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Sample records for cern axion solar

  1. The CERN axion solar telescope (CAST)

    Aalseth, C.E.; Arik, E.; Autiero, D.; Avignone, F.T.; Barth, K.; Bowyer, S.M.; Brauninger, H.; Brodzinski, R.L.; Carmona, J.M.; Cebrian, S.; Celebi, G.; Cetin, S.; Collar, J.I.; Creswick, R.; Delbart, A.; Delattre, M.; DiLella, L.; De Oliveira, R.; Eleftheriadis, Ch.; Erdutan, N.; Fanourakis, G.; Farach, H.A.; Fiorini, C.; Geralis, Th.; Giomataris, I.; Girard, T.A.; Gninenko, S.N.; Golubev, N.A.; Hasinoff, M.; Hoffmann, D.; Irastorza, I.G.; Jacoby, J.; Jeanneau, F.; Knopf, M.A.; Kovzelev, A.V.; Kotthaus, R.; Krcmar, M.; Krecak, Z.; Lakic, B.; Liolios, A.; Ljubicic, A.; Lutz, G.; Longoni, A.; Luzon, 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.; Sampieto, 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, K.

    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 gαγγ -11 GeV -1 can be reached for m α ≤ 10 -2 eV, and with a gas filled tube-can reach gαγγ ≤ 10 -10 GeV -1 for axion masses m α < 2eV

  2. Prospects for the CERN Axion Solar Telescope Sensitivity to 14.4 keV Axions

    Jakovcic, K; Aune, S; Avignone, F T; Barth, K; Belov, A; Beltrn, B; Bruninger, H; Carmona, J M; Cebrin, S; Collar, J I; Dafni, T; Davenport, M; Di Lella, L; Eleftheriadis, C; Fanourakis, G K; Ferrer-Ribas, E; Fischer, H; Franz, J; Friedrich, P; Geralis, T; Giomataris, Ioanis; Gninenko, S; Hasinoff, M D; Heinsius, F H; Hoffmann, Dieter H H; Irastorza, I G; Jacoby, J; Kang, D; Knigsmann, K; Kotthaus, R; Krcmar, M; Kousouris, a K; Kuster, M; Laki, B; Lasseur, C; Liolios, A; Ljubici, A; Lutz, G; Luzn, G; Miller, D W; Morales, A; Morales, J; Ortiz, A; Papaevangelou, T; Placci, A; Raffelt, G; Ruz, J; Riege, H; Semertzidis, Y K; Serpico, Pasquale Dario; Stewart, o L; Vieira, J D; Villar, J; Vogel, J; Walckiers, L; Zioutas, K; Jakovcic, Kresimir

    2007-01-01

    The CERN Axion Solar Telescope (CAST) is searching for solar axions using the 9.0 T strong and 9.26 m long transverse magnetic field of a twin aperture LHC test magnet, where axions could be converted into X-rays via reverse Primakoff process. Here we explore the potential of CAST to search for 14.4 keV axions that could be emitted from the Sun in M1 nuclear transition between the first, thermally excited state, and the ground state of 57Fe nuclide. Calculations of the expected signals, with respect to the axion-photon coupling, axion-nucleon coupling and axion mass, are presented in comparison with the experimental sensitivity.

  3. New solar axion search using the CERN Axion Solar Telescope with 4He filling

    Arik, M.; Aune, S.; Barth, K.; Belov, A.; Bräuninger, H.; Bremer, J.; Burwitz, V.; Cantatore, G.; Carmona, J. M.; Cetin, S. A.; Collar, J. I.; Da Riva, E.; Dafni, T.; Davenport, M.; Dermenev, A.; Eleftheriadis, C.; Elias, N.; Fanourakis, G.; Ferrer-Ribas, E.; Galán, J.; García, J. A.; Gardikiotis, A.; Garza, J. G.; Gazis, E. N.; Geralis, T.; Georgiopoulou, E.; Giomataris, I.; Gninenko, S.; Gómez Marzoa, M.; Hasinoff, M. D.; Hoffmann, D. H. H.; Iguaz, F. J.; Irastorza, I. G.; Jacoby, J.; Jakovčić, K.; Karuza, M.; Kavuk, M.; Krčmar, M.; Kuster, M.; Lakić, B.; Laurent, J. M.; Liolios, A.; Ljubičić, A.; Luzón, G.; Neff, S.; Niinikoski, T.; Nordt, A.; Ortega, I.; Papaevangelou, T.; Pivovaroff, M. J.; Raffelt, G.; Rodríguez, A.; Rosu, M.; Ruz, J.; Savvidis, I.; Shilon, I.; Solanki, S. K.; Stewart, L.; Tomás, A.; Vafeiadis, T.; Villar, J.; Vogel, J. K.; Yildiz, S. C.; Zioutas, K.; CAST Collaboration

    2015-07-01

    The CERN Axion Solar Telescope (CAST) searches for a →γ conversion in the 9 T magnetic field of a refurbished LHC test magnet that can be directed toward the Sun. Two parallel magnet bores can be filled with helium of adjustable pressure to match the x-ray refractive mass mγ to the axion search mass ma. After the vacuum phase (2003-2004), which is optimal for ma≲0.02 eV , we used 4He in 2005-2007 to cover the mass range of 0.02-0.39 eV and 3He in 2009-2011 to scan from 0.39 to 1.17 eV. After improving the detectors and shielding, we returned to 4He in 2012 to investigate a narrow ma range around 0.2 eV ("candidate setting" of our earlier search) and 0.39-0.42 eV, the upper axion mass range reachable with 4He, to "cross the axion line" for the KSVZ model. We have improved the limit on the axion-photon coupling to ga γ<1.47 ×10-10 GeV-1 (95% C.L.), depending on the pressure settings. Since 2013, we have returned to the vacuum and aim for a significant increase in sensitivity.

  4. CrossRef The CERN Axion Solar Telescope

    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.

  5. The CERN Axion Solar Telescope (CAST): Status and Prospects

    Irastorza, I. G.(Universidad de Zaragoza); Andriamonje, S (DAPNIA, Centre d' Etudes de Saclay); Arik, E (Bogazici Universitesi); Autiero, D (European Organization for Nuclear Research); Avignone, F T.(South Carolina, Univ Of); Barth, K (European Organization for Nuclear Research); Brauninger, H (Max-Planck-Institut fur Extraterrestrische Physik); Brodzinski, Ronald L.(BATTELLE (PACIFIC NW LAB)); Carmona, J. M.(Universidad de Zaragoza); Cebrian, S (Unknown); Cetin, S (Bogazici Universitesi); Collar, J I.(Chicago, University Of); Creswick, R (South Carolina, Univ Of); De Oliveira, R (European Organization for Nuclear Research); Delbart, A (Centre d' Etudes de Saclay); Di Lella, L (European Organization for Nuclear Research); Eleftheriadis, Ch (Aristotle University of Thessaloniki); Fanourakis, G (National Research Center for Physical Sciences, Demokritos, Greece); Farach, H A.(South Carolina, Univ Of); Fischer, H (Albert-Ludwigs-Universitat Freiburg); Formenti, F (European Org for Nuclear Research); Geralis, Th. (National Research Center for Physical Sciences, Demokritos, Greece); Giomataris, I (Centre d' Etudes de Saclay, Gif-Sur-Yvette, France); Gninenko, S. N.(Institue for Nuclear Research, Moscow, Russia); Goloubev, N (Institute for Nuclear Research); Hartman, R (Max-Planck-Institut fur Extraterrestrische Physik); Hasinoff, M (British Columbia,University of); Hoffmann, D (Technische Universitat Darmstadt); Jacoby, J (Technische Universitat Darmstadt); Kang, D (Albert-Ludwigs-Universitat Freiburg); Konigsmann, K (Albert-Ludwigs-Universitat Freiburg); Kotthaus, R (Max-Planck-Institut fur Physik, Muenchen, Germany); Krcmar, M (Ruder Boskovic Institute); Kuster, M (Max-Planck-Institute fur Extraterrestrische Physik); Lakic, B (Ruder Boskovic Institute, Zagreb, Croatia); Liolios, A (Universidade de Lisboa); Ljubicic, A (Ruder Boskovic Institute, Zagreb, Croatia); Lutz, G (Max-Planck-Institut fur Physik, Muenchen, Germany); Luzon, G (Universidad de Zaragoza); Miley, Harr

    2003-02-10

    The CAST experiment is being mounted at CERN. It will make use of a decommissioned LHC test magnet to look for solar axions through its conversion into Photons inside the magnetic field. The magnet has a field of 9.6 Tesla and length of 10 m and is installed in a platform which allows to move it+ or - 8 degrees vertically and+ or - 10 to the 11th power horizontally. According to these numbers we expect a sensitivity in axion-photon coupling gaT"~ ,~< 5 10 -11 GeV -1 for ma~< 0.02 eV, and with a gas filled tube ga~~< 10 -l GeV -a for ma~< 1 eV.

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

    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.

  7. Search for solar axions the CAST experiment at CERN

    Beltran, Berta; Arsov, V.; Aune, S.; Autiero, D.; Avignone, F.; Barth, K.; Belov, A.; Brauninger, H.; Carmona, J.M.; Cebrian, 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.; Hartmann, R.; Hasinoff, M.D.; Heinsius, F.H.; Hoffmann, D.H.H.; Irastorza, I.G.; Jacoby, J.; Kang, D.; Konigsmann, Kay; Kotthaus, R.; Krcmar, M.; Kousouris, K.; Kuster, M.; Lakic, B.; Lasseur, C.; Liolios, A.; Ljubicic, A.; Lutz, G.; Luzon, G.; Miller, David Wilkins; 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.; Zioutas, K.; Beltran, Berta

    2006-01-01

    Hypothetical axion-like particles with a two-photon interaction would be produced in the sun by the Primakoff process. In a laboratory magnetic field they would be transformed into X-rays with energies of a few keV. The CAST experiment at CERN is using a decommissioned LHC magnet as an axion helioscope in order to search for these axion-like particles. The analysis of the 2003 data has shown no signal above the background, thus implying an upper limit to the axion-photon coupling < 1.16*10^{-10} GeV^{-1} at 95% CL for m_{a} <~ 0.02 eV. The stable operation of the experiment during 2004 data taking allow us to anticipate that this value will be improved. At the end of 2005 we expect to start with the so-called second phase of CAST, when the magnet pipes will be filled with a buffer gas so that the axion-photon coherence will be extended. In this way we will be able to search for axions with masses up to 1 eV.

  8. Suche nach solaren Axionen mit dem CCD-Detektor in CAST (CERN Axion Solar Telescope)

    Kang, Donghwa

    2007-01-01

    The CERN Axion Solar Telescope (CAST) experiment at CERN searches for solar axions with energies in the keV range. Axions could be produced in the Sun's core by the interaction of thermal photons with virtual photons of the strong electromagnetic field. In this experiment, the solar axions can be converted to photons in the field of a 9 Tesla superconducting magnet. At both ends of the 10 m long dipole magnet, three different X-ray detectors were installed, which are sensitive in the interesting photon energy range. This thesis is devoted to the determination of an upper limit on the axion-photon coupling constant g$_{a\\gamma}$. The analysis is based on the data taken by the CCD detector in the CAST experiment during the years 2003 and 2004. First results of the 2003 data taking were published showing no significant signal above background. However, these results constrain the upper limit of the axion-photon coupling constant by a factor 5 compared to previous axion search experiments. Moreover, the result of...

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

    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

    2014-03-07

    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.

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

    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.; CAST Collaboration

    2014-03-01

    The CERN Axion Solar Telescope has finished its search for solar axions with He3 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.

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

    Arik, M.; 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.; Lozza, V.; 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.

    2014-01-01

    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.

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

    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.

  13. Commissioning and First Operation of the Cryogenics for the CERN Axion Solar Telescope (CAST)

    Barth, K; Passardi, Giorgio; Pezzetti, M; Pirotte, O; Stewart, L; Vullierme, B; Walckiers, L; Zioutas, Konstantin

    2004-01-01

    A new experiment, the CERN Axion Solar Telescope (CAST) was installed and commissioned in 2002. Its aim is to experimentally prove the existence of an as yet hypothetical particle predicted by theory as a solution of the strong CP problem and possible candidate for galactic dark matter. The heart of the detector consists of a decommissioned 10-m long LHC superconducting dipole prototype magnet, providing a magnetic field of up to 9.5 T. The whole telescope assembly is aligned with high precision to the core of the sun. If they exist, axions could be copiously produced in the core of the sun and converted into photons within the transverse magnetic field of the telescope. The converted low-energy solar axion spectrum, peaked around a mean energy of 4.4 keV, can then be focused by a special x-ray mirror system and detected by low-background photon detectors, installed on each end of the telescopes twin beam pipes. This paper describes the external and proximity cryogenic system and magnet commissioning as well ...

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

    Cebrián, S; Kuster, M.; Beltran, B.; Gomez, H.; Hartmann, R.; Irastorza, I. G.; Kotthaus, R.; Luzon, G.; Morales, J.; Ruz, J.; Struder, 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...

  15. Axion searches at CERN with the CAST Telescope

    Eleftheriadis, Christos; Arik, E.; Autiero, D.; Avignone, F.; Barth, K.; Bingol, E.; Brauninger, H.; Brodzinski, R.; Carmona, J.; Chesi, E.; Cebrian, S.; Cetin, S.; Cipolla, G.; Collar, J.; Creswick, R.; Dafni, T.; Davenport, M.; De Oliveira, R.; Dedoussis, S.; Delbart, A.; Di Lella, L.; Fanourakis, G.; Farach, H.; Fischer, H.; Formenti, F.; Geralis, T.; Giomataris, I.; Gninenko, S.; Goloubev, N.; Hartmann, R.; Hasinoff, M.; Hoffmann, D.; Irastorza, I.G.; Jacoby, J.; Kang, D.; Konigsmann, Kay; 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.; Vasileiou, V.; Villar, J.; Vullierme, B.; Walckiers, L.; Zachariadou, K.; Zioutas, K.

    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.

  16. Solar axion search with the CAST experiment

    Aune, S.

    2008-01-01

    The CAST (CERN Axion Solar Telescope) experiment is searching for solar axions by their conversion into photons inside the magnet pipe of an LHC dipole. The analysis of the data recorded during the first phase of the experiment with vacuum in the magnet pipes has resulted in the most restrictive experimental limit on the coupling constant of axions to photons. In the second phase, CAST is operating with a buffer gas inside the magnet pipes in order to extent the sensitivity of the experiment to higher axion masses. We will present the first results on the $^4{He}$ data taking as well as the system upgrades that have been operated in the last year in order to adapt the experiment for the $^3{He}$ data taking. Expected sensitivities on the coupling constant of axions to photons will be given for the recent $^3{He}$ run just started in March 2008.

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

    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.

  18. The search for solar axions in the CAST experiment

    Kang, Donghwa; Arsov, V.; Aune, S.; Autiero, D.; Avignone, F.T.; Barth, K.; Belov, A.; Beltran, B.; Brauninger, H.; Carmona, J.M.; Cebrian, 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.; Konigsmann, Kay; Kotthaus, R.; Krcmar, M.; Kousouris, K.; Kuster, M.; Lakic, B.; Lasseur, C.; Liolios, A.; Ljubicic, A.; Lutz, G.; Luzlon, G.; Miller, David Wilkins; 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.; Serpico, P.; Semertzidis, Y.; Stewart, L.; Vieira, J.D.; Villar, J.; Vogel, J.; Walckiers, L.; Zachariadou, K.; Zioutas, K.; Kang, Donghwa

    2006-01-01

    The CAST (CERN Axion Solar Telescope) experiment at CERN searches for solar axions with energies in the keV range. It is possible that axions are produced in the core of the sun by the interaction of thermal photons with virtual photons of strong electromagnetic fields. In this experiment, the solar axions can be reconverted to photons in the transversal field of a 9 Tesla superconducting magnet. At both ends of the 10m-long dipole magnet three different X-ray detectors were installed, which are sensitive in the interesting photon energy range. Preliminary results from the analysis of the 2004 data are presented: g$_{a\\gamma}<0.9\\times10^{-10}$ GeV$^{-1}$ at 95% C.L. for axion masses m$_{a} <$ 0.02 eV. At the end of 2005, data started to be taken with a buffer gas in the magnet pipes in order to extend the sensitivity to axion masses up to 0.8 eV.

  19. Search for Solar Axions with the CAST-Experiment

    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.

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

    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 ...

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

    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 ...

  2. New solar axion search in CAST with $^4$He filling

    Arik, M; Barth, K; Belov, A; Brauninger, H; Bremer, J; Burwitz, V; Cantatore, G; Carmona, J M; Cetin, S A; Collar, J I; Da Riva, E; Dafni, T; Davenport, M; Dermenev, A; Eleftheriadis, C; Elias, N; Fanourakis, G; Ferrer-Ribas, E; Galan, J; Garcia, J A; Gardikiotis, A.; Garza, J G; Gazis, E N; Geralis, T; Georgiopoulou, E; Giomataris, I; Gninenko, S; Marzoa, M Gomez; Hasinoff, M D; Hoffmann, D H H; Iguaz, F J; Irastorza, I G; Jacoby, J; K.Jakovcic; Karuza, M; Kavuk, M; Krcmar, M; Kuster, M; Lakic, B; Laurent, J M; Liolios, A; Ljubicic, A; Luzon, G; Neff, S; Niinikoski, T; Nordt, A; Ortega, I; Papaevangelou, T; Pivovaroff, M .J; Raffelt, G; Rodriguez, A; Rosu, M; Ruz, J; Savvidis, I; Shilon, I; Solanki, S K; Stewart, L; Tomas, A; Vafeiadis, T; Villar, J; Vogel, J K; Yildiz, S C; Zioutas, K

    2015-01-01

    The CERN Axion Solar Telescope (CAST) searches for $a\\to\\gamma$ conversion in the 9 T magnetic field of a refurbished LHC test magnet that can be directed toward the Sun. Two parallel magnet bores can be filled with helium of adjustable pressure to match the X-ray refractive mass $m_\\gamma$ to the axion search mass $m_a$. After the vacuum phase (2003--2004), which is optimal for $m_a\\lesssim0.02$ eV, we used $^4$He in 2005--2007 to cover the mass range of 0.02--0.39 eV and $^3$He in 2009--2011 to scan from 0.39--1.17 eV. After improving the detectors and shielding, we returned to $^4$He in 2012 to investigate a narrow $m_a$ range around 0.2 eV ("candidate setting" of our earlier search) and 0.39--0.42 eV, the upper axion mass range reachable with $^4$He, to "cross the axion line" for the KSVZ model. We have improved the limit on the axion-photon coupling to $g_{a\\gamma}< 1.47\\times10^{-10} {\\rm GeV}^{-1}$ (95% C.L.), depending on the pressure settings. Since 2013, we have returned to vacuum and aim for a s...

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

    García, 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...

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

    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...

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

    Ferrer Ribas, E.; Aunes, S.; Barth, K.; 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.; 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.; 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...

  6. Results and perspectives of the Solar axion search with the CAST experiment

    Ferrer Ribas, E.; Aune, S.; Arik, M.

    2014-01-01

    The status of the solar axion search with the CERN Axion Solar Telescope (CAST) will be presented. The detection principle is based on the coupling of an incoming axion to a virtual photon provided by the transverse field of an intense dipole magnet, being transformed into a real, detectable photon that carries the energy and the momentum of the original axion. The magnet can be filled with a buffer gas providing an effective mass to the photon. 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 hour of data taking at each of 252 different pressure settings we have scanned the axion mass range 0.30 eV ≤ m a ≤ 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 aγ ≤2.3*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 shown teaching mean upper limits on the axion-photon coupling of g aγ ≤3.5*10 -10 GeV -1 at 95% C.L. Expected sensibilities for the extension of the CAST program up to 2014 will be presented. Moreover long term options for a new helio-scope experiment will be evoked

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

    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.

  8. Search for solar axions with the X-ray telescope of the CAST experiment (phase II)

    Nordt, Annika

    2009-01-01

    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 ( 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 4 He inside the magnet. The result for the coupling constant of axions to photons is: g αγγ -10 GeV -1 (95%C.L.) for m 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.)

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

    Vogel, J.

    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 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)

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

    Irastorza, Igor G; Avignone, F. T.; 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.; Dobrich, B. D.; Dratchnev, I.; Dudarev, A.; Eleftheriadis, C.; Fanourakis, G.; Ferrer-Ribas, E.; Galan, J.; Garcia, J. A.; Garza, J. G.; Geralis, T.; Gimeno, B.; Giomataris, I.; Gninenko, S.; Gomez, H.; Gonzalez-Diaz, D.; Guendelman, E.; Hailey, C. J.; Hiramatsu, T.; Hoffmann, D. H. H.; Horns, D.; Iguaz, F. J.; Isern, J.; Imai, K.; Jakobsen, A. C.; Jaeckel, J.; Jakovcic, K.; Kaminski, J.; Kawasaki, M.; Karuza, M.; Krcmar, M.; Kousouris, K.; Krieger, C.; Lakic, B.; Limousin, O.; Lindner, A.; Liolios, A.; Luzon, 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.; van Bibber, K.; Vedrine, P.; Villar, J. A.; Vogel, J. K.; Walckiers, L.; Weltman, A.; Wester, W.; Yildiz, S. C.; Zioutas, K.; CERN. Geneva. SPS and PS Experiments Committee; SPSC

    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...

  11. CERN... Solar Style

    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. A Solar Axion Search Using a Decommissioned LHC Test Magnet

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

    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...

  13. Axion experiment makes its debut

    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)

  14. Axions

    Rosenfeld, R.

    1985-01-01

    The Peccei-Quinn symmetry is a possible solution to the strong C.P. violation problem resulting from instantons contributions. It is the objective of this dissertation to study models which incorporate the Paccei-Ouinn symmetry as well as its consequences, for instance, the exiatence of a Goldstone pseudoboson named axion and the appearence of topologically satble structures generated at the spontaneous breakdown of the Peccei-Quinn symmetry. We also study the interchanged between axion models and Cosmology, particularly the influence of axions on the process of galsxy formation. (author) [pt

  15. Search for Axions with Micromegas Detectors in the CERN CAST Experiment

    YILDIZ, Suleyman Cenk

    The CAST experiment is searching for the axion, which is a light, weakly interacting pseudoscalar particle, that is proposed to solve the so called Strong Charge-Parity Problem. The axions CAST is looking for are produced from photons in the solar core and CAST aims to convert them back into photons in a superconducting LHC dipole magnet and detect the photons in the x-ray detectors attached to ends of each magnet bore. CAST uses three micromegas and a CCD detector and can track the Sun during sunset and sunrise. The two of the micromegas take tracking data during the sunset solar tracking, and were used for the first time in 2008. The analysis of the data taken in 2008 with these two detectors show no signal of axions, and new upper limits on the axion mass-coupling constant parameter space are established due to sensitivity of detectors for the axion mass range of $0.38\\eV$ to $0.65\\eV$.

  16. Search for solar axions with mass around 1 eV using coherent conversion of axions into photons

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

    2008-01-01

    A search for solar axions has been performed using an axion helioscope which is equipped with a 2.3-m long 4 T superconducting magnet, a gas container to hold dispersion-matching gas, PIN-photodiode X-ray detectors, and a telescope mount mechanism to track the sun. A mass region around m a =1 eV was newly explored. From the absence of any evidence, analysis sets a limit on axion-photon coupling constant to be g aγγ -10 GeV -1 for the axion mass of 0.84 a aγγ -m a parameter region of the preferred axion models with a magnetic helioscope

  17. Search for 14.4 keV solar axions emitted in the M1-transition of $^{57}$Fe nuclei with CAST

    Andriamonje, S; Autiero, D; Barth, K; Belov, A; Beltrán, B; Bräuninger, H; Carmona, J M; Cebrián, S; Collar, J I; Dafni, T; Davenport, M; Di Lella, L; Eleftheriadis, C; Englhauser, J; Fanourakis, G K; Ferrer-Ribas, E; Fischer, H; Franz, J; Friedrich, P; Geralis, T; Giomataris, Yu; Gninenko, S; Gómez, H; Hasinoff, M; Heinsius, F H; Hoffmann, D H H; Irastorza, I G; Jacoby, J; Jakovčić, K; Kang, D; Königsmann, K C; Kotthaus, R; Krčmar, M; Kousouris, K; Kuster, M; Lakić, B; Lasseur, C; Liolios, A; Ljubičić, A; Lutz, G; Luzón, G; Miller, D; Morales, J; Ortiz, A; Papaevangelou, T; Placci, A; Raffelt, G; Riege, H; Rodríguez, A; Ruz, J; Savvidis, I; Semertzidis, Y; Serpico, P; Stewart, L; Vieira, J; Villar, J; Vogel, J; Walckiers, L; Zioutas, K

    2009-01-01

    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_{a\\gamma} |-1.19 g_{aN}^{0}+g_{aN}^{3}|<1.36\\times 10^{-16} GeV^{-1} for m_{a}<0.03 eV at the 95% confidence level.

  18. Search for low Energy solar Axions with CAST

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

    2008-01-01

    We have started the development of a detector system, sensitive to single photons in the eV energy range, to be suitably coupled to one of the CAST magnet ports. This system should open to CAST a window on possible detection of low energy Axion Like Particles emitted by the sun. Preliminary tests have involved a cooled photomultiplier tube coupled to the CAST magnet via a Galileian telescope and a switched 40 m long optical fiber. This system has reached the limit background level of the detector alone in ideal conditions, and two solar tracking runs have been performed with it at CAST. Such a measurement has never been done before with an axion helioscope. We will present results from these runs and briefly discuss future detector developments.

  19. Axion Searches, Old and New

    CERN. Geneva

    2005-01-01

    Outline of the lecture: Constraints from laboratory searches and astrophysics, axion cosmology, the cavity detector of dark matter axions, solar axion searches, laser experiments, a telescope search, macroscopic forces mediated by axions.

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

    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.

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

    Yoon, Y.S. [Center for Underground Physics, Institute for Basic Science (IBS), Daejon 34047 (Korea, Republic of); Park, H.K. [Center for Underground Physics, Institute for Basic Science (IBS), Daejon 34047 (Korea, Republic of); Basic Science, IBS-UST School, Daejeon 34047 (Korea, Republic of); Bhang, H.; Choi, J.H. [Department of Physics and Astronomy, Seoul National University, Seoul 08826 (Korea, Republic of); Collaboration: The KIMS collaboration

    2016-06-01

    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 kg⋅days, we set a 90 % confidence level upper limit on the axion-electron coupling, g{sub ae}, of 1.39×10{sup −11} for an axion mass less than 1 keV/c{sup 2}. This limit is lower than the indirect solar neutrino bound, and fully excludes QCD axions heavier than 0.48 eV/c{sup 2} and 140.9 eV/c{sup 2} for the DFSZ and KSVZ models respectively.

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

    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.

  3. 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)

    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.)

  4. Solar X-rays from Axions: Rest-Mass Dependent Signatures

    Zioutas, Konstantin; Semertzidis, Yannis; Papaevangelou, Thomas; Gardikiotis, Antonios; Dafni, Theopisti; Anastassopoulos, Vassilis

    2010-01-01

    The spectral shape of solar X-rays is a power law. The more active the Sun is, the less steep the distribution. This behaviour can be explained by axion regeneration to X-rays occurring ~400km deep into the photosphere. Their down-comptonization reproduces the measured spectral shape, pointing at axions with rest mass m_a~17 meV/c2, without contradicting astrophysical-laboratory limits. Directly measured soft X-ray spectra from the extremely quiet Sun during 2009 (SphinX mission), though hitherto overlooked, fitt the axion scenario.

  5. Recent Results of Search for Solar Axions Using Resonant Absorption by 83Kr nuclei

    Derbin, A. V.; Drachnev, I. S.; Gangapshev, A. M.; Gavrilyuk, Yu M.; Kazalov, V. V.; Kobychev, V. V.; Kuzminov, V. V.; Muratova, V. N.; Panashenko, S. I.; Ratkevich, S. S.; Tekueva, D. A.; Unzhakov, E. V.; Yakimenko, S. P.

    2017-12-01

    A search for resonant absorption of the solar axion by 83Kr nuclei was performed using the proportional counter installed inside the low-background setup at the Baksan Neutrino Observatory. The obtained model independent upper limit on the combination of isoscalar and isovector axion-nucleon couplings |g 3 - g 0| ≤ 8.4 × 10-7 allowed us to set the new upper limit on the hadronic axion mass of mA ≤ 65 eV (95% C.L.) with the generally accepted values S=0.5 and z=0.56.

  6. The Tokyo axion helioscope

    Ohta, R.; Akimoto, Y.; Inoue, Y.; Minowa, M.; Mizumoto, T.; Moriyama, S.; Namba, T.; Takasu, Y.; Yamamoto, A.

    2012-01-01

    The Tokyo Axion Helioscope experiment aims to detect axions which are produced in the solar core. The helioscope uses a strong magnetic field in order to convert axions into X-ray photons and has a mounting to follow the sun very accurately. The photons are detected by an X-ray detector which is made of 16 PIN-photodiodes. In addition, a gas container and a gas regulation system are adopted for recovering the coherence between axions and photons in the conversion region giving sensitivity to axions with masses up to 2 eV. In this paper, we report on the technical detail of the Tokyo Axion Helioscope.

  7. Searches for Astrophysical and Cosmological Axions

    Asztalos, S J; Rosenberg, L J; van Bibber, K; Sikivie, P; Zioutas, K

    2006-01-01

    ). Last, the searches for solar axions will be discussed, with particular attention to the CAST experiment at CERN. The conclusion provides a basis for cautious optimism that a definitive verdict on the axion, or at least its role as a dark matter component, could be expected within a decade

  8. Probing eV-scale axions with CAST

    Ruz, J

    2009-01-01

    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 having four X-ray detectors mounted on both ends of the magnet to look for photons from axion-to-photon conversions. During its First Phase, which concluded in 2004, CAST searched for axions with masses up to 0.02 eV. By using a buffer gas the coherence needed to scan for axions with masses up to 1.20 eV is re-established in CAST’s Second Phase. This technique enables the experiment to study the theoretical regions for axions. During the years 2005 and 2006, the use of 4He has already enabled the search for axions with masses up to 0.39 eV. Up to present time, CAST has upgraded its experimental setup to operate with 3He in the magnetic field.

  9. Axions-motivation, limits and searches

    Raffelt, G G

    2007-01-01

    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

  10. arXiv New CAST Limit on the Axion-Photon Interaction

    Anastassopoulos, V.; Barth, K.; Belov, A.; Bräuninger, H.; Cantatore, G.; Carmona, J.M.; Castel, J.F.; Cetin, S.A.; Christensen, F.; Collar, J.I.; Dafni, T.; Davenport, M.; Decker, T.A.; Dermenev, A.; Desch, K.; Eleftheriadis, C.; Fanourakis, G.; Ferrer-Ribas, E.; Fischer, H.; Garć ia, J.A.; Gardikiotis, A.; Garza, J.G.; Gazis, E.N.; Geralis, T.; Giomataris, I.; Gninenko, S.; Hailey, C.J.; Hasinoff, M.D.; Hoffmann, D.H.H.; Iguaz, F.J.; Irastorza, Igor Garcia; Jakobsen, A.; Jacoby, J.; Jakovčí c, K.; Kaminski, J.; Karuza, M.; Kralj, N.; Krčmar, M.; Kostoglou, S.; Krieger, Ch.; Lakić, B.; Laurent, J.M.; Liolios, A.; Ljubičić, A.; Luzón, G.; Maroudas, M.; Miceli, L.; Neff, S.; Ortega, I.; Papaevangelou, T.; Paraschou, K.; Pivovaroff, M.J.; Raffelt, G.; Rosu, M.; Ruz, J.; Ruiz Chóliz, E.; Savvidis, I.; Schmidt, S.; Semertzidis, Y.K.; Solanki, S.K.; Stewart, L.; Vafeiadis, T.; Vogel, J.K.; Yildiz, S.C.; Zioutas, K.

    2017-05-01

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

  11. The BGU/CERN solar hydrothermal reactor

    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.

  12. Experimental bounds on ββ-decay, cold dark matter and solar axions with an ultralow background Ge detector

    Avignone, F.T. III; Ahlen, S.P.; Brodzinski, R.L.

