Author: "Yang, Zhaoyu" / Publisher: fysikum - Searchworks@Jio Institute Digital Library Search Results

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174 results on '"Yang, Zhaoyu"'

1. Search for Dark Matter in Events with a Hadronically Decaying W or Z Boson and Missing Transverse Momentum in pp Collisions at root s=8 TeV with the ATLAS Detector

Author: Abulaiti, Yiming, Åsman, Barbro, Bendtz, Katarina, Bessidskaia, Olga, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Molander, Simon, Ohm, Christian C., Petridis, Andreas, Plucinski, Pawel, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Abulaiti, Yiming, Åsman, Barbro, Bendtz, Katarina, Bessidskaia, Olga, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Molander, Simon, Ohm, Christian C., Petridis, Andreas, Plucinski, Pawel, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: A search is presented for dark matter pair production in association with a W or Z boson in pp collisions representing 20.3 fb(-1) of integrated luminosity at root s = 8 TeV using data recorded with the ATLAS detector at the Large Hadron Collider. Events with a hadronic jet with the jet mass consistent with a W or Z boson, and with large missing transverse momentum are analyzed. The data are consistent with the standard model expectations. Limits are set on the mass scale in effective field theories that describe the interaction of dark matter and standard model particles, and on the cross section of Higgs production and decay to invisible particles. In addition, cross section limits on the anomalous production of W or Z bosons with large missing transverse momentum are set in two fiducial regions., AuthorCount:2937
Published: 2014
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2. THE FIRST FERMI-LAT GAMMA-RAY BURST CATALOG

Author: Ackermann, M., Ajello, M., Asano, K., Axelsson, Magnus, Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bhat, P. N., Bissaldi, E., Bloom, E. D., Bonamente, E., Bonnell, J., Bouvier, A., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Burgess, J. Michael, Buson, S., Byrne, D., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Charles, E., Chaves, R. C. G., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Connaughton, V., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Desiante, R., Digel, S. W., Dingus, B. L., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Dubois, R., Favuzzi, C., Ferrara, E. C., Fitzpatrick, G., Foley, S., Franckowiak, A., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Goldstein, A., Granot, J., Grenier, I. A., Grove, J. E., Gruber, D., Guiriec, S., Hadasch, D., Hanabata, Y., Hayashida, M., Horan, D., Hou, X., Hughes, R. E., Inoue, Y., Jackson, M. S., Jogler, T., Johannesson, G., Johnson, A. S., Johnson, W. N., Kamae, T., Kataoka, J., Kawano, T., Kippen, R. M., Knoedlseder, J., Kocevski, D., Kouveliotou, C., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lee, S. -H, Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Massaro, F., Mayer, M., Mazziotta, M. N., McBreen, S., McEnery, J. E., McGlynn, S., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Moretti, E., Morselli, A., Murgia, S., Nemmen, R., Nuss, E., Nymark, T., Ohno, M., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Paciesas, W. S., Paneque, D., Panetta, J. H., Pelassa, V., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Preece, R., Racusin, J. L., Raino, S., Rando, R., Rau, A., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Ritz, S., Romoli, C., Roth, M., Ryde, F., Parkinson, P. M. Saz, Schalk, T. L., Sgro, C., Siskind, E. J., Sonbas, E., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Takahashi, H., Takeuchi, Y., Tanaka, Y., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tierney, D., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Tronconi, V., Usher, T. L., Vandenbroucke, J., van der Horst, A. J., Vasileiou, V., Vianello, G., Vitale, V., von Kienlin, A., Winer, B. L., Wood, K. S., Wood, M., Xiong, S., Yang, Zhaoyu, Ackermann, M., Ajello, M., Asano, K., Axelsson, Magnus, Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bhat, P. N., Bissaldi, E., Bloom, E. D., Bonamente, E., Bonnell, J., Bouvier, A., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Burgess, J. Michael, Buson, S., Byrne, D., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Charles, E., Chaves, R. C. G., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Connaughton, V., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Desiante, R., Digel, S. W., Dingus, B. L., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Dubois, R., Favuzzi, C., Ferrara, E. C., Fitzpatrick, G., Foley, S., Franckowiak, A., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Goldstein, A., Granot, J., Grenier, I. A., Grove, J. E., Gruber, D., Guiriec, S., Hadasch, D., Hanabata, Y., Hayashida, M., Horan, D., Hou, X., Hughes, R. E., Inoue, Y., Jackson, M. S., Jogler, T., Johannesson, G., Johnson, A. S., Johnson, W. N., Kamae, T., Kataoka, J., Kawano, T., Kippen, R. M., Knoedlseder, J., Kocevski, D., Kouveliotou, C., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lee, S. -H, Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Massaro, F., Mayer, M., Mazziotta, M. N., McBreen, S., McEnery, J. E., McGlynn, S., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Moretti, E., Morselli, A., Murgia, S., Nemmen, R., Nuss, E., Nymark, T., Ohno, M., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Paciesas, W. S., Paneque, D., Panetta, J. H., Pelassa, V., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Preece, R., Racusin, J. L., Raino, S., Rando, R., Rau, A., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Ritz, S., Romoli, C., Roth, M., Ryde, F., Parkinson, P. M. Saz, Schalk, T. L., Sgro, C., Siskind, E. J., Sonbas, E., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Takahashi, H., Takeuchi, Y., Tanaka, Y., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tierney, D., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Tronconi, V., Usher, T. L., Vandenbroucke, J., van der Horst, A. J., Vasileiou, V., Vianello, G., Vitale, V., von Kienlin, A., Winer, B. L., Wood, K. S., Wood, M., Xiong, S., and Yang, Zhaoyu
Abstract: In three years of observations since the beginning of nominal science operations in 2008 August, the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope has observed high-energy (greater than or similar to 20 MeV) gamma-ray emission from 35 gamma-ray bursts (GRBs). Among these, 28 GRBs have been detected above 100 MeV and 7 GRBs above similar to 20 MeV. The first Fermi-LAT catalog of GRBs is a compilation of these detections and provides a systematic study of high-energy emission from GRBs for the first time. To generate the catalog, we examined 733 GRBs detected by the Gamma-Ray Burst Monitor (GBM) on Fermi and processed each of them using the same analysis sequence. Details of the methodology followed by the LAT collaboration for the GRB analysis are provided. We summarize the temporal and spectral properties of the LAT-detected GRBs. We also discuss characteristics of LAT-detected emission such as its delayed onset and longer duration compared with emission detected by the GBM, its power-law temporal decay at late times, and the fact that it is dominated by a power-law spectral component that appears in addition to the usual Band model., AuthorCount:180
Published: 2013
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3. THE SECOND FERMI LARGE AREA TELESCOPE CATALOG OF GAMMA-RAY PULSARS

