

    2011-12-23

    The CERN Axion Solar Telescope (CAST) has extended its search for solar axions by using (3)He as a buffer gas. At T=1.8 K this allows for larger pressure settings and hence sensitivity to higher axion masses than our previous measurements with (4)He. With about 1 h of data taking at each of 252 different pressure settings we have scanned the axion mass range 0.39 eV≲m(a)≲0.64 eV. 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)≲2.3×10(-10) GeV(-1) at 95% C.L., the exact value depending on the pressure setting. Kim-Shifman-Vainshtein-Zakharov axions are excluded at the upper end of our mass range, the first time ever for any solar axion search. In the future we will extend our search to m(a)≲1.15 eV, comfortably overlapping with cosmological hot dark matter bounds.

  10. Search for solar axions with the Time Projection Chamber of the CERN Axion Solar Telescope with 4-Helium as buffer gas

    CERN Document Server

    Ruz, J; García Irastorza, I

    CAST (CERN Axion Solar Telescope) is a helioscope looking for axions coming from the solar core to the Earth. The experiment, located at CERN, is based on the Primakoff effect and uses a magnetic field of 9 Tesla provided by a decommissioned LHC magnet. CAST is able to follow the Sun during sunrise and sunset and, therefore, different X-ray detectors are mounted on both ends of the magnet waiting for a photon from axion-to-photon conversion due to the Primakoff effect. During its First Phase, which concluded in 2004, the TPC detector of CAST looked for axions with masses up to 0.02 eV. By using a Helium-4 buffer gas, CAST's TPC detector has been able to re-establish the coherence needed to scan for axions with masses up to 0.39 eV, technique that allows CAST to look into the theoretical regions for axions.

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

    Science.gov (United States)

    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, K; Karuza, M; Königsmann, K; Kotthaus, R; Krčmar, M; Kuster, M; Lakić, B; Lang, P M; Laurent, J M; Liolios, A; Ljubičić, 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; Zioutas, K

    2014-03-01

    The CERN Axion Solar Telescope has finished its search for solar axions with (3)He 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 gaγ ≲ 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 gaγ, for example by the currently discussed next generation helioscope International AXion Observatory.

  12. Background study for the pn-CCD detector of CERN Axion Solar Telescope

    OpenAIRE

    Cebrián, S.; Rodríguez, A; M. Kuster(Technische Universität Darmstadt); Beltrán, B; Carmona, J.M.; H Gómez; Hartmann, R.; Irastorza, I. G.; R. Kotthaus; Luzón, G.; MORALES, J., CRUZ, D., DELGADO, P., LIZANA, M., LÓPEZ, V.; de Solórzano, A. Ortiz(Laboratorio de Física Nuclear y Astropartículas, Universidad de Zaragoza, Calle Pedro Cerbuna 12, 50009, Zaragoza, Spain); Ruz, J.; Strüder, L.; Villar, J. A.

    2007-01-01

    The CERN Axion Solar Telescope (CAST) experiment searches for axions from the Sun converted into photons with energies up to around 10 keV via the inverse Primakoff effect in the high magnetic field of a superconducting Large Hadron Collider (LHC) prototype magnet. A backside illuminated pn-CCD detector in conjunction with an X-ray mirror optics is one of the three detectors used in CAST to register the expected photon signal. Since this signal is very rare and different background components...

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

    CERN Document Server

    Arik, M; 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.; 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.

    2014-01-01

    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 <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_ag < 3.3 x 10^{-10} GeV^{-1} at 95% CL, 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, for example by the currently discussed next generation helioscope IAXO.

  14. First results from the CERN Axion Solar Telescope (CAST)

    CERN Document Server

    Andriamonje, Samuel A; Aune, S; Autiero, D; Barth, K; Belov, A; Beltran, B; Bräuninger, H; Carmona, J M; Cebrián, S; Chesi, Enrico Guido; Collar, J I; Creswick, R; Dafni, T; Davenport, M; Di Lella, L; Englhauser, J; Fanourakis, G K; Farach, H A; Ferrer, E; Fischer, H; Franz, J; Friedrich, P; Geralis, T; Giomataris, Ioanis; Gninenko, S; Goloubev, N; Hasinoff, M D; Heinsius, F H; Hoffmann, Dieter H H; Irastorza, I G; Jacoby, J; Kang, D; Königsmann, K C; Kotthaus, R; Krcmar, M; Kousouris, K; Kuster, M; Lakic, B; Lasseur, C; Liolios, A; Ljubicic, A; Lutz, Gerhard; Luzón, G; Miller, D W; Morales, A; Mutterer, M; Nikolaidis, A; Ortiz, A; Papaevangelou, T; Placci, A; Raffelt, Georg G; Ruz, J; Riege, H; Sarsa, M L; Savvidis, I; Serber, W; Serpico, Pasquale Dario; Semertzidis, Y K; Vieira, J D; Villar, José Angel; Walckiers, L; Zachariadou, K; Zioutas, Konstantin

    2005-01-01

    Hypothetical axion-like particles with a two-photon interaction would be produced in the Sun by the Primakoff process. In a laboratory magnetic field (``axion helioscope'') they would be transformed into X-rays with energies of a few keV. Using a decommissioned LHC test magnet, CAST has been running for about 6 months during 2003. The first results from the analysis of these data are presented here. No signal above background was observed, implying an upper limit to the axion-photon coupling < 1.16 10^{-10} GeV^-1 at 95% CL for m_a <~0.02 eV. This limit is comparable to the limit from stellar energy-loss arguments and considerably more restrictive than any previous experiment in this axion mass range.

  15. Cryogenics for the CERN Solar Axion Telescope (CAST) using a LHC Dipole Prototype Magnet

    CERN Document Server

    Barth, K; Pezzetti, M; Pirotte, O; Riege, H; Vullierme, B; Walckiers, L; Zioutas, Konstantin

    2002-01-01

    The axion, an as yet hypothetical particle predicted from the solution of the strong CP problem, constitutes a prime candidate for the galactic dark matter and also arises in supersymmetry and superstring theories. If existing, axions should be copiously produced in stellar interiors and there are theoretical expectations for a low-energy axion emission spectrum peaked around a mean energy of ~ 4.4 keV. To provide the experimental proof, a solar axion telescope is at present installed at CERN, which is expected to be in total 10-12 times more efficient than the present largest set-up in operation at the University of Tokyo. The telescope will use a decommissioned 10-m long LHC superconducting dipole prototype magnet, providing a magnetic field of 9 T in operation, to catalyse the solar axion to photon conversion, which then can be detected by low-background x-ray detectors. The paper describes the external and proximity cryogenic systems and their integration into the overall telescope assembly.

  16. Background study for the pn-CCD detector of CERN Axion Solar Telescope

    CERN Document Server

    Cebrián, S; Kuster, M; Beltrán, B; Carmona, J M; Gómez, H; Hartmann, R; Irastorza, I G; Kotthaus, R; Luzón, G; Morales, J; de Solórzano, A Ortiz; Ruz, J; Strüder, L; Villar, J A

    2007-01-01

    The CERN Axion Solar Telescope (CAST) experiment searches for axions from the Sun converted into photons with energies up to around 10 keV via the inverse Primakoff effect in the high magnetic field of a superconducting Large Hadron Collider (LHC) prototype magnet. A backside illuminated pn-CCD detector in conjunction with an X-ray mirror optics is one of the three detectors used in CAST to register the expected photon signal. Since this signal is very rare and different background components (environmental gamma radiation, cosmic rays, intrinsic radioactive impurities in the set-up, ...) entangle it, a detailed study of the detector background has been undertaken with the aim to understand and further reduce the background level of the detector. The analysis is based on measured data taken during the Phase I of CAST and on Monte Carlo simulations of different background components. This study will show that the observed background level (at a rate of (8.00+-0.07)10^-5 counts/cm^2/s/keV between 1 and 7 keV) s...

  17. Axion searches at CERN with the CAST Telescope

    OpenAIRE

    al, C. Eleftheriadis et

    2003-01-01

    The CERN Axion Solar Telescope (CAST) searches for axions coming from photon to axion conversion in the sun's core, as stated by the Primakoff effect. Axions arise in particle physics as a consequence of the breaking of Peccei-Quinn symmetry which has been introduced as a solution to the strong CP problem. As cosmological axions they are candidates for at least some part of cold Dark Matter.They are also expected to be produced copiously in stellar interiors with energies as high as the therm...

  18. Axion searches at CERN with the CAST Telescope

    CERN Document Server

    Eleftheriadis, C; Arik, E; Autiero, D; Avignone, F T; Barth, K; Bingol, E; Bräuninger, H; Brodzinski, R L; Carmona, J M; Cebrián, S; Cetin, S A; Chesi, Enrico Guido; Cipolla, G; Collar, J I; Creswick, R; Dafni, T; Davenport, M; De Oliveira, R; Dedoussis, S; Delbart, A; Di Lella, L; Fanourakis, G K; Farach, H A; Fischer, H; Formenti, F; Geralis, T; Glomataris, I; Gninenko, S N; Goloubev, N; Hartmann, R; Hasinoff, M D; Hoffmann, D; Irastorza, I G; Jacoby, J; Kang, D; Königsmann, K C; Kotthaus, R; Krcmar, M; Kuster, M; Lakic, B; Liolios, A; Ljubicic, A; Lutz, Gerhard; Luzón, G; Miley, H S; Morales, A; Morales, L; Mutterer, M; Nikolaidis, A; Ortiz, A; Papaevangelou, T; Placci, A; Raffelt, Georg G; Riege, H; Sarsa, M; Savvidis, I; Schopper, R; Semertzidis, Y K; Spanos, V C; Vasilelou, V; Villar, José Angel; Vullierme, B; Walckiers, L; Zachariadou, K; Zioutas, Konstantin

    2003-01-01

    The CERN Axion Solar Telescope (CAST) searches for axions coming from photon to axion conversion in the sun's core, as stated by the Primakoff effect. Axions arise in particle physics as a consequence of the breaking of Peccei-Quinn symmetry which has been introduced as a solution to the strong CP problem. As cosmological axions they are candidates for at least some part of cold Dark Matter.They are also expected to be produced copiously in stellar interiors with energies as high as the thermal photons undergoing photon to axion conversion. In our sun the axion energy spectrum peaks at about 4.4 keV, extending up to 10 keV. CAST collected preliminary data in 2002 and data taking with its full capability will start in the beginning of 2003.

  19. Results on axion physics from the CAST Experiment at CERN

    CERN Document Server

    Eleftheriadis, Christos A; Aune, S; Barth, K; Belov, A; Beltran, B; Bräuninger, H; Carmona, J; Cebrián, S; Collar, J I; Dafni, T; Davenport, M; Di Lella, L; Englhauser, J; Fanourakis, G K; Ferrer-Ribas, E; Fischer, H; Franz, J; Friedrich, P; Geralis, T; Giomataris, Ioanis; Gninenko, S; Gomez, H; Hasinoff, M; Heinsius, F H; Hoffmann, D H H; Irastorza, I G; Jacoby, J; Jakovcic, K; Kang, D; Königsmann, K C; Kotthaus, R; Krcmar, M; Kousouris, K; Kuster, M; Laki, B; Lasseur, C; Liolios, A; Ljubicic, cA; Lutz, G; Luzón, G; Miller, D; Morales, A; Morales, J; Nordt, A; Ortiz, A; Papaevangelou, T; Placci, A; Raffelt, G; Riege1, H; Rodríguez, A; Ruz, J; Savvidis, I; Semertzidis, Y K; Serpico, Pasquale Dario; Stewart, L; Villar, J; Vogel, J; Walckiers, L; Zioutas, K

    2007-01-01

    Axions are expected to be produced in the sun via the Primakoff process. They may be detected through the inverse process in the laboratory, under the influence of a strong magnetic field, giving rise to X-rays of energies in the range of a few keV. Such an Axion detector is the CERN Axion Solar Telescope (CAST), collecting data since 2003. Results have been published, pushing the axion-photon coupling g$_{a\\gamma}$ below the 10$^{-10}$ GeV$^{-1}$ limit at 95% CL, for axion masses less than 0.02 eV. This limit is nearly an order of magnitude lower than previous experimental limits and surpassed for the first time limits set from astrophysical arguments based on the energy-loss concept. The experiment is currently exploring axion masses in the range of 0.02 eV $< m_a <$ 1.1 eV. In the next run, currently under preparation, the axion mass explored will be extended up to the limit of 1.1 eV, testing for the first time the region of theoretical axion models with the axion helioscope method.

  20. Search for Solar Axions with the CCD Detector and X-ray Telescope at CAST Experiment

    OpenAIRE

    Rosu, Madalin-Mihai

    2015-01-01

    The CERN Axion Solar Telescope (CAST) is an experiment that uses the world’s highest sensitivity Helioscope to date for solar Axions searches. Axions are weakly interacting pseudoscalar particles proposed to solve the so-called Strong Charge-Parity Problem of the Standard Model. The principle of detection is the inverse Primakoff Effect, which is a mechanism for converting the Axions into easily detectable X-ray photons in a strong transverse magnetic field. The solar Axions are produced d...

  1. CAST begins its search for solar axions.

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    The CERN Axion Solar Telescope (CAST) consists of a prototype LHC dipole magnet with photon detectors at each end. It has started searching for very weakly interacting neutral particles called axions, which should originate in the core of the Sun. Photos 01 02: The telescope, located at Point 8, can move vertically within its wheeled yellow platform, which travels horizontally along tracks in the floor. In this way, the telescope can view the Sun at sunrise through one end (left) and at sunset through the other. Photos 03 04: Sunrise photon detectors at one end of the telescope.

  2. Academic Training: Joint ILIAS-CAST-CERN Axion Training at CERN

    CERN Multimedia

    Françoise Benz

    2005-01-01

    2005-2006 ACADEMIC TRAINING PROGRAMME 30 November, 1 and 2 December PLACE - DETAILS: http://agenda.cern.ch/fullAgenda.php?ida=a056218 Joint ILIAS-CAST-CERN Axion Training at CERN The ILIAS (Integrated Large Infrastructure for Astroparticle Science) is co-organising a 3 day academic training session together with the CAST collaboration and the CERN Academic Training Programme on physics related to axion research, including open discussions between theorists and experimentalists. The intention of the lectures is to provide academic training for scientists engaged in axion research and to facilitate the often missing link between experiment and theory with the aim of encouraging young researchers to communicate with experts in the field. The lectures include topics which are not regularly covered by standard lectures at universities and should lead to a deeper understanding of the physics related to axions, which covers a broad field from QCD to astrophysics and cosmology. There will be an opportunity for ...

  3. Academic Training: Joint ILIAS-CAST-CERN Axion Training at CERN

    CERN Multimedia

    Françoise Benz

    2005-01-01

    2005-2006 ACADEMIC TRAINING PROGRAMME 30 November, 1 and 2 December PLACE - DETAILS: http://agenda.cern.ch/fullAgenda.php?ida=a056218 Joint ILIAS-CAST-CERN Axion Training at CERN The ILIAS (Integrated Large Infrastructure for Astroparticle Science) is co-organising a 3 day academic training session together with the CAST collaboration and the CERN Academic Training Programme on physics related to axion research, including open discussions between theorists and experimentalists. The intention of the lectures is to provide academic training for scientists engaged in axion research and to facilitate the often missing link between experiment and theory with the aim of encouraging young researchers to communicate with experts in the field. The lectures include topics which are not regularly covered by standard lectures at universities and should lead to a deeper understanding of the physics related to axions, which covers a broad field from QCD to astrophysics and cosmology. There will be an opportunity for ...

  4. Search for Solar Axions with the CAST-Experiment

    CERN Document Server

    Vogel, J.; Aune, S.; Autiero, D.; Barth, K.; Belov, A.; Beltran, B.; Borghi, S.; Bourlis, G.; Boydag, F. S.; Brauninger, H.; Carmona, J.; Cebrian, S.; Cetin, S. A.; Collar, J.I.; Dafni, T.; Davenport, M.; Di Lella, L.; Dogan, O. B.; Elefheriadis, C.; Elias, N.; Fanourakis, G.; Ferrer-Ribas, E.; Fisher, H.; Franz, J.; Galan, J.; Geralis, T.; Giomataris, I.; Gninenko, S.; Gomez, H.; Hasinoff, M.; Heinsius, H.; Hikmet, I.; Hoffmann, D. H. H.; Irastorza, I. G.; Jacoby, J.; Jakovcic, K.; Kang, D.; Konigsmann, K.; Kotthaus, R.; Krcmar, M.; Kousouris, K.; Kuster, M.; Lakic, B.; Lasseur, C.; Liolios, A.; Ljubicic, A.; Lutz, G.; Luzon, G.; Miller, D.; Morales, J.; Niinikoski, T.; Nordt, A.; Ortiz, A.; Papaevangelou, T.; Pivovaroff, M.; Placci, A.; Raffelt, G.; Riege, H.; Rodriguez, A.; Ruz, J.; Savvidis, I.; Semertzidis, Y.; Serpico, P.; Soufli, R.; Stewart, L.; Tzamarias, S.; Van Bibber, K.; Villar, J.; Walckiers, L.; Zioutas, K.; Morales, A.

    2008-01-01

    Solar axions can be produced in the Sun via the so-called Primakoff effect. The CERN Axion Solar Telescope (CAST) uses an LHC prototype magnet of about 9 T to reconvert these axions into photons. The magnet is able to follow the Sun for about 3 hours per day. Three different X-Ray detectors are mounted on its ends to detect photons from axion-to-photon conversion: a Time Projection Chamber (TPC), a MICROMEGAS (MICROMEsh GAseous Structure) and a Charge Coupled Device (CCD). For the CCD an X-ray focusing device is used to improve the signal-to-background ratio significantly. With the completion of CAST'S first phase, the current limits on the coupling constant gaγ for axion masses up to 0.02 eV have been improved. In its second phase, CAST extends the axion mass range by filling the magnet with a buffer gas. Masses up to about 0.4 eV have already been covered and thus the experiment is entering the regions favored by axion models. This paper will present the status of CAST'S second phase.

  5. Solar Axion search with Micromegas detectors in the CAST Experiment with $^{3}$He as buffer gas

    CERN Document Server

    Garcia Pascual, Juan Antonio

    2015-01-01

    Axions are well motivated particles proposed in an extension of the Standard Model (SM) as a solution to the CP problem in strong interactions. On the other hand, there is the category of axion-like particles (ALPs) which appear in diverse extensions of the SM and share the same phenomenology of the axion. Axions and ALPs are hypothetical neutral particles that interact weakly with matter, being candidates to solve the Dark Matter problem. CAST, the CERN Axion Solar Telescope is looking for solar axions since 2003. CAST exploit the helioscope technique using a decommissioned LHC dipole magnet in which solar axions could be reconverted into photons. The magnet is mounted on a movable platform that allows tracking the Sun $\\sim$1.5 hours during sunset and during sunrise. The axion signal would be an excess of X-rays in the detectors located at the magnet bore ends and thus low background detectors are mandatory. Three of the four detectors operating at CAST are of the Micromegas type. The analysis of the data o...

  6. Search for Solar Axions with the CCD Detector and X-ray Telescope at CAST Experiment

    CERN Document Server

    Rosu, Madalin Mihai; Zioutas, Konstantin

    2015-06-09

    The CERN Axion Solar Telescope (CAST) is an experiment that uses the world’s highest sensitivity Helioscope to date for solar Axions searches. Axions are weakly interacting pseudoscalar particles proposed to solve the so-called Strong Charge-Parity Problem of the Standard Model. The principle of detection is the inverse Primakoff Effect, which is a mechanism for converting the Axions into easily detectable X-ray photons in a strong transverse magnetic field. The solar Axions are produced due to the Primakoff effect in the hot and dense core of from the coupling of a real and a virtual photon. The solar models predict a peak Axion luminosity at an energy of 3 keV originating mostly from the inner 20% of the solar radius. Thus an intensity peak at an energy of 3 keV is also expected in the case of the X-ray radiation resulting from Axion conversion. CAST uses a high precision movement system for tracking the Sun twice a day with a LHC dipole twin aperture prototype magnet, 9.26 meters long and with a field of...

  7. Results and perspectives of the solar axion search with the CAST experiment

    CERN Document Server

    Ferrer-Ribas, E; Aune, S; Barth, K; Belov, A; Borghi, S; Bräuninger, H; Cantatore, G; Carmona, J M; Cetin, S A; Collar, J I; Dafni, T; Davenport, M; Eleftheriadis, C; Elias, N; Ezer, C; Fanourakis, G; Friedrich, P; Galán, J; García, J A; Gardikiotis, A; Gazis, E N; Geralis, T; Giomataris, I; Gninenko, S; Gómez, H; Gruber, E; Guthörl, T; Hartmann, R; Haug, F; Hasinoff, M D; Hoffmann, D H H; Iguaz, F J; Irastorza, I G; Jacoby, J; Jakov\\vcić, K; Karuza, M; Königsmann, K; Kotthaus, R; Krčmar, M; Kuster, M; Lakić, B; Laurent, J M; Liolios, A; Ljubičić, A; Lozza, V; Lutz, G; Luzón, G; Morales, J; Niinikoski, T; Nordt, A; Papaevangelou, T; Pivovaroff, M J; Raffelt, G; Rashba, T; Riege, H; Rodríguez, A; Rosu, M; Ruz, J; Savvidis, 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; Zioutas, K

    2012-01-01

    The status of the solar axion search with the CERN Axion Solar Telescope (CAST) will be presented. Recent results obtained by the use of $^3$He as a buffer gas has allowed us to extend our sensitivity to higher axion masses than our previous measurements with $^4$He. With about 1 h of data taking at each of 252 different pressure settings we have scanned the axion mass range 0.39 eV$ \\le m_{a} \\le $ 0.64 eV. From the absence of an excess of x rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of g$_{a\\gamma} \\le 2.3\\times 10^{-10}$ GeV$^{-1}$ at 95% C.L., the exact value depending on the pressure setting. CAST published results represent the best experimental limit on the photon couplings to axions and other similar exotic particles dubbed WISPs (Weakly Interacting Slim Particles) in the considered mass range and for the first time the limit enters the region favored by QCD axion models. Preliminary sensitivities for axion masses up to 1.16 eV will also be s...

  8. CAST search for sub-eV mass solar axions with $^{3}$He buffer gas

    CERN Document Server

    Aune, S; Belov, A; Borghi, S; Brauninger, H; Cantatore, G; Carmona, J M; Cetin, S A; Collar, J I; Dafni, T; Davenport, M; Eleftheriadis, C; Elias, N; Ezer, C; Fanourakis, G; Ferrer-Ribas, E; Friedrich, P; Galan, J; Garcia, J A; Gardikiotis, A; Gazis, E N; Geralis, T; Giomataris, I; Gninenko, S; Gomez, H; Gruber, E; Guthorl, T; Hartmann, R; 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; Laurent, J M; Liolios, A; Ljubicic, A; Lozza, V; Lutz, G; Luzon, G; Morales, J; Niinikoski, T; Nordt, A; Papaevangelou, T; Pivovaroff, M J; Raffelt, G; Rashba, T; Riege, H; Rodriguez, A; Rosu, M; Ruz, J; Savvidis, I; Silva, P S; Solanki, S.K; Stewart, L; Tomas, A; Tsagri, M; van Bibber, K; Vafeiadis, T; Villar, J A; Vogel, J K; Yildiz, S C; Zioutas, K

    2011-01-01

    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 for 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 of 252 different pressure settings we have scanned the axion mass range 0.39 eV < m_a < 0.64 eV. 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_ag < 2.3 x 10^{-10} GeV^{-1} at 95% CL, the exact value depending on the pressure setting. KSVZ axions are excluded at the upper end of our mass range, the first time ever for any solar axion search. In future we will extend our search to m_a < 1.15 eV, comfortably overlapping with cosmological hot dark matter bounds.

  9. Probing the eV-Mass Range for Solar Axions with the CAST Experiment

    CERN Document Server

    VOGEL, Julia

    2009-01-01

    The CERN Axion Solar Telescope (CAST) is searching for solar axions, which could be produced in the core of the Sun via the so-called Primakoff effect. For this purpose, CAST uses a decommissioned LHC prototype magnet. In its magnetic field of 9 Tesla, axions could be reconverted into X-ray photons. The magnet is mounted on a structure built to follow the Sun during sunrise and sunset for a total of about 3 hours per day. The analysis of the data acquired during the first phase of the experiment with vacuum in the magnetic field region yielded the most restrictive experimental upper limit on the axion-to-photon coupling constant for axion masses up to about 0.02 eV. In order to extend the sensitivity of the experiment to a wider mass range, the CAST experiment continued its search for axions with helium in the magnet bores. In this way it is possible to restore coherence for larger masses. Changing the pressure of the helium gas enables the experiment to scan different axion masses. In the first part of this ...

  10. Probing the eV-mass range for solar axions with the CAST experiment

    International Nuclear Information System (INIS)

    The CERN Axion Solar Telescope (CAST) is searching for solar axions, which could be produced in the core of the Sun via the so-called Primakoff effect. For this purpose, CAST uses a decommissioned LHC prototype magnet. In its magnetic field of 9 Tesla axions could be reconverted into X-ray photons. The magnet is mounted on a structure built to follow the Sun during sunrise and sunset for a total of about 3 hours per day. The analysis of the data acquired during the first phase of the experiment with vacuum in the magnetic field region yielded the most restrictive experimental upper limit on the axion-to-photon coupling constant for axion masses up to about 0.02 eV. In order to extend the sensitivity of the experiment to a wider mass range, the CAST experiment continued its search for axions with helium in the magnet bores. In this way it is possible to restore coherence for larger masses. Changing the pressure of the helium gas enables the experiment to scan different axion masses. In the first part of this second phase of CAST, helium-4 has been used and the axion mass region was extended up to 0.4 eV. Therefore the experiment enters the regions favored by axion models. In CAST's ongoing helium-3 phase the studied mass range is now further extended. We will present the final results of CAST's helium-4 phase. Furthermore the latest upgrades of the experiments will be shown and an outlook on CAST's status and prospects will be given. (author)

  11. CERN... Solar Style

    CERN Multimedia

    2001-01-01

    Inventor William van Sprolant presenting the Solar Club's latest invention, the solar fountain. The CERN Solar Club is giving new meaning to the phrase 'fun in the sun' with their most recently developed contraption, the Solar Fountain. The Fountain was presented to the public just outside of Restaurant 1 on Wednesday October, 17th and uses solar energy to run a water pump at its base to propel a golden plastic ball up into the air. As lovely as the fountain is, the funny thing about it is that the height of the water jet and the ball are an artistic method of measuring the amount of solar power being captured by the photovoltaique panel (no batteries included). The day it was presented started out cloudy, but as the afternoon wore on, the weather brightened and the fountain jumped to life. William van Sprolant, the Solar Fountain's inventor, had great fun with the fountain in front of a group of visiting children swiveling the solar panel in multiple directions. 'Everyone who installs solar panels worrie...

  12. The International Axion Observatory IAXO. Letter of Intent to the CERN SPS committee

    CERN Document Server

    Irastorza, Igor G

    2013-01-01

    This Letter of Intent describes IAXO, the International Axion Observatory, a proposed 4th generation axion helioscope. As its primary physics goal, IAXO will look for axions or axion-like particles (ALPs) originating in the Sun via the Primakoff conversion of the solar plasma photons. In terms of signal to background ratio, IAXO will be about 4-5 orders of magnitude more sensitive than CAST, which means that this instrument will reach sensitivity to axion-photon couplings down to a few $\\times 10^{-12}$ GeV$^{-1}$. IAXO has the potential for the discovery of axions and other ALPs, since it will deeply enter into unexplored parameter space. At the very least it will firmly exclude a large region of this space of high cosmological and astrophysical relevance. In particular it will probe a large fraction of the high mass part (1 meV to 1 eV) of the QCD axion allowed window. Additional physics cases for IAXO include the possibility of detecting solar axions produced by mechanisms mediated by the axion-electron co...

  13. The axion hunting; La chasse aux axions

    Energy Technology Data Exchange (ETDEWEB)

    Robillard, C. [Laboratoire Collisions, Agregats, Reactivite (CNRS / Universite Toulouse 3), 31 (France)

    2009-05-15

    The axion is a neutral, light and very weakly interacting particle that was imagined in the seventies to unify some aspects of the basic interactions. Another important feature of axions is their capacity to transform themselves into photons when crossing a magnetic field, the probability of this conversion is very low, proportional to the intensity of the magnetic field and all the less low as the mass of the axion is tiny. Axions are perfect candidates to dark matter and could also explain why the solar corona is so hot. The magnetic fields inside the sun are so intense that they could enable axions to mutate into photons leading to an excess of energy and light in the out layers of the sun. Till now, no experiment has led to the detection of axions despite the announcement made in march 2006 of their discovery by an Italian team, these experimental results were unanimously acknowledged as biased. The ADMX program (Axion Dark Matter eXperiment) launched in the nineties, has led to constrains on the mass of the axions: the 1.9 - 3.3 eV range for the mass has been experimentally barred. Other experiments like CAST (CERN Axion Solar Telescope) have led to complementary constrains on the mass or to new constrains on the axion-photon coupling. (A.C.)

  14. Probing the eV-Mass Range for Solar Axions with CAST

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, J K; Pivovaroff, M J; Soufli, R; van Bibber, K; CAST, C

    2010-11-11

    The CERN Axion Solar Telescope (CAST) is searching for solar axions which could be produced in the core of the Sun via the so-called Primakoff effect. Not only would these hypothetical particles solve the strong CP problem, but they are also one of the favored candidates for dark matter. In order to look for axions originating from the Sun, CAST uses a decommissioned LHC prototype magnet. In its 10 m long magnetic field region of 9 Tesla, axions could be reconverted into X-ray photons. Different X-ray detectors are installed on both ends of the magnet, which is mounted on a structure built to follow the Sun during sunrise and sunset for a total of about 3 hours per day. The analysis of the data acquired during the first phase of the experiment with vacuum in the magnetic field region yielded the most restrictive experimental upper limit on the axion-to-photon coupling constant for axion masses up to about 0.02 eV. In order to extend the sensitivity of the experiment to a wider mass range, the CAST experiment continues its search for axions with helium in the magnet bores. In this way it is possible to restore coherence of conversion for larger masses. Changing the pressure of the helium gas enables the experiment to scan different axion masses in the range of up to about 1.2 eV. Especially at high pressures, a precise knowledge of the gas density distribution is crucial to obtain accurate results. In the first part of this second phase of CAST, {sup 4}He was used and the axion mass region was extended up to 0.39 eV, a part of phase space favored by axion models. In CAST's ongoing {sup 3}He phase the studied mass range is now being extended further. In this contribution the final results of CAST's {sup 4}He phase will be presented and the current status of the {sup 3}He run will be given. This includes latest results as well as prospects of future axion experiments.

  15. Recent searches for solar axions and large extra dimensions

    CERN Document Server

    Horváth, R; Lakic, B

    2002-01-01

    We analyze the data from two recent experiments designed to search for solar axions within the context of multi-dimensional theories of the Kaluza-Klein type. In these experiments, axions were supposed to be emitted from the solar core, in M1 transitions between the first excited state and the ground state of 57Fe and 7Li. Because of the high multiplicity of axionic Kaluza-Klein states which couple with strength of ordinary QCD axions, we obtain much more stringent experimental limits on the four-dimensional Peccei-Quinn breaking scale f_{PQ}, compared with the solar QCD axion limit. Specifically, for the 57Fe experiment, f_{PQ}>1x10^6 GeV in theories with 2 extra dimensions and a higher-dimensional gravitational scale M_H of order 100 TeV, and f_{PQ}>1x10^6 GeV in theories with 3 extra dimensions and M_H of order 1 TeV (to be compared with the QCD axion limit, f_{PQ}>8x10^3 GeV). For the 7Li experiment, f_{PQ}>1.4x10^5 GeV and 3.4x10^5 GeV, respectively (to be compared with the QCD axion limit, f_{PQ}>1.9x10...

  16. Searching for Solar Axions in the eV-MassRegion with the CCD Detector at CAST

    CERN Document Server

    Vogel, J K

    2009-01-01

    The CERN Axion Solar Telescope (CAST) is searching for solar axions, which could be produced in the core of the Sun via the so-called Primakoff effect. For this purpose, CAST uses a decommissioned LHC prototype magnet. In its magnetic field of 9 Tesla axions could be reconverted into X-ray photons. The magnet is mounted on a structure built to follow the Sun during sunrise and sunset for a total of about 3 hours per day. The analysis of the data acquired during the first phase of the experiment with vacuum in the magnetic field region yielded the best experimental upper limit on the axion-to-photon coupling constant for axion masses up to about 0.02 eV. In order to extend the sensitivity of the experiment to a wider mass range, the CAST experiment continued its search for axions with helium in the magnet bores. In this way it is possible to restore coherence for larger masses. Changing the pressure of the helium gas enables the experiment to scan different axion masses. In the first part of this second phase ...

  17. Axion experiment makes its debut

    CERN Multimedia

    Dumé, Belle

    2004-01-01

    An experiment built from components recycled from other experiments has put new limits on the properties of particles that might be the "dark matter" that makes up about 25% of the universe. The CERN Axion Solar telescope (CAST) was built to search for exotic particles called axions that might be produced inside the sun (1 page)

  18. A Solar Axion Search Using a Decommissioned LHC Test Magnet

    CERN Multimedia

    Raffelt, G; Geralis, T; Lozza, V; Christensen, F E; Jakobsen, A C; Neff, S H; Dafni, T; Carmona martinez, J M; Giomataris, I; Krcmar, M; Vafeiadis, T; Bayirli, A; Luzon marco, G M; Lakic, B; Solanki, S K; Ozbey, A; Davenport, M; Funk, W; Desch, K K; Laurent, J; Villar, J A; Jakovcic, K; Eleftheriadis, C; Cantatore, G; Diago ortega, A; Gracia garza, J; Ortega ruiz, I; Papaevangelou, T; Zioutas, K; Gardikiotis, A; Hasinoff, M D; Hoffmann, D; Iguaz gutierrez, F J; Castel pablo, J F; Gninenko, S; Ferrer ribas, E; Liolios, A; Anastasopoulos, V; Kaminski, J; Garcia irastorza, I; Ruiz choliz, E; Krieger, C; Lutz, G; Fanourakis, G; Ruz armendariz, J; Vogel, J K; Pivovaroff, M J

    2002-01-01

    Previous solar axion searches have been carried out in Brookhaven (1990) and in Tokyo (2000- ), tracking the Sun with a dipole magnet. QCD inspired axions should be produced after the Big Bang, being thus candidates for the dark matter. The Sun is a very useful source of weakly interacting particles for fundamental research. Axions can be produced also in the Sun's core through the scattering of thermal photons in the Coulomb field of electric charges (Primakoff effect). In a transverse magnetic field the Primakoff effect can work in reverse, coherently converting the solar axions or other axion-like particles (ALPS) back into X-ray photons in the keV range. The conversion efficiency increases with $(B⋅L)^2$. In the CAST experiment an LHC prototype dipole magnet (B = 9 T and L = 10 m) with straight beam pipes provides a conversion efficiency exceeding that of the two earlier solar axion telescopes by almost a factor of 100. This magnet is mounted on a moving platform and coupled to both gas filled and soli...

  19. Design for a practical laboratory detector for solar axions

    International Nuclear Information System (INIS)

    We present a practical design for a detector sensitive to axions and other light particles with a two-photon interaction vertex. Such particles would be produced in the solar interior by Primakoff conversion of blackbody photons and could be detected by their reconversion into x rays (average energy about 4 keV) in a strong laboratory magnetic field. An existing large superconducting magnet would be suitable for this purpose. The transition rate is enhanced by filling the conversion region with a buffer gas (H2 or He). This induces an effective photon mass (plasma frequency) which can be adjusted to equal the axion mass being searched for. Axion-photon conversion is then coherent throughout the detector volume for all axion energies. Axions with mass in the range 0.1 eVapprox. < m/sub a/approx. <5 eV can be detected using gas pressures of 0.1--300 atm. Axions with the standard coupling strength to photons would give counting rates of 10/sup -5/--10 sec/sup -1/ over this mass range. The search would definitively test one of the only two regions of axion parameters not excluded by astrophysical constraints

  20. Propagation of converted solar axions inside the surface cool plasma

    Science.gov (United States)

    Zioutas, K.; Tsagri, M.; Semertzidis, Y.; Papaevangelou, Th.

    2009-04-01

    Under certain conditions of solar plasma density, magnetic field and eventually field gradient, axions or other exotica with similar properties can be converted back to hard X-rays as they stream out of the hot solar core. A GEANT4 simulation was performed for the propagation of ~1-10 keV photons in a relatively cool plasma, some 100 km below the solar surface. Due to multiple Compton scattering, the photon's random path depends sensitively on the actual depth of the axion-to-photon conversion place, where the otherwise unexpected X-rays are assumed to be emitted radially outwards. This results to a continuous non-linear energy degradation of the converted solar axion energy spectrum: an initially wide and hard X-ray spectrum is being continuously redshifted into an exponential form, whose steepness (i.e., the power law index) critically depends on the plasma column density above the place of conversion. In addition, an initial pencil-like beam of hard X-rays, when escaping from the solar surface gives rise to a characteristic wide spot (e.g., some Mm). Thus, the measured shape of the energy spectrum, the spatial extension of the outstreaming X-rays, etc., can be regarded (individually or combined) as novel signatures of the solar axion particle ID. If plasma resonance effects are at work for the enhanced conversion to occur, a comparison with X-ray observations from the flaring Sun results, within the axion(-like) scenario, to a rest mass of m_axion ~10 [meV]. We note that the Monte Carlo results of this work are conventional in nature. Only the origin of the suddenly appearance of X-rays has been motivated by axions or the like. Further reading: http://xxx.lanl.gov/ftp/arxiv/papers/0808/0808.1545.pdf

  1. Solar Axion Search Technique with Correlated Signals from Multiple Detectors

    CERN Document Server

    Xu, Wenqin

    2016-01-01

    The coherent Bragg scattering of solar axions inside crystals would boost the signal for axion-photon coupling enhancing experimental sensitivity for these hypothetical particles. Knowledge of the scattering angle of solar axions with respect to the crystal lattice is required to make theoretical predications of signal strength. Hence, both the lattice axis angle within a crystal and the absolute angle between the crystal and the Sun must be known. In this paper, we demonstrate that, in a multiple-crystal setup, knowledge of the relative axis orientation between multiple crystals can improve the experimental sensitivity, or equivalently, relax the precision on the absolute solar angle measurement. However, if absolute angles of all crystal axes are measured, we find that a precision of 2 degrees to 4 degrees will suffice. Finally, we also show that, given a minimum number of detectors, a signal model averaged over angles can substitute for precise crystal angular measurements, with some loss of sensitivity.

  2. The Next Generation of Axion Helioscopes: The International Axion Observatory (IAXO)

    DEFF Research Database (Denmark)

    Vogel, J.K.; Armengaud, E.; Avignone, F.T.;

    2015-01-01

    The International Axion Observatory (IAXO) is a proposed 4th-generation axion helioscope with the primary physics research goal to search for solar axions via their Primakoff conversion into photons of 1 – 10 keV energies in a strong magnetic field. IAXO will achieve a sensitivity to the axion......-photon coupling gaγ down to a few ×10−12 GeV−1 for a wide range of axion masses up to ∼ 0.25eV. This is an improvement over the currently best (3rd generation) axion helioscope, the CERN Axion Solar Telescope (CAST), of about 5 orders of magnitude in signal strength, corresponding to a factor ∼ 20 in the axion...

  3. Search for Solar Axions with the CDMS-II Experiment

    CERN Document Server

    Bruch, T

    2008-01-01

    The CDMS-II experiment operates 19 germanium detectors with a mass of 250g each in a very low background environment. Originally designed for the search for Dark Matter the experiment can also detect solar axions by Primakoff conversion to photons. The Bragg condition for X-ray momentum transfer in a crystal allows for coherent amplification of the Primakoff process. Since the orientation of the crystal lattice with respect to the Sun changes with daytime an unique pattern in time and energy of solar axion conversions is expected. The low background ~1.5 counts/kg/day/keV and knowledge of the exact orientation of all three crystal axes with respect to the Sun make the CDMS-II experiment very sensitive to solar axions. In contrast to helioscopes, the high mass region < 1 keV can also be probed effectively. The alternating orientations of the individual crystals in the experimental setup provide different patterns of solar axion conversion, making a false positive result extremely unlikely. The result of an ...

  4. Search for 14.4-KeV Solar Axions Emitted in the M1-Transition of Fe-57 Nuclei with CAST

    Energy Technology Data Exchange (ETDEWEB)

    Andriamonje, S.; Aune, S.; /DAPNIA, Saclay; Autiero, D.; /CERN /Lyon, IPN; Barth, K.; /CERN; Belov, A.; /Moscow, INR; Beltran, B.; /Zaragoza U. /Queen' s U., Kingston; Brauninger, H.; /Garching, Max Planck Inst., MPE; Carmona, J.M.; Cebrian, S.; /Zaragoza U.; Collar, J.I.; /Chicago U., EFI /Chicago U., KICP; Dafni, T.; /DAPNIA, Saclay /Darmstadt, Tech. Hochsch. /Zaragoza U.; Davenport, M.; /CERN; Di Lella, L.; /CERN /Pisa, Scuola Normale Superiore; Eleftheriadis, C.; /Aristotle U., Thessaloniki; Englhauser, J.; /Garching, Max Planck Inst., MPE; Fanourakis, G.; /Democritos Nucl. Res. Ctr.; Ferrer-Ribas, E.; /DAPNIA, Saclay; Fischer, H.; Franz, J.; /Freiburg U.; Friedrich, P.; /Garching, Max Planck Inst., MPE; Geralis, T.; /Democritos Nucl. Res. Ctr. /DAPNIA, Saclay /Moscow, INR /Zaragoza U. /British Columbia U. /Freiburg U. /Darmstadt, Tech. Hochsch. /DAPNIA, Saclay /Zaragoza U. /Frankfurt U. /Boskovic Inst., Zagreb /Freiburg U. /Munich, Max Planck Inst. /Boskovic Inst., Zagreb /Democritos Nucl. Res. Ctr. /Darmstadt, Tech. Hochsch. /Garching, Max Planck Inst., MPE /Boskovic Inst., Zagreb /CERN /Aristotle U., Thessaloniki /Boskovic Inst., Zagreb /Munich, Max Planck Inst. /Zaragoza U. /Chicago U., EFI /Chicago U., KICP /Stanford U., Phys. Dept. /SLAC /Zaragoza U. /CERN /DAPNIA, Saclay /CERN /Munich, Max Planck Inst. /Darmstadt, Tech. Hochsch. /Zaragoza U. /Aristotle U., Thessaloniki /Patras U. /Brookhaven /CERN /Munich, Max Planck Inst. /CERN /Chicago U., EFI /Chicago U., KICP /Zaragoza U. /Freiburg U. /CERN /CERN /Patras U.

    2011-12-02

    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 the axion-to-photon conversion in the CERN Axion Solar Telescope (CAST) with evacuated magnet bores (Phase I). From the absence of excess of the monoenergetic X-rays when the magnet was pointing to the Sun, we set model-independent constraints on the coupling constants of pseudoscalar particles that couple to two photons and to a nucleon g{sub ay}|-1.19g{sub aN}{sup 0}+g{sub aN}{sup 3}| < 1.36 x 10{sup -16} GeV{sup -1} for ma < 0.03 eV at the 95% confidence level.

  5. Status report of the CERN light shining through the wall experiment with microwave axions and related aspects

    CERN Document Server

    Betz, M; Gasior, M; Thumm, M

    2012-01-01

    One way to proof or exclude the existence of axion like particles is a microwave light shining through the wall experiment. In this publication we will emphasize on the engineering aspects of such a setup, currently under development at CERN. One critical point, to achieve meaningful results, is the electromagnetic shielding between axion-emitter and -receiver cavity, which needs to be in the order of 300 dB to improve over existing experimental bounds. The RF leakage or electromagnetic crosstalk between both cavities must be well controlled and quantified during the complete duration of the experiment. A very narrow band (in the 10^-6 Hz range) homodyne detection method is used to reveal the axion signal from background thermal noise. The current status of the experiment is presented.

  6. Experimental Search for Solar Axions via Coherent Primakoff Conversion in a Germanium Spectrometer

    CERN Document Server

    Avignone, F T; Brodzinski, R; Collar, J I; Creswick, R J; Di Gregorio, D E; Farach, H A; Gattone, A O; Guérard, C K; Hasenbalg, F; Huck, H; Miley, H S; Morales, A; Morales, J; Nussinov, S; De Solorzano, A O; Reeves, J H; Villar, J; Zioutas, Konstantin

    1998-01-01

    Results are reported of an experimental search for the unique, rapidly varying temporal pattern of solar axions coherently converting into photons via the Primakoff effect in a single crystal germanium detector. This conversion is predicted when axions are incident at a Bragg angle with a crystalline plane. The analysis of approximately 1.94 kg.yr of data from the 1 kg DEMOS detector in Sierra Grande, Argentina, yields a new laboratory bound on axion-photon coupling of $g_{a\\gamma \\gamma} < 2.7\\cdot 10^{-9}$ GeV$^{-1}$, independent of axion mass up to ~ 1 keV.

  7. Experimental Search for Solar Axions via Coherent Primakoff Conversion in a Germanium Spectrometer

    International Nuclear Information System (INIS)

    Results are reported of an experimental search for the unique, rapidly varying temporal pattern of solar axions coherently converting into photons via the Primakoff effect in a single crystal germanium detector when axions are incident at a Bragg angle with a crystalline plane. The analysis of 1.94kgyr of data from the 1kg DEMOS detector in Sierra Grande, Argentina, yields a new laboratory bound by an axion-photon coupling of gaγγ-9 GeV-1 , independent of axion mass up to ∼1 keV . copyright 1998 The American Physical Society

  8. Search for solar axions with CsI(Tl) crystal detectors

    CERN Document Server

    Yoon, Y S; Bhang, H; Choi, J H; Choi, S; Hahn, I S; Jeon, E J; Joo, H W; Kang, W G; Kim, B H; Kim, G B; Kim, H J; Kim, K W; Kim, S C; Kim, S K; Kim, Y D; Kim, Y H; Lee, H S; Lee, J H; Lee, J K; Lee, S J; Leonard, D S; Li, J; Myung, S S; Olsen, S L; So, J H

    2016-01-01

    The results of a search for solar axions from the Korea Invisible Mass Search (KIMS) experiment at the Yangyang Underground Laboratory are presented. Low-energy electron-recoil events would be produced by conversion of solar axions into electrons via the axio-electric effect in CsI(Tl) crystals. Using data from an exposure of 34,596 $\\rm kg \\cdot days$, we set a 90 \\% confidence level upper limit on the axion-electron coupling, $g_{ae}$, of $1.39 \\times 10^{-11}$ for an axion mass less than 1 keV/$\\rm c^2$. This limit is lower than the indirect solar neutrino bound, and fully excludes QCD axions heavier than 0.48 eV/$\\rm c^2$ and 140.9 eV/$\\rm c^2$ for the DFSZ and KSVZ models respectively.

  9. Magnetic Scope Angles for Axions

    CERN Multimedia

    Seife, Charles

    2005-01-01

    After 2 years of staring at the sun, an unconventional "telescope" made from a leftover magnet has returned its first results. Although it hasn't yet found the quarry it was designed to spot - a particle that might or might not exist physicists say the CERN Axion Solar Telescope (CAST) is beginning to glimpse uncharted territory

  10. Search for Solar Axions Produced in the $p + d \\rightarrow\\rm{^3He}+ A$ Reaction

    CERN Document Server

    Derbin, A V; Muratova, V N; 10.3103/S106287381006016X

    2010-01-01

    A search for the axioelectric absorption of 5.5-MeV solar axions produced in the $p+d\\rightarrow \\rm{^3He}+\\gamma(5.5 \\rm{MeV})$ reaction was performed with two BGO detectors placed inside a low-background setup. A model independent limit on axion-photon and axion-nucleon couplings was obtained: $|g_{Ae}\\times g_{AN}| \\leq 3.2\\times 10^{-9} (m_A=0)$. Constraints on the axion-electron coupling constant were obtained for axions with masses in the $(0.1-1.0)$ MeV range: $g_{Ae}\\leq (1.8-9.0)\\times 10^{-7}$. The solar positron flux from $A\\rightarrow e^-+e^+$ decay was determined for axions with masses $m_A > 2m_e$. Using the existing experimental data on the interplanetary positron flux, a new constraint on the axion-electron coupling constant for axions with masses in the $(1.2-5.4)$ MeV range was obtained: $g_{Ae} \\leq (1-5)\\times 10^{-17}$.

  11. Search for solar axions with the X-ray telescope of the CAST experiment (phase II); Suche nach solaren Axionen mit dem Roentgenteleskop des CAST-Experiments (Phase II)

    Energy Technology Data Exchange (ETDEWEB)

    Nordt, Annika

    2009-10-14

    The CAST (CERN Solar Axion Telescope) experiment is searching for solar axions by their conversion into photons inside a transverse magnetic field. So far, no solar axionsignal has been detected, but a new upper limit could be given (CAST Phase I). Since 2005, CAST entered in its second phase where it operates with a buffer gas ({sup 4}He) in the conversion region to extend the sensitivity of the experiment to higher axionmasses. For the first time it is possible to enter the theoretically favored axion massrange and to give an upper limit for this solar axion mass-range (>0.02 eV). This thesis is about the analysis of the X-ray telescope data Phase II with {sup 4}He inside the magnet. The result for the coupling constant of axions to photons is: g{sub {alpha}}{sub {gamma}}{sub {gamma}}<1.6-6.0 x 10{sup -10} GeV{sup -1} (95%C.L.) for m{sub a}=0.02-0.4 eV. (2) This result is better than any result that has been given before in this mass range for solar axions. (orig.)