    1986-01-01

    The PNL/USC ultralow background prototype Ge detector in the Homestake goldmine is being applied to searches for O nu ββ-decay, dark matter candidates and solar axions. An upper bound of 2.2 eV has been placed on the Majorana mass of the electron neutrino. The low energy data exclude particles with spin independent Z 0 exchange interactions having masses between 20 GeV and 5 TeV, as significant contributors to the cold dark matter of the halo of their galaxy. The existence of stable Dirac neutrinos more massive than 20 GeV is also excluded except for a narrow region around the Z 0 resonance. Finally, Dine-Fischler-Srednicki (DFS) axion models with F/2x/sub e/' ≤ 0.5 x10 7 GeV are ruled out by the maximum count rate attributable to solar axions

  13. Experimental bounds on ββ-decay, cold dark matter and solar axions with an ultralow background Ge detector

    Avignone, F.T. III; Ahlen, S.P.; Brodzinski, R.L.

    1986-01-01

    The PNL/USC ultralow background prototype Ge detector in the Homestake goldmine is being applied to searches for 0 nu ββ-decay, dark matter candidates and solar axions. An upper bound of 2.2 eV has been placed on the Majorana mass of the electron neutrino. The low energy data exclude particles with spin independent Z 0 exchange interactions having masses between 20 GeV and 5 TeV as significant contributors to the cold dark matter of the halo of our galaxy. The existence of stable Dirac neutrinos more massive than 20 GeV is also excluded except for a narrow region around the Z 0 resonance. Finally, Dine-Fischler-Srednicki (DFS) axion models with F/2x'/sub e/ ≤ 0.5 x 10 7 GeV are ruled out by the maximum count rate attributable to solar axions. 36 refs., 11 figs

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

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

    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....

  15. Cosmic axions

    Sikivie, P.

    1984-01-01

    Axion physics is briefly reviewed, including the constraints on the axion decay constant from laboratory experiments, from stellar evolution and from the cosmological axion energy density. Experiments to detect axions emitted by the sun or axions floating about in the halo of our galaxy are discussed. 19 references

  16. An improved limit on the axion-photon coupling from the CAST experiment

    Andriamonje, S.; Aune, S.; Dafni, T.; Ferrer Ribas, E.; Giomataris, I.; Irastorza, I.G. [CEA Saclay, DAPNIA, F-91191 Gif Sur Yvette, (France); Autiero, D.; Barth, K.; Davenport, M.; Di Lella, L.; Lasseur, C.; Papaevangelou, T.; Placci, A.; Stewart, L.; Walckiers, L.; Zioutas, K. [CERN, European Org Nucl Res, CH-1211 Geneva 23, (Switzerland); Belov, A.; Gninenko, S. [Russian Acad Sci, Inst Nucl Res, Moscow, (Russian Federation); Beltran, B.; Carmona, J.M.; Cebrian, S.; Gomez, H.; Irastorza, I.G.; Luzon, G.; Morales, A.; Morales, J.; Ortiz, A.; Rodriguez, A.; Ruz, J.; Villar, J. [Univ Zaragoza, Inst Fis Nucl and Altas Energias, Zaragoza, (Spain); Brauninger, H.; Englhauser, J.; Friedrich, P.; Kuster, M. [Max Planck Inst Extraterr Phys, D-85748 Garching, (Germany); Collar, J.I.; Miller, D.; Vieira, J. [Univ Chicago, Enrico Fermi Inst and KICP, Chicago, IL 60637 (United States); Dafni, T.; Hoffmann, D.H.H.; Kuster, M.; Riege, H. [Tech Univ Darmstadt, Inst Kernphys, D-64289 Darmstadt, (Germany); Eleftheriadis, C.; Liolios, A.; Savvidis, I. [Aristotle Univ Thessaloniki, GR-54006 Thessaloniki, (Greece); Fanourakis, G.; Geralis, T.; Kousouris, K. [Natl Ctr Sci Res Demokritos, Athens, (Greece); Fischer, H.; Franz, J.; Heinsius, F.H.; Kang, D.; Konigsmann, K.; Vogel, J. [Univ Freiburg, Freiburg, (Germany)] (and others)

    2007-04-15

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

  17. An update on the Axion Helioscopes front: Current activities at CAST and the IAXO project

    Dafni, T.; Arik, M.; Armengaud, E.

    2016-01-01

    . Their property of coupling to photons has inspired different experimental methods for their detection, one of which is the helioscope technique. The CERN Axion Solar Telescope (CAST) is the most sensitive helioscope built up to date and has recently published part of the latest data taken with the magnet bores...

  18. An application of space technology to the terrestrial search for axions The X-ray mirror telescope at CAST

    Lutz, Gerhard; Englhauser, J; Hartmann, R; Kang, D; Kotthaus, R; Kuster, M; Serber, W; Strüder, L

    2004-01-01

    An X-ray mirror telescope consisting of a Wolter I type mirror assembly as used in X-ray astronomy and a new type X-ray CCD has been added to the CERN Axion Solar Telescope experiment. It will strongly improve the sensitivity in the search for axions, a so far elusive particle. The axion is predicted in order to explain the observed CP conservation in strong interaction which is not expected within the generally accepted "standard model". Construction and performance of the X-ray telescope are described. An improvement by two orders of magnitude in the signal over background S/B event ratio is estimated.

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

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

    2014-01-01

    Almost 35 years since their suggestion as a good solution to the strong CP-problem, axions remainone of the few viable candidates for the Dark Matter, although still eluding detection. Mostof the methods for their detection are based on their coupling to photons, one of the most sensitiveones being...... the helioscope technique. We report on the current status of the CERN Axion SolarTelescope and the future International Axion Observatory (IAXO). Recent results from the secondpart of CAST phase II, where the magnet bores were filled with 3He gas at variable pressureachieving sensibilities on the axion mass up...... 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...

  20. Probing eV-scale axions with CAST

    Arik, E.; Autiero, D.; Barth, K.; Belov, A.; Beltran, B.; Borghi, S.; Bourlis, G.; Boydag, F.S.; Brauninger, H.; Carmona, J.M.; Cebrian, S.; Cetin, S.A.; Collar, J.I.; Dafni, T.; Davenport, M.; Di Lella, L.; Dogan, O.B.; Eleftheriadis, C.; Elias, N.; Fanourakis, G.; Ferrer-Ribas, E.; Fischer, H.; Friedrich, P.; Franz, J.; Galan, J.; Geralis, T.; Giomataris, I.; Gninenko, S.; Gomez, H.; Hartmann, R.; Hasinoff, M.; Heinsius, F.H.; Hikmet, I.; Hoffmann, D.H.H.; Irastorza, I.G.; Jacoby, J.; Jakovcic, K.; Kang, D.; Konigsmann, Kay; 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.J.; Placci, A.; Raffelt, G.; Riege, H.; Rodriguez, A.; Ruz, J.; Savvidis, 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...

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

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

    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 wi...

  2. Searching for Axions from Celestial Objects with the X-Ray Telescope at CAST

    Guthörl, T

    2009-01-01

    The CAST (CERN Solar Axion Telescope) experiment is designed to detect axions from the sun by making use of the inverse Primakoff effekt i.e. reconversion of axions into X-ray photons under the influence of a strong magnetic field. In order to track the sun the magnet used is mounted to a moveable device. This movability can also be used to track celestial objects of interest such as the galactic centre or Scorpio X-1, which is the brightest X-ray source besides the sun. The data gained with the CCD detector during trackings of these objects are analysed in this work. Since no signal above background can be observed an upper limit on the free parameter flux times axion-photon coupling constant^2 is determined. This upper limit in turn can be used to calculate a maximum energy loss due to axion emission for both the galactic centre and Sco X-1. The results presented in this work imply that e.g. the galactic centre can emit axions with up to 10^42 W without being detected by CAST.

  3. An update on the Axion Helioscopes front: current activities at CAST and the IAXO project

    Dafni, T.; Arik, M.; Armengaud, E.; Aune, S.; Avignone, F. T.; Barth, K.; Belov, A.; Betz, M.; Bräuninger, H.; Brax, P.; Breijnholt, N.; Brun, P.; Cantatore, G.; Carmona, J. M.; Carosi, G. P.; Caspers, F.; Caspi, S.; Cetin, S. A.; Chelouche, D.; Christensen, F. E.; Collar, J. I.; Dael, A.; Davenport, M.; Derbin, A. V.; Desch, K.; Diago, A.; Döbrich, B.; Dratchnev, I.; Dudarev, A.; Eleftheriadis, C.; Fanourakis, G.; Ferrer-Ribas, E.; Friedrich, P.; Galán, J.; García, J. A.; Gardikiotis, A.; Garza, J. G.; Gazis, E. N.; Georgiopoulou, E.; Geralis, T.; Gimeno, B.; Giomataris, I.; Gninenko, S.; Gómez, H.; González-Díaz, D.; Gruber, E.; Guendelman, E.; Guthörl, T.; Hailey, C. J.; Hartmann, R.; Hauf, S.; Haug, F.; Hasinoff, M. D.; Hiramatsu, T.; Hoffmann, D. H. H.; Horns, D.; Iguaz, F. J.; Irastorza, I. G.; Isern, J.; Imai, K.; Jacoby, J.; Jaeckel, J.; Jakobsen, A. C.; Jakovčić, K.; Kaminski, J.; Kawasaki, M.; Karuza, M.; Königsmann, K.; Kotthaus, R.; Krčmar, M.; Kousouris, K.; Krieger, C.; Kuster, M.; Lakić, B.; Laurent, J. M.; Limousin, O.; Lindner, A.; Liolios, A.; Ljubičić, A.; Luzón, G.; Matsuki, S.; Muratova, V. N.; Neff, S.; Niinikoski, T.; Nones, C.; Ortega, I.; Papaevangelou, T.; Pivovaroff, M. J.; Raffelt, G.; Redondo, J.; Riege, H.; Ringwald, A.; Rodríguez, A.; Rosu, M.; Russenschuck, S.; Ruz, J.; Saikawa, K.; Savvidis, I.; Sekiguchi, T.; Semertzidis, Y. K.; Shilon, I.; Sikivie, P.; Silva, H.; Solanki, S. K.; Stewart, L.; ten Kate, H. H. J.; Tomas, A.; Troitsky, S.; Vafeiadis, T.; van Bibber, K.; Vedrine, P.; Villar, J. A.; Vogel, J. K.; Walckiers, L.; Weltman, A.; Wester, W.; Yildiz, S. C.; Zioutas, K.

    2016-04-01

    Although they have not yet been detected, axions and axion-like particles (ALPs) continue to maintain the interest (even increasingly so) of the rare-event searches community as viable candidates for the Dark Matter of the Universe but also as a solution for several other puzzles of astrophysics. Their property of coupling to photons has inspired different experimental methods for their detection, one of which is the helioscope technique. The CERN Axion Solar Telescope (CAST) is the most sensitive helioscope built up to date and has recently published part of the latest data taken with the magnet bores gradually filled with 3He, probing the mass range up to 1.17 eV. The International AXion Observatory (IAXO) is being proposed as a facility where different axion studies can be performed, with the primary goal to study axions coming from the Sun. Designed to maximize sensitivity, it will improve the levels reached by CAST by almost 5 orders of magnitude in signal detection, that is more than one order of magnitude in terms of gaγ. Here we will summarize the most important aspects of the helioscopes, and focus mainly on IAXO, based on the recent papers [1, 2].

  4. The Search of Axion Dark Matter

    CERN. Geneva

    2006-01-01

    The axion provides a solution to the strong CP problem and is a cold dark matter candidate. I will review the limits on the axion from particle physics, stellar evolution and cosmology. The various constraints suggest that the axion mass is in the micro-eV to milli-eV range. In this range, axions contribute significantly to the energy density of the universe in the form of cold dark matter. Dark matter axions can be searched for on Earth by stimulating their conversion to microwave photons in an electromagnetic cavity permeated by a strong magnetic field. Using this technique, limits on the local halo density have been placed by the Axion Dark Matter experiment at Lawrence Livermore National Laboratory. I will give a status report on ADMX and its upgrade presently under construction. I will also discuss the results from solar axion searches (Tokyo helioscope, CAST) and laser experiments (PVLAS).

  5. Search for solar Axion Like Particles in the low energy range at CAST

    Cantatore, G.; Karuza, M.; Lozza, V.; Raiteri, G.

    2010-01-01

    Axion Like Particles (ALPs) could be continuously produced in the Sun via the Primakoff process. The ALP flux could be seen on Earth by observing the photons produced by the ALP decay. The expected energy distribution of reconverted photons is peaked at 3 keV. There could be, however, a low energy tail due to various processes active in the Sun. We report results of the first test measurements in the low energy range performed at CAST along with a description of the experimental setup. Future detector developments are discussed and preliminary results on a liquid nitrogen cooled Avalanche Photodiode are presented.

  6. Resonantly Enhanced Axion-Photon Regeneration

    Sikivie, P; Van Bibber, K; Bibber, Karl van

    2007-01-01

    We point out that photon regeneration-experiments that search for the axion, or axion-like particles, may be resonantly enhanced by employing matched Fabry-Perot optical cavities encompassing both the axion production and conversion magnetic field regions. Compared to a simple photon regeneration experiment, which uses the laser in a single-pass geometry, this technique can result in a gain in rate of order ${\\cal F}^2$, where ${\\cal F}$ is the finesse of the cavities. This gain could feasibly be $10^{(10-12)}$, corresponding to an improvement in sensitivity in the axion-photon coupling, $g_{a\\gamma\\gamma}$ , of order ${\\cal F}^{1/2} \\sim 10^{(2.5-3)}$, permitting a practical purely laboratory search to probe axion-photon couplings not previously excluded by stellar evolution limits, or solar axion searches.

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

    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-ph...... low background x-ray detectors. The magnet will be built into a structure with elevation and azimuth drives that will allow solar tracking for 12hours each day. This contribution is a summary of our papers [1–3] and we refer to these for further details....

  8. Search for Axions with the CDMS Experiment

    CDMS Collaboration

    2009-01-01

    We report on the first axion search results from the Cryogenic Dark Matter Search (CDMS) experiment at the Soudan Underground Laboratory. An energy threshold of 2 keV for electron-recoil events allows a search for possible solar axion conversion into photons or local Galactic axion conversion into electrons in the germanium crystal detectors. The solar axion search sets an upper limit on the Primakov coupling g aγγ of 2.4 x 10 ?9 GeV -1 at the 95% confidence level for an axion mass less than 0.1 keV/c 2 . This limit benefits from the first precise measurement of the absolute crystal plane orientations in this type of experiment. The Galactic axion search analysis sets a world-leading experimental upper limit on the axio-electric coupling g a# bar e# e of 1.4 x 10 -12 at the 90% confidence level for an axion mass of 2.5 keV/c 2 . This analysis excludes an interpretation of the DAMA annual modulation result in terms of Galactic axion interactions for axion masses above 1.4 keV/c 2

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

    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.

  10. Search for solar axion emission from $^7$Li and D(p,$\\gamma)^3$He nuclear decays with the CAST $\\gamma$-ray calorimeter

    Andriamonje, S.; Autiero, D.; Barth, K.; Belov, A.; Beltran, B.; Brauninger, H.; Carmona, J.M.; Cebrian, S.; 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.; Geralis, T.; Giomataris, I.; Gninenko, S.; Gomez, H.; Hasinoff, M.; Heinsius, F.H.; 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.W.; Morales, J.; Ortiz, A.; Papaevangelou, T.; Placci, A.; Raffelt, G.; Riege, H.; Rodriguez, A.; Ruz, J.; Savvidis, I.; Semertzidis, Y.; Serpico, P.; Stewart, L.; Vieira, J.D.; Villar, J.; Vogel, J.; Walckiers, L.; Zioutas, K.

    2010-01-01

    We present the results of a search for a high-energy axion emission signal from 7Li (0.478 MeV) and D(p,gamma)3He (5.5 MeV) nuclear transitions using a low-background gamma-ray calorimeter during Phase I of the CAST experiment. These so-called "hadronic axions" could provide a solution to the long-standing strong-CP problem and can be emitted from the solar core from nuclear M1 transitions. This is the first such search for high-energy pseudoscalar bosons with couplings to nucleons conducted using a helioscope approach. No excess signal above background was found.

  11. CERN

    2007-01-01

    "Geat ready for the mother of all particle accelerator: the Large Hadron Collider (LHC), nearing completion at CERN, the International particle physics lab headquartered in Geneva, Switzerland." (1 paragraph)

  12. An application of space technology to the terrestrial search for axions: the X-ray mirror telescope at CAST

    Lutz, Gerhard E-mail: gerhard.lutz@cern.ch; Braeuninger, H.; Englhauser, J.; Hartmann, R.; Kang, D.; Kotthaus, R.; Kuster, M.; Serber, W.; Strueder, L

    2004-02-01

    An X-ray mirror telescope consisting of a Wolter I type mirror assembly as used in X-ray astronomy and a new type X-ray CCD has been added to the CERN Axion Solar Telescope experiment. It will strongly improve the sensitivity in the search for axions, a so far elusive particle. The axion is predicted in order to explain the observed CP conservation in strong interaction which is not expected within the generally accepted 'standard model'. Construction and performance of the X-ray telescope are described. An improvement by two orders of magnitude in the signal over background S/B event ratio is estimated.

  13. Axionic membranes

    Aurilia, A.; Spallucci, E.

    1992-01-01

    A metal ring removed from a soap-water solution encloses a film of soap which can be mathematically described as a minimal surface having the ring as its only boundary. This is known to everybody. In this letter we suggest a relativistic extension of the above fluidodynamic system where the soap film is replaced by a Kalb-Ramand gauge potential B μν (x) and the ring by a closed string. The interaction between the B μν field and the string current excites a new configuration of the system consisting of a relativistic membrane bounded by the string. We call such a classical solution of the equation of motion an axionic membrane. As a dynamical system, the axionic membrane admits a Hamilton-Jacobi formulation which is an extension of the HJ theory of electromagnetic strings. (orig.)

  14. Ultrasensitive searches for the axion

    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. CERN

    Anon.

    1988-01-01

    Over the years the efforts at CERN to stimulate exchange of technological information with industry have steadily gained momentum. A 'Meeting on technology arising from high energy physics' was held in April 1974. Over 300 participants from industry, other research centres and universities heard three days of review talks on advanced technology and were able to see over 250 exhibits of equipment and the techniques emerging from the European particle physics programme

  16. Cern

    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)

  17. ''Invisible'' axion detectors

    Sikivie, P.

    1985-01-01

    A brief review is given of various ideas which have been put forth to detect ''invisible'' axions, i.e., axions with f/sub a/ between 3 x 10 7 GeV and 2 x 10 12 GeV. These experiments would attempt to detect the axions which constitute the halo of our galaxy or axions which are emitted by our sun; or they would attempt to detect the force mediated by virtual axions. Various relevant axion parameters are given as f/sub a/. Among the experiments described are: galactic axion detector using a cavity; ''spin coupled'' axion detection; axion to photon conversion in an inhomogeneous static magnetic field; and macroscopic forces mediated by axions. 27 refs

  18. Do axions need inflation?

    Davis, R.L.; Shellard, E.P.S.; Massachusetts Inst. of Tech., Cambridge

    1989-01-01

    Without inflation the energy density of relic axions in a Robertson-Walker universe arises not from coherent oscillations of a zero-momentum mode but from radiative decay of axion strings. An estimate of the upper bound on the PQ scale coming from these axions is in conflict with the lower bound from SN1987a. We present analytical and numerical evidence supporting this estimate. If true, then the axion needs inflation. With inflation the axion is safe, but the motivation for axion search experiments is weakened. (orig.)

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

    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...

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

    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$^{-1}$ ...

  1. In the footsteps of axions or the like

    CERN. Geneva

    2006-01-01

    Axions were invented to solve the strong CP-problem and are one of the leading dark matter particle candidates. Axions could be copiously produced in the Sun. In magnetic fields they can oscillate to photons and vice versa. The axion helioscope CAST uses an LHC magnet to convert solar axions to X-rays. Also, in the solar atmosphere the large scale magnetic fields reach occasionally several kGauss. Assuming the CAST working principle occurring there much more efficiently, it could explain the unexpected appearance of X-rays (from axions) or disappearance of light (into axions). Such processes can be behind persisting solar mysteries, suggesting the participation of a) solar magnetic fields, and b) radiatively decaying massive particles. Enigmatic behaviour leading to solar X-ray emission, coronal heating, flares, sunspots, etc. is considered as evidence of overlooked signature of axions or other particles with similar properties. New solar axion searches in the lab and with space X-ray telescopes, have been mo...

  2. Dark matter axions '96

    Sikivie, P.

    1996-01-01

    This report discusses why axions have been postulated to exist, what cosmology implies about their presence as cold dark matter in the galactic halo, how axions might be detected in cavities wherein strong magnetic fields stimulate their conversion into photons, and relations between axions' energy spectra and galactic halos' properties

  3. An ultra-low-background detector for axion searches

    Aune, S; Ferrer Ribas, E; Giomataris, I; Mols, J P; Papaevangelou, T [IRFU, Centre d' Etudes de Saclay, Gif sur Yvette CEDEX (France); Dafni, T; Lacarra, J Galan; Iguaz, F J; Irastorza, I G; Morales, J; Ruz, J; Tomas, A [Instituto de Fisica Nuclear y Altas EnergIas, Zaragoza (Spain); Fanourakis, G; Geralis, T; Kousouris, K [Institute of Nuclear Physics, NCSR Demokritos, Athens (Greece); Vafeiadis, T, E-mail: Thomas.Papaevangelou@cern.c [Physics Department, Aristotle University, Thessaloniki (Greece)

    2009-07-01

    A low background Micromegas detector has been operating in the CAST experiment at CERN for the search of solar axions since the start of data taking in 2002. The detector, made out of low radioactivity materials, operated efficiently and achieved a very low level of background (5x10{sup -5} keV{sup -1}-cm{sup -2}-s{sup -1}) without any shielding. New manufacturing techniques (Bulk/Microbulk) have led to further improvement of the characteristics of the detector such as uniformity, stability and energy resolution. These characteristics, the implementation of passive shielding and the improvement of the analysis algorithms have dramatically reduced the background level (2x10{sup -7} keV{sup -1}-cm{sup -2}|s{sup -1}), improving thus the overall sensitivity of the experiment and opening new possibilities for future searches.

  4. An ultra-low-background detector for axion searches

    Aune, S; Ferrer Ribas, E; Giomataris, I; Mols, J P; Papaevangelou, T; Dafni, T; Lacarra, J Galan; Iguaz, F J; Irastorza, I G; Morales, J; Ruz, J; Tomas, A; Fanourakis, G; Geralis, T; Kousouris, K; Vafeiadis, T

    2009-01-01

    A low background Micromegas detector has been operating in the CAST experiment at CERN for the search of solar axions since the start of data taking in 2002. The detector, made out of low radioactivity materials, operated efficiently and achieved a very low level of background (5x10 -5 keV -1 -cm -2 -s -1 ) without any shielding. New manufacturing techniques (Bulk/Microbulk) have led to further improvement of the characteristics of the detector such as uniformity, stability and energy resolution. These characteristics, the implementation of passive shielding and the improvement of the analysis algorithms have dramatically reduced the background level (2x10 -7 keV -1 -cm -2 |s -1 ), improving thus the overall sensitivity of the experiment and opening new possibilities for future searches.

  5. Axions in inflationary cosmology

    Linde, A.

    1991-01-01

    The problem of the cosmological constraints on the axion mass is re-examined. It is argued that in the context of inflationary cosmology the constraint m a > or approx.10 -5 eV can be avoided even when the axion perturbations produced during inflation are taken into account. It is shown also that in most axion models the effective parameter f a rapidly changes during inflation. This modifies some earlier statements concerning isothermal perturbations in the axion cosmology. A hybrid inflation scenario is proposed which combines some advantages of chaotic inflation with specific features of new and/or extended inflation. Its implications for the axion cosmology are discussed. (orig.)

  6. Stellar axion models

    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.

  7. Pinning down the axion

    Dabholkar, A.; Quashnock, J.M.

    1990-01-01

    Davis has argued that, without inflation, the decay of axionic strings is the primary source of axions. This implies a cosmological lower bound on the axion mass of 10 -5 to 10 -3 eV. In order to obtain a sharper bound it is essential to know the spectrum of emitted axions and the detailed motion of a global string strongly coupled to the axionic field. To this end, we obtain self-consistent, renormalized equations that describe the dynamics of a radiating global string interacting with its surrounding axionic field. We describe the numerical formalism for evolving string trajectories using these equations. From the numerical and analytical evidence we argue that, with appropriate renormalization, the motion of an interacting cosmic string loop can be well approximated by the motion of a free Nambu-Goto string. This implies a lower bound for the axion mass of 10 -3 eV. Together with the recent upper bound of 4x10 -4 eV from the supernova SN1987a, this marginally rules out the invisible axion, or at least pins down the axion mass to a very narrow window around 10 -3 eV. This still leaves open the window around 2 eV for hardronic axions, but in that case the axion is no longer a serious dark matter candidate. (orig.)

  8. Detection of a Hypercharge Axion in ATLAS

    Elfgren, E

    This Master of Science thesis treats the hypercharge axion, which is a hypothetical pseudo-scalar particle with electroweak interactions. First, the theoretical context and the motivations for this study are discussed. In short, the hypercharge axion is introduced to explain the dominance of matter over antimatter in the universe and the existence of large-scale magnetic fields. Second, the phenomenological properties are analyzed and the distinguishing marks are underlined. These are basically the products of photons and $Z^0$s with high transverse momenta and invariant mass equal to that of the axion. Third, the simulation is carried out with two photons producing the axion which decays into $Z^0$s and/or photons. The event simulation is run through the simulator ATLFAST of ATLAS (A Toroidal Large Hadron Collider ApparatuS) at CERN. Finally, the characteristics of the axion decay are analyzed and the criteria for detection are presented. A study of the background is also included. The result is that for cer...

  9. Axions and Their Relatives

    CERN. Geneva

    2005-01-01

    A summary of the status of axions and axion-like particles will be given. Special attention is devoted to the recent results of the PVLAS collaboration, which are in conflict with CAST data and with astrophysical constraints. Solutions to this puzzle and the implications for new physics are dicussed. The subject of axion-like particles as dark matter will be included in the lecture. Finally some new results on new forces mediated by light scalars are debated.

  10. Inflationary Axion Cosmology

    Wilczek, Frank; Turner, Michael S.

    1990-09-01

    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 10-6 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, .1 . (ma/10-6eV)0.59. We show consideration of fluctuations induced during inflation severely constrains the latter alternative.

  11. Inflationary axion cosmology

    Turner, M.S.; Wilczek, F.

    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 -6 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, θ 1 approx-lt[m a /10 -6 eV 0.59 .] We show consideration of fluctuations induced during inflation severely constrains the latter alternative

  12. Experimental Axion Review

    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.

  13. Future cosmological sensitivity for hot dark matter axions

    Archidiacono, Maria; Hamann, Jan; Hannestad, Steen; Raffelt, Georg; Wong, Yvonne Y Y

    2015-01-01

    We study the potential of a future, large-volume photometric survey to constrain the axion mass $m_a$ in the hot dark matter limit. Future surveys such as Euclid will have significantly more constraining power than current observations for hot dark matter. Nonetheless, the lowest accessible axion masses are limited by the fact that axions lighter than $\\sim 0.15$ eV decouple before the QCD epoch, assumed here to occur at a temperature $T_{\\rm QCD} \\sim 170$ MeV; this leaves an axion population of such low density that its late-time cosmological impact is negligible. For larger axion masses, $m_a \\gtrsim 0.15$ eV, where axions remain in equilibrium until after the QCD phase transition, we find that a Euclid-like survey combined with Planck CMB data can detect $m_a$ at very high significance. Our conclusions are robust against assumptions about prior knowledge of the neutrino mass. Given that the proposed IAXO solar axion search is sensitive to $m_a\\lesssim 0.2$ eV, the axion mass range probed by cosmology is n...

  14. Windows on the axion

    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 Θ 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 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

  15. Axions: a review

    Davier, M.

    1987-05-01

    The axion particle is the experimental consequence of a particular way to restore P conservation into the QCD theory. The standard axion phenomenology proceeds on a scale given by the electroweak symmetry breaking. Such an axion is ruled out experimentally. Recently, observation of monochromatic peaks in e ± production in heavy-ion collisions at GSI Darmstadt has motivated some re-examination of the situation. There appears to be no way to save the notion of an axion at the electroweak scale. Furthermore, experiments with electron beam-dumps have proven, together with g-2 measurements that the GSI effect cannot be explained in terms of a fundamental particle coupled to the e + e - channel

  16. The hunt for axions

    Ringwald, Andreas

    2015-06-01

    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.

  17. The hunt for axions

    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.

  18. Axion searches with microwave filters: the RADES project

    Álvarez Melcón, Alejandro; Arguedas Cuendis, Sergio; Cogollos, Cristian; Díaz-Morcillo, Alejandro; Döbrich, Babette; Gallego, Juan Daniel; Gimeno, Benito; Irastorza, Igor G.; José Lozano-Guerrero, Antonio; Malbrunot, Chloé; Navarro, Pablo; Peña Garay, Carlos; Redondo, Javier; Vafeiadis, Theodoros; Wuensch, Walter

    2018-05-01

    We propose, design and construct a variant of the conventional axion haloscope concept that could be competitive in the search for dark matter axions of masses in the decade 10–100 μeV. Theses masses are located somewhat above the mass range in which existing experiments have reached sensitivity to benchmark QCD axion models. Our haloscope consists of an array of small microwave cavities connected by rectangular irises, in an arrangement commonly used in radio-frequency filters. The size of the unit cavity determines the main resonant frequency, while the possibility to connect a large number of cavities allows to reach large detection volumes. We develop the theoretical framework of the detection concept, and present design prescriptions to optimize detection capabilities. We describe the design and realization of a first small-scale prototype of this concept, called Relic Axion Detector Exploratory Setup (RADES). It consists of a copper-coated stainless steel five-cavities microwave filter with the detecting mode operating at around 8.4 GHz. This structure has been electromagnetically characterized at 2 K and 298 K, and it is now placed in ultra-high vacuum in one of the twin-bores of the 9 T CAST dipole magnet at CERN. We describe the data acquisition system developed for relic axion detection, and present preliminary results of the electromagnetic properties of the microwave filter, which show the potential of filters to reach QCD axion window sensitivity at X-band frequencies.

  19. In quest of axionic hairs in quasars

    Banerjee, Indrani; Mandal, Bhaswati; SenGupta, Soumitra

    2018-03-01

    The presence of axionic field can provide plausible explanation to several long standing problems in physics such as dark matter and dark energy. The pseudo-scalar axion whose derivative corresponds to the Hodge dual of the Kalb-Ramond field strength in four dimensions plays crucial roles in explaining several astrophysical and cosmological observations. Therefore, the detection of axionic hairs/Kalb-Ramond field which appears as closed string excitations in the heterotic string spectrum may provide a profound insight to our understanding of the current universe. The current level of precision achieved in solar-system based tests employed to test general relativity, is not sufficient to detect the presence of axion. However, the near horizon regime of quasars where the curvature effects are maximum seems to be a natural laboratory to probe such additions to the matter sector. The continuum spectrum emitted from the accretion disk around quasars encapsulates the imprints of the background spacetime and hence acts as a storehouse of information regarding the nature of gravitational interaction in extreme situations. The surfeit of data available in the electromagnetic domain provides a further motivation to explore such systems. Using the optical data for eighty Palomar Green quasars we demonstrate that the theoretical estimates of optical luminosity explain the observations best when the axionic field is assumed to be absent. However, axion which violates the energy condition seems to be favored by observations which has several interesting consequences. Error estimators, including reduced χ2, Nash-Sutcliffe efficiency, index of agreement and modified versions of the last two are used to solidify our conclusion and the implications of our result are discussed.

  20. Tidal streams from axion miniclusters and direct axion searches

    Tinyakov, Peter; Zioutas, Konstantin

    2016-01-19

    In some axion dark matter models a dominant fraction of axions resides in dense small-scale substructures, axion miniclusters. A fraction of these substructures is disrupted and forms tidal streams where the axion density may still be an order of magnitude larger than the average. We discuss implications of these streams for the direct axion searches. We estimate the fraction of disrupted miniclusters and the parameters of the resulting streams, and find that stream-crossing events would occur at a rate of about $1/(20 {\\rm yr})$ for 2-3 days, during which the signal in axion detectors would be amplified by a factor $\\sim 10$. These estimates suggest that the effect of the tidal disruption of axion miniclusters may be important for direct axion searches and deserves a more thorough study.