Author: Abdo, A. A., Ajello, M., Allafort, A., Baldini, L., Ballet, J., Barbiellini, G., Baring, M. G., Bastieri, D., Belfiore, A., Bellazzini, R., Bhattacharyya, B., Bissaldi, E., Bloom, E. D., Bonamente, E., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Burgay, M., Burnett, T. H., Busetto, G., Buson, S., Caliandro, G. A., Cameron, R. A., Camilo, F., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Celik, Oe ., Charles, E., Chaty, S., Chaves, R. C. G., Chekhtman, A., Chen, A. W., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cognard, I., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, Cutini, S., D'Ammando, F., De Angelis, A., DeCesar, M. E., De Luca, A., Den Hartog, P. R., De Palma, F., Dermer, C. D., Desvignes, G., Digel, S. W., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Dubois, R., Dumora, D., Espinoza, C. M., Falletti, L., Favuzzi, C., Ferrara, E. C., Focke, W. B., Franckowiak, A., Freire, P. C. C., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gotthelf, E. V., Grenier, I. A., Grondin, M. -H, Grove, J. E., Guillemot, L., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hays, E., Hessels, J., Hewitt, J., Hill, A. B., Horan, D., Hou, X., Hughes, R. E., Jackson, M. S., Janssen, G. H., Jogler, T., Johannesson, G., Johnson, R. P., Johnson, A. S., Johnson, T. J., Johnson, W. N., Johnston, S., Kamae, T., Kataoka, J., Keith, M., Kerr, M., Knoedlseder, J., Kramer, M., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Lyne, A. G., Manchester, R. N., Marelli, M., Massaro, F., Mayer, M., Mazziotta, M. N., McEnery, J. E., McLaughlin, M. A., Mehault, J., Michelson, P. F., Mignani, R. P., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Nemmen, R., Nuss, E., Ohno, M., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Parent, D., Perkins, J. S., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Pletsch, H. J., Porter, T. A., Possenti, A., Raino, S., Rando, R., Ransom, S. M., Ray, P. S., Razzano, M., Rea, N., Reimer, A., Reimer, O., Renault, N., Reposeur, T., Ritz, S., Romani, R. W., Roth, M., Rousseau, R., Roy, J., Ruan, J., Sartori, A., Parkinson, P. M. Saz, Scargle, J. D., Schulz, A., Sgro, C., Shannon, R., Siskind, E. J., Smith, D. A., Spandre, G., Spinelli, P., Stappers, B. W., Strong, A. W., Suson, D. J., Takahashi, H., Thayer, J. G., Thayer, J. B., Theureau, G., Thompson, D. J., Thorsett, S. E., Tibaldo, L., Tibolla, O., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Venter, C., Vianello, G., Vitale, V., Wang, N., Weltevrede, P., Winer, B. L., Wolff, M. T., Wood, D. L., Wood, K. S., Wood, M., Yang, Zhaoyu, Abdo, A. A., Ajello, M., Allafort, A., Baldini, L., Ballet, J., Barbiellini, G., Baring, M. G., Bastieri, D., Belfiore, A., Bellazzini, R., Bhattacharyya, B., Bissaldi, E., Bloom, E. D., Bonamente, E., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Burgay, M., Burnett, T. H., Busetto, G., Buson, S., Caliandro, G. A., Cameron, R. A., Camilo, F., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Celik, Oe ., Charles, E., Chaty, S., Chaves, R. C. G., Chekhtman, A., Chen, A. W., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cognard, I., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, Cutini, S., D'Ammando, F., De Angelis, A., DeCesar, M. E., De Luca, A., Den Hartog, P. R., De Palma, F., Dermer, C. D., Desvignes, G., Digel, S. W., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Dubois, R., Dumora, D., Espinoza, C. M., Falletti, L., Favuzzi, C., Ferrara, E. C., Focke, W. B., Franckowiak, A., Freire, P. C. C., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gotthelf, E. V., Grenier, I. A., Grondin, M. -H, Grove, J. E., Guillemot, L., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hays, E., Hessels, J., Hewitt, J., Hill, A. B., Horan, D., Hou, X., Hughes, R. E., Jackson, M. S., Janssen, G. H., Jogler, T., Johannesson, G., Johnson, R. P., Johnson, A. S., Johnson, T. J., Johnson, W. N., Johnston, S., Kamae, T., Kataoka, J., Keith, M., Kerr, M., Knoedlseder, J., Kramer, M., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Lyne, A. G., Manchester, R. N., Marelli, M., Massaro, F., Mayer, M., Mazziotta, M. N., McEnery, J. E., McLaughlin, M. A., Mehault, J., Michelson, P. F., Mignani, R. P., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Nemmen, R., Nuss, E., Ohno, M., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Parent, D., Perkins, J. S., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Pletsch, H. J., Porter, T. A., Possenti, A., Raino, S., Rando, R., Ransom, S. M., Ray, P. S., Razzano, M., Rea, N., Reimer, A., Reimer, O., Renault, N., Reposeur, T., Ritz, S., Romani, R. W., Roth, M., Rousseau, R., Roy, J., Ruan, J., Sartori, A., Parkinson, P. M. Saz, Scargle, J. D., Schulz, A., Sgro, C., Shannon, R., Siskind, E. J., Smith, D. A., Spandre, G., Spinelli, P., Stappers, B. W., Strong, A. W., Suson, D. J., Takahashi, H., Thayer, J. G., Thayer, J. B., Theureau, G., Thompson, D. J., Thorsett, S. E., Tibaldo, L., Tibolla, O., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Venter, C., Vianello, G., Vitale, V., Wang, N., Weltevrede, P., Winer, B. L., Wolff, M. T., Wood, D. L., Wood, K. S., Wood, M., and Yang, Zhaoyu
Abstract: This catalog summarizes 117 high-confidence >= 0.1 GeV gamma-ray pulsar detections using three years of data acquired by the Large Area Telescope (LAT) on the Fermi satellite. Half are neutron stars discovered using LAT data through periodicity searches in gamma-ray and radio data around LAT unassociated source positions. The 117 pulsars are evenly divided into three groups: millisecond pulsars, young radio-loud pulsars, and young radio-quiet pulsars. We characterize the pulse profiles and energy spectra and derive luminosities when distance information exists. Spectral analysis of the off-peak phase intervals indicates probable pulsar wind nebula emission for four pulsars, and off-peak magnetospheric emission for several young and millisecond pulsars. We compare the gamma-ray properties with those in the radio, optical, and X-ray bands. We provide flux limits for pulsars with no observed gamma-ray emission, highlighting a small number of gamma-faint, radio-loud pulsars. The large, varied gamma-ray pulsar sample constrains emission models. Fermi's selection biases complement those of radio surveys, enhancing comparisons with predicted population distributions., AuthorCount:211
Published: 2013
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4. CONSTRAINTS ON THE GALACTIC POPULATION OF TeV PULSAR WIND NEBULAE USING FERMI LARGE AREA TELESCOPE OBSERVATIONS