  12. Searching for Solar Axions using the MAJORANA DEMONSTRATOR

    Science.gov (United States)

    O'Shaughnessy, Christopher; Majorana Collaboration

    2015-10-01

    The choice of P-Type Point Contact (PPC) detectors for the Majorana Demonstrator (MJD) was driven by the high energy resolution and superb pulse shape analysis capability of this technology. Due to its low-capacitance this technology also boasts good energy resolution even at low energy, at the keV scale or better. This opens up an ensemble of searches for new physics that can be pursued in parallel with the main goals of searching for neutrinoless double beta decay. Here I will discuss the efforts toward measuring crystal axes in the as-built detector units of MJD to improve sensitivity to the detection of solar axions. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, the Particle Astrophysics Program of the National Science Foundation, and the Sanford Underground Research Facility.

  13. Search for axioelectric effect of solar axions using BGO scintillating bolometer

    Energy Technology Data Exchange (ETDEWEB)

    Derbin, A.V.; Kayunov, A.S.; Muratova, V.N.; Semenov, D.A.; Unzhakov, E.V. [St. Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Gironi, L.; Biassoni, M.; Capelli, S.; Clemenza, M.; Ferri, E.; Giachero, A.; Gotti, C.; Maiano, C.; Maino, M.; Pavan, M.; Sisti, M. [INFN-Sezione di Milano Bicocca, Milano (Italy); Universita di Milano-Bicocca, Dipartimento di Fisica, Milano (Italy); Nagorny, S.S. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Gran Sasso Science Institute, INFN, L' Aquila, AQ (Italy); Pattavina, L.; Pirro, S. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Beeman, J.W. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Bellini, F. [INFN-Sezione di Roma, Rome (Italy); Universita di Roma La Sapienza, Dipartimento di Fisica, Rome (Italy); Drachnev, I.S. [St. Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Gran Sasso Science Institute, INFN, L' Aquila, AQ (Italy)

    2014-09-15

    A search for axioelectric absorption of solar axions produced in the p + d → {sup 3}He + γ(5.5 MeV) reaction has been performed with a BGO detector placed in a low-background setup. A model-independent limit on the combination of axion.nucleon and axion.electron coupling constants has been obtained: vertical stroke g{sub Ae} x g{sup 3}{sub AN} vertical stroke < 1.9 x 10{sup -10} for 90 % confidence level. The constraint of the axion.electron coupling constant has been obtained for hadronic axion with masses of (0.1.1) MeV: vertical stroke g{sub Ae} vertical stroke ≤ (0.96. 8.2) x 10{sup -8}. (orig.)

  14. Searches for axioelectric effect of solar axions with BGO-scintillator and BGO-bolometer detectors

    CERN Document Server

    Muratova, V N; Giorni, L; Nagorny, S S; Pattavina, L; Bakhlanov, S V; Beeman, J W; Bellini, F; Biassoni, M; Capelli, S; Clemenza, M; Dratchnev, I S; Ferri, E; Giachero, A; Gotti, C; Kayunov, A S; Maiano, C; Maino, M; Pavan, M; Pirro, S; Semenov, D A; Sisti, M; Unzhakov, E V

    2015-01-01

    A search for axioelectric absorption of 5.5 MeV solar axions produced in the $p + d \\rightarrow {^3\\rm{He}}+\\gamma~(5.5~ \\rm{MeV})$ reaction has been performed with a BGO detectors. A model-independent limit on the product of axion-nucleon $g_{AN}^3$ and axion-electron $g_{Ae}$ coupling constants has been obtained: $| g_{Ae}\\times g_{AN}^3|< 1.9\\times 10^{-10}$ for 90\\% C.L..

  15. Experimental Search for Solar Axions via Coherent Primakoff Conversion in a Germanium Spectrometer

    OpenAIRE

    Avignone, F. T.; Abriola, D.; Brodzinski, R. L.; J. I. Collar; Creswick, R.J.; DiGregorio, D. E.; Farach, H. A.; Gattone, A. O.; Guerard, C. K.; Hasenbalg, F.; Huck, H.; Miley, H. S.; Morales, A.; MORALES, J., CRUZ, D., DELGADO, P., LIZANA, M., LÓPEZ, V.; Nussinov, S.

    1997-01-01

    Results are reported of an experimental search for the unique, rapidly varying temporal pattern of solar axions coherently converting into photons via the Primakoff effect in a single crystal germanium detector. This conversion is predicted when axions are incident at a Bragg angle with a crystalline plane. The analysis of approximately 1.94 kg.yr of data from the 1 kg DEMOS detector in Sierra Grande, Argentina, yields a new laboratory bound on axion-photon coupling of $g_{a\\gamma \\gamma} < 2...

  16. Axions - Motivation, limits and searches

    OpenAIRE

    Raffelt, Georg G.

    2006-01-01

    The axion solution of the strong CP problem provides a number of possible windows to physics beyond the standard model, notably in the form of searches for solar axions and for galactic axion dark matter, but in a broader context also inspires searches for axion-like particles in pure laboratory experiments. We briefly review the motivation for axions, astrophysical limits, their possible cosmological role, and current searches for axions and axion-like particles.

  17. Experimental probes of axions

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Aaron S.; /Fermilab

    2009-10-01

    Experimental searches for axions or axion-like particles rely on semiclassical phenomena resulting from the postulated coupling of the axion to two photons. Sensitive probes of the extremely small coupling constant can be made by exploiting familiar, coherent electromagnetic laboratory techniques, including resonant enhancement of transitions using microwave and optical cavities, Bragg scattering, and coherent photon-axion oscillations. The axion beam may either be astrophysical in origin as in the case of dark matter axion searches and solar axion searches, or created in the laboratory from laser interactions with magnetic fields. This note is meant to be a sampling of recent experimental results.

  18. Search for Solar Axions Produced in $p(d,\\rm{^3He})A$ Reaction with Borexino Detector

    OpenAIRE

    Bellini, G.; Benziger, J.; Bick, D.; Bonfini, G.; Bravo, D.; Avanzini, M.; Caccianiga, B.; Cadonati, L.; Calaprice, F.; Carraro, C.; Cavalcante, P.; Chavarria, A.(Kavli Institute, Enrico Fermi Institute, Dept. of Physics, University of Chicago, Chicago, IL, 60637, USA); D. D’Angelo; Davini, S.; Derbin, A.

    2012-01-01

    A search for 5.5-MeV solar axions produced in the $p+d\\rightarrow\\rm{^3He}+A (5.5 \\rm{MeV})$ reaction was performed using the Borexino detector. The Compton conversion of axions to photons, ${\\rm A}+e\\rightarrow e+\\gamma$; the axio-electric effect, ${\\rm A}+e+Z\\rightarrow e+Z$; the decay of axions into two photons, ${\\rm A}\\rightarrow2\\gamma$; and inverse Primakoff conversion on nuclei, ${\\rm A}+Z\\rightarrow\\gamma+Z$, are considered. Model independent limits on axion-electron ($g_{Ae}$), axio...

  19. Axion mechanism of the Sun luminosity and solar dynamo - geodynamo connection

    CERN Document Server

    Rusov, V D; Kudela, K; Mavrodiev, S Cht; Sharph, I V; Zelentsova, T N; Smolyar, V P; Merkotan, K K

    2010-01-01

    We show existence of strong negative correlation between the temporal varia-tions of magnetic field toroidal component of the solar tachocline (the bottom of convective zone) and the Earth magnetic field (Y-component). The possibility that hypothetical solar axions, which can transform into photons in external electric or magnetic fields (the inverse Primakoff effect), can be the instrument by which the magnetic field of convective zone of the Sun modulates the magnetic field of the Earth is considered. We propose the axion mechanism of Sun luminosity and "solar dynamo - geodynamo" connection, where an energy of solar axions emitted in M1 transition in 57Fe nuclei is modulated at first by the magnetic field of the solar tachocline zone (due to the inverse coherent Primakoff effect) and after that is resonance absorbed in the core of the Earth, thereby playing the role of an energy source and a modulator of the Earth magnetic field. Within the framework of this mechanism estimations of the strength of an axion...

  20. New axion and hidden photon constraints from a solar data global fit

    CERN Document Server

    Vinyoles, Núria; Villante, Francesco L; Basu, Sarbani; Redondo, Javier; Isern, Jordi

    2015-01-01

    We present a new statistical analysis that combines helioseismology (sound speed, surface helium and convective radius) and solar neutrino observations (boron and beryllium fluxes) to place upper limits to the properties of non standard weakly interacting particles. Our analysis includes theoretical and observational errors, accounts for tensions between input parameters of solar models and can be easily extended to include other observational constraints. We present two applications to test the method: the well studied case of axions and axion-like particles and the more novel case of low mass hidden photons. For axions we obtain an upper limit at 3 sigma for the axion-photon coupling constant of g_a-gamma < 4 x 10^-10 GeV^-1. For hidden photons we obtain the most restrictive upper limit for the product of the kinetic mixing and mass of chi < 1.82 x 10^-12 eV/m at 3 sigma. Both cases improve the previous solar constraints based on the Standard Solar Models showing the power of our global statistical ap...

  1. Potential solar axion signatures in X-ray observations with the XMM-Newton observatory

    OpenAIRE

    Fraser, G. W.; Read, A. M.; Sembay, S.; Carter, J. A.; Schyns, E.

    2014-01-01

    The soft X-ray flux produced by solar axions in the Earth's magnetic field is evaluated in the context of ESA's XMM-Newton observatory. Recent calculations of the scattering of axion-conversion X-rays suggest that the sunward magnetosphere could be an observable source of 0.2-10 keV photons. For XMM-Newton, any conversion X-ray intensity will be seasonally modulated by virtue of the changing visibility of the sunward magnetic field region. A simple model of the geomagnetic field is combined w...

  2. The BGU/CERN solar hydrothermal reactor

    CERN Document Server

    Bertolucci, Sergio; Caspers, Fritz; Garb, Yaakov; Gross, Amit; Pauletta, Stefano

    2014-01-01

    We describe a novel solar hydrothermal reactor (SHR) under development by Ben Gurion University (BGU) and the European Organization for Nuclear Research CERN. We describe in broad terms the several novel aspects of the device and, by extension, of the niche it occupies: in particular, enabling direct off-grid conversion of a range of organic feedstocks to sterile useable (solid, liquid) fuels, nutrients, products using only solar energy and water. We then provide a brief description of the high temperature high efficiency panels that provide process heat to the hydrothermal reactor, and review the basics of hydrothermal processes and conversion taking place in this. We conclude with a description of a simulation of the pilot system that will begin operation later this year.

  3. Solar axions as an energy source and modulator of the Earth magnetic field

    OpenAIRE

    Rusov, V. D.; Linnik, E. P.; Kudela, K.; Mavrodiev, S. Cht.; Zelentsova, T. N.; Smolyar, V. P.; Merkotan, K. K.

    2010-01-01

    We show existence of strong negative correlation between the temporal variations of magnetic field toroidal component of the solar tachocline (the bottom of convective zone) and the Earth magnetic field (Y-component). The possibility that hypothetical solar axions, which can transform into photons in external electric or magnetic fields (the inverse Primakoff effect), can be the instrument by which the magnetic field of convective zone of the Sun modulates the magnetic field of the Earth is c...

  4. Axion mechanism of the Sun luminosity and solar dynamo - geodynamo connection

    OpenAIRE

    Rusov, V. D.; Linnik, E. P.; Kudela, K.; Mavrodiev, S. Cht.; Sharph, I. V.; Zelentsova, T. N.; Beglaryan, R.; Smolyar, V. P.; Merkotan, K. K.

    2010-01-01

    We show existence of strong negative correlation between the temporal variations of magnetic field toroidal component of the solar tachocline (the bottom of convective zone) and the Earth magnetic field (Y-component). The possibility that hypothetical solar axions, which can transform into photons in external electric or magnetic fields (the inverse Primakoff effect), can be the instrument by which the magnetic field of convective zone of the Sun modulates the magnetic field of the Earth is c...

  5. A search for bremsstrahlung solar axions using the Majorana low-background BEGe detector at Kimballton (MALBEK)

    CERN Document Server

    Abgrall, N; Avignone, F T; Barabash, A S; Bertrand, F E; Boswell, M; Brudanin, V; Busch, M; Caldwell, A S; Chan, Y-D; Christofferson, C D; Combs, D C; Cooper, R J; Creswick, R J; Detwiler, J A; Doe, P J; Efremenko, Yu; Egorov, V; Elliott, S R; Fast, J E; Finnerty, P; Giovanetti, G K; Goett, J; Green, M P; Gruszko, J; Guiseppe, V E; Gusev, K; Hegai, A; Henning, R; Hoppe, E W; Howard, S; Howe, M A; Keeter, K J; Kidd, M F; Knecht, A; Kochetov, O; Konovalov, S I; Kouzes, R T; LaFerriere, B D; Leon, J; Leviner, L E; Loach, J C; MacMullin, J; MacMullin, S; Marino, M G; Martin, R D; Mertens, S; Orrell, J L; O'Shaughnessy, C; Overman, N R; Phillips, D G; Poon, A W P; Pushkin, K; Radford, D C; Robertson, R G H; Ronquest, M C; Schubert, A G; Shanks, B; Shirchenko, M; Snavely, K J; Snyder, N; Steele, D; Suriano, A M; Thompson, J; Timkin, V; Varner, R L; Vasilyev, S; Vetter, K; Vorren, K; White, B R; Wilkerson, J F; Xu, W; Yakushev, E; Young, A R; Yu, C H; Yumatov, V

    2014-01-01

    A low-background, high-purity germanium detector has been used to search for evidence of low-energy, bremsstrahlung-generated solar axions. An upper bound of $1.36\\times 10^{-11}$ $(95\\% CL)$ is placed on the direct coupling of DFSZ model axions to electrons. The prospects for the sensitivity of the Majorana Demonstrator array of point-contact germanium detectors to solar axions are discussed in the context of the model-independent annual modulation due to the seasonal variation of the earth-sun distance.

  6. Solar axions as an energy source and modulator of the Earth magnetic field

    CERN Document Server

    Rusov, V D; Kudela, K; Mavrodiev, S Cht; Zelentsova, T N; Smolyar, V P; Merkotan, K K

    2010-01-01

    We show existence of strong negative correlation between the temporal variations of magnetic field toroidal component of the solar tachocline (the bottom of convective zone) and the Earth magnetic field (Y-component). The possibility that hypothetical solar axions, which can transform into photons in external electric or magnetic fields (the inverse Primakoff effect), can be the instrument by which the magnetic field of convective zone of the Sun modulates the magnetic field of the Earth is considered. We propose the axion mechanism of "solar dynamo-geodynamo" connection, where an energy of axions, which form in the Sun core, is modulated at first by the magnetic field of the solar tachocline zone (due to the inverse coherent Primakoff effect) and after that is absorbed in the liquid core of the Earth under influence of the terrestrial magnetic field, thereby playing the role of an energy source and a modulator of the Earth magnetic field. Within the framework of this mechanism new estimations of the strength...

  7. Detection chamber for search of low Mass WIMP and solar axions

    CERN Document Server

    Ovchinnikov, B M

    2016-01-01

    A chamber for direct detection of WIMPs with masses < 10 GeV/c2 and solar axions is developed. The chamber is filled with a gas mixture of H2 +3ppm TMAE (1,5,10 bar), or D2 + 3ppm TMAE. These gas fillings make it possible to suppress an electron background. For detection of events, the system GEM+pin-anode with a multiplication coefficient of about 10E+05 is constructed.

  8. Search for hadronic axions

    International Nuclear Information System (INIS)

    The existence of axions, proposed as very light neutral pseudoscalar bosons, would solve the strong CP problem in the QCD. Axions also arise in supersymmetric and superstring theories and are candidates for dark matter in the universe. Cosmological and astrophysical arguments restrict the masses (ma) of invisible axions to rather narrow 10-5 eV → ma → 10-22 eV range, but with large uncertainties on either side. The KSVZ or hadronic axion is one version of invisible axions, which predicts small coupling of axions to electrons. Models of hadronic axions with E/N ≅ 2 allow for a near or complete cancellation of the axion-photon coupling constant. In this case there is no stellar-evolution limits on ma and for hadronic axions there exists a small window 10 eV ≤ ma ≤ 40 eV between supernova cooling and axion burst arguments. So far the best and only discussed candidate for hot dark matter has been the massive neutrino with a mass of a few eV. Because the Super-Kamiokande experiment suggests the tau neutrino mass of only 0.03-0.1 eV, the hadronic axion in the so-called hadronic axion window could be a good candidate for a cosmological hot dark matter within the mixed dark matter scenario. To verify this window one can search for axions by appealing only to their coupling to nucleons. The most promising methods are the observation of an axion burst from a future supernova and the resonant absorption of almost monochromatic solar axions. We have performed the first experiment along this new line of solar axion investigations. Using a small target of 0.03 g of 57Fe we have made a search for 14.4 keV gamma rays induced by resonant absorption of almost monochromatic solar axions. These Doppler broadened axions could be emitted from the Sun, in M1 transition between the first, thermally excited state and the ground state of 57Fe. An upper limit on hadronic axion mass of 745 eV is obtained at the 95 % confidence level. Search for solar axions is beginning to become

  9. Bounds on galactic cold dark matter particle candidates and solar axions from a Ge-spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Gelmini, G.

    1986-11-01

    The ultralow background Ge spectrometer developed by the USC/PNL group is used as a detector of cold dark matter candidates from the halo of our galaxy and of solar axions (and other light bosons), yielding interesting bounds. Some of them are: heavy standard Dirac neutrinos with mass 20 GeV less than or equal to m less than or equal to 1 TeV are excluded as main components of the halo of our galaxy; Dine-Fischler-Srednicki axion models with F/2x/sub e/' less than or equal to 0.5 x 10/sup 7/ GeV are excluded. 22 refs., 7 figs.

  10. Search for Solar Axions Produced in $p(d,\\rm{^3He})A$ Reaction with Borexino Detector

    CERN Document Server

    ,

    2012-01-01

    A search for 5.5-MeV solar axions produced in the $p+d\\rightarrow\\rm{^3He}+A (5.5 \\rm{MeV})$ reaction was performed using the Borexino detector. The Compton conversion of axions to photons, ${\\rm A}+e\\rightarrow e+\\gamma$; the axio-electric effect, ${\\rm A}+e+Z\\rightarrow e+Z$; the decay of axions into two photons, ${\\rm A}\\rightarrow2\\gamma$; and inverse Primakoff conversion on nuclei, ${\\rm A}+Z\\rightarrow\\gamma+Z$, are considered. Model independent limits on axion-electron ($g_{Ae}$), axion-photon ($g_{A\\gamma}$), and isovector axion-nucleon ($g_{3AN}$) couplings are obtained: $|g_{Ae}\\times g_{3AN}| \\leq 5.5\\times 10^{-13}$ and $|g_{A\\gamma}\\times g_{3AN}| \\leq 4.6\\times 10^{-11} \\rm{GeV}^{-1}$ at $m_A <$ 1 MeV (90% c.l.). These limits are 2-4 orders of magnitude stronger than those obtained in previous laboratory-based experiments using nuclear reactors and accelerators.

  11. The Superconducting Toroid for the New International AXion Observatory (IAXO)

    CERN Document Server

    Shilon, I; Silva, H; Wagner, U; Kate, H H J ten

    2013-01-01

    IAXO, the new International AXion Observatory, will feature the most ambitious detector for solar axions to date. Axions are hypothetical particles which were postulated to solve one of the puzzles arising in the standard model of particle physics, namely the strong CP (Charge conjugation and Parity) problem. This detector aims at achieving a sensitivity to the coupling between axions and photons of one order of magnitude beyond the limits of the current detector, the CERN Axion Solar Telescope (CAST). The IAXO detector relies on a high-magnetic field distributed over a very large volume to convert solar axions to detectable X-ray photons. Inspired by the ATLAS barrel and end-cap toroids, a large superconducting toroid is being designed. The toroid comprises eight, one meter wide and twenty one meters long racetrack coils. The assembled toroid is sized 5.2 m in diameter and 25 m in length and its mass is about 250 tons. The useful field in the bores is 2.5 T while the peak magnetic field in the windings is 5....

  12. New superconducting toroidal magnet system for IAXO, the international AXion observatory

    Energy Technology Data Exchange (ETDEWEB)

    Shilon, I.; Dudarev, A.; Silva, H.; Wagner, U.; Kate, H. H. J. ten [European Organization for Nuclear Research (CERN), CH-1211, Genève 23 (Switzerland)

    2014-01-29

    Axions are hypothetical particles that were postulated to solve one of the puzzles arising in the standard model of particle physics, namely the strong CP (Charge conjugation and Parity) problem. The new International AXion Observatory (IAXO) will incorporate the most promising solar axions detector to date, which is designed to enhance the sensitivity to the axion-photon coupling by one order of magnitude beyond the limits of the current state-of-the-art detector, the CERN Axion Solar Telescope (CAST). The IAXO detector relies on a high-magnetic field distributed over a very large volume to convert solar axions into X-ray photons. Inspired by the successful realization of the ATLAS barrel and end-cap toroids, a very large superconducting toroid is currently designed at CERN to provide the required magnetic field. This toroid will comprise eight, one meter wide and twenty one meter long, racetrack coils. The system is sized 5.2 m in diameter and 25 m in length. Its peak magnetic field is 5.4 T with a stored energy of 500 MJ. The magnetic field optimization process to arrive at maximum detector yield is described. In addition, materials selection and their structure and sizing has been determined by force and stress calculations. Thermal loads are estimated to size the necessary cryogenic power and the concept of a forced flow supercritical helium based cryogenic system is given. A quench simulation confirmed the quench protection scheme.

  13. Determination of effective axion masses in the helium-3 buffer of CAST

    Energy Technology Data Exchange (ETDEWEB)

    Ruz, J

    2011-11-18

    The CERN Axion Solar Telescope (CAST) is a ground based experiment located in Geneva (Switzerland) searching for axions coming from the Sun. Axions, hypothetical particles that not only could solve the strong CP problem but also be one of the favored candidates for dark matter, can be produced in the core of the Sun via the Primakoff effect. They can be reconverted into X-ray photons on Earth in the presence of strong electromagnetic fields. In order to look for axions, CAST points a decommissioned LHC prototype dipole magnet with different X-ray detectors installed in both ends of the magnet towards the Sun. The analysis of the data acquired during the first phase of the experiment yielded the most restrictive experimental upper limit on the axion-to-photon coupling constant for axion masses up to about 0.02 eV/c{sup 2}. During the second phase, CAST extends its mass sensitivity by tuning the electron density present in the magnetic field region. Injecting precise amounts of helium gas has enabled CAST to look for axion masses up to 1.2 eV/c{sup 2}. This paper studies the determination of the effective axion masses scanned at CAST during its second phase. The use of a helium gas buffer at temperatures of 1.8 K has required a detailed knowledge of the gas density distribution. Complete sets of computational fluid dynamic simulations validated with experimental data have been crucial to obtain accurate results.

  14. Determination of effective axion masses in the helium-3 buffer of CAST

    International Nuclear Information System (INIS)

    The CERN Axion Solar Telescope (CAST) is a ground based experiment located in Geneva (Switzerland) searching for axions coming from the Sun. Axions, hypothetical particles that not only could solve the strong CP problem but also be one of the favored candidates for dark matter, can be produced in the core of the Sun via the Primakoff effect. They can be reconverted into X-ray photons on Earth in the presence of strong electromagnetic fields. In order to look for axions, CAST points a decommissioned LHC prototype dipole magnet with different X-ray detectors installed in both ends of the magnet towards the Sun. The analysis of the data acquired during the first phase of the experiment yielded the most restrictive experimental upper limit on the axion-to-photon coupling constant for axion masses up to about 0.02 eV/c2. During the second phase, CAST extends its mass sensitivity by tuning the electron density present in the magnetic field region. Injecting precise amounts of helium gas has enabled CAST to look for axion masses up to 1.2 eV/c2. This paper studies the determination of the effective axion masses scanned at CAST during its second phase. The use of a helium gas buffer at temperatures of 1.8 K has required a detailed knowledge of the gas density distribution. Complete sets of computational fluid dynamic simulations validated with experimental data have been crucial to obtain accurate results.

  15. Tokyo Axion Helioscope

    CERN Document Server

    Minowa, M; Akimoto, Y; Ohta, R; Mizumoto, T; Yamamoto, A

    2008-01-01

    A new search result of the Tokyo axion helioscope is presented. The axion helioscope consists of a dedicated cryogen-free 4T superconducting magnet with an effective length of 2.3 m and PIN photodiodes as x-ray detectors. Solar axions, if exist, would be converted into X-ray photons through the inverse Primakoff process in the magnetic field. Conversion is coherently enhanced even for massive axions by filling the conversion region with helium gas. The present third phase measurement sets a new limit of g_{a\\gamma\\gamma}<(5.6--13.4)\\times10^{-10} GeV^{-1} for the axion mass of 0.84

  16. Probing eV-scale axions with CAST

    CERN Document Server

    Arik, E; Autiero, D; Barth, K; Belov, A; Beltrán, B; Borghi, S; Bourlis, G; Boydag, F S; Bräuninger, H; Carmona, J M; Cebrián, S; Cetin, S A; Collar, J I; Dafni, T; Davenport, M; Di Lella, L; Dogan, O B; Eleftheriadis, C; Elias, N; Fanourakis, G K; Ferrer-Ribas, E; Fischer, H; Friedrich, P; Franz, J; Galán, J; Geralis, T; Giomataris, Yu; Gninenko, S; Gómez, H; Hartmann, R; Hasinoff, M; Heinsius, F H; Hikmet, I; Hoffmann, D H H; Irastorza, I G; Jacoby, J; Jakovcic, K; Kang, D; Königsmann, K C; Kotthaus, R; Krcmar, M; Kousouris, K; Kuster, M; Lakic, B; Lasseur, C; Liolios, A; Ljubicic, A; Lutz, G; Luzón, G; Miller, D; Morales, J; Niinikoski, T; Nordt, A; Ortiz, A; Papaevangelou, T; Pivovaroff, M J; Placci, A; Raffelt, G; Riege, H; Rodríguez, A; Ruz, J; Sawidis, I; Semertzidis, Y; Serpico, P; Soufli, R; Stewart, L; van Bibber, K; Villar, J; Vogel, J; Walckiers, L; Zioutas, K

    2009-01-01

    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 have reported results from CAST with evacuated magnet bores (Phase I), setting limits on lower mass axions, here we report results from CAST where the magnet bores were filled with \\hefour gas (Phase II) of variable pressure. The introduction of gas generated a refractive photon mass $m_\\gamma$, thereby achieving the maximum possible conversion rate for those axion masses \\ma that match $m_\\gamma$. With 160 different pressure settings we have scanned \\ma up to about 0.4 eV, taking approximately 2 h of data for each setting. 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 $\\gag\\lesssim 2.17\\times 10^{-10} {\\rm GeV}^{-1}$ at 95% CL for $\\ma \\lesssim 0.4$ eV, the exact result depending on the pressure setting. The excluded parameter range covers realistic axio...

  17. Transplanckian axions !?

    CERN Document Server

    Montero, Miguel; Valenzuela, Irene

    2015-01-01

    We discuss quantum gravitational effects in Einstein theory coupled to periodic axion scalars to analyze the viability of several proposals to achieve superplanckian axion periods (aka decay constants) and their possible application to large field inflation models. The effects we study correspond to the nucleation of euclidean gravitational instantons charged under the axion, and our results are essentially compatible with (but independent of) the Weak Gravity Conjecture, as follows: Single axion theories with superplanckian periods contain gravitational instantons inducing sizable higher harmonics in the axion potential, which spoil superplanckian inflaton field range. A similar result holds for multi-axion models with lattice alignment (like the Kim-Nilles-Peloso model). Finally, theories with $N$ axions can still achieve a moderately superplanckian periodicity (by a $\\sqrt{N}$ factor) with no higher harmonics in the axion potential. The Weak Gravity Conjecture fails to hold in this case due to the absence ...

  18. The X-ray signature of the solar axion flux observed by XMM-Newton

    CERN Document Server

    Fraser, G W; Sembay, S; Carter, J A; Schyns, E

    2014-01-01

    Recent calculations of the 3-D scattering of X-rays produced by the conversion of solar axions suggest that the sunward magnetosphere could be a source of 0.2-10keV photons, observable without violating the Sun-/Earth-avoidance constraints of operational telescopes. Observed from High Earth Orbit, this conversion X-ray intensity may be seasonally modulated due to the changing visibility of the sunward magnetic field region. A simple model of the geomagnetic field is combined with the full ephemeris of XMM to predict the seasonal variation of the conversion X-ray intensity and its north-south asymmetry relative to the ecliptic. This model is compared with stacked XMM EPIC pn, MOS1 and MOS2 blank sky datasets from which point sources have been systematically removed and which have been rigorously screened against 1-500keV soft protons. Remarkably, when the residual flux is segregated according to spacecraft season, a very significant (>3sigma), seasonally-varying X-ray background signal is observed. The EPIC co...

  19. Axion cosmology

    Science.gov (United States)

    Marsh, David J. E.

    2016-07-01

    Axions comprise a broad class of particles that can play a major role in explaining the unknown aspects of cosmology. They are also well-motivated within high energy physics, appearing in theories related to CP-violation in the standard model, supersymmetric theories, and theories with extra-dimensions, including string theory, and so axion cosmology offers us a unique view onto these theories. I review the motivation and models for axions in particle physics and string theory. I then present a comprehensive and pedagogical view on the cosmology and astrophysics of axion-like particles, starting from inflation and progressing via BBN, the CMB, reionization and structure formation, up to the present-day Universe. Topics covered include: axion dark matter (DM); direct and indirect detection of axions, reviewing existing and future experiments; axions as dark radiation; axions and the cosmological constant problem; decays of heavy axions; axions and stellar astrophysics; black hole superradiance; axions and astrophysical magnetic fields; axion inflation, and axion DM as an indirect probe of inflation. A major focus is on the population of ultralight axions created via vacuum realignment, and its role as a DM candidate with distinctive phenomenology. Cosmological observations place robust constraints on the axion mass and relic density in this scenario, and I review where such constraints come from. I next cover aspects of galaxy formation with axion DM, and ways this can be used to further search for evidence of axions. An absolute lower bound on DM particle mass is established. It is ma > 10-24eV from linear observables, extending to ma ≳ 10-22eV from non-linear observables, and has the potential to reach ma ≳ 10-18eV in the future. These bounds are weaker if the axion is not all of the DM, giving rise to limits on the relic density at low mass. This leads to the exciting possibility that the effects of axion DM on structure formation could one day be detected

  20. A Micromegas-based low-background x-ray detector coupled to a slumped-glass telescope for axion research

    DEFF Research Database (Denmark)

    Aznar, F.; Castel, J.; Christensen, F. E.;

    2015-01-01

    -approximation Wolter I x-ray telescope (XRT) assembled from thermally-formed (or "slumped") glass substrates deposited with multilayer coatings. The system has been conceived as a technological pathfinder for the future International Axion Observatory (IAXO), as it combines two of the techniques (optic and detector......) proposed in the conceptual design of the project. It is innovative for two reasons: it is the first time an x-ray optic has been designed and fabricated specifically for axion research, and the first time a Micromegas detector has been operated with an x-ray optic. The line has been installed at one end of...... the CERN Axion Solar Telescope (CAST) magnet and is currently looking for solar axions. The combination of the XRT and Micromegas detector provides the best signal-to-noise ratio obtained so far by any detection system of the CAST experiment with a background rate of 5.4×10−3 counts per hour in the...

  1. Cern

    CERN Multimedia

    2009-01-01

    "La réparation de l'accélérateur géant de particules LHC, qui devrait redémarrer mi-novembre aprés une panne de plus d'un an, a coûté 23 millions d'euros, selon un haut responsable du Centre européen de recherche nucléaire (CERN), cité vendredi par les médias espagnols" (1 paragraph)

  2. Domestic Axion

    CERN Document Server

    Dvali, Gia

    2016-01-01

    We attempt to identify a phenomenologically viable solution to the strong $CP$ problem in which the axion is composed entirely out of Standard Model fermion species. The axion consists predominantly of the $\\eta'$ meson with a minuscule admixture of a pseudoscalar bilinear composite of neutrinos, $\\eta_{\

  3. Ultrasensitive Searches for the Axion

    Energy Technology Data Exchange (ETDEWEB)

    van Bibber, K A; Rosenberg, L J

    2006-07-14

    The axion, a hypothetical elementary particle arising from a compelling solution to the strong-CP problem, has eluded discovery for three decades. Experiments based on coherent axion-photon mixing in strong magnetic fields are just now reaching the sensitivity to detect it, either as the dark matter or as a component of the solar flux. Although of lower sensitivity, purely laboratory experiments hold potential for surprise.

  4. Sensitivity of the CUORE detector to $14.4$ keV solar axions emitted by the M1 nuclear transition of$~^{57}$Fe

    CERN Document Server

    Li, Dawei; Avignone, Frank T; Wang, Yuanxu

    2015-01-01

    In this paper we present a calculation of the sensitivity of the CUORE detector to the monoenergetic $14.4$ keV solar axions emitted by the M1 nuclear transition of$~^{57}$Fe in the Sun and detected by inverse coherent Bragg-Primakoff conversion in single-crystal $TeO_2$ bolometers. The expected counting rate is calculated using density functional theory for the electron charge density of $TeO_2$ and realistic background and energy resolution of CUORE. Monte Carlo simulations for $5$ y $\\times$ $741$ kg=$3705-$kg$\\cdot$y of exposure are analyzed using time correlation of individual events with the theoretical time-dependent counting rate. We find an expected model-independent limit on the product of the axion-photon coupling and the axion-nucleon coupling $g_{a\\gamma\\gamma}\\{|-1.19g^0_{aN}+g^3_{aN}|\\}<1.105\\times 10^{-16}$ /GeV for axion masses less than 500 eV with $95\\%$ confidence level.

  5. Pierre Sikivie from the University of Florida invented the working principle of all magnetic axion telescopes, such as CAST.

    CERN Multimedia

    Claudia Marcelloni

    2006-01-01

    The possible existence of axions in the universe means that they are a candidate for (very) cold dark matter, as another axion pioneer, Pierre Sikivie, from the University of Florida explained during the first Joint ILIAS-CAST-CERN Axion Training workshop. He also described the technique that he invented in 1983 for detecting axions. The idea is that axions in the galactic halo may be resonantly converted to microwave photons in a cavity permeated by a strong magnetic field.

  6. Conceptual design of the International Axion Observatory (IAXO)

    DEFF Research Database (Denmark)

    Armengaud, E.; Avignone, F. T.; Betz, M.;

    2014-01-01

    to solar axions produced by mechanisms mediated by the axion-electron coupling gae with sensitivity — for the first time — to values of gae not previously excluded by astrophysics. With several other possible physics cases, IAXO has the potential to serve as a multi-purpose facility for generic axion...

  7. Rotating Drops of Axion Dark Matter

    CERN Document Server

    Davidson, Sacha

    2016-01-01

    We consider how QCD axions produced by the misalignment mechanism could form galactic dark matter halos. We recall that stationary, gravitationally stable axion field configurations have the size of an asteroid with masses of order $10^{-13} $ solar masses (because gradient pressure is insufficient to support a larger object). We call such field configurations "drops". We explore whether rotating drops could be larger, and find that their mass could increase by a factor ~ 10. Remarkably this mass is comparable to the mass of miniclusters generated from misalignment axions in the scenario where the axion is born after inflation. We speculate that misalignment axions today are in the form of drops, contributing to dark matter like a distribution of asteroids (and not as a coherent oscillating background field). We consider some observational signatures of the drops, which seem consistent with a galactic halo made of axion dark matter.

  8. A search for solar axions with the MICROMEGAS detector in CAST

    CERN Document Server

    Dafni, Theopisti

    The CAST Experiment completed its first phase in the end of 2004, after having run successfully for two years. The results of the data analysis of the Micromegas detector at CAST for 2003 and a first result of 2004 are presented here. This experiment has a sensitivity of almost a factor 100 better compared with previous searches. The coupling constant of axions of mass up to 0.02 eV to photons has been restricted with a 95% Confidence Level to gαγ≤ 1.50 x 10-10 GeV-1 for the 2003 Micromegas detector [and ga ≤ 1.16 × 1010 GeV1 after combining the result of all the detectors of the experiment]. The preliminary limit acquired for the 2004 data is more strict, at gαγ≤ 1.21 x 10-10 GeV-1 concerning the Micromegas detector.

  9. Axion Crystals

    CERN Document Server

    Ozaki, Sho

    2016-01-01

    The low-energy effective theories for gapped insulators are classified by three parameters: permittivity $\\epsilon$, permeability $\\mu$, and theta angle $\\theta$. Crystals with periodic $\\epsilon$ are known as photonic crystals. We here study the band structure of photons in a new type of crystals with periodic $\\theta$ (modulo $2\\pi$) in space, which we call the axion crystals. We find that the axion crystals have a number of new properties that the usual photonic crystals do not possess, such as the helicity-dependent photonic band gaps and the nonrelativistic gapless dispersion relation at small momentum. We briefly discuss possible realizations of axion crystals in condensed matter systems as well as high-energy physics.

  10. Low background x-ray detection with Micromegas for axion research

    CERN Document Server

    Aune, S; Dafni, T; Davenport, M; Fanourakis, G; Ferrer-Ribas, E; Galan, J; Garcia, J A; Gardikiotis, A; Geralis, T; Giomataris, I; Gomez, H; Garza, J G; Herrera, D C; Iguaz, F J; Irastorza, I G; Jourde, D; Luzon, G; Mols, J P; Papaevangelou, T; Rodriguez, A; Ruz, J; Segui, L; Tomas, A; Vafeiadis, T; Yildiz, S C

    2014-01-01

    Axion helioscopes aim at the detection of solar axions through their conversion into x-rays in laboratory magnetic fields. The use of low background x-ray detectors is an essential component contributing to the sensitivity of these searches. Here we review the recent advances on Micromegas detectors used in the CERN Axion Solar Telescope (CAST) and proposed for the future International Axion Observatory (IAXO). The most recent Micromegas setups in CAST have achieved background levels of 1.5$\\times10^{-6}$\\ckcs, a factor of more than 100 lower than the ones obtained by the first generation of CAST detectors. This improvement is due to the development of active and passive shielding techniques, offline discrimination techniques allowed by highly granular readout patterns, as well as the use of radiopure detector components. The status of the intensive R&D to reduce the background levels will be described, including the operation of replica detectors in test benches and the detailed Geant4 simulation of the ...

  11. Low background x-ray detection with Micromegas for axion research

    International Nuclear Information System (INIS)

    Axion helioscopes aim at the detection of solar axions through their conversion into x-rays in laboratory magnetic fields. The use of low background x-ray detectors is an essential component contributing to the sensitivity of these searches. Here we review the recent advances on Micromegas detectors used in the CERN Axion Solar Telescope (CAST) and proposed for the future International Axion Observatory (IAXO). The most recent Micromegas setups in CAST have achieved background levels of 1.5 × 10−6 keV−1 cm−2 s−1, a factor of more than 100 lower than the ones obtained by the first generation of CAST detectors. This improvement is due to the development of active and passive shielding techniques, offline discrimination techniques allowed by highly granular readout patterns, as well as the use of radiopure detector components. The status of the intensive R and D to reduce the background levels will be described, including the operation of replica detectors in test benches and the detailed Geant4 simulation of the detector setup and the detector response, which has allowed the progressive understanding of background origins. The best levels currently achieved in a test setup operating in the Canfranc Underground Laboratory (LSC) are as low as ∼ 10−7 keV−1 cm−2 s−1, showing the good prospects of this technology for application in the future IAXO

  12. Axions from the Earth

    International Nuclear Information System (INIS)

    The possibility of axion production in the Earth's interior due to natural radioactive decay is considered. Axions, or axion-like particles, could be created in nuclear disintegrations and deexitations of natural radionuclides present in the Earth's crust and mantle, as well as due to photon to axion conversion of the emitted gamma rays via the Primakoff effect. The estimated geo-axion production rates and fluxes on the Earth's surface are given along with the axion coupling to ordinary matter in the frame of the simple axion models as well as for axion-like particles with stronger couplings

  13. Emission of Photons and Relativistic Axions from Axion Stars

    CERN Document Server

    Braaten, Eric; Zhang, Hong

    2016-01-01

    The number of nonrelativistic axions can be changed by inelastic reactions that produce photons or relativistic axions. Any odd number of axions can annihilate into two photons. Any even number of nonrelativistic axions can scatter into two relativistic axions. We calculate the rate at which axions are lost from axion stars from these inelastic reactions. In dilute systems of axions, the dominant inelastic reaction is axion decay into two photons. In sufficiently dense systems of axions, the dominant inelastic reaction is the scattering of four nonrelativistic axions into two relativistic axions. The scattering of odd numbers of axions into two photons produces monochromatic radio-frequency signals at odd-integer harmonics of the fundamental frequency set by the axion mass. This provides a unique signature for dense systems of axions, such as a dense axion star or a collapsing dilute axion star.

  14. Ultrasensitive searches for the axion

    CERN Multimedia

    Van Bibber, Karl

    2006-01-01

    "The axion is a hypothetical particle with a mass possibly a trillion times lighter than an electron and exceedingly small couplings to ordinary matter. Yet experiments may soon detect its presence, either as dark matter or as a component of solar flux." (6 pages)

  15. Axion cooling of neutron stars

    Science.gov (United States)

    Sedrakian, Armen

    2016-03-01

    Cooling simulations of neutron stars and their comparison with the data from thermally emitting x-ray sources put constraints on the properties of axions, and by extension, of any light pseudoscalar dark matter particles, whose existence has been postulated to solve the strong-C P problem of QCD. We incorporate the axion emission by pair-breaking and formation processes by S - and P -wave nucleonic condensates in a benchmark code for cooling simulations, as well as provide fit formulas for the rates of these processes. Axion cooling of neutron stars has been simulated for 24 models covering the mass range 1 to 1.8 solar masses, featuring nonaccreted iron and accreted light-element envelopes, and a range of nucleon-axion couplings. The models are based on an equation state predicting conservative physics of superdense nuclear matter that does not allow for the onset of fast cooling processes induced by phase transitions to non-nucleonic forms of matter or high proton concentration. The cooling tracks in the temperature vs age plane were confronted with the (time-averaged) measured surface temperature of the central compact object in the Cas A supernova remnant as well as surface temperatures of three nearby middle-aged thermally emitting pulsars. We find that the axion coupling is limited to fa/107 GeV ≥(5 - 10 ) , which translates into an upper bound on axion mass ma≤(0.06 - 0.12 ) eV for Peccei-Quinn charges of the neutron |Cn|˜0.04 and proton |Cp|˜0.4 characteristic for hadronic models of axions.

  16. Future Perspectives at CERN

    OpenAIRE

    Ellis, John

    2002-01-01

    Current and future experiments at CERN are reviewed,with emphasis on those relevant to astrophysics and cosmology. These include experiments related to nuclear astrophysics, matter-antimatter asymmetry, dark matter, axions, gravitational waves, cosmic rays, neutrino oscillations, inflation, neutron stars and the quark-gluon plasma. The centrepiece of CERN's future programme is the LHC, but some ideas for perspectives after the LHC are also presented.

  17. Lowering the background level and the energy threshold of Micromegas x-ray detectors for axion searches

    CERN Document Server

    Iguaz, F J; Aznar, F; Castel, J F; Dafni, T; Davenport, M; Ferrer-Ribas, E; Galan, J; Garcia, J A; Garza, J G; Giomataris, I; Irastorza, I G; Papaevangelou, T; Rodriguez, A; Tomas, A; Vafeiadis, T; Yildiz, S C

    2014-01-01

    Axion helioscopes search for solar axions by their conversion in x-rays in the presence of high magnetic fields. The use of low background x-ray detectors is an essential component contributing to the sensitivity of these searches. In this work, we review the recent advances on Micromegas detectors used in the CERN Axion Solar Telescope (CAST) and proposed for the future International Axion Observatory (IAXO). The actual setup in CAST has achieved background levels below 10$^{-6}$ keV$^{-1}$ cm$^{-2}$ s$^{-1}$, a factor 100 lower than the first generation of Micromegas detectors. This reduction is based on active and passive shielding techniques, the selection of radiopure materials, offline discrimination techniques and the high granularity of the readout. We describe in detail the background model of the detector, based on its operation at CAST site and at the Canfranc Underground Laboratory (LSC), as well as on Geant4 simulations. The best levels currently achieved at LSC are low than 10$^{-7}$ keV$^{-1}$ ...

  18. Dense Axion Stars

    Science.gov (United States)

    Mohapatra, Abhishek; Braaten, Eric; Zhang, Hong

    2016-03-01

    If the dark matter consists of axions, gravity can cause them to coalesce into axion stars, which are stable gravitationally bound Bose-Einstein condensates of axions. In the previously known axion stars, gravity and the attractive force between pairs of axions are balanced by the kinetic pressure. If the axion mass energy is mc2 =10-4 eV, these dilute axion stars have a maximum mass of about 10-14M⊙ . We point out that there are also dense axion stars in which gravity is balanced by the mean-field pressure of the axion condensate. We study axion stars using the leading term in a systematically improvable approximation to the effective potential of the nonrelativistic effective field theory for axions. Using the Thomas-Fermi approximation in which the kinetic pressure is neglected, we find a sequence of new branches of axion stars in which gravity is balanced by the mean-field interaction energy of the axion condensate. If mc2 =10-4 4 eV, the first branch of these dense axion stars has mass ranging from about 10-11M⊙ toabout M⊙.

  19. Dense Axion Stars

    CERN Document Server

    Braaten, Eric; Zhang, Hong

    2015-01-01

    If the dark matter consists of axions, gravity can cause them to coalesce into axion stars, which are stable gravitationally bound Bose-Einstein condensates of axions. In the previously known axion stars, gravity and the attractive force between pairs of axions are balanced by the kinetic pressure.If the axion mass energy is $mc^2= 10^{-4}$ eV, these dilute axion stars have a maximum mass of about $10^{-14} M_\\odot$. We point out that there are also dense axion stars in which gravity is balanced by the mean-field pressure of the axion condensate. We study axion stars using the leading term in a systematically improvable approximation to the effective potential of the nonrelativistic effective field theory for axions. Using the Thomas-Fermi approximation in which the kinetic pressure is neglected, we find a sequence of new branches of axion stars in which gravity is balanced by the mean-field interaction energy of the axion condensate. If $mc^2 = 10^{-4}$ eV, the first branch of these dense axion stars has mas...

  20. Conceptual Design of the International Axion Observatory (IAXO)

    CERN Document Server

    Armengaud, E; Betz, M; Brax, P; Brun, P; Cantatore, G; Carmona, J M; Carosi, G P; Caspers, F; Caspi, S; Cetin, S A; Chelouche, D; Christensen, F E; Dael, A; Dafni, T; Davenport, M; Derbin, A V; Desch, K; Diago, A; Döbrich, B; Dratchnev, I; Dudarev, A; Eleftheriadis, C; Fanourakis, G; Ferrer-Ribas, E; Galán, J; García, J A; Garza, J G; Geralis, T; Gimeno, B; Giomataris, I; Gninenko, S; Gómez, H; González-Díaz, D; Guendelman, E; Hailey, C J; Hiramatsu, T; Hoffmann, D H H; Horns, D; Iguaz, F J; Irastorza, I G; Isern, J; Imai, K; Jakobsen, A C; Jaeckel, J; Jakovčić, K; Kaminski, J; Kawasaki, M; Karuza, M; Krčmar, M; Kousouris, K; Krieger, C; Lakić, B; Limousin, O; Lindner, A; Liolios, A; Luzón, G; Matsuki, S; Muratova, V N; Nones, C; Ortega, I; Papaevangelou, T; Pivovaroff, M J; Raffelt, G; Redondo, J; Ringwald, A; Russenschuck, S; Ruz, J; Saikawa, K; Savvidis, I; Sekiguchi, T; Semertzidis, Y K; Shilon, I; Sikivie, P; Silva, H; Kate, H ten; Tomas, A; Troitsky, S; Vafeiadis, T; Bibber, K van; Vedrine, P; Villar, J A; Vogel, J K; Walckiers, L; Weltman, A; Wester, W; Yildiz, S C; Zioutas, K

    2014-01-01

    The International Axion Observatory (IAXO) will be a forth generation axion helioscope. As its primary physics goal, IAXO will look for axions or axion-like particles (ALPs) originating in the Sun via the Primakoff conversion of the solar plasma photons. In terms of signal-to-noise ratio, IAXO will be about 4-5 orders of magnitude more sensitive than CAST, currently the most powerful axion helioscope, reaching sensitivity to axion-photon couplings down to a few $\\times 10^{-12}$ GeV$^{-1}$ and thus probing a large fraction of the currently unexplored axion and ALP parameter space. IAXO will also be sensitive to solar axions produced by mechanisms mediated by the axion-electron coupling $g_{ae}$ with sensitivity $-$for the first time$-$ to values of $g_{ae}$ not previously excluded by astrophysics. With several other possible physics cases, IAXO has the potential to serve as a multi-purpose facility for generic axion and ALP research in the next decade. In this paper we present the conceptual design of IAXO, w...

  1. Axion Cooling of Neutron Stars

    CERN Document Server

    Sedrakian, Armen

    2015-01-01

    Cooling simulations of neutron stars and their comparison with the data from thermally emitting X-ray sources puts constraints on the properties of axions, and by extension of any light pseudo-scalar dark matter particles, whose existence has been postulated to solve the strong-CP problem of QCD. We incorporate the axion emission by pair-breaking and formation processes by $S$- and $P$-wave nucleonic condensates in a benchmark code for cooling simulations as well as provide fit formulae for the rates of these processes. Axion cooling of neutron stars has been simulated for 24 models covering the mass range 1 to 1.8 solar masses, featuring non-accreted iron and accreted light element envelopes, and a range of nucleon-axion coupling. The models are based on an equation state predicting conservative physics of superdense nuclear matter that does not allow for onset of fast cooling processes induced by phase transitions to non-nucleonic forms of matter or high proton concentration. The cooling tracks in the tempe...

  2. Detecting ultralight axion dark matter wind with laser interferometers

    OpenAIRE

    Aoki, Arata; Soda, Jiro

    2016-01-01

    The ultralight axion with mass around $10^{-23}$ eV is known as a candidate of dark matter. A peculiar feature of the ultralight axion is oscillating pressure in time, which produces oscillation of gravitational potentials. Since the solar system moves through the dark matter halo at the velocity of about $v \\sim 300 \\, \\text{km} / \\text{s} = 10^{-3}$, there exists axion wind, which looks like scalar gravitational waves for us. Hence, there is a chance to detect ultralight axion dark matter w...