  1. Anomaly mediation deformed by axion

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

    2013-05-13

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

    Irastorza, I G; Cantatore, G; Carmona, J M; Caspi, S; Cetin, S A; Christensen, F E; Dael, A; Dafni, T; Davenport, M; Derbin, A V; Desch, K; Diago, A; Döbrich, B; 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; Guendelman, E; Hailey, C J; Hiramatsu, T; Hoffmann, D H H; Horns, D; Iguaz, F J; Isern, J; Jakobsen, A C; Jaeckel, J; Jakovčić, K; Kaminski, J; Kawasaki, M; Krčmar, M; Krieger, C; Lakić, B; Lindner, A; Liolios, A; Luzón, G; Ortega, I; Papaevangelou, T; Pivovaroff, M J; Raffelt, G; Redondo, J; Ringwald, A; Russenschuck, S; Ruz, J; Saikawa, K; Savvidis, I; Sekiguchi, T; 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; Wester, W; Yildiz, S C; Zioutas, K

    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 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.

  3. Dark matter in axion landscape

    Ryuji Daido

    2017-02-01

    Full Text Available 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.

  4. Tunneling in axion monodromy

    Brown, Jon; Cottrell, William; Shiu, Gary; Soler, Pablo [Department of Physics, University of Wisconsin,Madison, WI 53706 (United States)

    2016-10-06

    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.

  5. A viable axion model

    Peccei, R.D.; Wu Taitsun; Yanagida, T.

    1986-02-01

    We discuss whether an axion like excitation can be the source for the monoenergetic positrons observed at GSI. Although a direct extension of the original Peccei Quinn model is experimentally ruled out, it is possible to construct an alternative model which avoids all previous axion bounds, involving quarkonia decays, K decays, nuclear decays and beam dump experiments. The model predicts, at some level, the possibility of flavor changing interactions involving charmed quarks and suggests an appealing regularity for the quark and lepton masses. The expectations of the model for resonant e + e - scattering are briefly discussed. (orig.)

  6. First Axion Results from the XENON100 Experiment

    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.

    2014-09-09

    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$^2$.

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

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

    2013-01-01

    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....

  8. Sensitivity of proposed search for axion-induced magnetic field using optically pumped magnetometers

    Chu, P.-H.; Duffy, L. D.; Kim, Y. J.; Savukov, I. M.

    2018-04-01

    We investigate the sensitivity of a search for the oscillating current induced by axion dark matter in an external magnetic field using optically pumped magnetometers. This experiment is based upon the LC circuit (circuit with inductor and capacitor) axion detection concept of Sikivie et al. [Phys. Rev. Lett. 112, 131301 (2014), 10.1103/PhysRevLett.112.131301]. The modification of Maxwell's equations caused by the axion-photon coupling results in a minute magnetic field oscillating at a frequency equal to the axion mass, in the presence of an external magnetic field. The axion-induced magnetic field could be searched for using a LC circuit amplifier with an optically pumped magnetometer, the most sensitive cryogen-free magnetic-field sensor, in a room-temperature experiment, avoiding the need for a complicated and expensive cryogenic system. We discuss how an existing magnetic resonance imaging experiment can be modified to search for axions in a previously unexplored part of the parameter space. Our existing detection setup, optimized for magnetic resonance imagining, is already sensitive to an axion-photon coupling of 10-7 GeV-1 for an axion mass near 3 ×10-10 eV , which is already limited by astrophysical processes and solar axion searches. We show that realistic modifications, and optimization of the experiment for axion detection, can probe the axion-photon coupling up to 4 orders of magnitude beyond the current best limit, for axion masses between 10-11 and 10-7 eV .

  9. Axions in astrophysics and cosmology

    Sikivie, P.

    1984-07-01

    Axion models often have a spontaneously broken exact discrete symmetry. In that case, they have discretely degenerate vacua and hence domain walls. The properties of the domain walls, the cosmological catastrophe they produce and the ways in which this catastrophe may be avoided are explained. Cosmology and astrophysics provide arguments that imply the axion decay constant should lie in the range 10 8 GeV less than or equal to f/sub a/ less than or equal to 10 12 GeV. Reasons are given why axions are an excellent candidate to constitute the dark matter of galactic halos. Using the coupling of the axions to the electromagnetic field, detectors are described to look for axions floating about in the halo of our galaxy and for axions emitted by the sun

  10. Axions and the anthropic principle

    Dowrick, N.; McDougall, N.A.

    1988-01-01

    We consider the possibility that the axion density in the Universe today may be constrained by the anthropic requirement that life should have evolved. If this were the case, the force of the usual cosmological bound on the axion decay constant would be greatly lessened. However, we find no mechanism by which excessive axion energy density could prevent the condensation of matter into potentially life-nurturing structures

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

    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...

  12. Alternative dark matter candidates. Axions

    Ringwald, Andreas

    2017-01-01

    The axion is arguably one of the best motivated candidates for dark matter. For a decay constant >or similar 10 9 GeV, axions are dominantly produced non-thermally in the early universe and hence are ''cold'', their velocity dispersion being small enough to fit to large scale structure. Moreover, such a large decay constant ensures the stability at cosmological time scales and its behaviour as a collisionless fluid at cosmological length scales. Here, we review the state of the art of axion dark matter predictions and of experimental efforts to search for axion dark matter in laboratory experiments.

  13. Alternative dark matter candidates. Axions

    Ringwald, Andreas

    2017-01-15

    The axion is arguably one of the best motivated candidates for dark matter. For a decay constant >or similar 10{sup 9} GeV, axions are dominantly produced non-thermally in the early universe and hence are ''cold'', their velocity dispersion being small enough to fit to large scale structure. Moreover, such a large decay constant ensures the stability at cosmological time scales and its behaviour as a collisionless fluid at cosmological length scales. Here, we review the state of the art of axion dark matter predictions and of experimental efforts to search for axion dark matter in laboratory experiments.

  14. Dynamical clockwork axions

    Coy, Rupert; Frigerio, Michele; Ibe, Masahiro

    2017-10-01

    The clockwork mechanism is a novel method for generating a large separation between the dynamical scale and interaction scale of a theory. We demonstrate how the mechanism can arise from a sequence of strongly-coupled sectors. This framework avoids elementary scalar fields as well as ad hoc continuous global symmetries, both of which are subject to serious stability issues. The clockwork factor, q, is determined by the consistency of the strong dynamics. The preserved global U(1) of the clockwork appears as an accidental symmetry, resulting from discrete or U(1) gauge symmetries, and it is spontaneously broken by the chiral condensates. We apply such a dynamical clockwork to construct models with an effectively invisible QCD axion from TeV-scale strong dynamics. The axion couplings are determined by the localisation of the Standard Model interactions along the clockwork sequence. The TeV spectrum includes either coloured hadrons or vector-like quarks. Dark matter can be accounted for by the axion or the lightest neutral baryons, which are accidentally stable.

  15. Dilute and dense axion stars

    Visinelli, Luca; Baum, Sebastian; Redondo, Javier; Freese, Katherine; Wilczek, Frank

    2018-02-01

    Axion stars are hypothetical objects formed of axions, obtained as localized and coherently oscillating solutions to their classical equation of motion. Depending on the value of the field amplitude at the core |θ0 | ≡ | θ (r = 0) |, the equilibrium of the system arises from the balance of the kinetic pressure and either self-gravity or axion self-interactions. Starting from a general relativistic framework, we obtain the set of equations describing the configuration of the axion star, which we solve as a function of |θ0 |. For small |θ0 | ≲ 1, we reproduce results previously obtained in the literature, and we provide arguments for the stability of such configurations in terms of first principles. We compare qualitative analytical results with a numerical calculation. For large amplitudes |θ0 | ≳ 1, the axion field probes the full non-harmonic QCD chiral potential and the axion star enters the dense branch. Our numerical solutions show that in this latter regime the axions are relativistic, and that one should not use a single frequency approximation, as previously applied in the literature. We employ a multi-harmonic expansion to solve the relativistic equation for the axion field in the star, and demonstrate that higher modes cannot be neglected in the dense regime. We interpret the solutions in the dense regime as pseudo-breathers, and show that the life-time of such configurations is much smaller than any cosmological time scale.

  16. Axion as a Cold Dark Matter Candidate: Proof to Fully Nonlinear Order

    Noh, Hyerim [Center for Large Telescope, Korea Astronomy and Space Science Institute, Daejon (Korea, Republic of); Hwang, Jai-chan [Department of Astronomy and Atmospheric Sciences, Kyungpook National University, Daegu (Korea, Republic of); Park, Chan-Gyung [Division of Science Education and Institute of Fusion Science, Chonbuk National University, Jeonju (Korea, Republic of)

    2017-09-01

    We present proof of the axion as a cold dark matter (CDM) candidate to the fully nonlinear order perturbations based on Einstein’s gravity. We consider the axion as a coherently oscillating massive classical scalar field without interaction. We present the fully nonlinear and exact, except for ignoring the transverse-tracefree tensor-type perturbation, hydrodynamic equations for an axion fluid in Einstein’s gravity. We show that the axion has the characteristic pressure and anisotropic stress; the latter starts to appear from the second-order perturbation. But these terms do not directly affect the hydrodynamic equations in our axion treatment. Instead, what behaves as the effective pressure term in relativistic hydrodynamic equations is the perturbed lapse function and the relativistic result coincides exactly with the one known in the previous non-relativistic studies. The effective pressure term leads to a Jeans scale that is of the solar-system scale for conventional axion mass. As the fully nonlinear and relativistic hydrodynamic equations for an axion fluid coincide exactly with the ones of a zero-pressure fluid in the super-Jeans scale, we have proved the CDM nature of such an axion in that scale.

  17. Axionic mirage mediation

    Nakamura, Shuntaro; Okumura, Ken-ichi; Yamaguchi, Masahiro

    2008-01-01

    Although mirage mediation is one of the most plausible mediation mechanisms of supersymmetry breaking, it suffers from two crucial problems. One is the μ/Bμ problem, and the second is the cosmological one. The former stems from the fact that the B parameter tends to be comparable with the gravitino mass, which is 2 orders of magnitude larger than the other soft masses. The latter problem is caused by the decay of the modulus whose branching ratio into the gravitino pair is sizable. In this paper, we propose a model of mirage mediation, in which Peccei-Quinn symmetry is incorporated. In this axionic mirage mediation, it is shown that the Peccei-Quinn symmetry breaking scale is dynamically determined around 10 10 GeV to 10 12 GeV due to the supersymmetry breaking effects, and the μ problem can be solved naturally. Furthermore, in our model, the lightest supersymmetric particle (LSP) is the axino, that is, the superpartner of the axion. The overabundance of the LSPs due to decays of the modulus/gravitino, which is the most serious cosmological difficulty in the mirage mediation, can be avoided if the axino is sufficiently light. The next-LSPs (NLSPs) produced by the gravitino decay eventually decay into the axino LSPs, yielding the dominant component of the axinos remaining today. It is shown that the axino with a mass of O(100) MeV is naturally realized, which can constitute the dark matter of the Universe, with a free-streaming length of the order of 0.1 Mpc. The saxion, the real scalar component of the axion supermultiplet, can also be cosmologically harmless due to the dilution of the modulus decay. The lifetime of the NLSP is relatively long, but much shorter than 1 sec, when the big-bang nucleosynthesis commences. The decay of the NLSP would provide intriguing collider signatures

  18. Magnetogenesis from axion inflation

    Adshead, Peter; Scully, Timothy R.; Sfakianakis, Evangelos I. [Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801 (United States); Giblin, John T., E-mail: adshead@illinois.edu, E-mail: giblinj@kenyon.edu, E-mail: tscully2@illinois.edu, E-mail: esfaki@illinois.edu [Department of Physics, Kenyon College, 201 North College Rd, Gambier, Ohio 43022 (United States)

    2016-10-01

    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) {sub Y} can reach B {sub eff} ∼> 10{sup −16} G, exhibiting a field strength B {sub phys} ≈ 10{sup −13} G and a correlation length λ{sub phys} ≈10 pc. This result is insensitive to the exact value of the coupling, as long as the coupling is large enough to allow for instantaneous preheating. Depending on the assumptions for the physical processes that determine blazar properties, these fields can be found consistent with blazar observations based on the value of B {sub eff}. Finally, the intensity of the magnetic field for large coupling can be enough to satisfy the requirements for a recently proposed baryogenesis mechanism, which utilizes the chiral anomaly of the Standard Model.

  19. Axions...The search continues

    Krauss, L.M.

    1986-01-01

    Axion physics relates to the following areas discussed at the Theoretical Advanced Study Institute: 1. Topology; 2. Anomalies; 3. Current Algebra, Chiral Lagrangians; 4. Effective Lagrangians; 5. Dark Matter; 6. Inflation, Early Universe; 7. ''String'' Theories; 8. New Physics at Collider Energies-Technicolor; 9. Rare Kaon Decays; 10. Experimental Probes of High Energy Physics. In the course of this paper, the authors review axion physics, from its origins in theory, to the prospects for detection. In doing this, he demonstrates, using axions as an example, how particle physics manages to turn seemingly obscure mathematical formalism into the stuff from which experiments are born

  20. ADMX Dark-Matter Axion Search

    Rosenberg, Leslie J.

    2004-01-01

    The axion, a hypothetical elementary particle, emerged from a compelling solution to the Strong-CP Problem in QCD. Subsequently, the axion was recognized to be a good Cold Dark Matter candidate. Although dark-matter axions have only feeble couplings to matter and radiation, these axions may be detected through resonant conversion of axions into microwave photons in a high-Q cavity threaded by a strong static magnetic field. This technique is at present the only means whereby dark-matter axions with plausible couplings may be detected at the required sensitivity. This talk describes recent results from the Axion Dark Matter Experiment (ADMX), now the world's most sensitive search for axions. There will also be a short overview of the ADMX upgrade, which promises sensitivity to even the more feebly coupled dark matter axions even should they make up only a minority fraction of the local dark matter halo

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

    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...

  2. The Astrophobic Axion arXiv

    Di Luzio, Luca; Nardi, Enrico; Panci, Paolo; Ziegler, Robert

    We propose a class of axion models with generation dependent Peccei-Quinn charges for the known fermions that allow to suppress the axion couplings to nucleons and electrons. Astrophysical limits are thus relaxed, allowing for axion masses up to ${\\cal O}(0.1)$ eV. The axion-photon coupling remains instead sizeable, so that next generation helioscopes will be able to probe this scenario. Astrophobia unavoidably implies flavor violating axion couplings, so that experimental limits on flavour-violating processes can provide complementary probes. The astrophobic axion can be a viable dark matter candidate in the heavy mass window, and can also account for anomalous energy loss in stars.

  3. From axions to other WISPs

    Ringwald, Andreas

    2008-10-15

    We illustrate, taking a top-down point of view, how axions and other very weakly interacting sub-eV particles (WISPs) arise in the course of compactification of the extra spatial dimensions in string/M-theory. (orig.)

  4. Can Radio Telescopes Find Axions?

    Kohler, Susanna

    2017-08-01

    In the search for dark matter, the most commonly accepted candidates are invisible, massive particles commonly referred to as WIMPs. But as time passes and we still havent detected WIMPs, alternative scenarios are becoming more and more appealing. Prime among these is the idea of axions.A Bizarre ParticleThe Italian PVLAS is an example of a laboratory experiment that attempted to confirm the existence of axions. [PVLAS]Axions are a type of particle first proposed in the late 1970s. These theorized particles arose from a new symmetry introduced to solve ongoing problems with the standard model for particle physics, and they were initially predicted to have more than a keV in mass. For this reason, their existence was expected to be quickly confirmed by particle-detector experiments yet no detections were made.Today, after many unsuccessful searches, experiments and theory tell us that if axions exist, their masses must lie between 10-610-3 eV. This is minuscule an electrons mass is around 500,000 eV, and even neutrinos are on the scale of a tenth of an eV!But enough of anything, even something very low-mass, can weigh a lot. If they are real, then axions were likely created in abundance during the Big Bang and unlike heavier particles, they cant decay into anything lighter, so we would expect them all to still be around today. Our universe could therefore be filled with invisible axions, potentially providing an explanation for dark matter in the form of many, many tiny particles.Artists impression of the central core of proposed Square Kilometer Array antennas. [SKA/Swinburne Astronomy Productions]How Do We Find Them?Axions barely interact with ordinary matter and they have no electric charge. One of the few ways we can detect them is with magnetic fields: magnetic fields can change axions to and from photons.While many studies have focused on attempting to detect axions in laboratory experiments, astronomy provides an alternative: we can search for cosmological

  5. From axions to other WISPs

    Ringwald, Andreas

    2008-10-01

    We illustrate, taking a top-down point of view, how axions and other very weakly interacting sub-eV particles (WISPs) arise in the course of compactification of the extra spatial dimensions in string/M-theory. (orig.)

  6. Eclipses could clarify axion mystery

    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)

  7. Stellar recipes for axion hunters

    Giannotti, Maurizio [Barry Univ., Miami Shores, FL (United States). Physical Sciences; Irastorza, Igor G. [Zaragoza Univ. (Spain). Dept. de Fisica Teorica; Redondo, Javier [Zaragoza Univ. (Spain). Dept. de Fisica Teorica; Max-Planck-Institut fuer Physik, Muenchen (Germany); Ringwald, Andreas; Saikawa, Ken' ichi [DESY, Hamburg (Germany). Theory Group

    2017-08-15

    There are a number of observational hints from astrophysics which point to the existence of stellar energy losses beyond the ones accounted for by neutrino emission. These excessive energy losses may be explained by the existence of a new sub-keV mass pseudoscalar Nambu-Goldstone boson with tiny couplings to photons, electrons, and nucleons. An attractive possibility is to identify this particle with the axion - the hypothetical pseudo Nambu-Goldstone boson predicted by the Peccei-Quinn solution to the strong CP problem. We explore this possibility in terms of a DFSZ-type axion and of a KSVZ-type axion/majoron, respectively. Both models allow a good global fit to the data, prefering an axion mass around 10 meV. We show that future axion experiments - the fifth force experiment ARIADNE and the helioscope IAXO - can attack the preferred mass range from the lower and higher end, respectively. An axion in this mass range can also be the main constituent of dark matter.

  8. Stellar recipes for axion hunters

    Giannotti, Maurizio; Ringwald, Andreas; Saikawa, Ken'ichi

    2017-08-01

    There are a number of observational hints from astrophysics which point to the existence of stellar energy losses beyond the ones accounted for by neutrino emission. These excessive energy losses may be explained by the existence of a new sub-keV mass pseudoscalar Nambu-Goldstone boson with tiny couplings to photons, electrons, and nucleons. An attractive possibility is to identify this particle with the axion - the hypothetical pseudo Nambu-Goldstone boson predicted by the Peccei-Quinn solution to the strong CP problem. We explore this possibility in terms of a DFSZ-type axion and of a KSVZ-type axion/majoron, respectively. Both models allow a good global fit to the data, prefering an axion mass around 10 meV. We show that future axion experiments - the fifth force experiment ARIADNE and the helioscope IAXO - can attack the preferred mass range from the lower and higher end, respectively. An axion in this mass range can also be the main constituent of dark matter.

  9. Dark matter axions and caustic rings

    Sikivie, P.

    1997-01-01

    This report contains discussions on the following topics: the strong CP problem; dark matter axions; the cavity detector of galactic halo axions; and caustic rings in the density distribution of cold dark matter halos

  10. Axion: Mass -- Dark Matter Abundance Relation

    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. Stellar recipes for axion hunters

    Giannotti, Maurizio [Physical Sciences, Barry University, 11300 NE 2nd Ave., Miami Shores, FL 33161 (United States); Irastorza, Igor G.; Redondo, Javier [Departamento de Física Teórica, Universidad de Zaragoza, Pedro Cerbuna 12, E-50009, Zaragoza (Spain); Ringwald, Andreas; Saikawa, Ken' ichi, E-mail: mgiannotti@barry.edu, E-mail: igor.irastorza@cern.ch, E-mail: jredondo@unizar.es, E-mail: andreas.ringwald@desy.de, E-mail: kenichi.saikawa@desy.de [Theory Group, Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, D-22607 Hamburg (Germany)

    2017-10-01

    There are a number of observational hints from astrophysics which point to the existence of stellar energy losses beyond the ones accounted for by neutrino emission. These excessive energy losses may be explained by the existence of a new sub-keV mass pseudoscalar Nambu-Goldstone boson with tiny couplings to photons, electrons, and nucleons. An attractive possibility is to identify this particle with the axion—the hypothetical pseudo Nambu-Goldstone boson predicted by the Peccei-Quinn solution to the strong CP problem. We explore this possibility in terms of a DFSZ-type axion and of a KSVZ-type axion/majoron, respectively. Both models allow a good global fit to the data, prefering an axion mass around 10 meV. We show that future axion experiments—the fifth force experiment ARIADNE and the helioscope IAXO—can attack the preferred mass range from the lower and higher end, respectively. An axion in this mass range can also be the main constituent of dark matter.

  12. High-temperature axion potential

    Dowrick, N.J.; McDougall, N.A.

    1989-01-01

    We investigate the possibility of new terms in the high-temperature axion potential arising from the dynamical nature of the axion field and from higher-order corrections to the θ dependence in the free energy of the quark-gluon plasma. We find that the dynamical nature of the axion field does not affect the potential but that the higher-order effects lead to new terms in the potential which are larger than the term previously considered. However, neither the magnitude nor the sign of the potential can be calculated by a perturbative expansion of the free energy since the coupling is too large. We show that a change in the magnitude of the potential does not significantly affect the bound on the axion decay constant but that the sign of the potential is of crucial importance. By investigating the formal properties of the functional integral within the instanton dilute-gas approximation, we find that the sign of the potential does not change and that the minimum remains at θ=0. We conclude that the standard calculation of the axion energy today is not significantly modified by this investigation

  13. The axion mass in modular invariant supergravity

    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)

  14. Axion-dilation black holes

    Kallosh, R.

    1993-01-01

    In this talk some essential features of stringy black holes are described. The author considers charged U(1) and U(1) x U(1) four-dimensional axion-dilaton black holes. The Hawking temperature and the entropy of all solutions are shown to be simple functions of the squares of supercharges, defining the positivity bounds. Spherically symmetric and multi black hole solutions are presented. The extreme solutions with zero entropy (holons) represent a ground state of the theory and are characterized by elementary dilaton, axion, electric, and magnetic charges. The attractive gravitational and axion-dilaton force is balanced by the repulsive electromagnetic force. The author discusses the possibility of splitting of nearly extreme black holes. 11 refs

  15. Dark-matter QCD-axion searches

    Rosenberg, Leslie J

    2010-01-01

    The axion is a hypothetical elementary particle appearing in a simple and elegant extension to the Standard Model of particle physics that cancels otherwise huge CP-violating effects in QCD; this extension has a broken U(1) axial symmetry, where the resulting Goldstone Boson is the axion. A light axion of mass 10 -(6-3) eV (the so-called i nvisible 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 would be a compelling dark-matter candidate and is therefore a target of a number of searches. Compared to other dark-matter candidates, the plausible range of axion dark-matter couplings and masses is narrowly constrained. This restricted search space allows for 'definitive' searches, where non-observation would seriously impugn the dark-matter QCD-axion hypothesis. Axion searches employ a wide range of technologies and techniques, from astrophysical observations to laboratory electromagnetic signal detection. For some experiments, sensitivities are have reached likely dark-matter axion couplings and masses. This is a brief and selective overview of axion searches. With only very limited space, I briefly describe just two of the many experiments that are searching for dark-matter axions.

  16. Harmful axions in superstring models

    Choi, K.; Kim, J.E.

    1985-01-01

    We show in this paper that the existing superstring models, E 8 x E 8 and O(32), have the axion decay constant problem. It is either 300 GeV or 10 16 GeV, which are outside the cosmologically allowed region. It is also pointed out that the invisible axion with 10 8 GeV 12 GeV is a necessity for all theories which have an effective interaction (PHIsub(n)/Msub(Pl))F tilde below the Planck scale. (orig.)

  17. Backreacted axion field ranges in string theory

    Baume, Florent; Palti, Eran [Institut für Theoretische Physik, Ruprecht-Karls-Universität, Philosophenweg 19, Heidelberg, 69120 (Germany)

    2016-08-05

    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.

  18. Thermalized axion inflation

    Ferreira, Ricardo Z.; Notari, Alessio, E-mail: rferreira@icc.ub.edu, E-mail: notari@ub.edu [Departament de Física Quàntica i Astrofísica i Institut de Ciències del Cosmos (ICCUB), Universitat de Barcelona, Martí i Franquès, 1, E-08028, Barcelona (Spain)

    2017-09-01

    We analyze the dynamics of inflationary models with a coupling of the inflaton φ to gauge fields of the form φ F F-tilde / f , as in the case of axions. It is known that this leads to an instability, with exponential amplification of gauge fields, controlled by the parameter ξ= φ-dot /(2 fH ), which can strongly affect the generation of cosmological perturbations and even the background. We show that scattering rates involving gauge fields can become larger than the expansion rate H , due to the very large occupation numbers, and create a thermal bath of particles of temperature T during inflation. In the thermal regime, energy is transferred to smaller scales, radically modifying the predictions of this scenario. We thus argue that previous constraints on ξ are alleviated. If the gauge fields have Standard Model interactions, which naturally provides reheating, they thermalize already at ξ∼>2.9, before perturbativity constraints and also before backreaction takes place. In absence of SM interactions (i.e. for a dark photon), we find that gauge fields and inflaton perturbations thermalize if ξ∼>3.4; however, observations require ξ∼>6, which is above the perturbativity and backreaction bounds and so a dedicated study is required. After thermalization, though, the system should evolve non-trivially due to the competition between the instability and the gauge field thermal mass. If the thermal mass and the instabilities equilibrate, we expect an equilibrium temperature of T {sub eq} ≅ ξ H / g-bar where g-bar is the effective gauge coupling. Finally, we estimate the spectrum of perturbations if φ is thermal and find that the tensor to scalar ratio is suppressed by H /(2 T ), if tensors do not thermalize.

  19. Thermalized axion inflation

    Ferreira, Ricardo Z.; Notari, Alessio

    2017-09-01

    We analyze the dynamics of inflationary models with a coupling of the inflaton phi to gauge fields of the form phi F tilde F/f, as in the case of axions. It is known that this leads to an instability, with exponential amplification of gauge fields, controlled by the parameter ξ= dot phi/(2fH), which can strongly affect the generation of cosmological perturbations and even the background. We show that scattering rates involving gauge fields can become larger than the expansion rate H, due to the very large occupation numbers, and create a thermal bath of particles of temperature T during inflation. In the thermal regime, energy is transferred to smaller scales, radically modifying the predictions of this scenario. We thus argue that previous constraints on ξ are alleviated. If the gauge fields have Standard Model interactions, which naturally provides reheating, they thermalize already at ξgtrsim2.9, before perturbativity constraints and also before backreaction takes place. In absence of SM interactions (i.e. for a dark photon), we find that gauge fields and inflaton perturbations thermalize if ξgtrsim3.4 however, observations require ξgtrsim6, which is above the perturbativity and backreaction bounds and so a dedicated study is required. After thermalization, though, the system should evolve non-trivially due to the competition between the instability and the gauge field thermal mass. If the thermal mass and the instabilities equilibrate, we expect an equilibrium temperature of Teq simeq ξ H/bar g where bar g is the effective gauge coupling. Finally, we estimate the spectrum of perturbations if phi is thermal and find that the tensor to scalar ratio is suppressed by H/(2T), if tensors do not thermalize.

  20. Axion cooling of white dwarfs

    Isern, J.; Catalan, S.; 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.

  1. Axions and polarisation of quasars

    Payez, A.; Cudell, J. R.; Hutsemekers, D.

    2008-01-01

    We present results showing that, thanks to axion-photon mixing in external magnetic fields, it is actually possible to produce an effect similar to the one needed to explain the large-scale coherent orientations of quasar polarisation vectors in visible light that have been observed in some regions of the sky

  2. Invisible Axions and Large-Radius Compactifications

    Dienes, Keith R.; Gherghetta, Tony; Dienes, Keith R.; Dudas, Emilian; Gherghetta, Tony

    2000-01-01

    We study some of the novel effects that arise when the QCD axion is placed in the ``bulk'' of large extra spacetime dimensions. First, we find that the mass of the axion can become independent of the energy scale associated with the breaking of the Peccei-Quinn symmetry. This implies that the mass of the axion can be adjusted independently of its couplings to ordinary matter, thereby providing a new method of rendering the axion invisible. Second, we discuss the new phenomenon of laboratory axion oscillations (analogous to neutrino oscillations), and show that these oscillations cause laboratory axions to ``decohere'' extremely rapidly as a result of Kaluza-Klein mixing. This decoherence may also be a contributing factor to axion invisibility. Third, we discuss the role of Kaluza-Klein axions in axion-mediated processes and decays, and propose several experimental tests of the higher-dimensional nature of the axion. Finally, we show that under certain circumstances, the presence of an infinite tower of Kaluza...

  3. Planckian axions in string theory

    Bachlechner, Thomas C.; Long, Cody; McAllister, Liam

    2015-01-01

    We argue that super-Planckian diameters of axion fundamental domains can arise in Calabi-Yau compactifications of string theory. In a theory with N axions θ i , the fundamental domain is a polytope defined by the periodicities of the axions, via constraints of the form −π√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 http://dx.doi.org/10.4310/ATMP.2005.v9.n6.a1, the largest metric eigenvalue obeys f N ≈0.013M pl . The random matrix analysis then predicts, and we exhibit, axion diameters ≈M pl for the precise vacuum parameters found in http://dx.doi.org/10.4310/ATMP.2005.v9.n6.a1. Our results provide a framework for pursuing large-field axion inflation in well-understood flux vacua.

  4. Observational evidence for gravitationally trapped massive axion(-like) particles

    Di Lella, L

    2003-01-01

    Several unexpected astrophysical observations can be explained by gravitationally captured massive axions or axion-like particles, which are produced inside the Sun or other stars and are accumulated over cosmic times. Their radiative decay in solar outer space would give rise to a `self-irradiation' of the whole star, providing the time-independent component of the corona heating source (we do not address here the flaring Sun). In analogy with the Sun-irradiated Earth atmosphere, the temperature and density gradient in the corona$-$chromosphere transition region is suggestive for an omnipresent irradiation of the Sun, which is the strongest evidence for the generic axion-like scenario. The same mechanism is compatible with phenomena like the solar wind, the X-rays from the dark-side of the Moon, the X-Ray Background Radiation, the diffuse X-ray excesses (below $\\sim 1$ keV), the non-cooling of oldest Stars, etc. A temperature of $\\sim 10^6$ K is observed in various places, while the radiative decay of a popu...

  5. 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.

    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.

  6. Planck-scale corrections to axion models

    Barr, S.M.; Seckel, D.

    1992-01-01

    It has been argued that quantum gravitational effects will violate all nonlocal symmetries. Peccei-Quinn symmetries must therefore be an ''accidental'' or automatic consequence of local gauge symmetry. Moreover, higher-dimensional operators suppressed by powers of M Pl are expected to explicitly violate the Peccei-Quinn symmetry. Unless these operators are of dimension d≥10, axion models do not solve the strong CP problem in a natural fashion. A small gravitationally induced contribution to the axion mass has little if any effect on the density of relic axions. If d=10, 11, or 12 these operators can solve the axion domain-wall problem, and we describe a simple class of Kim-Shifman-Vainshtein-Zakharov axion models where this occurs. We also study the astrophysics and cosmology of ''heavy axions'' in models where 5≤d≤10

  7. A possible laboratory test for the axions

    Ramachandran, G.; Vinay Deepak, H.S.; Thomas, Sujith; Raghunath, C.; Cowsik, R.

    2011-01-01

    The axion is a hypothetical light boson with spin zero which was introduced theoretically more than 3 decades ago, following the Peccei-Quinn solution to the strong CP problem. The axion is one amongst the candidates for dark matter along with neutrinos, WIMPS, SIMPS, CHAMPS and Super heavy particles which could possibly be detected by neutrino facilities like IceCube. The purpose of the present contribution is to suggest a laboratory test for the existence of axions

  8. On supersymmetric effective theories of axion

    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.)