Author: Acero, F., Ackermann, M., Ajello, M., Allafort, A., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Blandford, R. D., Bloom, E. D., Bonamente, E., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Charles, E., Chaves, R. C. G., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., Dalton, M., D'Ammando, F., de Palma, F., Dermer, C. D., Di Venere, L., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Falletti, L., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gregoire, T., Grenier, I. A., Grondin, M. -H, Grove, J. E., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hayashi, K., Hays, E., Hewitt, J., Hill, A. B., Horan, D., Hou, X., Hughes, R. E., Inoue, Y., SUBJackson, M. S., Jogler, T., Johannesson, G., Johnson, A. S., Kamae, T., Kawano, T., Kerr, M., Knoedlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Marelli, M., Massaro, F., Mayer, M., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Nemmen, R., Nuss, E., Ohsugi, T., Okumura, A., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Reposeur, T., Ritz, S., Roth, M., Rousseau, R., Parkinson, P. M. Saz, Schulz, A., Sgro, C., Siskind, E. J., Smith, D. A., Spandre, G., Spinelli, P., Suson, D. J., Takahashi, H., Takeuchi, Y., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tibolla, O., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Werner, M., Winer, B. L., Wood, K. S., Yang, Zhaoyu, Acero, F., Ackermann, M., Ajello, M., Allafort, A., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Blandford, R. D., Bloom, E. D., Bonamente, E., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Charles, E., Chaves, R. C. G., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., Dalton, M., D'Ammando, F., de Palma, F., Dermer, C. D., Di Venere, L., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Falletti, L., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gregoire, T., Grenier, I. A., Grondin, M. -H, Grove, J. E., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hayashi, K., Hays, E., Hewitt, J., Hill, A. B., Horan, D., Hou, X., Hughes, R. E., Inoue, Y., SUBJackson, M. S., Jogler, T., Johannesson, G., Johnson, A. S., Kamae, T., Kawano, T., Kerr, M., Knoedlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Marelli, M., Massaro, F., Mayer, M., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Nemmen, R., Nuss, E., Ohsugi, T., Okumura, A., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Reposeur, T., Ritz, S., Roth, M., Rousseau, R., Parkinson, P. M. Saz, Schulz, A., Sgro, C., Siskind, E. J., Smith, D. A., Spandre, G., Spinelli, P., Suson, D. J., Takahashi, H., Takeuchi, Y., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tibolla, O., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Werner, M., Winer, B. L., Wood, K. S., and Yang, Zhaoyu
Abstract: Pulsar wind nebulae (PWNe) have been established as the most populous class of TeV gamma-ray emitters. Since launch, the Fermi Large Area Telescope (LAT) has identified five high-energy (100 MeV < E < 100 GeV) gamma-ray sources as PWNe and detected a large number of PWN candidates, all powered by young and energetic pulsars. The wealth of multi-wavelength data available and the new results provided by Fermi-LAT give us an opportunity to find new PWNe and to explore the radiative processes taking place in known ones. The TeV gamma-ray unidentified (UNID) sources are the best candidates for finding new PWNe. Using 45 months of Fermi-LAT data for energies above 10 GeV, an analysis was performed near the position of 58 TeV PWNe and UNIDs within 5. of the Galactic plane to establish new constraints on PWN properties and find new clues on the nature of UNIDs. Of the 58 sources, 30 were detected, and this work provides their gamma-ray fluxes for energies above 10 GeV. The spectral energy distributions and upper limits, in the multi-wavelength context, also provide new information on the source nature and can help distinguish between emission scenarios, i.e., between classification as a pulsar candidate or as a PWN candidate. Six new GeV PWN candidates are described in detail and compared with existing models. A population study of GeV PWN candidates as a function of the pulsar/PWN system characteristics is presented., AuthorCount:158
Published: 2013
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5. DETERMINATION OF THE POINT-SPREAD FUNCTION FOR THE FERMI LARGE AREA TELESCOPE FROM ON-ORBIT DATA AND LIMITS ON PAIR HALOS OF ACTIVE GALACTIC NUCLEI