  3. Stellar axion models

    Energy Technology Data Exchange (ETDEWEB)

    Nowakowski, Daniel; Kuster, Markus; Meister, Claudia V.; Fuelbert, Florian; Hoffmann, Dieter H.H. [TU Darmstadt (Germany). Institut fuer Kernphysik; Weiss, Achim [Max-Planck-Institut fuer Astrophysik, Garching (Germany)

    2010-07-01

    An axion helioscope is typically operated to observe the sun as an axion source. Additional pointings at celestial sources, e.g. stars in other galaxies, result in possible detections of axions from distant galactic objects. For the observation of supplementary axion sources we therefore calculate the thereotical axion flux from distant stars by extending axionic flux models for the axion Primakoff effect in the sun to other main sequence stars. The main sequence star models used for our calculations are based on full stellar structure calculations. To deduce the effective axion flux of stellar objects incident on the Earth the All-Sky catalogue was used to obtain the spectral class and distance of the stars treated. Our calculations of the axion flux in the galactic plane show that for a zero age main sequence star an maximum axion flux of {phi}{sub a}=303.43 cm{sup -2}s{sup -1} could be expected. Furthermore we present estimates of axion fluxes from time-evolved stars.

  4. Stellar axion models

    International Nuclear Information System (INIS)

    An axion helioscope is typically operated to observe the sun as an axion source. Additional pointings at celestial sources, e.g. stars in other galaxies, result in possible detections of axions from distant galactic objects. For the observation of supplementary axion sources we therefore calculate the thereotical axion flux from distant stars by extending axionic flux models for the axion Primakoff effect in the sun to other main sequence stars. The main sequence star models used for our calculations are based on full stellar structure calculations. To deduce the effective axion flux of stellar objects incident on the Earth the All-Sky catalogue was used to obtain the spectral class and distance of the stars treated. Our calculations of the axion flux in the galactic plane show that for a zero age main sequence star an maximum axion flux of Φa=303.43 cm-2s-1 could be expected. Furthermore we present estimates of axion fluxes from time-evolved stars.

  5. Conceptual design of the International Axion Observatory (IAXO)

    International Nuclear Information System (INIS)

    The International Axion Observatory (IAXO) will be a forth generation axion helioscope. As its primary physics goal, IAXO will look for axions or axion-like particles (ALPs) originating in the Sun via the Primakoff conversion of the solar plasma photons. In terms of signal-to-noise ratio, IAXO will be about 4–5 orders of magnitude more sensitive than CAST, currently the most powerful axion helioscope, reaching sensitivity to axion-photon couplings down to a few × 10−12 GeV−1 and thus probing a large fraction of the currently unexplored axion and ALP parameter space. IAXO will also be sensitive to solar axions produced by mechanisms mediated by the axion-electron coupling gae with sensitivity — for the first time — to values of gae not previously excluded by astrophysics. With several other possible physics cases, IAXO has the potential to serve as a multi-purpose facility for generic axion and ALP research in the next decade. In this paper we present the conceptual design of IAXO, which follows the layout of an enhanced axion helioscope, based on a purpose-built 20 m-long 8-coils toroidal superconducting magnet. All the eight 60cm-diameter magnet bores are equipped with focusing x-ray optics, able to focus the signal photons into ∼ 0.2 cm2 spots that are imaged by ultra-low-background Micromegas x-ray detectors. The magnet is built into a structure with elevation and azimuth drives that will allow for solar tracking for ∼ 12 h each day

  6. Redefining the Axion Window

    CERN Document Server

    Di Luzio, Luca; Nardi, Enrico

    2016-01-01

    A major goal of axion searches is to reach inside the parameter space region of realistic axion models. Currently, the boundaries of this region depend on somewhat arbitrary criteria, and it would be desirable to specify them in terms of precise phenomenological requirements. We consider hadronic axion models and classify the representations $R_Q$ of the new heavy quarks $Q$. By requiring that $i)$ the $Q$ are sufficiently short lived to avoid issues with long lived strongly interacting relics, $ii)$ no Landau poles are induced below the Planck scale, fifteen cases are selected, which define a phenomenologically preferred axion window bounded by a maximum (minimum) value of the axion-photon coupling about twice (four times) larger than commonly assumed. Allowing for more than one $R_Q$, larger couplings, as well as complete axion-photon decoupling, become possible.

  7. Magnetic Induced Axion Mass

    CERN Document Server

    Campanelli, L

    2006-01-01

    We study the effect of a uniform magnetic field on the dynamics of axions. In particular, we show that the Peccei-Quinn symmetry is explicitly broken by the presence of an external magnetic field. This breaking is induced by the non-conservation of the magnetic helicity and generates an electromagnetic contribution to the axion mass. We compute the magnetic axion mass in one loop approximation, with no restriction on the intensity of the magnetic field, and including thermal effects.

  8. Experimental Axion Review

    CERN Document Server

    CERN. Geneva

    2016-01-01

    Axions are a natural consequence of the Peccei-Quinn mechanism, the most compelling solution to the strong-CP problem. Similar axion-like particles (ALPs) also appear in a number of possible extensions of the Standard Model, notably in string theories. Both axions and ALPs are very well motivated candidates for the Dark Matter, and in addition would be copiously produced at the stellar cores. Some anomalous astrophysical observations could be hinting the existence of these particles. They are object of increasing interest by experimentalists. I will briefly review the motivation to search for axions and ALPs, as well as the current status and future prospects of the experimental landscape.

  9. Inflationary axion cosmology

    Science.gov (United States)

    Turner, Michael S.; Wilczek, Frank

    1991-01-01

    If Peccei-Quinn (PQ) symmetry is broken after inflation, the initial axion angle is a random variable on cosmological scales; based on this fact, estimates of the relic-axion mass density give too large a value if the axion mass is less than about 10 to the -6th eV. This bound can be evaded if the universe underwent inflation after PQ-symmetry breaking and if the observable universe happens to be a region where the initial axion angle was atypically small. Consideration of fluctuations induced during inflation severely constrains the latter alternative is shown.

  10. Future axion searches with the International Axion Observatory (IAXO)

    DEFF Research Database (Denmark)

    Irastorza, I G; Avignone, F T; Cantatore, G;

    2013-01-01

    The International Axion Observatory (IAXO) is a new generation axion helioscope aiming at a sensitivity to the axion-photon coupling of gaγ (≳) few × 10−12 GeV−1, i.e. 1–1.5 orders of magnitude beyond the one achieved by CAST, currently the most sensitive axion helioscope. The main elements of IAXO...

  11. Detecting ultralight axion dark matter wind with laser interferometers

    CERN Document Server

    Aoki, Arata

    2016-01-01

    The ultralight axion with mass around $10^{-23}$ eV is known as a candidate of dark matter. A peculiar feature of the ultralight axion is oscillating pressure in time, which produces oscillation of gravitational potentials. Since the solar system moves through the dark matter halo at the velocity of about $v \\sim 300 \\, \\text{km} / \\text{s} = 10^{-3}$, there exists axion wind, which looks like scalar gravitational waves for us. Hence, there is a chance to detect ultralight axion dark matter with a wide mass range by using laser interferometer detectors. We calculate the detector signal induced by the oscillating pressure of the ultralight axion field, which would be detected by future laser interferometer experiments. We also argue that the detector signal can be enhanced due to the resonance in modified gravity theory explaining the dark energy.

  12. (Mainly) axion dark matter

    Science.gov (United States)

    Baer, Howard

    2016-06-01

    The strong CP problem of QCD is at heart a problem of naturalness: why is the FF ˜ term highly suppressed in the QCD Lagrangian when it seems necessary to explain why there are three and not four light pions? The most elegant solution posits a spontaneously broken Peccei-Quinn (PQ) symmetry which requires the existence of the axion field a. The axion field settles to the minimum of its potential thus removing the offensive term but giving rise to the physical axion whose coherent oscillations can make up the cold dark matter. Only now are experiments such as ADMX beginning to explore QCD axion parameter space. Since a bonafide scalar particle- the Higgs boson- has been discovered, one might expect its mass to reside at the axion scale fa ˜ 1011 GeV. The Higgs mass is elegantly stabilized by supersymmetry: in this case the axion is accompanied by its axino and saxion superpartners. Requiring naturalness also in the electroweak sector implies higgsino-like WIMPs so then we expect mixed axion-WIMP dark matter. Ultimately we would expect detection of both an axion and a WIMP while signals for light higgsinos may show up at LHC and must show up at ILC.

  13. Axion Dark Matter Searches

    CERN Document Server

    Stern, I

    2014-01-01

    Nearly all astrophysical and cosmological data point convincingly to a large component of cold dark matter in the Universe. The axion particle, first theorized as a solution to the strong charge-parity problem of quantum chromodynamics, has been established as a prominent CDM candidate. Cosmic observation and particle physics experiments have bracketed the unknown mass of the axion between approximately a $\\mu$eV and a meV. The Axion Dark Matter eXperiement (ADMX) has successfully completed searches between 1.9 and 3.7 $\\mu$eV down to the KSVZ photon-coupling limit. ADMX and the Axion Dark Matter eXperiement High-Frequency (ADMX-HF) will search for axions at weaker coupling and/or higher frequencies within the next few years. Status of the experiments, current research and development, and projected mass-coupling exclusion limits are presented.

  14. Can the dark matter halo be a collisionless ensemble of axion stars?

    CERN Document Server

    Barranco, J; Delepine, D

    2012-01-01

    If dark matter is mainly composed of axions, the density distribution can be non uniform distributed but clumpy instead. By solving the Einstein-Klein Gordon system of a scalar field with a potential energy density of an axion like particle, we obtain the maximum mass of the self gravitating system made of axions called axion stars. The collision of axion stars with neutron stars may release the energy of axions due to the conversion of axions into photons in the presence of the neutron star magnetic field. We estimate the energy release and shown that it may exceed the solar luminosity per collision but should be much less than previous estimates. Future data from femtolensing should strongly constrain this scenario.

  15. Windows on the axion

    Energy Technology Data Exchange (ETDEWEB)

    Turner, M.S.

    1989-04-01

    Peccei-Quinn symmetry with attendant axion is a most compelling, and perhaps the most minimal, extension of the standard model, as it provides a very elegant solution to the nagging strong CP-problem associated with the THETA vacuum structure of QCD. However, particle physics gives little guidance as to the axion mass; a priori, the plausible values span the range: 10/sup /minus/12/ eV /approx lt/ m/sub a/ /approx lt/ 10/sup 6/ eV, some 18 orders-of-magnitude. Axions have a host of interesting astrophysical and cosmological effects, including, modifying the evolution of stars of all types (our sun, red giants, white dwarfs, and neutron stars), contributing significantly to the mass density of the Universe today, and producing detectable line radiation through the decays of relic axions. Consideration of these effects has probed 14 orders-of-magnitude in axion mass, and has left open only two windows for further exploration: 10/sup /minus/6/ eV /approx lt/ m/sub a/ /approx lt/ 10/sup /minus/3/ eV and 1 eV /approx lt/ m/sub a/ /approx lt/ 5 eV (hadronic axions only). Both these windows are accessible to experiment, and a variety of very interesting experiments, all of which involve ''heavenly axions,'' are being planned or are underway. 58 refs., 6 figs., 1 tab.

  16. (Mainly) axion dark matter

    CERN Document Server

    Baer, Howard

    2015-01-01

    The strong CP problem of QCD is at heart a problem of naturalness: why is the F\\tilde{F} term highly suppressed in the QCD Lagrangian when it seems necessary to explain why there are three and not four light pions? The most elegant solution posits a spontaneously broken Peccei-Quinn (PQ) symmetry which requires the existence of the axion field a. The axion field settles to the minimum of its potential thus removing the offensive term but giving rise to the physical axion whose coherent oscillations can make up the cold dark matter. Only now are experiments such as ADMX beginning to explore QCD axion parameter space. Since a bonafide scalar particle-- the Higgs boson-- has been discovered, one might expect its mass to reside at the axion scale f_a~ 10^{11} GeV. The Higgs mass is elegantly stabilized by supersymmetry: in this case the axion is accompanied by its axino and saxion superpartners. Requiring naturalness also in the electroweak sector implies higgsino-like WIMPs so then we expect mixed axion-WIMP dar...

  17. Axions from wall decay

    Energy Technology Data Exchange (ETDEWEB)

    Chang, S; Hagmann, C; Sikivie, P

    2001-01-08

    The authors discuss the decay of axion walls bounded by strings and present numerical simulations of the decay process. In these simulations, the decay happens immediately, in a time scale of order the light travel time, and the average energy of the radiated axions is {approx_equal} 7m{sub a} for v{sub a}/m{sub a} {approx_equal} 500. is found to increase approximately linearly with ln(v{sub a}/m{sub a}). Extrapolation of this behavior yields {approx_equal} 60 m{sub a} in axion models of interest.

  18. Collapse of Axion Stars

    CERN Document Server

    Eby, Joshua; Suranyi, Peter; Wijewardhana, L C R

    2016-01-01

    Axion stars, gravitationally bound states of low-energy axion particles, have a maximum mass allowed by gravitational stability. Weakly bound states obtaining this maximum mass have sufficiently large radii such that they are dilute, and as a result, they are well described by a leading-order expansion of the axion potential. Heavier states are susceptible to gravitational collapse. Inclusion of higher-order interactions, present in the full potential, can give qualitatively different results in the analysis of collapsing heavy states, as compared to the leading-order expansion. In this work, we find that collapsing axion stars are stabilized by repulsive interactions present in the full potential, providing evidence that such objects do not form black holes. These dense configurations, which are the endpoints of collapse, have extremely high binding energy, and as a result, decay through number changing $3\\,a\\rightarrow a$ interactions with an extremely short lifetime.

  19. Axions and Dark Matter

    OpenAIRE

    Yang, Qiaoli

    2015-01-01

    Dark matter particles constitute $23\\%$ of the total energy density of our universe and their exact properties are still unclear besides that they must be very cold and weakly interacting with the standard model particles. Many beyond standard model theories provide proper candidates to serve as the dark matter. The axions were introduced to solve the strong CP problem and later turned out to be a very attractive dark matter candidate. In this paper, we briefly review the physics of axions an...

  20. The hunt for axions

    Energy Technology Data Exchange (ETDEWEB)

    Ringwald, Andreas

    2015-06-15

    Many theoretically well-motivated extensions of the Standard Model of particle physics predict the existence of the axion and further ultralight axion-like particles. They may constitute the mysterious dark matter in the universe and solve some puzzles in stellar and high-energy astrophysics. There are new, relatively small experiments around the globe, which started to hunt for these elusive particles and complement the accelerator based search for physics beyond the Standard Model.

  1. Anomaly mediation deformed by axion

    International Nuclear Information System (INIS)

    We show that in supersymmetric axion models the axion supermultiplet obtains a sizable F-term due to a non-supersymmetric dynamics and it generally gives the gaugino masses comparable to the anomaly mediation contribution. Thus the gaugino mass relation predicted by the anomaly mediation effect can be significantly modified in the presence of axion to solve the strong CP problem

  2. Probing the axion-photon coupling: phenomenological and experimental perspectives. A snowmass white paper

    CERN Document Server

    Carosi, G; Giannotti, M; Pivovaroff, M J; Vogel, J K

    2013-01-01

    We present a brief overview of the ongoing searches for the axion particle via its coupling to photons. Both the classical QCD axions and more recently proposed Axion-Like-Particles are considered. Astrophysical bounds on the axion-photon coupling come from considerations of stellar energy loss during Helium burning, in both low- and high-mass stars. Helioscopes look for back-conversion of solar axions into x-ray photons in strong laboratory magnetic fields. Finally, haloscopes aim to detect dark matter axions in our galactic halo. Both types of searches are expecting significant advances in the future, which will enable them to probe large, well-motivated parts of the parameter space below the stellar cooling bounds.

  3. Future axion searches with the International Axion Observatory (IAXO)

    International Nuclear Information System (INIS)

    The International Axion Observatory (IAXO) is a new generation axion helioscope aiming at a sensitivity to the axion-photon coupling of gaγ ∼> few × 10−12 GeV−1, i.e. 1–1.5 orders of magnitude beyond the one achieved by CAST, currently the most sensitive axion helioscope. The main elements of IAXO are an increased magnetic field volume together with extensive use of x-ray focusing optics and low background detectors, innovations already successfully tested in CAST. Additional physics cases of IAXO could include the detection of electron-coupled axions invoked to explain the white dwarf cooling, relic axions, and a large variety of more generic axion-like particles (ALPs) and other novel excitations at the low-energy frontier of elementary particle physics

  4. Dark Matter in Axion Landscape

    OpenAIRE

    Daido, Ryuji; Kobayashi, Takeshi; Takahashi, Fuminobu

    2016-01-01

    If there are a plethora of axions in nature, they may have a complicated potential and create an axion landscape. We study a possibility that one of the axions is so light that it is cosmologically stable, explaining the observed dark matter density. In particular we focus on a case in which two (or more) shift-symmetry breaking terms conspire to make the axion sufficiently light at the potential minimum. In this case the axion has a flat-bottomed potential. In contrast to the case in which a...

  5. Axion domain wall baryogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Daido, Ryuji; Kitajima, Naoya [Department of Physics, Tohoku University,Sendai 980-8578 (Japan); Takahashi, Fuminobu [Department of Physics, Tohoku University,Sendai 980-8578 (Japan); Kavli IPMU, TODIAS, University of Tokyo,Kashiwa 277-8583 (Japan)

    2015-07-28

    We propose a new scenario of baryogenesis, in which annihilation of axion domain walls generates a sizable baryon asymmetry. Successful baryogenesis is possible for a wide range of the axion mass and decay constant, m≃10{sup 8}–10{sup 13} GeV and f≃10{sup 13}–10{sup 16} GeV. Baryonic isocurvature perturbations are significantly suppressed in our model, in contrast to various spontaneous baryogenesis scenarios in the slow-roll regime. In particular, the axion domain wall baryogenesis is consistent with high-scale inflation which generates a large tensor-to-scalar ratio within the reach of future CMB B-mode experiments. We also discuss the gravitational waves produced by the domain wall annihilation and its implications for the future gravitational wave experiments.

  6. Dark Matter in Axion Landscape

    CERN Document Server

    Daido, Ryuji; Takahashi, Fuminobu

    2016-01-01

    If there are a plethora of axions in nature, they may have a complicated potential and create an axion landscape. We study a possibility that one of the axions is so light that it is cosmologically stable, explaining the observed dark matter density. In particular we focus on a case in which two (or more) shift-symmetry breaking terms conspire to make the axion sufficiently light at the potential minimum. In this case the axion has a flat-bottomed potential. In contrast to the case in which a single cosine term dominates the potential, the axion abundance as well as its isocurvature perturbations are significantly suppressed. This allows an axion with a rather large mass to serve as dark matter without fine-tuning of the initial misalignment, and further makes higher-scale inflation to be consistent with the scenario.

  7. The lifetime of axion stars

    Science.gov (United States)

    Eby, Joshua; Suranyi, Peter; Wijewardhana, L. C. R.

    2016-05-01

    We investigate the decay of condensates of scalars in a field theory defined by V (𝒜) = m2f2[1 -cos(𝒜/f)], where m and f are the mass and decay constant of the scalar field. An example of such a theory is that of the axion, in which case the condensates are called axion stars. The axion field, 𝒜, is self-adjoint. As a result, the axion number is not an absolutely conserved quantity. Therefore, axion stars are not stable and have finite lifetimes. Bound axions, localized on the volume of the star, have a coordinate uncertainty δx ˜ R ˜ 1/(maΔ), where R is the radius of the star and Δ = 1 - E0 2/ma 2. Here ma and E0 are the mass, and the ground state energy of the bound axion. Then the momentum distribution of axions has a width of δp ˜ maΔ. At strong binding, Δ = 𝒪(1), bound axions can easily transfer a sufficient amount of momentum to create and emit a free axion, leading to fast decay of the star with a transition rate Γ ˜ ma. However, when Δ ≪ 1, the momentum distribution is more restricted, and as shown in this paper, the transition rate for creating a free axion decreases as exp(-pδx) ˜exp(-Δ-1). Then sufficiently large, weakly bound axion stars, produced after the Big Bang, survive until the present time. We plot the region of their stability, limited by decay through axion loss and by gravitational instability, as a function of the mass of the axion and the mass of the star.

  8. Tunneling in Axion Monodromy

    CERN Document Server

    Brown, Jon; Shiu, Gary; Soler, Pablo

    2016-01-01

    The Coleman formula for vacuum decay and bubble nucleation has been used to estimate the tunneling rate in models of axion monodromy in recent literature. However, several of Coleman's original assumptions do not hold for such models. Here we derive a new estimate with this in mind using a similar Euclidean procedure. We find that there are significant regions of parameter space for which the tunneling rate in axion monodromy is not well approximated by the Coleman formula. However, there is also a regime relevant to large field inflation in which both estimates parametrically agree. We also briefly comment on the applications of our results to the relaxion scenario.

  9. A Micromegas-based low-background x-ray detector coupled to a slumped-glass telescope for axion research

    CERN Document Server

    Aznar, F; Christensen, F E; Dafni, T; Decker, T A; Ferrer-Ribas, E; Garcia, J A; Giomataris, I; Gracia, J G; Hailey, C J; Hill, R M; Iguaz, F J; Irastorza, I G; Jakobsen, A C; Luzon, G; Mirallas, H; Papaevangelou, T; Pivovaroff, M J; Ruz, J; Vafeiadis, T; Vogel, J K

    2015-01-01

    We report on the design, construction and operation of a low background x-ray detection line composed of a shielded Micromegas (micromesh gaseous structure) detector of the microbulk technique. The detector is made from radiopure materials and is placed at the focal point of a $\\sim$~5 cm diameter, 1.3 m focal-length, cone-approximation Wolter I x-ray telescope (XRT) comprised of thermally-formed (or "slumped") glass substrates deposited with multilayer coatings. The system has been conceived as a technological pathfinder for the future International Axion Observatory (IAXO), as it combines two of the techniques (optic and detector) proposed in the conceptual design of the project. It is innovative for two reasons: it is the first time an x-ray optic has been designed and fabricated specifically for axion research, and the first time a Micromegas detector has been operated with an x-ray optic. The line has been installed at one end of the CERN Axion Solar Telescope (CAST) magnet and is currently looking for s...

  10. First Axion Results from the XENON100 Experiment

    CERN Document Server

    Aprile, E.; Alfonsi, M.; Arisaka, K.; Arneodo, F.; Auger, M.; Balan, C.; Barrow, P.; Baudis, L.; Bauermeister, B.; Behrens, A.; Beltrame, P.; Bokeloh, K.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Cardoso, J.M.R.; Colijn, A.P.; Contreras, H.; Cussonneau, J.P.; Decowski, M.P.; Duchovni, E.; Fattori, S.; Ferella, A.D.; Fulgione, W.; Gao, F.; Garbini, M.; Geis, C.; Goetzke, L.W.; Grignon, C.; Gross, E.; Hampel, W.; Itay, R.; Kaether, F.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R.F.; Calloch, M. Le; Lellouch, D.; Levy, C.; Lindemann, S.; Lindner, M.; Lopes, J.A.M.; Lung, K.; Lyashenko, A.; Macmullin, S.; Marrodan Undagoitia, T.; Masbou, J.; Massoli, F.V.; Mayani Paras, D.; Melgarejo Fernandez, A. J.; Meng, Y.; Messina, M.; Miguez, B.; Molinario, A.; Murra, M.; Naganoma, J.; Oberlack, U.; Orrigo, S.E.A.; Pantic, E.; Persiani, R.; Piastra, F.; Pienaar, J.; Plante, G.; Priel, N.; Reichard, S.; Reuter, C.; Rizzo, A.; Rosendahl, S.; dos Santos, J. M. F.; Sartorelli, G.; Schindler, S.; Schreiner, J.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Shagin, P.; Simgen, H.; Teymourian, A.; Thers, D.; Tiseni, A.; Trinchero, G.; Vitells, O.; Wang, H.; Weber, M.; Weinheimer, C.

    2014-01-01

    We present the first results of searches for axions and axion-like-particles with the XENON100 experiment. The axion-electron coupling constant, $g_{Ae}$, has been tested by exploiting the axio-electric effect in liquid xenon. A profile likelihood analysis of 224.6 live days $\\times$ 34 kg exposure has shown no evidence for a signal. By rejecting $g_{Ae}$, larger than $7.7 \\times 10^{-12}$ (90% CL) in the solar axion search, we set the best limit to date on this coupling. In the frame of the DFSZ and KSVZ models, we exclude QCD axions heavier than 0.3 eV/c$^2$ and 80 eV/c$^2$, respectively. For axion-like-particles, under the assumption that they constitute the whole abundance of dark matter in our galaxy, we constrain $g_{Ae}$, to be lower than $1 \\times 10^{-12}$ (90% CL) for masses between 5 and 10 keV/c$^2$.

  11. Cosmological Consequences of String Axions

    International Nuclear Information System (INIS)

    Axion fluctuations generated during inflation lead to isocurvature and non-Gaussian temperature fluctuations in the cosmic microwave background radiation. Following a previous analysis for the model independent string axion we consider the consequences of a measurement of these fluctuations for two additional string axions. We do so independent of any cosmological assumptions except for the axions being massless during inflation. The first axion has been shown to solve the strong CP problem for most compactifications of the heterotic string while the second axion, which does not solve the strong CP problem, obeys a mass formula which is independent of the axion scale. We find that if gravitational waves interpreted as arising from inflation are observed by the PLANCK polarimetry experiment with a Hubble constant during inflation of Hinf ∼> 1013 GeV the existence of the first axion is ruled out and the second axion cannot obey the scale independent mass formula. In an appendix we quantitatively justify the often held assumption that temperature corrections to the zero temperature QCD axion mass may be ignored for temperatures T ∼QCD

  12. The Lifetime of Axion Stars

    CERN Document Server

    Eby, Joshua; Wijewardhana, L C R

    2015-01-01

    We investigate the decay of condensates of scalars in a field theory defined by $V({\\cal A})=m^2 f^2 [1-\\cos({\\cal A}/f)]$, where $m$ and $f$ are the mass and decay constant of the scalar field. An example of such a theory is that of the axion, in which case the condensates are called axion stars. The axion field, $\\cal A$, is self adjoint. As a result the axion number is not an absolutely conserved quantity. Therefore, axion stars are not stable and have finite lifetimes. Bound axions, localized on the volume of the star, have a coordinate uncertainty $\\Delta x \\sim R \\sim 1/(m_a \\Delta)$, where $R$ is the radius of the star and $\\Delta = \\sqrt{1-E_0^2/m_a^2}$. Here $m_a$ and $E_0$ are the mass and the ground state energy of the bound axion. Then the momentum distribution of axions has a width of $\\Delta p \\sim m_a\\Delta$. At strong binding, $\\Delta={\\cal O}(1)$, bound axions can easily transfer a sufficient amount of momentum to create and emit a free axion, leading to fast decay of the star with a transiti...

  13. Axion inflation with cross-correlated axion isocurvature perturbations

    Energy Technology Data Exchange (ETDEWEB)

    Kadota, Kenji [Center for Theoretical Physics of the Universe, Institute for Basic Science,Daejeon 305-811 (Korea, Republic of); Kobayashi, Tatsuo [Department of Physics, Hokkaido University,Sapporo 060-0810 (Japan); Otsuka, Hajime [Department of Physics, Waseda University,Tokyo 169-8555 (Japan)

    2016-01-25

    We study the inflation scenarios, in the framework of superstring theory, where the inflaton is an axion producing the adiabatic curvature perturbations while there exists another light axion producing the isocurvature perturbations. We discuss how the non-trivial couplings among string axions can generically arise, and calculate the consequent cross-correlations between the adiabatic and isocurvature modes through concrete examples. Based on the Planck analysis on the generally correlated isocurvature perturbations, we show that there is a preference for the existence of the correlated isocurvature modes for the axion monodromy inflation while the natural inflation disfavors such isocurvature modes.

  14. The QCD axion from aligned axions and diphoton excess

    Directory of Open Access Journals (Sweden)

    Tetsutaro Higaki

    2016-04-01

    Full Text Available We argue that the QCD axion can arise from many aligned axions with decay constants much smaller than the conventional axion window. If the typical decay constant is of O(100 GeV to 1 TeV, one or more of the axions or saxions may account for the recently found diphoton excess at ∼750 GeV. Our scenario predicts many axions and saxions coupled to gluons with decay constants of order the weak scale, and therefore many collider signatures by heavy axions and saxions will show up at different energy scales. In particular, if the inferred broad decay width is due to multiple axions or saxions, a non-trivial peak structure may become evident when more data is collected. We also discuss cosmological implications of the aligned QCD axion scenario. In the Appendix we give a possible UV completion and argue that the high quality of the Peccei–Quinn symmetry is naturally explained in our scenario.

  15. Magnetogenesis from axion inflation

    CERN Document Server

    Adshead, Peter; Scully, Timothy R; Sfakianakis, Evangelos I

    2016-01-01

    In this work we compute the production of magnetic fields in models of axion inflation coupled to the hypercharge sector of the Standard Model through a Chern-Simons interaction term. We make the simplest choice of a quadratic inflationary potential and use lattice simulations to calculate the magnetic field strength, helicity and correlation length at the end of inflation. For small values of the axion-gauge field coupling strength the results agree with no-backreaction calculations and estimates found in the literature. For larger couplings the helicity of the magnetic field differs from the no-backreaction estimate and depends strongly on the comoving wavenumber. We estimate the post-inflationary evolution of the magnetic field based on known results for the evolution of helical and non-helical magnetic fields. The magnetic fields produced by axion inflation with large couplings to $U(1)_Y$ can reach $B_{\\rm eff} \\gtrsim 10^{-16}\\, G$. This result is insensitive to the exact value of the coupling, as long ...

  16. Level Crossing between QCD Axion and Axion-Like Particle

    CERN Document Server

    Daido, Ryuji; Takahashi, Fuminobu

    2015-01-01

    We study a level crossing between the QCD axion and an axion-like particle, focusing on the recently found phenomenon, the axion roulette, where the axion-like particle runs along the potential, passing through many crests and troughs, until it gets trapped in one of the potential minima. We perform detailed numerical calculations to determine the parameter space where the axion roulette takes place, and as a result domain walls are likely formed. The domain wall network without cosmic strings is practically stable, and it is nothing but a cosmological disaster. In a certain case, one can make domain walls unstable and decay quickly by introducing an energy bias without spoiling the Peccei-Quinn solution to the strong CP problem.

  17. Constraints on small-field axion inflation

    CERN Document Server

    Kobayashi, Tatsuo; Omoto, Naoya; Otsuka, Hajime; Saga, Ikumi

    2016-01-01

    We study general class of small-field axion inflations which are the mixture of polynomial and sinusoidal functions suggested by the natural and axion monodromy inflations. The axion decay constants leading to the successful axion inflations are severely constrained in order not to spoil the Big-Bang nucleosynthesis and overproduce the isocurvature perturbation originating from the QCD axion. We in turn find that the cosmologically favorable axion decay constants are typically of order the grand unification scale or the string scale which is consistent with the prediction of closed string axions.

  18. Expected Sensitivity to Galactic/Solar Axions and Bosonic Super-WIMPs based on the Axio-electric Effect in Liquid Xenon Dark Matter Detectors

    CERN Document Server

    Arisaka, K; Ghag, C; Kaidi, J; Lung, K; Lyashenko, A; Peccei, R D; Smith, P; Ye, K

    2012-01-01

    We present systematic case studies to investigate the sensitivity of axion searches by liquid xenon detectors, using the axio-electric effect (analogue of the photoelectric effect) on xenon atoms. Liquid xenon is widely considered to be one of the best target media for detection of WIMPs (Weakly Interacting Massive Particles which may form the galactic dark matter) using nuclear recoils. Since these detectors also provide an extremely low radioactivity environment for electron recoils, very weakly-interacting low-mass particles ( 10^-33 (for mass 1 keV/c^2) or > 10^-27 (for mass 100 keV/c^2).

  19. Axion dark matter detection using atomic transitions.

    Science.gov (United States)

    Sikivie, P

    2014-11-14

    Dark matter axions may cause transitions between atomic states that differ in energy by an amount equal to the axion mass. Such energy differences are conveniently tuned using the Zeeman effect. It is proposed to search for dark matter axions by cooling a kilogram-sized sample to millikelvin temperatures and count axion induced transitions using laser techniques. This appears to be an appropriate approach to axion dark matter detection in the 10^{-4}  eV mass range.

  20. Axion Dark Matter Detection using Atomic Transitions

    CERN Document Server

    Sikivie, P

    2014-01-01

    Dark matter axions may cause transitions between atomic states that differ in energy by an amount equal to the axion mass. Such energy differences are conveniently tuned using the Zeeman effect. It is proposed to search for dark matter axions by cooling a kilogram-sized sample to milliKelvin temperatures and count axion induced transitions using laser techniques. This appears an appropriate approach to axion dark matter detection in the $10^{-4}$ eV mass range.

  1. Cosmological Constant and Axions in String Theory

    Energy Technology Data Exchange (ETDEWEB)

    Svrcek, Peter; /Stanford U., Phys. Dept. /SLAC

    2006-08-18

    String theory axions appear to be promising candidates for explaining cosmological constant via quintessence. In this paper, we study conditions on the string compactifications under which axion quintessence can happen. For sufficiently large number of axions, cosmological constant can be accounted for as the potential energy of axions that have not yet relaxed to their minima. In compactifications that incorporate unified models of particle physics, the height of the axion potential can naturally fall close to the observed value of cosmological constant.

  2. Literature in Focus: "Axions: Theory, Cosmology, and Experimental Searches"

    CERN Multimedia

    2009-01-01

    Axions are peculiar hypothetical particles that could both solve the CP problem of quantum chromodynamics and at the same time account for the dark matter of the universe. Based on a series of lectures by world experts in this field held at CERN, this volume provides a pedagogical introduction to the theory, cosmology and astrophysics of these fascinating particles and gives an up-to-date account of the status and prospect of ongoing and planned experimental searches. Learners and practitioners of astroparticle physics will find in this book both a concise introduction and a current reference work to a showcase topic that connects the "inner space" of the elementary particle world with the "outer space" of the universe at large. The book will be presented by Markus Kuster. "Axions: Theory, Cosmology, and Experimental Searches", edited by M. Kuster (Technische Universität Darmstadt), G. Raffelt (Max-Planck-Institu...

  3. Axions and White Dwarfs

    CERN Document Server

    Isern, J; Garcia-Berro, E; Salaris, M; Torres, S

    2010-01-01

    White dwarfs are almost completely degenerate objects that cannot obtain energy from the thermonuclear sources and their evolution is just a gravothermal process of cooling. The simplicity of these objects, the fact that the physical inputs necessary to understand them are well identified, although not always well understood, and the impressive observational background about white dwarfs make them the most well studied Galactic population. These characteristics allow to use them as laboratories to test new ideas of physics. In this contribution we discuss the robustness of the method and its application to the axion case.

  4. Prof. Cristoforo Benvenuti stands in front of solar panels installed on the roof of Geneva airport. These panels, produced by the commpany SRB, are based on a technology developed at CERN by Cristoforo Benvenuti.

    CERN Document Server

    Maximilien Brice

    2012-01-01

    Prof. Cristoforo Benvenuti stands in front of solar panels installed on the roof of Geneva airport. These panels, produced by the commpany SRB, are based on a technology developed at CERN by Cristoforo Benvenuti.

  5. Eclipses could clarify axion mystery

    CERN Multimedia

    2007-01-01

    "Physicists in Europe have proposed an outlandish experiment that could determine once and for all whether ultralight particles called axions - one of the leading candidates for dark matter - exist." (1/2 page)

  6. Axions, majorons and neutrino masses

    International Nuclear Information System (INIS)

    We point out that there is an intimate connection between the seesaw scale for the light neutrinos and the invisible axion scale based on a series of recent investigations on the neutrino masses and mixings within a class of realistic SO(10) models. We can then extend the standard model accordingly so that both the standard invisible axion and majoron can be treated in a naturally unified manner. 7 refs

  7. Two applications of axion electrodynamics

    Science.gov (United States)

    Wilczek, Frank

    1987-01-01

    The equations of axion electrodynamics are studied. Variations in the axion field can give rise to peculiar distributions of charge and current. These effects provide a simple understanding of the fractional electric charge on dyons and of some recently discovered oddities in the electrodynamics of antiphase boundaries in PbTe. Some speculations regarding the possible occurrence of related phenomena in other solids are presented.

  8. Detailed design of a resonantly enhanced axion-photon regeneration experiment

    International Nuclear Information System (INIS)

    A resonantly enhanced photon-regeneration experiment to search for the axion or axionlike particles is described. This experiment is a shining light through walls study, where photons traveling through a strong magnetic field are (in part) converted to axions; the axions can pass through an opaque wall and convert (in part) back to photons in a second region of strong magnetic field. The photon regeneration is enhanced by employing matched Fabry-Perot optical cavities, with one cavity within the axion generation magnet and the second within the photon-regeneration magnet. Compared to simple single-pass photon regeneration, this technique would result in a gain of (F/π)2, where F is the finesse of each cavity. This gain could feasibly be as high as 1010, corresponding to an improvement in the sensitivity to the axion-photon coupling, gaγγ, of order (F/π)1/2∼300. This improvement would enable, for the first time, a purely laboratory experiment to probe axion-photon couplings at a level competitive with, or superior to, limits from stellar evolution or solar axion searches. This report gives a detailed discussion of the scheme for actively controlling the two Fabry-Perot cavities and the laser frequencies, and describes the heterodyne signal detection system, with limits ultimately imposed by shot noise.

  9. CERN, Geneva

    CERN Multimedia

    2007-01-01

    "The Large Hadron Collider (pages 1-3) is being built at CERN, the European Centre for Nuclear Research near Geneva. CERN offers some extremely exciting opportunities to see "big bang" in action. (1 page)

  10. Axion: Mass -- Dark Matter Abundance Relation

    CERN Document Server

    CERN. Geneva

    2016-01-01

    The axion is a hypothetical particle which would explain why QCD is approximately T-conserving, and is also an excellent Cold Dark Matter candidate. It should be possible to make a clean theoretical prediction relating the dark matter density in axions and the axion mass (under reasonable assumptions about inflation). But the axion's early-Universe dynamics, which establish its density as dark matter, are unexpectedly rich in a way which is only starting to yield to quantitative numerical study.

  11. Mirror World and Axion: Relaxing Cosmological Bounds

    CERN Document Server

    Maurizio, G

    2005-01-01

    The cosmological (upper) limit on the Peccei-Quinn constant, related to the primordial oscillations of the axion field, can be relaxed for a mirror axion model. The simple reason is that the mirror world is colder and so the behavior of the axion temperature-dependent mass is dominated by the contribution from the mirror sector. So the coherent oscillations start earlier and correspondingly the axion mass density \\Omega_a h^2 is reduced.

  12. Experimental Searches for the Axion and Axion-like Particles

    CERN Document Server

    Graham, Peter W; Lamoreaux, Steven K; Lindner, Axel; van Bibber, Karl A

    2016-01-01

    Four decades after its prediction, the axion remains the most compelling solution to the Strong-CP problem and a well-motivated dark matter candidate, inspiring a host of elegant and ultrasensitive experiments based on axion-photon mixing. This report reviews the experimental situation on several fronts. The microwave cavity experiment is making excellent progress in the search for dark matter axions in the microelectronvolt range and may be plausibly extended up to 100 mu eV. Within the past several years however, it has been realized that axions are pervasive throughout string theories, but with masses that fall naturally in the nanoelectronvolt range, for which a NMR-based search is under development. Searches for axions emitted from the Sun's burning core, and purely laboratory experiments based on photon regeneration have both made great strides in recent years, with ambitious projects proposed for the coming decade. Each of these campaigns has pushed the state of the art in technology, enabling large ga...

  13. Active galaxies can make axionic dark energy

    OpenAIRE

    Dimopoulos, Konstantinos; Cormack, Sam

    2016-01-01

    AGN jets carry helical magnetic fields, which can affect dark matter if the latter is axionic. This preliminary study shows that, in the presence of strong helical magnetic fields, the nature of the axionic condensate may change and become dark energy. Such dark energy may affect galaxy formation and galactic dynamics, so this possibility should not be ignored when considering axionic dark matter.

  14. Production of Axions by Cosmic Magnetic Helicity

    CERN Document Server

    Campanelli, L

    2006-01-01

    We study the effects of an external magnetic helicity production on the evolution of the cosmic axion field. It is shown that a helicity larger than (10^{-15} \\G)^2 Mpc, if produced at temperatures above a few GeV, is in contradiction with the existence of the axion, since it would produce too much of an axion relic abundance.

  15. Interaction of axions with relativistic spinning particles

    CERN Document Server

    Popov, V A

    2016-01-01

    We consider a covariant phenomenological model, which describes an interaction between a pseudoscalar (axion) field and massive spinning particles. The model extends the Bagrmann-Michel-Telegdy approach in application to the axion electrodynamics. We present some exact solutions and discuss them in the context of experimental tests of the model and axion detection.

  16. Constraints on Axion couplings from the CDEX-1 experiment at the China Jinping Underground Laboratory

    CERN Document Server

    Liu, S K; Kang, K J; Cheng, J P; Wong, H T; Li, Y J; Li, H B; Lin, S T; Chang, J P; Chen, J H; Chen, N; Chen, Q H; Chen, Y H; Deng, Z; Du, Q; Gong, H; He, H J; He, Q J; Huang, H X; Jiang, H; Li, J M; Li, J; Li, J; Li, X; Li, X Q; Li, X Y; Li, Y L; Lin, F K; Lü, L C; Ma, H; Ma, J L; Mao, S J; Qin, J Q; Ren, J; Ren, J; Ruan, X C; Sharma, V; Shen, M B; Singh, L; Singh, M K; Soma, A K; Su, J; Tang, C J; Wang, J M; Wang, L; Wang, Q; Wu, S Y; Wu, Y C; Wu, Y C; Xianyu, Z Z; Xiao, R Q; Xing, H Y; Xu, F Z; Xu, Y; Xu, X J; Xue, T; Yang, C W; Yang, L T; Yang, S W; Yi, N; Yu, C X; Yu, H; Yu, X Z; Zeng, X H; Zeng, Z; Zhang, L; Zhang, Y H; Zhao, M G; Zhao, W; Zhou, Z Y; Zhu, J J; Zhu, W B; Zhu, X Z; Zhu, Z H

    2016-01-01

    We report the results of searches for solar axions and galactic dark matter axions or axion-like particles with CDEX-1 experiment at the China Jinping Underground Laboratory, using 335.6 kg-days of data from a p-type point-contact germanium detector. The data are compatible with the background model and no excess signals are observed. Limits of solar axions on the model independent coupling $g_{Ae}<2.5\\times10^{-11}$ from Compton, bremsstrahlung, atomic-recombination and deexcitation channel and $g^{\\text{eff}}_{AN}\\times g_{Ae}<6.1\\times10^{-17}$ from $^{57}$Fe M1 transition at 90 % confidence level are derived. Within the framework of the DFSZ and KSVZ models, our results exclude the axion mass heavier than 0.9 eV/c$^{2}$ and 173 eV/c$^{2}$, respectively. The derived constraints for dark matter axions below 1 keV improves over the previous results.

  17. Planckian Axions in String Theory

    CERN Document Server

    Bachlechner, Thomas C; McAllister, Liam

    2014-01-01

    We argue that super-Planckian diameters of axion fundamental domains can naturally arise in Calabi-Yau compactifications of string theory. In a theory with $N$ axions $\\theta^i$, the fundamental domain is a polytope defined by the periodicities of the axions, via constraints of the form $-\\pi\\sqrt{N}$. This result is robust in the presence of $P>N$ constraints, while for $P=N$ the diameter is further enhanced by eigenvector delocalization to $N^{3/2}f_N$. We directly verify our results in explicit Calabi-Yau compactifications of type IIB string theory. In the classic example with $h^{1,1}=51$ where parametrically controlled moduli stabilization was demonstrated by Denef et al. in [1], the largest metric eigenvalue obeys $f_N \\approx 0.013 M_{pl}$. The random matrix analysis then predicts, and we exhibit, axion diameters $>M_{pl}$ for the precise vacuum parameters found in [1]. Our results provide a framework for achieving large-field axion inflation in well-understood flux vacua.

  18. Axion landscape and natural inflation

    Energy Technology Data Exchange (ETDEWEB)

    Higaki, Tetsutaro, E-mail: thigaki@post.kek.jp [Theory Center, KEK, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Takahashi, Fuminobu, E-mail: fumi@tuhep.phys.tohoku.ac.jp [Department of Physics, Tohoku University, Sendai 980-8578 (Japan); Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, University of Tokyo, Kashiwa 277-8583 (Japan)

    2015-05-11

    Multiple axions form a landscape in the presence of various shift symmetry breaking terms. Eternal inflation populates the axion landscape, continuously creating new universes by bubble nucleation. Slow-roll inflation takes place after the tunneling event, if a very flat direction with a super-Planckian decay constant arises due to the alignment mechanism. We study the vacuum structure as well as possible inflationary dynamics in the axion landscape scenario, and find that the inflaton dynamics is given by either natural or multi-natural inflation. In the limit of large decay constant, it is approximated by the quadratic chaotic inflation, which however is disfavored if there is a pressure toward shorter duration of inflation. Therefore, if the spectral index and the tensor-to-scalar ratio turn out to be different from the quadratic chaotic inflation, there might be observable traces of the bubble nucleation. Also, the existence of small modulations to the inflaton potential is a common feature in the axion landscape, which generates a sizable and almost constant running of the scalar spectral index over CMB scales. Non-Gaussianity of equilateral type can also be generated if some of the axions are coupled to massless gauge fields.

  19. Axion landscape and natural inflation

    International Nuclear Information System (INIS)

    Multiple axions form a landscape in the presence of various shift symmetry breaking terms. Eternal inflation populates the axion landscape, continuously creating new universes by bubble nucleation. Slow-roll inflation takes place after the tunneling event, if a very flat direction with a super-Planckian decay constant arises due to the alignment mechanism. We study the vacuum structure as well as possible inflationary dynamics in the axion landscape scenario, and find that the inflaton dynamics is given by either natural or multi-natural inflation. In the limit of large decay constant, it is approximated by the quadratic chaotic inflation, which however is disfavored if there is a pressure toward shorter duration of inflation. Therefore, if the spectral index and the tensor-to-scalar ratio turn out to be different from the quadratic chaotic inflation, there might be observable traces of the bubble nucleation. Also, the existence of small modulations to the inflaton potential is a common feature in the axion landscape, which generates a sizable and almost constant running of the scalar spectral index over CMB scales. Non-Gaussianity of equilateral type can also be generated if some of the axions are coupled to massless gauge fields

  20. Axion helioscopes update: the status of CAST & IAXO

    DEFF Research Database (Denmark)

    Dafni, T; Iguaz, F. J.; Jakobsen, Anders Clemen

    2014-01-01

    to 1.2 eV, are presented. Currently, CAST is expectingto improve its sensitivity to solar axions with rest mass below 0.02 eV/c2 after the upgradeof the X-ray detectors and with the implementation of a second X-ray optic. At the same time,it is exploring other possibilities at the low energy physics...

  1. Theory of Light Scattering in Axion Electrodynamics

    Science.gov (United States)

    Ochiai, Tetsuyuki

    2012-09-01

    Taking account of the axion term in the Maxwell Lagrangian, we present a rigorous theory of light scattering in piecewise-constant axion fields. In particular, we focus on axionic substances with confined and/or curved geometries, and the scattering matrices of an axionic slab, cylinder, and sphere are derived analytically. The axion term generates a surface current with off-diagonal optical conductivity, giving rise to a new type of photospin--orbit interaction. As a result, various novel light-scattering phenomena can take place. We demonstrate enhanced Faraday rotation, parity-violating light scattering, and strong perturbation of dipole radiation.

  2. The Axion Mass in Modular Invariant Supergravity

    CERN Document Server

    Butter, D; Butter, Daniel; Gaillard, Mary K.

    2005-01-01

    When supersymmetry is broken by condensates with a single condensing gauge group, there is a nonanomalous R-symmetry that prevents the universal axion from acquiring a mass. It has been argued that, in the context of supergravity, higher dimension operators will break this symmetry and may generate an axion mass too large to allow the identification of the universal axion with the QCD axion. We show that such contributions to the axion mass are highly suppressed in a class of models where the effective Lagrangian for gaugino and matter condensation respects modular invariance (T-duality).

  3. Inflationary dilaton-axion magnetogenesis

    CERN Document Server

    Cheng, Shu-Lin; Ng, Kin-Wang

    2014-01-01

    We discuss the generation of primordial magnetic fields during inflation in the dilaton-axion electromagnetism, in which the dilaton and axion dynamics are introduced in terms of two time dependent functions of the cosmic scale factor, $I(a) F^2/4$ and $J(a) F\\tilde{F}/4$, respectively, where $F$ is the electromagnetic field strength and $\\tilde{F}$ is its dual. We study the form of $J(a)$ that can generate a large seed magnetic field in the weak coupling regime, $I(a)<1$. Although the $J(a)$ function is model dependent, the axion-photon coupling indeed opens up a new window for a successful inflationary magnetogenesis.

  4. Axion dark matter: strings and their cores

    Energy Technology Data Exchange (ETDEWEB)

    Fleury, Leesa [McGill University, Department of Physics,3600 rue University, Montréal QC H3A 2T8 (Canada); Moore, Guy D. [Institut für Kernphysik, Technische Universität Darmstadt,Schlossgartenstraße 2, D-64289 Darmstadt (Germany)

    2016-01-04

    Axions constitute a well-motivated dark matter candidate, and if PQ symmetry breaking occurred after inflation, it should be possible to make a clean prediction for the relation between the axion mass and the axion dark matter density. We show that axion (or other global) string networks in 3D have a network density that depends logarithmically on the string separation-to-core ratio. This logarithm would be about 10 times larger in axion cosmology than what we can achieve in numerical simulations. We simulate axion production in the early Universe, finding that, for the separation-to-core ratios we can achieve, the changing density of the network has little impact on the axion production efficiency.