  9. Axions as hot and cold dark matter

    Jeong, Kwang Sik; Kawasaki, Masahiro; Tokyo Univ., Kashiwa; Takahashi, Fuminobu; Tokyo Univ., Kashiwa

    2013-10-01

    The presence of a hot dark matter component has been hinted at 3σ 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 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.

  10. Search for Invisible Axion Dark Matter with the Axion Dark Matter Experiment.

    Du, N; Force, N; Khatiwada, R; Lentz, E; Ottens, R; Rosenberg, L J; Rybka, G; Carosi, G; Woollett, N; Bowring, D; Chou, A S; Sonnenschein, A; Wester, W; Boutan, C; Oblath, N S; Bradley, R; Daw, E J; Dixit, A V; Clarke, J; O'Kelley, S R; Crisosto, N; Gleason, J R; Jois, S; Sikivie, P; Stern, I; Sullivan, N S; Tanner, D B; Hilton, G C

    2018-04-13

    This Letter reports the results from a haloscope search for dark matter axions with masses between 2.66 and 2.81  μeV. The search excludes the range of axion-photon couplings predicted by plausible models of the invisible axion. This unprecedented sensitivity is achieved by operating a large-volume haloscope at subkelvin temperatures, thereby reducing thermal noise as well as the excess noise from the ultralow-noise superconducting quantum interference device amplifier used for the signal power readout. Ongoing searches will provide nearly definitive tests of the invisible axion model over a wide range of axion masses.

  11. Axions in cosmology and laboratory

    Axions are dark matter candidates [3]. Let us summarize how they are created. Consider the early Universe at high temperatures qcd ≪ T < f but with a broken PQ symmetry. In this period of the early Universe, we have a vacuum with θi = 0. In the expansion, the Universe cools down. When T ∼ qcd is reached, the vacuum ...

  12. Gravitational waves from axion monodromy

    Hebecker, Arthur; Jaeckel, Joerg; Rompineve, Fabrizio; Witkowski, Lukas T. [Institute for Theoretical Physics, University of Heidelberg,Philosophenweg 19, 69120 Heidelberg (Germany)

    2016-11-02

    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, possibly within reach of next-generation interferometers. We also note that this “dynamical phase decomposition' phenomenon and its gravitational wave signal are more general and may apply to other inflationary or reheating scenarios with axions and modulated potentials.

  13. Vacuum selection on axionic landscapes

    Wang, Gaoyuan; Battefeld, Thorsten

    2016-01-01

    We compute the distribution of minima that are reached dynamically on multi-field axionic landscapes, both numerically and analytically. Such landscapes are well suited for inflationary model building due to the presence of shift symmetries and possible alignment effects (the KNP mechanism). The resulting distribution of dynamically reached minima differs considerably from the naive expectation based on counting all vacua. These differences are more pronounced in the presence of many fields due to dynamical selection effects: while low lying minima are preferred as fields roll down the potential, trajectories are also more likely to get trapped by one of the many nearby minima. We show that common analytic arguments based on random matrix theory in the large D-limit to estimate the distribution of minima are insufficient for quantitative arguments pertaining to the dynamically reached ones. This discrepancy is not restricted to axionic potentials. We provide an empirical expression for the expectation value of such dynamically reached minimas' height and argue that the cosmological constant problem is not alleviated in the absence of anthropic arguments. We further comment on the likelihood of inflation on axionic landscapes in the large D-limit

  14. X-ray optics for axion helioscopes

    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....

  15. Axions: on the way to invisibility

    Girardi, G.

    1982-01-01

    We present a survey of the theoretical motivation which lead to the axion and we summarize its properties. A brief account of the experimental situation is given, which in addition to cosmological constraints imposes to the axion the way of invisibility in Grand Unified Theories

  16. The search for axion dark matter

    Sikivie, P.

    1998-01-01

    This talk reviews the original motivation for the axion as a solution to the strong CP problem and the constraints that have been placed on the axion by experimental searches and by astrophysical and cosmological considerations. As a result of the bounds, the axion mass is presently restricted to a window extending from about 10 -2 ampersand hthinsp;eV to about 10 -6 ampersand hthinsp;eV. In this window, axions are a form of cold dark matter. It is possible to detect galactic halo axions by stimulating their conversion to photons in a laboratory magnetic field. I close-quote ll report on two experiments of this type, one at Lawrence Livermore National Laboratory and the other at Kyoto University. I close-quote ll also discuss what can be learned about the structure of our galactic halo if a signal is found. copyright 1998 American Institute of Physics

  17. A search for axions and massive neutrinos

    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.

  18. Non-Abelian strings and axions

    Gorsky, A.; Shifman, M.; Yung, A.

    2006-01-01

    We address two distinct but related issues: (i) the impact of (two-dimensional) axions in a two-dimensional theory known to model confinement, the CP(N-1) model; (ii) bulk axions in four-dimensional Yang-Mills theory supporting non-Abelian strings. In the first case n, n kinks play the role of 'quarks'. They are known to be confined. We show that introduction of axions leads to deconfinement (at very large distances). This is akin to the phenomenon of wall liberation in four-dimensional Yang-Mills theory. In the second case we demonstrate that the bulk axion does not liberate confined (anti)monopoles, in contradistinction with the two-dimensional model. A novel physical effect which we observe is the axion radiation caused by monopole-antimonopole pairs attached to the non-Abelian strings

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

    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.

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

    Ringwald, Andreas

    2012-01-01

    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.

  1. Improving axion detection sensitivity in high purity germanium detector based experiments

    Xu, Wenqin; Elliott, Steven

    2015-04-01

    Thanks to their excellent energy resolution and low energy threshold, high purity germanium (HPGe) crystals are widely used in low background experiments searching for neutrinoless double beta decay, e.g. the MAJORANA DEMONSTRATOR and the GERDA experiments, and low mass dark matter, e.g. the CDMS and the EDELWEISS experiments. A particularly interesting candidate for low mass dark matter is the axion, which arises from the Peccei-Quinn solution to the strong CP problem and has been searched for in many experiments. Due to axion-photon coupling, the postulated solar axions could coherently convert to photons via the Primakeoff effect in periodic crystal lattices, such as those found in HPGe crystals. The conversion rate depends on the angle between axions and crystal lattices, so the knowledge of HPGe crystal axis is important. In this talk, we will present our efforts to improve the HPGe experimental sensitivity to axions by considering the axis orientations in multiple HPGe crystals simultaneously. We acknowledge the support of the U.S. Department of Energy through the LANL/LDRD Program.

  2. Hydrogen axion star: metallic hydrogen bound to a QCD axion BEC

    Bai, Yang; Barger, Vernon; Berger, Joshua [Department of Physics, University of Wisconsin-Madison,1150 University Ave, Madison, WI 53706 (United States)

    2016-12-23

    As a cold dark matter candidate, the QCD axion may form Bose-Einstein condensates, called axion stars, with masses around 10{sup −11} M{sub ⊙}. In this paper, we point out that a brand new astrophysical object, a Hydrogen Axion Star (HAS), may well be formed by ordinary baryonic matter becoming gravitationally bound to an axion star. We study the properties of the HAS and find that the hydrogen cloud has a high pressure and temperature in the center and is likely in the liquid metallic hydrogen state. Because of the high particle number densities for both the axion star and the hydrogen cloud, the feeble interaction between axion and hydrogen can still generate enough internal power, around 10{sup 13} W×(m{sub a}/5 meV){sup 4}, to make these objects luminous point sources. High resolution ultraviolet, optical and infrared telescopes can discover HAS via black-body radiation.

  3. Structure formation and microlensing with axion miniclusters

    Fairbairn, Malcolm; Marsh, David J. E.; Quevillon, Jérémie; Rozier, Simon

    2018-04-01

    If the symmetry breaking responsible for axion dark matter production occurs during the radiation-dominated epoch in the early Universe, then this produces large amplitude perturbations that collapse into dense objects known as axion miniclusters. The characteristic minicluster mass, M0, is set by the mass inside the horizon when axion oscillations begin. For the QCD axion M0˜10-10 M⊙, however, for an axionlike particle, M0 can approach M⊙ or higher. Using the Press-Schechter formalism we compute the mass function of halos formed by hierarchical structure formation from these seeds. We compute the concentrations and collapse times of these halos and show that they can grow to be as massive as 1 06M0. Within the halos, miniclusters likely remain tightly bound, and we compute their gravitational microlensing signal taking the fraction of axion dark matter collapsed into miniclusters, fMC, as a free parameter. A large value of fMC severely weakens constraints on axion scenarios from direct detection experiments. We take into account the non-Gaussian distribution of sizes of miniclusters and determine how this affects the number of microlensing events. We develop the tools to consider microlensing by an extended mass function of nonpointlike objects, and we use microlensing data to place the first observational constraints on fMC. This opens a new window for the potential discovery of the axion.

  4. Axion mass limits from pulsar x rays

    Morris, D.E.

    1984-12-01

    Axions thermally emitted by a neutron star would be converted into x rays in the strong magnetic field surrounding the star. An improvement in the observational upper limit of pulsed x rays from the Vela pulsar (PSR 0833-45) by a factor of 12 would constrain the axion mass M/sub a/ -3 eV if the core is non-superfluid and at temperature T/sub c/ greater than or equal to 2 x 10 8 K. If the core is superfluid throughout, an improvement factor of 240 would be needed to provide the same constraint on the axion mass, while in the absence of superfluidity, an improvement factor of 200 could constrain M/sub a/ -4 eV. A search for modulated hard x rays from PSR 1509-58 or other young pulsars at presently attainable sensitivities may enable the setting of an upper limit for the axion mass. Observation of hard x rays from a very young hot pulsar with T/sub c/ greater than or equal to 7 x 10 8 K could set a firm bound on the axion mass, since neutron superfluidity is not expected above this temperature. The remaining axion mass range 6 x 10 -4 eV > M/sub a/ > 10 -5 eV (the cosmological lower bound) can be covered by an improved Sikivie type laboratory cavity detector for relic axions constituting the galactic halo. 48 refs

  5. CERN, Geneva

    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)

  6. Universal constraints on axions from inflation

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

    2014-01-01

    -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...... that the generation of curvature perturbation at horizon crossing due to the axial coupling has a universal form and remains unmodified in terms of the xi parameter even if the axion, sigma, is not identified with the inflaton. As a consequence, it does not appear to be possible to generate CMB tensor perturbations...

  7. Black hole formation from axion stars

    Helfer, Thomas; Marsh, David J.E.; Clough, Katy; Fairbairn, Malcolm; Lim, Eugene A. [King' s College London, Strand, London, WC2R 2LS (United Kingdom); Becerril, Ricardo, E-mail: thomas.1.helfer@kcl.ac.uk, E-mail: david.marsh@kcl.ac.uk, E-mail: katy.clough@phys.uni-goettingen.de, E-mail: malcolm.fairbairn@kcl.ac.uk, E-mail: eugene.lim@kcl.ac.uk, E-mail: becerril@ifm.umich.mx [Instituto de Física y Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo, Ciudad Universitaria, CP 58040 Morelia, Michoacán (Mexico)

    2017-03-01

    The classical equations of motion for an axion with potential V (φ)= m {sub a} {sup 2} f {sub a} {sup 2} [1−cos (φ/ f {sub 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 {sub ADM}, and axion decay constant, f {sub a} . We identify three regions of the parameter space: i) long-lived oscillating axion star solutions, with a base frequency, m {sub 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 {sub TP}, f {sub TP}) ∼ (2.4 M {sub pl}{sup 2}/ m {sub a} ,0.3 M {sub pl}). For f {sub a} below the triple point BH formation proceeds during winding (in the complex U(1) picture) of the axion field near the dispersal phase. This could prevent astrophysical BH formation from axion stars with f {sub a} || M {sub pl}. For larger f {sub a} ∼> f {sub TP}, BH formation occurs through the stable branch and we estimate the mass ratio of the BH to the stable state at the phase boundary to be O(1) within numerical uncertainty. We discuss the observational relevance of our findings for axion stars as BH seeds, which are supermassive in the case of ultralight axions. For the QCD axion, the typical BH mass formed from axion star collapse is M {sub BH} ∼ 3.4 ( f {sub a} /0.6 M {sub pl}){sup 1.2} M {sub ⊙}.

  8. Axions as hot and cold dark matter

    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.

  9. Cavity Microwave Searches for Cosmological Axions

    CERN. Geneva

    2005-01-01

    The lecture will cover the searches for dark matter axions based on the microwave cavity experiment of Sikivie. The topics will begin 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, and practical considerations in optimizing the experiment as a signal-to-noise problem. A major focus of the lecture 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 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 lecture will conclude with a discussion of future plans and challenges for the microwave ca...

  10. Dark-matter QCD-axion searches.

    Rosenberg, Leslie J

    2015-10-06

    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

  11. CERN SOLAR CLUB

    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 !

  12. Update of axion CDM energy density

    Huh, Ji-Haeng

    2008-01-01

    We update cosmological bound on axion model. The contribution from the anharmonic effect and the newly introduced initial overshoot correction are considered. We present an explicit formula for the axion relic density in terms of the QCD scale Λ QCD , the current quark masses m q 's and the Peccei-Quinn scale F a , including firstly introduced 1.85 factor which is from the initial overshoot.

  13. Planckian axions and the Weak Gravity Conjecture

    Bachlechner, Thomas C.; Long, Cody; McAllister, Liam

    2016-01-01

    Several recent works http://dx.doi.org/10.1088/1475-7516/2015/09/020, http://dx.doi.org/10.1007/JHEP08(2015)032, http://dx.doi.org/10.1007/JHEP10(2015)023 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≫1 axions, super-Planckian axion diameters 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≤…≤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_N M_p_l 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 satisfied by gravitational instantons that make negligible contributions to the potential.

  14. Photon - axion conversions in a periodic electromagnetic field with axion frequency

    Dang Van Soa

    1998-09-01

    The conversion of photons into axions in a periodic external electromagnetic field with axion frequency is considered in detail by Feynman methods. The differential cross sections are given. It is shown that there is a resonant conversion for the considered process. (author)

  15. Evidence for inflation in an axion landscape

    Nath, Pran; Piskunov, Maksim

    2018-03-01

    We discuss inflation models within supersymmetry and supergravity frameworks with a landscape of chiral superfields and one U(1) shift symmetry which is broken by non-perturbative symmetry breaking terms in the superpotential. We label the pseudo scalar component of the chiral fields axions and their real parts saxions. Thus in the models only one combination of axions will be a pseudo-Nambu-Goldstone-boson which will act as the inflaton. The proposed models constitute consistent inflation for the following reasons: the inflation potential arises dynamically with stabilized saxions, the axion decay constant can lie in the sub-Planckian region, and consistency with the Planck data is achieved. The axion landscape consisting of m axion pairs is assumed with the axions in each pair having opposite charges. A fast roll-slow roll splitting mechanism for the axion potential is proposed which is realized with a special choice of the axion basis. In this basis the 2 m coupled equations split into 2 m - 1 equations which enter in the fast roll and there is one unique linear combination of the 2 m fields which controls the slow roll and thus the power spectrum of curvature and tensor perturbations. It is shown that a significant part of the parameter space exists where inflation is successful, i.e., N pivot = [50, 60], the spectral index n s of curvature perturbations, and the ratio r of the power spectrum of tensor perturbations and curvature perturbations, lie in the experimentally allowed regions given by the Planck experiment. Further, it is shown that the model allows for a significant region of the parameter space where the effective axion decay constant can lie in the sub-Planckian domain. An analysis of the tensor spectral index n t is also given and the future experimental data which constraints n t will further narrow down the parameter space of the proposed inflationary models. Topics of further interest include implications of the model for gravitational waves

  16. Cosmological abundance of the QCD axion coupled to hidden photons

    Kitajima, Naoya; Sekiguchi, Toyokazu; Takahashi, Fuminobu

    2018-06-01

    We study the cosmological evolution of the QCD axion coupled to hidden photons. For a moderately strong coupling, the motion of the axion field leads to an explosive production of hidden photons by tachyonic instability. We use lattice simulations to evaluate the cosmological abundance of the QCD axion. In doing so, we incorporate the backreaction of the produced hidden photons on the axion dynamics, which becomes significant in the non-linear regime. We find that the axion abundance is suppressed by at most O (102) for the decay constant fa =1016GeV, compared to the case without the coupling. For a sufficiently large coupling, the motion of the QCD axion becomes strongly damped, and as a result, the axion abundance is enhanced. Our results show that the cosmological upper bound on the axion decay constant can be relaxed by a few hundred for a certain range of the coupling to hidden photons.

  17. Axion dark matter and the 21-cm signal

    Sikivie, Pierre

    2018-01-01

    It was shown in ref. [1] that cold dark matter axions reach thermal contact with baryons, and therefore cool them, shortly after the axions thermalize among themselves and form a Bose-Einstein condensate. The recent observation by the EDGES collaboration of a baryon temperature at cosmic dawn lower than expected under "standard" assumptions is interpreted as new evidence that the dark matter is axions, at least in part. Baryon cooling by dark matter axions is found to be consistent with the o...

  18. CERN Choir

    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

  19. Universal constraints on axions from inflation

    Ferreira, Ricardo Z.; Sloth, Martin S. [CP-Origins, Center for Cosmology and Particle Physics Phenomenology,University of Southern Denmark, Campusvej 55, 5230 Odense M (Denmark)

    2014-12-19

    We consider the presence of an axion like particle, σ, with a generic CP violating axial coupling of the form (α σ/f)FF-tilde, where F{sub μν} is the gauge field strength of a generic abelian U(1) gauge group, not necessarily associated with the standard electromagnetism, and f is the decay 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 ξ=α σ-dot /(fH). In the present paper we will show that the generation of curvature perturbation at horizon crossing due to the axial coupling has a universal form and remains unmodified in terms of the ξ parameter even if the axion, σ, is not identified with the inflaton. As a consequence, it does not appear to be possible to generate CMB tensor perturbations through this mechanism, larger than the vacuum ones, without violating the observational constraints unless we combine this mechanism with a curvaton or if the σ 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 is an axion.

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

    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); Oikawa, Akane [Department of Physics, Waseda University,Tokyo 169-8555 (Japan); Omoto, Naoya [Department of Physics, Hokkaido University,Sapporo 060-0810 (Japan); Otsuka, Hajime [Department of Physics, Waseda University,Tokyo 169-8555 (Japan); Tatsuishi, Takuya H. [Department of Physics, Hokkaido University,Sapporo 060-0810 (Japan)

    2016-10-10

    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.

  1. First Searches for Axions and Axionlike Particles with the LUX Experiment

    Akerib, D. S.; Alsum, S.; Aquino, C.; Araújo, H. M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Beltrame, P.; Bernard, E. P.; Bernstein, A.; Biesiadzinski, T. P.; Boulton, E. M.; Brás, P.; Byram, D.; Cahn, S. B.; Carmona-Benitez, M. C.; Chan, C.; Chiller, A. A.; Chiller, C.; Currie, A.; Cutter, J. E.; Davison, T. J. R.; Dobi, A.; Dobson, J. E. Y.; Druszkiewicz, E.; Edwards, B. N.; Faham, C. H.; Fallon, S. R.; Fiorucci, S.; Gaitskell, R. J.; Gehman, V. M.; Ghag, C.; Gibson, K. R.; Gilchriese, M. G. D.; Hall, C. R.; Hanhardt, M.; Haselschwardt, S. J.; Hertel, S. A.; Hogan, D. P.; Horn, M.; Huang, D. Q.; Ignarra, C. M.; Jacobsen, R. G.; Ji, W.; Kamdin, K.; Kazkaz, K.; Khaitan, D.; Knoche, R.; Larsen, N. A.; Lee, C.; Lenardo, B. G.; Lesko, K. T.; Lindote, A.; Lopes, M. I.; Manalaysay, A.; Mannino, R. L.; Marzioni, M. F.; McKinsey, D. N.; Mei, D.-M.; Mock, J.; Moongweluwan, M.; Morad, J. A.; Murphy, A. St. J.; Nehrkorn, C.; Nelson, H. N.; Neves, F.; O'Sullivan, K.; Oliver-Mallory, K. C.; Palladino, K. J.; Pease, E. K.; Reichhart, L.; Rhyne, C.; Shaw, S.; Shutt, T. A.; Silva, C.; Solmaz, M.; Solovov, V. N.; Sorensen, P.; Stephenson, S.; Sumner, T. J.; Szydagis, M.; Taylor, D. J.; Taylor, W. C.; Tennyson, B. P.; Terman, P. A.; Tiedt, D. R.; To, W. H.; Tripathi, M.; Tvrznikova, L.; Uvarov, S.; Velan, V.; Verbus, J. R.; Webb, R. C.; White, J. T.; Whitis, T. J.; Witherell, M. S.; Wolfs, F. L. H.; Xu, J.; Yazdani, K.; Young, S. K.; Zhang, C.; LUX Collaboration

    2017-06-01

    The first searches for axions and axionlike particles with the Large Underground Xenon experiment are presented. Under the assumption of an axioelectric interaction in xenon, the coupling constant between axions and electrons gAe is tested using data collected in 2013 with an exposure totaling 95 live days ×118 kg . A double-sided, profile likelihood ratio statistic test excludes gAe larger than 3.5 ×10-12 (90% C.L.) for solar axions. Assuming the Dine-Fischler-Srednicki-Zhitnitsky theoretical description, the upper limit in coupling corresponds to an upper limit on axion mass of 0.12 eV /c2 , while for the Kim-Shifman-Vainshtein-Zhakharov description masses above 36.6 eV /c2 are excluded. For galactic axionlike particles, values of gAe larger than 4.2 ×10-13 are excluded for particle masses in the range 1 - 16 keV /c2 . These are the most stringent constraints to date for these interactions.

  2. Axion forces, gravity experiments and T violation

    Moody, J.E.

    1984-01-01

    A variety of light, weakly-coupled bosons have recently been suggested. Among them is the axion. This thesis considers the possibility of detecting axions or other light bosons via the macroscopic forces they mediate. The motivation for the axion is reviewed along with a detailed calculation of its mass and couplings. The microphysical basis of macroscopic forces is described and the three distinct axion force laws are thereby obtained. Of particular interest is the unique P and T violating monopole-dipole force. The magnitudes and ranges of axion forces are compared with the existing experimental limits. The possibilities for searching for (monopole) 2 , spin-spin and monopole-dipole forces are evaluated. Monopole-dipole experiments seem promising because the sensitive high-Q techniques of gravity wave research are applicable. Ultimate sensitivity, as limited by thermal noise, is evaluated for crystal oscillators and levitated systems. The very interesting problem of quantum uncertainty in weak force measurement is considered along with a way of getting around it called back action evasion. This is followed by a presentation of signal to noise analysis which folds together amplifier noise, quantum uncertainty, and Langevin noise

  3. Courrier CERN

    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.

  4. 30 CERN

    Anon.

    1984-01-01

    September marked the 30th Anniversary of the coming into force of the Convention establishing the European Organization for Nuclear Research (CERN). A formal ceremony, attended by the King of Spain, was the highlight of the celebrations. Throughout the month, an exhibition of many of the important documents from CERN's early history (including the original Convention, kindly loaned by UNESCO, with the signatures of representatives of the twelve founding States) was presented at CERN. A concert by the Geneva Orchestre de la Suisse Romande was given in CERN's honour. An Open Day at the Laboratory drew thousands of visitors. A full day's 'history seminar' enabled a team presently working on CERN history to consult with many of the pioneers

  5. 30 CERN

    Anon.

    1984-11-15

    September marked the 30th Anniversary of the coming into force of the Convention establishing the European Organization for Nuclear Research (CERN). A formal ceremony, attended by the King of Spain, was the highlight of the celebrations. Throughout the month, an exhibition of many of the important documents from CERN's early history (including the original Convention, kindly loaned by UNESCO, with the signatures of representatives of the twelve founding States) was presented at CERN. A concert by the Geneva Orchestre de la Suisse Romande was given in CERN's honour. An Open Day at the Laboratory drew thousands of visitors. A full day's 'history seminar' enabled a team presently working on CERN history to consult with many of the pioneers.

  6. Drifting oscillations in axion monodromy

    Flauger, Raphael [Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); McAllister, Liam [Department of Physics, Cornell University, Ithaca, NY 14853 (United States); Silverstein, Eva [Stanford Institute for Theoretical Physics, Stanford University, Stanford, CA 94305 (United States); Westphal, Alexander, E-mail: flauger@physics.ucsd.edu, E-mail: mcallister@cornell.edu, E-mail: evas@stanford.edu, E-mail: alexander.westphal@desy.de [Theory Group, Deutsches Elektronen-Synchrotron DESY, D-22603 Hamburg (Germany)

    2017-10-01

    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.

  7. Drifting oscillations in axion monodromy

    Flauger, Raphael; Westphal, Alexander

    2014-12-01

    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.

  8. Dark matter through the axion portal

    Nomura, Yasunori; Thaler, Jesse

    2009-04-01

    Motivated by the galactic positron excess seen by PAMELA and ATIC/PPB-BETS, we propose that dark matter is a TeV-scale particle that annihilates into a pseudoscalar “axion.” The positron excess and the absence of an antiproton or gamma ray excess constrain the axion mass and branching ratios. In the simplest realization, the axion is associated with a Peccei-Quinn symmetry, in which case it has a mass around 360-800 MeV and decays into muons. We present a simple and predictive supersymmetric model implementing this scenario, where both the Higgsino and dark matter obtain masses from the same source of TeV-scale spontaneous symmetry breaking.

  9. Dark matter through the axion portal

    Nomura, Yasunori; Thaler, Jesse

    2009-01-01

    Motivated by the galactic positron excess seen by PAMELA and ATIC/PPB-BETS, we propose that dark matter is a TeV-scale particle that annihilates into a pseudoscalar 'axion'. The positron excess and the absence of an antiproton or gamma ray excess constrain the axion mass and branching ratios. In the simplest realization, the axion is associated with a Peccei-Quinn symmetry, in which case it has a mass around 360-800 MeV and decays into muons. We present a simple and predictive supersymmetric model implementing this scenario, where both the Higgsino and dark matter obtain masses from the same source of TeV-scale spontaneous symmetry breaking.

  10. Astrophysical axion bounds diminished by screening effects

    Raffelt, G.G.

    1986-01-01

    ''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/ 2 β 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

  11. Axion cold dark matter in nonstandard cosmologies

    Visinelli, Luca; Gondolo, Paolo

    2010-01-01

    We study the parameter space of cold dark matter axions in two cosmological scenarios with nonstandard thermal histories before big bang nucleosynthesis: the low-temperature reheating (LTR) cosmology and the kination cosmology. If the Peccei-Quinn symmetry breaks during inflation, we find more allowed parameter space in the LTR cosmology than in the standard cosmology and less in the kination cosmology. On the contrary, if the Peccei-Quinn symmetry breaks after inflation, the Peccei-Quinn scale is orders of magnitude higher than standard in the LTR cosmology and lower in the kination cosmology. We show that the axion velocity dispersion may be used to distinguish some of these nonstandard cosmologies. Thus, axion cold dark matter may be a good probe of the history of the Universe before big bang nucleosynthesis.

  12. Axion inflation in F-theory

    Grimm, Thomas W.

    2014-12-12

    We study the dynamics of axion-like fields in F-theory and suggest that they can serve as inflatons in models of natural inflation. The axions arise from harmonic three-forms on the F-theory compactification space and parameterize a complex torus that varies over the geometric moduli space. In particular, this implies that the axion decay constants depend on the complex structure moduli that can be fixed by background fluxes. This might allow tuning them to be super-Planckian in a controlled way and allow for interesting single field inflationary models. We argue that this requires a localization of the three-forms near regions of strong string coupling, analogously to the reasoning that GUT physics requires the use of F-theory. These models can admit a tensor to scalar ratio r>0.1.

  13. Isocurvature forecast in the anthropic axion window

    Hamann, J; Raffelt, G G; Wong, Y Y Y

    2009-01-01

    We explore the cosmological sensitivity to the amplitude of isocurvature fluctuations that would be caused by axions in the "anthropic window" where the axion decay constant f_a >> 10^12 GeV and the initial misalignment angle Theta_i << 1. In a minimal Lambda-CDM cosmology extended with subdominant scale-invariant isocurvature fluctuations, existing data constrain the isocurvature fraction to alpha < 0.09 at 95% C.L. If no signal shows up, Planck can improve this constraint to 0.042 while an ultimate CMB probe limited only by cosmic variance in both temperature and E-polarisation can reach 0.017, about a factor of five better than the current limit. In the parameter space of f_a and H_I (Hubble parameter during inflation) we identify a small region where axion detection remains within the reach of realistic cosmological probes.

  14. Axion excursions of the landscape during inflation

    Palma, Gonzalo A.; Riquelme, Walter

    2017-07-01

    Because of their quantum fluctuations, axion fields had a chance to experience field excursions traversing many minima of their potentials during inflation. We study this situation by analyzing the dynamics of an axion field ψ , present during inflation, with a periodic potential given by v (ψ )=Λ4[1 -cos (ψ /f )]. By assuming that the vacuum expectation value of the field is stabilized at one of its minima, say, ψ =0 , we compute every n -point correlation function of ψ up to first order in Λ4 using the in-in formalism. This computation allows us to identify the distribution function describing the probability of measuring ψ at a particular amplitude during inflation. Because ψ is able to tunnel between the barriers of the potential, we find that the probability distribution function consists of a non-Gaussian multimodal distribution such that the probability of measuring ψ at a minimum of v (ψ ) different from ψ =0 increases with time. As a result, at the end of inflation, different patches of the Universe are characterized by different values of the axion field amplitude, leading to important cosmological phenomenology: (a) Isocurvature fluctuations induced by the axion at the end of inflation could be highly non-Gaussian. (b) If the axion defines the strength of standard model couplings, then one is led to a concrete realization of the multiverse. (c) If the axion corresponds to dark matter, one is led to the possibility that, within our observable Universe, dark matter started with a nontrivial initial condition, implying novel signatures for future surveys.

  15. CAST constraints on the axion-electron coupling

    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. Generating a synthetic axion signal for cold cark matter axion searches using microwave cavities

    AUTHOR|(CDS)2108502; Miceli, Lino

    2017-01-01

    We demonstrated that an axion signal in a RF resonator can be synthesized and controlled with commercially available instrumentation. Although this signal needs refinements, it can be customized to the needs of a specific cold dark matter axion search experiment. Since the modulator in the setup has arbitrary function generator capabilities, this apparatus is already capable to produce the necessary refinements, for instance a maxwellian line shape.

  17. CERN presentations

    CERN. Geneva

    2011-01-01

    Presentation by CERN (10 minutes each) Rolf Landua - Education and Outreach Salvatore Mele - Open Access Jean-Yves Le Meur - Digital Library in Africa Francois Fluckiger - Open Source/Standards (tbc) Tim Smith - Open Data for Science Tullio Basiglia - tbc

  18. CERN Rocks

    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.

  19. The pooltable analogy to axion physics

    Sikivie, P.

    1996-01-01

    An imaginary character named TSP finds himself in a playroom whose floor is tilted to one side. However, the pooltable in the playroom is horizontal. TSP wonders how this can be. In doing so, he embarks upon an intellectual journey which parallels that which has been travelled during the past two decades by physicists interested in the Strong CP Problem and axion physics

  20. The context of the search for axions

    Morgan, D.

    1978-01-01

    Axions are here defined as possible new elementary particles of mass less than or comparable to electrons. It is stated that if they really exist their discovery would be a major scientific advance. The facts and the motivation underlying the recent search for these conjectured new particles are outlined in this review. 27 references. (Author)

  1. The pooltable analogy to axion physics

    Sikivie, P.

    1996-01-01

    An imaginary character named TSP finds himself in a playroom whose floor is tilted to one side. However, the pooltable in the playroom is horizontal. TSP wonders how this can be. In doing so, he embarks upon an intellectual journey which parallels that which has been travelled during the past two decades by physicists interested in the Strong CP Problem and axion physics.