Author: Ackermann, M., Ajello, M., Allafort, A., Asano, K., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bloom, E. D., Bonamente, E., Borgland, A. W., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Burnett, T. H., Busetto, G., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Charles, E., Chaty, S., Chekhtman, A., Cheung, C. C., Chiang, J., Cillis, A. N., Ciprini, S., Claus, R., Cohen-Tanugi, J., Colafrancesco, S., Conrad, Jan, Cutini, S., D'Ammando, F., de Palma, F., Dermer, C. D., do Couto e Silva, E., Drell, S., Drlica-Wagner, A., Dubois, R., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Fortin, P., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grandi, P., Grenier, I. A., Grove, J. E., Guiriec, S., Hadasch, D., Hayashida, M., Hays, E., Horan, D., Hou, X., Hughes, R. E., Jackson, M. S., Jogler, T., Johannesson, G., Johnson, R. P., Johnson, A. S., Kamae, T., Kataoka, J., Kerr, M., Knoedlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lavalley, C., Lee, S. -H, Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Mazziotta, M. N., McConville, W., McEnery, J. E., Mehault, J., Michelson, P. F., Mignani, R. P., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Naumann-Godo, M., Nemmen, R., Nishino, S., Norris, J. P., Nuss, E., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Pelassa, V., Perkins, J. S., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Poon, H., Porter, T. A., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reyes, L. C., Ritz, S., Rochester, L. S., Romoli, C., Roth, M., Sanchez, D. A., Parkinson, P. M. Saz, Scargle, J. D., Sgro, C., Siskind, E. J., Snyder, A., Spandre, G., Spinelli, P., Stephens, T. E., Suson, D. J., Tajima, H., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tibolla, O., Tinivella, M., Tosti, G., Troja, E., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., von Kienlin, A., Waite, A. P., Wallace, E., Weltevrede, P., Winer, B. L., Wood, K. S., Wood, M., Yang, Zhaoyu, Zimmer, Stephan, Ackermann, M., Ajello, M., Allafort, A., Asano, K., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bloom, E. D., Bonamente, E., Borgland, A. W., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Burnett, T. H., Busetto, G., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Charles, E., Chaty, S., Chekhtman, A., Cheung, C. C., Chiang, J., Cillis, A. N., Ciprini, S., Claus, R., Cohen-Tanugi, J., Colafrancesco, S., Conrad, Jan, Cutini, S., D'Ammando, F., de Palma, F., Dermer, C. D., do Couto e Silva, E., Drell, S., Drlica-Wagner, A., Dubois, R., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Fortin, P., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grandi, P., Grenier, I. A., Grove, J. E., Guiriec, S., Hadasch, D., Hayashida, M., Hays, E., Horan, D., Hou, X., Hughes, R. E., Jackson, M. S., Jogler, T., Johannesson, G., Johnson, R. P., Johnson, A. S., Kamae, T., Kataoka, J., Kerr, M., Knoedlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lavalley, C., Lee, S. -H, Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Mazziotta, M. N., McConville, W., McEnery, J. E., Mehault, J., Michelson, P. F., Mignani, R. P., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Naumann-Godo, M., Nemmen, R., Nishino, S., Norris, J. P., Nuss, E., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Pelassa, V., Perkins, J. S., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Poon, H., Porter, T. A., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reyes, L. C., Ritz, S., Rochester, L. S., Romoli, C., Roth, M., Sanchez, D. A., Parkinson, P. M. Saz, Scargle, J. D., Sgro, C., Siskind, E. J., Snyder, A., Spandre, G., Spinelli, P., Stephens, T. E., Suson, D. J., Tajima, H., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tibolla, O., Tinivella, M., Tosti, G., Troja, E., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., von Kienlin, A., Waite, A. P., Wallace, E., Weltevrede, P., Winer, B. L., Wood, K. S., Wood, M., Yang, Zhaoyu, and Zimmer, Stephan
Abstract: The Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope is a pair-conversion telescope designed to detect photons with energies from approximate to 20 MeV to > 300 GeV. The pre-launch response functions of the LAT were determined through extensive Monte Carlo simulations and beam tests. The point-spread function (PSF) characterizing the angular distribution of reconstructed photons as a function of energy and geometry in the detector is determined here from two years of on-orbit data by examining the distributions of gamma rays from pulsars and active galactic nuclei (AGNs). Above 3 GeV, the PSF is found to be broader than the pre-launch PSF. We checked for dependence of the PSF on the class of gamma-ray source and observation epoch and found none. We also investigated several possible spatial models for pair-halo emission around BL Lac AGNs. We found no evidence for a component with spatial extension larger than the PSF and set upper limits on the amplitude of halo emission in stacked images of low-and high-redshift BL Lac AGNs and the TeV blazars 1ES0229 + 200 and 1ES0347-121., AuthorCount:174
Published: 2013
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6. Search for long-lived stopped R-hadrons decaying out of time with pp collisions using the ATLAS detector

Author: Abulaiti, Yabul, Åsman, Barbro, Bendtz, Katarina, Bessidskaia, Olga, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olle, Milstead, David A., Moa, Torbjörn, Molander, Simon, Ohm, Christian, Papadelis, Aras, Petridis, Andreas, Plucinski, Pawel, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Abulaiti, Yabul, Åsman, Barbro, Bendtz, Katarina, Bessidskaia, Olga, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olle, Milstead, David A., Moa, Torbjörn, Molander, Simon, Ohm, Christian, Papadelis, Aras, Petridis, Andreas, Plucinski, Pawel, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: An updated search is performed for gluino, top squark, or bottom squark R-hadrons that have come to rest within the ATLAS calorimeter, and decay at some later time to hadronic jets and a neutralino, using 5.0 and 22.9 fb(-1) of pp collisions at 7 and 8 TeV, respectively. Candidate decay events are triggered in selected empty bunch crossings of the LHC in order to remove pp collision backgrounds. Selections based on jet shape and muon system activity are applied to discriminate signal events from cosmic ray and beam-halo muon backgrounds. In the absence of an excess of events, improved limits are set on gluino, stop, and sbottom masses for different decays, lifetimes, and neutralino masses. With a neutralino of mass 100 GeV, the analysis excludes gluinos with mass below 832 GeV (with an expected lower limit of 731 GeV), for a gluino lifetime between 10 mu s and 1000 s in the generic R-hadron model with equal branching ratios for decays to q (q) over bar(chi) over tilde (0) and g (chi) over tilde (0). Under the same assumptions for the neutralino mass and squark lifetime, top squarks and bottom squarks in the Regge R-hadron model are excluded with masses below 379 and 344 GeV, respectively., AuthorCount:2885, ATLAS Collaboration
Published: 2013
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7. Search for excited electrons and muons in root s=8 TeV proton-proton collisions with the ATLAS detector

Author: Abulaiti, Yiming, Åsman, Barbro, Bendtz, Katarina, Bessidskaia, Olga, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olle, Milstead, David, Moa, Torbjörn, Molander, Simon, Ohm, Christian C., Papadelis, Aras, Petridis, Andreas, Plucinski, Pawel, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Abulaiti, Yiming, Åsman, Barbro, Bendtz, Katarina, Bessidskaia, Olga, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olle, Milstead, David, Moa, Torbjörn, Molander, Simon, Ohm, Christian C., Papadelis, Aras, Petridis, Andreas, Plucinski, Pawel, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: The ATLAS detector at the Large Hadron Collider is used to search for excited electrons and excited muons in the channel pp -> ll* -> ll gamma, assuming that excited leptons are produced via contact interactions. The analysis is based on 13 fb(-1) of pp collisions at a centre-of-mass energy of 8 TeV. No evidence for excited leptons is found, and a limit is set at the 95% credibility level on the cross section times branching ratio as a function of the excited-lepton mass m(l*). For m(l*) >= 0.8 TeV, the respective upper limits on sigma B(l(*) -> l gamma) are 0.75 and 0.90 fb for the e* and mu* searches. Limits on sigma B are converted into lower bounds on the compositeness scale 3. In the special case where Lambda = m(l*), excited-electron and excited-muon masses below 2.2 TeV are excluded., AuthorCount: 2916, Atlas Collaboration
Published: 2013
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8. Measurement of Top Quark Polarization in Top-Antitop Events from Proton- Proton Collisions at root s=7 TeV Using the ATLAS Detector

Author: Abulaiti, Yiming, Åsman, Barbro, Bendtz, Katarina, Bessidskaia, Olga, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Molander, Simon, Ohm, Christian C., Papadelis, Aras, Petridis, Andreas, Plucinski, Pawel, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Abulaiti, Yiming, Åsman, Barbro, Bendtz, Katarina, Bessidskaia, Olga, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Molander, Simon, Ohm, Christian C., Papadelis, Aras, Petridis, Andreas, Plucinski, Pawel, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: This Letter presents measurements of the polarization of the top quark in top-antitop quark pair events, using 4: 7 fb(-1) of proton-proton collision data recorded with the ATLAS detector at the Large Hadron Collider at root s = 7 TeV. Final states containing one or two isolated leptons ( electrons or muons) and jets are considered. Two measurements of alpha P-l, the product of the leptonic spin-analyzing power and the top quark polarization, are performed assuming that the polarization is introduced by either a CP conserving or a maximally CP violating production process. The measurements obtained, alpha P-l(CPC) = -0: 035 +/- 0: 014(stat) +/- 0: 037(syst) and alpha P-l(CPV) = 0: 020 +/- 0: 016(stat)(-0.017)(+0.013)(syst), are in good agreement with the standard model prediction of negligible top quark polarization., AuthorCount:2926
Published: 2013
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9. Search for microscopic black holes in a like-sign dimuon final state using large track multiplicity with the ATLAS detector