  5. Backreacted axion field ranges in string theory

    Science.gov (United States)

    Baume, Florent; Palti, Eran

    2016-08-01

    String theory axions are interesting candidates for fields whose potential might be controllable over super-Planckian field ranges and therefore as possible candidates for inflatons in large field inflation. Axion monodromy scenarios are setups where the axion shift symmetry is broken by some effect such that the axion can traverse a large number of periods potentially leading to super-Planckian excursions. We study such scenarios in type IIA string theory where the axion shift symmetry is broken by background fluxes. In particular we calculate the backreaction of the energy density induced by the axion vacuum expectation value on its own field space metric. We find universal behaviour for all the compactifications studied where up to a certain critical axion value there is only a small backreaction effect. Beyond the critical value the backreaction is strong and implies that the proper field distance as measured by the backreacted metric increases at best logarithmically with the axion vev, thereby placing strong limitations on extending the field distance any further. The critical axion value can be made arbitrarily large by the choice of fluxes. However the backreaction of these fluxes on the axion field space metric ensures a precise cancellation such that the proper field distance up to the critical axion value is flux independent and remains sub-Planckian. We also study an axion alignment scenario for type IIA compactifications on a twisted torus with four fundamental axions mixing to leave an axion with an effective decay constant which is flux dependent. There is a choice of fluxes for which the alignment parameter controlling the effective decay constant is unconstrained by tadpoles and can in principle lead to an arbitrarily large effective decay constant. However we show that these fluxes backreact on the fundamental decay constants so as to precisely cancel any enhancement leaving a sub-Planckian effective decay constant.

  6. Axion hot dark matter bounds

    CERN Document Server

    Raffelt, G; Mirizzi, A; Wong, Y Y Y

    2008-01-01

    We derive cosmological limits on two-component hot dark matter consisting of neutrinos and axions. We restrict the large-scale structure data to the safely linear regime, excluding the Lyman-alpha forest. We derive Bayesian credible regions in the two-parameter space consisting of m_a and sum(m_nu). Marginalizing over sum(m_nu) provides m_a<1.02 eV (95% CL). In the absence of axions the same data and methods give sum(m_nu)< 0.63 eV (95% CL).

  7. CERN Choir

    CERN Multimedia

    Staff Association

    2015-01-01

      Do you like singing? The CERN Choir is looking for basses and tenors Join us! Programme Spring Session 2015: Donizetti: Misere & Missa di Gloria e Credo Bellini: Salve Regina Bruckner: Requiem in D minor Next concert: Sunday 31 May 2015 at 17:00 Musicales de Comesières (GE) Rehearsals at CERN Main Auditorium, building 500 On Wednesdays from 20.00 to 22:00 Membership fee: January to June 150 CHF September to December: 100CHF Contact: Baudouin.bleus@cern.ch Facebook/Choeur-du-CERN

  8. Axion cooling of white dwarfs

    CERN Document Server

    Isern, J; Garcia--Berro, E; Salaris, M; Torres, S

    2013-01-01

    The evolution of white dwarfs is a simple gravothermal process. This process can be tested in two ways, through the luminosity function of these stars and through the secular variation of the period of pulsation of those stars that are variable. Here we show how the mass of the axion can be constrained using the white dwarf luminosity function.

  9. Axion as a cold dark matter candidate: Analysis to third order perturbation for classical axion

    CERN Document Server

    Noh, Hyerim; Park, Chan-Gyung

    2015-01-01

    We investigate aspects of axion as a coherently oscillating massive classical scalar field by analyzing third order perturbations in Einstein's gravity in the axion-comoving gauge. The axion fluid has its characteristic pressure term leading to an axion Jeans scale which is cosmologically negligible for a canonical axion mass. Our classically derived axion pressure term in Einstein's gravity is identical to the one derived in the non-relativistic quantum mechanical context in the literature. We show that except for the axion pressure term, the axion fluid equations are exactly the same as the general relativistic continuity and Euler equations of a zero-pressure fluid up to third order perturbation. The general relativistic density and velocity perturbations of the CDM in the CDM-comoving gauge are exactly the same as the Newtonian perturbations to the second order (in all scales), and the pure general relativistic corrections appearing from the third order are numerically negligible (in all scales as well) i...

  10. Courrier CERN

    CERN Multimedia

    2015-01-01

    Example of the cover page of the French version of the CERN Courier; Courrier CERN from January 1962. The journal was published both in English and French up to volume 45, no. 5, June 2005. Since then there is a single-language edition where articles are published either in French or English with an abstract in the other language.

  11. Axion overview and the U.S. RF cavity axion search

    Energy Technology Data Exchange (ETDEWEB)

    Rosenberg, L.J. [Massachusetts Inst. of Tech., Cambridge, MA (United States); van Bibber, K.A.

    1998-01-01

    The axion, a hypothetical elementary particle, originally emerged from a solution to the strong CP problem in QCD. Later, axions were recognized as good dark matter candidates. Dark matter axions have only feeble couplings to matter and radiation, so their detection offers considerable challenge. Nonetheless, a new generation of exquisitely sensitive searches is underway. One such effort, in the United States, has already achieved sensitivity to plausible halo dark matter axion to photon couplings.

  12. CERN & Society

    CERN Multimedia

    2016-01-01

    Non Member State Summer Students 2015 are interviewed about their decision to study STEM subjects, to apply for CERN NMSSS programme, their experience onsite @CERN and takeaways, their future goals and aspirations, offering also advice to fellow students.The Non Member State Summer Student Programme stands for a unique opportunity for students from all over the world to spend their summer at CERN in Geneva, getting involved in some of the world’s biggest experiments. For 8 weeks, summer students gather on-site at CERN and join in the day-to-day work of research. The Programme targets advanced undergraduate and beginning graduate students of physics, computing and engineering, particularly from developing countries. Participating students receive scientific training, attend lectures and work on laboratory-based projects alongside with CERN experts and fellow students.

  13. CERN SOLAR CLUB

    CERN Multimedia

    Solar Club

    2011-01-01

    Le club tiendra son Assemblée générale le mercredi 13 avril 2011 à la suite de la conférence organisée par l'Association du personnel Sur la route du soleil levant Une première en vélo électrique solaire qui a lieu à 18 h 30 * * * * * * L’AG aura donc lieu vers 20 h 15. Ordre du jour habituel avec comptes rendus des Activités et finances, et présentations des projets pour le futur. Rejoignez-nous pour parler du solaire et des énergies renouvelables en général, proposer des projets et y participer. L’AG se termine avec le verre de l'amitié !

  14. On supersymmetric effective theories of axion

    Energy Technology Data Exchange (ETDEWEB)

    Higaki, Tetsutaro [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Kitano, Ryuichiro [Tohoku Univ., Sendai (Japan). Dept. of Physics

    2011-04-15

    We study effective theories of an axion in spontaneously broken supersymmetric theories. We consider a system where the axion supermultiplet is directly coupled to a supersymmetry breaking sector whereas the standard model sector is communicated with those sectors through loops of messenger fields. The gaugino masses and the axion-gluon coupling necessary for solving the strong CP problem are both obtained by the same effective interaction. We discuss cosmological constraints on this framework. (orig.)

  15. Dynamical Axion Field in Topological Magnetic Insulators

    OpenAIRE

    Li, Rundong; Jing WANG; Qi, Xiaoliang; Zhang, Shou-Cheng

    2009-01-01

    Axions are very light, very weakly interacting particles postulated more than 30 years ago in the context of the Standard Model of particle physics. Their existence could explain the missing dark matter of the universe. However, despite intensive searches, they have yet to be detected. In this work, we show that magnetic fluctuations of topological insulators couple to the electromagnetic fields exactly like the axions, and propose several experiments to detect this dynamical axion field. In ...

  16. On supersymmetric effective theories of axion

    International Nuclear Information System (INIS)

    We study effective theories of an axion in spontaneously broken supersymmetric theories. We consider a system where the axion supermultiplet is directly coupled to a supersymmetry breaking sector whereas the standard model sector is communicated with those sectors through loops of messenger fields. The gaugino masses and the axion-gluon coupling necessary for solving the strong CP problem are both obtained by the same effective interaction. We discuss cosmological constraints on this framework. (orig.)

  17. A method to measure the axion mass

    Science.gov (United States)

    Carboni, G.

    1981-05-01

    We have calculated the decay rate of the triplet state of positronium into axion + gamma, under the hypothesis that the axion mass is less than 1 MeV. The branching ratio is found to be ~3 × 10-8. We describe a possible experiment that could detect the axion and measure its mass. On leave from Istituto Nazionale di Fisica Nuclear, Sezione di Pisa, Pisa, Italy.

  18. Axion induced oscillating electric dipole moments

    Energy Technology Data Exchange (ETDEWEB)

    Hill, Christopher T. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2015-06-24

    In this study, the axion electromagnetic anomaly induces an oscillating electric dipole for any magnetic dipole. This is a low energy theorem which is a consequence of the space-time dependent cosmic background field of the axion. The electron will acquire an oscillating electric dipole of frequency ma and strength ~ 10-32 e-cm, within four orders of magnitude of the present standard model DC limit, and two orders of magnitude above the nucleon, assuming standard axion model and dark matter parameters. This may suggest sensitive new experimental venues for the axion dark matter search.

  19. Axions as Hot and Cold Dark Matter

    CERN Document Server

    Jeong, Kwang Sik; Takahashi, Fuminobu

    2014-01-01

    The presence of a hot dark matter component has been hinted at 3 sigma by a combination of the results from different cosmological observations. We examine a possibility that pseudo Nambu-Goldstone bosons account for both hot and cold dark matter components. We show that the QCD axions can do the job for the axion decay constant f_a < O(10^10) GeV, if they are produced by the saxion decay and the domain wall annihilation. We also investigate the cases of thermal QCD axions, pseudo Nambu-Goldstone bosons coupled to the standard model sector through the Higgs portal, and axions produced by modulus decay.

  20. Fast Radio Bursts from Axion Stars

    CERN Document Server

    Iwazaki, Aiichi

    2014-01-01

    Axions are one of the most promising candidates of dark matter. The axions have been shown to form miniclusters with masses $\\sim 10^{-12}M_{\\odot}$ and to become dominant component of dark matter. These axion miniclusters condense to form axion stars. We show a possible origin of fast radio bursts ( FRBs ) by assuming the axion stars being dark matter: FRBs arise from the collisions between the axion stars and neutron stars. The FRBs are caused by the rapid conversion of the axions into electromagnetic fields under strong magnetic fields. Electric fields are induced on the axion stars under strong magnetic fields of neutron stars. The electric fields parallel to the magnetic fields oscillate with a frequency and make electrons in atmospheres of neutron stars coherently oscillate. Thus, the coherent radiations are emitted. The observed frequencies ( $\\sim 1.4$GHz ) of the bursts are given by the axion mass $m_a$ such as $m_a/2\\pi\\simeq 2.3\\,\\mbox{GHz}\\,\\big(m_a/10^{-5}\\mbox{eV}\\big)$. The frequency is affecte...

  1. R-axion detection at LHC

    Energy Technology Data Exchange (ETDEWEB)

    Goh, Hock-Seng; /UC, Berkeley /LBL, Berkeley; Ibe, Masahiro; /SLAC

    2009-06-19

    Supersymmetric models with spontaneously broken approximate R-symmetry contains a light spin 0 particle, the R-axion. The properties of the particle can be a powerful probe of the structure of the new physics. In this paper, we discuss the possibilities of the R-axion detection at the LHC experiments. It is challenge to observe this light particle in the LHC environment. However, for typical values in which the mass of the R-axion is a few hundred MeV, we show that those particles can be detected by searching for displaced vertices from R-axion decay.

  2. Neutrino-axion-dilaton interconnection

    CERN Document Server

    Bertolini, Stefano; Kolešová, Helena; Malinský, Michal; Vasquez, Juan Carlos

    2016-01-01

    We show that a recently proposed framework that provides a simple connection between Majorana neutrinos and an invisible axion in minimal scalar extensions of the standard electroweak model can be naturally embedded in a classically scale-invariant setup. The explicit breaking of the scale invariance \\`a la Coleman-Weinberg generates the Peccei-Quinn and electroweak scales. The spontaneous breaking of the chiral $U(1)_{PQ}$ triggers the generation of neutrino masses via Type-II seesaw and, at the same time, provides a dynamical solution to the strong CP problem as well as the axion as a dark matter candidate. The electroweak and neutrino mass scales are obtained via a technically natural ultraweak limit of the singlet scalar interactions. Accordingly, a realistic and perturbatively stable scalar spectrum, possibly in the reach of the LHC, is naturally obtained. A very light pseudo-dilaton characterizes such a setting. The vacuum stability of the extended setup is discussed.

  3. CERN Rocks

    CERN Multimedia

    2004-01-01

    The 15th CERN Hardronic Festival took place on 17 July on the terrace of Rest 3 (Prévessin). Over 1000 people, from CERN and other International Organizations, came to enjoy the warm summer night, and to watch the best of the World's High Energy music. Jazz, rock, pop, country, metal, blues, funk and punk blasted out from 9 bands from the CERN Musiclub and Jazz club, alternating on two stages in a non-stop show.  The night reached its hottest point when The Canettes Blues Band got everybody dancing to sixties R&B tunes (pictured). Meanwhile, the bars and food vans were working at full capacity, under the expert management of the CERN Softball club, who were at the same time running a Softball tournament in the adjacent "Higgs Field". The Hardronic Festival is the main yearly CERN music event, and it is organized with the support of the Staff Association and the CERN Administration.

  4. Axion Landscape and Natural Inflation

    CERN Document Server

    Higaki, Tetsutaro

    2015-01-01

    Multiple axions form a landscape in the presence of various shift symmetry breaking terms. Eternal inflation populates the axion landscape, continuously creating new universes by bubble nucleation. Slow-roll inflation naturally takes place after the tunneling event, because a very flat direction with a super-Planckian decay constant arises due to the alignment mechanism. We study the vacuum structure as well as possible inflationary dynamics in the axion landscape scenario, and find that the inflaton dynamics is given by either natural or multi-natural inflation. In the limit of large decay constant, it is approximated by the quadratic chaotic inflation, which however is disfavored if there is a pressure toward shorter duration of inflation. If the spectral index and the tensor-to-scalar ratio turn out to be different from the quadratic chaotic inflation, there might be observable traces of the bubble nucleation. Also, the existence of small modulations to the inflaton potential is a common feature in the axi...

  5. X-ray optics for axion helioscopes

    DEFF Research Database (Denmark)

    Jakobsen, Anders Clemen; Pivovaroff, Michael J.; Christensen, Finn Erland

    2013-01-01

    A method of optimizing grazing incidence x-ray coatings in ground based axion helioscopes is presented. Software has been been developed to find the optimum coating when taking both axion spectrum and Micromegas detector quantum efficiency into account. A comparison of the relative effective area...... of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only....

  6. Some Considerations About Podolsky-Axionic Electrodynamics

    OpenAIRE

    Gaete, Patricio(Departmento de Física and Centro Científico-Tecnológico de Valparaíso, Universidad Técnica Federico Santa María, Valparaiso, Chile)

    2011-01-01

    For a Podolsky-axionic electrodynamics, we compute the interaction potential within the structure of the gauge-invariant but path-dependent variables formalism. The result is equivalent to that of axionic electrodynamics from a new noncommutative approach, up to first order in $\\theta$.

  7. Influence of galactic cosmic rays and solar variability on aerosols, clouds and climate: Results from the CLOUD experiment at CERN

    International Nuclear Information System (INIS)

    The potential influence of ions produced from galactic cosmic rays on the formation of new aerosol particles in the atmosphere may play an important role relevant for aerosol properties, cloud formation and climate. Variability of galactic cosmic rays due to modulating influences from the sun therefore may affect (regional) climate on various time scales. A quantitative understanding of the role of ions for atmospheric aerosol formation has not been reached, but also the dependence of aerosol formation on the concentration of the nucleating substances such as gaseous sulfuric acid, ammonia and amines is missing. Here results from the CLOUD experiment at CERN are presented. CLOUD is a new aerosol and cloud chamber facility at CERN. The chamber can be exposed to a pion beam from CERN to simulate various levels of atmospheric ionization. CLOUD has been set up to investigate aerosol and cloud processes under well-controlled laboratory conditions. We find that cosmic ray ionization substantially increases the nucleation rate of pure sulfuric acid/water particles while charge effects are much less pronounced for ternary systems including ammonia or dimethylamine. The results from the CLOUD experiments have been used to develop a new parameterization of aerosol nucleation which has been included in a global climate model. Impacts of our findings for cloud formation and climate are discussed.

  8. Exploring the role of axions and other WISPs in the dark universe

    Energy Technology Data Exchange (ETDEWEB)

    Ringwald, Andreas

    2012-10-18

    Axions and other very weakly interacting slim particles (WISPs) may be non-thermally produced in the early universe and survive as constituents of the dark universe. We describe their theoretical motivation and their phenomenology. A huge region in parameter space spanned by their couplings to photons and their masses can give rise to the observed cold dark matter abundance. A wide range of experiments - direct dark matter searches exploiting microwave cavities, searches for solar axions or WISPs, and lightshining-through-a-wall searches - can probe large parts of this parameter space in the foreseeable future.

  9. Axion String Dynamics I: 2+1D

    CERN Document Server

    Fleury, Leesa M

    2016-01-01

    If the axion exists and if the initial axion field value is uncorrelated at causally disconnected points, then it should be possible to predict the efficiency of cosmological axion production, relating the axionic dark matter density to the axion mass. The main obstacle to making this prediction is correctly treating the axion string cores. We develop a new algorithm for treating the axionic string cores correctly in 2+1 dimensions. When the axionic string cores are given their full physical string tension, axion production is about twice as efficient as in previous simulations. We argue that the string network in 2+1 dimensions should behave very differently than in 3+1 dimensions, so this result cannot be simply carried over to the physical case. We outline how to extend our method to 3+1D axion string dynamics.

  10. F-term Axion Monodromy Inflation

    CERN Document Server

    Marchesano, Fernando; Uranga, Angel M

    2014-01-01

    The continuous shift symmetry of axions is at the heart of several realizations of inflationary models. In particular, axion monodromy inflation aims at achieving super-Planckian field ranges for the inflaton in the context of string theory. Despite the elegant underlying principle, explicit models constructed hitherto are exceedingly complicated. Moreover, we show that they are incompatible with the underlying supersymmetry structure, and that the problem stems from the D-term nature of the proposed axion potential. We propose a new axion monodromy inflationary scenario where the inflaton potential arises from an F-term and such inconsistencies are absent. We present several scenarios, where the axion arises from the Kaluza-Klein compactification of higher dimensional gauge fields (or $p$-form potentials) in the presence of fluxes and/or torsion homology. The monodromy corresponds to a change in the background fluxes, and its F-term nature manifests in the existence of domain walls interpolating among flux c...

  11. Oscillating Chiral Tensor Spectrum from Axionic Inflation

    CERN Document Server

    Obata, Ippei

    2016-01-01

    We study the axionic inflation with a modulated potential and examine if the primordial tensor power spectrum exhibits oscillatory feature, which is testable with future space-based gravitational wave experiments such as DECIGO and BBO. In the case of the single-field axion monodromy inflation, it turns out that it is difficult to detect the oscillation in the spectrum due to suppression of the sub-Planckian decay constant of axion. On the other hand, in the case of aligned chromo-natural inflation where the axion is coupled to a SU(2) gauge field, it turns out that the sizable oscillation in the tensor spectrum can occur due to the enhancement of chiral gravitational waves sourced by the gauge field. We expect that this feature will be a new probe to axion phenomenologies in early universe through the chiral gravitational waves.

  12. Fermion production during and after axion inflation

    Energy Technology Data Exchange (ETDEWEB)

    Adshead, Peter; Sfakianakis, Evangelos I. [Department of Physics, University of Illinois at Urbana-Champaign,Urbana, Illinois 61801 (United States)

    2015-11-11

    We study derivatively coupled fermions in axion-driven inflation, specifically m{sub ϕ}{sup 2}ϕ{sup 2} and monodromy inflation, and calculate particle production during the inflationary epoch and the post-inflationary axion oscillations. During inflation, the rolling axion acts as an effective chemical potential for helicity which biases the gravitational production of one fermion helicity over the other. This mechanism allows for efficient gravitational production of heavy fermion states that would otherwise be highly suppressed. Following inflation, the axion oscillates and fermions with both helicities are produced as the effective frequency of the fermion field changes non-adiabatically. For certain values of the fermion mass and axion-fermion coupling strength, the two helicity states are produced asymmetrically, resulting in unequal number-densities of left- and right-helicity fermions.

  13. Fermion production during and after axion inflation

    International Nuclear Information System (INIS)

    We study derivatively coupled fermions in axion-driven inflation, specifically mϕ2ϕ2 and monodromy inflation, and calculate particle production during the inflationary epoch and the post-inflationary axion oscillations. During inflation, the rolling axion acts as an effective chemical potential for helicity which biases the gravitational production of one fermion helicity over the other. This mechanism allows for efficient gravitational production of heavy fermion states that would otherwise be highly suppressed. Following inflation, the axion oscillates and fermions with both helicities are produced as the effective frequency of the fermion field changes non-adiabatically. For certain values of the fermion mass and axion-fermion coupling strength, the two helicity states are produced asymmetrically, resulting in unequal number-densities of left- and right-helicity fermions

  14. A Search for Axions and massive neutrinos

    CERN Multimedia

    2002-01-01

    This experiment relies on the production of a strong, contamination free (10$ ^{-12} $) source of radioactive $^{125}$I at the ISOLDE facility. Technical developments to achieve the necessary beam intensity are in progress. \\\\ \\\\The possible emission of axions in the 35.5 keV M1 transition of the $^{125}$Te daughter isotope is searched for by the axion analogue of the Mössbauer effect, i.e. the axion resonance absorption in a $^{125}$Te resonance absorber. For this purpose all other radiation emitted from the source is shielded by a non-resonant absorber, which is transparent, however, to axions. The resonance absorption is detected by measurement of subsequently emitted X-rays. A sensitivity to the axion emission branching ratio in the nuclear decay of 10$ ^{-7} $ is strived for.

  15. Photon production from the scattering of axions out of a solenoidal magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Guendelman, Eduardo I.; Shilon, Idan [Physics Department, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel); Cantatore, Giovanni [Università and INFN Trieste, via Valerio 2, 34127 Trieste (Italy); Zioutas, Konstantin, E-mail: guendel@bgu.ac.il, E-mail: silon@bgu.ac.il, E-mail: cantatore@trieste.infn.it, E-mail: Konstantin.Zioutas@cern.ch [Physics Department, University of Patras, Rio, 26504 Patras (Greece)

    2010-06-01

    We calculate the total cross section for the production of photons from the scattering of axions by a strong inhomogeneous magnetic field in the form of a 2D δ-function, a cylindrical step function and a 2D Gaussian distribution, which can be approximately produced by a solenoidal current. The theoretical result is used to estimate the axion-photon conversion probability which could be expected in a reasonable experimental situation. Comparison between the 2D conversion probabilities for QCD inspired axions and those derived by applying the celebrated 1D calculation of the (inverse) coherent Primakoff effect is made using an averaging prescription procedure of the 1D case. We also consider scattering at a resonance E{sub axion} ∼ m{sub axion}, which corresponds to the scattering from a δ-function and gives the most enhanced results. Finally, we analyze the results of this work in the astrophysical extension to suggest a way in which they may be directed to a solution to some basic solar physics problems and, in particular, the coronal heating problem.

  16. Robot adventures at CERN

    CERN Multimedia

    2015-01-01

    Imagine if the CERN robots had an end-of-year party... From retrieving data tapes to handling material safely, the robots at CERN fulfill numerous tasks. Find out more: http://cern.ch/go/VjX7 Produced by: CERN Video Productions Director: Christoph M. Madsen Copyright © 2015 CERN. Terms of use: http://copyright.web.cern.ch/

  17. CERN choir

    CERN Document Server

    2004-01-01

    Don't forget a special performance of Joseph Haydn's Creation, an oratorio in three parts, given by the CERN choir and the Annecy choir Pro Musica, this Sunday at 8.30 p.m. at the Grand Casino. Tickets (38 CHF) are available at Fnac Rive and Balexert.

  18. Axion mechanism of Sun luminosity, dark matter and extragalactic background light

    OpenAIRE

    Rusov, V. D.; Sharf, I. V.; Tarasov, V. A.; Eingorn, M. V.; Smolyar, V. P.; Vlasenko, D. S.; Zelentsova, T. N.; Linnik, E. P.; Beglaryan, M. E.

    2013-01-01

    We show the existence of the strong inverse correlation between the temporal variations of the toroidal component of the magnetic field in the solar tachocline (the bottom of the convective zone) and the Earth magnetic field (the Y-component). The possibility that the hypothetical solar axions, which can transform into photons in external electric or magnetic fields (the inverse Primakoff effect), can be the instrument by which the magnetic field of the Sun convective zone modulates the magne...

  19. A 2nd generation cosmic axion experiment

    OpenAIRE

    Hagmann, C; Stoeffl, W.; Van Bibber, K.; Daw, E.; Kinion, D.; Rosenberg, L; Sikivie, P.; Sullivan, N.; D. Tanner; Moltz, D.; Nezrick, F.; Turner, M; Golubev, N.; Kravchuk, L.

    1995-01-01

    An experiment is described to detect dark matter axions trapped in the halo of our galaxy. Galactic axions are converted into microwave photons via the Primakoff effect in a static background field provided by a superconducting magnet. The photons are collected in a high Q microwave cavity and detected by a low noise receiver. The axion mass range accessible by this experiment is 1.3-13 micro-eV. The expected sensitivity will be roughly 50 times greater than achieved by previous experiments i...

  20. A 2nd generation cosmic axion experiment

    CERN Document Server

    Hagmann, C A; Van Bibber, K; Daw, E J; Kinion, D S; Rosenberg, L J; Sikivie, P; Sullivan, N; Tanner, D B; Moltz, D M; Nezrick, F A; Turner, M; Golubev, N A; Kravchuk, L V

    1995-01-01

    An experiment is described to detect dark matter axions trapped in the halo of our galaxy. Galactic axions are converted into microwave photons via the Primakoff effect in a static background field provided by a superconducting magnet. The photons are collected in a high Q microwave cavity and detected by a low noise receiver. The axion mass range accessible by this experiment is 1.3-13 micro-eV. The expected sensitivity will be roughly 50 times greater than achieved by previous experiments in this mass range. The assembly of the detector is well under way at LLNL and data taking will start in mid-1995.

  1. Gravitational Waves from Axion Monodromy

    CERN Document Server

    Hebecker, Arthur; Rompineve, Fabrizio; Witkowski, Lukas T

    2016-01-01

    Large field inflation is arguably the simplest and most natural variant of slow-roll inflation. Axion monodromy may be the most promising framework for realising this scenario. As one of its defining features, the long-range polynomial potential possesses short-range, instantonic modulations. These can give rise to a series of local minima in the post-inflationary region of the potential. We show that for certain parameter choices the inflaton populates more than one of these vacua inside a single Hubble patch. This corresponds to a dynamical phase decomposition, analogously to what happens in the course of thermal first-order phase transitions. In the subsequent process of bubble wall collisions, the lowest-lying axionic minimum eventually takes over all space. Our main result is that this violent process sources gravitational waves, very much like in the case of a first-order phase transition. We compute the energy density and peak frequency of the signal, which can lie anywhere in the mHz-GHz range, possib...

  2. Axion monodromy inflation with sinusoidal corrections

    CERN Document Server

    Kobayashi, Tatsuo; Yamaguchi, Yuya

    2014-01-01

    We study the axion monodromy inflation with a non-perturbatively generated sinusoidal term. The potential form is a mixture between the natural inflation and the axion monodromy inflation potentials. The sinusoidal term is subdominant in the potential, but leaves significant effects on the resultant fluctuation generated during inflation. A larger tensor-to-scalar ratio can be obtained in our model. We study two scenarios, single inflation scenario and the double inflation scenario. In the first scenario, the axion monodromy inflation with a sufficient number of e-fold generates a larger tensor-to-scalar ratio about $0.1 - 0.15$ but also a tiny running of spectral index. In the second scenario of double inflation, axion monodromy inflation is its first stage and, we assume another inflation follows. In this case, our model can realize a larger tensor-to-scalar ratio and a large negative running of spectral index simultaneously.

  3. Nonrelativistic Effective Field Theory for Axions

    CERN Document Server

    Braaten, Eric; Zhang, Hong

    2016-01-01

    Axions can be described by a relativistic field theory with a real scalar field $\\phi$ whose self-interaction potential is a periodic function of $\\phi$. Low-energy axions, such as those produced in the early universe by the vacuum misalignment mechanism, can be described more simply by a nonrelativistic effective field theory with a complex scalar field $\\psi$ whose effective potential is a function of $\\psi^*\\psi$. We determine the coefficients in the expansion of the effective potential to fifth order in $\\psi^*\\psi$ by matching low-energy axion scattering amplitudes. In order to describe a Bose-Einstein condensate of axions that is too dense to expand the effective potential in powers of $\\psi^*\\psi$, we develop a sequence of systematically improvable approximations to the effective potential that include terms of all orders in $\\psi^*\\psi$.

  4. Nonthermal axion dark radiation and constraints

    Science.gov (United States)

    Mazumdar, Anupam; Qutub, Saleh; Saikawa, Ken'ichi

    2016-09-01

    The Peccei-Quinn mechanism presents a neat solution to the strong C P problem. As a by-product, it provides an ideal dark matter candidate, "the axion", albeit with a tiny mass. Axions therefore can act as dark radiation if excited with large momenta after the end of inflation. Nevertheless, the recent measurement of relativistic degrees of freedom from cosmic microwave background radiation strictly constrains the abundance of such extra relativistic species. We show that ultrarelativistic axions can be abundantly produced if the Peccei-Quinn field was initially displaced from the minimum of the potential. This in lieu places an interesting constraint on the axion dark matter window with large decay constant which is expected to be probed by future experiments. Moreover, an upper bound on the reheating temperature can be placed, which further constrains the thermal history of our Universe.

  5. Universal constraints on axions from inflation

    DEFF Research Database (Denmark)

    Ferreira, R. Z.; Sloth, M. S.

    2014-01-01

    constant of the axion. It has previously been demonstrated that if the axion is identified with the inflaton, such an interaction can lead to measurable cosmological signatures (non-Gaussian modifications of the curvature perturbation spectrum) depending on the parameter . In the present paper we will show...... through this mechanism, larger than the vacuum ones, without violating the observational constraints unless we combine this mechanism with a curvaton or if the sigma field becomes heavy and decays during inflation. Even in this last case there are non-trivial constraints coming from the slow......-roll evolution of the curvature perturbation on super horizon scales which should be taken into account. We also comment on implications for inflationary models where axions play an important role as, for example, models of natural inflation where more than one axion are included and models where the curvaton...

  6. Axions as hot and cold dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Kwang Sik [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Kawasaki, Masahiro [Tokyo Univ., Kashiwa (Japan). Inst. for Cosmic Ray Research; Tokyo Univ., Kashiwa (Japan). Kavli IPMU, TODIAS; Takahashi, Fuminobu [Tohoku Univ., Sendai (Japan). Dept. of Physics; Tokyo Univ., Kashiwa (Japan). Kavli IPMU, TODIAS

    2013-10-15

    The presence of a hot dark matter component has been hinted at 3{sigma} by a combination of the results from different cosmological observations. We examine a possibility that pseudo Nambu- Goldstone bosons account for both hot and cold dark matter components. We show that the QCD axions can do the job for the axion decay constant f{sub a}axions, pseudo Nambu-Goldstone bosons coupled to the standard model sector through the Higgs portal, and axions produced by modulus decay.

  7. Dark-matter QCD-axion searches.

    Science.gov (United States)

    Rosenberg, Leslie J

    2015-10-01

    In the late 20th century, cosmology became a precision science. Now, at the beginning of the next century, the parameters describing how our universe evolved from the Big Bang are generally known to a few percent. One key parameter is the total mass density of the universe. Normal matter constitutes only a small fraction of the total mass density. Observations suggest this additional mass, the dark matter, is cold (that is, moving nonrelativistically in the early universe) and interacts feebly if at all with normal matter and radiation. There's no known such elementary particle, so the strong presumption is the dark matter consists of particle relics of a new kind left over from the Big Bang. One of the most important questions in science is the nature of this dark matter. One attractive particle dark-matter candidate is the axion. The axion is a hypothetical elementary particle arising in a simple and elegant extension to the standard model of particle physics that nulls otherwise observable CP-violating effects (where CP is the product of charge reversal C and parity inversion P) in quantum chromo dynamics (QCD). A light axion of mass 10(-(6-3)) eV (the invisible axion) would couple extraordinarily weakly to normal matter and radiation and would therefore be extremely difficult to detect in the laboratory. However, such an axion is a compelling dark-matter candidate and is therefore a target of a number of searches. Compared with other particle dark-matter candidates, the plausible range of axion dark-matter couplings and masses is narrowly constrained. This focused search range allows for definitive searches, where a nonobservation would seriously impugn the dark-matter QCD-axion hypothesis. Axion searches use a wide range of technologies, and the experiment sensitivities are now reaching likely dark-matter axion couplings and masses. This article is a selective overview of the current generation of sensitive axion searches. Not all techniques and experiments

  8. Dark-matter QCD-axion searches.

    Science.gov (United States)

    Rosenberg, Leslie J

    2015-10-01

    In the late 20th century, cosmology became a precision science. Now, at the beginning of the next century, the parameters describing how our universe evolved from the Big Bang are generally known to a few percent. One key parameter is the total mass density of the universe. Normal matter constitutes only a small fraction of the total mass density. Observations suggest this additional mass, the dark matter, is cold (that is, moving nonrelativistically in the early universe) and interacts feebly if at all with normal matter and radiation. There's no known such elementary particle, so the strong presumption is the dark matter consists of particle relics of a new kind left over from the Big Bang. One of the most important questions in science is the nature of this dark matter. One attractive particle dark-matter candidate is the axion. The axion is a hypothetical elementary particle arising in a simple and elegant extension to the standard model of particle physics that nulls otherwise observable CP-violating effects (where CP is the product of charge reversal C and parity inversion P) in quantum chromo dynamics (QCD). A light axion of mass 10(-(6-3)) eV (the invisible axion) would couple extraordinarily weakly to normal matter and radiation and would therefore be extremely difficult to detect in the laboratory. However, such an axion is a compelling dark-matter candidate and is therefore a target of a number of searches. Compared with other particle dark-matter candidates, the plausible range of axion dark-matter couplings and masses is narrowly constrained. This focused search range allows for definitive searches, where a nonobservation would seriously impugn the dark-matter QCD-axion hypothesis. Axion searches use a wide range of technologies, and the experiment sensitivities are now reaching likely dark-matter axion couplings and masses. This article is a selective overview of the current generation of sensitive axion searches. Not all techniques and experiments

  9. CERN Shuttle

    CERN Multimedia

    General Infrastructure Services Department

    2011-01-01

    As of Monday 21 February, a new schedule will come into effect for the Airport Shuttle (circuit No. 4) at the end of the afternoon: Last departure at 7:00 pm from Main Buildig, (Bldg. 500) to Airport (instead of 5:10 p.m.); Last departure from Airport to CERN, Main Buildig, (Bldg. 500), at 7:30 p.m. (instead of 5:40 p.m.). Group GS-IS

  10. Gravity wave and model-independent axion

    CERN Document Server

    Kim, Jihn E

    2016-01-01

    In this short comment, we notice that the model-independent axion contribution to the graviton mass at just outside the Schwarzschild radius is completely negligible in GW150914. The model-independent axion contribution to the graviton mass at the order $10^{-22}\\,$eV might be possible for merger of black holes of mass of order $2\\times 10^{14}\\,$kg.

  11. Axion Research at CAPP/IBS

    Science.gov (United States)

    Youn, Sungwoo

    2016-07-01

    The axion, a hypothetical fundamental particle, was postulated as an attractive solution to the CP problem in quantum chromodynamics and believed to be an ideal candidate for the cold dark matter. The Center for Axion and Precision Physics Research of the Institute for Basic Science has launched a state of the art experiment to search for the hypothesised new particle using microwave resonant cavities. I will discuss R&D efforts at our center and plans for the experiment.

  12. Planckian Axions and the Weak Gravity Conjecture

    CERN Document Server

    Bachlechner, Thomas C; McAllister, Liam

    2015-01-01

    Several recent works have claimed that the Weak Gravity Conjecture (WGC) excludes super-Planckian displacements of axion fields, and hence large-field axion inflation, in the absence of monodromy. We argue that in theories with $N\\gg1$ axions, super-Planckian axion diameters $\\cal{D}$ are readily allowed by the WGC. We clarify the nontrivial relationship between the kinetic matrix $K$ --- unambiguously defined by its form in a Minkowski-reduced basis --- and the diameter of the axion fundamental domain, emphasizing that in general the diameter is not solely determined by the eigenvalues $f_1^2 \\le ... \\le f_N^2$ of $K$: the orientations of the eigenvectors with respect to the identifications imposed by instantons must be incorporated. In particular, even if one were to impose the condition $f_NM_{pl}$ does not immediately imply the existence of unsuppressed higher harmonic contributions to the potential. Finally, we argue that in effective axion-gravity theories, the zero-form version of the WGC can be satisf...

  13. Black hole formation from axion stars

    CERN Document Server

    Helfer, Thomas; Clough, Katy; Fairbairn, Malcolm; Lim, Eugene A; Becerril, Ricardo

    2016-01-01

    The classical equations of motion for an axion with potential $V(\\phi)=m_a^2f_a^2 [1-\\cos (\\phi/f_a)]$ possess quasi-stable, localized, oscillating solutions, which we refer to as "axion stars". We study, for the first time, collapse of axion stars numerically using the full non-linear Einstein equations of general relativity and the full non-perturbative cosine potential. We map regions on an "axion star stability diagram", parameterized by the initial ADM mass, $M_{\\rm ADM}$, and axion decay constant, $f_a$. We identify three regions of the parameter space: i) long-lived oscillating axion star solutions, with a base frequency, $m_a$, modulated by self-interactions, ii) collapse to a BH and iii) complete dispersal due to gravitational cooling and interactions. We locate the boundaries of these three regions and an approximate "triple point" $(M_{\\rm TP},f_{\\rm TP})\\sim (2.4 M_{pl}^2/m_a,0.3 M_{pl})$. For $f_a$ below the triple point BH formation proceeds during winding (in the complex $U(1)$ picture) of the ...

  14. Axion mechanism of Sun luminosity, dark matter and extragalactic background light

    CERN Document Server

    Rusov, V D; Tarasov, V A; Eingorn, M V; Smolyar, V P; Vlasenko, D S; Zelentsova, T N; Linnik, E P; Beglaryan, M E

    2013-01-01

    We show the existence of the strong inverse correlation between the temporal variations of the toroidal component of the magnetic field in the solar tachocline (the bottom of the convective zone) and the Earth magnetic field (the Y-component). The possibility that the hypothetical solar axions, which can transform into photons in external electric or magnetic fields (the inverse Primakoff effect), can be the instrument by which the magnetic field of the Sun convective zone modulates the magnetic field of the Earth is considered. We propose the axion mechanism of Sun luminosity and "solar dynamo -- geodynamo" connection, where the energy of one of the solar axion flux components emitted in M1 transition in 57Fe nuclei is modulated at first by the magnetic field of the solar tachocline zone (due to the inverse coherent Primakoff effect) and after that is resonantly absorbed in the core of the Earth, thereby playing the role of the energy modulator of the Earth magnetic field. Within the framework of this mechan...

  15. Large-scale search for dark-matter axions

    Energy Technology Data Exchange (ETDEWEB)

    Hagmann, C.A., LLNL; Kinion, D.; Stoeffl, W.; Van Bibber, K.; Daw, E.J. [Massachusetts Inst. of Tech., Cambridge, MA (United States); McBride, J. [Massachusetts Inst. of Tech., Cambridge, MA (United States); Peng, H. [Massachusetts Inst. of Tech., Cambridge, MA (United States); Rosenberg, L.J. [Massachusetts Inst. of Tech., Cambridge, MA (United States); Xin, H. [Massachusetts Inst. of Tech., Cambridge, MA (United States); Laveigne, J. [Florida Univ., Gainesville, FL (United States); Sikivie, P. [Florida Univ., Gainesville, FL (United States); Sullivan, N.S. [Florida Univ., Gainesville, FL (United States); Tanner, D.B. [Florida Univ., Gainesville, FL (United States); Moltz, D.M. [Lawrence Berkeley Lab., CA (United States); Powell, J. [Lawrence Berkeley Lab., CA (United States); Clarke, J. [Lawrence Berkeley Lab., CA (United States); Nezrick, F.A. [Fermi National Accelerator Lab., Batavia, IL (United States); Turner, M.S. [Fermi National Accelerator Lab., Batavia, IL (United States); Golubev, N.A. [Russian Academy of Sciences, Moscow (Russia); Kravchuk, L.V. [Russian Academy of Sciences, Moscow (Russia)

    1998-01-01

    Early results from a large-scale search for dark matter axions are presented. In this experiment, axions constituting our dark-matter halo may be resonantly converted to monochromatic microwave photons in a high-Q microwave cavity permeated by a strong magnetic field. Sensitivity at the level of one important axion model (KSVZ) has been demonstrated.

  16. Small field axion inflation with sub-Planckian decay constant

    CERN Document Server

    Kadota, Kenji; Oikawa, Akane; Omoto, Naoya; Otsuka, Hajime; Tatsuishi, Takuya H

    2016-01-01

    We study an axion inflation model recently proposed within the framework of type IIB superstring theory, where we pay a particular attention to a sub-Planckian axion decay constant. Our axion potential can lead to the small field inflation with a small tensor-to-scalar ratio, and a typical reheating temperature can be as low as GeV.

  17. Small field axion inflation with sub-Planckian decay constant

    Science.gov (United States)

    Kadota, Kenji; Kobayashi, Tatsuo; Oikawa, Akane; Omoto, Naoya; Otsuka, Hajime; Tatsuishi, Takuya H.

    2016-10-01

    We study an axion inflation model recently proposed within the framework of type IIB superstring theory, where we pay a particular attention to a sub-Planckian axion decay constant. Our axion potential can lead to the small field inflation with a small tensor-to-scalar ratio, and a typical reheating temperature can be as low as GeV.

  18. CERN moves to http://home.cern

    CERN Multimedia

    2015-01-01

    A new top-level domain for CERN will be inaugurated next week, with the migration of the core website to http://home.cern.   The new home.cern webpage. The .cern top-level domain is intended for the exclusive use of CERN and its affiliates, and will soon be open for applications from within the community. Clear governance mechanisms for registration and management of .cern domains have been put in place. Applications for domains may be submitted by current members of the CERN personnel, and must be sponsored by a CERN entity such as a department, experiment, project or CERN-recognised experiment. For more information please refer to the registration policy. The acquisition of the .cern top-level domain was negotiated via ICANN’s new gTLD programme by a board comprising members of the CERN Legal Service, Communications group and IT department. .cern is one of over 1,300 new top-level domains that will launch over the coming months and years. The .cern domain nam...

  19. UK @ CERN

    CERN Multimedia

    FI Department

    2008-01-01

    17 – 18 November 2008 9.00 a.m. - 5.00 p.m. on Monday 17 November 9.00 a.m. - 5.00 p.m. on Tuesday 18 November Individual meetings will take place in the technicians’ or engineers’ offices. The companies will contact relevant users/technicians but anyone wishing to arrange an appointment with a specific company can contact Caroline Laignel (mailto:caroline.laignel@cern.ch, tel. 73722). A list of the companies is available from all departmental secretariats and on the web at: http://fi-dep.web.cern.ch/fi-dep/structure/memberstates/exhibitions_visits.htm List of companies: 1. Caburn MDC Europe Ltd. 2. Croft Engineering Services 3. Cryox Ltd. 4. Goodfellow Cambridge Ltd. 5. Gravatom Engineering Systems Ltd. 6. High Voltage Technology 7. Lilco Ltd. 8. Micro Metalsmiths Ltd. 9. Photek Ltd. 10. Shadow Robot Company 11. Sundance Multiprocessor Technology Ltd. 12. Tessella plc 13. Thermal Resources Management Ltd. 14. Torr Scientific Ltd. For further information please contact Mrs C. Laignel, FI-DI, tel. 7372...

  20. Response properties of axion insulators and Weyl semimetals driven by screw dislocations and dynamical axion strings

    Science.gov (United States)

    You, Yizhi; Cho, Gil Young; Hughes, Taylor L.

    2016-08-01

    In this paper, we investigate the theory of dynamical axion strings emerging from chiral symmetry breaking in three-dimensional Weyl semimetals. The chiral symmetry is spontaneously broken by a charge density wave (CDW) order which opens an energy gap and converts the Weyl semimetal into an axion insulator. Indeed, the phase fluctuations of the CDW order parameter act as a dynamical axion field θ (x ⃗,t ) and couple to electromagnetic field via Lθ=θ/(x ⃗,t ) 32 π2 ɛσ τ ν μFσ τFν μ. Additionally, when the axion insulator is coupled to deformations of the background geometry/strain fields via torsional defects, e.g., screw dislocations, there is interesting interplay between the crystal dislocations and dynamical axion strings. For example, the screw dislocation traps axial charge, and there is a Berry phase accumulation when an axion string (which carries axial flux) is braided with a screw dislocation. In addition, a cubic coupling between the axial current and the geometry fields is nonvanishing and indicates a Berry phase accumulation during a particular three-loop braiding procedure where a dislocation loop is braided with another dislocation and they are both threaded by an axion string. We also observe a chiral magnetic effect induced by a screw dislocation density in the absence of a nodal energy imbalance between Weyl points and describe an additional chiral geometric effect and a geometric Witten effect.

  1. Axion-dilaton cosmology and dark energy

    Energy Technology Data Exchange (ETDEWEB)

    Catena, R.; Moeller, J.

    2007-09-15

    We discuss a class of flat FRW cosmological models based on D=4 axion-dilaton gravity universally coupled to cosmological background fluids. In particular, we investigate the possibility of recurrent acceleration, which was recently shown to be generically realized in a wide class of axion-dilaton models, but in absence of cosmological background fluids. We observe that, once we impose the existence of radiation - and matter - dominated earlier stages of cosmic evolution, the axion-dilaton dynamics is altered significantly with respect to the case of pure axion-dilaton gravity. During the matter dominated epoch the scalar fields remain either frozen, due to the large expansion rate, or enter a cosmological scaling regime. In both cases, oscillations of the effective equation of state around the acceleration boundary value are impossible. Models which enter an oscillatory stage in the low redshift regime, on the other hand, are disfavored by observations. We also comment on the viability of the axion-dilaton system as a candidate for dynamical dark energy. In a certain subclass of models, an intermediate scaling regime is succeeded by eternal acceleration. We also briefly discuss the issue of dependence on initial conditions. (orig.)

  2. Axion from Quivers in Type II Superstrings

    CERN Document Server

    Belhaj, Adil; del Moral, Maria Pilar Garcia

    2015-01-01

    We investigate a string-inspired axion extension of the standard model obtained from Type II superstrings using quiver method. In the first part, we discuss intersecting Type IIA D6-branes wrapping non trivial 3-cycles in the presence of the Peccei-Quinn symmetry U(1)$_{PQ}$. Concretely, a complex scalar field $\\phi =\\rho exp(\\frac{i\\sigma}{f_{\\sigma}})$, where $\\sigma$ is a closed string axion generates a general fermion Yukawa coupling weighted by a flavor-dependent power $n_{f}$ taking specific values. Using string theory and standard model data, we find that the corresponding axion window is in the allowed range $10^{9}GeV\\leq f_{\\sigma}\\leq 10^{12}GeV $ matching with the recent cosmological results. Then, we extend these results to the case of the hyperbolic quiver whose the moduli is related to the stringy axion using root systems of ADE Lie algebras. For the hyperbolic quiver case, we observe that the closed axion decay constant becomes disentangled from the string scale.

  3. Coupled Boltzmann computation of mixed axion neutralino dark matter in the SUSY DFSZ axion model

    International Nuclear Information System (INIS)

    The supersymmetrized DFSZ axion model is highly motivated not only because it offers solutions to both the gauge hierarchy and strong CP problems, but also because it provides a solution to the SUSY μ-problem which naturally allows for a Little Hierarchy. We compute the expected mixed axion-neutralino dark matter abundance for the SUSY DFSZ axion model in two benchmark cases—a natural SUSY model with a standard neutralino underabundance (SUA) and an mSUGRA/CMSSM model with a standard overabundance (SOA). Our computation implements coupled Boltzmann equations which track the radiation density along with neutralino, axion, axion CO (produced via coherent oscillations), saxion, saxion CO, axino and gravitino densities. In the SUSY DFSZ model, axions, axinos and saxions go through the process of freeze-in—in contrast to freeze-out or out-of-equilibrium production as in the SUSY KSVZ model—resulting in thermal yields which are largely independent of the re-heat temperature. We find the SUA case with suppressed saxion-axion couplings (ξ=0) only admits solutions for PQ breaking scale fa∼< 6× 1012 GeV where the bulk of parameter space tends to be axion-dominated. For SUA with allowed saxion-axion couplings (ξ =1), then fa values up to ∼ 1014 GeV are allowed. For the SOA case, almost all of SUSY DFSZ parameter space is disallowed by a combination of overproduction of dark matter, overproduction of dark radiation or violation of BBN constraints. An exception occurs at very large fa∼ 1015–1016 GeV where large entropy dilution from CO-produced saxions leads to allowed models

  4. Flares as fingerprints of inner solar darkness

    CERN Document Server

    Zioutas, K; Semertzidis, Y; Papaevangelou, T

    2008-01-01

    Xray flares and other much weaker solar brightenings have their roots in magnetized regions. Until now, such a solar Xray emission had been discarded as potential axion signature, as it did not match the expectations of the standard axion model: signal must appear exclusively near disk centre and its analog spectrum must peak at 4.2 keV. We argue how to reconcile model with observation. This work is in support of previous claims about the axion origin of specific solar observations.