  2. A low-background Micromegas detector for axion searches

    Andriamonje, Samuel A; Dafni, T; Delagnes, E; Fanourakis, G K; Ferrer-Ribas, Esther; Geralis, T; Giomataris, Ioanis; Kousouris, K; Papaevangelou, T; Zachariadou, K

    2004-01-01

    A micropattern low-background detector based on the Micromegas technology has been designed and constructed for the CERN Axion Search experiment CAST. The detector is made of low natural radioactivity materials and has a two-dimensional readout with X-Y strip structure. It is operated with an Argon/Isobutane (95%/5%) mixture and is controlled by a VME data acquisition system. The detector is sensitive to photons in the energy range of 1-10 keV, it has a linear response, excellent stability and a very good energy resolution (14% FWHM at 5.9 keV). This device has been in stable operation since October 2002, taking data during the running periods of the CAST experiment. At the end of summer 2003, the detector was upgraded with a flash ADC readout of the grid signal to further improve its background rejection capability. The currently achieved background rate under normal operation is about 2.0 multiplied by 10 **-**5 events/keV/cm**2/s with better than 85% software efficiency.

  3. Broadband and Resonant Approaches to Axion Dark Matter Detection.

    Kahn, Yonatan; Safdi, Benjamin R; Thaler, Jesse

    2016-09-30

    When ultralight axion dark matter encounters a static magnetic field, it sources an effective electric current that follows the magnetic field lines and oscillates at the axion Compton frequency. We propose a new experiment to detect this axion effective current. In the presence of axion dark matter, a large toroidal magnet will act like an oscillating current ring, whose induced magnetic flux can be measured by an external pickup loop inductively coupled to a SQUID magnetometer. We consider both resonant and broadband readout circuits and show that a broadband approach has advantages at small axion masses. We estimate the reach of this design, taking into account the irreducible sources of noise, and demonstrate potential sensitivity to axionlike dark matter with masses in the range of 10^{-14}-10^{-6}  eV. In particular, both the broadband and resonant strategies can probe the QCD axion with a GUT-scale decay constant.

  4. Dielectric haloscopes: sensitivity to the axion dark matter velocity

    Millar, Alexander J.; Redondo, Javier; Steffen, Frank D., E-mail: millar@mpp.mpg.de, E-mail: jredondo@unizar.es, E-mail: steffen@mpp.mpg.de [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, 80805 München (Germany)

    2017-10-01

    We study the effect of the axion dark matter velocity in the recently proposed dielectric haloscopes, a promising avenue to search for well-motivated high mass (40–400 μeV) axions. We describe non-zero velocity effects for axion-photon mixing in a magnetic field and for the phenomenon of photon emission from interfaces between different dielectric media. As velocity effects are only important when the haloscope is larger than about 20% of the axion de Broglie wavelength, for the planned MADMAX experiment with 80 dielectric disks the velocity dependence can safely be neglected. However, an augmented MADMAX or a second generation experiment would be directionally sensitive to the axion velocity, and thus a sensitive measure of axion astrophysics.

  5. The strong CP problem and the visibility of invisible axions

    Buchmueller, W.

    1986-12-01

    The main subject of these lectures are general properties of axions and recent suggestions of how to detect invisible axions. After a brief review of the strong CP problem and the Peccei-Quinn mechanism in sects. 2 and 3, we discuss axion properties by means of an effective lagrangian approach in sect. 4. Experimental bounds on axion production and decays are reviewed in sect. 5. Sect. 6 deals briefly with the recently proposed variant axion models, and in sect. 7 we discuss the possible relevance of supersymmetry to the strong CP problem. In sect. 8 we then review the different proposals for the detection of invisible axions. Some conclusions are given in sect. 9. (orig./HSI)

  6. Hierarchy in fermion masses and the phantom axion

    Nanopoulos, D.V.

    1981-01-01

    An SU(5) model is presented with hierarchical fermion masses without strong CP violation and with an almost unobservable axion. The key point is to ''tie'' the highly desirable U(1)sub(P-Q) symmetry to the symmetry needed for the fermion mass hierarchy. Since the symmetry is broken at super-high energies (10 15 GeV), the axion becomes super-difficult to detect. This is the Phantom Axion. (author)

  7. Axion oscillations and the quark-hadron phase transition

    Dowrick, N.; McDougall, N.A.

    1988-12-01

    We consider the possibility that the quark-hadron phase transition occurs when the axion field passes through the minimum of its potential during its oscillation cycle. If this were to occur, the axion field would gain no energy from the associated increase in mass thus permitting the cosmological bound on the axion decay constant to be raised. However, we find that the probability of this happening is small.

  8. Axion oscillations and the quark-hadron phase transition

    Dowrick, N.; McDougall, N.A.

    1988-01-01

    We consider the possibility that the quark-hadron phase transition occurs when the axion field passes through the minimum of its potential during its oscillation cycle. If this were to occur, the axion field would gain no energy from the associated increase in mass thus permitting the cosmological bound on the axion decay constant to be raised. However, we find that the probability of this happening is small. (orig.)

  9. CMB probes on the correlated axion isocurvature perturbation

    Kadota, Kenji; Gong, Jinn-Ouk; Ichiki, Kiyotomo; Matsubara, Takahiko

    2015-01-01

    We explore the possible cosmological consequence of the gravitational coupling between the inflaton and axion-like fields. In view of the forthcoming cosmic microwave background (CMB) polarization and lensing data, we study the sensitivity of the CMB data on the cross-correlation between the curvature and axion isocurvature perturbations. Through a concrete example, we illustrate the explicit dependence of the scale dependent cross-correlation power spectrum on the axion parameters

  10. QCD Axion Dark Matter with a Small Decay Constant.

    Co, Raymond T; Hall, Lawrence J; Harigaya, Keisuke

    2018-05-25

    The QCD axion is a good dark matter candidate. The observed dark matter abundance can arise from misalignment or defect mechanisms, which generically require an axion decay constant f_{a}∼O(10^{11})  GeV (or higher). We introduce a new cosmological origin for axion dark matter, parametric resonance from oscillations of the Peccei-Quinn symmetry breaking field, that requires f_{a}∼(10^{8}-10^{11})  GeV. The axions may be warm enough to give deviations from cold dark matter in large scale structure.

  11. QCD Axion Dark Matter with a Small Decay Constant

    Co, Raymond T.; Hall, Lawrence J.; Harigaya, Keisuke

    2018-05-01

    The QCD axion is a good dark matter candidate. The observed dark matter abundance can arise from misalignment or defect mechanisms, which generically require an axion decay constant fa˜O (1011) GeV (or higher). We introduce a new cosmological origin for axion dark matter, parametric resonance from oscillations of the Peccei-Quinn symmetry breaking field, that requires fa˜(108- 1011) GeV . The axions may be warm enough to give deviations from cold dark matter in large scale structure.

  12. First results from a second generation galactic axion experiment

    Hagmann, C A; Stoeffl, W; Van Bibber, K; Daw, E J; McBride, J; Peng, H; Rosenberg, L J; Xin, H; La Veigne, J D; Sikivie, P; Sullivan, N; Tanner, D B; Moltz, D M; Nezrick, F A; Turner, M; Golubev, N A; Kravchuk, L V

    1996-01-01

    We report first results from a large scale search for dark matter axions. The experiment probes axion masses of 1.3-13 micro-eV at a sensitivity which is about 50 times higher than previous pilot experiments. We have already scanned part of this mass range at a sensitivity better than required to see at least one generic axion model, the KSVZ axion. Data taking at full sensitivity commenced in February 1996 and scanning the proposed mass range will require three years.

  13. An argument that the dark matter is axions

    Sikivie, P.

    2014-01-01

    An argument is presented that the dark matter is axions, at least in part. It has 3 steps. First, axions behave differently from the other forms of cold dark matter because they form a re-thermalizing Bose-Einstein condensate (BEC)). Second, there is a tool to distinguish axion BEC from the other dark matter candidates on the basis of observation, namely the study of the inner caustics of galactic halos. Third, the observational evidence for caustic rings of dark matter is consistent in every aspect with axion BEC, but not with the other proposed forms of dark matter. (author)

  14. On the possibility of large axion moduli spaces

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

    2015-04-28

    We study the diameters of axion moduli spaces, focusing primarily on type IIB compactifications on Calabi-Yau three-folds. In this case, we derive a stringent bound on the diameter in the large volume region of parameter space for Calabi-Yaus with simplicial Kähler cone. This bound can be violated by Calabi-Yaus with non-simplicial Kähler cones, but additional contributions are introduced to the effective action which can restrict the field range accessible to the axions. We perform a statistical analysis of simulated moduli spaces, finding in all cases that these additional contributions restrict the diameter so that these moduli spaces are no more likely to yield successful inflation than those with simplicial Kähler cone or with far fewer axions. Further heuristic arguments for axions in other corners of the duality web suggest that the difficulty observed in http://dx.doi.org/10.1088/1475-7516/2003/06/001 of finding an axion decay constant parametrically larger than M{sub p} applies not only to individual axions, but to the diagonals of axion moduli space as well. This observation is shown to follow from the weak gravity conjecture of http://dx.doi.org/10.1088/1126-6708/2007/06/060, so it likely applies not only to axions in string theory, but also to axions in any consistent theory of quantum gravity.

  15. Constraining axion dark matter with Big Bang Nucleosynthesis

    Blum, Kfir; D' Agnolo, Raffaele Tito [Institute for Advanced Study, Princeton, NJ 08540 (United States); Lisanti, Mariangela; Safdi, Benjamin R. [Department of Physics, Princeton University, Princeton, NJ 08544 (United States)

    2014-10-07

    We show that Big Bang Nucleosynthesis (BBN) significantly constrains axion-like dark matter. The axion acts like an oscillating QCD θ 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 {sup 4}He during BBN and is thus excluded. The BBN bound overlaps with much of the parameter space that would be covered by proposed searches for a time-varying neutron EDM. The QCD axion does not couple strongly enough to affect BBN.

  16. Constraining axion dark matter with Big Bang Nucleosynthesis

    Kfir Blum

    2014-10-01

    Full Text Available We show that Big Bang Nucleosynthesis (BBN significantly constrains axion-like dark matter. The axion acts like an oscillating QCD θ 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 He4 during BBN and is thus excluded. The BBN bound overlaps with much of the parameter space that would be covered by proposed searches for a time-varying neutron EDM. The QCD axion does not couple strongly enough to affect BBN.

  17. Constraining axion dark matter with Big Bang Nucleosynthesis

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

    2014-01-01

    We show that Big Bang Nucleosynthesis (BBN) significantly constrains axion-like dark matter. The axion acts like an oscillating QCD θ 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 4 He during BBN and is thus excluded. The BBN bound overlaps with much of the parameter space that would be covered by proposed searches for a time-varying neutron EDM. The QCD axion does not couple strongly enough to affect BBN

  18. Constraining axion dark matter with Big Bang Nucleosynthesis

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

    2014-10-01

    We show that Big Bang Nucleosynthesis (BBN) significantly constrains axion-like dark matter. The axion acts like an oscillating QCD θ 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 a time-varying neutron EDM. The QCD axion does not couple strongly enough to affect BBN.

  19. CERN choir

    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.

  20. CERN Jackfest

    Anon.

    1986-01-01

    Over four decades, from his initial investigations which helped open up meson physics at the end of the 1940s to leadership of one of the big experiments being prepared or CERN's LEP electron-positron Collider, the career of Jack Steinberger has paced the development of particle physics

  1. CERN Jackfest

    Anon.

    1986-07-15

    Over four decades, from his initial investigations which helped open up meson physics at the end of the 1940s to leadership of one of the big experiments being prepared or CERN's LEP electron-positron Collider, the career of Jack Steinberger has paced the development of particle physics.

  2. Mixed axion-wino dark matter

    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.

  3. PBH dark matter from axion inflation

    Domcke, Valerie; Pieroni, Mauro; Witkowski, Lukas T. [AstroParticule et Cosmologie, Université Paris Diderot, CNRS, CEA, Observatoire de Paris, Sorbonne Paris Cité, 10, rue Alice Domon et Léonie Duquet, F-75205 Paris Cedex 13 (France); Muia, Francesco, E-mail: valerie.domcke@apc.univ-paris7.fr, E-mail: francesco.muia@physics.ox.ac.uk, E-mail: mpieroni@apc.univ-paris7.fr, E-mail: lwitkow@apc.univ-paris7.fr [Paris Centre for Cosmological Physics, 10, rue Alice Domon et Léonie Duquet, F-75205 Paris Cedex 13 (France)

    2017-07-01

    Protected by an approximate shift symmetry, axions are well motivated candidates for driving cosmic inflation. Their generic coupling to the Chern-Simons term of any gauge theory gives rise to a wide range of potentially observable signatures, including equilateral non-Gaussianites in the CMB, chiral gravitational waves in the range of direct gravitational wave detectors and primordial black holes (PBHs). In this paper we revisit these predictions for axion inflation models non-minimally coupled to gravity. Contrary to the case of minimally coupled models which typically predict scale-invariant mass distributions for the generated PBHs at small scales, we demonstrate how broadly peaked PBH spectra naturally arises in this setup. For specific parameter values, all of dark matter can be accounted for by PBHs.

  4. Large volume axionic Swiss cheese inflation

    Misra, Aalok; Shukla, Pramod

    2008-09-01

    Continuing with the ideas of (Section 4 of) [A. Misra, P. Shukla, Moduli stabilization, large-volume dS minimum without anti-D3-branes, (non-)supersymmetric black hole attractors and two-parameter Swiss cheese Calabi Yau's, arXiv: 0707.0105 [hep-th], Nucl. Phys. B, in press], after inclusion of perturbative and non-perturbative α corrections to the Kähler potential and (D1- and D3-) instanton generated superpotential, we show the possibility of slow roll axionic inflation in the large volume limit of Swiss cheese Calabi Yau orientifold compactifications of type IIB string theory. We also include one- and two-loop corrections to the Kähler potential but find the same to be subdominant to the (perturbative and non-perturbative) α corrections. The NS NS axions provide a flat direction for slow roll inflation to proceed from a saddle point to the nearest dS minimum.

  5. Large volume axionic Swiss cheese inflation

    Misra, Aalok; Shukla, Pramod

    2008-01-01

    Continuing with the ideas of (Section 4 of) [A. Misra, P. Shukla, Moduli stabilization, large-volume dS minimum without anti-D3-branes, (non-)supersymmetric black hole attractors and two-parameter Swiss cheese Calabi-Yau's, (arXiv: 0707.0105 [hep-th]), Nucl. Phys. B, in press], after inclusion of perturbative and non-perturbative α ' corrections to the Kaehler potential and (D1- and D3-) instanton generated superpotential, we show the possibility of slow roll axionic inflation in the large volume limit of Swiss cheese Calabi-Yau orientifold compactifications of type IIB string theory. We also include one- and two-loop corrections to the Kaehler potential but find the same to be subdominant to the (perturbative and non-perturbative) α ' corrections. The NS-NS axions provide a flat direction for slow roll inflation to proceed from a saddle point to the nearest dS minimum

  6. CERN: Fixed target targets

    Anon.

    1993-03-15

    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.

  7. Studies on Axions as the Energy Source in Magnetar

    Pranita Das

    2017-11-23

    Nov 23, 2017 ... Abstract. Highly magnetized neutron stars known as magnetars are some of the most interesting objects in the Universe. Non-baryonic dark matter candidate axions are produced in the highly magnetized neutron star via Bremsstrahlung process in the highly dense medium. These axions thus produced are ...

  8. Cosmological problems with multiple axion-like fields

    Mack, Katherine J.; Steinhardt, Paul J.

    2011-01-01

    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 f a > 10 12 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 F that measures the fractional volume of allowed parameter space: the product of the slow roll parameter ε and each of the axion misalignment angles, θ 0 . For a single axion, F∼ −11 is needed to avoid conflict with observations. We show that the fine tuning of 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. Photoproduction of axions in a resonant electromagnetic cavity

    Dang Van Soa; Hoang Ngoc Long; Ha Huy Bang; Nguyen Mai Hung

    2000-09-01

    Photon-axion conversions in a resonant electromagnetic cavity with frequency equal to the axion mass are considered in detail by the Feynman diagram methods. The differential cross sections are presented and numerical evaluations are given. It is shown that there is a resonant conversion for the considered process. From our results, some estimates for experimental conditions are given. (author)

  10. Photon - axion conversion cross sections in an electromagnetic field

    Dang Van Soa; Ha Huy Bang

    1999-12-01

    Photon - axion conversions in static magnetic fields and in a periodic field with frequency equal to the axion mass are reconsidered in detail by Feynman methods. The differential cross sections are presented and numerical evaluations are given. It is shown that there is a resonant conversion for the considered process. Some estimates for experiments are given from our results. (author)

  11. CERN Shuttle

    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

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

    Beck, Christian

    2013-12-06

    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.

  13. Axions from cooling compact stars: pair-breaking processes

    Keller, Jochen; Sedrakian, Armen [Frankfurt Univ. (Germany). Inst. fuer Theoretische Physik

    2013-07-01

    Once formed in a supernova explosion, a neutron star cools rapidly via neutrino emission during the first 10{sup 4}-10{sup 5} years of its life-time. Here we compute the axion emission rate from baryonic components of a star at temperatures below their respective critical temperatures T{sub c} for normal-superfluid phase transition. The axion production is driven by a charge neutral weak process, associated with Cooper pair breaking and recombination. The requirement that the axion cooling does not overshadow the neutrino cooling yields a lower bound on the axion decay constant f{sub a} > 6 x 10{sup 9} T{sup -1}{sub c9} GeV, with T{sub c9} = T{sub c}/10{sup 9} K. This translates into an upper bound on the axion mass m{sub a} < 10{sup -3} T{sub c9} eV.

  14. Axions from cooling compact stars: Pair-breaking processes

    Keller, Jochen [Institute for Theoretical Physics, J.W. Goethe-University, D-60438 Frankfurt am Main (Germany); Sedrakian, Armen, E-mail: sedrakian@th.physik.uni-frankfurt.de [Institute for Theoretical Physics, J.W. Goethe-University, D-60438 Frankfurt am Main (Germany)

    2013-01-02

    Once formed in a supernova explosion, a neutron star cools rapidly via neutrino emission during the first 10{sup 4}-10{sup 5} yr of its life-time. Here we compute the axion emission rate from baryonic components of a star at temperatures below their respective critical temperatures T{sub c} for normal-superfluid phase transition. The axion production is driven by a charge neutral weak process, associated with Cooper pair breaking and recombination. The requirement that the axion cooling does not overshadow the neutrino cooling puts a lower bound on the axion decay constant f{sub a}>6 Multiplication-Sign 10{sup 9}T{sub c9}{sup -1} GeV, with T{sub c9}=T{sub c}/10{sup 9} K. This translates into an upper bound on the axion mass m{sub a}<10{sup -3}T{sub c9} eV.

  15. Testing the Rotation Stage in the ARIADNE Axion Experiment

    Dargert, Jordan; Lohmeyer, Chloe; Harkness, Mindy; Cunningham, Mark; Fosbinder-Elkins, Harry; Geraci, Andrew; Ariadne Collaboration

    2017-04-01

    The Axion Resonant InterAction Detection Experiment (ARIADNE) will search for the Peccei-Quinn (PQ) axion, a hypothetical particle that is a dark matter candidate. Using a new technique based on Nuclear Magnetic Resonance, this new method can probe well into the allowed PQ axion mass range. Additionally, it does not rely on cosmological assumptions, meaning that the PQ Axion would be sourced locally. Our project relies on the stability of a rotating segmented source mass and superconducting magnetic shielding. Superconducting shielding is essential for limiting magnetic noise, thus allowing a feasible level of sensitivity required for PQ Axion detection. Progress on testing the stability of the rotary mechanism will be reported, and the design for the superconducting shielding in the experiment will be discussed, along with plans for moving the experiment forward. NSF Grant PHY-1509176.

  16. Prospects for axion detection in natural SUSY with mixed axion-higgsino dark matter: back to invisible?

    Bae, Kyu Jung [Center for Theoretical Physics of the Universe, Institute for Basic Science (IBS), Daejeon 34051 (Korea, Republic of); Baer, Howard; Serce, Hasan, E-mail: kyujungbae@ibs.re.kr, E-mail: baer@nhn.ou.edu, E-mail: serce@ou.edu [Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States)

    2017-06-01

    Under the expectation that nature is natural, we extend the Standard Model to include SUSY to stabilize the electroweak sector and PQ symmetry to stabilize the QCD sector. Then natural SUSY arises from a Kim-Nilles solution to the SUSY μ problem which allows for a little hierarchy where μ∼ f {sub a} {sup 2}/ M {sub P} {sub ∼} 100−300 GeV while the SUSY particle mass scale m {sub SUSY}∼ 1−10 TeV >> μ. Dark matter then consists of two particles: a higgsino-like WIMP and a SUSY DFSZ axion. The range of allowed axion mass values m {sub a} depends on the mixed axion-higgsino relic density. The range of m {sub a} is actually restricted in this case by limits on WIMPs from direct and indirect detection experiments. We plot the expected axion detection rate at microwave cavity experiments. The axion-photon-photon coupling is severely diminished by charged higgsino contributions to the anomalous coupling. In this case, the axion may retreat, at least temporarily, back into the regime of near invisibility. From our results, we urge new ideas for techniques which probe both deeper and more broadly into axion coupling versus axion mass parameter space.

  17. Axion mediated photon to dark photon mixing

    Ejlli, Damian [Novosibirsk State University, Department of Physics, Novosibirsk (Russian Federation); Laboratori Nazionali del Gran Sasso, Theory Group, Assergi, L' Aquila (Italy)

    2018-01-15

    The interaction between the dark/mirror sector and the ordinary sector is considered, where the two sectors interact with each other by sharing the same QCD axion field. This feature makes the mixing between ordinary and dark/mirror photons in ordinary and dark electromagnetic fields possible. Perturbative solutions of the equations of motion describing the evolution of fields in ordinary and dark external magnetic fields are found. User-friendly quantities such as transition probability rates and Stokes parameters are derived. Possible astrophysical and cosmological applications of this model are suggested. (orig.)

  18. New micromegas for axion searches in CAST

    Dafni, T.; Aune, S.; Fanourakis, G.; Ferrer-Ribas, E.; Galan, J.; Gardikiotis, A.; Geralis, T.; Giomataris, I.; Gomez, H.; Iguaz, F.J.; Irastorza, I.G.; Luzon, G.; Morales, J.; Papaevangelou, T.; Rodriguez, A.; Ruz, J.; Tomas, A.; Vafeiadis, T.; Yildiz, S.C.

    2011-01-01

    Micromegas detectors have been taking data in the CAST experiment since 2002, occupying one opening (out of the two looking for sunrise axions) of the magnet and showing good performance and stability. Currently, three of the four X-ray detectors used in the experiment are micromegas. The new detectors are of the Microbulk technology, which have attracted a lot of attention because of the advantages they present, among them the low-material construction, high radiopurity and good energy resolution. Here, their performance during the last year will be commented. In particular, the low background levels reached in some detectors have triggered a set of studies in order to understand the effect.

  19. Protecting the axion with local baryon number

    Duerr, Michael; Schmidt-Hoberg, Kai; Unwin, James

    2018-05-01

    The Peccei-Quinn (PQ) solution to the Strong CP Problem is expected to fail unless the global symmetry U(1)PQ is protected from Planck-scale operators up to high mass dimension. Suitable protection can be achieved if the PQ symmetry is an automatic consequence of some gauge symmetry. We highlight that if baryon number is promoted to a gauge symmetry, the exotic fermions needed for anomaly cancellation can elegantly provide an implementation of the Kim-Shifman-Vainshtein-Zakharov 'hidden axion' mechanism with a PQ symmetry protected from Planck-scale physics.

  20. CERN Medtech:Hackathon

    Olofsson, Simon

    2018-01-01

    The CERN Medtech:Hackathon, organised by CERN Knowledge Transfer, was held in IdeaSquare during 6-9 April. Teams from all around the world gathered, by using CERN technology, to solve problems posed by the Medtech industry.

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

    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...

  2. What is the magnetic Weak Gravity Conjecture for axions

    Hebecker, Arthur; Henkenjohann, Philipp [Institute for Theoretical Physics, University of Heidelberg (Germany); Witkowski, Lukas T. [APC, Universite Paris 7, CNRS/IN2P3, CEA/IRFU, Obs. de Paris, Sorbonne Paris Cite, Paris (France)

    2017-03-15

    The electric Weak Gravity Conjecture demands that axions with large decay constant f couple to light instantons. The resulting large instantonic corrections pose problems for natural inflation. We explore an alternative argument based on the magnetic Weak Gravity Conjecture for axions, which we try to make more precise. Roughly speaking, it demands that the minimally charged string coupled to the dual 2-form-field exists in the effective theory. Most naively, such large-f strings curve space too much to exist as static solutions, thus ruling out large-f axions. More conservatively, one might allow non-static string solutions to play the role of the required charged objects. In this case, topological inflation would save the superplanckian axion. Furthermore, a large-f axion may appear in the low-energy effective theory based on two subplanckian axions in the UV. The resulting effective string is a composite object built from several elementary strings and domain walls. It may or may not satisfy the magnetic Weak Gravity Conjecture depending on how strictly the latter is interpreted and on the cosmological dynamics of this composite object, which remain to be fully understood. Finally, we recall that large-field brane inflation is naively possible in the codimension-one case. We show how string-theoretic back-reaction closes this apparent loophole of large-f (non-periodic) pseudo-axions. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. UK @ CERN

    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...

  4. This way for the new CERN visits!

    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, ...

  5. Cosmological bounds on sub-MeV mass axions

    Cadamuro, Davide; Hannestad, Steen; Raffelt, Georg

    2011-01-01

    Axions with mass ma >~ 0.7 eV are excluded by cosmological precision data because they provide too much hot dark matter. While for ma >~ 20 eV the a → 2γ lifetime drops below the age of the universe, we show that the cosmological exclusion range can be extended to 0.7eV lesssim ma lesssim 300 ke......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...

  6. Heavy axions from strong broken horizontal gauge symmetry

    Elliott, T.; King, S.F.

    1993-01-01

    We study the consequences of the existence and breaking of a Peccei-Quinn symmetry within the context of a dynamical model of electroweak symmetry breaking based on broken gauged flavour symmetries. We perform an estimate of the axion mass by including flavour instanton effects and show that, for low cut-offs, the axion is sufficiently massive to prevent it from being phenomenologically unacceptable. We conclude with an examination of the strong CP problem and show that our axion cannot solve the problem, though we indicate ways in which the model can be extended so that the strong CP problem is solved. (orig.)

  7. Enhanced axion-photon coupling in GUT with hidden photon

    Daido, Ryuji; Takahashi, Fuminobu; Yokozaki, Norimi

    2018-05-01

    We show that the axion coupling to photons can be enhanced in simple models with a single Peccei-Quinn field, if the gauge coupling unification is realized by a large kinetic mixing χ = O (0.1) between hypercharge and unbroken hidden U(1)H. The key observation is that the U(1)H gauge coupling should be rather strong to induce such large kinetic mixing, leading to enhanced contributions of hidden matter fields to the electromagnetic anomaly. We find that the axion-photon coupling is enhanced by about a factor of 10-100 with respect to the GUT-axion models with E / N = 8 / 3.

  8. Unified models of the QCD axion and supersymmetry breaking

    Keisuke Harigaya

    2017-08-01

    Full Text Available Similarities between the gauge meditation of supersymmetry breaking and the QCD axion model suggest that they originate from the same dynamics. We present a class of models where supersymmetry and the Peccei–Quinn symmetry are simultaneously broken. The messengers that mediate the effects of these symmetry breakings to the Standard Model are identical. Since the axion resides in the supersymmetry breaking sector, the saxion and the axino are heavy. We show constraints on the axion decay constant and the gravitino mass.

  9. Suppressing the QCD axion abundance by hidden monopoles

    Kawasaki, Masahiro

    2015-11-01

    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 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.

  10. D6-branes and axion monodromy inflation

    Escobar, Dagoberto; Landete, Aitor; Marchesano, Fernando [Instituto de Física Teórica UAM-CSIC,Cantoblanco, 28049 Madrid (Spain); Regalado, Diego [Max-Planck-Institut für Physik,Föhringer Ring 6, 80805 Munich (Germany); Institute for Theoretical Physics and Center for Extreme Matter and Emergent Phenomena, Utrecht University,Leuvenlaan 4, 3584 CE Utrecht (Netherlands)

    2016-03-16

    We develop new scenarios of large field inflation in type IIA string compactifications in which the key ingredient is a D6-brane that creates a potential for a B-field axion. The potential has the multi-branched structure typical of F-term axion monodromy models and, near its supersymmetric minima, it is described by a 4d supergravity model of chaotic inflation with a stabiliser field. The same statement applies to the D6-brane Wilson line, which can also be considered as an inflaton candidate. We analyse both cases in the context of type IIA moduli stabilisation, finding an effective potential for the inflaton system and a simple mechanism to lower the inflaton mass with respect to closed string moduli stabilised by fluxes. Finally, we compute the B-field potential for trans-Planckian field values by means of the DBI action. The effect of Planck suppressed corrections is a flattened potential which, in terms of the compactification parameters, interpolates between linear and quadratic inflation. This renders the cosmological parameters of these models compatible with current experimental bounds, with the tensor-to-scalar ratio ranging as 0.08≲r≲0.12.

  11. Non-thermal axion dark radiation and constraints

    Mazumdar, Anupam

    2016-07-01

    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.

  12. N-flation with hierarchically light axions in string compactifications

    Cicoli, Michele [Dipartimento di Fisica ed Astronomia, Università di Bologna, via Irnerio 46, 40126 Bologna (Italy); Dutta, Koushik [Theory Division, Saha Institute of Nuclear Physics, 1/AF Salt Lake, Kolkata, 700064 (India); Maharana, Anshuman, E-mail: mcicoli@ictp.it, E-mail: koushik.dutta@saha.ac.in, E-mail: anshumanmaharana@hri.res.in [Harish Chandra Research Intitute, Chattnag Road, Jhunsi, Allahabad, 211019 (India)

    2014-08-01

    We propose a possible embedding of axionic N-flation in type IIB string compactifications where most of the Kähler moduli are stabilised by perturbative effects, and so are hierarchically heavier than the corresponding N>> 1 axions whose collective dynamics drives inflation. This is achieved in the framework of the LARGE Volume Scenario for moduli stabilisation. Our set-up can be used to realise a model of either large field inflation or quintessence, just by varying the volume of the internal space which controls the scale of the axionic potential. Both cases predict a very high scale of supersymmetry breaking. A fully explicit stringy embedding of N-flation would require control over dangerous back-reaction effects due to a large number of species. A viable reheating of the Standard Model degrees of freedom can be achieved after the end of inflation due to the perturbative decay of the N light axions which drive inflation.

  13. N-flation with hierarchically light axions in string compactifications

    Cicoli, Michele; Dutta, Koushik; Maharana, Anshuman

    2014-01-01

    We propose a possible embedding of axionic N-flation in type IIB string compactifications where most of the Kähler moduli are stabilised by perturbative effects, and so are hierarchically heavier than the corresponding N>> 1 axions whose collective dynamics drives inflation. This is achieved in the framework of the LARGE Volume Scenario for moduli stabilisation. Our set-up can be used to realise a model of either large field inflation or quintessence, just by varying the volume of the internal space which controls the scale of the axionic potential. Both cases predict a very high scale of supersymmetry breaking. A fully explicit stringy embedding of N-flation would require control over dangerous back-reaction effects due to a large number of species. A viable reheating of the Standard Model degrees of freedom can be achieved after the end of inflation due to the perturbative decay of the N light axions which drive inflation

  14. Radio-loud magnetars as detectors for axions and axion-like particles

    Guendelman, E.I.; Chelouche, D.

    2011-01-01

    We show that, by studying the arrival times of radio pulses from highly-magnetized transient beamed sources, it may be possible to detect light pseudo-scalar particles, such as axions and axion-like particles, whose existence could have considerable implications for the strong-CP problem of QCD as well as the dark matter problem in cosmology. Specifically, such light bosons may be detected with a much greater sensitivity, over a broad particle mass range, than is currently achievable by terrestrial experiments, and using indirect astrophysical considerations. The observable effect was discussed in Chelouche & Guendelman (2009), and is akin to the Stern-Gerlach experiment: the splitting of a photon beam naturally arises when finite coupling exists between the electro-magnetic field and the axion field. The splitting angle of the light beams linearly depends on the photon wavelength, the size of the magnetized region, and the magnetic field gradient in the transverse direction to the propagation direction of the photons. If radio emission in radio-loud magnetars is beamed and originates in regions with strong magnetic field gradients, then splitting of individual pulses may be detectable. We quantify the effect for a simplified model for magnetars, and search for radio beam splitting in the 2GHz radio light curves of the radio loud magnetar XTEJ1810-197. (author)

  15. Search for axion production in Υ(1S) decays

    Fairfield, K.H.