Author: Abulaiti, Yiming, Åsman, Barbro, Bendtz, Katarina, Bessidskaia, Olga, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon Jin, Klimek, Pawel, Lundberg, Johan, Lundberg, Olle, Milstead, David A., Moa, Torbjörn, Molander, Simon, Ohm, Christian, Papadelis, Aras, Petridis, Andreas, Plucinski, Pawel, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Abulaiti, Yiming, Åsman, Barbro, Bendtz, Katarina, Bessidskaia, Olga, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon Jin, Klimek, Pawel, Lundberg, Johan, Lundberg, Olle, Milstead, David A., Moa, Torbjörn, Molander, Simon, Ohm, Christian, Papadelis, Aras, Petridis, Andreas, Plucinski, Pawel, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: A search is presented for microscopic black holes in a like-sign dimuon final state in proton-proton collisions at root s = 8 TeV. The data were collected with the ATLAS detector at the Large Hadron Collider in 2012 and correspond to an integrated luminosity of 20.3 fb(-1). Using a high track multiplicity requirement, 0.6 +/- 0.2 background events from Standard Model processes are predicted and none observed. This result is interpreted in the context of low-scale gravity models and 95% C.L. lower limits on microscopic black hole masses are set for different model assumptions., AuthorCount:2941
Published: 2013
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10. Measurement of the inclusive jet cross-section in pp collisions at root s=2.76 TeV and comparison to the inclusive jet cross-section at root s=7 TeV using the ATLAS detector

Author: Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: The inclusive jet cross-section has been measured in proton-proton collisions at root s = 2.76 TeV in a dataset corresponding to an integrated luminosity of 0.20 pb(-1) collected with the ATLAS detector at the Large Hadron Collider in 2011. Jets are identified using the anti-k(t) algorithm with two radius parameters of 0.4 and 0.6. The inclusive jet double-differential cross-section is presented as a function of the jet transverse momentum p(T) and jet rapidity y, covering a range of 20 <= p(T) < 430 GeV and vertical bar y vertical bar < 4.4. The ratio of the cross-section to the inclusive jet cross-section measurement at root s = 7 TeV, published by the ATLAS Collaboration, is calculated as a function of both transverse momentum and the dimensionless quantity x(T) = 2p(T)/root s, in bins of jet rapidity. The systematic uncertainties on the ratios are significantly reduced due to the cancellation of correlated uncertainties in the two measurements. Results are compared to the prediction from next-to-leading order perturbative QCD calculations corrected for non-perturbative effects, and next-to-leading order Monte Carlo simulation. Furthermore, the ATLAS jet cross-section measurements at root s = 2.76 TeV and root s = 7 TeV are analysed within a framework of next-to-leading order perturbative QCD calculations to determine parton distribution functions of the proton, taking into account the correlations between the measurements., AuthorCount:2893
Published: 2013
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11. Measurement of the production cross section of jets in association with a Z boson in pp collisions at root s=7 TeV with the ATLAS detector

Author: Abulaiti, Yiming, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Petridis, Andreas, Plucinski, Pawel, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Abulaiti, Yiming, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Petridis, Andreas, Plucinski, Pawel, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: Measurements of the production of jets of particles in association with a Z boson in pp collisions at root s = 7 TeV are presented, using data corresponding to an integrated luminosity of 4.6 fb(-1) collected by the ATLAS experiment at the Large Hadron Collider. Inclusive and differential jet cross sections in Z events, with Z decaying into electron or muon pairs, are measured for jets with transverse momentum p(T) > 30 GeV and rapidity vertical bar y vertical bar < 4.4. The results are compared to next-to-leading-order perturbative QCD calculations, and to predictions from different Monte Carlo generators based on leading-order and next-to-leading-order matrix elements supplemented by parton showers., AuthorCount:2920
Published: 2013
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12. Performance of jet substructure techniques for large-R jets in proton-proton collisions at root s=7 TeV using the ATLAS detector

Author: Abulaiti, Yiming, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon Jin, Klimek, Pawel, Lundberg, Johan, Lundberg, Olle, Milstead, David A., Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Petridis, Andreas, Plucinski, Pawel, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Abulaiti, Yiming, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon Jin, Klimek, Pawel, Lundberg, Johan, Lundberg, Olle, Milstead, David A., Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Petridis, Andreas, Plucinski, Pawel, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: This paper presents the application of a variety of techniques to study jet substructure. The performance of various modified jet algorithms, or jet grooming techniques, for several jet types and event topologies is investigated for jets with transverse momentum larger than 300 GeV. Properties of jets subjected to the mass-drop filtering, trimming, and pruning algorithms are found to have a reduced sensitivity to multiple proton-proton interactions, are more stable at high luminosity and improve the physics potential of searches for heavy boosted objects. Studies of the expected discrimination power of jet mass and jet substructure observables in searches for new physics are also presented. Event samples enriched in boosted W and Z bosons and top-quark pairs are used to study both the individual jet invariant mass scales and the efficacy of algorithms to tag boosted hadronic objects. The analyses presented use the full 2011 ATLAS dataset, corresponding to an integrated luminosity of 4.7 +/- 0.1 fb(-1) from proton-proton collisions produced by the Large Hadron Collider at a centre-of-mass energy of root s = 7 TeV., AuthorCount:2910
Published: 2013
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13. Search for WH production with a light Higgs boson decaying to prompt electron-jets in proton-proton collisions at root s=7 TeV with the ATLAS detector

Author: Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Plucinski, Pawel, Sellden, Björn, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Plucinski, Pawel, Sellden, Björn, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: A search is performed for WH production with a light Higgs boson decaying to hidden-sector particles resulting in clusters of collimated electrons, known as electron-jets. The search is performed with 2.04 fb(-1) of data collected in 2011 with the ATLAS detector at the Large Hadron Collider in proton-proton collisions at root s = 7 TeV. One event satisfying the signal selection criteria is observed, which is consistent with the expected background rate. Limits on the product of the WH production cross section and the branching ratio of a Higgs boson decaying to prompt electron-jets are calculated as a function of a Higgs boson mass in the range from 100 to 140 GeV., AuthorCount:2916
Published: 2013
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14. Searches for heavy long-lived sleptons and R-hadrons with the ATLAS detector in pp collisions at root s=7 TeV