  5. Status of the U.S. Dark Matter Axion Search

    Energy Technology Data Exchange (ETDEWEB)

    Hagmann, C.; Asztalos, S.; Daw, E.; Golubev, N.A.; Kinion, D.; Moltz, D.M.; Nezrick, F.; Peng, H.; Powell, J.; Rosenberg, L.J.; Sikivie, P.; Stoeffl, W.; Sullivan, N.S.; Tanner, D.B.; Turner, M.S.; Van Bibber, K.

    2000-10-04

    We describe the status of a sensitive search for halo axions with masses in the {mu}eV range. A tunable large-volume and low-loss microwave cavity is operated at low temperature in a strong magnetic field. Resonant Primakoff conversion of axions into photons takes place when the cavity frequency is matched to the axion mass. No positive signal has been found so far, and we are able to exclude hadronic axions as the dominant halo component over a significant axion mass range. Future plans for a detector upgrade are outlined.

  6. Constraining the Axion Portal with B -> K l+ l-

    CERN Document Server

    Freytsis, Marat; Thaler, Jesse

    2009-01-01

    We investigate the bounds on axion-like states from flavor-changing neutral current b->s decays, assuming the axion couples to the standard model through mixing with the Higgs sector. Such GeV-scale axions have received renewed attention in connection with observed cosmic ray excesses. We find that existing B->K l+ l- data impose stringent bounds on the axion decay constant in the multi-TeV range, relevant for constraining the "axion portal" model of dark matter. Such bounds also constrain light Higgs scenarios in the NMSSM. These bounds can be improved by dedicated searches in B-factory data and at LHCb.

  7. Measuring a piecewise constant axion field in classical electrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Obukhov, Yuri N. [Institute for Theoretical Physics, University of Cologne, 50923 Cologne (Germany)]. E-mail: yo@thp.uni-koeln.de; Hehl, Friedrich W. [Institute for Theoretical Physics, University of Cologne, 50923 Cologne (Germany)

    2005-06-27

    In order to settle the problem of the 'Post constraint' in material media, we consider the propagation of a plane electromagnetic wave in a medium with a piecewise constant axion field. Although a constant axion field does not affect the wave propagation in a homogeneous medium, we show that the reflection and transmission of a wave at an interface between the two media is sensitive to the difference of the axion values. This observation can be used to determine experimentally the axion piece in matter despite the fact that a constant axion value does not contribute to the Maxwell equations.

  8. Measuring a piecewise constant axion field in classical electrodynamics

    CERN Document Server

    Obukhov, Yu N; Obukhov, Yuri N.; Hehl, Friedrich W.

    2005-01-01

    In order to settle the problem of the "Post constraint" in material media, we consider the propagation of a plane electromagnetic wave in a medium with a piecewise constant axion field. Although a constant axion field does not affect the wave propagation in a homogeneous medium, we show that the reflection and transmission of a wave at an interface between the two media is sensitive to the difference of the axion values. This observation can be used to determine experimentally the axion piece in matter despite the fact that a constant axion value does not contribute to the Maxwell equations.

  9. Dynamical Axion String, Torsion Defects in Axion Insulator and Weyl Semimetals

    CERN Document Server

    You, Yizhi; Hughes, Taylor L

    2016-01-01

    In this paper, we investigate the theory of dynamical axion string emerging from chiral symmetry breaking in three-dimensional Weyl semimetals. The chiral symmetry is spontaneously broken by a charge density wave (CDW) order which opens an energy gap and converts the Weyl semimetal into an axion insulator. Indeed, the phase fluctuations of the CDW order parameter act as a dynamical axion field $\\theta({\\vec{x}},t)$ and couples to electromagnetic field via $\\mathcal{L}_{\\theta}=\\frac{\\theta(\\vec{x},t)}{32\\pi^2} \\epsilon^{\\sigma\\tau\

  10. Axionic suppression of plasma wakefield acceleration

    Science.gov (United States)

    Burton, D. A.; Noble, A.; Walton, T. J.

    2016-09-01

    Contemporary attempts to explain the existence of ultra-high energy cosmic rays using plasma-based wakefield acceleration deliberately avoid non-standard model particle physics. However, such proposals exploit some of the most extreme environments in the Universe and it is conceivable that hypothetical particles outside the standard model have significant implications for the effectiveness of the acceleration process. Axions solve the strong CP problem and provide one of the most important candidates for cold dark matter, and their potential significance in the present context should not be overlooked. Our analysis of the field equations describing a plasma augmented with axions uncovers a dramatic axion-induced suppression of the energy gained by a test particle in the wakefield driven by a particle bunch, or an intense pulse of electromagnetic radiation, propagating at ultra-relativistic speeds within the strongest magnetic fields in the Universe.

  11. Astrophysical axion bounds diminished by screening effects

    International Nuclear Information System (INIS)

    ''Invisible axions'' could be produced in stellar interiors through Compton- and Primakoff-type photoproduction and through bremsstrahlung processes. We point out that in a plasma screening effects lead to important reductions of these emission rates. Limits on the axion mass and interaction strength are thereby relaxed to values less restrictive than limits previously thought to be firm. For the case of the Sun the Primakoff rate is reduced by two orders of magnitude. This process is the dominant emission mechanism for Kim-Shifman-Vainshtein-Zakharov- (KSVZ) type axions which do not couple directly to electrons. The mass limit is then relaxed by an order of magnitude to m/sub a/2β of the model equals unity. Our results can be easily translated to other hypothetical pseudoscalar particles if they are light compared with typical stellar temperatures

  12. Axion Stars and Fast Radio Bursts

    CERN Document Server

    Iwazaki, A

    2014-01-01

    We show that fast radio bursts arise from collisions between axion stars and neutron stars. The bursts are emitted in the atmosphere of the neutron stars. The observed frequencies of the bursts are given by the axion mass $m_a$ such as $m_a/2\\pi\\simeq 1.4\\,\\mbox{GHz}\\,\\big(m_a/(6\\times 10^{-6}\\mbox{eV})\\big)$. From the event rate $\\sim 10^{-3}$ per year in a galaxy, we can determine the mass $\\sim 10^{-11}M_{\\odot}$ of the axion stars. Using these values we can explain short durations ( $\\sim $ms ) and amount of radiation energies ( $\\sim 10^{43}$GeV ) of the bursts.

  13. Cosmological Perturbations of Axion with a Dynamical Decay Constant

    CERN Document Server

    Kobayashi, Takeshi

    2016-01-01

    A QCD axion with a time-dependent decay constant has been known to be able to accommodate high-scale inflation without producing topological defects or too large isocurvature perturbations on CMB scales. We point out that a dynamical decay constant also has the effect of enhancing the small-scale axion isocurvature perturbations. The enhanced axion perturbations can even exceed the periodicity of the axion potential, and thus lead to the formation of axionic domain walls. Unlike the well-studied axionic walls, the walls produced from the enhanced perturbations are not bounded by cosmic strings, and thus would overclose the universe independently of the number of degenerate vacua along the axion potential.

  14. Cosmological perturbations of axion with a dynamical decay constant

    Science.gov (United States)

    Kobayashi, Takeshi; Takahashi, Fuminobu

    2016-08-01

    A QCD axion with a time-dependent decay constant has been known to be able to accommodate high-scale inflation without producing topological defects or too large isocurvature perturbations on CMB scales. We point out that a dynamical decay constant also has the effect of enhancing the small-scale axion isocurvature perturbations. The enhanced axion perturbations can even exceed the periodicity of the axion potential, and thus lead to the formation of axionic domain walls. Unlike the well-studied axionic walls, the walls produced from the enhanced perturbations are not bounded by cosmic strings, and thus would overclose the universe independently of the number of degenerate vacua along the axion potential.

  15. CAST constraints on the axion-electron coupling

    CERN Document Server

    Barth, K; Beltran, B; Bräuninger, H; Carmona, J M; Collar, J I; Dafni, T; Davenport, M; Di Lella, L; Eleftheriadis, C; Englhauser, J; Fanourakis, G; Ferrer-Ribas, E; Fischer, H; Franz, J; Friedrich, P; Galan, J; Garcia, J A; Geralis, T; Giomataris, I; Gninenko, S; Gomez, H; Hasinoff, M D; Heinsius, F H; Hoffmann, D H H; Irastorza, I G; Jacoby, J; Jakovcic, K; Kang, D; Königsmann, K; Kotthaus, R; Kousouris, K; Krcmar, M; Kuster, M; Lakic, B; Liolios, A; Ljubicic, A; Lutz, G; Luzon, G; Miller, D W; Papaevangelou, T; Pivovaroff, M J; Raffelt, G; Redondo, J; Riege, H; Rodriguez, A; Ruz, J; Savvidis, I; Semertzidis, Y; Stewart, L; Van Bibber, K; Vieira, J D; Villar, J A; Vogel, J K; Walckiers, L; Zioutas, K

    2013-01-01

    In non-hadronic axion models, which have a tree-level axion-electron interaction, the Sun produces a strong axion flux by bremsstrahlung, Compton scattering, and axio-recombination, the "BCA processes." Based on a new calculation of this flux, including for the first time axio-recombination, we derive limits on the axion-electron Yukawa coupling g_ae and axion-photon interaction strength g_ag using the CAST phase-I data (vacuum phase). For m_a < 10 meV/c2 we find g_ag x g_ae< 8.1 x 10^-23 GeV^-1 at 95% CL. We stress that a next-generation axion helioscope such as the proposed IAXO could push this sensitivity into a range beyond stellar energy-loss limits and test the hypothesis that white-dwarf cooling is dominated by axion emission.

  16. Drifting oscillations in axion monodromy

    Energy Technology Data Exchange (ETDEWEB)

    Flauger, Raphael [Pittsburgh Univ., PA (United States). Dept. of Physics; McAllister, Liam [Cornell Univ., Ithaca, NY (United States). Dept. of Physics; Silverstein, Eva [Cornell Univ., Ithaca, NY (United States). Dept. of Physics; Stanford National Accelerator Laboratory, Menlo Park, CA (United States); Kavli Institute for Particle Astrophysics and Cosmology, Stanford, CA (United States); Westphal, Alexander [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2014-12-15

    We study the pattern of oscillations in the primordial power spectrum in axion monodromy inflation, accounting for drifts in the oscillation period that can be important for comparing to cosmological data. In these models the potential energy has a monomial form over a super-Planckian field range, with superimposed modulations whose size is model-dependent. The amplitude and frequency of the modulations are set by the expectation values of moduli fields. We show that during the course of inflation, the diminishing energy density can induce slow adjustments of the moduli, changing the modulations. We provide templates capturing the effects of drifting moduli, as well as drifts arising in effective field theory models based on softly broken discrete shift symmetries, and we estimate the precision required to detect a drifting period. A non-drifting template suffices over a wide range of parameters, but for the highest frequencies of interest, or for sufficiently strong drift, it is necessary to include parameters characterizing the change in frequency over the e-folds visible in the CMB. We use these templates to perform a preliminary search for drifting oscillations in a part of the parameter space in the Planck nominal mission data.

  17. Drifting oscillations in axion monodromy

    International Nuclear Information System (INIS)

    We study the pattern of oscillations in the primordial power spectrum in axion monodromy inflation, accounting for drifts in the oscillation period that can be important for comparing to cosmological data. In these models the potential energy has a monomial form over a super-Planckian field range, with superimposed modulations whose size is model-dependent. The amplitude and frequency of the modulations are set by the expectation values of moduli fields. We show that during the course of inflation, the diminishing energy density can induce slow adjustments of the moduli, changing the modulations. We provide templates capturing the effects of drifting moduli, as well as drifts arising in effective field theory models based on softly broken discrete shift symmetries, and we estimate the precision required to detect a drifting period. A non-drifting template suffices over a wide range of parameters, but for the highest frequencies of interest, or for sufficiently strong drift, it is necessary to include parameters characterizing the change in frequency over the e-folds visible in the CMB. We use these templates to perform a preliminary search for drifting oscillations in a part of the parameter space in the Planck nominal mission data.

  18. Non-Gaussianity from Axion Monodromy Inflation

    DEFF Research Database (Denmark)

    Hannestad, Steen; Haugboelle, Troels; R. Jarnhus, Philip;

    2010-01-01

    We study the primordial non-Gaussinity predicted from simple models of inflation with a linear potential and superimposed oscillations. This generic form of the potential is predicted by the axion monodromy inflation model, that has recently been proposed as a possible realization of chaotic...... inflation in string theory, where the monodromy from wrapped branes extends the range of the closed string axions to beyond the Planck scale. The superimposed oscillations in the potential can lead to new signatures in the CMB spectrum and bispectrum. In particular the bispectrum will have a new distinct...

  19. This way for the new CERN visits!

    CERN Multimedia

    2008-01-01

    As the LHC start-up draws near, visits to the underground experiments by members of the public are no longer possible. Still, that doesn’t mean that there will be no more CERN visits. Far from it! Three new itineraries for visits to the above-ground facilities are already available to visitors. Follow the guide… CAST: How a magnet became a telescope. Hunting axions from the sun. Visitors to the CAST experiments will see, among other things, how a prototype dipole magnet built for the LHC has been turned into an unusual telescope that tracks the sun in search of the ‘axion’ particle postulated by theory. SM18: Super-cool magnets. This strategic building, where thousands of superconducting magnets for the LHC were assembled in their cryostats and tested, lets visitors into the secret world of magnet technology, radio frequency and cryogenics, ...

  20. Bienvenue au CERN !

    CERN Multimedia

    CERN Press Office. Geneva

    1998-01-01

    CERN, the Laboratory which invented the World-Wide Web has re-invented its public Web site. The new face of CERN has gone live at http://www.cern.ch/ Public . CERN's new Web pages have been designed to give visitors an informative introduction to the fascinating world of particle physics. For those whose whirl around the Web only allows a short stop, there's the 'CERN in two minutes' page.

  1. UK @ CERN

    CERN Multimedia

    FI Department

    2008-01-01

    17 – 18 November 2008 9.00 a.m. - 5.00 p.m. on Monday 17 November 9.00 a.m. - 5.00 p.m. on Tuesday 18 November Individual meetings will take place in the technicians’ or engineers’ offices. The companies will contact relevant users/technicians but anyone wishing to arrange an appointment with a specific company can contact Caroline Laignel (caroline.laignel@cern.ch, tel. 73722). A list of the companies is available from all departmental secretariats and on the web here. List of companies: 1. Caburn MDC Europe Ltd. 2. Croft Engineering Services 3. Cryox Ltd. 4. Goodfellow Cambridge Ltd. 5. Gravatom Engineering Systems Ltd. 6. High Voltage Technology 7. Lilco Ltd. 8. Micro Metalsmiths Ltd. 9. Photek Ltd. 10. Shadow Robot Company 11. Sundance Multiprocessor Technology Ltd. 12. Tessella plc 13. Thermal Resources Management Ltd. 14. Torr Scientific Ltd. For further information please contact Mrs C. Laignel, FI-DI, tel. 73722.

  2. CERN: Fixed target targets

    International Nuclear Information System (INIS)

    visible for the first time, and help explain the continuing dilemma of the dearth of solar neutrinos (December 1992, page 12). For the longer term future, a larger detector could provide an increased yield, boosting the neutrino capture rate by up to a factor of ten. Other, more spectacular, option is to shine the CERN neutrino beam towards a detector a long way off. Such a beam is practically unimpeded by matter and could pass right through the earth. Possible contenders for underground target stations equipped with big detectors are the Italian Gran Sasso laboratory, 730 kilometres south, or Superkamiokande, 8750 kilometres away in Japan. Other major ongoing 'flagship' SPS projects include the NA48 experiment to continue precision measurements on the still unexplained phenomenon of CP violation (March 1992, page 7) and the 'Spin Muon Collaboration' looking to probe the spin structure of the proton and the neutron using high energy muon beams (April 1992, page 21). Both these experiments address important physics issues. While SMC is already taking data, NA48 will not become operational until 1995, but should run then for more than three years. Elsewhere at the SPS, ongoing studies include a programme using hyperon beams, and a study of beauty particles (WA92) which would be hampered once the new neutrino programme starts. The spectroscopy of particles containing light quarks, although far from having solved all outstanding questions, is slowly coming to the end of its SPS career. The WA91 glueball search at the big Omega detector will continue taking data in 1994. The GAMS experiment took its final CERN data last year. One of the long-standing examples of CERN-Russian collaboration, GAMS earned its acronym from the Russian abbreviation for its characteristic large lead-glass arrays. GAMS experiments have run both at CERN and at Serpukhov's Institute for High Energy Physics near Moscow

  3. Heavy axion in asymptotically safe QCD

    CERN Document Server

    Kobakhidze, Archil

    2016-01-01

    Assuming QCD exhibits an interacting fixed-point behaviour in the ultraviolet regime, I argue that the axion can be substantially heavier than in the conventional case of asymptotically free QCD due to the enhanced contribution of small size instantons to its mass.

  4. Axions and the white dwarf luminosity function

    CERN Document Server

    Isern, J; García-Berro, E; Torres, S

    2008-01-01

    The evolution of white dwarfs can be described as a simple cooling process. Recently, it has been possible to determine with an unprecedented precision their luminosity function, that is, the number of stars per unit volume and luminosity interval. Since the shape of the bright branch of this function is only sensitive to the average cooling rate, we use this property to check the possible existence of axions, a proposed but not yet detected weakly interacting particle. We show here that the inclusion of the axion emissivity in the evolutionary models of white dwarfs noticeably improves the agreement between the theoretical calculations and the observational white dwarf luminosity function, thus providing the first positive indication that axions could exist. Our results indicate that the best fit is obtained for m_a cos^2beta ~ 2-6 meV, where m_a is the mass of the axion and cos^2beta is a free parameter, and that values larger than 10 meV are clearly excluded.

  5. Cosmic strings in axionic-dilatonic gravity

    Science.gov (United States)

    Santos, Caroline

    2001-05-01

    We first consider local cosmic strings in dilaton-axion gravity and show that they are singular solutions. Then we take a supermassive Higgs limit and present expressions for the fields at far distances from the core by applying a Pecci-Quinn and a duality transformation to the dilatonic Melvin's magnetic universe.

  6. Cosmic strings in axionic-dilatonic gravity

    CERN Document Server

    Santos, C

    2001-01-01

    We first consider local cosmic strings in dilaton-axion gravity and show that they are singular solutions. Then we take a supermassive Higgs limit and present expressions for the fields at far distances from the core by applying a Pecci-Quinn and a duality transformation to the dilatonic Melvin's magnetic universe.

  7. Axion Dark Matter Detection with Cold Molecules

    CERN Document Server

    Graham, Peter W

    2011-01-01

    Current techniques cannot detect axion dark matter over much of its parameter space, particularly in the theoretically well-motivated region where the axion decay constant f_a lies near the GUT and Planck scales. We suggest a novel experimental method to search for QCD axion dark matter in this region. The axion field oscillates at a frequency equal to its mass when it is a component of dark matter. These oscillations induce time varying CP-odd nuclear moments, such as electric dipole and Schiff moments. The coupling between internal atomic fields and these nuclear moments gives rise to time varying shifts to atomic energy levels. These effects can be enhanced by using elements with large Schiff moments such as the light Actinides, and states with large spontaneous parity violation, such as molecules in a background electric field. The energy level shift in such a molecule can be ~ 10^-24 eV or larger. While challenging, this energy shift may be observable in a molecular clock configuration with technology pr...

  8. Cavity Microwave Searches for Cosmological Axions

    Energy Technology Data Exchange (ETDEWEB)

    Carosi, G; van Bibber, K

    2007-01-22

    This chapter will cover the search for dark matter axions based on microwave cavity experiments proposed by Pierre Sikivie. We will start with a brief overview of halo dark matter and the axion as a candidate. The principle of resonant conversion of axions in an external magnetic field will be described as well as practical considerations in optimizing the experiment as a signal-to-noise problem. A major focus of this chapter will be the two complementary strategies for ultra-low noise detection of the microwave photons--the 'photon-as-wave' approach (i.e. conventional heterojunction amplifiers and soon to be quantum-limited SQUID devices), and 'photon-as-particle' (i.e. Rydberg-atom single-quantum detection). Experimental results will be presented; these experiments have already reached well into the range of sensitivity to exclude plausible axion models, for limited ranges of mass. The section will conclude with a discussion of future plans and challenges for the microwave cavity experiment.

  9. Nucleon-Nucleon Bremsstrahlung emission of massive Axion

    CERN Document Server

    Giannotti, M

    2005-01-01

    We consider the problem of axion production by bremsstrahlung emission in a nuclear medium. The usual assumption of a massless axion is replaced by more general hypotheses, so that we can describe the emission process for axions with mass up to a few MeV. We point out that in certain physical situations the contribution from non-zero mass is non-negligible. In particular, in the mechanism for the production of Gamma Ray Bursts via emission of heavy axions the axion mass m_a ~ 1MeV is comparable with the temperature of the nuclear medium and thus can not be disregarded. Looking at our results we find, in fact, a fairly considerable reduction of the axion luminosity in that mechanism.

  10. Small Instanton Contribution to the Axion Potential in Supersymmetric Models

    OpenAIRE

    Choi, Kiwoon; Kim, Hyungdo

    1998-01-01

    Small size QCD instantons may spoil the axion solution to the strong CP problem if QCD is not asymptotically free at high energy scales. We examine this issue in supersymmetric models using a manifestly supersymmetric scheme to compute the axion potential induced by small size instantons. Applying this scheme for a class of illustrative models, it is found that the resulting high energy axion potential is highly model-dependent, but suppressed by more powers of the soft supersymmetry breaking...

  11. Thermal axion constraints in non-standard thermal histories

    OpenAIRE

    Grin, Daniel; Smith, Tristan; Kamionkowski, Marc

    2010-01-01

    There is no direct evidence for radiation domination prior to big-bang nucleosynthesis, and so it is useful to consider how constraints to thermally-produced axions change in non-standard thermal histories. In the low-temperature-reheating scenario, radiation domination begins at temperatures as low as 1 MeV, and is preceded by significant entropy generation. Axion abundances are then suppressed, and cosmological limits to axions are significantly loosened. In a kination scenario, a more mode...

  12. Accelerating dark-matter axion searches with quantum measurement technology

    OpenAIRE

    Zheng, Huaixiu; Silveri, Matti; Brierley, R. T.; Girvin, S. M.; Lehnert, K. W.

    2016-01-01

    The axion particle, a consequence of an elegant hypothesis that resolves the strong-CP problem of quantum chromodynamics, is a plausible origin for cosmological dark matter. In searches for axionic dark matter that detect the conversion of axions to microwave photons, the quantum noise associated with microwave vacuum fluctuations will soon limit the rate at which parameter space is searched. Here we show that this noise can be partially overcome either by squeezing the quantum vacuum using r...

  13. Hangout with CERN: Welcome to CERN (S01E01)

    CERN Multimedia

    Kahle, Kate

    2012-01-01

    In this first Hangout with CERN "Welcome to CERN" ATLAS physicist Steven Goldfarb, CERN theorist Alvaro De Rujula and Mick Storr from the CERN education group introduce CERN and answer some of the questions received via #askCERN on Twitter and Google+. Recorded live on 1st November 2012.

  14. Doing business with CERN

    CERN Multimedia

    2015-01-01

    The Procurement Service, in collaboration with the Communications group’s Design team, has recently launched a new information campaign targeted at companies wishing to supply their products and services to CERN. This campaign comprises:   A brochure, available in hard and soft copy:  http://procurement.web.cern.ch/brochures/doing-business-with-cern.   A 6-minute video overview: https://procurement-dev.web.cern.ch/doing-business-with-cern. This campaign is intended for Member State firms with whom CERN is yet to do business. The key objectives are: To emphasise that CERN can be considered a major customer across a wide range of activities;   To present CERN’s procurement procedures in a dynamic and digestible way;   To highlight the information available on CERN’s procurement website: http://procurement.web.cern.ch. Furthermore, a new section called “Having a contract with CERN” is also now ava...

  15. Virgin Galactic explores CERN

    CERN Multimedia

    2016-01-01

    Virgin Galactic visited CERN with a group of future astronauts and Sir Richard Branson. During their visit the group was shown around various experiments, including the Globe, SM18, AMS and the CERN Control Centre.

  16. CERN Shop Christmas Sale

    CERN Multimedia

    Visits & Exhibition Service/ETT-VE

    2001-01-01

    11-13.12.2001 Looking for Christmas present ideas? Come to the Reception Shop Special Stand in Meyrin, Main Building, ground floor, from Tuesday 11 to Thursday 13 December from 10.30 to 16.00. CERN Calendar 10.- CERN Sweat-shirts(M, L, XL) 30.- CERN T-shirt (M, L, XL) 20.- New CERN silk tie (2 colours) 35.- Fancy silk tie (blue, bordeau) 25.- Silk scarf (light blue, red, yellow) 35.- Swiss army knife with CERN logo 25.- CERN watch 25.- CERN baseball cap 15.- CERN briefcase 15.- Book 'Antimatter' (English) 35.- Book 'How the web was born' (English) 25.- The Search for Infinity (French, Italian, English, German) 40.-   If you miss this special occasion, the articles are also available at the Reception Shop in Building 33 from Monday to Saturday between 08.30 and 17.30 hrs.

  17. STAX. An Axion-like Particle Search with Microwave Photons

    CERN Document Server

    Ferretti, J

    2016-01-01

    We discuss an improved detection scheme for a light-shining-through-wall (LSW) experiment for axion-like particle searches. We propose to use: gyrotrons or klystrons, which can provide extremely intense photon fluxes at frequencies around 30 GHz; transition-edge-sensors (TES) single photon detectors in this frequency domain, with efficiency $\\approx1$; high quality factor Fabry-Perot cavities in the microwave domain, both on the photon-axion conversion and photon regeneration sides. We compute that present laboratory exclusion limits on axion-like particles might be improved by at least four orders of magnitude for axion masses $\\lesssim 0.02$ meV.

  18. Natural inflation with multiple sub-Planckian axions

    OpenAIRE

    Choi, Kiwoon; Kim, Hyungjin; Yun, Seokhoon

    2014-01-01

    We extend the Kim-Nilles-Peloso (KNP) alignment mechanism for natural inflation to models with $N>2$ axions, which obtains a super-Planckian effective axion decay constant $f_{\\textrm{eff}}\\gg M_{Pl}$ through an alignment of the anomaly coefficients of multiple axions having sub-Planckian fundamental decay constants $f_0\\ll M_{Pl}$. The original version of the KNP mechanism realized with two axions requires that some of the anomaly coefficients should be of the order of $f_{\\textrm{eff}}/f_0$...

  19. Axion cold dark matter in view of BICEP2 results.

    Science.gov (United States)

    Gondolo, Paolo; Visinelli, Luca

    2014-07-01

    The properties of axions that constitute 100% of cold dark matter (CDM) depend on the tensor-to-scalar ratio r at the end of inflation. If r=0.20(-0.05)(+0.07) as reported by the BICEP2 Collaboration, then "half" of the CDM axion parameter space is ruled out. Namely, in the context of single-field slow-roll inflation, for axions to be 100% of the CDM, the Peccei-Quinn symmetry must be broken after the end of inflation, so that axion nonadiabatic primordial fluctuations are compatible with observational constraints. The cosmic axion density is then independent of the tensor-to-scalar ratio r, and the axion mass is expected to be in a narrow range that, however, depends on the cosmological model before primordial nucleosynthesis. In the standard Lambda CDM cosmology, the CDM axion mass range is ma=(71±2  μeV)(αdec+1)6/7, where αdec is the fractional contribution to the cosmic axion density from decays of axionic strings and walls.

  20. Axion star collisions with Neutron stars and Fast Radio Bursts

    CERN Document Server

    Raby, Stuart

    2016-01-01

    Axions may make a significant contribution to the dark matter of the universe. It has been suggested that these dark matter axions may condense into localized clumps, called "axion stars." In this paper we argue that collisions of dilute axion stars with neutron stars may be the origin of most of the observed fast radio bursts. This idea is a variation of an idea originally proposed by Iwazaki. However, instead of the surface effect of Iwazaki, we propose a perhaps stronger volume effect caused by the induced time dependent electric dipole moment of neutrons.

  1. Constraining the Axion Portal with B -> K l+ l-

    OpenAIRE

    Freytsis, Marat; Ligeti, Zoltan; Thaler, Jesse

    2009-01-01

    We investigate the bounds on axionlike states from flavor-changing neutral current b->s decays, assuming the axion couples to the standard model through mixing with the Higgs sector. Such GeV-scale axions have received renewed attention in connection with observed cosmic ray excesses. We find that existing B->K l+ l- data impose stringent bounds on the axion decay constant in the multi-TeV range, relevant for constraining the "axion portal" model of dark matter. Such bounds also constrain lig...

  2. Bose Einstein condensation of the classical axion field in cosmology?

    CERN Document Server

    Davidson, Sacha

    2013-01-01

    The axion is a motivated cold dark matter candidate, which it would be interesting to distinguish from weakly interacting massive particles. Sikivie has suggested that axions could behave differently during non-linear galaxy evolution, if they form a bose einstein condensate. Using classical equations of motion during linear structure formation, we explore whether "gravitational thermalisation" can drive axions to a bose einstein condensate. At linear order in G_N, we interpret that the principle activities of gravity are to expand the Universe and grow density fluctuations. From the anisotropic stress, we estimate a short dissipation scale for axions which does not confirm previous estimates of their gravitational thermalisation rate.

  3. Coupled Boltzmann computation of mixed axion neutralino dark matter in the SUSY DFSZ axion model

    CERN Document Server

    Bae, Kyu Jung; Lessa, Andre; Serce, Hasan

    2014-01-01

    The supersymmetrized DFSZ axion model is highly motivated not only because it offers solutions to both the gauge hierarchy and strong CP problems, but also because it provides a solution to the SUSY mu problem which naturally allows for a Little Hierarchy. We compute the expected mixed axion-neutralino dark matter abundance for the SUSY DFSZ axion model in two benchmark cases-- a natural SUSY model with a standard neutralino underabundance (SUA) and an mSUGRA/CMSSM model with a standard overabundance (SOA). Our computation implements coupled Boltzmann equations which track the radiation density along with neutralino, axion (produced thermally (TH) and via coherent oscillations (CO)), saxion (TH- and CO-produced), axino and gravitino densities. In the SUSY DFSZ model, axions, axinos and saxions go through the process of freeze-in-- in contrast to freeze-out or out-of-equilibrium production as in the SUSY KSVZ model-- resulting in thermal yields which are largely independent of the re-heat temperature. We find ...

  4. Mixed axion/neutralino dark matter in the SUSY DFSZ axion model

    International Nuclear Information System (INIS)

    We examine mixed axion/neutralino cold dark matter production in the SUSY DFSZ axion model where an axion superfield couples to Higgs superfields. We calculate a wide array of axino and saxion decay modes along with their decay temperatures, and thermal and non-thermal production rates. For a SUSY benchmark model with a standard underabundance (SUA) of Higgsino-like dark matter (DM), we find for the PQ scale fa∼<1012 GeV that the DM abundance is mainly comprised of axions as the saxion/axino decay occurs before the standard neutralino freeze-out and thus its abundance remains suppressed. For 1012∼1014 GeV, both neutralino dark matter and dark radiation are typically overproduced. For judicious parameter choices, these can be suppressed and the combined neutralino/axion abundance brought into accord with measured values. A SUSY benchmark model with a standard overabundance (SOA) of bino DM is also examined and typically remains excluded due at least to too great a neutralino DM abundance for fa∼<1015 GeV. For fa∼>1015 GeV and lower saxion masses, large entropy production from saxion decay can dilute all relics and the SOA model can be allowed by all constraints

  5. Greece at CERN

    CERN Multimedia

    CERN Press Office. Geneva

    1997-01-01

    Greece, one of CERN*'s founding Member States, inaugurated its first Industrial Exhibition at the Meyrin site on Tuesday, 14 October. After a meeting with CERN's Director General, Professor Christopher Llewellyn Smith, Professor Emmanuel Frangoulis, the General Secretary of the Greek Ministry of Industry, accompanied by Prof Emmanuel Floratos, Greek delegate to CERN council visited the DELPHI experiment on the LEP collider, guided by Andromachi Tsirou, a Greek physicist.

  6. France at CERN

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Rolf Heuer, CERN Director General, visits the exhibition "La France au CERN". The exhibition France at CERN, organized by UBIFRANCE in collaboration with CERN's GS/SEM (Site Engineering and Management) service, took place from Monday 7 to Wednesday 9 June in the Main Building. The 36 French firms taking part came to present their products and technologies related to the Organization's activities. The next exhibition will be "Netherlands at CERN" in November.

  7. The CERN Library

    CERN Multimedia

    Hester, Alec G

    1968-01-01

    Any advanced research centre needs a good Library. It can be regarded as a piece of equipment as vital as any machine. At the present time, the CERN Library is undergoing a number of modifications to adjust it to the changing scale of CERN's activities and to the ever increasing flood of information. This article, by A.G. Hester, former Editor of CERN COURIER who now works in the Scientific Information Service, describes the purposes, methods and future of the CERN Library.

  8. In the CERN Library

    CERN Multimedia

    1963-01-01

    Seen in this picture is Noria Christophoridou, librarian of the Greek Atomic Energy Commission, who has been sent by her government to CERN for a year to widen her experience of library and documentation services. In the photograph she is providing information to Kurt Gottfried, a CERN visiting scientist from Harvard University, who is spending a year with CERN's Theory Division

  9. 2005 CERN Relay Race

    CERN Document Server

    Patrice Loiez

    2005-01-01

    The CERN Relay Race takes place each year in May and sees participants from all areas of the CERN staff. The winners in 2005 were The Shabbys with Los Latinos Volantes in second and Charmilles Technologies a close third. To add a touch of colour and levity, the CERN Jazz Club provided music at the finishing line.

  10. CERN Photowalk 2015

    CERN Multimedia

    2015-01-01

    CERN is organising a Photowalk on Friday 25 September 2015. At this event a few selected photographers will get the chance to come to CERN, the European Organization for Nuclear Research, for an exclusive behind-the-scenes tour of the laboratory. For more information: http://photowalk2015.web.cern.ch/

  11. A technology developed at CERN captures the sun's energy

    CERN Multimedia

    Alizée Dauvergne

    2010-01-01

    A civil-engineering company has recently started using thermal solar panels based on ultra-high vacuum technology developed at CERN. By efficiently preventing heat loss, the technology allows water to be heated to several hundred degrees, even in a temperate climate.   The field of solar panels using technology developed at CERN. On Tuesday 15 June the Geneva branch of the civil-engineering company Colas opened a new solar power plant based on ultra-high vacuum technology developed at CERN. Measuring a total of 80 square metres, the environmentally friendly "solar field" heats close to 80,000 litres of bitumen to 180 degrees. "To be able to reach such a high temperature, I drew on the ultra-high vacuum technologies I learned about at CERN", explains Cristoforo Benvenuti, who invented the panels. The ultra-high vacuum is what makes these solar panels so innovative. "It's very attractive because it minimises heat loss", continues Benvenuti. &...

  12. Mixed axion-wino dark matter

    Directory of Open Access Journals (Sweden)

    Kyu Jung Bae

    2015-07-01

    Full Text Available A variety of supersymmetric models give rise to a split mass spectrumcharacterized by very heavy scalars but sub-TeV gauginos, usually with awino-like LSP. Such models predict a thermally-produced underabundance ofwino-like WIMP dark matter so that non-thermal DM production mechanisms arenecessary.We examine the case where theories with a wino-like LSP are augmented by aPeccei-Quinn sector including an axion-axino-saxion supermultiplet in either theSUSY KSVZ or SUSY DFSZ models and with/without saxion decays to axions/axinos.We show allowed ranges of PQ breaking scale f_a for various cases which aregenerated by solving the necessary coupled Boltzmann equations.We also present results for a model with radiatively-driven naturalnessbut with a wino-like LSP.

  13. Relativistic axions from collapsing Bose stars

    CERN Document Server

    Levkov, D G; Tkachev, I I

    2016-01-01

    The substructures of light bosonic (axion-like) dark matter may condense into compact Bose stars. We study collapses of the critical-mass stars caused by attractive self-interaction of the axion-like particles and find that these processes proceed in an unexpected universal way. First, nonlinear self-similar evolution (similar to "wave collapse" in plasma physics) forces the particles to fall into the star center. Second, collisions in the dense center create an outgoing stream of mildly relativistic particles which carries away an essential part of the star mass. The collapse stops when the star remnant is no longer able to support the self-similar infall feeding the collisions. We shortly discuss possible astrophysical and cosmological implications of these phenomena.

  14. Large non-gaussianity in axion inflation.

    Science.gov (United States)

    Barnaby, Neil; Peloso, Marco

    2011-05-01

    The inflationary paradigm has enjoyed phenomenological success; however, a compelling particle physics realization is still lacking. Axions are among the best-motivated inflaton candidates, since the flatness of their potential is naturally protected by a shift symmetry. We reconsider the cosmological perturbations in axion inflation, consistently accounting for the coupling to gauge fields cΦFF, which is generically present in these models. This coupling leads to production of gauge quanta, which provide a new source of inflaton fluctuations, δΦ. For c≥10(2)M(p)(-1), these dominate over the vacuum fluctuations, and non-Gaussianity exceeds the current observational bound. This regime is typical for concrete realizations that admit a UV completion; hence, large non-Gaussianity is easily obtained in minimal and natural realizations of inflation.

  15. The Invisible Axion and Neutrino Masses

    CERN Document Server

    Dias, A G; Dias, Alex G.

    2006-01-01

    We show that in any invisible axion model due to the effects of effective non-renormalizable interactions related to an energy scale near the Peccei-Quinn, grand unification or even the Planck scale, active neutrinos necessarily acquire masses in the sub-eV range. Moreover, if sterile neutrinos are also included and if appropriate cyclic $Z_N$ symmetries are imposed, it is possible that some of these neutrinos are heavy while others are light.

  16. Axion topological field theory of topological superconductors

    OpenAIRE

    Qi, Xiao-Liang; Witten, Edward; Zhang, Shou-Cheng

    2012-01-01

    Topological superconductors are gapped superconductors with gapless and topologically robust quasiparticles propagating on the boundary. In this paper, we present a topological field theory description of three-dimensional time-reversal invariant topological superconductors. In our theory the topological superconductor is characterized by a topological coupling between the electromagnetic field and the superconducting phase fluctuation, which has the same form as the coupling of "axions" with...

  17. Collide@CERN Geneva

    CERN Document Server

    CERN. Geneva; Kieffer, Robert; Blas Temino, Diego; Bertolucci, Sergio; Mr. Decelière, Rudy; Mr. Hänni, Vincent

    2014-01-01

    CERN, the Republic and Canton of Geneva, and the City of Geneva are delighted to invite you to “Collide@CERN Geneva Music”. Come to the public lecture about collisions between music and particle physics by the third winners of Collide@CERN Geneva, Vincent Hänni & Rudy Decelière, and their scientific inspiration partners, Diego Blas and Robert Kieffer. The event marks the beginning of their residency at CERN, and will be held at the CERN Globe of Science and Innovation on 16 October 2014 at 19.00. Doors will open at 18.30.

  18. CERN Photo club

    CERN Multimedia

    CERN Photo club

    2016-01-01

    The CERN Photo Club organizes in collaboration with Canon Switzerland a photo contest open to all members of the CERN (Persons with a CERN access card). The only restriction is that the photos must have been taken with a CANON camera (DSLR, bridge or compact) between 1 and 31 October 2016. Send your three best pictures at  Photo.Contest@cern.ch with a short description explaining the images. Further information on the Photo club website: http://photoclub.web.cern.ch/content/photo-contest-october-2016

  19. Britain at CERN

    CERN Multimedia

    CERN Press Office. Geneva

    1996-01-01

    On 8 October, H.E. Mr David Beattie, British Ambassador to Switzerland, Mr John R. Nichols, H.M. Consul-General in Geneva and, Prof. Christopher Llewellyn Smith, CERN*'s Director General, formally opened the industrial exhibition of thirty-three British hi-tech companies at CERN, which takes place from 8 to 11 October, 1996. The exhibition offers British companies the opportunity to display their products in fields that are of immediate importance to the scientists, engineers and technicians working at CERN, and also to scientists from non-Member States who take part in research projects at CERN.

  20. CERN Cricket Club

    CERN Multimedia

    CERN Cricket Club

    2010-01-01

    CERN Cricket Club Match Reports The cricket season is well under way, despite the weather, and several matches have been played. The match reporters have, however, found it too difficult to limit their reports to ¼ of a page, hence the reports have not appeared in the bulletin. All reports can be found at http://cern.ch/Club-Cricket/reports/reports.html The list of forthcoming matches can be consulted at http://cern.ch/Club-Cricket/fixtures.html Further information about the CERN Cricket Club can be found at http://cern.ch/Club-Cricket/

  1. Axion monodromy and the weak gravity conjecture

    Science.gov (United States)

    Hebecker, Arthur; Rompineve, Fabrizio; Westphal, Alexander

    2016-04-01

    Axions with broken discrete shift symmetry (axion monodromy) have recently played a central role both in the discussion of inflation and the `relaxion' approach to the hierarchy problem. We suggest a very minimalist way to constrain such models by the weak gravity conjecture for domain walls: while the electric side of the conjecture is always satisfied if the cosine-oscillations of the axion potential are sufficiently small, the magnetic side imposes a cutoff, Λ3 ˜ mf M pl, independent of the height of these `wiggles'. We compare our approach with the recent related proposal by Ibanez, Montero, Uranga and Valenzuela. We also discuss the non-trivial question which version, if any, of the weak gravity conjecture for domain walls should hold. In particular, we show that string compactifications with branes of different dimensions wrapped on different cycles lead to a `geometric weak gravity conjecture' relating volumes of cycles, norms of corresponding forms and the volume of the compact space. Imposing this `geometric conjecture', e.g. on the basis of the more widely accepted weak gravity conjecture for particles, provides at least some support for the (electric and magnetic) conjecture for domain walls.

  2. Axion Monodromy and the Weak Gravity Conjecture

    CERN Document Server

    Hebecker, Arthur; Westphal, Alexander

    2015-01-01

    Axions with broken discrete shift symmetry (axion monodromy) have recently played a central role both in the discussion of inflation and the `relaxion' approach to the hierarchy problem. We suggest a very minimalist way to constrain such models by the weak gravity conjecture for domain walls: While the electric side of the conjecture is always satisfied if the cosine-oscillations of the axion potential are sufficiently small, the magnetic side imposes a cutoff, $\\Lambda^3 \\sim m f M_{pl}$, independent of the height of these `wiggles'. We compare our approach with the recent related proposal by Ibanez, Montero, Uranga and Valenzuela. We also discuss the non-trivial question which version, if any, of the weak gravity conjecture for domain walls should hold. In particular, we show that string compactifications with branes of different dimensions wrapped on different cycles lead to a `geometric weak gravity conjecture' relating volumes of cycles, norms of corresponding forms and the volume of the compact space. I...

  3. Axion monodromy and the weak gravity conjecture

    Energy Technology Data Exchange (ETDEWEB)

    Hebecker, Arthur; Rompineve, Fabrizio [Heidelberg Univ. (Germany). Inst. for Theoretical Physics; Westphal, Alexander [DESY Hamburg (Germany). Theory Group

    2015-12-15

    Axions with broken discrete shift symmetry (axion monodromy) have recently played a central role both in the discussion of inflation and the 'relaxion' approach to the hierarchy problem. We suggest a very minimalist way to constrain such models by the weak gravity conjecture for domain walls: While the electric side of the conjecture is always satisfied if the cosine-oscillations of the axion potential are sufficiently small, the magnetic side imposes a cutoff, Λ{sup 3}∝mfM{sub pl}, independent of the height of these 'wiggles'. We compare our approach with the recent related proposal by Ibanez, Montero, Uranga and Valenzuela. We also discuss the non-trivial question which version, if any, of the weak gravity conjecture for domain walls should hold. In particular, we show that string compactifications with branes of different dimensions wrapped on different cycles lead to a 'geometric weak gravity conjecture' relating volumes of cycles, norms of corresponding forms and the volume of the compact space. Imposing this 'geometric conjecture', e.g. on the basis of the more widely accepted weak gravity conjecture for particles, provides at least some support for the (electric and magnetic) conjecture for domain walls.

  4. Axion monodromy and the weak gravity conjecture

    International Nuclear Information System (INIS)

    Axions with broken discrete shift symmetry (axion monodromy) have recently played a central role both in the discussion of inflation and the 'relaxion' approach to the hierarchy problem. We suggest a very minimalist way to constrain such models by the weak gravity conjecture for domain walls: While the electric side of the conjecture is always satisfied if the cosine-oscillations of the axion potential are sufficiently small, the magnetic side imposes a cutoff, Λ3∝mfMpl, independent of the height of these 'wiggles'. We compare our approach with the recent related proposal by Ibanez, Montero, Uranga and Valenzuela. We also discuss the non-trivial question which version, if any, of the weak gravity conjecture for domain walls should hold. In particular, we show that string compactifications with branes of different dimensions wrapped on different cycles lead to a 'geometric weak gravity conjecture' relating volumes of cycles, norms of corresponding forms and the volume of the compact space. Imposing this 'geometric conjecture', e.g. on the basis of the more widely accepted weak gravity conjecture for particles, provides at least some support for the (electric and magnetic) conjecture for domain walls.

  5. CERN honours Georges Charpak

    CERN Multimedia

    2009-01-01

    CERN pays tribute to the work of Georges Charpak at a colloquium in honour of his 85th birthday. var flash_video_player=get_video_player_path(); insert_player_for_external('Video/Public/Movies/2009/CERN-MOVIE-2009-008/CERN-MOVIE-2009-008-0753-kbps-480x360-25-fps-audio-64-kbps-44-kHz-stereo', 'mms://mediastream.cern.ch/MediaArchive/Video/Public/Movies/2009/CERN-MOVIE-2009-008/CERN-MOVIE-2009-008-Multirate-200-to-753-kbps-480x360.wmv', 'false', 480, 360, 'https://mediastream.cern.ch/MediaArchive/Video/Public/Movies/2009/CERN-MOVIE-2009-008/CERN-MOVIE-2009-008-posterframe-480x360-at-10-percent.jpg', '1167500', true, 'Video/Public/Movies/2009/CERN-MOVIE-2009-008/CERN-MOVIE-2009-008-0600-kbps-maxH-360-25-fps-audio-128-kbps-48-kHz-stereo.mp4'); Watch the video conference of Georges Charpak.   On 9 March CERN’s Main Auditorium was the venue for a fascinating and moving celebration marking the 85th birthday of Georges Charpak, who was awarded the Nobel Prize for Physics in 1992 for his inven...

  6. CERN Holiday Gift Guide

    CERN Multimedia

    2013-01-01

    Do you have last-minute gifts to get? Stuck for ideas? The CERN Shop and the ATLAS and CMS secretariats have some wonderfully unique gifts and stocking-fillers for sale this year - perfect for the physics fanatics in your life. Let's take a look...   1. CERN Notebook, 10 CHF - 2. CERN Pop-up book, 30 CHF - 3. USB Stick 8GB, 25 CHF - 4. CERN Tumbler, 12 CHF 5. ATLAS 3D Viewer, 5 CHF - 6. ATLAS Puzzle, 15 CHF - 7. CMS Umbrella, 25 CHF   These gifts are all available at the CERN Shop, with the exception of the ATLAS 3D Viewer and the CMS umbrella, which are only available from the respective secretariats. Don’t forget! If you’re from CERN, you still have time to take advantage of a 10% off discount at the CERN shop. Offer ends 20 December.

  7. 3D lumped LC resonators as low mass axion haloscopes

    Science.gov (United States)

    McAllister, Ben T.; Parker, Stephen R.; Tobar, Michael E.

    2016-08-01

    The axion is a hypothetical particle considered to be the most economical solution to the strong C P problem. It can also be formulated as a compelling component of dark matter. The haloscope, a leading axion detection scheme, relies on the conversion of galactic halo axions into real photons inside a resonant cavity structure in the presence of a static magnetic field, where the generated photon frequency corresponds to the mass of the axion. For maximum sensitivity it is key that the central frequency of the cavity mode structure coincides with the frequency of the generated photon. As the mass of the axion is unknown, it is necessary to perform searches over a wide range of frequencies. Currently there are substantial regions of the promising preinflationary low-mass axion range without any viable proposals for experimental searches. We show that three-dimensional resonant LC circuits with separated magnetic and electric fields, commonly known as reentrant cavities, can be sensitive dark matter haloscopes in this region, with frequencies inherently lower than those achievable in the equivalent size of empty resonant cavity. We calculate the sensitivity and accessible axion mass range of these experiments, designing geometries to exploit and maximize the separated magnetic and electric coupling of the axion to the cavity mode.

  8. Cosmological problems with multiple axion-like fields

    Science.gov (United States)

    Mack, Katherine J.; Steinhardt, Paul J.

    2011-05-01

    Incorporating the QCD axion and simultaneously satisfying current constraints on the dark matter density and isocurvature fluctuations requires non-minimal fine-tuning of inflationary parameters or the axion misalignment angle (or both) for Peccei-Quinn symmetry-breaking scales fa > 1012 GeV. To gauge the degree of tuning in models with many axion-like fields at similar symmetry-breaking scales and masses, as may occur in string theoretic models that include a QCD axion, we introduce a figure of merit Script F that measures the fractional volume of allowed parameter space: the product of the slow roll parameter epsilon and each of the axion misalignment angles, θ0. For a single axion, Script Flesssim10-11 is needed to avoid conflict with observations. We show that the fine tuning of Script F becomes exponentially more extreme in the case of numerous axion-like fields. Anthropic arguments are insufficient to explain the fine tuning because the bulk of the anthropically allowed parameter space is observationally ruled out by limits on the cosmic microwave background isocurvature modes. Therefore, this tuning presents a challenge to the compatibility of string-theoretic models with light axions and inflationary cosmology.