    1988-06-01

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

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

    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...

  17. Searching for axions and ALPs from string theory

    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.

  18. Bienvenue au CERN !

    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.

  19. UK @ CERN

    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.

  20. Bifid Throats for Axion Monodromy Inflation

    Retolaza, Ander

    2015-04-01

    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 3 x Z 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.

  1. Minimal models for axion and neutrino

    Y.H. Ahn

    2016-01-01

    Full Text Available The PQ mechanism resolving the strong CP problem and the seesaw mechanism explaining the smallness of neutrino masses may be related in a way that the PQ symmetry breaking scale and the seesaw scale arise from a common origin. Depending on how the PQ symmetry and the seesaw mechanism are realized, one has different predictions on the color and electromagnetic anomalies which could be tested in the future axion dark matter search experiments. Motivated by this, we construct various PQ seesaw models which are minimally extended from the (non- supersymmetric Standard Model and thus set up different benchmark points on the axion–photon–photon coupling in comparison with the standard KSVZ and DFSZ models.

  2. Astrophysical hints of axion-like particles

    Roncadelli, M.; Galanti, G.; Tavecchio, F.; Bonnoli, G.

    2015-01-01

    After reviewing three astrophysical hints of the existence of axion-like particles (ALPs), we describe in more detail a new similar hint involving flat spectrum radio quasars (FSRQs). Detection of FSRQs above about 20GeV pose a challenge to very-high-energy (VHE) astrophysics, because at those energies the ultraviolet emission from their broad line region should prevent photons produced by the central engine to leave the source. Although a few astrophysical explanations have been put forward, they are totally ad hoc. We show that a natural explanation instead arises within the conventional models of FSRQs provided that photon-ALP oscillations occur inside the source. Our analysis takes the FSRQ PKR 1222+206 as an example, and it looks tantalizing that basically the same choice of the free model parameters adopted in this case is consistent with those that provide the other three hints of the existence of ALPs.

  3. CERN: Fixed target targets

    Anon.

    1993-01-01

    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

  4. Solar flares as harbinger of new physics

    Zioutas, K; Semertzidis, Y.; Papaevangelou, T.; Georgiopoulou, E.; Gardikiotis, A.; Dafni, T.; Tsagri, M.; Semertzidis, Y.; Papaevangelou, T.; Dafni, T.

    2011-01-01

    This work provides additional evidence on the involvement of exotic particles like axions and/or other WISPs, following recent measurements during the quietest Sun and flaring Sun. Thus, SPHINX mission observed a minimum basal soft X-rays emission in the extreme solar minimum in 2009. The same scenario (with ~17 meV axions) fits also the dynamical behaviour of white-light solar flares, like the measured spectral components in the visible and in soft X-rays, and, the timing between them. Solar chameleons remain a viable candidate, since they may preferentially convert to photons in outer space.

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

    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. &...

  6. Cosmological axion and a quark nugget dark matter model

    Ge, Shuailiang; Liang, Xunyu; Zhitnitsky, Ariel

    2018-02-01

    We study a dark matter (DM) model offering a very natural explanation of two (naively unrelated) problems in cosmology: the observed relation ΩDM˜Ωvisible and the observed asymmetry between matter and antimatter in the Universe, known as the "baryogenesis" problem. In this framework, both types of matter (dark and visible) have the same QCD origin, form at the same QCD epoch, and are proportional to one and the same dimensional parameter of the system, ΛQCD, which explains how these two naively distinct problems could be intimately related, and could be solved simultaneously within the same framework. More specifically, the DM in this model is composed by two different ingredients: the (well-studied) DM axions and the (less-studied) quark nuggets made of matter or antimatter. We focus on the quantitative analysis of the relation between these two distinct components contributing to the dark sector of the theory determined by ΩDM≡[ΩDM(nuggets)+ΩDM(axion)] . We argue that the nuggets' DM component always traces the visible matter density, i.e., ΩDM(nuggets)˜Ωvisible , and this feature is not sensitive to the parameters of the system such as the axion mass ma or the misalignment angle θ0. It should be contrasted with conventional axion production mechanisms due to the misalignment when ΩDM(axion) is highly sensitive to the axion mass ma and the initial misalignment angle θ0. We also discuss the constraints on this model related to the inflationary scale HI, nonobservation of the isocurvature perturbations and the tensor modes. We also comment on some constraints related to various axion search experiments.

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

    Enghardt, W.; Kaun, K.H.; Prade, H.; Bluemlein, J.; Lanius, K.

    1987-01-01

    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)

  8. Experiments at CERN in 1981

    1981-08-01

    This report contains the preliminary abstracts of the current experiments at the CERN SPS synchrotron, the anti p colliding beams, the CERN ISR, the CERN PS synchrotron, and the CERN synchrocyclotron. See hints under the relevant topics. (HSI)

  9. Doing business with CERN

    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...

  10. CERN Shop Christmas Sale

    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.

  11. Quantitative analysis of the thermal damping of coherent axion oscillations

    Turner, M.S.

    1985-01-01

    Unruh and Wald have recently discussed a new mechanism for damping coherent axion oscillations, ''thermal damping,'' which occurs due to the temperature dependence of the axion mass and neutrino viscosity. We investigate the effect quantitatively and find that the present energy density in axions can be written as rho/sub a/ = rho/sub a0//(1+J/sub UW/), where rho/sub a/0 is what the axion energy density would be in the absence of the thermal-damping effect and J/sub UW/ is an integral whose integrand depends upon (dm/sub a//dT) 2 . As a function of f(equivalentPeccei-Quinn symmetry-breaking scale) J/sub UW/ achieves its maximum value for f/sub PQ/approx. =3 x 10 12 GeV; unless the axion mass turn-on is very sudden, Vertical Bar(T/m/sub a/)(dm/sub a//dT)Vertical Bar>>1, J/sub UW/ is <<1, implying that this damping mechanism is not significant

  12. France at CERN

    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.

  13. The CERN Library

    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.

  14. Irradiation Facilities at CERN

    Gkotse, Blerina; Carbonez, Pierre; Danzeca, Salvatore; Fabich, Adrian; Garcia, Alia, Ruben; Glaser, Maurice; Gorine, Georgi; Jaekel, Martin, Richard; Mateu,Suau, Isidre; Pezzullo, Giuseppe; Pozzi, Fabio; Ravotti, Federico; Silari, Marco; Tali, Maris

    2017-01-01

    CERN provides unique irradiation facilities for applications in many scientific fields. This paper summarizes the facilities currently operating for proton, gamma, mixed-field and electron irradiations, including their main usage, characteristics and information about their operation. The new CERN irradiation facilities database is also presented. This includes not only CERN facilities but also irradiation facilities available worldwide.

  15. In the CERN Library

    CERN PhotoLab

    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

  16. 2005 CERN Relay Race

    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.

  17. Axion production from Landau quantization in the strong magnetic field of magnetars

    Maruyama, Tomoyuki; Balantekin, A. Baha; Cheoun, Myung-Ki; Kajino, Toshitaka; Mathews, Grant J.

    2018-04-01

    We utilize an exact quantum calculation to explore axion emission from electrons and protons in the presence of the strong magnetic field of magnetars. The axion is emitted via transitions between the Landau levels generated by the strong magnetic field. The luminosity of axions emitted by protons is shown to be much larger than that of electrons and becomes stronger with increasing matter density. Cooling by axion emission is shown to be much larger than neutrino cooling by the Urca processes. Consequently, axion emission in the crust may significantly contribute to the cooling of magnetars. In the high-density core, however, it may cause heating of the magnetar.

  18. Can gravitational instantons really constrain axion inflation?

    Hebecker, Arthur; Mangat, Patrick [Institut für Theoretische Physik, Universität Heidelberg,Philosophenweg 19, D-69120 Heidelberg (Germany); Theisen, Stefan [Max-Planck-Institut für Gravitationsphysik,Albert-Einstein-Institut, 14476 Golm (Germany); Witkowski, Lukas T. [Institut für Theoretische Physik, Universität Heidelberg,Philosophenweg 19, D-69120 Heidelberg (Germany)

    2017-02-20

    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-Nordström black holes. We attempt to dispel possible doubts that wormholes contribute to the scalar potential by an explicit calculation. We analyse the role of stabilised dilaton-like moduli. Finally, we argue that Euclidean wormholes may be the objects satisfying the Weak Gravity Conjecture extended to instantons.

  19. Axionic D3-D7 Inflation

    Burgess, C P; Postma, M

    2009-01-01

    We study the motion of a D3 brane moving within a Type IIB string vacuum compactified to 4D on K3 x T_2/Z_2 in the presence of D7 and O7 planes. We work within the effective 4D supergravity describing how the mobile D3 interacts with the lightest bulk moduli of the compactification, including the effects of modulus-stabilizing fluxes. We seek inflationary solutions to the resulting equations, performing our search numerically in order to avoid resorting to approximate parameterizations of the low-energy potential. We consider uplifting from D-terms and from the supersymmetry-breaking effects of anti-D3 branes. We find examples of slow-roll inflation (with anti-brane uplifting) with the mobile D3 moving along the toroidal directions, falling towards a D7-O7 stack starting from the antipodal point. The inflaton turns out to be a linear combination of the brane position and the axionic partner of the K3 volume modulus, and the similarity of the potential along the inflaton direction with that of racetrack inflat...

  20. Axion-dilaton domain walls and fake supergravity

    Sonner, Julian; Townsend, Paul K

    2007-01-01

    Dynamical systems methods are used to investigate domain-wall solutions of a two-parameter family of models in which gravity is coupled to an axion and to a dilaton with an exponential potential of either sign. A complete global analysis is presented for (i) constant axion and (ii) flat walls, including a study of bifurcations and a new exact domain-wall solution with non-constant axion. We reconsider 'fake-supergravity' issues in light of these results. We show, by example, how domain walls determine multi-valued superpotentials that branch at stationary points that are not stationary points of the potential, and we apply this result to potentials with anti-de Sitter vacua. We also show by example that 'adapted' truncation to a single-scalar model may be inconsistent, and we propose a 'generalized' fake-supergravity formalism that applies in some such cases

  1. Solar chameleons

    Brax, Philippe; Zioutas, Konstantin

    2010-01-01

    We analyze the creation of chameleons deep inside the Sun (R∼0.7R sun ) and their subsequent conversion to photons near the magnetized surface of the Sun. We find that the spectrum of the regenerated photons lies in the soft x-ray region, hence addressing the solar corona problem. Moreover, these back-converted photons originating from chameleons have an intrinsic difference with regenerated photons from axions: their relative polarizations are mutually orthogonal before Compton interacting with the surrounding plasma. Depending on the photon-chameleon coupling and working in the strong coupling regime of the chameleons to matter, we find that the induced photon flux, when regenerated resonantly with the surrounding plasma, coincides with the solar flux within the soft x-ray energy range. Moreover, using the soft x-ray solar flux as a prior, we find that with a strong enough photon-chameleon coupling, the chameleons emitted by the Sun could lead to a regenerated photon flux in the CAST magnetic pipes, which could be within the reach of CAST with upgraded detector performance. Then, axion helioscopes have thus the potential to detect and identify particle candidates for the ubiquitous dark energy in the Universe.

  2. CERN Photo club

    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

  3. Collide@CERN Geneva

    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.

  4. CERN Video News

    2003-01-01

    From Monday you can see on the web the new edition of CERN's Video News. Thanks to a collaboration between the audiovisual teams at CERN and Fermilab, you can see a report made by the American laboratory. The clip concerns the LHC magnets that are being constructed at Fermilab. Also in the programme: the spectacular rotation of one of the ATLAS coils, the arrival at CERN of the first American magnet made at Brookhaven, the story of the discovery 20 years ago of the W and Z bosons at CERN. http://www.cern.ch/video or Bulletin web page.

  5. Britain at CERN

    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.

  6. CERN Cricket Club

    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/

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

    García-Valdecasas, Eduardo [Instituto de Física Teórica UAM-CSIC,C/Nicolás Cabrera 13-15, Campus de Cantoblanco, 28049 Madrid (Spain); Departamento de Física Teórica, Universidad Autónoma de Madrid,Campus de Cantoblanco, 28049 Madrid (Spain); Uranga, Angel [Instituto de Física Teórica UAM-CSIC,C/Nicolás Cabrera 13-15, Campus de Cantoblanco, 28049 Madrid (Spain)

    2017-02-16

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

    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...

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

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

    2016-01-01

    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.

  10. Axion as a non-WIMP dark matter candidate

    Saikawa, Ken'ichi

    2017-09-01

    The axion arises in well-motivated extensions of the Standard Model of particle physics and is regarded as an alternative to the weakly interacting massive particle paradigm to explain the nature of dark matter. In this contribution, we review theoretical aspects of dark matter axions, particularly focusing on recent developments in the estimation of their relic abundance. A closer look at their non-thermal production mechanisms in the early universe reveals the possibility of explaining the observed dark matter abundance in various mass ranges. The mass ranges predicted in various cosmological scenarios are briefly summarized.

  11. Towards universal axion inflation and reheating in string theory

    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.

  12. A problem of the QCD axion in supergravity

    Endo, M.; Takahashi, F.; Tokyo Univ.; Yanagida, T.T.; Tokyo Univ.

    2007-12-01

    We point out that the QCD axion generally couples to all the gauge fields in nature through the Super-Weyl, Kaehler and sigma-model anomalies in supergravity. If supersymmetry is dynamically broken by the hidden-sector gauge interactions, the axion potential receives corrections due to the instanton in the hidden sector. We show that the supersymmetry breaking models are tightly constrained for the Peccei-Quinn mechanism to successfully solve the strong CP problem. In particular, the gravity mediation turns out to be strongly disfavored. (orig.)

  13. CERN honours Georges Charpak

    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...

  14. CERN Holiday Gift Guide

    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.

  15. CERN plans global-warming experiment

    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).

  16. Collider probes of axion-like particles

    Bauer, Martin; Neubert, Matthias; Thamm, Andrea

    2017-12-01

    Axion-like particles (ALPs), which are gauge-singlets under the Standard Model (SM), appear in many well-motivated extensions of the SM. Describing the interactions of ALPs with SM fields by means of an effective Lagrangian, we discuss ALP decays into SM particles at one-loop order, including for the first time a calculation of the a → πππ decay rates for ALP masses below a few GeV. We argue that, if the ALP couples to at least some SM particles with couplings of order (0.01 - 1) TeV-1, its mass must be above 1 MeV. Taking into account the possibility of a macroscopic ALP decay length, we show that large regions of so far unconstrained parameter space can be explored by searches for the exotic, on-shell Higgs and Z decays h → Za, h → aa and Z → γa in Run-2 of the LHC with an integrated luminosity of 300 fb-1. This includes the parameter space in which ALPs can explain the anomalous magnetic moment of the muon. Considering subsequent ALP decays into photons and charged leptons, we show that the LHC provides unprecedented sensitivity to the ALP-photon and ALP-lepton couplings in the mass region above a few MeV, even if the relevant ALP couplings are loop suppressed and the a → γγ and a → ℓ+ℓ- branching ratios are significantly less than 1. We also discuss constraints on the ALP parameter space from electroweak precision tests.

  17. CERN Table Tennis Club

    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;...

  18. The Weak Gravity Conjecture and the axionic black hole paradox

    Hebecker, Arthur; Soler, Pablo

    2017-09-01

    In theories with a perturbatively massless 2-form (dual to an axion), a paradox may arise in the process of black hole evaporation. Schwarzschild black holes can support a non-trivial Wilson-line-type field, the integral of the 2-form around their horizon. After such an `axionic black hole' evaporates, the Wilson line must be supported by the corresponding 3-form field strength in the region formerly occupied by the black hole. In the limit of small axion decay-constant f, the energy required for this field configuration is too large. Thus, energy cannot be conserved in the process of black hole evaporation. The natural resolution of this paradox is through the presence of light strings, which allow the black hole to "shed" its axionic hair sufficiently early. This gives rise to a new Weak-Gravity-type argument in the 2-form context: small coupling, in this case f , enforces the presence of light strings or a low cutoff. We also discuss how this argument may be modified in situations where the weak coupling regime is achieved in the low-energy effective theory through an appropriate gauging of a model with a vector field and two 2-forms.

  19. Brane solutions of gravity-dilaton-axion systems

    Bergshoeff, E; Collinucci, A; Gran, U; Roest, D; Vandoren, S; Lukierski, J; Sorokin, D

    2005-01-01

    We consider general properties of brane solutions of gravity-dilaton-axion systems. We focus on the case of 7-branes and instantons. In both cases we show that besides the standard solutions there are new deformed solutions whose charges take value in any of the three conjugacy classes of SL(2, R).

  20. Limits on the abundance and coupling of cosmic axions

    DePanfilis, S.; Melissinos, A.C.; Moskowitz, B.E.

    1987-03-01

    We report preliminary results from a search for galactic axions in the mass range 4.5 -13 eV, we obtain the experimental limit (g/sub aγγ/m/sub a/) 2 rho/sub a/ -41 . The theoretical prediction is (g/sub aγγ/m/sub a/) 2 rho/sub a/ = 3.9 x 10 -44 with the local galactic axion density rho/sub a/ = 300 MeV/cm 3 . We have also searched for the presence of a continuous spectrum of light pseudoscalar particles; assuming that the local galactic axion density is composed of axions with masses uniformly distributed between 4.5 and 5.0 μeV, we find that g/sub aγγ/ -30 MeV/sup 1/2/ cm/sup 3/2/ ≅ 10 11 GeV -1 . Limits have also been set on the production of light pseudoscalar x particles; we find g/sub xγγ/ -24 MeV/sup 1/2/ cm/sup 3/2/ ≅ 10 -5 GeV -1 for 0< m/sub x/ ≤ 4μeV. 20 refs., 7 figs., 1 tab

  1. Studies on Axions as the Energy source in Magnetar

    61

    Highly magnetized neutron stars known as magnetars are some of the most interesting objects in the Universe. Non-baryonic dark matter candidate ax- ions are produced in the highly magnetized neutron star via bremsstrahlung process in the highly dense medium . These axions thus produced are then converted into ...

  2. Young Artists@ CERN

    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/

  3. German visits to CERN

    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. CERN and the environment

    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...

  5. CERN Cricket club

    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 Cricket Club

    CERN Cricket Club

    2018-01-01

    The CERN Cricket Club 2018 season begins soon, the first net practice is scheduled (weather permitting) for Thursday April 12th, 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/cricket/ or turn up for net practice, which takes place each Thursday evening (apart from CERN official holidays) until the end of September (starting at 18:00 to around 20:00) at the CERN Prévessin site: http://cern.ch/cricket/CERN-Ground.html The first matches will be in the Geneva T20 competition on Saturday and Sunday, April 14th / 15th. 

  7. Germany at CERN

    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.

  8. CERN - better than science fiction!

    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).

  9. Sharing resources@CERN

    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.

  10. Britain at CERN

    CERN Press Office. Geneva

    1994-01-01

    Thirty-two British hi-tech companies present their products at this new industrial exhibition at CERN which takes place from 22 to 25 November, 1994. 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.

  11. CERN Relay Race

    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

  12. The CERN PC farm

    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.

  13. Integrity at CERN

    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”.

  14. Britain at CERN

    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 ...

  15. First Tuesday @ CERN: Industrial Impact of Information Technology from CERN

    CERN. Geneva

    2004-01-01

    CERN is where the web was born, and remains a hothouse of innovation in information technology (IT). In this fourth First Tuesday @ CERN, we look at industrial partnership at CERN in the IT area from several different angles. The approach taken by CERN with software licencing - a very hot topic in the world of IT - will be discussed. The benefits that CERN hardware and software suppliers gain from working with CERN will be presented, and the CERN openlab, a new approach to industrial partnership at CERN, will be covered. A novel ingredient of this First Tuesday @ CERN is that it will be run in parallel with a similar event for the business community in London, and there will be webcast presentations between the Queen Elizabeth II Conference Centre in London and CERN during the event. Thus, First Tuesday @ CERN will take on a truly European dimension, to reflect CERN's European character.

  16. arXiv Axion-photon conversion caused by dielectric interfaces: quantum field calculation

    Ioannisian, Ara N.; Millar, Alexander J.; Raffelt, Georg G.

    2017-09-05

    Axion-photon conversion at dielectric interfaces, immersed in a near-homogeneous magnetic field, is the basis for the dielectric haloscope method to search for axion dark matter. In analogy to transition radiation, this process is possible because the photon wave function is modified by the dielectric layers ("Garibian wave function") and is no longer an eigenstate of momentum. A conventional first-order perturbative calculation of the transition probability between a quantized axion state and these distorted photon states provides the microwave production rate. It agrees with previous results based on solving the classical Maxwell equations for the combined system of axions and electromagnetic fields. We argue that in general the average photon production rate is given by our result, independently of the detailed quantum state of the axion field. Moreover, our result provides a new perspective on axion-photon conversion in dielectric haloscopes because the rate is based on an overlap integral between unpertu...

  17. Searching for axion-like particles with active-galactic nuclei

    Burrage, Clare; Davis, Anne-Christine; Shaw, Douglas J.

    2009-12-01

    Strong mixing between photons and axion-like particles in the magnetic fields of clusters of galaxies induces a scatter in the observed luminosities of compact sources in the cluster. This is used to construct a new test for axion-like particles; applied to observations of active galactic nuclei it is strongly suggestive of the existence of a light axion-like particle. (orig.)

  18. The GammeV suite of experimental searches for axion-like particles

    Steffen, Jason H.; Upadhye, Amol

    2009-01-01

    We report on the design and results of the GammeV search for axion-like particles and for chameleon particles. We also discuss plans for an improved experiment to search for chameleon particles, one which is sensitive to both cosmological and power-law chameleon models. Plans for an improved axion-like particle search using coupled resonant cavities are also presented. This experiment will be more sensitive to axion-like particles than stellar astrophysical models or current helioscope experiments

  19. F-term stabilization of odd axions in LARGE volume scenario

    Gao, Xin; Shukla, Pramod

    2014-01-01

    In the context of the LARGE volume scenario, stabilization of axionic moduli is revisited. This includes both even and odd axions with their scalar potential being generated by F-term contributions via various tree-level and non-perturbative effects like fluxed E3-brane instantons and fluxed poly-instantons. In all the cases, we estimate the decay constants and masses of the axions involved

  20. Searching for axion-like particles with active-galactic nuclei

    Burrage, Clare [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Davis, Anne-Christine [Centre for Mathematical Sciences, Cambridge (United Kingdom). Dept. of Applied Mathematics and Theoretical Physics; Shaw, Douglas J. [Queen Mary Univ. of London (United Kingdom). Astronomy Unit, School of Mathematical Sciences

    2009-12-15

    Strong mixing between photons and axion-like particles in the magnetic fields of clusters of galaxies induces a scatter in the observed luminosities of compact sources in the cluster. This is used to construct a new test for axion-like particles; applied to observations of active galactic nuclei it is strongly suggestive of the existence of a light axion-like particle. (orig.)

  1. Invisible axion in the hidden sector of no-scale supergravity

    Sato, Hikaru

    1987-01-01

    We propose a new axion model which incorporates the U(1) PQ symmetry into a hidden sector, as well as an observable sector, of no-scale supergravity models. The axion is a spin-zero field in the hidden sector. The U(1) PQ symmetry is naturally embedded in the family symmetry of the no-scale models. Invisible axions live in the gravity hidden sector without conflict with the cosmological and astrophysical constraints. (orig.)

  2. CERN and the LHC

    Cramer, J G

    1992-01-01

    CERN, a high-energy physics laboratory in Europe, is planning to build a more powerful particle accelerator, the Large Hadronic Collider. The US spreads its accelerators around the country while most of Europe's research is conducted at and around CERN.

  3. ESO: The CERN Years

    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.

  4. CERN: SC-33

    Anon.

    1991-01-01

    On 22 April a forward-looking CERN also looked back for a day, when the 'SC-33' event reviewed the achievements of CERN's first machine, the 600 MeV SynchroCyclotron (SC), which closed down on 17 December after 33 years of valiant service

  5. CERN Code of Conduct

    Department, HR

    2010-01-01

    The Code is intended as a guide in helping us, as CERN contributors, to understand how to conduct ourselves, treat others and expect to be treated. It is based around the five core values of the Organization. We should all become familiar with it and try to incorporate it into our daily life at CERN.

  6. The CERN Accelerator School

    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/.

  7. CERN's Early History Revisited

    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

  8. UK Mission to CERN

    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.

  9. CERN: SC-33

    Anon.

    1991-06-15

    On 22 April a forward-looking CERN also looked back for a day, when the 'SC-33' event reviewed the achievements of CERN's first machine, the 600 MeV SynchroCyclotron (SC), which closed down on 17 December after 33 years of valiant service.

  10. CERN welcomes new members

    2017-08-01

    Lithuania is on course to become an associate member of CERN, pending final approval by the Lithuanian parliament. Associate membership will allow representatives of the Baltic nation to take part in meetings of the CERN Council, which oversees the Geneva-based physics lab.

  11. CERN openlab Open Day

    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.

  12. Integration of CERN staff

    CERN PhotoLab

    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.

  13. CERN's 25th Anniversary

    CERN PhotoLab

    1979-01-01

    A ceremony in the Main Auditorium on 23 June 1979 to mark the 25th Anniversary of CERN. A photo of the five Director-Generals of CERN, from left to right: John Adams, Willi Jentschke, Felix Bloch, Viki Weisskopf and Leon van Hove.

  14. Punctualizaciones del CERN

    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).

  15. CERN in the park

    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

  16. France at CERN

    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 ...

  17. Lectures for CERN pensioners

    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)

  18. Romanian President Visits CERN

    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 ...

  19. CERN Mobility Survey

    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 ...

  20. Axion-photon conversion in space and in low symmetrical dielectric crystals

    Gorelik, V S

    2016-01-01

    The opportunities of axions detection as the result of axion-photon conversion processes in the space and in low symmetrical dielectric crystals are discussed. In accordance with the modern theory predictions, axions are pseudoscalar vacuum particles having very small (0.001-1.0 meV) rest energy. The possibility of axions conversion into photons and vice-versa processes in vacuum at the presence of outer magnetic field has been analyzed before. Pseudoscalar (axion type) modes are existing in some types of crystals. Polar pseudoscalar lattice and exciton modes in low symmetrical crystals are strongly interacted with axions. In this work, optical excitation of axion-type modes in low symmetrical crystals is proposed for observation of axion - photon conversion processes. Instead of outer magnetic field, the crystalline field of such crystals may be used. The experimental schemes for axion-photon conversion processes observation with recording the secondary emission of luminescence, infrared or Stimulated Raman Scattering in some dielectric crystals are discussed. (paper)

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

    Battesti, R; Davoudiasl, H; Kuster, M; Pugnat, P; Rabadan, R; Ringwald, A; Spooner, N J C; Zioutas, K

    2008-01-01

    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 outlook on experiments planned for the near future.

  2. 5th Patras workshop on axions, WIMPs and WISPs (PATRAS 2009). Proceedings

    Jaeckel, Joerg; Lindner, Axel; Redondo, Javier [eds.

    2010-06-15

    The following topics were dealt with: Direct searches for dark matter, indirect searches for WIMPS, photon generation and laser polarization experiments, direct axion signals, theoretic WISP developments. (HSI)

  3. 5th Patras workshop on axions, WIMPs and WISPs (PATRAS 2009). Proceedings

    Jaeckel, Joerg; Lindner, Axel; Redondo, Javier

    2010-06-01

    The following topics were dealt with: Direct searches for dark matter, indirect searches for WIMPS, photon generation and laser polarization experiments, direct axion signals, theoretic WISP developments. (HSI)

  4. Axion cosmology, lattice QCD and the dilute instanton gas

    Borsanyi, S.; Fodor, Z.; Mages, S.W.; Nogradi, D.; Szabo, K.K.

    2015-08-01

    Axions are one of the most attractive dark matter candidates. The evolution of their number density in the early universe can be determined by calculating the topological susceptibility χ(T) of QCD as a function of the temperature. Lattice QCD provides an ab initio technique to carry out such a calculation. A full result needs two ingredients: physical quark masses and a controlled continuum extrapolation from non-vanishing to zero lattice spacings. We determine χ(T) in the quenched framework (infinitely large quark masses) and extrapolate its values to the continuum limit. The results are compared with the prediction of the dilute instanton gas approximation (DIGA). A nice agreement is found for the temperature dependence, whereas the overall normalization of the DIGA result still differs from the non-perturbative continuum extrapolated lattice results by a factor of order ten. We discuss the consequences of our findings for the prediction of the amount of axion dark matter.

  5. Axion production from gravitons off interacting 0-branes

    Hussain, F.; Iengo, R.; Nunez, C.

    1997-01-01

    We study axion-graviton scattering from a system of two D0-branes in a type II superstring theory, a process which does not occur on a single brane. The two D0-branes interact via the exchange of closed string states which form a cylinder joining them. By compactifying on the Z 3 orbifold we find a non-vanishing amplitude coming from the odd spin structure sector, thus from the exchanged RR states. We compute, in particular, the leading term of the amplitude at large distance from the branes, which corresponds to taking a field theory limit. This seems to suggest that the process takes place through the coupling of an axion to the RR states exchanged between the 0-branes. (orig.)

  6. Cosmologically safe QCD axion without fine-tuning

    Yamada, Masaki; Yanagida, Tsutomu T.; Yonekura, Kazuya

    2015-10-01

    Although QCD axion models are widely studied as solutions to the strong CP problem, they generically confront severe fine-tuning problems to guarantee the anomalous PQ symmetry. In this letter, we propose a simple QCD axion model without any fine-tunings. We introduce an extra dimension and a pair of extra quarks living on two branes separately, which is also charged under a bulk Abelian gauge symmetry. We assume a monopole condensation on our brane at an intermediate scale, which implies that the extra quarks develop the chiral symmetry breaking and the PQ symmetry is broken. In contrast to the original Kim's model, our model explains the origin of the PQ symmetry thanks to the extra dimension and avoids the cosmological domain wall problem because of the chiral symmetry breaking in the Abelian gauge theory.

  7. The 1956 CERN Symposium

    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...

  8. CERN in 2030

    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...

  9. CERN honours its guides

    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...

  10. CERN: Digitally open, too

    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...

  11. Entropy of charged dilaton-axion black hole

    Ghosh, Tanwi; SenGupta, Soumitra

    2008-01-01

    Using the brick wall method, the entropy of the charged dilaton-axion black hole is determined for both asymptotically flat and nonflat cases. The entropy turns out to be proportional to the horizon area of the black hole confirming the Bekenstein-Hawking area-entropy formula for black holes. The leading order logarithmic corrections to the entropy are also derived for such black holes.

  12. White dwarfs as physics laboratories: the case of axions

    Isern, J.; Althaus, L.; Catalan, S.; Corsico, A.; Garcia-Berro, E.; Salaris, M.; Torres, S.

    2012-01-01

    White dwarfs are almost completely degenerate objects that cannot obtain energy from thermonuclear sources, so their evolution is just a gravothermal cooling process. Recent improvements in the accuracy and precision of the luminosity function and in pulsational data of variable white dwarfs suggest that they are cooling faster than expected from conventional theory. In this contribution we show that the inclusion of an additional cooling term due to axions able to interact with electrons wit...

  13. The quest for axions and other new light particles

    Baker, K. [Yale Univ., New Haven, CT (United States). Physics Dept.; Cantatore, G. [Trieste Univ. (Italy); INFN Trieste (Italy); Cetin, S.A. [Dogus Univ., Istanbul (Turkey)] [and others; Collaboration: Working Group

    2013-05-15

    Standard Model extensions often predict low-mass and very weakly interacting particles, such as the axion. A number of small-scale experiments at the intensity/ precision frontier are actively searching for these elusive particles, complementing searches for physics beyond the Standard Model at colliders. Whilst a next generation of experiments will give access to a huge unexplored parameter space, a discovery would have a tremendous impact on our understanding of fundamental physics.

  14. The quest for axions and other new light particles

    Baker, K.; Cetin, S.A.

    2013-05-01

    Standard Model extensions often predict low-mass and very weakly interacting particles, such as the axion. A number of small-scale experiments at the intensity/ precision frontier are actively searching for these elusive particles, complementing searches for physics beyond the Standard Model at colliders. Whilst a next generation of experiments will give access to a huge unexplored parameter space, a discovery would have a tremendous impact on our understanding of fundamental physics.