Author: Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne M., Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Ohm, C. C., Papadelis, Aras, Sellden, Björn, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne M., Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Ohm, C. C., Papadelis, Aras, Sellden, Björn, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: A search for long-lived particles is performed using a data sample of 4.7 fb(-1) from proton-proton collisions at a centre-of-mass energy. root s = 7 TeV collected by the ATLAS detector at the LHC. No excess is observed above the estimated background and lower limits, at 95% confidence level, are set on the mass of the long-lived particles in different scenarios, based on their possible interactions in the inner detector, the calorimeters and the muon spectrometer. Long-lived staus in gauge-mediated SUSY-breaking models are excluded up to a mass of 300 GeV for tan beta = 5-20. Directly produced long-lived sleptons are excluded up to a mass of 278 GeV. R-hadrons, composites of gluino (stop, sbottom) and light quarks, are excluded up to a mass of 985 GeV (683 GeV, 612 GeV) when using a generic interaction model. Additionally two sets of limits on R-hadrons are obtained that are less sensitive to the interaction model for R-hadrons. One set of limits is obtained using only the inner detector and calorimeter observables, and a second set of limits is obtained based on the inner detector alone., AuthorCount:2904
Published: 2013
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15. Search for extra dimensions in diphoton events from proton-proton collisions at root s=7 TeV in the ATLAS detector at the LHC

Author: Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Sellden, Björn, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Yang, Zhaoyu, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Sellden, Björn, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, and Yang, Zhaoyu
Abstract: The large difference between the Planck scale and the electroweak scale, known as the hierarchy problem, is addressed in certain models through the postulate of extra spatial dimensions. A search for evidence of extra spatial dimensions in the diphoton channel has been performed using the full set of proton-proton collisions at root s = 7 TeV recorded in 2011 with the ATLAS detector at the CERN Large Hadron Collider. This dataset corresponds to an integrated luminosity of 4.9 fb(-1). The diphoton invariant mass spectrum is observed to be in good agreement with the Standard Model expectation. In the context of the model proposed by Arkani-Hamed, Dimopoulos and Dvali, 95% confidence level lower limits of between 2.52 and 3.92 TeV are set on the ultraviolet cutoff scale MS depending on the number of extra dimensions and the theoretical formalism used. In the context of the Randall-Sundrum model, a lower limit of 2.06 (1.00) TeV at 95% confidence level is set on the mass of the lightest graviton for couplings of k/(M) over bar (Pl) = 0.1(0.01). Combining with the ATLAS dilepton searches based on the 2011 data, the 95% confidence level lower limit on the Randall-Sundrum graviton mass is further tightened to 2.23 (1.03) TeV for k/(M) over bar (Pl) = 0.1(0.01)., AuthorCount:2905
Published: 2013
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16. Search for displaced muonic lepton jets from light Higgs boson decay in proton-proton collisions at root s=7 TeV with the ATLAS detector

Author: Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Sellden, Björn, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Sellden, Björn, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: A search is performed for collimated muon pairs displaced from the primary vertex produced in the decay of long-lived neutral particles in proton-proton collisions at root s = 7 TeV centre-of-mass energy, with the ATLAS detector at the LHC. In a 1.9 fb(-1) event sample collected during 2011, the observed data are consistent with the Standard Model background expectations. Limits on the product of the production cross section and the branching ratio of a Higgs boson decaying to hidden-sector neutral long-lived particles are derived as a function of the particles' mean lifetime., AuthorCount:2903
Published: 2013
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17. Search for single b*-quark production with the ATLAS detector at root s=7 TeV

Author: Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Sellden, Björn, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Sellden, Björn, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: The results of a search for an excited bottom-quark b* in pp collisions at root s = 7 TeV, using 4.7 fb(-1) of data collected by the ATLAS detector at the LHC are presented. In the model studied, a single b*-quark is produced through a chromomagnetic interaction and subsequently decays to a W boson and a top quark. The search is performed in the dilepton and lepton + jets final states, which are combined to set limits on b*-quark couplings for a range of b*-quark masses. For a benchmark with unit size chromomagnetic and Standard Model-like electroweak b* couplings, b* quarks with masses less than 870 GeV are excluded at the 95% credibility level., AuthorCount:2905
Published: 2013
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18. Search for pair production of heavy top-like quarks decaying to a high-p(T) W boson and a b quark in the lepton plus jets final state at root s=7 TeV with the ATLAS detector

Author: Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Sellden, Björn, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Sellden, Björn, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: A search is presented for production of a heavy up-type quark (t') together with its antiparticle, assuming a significant branching ratio for subsequent decay into a W boson and a b quark. The search is based on 4.7 fb(-1) of pp collisions root s = 7 TeV recorded in 2011 with the ATLAS detector at the CERN Large Hadron Collider. Data are analyzed in the lepton + jets final state, characterized by a high-transverse-momentum isolated electron or muon, large missing transverse momentum and at least three jets. The analysis strategy relies on the substantial boost of the W bosons in the t'(t') over bar signal when m(t') greater than or similar to 400 GeV. No significant excess of events above the Standard Model expectation is observed and the result of the search is interpreted in the context of fourth-generation and vector-like quark models. Under the assumption of a branching ratio BR(t' -> W b) = I, a fourth-generation t' quark with mass lower than 656 GeV is excluded at 95% confidence level. In addition, in light of the recent discovery of a new boson of mass similar to 126 GeV at the LHC, upper limits are derived in the two-dimensional plane of BR(t' -> Wb) versus BR(t' -> Ht), where H is the Standard Model Higgs boson, for vector-like quarks of various masses., AuthorCount:2905
Published: 2013
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19. Search for supersymmetry in events with photons, bottom quarks, and missing transverse momentum in proton-proton collisions at a centre-of-mass energy of 7 TeV with the ATLAS detector

Author: Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Sellden, Björn, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Sellden, Björn, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: A search has been performed for the experimental signature of an isolated photon with high transverse momentum, at least one jet identified as originating from a bottom quark, and high missing transverse momentum. Such a final state may originate from supersymmetric models with gauge-mediated supersymmetry breaking in events in which one of a pair of higgsino-like neutralinos decays into a photon and a gravitino while the other decays into a Higgs boson and a gravitino. The search is performed using the full dataset of 7 TeV proton-proton collisions recorded with the ATLAS detector at the LHC in 2011, corresponding to an integrated luminosity of 4.7 fb(-1). A total of 7 candidate events are observed while 7.5 +/- 2.2 events are expected from the Standard Model background. The results of the search are interpreted in the context of general gauge mediation to exclude certain regions of a benchmark plane for higgsino-like neutralino production., AuthorCount:2897
Published: 2013
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20. Measurement of W+W- production in pp collisions at root s=7 TeV with the ATLAS detector and limits on anomalous WWZ and WW gamma couplings