  9. Black Hole Mergers and the QCD Axion at Advanced LIGO

    CERN Document Server

    Arvanitaki, Asimina; Dimopoulos, Savas; Dubovsky, Sergei; Lasenby, Robert

    2016-01-01

    In the next few years Advanced LIGO (aLIGO) may see gravitational waves (GWs) from thousands of black hole (BH) mergers. This marks the beginning of a new precision tool for physics. Here we show how to search for new physics beyond the standard model using this tool, in particular the QCD axion in the mass range ma ~ 10^-14 to 10^-10 eV. Axions (or any bosons) in this mass range cause rapidly rotating BHs to shed their spin into a large cloud of axions in atomic Bohr orbits around the BH, through the effect of superradiance. This results in a gap in the mass vs. spin distribution of BHs when the BH size is comparable to the axion's Compton wavelength. By measuring the spin and mass of the merging objects observed at LIGO, we could verify the presence and shape of the gap in the BH distribution produced by the axion. The axion cloud can also be discovered through the GWs it radiates via axion annihilations or level transitions. A blind monochromatic GW search may reveal up to 10^5 BHs radiating through axion ...

  10. Cosmological bounds on sub-MeV mass axions

    DEFF Research Database (Denmark)

    Cadamuro, Davide; Hannestad, Steen; Raffelt, Georg;

    2011-01-01

    V, primarily by the cosmic deuterium abundance: axion decays would strongly modify the baryon-to-photon ratio at BBN relative to the one at CMB decoupling. Additional arguments include neutrino dilution relative to photons by axion decays and spectral CMB distortions. Our new cosmological constraints...

  11. Higgs inflation and suppression of axion isocurvature perturbation

    Energy Technology Data Exchange (ETDEWEB)

    Nakayama, Kazunori, E-mail: kazunori@hep-th.phys.s.u-tokyo.ac.jp [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, UTIAS, University of Tokyo, Kashiwa 277-8583 (Japan); Takimoto, Masahiro [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan)

    2015-09-02

    We point out that cosmological constraint from the axion isocurvature perturbation is relaxed if the Higgs field obtains a large field value during inflation in the DFSZ axion model. This scenario is consistent with the Higgs inflation model, in which two Higgs doublets have non-minimal couplings and play a role of inflaton.

  12. Higgs inflation and suppression of axion isocurvature perturbation

    Directory of Open Access Journals (Sweden)

    Kazunori Nakayama

    2015-09-01

    Full Text Available We point out that cosmological constraint from the axion isocurvature perturbation is relaxed if the Higgs field obtains a large field value during inflation in the DFSZ axion model. This scenario is consistent with the Higgs inflation model, in which two Higgs doublets have non-minimal couplings and play a role of inflaton.

  13. Light-by-light contributions of axion-like particles to lepton dipole moments

    CERN Document Server

    Marciano, W J; Paradisi, P; Passera, M

    2016-01-01

    Contributions of a spin 0 axion-like particle (ALP) to lepton dipole moments, g-2 and EDMs, are examined. Light-by-light loop effects from a light pseudoscalar ALP are found to be capable of resolving the long-standing muon g-2 discrepancy at the expense of relatively large ALP- gamma gamma couplings. The compatibility of such large couplings with direct experimental constraints and perturbative unitarity bounds is discussed. Future tests of such a scenario are described. For CP violating ALP couplings, the electron EDM is found to probe much smaller, theoretically more easily accommodated ALP interactions for mass and coupling parameters that could also be studied by the SHiP (Search for Hidden Particles) proposal at CERN.

  14. Axion Haloscopes with Toroidal Geometry at CAPP/IBS

    CERN Document Server

    Ko, B R

    2016-01-01

    The present state of the art axion haloscope employs a cylindrical resonant cavity in a solenoidal field. We, the Center for Axion and Precision Physics Research (CAPP) of the Institute for Basic Science (IBS) in Korea, are also pursuing halo axion discovery using this cylindrical geometry. However, the presence of end caps of cavities increases challenges as we explore higher frequency regions for the axion at above 2 GHz. To overcome these challenges we exploit a toroidal design of cavity and magnetic field. A toroidal geometry offers several advantages, two of which are a larger volume for a given space and greatly reduced fringe fields which interfere with our preamps, in particular the planned quantum-based devices. We introduce the concept of toroidal axion haloscopes and present ongoing research activities and plans at CAPP/IBS.

  15. A Fresh Look at Axions and SN 1987A

    CERN Document Server

    Keil, W; Schramm, David N; Sigl, G; Turner, M S; Ellis, Jonathan Richard; Keil, Wolfgang; Janka, Hans-Thomas; Schramm, David N.; Sigl, Guenter; Turner, Michael S.; Ellis, John

    1997-01-01

    We re-examine the very stringent limits on the axion mass based on the strength and duration of the neutrino signal from SN 1987A, in the light of new measurements of the axial-vector coupling strength of nucleons, possible suppression of axion emission due to many-body effects, and additional emission processes involving pions. The suppression of axion emission due to nucleon spin fluctuations induced by many-body effects degrades previous limits by a factor of about 2. Emission processes involving thermal pions can strengthen the limits by a factor of 3-4 within a perturbative treatment that neglects saturation of nucleon spin fluctuations. Inclusion of saturation effects, however, tends to make the limits less dependent on pion abundances. The resulting axion mass limit also depends on the precise couplings of the axion and ranges from 0.5x10**(-3) eV to 6x10**(-3) eV.

  16. Possible resonance effect of axionic dark matter in Josephson junctions.

    Science.gov (United States)

    Beck, Christian

    2013-12-01

    We provide theoretical arguments that dark-matter axions from the galactic halo that pass through Earth may generate a small observable signal in resonant S/N/S Josephson junctions. The corresponding interaction process is based on the uniqueness of the gauge-invariant axion Josephson phase angle modulo 2π and is predicted to produce a small Shapiro steplike feature without externally applied microwave radiation when the Josephson frequency resonates with the axion mass. A resonance signal of so far unknown origin observed by C. Hoffmann et al. [Phys. Rev. B 70, 180503(R) (2004)] is consistent with our theory and can be interpreted in terms of an axion mass m(a)c2=0.11  meV and a local galactic axionic dark-matter density of 0.05  GeV/cm3. We discuss future experimental checks to confirm the dark-matter nature of the observed signal.

  17. Weak Gravity Strongly Constrains Large-Field Axion Inflation

    CERN Document Server

    Heidenreich, Ben; Rudelius, Tom

    2015-01-01

    Models of large-field inflation based on axion-like fields with shift symmetries can be simple and natural, and make a promising prediction of detectable primordial gravitational waves. The Weak Gravity Conjecture is known to constrain the simplest case in which a single axion descends from a gauge field in an extra dimension. By supplementing the Weak Gravity Conjecture with considerations of how the mass spectrum of the theory varies across the axion moduli space, we obtain more powerful constraints that apply to a variety of multi-axion theories including N-flation and alignment models. In every case that we consider, plausible assumptions lead to field ranges that cannot be parametrically larger than the Planck scale. Our results are strongly suggestive of a general inconsistency in models of large-field inflation based on axions, and possibly of a more general principle forbidding super-Planckian field ranges.

  18. CERN Table Tennis Club

    CERN Multimedia

    CERN Table Tennis Club

    2014-01-01

    CERN Table Tennis Club Announcing CERN 60th Anniversary Table Tennis Tournament to take place at CERN, from July 1 to July 15, 2014   The CERN Table Tennis Club, reborn in 2008, is encouraging people at CERN to take more regular exercise. This is why the Club, thanks to the strong support of the CERN Staff Association, installed last season a first outdoor table on the terrace of restaurant # 1, and will install another one this season on the terrace of Restaurant # 2. Table tennis provides both physical exercise and friendly social interactions. The CERN Table Tennis club is happy to use the unique opportunity of the 60th CERN anniversary to promote table tennis at CERN, as it is a game that everybody can easily play, regardless of level. Table tennis is particularly well suited for CERN, as many great physicists play table tennis, as you might already know: “Heisenberg could not even bear to lose a game of table tennis”; “Otto Frisch played a lot of table tennis;...

  19. Mixed axion/neutralino dark matter in the SUSY DFSZ axion model

    CERN Document Server

    Bae, Kyu Jung; Chun, Eung Jin

    2013-01-01

    We examine mixed axion/neutralino cold dark matter production in the SUSY DFSZ axion model where an axion superfield couples to Higgs superfields. We calculate a wide array of axino and saxion decay modes along with their decay temperatures, and thermal and non-thermal production rates. For a SUSY benchmark model with a standard underabundance (SUA) of Higgsino-like dark matter (DM), we find for the PQ scale f_a~ 10^{14} GeV, both neutralino dark matter and dark radiation are typically overproduced. For judicious parameter choices, these can be suppressed and the combined neutralino/axion abundance brought into accord with measured values. A SUSY benchmark model with a standard overabundance (SOA) of bino DM is also examined and typically remains excluded due at least to too great a neutralino DM abundance for f_a~ 10^{15} GeV and lower saxion masses, large entropy production from saxion decay can dilute all relics and the SOA model can be allowed by all constraints.

  20. CERN plans global-warming experiment

    CERN Multimedia

    De Laine, M

    1998-01-01

    A controversial theory that proposes that cosmic rays are responsible for global warming, is going to be tested at CERN. Experimentalists will use a cloud chamber to mimic the Earth's atmosphere in order to try and find out if cloud formation is influenced by solar activity (1 page).

  1. Young Artists@ CERN

    CERN Document Server

    2004-01-01

    In view of 50th anniversary of CERN, about 20 young artists will be visiting CERN from 26 to 31 January to learn about the laboratory's research and the mysterious world of particle physics. The impressions they take home will be the main inspiration for the artwork they will then produce for an exhibition to be inaugurated in October 2004 as part of CERN's 50th anniversary celebration. We are looking for scientists who are interested in the Art-Science synergy and who can volunteer to discuss their work at CERN to these young artists during this week (25-31/01). Please contact renilde.vanden.broeck@cern.ch if you are interested. The project is called Young Artists@ CERN and for more information look at this website: http://www.hep.ucl.ac.uk/~andy/CERNart/

  2. CERN and the environment

    CERN Multimedia

    Corinne Pralavorio

    2016-01-01

    New webpages answer common questions about CERN and the environment.   One of the new public webpages dedicated to CERN and the environment. Do your neighbours ever ask you about CERN’s environmental impact? And about radiation in particular? If so, the answers to those questions can now be found online on a new set of public webpages dedicated to CERN and the environment. These pages, put together by the Occupational Health, Safety and Environmental Protection (HSE) unit and the groups responsible for CERN's site maintenance, contain a wealth of information on topics linked to the environment, such as biodiversity at CERN, waste management, ionising radiation, and water and electricity consumption. “CERN forms part of the local landscape, with its numerous sites and scientific activities. It’s understandable that people living nearby have questions about the impact of these activities and it’s important that we respond with complete transp...

  3. German visits to CERN

    CERN Multimedia

    2007-01-01

    State secretary to Germany's Federal Ministry of Education and Research, Frieder Meyer-Krahmer, with CERN's Director-General Robert Aymar.On 21 February, Professor Frieder Meyer-Krahmer, State Secretary to Germany's Federal Ministry of Education and Research, came to CERN. He visited the ALICE and ATLAS experiments and the computing centre before meeting the CERN's Director-General, some German physicists and members of the top management. The Minister of Science, Research and the Arts of the Baden-Württemberg regional government, Peter Frankenberg, and CERN's Director-General, Robert Aymar, signing an agreement on education. In the background: Sigurd Lettow, CERN's Director of Finance and Human Resources, and Karl-Heinz Meisel, Rector of the Fachhochschule Karlsruhe. The Minister of Science, Research and the Arts of the Baden-Württemberg regional government, Prof. Peter Frankenberg, visited CERN on 23 February. He was accompanied by the Rector of the Fachhochschule Karlsruhe, Prof. Karl-Heinz Meisel, and b...

  4. Germany at CERN

    CERN Multimedia

    2005-01-01

    From left to right: Maximilian Metzger, CERN's Secretary-General, Hermann Schunck, Director at the German Federal Ministry of Education and Research, and Robert Aymar, CERN's Director-General, talking to Wolfgang Holler from Butting, one of the companies at the "Germany at CERN" exhibition. Far right : Susanne-Corinna Langer-Greipl from BMBF, delegate to the CERN Finance Committee. For three days, CERN's Main Building was transformed into a showcase for German industry. Twenty-nine companies from sectors related to particle physics (electrical engineering, vacuum and low temperature technology, radiation protection, etc.) were here for the ninth "Germany at CERN" exhibition, organised by the German Federal Ministry of Education and Research (BMBF), which gave them the opportunity to meet scientists and administrators from the Laboratory. On 1 March the exhibition was visited by a German delegation headed by Dr Hermann Schunck, Director at BMBF.

  5. CERN Cricket club

    CERN Multimedia

    CERN Cricket club

    2015-01-01

    The CERN Cricket Club 2015 season begins soon, the first net practice is scheduled (weather permitting) for Thursday April 16th, at 18:00! The club is always looking for new players and newcomers will be made very welcome. Anyone who is interested in joining the club should sign up on our web site: http://cern.ch/Club-Cricket/ or turn up for net practice, which takes place each Thursday evening from April 16th (apart from CERN official holidays) until the end of September (starting at 18:00 to around 19:30) at the CERN Prévessin site: http://club-cricket.web.cern.ch/Club-Cricket/CERN-Ground.html The first match will be at home on Sunday, April 19th against Rhone CC from Lyon.

  6. CERN - better than science fiction!

    CERN Multimedia

    2007-01-01

    From left to right: Allan Cameron (Production Designer), Sam Breckham (Location Manager), James Gillies (Head of Communication at CERN), Jacques Fichet (from the CERN audiovisual service), Rolf Landua (former spokesman of the ATHENA antihydrogen experiment at CERN and Head of CERN's Education Group), Ron Howard, and Renilde Vanden Broeck (CERN press officer).

  7. The CERN PC farm

    CERN Multimedia

    Serge Bellegarde

    2005-01-01

    Housed in the CERN Computer Centre, these banks of computers process and store data produced on the CERN systems. When the LHC starts operation in 2008, it will produce enough data every year to fill a stack of CDs 20 km tall. To handle this huge amount of data, CERN has also developed the Grid, allowing the processing power to be shared between computer centres around the world.

  8. Sharing resources@CERN

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    The library is launching a 'sharing resources@CERN' campaign, aiming to increase the library's utility by including the thousands of books bought by individual groups at CERN. This will improve sharing of information among CERN staff and users. Photo 01: L. to r. Eduardo Aldaz, from the PS division, Corrado Pettenati, Head Librarian, and Isabel Bejar, from the ST division, read their divisional copies of the same book.

  9. CERN Relay Race

    CERN Document Server

    CERN Running Club

    2010-01-01

    The CERN relay race will take place around the Meyrin site on Thursday 20 May, starting at 12.15. If possible, please avoid driving on the site during this 20-minute period. If you do meet runners while driving your car, please STOP until they have all passed. Thank you for your cooperation. Details on the route, and how to register your team for the relay race, can be found at: https://espace.cern.ch/Running-Club/CERN-Relay

  10. Radiation protection at CERN

    OpenAIRE

    Forkel-Wirth, Doris; Roesler, Stefan; Silari, Marco; Streit-Bianchi, Marilena; Theis, Christian; Vincke, Heinz; Vincke, Helmut

    2013-01-01

    This paper gives a brief overview of the general principles of radiation protection legislation; explains radiological quantities and units, including some basic facts about radioactivity and the biological effects of radiation; and gives an overview of the classification of radiological areas at CERN, radiation fields at high-energy accelerators, and the radiation monitoring system used at CERN. A short section addresses the ALARA approach used at CERN.

  11. Britain at CERN

    CERN Multimedia

    2000-01-01

    H. E. Mr Christopher Hulse, Ambassador of United Kingdom in Switzerland, CERN Director General Luciano Maiani, Sir David Wright, Chief Executive of British Trade International and Roger Cashmore, CERN Director of research visit the Britain at CERN exhibition. From 14 to 17 November 30 British companies exhibited leading edge technologies at CERN. This is Britain's 18th exhibition at CERN since 1968. Out of the 30 companies, which attended the Britain at CERN exhibition in 1998, 25 have received an order or a contract relating to CERN during the last two years. The exhibition was inaugurated on Tuesday by Sir David Wright, Chief Executive of British Trade International. He was accompanied by H.E. Mr Christopher Hulse CMG, OBE, Her Majesty's Ambassador to Switzerland, and Mr. David Roberts, Deputy Head of Mission and Director of Trade Promotion at the British Embassy in Bern. CERN Director-General, Professor Luciano Maiani, underlined the major contribution of British physicists to CERN, pointing out the fact ...

  12. Integrity at CERN

    CERN Document Server

    Department, HR

    2015-01-01

    In the fulfillment of its mission, CERN relies upon the trust and material support of its Member States and partners, and is committed to exercising exemplary stewardship of the resources with which it is entrusted. Accordingly, CERN expects the highest level of integrity from all its contributors (whether members of the personnel, consultants, contractors working on site, or persons engaged in any other capacity at or on behalf of CERN). Integrity is a core value of CERN, defined in the Code of Conduct as “behaving ethically, with intellectual honesty and being accountable for one’s own actions”.

  13. Axion mediated photon to dark photon mixing

    CERN Document Server

    Ejlli, Damian

    2016-01-01

    The interaction between dark/mirror sector and ordinary sector is considered, where the two sectors interact with each other by sharing the same QCD axion field. This feature makes possible the mixing between ordinary and dark/mirror photons in ordinary and dark electromagnetic fields. Exact and perturbative solutions of equation of motions describing the evolution of fields in ordinary and dark external magnetic fields are found. User friendly quantities such as transition probability rates, induced phase shifts and angle of rotation of the polarization plane of light are derived. Possible astrophysical and cosmological applications of this mechanism are suggested.

  14. A New Target for Cosmic Axion Searches

    CERN Document Server

    Baumann, Daniel; Wallisch, Benjamin

    2016-01-01

    Future CMB experiments have the potential to probe the density of relativistic species at the sub-percent level. Sensitivity at this level allows light thermal relics to be detected up to arbitrarily high decoupling temperatures. Conversely, the absence of a detection would require extra light species never to have been in equilibrium with the Standard Model. In this paper, we exploit this feature to demonstrate the sensitivity of future cosmological observations to the couplings of axions to all of the Standard Model degrees of freedom. In many cases, the constraints achievable from cosmology will surpass existing bounds from laboratory experiments and astrophysical observations by orders of magnitude.

  15. Electric and magnetic energy at axion haloscopes

    CERN Document Server

    Ko, B R; Jang, W; Choi, J; Kim, D; Lee, M J; Lee, J; Won, E; Semertzidis, Y K

    2016-01-01

    We review a recent letter published in Phys. Rev. Lett. $\\textbf{116}$, 161804 (2016) of which the main argument is that the mode dependent magnetic form factors at axion haloscopes depend on the position of the cavity inside the solenoid while the corresponding electric form factors do not. We, however, find no such dependence, which is also equivalent to the statement that the electric and corresponding magnetic energy stored in the cavity modes are the same regardless of the position of the cavity inside the solenoid. Furthermore, we extend the statement to the cases satisfying $\\vec{\

  16. Modulation sensitive search for nonvirialized dark-matter axions

    Science.gov (United States)

    Hoskins, J.; Crisosto, N.; Gleason, J.; Sikivie, P.; Stern, I.; Sullivan, N. S.; Tanner, D. B.; Boutan, C.; Hotz, M.; Khatiwada, R.; Lyapustin, D.; Malagon, A.; Ottens, R.; Rosenberg, L. J.; Rybka, G.; Sloan, J.; Wagner, A.; Will, D.; Carosi, G.; Carter, D.; Duffy, L. D.; Bradley, R.; Clarke, J.; O'Kelley, S.; van Bibber, K.; Daw, E. J.

    2016-10-01

    Nonvirialized dark-matter axions may be present in the Milky Way halo in the form of low-velocity-dispersion flows. The Axion Dark-Matter eXperiment performed a search for the conversion of these axions into microwave photons using a resonant cavity immersed in a strong, static magnetic field. The spread of photon energy in these measurements was measured at spectral resolutions of the order of 1 Hz and below. If the energy variation were this small, the frequency modulation of any real axion signal due to the orbital and rotational motion of Earth would become non-negligible. Conservative estimates of the expected signal modulation were made and used as a guide for the search procedure. The photon frequencies covered by this search are 812-852 and 858-892 MHz, which correspond to an axion mass of 3.36-3.52 and 3.55 - 3.69 μ eV . No axion signal was found, and limits were placed on the maximum local density of nonvirialized axions of these masses.

  17. CAST constraints on the axion-electron coupling

    Energy Technology Data Exchange (ETDEWEB)

    Barth, K.; Davenport, M.; Lella, L. Di [European Organization for Nuclear Research (CERN), Geneve (Switzerland); Belov, A. [Institute for Nuclear Research (INR), Russian Academy of Sciences, Moscow (Russian Federation); Beltran, B.; Carmona, J.M.; Dafni, T.; Galan, J.; García, J.A. [Laboratorio de Fisica Nuclear y Altas Energias, Universidad de Zaragoza, Zaragoza (Spain); Braeuninger, H.; Englhauser, J.; Friedrich, P. [Max-Planck-Institut fuer extraterrestrische Physik, Garching (Germany); Collar, J.I. [Enrico Fermi Institute and KICP, University of Chicago, Chicago, IL (United States); Eleftheriadis, C. [Aristoteles University of Thessaloniki, Thessaloniki (Greece); Fanourakis, G.; Geralis, T. [National Center for Scientific Research ' ' Demokritos' ' , Athens (Greece); Ferrer-Ribas, E.; Giomataris, I. [IRFU, Centre d' Etudes Nucleaires de Saclay (CEA-Saclay), Gif-sur-Yvette (France); Fischer, H.; Franz, J., E-mail: Jaime.Ruz@cern.ch, E-mail: Julia.Vogel@cern.ch, E-mail: redondo@mpp.mpg.de [Albert-Ludwigs-Universitaet Freiburg, Freiburg (Germany); and others

    2013-05-01

    In non-hadronic axion models, which have a tree-level axion-electron interaction, the Sun produces a strong axion flux by bremsstrahlung, Compton scattering, and axio-recombination, the ''BCA processes.'' Based on a new calculation of this flux, including for the first time axio-recombination, we derive limits on the axion-electron Yukawa coupling g{sub ae} and axion-photon interaction strength g{sub aγ} using the CAST phase-I data (vacuum phase). For m{sub a}∼<10 meV/c{sup 2} we find g{sub aγ} g{sub ae} < 8.1 × 10{sup −23} GeV{sup −1} at 95% CL. We stress that a next-generation axion helioscope such as the proposed IAXO could push this sensitivity into a range beyond stellar energy-loss limits and test the hypothesis that white-dwarf cooling is dominated by axion emission.

  18. Searching for galactic axions through magnetized media: the QUAX proposal

    OpenAIRE

    Barbieri, R.; Braggio, C.; Carugno, G.; Gallo, C. S.; Lombardi, A; Ortolan, A.; Pengo, R.; Ruoso, G.; Speake, C. C.

    2016-01-01

    We present a proposal to search for QCD axions with mass in the 100 $\\mu$eV range, assuming that they make a dominant component of dark matter. Due to the axion-electron spin coupling, their effect is equivalent to the application of an oscillating rf field with frequency and amplitude fixed by the axion mass and coupling respectively. This equivalent magnetic field would produce spin flips in a magnetic sample placed inside a static magnetic field, which determines the resonant interaction a...

  19. Constraining Axion Dark Matter with Big Bang Nucleosynthesis

    OpenAIRE

    Kfir Blum; Raffaele Tito D'Agnolo; Mariangela Lisanti; Benjamin R. Safdi

    2014-01-01

    We show that Big Bang Nucleosynthesis (BBN) significantly constrains axion-like dark matter. The axion acts like an oscillating QCD $\\theta$ angle that redshifts in the early universe, increasing the neutron-proton mass difference at neutron freeze-out. An axion-like particle that couples too strongly to QCD results in the underproduction of 4He during BBN and is thus excluded. The BBN bound overlaps with much of the parameter space that would be covered by proposed searches for time-varying ...

  20. Active galaxies may harbour wormholes if dark matter is axionic

    CERN Document Server

    Dimopoulos, Konstantinos

    2016-01-01

    AGN jets carry helical magnetic fields, which can affect dark matter if the latter is axionic. This preliminary study shows that the nature of the axionic condensate may change and instead of dark matter may behave more like exotic matter, which violates the null energy condition. If the central supermassive black hole of an active galaxy is laced with exotic matter then it may become a wormhole. In general, the presence of exotic matter may affect galaxy formation and galactic dynamics, so this possibility should not be ignored when considering axionic dark matter.

  1. Accelerating dark-matter axion searches with quantum measurement technology

    CERN Document Server

    Zheng, Huaixiu; Brierley, R T; Girvin, S M; Lehnert, K W

    2016-01-01

    The axion particle, a consequence of an elegant hypothesis that resolves the strong-CP problem of quantum chromodynamics, is a plausible origin for cosmological dark matter. In searches for axionic dark matter that detect the conversion of axions to microwave photons, the quantum noise associated with microwave vacuum fluctuations will soon limit the rate at which parameter space is searched. Here we show that this noise can be partially overcome either by squeezing the quantum vacuum using recently developed Josephson parametric devices, or by using superconducting qubits to count microwave photons.

  2. Suppressing the QCD axion abundance by hidden monopoles

    Energy Technology Data Exchange (ETDEWEB)

    Kawasaki, Masahiro [Tokyo Univ., Chiba (Japan). Inst. for Cosmic Ray Research; Tokyo Univ., Chiba (Japan). Kavli IPMU (WPI), UTIAS; Takahashi, Fuminobu [Tokyo Univ., Miyagi (Japan). Dept. of Physics; Tokyo Univ., Chiba (Japan). Kavli IPMU (WPI), UTIAS; Yamada, Masaki [Tokyo Univ., Chiba (Japan). Inst. for Cosmic Ray Research; Tokyo Univ., Chiba (Japan). Kavli IPMU (WPI), UTIAS; DESY Hamburg (Germany)

    2015-11-15

    We study the Witten effect of hidden monopoles on the QCD axion dynamics, and show that its abundance as well as isocurvature perturbations can be significantly suppressed if there is a sufficient amount of hidden monopoles. When the hidden monopoles make up a significant fraction of dark matter, the Witten effect suppresses the abundance of axion with the decay constant smaller than 10{sup 12} GeV. The cosmological domain wall problem of the QCD axion can also be avoided, relaxing the upper bound on the decay constant when the Peccei-Quinn symmetry is spontaneously broken after inflation.

  3. Suppressing the QCD axion abundance by hidden monopoles

    Directory of Open Access Journals (Sweden)

    Masahiro Kawasaki

    2016-02-01

    Full Text Available We study the Witten effect of hidden monopoles on the QCD axion dynamics, and show that its abundance as well as isocurvature perturbations can be significantly suppressed if there is a sufficient amount of hidden monopoles. When the hidden monopoles make up a significant fraction of dark matter, the Witten effect suppresses the abundance of axion with the decay constant smaller than 1012GeV. The cosmological domain wall problem of the QCD axion can also be avoided, relaxing the upper bound on the decay constant when the Peccei–Quinn symmetry is spontaneously broken after inflation.

  4. Axion cyclotron emissivity of magnetized white dwarfs and neutron stars

    OpenAIRE

    Kachelriess, M.; Wilke, C.; Wunner, G.

    1997-01-01

    The energy loss rate of a magnetized electron gas emitting axions a due to the process $e^- \\to e^- +a$ is derived for arbitrary magnetic field strength B. Requiring that for a strongly magnetized neutron star the axion luminosity is smaller than the neutrino luminosity we obtain the bound $g_{ae}\\lsim 10^{-10}$ for the axion electron coupling constant. This limit is considerably weaker than the bound derived earlier by Borisov and Grishina using the same method. Applying a similar argument t...

  5. Magnetic Helicity Generation from the Cosmic Axion Field

    CERN Document Server

    Campanelli, L

    2005-01-01

    The coupling between a primordial magnetic field and the cosmic axion field generates a helical component of the magnetic field around the time in which the axion starts to oscillate. If the energy density of the seed magnetic field is comparable to the energy density of the universe at that time, then the resulting magnetic helicity is about |H_B| \\simeq (10^{-20} G)^2 kpc and remains constant after its generation. As a corollary, we find that the standard properties of the oscillating axion remain unchanged even in the presence of very strong magnetic fields.

  6. Dilution of axion dark radiation by thermal inflation

    CERN Document Server

    Hattori, Hironori; Omoto, Naoya; Seto, Osamu

    2015-01-01

    Axion in the Peccei-Quinn (PQ) mechanism provides a promising solution to the strong CP problem in the standard model of particle physics. Coherently generated PQ scalar fields could dominate the energy density in the early Universe and decay into relativistic axions, which would confront with the current dark radiation constraints. We study the possibility that a thermal inflation driven by a $U(1)$ gauged Higgs field dilutes such axions. A well motivated extra gauged $U(1)$ would be the local $B-L$ symmetry. We also discuss the implication for the case of $U(1)_{B-L}$ and available baryogenesis mechanism in such cosmology.

  7. Dilution of axion dark radiation by thermal inflation

    Science.gov (United States)

    Hattori, Hironori; Kobayashi, Tatsuo; Omoto, Naoya; Seto, Osamu

    2015-07-01

    Axions in the Peccei-Quinn (PQ) mechanism provide a promising solution to the strong C P problem in the standard model of particle physics. Coherently generated PQ scalar fields could dominate the energy density in the early Universe and decay into relativistic axions, which would conflict with the current dark radiation constraints. We study the possibility that a thermal inflation driven by a U (1 ) gauged Higgs field dilutes such axions. A well-motivated extra gauged U (1 ) would be the local B -L symmetry. We also discuss the implication for the case of U (1 )B-L and an available baryogenesis mechanism in such cosmology.

  8. Energy Dissipation of Axionic Boson Stars in Magnetized Conducting Media

    CERN Document Server

    Iwazaki, A

    1999-01-01

    Axions are possible candidates of dark matter in the present Universe. They have been argued to form axionic boson stars. Since they are shown to possess oscillating electric fields in a magnetic field, they loose their energies in magnetized conducting media. We show that colliding with a white dwarf, the axionic boson stars dissipate their energies with the rate being roughly $\\sim 10^{35}$ erg/s. According to recent evaluation of the population of the white dwarfs as candidates of MACHOs, we estimate that the event rate of the collisions is roughly 4 per year in a solid angle $5^{\\circ}\\times 5^{\\circ}$.

  9. Axion Emission from Red Giants and White Dwarfs

    CERN Document Server

    Altherr, Tanguy; Gaztelurrutia, T R

    1994-01-01

    Using thermal field theory methods, we recalculate axion emission from dense plasmas. We study in particular the Primakoff and the bremsstrahlung processes. The Primakoff rate is significantly suppressed at high densities, when the electrons become relativistic. However, the bound on the axion-photon coupling, $G<10^{-10}$ GeV, is unaffected, as it is constrained by the evolution of HB stars, which have low densities. In contradistinction, the same relativistic effects enhance the bremsstrahlung processes. From the red giants and white dwarfs evolution, we obtain a conservative bound on the axion-electron coupling, $g_{ae} < 2\\times 10^{-13}$.

  10. Punctualizaciones del CERN

    CERN Document Server

    2002-01-01

    "Viene de la pagina anterior. Puntualizaciones del CERN. La valoracion que me merece la aprobacion en el Consejo de Ministros el 24 de mayo de un acuerdo de colaboracion entre el MCYT y el CERN para el proyecto de neutrinos al Gran Sasso es positiva" (1 page).

  11. Integration of CERN staff

    CERN Document Server

    1965-01-01

    An example of the integration of CERN staff in the neighbouring communes is provided by the hamlet of Bugnon at St-Genis-Pouilly (Ain), FRance. The CERN installation on the Swiss site are visible on the left in the background. Behind them the Saleve mountain in Haute-Savoie.

  12. UK Mission to CERN

    CERN Multimedia

    2004-01-01

    At the end of June, nine experts from UK industry visited CERN to study techniques for developing distributed computing systems and to look at some specific applications. In a packed three-day programme, almost 40 CERN experts presented a comprehensive survey of achievements.

  13. CERN's Early History Revisited

    CERN Multimedia

    Schopper, Herwig Franz; Krige, Gerhard John

    2005-01-01

    As a member of the group of historians charged to write the history of the founding of CERN, John Krige particularly underlines the important role I.I. Rabi played. The first author, former Director General of CERN add a few comments. S.A. Khan gives precisions about the role played by E. Amaldi and P. Auger; then J. Krige replies

  14. Romanian Visit to CERN

    CERN Multimedia

    2001-01-01

    Romanian Minister for Foreign Affairs, Mr Mircea Dan Geoana, visited CERN on 30 March to discuss collaboration between his country and the Laboratory. Above, Mr Dan Geoana signs the visitors' book in the presence of CERN Director General Luciano Maiani and Mrs Anda Flip, Ambassador and permanent representative of Romania at the United Nations.

  15. CERN openlab Open Day

    CERN Multimedia

    Purcell, Andrew Robert

    2015-01-01

    The CERN openlab Open Day took place on 10 June, 2015. This was the first in a series of annual events at which research and industrial teams from CERN openlab can present their projects, share achievements, and collect feedback from their user communities.

  16. The CERN Accelerator School

    CERN Multimedia

    2016-01-01

    Introduction to accelerator physics This course will take place in Budapest, Hungary, from 2 to 14 October 2016. It is now open for registration and further information can be found at: http://cas.web.cern.ch/cas/Hungary2016/Hungary-advert.html and http://indico.cern.ch/event/532397/.

  17. Child Care at CERN

    CERN Document Server

    CERN, Child Care Initiative

    2008-01-01

    This is a document summarizing a survey of child care needs of CERN staff and users which was performed in February 2008 by the CERN Child Care Initiative. The document presents the analysis of this data. Conclusions on the minimal facilities size are derived and possible funding source at the European Union are discussed.

  18. ESO: The CERN Years

    CERN Multimedia

    Schaeffer, A

    2012-01-01

    In 1970, CERN and ESO signed a collaboration agreement for the construction of the Observatory’s first telescope. That same year, ESO’s Telescope Division and Sky Atlas laboratory settled on the CERN site in Meyrin. Let’s turn back to the beginnings of this lasting and fruitful alliance.

  19. The CERN Resonant Weakly Interacting Sub-eV Particle Search (CROWS)

    CERN Document Server

    Betz, Michael; Gasior, Marek; Thumm, Manfred

    The subject of this thesis is the design, implementation and first results of the ``CERN Resonant WISP Search'' (CROWS) experiment, which probes the existence of Weakly Interacting Sub-eV Particles (WISPs) using microwave techniques. Axion Like Particles and Hidden Sector Photons are two well motivated members of the WISP family. Their existence could reveal the composition of cold dark matter in the universe and explain a large number of astrophysical phenomena. Particularly, the discovery of an axion would solve a long standing issue in the standard model, known as the ``strong CP problem''. Despite their strong theoretical motivation, the hypothetical particles have not been observed in any experiment so far. One way to probe the existence of WISPs is to exploit their interaction with photons in a ``light shining through the wall'' experiment. A laser beam is guided through a strong magnetic field in the ``emitting region'' of the experiment. This provides photons, which can convert into hypothetical Axi...

  20. Lectures for CERN pensioners

    CERN Multimedia

    GS Department

    2009-01-01

    The CERN Medical Service and the Pensioners Association are pleased to invite CERN pensioners to a series of lectures given by professors and specialists from the Teaching Hospitals and the Faculty of Medicine of the University of Geneva on the following topic: PROMOTION OF OPTIMUM BRAIN AGEING The lectures will take place in the Main CERN Auditorium (Building 60) from 2.30 p.m. to 4.30 p.m. on the following dates: Thursday 15 January 2009: Diagnosing and treating Alzheimer’s disease Pr Gabriel GOLD Wednesday 25 February 2009: What is the brain reserve? Speaker’s name to be announced at a later date. The lectures will be given in French, with transparencies in English, and will be followed by a wide-ranging debate with the participants. CERN Medical Service - Pensioners Association - CERN-ESO (GAC-EPA)

  1. Romanian President Visits CERN

    CERN Multimedia

    2001-01-01

    Director General Luciano Maiani watches as Romanian President Ion Iliescu signs the CERN guest book. On Friday the 12th of October, Romanian President Ion Iliescu arrived at CERN and was warmly greeted by Director General Luciano Maiani at the steps of building 500. After initial greetings and a general presentation of the laboratory, President Iliescu and his entourage embarked on a whistle stop tour of the CERN facilities. They visited the CMS magnet assembly hall and civil engineering work where presentations were made by CMS spokesperson Michel Della Negra and the ATLAS Tile Calorimeter where the president was introduced to Romanian physicists working here at CERN. Michel Della Negra explains some of the general principles behind CMS to President Iliescu during his visit last week. The Romanian teams working on CERN projects make very visible contributions, for example to the construction of the ATLAS experiment and to the preparation of its eventual scientific exploitation. 'Those of us on the ATLAS ...

  2. CERN in the park

    CERN Multimedia

    2002-01-01

    CERN will be the centre of debate at a 'Café scientifique' on Monday 29 April. The aim of the Cafés scientifiques, which are organised by the association of Bancs Publics, is to kindle discussion between ordinary people and specialists in a scientific field. This Monday, Maurice Bourquin, President of the CERN Council, Hans Hoffmann, Director of Technology Transfer and Scientific Computing at CERN, Gilbert Guignard, a physicist at CERN, and Ruhal Floris, who teaches mathematical didactics at the University of Geneva, will explain the usefulness and contributions to science of the world's biggest laboratory for particle physics. What is CERN for? Monday 29 April at 18.30 Musée d'histoire des sciences, Geneva (in the park Perle du Lac) Entry free Wine and buffet after the discussion

  3. France at CERN

    CERN Multimedia

    2001-01-01

    From 19 to 22 June, for the 8th edition of France at CERN, 31 French companies presented their latest technology to the Laboratory. Demonstrating the latest in French technology during France at CERN. The France at CERN exhibition was inaugurated by Mr. Bernard Frois, Director of the Department Energy, Transport, Environment and Natural Resources at the Technology Directorate of the Ministry of Research. 'France is happy to be a Member of CERN, which is a successful example of the construction of scientific Europe,' he declared during the inauguration, 'this exhibition is an excellent opportunity to put fundamental research and advanced technology in contact.' Mr. Philippe Petit, French Ambassador to Switzerland, and Mr. Alexandre Defay, technical adviser of the Minister of Research, were also present to represent France and its industry. Representing CERN at the 19 June opening of the exhibition was Claude Detraz, who said, 'I hope that this exhibition will make it possible to weave stronger links between ...

  4. CERN Mobility Survey

    CERN Multimedia

    GS Department

    2011-01-01

    The Institute of Shipping and Transport of the University of the Aegean and the National Technical University of Athens are partners with CERN in a study of mobility patterns between and within the CERN sites and to that effect have realized a mobility survey dedicated to the CERN community.         The study aims to understand: How you presently get around the CERN sites; What problems you encounter regarding mobility; What your needs are; What improvements you’d like to see; What measures you would like to see implemented most. The replies we receive will enable us to define a general policy promoting the diversity of mobility at CERN and to establish and quantify the strategic actions to be implemented for both the short and medium term. The objectives of the transport mobility plans are to: Facilitate mobility within and between the CERN sites by identifying adequate solutions in response to individual ...

  5. Non-gaussianity from axion monodromy inflation

    Energy Technology Data Exchange (ETDEWEB)

    Hannestad, Steen; Haugbolle, Troels; Jarnhus, Philip R. [Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark); Sloth, Martin S., E-mail: sth@phys.au.dk, E-mail: haugboel@nbi.ku.dk, E-mail: pjarn@phys.au.dk, E-mail: martin.sloth@cern.ch [CERN, Physics Department, Theory Unit, CH-1211 Geneva 23 (Switzerland)

    2010-06-01

    We study the primordial non-Gaussianity predicted from simple models of inflation with a linear potential and superimposed oscillations. This generic form of the potential is predicted by the axion monodromy inflation model, that has recently been proposed as a possible realisation of chaotic inflation in string theory, where the monodromy from wrapped branes extends the range of the closed string axions to beyond the Planck scale. The superimposed oscillations in the potential can lead to new signatures in the CMB spectrum and bispectrum. In particular the bispectrum will have a new distinct shape. We calculate the power spectrum and bispectrum of curvature perturbations in the model, as well as make analytic estimates in various limiting cases. From the numerical analysis we find that for a wide range of allowed parameters the model produces a feature in the bispectrum with f{sub NL} ∼ 5−50 or larger while the power spectrum is almost featureless. This model is therefore an example of a string inspired inflationary model which is testable mainly through its non-Gaussian features. Finally we provide a simple analytic fitting formula for the bispectrum which is accurate to approximately 5 % in all cases, and easily implementable in codes designed to provide non-Gaussian templates for CMB analyses.

  6. Non-gaussianity from axion monodromy inflation

    International Nuclear Information System (INIS)

    We study the primordial non-Gaussianity predicted from simple models of inflation with a linear potential and superimposed oscillations. This generic form of the potential is predicted by the axion monodromy inflation model, that has recently been proposed as a possible realisation of chaotic inflation in string theory, where the monodromy from wrapped branes extends the range of the closed string axions to beyond the Planck scale. The superimposed oscillations in the potential can lead to new signatures in the CMB spectrum and bispectrum. In particular the bispectrum will have a new distinct shape. We calculate the power spectrum and bispectrum of curvature perturbations in the model, as well as make analytic estimates in various limiting cases. From the numerical analysis we find that for a wide range of allowed parameters the model produces a feature in the bispectrum with fNL ∼ 5−50 or larger while the power spectrum is almost featureless. This model is therefore an example of a string inspired inflationary model which is testable mainly through its non-Gaussian features. Finally we provide a simple analytic fitting formula for the bispectrum which is accurate to approximately 5 % in all cases, and easily implementable in codes designed to provide non-Gaussian templates for CMB analyses

  7. Axion Search with Q & A Experiment

    CERN Document Server

    Mei, Hsien-Hao; Chen, Sheng-Jui; Pan, Sheau-Shi

    2010-01-01

    Dark matter is a focused issue in galactic evolution and cosmology. Axion is a viable particle candidate for dark matter. Its interaction with photon is an effective way to detect it, e.g., pseudoscalar-photon interaction will generate vacuum dichroism in a magnetic field. Motivated to measure the QED vacuum birefringence and to detect pseudoscalar-photon interaction, we started to build up the Q & A experiment (QED [Quantum Electrodynamics] and Axion experiment) in 1994. In this talk, we first give a brief historical account of planet hunting and dark matter evidence. We then review our 3.5 m Fabry-Perot interferometer together with our results of measuring vacuum dichroism and gaseous Cotton-Mouton effects. Our first results give (-0.2 $\\pm$ 2.8) $\\times$ 10$^{-13}$ rad/pass, at 2.3 T with 18,700 passes through a 0.6 m long magnet, for vacuum dichroism measurement. We are upgrading our interferometer to 7 m arm-length with a new 1.8 m 2.3 T permanent magnet capable of rotation up to 13 cycles per second...

  8. Search of axions from a nuclear power reactor with a high-purity germanium detector

    International Nuclear Information System (INIS)

    This article reports the first study of possible emissions of axions from power reactors using Primakoff and Compton conversions as the detection mechanisms. The expected experimental signatures are mono-energetic lines produced by their Primakoff or Compton conversions at a high-purity germanium (HPGe) detector. No evidence of axion emissions were observed and constraints on axion couplings versus axion mass within the framework of invisible axion models were placed. This experimental approach provides a unique probe for axion mass at the keV-MeV range not accessible to the other techniques

  9. Constraints on axion inflation from the weak gravity conjecture

    International Nuclear Information System (INIS)

    We derive constraints facing models of axion inflation based on decay constant alignment from a string-theoretic and quantum gravitational perspective. In particular, we investigate the prospects for alignment and ‘anti-alignment’ of C4 axion decay constants in type IIB string theory, deriving a strict no-go result in the latter case. We discuss the relationship of axion decay constants to the weak gravity conjecture and demonstrate agreement between our string-theoretic constraints and those coming from the ‘generalized’ weak gravity conjecture. Finally, we consider a particular model of decay constant alignment in which the potential of C4 axions in type IIB compactifications on a Calabi-Yau three-fold is dominated by contributions from D7-branes, pointing out that this model evades some of the challenges derived earlier in our paper but is highly constrained by other geometric considerations

  10. A scientist finally proves existence of elusive axion

    CERN Multimedia

    2006-01-01

    "Using a visual target/detector, a University of Buffalo researcher has revealed the existence of the axion, a tiny particle with no charge, a very low mass and a lifetime much shorter than a nanosecond." (1,5 page)

  11. The electroweak axion, dark energy, inflation and baryonic matter

    International Nuclear Information System (INIS)

    In a previous paper [1], the standard model was generalized to include an electroweak axion which carries baryon plus lepton number, B + L. It was shown that such a model naturally gives the observed value of the dark energy, if the scale of explicit baryon number violation A was chosen to be of the order of the Planck mass. In this paper, we consider the effect of the modulus of the axion field. Such a field must condense in order to generate the standard Goldstone boson associated with the phase of the axion field. This condensation breaks baryon number. We argue that this modulus might be associated with inflation. If an additional B − L violating scalar is introduced with a mass similar to that of the modulus of the axion field, we argue that decays of particles associated with this field might generate an acceptable baryon asymmetry

  12. Constraints on axion inflation from the weak gravity conjecture

    Energy Technology Data Exchange (ETDEWEB)

    Rudelius, Tom [Jefferson Physical Laboratory, Harvard University,Cambridge, MA 02138 (United States)

    2015-09-08

    We derive constraints facing models of axion inflation based on decay constant alignment from a string-theoretic and quantum gravitational perspective. In particular, we investigate the prospects for alignment and ‘anti-alignment’ of C{sub 4} axion decay constants in type IIB string theory, deriving a strict no-go result in the latter case. We discuss the relationship of axion decay constants to the weak gravity conjecture and demonstrate agreement between our string-theoretic constraints and those coming from the ‘generalized’ weak gravity conjecture. Finally, we consider a particular model of decay constant alignment in which the potential of C{sub 4} axions in type IIB compactifications on a Calabi-Yau three-fold is dominated by contributions from D7-branes, pointing out that this model evades some of the challenges derived earlier in our paper but is highly constrained by other geometric considerations.

  13. Non-thermal Axion Dark Radiation and Constraints

    CERN Document Server

    Mazumdar, Anupam; Saikawa, Ken'ichi

    2016-01-01

    The Peccei-Quinn mechanism presents a neat solution to the strong CP problem. As a by-product, it provides an ideal dark matter candidate, "the axion", albeit with a tiny mass. Axions therefore can act as dark radiation if excited with large momenta after the end of inflation. Nevertheless, the recent measurement of relativistic degrees of freedom from cosmic microwave background radiation strictly constrains the abundance of such extra relativistic species. We show that ultra-relativistic axions can be abundantly produced if the Peccei-Quinn field was initially displaced from the minimum of the potential. This in lieu places an interesting constraint on the axion dark matter window with large decay constant which is expected to be probed by future experiments. Moreover, an upper bound on the reheating temperature can be placed, which further constrains the thermal history of our Universe.

  14. The 1956 CERN Symposium

    CERN Document Server

    Jarlskog, Cecilia

    2014-01-01

    CERN, currently the largest organization in the world for particle physics, was founded in 1954. Originally located in Meyrin, at the outskirts of the city of Geneva in Switzerland, it has with time extended into neighboring France. The Theoretical Study Division of CERN, however, was created already in 1952, i.e., before the official inauguration of CERN. It was situated in Copenhagen. Christian Møller [1] was appointed (part-time) as the Director and there were two full time senior staff members, Gunnar Källén and Ben R. Mottelson. While constructing buildings and accelerators were in progress, an international conference was organized by CERN in the city of Geneva. This “CERN Symposium on High Energy Accelerators and Pion Physics”, 11–23 June 1956, attracted about 250 participants from outside CERN, among them at least 18 Nobel Laureates or future Laureates. Unfortunately, the participants from CERN are not listed in the Proceedings [2]. The conference focused on measuring devices such as bubbl...

  15. CERN: Digitally open, too

    CERN Multimedia

    Computer Security Team

    2013-01-01

    The Open Days are here!! From tomorrow onwards, we will be welcoming thousands of people to CERN. No barriers, no boundaries!   For decades, we have welcomed researchers and visitors from around the world to work at CERN, discuss physics research and attend our training sessions, lectures and conferences. This is how fundamental research should be conducted!!! But have you ever noticed how you are welcome at CERN in the digital world, too? Once you are affiliated and are registered with CERN, you receive a CERN computing account and e-mail address.  You can register your laptops, PCs and smartphones to use our (wireless) network, you can easily create your personal webpage, and profit from a vast disk space for file storage (AFS and DFS). CERN is indeed an Open Campus and not only during the Open Days. CERN is an Open Campus in the digital world. This digital Open Campus culture is exactly the reason why “computer security” has been dele...

  16. CERN honours its guides

    CERN Multimedia

    2004-01-01

    At the end of January, CERN's guides were rewarded for their devotion to the Laboratory. They have a passion for their work, know CERN inside-out and for 40 years have shown people of all ages and nationalities, from all walks of life, around the Laboratory. Who are they? Why, the CERN guides, of course. On 27 January, ten of CERN's 180 guides received special honours for their impressive number of guided tours in 2003. Presenting the awards in the Microcosm hall, CERN's Director-General Robert Aymar congratulated the winners on the key role they play with respect to the general public. "CERN would be nothing without you who show them its activities," he stressed. CERN's Director-General Robert Aymar congratulates Alberto Ribon for his tally of over 40 visits in the course of 2003.One of the prizes was the book «The Particle Odyssey». Here the book's co-author Christine Sutton dedicates it for Sijin Qian. Tzanko Spassoff (PH) and retired staff members Klaus Batzner and Antonio Francano wo...