  15. A Princess at CERN

    2009-01-01

    On 16 March HRH Princess Maha Chakri Sirindhorn of Thailand visited CERN for the third time. After meeting the Director-General, she toured the CMS experimental area and LHC tunnel with Coordinator for external relations Felicitas Pauss and CMS Spokesperson Jim Virdee. During her visit she took a particular interest in CERN’s education programme. From left to right, Emmanuel Tsesmelis, from the CERN Directorate’s office, Jim Virdee, CMS Spokesperson, the Princess of Thailand and Felicitas Pauss, CERN Coordinator for external relations.

  16. CERN Infrastructure Evolution

    Bell, Tim

    2012-01-01

    The CERN Computer Centre is reviewing strategies for optimizing the use of the existing infrastructure in the future, and in the likely scenario that any extension will be remote from CERN, and in the light of the way other large facilities are today being operated. Over the past six months, CERN has been investigating modern and widely-used tools and procedures used for virtualisation, clouds and fabric management in order to reduce operational effort, increase agility and support unattended remote computer centres. This presentation will give the details on the project’s motivations, current status and areas for future investigation.

  17. CERN Yoga club

    Le comité du club de yoga du CERN

    2017-01-01

    Members of the CERN Yoga club are invited to the General Assembly of the club which will take place on: Wednesday 5 July at 14.00 in conference room 504-E-005 (Next to Yoga room) The agenda is available on the club's website: cern.ch/club-yoga/ If you are unable to participate, please elect a proxy voter to vote on your behalf (available from your teacher or in the Yoga room) – these can be addressed to: cernyoga@cern.ch

  18. Britain at CERN

    CERN Press Office. Geneva

    1998-01-01

    It was thirty years ago that British industry held the first ever trade fair at CERN and industrial links between Britain and the Laboratory have never looked back. Speaking at the opening of the 1998 "Britain at CERN" exhibition on 20 October, H.E. Mr Christopher Hulse, British Ambassador to Switzerland, underlined the value of CERN contracts to British industry saying that "The prize is well worth going for, I understand that contracts worth  1.5bn will be awarded over the next six years".

  19. La Hollande au CERN

    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.

  20. Oscillations in the CMB from Axion Monodromy Inflation

    Flauger, Raphael; /Texas U.; McAllister, Liam; Pajer, Enrico; /Cornell U., Phys. Dept.; Westphal, Alexander; /SLAC /Stanford U., Phys. Dept.; Xu, Gang; /Cornell U., Phys. Dept.

    2011-12-01

    We study the CMB observables in axion monodromy inflation. These well-motivated scenarios for inflation in string theory have monomial potentials over super-Planckian field ranges, with superimposed sinusoidal modulations from instanton effects. Such periodic modulations of the potential can drive resonant enhancements of the correlation functions of cosmological perturbations, with characteristic modulations of the amplitude as a function of wavenumber. We give an analytical result for the scalar power spectrum in this class of models, and we determine the limits that present data places on the amplitude and frequency of modulations. Then, incorporating an improved understanding of the realization of axion monodromy inflation in string theory, we perform a careful study of microphysical constraints in this scenario. We find that detectable modulations of the scalar power spectrum are commonplace in well-controlled examples, while resonant contributions to the bispectrum are undetectable in some classes of examples and detectable in others. We conclude that resonant contributions to the spectrum and bispectrum are a characteristic signature of axion monodromy inflation that, in favorable cases, could be detected in near-future experiments.

  1. Axion-assisted production of sterile neutrino dark matter

    Berlin, Asher; Hooper, Dan

    2017-04-12

    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.

  2. Gauge-preheating and the end of axion inflation

    Adshead, Peter; Sfakianakis, Evangelos I. [Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801 (United States); Giblin, John T. Jr.; Scully, Timothy R., E-mail: adshead@illinois.edu, E-mail: giblinj@kenyon.edu, E-mail: tscully2@illinois.edu, E-mail: esfaki@illinois.edu [Department of Physics, Kenyon College, 201 North College Rd, Gambier, Ohio 43022 (United States)

    2015-12-01

    We study the onset of the reheating epoch at the end of axion-driven inflation where the axion is coupled to an Abelian, U(1), gauge field via a Chern-Simons interaction term. We focus primarily on m{sup 2φ2} inflation and explore the possibility that preheating can occur for a range of coupling values consistent with recent observations and bounds on the overproduction of primordial black holes. We find that for a wide range of parameters preheating is efficient. In certain cases the inflaton transfers all of its energy to the gauge fields within a few oscillations. In most cases, we find that the gauge fields on sub-horizon scales end preheating in an unpolarized state due to the existence of strong rescattering between the inflaton and gauge-field modes. We also present a preliminary study of an axion monodromy model coupled to U(1) gauge fields, seeing a similarly efficient preheating behavior as well as indications that the coupling strength has an effect on the creation of oscillons.

  3. Gauge-preheating and the end of axion inflation

    Adshead, Peter; Sfakianakis, Evangelos I.; Giblin, John T. Jr.; Scully, Timothy R.

    2015-01-01

    We study the onset of the reheating epoch at the end of axion-driven inflation where the axion is coupled to an Abelian, U(1), gauge field via a Chern-Simons interaction term. We focus primarily on m 2φ2 inflation and explore the possibility that preheating can occur for a range of coupling values consistent with recent observations and bounds on the overproduction of primordial black holes. We find that for a wide range of parameters preheating is efficient. In certain cases the inflaton transfers all of its energy to the gauge fields within a few oscillations. In most cases, we find that the gauge fields on sub-horizon scales end preheating in an unpolarized state due to the existence of strong rescattering between the inflaton and gauge-field modes. We also present a preliminary study of an axion monodromy model coupled to U(1) gauge fields, seeing a similarly efficient preheating behavior as well as indications that the coupling strength has an effect on the creation of oscillons

  4. CERN at ESOF 2016

    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...

  5. Open Hardware at CERN

    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.

  6. CERN confirms LHC schedule

    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.

  7. Safety at CERN

    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...

  8. Iran approaches CERN

    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.

  9. CERN meets Facebook

    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 ...

  10. CERN recognises LHC suppliers

    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'.

  11. Britain exhibition at CERN

    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.

  12. Rejuvenating CERN's Accelerators

    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.

  13. Star spotting at CERN

    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. Industrial Activity at CERN

    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...

  15. Indian President visits CERN

    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...

  16. YOUR LIFE@CERN

    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!

  17. CERN stationery rejuvenated

    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...

  18. Fusion Revisits CERN

    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

  19. CERN scientists predict supernova

    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).

  20. Hierarchies in Quantum Gravity: Large Numbers, Small Numbers, and Axions

    Stout, John Eldon

    Our knowledge of the physical world is mediated by relatively simple, effective descriptions of complex processes. By their very nature, these effective theories obscure any phenomena outside their finite range of validity, discarding information crucial to understanding the full, quantum gravitational theory. However, we may gain enormous insight into the full theory by understanding how effective theories with extreme characteristics--for example, those which realize large-field inflation or have disparate hierarchies of scales--can be naturally realized in consistent theories of quantum gravity. The work in this dissertation focuses on understanding the quantum gravitational constraints on these "extreme" theories in well-controlled corners of string theory. Axion monodromy provides one mechanism for realizing large-field inflation in quantum gravity. These models spontaneously break an axion's discrete shift symmetry and, assuming that the corrections induced by this breaking remain small throughout the excursion, create a long, quasi-flat direction in field space. This weakly-broken shift symmetry has been used to construct a dynamical solution to the Higgs hierarchy problem, dubbed the "relaxion." We study this relaxion mechanism and show that--without major modifications--it can not be naturally embedded within string theory. In particular, we find corrections to the relaxion potential--due to the ten-dimensional backreaction of monodromy charge--that conflict with naive notions of technical naturalness and render the mechanism ineffective. The super-Planckian field displacements necessary for large-field inflation may also be realized via the collective motion of many aligned axions. However, it is not clear that string theory provides the structures necessary for this to occur. We search for these structures by explicitly constructing the leading order potential for C4 axions and computing the maximum possible field displacement in all compactifications of

  1. Radiation safety at CERN

    Hoefert, M [CERN, Geneva (Switzerland)

    1995-09-01

    CERN, the European Laboratory for Particle Physics, operates proton accelerators up to an energy of 450 GeV and an electron-positron storage ring in the 50 GeV energy range for fundamental high-energy particle physics. A strong radiation protection group assures the radiation safety of these machines both during their operation and in periods of maintenance and repair. Particular radiation problems in an accelerator laboratory are presented and recent developments in radiation protection at CERN discussed. (author)

  2. CERN, Accelerating Science

    AUTHOR|(CDS)2086185

    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.

  3. The CERN's year

    Chadli, M.; Coppier, H.; Pezzeti, M.

    2007-01-01

    CERN, the European organization for nuclear research, has just celebrated its fifty years of existence. Its first goal was to counterbalance the migration of physics scientists towards the USA by the creation of a physics laboratory gathering scientists from the different European countries. Today, the CERN's mission has changed and has overcome all the expectations of its founders. In 2008, it will become, with the LHC (Large Hadron Collider), the biggest particle accelerator in the world. The CERN employs about 3000 physicists, engineers, technicians and workers. There is also 6500 people from 80 different countries who use the CERN's facilities during the year. The CERN is controlled by 20 European member states and 6 observer countries, and 20 non-member countries participate to the programs in progress. The CERN's power comes from its international and cosmopolitan spirit. The whole most famous physicists of the world can work together for the progress of science and for a better understanding of matter, of its interactions and of our universe. Two Nobel prices of physics come from the CERN: C. Rubbia and S. Van der Meer in 1983 for the discovery of W + , W - and Z 0 bosons, and G. Charpak for the development of particle detectors. One can foresee that the LHC will allow new scientific achievements, like for instance, during experiments for the quest of the famous Higgs boson. It is important also to mention that the CERN has been at the origin of several technological innovations in all technical and engineering domains in the framework of its fundamental physics researches. (J.S.)

  4. CERN: Making CLIC tick

    Anon.

    1990-01-01

    While the Large Hadron Collider (LHC) scheme for counter-rotating proton beams in a new superconducting ring to be built in CERN's existing 27-kilometre LEP tunnel is being pushed as the Laboratory's main construction project for the 1990s, research and development continues in parallel for an eventual complementary attack on new physics frontiers with CERN's Linear Collider - CLIC - firing TeV electron and positron beams at each other

  5. Cern women's club

    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/

  6. CHT, CERN HIPPI Testbox

    1990-01-01

    To allow CERN to test and maintain HIPPI equipment (High Performance Parallel Interface), a powerful test falcility is required. A tester has been developed at Los Alamos National Laboratories [9,10]. The CERN HIPPI testbox allows testing of HIPPI equipment both inside and outside the specifications. This includes the possibility of deliberately introducing errors. The main features of this testbox are: Manual set-up Processor controlled set-up Possibilities for remote analysis Checking the HIPPI specifications Checking illegal conditions

  7. Germany at CERN

    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.

  8. Cern Women's Club

    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/

  9. CERN: Producing radioactive beams

    Anon.

    1994-01-01

    Accelerating radioactive beams has long been of interest at CERN's ISOLDE on-line isotope separator - the possibility was discussed at a CERN Workshop on intermediate energy physics as early as 1977. Meanwhile, as was highlighted in the 1991 report of the Nuclear Physics European Collaboration Committee, widespread scientific interest in these beams has developed and a range of projects are proposed, under construction or operational throughout the world

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

    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...

  11. Some remarks about possible common footing of second-class currents and the axion

    Rodenberg, R.

    1981-01-01

    Both, second class currents (SCC) as well as the axion have a common footing mediated via the ''Higgs sector''. So far, both massive particles, the axion a 0 as well as B 0 , a possible candidate to represent SCC with msub(B) 0 approximately > 5 GeV belong in that sense to the same multiplet. (author)

  12. Exploring 0.1–10 eV axions with a new helioscope concept

    Galán, J.; Dafni, T.; Iguaz, F.J.

    2015-01-01

    We explore the possibility to develop a new axion helioscope type, sensitive to the higher axion mass region favored by axion models. We propose to use a low background large volume TPC immersed in an intense magnetic field. Contrary to traditional tracking helioscopes, this detection technique takes advantage of the capability to directly detect the photons converted on the buffer gas which defines the axion mass sensitivity region, and does not require pointing the magnet to the Sun. The operation flexibility of a TPC to be used with different gas mixtures (He, Ne, Xe, etc.) and pressures (from 10 mbar to 10 bar) will allow to enhance sensitivity for axion masses from few meV to several eV. We present different helioscope data taking scenarios, considering detection efficiency and axion absorption probability, and show the sensitivities reachable with this technique to be few × 10 −11  GeV −1 for a 5 T, m 3 scale TPC. We show that a few years program taking data with such setup would allow to probe the KSVZ axion model for axion masses above 0∼> 10 meV

  13. Spontaneous CP breaking and the axion potential: an effective Lagrangian approach

    CERN. Geneva

    2017-01-01

    When we add to the model a generic axion field (in order to ensure CP at all values of $\\theta$) the above considerations have a bearing on the shape of the axion potential near the boundary of its periodicity interval. This ...

  14. CERN Relay Race 2018

    CERN Running club

    2018-01-01

    The CERN running club, in collaboration with the Staff Association, is happy to announce the 2018 relay race edition. It will take place on Thursday, May 24th and will consist as every year in a round trip of the CERN Meyrin site in teams of 6 members. It is a fun event, and you do not have to run fast to enjoy it. Registrations will be open from May 1st to May 22nd on the running club web site. All information concerning the race and the registration are available there too: http://runningclub.web.cern.ch/content/cern-relay-race. A video of the previous edition is also available here : http://cern.ch/go/Nk7C. As every year, there will be animations starting at noon on the lawn in front of restaurant 1, and information stands for many CERN associations and clubs will be available. The running club partners will also be participate in the event, namely Berthie Sport, Interfon and Uniqa.

  15. CERN Relay Race

    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.  

  16. CREATIVE COLLISIONS: ARTS @CERN

    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...

  17. CERN openlab Open Day

    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...

  18. CERN Pensioners Association

    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...

  19. Sharing resources@CERN

    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...

  20. The next phase of the Axion Dark Matter eXperiment

    Carosi, Gianpaolo; Asztalos, S.; Hagmann, C.; Kinion, D.; van Bibber, K.; Hotz, M.; Lyapustin, D.; Rosenberg, L.; Rybka, G.; Wagner, A.; Hoskins, J.; Martin, C.; Sikivie, P.; Sullivan, N.; Tanner, D.; Bradley, R.; Clarke, J.; ADMX Collaboration

    2011-04-01

    Axions are a well motivated dark matter candidate which may be detected by their resonant conversion to photons in the presence of a large static magnetic field. The Axion Dark Matter eXperiment recently finished a search for DM axions using a new ultralow noise microwave receiver based on a SQUID amplifier. The success of this precursor experiment has paved the way for a definitive axion search which will see the system noise temperature lowered from 1.8 K to 100 mK, dramatically increasing sensitivity to even pessimistic axion models as well as increasing scan speed. Here we discuss the implementation of this next experimental phase. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Security, LLC, Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  1. Solving the tension between high-scale inflation and axion isocurvature perturbations

    Higaki, Tetsutaro; Takahashi, Fuminobu; Tokyo Univ., Kashiwa

    2014-03-01

    The BICEP2 experiment determined the Hubble parameter during inflation to be about 10 14 GeV. Such high inflation scale is in tension with the QCD axion dark matter if the Peccei-Quinn (PQ) symmetry remains broken during and after inflation, because too large axion isocurvature perturbations would be generated. The axion isocurvature perturbations can be suppressed if the axion acquires a sufficiently heavy mass during inflation. We show that this is realized if the PQ symmetry is explicitly broken down to a discrete symmetry and if the breaking is enhanced during inflation. We also show that, even when the PQ symmetry becomes spontaneously broken after inflation, such a temporarily enhanced PQ symmetry breaking relaxes the constraint on the axion decay constant.

  2. Probing axions with the neutrino signal from the next galactic supernova

    Fischer, Tobias; Giannotti, Maurizio; Payez, Alexandre; Ringwald, Andreas

    2016-05-01

    We study the impact of axion emission in simulations of massive star explosions, as an additional source of energy loss complementary to the standard neutrino emission. The inclusion of this channel shortens the cooling time of the nascent protoneutron star and hence the duration of the neutrino signal. We treat the axion-matter coupling strength as a free parameter to study its impact on the protoneutron star evolution as well as on the neutrino signal. We furthermore analyze the observability of the enhanced cooling in current and next-generation underground neutrino detectors, showing that values of the axion mass m a >or similar 8 x 10 -3 eV can be probed. Therefore a galactic supernova neutrino observation would provide a valuable possibility to probe axion masses in a range within reach of the planned helioscope experiment, the International Axion Observatory (IAXO).

  3. The 7 keV axion dark matter and the X-ray line signal

    Higaki, Tetsutaro [KEK, Tsukuba (Japan). Theory Center; Jeong, Kwang Sik [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Takahashi, Fuminobu [Tohoku Univ., Sendai (Japan). Dept. of Physics; Tokyo Univ., Kashiwa (Japan). Kavli IPMU, TODIAS

    2014-03-15

    We propose a scenario where the saxion dominates the energy density of the Universe and reheats the standard model sector via the dilatonic coupling, while its axionic partner contributes to dark matter decaying into photons via the same operator in supersymmetry. Interestingly, for the axion mass m{sub a} ≅ 7 keV and the decay constant f{sub a} ≅10{sup 14-15} GeV, the recently discovered X-ray line at 3.5 keV in the XMM Newton X-ray observatory data can be explained. We discuss various cosmological aspects of the 7 keV axion dark matter such as the production of axion dark matter, the saxion decay process, hot dark matter and isocurvature constraints on the axion dark matter, and the possible baryogenesis scenarios.

  4. Chiral primordial blue tensor spectra from the axion-gauge couplings

    Obata, Ippei, E-mail: obata@tap.scphys.kyoto-u.ac.jp [Department of Physics, Kyoto University, Kyoto, 606-8502 (Japan)

    2017-06-01

    We suggest the new feature of primordial gravitational waves sourced by the axion-gauge couplings, whose forms are motivated by the dimensional reduction of the form field in the string theory. In our inflationary model, as an inflaton we adopt two types of axion, dubbed the model-independent axion and the model-dependent axion, which couple with two gauge groups with different sign combination each other. Due to these forms both polarization modes of gauge fields are amplified and enhance both helicies of tensor modes during inflation. We point out the possibility that a primordial blue-tilted tensor power spectra with small chirality are provided by the combination of these axion-gauge couplings, intriguingly both amplitudes and chirality are potentially testable by future space-based gravitational wave interferometers such as DECIGO and BBO project.

  5. The QUAX proposal: a search of galactic axion with magnetic materials

    Ruoso, Giuseppe; Ortolan, Antonello; Pengo, Ruggero; Braggio, Caterina; Carugno, Giovanni; Gallo, Carmelo Sebastiano; Speake, Clive C.

    2016-06-09

    Aim of the QUAX (QUaerere AXion) proposal is to exploit the interaction of cosmological axions with the spin of electrons in a magnetized sample. Their effect is equivalent to the application of an oscillating rf field with frequency and amplitude which are fixed by axion mass and coupling constant, respectively. The rf receiver module of the QUAX detector consists of magnetized samples with the Larmor resonance frequency tuned to the axion mass by a polarizing static magnetic field. The interaction of electrons with the axion-equivalent rf field produces oscillations in the total magnetization of the samples. To amplify such a tiny field, a pump field at the same frequency is applied in a direction orthogonal to the polarizing field. The induced oscillatory magnetization along the polarizing field is measured by a SQUID amplifier operated at its quantum noise level.

  6. The 7 keV axion dark matter and the X-ray line signal

    Higaki, Tetsutaro; Takahashi, Fuminobu; Tokyo Univ., Kashiwa

    2014-03-01

    We propose a scenario where the saxion dominates the energy density of the Universe and reheats the standard model sector via the dilatonic coupling, while its axionic partner contributes to dark matter decaying into photons via the same operator in supersymmetry. Interestingly, for the axion mass m a ≅ 7 keV and the decay constant f a ≅10 14-15 GeV, the recently discovered X-ray line at 3.5 keV in the XMM Newton X-ray observatory data can be explained. We discuss various cosmological aspects of the 7 keV axion dark matter such as the production of axion dark matter, the saxion decay process, hot dark matter and isocurvature constraints on the axion dark matter, and the possible baryogenesis scenarios.

  7. Is it possible to explore Peccei-Quinn axions from frequency-dependence radiation dimming?

    Jimenez, Raul; Pena-Garay, Carlos; Verde, Licia

    2011-01-01

    We explore how the Peccei-Quinn (PQ) axion parameter space can be constrained by the frequency-dependence dimming of radiation from astrophysical objects. To do so we perform accurate calculations of photon-axion conversion in the presence of a variable magnetic field. We propose several tests where the PQ axion parameter space can be explored with current and future astronomical surveys: the observed spectra of isolated neutron stars, occultations of background objects by white dwarfs and neutron stars, the light-curves of eclipsing binaries containing a white dwarf. We find that the lack of dimming of the light-curve of a detached eclipsing white dwarf binary recently observed, leads to relevant constraints on the photon-axion conversion. Current surveys designed for Earth-like planet searches are well matched to strengthen and improve the constraints on the PQ axion using astrophysical objects radiation dimming.

  8. Phenomenology and Astrophysics of Gravitationally-Bound Condensates of Axion-Like Particles

    Eby, Joshua Armstrong [Univ. of Cincinnati, OH (United States)

    2017-01-01

    Light, spin-0 particles are ubiquitous in theories of physics beyond the Standard Model, and many of these make good candidates for the identity of dark matter. One very well-motivated candidate of this type is the axion. Due to their small mass and adherence to Bose statistics, axions can coalesce into heavy, gravitationally-bound condensates known as boson stars, also known as axion stars (in particular). In this work, we outline our recent progress in attempts to determine the properties of axion stars. We begin with a brief overview of the Standard Model, axions, and bosonic condensates in general. Then, in the context of axion stars, we will present our recent work, which includes: numerical estimates of the macroscopic properties (mass, radius, and particle number) of gravitationally stable axion stars; a calculation of their decay lifetime through number-changing interactions; an analysis of the gravitational collapse process for very heavy states; and an investigation of the implications of axion stars as dark matter. The basic conclusions of our work are that weakly-bound axion stars are only stable up to some calculable maximum mass, whereas states with larger masses collapse to a small radius, but do not form black holes. During collapse, a rapidly increasing binding energy implies a fast rate of decay to relativistic particles, giving rise to a Bosenova. Axion stars that are otherwise stable could be caused to collapse either by accretion of free particles to masses above the maximum, or through astrophysical collisions; in the latter case, we estimate the rate of collisions and the parameter space relevant to induced collapse.

  9. CERN and Portugal

    Anon.

    1995-01-01

    In its continual tour of CERN Member States, the European Committee for Future Accelerators (ECFA) visited Lisbon, Portugal, on 21-22 April, where it met at the Instituto Superiore Tecnico, a technical university with 9,000 students. Portuguese particle physics is in a particularly healthy situation, having developed considerably following Portugal's admission to CERN in 1985. With support from Brussels, scientific infrastructure has developed rapidly, although the science base has yet to attain the levels seen in larger nations. The 45-strong population of experimentalists in Portugal, including 14 PhDs, represents a 2.5-fold increase since Portugal joined CERN ten years ago and is in line with the goal stated at the time. This successful development of experimental particle physics has benefited much from physicists returning from abroad (mainly France and the UK). The direct result of the efforts of a few individuals (notably J.M. Gago), this splendid achievement provides an excellent role model for new and potential CERN Member States. At present, particle physics represents some 3 0% of all Portuguese physics publications. This very special role (and the financial support it implies) provides a visible target, but one which can be defended as it provides a catalyst for other national scientific developments. The national hub is the Laboratory for experimental high energy physics and related R&D projects (LIP), with centres in Lisbon (Head, J.M. Gago) and Coimbra (Head, A. Policarpo). LIP, with close links to two universities in Lisbon and to the University of Coimbra, has developed into a centre of expertise and training in electronics, computing and software engineering. Present LIP funding is some 2 million Swiss francs/year (70% in Lisbon and 3 0% in Coimbra), covering most of the salaries of the nonuniversity people, the remainder being supported by grants from Portuguese and European programmes. Portugal's contribution to CERN's 1995 budget

  10. CERN and Israel

    Anon.

    1995-01-01

    Israel (along with the US, Japan, Canada, the Russian Federation and India) is one of the CERN non- Member State nations targeted for substantial future participation in CERN's experimental programme, in particular for the LHC proton collider to be built in the 27-kilometre LEP tunnel and which was formally approved by CERN Council in December (January/February, page 1). In keeping with their illustrious scientific traditions, Israeli experimental physicists have collaborated in experiments at many of the world's major high energy Laboratories - Brookhaven, Fermilab and SLAC in the US, and in Europe, DESY, Hamburg, as well as CERN. However CERN, as the geographically closest major Laboratory (as well as the largest), plays a special role for Israeli scientists. At CERN, the advent of preparations in the early 1980s for the experimental programme at the LEP electron-positron collider was the signal for Israeli researchers to mount a concerted effort and contribute to one of the experiments - Opal - at a level comparable to that of major nations. This allowed Israeli teams to participate fully in the planning and construction phase of this branch of Big Science. Underlining this commitment, and to coordinate the various national agencies involved in this aspect of Big Science, in 1983 the Israel Commission for High Energy Physics (ICHEP) was formed. It is currently chaired by David Horn of Tel Aviv. The initial ICHEP/CERN contract established the official CERN/lsrael link under which, in the short-term, teams from three major research centres - the Weizmann Institute, Tel- Aviv University, and Haifa's Technion - contributed to Opal, as the flagship experiment, while providing a framework for longer-term collaboration. (At CERN, Israeli physicists also participate in the NA45 heavy ion experiment and the NA47 Spin Muon Collaboration - SMC.) Opal groups some 320 scientists from 32 research centres in eight countries, and includes a 21-strong Israeli

  11. Radiography at CERN

    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...

  12. Inspired by CERN

    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...

  13. Lectures for CERN pensioners

    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)

  14. CERN television news

    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...

  15. Apprenticeship at CERN

    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 ...

  16. CERN Phonebook evolution

    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...

  17. CERN Relay Race

    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...

  18. Spaceflight participant visits CERN!

    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...

  19. CERN CAR STICKERS

    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...

  20. EU Commissioner visits CERN

    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...

  1. Systematics of axion inflation in Calabi-Yau hypersurfaces

    Long, Cody; McAllister, Liam; Stout, John [Department of Physics, Cornell University,Ithaca, NY 14853 (United States)

    2017-02-03

    We initiate a comprehensive survey of axion inflation in compactifications of type IIB string theory on Calabi-Yau hypersurfaces in toric varieties. For every threefold with h{sup 1,1}≤4 in the Kreuzer-Skarke database, we compute the metric on Kähler moduli space, as well as the matrix of four-form axion charges of Euclidean D3-branes on rigid divisors. These charges encode the possibility of enlarging the field range via alignment. We then determine an upper bound on the inflationary field range Δϕ that results from the leading instanton potential, in the absence of monodromy. The bound on the field range in this ensemble is Δϕ≲0.3M{sub pl}, in a compactification where the smallest curve volume is (2π){sup 2}α{sup ′}, and we argue that the sigma model expansion is adequately controlled. The largest increase resulting from alignment is a factor ≈2.6. We also examine a set of threefolds with h{sup 1,1} up to 100 and characterize their axion charge matrices. While we find modest alignment in this ensemble, the maximum field range is ultimately suppressed by the volume of the internal space, which typically grows quickly with h{sup 1,1}. Furthermore, we find that many toric divisors are rigid — and the corresponding charge matrices are relatively trivial — at large h{sup 1,1}. It is therefore challenging to realize alignment via superpotentials generated only by Euclidean D3-branes, without taking into account the effects of flux, D7-branes, and orientifolding.

  2. Gamma-ray boxes from axion-mediated dark matter

    Ibarra, Alejandro; Gehler, Sergio López; Pato, Miguel; Lee, Hyun Min; Park, Wan-Il

    2013-01-01

    We compute the gamma-ray output of axion-mediated dark matter and derive the corresponding constraints set by recent data. In such scenarios the dark matter candidate is a Dirac fermion that pair-annihilates into axions and/or scalars. Provided that the axion decays (at least partly) into photons, these models naturally give rise to a box-shaped gamma-ray spectrum that may present two distinct phenomenological behaviours: a narrow box, resembling a line at half the dark matter mass, or a wide box, spanning an extensive energy range up to the dark matter mass. Remarkably, we find that in both cases a sizable gamma-ray flux is predicted for a thermal relic without fine-tuning the model parameters nor invoking boost factors. This large output is in line with recent Fermi-LAT observations towards the galactic centre region and is on the verge of being excluded. We then make use of the Fermi-LAT and H.E.S.S. data to derive robust, model-independent upper limits on the dark matter annihilation cross section for the narrow and wide box scenarios. H.E.S.S. constraints, in particular, turn out to match the ones from Fermi-LAT at hundreds of GeV and extend to multi-TeV masses. Future Čerenkov telescopes will likely probe gamma-ray boxes from thermal dark matter relics in the whole multi-TeV range, a region hardly accessible to direct detection, collider searches and other indirect detection strategies

  3. CERN and the Environment

    Aymar, Robert

    2005-01-01

    The impact of CERN’s activities on the surrounding environment is carefully monitored by the Organization via a complete environmental monitoring programme, which is defined and run in agreement with the authorities of Switzerland and France. This programme covers both radiological and conventional aspects. So far the environmental impact of CERN was shown to be negligible. In particular, CERN’s radiological impact is a fraction of the variation of the natural exposure at different locations of the surrounding region. As the site of the Organization is on the territory of two countries and straddles the Swiss-French border, the implementation of its environmental policy requires specific procedures and a very transparent communication towards the Host States authorities and the public opinion. This paper reports the official CERN speech delivered for the opening of the international conference Enviroinfo 2004 that was held at CERN in October 2004.

  4. Dalai Lama at CERN

    Anon.

    1983-01-01

    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

  5. HALO | Arts at CERN

    Caraban Gonzalez, Noemi

    2018-01-01

    In 2015, the artists participated in a research residency at CERN and began to work with data captured by ATLAS, one of the four detectors at the Large Hadron Collider (LHC) that sits in a cavern 100 metres below ground near the main site of CERN, in Meyrin (Switzerland). For Art Basel, they created HALO, an installation that surrounds visitors with data collected by the ATLAS experiment at the LHC. HALO consists of a 10 m wide cylinder defined by vertical piano wires, within which a 4-m tall screen displays particle collisions. The data also triggers hammers that strike the vertical wires and set up vibrations to create a truly multisensory experience. More info: https://arts.cern/event/unveiling-halo-art-basel

  6. CERN welcomes European science

    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...

  7. Cern Cricket Club

    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/    

  8. CERN's new safety policy

    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...

  9. CERN Relay Race

    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.

  10. CMS Centre at CERN

    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...

  11. Advising the CERN Courier

    Jacob, Maurice

    1983-01-01

    As an experiment, a 'CERN COURIER Advisory Panel' was set up two years ago. This Panel has now been granted continuing status. CERN COURIER is unique. It is now an international journal serving the whole high energy physics community, having moved far from its initial conception as the CERN 'house journal'. This international role emerged at the New Orleans meeting of Laboratory Directors in 1975, when it was decided 'to expand the COURIER coverage to give a balanced view of global activities in the high energy physics field'. During the first two years of its existence, the Advisory Panel understood its major task as improving the contact between the editors and the physics community, and helping to maintain a good balance of information. The Panel provided advice and comment but did not act at all as a refereeing body, leaving the editors with the journalistic freedom which should be theirs

  12. CHOEUR DU CERN

    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).  

  13. CERN Croquet club

    CERN Croquet Club

    2018-01-01

    The CERN Croquet Club warmly invites you to an “Open Day” at the CERN Croquet Club on Sunday afternoon, 1st July as of 14:00 We will show you how to play the different games and you can try them out yourselves. Croquet of course, but also the Japanese version, called Gateball, as well as Lawn Bowls, what one might call the British version of “Boules”. The Swiss Croquet Association will offer afternoon Tea and Cake For catering purposes, it would be nice if you can let us know in advance if you will be joining us. Friends and family ae welcome but they will require a CERN Access card. Hope to see you there.