Author: Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon Jin, Klimek, Pawel, Lundberg, Olle, Milstead, David, Moa, Torbjörn, Ohm, Christian, Papadelis, Aras, Sellden, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon Jin, Klimek, Pawel, Lundberg, Olle, Milstead, David, Moa, Torbjörn, Ohm, Christian, Papadelis, Aras, Sellden, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: This paper presents a measurement of the W+W- production cross section in pp collisions at root s = 7 TeV. The leptonic decay channels are analyzed using data corresponding to an integrated luminosity of 4: 6 fb(-1) collected with the ATLAS detector at the Large Hadron Collider. The W+W- production cross section sigma(pp -> W+W- + X) is measured to be 51.9 +/- 2.0(stat) +/- 3.9(syst) +/- 2.0(lumi) pb, compatible with the Standard Model prediction of 44.7(-1.9)(+2.1) pb. A measurement of the normalized fiducial cross section as a function of the leading lepton transverse momentum is also presented. The reconstructed transverse momentum distribution of the leading lepton is used to extract limits on anomalous WWZ and WW gamma couplings., AuthorCount:2912
Published: 2013
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21. Search for long-lived, multi-charged particles in pp collisions at root s=7 TeV using the ATLAS detector

Author: Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon Jin, Klimek, Pawel, Lundberg, Johan, Lundberg, Olle, Milstead, David, Moa, Torbjörn, Ohm, Christian, Papadelis, Aras, Sellden, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon Jin, Klimek, Pawel, Lundberg, Johan, Lundberg, Olle, Milstead, David, Moa, Torbjörn, Ohm, Christian, Papadelis, Aras, Sellden, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: A search for highly ionising, penetrating particles with electric charges from vertical bar q vertical bar = 2e to 6e is performed using the ATLAS detector at the CERN Large Hadron Collider. Proton-proton collision data taken at root s = 7 TeV during the 2011 running period, corresponding to an integrated luminosity of 4.4 fb(-1), are analysed. No signal candidates are observed, and 95% confidence level cross-section upper limits are interpreted as mass-exclusion lower limits for a simplified Drell-Yan production model. In this model, masses are excluded from 50 GeV up to 430, 480, 490, 470 and 420 GeV for charges 2e, 3e, 4e, 5e and 6e, respectively., AuthorCount:2898
Published: 2013
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22. Search for a heavy narrow resonance decaying to e mu, e tau, or mu tau with the ATLAS detector in root s=7 TeV pp collisions at the LHC

Author: Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David, Moa, Torbjörn, Ohm, Christian, Papadelis, Aras, Sellden, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David, Moa, Torbjörn, Ohm, Christian, Papadelis, Aras, Sellden, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: This Letter presents the results of a search for a heavy particle decaying into an e(+/-)mu(+/-), e(+/-)tau(+/-), or mu(+/-)tau(+/-) final state in pp collisions at root s = 7 TeV. The data were recorded with the ATLAS detector at the LHC during 2011 and correspond to an integrated luminosity of 4.6 fb(-1). No significant excess above the Standard Model expectation is observed, and exclusions at 95% confidence level are placed on the cross section times branching ratio for the production of an R-parity-violating supersymmetric tau sneutrino. For a sneutrino mass of 500 (2000) GeV, the observed limits on the production cross section times branching ratio are 3.2 (1.4) fb, 42 (17) fb, and 40 (18) fb for the e mu, e tau, and mu tau modes, respectively. These results considerably extend constraints from Tevatron experiments., AuthorCount:2896
Published: 2013
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23. Characterisation and mitigation of beam-induced backgrounds observed in the ATLAS detector during the 2011 proton-proton run

Author: Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon Jin, Klimek, Pawel, Lundberg, Johan, Lundberg, Olle, Milstead, David, Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Sellden, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon Jin, Klimek, Pawel, Lundberg, Johan, Lundberg, Olle, Milstead, David, Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Sellden, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: This paper presents a summary of beam-induced backgrounds observed in the ATLAS detector and discusses methods to tag and remove background contaminated events in data. Trigger-rate based monitoring of beam-related backgrounds is presented. The correlations of backgrounds with machine conditions, such as residual pressure in the beam-pipe, are discussed. Results from dedicated beam-background simulations are shown, and their qualitative agreement with data is evaluated. Data taken during the passage of unpaired, i.e. non-colliding, proton bunches is used to obtain background-enriched data samples. These are used to identify characteristic features of beam-induced backgrounds, which then are exploited to develop dedicated background tagging tools. These tools, based on observables in the Pixel detector, the muon spectrometer and the calorimeters, are described in detail and their efficiencies are evaluated. Finally an example of an application of these techniques to a monojet analysis is given, which demonstrates the importance of such event cleaning techniques for some new physics searches., AuthorCount:2913, Atlas Collaboration
Published: 2013
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24. Search for nonpointing photons in the diphoton and E-T(miss) final state in root s=7 TeV proton-proton collisions using the ATLAS detector

Author: Abulaiti, Yiming, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Papadelis, Aras, Petridis, Andreas, Plucinski, Pawel, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Abulaiti, Yiming, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Papadelis, Aras, Petridis, Andreas, Plucinski, Pawel, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: A search has been performed for photons originating in the decay of a neutral long-lived particle, exploiting the capabilities of the ATLAS electromagnetic calorimeter to make precise measurements of the flight direction of photons, as well as the calorimeter's excellent time resolution. The search has been made in the diphoton plus missing transverse energy final state, using the full data sample of 4.8 fb(-1) of 7 TeV proton-proton collisions collected in 2011 with the ATLAS detector at the LHC. No excess is observed above the background expected from Standard Model processes. The results are used to set exclusion limits in the context of gauge mediated supersymmetry breaking models, with the lightest neutralino being the next-to-lightest supersymmetric particle and decaying with a lifetime in excess of 0.25 ns into a photon and a gravitino., AuthorCount:2924
Published: 2013
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25. Measurement of the cross-section for W boson production in association with b-jets in pp collisions at root s=7 TeV with the ATLAS detector

Author: Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Plucinski, Pawel, Sellden, Björn, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Plucinski, Pawel, Sellden, Björn, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: This paper reports a measurement of the W+b-jets (W+b+X and W+b (b) over bar +X) production cross-section in proton-proton collisions at a centre-of-mass energy of 7 TeV at the LHC. These results are based on data corresponding to an integrated luminosity of 4.6 fb(-1), collected with the ATLAS detector. Cross-sections are presented as a function of jet multiplicity and of the transverse momentum of the leading b-jet for both the muon and electron decay modes of the W boson. The W+b-jets cross-section, corrected for all known detector effects, is quoted in a limited kinematic range. Combining the muon and electron channels, the fiducial cross-section for W+b-jets is measured to be 7.1 +/- 0.5 (stat) +/- 1.4 (syst) pb, consistent with the next-to-leading order QCD prediction, corrected for non-perturbative and double-parton interactions (DPI) contributions, of 4.70 +/- 0.09 (stat) (+0.60)(-0.49) (scale) +/- 0.06 (PDF) +/- 0.16 (non-pert) (+0.52)(-0.38) (DPI) pb., AuthorCount:2911
Published: 2013
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26. Search for a light charged Higgs boson in the decay channel H+ -> c(s)over-bar in t(t)over-bar events using pp collisions at root s=7 TeV with the ATLAS detector