  17. CERN in 2030

    CERN Multimedia

    Laëtitia Pedroso

    2011-01-01

    A competition will soon be launched to select the architect, urban planner or landscape designer to undertake the first phase of redevelopment of the parking area by the flagpoles, between Entrances A and B. This will be the first stage in a wider development project aimed at sprucing up the CERN site and enhancing its image. Work to create a pleasant and harmonious area at the CERN entrance will start in 2013 while preparatory work for other developments inside the CERN site has already begun…   CERN as it is today.  By 2030, CERN will be a greener place, much like a university campus. The arrival of the tramway on 30 April will be an opportunity to forge ahead with the urban plan aimed at rejuvenating the CERN site and redefining how it is organised. "Nearly sixty years after CERN's first buildings went up, this plan will help transform the site and give it a welcoming, friendly face, a bit like a university campus," explains Thierry Chanard, urban plannin...

  18. Class of Einstein-Maxwell-Dilaton-Axion Space-Times

    CERN Document Server

    Matos, Tonatiuh; Sanchez-Sanchez, Ruben; Wiederhold, Petra

    2009-01-01

    We use the harmonic maps ansatz to find exact solutions of the Einstein-Maxwell-Dilaton-Axion (EMDA) equations. The solutions are harmonic maps invariant to the symplectic real group in four dimensions $Sp(4,\\Rreal)\\sim O(5)$. We find solutions of the EMDA field equations for the one and two dimensional subspaces of the symplectic group. Specially, for illustration of the method, we find space-times that generalise the Schwarzschild solution with dilaton, axion and electromagnetic fields.

  19. Axion Cosmology with a Stronger QCD in the Early Universe

    OpenAIRE

    Choi, Kiwoon; Kim, Hang Bae; Kim, Jihn E.

    1996-01-01

    We examine in the context of supersymmetric models whether the usual cosmological upper bound on the axion decay constant can be relaxed by assuming a period of stronger QCD in the early universe. By evaluating the axion potential in the early universe and also taking into account the dilaton potential energy, it is argued that a stronger QCD is not useful for raising up the bound.

  20. Axion cosmology with a stronger QCD in the early universe

    Energy Technology Data Exchange (ETDEWEB)

    Choi Kiwoon [Korea Adv. Inst. of Sci. and Technol., Taejon (Korea, Republic of). Phys. Dept.; Kim, H.B. [Universidad Autonoma de Madrid (Spain). Dept. de Fisica Teorica; Kim, J.E. [Seoul National Univ. (Korea, Republic of). Dept. of Physics

    1997-04-14

    We examine in the context of supersymmetric models whether the usual cosmological upper bound on the axion decay constant can be relaxed by assuming a period of stronger QCD in the early universe. By evaluating the axion potential in the early universe and also taking into account the dilaton potential energy, it is argued that a stronger QCD is not useful for raising the bound. (orig.).

  1. Heavy Axion on Sark Bridge Between Higgs and Technicolor Models

    Science.gov (United States)

    Frampton, P. H.; Yanagida, T.

    It is shown how imposition of Peccei-Quinn symmetry leads to a heavy axion and strong constraints in the sark model. The axion and sark masses are derived. Analysis of chiral symmetry breaking leads to mass formulae for pseudo-Goldstone bosons; the lightest is between 44 and 125 GeV. A general picture which bridges between the sark model and a technicolor model, in terms of a new angle, is proposed.

  2. Search for axion production in UPSILON(1S) decays

    Energy Technology Data Exchange (ETDEWEB)

    Fairfield, K.H.

    1988-06-01

    We present a search for axion production in radiative UPSILON(1S) decays using the Crystal Ball detector. We find no evidence for a signal and give a new upper limit, Br(UPSILON(1S)..-->..a/degree/..gamma..) < 4 /times/ 10/sup /minus/5/, for m/sub a/ < 2m/sub e/. Results from previous axion searches in both the UPSILON and J//psi/ systems are discussed and compared to theoretical predictions.

  3. Primakoff effect: synchrotron and coulomb mechanisms of axion emission

    International Nuclear Information System (INIS)

    For the first time the axion radiative emission by alternating electromagnetic field Fa → γa is considered due to Primakoff effect. As a concrete supplement, the synchrotron and Coulomb mechanisms are discussed and in the last case the alternating field is formed at the infinite motion of a charge in a Coulomb center field. The estimates for contributions of these effects into axion luminosity of magnetic neutron stars and the Sun are determined

  4. Primakoff effect: Synchrotron and Coulomb mechanisms of axion emission

    International Nuclear Information System (INIS)

    The Primakoff effect-induced radiative emission of axions by an alternating electromagnetic field, Fa → γa, is considered for the first time. The synchrotron mechanism and the Coulomb mechanism--in the latter case, the alternating field is formed when a charge executes an infinite motion in the field of a Coulomb center--are considered as specific examples. The contributions of these effects to the axion emissivity of magnetic neutron stars and of the Sun are estimated

  5. La Hollande au CERN

    CERN Multimedia

    CERN Press Office. Geneva

    1995-01-01

    On 17 October the third industrial exhibition, "Holland at CERN" was officially opened by Dr R.J. van Duinen, President of the Dutch Organisation for Scientific Research (NWO). In his opening speech he encouraged scientific organisations such as CERN to take full advantage of industry's ability to design and invent new processes and equipment stressing that the purpose of the "Holland at CERN" exhibition was not simply to sell equipment, but to establish an efficient cross-fertilisation between fundamental science and industry.

  6. 3D Lumped LC Resonators as Low Mass Axion Haloscopes

    CERN Document Server

    McAllister, Ben T; Tobar, Michael E

    2016-01-01

    The axion is a hypothetical particle considered to be the most economical solution to the strong CP problem. It can also be formulated as a compelling component of dark matter. The haloscope, a leading axion detection scheme, relies on the conversion of galactic halo axions into real photons inside a resonant cavity structure in the presence of a static magnetic field, where the generated photon frequency corresponds to the mass of the axion. For maximum sensitivity it is key that the central frequency of the cavity mode structure coincides with the frequency of the generated photon. As the mass of the axion is unknown, it is necessary to perform searches over a wide range of frequencies. Currently there are substantial regions of the promising pre-inflationary low mass axion range without any viable proposals for experimental searches. We show that 3D resonant LC circuits with separated magnetic and electric fields, commonly known as re-entrant cavities, can be sensitive dark matter haloscopes in this region...

  7. Searching for axions and ALPs from string theory

    Energy Technology Data Exchange (ETDEWEB)

    Ringwald, Andreas

    2012-09-15

    We review searches for closed string axions and axion-like particles (ALPs) in IIB string flux compactifications. For natural values of the background fluxes and TeV scale gravitino mass, the moduli stabilisation mechanism of the LARGE Volume Scenario predicts the existence of a QCD axion candidate with intermediate scale decay constant, f{sub a} {proportional_to}10{sup 9/12} GeV, associated with the small cycles wrapped by the branes hosting the visible sector, plus a nearly massless and nearly decoupled ALP associated with the LARGE cycle. In setups where the visible sector branes are wrapping more than the minimum number of two intersecting cycles, there are more ALPs which have approximately the same decay constant and coupling to the photon as the QCD axion candidate, but which are exponentially lighter. There are exciting phenomenological opportunities to search for these axions and ALPs in the near future. For f{sub a} {proportional_to}10{sup 11/12} GeV, the QCD axion can be the dominant part of dark matter and be detected in haloscopes exploiting microwave cavities. For f{sub a} {proportional_to}10{sup 9/10} GeV, the additional ALPs could explain astrophysical anomalies and be searched for in the upcoming generation of helioscopes and light-shining-through-a-wall experiments.

  8. Searching for axions and ALPs from string theory

    CERN Document Server

    Ringwald, Andreas

    2012-01-01

    We review searches for closed string axions and axion-like particles (ALPs) in IIB string flux compactifications. For natural values of the background fluxes and TeV scale gravitino mass, the moduli stabilisation mechanism of the LARGE Volume Scenario predicts the existence of a QCD axion candidate with intermediate scale decay constant, f_a ~ 10^9 ... 10^12 GeV, associated with the small cycles wrapped by the branes hosting the visible sector, plus a nearly massless and nearly decoupled ALP associated with the LARGE cycle. In setups where the visible sector branes are wrapping more than the minimum number of two intersecting cycles, there are more ALPs which have approximately the same decay constant and coupling to the photon as the QCD axion candidate, but which are exponentially lighter. There are exciting phenomenological opportunities to search for these axions and ALPs in the near future. For f_a ~ 10^11 ... 10^12 GeV, the QCD axion can be the dominant part of dark matter and be detected in haloscopes ...

  9. Supersymmetric axion grand unified theories and their predictions

    Science.gov (United States)

    Co, Raymond T.; D'Eramo, Francesco; Hall, Lawrence J.

    2016-10-01

    We introduce a class of unified supersymmetric axion theories with unified and Peccei-Quinn (PQ) symmetries broken by the same set of fields at a scale ˜2 ×1 016 GeV . A typical domain wall number of order 30 leads to an axion decay constant fa of order 1 015 GeV . Inflation generates a large saxion condensate, giving a reheat temperature TR below the QCD scale for supersymmetry breaking of order 1-10 TeV. Axion field oscillations commence in the saxion matter-dominated era near the QCD scale, and recent lattice computations of the temperature dependence of the axion mass in this era allow a controlled calculation of the axion dark matter abundance. The observed abundance can be successfully explained by an initial axion misalignment angle of order unity, θi˜1 . A highly correlated set of predictions is discussed for fa, TR, the supersymmetric Higgs mass parameter μ , the amount of dark radiation Δ Neff, the proton decay rate Γ (p →e+π0), isocurvature density perturbations and the B mode of the cosmic microwave background. The last two are particularly interesting when the energy scale of inflation is also of order 1 016 GeV .

  10. Natural Inflation with Multiple Sub-Planckian Axions

    CERN Document Server

    Choi, Kiwoon; Yun, Seokhoon

    2014-01-01

    We extend the Kim-Nilles-Peloso (KNP) alignment mechanism for natural inflation to models with N>2 axions, which obtains a super-Planckian effective axion decay constant f_{eff} >> M_{Pl} through an alignment of the anomaly coefficients of multiple axions having sub-Planckian fundamental decay constants f_0 O(100) as suggested by the recent BICEP2 results. We note that the KNP mechanism can be realized with the anomaly coefficients of O(1) if the number of axions N is large as N ln N > 2 ln (f_{eff}/f_0), in which case the effective decay constant can be exponentially enhanced as f_{eff}/f_0 ~ sqrt(N!) n^{N-1} for n denoting the typical size of the integer-valued anomaly coefficients. Comparing to the other multiple axion scenario, the N-flation scenario which requires N ~ f_{eff}^2/f_0^2, the KNP mechanism has a virtue of not invoking to a too large number of axions, although it requires a specific alignment of the anomaly coefficients, which can be achieved with a probability of O(f_0/f_{eff}) under a rand...

  11. Second-generation dark-matter axion search

    Energy Technology Data Exchange (ETDEWEB)

    Sikivie, P.; Sullivan, N.S.; Tanner, D.B. [Univ. of Florida, Gainesville, FL (United States)

    1996-12-01

    This research project is a collaboration with the axion search experiment at Lawrence Livermore National Laboratory. The axion is a particle that affects two important issues in particle physics and astrophysics: the origin of CP symmetry in the strong interactions, and the composition of the dark-matter of the universe. First predicted in 1978, present laboratory, astrophysical, and cosmological constraints suggest axions have a mass in the 1 {mu}eV-1 meV range. Axions are especially significant as dark matter if their mass is in the range 1-10 {mu}eV. These dark matter axions may be detected by their coupling to photons through the E - B interaction in a tunable high-Q microwave cavity permeated by a strong external magnetic field. The present experiment is the first cavity experiment with the sensitivity to possibly observe cosmic axions. It has recently begun taking data and will operate for the next several years. The University of Florida plans to contribute to the operation of this detector and to the design and prototyping of cavities for the experiment.

  12. Conversion and Operation of CAST as a massive axion detector

    CERN Document Server

    Elias, Nuno; Bordalo, Paula

    2010-01-01

    The axion was postulated after an elegant solution proposed by R. Peccei and H. Quinn to solve the strong CP problem of Quantum Chromodynamics. The CAST experiment searches for axions created in the core of the Sun. It uses an LHC superconducting prototype magnet to trigger the axion conversion into detectable X-ray photons. During its First Phase, with the magnetic field region kept under vacuum, CAST searched with high sensitivity for axion masses up to 0.02 eV/c2, for higher values the conversion coherence is lost. This thesis reflects the work that allows CAST to extend its search up to axion masses of 1 eV/c2. To restore the lost coherence a buffer gas is introduced in the magnet cold bores, such that the photon arising from the Primakoff conversion acquires an effective mass. The axion mass can be effectively scanned by fine tuning the gas density. The conversion of the experiment required the study, design and construction of a complex gas handling system to deal with a rare helium isotope, 3He. It rep...

  13. Bifid Throats for Axion Monodromy Inflation

    Energy Technology Data Exchange (ETDEWEB)

    Retolaza, Ander [Univ. Autonoma de Madrid (Spain). Inst. de Fisica Teorica IFT-UAM/CSIC; Universidad Autonoma de Madrid (Spain). Dept. de Fisica Teorica; Uranga, Angel M. [Univ. Autonoma de Madrid (Spain). Inst. de Fisica Teorica IFT-UAM/CSIC; Westphal, Alexander [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2015-04-15

    We construct a simple explicit local geometry providing a 'bifid throat' for 5-brane axion monodromy. A bifid throat is a throat that splits into two daughter throats in the IR, containing a homologous 2-cycle family reaching down into each daughter throat. Our example consists of a deformed Z{sub 3} x Z{sub 2} orbifold of the conifold, which provides us with an explicit holographic dual of the bifid throat including D3-branes and fractional 5-branes at the toric singularities of our setup. Having the holographic description in terms of the dual gauge theory allows us to address the effect of 5-brane-antibrane pair backreaction including the warping effects. This leads to the size of the backreaction being small and controllable after imposing proper normalization of the inflaton potential and hence the warping scales.

  14. Axion-photon Propagation in Magnetized Universe

    CERN Document Server

    Wang, Chen

    2015-01-01

    Oscillations between photons and axion-like particles (ALP) travelling in intergalactic magnetic fields have been invoked to explain a number of astrophysical phenomena, or used to constrain ALP properties using observations. One example is the anomalous transparency of the universe to TeV gamma-rays. The intergalactic magnetic field is usually modeled as patches of coherent domains, each with a uniform magnetic field, but the field orientation changes randomly from one domain to the next ("discrete-$\\varphi$ model"). We show in this paper that in more realistic situations, when the magnetic field direction varies continuously along the propagation path, the photon-to-ALP conversion probability $P$ can be significantly different from the discrete-$\\varphi$ model. In particular, $P$ has a distinct dependence on the photon energy and ALP mass, and can be as large as 100 percent. This result may affect previous constraints on ALP properties based on ALP-photon propagation in intergalactic magnetic fields.

  15. Anisotropic plasmas from axion and dilaton deformations

    CERN Document Server

    Donos, Aristomenis; Sosa-Rodriguez, Omar

    2016-01-01

    We construct black hole solutions of type IIB supergravity that are holographically dual to anisotropic plasmas arising from deformations of an infinite class of four-dimensional CFTs. The CFTs are dual to $AdS_5\\times X_5$, where $X_5$ is an Einstein manifold, and the deformations involve the type IIB axion and dilaton, with non-trivial periodic dependence on one of the spatial directions of the CFT. At low temperatures the solutions approach smooth domain wall solutions with the same $AdS_5\\times X_5$ solution appearing in the far IR. For sufficiently large deformations an intermediate scaling regime appears which is governed by a Lifshitz-like scaling solution. We calculate the DC thermal conductivity and some components of the shear viscosity tensor.

  16. Cryogenics at CERN

    CERN Document Server

    Passardi, Giorgio

    2002-01-01

    The use of cryogenics at CERN was originated (in the 1960s) by High Energy Physics detectors requiring low temperature technologies to achieve the desired performance and indicates a sustained trend during the entire evolution of the CERN experimental program. More recently (in the 1980s) the need of cryogenics for CERN accelerators has shown an impressive increase due to the development of superconducting accelerating cavities and high field bending magnets. Today, the two largest detectors (ATLAS and CMS) of the LHC accelerator ask for a considerable variety of cryogenic equipments and the 27 km LHC magnets ring requires the largest 1.8 K helium refrigeration and distribution systems in the world. The status of CERN cryogenics is briefly reviewed including those systems not related to the LHC complex.

  17. Open Hardware at CERN

    CERN Multimedia

    CERN Knowledge Transfer Group

    2015-01-01

    CERN is actively making its knowledge and technology available for the benefit of society and does so through a variety of different mechanisms. Open hardware has in recent years established itself as a very effective way for CERN to make electronics designs and in particular printed circuit board layouts, accessible to anyone, while also facilitating collaboration and design re-use. It is creating an impact on many levels, from companies producing and selling products based on hardware designed at CERN, to new projects being released under the CERN Open Hardware Licence. Today the open hardware community includes large research institutes, universities, individual enthusiasts and companies. Many of the companies are actively involved in the entire process from design to production, delivering services and consultancy and even making their own products available under open licences.

  18. Rejuvenating CERN's Accelerators

    CERN Multimedia

    2004-01-01

    In the coming years and especially in 2005, CERN's accelerators are going to receive an extensive renovation programme to ensure they will perform reliably and effectively when the LHC comes into service.

  19. CERN recognises LHC suppliers

    CERN Multimedia

    2002-01-01

    CERN has just presented the first awards recognising LHC suppliers. The Russian institute BINP, the Belgian firm Cockerill-Sambre and the US company Wah-Chang are the recipients of the first 'Golden Hadrons'.

  20. PACMAN at CERN

    CERN Multimedia

    2015-01-01

    PACMAN Particle Accelerator Components Metrology and Alignment to the Nanometre scale. PACMAN is an Innovative Doctoral Program Network, offering training to 10 Early Stage Researchers hosted by CERN thanks to The European Commission FP7 Marie Curie Actions.

  1. YOUR LIFE@CERN

    CERN Multimedia

    Guinot, Genevieve

    2016-01-01

    Balancing work and home life, getting support for your family and thriving in an inclusive and respectful workplace: find out more about the support structures in place to enhance your working life@CERN!

  2. CERN scientists predict supernova

    CERN Multimedia

    2003-01-01

    "A team of theoretical physicists working at CERN and the Technion Institute of Technology in Israel has developed a theory to account for the mysterious gamma ray bursts that come from the depths of the Universe" (1/2 page).

  3. Fusion Revisits CERN

    CERN Multimedia

    2001-01-01

    It's going to be a hot summer at CERN. At least in the Main Building, where from 13 July to 20 August an exhibition is being hosted on nuclear fusion, the energy of the Stars. Nuclear fusion is the engine driving the stars but also a potential source of energy for mankind. The exhibition shows the different nuclear fusion techniques and research carried out on the subject in Europe. Inaugurated at CERN in 1993, following collaboration between Lausanne's CRPP-EPFL and CERN, with input from Alessandro Pascolini of Italy's INFN, this exhibition has travelled round Europe before being revamped and returning to CERN. 'Fusion, Energy of the Stars', from 13 July onwards, Main Building

  4. Industrial Activity at CERN

    CERN Document Server

    Kowalik, G

    2000-01-01

    The decrease in the number of CERN staff creates the need for optimization of the non-core, infrastructure-related activities. An industrial, service-orientated approach has long been considered as an appropriate way to cope with the problem of diminishing resources. This paper presents industrial and service activity issues at CERN based on the experience of the exploitation of the power network. The most important problems linked to the application of the industrial approach to the exploitation of equipment in the CERN research environment are covered. These include the interface between accelerators and electrical exploitation services, external and internal regulations, sharing of responsibility between CERN staff and external contractors, continuous modification of clients' requirements, the balance between the cost of accelerator downtime versus the cost of infrastructure upgrade. A benchmarking through a comparison with a big industrial manufacturer is followed by recommendations for possible improveme...

  5. Iran approaches CERN

    CERN Multimedia

    2002-01-01

    Members of Parliament from the Islamic Republic of Iran visit SM18. From left to right : Ali Mojtahed-Shabestari, Deputy Ambassador of the Islamic Republic of Iran in Geneva, Diether Blechschmidt, from CERN, Abdol-Rahim Baharvand and Hossain Amiri, from the Iranian Parliament, Norbert Siegel, from CERN, Hossain Afarideh, Rasool Seddighi and Ahmad Shirzad from the Iranian Parliament. Five members of the Parliament of the Islamic Republic of Iran visited CERN for three days at the beginning of May. All of them have PhD's in Physics, as well as holding their job in politics. They are involved in legislation for science, research and education funding in Iran. Apart from their interest in CERN in general, they were especially attracted to the CMS detector, since an Iranian contribution to the LHC is now starting through a collaboration with the Institute for Studies in Theoretical Physics and Mathematics in Tehran.

  6. Safety at CERN

    CERN Document Server

    2009-01-01

    Safety is an integral part of our working lives, and should be in our minds whatever job we do at CERN. Ultimately, safety is the responsibility of the Director General – your safety is my concern. That’s why I have this week appointed a new Safety Policy Committee (SAPOCO) that reflects the new Organizational structure of CERN. CERN’s Staff Rules and Regulations clearly lay out in chapter 3 the scope of safety at CERN as well as my responsibilities and yours in safety matters. At CERN, safety is considered in the broadest sense, encompassing occupational Health and Safety, environmental protection, and the safety of equipment and installations. It is my responsibility to put appropriate measures in place to ensure that these conditions are met. And it is the responsibility of us all to ensure that we are fully conversant with safety provisions applicable in our areas of work and that we comply with them. The appointment of a n...

  7. CERN Science and Technology

    OpenAIRE

    Di Meglio, Alberto

    2015-01-01

    A high-level overview of the relationship between science and technology at CERN and the impact of technology on research with a focus on ICT technologies. Presented as a 12-minute "power-talk" at CIOCity 2015, Brussels

  8. La nascita del CERN

    CERN Multimedia

    Fidecaro, Giuseppe

    2004-01-01

    CERN was born on 30th September 1954, after the ratification of the Convention by the Member States. After the war, there was a need for international collaboration to rebuild the half-destroyed Europe (2 pages)

  9. CERN stationery rejuvenated

    CERN Multimedia

    Anaïs Schaeffer

    2013-01-01

    With the introduction of CERN’s new graphic charter, our complete range of official communications stationery has been redesigned. Discover the newly harmonised and standardised range of CERN stationery.   As the Director-General announced in Bulletin 41-42/2012, a new graphic charter is now in force at CERN. The graphics team has taken this opportunity to redesign all the official CERN stationery, such as business cards, correspondence cards, letterheads, envelopes and file holders, all of which will now boast the same, unified format. In keeping with CERN’s new graphic charter, even the business cards have had a makeover: of a better quality than their predecessors, they now elegantly display the CERN colours (namely the familiar Pantone 286 blue). These new cards, which all follow a standardised format, help to project a standardised corporate image of the Organization. Order them online now! As the Director-General highlighted, “it's increasingly imp...

  10. Indian President visits CERN

    CERN Multimedia

    Katarina Anthony

    2011-01-01

    On 1 October, her Excellency Mrs Pratibha Devisingh Patil, President of India, picked CERN as the first stop on her official state visit to Switzerland. Accompanied by a host of Indian journalists, a security team, and a group of presidential delegates, the president left quite an impression when she visited CERN’s Point 2!   Upon arrival, Pratibha Patil was greeted by CERN Director General Rolf Heuer, as well as senior Indian scientists working at CERN, and various department directors. After a quick overview of the Organization, Rolf Heuer and the President addressed India’s future collaboration with CERN. India is currently an Observer State of the Organization, and is considering becoming an Associate Member State. A short stop in LHC operations gave Steve Myers and the Accelerator team the opportunity to take the President on a tour through the LHC tunnel. From there, ALICE’s Tapan Nayak and Spokesperson Paolo Giubellino took Pratibha Patil to the experiment&am...

  11. Ex / Noise / CERN / Deerhoof

    CERN Multimedia

    CERN, SM18,

    2015-01-01

    Indie rockers Deerhoof battled with the noise of CERN’s magnet test facilities on 30 August 2015. The band visited CERN at the invitation of ATLAS physicist James Beacham, whose pilot project Ex/Noise/CERN collides experimental music artists with experimental particle physics. Credits: -Producer- CERN Video Productions James Beacham François Briard -Director- Noemi Caraban -Camera- Yann Krajewski Piotr Traczyk Noemi Caraban -Crane operator- Antonio Henrique Jorge-Costa -Live recording at CERN- Mixing at Rec studio/Geneva By Serge Morattel -Infography- Daniel Dominguez Noemi Caraban -Deerhoof- John Dieterich Satomi Matsuzaki Ed Rodriguez Greg Saunier w/Deron Pulley SPECIAL THANKS TO: Michal Strychalski Marta Bajko Maryline Charrondiere Luca Bottura Christian Giloux Rodrigue Faes Mariane Catallon Georgina Hobgen Hailey Reissman Marine Bass

  12. Britain exhibition at CERN

    CERN Multimedia

    Bertin; CERN PhotoLab

    1969-01-01

    The United Kingdom inaugurated the Industrial Exhibitions in 1968, and it wasn't till 1971 that other countries staged exhibitions at CERN. This photo was taken in 1969, at the second British exhibition, where 16 companies were present.

  13. Star spotting at CERN

    CERN Multimedia

    2008-01-01

    This June, two American celebrities (and physics enthusiasts!) came to CERN. Brian Cox gave Mike Einziger (right), lead guitarist with the rock band Incubus, the star treatment in the ATLAS cavern. Jesse Dylan embraces the spirit of ATLAS! Mike Einziger, lead guitarist with the rock band Incubus, visited CERN on Friday 13 June between concerts in Finland and England. Einziger, a lifelong science enthusiast descended into the ATLAS and CMS caverns and visited the SM18 test magnet facility during his brief tour of CERN. Einziger learned about the LHC through watching online lectures from University of Manchester and ATLAS physicist Brian Cox, and was thrilled to have the chance to see the detectors in person. The musician has created an orchestral piece, inspired in part by the work being done at CERN for the LHC, which will have its debut in Los Angeles on 23 August. Just over a week earlier, Jesse Dylan, Hollywood film director a...

  14. CERN confirms LHC schedule

    CERN Multimedia

    2003-01-01

    The CERN Council held its 125th session on 20 June. Highlights of the meeting included confirmation that the LHC is on schedule for a 2007 start-up, and the announcement of a new organizational structure in 2004.

  15. CERN meets Facebook

    CERN Document Server

    2012-01-01

    Social networking sites like LinkedIn, MySpace, Google+ and Facebook are on the rise. In particular, the life of youngsters revolves more and more around these sites as they facilitate communication, networking and the exchange of niceties. Who does not today already have an account registered with one of them? A Facebook profile can contain photos, listings of hobbies, job information, preferences…   The on-going effort to externalise some of CERN's computing resources continues, and in order to promote a unified interface for personal information, CERN has decided to establish a partnership with Facebook starting on 1stApril. "CERN is a public and trustworthy international organisation, and as such, our staff and users have nothing to hide from the general public," said Alexi Spiner (IT), project leader responsible for this migration: * The computer profiles of all CERN users will be integrated into the Facebook portal; * In addition, we will also ...

  16. CERN at ESOF 2016

    CERN Document Server

    James Gillies

    2016-01-01

    CERN had a major presence at the ESOF2016 conference this week, largely in collaboration with our EIROforum partners. A keynote session featuring the CERN Director-General, Fabiola Gianotti, EMBL Director-General, Iain Mattaj, and ESO Director for Science, Rob Ivison, and chaired by BBC science correspondent Pallab Ghosh debated the value of European collaboration in science.   The focal point of EIROforum’s presence was a stand highlighting the societal benefit of EIROforum science. (Image: Matt Wilkinson Photography/ ESOF 2016) A double session covered the science of the EIROs, with ATLAS physicist Claire Lee representing CERN, and there was a session exploring the ways that the EIROforum organisations create business value locally, with the leader of the Knowledge Transfer group, Giovanni Anelli, representing CERN. The focal point of EIROforum’s presence was a stand highlighting the societal benefit of EIROforum science. Side events linked to the stand discussed subjects su...

  17. Cosmic axion background propagation in galaxies

    Directory of Open Access Journals (Sweden)

    Francesca V. Day

    2016-02-01

    Full Text Available Many extensions of the Standard Model include axions or axion-like particles (ALPs. Here we study ALP to photon conversion in the magnetic field of the Milky Way and starburst galaxies. By modelling the effects of the coherent and random magnetic fields, the warm ionized medium and the warm neutral medium on the conversion process, we simulate maps of the conversion probability across the sky for a range of ALP energies. In particular, we consider a diffuse cosmic ALP background (CAB analogous to the CMB, whose existence is suggested by string models of inflation. ALP–photon conversion of a CAB in the magnetic fields of galaxy clusters has been proposed as an explanation of the cluster soft X-ray excess. We therefore study the phenomenology and expected photon signal of CAB propagation in the Milky Way. We find that, for the CAB parameters required to explain the cluster soft X-ray excess, the photon flux from ALP–photon conversion in the Milky Way would be unobservably small. The ALP–photon conversion probability in galaxy clusters is 3 orders of magnitude higher than that in the Milky Way. Furthermore, the morphology of the unresolved cosmic X-ray background is incompatible with a significant component from ALP–photon conversion. We also consider ALP–photon conversion in starburst galaxies, which host much higher magnetic fields. By considering the clumpy structure of the galactic plasma, we find that conversion probabilities comparable to those in clusters may be possible in starburst galaxies.

  18. CERN, Accelerating Science

    CERN Multimedia

    De Melis, Cinzia

    2015-01-01

    What is the Universe made of? Where did it come from, where is it going and why does it behave the way it does? These are some of the questions that CERN set out to address when a small number of pioneering scientists created Europe’s first scientific international organization. Founded in 1954, in the aftermath of the Second World War, CERN is not only a first-class centre for fundamental research but also a pioneering adventure in international collaboration.

  19. Germany at CERN

    CERN Multimedia

    2001-01-01

    The Eighth Exhibition of German Industry, "Germany at CERN" started this week and offers German companies the opportunity to establish professional contacts with CERN. From left to right in the foreground: Maximilian Metzger (BMBF), Bettinna Schöneseffen (BMBF), Karl-Heinz Kissler (SPL division leader), Horst Wenninger, and Hans Hoffman. Behind and to the right of Karl-Heinz Kissler is His Excellency Mr Walter Lewalter, Ambassador and permanent representative of Germany to the UN office in Geneva.

  20. Cern Women's Club

    CERN Multimedia

    Cern Women's Club

    2014-01-01

      CERN WOMEN’S CLUB   Coffee Morning Tuesday 10th  June 2014, 12:30   Annual Club Lunch at the restaurant “Le Coq Rouge” in St-Genis-Pouilly Those interested in helping should come along. New arrivals and all members are cordially invited. You can enrol for membership, renew membership, find out about and sign up for our activities. Visit our website: http://web.cern.ch/Club-WomensClub/

  1. Cern women's club

    CERN Multimedia

    Club des cernoises

    2014-01-01

    CERN WOMEN’S CLUB Coffee Morning Tuesday 13th  May 2014, 9:30 Bldg 504,  (Restaurant No 2 – DSR) 1st Floor, Club Room 3   Annual General Meeting Those interested in helping should come along. New arrivals and all members are cordially invited. You can enrol for membership, renew membership, find out about and sign up for our activities. Visit our website: http://cern.ch/Club-WomensClub/

  2. CERN permanent exhibitions

    CERN Multimedia

    2016-01-01

    Explore by yourself the issues CERN's physicists are trying to solve: given that the entire universe is made of particles, where do they come from? Why do they behave in the way they do? Discover the massive apparatus used by physicists at CERN, like the LHC, and see how each part works. And if you have more time on site, follow the LHC circuit at ground level to understand in situ this giant machine. Enter our exhibitions. Welcome!

  3. CERN expositions permanentes

    CERN Multimedia

    2016-01-01

    Explore by yourself the issues CERN's physicists are trying to solve: given that the entire universe is made of particles, where do they come from? Why do they behave in the way they do? Discover the massive apparatus used by physicists at CERN, like the LHC, and see how each part works. And if you have more time on site, follow the LHC circuit at ground level to understand in situ this giant machine. Enter our exhibitions. Welcome!

  4. CERN Library | Agnes Chavez @ CERN | 3 May

    CERN Multimedia

    CERN Library

    2016-01-01

    Agnes Chavez is an artist and educator participating in a two-week research stay through the ATLAS Experiment at CERN.   Tuesday 3 May at 4 p.m. CERN Library (52 1-052) Artist/educator, Agnes Chavez will share video outcomes from Projecting Particles, an Art + Science + Education collaboration with ATLAS. The Sci-Art project combines the International Masterclass with Projection Art in a series of teen-led youth workshops and projection events. In this presentation Chavez will share her vision and describe the research and development behind the project, now in its third year.  For the Projecting pARTicles series of art installations she has formed an interdisciplinary team of programmers, artists, scientists and educators to investigate how we can create art and education interventions inspired by emerging particle physics theories. Chavez’s art experiments with data visualization, sound and projections to create participatory environments. She collaborates with programmers t...

  5. CREATIVE COLLISIONS: ARTS @CERN

    CERN Document Server

    CERN. Geneva

    2012-01-01

    In 2000, CERN hosted Signatures of the Invisible – one of the landmark initiatives in arts and science. In 2012, CERN is now initiating its own science/arts programme Collide@CERN in different arts disciplines. The first of these is in digital arts, and the international competition to find the winning artist is called the Prix Ars Electronica Collide@CERN. It was announced September 2011 at CERN’s first collaboration with an international arts festival – Ars Electronica in Linz. The competition attracted over 395 entries from 40 countries around the world. The winning artist, Julius Von Bismarck, will begin his two month residency here at CERN next month. Ariane Koek who leads on this initiative, discusses the residency programme, as well as the background about Art@CERN. History has shown that particle physics and the arts are great inspiration partners. The publication of the paper by Max Planck which gave birth to quantum mechanics as well as those by Einstein, heavily influenced some of the grea...

  6. CERN Pensioners Association

    CERN Multimedia

    The GAC Committee

    2004-01-01

    Open Day To all CERN retired staff As part of the celebrations organised for the 50th anniversary of CERN, an Open Day will be held on Saturday 16 October 2004. Anyone willing to act as a guide, either to help and inform visitors at the reception points or to guide groups of visitors, sharing your knowledge with them, is invited to fill in the attached form. A preparatory meeting will be arranged for those who left CERN some time ago and whose knowledge of the site may no longer be quite up-to-date. The Open Day organisers need your help, which will be very much appreciated. We hope that many pensioners will participate. People with internet access may enrol directly without coming to CERN, http://www.cern.ch/CERN50/openday The GAC Committee OPEN DAY : CALL FOR VOLUNTEERS 16th October 2004 So now you are excited about the Open Day, how can you participate? As you can imagine, for such a large number of activities, we need many volunteers. Please return the following form to Elena Battis...

  7. CERN Relay Race

    CERN Multimedia

    Running Club

    2010-01-01

    This year’s CERN Relay Race will take place around the Meyrin site on Thursday 20th May at 12h00. This annual event is for teams of 6 runners covering distances of 1000m, 800m, 800m, 500m, 500m and 300m respectively. Teams may be entered in the Seniors, Veterans, Ladies, Mixed or Open categories. The registration fee is 10 CHF per runner, and each runner receives a souvenir prize. As usual, there will be a programme of entertainments from 12h in the arrival area, in front of the Restaurant no. 1. Drinks, food, CERN club information and music will be available for the pleasure of both runners and spectators. The race starts at 12h15, with results and prize giving at 13:15.   For details of the race, and of how to sign up a team, please visit: https://espace.cern.ch/Running-Club/CERN-Relay The event is organised by the CERN Running Club with the support of the CERN Staff Association.  

  8. Sharing resources@CERN

    CERN Multimedia

    2002-01-01

    The library is launching a 'sharing resources@CERN' campaign, aiming to increase the library's utility by including the thousands of books bought by individual groups at CERN. This will improve sharing of information among CERN staff and users. Until now many people were unaware that copies of the same book (or standard, or journal) are often held not only by the library but by different divisions. (Here Eduardo Aldaz, from the PS division, and Isabel Bejar, from the ST division, read their divisional copies of the same book.) The idea behind the library's new sharing resources@CERN' initiative is not at all to collect the books in individual collections at the CERN library, but simply to register them in the Library database. Those not belonging to the library will in principle be unavailable for loan, but should be able to be consulted by anybody at CERN who is interested. "When you need a book urgently and it is not available in the library,' said PS Division engineer Eduardo Aldaz Carroll, it is a sham...

  9. CERN In Focus

    CERN Document Server

    CERN audiovisual service

    2008-01-01

    First edition 2008 of Cern in Focus. On behalf of the audiovisual team, a selection of the latest videos filmed at CERN. Every six weeks, we will bring you the latest in CERN's activities, from LHC start up to the Computing Grid, featuring the experiments and many other goings-on at CERN. The agenda of this first edition of CERN in Focus features the visit of the prime minister of Malta, Lawrence Gonzi... CMS and the final descent of the YE-1 end cap... The departure of UA1 magnets to Japan... The start up of sectors 4 and 5... And finally, in our sports round up... We'll talk about football. New in brief this month... The final bolt is in place : On 7th November, in the bowels of the LHC tunnel, CERN's Director General Robert Aymar tightened a gold-plated bolt for the last arc interconnection of sector 1-2. This symbolic gesture marks the completion of all the arc interconnections of the LHC. Last welding work: it was never going to be an easy task. On this day last year just one sector had been completed,...

  10. CERN openlab Open Day

    CERN Multimedia

    Andrew Purcell

    2015-01-01

    CERN openlab is the unique public-private partnership between CERN and leading companies in the field of information and communication technology. The programme is now entering an exciting new phase and is expanding to include other public research organisations for the first time. A special event will be held at CERN to mark this occasion.   CERN openlab was created in 2001 and is now entering its fifth three-year phase (2015-2017). Its mission is to accelerate the development of cutting-edge solutions to be used by the scientific community to control the operations of complex machines and to analyse the vast amounts of data produced by physics experiments. During Run 2 of the LHC, it is expected that the CERN Data Centre will store more than 30 petabytes of data per year from the LHC experiments, which is equivalent to about 1.2 million Blu-ray discs, or 250 years of HD video. Testing in this demanding environment provides the companies collaborating in CERN openlab with valuable feedback o...

  11. GammeV: Fermilab axion-like particle photon regeneration results

    Energy Technology Data Exchange (ETDEWEB)

    Wester, William; /Fermilab

    2008-09-01

    GammeV is an axion-like particle photon regeneration experiment conducted at Fermilab that employs the light shining through a wall technique. They obtain limits on the coupling of a photon to an axion-like particle that extend previous limits for both scalar and pseudoscalar axion-like particles in the milli-eV mass range. They are able to exclude the axion-like particle interpretation of the anomalous PVLAS 2006 result by more than 5 standard deviations.

  12. Constraining axion coupling constants from measuring the Casimir interaction between polarized test bodies

    OpenAIRE

    Bezerra, V. B.; Klimchitskaya, G. L.; Mostepanenko, V. M.; Romero, C.

    2016-01-01

    We propose an experiment for measuring the effective Casimir pressure between two parallel SiC plates with aligned nuclear spins. The prospective constraints on an axion-neutron coupling constant for both hadronic and GUT axions are calculated using the process of one-axion exchange. For this purpose, a general expression for the additional pressure arising between two polarized plates due to the exchange of one axion between their constituent fermions is derived. We demonstrate that only the...

  13. Axion Searches in the Past, at Present, and in the Near Future

    OpenAIRE

    Battesti, R.; Beltran, B.; Davoudiasl, H.; M. Kuster(Technische Universität Darmstadt); Pugnat, P.; Rabadan, R.; Ringwald, A.; Spooner, N.; Zioutas, K.

    2007-01-01

    Theoretical axion models state that axions are very weakly interacting particles. In order to experimentally detect them, the use of colorful and inspired techniques becomes mandatory. There is a wide variety of experimental approaches that were developed during the last 30 years, most of them make use of the Primakoff effect, by which axions convert into photons in the presence of an electromagnetic field. We review the experimental techniques used to search for axions and will give an outlo...

  14. Limits on heavy axion production from the reaction n(p,a)d

    International Nuclear Information System (INIS)

    A search has been made for the creation of shortlived axions in the isovector transition n(p,a)d decaying into e+e--pairs. The production of Peccei-Quinn axions can be excluded for 1.21 a -2 (90% CL). Limits on variant axion models are derived. (author)

  15. CP-Conservation in QCD and why only "invisible" Axions work

    CERN Document Server

    Kim, Jihn E

    2016-01-01

    Among solutions of the strong CP problem, the "invisible" axion in the narrow axion window is argued to be the remaining possibility among natural solutions on the smallness of $\\bar{\\theta}$. Related to the gravity spoil of global symmetries, some prospective invisible axions from theory point of view are discussed. In all these discussions, including the observational possibility, cosmological constraints must be included.

  16. Spotlight on CERN : Recruitment and professions at CERN

    CERN Multimedia

    CERN video productions

    2010-01-01

    Spotlight on CERN No. 3 Recruitment and professions at CERN Welcome to the Globe of Science and Innovation for this third edition of "Spotlight on CERN". When one thinks about professions at CERN, what springs to mind? Physicists? Engineers? In fact, the smooth operation of the Organisation relies on a diversity of professions and this in itself, poses a real challenge in terms of recruitment in CERN member states. Today, to tell us more about this challenge and about CERN professions in general, we welcome James Purvis, Head of the HR Recruitment, Programmes and Monitoring group, and Lore Taillieu, leader of the group's Recruitment section.

  17. Inspired by CERN

    CERN Multimedia

    2004-01-01

    Art students inspired by CERN will be returning to show their work 9 to 16 October in Building 500, outside the Auditorium. Seventeen art students from around Europe visited CERN last January for a week of introductions to particle physics and astrophysics, and discussions with CERN scientists about their projects. A CERN scientist "adopted"each artist so they could ask questions during and after the visit. Now the seeds planted during their visit have come to fruition in a show using many media and exploring varied concepts, such as how people experience the online world, the sheer scale of CERN's equipment, and the abstractness of the entities scientists are looking for. "The work is so varied, people are going to love some pieces and detest others," says Andrew Charalambous, the project coordinator from University College London who is also curating the exhibition. "It's contemporary modern art, and that's sometimes difficult to take in." For more information on this thought-provoking show, see: htt...

  18. CERN Phonebook evolution

    CERN Multimedia

    Sébastien Dellabella

    2012-01-01

    Consolidating phonebooks at CERN We have had many phonebooks in the past, Xwho (now decommissioned), the NICE phonebook on Windows PCs, and more recently the web site people.cern.ch. However, diversity doesn’t always equate to improved efficiency or quality. So in order to reduce the maintenance effort and to improve the user experience, we have consolidated these various phonebooks into a single web application: phonebook.cern.ch Motivations for change The NICE Phonebook was introduced in the year 2000 when Windows 95 was the major desktop platform. Since then, a lot has changed not only in technology and the desktop landscape but also in the variety of devices used to access the data (notably smartphones and tablets). Updating the NICE phonebook is slow. Once the master database is modified it can take up to two days for the data to propagate to the application. Thus, we are now planning the retirement of the NICE phonebook application. The new Phonebook.cern.ch The new phonebook.cern.ch...

  19. Lectures for CERN pensioners

    CERN Multimedia

    SC Unit

    2008-01-01

    The CERN Medical Service and the Pensioners Association are pleased to invite CERN pensioners to a series of lectures given by professors and specialists from the Teaching Hospitals and the Faculty of Medicine of the University of Geneva on the following topic: PROMOTION OF OPTIMUM BRAIN AGEING The lectures will take place in the Main CERN Auditorium (Building 60) from 2.30 p.m. to 4.30 p.m. on the following dates: Wednesday 12 November 2008: Assessing the extent of brain ageing Dr Dina ZEKRY Friday 12 December 2008: Can memory decline be prevented? Pr Jean-Pierre MICHEL Thursday 15 January 2009: Diagnosing and treating Alzheimer’s disease Pr Gabriel GOLD Wednesday 25 February 2009: What is the brain reserve? Speaker’s name to be announced at a later date The lectures will be given in French, with transparencies in English, and will be followed by a wide-ranging debate with the participants. CERN Medical Service - Pensioners Association - CERN-ESO (GAC-EPA)

  20. Apprenticeship at CERN

    CERN Multimedia

    Staff Association

    2016-01-01

    In 1961, based on the finding that the evolution of the labour market created a growing need for qualified staff, a first agreement between the Republic and Canton of Geneva and CERN was signed. One of the objectives of this agreement was the vocational training of young electronics and physics laboratory technicians. CERN, an important stakeholder in the local economy, highlighted with this agreement its willingness to participate in the local social and economic development. The first apprentice arrived at CERN in 1965. In 1971, the apprenticeship centre was created; it now hosts over twenty apprentices in total and welcomes about six new apprentices each year. These apprenticeships are for young people aged between 15 and 21 years, coming from one of the CERN Member States, and having completed their mandatory education, e.g. 11th grade in Switzerland or 3ème in France. The training is divided between working time at CERN and one or two days per week at school (CFPT in Geneva for electronics or ...

  1. Spaceflight participant visits CERN!

    CERN Multimedia

    Kathryn Coldham

    2016-01-01

    On 15 July, CERN welcomed spaceflight participant Anousheh Ansari.   Anousheh Ansari’s grin stretches from ear to ear, during an intriguing conversation with Nobel laureate Samuel C.C. Ting at AMS POCC. (Image: Maximilien Brice/CERN) Iranian-American Anousheh Ansari was the first-ever female spaceflight participant, spending eight days on the International Space Station (ISS) in 2006. She now has a new addition to her list of extraordinary sights ­– the home of the world’s largest particle accelerator: CERN.   On 15 July, Anousheh Ansari came to CERN and, unsurprisingly, visited the control room of the experiment attached to the ISS: the AMS. At the AMS Payload Operations Control Centre (AMS POCC) on CERN’s Prévessin site, she met the Nobel laureate Samuel Ting, spokesperson of the AMS experiment. Ansari and her accompanying guests were thrilled to expand their knowledge about CERN, its research and its...

  2. EU Commissioner visits CERN

    CERN Document Server

    2005-01-01

    European Commissioner Viviane Reding in front of one of the computers showing how the Grid works and, from left to right, Robert Aymar, CERN's Director-General, Wolfgang von Rüden, Head of the Information Technology Department, and Bob Jones, the newly appointed director of the EGEE project since 1st November. Viviane Reding, European Commissioner for Information Society and Media, visited CERN on 28 October. Accompanied throughout by CERN's Director-General, Robert Aymar, and the Head of the Information Technology Department, Wolfgang von Rüden, the Commissioner visited the ATLAS cavern before going on to the Information Technology Department, where she was given a complete overview of CERN's activities in the strategic field of Grid computing. Viviane Reding's visit coincided with the end of the EGEE (Enabling Grids for E-sciencE) conference, which took place in Pisa in Italy. Co-ordinated by CERN and funded by the European Commission, the EGEE project aims to set up a worldwide grid infrastructure for sc...

  3. CERN television news

    CERN Multimedia

    2002-01-01

    CERN events brought right to your desktop by the new video bulletin.   CERN now has its very own news broadcast , or rather 'webcast', with a host of special reports and even a star presenter. From today onwards, just go to the Bulletin's web page, click on the 'video news' link and sit back and enjoy the latest news about CERN, presented in images by Wendy Korda. The ten-minute newscast in both French and English, the Organization's two official languages, presents interviews, pictures of experiments and computer-generated graphics, bringing you right up to date with some of the Laboratory's latest stories. The show concludes with a selection of the best snapshots taken by the CERN Photo Lab. So every one or two months CERN's Audio-Video Service (ETT/DH) will be putting together a video news report that you can watch on your own desktop computer. Daniel Boileau, Patrick Gilbert de Vautibault and Jacques Fichet, the Service's three technicians, came up with the idea of producing this regular feat...

  4. CERN CAR STICKERS

    CERN Multimedia

    Service Accueil et Controle d'Accès; ST Division

    1999-01-01

    In accordance with Operational Circular n¡ 2, paragraph 21, CERN car stickers are to be renewed. The new stickers are now available and will be valid for a year.Youare therefore requested:either to obtain them from the distribution points for new stickers (see below); or to send us the application form below, duly completed, via the internal mail; or to complete the application form directly via the Web at the address: http://cern.ch/registration-stickers. Each vehicle has to carry a sticker and needs a separate application form.Vehicles bearing CERN diplomatic plates (CD07, 431K and CD series) do not need a sticker for access to the CERN areas.Thank you.List of distribution points:Registration Service (bldg 55 1st floor), open from 07h30 to 16h30. Building 33 (entrance hall), open from 08h00 to 18h00. Building 120 (ground floor), outside working hours.Name Surname CERN identification number Vehicle registration plates Country issuing the plates Vehicle ma...

  5. CERN Relay Race

    CERN Multimedia

    2009-01-01

    The CERN relay race, now in its 39th year, is already a well-known tradition, but this year the organizers say the event will have even more of a festival feeling. Just off the starting line of the CERN relay race.For the past few years, spectators and runners at the CERN relay race have been able to enjoy a beer while listening to music from the CERN music and jazz clubs. But this year the organizers are aiming for "even more of a festival atmosphere". As David Nisbet, President of the CERN running club and organizer of the relay race, says: "Work is not just about getting your head down and doing the theory, it’s also about enjoying the company of your colleagues." This year, on top of music from the Santa Luis Band and the Canettes Blues Band, there will be demonstrations from the Aikido and softball clubs, a stretching session by the Fitness club, as well as various stalls and of course, the well-earned beer from AGLUP, the B...

  6. Radiography at CERN

    CERN Multimedia

    HSE Unit

    2014-01-01

    What is industrial radiography? It is a non-destructive method with a wide variety of applications, such as inspecting the quality of a weld. It uses high-energy radioactive sources or an X-ray generator.   Is this inspection technique used at CERN? Yes, it is widely used at CERN by the EN-MME Group, which outsources the work to one or more companies, depending on the workload. Is it possible to carry out radiography anywhere at CERN? Yes, it is possible to carry out radiography in any building/accelerator/experiment area at CERN (including in areas which are not normally subject to radiological hazards). When is radiography carried out? It normally takes place outside of working hours (7 p.m. to 6 a.m.). How will I know if radiography is taking place in my building? If this activity is planned in a CERN building, notices will be affixed to all of its main entrance doors at least 24 hours in advance. What are the risks? There is a risk of exposure to very high levels of radiation, dep...