  14. CERN UN Roundtable

    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

  15. On axionic field ranges, loopholes and the weak gravity conjecture

    Brown, Jon; Cottrell, William; Shiu, Gary; Soler, Pablo

    2016-01-01

    In this short note we clarify some aspects of the impact that the Weak Gravity Conjecture has on models of (generalized) natural inflation. We address in particular certain technical and conceptual concerns recently raised regarding the stringent constraints and conclusions found in our previous work http://dx.doi.org/10.1007/JHEP10(2015)023. We also point out the difficulties faced by attempts to evade these constraints. These new considerations improve the understanding of the quantum gravity constraints we found and further support the conclusion that it remains challenging for axions to drive natural inflation.

  16. Supersymmetric SU(11), the invisible axion, and proton decay

    Alwis, S.P. de; Kim, J.E.

    1981-09-01

    We supersymmetrize the very attractive flavour unification model SU(11). As with other supersymmetric GUTs the gauge hierarchy problem is simplified, but we may also have observable (tausub(p) is approximately 10 33 yrs) proton decay. The required split multiplets are obtained by making the adjoint take a particular direction. Supersymmetry is broken softly at the TeV scale. There is a unique U(1)sub(A) symmetry, and hence there are no true Nambu-Goldstone bosons. The U(1)sub(A) is broken at the GUT scale and there result an invisible axion and neutrino masses. (author)

  17. Searching for axion-like-particles in the sky

    Burrage, C. [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany). Theory Group

    2009-06-15

    If dark energy couples to the fields of the standard model we can hope to detect or constrain it through non-gravitational effects. If the dark energy field couples to photons it behaves as an Axion-Like-Particle (ALP). ALPs mix with photons in the presence of magnetic fields and hence affect astronomical observations. We show that empirically established luminosity relations can be used as a new test for ALPs and that when applied to observations of active galactic nuclei this is highly suggestive of the existence of a very light ALP. (orig.)

  18. Wilson Fermions and Axion Electrodynamics in Optical Lattices

    Bermudez, A.; Martin-Delgado, M. A.; Mazza, L.; Rizzi, M.; Goldman, N.; Lewenstein, M.

    2010-01-01

    We show that ultracold Fermi gases in optical superlattices can be used as quantum simulators of relativistic lattice fermions in 3+1 dimensions. By exploiting laser-assisted tunneling, we find an analogue of the so-called naive Dirac fermions, and thus provide a realization of the fermion doubling problem. Moreover, we show how to implement Wilson fermions, and discuss how their mass can be inverted by tuning the laser intensities. In this regime, our atomic gas corresponds to a phase of matter where Maxwell electrodynamics is replaced by axion electrodynamics: a 3D topological insulator.

  19. Searching for axion-like-particles in the sky

    Burrage, C.

    2009-06-01

    If dark energy couples to the fields of the standard model we can hope to detect or constrain it through non-gravitational effects. If the dark energy field couples to photons it behaves as an Axion-Like-Particle (ALP). ALPs mix with photons in the presence of magnetic fields and hence affect astronomical observations. We show that empirically established luminosity relations can be used as a new test for ALPs and that when applied to observations of active galactic nuclei this is highly suggestive of the existence of a very light ALP. (orig.)

  20. HFSS Simulation on Cavity Coupling for Axion Detecting Experiment

    Yeo, Beomki

    2015-01-01

    In the resonant cavity experiment, it is vital maximize signal power at detector with the minimized reflection from source. Return loss is minimized when the impedance of source and cavity are matched to each other and this is called impedance matching. Establishing tunable antenna on source is required to get a impedance matching. Geometry and position of antenna is varied depending on the electromagnetic eld of cavity. This research is dedicated to simulation to nd such a proper design of coupling antenna, especially for axion dark matter detecting experiment. HFSS solver was used for the simulation.

  1. Effective cosmological constant within the expanding axion universe

    Pierpoint, M.P., E-mail: M.Pierpoint@lboro.ac.uk; Kusmartsev, F.V., E-mail: F.Kusmartsev@lboro.ac.uk

    2014-09-12

    We show that the value of an effective cosmological constant, Λ{sub eff}, is influenced by the dimensionality of the space. Results were obtained in the framework of the axion model describing expansion of the inhomogeneous universe. Λ{sub eff} determines the tension of the space (i.e. elasticity), and is relaxed when extra dimensions are accessible. We demonstrate that the effective value of the cosmological constant may be tuned to be consistent with experimental observation. Inhomogeneities considered are representative of temperature fluctuations observed within the cosmic microwave background radiation.

  2. CERN Photo Club (CPC) / Canon Contest - My View of CERN

    Steyaert, Didier

    2016-01-01

    The CERN Photo Club has organized 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.

  3. First Tuesday @ CERN: Industrial Impact of Information Technology from CERN

    CERN. Geneva

    2004-01-01

    CERN is where the web was born, and remains a hothouse of innovation in information technology (IT). In this fourth First Tuesday @ CERN, we look at industrial partnership at CERN in the IT area from several different angles. The approach taken by CERN with software licencing - a very hot topic in the world of IT - will be discussed. The benefits that CERN hardware and software suppliers gain from working with CERN will be presented, and the CERN openlab, a new approach to industrial partnership at CERN, will be covered. A novel ingredient of this First Tuesday @ CERN is that it will be run in parallel with a similar event for the business community in London, and there will be webcast presentations between the Queen Elizabeth II Conference Centre in London and CERN during the event. Thus, First Tuesday @ CERN will take on a truly European dimension, to reflect CERN's European character. More information: http://www.rezonance.ch, or view the joint UK event program

  4. CERN Technical Training : Vista !

    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

  5. CERN at 40

    Anon.

    1994-11-15

    CERN celebrated its 40th anniversary with a special family day on 17 September where the accent was on fun, games and entertainment for staff and their families. After a brief opening ceremony, pomp gave way to play, formality to frivolity. The following extracts from the DG's speech of welcome were freely translated from the French original: 'Forty is the traditional age for taking stock of the past and assessing future prospects. CERN is no exception to this rule and it is particularly appropriate at what is clearly a major turning point in its existence. Before looking to the future, allow me to say a few words about our past.

  6. The birth of CERN

    Parkins, David

    2017-01-01

    At an intergovernmental meeting of UNESCO in Paris in December 1951, the first resolution concerning the establishment of a European Council for Nuclear Research was adopted. Two months later, 11 countries signed an agreement establishing the provisional council – the acronym CERN was born. This humoristic drawing features some of the main characters who were involved in the establishment of CERN. On the American hen: Isidor Rabi and Robert Oppenheimer, while on the hatching egg we recognize Francis Perrin (France), Niels Bohr (Denmark), Werner Heisenberg (Germany) and Sir George Paget Thomson (United Kingdom).

  7. CERN Relay Race

    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

  8. CERN Relay Race

    2007-01-01

    The CERN relay race will take place around the Meyrin site on Wednesday 23 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 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

  9. Poland at CERN

    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.

  10. CERN Scuba Diving Club

    Club Subaquatique du CERN

    2017-01-01

    Interested in scuba diving? Fancy a fun trial dive? Like every year, the CERN Scuba Diving Club is organizing two free trial dive sessions. Where? Varembé Swimming Pool, Avenue Giuseppe Motta 46, 1202 Genève When? 25th October and 1st November at 19:15 (one session per participant) Price? Trial dives are FREE! Swimming pool entrance 5,40 CHF. What to bring? Swimwear, towel, shower necessities and a padlock – diving equipment will be provided by the CSC. For more information and to subscribe, follow the link below: http://cern.ch/csc-baptemes-2017 Looking forward to meeting you!

  11. The significance of Cern

    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.

  12. CERN Technical Training : Vista !

    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

  13. CERN Technical Training : Vista !

    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

  14. CERN Technical Training : Vista !

    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

  15. CERN Technical Training : Vista !

    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

  16. Axion-photon conversion caused by dielectric interfaces: quantum field calculation

    Ioannisian, Ara N. [Yerevan Physics Institute, Alikhanian Br. 2, 375036 Yerevan (Armenia); Kazarian, Narine [Institute for Theoretical Physics and Modeling, 375036 Yerevan (Armenia); Millar, Alexander J.; Raffelt, Georg G., E-mail: ara.ioannisyan@cern.ch, E-mail: narinkaz@gmail.com, E-mail: millar@mpp.mpg.de, E-mail: raffelt@mpp.mpg.de [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, 80805 München (Germany)

    2017-09-01

    Axion-photon conversion at dielectric interfaces, immersed in a near-homogeneous magnetic field, is the basis for the dielectric haloscope method to search for axion dark matter. In analogy to transition radiation, this process is possible because the photon wave function is modified by the dielectric layers ('Garibian wave function') and is no longer an eigenstate of momentum. A conventional first-order perturbative calculation of the transition probability between a quantized axion state and these distorted photon states provides the microwave production rate. It agrees with previous results based on solving the classical Maxwell equations for the combined system of axions and electromagnetic fields. We argue that in general the average photon production rate is given by our result, independently of the detailed quantum state of the axion field. Moreover, our result provides a new perspective on axion-photon conversion in dielectric haloscopes because the rate is based on an overlap integral between unperturbed axion and photon wave functions, in analogy to the usual treatment of microwave-cavity haloscopes.

  17. CERN Diversity Newsletter - March 2016

    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

  18. CERN Diversity Newsletter - April 2017

    AUTHOR|(CDS)2069427; Koutava, Ioanna; CERN. Geneva. HR Department

    2017-01-01

    The 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. CERN Diversity Newsletter - November 2015

    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

  20. CERN firemen share their expertise

    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.

  1. Une flamme pour le CERN

    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)

  2. CERN Diversity Newsletter - September 2016

    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

  3. The quest for an intermediate-scale accidental axion and further ALPs

    Dias, A.G.; Nishi, C.C. [Univ. Federal do ABC - UFABC, Sao Paulo (Brazil); Machado, A.C.B. [Teorica-Univ. Estadual Paulista, Sao Paulo (Brazil). Instituto de Fisica; Ringwald, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Vaudrevange, P. [Technische Univ. Muenchen, Garching (Germany). Excellence Cluster Universe

    2014-03-15

    The recent detection of the cosmic microwave background polarimeter experiment BICEP2 of tensor fluctuations in the B-mode power spectrum basically excludes all plausible axion models where its decay constant is above 10{sup 13} GeV. Moreover, there are strong theoretical, astrophysical, and cosmological motivations for models involving, in addition to the axion, also axion-like particles (ALPs), with decay constants in the intermediate scale range, between 10{sup 9} GeV and 10{sup 13} GeV. Here, we present a general analysis of models with an axion and further ALPs and derive bounds on the relative size of the axion and ALP photon (and electron) coupling. We discuss what we can learn from measurements of the axion and ALP photon couplings about the fundamental parameters of the underlying ultraviolet completion of the theory. For the latter we consider extensions of the Standard Model in which the axion and the ALP(s) appear as pseudo Nambu-Goldstone bosons from the breaking of global chiral U(1) (Peccei-Quinn (PQ)) symmetries, occuring accidentally as low energy remnants from exact discrete symmetries. In such models, the axion and the further ALP are protected from disastrous explicit symmetry breaking effects due to Planck-scale suppressed operators. The scenarios considered exploit heavy right handed neutrinos getting their mass via PQ symmetry breaking and thus explain the small mass of the active neutrinos via a seesaw relation between the electroweak and an intermediate PQ symmetry breaking scale. We show some models that can accommodate simultaneously an axion dark matter candidate, an ALP explaining the anomalous transparency of the universe for γ-rays, and an ALP explaining the recently reported 3.55 keV gamma line from galaxies and clusters of galaxies, if the respective decay constants are of intermediate scale.

  4. The quest for an intermediate-scale accidental axion and further ALPs

    Dias, A.G.; Nishi, C.C.; Machado, A.C.B.; Vaudrevange, P.

    2014-03-01

    The recent detection of the cosmic microwave background polarimeter experiment BICEP2 of tensor fluctuations in the B-mode power spectrum basically excludes all plausible axion models where its decay constant is above 10 13 GeV. Moreover, there are strong theoretical, astrophysical, and cosmological motivations for models involving, in addition to the axion, also axion-like particles (ALPs), with decay constants in the intermediate scale range, between 10 9 GeV and 10 13 GeV. Here, we present a general analysis of models with an axion and further ALPs and derive bounds on the relative size of the axion and ALP photon (and electron) coupling. We discuss what we can learn from measurements of the axion and ALP photon couplings about the fundamental parameters of the underlying ultraviolet completion of the theory. For the latter we consider extensions of the Standard Model in which the axion and the ALP(s) appear as pseudo Nambu-Goldstone bosons from the breaking of global chiral U(1) (Peccei-Quinn (PQ)) symmetries, occuring accidentally as low energy remnants from exact discrete symmetries. In such models, the axion and the further ALP are protected from disastrous explicit symmetry breaking effects due to Planck-scale suppressed operators. The scenarios considered exploit heavy right handed neutrinos getting their mass via PQ symmetry breaking and thus explain the small mass of the active neutrinos via a seesaw relation between the electroweak and an intermediate PQ symmetry breaking scale. We show some models that can accommodate simultaneously an axion dark matter candidate, an ALP explaining the anomalous transparency of the universe for γ-rays, and an ALP explaining the recently reported 3.55 keV gamma line from galaxies and clusters of galaxies, if the respective decay constants are of intermediate scale.

  5. Axion dark matter and Planck favor non-minimal couplings to gravity

    Folkerts, Sarah, E-mail: sarah.folkerts@lmu.de [Arnold Sommerfeld Center, Ludwig-Maximilians-University, Theresienstr. 37, 80333 München (Germany); Germani, Cristiano, E-mail: cristiano.germani@lmu.de [Arnold Sommerfeld Center, Ludwig-Maximilians-University, Theresienstr. 37, 80333 München (Germany); Redondo, Javier, E-mail: javier.redondo@lmu.de [Arnold Sommerfeld Center, Ludwig-Maximilians-University, Theresienstr. 37, 80333 München (Germany); Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, 80805 München (Germany)

    2014-01-20

    Constraints on inflationary scenarios and isocurvature perturbations have excluded the simplest and most generic models of dark matter based on QCD axions. Considering non-minimal kinetic couplings of scalar fields to gravity substantially changes this picture. The axion can account for the observed dark matter density avoiding the overproduction of isocurvature fluctuations. Finally, we show that assuming the same non-minimal kinetic coupling to the axion (dark matter) and to the standard model Higgs boson (inflaton) provides a minimal picture of early time cosmology.

  6. Flavor connections and neutrino mass hierarchy in variant invisible axion models without domain wall problem

    Geng, C.Q.; Ng, J.N.

    1988-08-01

    New types of invisible axion model based on the recent variant axion models are presented. They belong to the N=1 type model and hence are free of domain wall problems. The Peccei-Quinn symmetry transformations are not totally generation and flavor blind, which may help in understanding the small values of electron and u-quark and large t-quark masses. The light neutrino mass pattern in the two Higgs singlet models can have a very different hierarchy that differs from the other type invisible axion model. (Author) (25 refs.)

  7. The Axion Dark-Matter eXperiment (ADMX): Recent Results

    Rosenberg, Leslie J.

    2010-01-01

    The axion is a hypothetical elementary particle whose existence would explain the baffling absence of CP violation in the strong interactions. It's properties in addition make it a good dark-matter candidate. Even though dark-matter axions would make up the overwhelming majority of mass in the universe, they are extraordinarily difficult to detect. We have developed a detector, ADMX, for dark-matter axions that is at heart an exquisitely sensitive detector of electromagnetic radiation. This talk will describe the progress we have made in this experimental search.

  8. A Piezoelectrically Tuned RF-Cavity Search for Dark Matter Axions

    Boutan, Christian

    The Axion is a well motivated hypothetical elementary particle that must exist in nature if the strong CP problem of QCD is explained by the spontaneous breaking of a Peccei-Quinn symmetry. Not only would the discovery of the axion solve deep issues in QCD, an axion with a mass of mueV - meV could account for most or all of the missing mass in our galaxy and finally reveal the composition of dark matter. The Axion Dark Matter experiment (ADMX) seeks to resolve these two critical problems in physics by looking for the resonant conversion of dark-matter axions to microwave photons in a strong magnetic field. Utilizing state of the art electronics and dilution refrigerator cryogenics, ADMX is the world's leading haloscope search for axions - able to discover or rule out even the most pessimistically coupled QCD axions. With multi- TM0n0 functionality and with the commissioning of the new high-frequency Sidecar experiment, ADMX is also sensitive to a wide range of plausible axion masses. Here I motivate axions as ideal dark matter candidates, review techniques for detecting them and give a detailed description of the ADMX experiment. I discuss my contributions to the construction of the ADMX dual-channel receiver, which is the most sensitive microwave receiver on earth. I discuss the data acquisition, data taking and real-time analysis software. The primary focus of this work, however, is the ADMX Sidecar experiment which is a miniature axion haloscope that fits inside of the ADMX insert and has the capability of searching for axion masses between 16mueV - 24mueV on the TM0n0 and 26.4 - 30mueV on the TM 020. I discuss analysis of the Sidecar data and exclude axion-to-two-photon coupling gagammagamma matter. Over a narrow subsection of this range, 22.89 - 22.95mueV (˜15 MHz) I set a stricter limit gagammagamma < 10-12 GeV-1.

  9. CERN Video News on line

    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

  10. Axion monodromy inflation with warped KK-modes

    Hebecker, Arthur; Moritz, Jakob; Witkowski, Lukas T. [Heidelberg Univ. (Germany). Inst. for Theoretical Physics; Westphal, Alexander [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2015-12-15

    We present a particularly simple model of axion monodromy inflation: Our axion is the lowest-lying KK-mode of the RR-2-form-potential C{sub 2} in the standard Klebanov-Strassler throat. One can think of this inflaton candidate as being defined by the integral of C{sub 2} over the S{sup 2} cycle of the throat. It obtains an exponentially small mass from the IR-region in which the S{sup 2} shrinks to zero size. Crucially, the S{sup 2} cycle has to be shared between two throats, such that the second locus where the S{sup 2} shrinks is also in a warped region. Well-known problems like the potentially dangerous back-reaction of brane/antibrane pairs and explicit supersymmetry breaking are not present in our scenario. The inflaton back-reaction on the geometry turns out to be controlled by the string coupling g{sub s}. We hope that our setting is simple enough for many critical consistency issues of large-field inflation in string theory to be addressed at a quantitative level.

  11. Axion monodromy inflation with warped KK-modes

    Hebecker, Arthur; Moritz, Jakob; Witkowski, Lukas T.

    2015-12-01

    We present a particularly simple model of axion monodromy inflation: Our axion is the lowest-lying KK-mode of the RR-2-form-potential C 2 in the standard Klebanov-Strassler throat. One can think of this inflaton candidate as being defined by the integral of C 2 over the S 2 cycle of the throat. It obtains an exponentially small mass from the IR-region in which the S 2 shrinks to zero size. Crucially, the S 2 cycle has to be shared between two throats, such that the second locus where the S 2 shrinks is also in a warped region. Well-known problems like the potentially dangerous back-reaction of brane/antibrane pairs and explicit supersymmetry breaking are not present in our scenario. The inflaton back-reaction on the geometry turns out to be controlled by the string coupling g s . We hope that our setting is simple enough for many critical consistency issues of large-field inflation in string theory to be addressed at a quantitative level.

  12. Axion monodromy inflation with warped KK-modes

    Hebecker, Arthur; Moritz, Jakob; Westphal, Alexander; Witkowski, Lukas T.

    2016-03-01

    We present a particularly simple model of axion monodromy inflation: Our axion is the lowest-lying KK-mode of the RR-2-form-potential C2 in the standard Klebanov-Strassler throat. One can think of this inflaton candidate as being defined by the integral of C2 over the S2 cycle of the throat. It obtains an exponentially small mass from the IR-region in which the S2 shrinks to zero size. Crucially, the S2 cycle has to be shared between two throats, such that the second locus where the S2 shrinks is also in a warped region. Well-known problems like the potentially dangerous back-reaction of brane/antibrane pairs and explicit supersymmetry breaking are not present in our scenario. The inflaton back-reaction on the geometry turns out to be controlled by the string coupling gs. We hope that our setting is simple enough for many critical consistency issues of large-field inflation in string theory to be addressed at a quantitative level.

  13. CERN apprenticeship scheme honoured

    2008-01-01

    Prestigious awards for two apprentices who did their practical training at CERN. Sylvain Heinzen, apprentice physics lab technician at CERN, receiving his award from Pierre-François UNGER, State Councillor responsible for the Federal Department of the Economy and Health. The other award-winner, Cédric Gerber, is on the right of the photo.Among Geneva’s top apprentices who were honoured by the Fondation sociale de l’Union industrielle genevoise (UIG) on 28 October this year, were two CERN apprentices. Electronics technician Cédric Gerber and physics lab technician Sylvain Heinzen both did their four-year sandwich course at CERN, obtaining their professional qualification, the Certificat fédéral de capacité (CFC), in June. On top of that, Cédric Gerber, who had been a particularly outstanding apprentice, received two further distinctions at the CFC awards ceremony - the State Council prize for achieving one of the top-ten o...

  14. CERN celebrates another milestone

    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)

  15. Tragic loss at CERN

    CERN Ski Club

    2015-01-01

    Tragic loss at CERN The CERN community is mourning the tragic loss of two members of the CERN Ski Club. On Sunday, April 12, an avalanche buried four out of five skiers, taking part in a ski touring in the region of the Becs de Bosson in Valais (CH). The fifth skier, who had not been buried in the snow,  courageously managed to save two of the skiers, but Hervé Milcent, 49 years, federal ski instructor, and Mattieu Cattin, 33 years, were buried under two to three meters of snow, far down the avalanche slope, and did not survive, despite the fast arrival of the mountain rescue. In its 40 years of existence, the CERN Ski Club, one of the biggest in the Geneva area, has never been confronted with such a tragedy. The passing of Hervé and Matthieu has deeply shocked and saddened all volunteers of the Club as well as the entire alpine community. The ski touring section of the club would like to honour its friend Hervé, who joined the club in 1998. In 2003 he became res...

  16. CERN: LHC magnets

    Anon.

    1992-01-01

    With test magnets for CERN's LHC proton-proton collider regularly attaining field strengths which show that 10 Tesla is not forbidden territory, attention turns to why and where quenches happen. If 'training' can be reduced, superconducting magnets become easier to commission

  17. Neutrinos at CERN

    Anon.

    1993-01-01

    CERN's long and distinguished neutrino tradition began in 1958 at the then new 500 MeV synchrocyclotron (SC) with the first observation of the decay of a charged pion into an electron and a neutrino. At that time, the first ideas on the special (vector/axial vector) structure of the weak interactions had been put forward by Feynman and Gell-Mann and by Marshak and Sudarshan, but the continual non-observation of that charged pion decay was holding up progress. This decay is only one part in ten thousand, and is masked by the dominant muon-neutrino channel. A special telescope was built to pick up the high energy electrons from the pion decay. In 1962 came another SC neutrino success, with the first measurement of the decay of a charged pion into a neutral one, with emission of an electron and a neutrino. Meanwhile the main thrust of CERN's neutrino effort was taking shape at the PS. By the close of 1960, CERN had decided to attack neutrino physics using several detectors - a 1m heavy liquid bubble chamber from Andre Lagarrigue's team in Paris, a CERN 1 m heavy liquid bubble chamber, and a hybrid chamber/counter from a group led by Helmut Faissner

  18. Superplasticiteit bij Cern

    Snippe, Q.H.C.; Snippe, Corijn

    2008-01-01

    Op CERN, het Europees onderzoekscentrum voor subatomaire fysica in Genève, wordt dit jaar een nieuwe deeltjesversneller, de Large Hadron Collider (LHC), in werking gesteld die nieuwe inzichten moet bieden over hoe de kleinste deeltjes der materie zich gedragen. Om hierachter te komen, is op plaatsen

  19. CERN IRRADIATION FACILITIES.

    Pozzi, Fabio; Garcia Alia, Ruben; Brugger, Markus; Carbonez, Pierre; Danzeca, Salvatore; Gkotse, Blerina; Richard Jaekel, Martin; Ravotti, Federico; Silari, Marco; Tali, Maris

    2017-09-28

    CERN provides unique irradiation facilities for applications in dosimetry, metrology, intercomparison of radiation protection devices, benchmark of Monte Carlo codes and radiation damage studies to electronics. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. CERN Housing Service: Hostel

    CERN Housing Service

    2004-01-01

    Arrangements for the end of the year closure Hostel on the CERN site During the closure of CERN for Christmas and the New Year, the hostel will be closed from midday on Friday 17 December 2004 until Monday 3 January 2005 at 8:00. All accounts must be settled and room keys returned to the Reception before 10:00 on Friday 17 December 2004. Hostel in St. Genis-Pouilly The wing reserved for CERN will be closed from midday on Friday 17 December 2004 until Monday 3 January 2005 at 8:00. Anyone with no alternative but to stay in the Hostel during this period can be accommodated in another part of the building. The people concerned must make the appropriate reservations in person at the Reception of the St.-Genis Hostel, as far in advance as possible and in any case no later than Friday 10 December 2004. The total length of stay during the two weeks in question must be paid for in advance, no later than Friday10 December 2004. All reservations remaining unpaid after this date will be cancelled. Reception: CERN ...

  1. CERN Accelerator School

    Anon.

    1986-01-15

    The CERN Accelerator School (CAS) offers a regular course on general accelerator physics. The first basic course was given in September 1984 at Orsay, France, and last September the advanced course was jointly organized by CAS, Oxford's Nuclear Physics Laboratory and the Rutherford Appleton Laboratory, and held at The Queen's College, Oxford.

  2. Muse at CERN

    CERN Bulletin

    2016-01-01

    On 19 July, the world-famous, English rock band, Muse, visited CERN before taking centre-stage at Nyon’s Paléo Festival. They toured some of CERN’s installations, including the Synchrocyclotron and the Microcosm exhibition, and also looked in on CMS and the Antimatter Factory.    

  3. The CERN Accelerator School

    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.

  4. CERN in detail

    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...

  5. Satellite photo of CERN

    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.

  6. CERN's Guardian Angels

    2002-01-01

    Any trouble at CERN? The Technical Control Room operates the entire technical infrastructure of CERN every day, all year long. They deal with problems that go from simple water leaks to devastating power cuts.   The Technical Control Room with Kenneth Olesen and Mark Harvey, minutes before their starting time. This big room is probably the liveliest at CERN, since there's always someone there, everyday, all year long. Laurent Randot and Eric Lienard working in the Technical Control Room at CERN in building 212. They've started at 7 a.m. and today has been a relatively quiet day. There have been some microcuts in the electric net because of the wind. But these have been repaired rather quickly... The relief: It's 2.30 p.m. Time for Laurent Randot and Eric Lienard to show their colleagues Mark Harvey and Kenneth Olesen what has been going on during the morning. They are the next TCR team of the day. Mark Harvey and Kenneth Olesen start their working day. They will work until 11p.m., when another team wil...

  7. CERN SHOP CHRISTMAS SALE

    Visits & Exhibition Service

    2000-01-01

    Looking for Christmas present ideas? Come to the Reception Shop Special Stand in Meyrin, Main Building, ground floor, from Tuesday 12 to Thursday 14 December from 10.00 to 16.00.   Sweat-shirt col zippé, grey, blue, black (M, L, XL) 30.- Sweat-shirt col polo, grey, collar blue (M, L, XL) 30.- T-shirt, black, (M, L, XL) 15.- WWW T-shirt, white, bordeau (M, L, XL) 15.- CERN silk tie (3 colours) 33.- Fancy silk tie (blue, bordeau 25.- Silk scarf (blue, red, yellow) 35.- Swiss army knife with CERN logo 25.- New model of CERN watch 25.- New CERN baseball cap 10.- Antimatter (English/anglais) 30.- The Search for Infinity (French, Italian, English,) 35.- Auf der Suche nach dem Unendlichen 45.- 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 (Shop will be closed at 12.00 on 22.12.).

  8. 50 years of CERN

    He Jingtang

    2006-01-01

    The successes of CERN during the past 50 years since the organization was established in 1954 are described, with emphasis on the areas of scientific achievement, science globalization, creating new technologies for society, and the scientific exchanges and cooperation with China. (authors)

  9. Commissaire Moulin visits CERN

    CERN Bulletin

    2014-01-01

    The French actor and film-maker Yves Rénier was shown around the Laboratory on Friday 6 June by friends at CERN.   Yves Rénier at LEIR. (Photo: Ludwig Pregernig) A keen diver and star of the long-running French television police drama Commissaire Moulin, Yves Rénier took advantage of a stopover in Geneva on his way to the Red Sea to meet up with his friends from the CERN Diving Club, who were only too pleased to take him on a tour of the Laboratory. In the morning, Yves Rénier visited the CERN Control Centre (CCC), Linac2 and LEIR. After lunch at the brasserie in Restaurant No. 2, the actor continued his tour with the CERN Computer Centre, the SM18 superconducting magnet test facility, and lastly the ATLAS experiment. “Thank you so much for showing me around and introducing me to a world I knew so little about,” confided Yves Rénier. “It’s fascinating to see so many scientists of different cultures,...

  10. CERN CAR CLUB

    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&...

  11. CERN Relay Race

    2004-01-01

    The CERN Relay Race will take place around the Meyrin site on Wednesday 19 May between 12.15 and 12.35. 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

  12. CERN Relay Race

    2003-01-01

    The CERN Relay Race will take place around the Meyrin site on Wednesday May 21st between 12h15 and 12h35. 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

  13. CERN Relay Race

    2001-01-01

    The CERN Relay Race will take place around the Meyrin site on Wednesday 23 May between 12:20 and 12:35. If possible, please avoid driving on the site during this 15 minute period. If you do meet runners in your car, please stop until they all have passed. Thank you for your understanding.

  14. CERN Relay Race

    2002-01-01

    The CERN Relay Race will take place around the Meyrin site on Wednesday 22 May between 12h20 and 12h35. If possible, please avoid driving on the site during this 15 minute period. If you do meet runners in your car, please STOP until they all have passed. Thank you for your understanding.

  15. Women at CERN

    2004-01-01

    To mark International Women's Day on 8 March, the Weekly Bulletin has looked at the careers of six female physicists, engineers and administrators working at CERN. A frequent question on the lips of newcomers to CERN as they take a quick look around them is 'But where are the women?' However, while it's true that the Laboratory has never had a huge number of female personnel, a closer look reveals that there are in fact quite a few around. To mark International Women's Day, the Bulletin has interviewed six women working at CERN to find out how they see the Organization, what they do and what they think about their daily working lives. Creating a link 'Maybe because I grew up during World War II, my parents always taught me to respect people of other nationalities, religions, colour, etc., so one thing I have always appreciated about CERN is that it promotes this tolerance and understanding by giving us the great privilege of working side by side with colleagues from many cultures and walks of life.' Pegg...

  16. CERN in the blogosphere

    CERN Bulletin

    2011-01-01

    CERN communicates with the outside world in many different ways – websites, publications, through the media and via twitter to name but a few. As of January, CERN has a new way of engaging with the world: a CERN institutional blog.   CERN’s blog was launched on 10 January on the Quantum Diaries platform, adding a new strand to a well-established site. Quantum Diaries was launched in 2005 as an initiative for the World Year of Physics promoted by the InterAction collaboration, a group that brings together the communication offices of some of the world’s major particle physics labs and organisations. The launch of institutional blogs from Brookhaven, CERN, Fermilab and TRIUMF has added an extra dimension to Quantum Diaries. Visits to the site jumped to 3000 per day with the addition of the institutional blogs, and that number is already growing. CERN’s first post explains one of the reasons we’re doing this. With the incredible thirst for informati...

  17. Induced radioactivity at CERN

    1970-01-01

    A description of some of the problems and some of the advantages associated with the phenomenon of induced radioactivity at accelerator centres such as CERN. The author has worked in this field for several years and has recently written a book 'Induced Radioactivity' published by North-Holland.

  18. A heatwave at CERN

    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...

  19. CERN and space science

    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...

  20. DESY greets CERN

    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 ...