  7. Axions and the pulsation periods of variable white dwarfs revisited

    CERN Document Server

    Isern, J; Althaus, L G; Córsico, A H

    2010-01-01

    Axions are the natural consequence of the introduction of the Peccei-Quinn symmetry to solve the strong CP problem. All the efforts to detect such elusive particles have failed up to now. Nevertheless, it has been recently shown that the luminosity function of white dwarfs is best fitted if axions with a mass of a few meV are included in the evolutionary calculations. Our aim is to show that variable white dwarfs can provide additional and independent evidence about the existence of axions. The evolution of a white dwarf is a slow cooling process that translates into a secular increase of the pulsation periods of some variable white dwarfs, the so-called DAV and DBV types. Since axions can freely escape from such stars, their existence would increase the cooling rate and, consequently, the rate of change of the periods as compared with the standard ones. The present values of the rate of change of the pulsation period of G117-B15A are compatible with the existence of axions with the masses suggested by the lu...

  8. Mirror World, Supersymmetric Axion and Gamma Ray Bursts

    CERN Document Server

    Gianfagna, L; Nesti, F

    2004-01-01

    A modification of the relation between axion mass and the PQ constant permits a relaxation of the astrophysical constraints, considerably enlarging the allowed axion parameter space. We develop this idea in this paper, discussing a model for an {\\it ultramassive} axion, which essentially represents a supersymmetric Weinberg-Wilczek axion of the mirror world. The experimental and astrophysical limits allow a PQ scale $f_a\\sim 10^4-10^6$ GeV and a mass $m_a\\sim$ MeV, which can be accessible for future experiments. On a phenomenological ground, such an {\\it ultramassive} axion turns out to be quite interesting. It can be produced during the gravitational collapse or during the merging of two compact objects, and its subsequent decay into $e^+e^-$ provides an efficient mechanism for the transfer of the gravitational energy of the collapsing system to the electron-positron plasma. This could resolve the energy budget problem in the Gamma Ray Bursts and also help in understanding the SN type II explosion phenomena.

  9. Mirror world, supersymmetric axion and gamma ray bursts

    Energy Technology Data Exchange (ETDEWEB)

    Gianfagna, Leonida; Nesti, Fabrizio [Dipartimento di Fisica, Universita di L' Aquila, I-67010 Coppito AQ (Italy); INFN, Laboratori Nazionali del Gran Sasso, I-67010 Assergi, AQ (Italy); Giannotti, Maurizio [Sezione INFN di Ferrara, I 44100 FE (Italy)]. E-mail: giannotti@fe.infn.it

    2004-10-01

    A modification of the relation between axion mass and the PQ constant permits a relaxation of the astrophysical constraints, considerably enlarging the allowed axion parameter space. We develop this idea in this paper, discussing a model for an ultramassive axion, which essentially represents a supersymmetric Weinberg-Wilczek axion of the mirror world. The experimental and astrophysical limits allow a PQ scale f{sub a} {approx} 10{sup 4}-10{sup 6} GeV and a mass m{sub a} {approx} MeV, which can be accessible for future experiments. On a phenomenological ground, such an ultramassive axion turns out to be quite interesting. It can be produced during the gravitational collapse or during the merging of two compact objects, and its subsequent decay into e{sup +}e{sup -} provides an efficient mechanism for the transfer of the gravitational energy of the collapsing system to the electron-positron plasma. This could resolve the energy budget problem in the Gamma Ray Bursts and also help in understanding the SN type-II explosion phenomena. (author)

  10. Cosmic D-strings as Axionic D-term Strings

    CERN Document Server

    Blanco-Pillado, J J; Redi, M; Blanco-Pillado, Jose J.; Dvali, Gia; Redi, Michele

    2005-01-01

    In this work we derive non-singular BPS string solutions from an action that captures the essential features of a D-brane-anti-D-brane system compactified to four dimensions. The model we consider is a supersymmetric abelian Higgs model with a D-term potential coupled to an axion-dilaton multiplet. The strings in question are axionic D-term strings which we identify with the D-strings of type II string theory. In this picture the Higgs field represents the open string tachyon of the D-Dbar pair and the axion is dual to a Ramond Ramond form. The crucial term allowing the existence of non-singular BPS strings is the Fayet-Iliopoulos term, which is related to the tensions of the D-string and of the parent branes. Despite the presence of the axion, the strings are BPS and carry finite energy, due to the fact that the space gets very slowly decompactified away from the core, screening the long range axion field (or equivalently the theory approaches an infinitely weak 4D coupling). Within our 4D effective action w...

  11. Dalai Lama at CERN

    International Nuclear Information System (INIS)

    On 30 August CERN turned aside from its usual day-to-day preoccupations when Director-General Herwig Schopper played host to the Dalai Lama of Tibet and his entourage during the holy man's 1983 visit to Europe. In welcoming his visitor, Professor Schopper stressed the role of particle physics in helping to understand man's place in the cosmos, and how the Dalai Lama's interest would further the interrelation of science, philosophy and religion. The Dalai Lama visited the UA 1 experiment (rolled back into its 'garage' during the present fixed target operations at CERN) and the large installations for the neutrino experiments in the West Area of the SPS machine. There was an intriguing exchange of views with CERN theorists, who described how science has continually modified our view of the world around us

  12. Safety alarms at CERN

    CERN Document Server

    Ninin, P; Henny, L

    1998-01-01

    In order to operate the CERN accelerators complex safely, the acquisition, transport and management of safety alarms is of crucial importance. The French regulatory authority [Direction de Sûreté des Installations Nucléaires de Base (INB)] defines them as Level 3 alarms; they represent as such a danger for the life and require an immediate intervention of the Fire Brigade. Safety alarms are generated by fire and flammable gas detection systems, electrical emergency stops, and other safety related systems. Level 3 alarms are transmitted for reliability reasons to their operation centre: the CERN Safety Control Room (SCR) using two different media: the hard-wired network and a computer based system. The hard-wired networks are connected to local panels summarizing in 34 security areas the overall CERN geography. The computer based system offers data management facilities such as alarm acquisition, distribution, archiving and information correlation. The Level 3 alarms system is in constant evolution in order...

  13. CERN's new safety policy

    CERN Multimedia

    2014-01-01

    The documents below, published on 29 September 2014 on the HSE website, together replace the document SAPOCO 42 as well as Safety Codes A1, A5, A9, A10, which are no longer in force. As from the publication date of these documents any reference made to the document SAPOCO 42 or to Safety Codes A1, A5, A9 and A10 in contractual documents or CERN rules and regulations shall be deemed to constitute a reference to the corresponding provisions of the documents listed below.   "The CERN Safety Policy" "Safety Regulation SR-SO - Responsibilities and organisational structure in matters of Safety at CERN" "General Safety Instruction GSI-SO-1 - Departmental Safety Officer (DSO)" "General Safety Instruction GSI-SO-2 - Territorial Safety Officer (TSO)" "General Safety Instruction GSI-SO-3 - Safety Linkperson (SLP)" "General Safety Instruction GSI-SO-4 - Large Experiment Group Leader In Matters of Safety (LEXGLI...

  14. CERN welcomes European science

    CERN Multimedia

    2002-01-01

    On 3 and 4 October CERN will host a special workshop for Marie Curie fellows. This programme is a key plank in the EU's strategy for creating a European research area.     With thousands of scientists from all over the continent working together, CERN is already an exemplary European science showcase. On 3 and 4 October, the Laboratory will contribute further to unifying all European science by hosting a special workshop for EU-funded Marie Curie fellows. This scheme gives young researchers from around the continent the mobility to go to wherever Europe's best facilities in their chosen field happen to be. The event that will take place at CERN, entitled 'Special workshop of Marie Curie Fellows on research and training in physics and technology', organised together with the European Commission, is a continuation of a series of workshops with the aim, among others, of promoting young researchers, supporting their training and mobility, and facilitating the interdisciplinary dissemination of knowledge. Dur...

  15. CERN UN Roundtable

    CERN Document Server

    CERN. Geneva; Del Rosso, Antonella; Gillies, James

    2014-01-01

    In the spirit of strengthening links and sharing best practices among the two Organizations, UNOG and CERN will be jointly organizing a round table discussion on the issue of “The challenge of communicating science and technology to the world: issues and solutions”. It is hoped that the discussions can highlight the experience of various organizations and institutions in their efforts to communicate and inform in several languages on topics – science and technology – that are often perceived as distant and arduous by the layman. ==>> Please note that registrations are now closed. It is not necessary to register for this event if you plan to watch it live on http://webcast.cern.ch. Send your questions to the speakers by email to: question@cern.ch

  16. CMS Centre at CERN

    CERN Multimedia

    2007-01-01

    A new "CMS Centre" is being established on the CERN Meyrin site by the CMS collaboration. It will be a focal point for communications, where physicists will work together on data quality monitoring, detector calibration, offline analysis of physics events, and CMS computing operations. Construction of the CMS Centre begins in the historic Proton Synchrotron (PS) control room. The historic Proton Synchrotron (PS) control room, Opened by Niels Bohr in 1960, will be reused by CMS to built its control centre. TThe LHC@FNAL Centre, in operation at Fermilab in the US, will work very closely with the CMS Centre, as well as the CERN Control Centre. (Photo Fermilab)The historic Proton Synchrotron (PS) control room is about to start a new life. Opened by Niels Bohr in 1960, the room will be reused by CMS to built its control centre. When finished, it will resemble the CERN Contro...

  17. CHOEUR DU CERN

    CERN Document Server

    CHOEUR DU CERN

    2010-01-01

    Les répétitions du chœur du CERN reprendront le mercredi 15 septembre à 20.00 heures à l’amphithéâtre principal – bâtiment 500. Au programme la préparation de notre concert de Noël avec la Missa Brevis, KV115, de Léopold Mozart et de la musique de Noël d’Europe. Les personnes qui aiment chanter, notamment des sopranes et des ténors, sont les bienvenues. Pour tout contact s’adresser à : Baudouin Bleus - (tél.CERN 767 82 44) -(baudouin.bleus@cern.ch) ou Martin Gatehouse ( martin.gatehouse@wanadoo.fr) ou Jean-Paul Diss (jean-pauldiss@wanadoo.fr).  

  18. CERN Relay Race

    CERN Multimedia

    2005-01-01

    The CERN Relay Race will take place around the Meyrin site on Wednesday 18 May between 12.15 and 12.35. This year, weather permitting, there will be some new attractions in the start/finish area on the field behind the Main Building. You will be able to: listen to music played by the CERN Jazz Club; buy drinks at the bar organised by the CERN Running Club; buy lunch served directly on the terrace by the restaurant Novae. ATTENTION: concerning traffic, the recommendations are the same as always: If possible, please avoid driving on the site during this 20 minute period. If you do meet runners in your car, please STOP until they all have passed. Thank you for your understanding.

  19. Cern Cricket Club

    CERN Multimedia

    Cern Cricket Club

    2014-01-01

      Cern Cricket Club The CERN Cricket Club 2014 season has started earlier than usual, with a game scheduled for the first time ever on Easter Sunday.  Due to repair work for the damage done to the ground because of the “Bosons&More” party at the end of September, all games until June have had to be scheduled away. Net practice, which normally takes place on the ground from mid-April, will not start until mid-June. The club is always looking for new players and newcomers will be made very welcome. Anyone who is interested in joining the club should sign up on our web site: http://cern.ch/Club-Cricket/    

  20. Kandinsky College Visits CERN

    CERN Document Server

    CERN Video productions; Angelos Alexopoulos

    2012-01-01

    This video documents the visit of nine senior high school students of the Kandinsky College in Nijmegen (Netherelands) to CERN. The students visited many of CERN's experimental facilities, took part in a Cloud Chamber workshop, attended talks and roundtable discussions of SpacePart12 and worked on the evaluation of the Microcosm exhibition as part of a school inquiry-based research project. The students and their teacher, Paul de Haas (a participant of the High School Teachers 2012 Programme at CERN) were connected with Prof. Christine Kourkoumelis and George Vasileiadis at the University of Athens and learned hands-on how to analyse real physics events, including Higgs-like ones, from the ATLAS experiment at the LHC using the HYPATIA Applet.

  1. A SQUID-based microwave cavity search for dark-matter axions

    Energy Technology Data Exchange (ETDEWEB)

    Asztalos, S J; Carosi, G; Hagmann, C; Kinion, D; van Bibber, K; Hotz, M; Rosenberg, L; Rybka, G; Hoskins, J; Hwang, J; Sikivie, P; Tanner, D B; Bradley, R; Clarke, J

    2009-10-21

    Axions in the {mu}eV mass range are a plausible cold dark matter candidate and may be detected by their conversion into microwave photons in a resonant cavity immersed in a static magnetic field. The first result from such an axion search using a superconducting first-stage amplifier (SQUID) is reported. The SQUID amplifier, replacing a conventional GaAs field-effect transistor amplifier, successfully reached axion-photon coupling sensitivity in the band set by present axion models and sets the stage for a definitive axion search utilizing near quantum-limited SQUID amplifiers.

  2. Search for energetic cosmic axions utilizing terrestrial/celestial magnetic fields

    OpenAIRE

    Zioutas, K.; Thompson, D J; E. A. Paschos

    1998-01-01

    Orbiting $\\gamma$-detectors combined with the magnetic field of the Earth or the Sun can work parasitically as cosmic axion telescopes. The relatively short field lengths allow the axion-to-photon conversion to be coherent for $m_{axion} \\sim 10^{-4}$ eV, if the axion kinetic energy is above $\\sim 500$ keV (Earth's field), or, $\\sim 50$ MeV (Sun's field), allowing thus to search for axions from $e^+e^-$ annihilations, from supernova explosions, etc. With a detector angular resolution of $\\sim...

  3. Poland at CERN

    CERN Multimedia

    CERN Press Office. Geneva

    2000-01-01

    On 17 October 2000, the second Polish industrial and technological exhibition opens at CERN*. The first one was held five years ago and nine of the companies that were present then have come back again this year. Six of those companies were awarded contracts with CERN in 1995. Three Polish officials were present at the Opening Ceremony today: Mrs Malgorzata Kozlowska, Under-secretary of State in the State Committee for Scientific Research, Mr Henryk Ogryczak, Under-secretary of State in Ministry of Economy and Prof. Jerzy Niewodniczanski, President of National Atomic Energy Agency.

  4. CERN Relay Race

    CERN Document Server

    2008-01-01

    The CERN relay race will take place around the Meyrin site on Thursday 5 June starting at 12:15 p.m. If possible, please avoid driving on the site during this 20-minute period. If you do meet runners while driving your car, please STOP until they have all passed. Thank you for your cooperation. Details on how to register your team for the relay race are given on the Staff Association Bulletin web site. You can access the online registration form at: http://cern.ch/club-running-relay/form.html

  5. The significance of Cern

    CERN Multimedia

    Weisskopf,V

    Le Prof. V.Weisskopf, DG du Cern de 1961 à 1965, est né à Vienne, a fait ses études à Göttingen et a une carrière académique particulièrement riche. Il a travaillé à Berlin, Copenhague et Berlin et est parti aux Etats Unis pour participer au projet Manhattan et était Prof. au MTT jusqu'à 1960. Revenu en Europe, il a été DG du Cern et lui a donné l'impulsion que l'on sait.

  6. CERN Technical Training : Vista !

    CERN Multimedia

    HR Department

    2008-01-01

    You are running Vista on your new PC – or are planning to install it? The Technical Training service is organizing a half-day training course on the new features of the VISTA operating system. This course introduces the new interfaces and presents the new functionalities for people who are experienced in the use of Windows XP. The next bilingual sessions of this course will take place on 12 December 2008 and 30 January 2009. Register using our catalogue: http://cta.cern.ch/cta2/f?p=110:9 or contact us with your questions/comments at mailto:Technical.Training@cern.ch

  7. CERN Technical Training : Vista !

    CERN Multimedia

    HR Department

    2009-01-01

    Are you running Vista on your new PC – or are you planning to install it? The Technical Training service is organizing a half-day training course on the new features of the VISTA operating system. This course introduces the new interfaces and presents the new functionalities for people who are experienced in the use of Windows XP. The next bilingual session of this course will take place on 30 January 2009. Register using our catalogue: http://cta.cern.ch/cta2/f?p=110:9 or contact us with your questions/comments at mailto:Technical.Training@cern.ch

  8. CERN Technical Training : Vista !

    CERN Multimedia

    HR Department

    2008-01-01

    You are running Vista on your new PC – or are planning to install it? The Technical Training service is organizing a half-day training on the new features of the VISTA operating system. This course introduces the new interfaces and presents the new functionalities for people who are experienced using Windows XP. The next bilingual sessions of this course will take place on December 12, 2008 and January 30, 2009. Register using our catalogue : http://cta.cern.ch/cta2/f?p=110:9 or contact us with your questions/comments at Technical.Training@cern.ch

  9. CERN Technical Training : Vista !

    CERN Multimedia

    HR Department

    2008-01-01

    Are you running Vista on your new PC – or are you planning to install it? The Technical Training service is organizing a half-day training course on the new features of the VISTA operating system. This course introduces the new interfaces and presents the new functionalities for people who are experienced in the use of Windows XP. The next bilingual sessions of this course will take place on 12 December 2008 and 30 January 2009. Register using our catalogue: http://cta.cern.ch/cta2/f?p=110:9 or contact us with your questions/comments at mailto:Technical.Training@cern.ch

  10. CERN Technical Training : Vista !

    CERN Multimedia

    HR Department

    2008-01-01

    Are you running Vista on your new PC – or are planning to install it? The Technical Training service is organizing a half-day training course on the new features of the VISTA operating system. This course introduces the new interfaces and presents the new functionalities for people who are experienced in the use of Windows XP. The next bilingual sessions of this course will take place on 12 December 2008 and 30 January 2009. Register using our catalogue: http://cta.cern.ch/cta2/f?p=110:9 or contact us with your questions/comments at Technical.Training@cern.ch

  11. Constraining axion coupling constants from measuring the Casimir interaction between polarized test bodies

    Science.gov (United States)

    Bezerra, V. B.; Klimchitskaya, G. L.; Mostepanenko, V. M.; Romero, C.

    2016-08-01

    We propose an experiment for measuring the effective Casimir pressure between two parallel silicon carbide (SiC) plates with aligned nuclear spins. The prospective constraints on an axion-neutron coupling constant for both hadronic and grand unified theory (GUT) axions are calculated using the process of one-axion exchange. For this purpose, a general expression for the additional pressure arising between two polarized plates due to the exchange of one axion between their constituent fermions is derived. We demonstrate that only the polarization component perpendicular to the plates contributes to the pressure. The obtained pressure can be both repulsive and attractive depending on whether the polarizations of both plates are unidirectional or directed in opposite directions. It is shown that although the constraints on an axion-electron coupling obtained in the case of magnetized plates are not competitive, the constraints on an axion-neutron coupling found for plates with polarized nuclear spins are of the same order of magnitude as those obtained previously for the GUT axions alone using the process of two-axion exchange. The proposed experiment allows us also to strengthen the presently known constraints on the axion-neutron coupling constants of GUT axions by using both processes of one- and two-axion exchange.

  12. Quality of the Peccei-Quinn symmetry in the Aligned QCD Axion and Cosmological Implications

    CERN Document Server

    Higaki, Tetsutaro; Kitajima, Naoya; Takahashi, Fuminobu

    2016-01-01

    We show that the required high quality of the Peccei-Quinn symmetry can be naturally explained in the aligned QCD axion models where the QCD axion arises from multiple axions with decay constants much smaller than the axion window, e.g., around the weak scale. Even in the presence of general Planck-suppressed Peccei-Quinn symmetry breaking operators, the effective strong CP phase remains sufficiently small in contrast to the standard axion models without the alignment. The QCD axion potential has small or large modulations due to the symmetry breaking operators, which can significantly affect the axion cosmology. When the axions are trapped in different minima, domain walls appear and their scaling behavior suppresses the axion isocurvature perturbations at super-horizon scales. In extreme cases the QCD axion mass can be much heavier than in the conventional scenario, and becomes unstable in a cosmological time scale. Our scenario predicts many axions and saxions coupled to gluons, and they may be searched fo...

  13. CERN Diversity Newsletter - November 2015

    CERN Document Server

    Kaltenhauser, Kristin; CERN. Geneva. HR Department

    2015-01-01

    Quarterly CERN Diversity Newsletter, informing on recent and ongoing diversity activities, and interesting reads, videos and other links related to diversity. Subscribe here: https://diversity.web.cern.ch/2015/07/subscribe-diversity-newsletter

  14. Le CERN chasse les neutrinos

    CERN Document Server

    2005-01-01

    CERN Scientists have just completed the construction of the "target chamber", essential link of the CNGS Project (CERN Neutrinos to Gran Sasso) intended for better understanding these mysterious particles , the neutrinos

  15. CERN firemen share their expertise

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    Firemen from local fire brigades have been coming to CERN to learn modern fire-fighting techniques. This apparatus allows the simulation of the spectacular backdraft phenomenon, so firemen training at CERN learn to understand it.

  16. Une flamme pour le CERN

    CERN Multimedia

    2004-01-01

    For the 50th anniversary of CERN, letters posted from Saint Genis will bear a postmark to celebrate CERN's anniversary. Envelopes are also available from the Saint-Genis-Pouilly (France) post office (3 paragraphs)

  17. CERN Diversity Newsletter - September 2016

    CERN Document Server

    Guinot, Genevieve

    2016-01-01

    Quarterly CERN Diversity Newsletter, informing on recent and ongoing diversity activities, and interesting reads, videos and other links related to diversity. Subscribe here: https://diversity.web.cern.ch/2015/07/subscribe-diversity-newsletter

  18. CERN Diversity Newsletter - March 2016

    CERN Document Server

    Kaltenhauser, Kristin; CERN. Geneva. HR Department

    2016-01-01

    Quarterly CERN Diversity Newsletter, informing on recent and ongoing diversity activities, and interesting reads, videos and other links related to diversity. Subscribe here: https://diversity.web.cern.ch/2015/07/subscribe-diversity-newsletter

  19. Leptogenesis from Left-Handed Neutrino Production during Axion Inflation.

    Science.gov (United States)

    Adshead, Peter; Sfakianakis, Evangelos I

    2016-03-01

    We propose that the observed matter-antimatter asymmetry can be naturally produced as a by-product of axion-driven slow-roll inflation by coupling the axion to standard model neutrinos. We assume that grand unified theory scale right-handed neutrinos are responsible for the masses of the standard model neutrinos and that the Higgs field is light during inflation and develops a Hubble-scale root-mean-square value. In this setup, the rolling axion generates a helicity asymmetry in standard model neutrinos. Following inflation, this helicity asymmetry becomes equal to a net lepton number as the Higgs condensate decays and is partially reprocessed by the SU(2)_{L} sphaleron into a net baryon number. PMID:26991168

  20. Effects of axions on Nucleosynthesis in massive stars

    CERN Document Server

    Aoyama, Shohei

    2015-01-01

    We investigate the effect of the axion cooling on the nucleosynthesis in a massive star with $16M_{\\odot}$ by standard stellar evolution calculation. We find that the axion cooling suppresses the nuclear reactions in carbon, oxygen and silicon burning phases because of the extraction of the energy. As a result, larger amounts of the already synthesized neon and magnesium remain without being consumed to produce further heavier elements. Even in the case with the axion-photon coupling constant $g_{a\\gamma}= 10^{-11}$ GeV$^{-1}$, which is six times smaller than the current upper limit, the amount of neon and magnesium that remain just before the core-collapse supernova explosion is considerably larger than the standard value. This implies that we could give a more stringent constraint on $g_{a\\gamma}$ from the nucleosynthesis of heavy elements in massive stars.

  1. Searching for galactic axions through magnetized media: the QUAX proposal

    CERN Document Server

    Barbieri, R; Carugno, G; Gallo, C S; Lombardi, A; Ortolan, A; Pengo, R; Ruoso, G; Speake, C C

    2016-01-01

    We present a proposal to search for QCD axions with mass in the 100 $\\mu$eV range, assuming that they make a dominant component of dark matter. Due to the axion-electron spin coupling, their effect is equivalent to the application of an oscillating rf field with frequency and amplitude fixed by the axion mass and coupling respectively. This equivalent magnetic field would produce spin flips in a magnetic sample placed inside a static magnetic field, which determines the resonant interaction at the Larmor frequency. Spin flips would subsequently emit radio frequency photons that can be detected by a suitable quantum counter in an ultra-cryogenic environment. This new detection technique is crucial to keep under control the thermal photon background which would otherwise produce a too large noise.

  2. New constraints for heavy axion-like particles from supernovae

    CERN Document Server

    Giannotti, Maurizio; Nita, Rafaela

    2010-01-01

    We derive new constraints on the coupling of heavy pseudoscalar (axion-like) particles to photons, based on the gamma ray flux expected from the decay of these particles into photons. After being produced in the supernova core, these heavy axion-like particles would escape and a fraction decay into photons before reaching the Earth. We have calculated the expected flux on Earth of these photons from the supernovae SN 1987A and Cassiopeia A and compared our results to data from the Fermi Large Area Telescope. This analysis provides strong constraints on the parameter space for axion-like particles. For a particle mass of 100 MeV, we find that the Peccei-Quinn constant, $f_{pq}$, must be greater than $10^{15}$ GeV. Alternatively, for $\\fa=10^{12}$ GeV, we exclude the mass region between approximately 50 keV and 1 GeV

  3. A Bump in the Blue Axion Isocurvature Spectrum

    CERN Document Server

    Chung, Daniel J H

    2016-01-01

    Blue axion isocurvature perturbations are both theoretically well-motivated and interesting from a detectability perspective. These power spectra generically have a break from the blue region to a flat region. Previous investigations of the power spectra were analytic, which left a gap in the predicted spectrum in the break region due to the non-applicability of the used analytic techniques. We therefore compute the isocurvature spectrum numerically for an explicit supersymmetric axion model. We find a bump that enhances the isocurvature signal for this class of scenarios. A fitting function of three parameters is constructed that fits the spectrum well for the particular axion model we study. This fitting function should be useful for blue isocurvature signal hunting in data and making experimental sensitivity forecasts.

  4. Axion-Assisted Production of Sterile Neutrino Dark Matter

    CERN Document Server

    Berlin, Asher

    2016-01-01

    Sterile neutrinos can be generated in the early universe through oscillations with active neutrinos and represent a popular and well-studied candidate for our universe's dark matter. Stringent constraints from X-ray and gamma-ray line searches, however, have excluded the simplest of such models. In this letter, we propose a novel alternative to the standard scenario in which the mixing angle between the sterile and active neutrinos is a dynamical quantity, induced through interactions with a light axion-like field. As the energy density of the axion-like particles is diluted by Hubble expansion, the degree of mixing is reduced at late times, suppressing the decay rate and easily alleviating any tension with X-ray or gamma-ray constraints. We present a simple model which illustrates the phenomenology of this scenario, and also describe a framework in which the QCD axion is responsible for the production of sterile neutrinos in the early universe.

  5. Gravity Waves and Linear Inflation From Axion Monodromy

    Energy Technology Data Exchange (ETDEWEB)

    McAllister, Liam; /Cornell U., LEPP /Cornell U., Phys. Dept.; Silverstein, Eva; Westphal, Alexander; /SLAC /Stanford U., Phys. Dept.

    2010-08-26

    Wrapped branes in string compactifications introduce a monodromy that extends the field range of individual closed-string axions to beyond the Planck scale. Furthermore, approximate shift symmetries of the system naturally control corrections to the axion potential. This suggests a general mechanism for chaotic inflation driven by monodromy-extended closed-string axions. We systematically analyze this possibility and show that the mechanism is compatible with moduli stabilization and can be realized in many types of compactifications, including warped Calabi-Yau manifolds and more general Ricci-curved spaces. In this broad class of models, the potential is linear in the canonical inflaton field, predicting a tensor to scalar ratio r {approx} 0.07 accessible to upcoming cosmic microwave background (CMB) observations.

  6. Leptogenesis from left-handed neutrino production during axion inflation

    CERN Document Server

    Adshead, Peter

    2015-01-01

    We propose that the observed matter-antimatter asymmetry can be naturally produced as a byproduct of axion-driven slow-roll inflation by coupling the axion to standard-model neutrinos. We assume that GUT scale right-handed neutrinos are responsible for the masses of the standard model neutrinos and that the Higgs is a light field during inflation and develops a Hubble scale vacuum expectation value (VEV). In this set up, the rolling axion generates a helicity asymmetry in standard-model neutrinos. Following inflation, this helicity asymmetry becomes equal to a net lepton number as the Higgs VEV decays and is partially re-processed by the $SU(2)_{L}$ sphaleron into a net baryon number.

  7. On the 3-form formulation of axion potentials from D-brane instantons

    CERN Document Server

    García-Valdecasas, Eduardo

    2016-01-01

    The study of axion models and quantum corrections to their potential has experienced great progress by phrasing the axion potential in terms of a 3-form field eating up the 2-form field dual to the axion. Such reformulation of the axion potential has been described for axion monodromy models, and for axion potentials from non-perturbative gauge dynamics. In this paper we propose a 3-form description of the axion potentials from non-gauge D-brane instantons. Interestingly, the required 3-form field does not arise in the underlying geometry, but rather shows up in the KK compactification in the generalized geometry obtained when the backreaction of the D-brane instanton is taken into account.

  8. Widening the Axion Window via Kinetic and Stückelberg Mixings.

    Science.gov (United States)

    Shiu, Gary; Staessens, Wieland; Ye, Fang

    2015-10-30

    We point out that kinetic and Stückelberg mixings that are generically present in the low energy effective action of axions can significantly widen the window of axion decay constants. We show that an effective super-Planckian decay constant can be obtained even when the axion kinetic matrix has only sub-Planckian entries. Our minimal model involves only two axions, a Stückelberg U(1) and a modest rank instanton generating non-Abelian group. Below the mass of the Stückelberg U(1), there is only a single axion with a nonperturbatively generated potential. In contrast to previous approaches, the enhancement of the axion decay constant is not tied to the number of degrees of freedom introduced. We also discuss how kinetic mixings can lower the decay constant to the desired axion dark matter window. String theory embeddings of this scenario and their phenomenological features are briefly discussed. PMID:26565455

  9. Can Gravitational Instantons Really Constrain Axion Inflation?

    CERN Document Server

    Hebecker, Arthur; Theisen, Stefan; Witkowski, Lukas T

    2016-01-01

    Axions play a central role in inflationary model building and other cosmological applications. This is mainly due to their flat potential, which is protected by a global shift symmetry. However, quantum gravity is known to break global symmetries, the crucial effect in the present context being gravitational instantons or Giddings-Strominger wormholes. We attempt to quantify, as model-independently as possible, how large a scalar potential is induced by this general quantum gravity effect. We pay particular attention to the crucial issue which solutions can or cannot be trusted in the presence of a moduli-stabilisation and a Kaluza-Klein scale. An important conclusion is that, due to specific numerical prefactors, the effect is surprisingly small even in UV-completions with the highest possible scale offered by string theory. As we go along, we discuss in detail Euclidean wormholes, cored and extremal instantons, and how the latter arise from 5d Reissner-Nordstrom black holes. We attempt to dispel possible do...

  10. Axion-photon propagation in magnetized universe

    Science.gov (United States)

    Wang, Chen; Lai, Dong

    2016-06-01

    Oscillations between photons and axion-like particles (ALP) travelling in intergalactic magnetic fields have been invoked to explain a number of astrophysical phenomena, or used to constrain ALP properties using observations. One example is the anomalous transparency of the universe to TeV gamma rays. The intergalactic magnetic field is usually modeled as patches of coherent domains, each with a uniform magnetic field, but the field orientation changes randomly from one domain to the next (``discrete-varphi model''). We show in this paper that in more realistic situations, when the magnetic field direction varies continuously along the propagation path, the photon-to-ALP conversion probability P can be significantly different from the discrete-varphi model. In particular, P has a distinct dependence on the photon energy and ALP mass, and can be as large as 100%. This result can affect previous constraints on ALP properties based on ALP-photon propagation in intergalactic magnetic fields, such as TeV photons from distant Active Galactic Nucleus.

  11. Solitons of axion-dilaton gravity

    CERN Document Server

    Bakas, Ioannis

    1996-01-01

    We use soliton techniques of the two-dimensional reduced beta-function equations to obtain non-trivial string backgrounds from flat space. These solutions are characterized by two integers (n, m) referring to the soliton numbers of the metric and axion-dilaton sectors respectively. We show that the Nappi-Witten universe associated with the SL(2) x SU(2) / SO(1, 1) x U(1) CFT coset arises as an (1, 1) soliton in this fashion for certain values of the moduli parameters, while for other values of the soliton moduli we arrive at the SL(2)/SO(1, 1) x SO(1, 1)^2 background. Ordinary 4-dim black-holes arise as 2-dim (2, 0) solitons, while the Euclidean worm-hole background is described as a (0, 2) soliton on flat space. The soliton transformations correspond to specific elements of the string Geroch group. These could be used as starting point for exploring the role of U-dualities in string compactifications to two dimensions.

  12. WILL I AM visits CERN

    CERN Multimedia

    Noemi Caraban

    2013-01-01

    Will.i.am visited CERN in December 2013, fulfilling a wish he made in a video-link appearance at TEDxCERN earlier that year http://tedxcern.web.cern.ch/video/choral-performance-reach-stars-william. During his visit, he was shown the Antimatter Decelerator, the underground ATLAS experiment cavern and the CERN Control Centre. He also took the opportunity to promote CERN’s beam line for schools competition.

  13. CERN Video News on line

    CERN Document Server

    2003-01-01

    The latest CERN video news is on line. In this issue : an interview with the Director General and reports on the new home for the DELPHI barrel and the CERN firemen's spectacular training programme. There's also a vintage video news clip from 1954. See: www.cern.ch/video or Bulletin web page

  14. The CERN fire-fighters

    CERN Multimedia

    CERN PhotoLab

    1959-01-01

    CERN is one of the few laboratories to have its own fire station. The CERN fire brigade was set up in July 1956 to provide a rapid response in the event of an accident and to tackle the risks specific to the Organisation's activities. Six members of the CERN fire brigade in 1959. From left to right: Messrs. Ubertin, Dalbignat, Verny, Vosdey, Lissajoux, Favre.

  15. Cavity design for high-frequency axion dark matter detectors

    CERN Document Server

    Stern, I; Hoskins, J; Sikivie, P; Sullivan, N S; Tanner, D B; Carosi, G; van Bibber, K

    2016-01-01

    In an effort to extend the usefulness of microwave cavity detectors to higher axion masses, above ~8 $\\mu$eV (~2 GHz), a numerical trade study of cavities was conducted to investigate the merit of using variable periodic post arrays and regulating vane designs for higher-frequency searches. The results show that both designs could be used to develop resonant cavities for high-mass axion searches. Multiple configurations of both methods obtained the scanning sensitivity equivalent to approximately 4 coherently coupled cavities with a single tuning rod.

  16. May axion clusters be sources of fast radio bursts?

    CERN Document Server

    Pshirkov, Maxim S

    2016-01-01

    Fast radio bursts can be caused by some phenomena related to 'new physics'. One of the most prominent candidates of the kind are axion miniclusters which can undergo conversion into photons in magnetospheres of neutron stars. In this short research note this scenario is investigated and important caveats are examined. First, tidal disruption of miniclusters can considerably extend the time span of conversion process, making it impossible to reach necessary $\\mathcal{O}$(ms) level. Second, existing observations at two widely separated frequencies imply that axion-related scenarios can hardly explain entirety of FRBs.

  17. Gravity and axions from a random UV QFT

    CERN Document Server

    Kiritsis, Elias

    2014-01-01

    It is postulated that the UV QFT is enormous and random. The coupling of the Standard Model to such QFT is analyzed. It is argued that massless 4d gravity and axions are general avatars of the postulate. The equivalence principle emerges naturally as well as a concrete set of sources for its breaking. The axion scale is related to the 4d Planck scale as $f=M_P/N$, where $N$ is the "number of colors" of the (almost) hidden UV CFT.

  18. Modulation and diurnal variation in axionic dark matter searches

    CERN Document Server

    Semertzidis, Y

    2015-01-01

    In the present work we study possible time dependent effects in Axion Dark Matter searches employing resonant cavities. We find that the width of the resonance, which depends on the axion mean square velocity in the local frame, will show an annual variation due to the motion of the Earth around the sun (modulation). Furthermore, if the experiments become directional, employing suitable resonant cavities, one expects large asymmetries in the observed widths relative to the sun's direction of motion. Due to the rotation of the Earth around its axis, these asymmetries will manifest themselves as a diurnal variation in the observed width.

  19. Axion-like particle searches with sub-THz photons

    Science.gov (United States)

    Capparelli, L. M.; Cavoto, G.; Ferretti, J.; Giazotto, F.; Polosa, A. D.; Spagnolo, P.

    2016-06-01

    We propose a variation, based on very low energy and extremely intense photon sources, on the well established technique of Light-Shining-through-Wall (LSW) experiments for axion-like particle searches. With radiation sources at 30 GHz, we compute that present laboratory exclusion limits on axion-like particles might be improved by at least four orders of magnitude, for masses ma ≲ 0.01 meV. This could motivate research and development programs on dedicated single-photon sub-THz detectors.

  20. Axion-like particle searches with sub-THz photons

    CERN Document Server

    Capparelli, L; Ferretti, J; Giazotto, F; Polosa, A D; Spagnolo, P

    2015-01-01

    We propose a variation, based on very low energy and extremely intense photon sources, on the well established technique of Light-Shining-through-Wall (LSW) experiments for axion-like particle searches. With radiation sources at 30 GHz, we compute that present laboratory exclusion limits on axion-like particles might be improved by at least four orders of magnitude, for masses m_a <~ 0.01~meV. This could motivate research and development programs on dedicated single-photon sub-THz detectors.

  1. Towards universal axion inflation and reheating in string theory

    Energy Technology Data Exchange (ETDEWEB)

    Blumenhagen, Ralph [Max-Planck-Institut für Physik, Föhringer Ring 6, 80805 München (Germany); Plauschinn, Erik [Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università di Padova, Via Marzolo 8, 35131 Padova (Italy); INFN, Sezione di Padova, Via Marzolo 8, 35131 Padova (Italy)

    2014-09-07

    The recent BICEP2 measurements of B-modes indicate a large tensor-to-scalar ratio in inflationary cosmology, which points towards trans-Planckian evolution of the inflaton. We propose possible string-theory realizations thereof. Schemes for natural and axion monodromy inflation are presented in the framework of the type IIB large volume scenario. The inflaton in both cases is given by the universal axion and its potential is generated by F-terms. Our models are shown to feature a natural mechanism for inflaton decay into predominantly Standard Model particles.

  2. Towards axionic Starobinsky-like inflation in string theory

    Energy Technology Data Exchange (ETDEWEB)

    Blumenhagen, Ralph, E-mail: blumenha@mpp.mpg.de [Max-Planck-Institut für Physik, Föhringer Ring 6, 80805 München (Germany); Font, Anamaría, E-mail: anamaria.font@physik.lmu.de [Max-Planck-Institut für Physik, Föhringer Ring 6, 80805 München (Germany); Arnold Sommerfeld Center for Theoretical Physics, LMU, Theresienstr. 37, 80333 München (Germany); Fuchs, Michael, E-mail: mfuchs@mpp.mpg.de [Max-Planck-Institut für Physik, Föhringer Ring 6, 80805 München (Germany); Herschmann, Daniela, E-mail: herschma@mpp.mpg.de [Max-Planck-Institut für Physik, Föhringer Ring 6, 80805 München (Germany); Plauschinn, Erik, E-mail: erik.plauschinn@pd.infn.it [Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università di Padova, Via Marzolo 8, 35131 Padova (Italy); INFN, Sezione di Padova, Via Marzolo 8, 35131 Padova (Italy)

    2015-06-30

    It is shown that Starobinsky-like potentials can be realized in non-geometric flux compactifications of string theory, where the inflaton involves an axion whose shift symmetry can protect UV-corrections to the scalar potential. For that purpose we evaluate the backreacted, uplifted F-term axion-monodromy potential, which interpolates between a quadratic and a Starobinsky-like form. Limitations due to the requirements of having a controlled approximation of the UV theory and of realizing single-field inflation are discussed.

  3. Towards axionic Starobinsky-like inflation in string theory

    Directory of Open Access Journals (Sweden)

    Ralph Blumenhagen

    2015-06-01

    Full Text Available It is shown that Starobinsky-like potentials can be realized in non-geometric flux compactifications of string theory, where the inflaton involves an axion whose shift symmetry can protect UV-corrections to the scalar potential. For that purpose we evaluate the backreacted, uplifted F-term axion-monodromy potential, which interpolates between a quadratic and a Starobinsky-like form. Limitations due to the requirements of having a controlled approximation of the UV theory and of realizing single-field inflation are discussed.

  4. Towards universal axion inflation and reheating in string theory

    Directory of Open Access Journals (Sweden)

    Ralph Blumenhagen

    2014-09-01

    Full Text Available The recent BICEP2 measurements of B-modes indicate a large tensor-to-scalar ratio in inflationary cosmology, which points towards trans-Planckian evolution of the inflaton. We propose possible string-theory realizations thereof. Schemes for natural and axion monodromy inflation are presented in the framework of the type IIB large volume scenario. The inflaton in both cases is given by the universal axion and its potential is generated by F-terms. Our models are shown to feature a natural mechanism for inflaton decay into predominantly Standard Model particles.

  5. Constraining the Axion-Photon Coupling with Massive Stars

    CERN Document Server

    Friedland, Alexander; Wise, Michael

    2012-01-01

    We point out that stars in the mass window ~ 8-12 Msun can serve as sensitive probes of the axion-photon interaction, g_{A\\gamma\\gamma}. Specifically, for these stars axion energy losses from the helium-burning core would shorten and eventually eliminate the blue loop phase of the evolution. This would contradict observational data, since the blue loops are required, e.g., to account for the existence of Cepheid stars. Using the MESA stellar evolution code, modified to include the extra cooling, we conservatively find g_{A\\gamma\\gamma} <~ 0.8 * 10^{-10} GeV^{-1}, which compares favorably with the existing bounds.

  6. CERN's future secured

    CERN Multimedia

    2003-01-01

    The CERN Council held its 123rd session on 13 December under the chairmanship of Professor Maurice Bourquin. The election of the next Director General, the Baseline Plan for 2003-2010 and a new status for non-European states were among the items agreed. In addition, the European Investment Bank has agreed a loan of 300 million EUR to complete the LHC.

  7. Satellite photo of CERN

    CERN Multimedia

    1991-01-01

    This photo from the Landsat5 orbital telescope shows the locations of CERN's Meyrin and Prevessin sites near Geneva on the Swiss-France border. The tunnels housing the LHC and SPS accelerators are also illustrated. Photo credit: US Geological Survey/photo by Jane Doe.

  8. CERN and space science

    CERN Multimedia

    2009-01-01

    The connection between CERN and space is tangible this week, as former CERN Fellow and ESA astronaut Christer Fuglesang begins the second week of his mission on space shuttle flight STS-128. I had the pleasure to meet Christer back in October 2008 at an IEEE symposium in Dresden, and he asked me whether we could give him something related to CERN for his official flight kit. We thought of caps and tee-shirts, but in the end decided to give him a neutralino as a symbol of the link between particle physics and the science of the Universe. Neutralinos are theoretical particles that the LHC will be looking for, and if they exist, they’re strong candidates for the Universe’s dark matter. Christer’s neutralino is just a model, of course, escaped from the particle zoo, but what better symbol of the connectedness of science? Christer Fuglesang is not the only link CERN has with the space shuttle programme. We’ve recently learned that...

  9. DESY greets CERN

    CERN Multimedia

    Helmut Dosch, Chairman of the DESY Board of Directors, continues the series of occasional exchanges between CERN and other laboratories world-wide. As part of this exchange, CERN Director-General Rolf Heuer wrote a message in DESY inForm. Helmut Dosch took over from Albrecht Wagner in March 2009. You may think that the connections between CERN and DESY are obvious – particle physics labs with record-breaking accelerators and users from all around the world trying to solve mankind’s great mysteries. We even exchanged a few Directors. But did you know that there are similarities that are much closer to home – for example that both labs have names for their staff in the host language that are untranslatable into English? You are CERNoises and CERNois, we are DESYanerinnen and DESYaner. And in the end it’s the people it all comes down to. We at DESY admire the resourcefulness, enthusiasm, dedication and perseverance with which you at CERN have designed, built, started ...

  10. CERN celebrates another milestone

    CERN Multimedia

    2007-01-01

    "CERN (the European Organization for Nuclear Research) recently celebrated the lowering of the gigantic toroid magnet end-cap, using an EOT crane, onto the cavern floor. After a two-hour operation, the installation teams from ATLAS, PH-ATI and TS could finally breath a sigh of relief." (1/2 page)

  11. A heatwave at CERN

    CERN Multimedia

    Anaïs Schaeffer

    2011-01-01

    It's getting hot in Buildings 201 and 860, over-heating even... But no reason to panic! We're talking about the superheated water boilers of CERN's two heating plants, which heat all the buildings on the Meyrin and Prévessin sites.   View of the three boilers and the control centre of the Meyrin heating plant. CERN's two heating plants each comprise three gas* boilers, with generators of 15 MW in the case of Meyrin and 5 MW in the case of Prévessin. Both inject pressurised water, superheated to 125 degrees, into several kilometres of pipes, 22 km on the Meyrin site and 5 km in Prévessin. "A single boiler is sufficient most of the time but a second kicks in automatically during very cold weather, and a third is there on stand-by," explains Christophe Martel, head of the GS Department section responsible for CERN's heating and air-conditioning systems. All of CERN's buildings have a sub-station that receives the superheated water from the boilers an...

  12. CERN fellows and visitors

    CERN Multimedia

    Penney, R. W.

    1963-01-01

    This article describes the Fellowship and Visitor Programme as it is at present, detailing the various headings under which the visitors come and indicating the methods by which they are chosen. The way in which their work is integrated into the general scientific activity of CERN is discussed briefly.

  13. CERN CROQUET CLUB

    CERN Multimedia

    Cern Croquet Club

    2015-01-01

    CERN CROQUET CLUB   Prévessin site Introduction to croquet, and barbecue, at the club from 18.00 on Thursday 30th April. Please Email norferga@orange.fr by 28th April if you are coming.  Please wear flat-soled shoes. Looking forward to seeing. Norman Eatough, President

  14. CERN-Russian meeting

    CERN Multimedia

    1974-01-01

    (front) V.P Dzhelepov (Dubna) (2nd row) A. Serov (State Committee), I.G. Morozov (Vice-Minister for Atomic Energy), V.S. Kaftanov (ITEP) (back) A. Derevschikov, R. Anthoine, V. Savrin, S. Nurushev, E. Gabathuler, M. Steuer (see CERN Courier of August 1974)

  15. CERN confirms LHC schedule

    CERN Multimedia

    2003-01-01

    The CERN Council held its 125th session under the chairmanship of Professor Maurice Bourquin. Highlights of the meeting included confirmation that the Large Hadron Collider (LHC) and its detectors are on schedule for a 2007 start-up, and that the LHC computing grid (LCG) project is about to reach a major milestone (1 page).

  16. CERN in detail

    CERN Multimedia

    Laëtitia Pedroso

    2010-01-01

    Before, you had to go on the TPG website to find a tram-route, use Google Maps to see an aerial photo of CERN, and look for CERN buildings on map.web.cern.ch. Now, that's ancient history, with a new Geographical Information System (GIS) Portal set up by the Design Office and Patrimony Service (GS/SEM/DOP).  It's a one-stop-shop for all this information and much more.   A screenshot of the GIS Portal. Over the past few days, you might have noticed the new interface called MAPSearch that pops up when you make a building search using the Building and Roads field on the CERN homepage. This is a simplified version of the new GIS web Portal, a project on which the GS Department's Design Office and Patrimony Service has been working since January 2010. "In today's informatics age, we need to respond ever more quickly to increasing numbers of specific user requests," explains Project Leader Youri Robert. This is more than just a new release of an old tool, it's a completely n...

  17. The CERN Accelerator School

    CERN Multimedia

    2016-01-01

    Introduction to accelerator physics The CERN Accelerator School: Introduction to Accelerator Physics, which should have taken place in Istanbul, Turkey, later this year has now been relocated to Budapest, Hungary.  Further details regarding the new hotel and dates will be made available as soon as possible on a new Indico site at the end of May.

  18. The CERN Accelerator School

    CERN Multimedia

    2016-01-01

      Introduction to accelerator physics This course will take place in Istanbul, Turkey, from 18 to 30 September 2016. It is now open for registration, and further information can be found here: http://cas.web.cern.ch/cas/Turkey-2016/Turkey-advert.html

  19. Cern Women's Club

    CERN Multimedia

    Club des cernoises

    2013-01-01

    Christmas SaleTuesday 26th November 2013, from 9:00 to 11:00 Main Building 60 Ground Floor Those interested in helping should come along. New arrivals and all members are cordially invited. You can enrol for membership, renew membership, find out about and sign up for our activities. Visit our website: http://club-womensclub.web.cern.ch.

  20. CERN CAR CLUB

    CERN Multimedia

    Automobile club

    2009-01-01

    You are cordially invited to the next General Assembly of the CERN Car Club Tuesday 12 January 2010 at 5:45pm Bldg. 593 / room 11 As the end of 2009 is approaching, it is time to think about renewing your subscription. Therefore next time you are on the CERN-Meyrin site or at the Post Office counter don’t forget to fill in the payment slip to continue to be a part of our large family. The fee remains unchanged: 50 CHF. For those of you who are regular users of our equipment and who know of all the advantages that the club is in a position to offer, it seems pointless to give details, we are sure that many of you have made use of them and are satisfied. We remind you everyone working on CERN site is entitled to become a member of our club, this includes industrial support personnel and staff of companies which have a contract with CERN. If you are not yet a member, come and visit us! We will be happy to welcome you and show you the facilities, or you can visit our web site. The use of the club&...