Author: Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Sellden, Björn, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Sellden, Björn, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: A search for a charged Higgs boson (H+) in t (t) over bar decays is presented, where one of the top quarks decays via t -> H(+)b, followed by H+ -> two jets (c (s) over bar). The other top quark decays to Wb, where the W boson then decays into a lepton (e/mu) and a neutrino. The data were recorded in pp collisions at root s = 7 TeV by the ATLAS detector at the LHC in 2011, and correspond to an integrated luminosity of 4.7 fb(-1). With no observation of a signal, 95 % confidence level (CL) upper limits are set on the decay branching ratio of top quarks to charged Higgs bosons varying between 5 % and 1 % for H+ masses between 90 GeV and 150 GeV, assuming B(H+ -> c (s) over bar) = 100 %., AuthorCount:2894
Published: 2013
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27. Measurement with the ATLAS detector of multi-particle azimuthal correlations in p plus Pb collisions at root s(NN)=5.02 TeV

Author: Abulaiti, Yabul, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon Jin, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David, Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Petridis, Andreas, Plucinski, Pawel, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Abulaiti, Yabul, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon Jin, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David, Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Petridis, Andreas, Plucinski, Pawel, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: In order to study further the long-range correlations (ridge) observed recently in p + Pb collisions at root s(NN) = 5.02 TeV, the second-order azimuthal anisotropy parameter of charged particles, v(2), has been measured with the cumulant method using the ATLAS detector at the LHC. In a data sample corresponding to an integrated luminosity of approximately 1 mu b(-1), the parameter v(2) has been obtained using two- and four-particle cumulants over the pseudorapidity range vertical bar eta vertical bar < 2.5. The results are presented as a function of transverse momentum and the event activity, defined in terms of the transverse energy summed over 3.1 < eta < 4.9 in the direction of the Pb beam. They show features characteristic of collective anisotropic flow, similar to that observed in Pb + Pb collisions. A comparison is made to results obtained using two-particle correlation methods, and to predictions from hydrodynamic models of p + Pb collisions. Despite the small transverse spatial extent of the p + Pb collision system, the large magnitude of v(2) and its similarity to hydrodynamic predictions provide additional evidence for the importance of final-state effects in p + Pb reactions., AuthorCount:2922
Published: 2013
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28. Triggers for displaced decays of long-lived neutral particles in the ATLAS detector

Author: Abulaiti, Yiming, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon Jin, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David, Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Petridis, Andreas, Plucinski, Pawel, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Abulaiti, Yiming, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon Jin, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David, Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Petridis, Andreas, Plucinski, Pawel, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: A set of three dedicated triggers designed to detect long-lived neutral particles decaying throughout the ATLAS detector to a pair of hadronic jets is described. The efficiencies of the triggers for selecting displaced decays as a function of the decay position are presented for simulated events. The effect of pile-up interactions on the trigger efficiencies and the dependence of the trigger rate on instantaneous luminosity during the 2012 data-taking period at the LHC are discussed., AuthorCount:2917
Published: 2013
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29. Search for dark matter candidates and large extra dimensions in events with a jet and missing transverse momentum with the ATLAS detector

Author: Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Sellden, Björn, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, Yang, Zhaoyu, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olof, Milstead, David A., Moa, Torbjörn, Ohm, Christian C., Papadelis, Aras, Sellden, Björn, Silverstein, Samuel B., Sjölin, Jörgen, Strandberg, Sara, and Yang, Zhaoyu
Abstract: A search for new phenomena in events with a high-energy jet and large missing transverse momentum is performed using data from proton-proton collisions at root s = 7 TeV with the ATLAS experiment at the Large flatiron Collider. Four kinematic regions are explored using a dataset corresponding to an integrated luminosity of 4.7 fb(-1). No excess of events beyond expectations from Standard Model processes is observed, and limits are set on large extra dimensions and the pair production of dark matter particles., AuthorCount:2869
Published: 2013
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30. Measurements of W gamma and Z gamma production in pp collisions at root s=7 TeV with the ATLAS detector at the LHC

Author: Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olle, Milstead, David, Moa, Torbjörn, Ohm, Christian, Papadelis, Aras, Plucinski, Pawel, Sellden, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Åsman, Barbro, Bendtz, Katarina, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Khandanyan, Hovhannes, Kim, Hyeon, Klimek, Pawel, Lundberg, Johan, Lundberg, Olle, Milstead, David, Moa, Torbjörn, Ohm, Christian, Papadelis, Aras, Plucinski, Pawel, Sellden, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: The integrated and differential fiducial cross sections for the production of a W or Z boson in association with a high-energy photon are measured using pp collisions at root s = 7 TeV. The analyses use a data sample with an integrated luminosity of 4.6 fb(-1) collected by the ATLAS detector during the 2011 LHC data-taking period. Events are selected using leptonic decays of the W and Z bosons [W(e nu, mu nu) and Z(e(+)e(-), mu(+)mu(-), nu(nu) over bar)] with the requirement of an associated isolated photon. The data are used to test the electroweak sector of the Standard Model and search for evidence for new phenomena. The measurements are used to probe the anomalous WW gamma, ZZ gamma, and Z gamma gamma triple-gauge-boson couplings and to search for the production of vector resonances decaying to Z gamma and W gamma. No deviations from Standard Model predictions are observed and limits are placed on anomalous triple-gauge-boson couplings and on the production of new vector meson resonances., AuthorCount:2912
Published: 2013
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31. Gamma ray observations of the orion molecular clouds with the fermi large area telescope

Author: Ackermann, M., Ajello, M., Allafort, A., Antolini, E., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Chekhtman, A., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Enoto, T., Falletti, L., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Fukazawa, Y., Fukui, Y., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hayashi, K., Horan, D., Hou, X., Hughes, R. E., Jackson, M. S., Johannesson, G., Johnson, A. S., Kamae, T., Katagiri, H., Kataoka, J., Kerr, M., Knodlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Lee, S. -H, Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Makishima, K., Mazziotta, M. N., Mehault, J., Mitthumsiri, W., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Naumann-Godo, M., Nishino, S., Norris, J. P., Nuss, E., Ohno, M., Ohsugi, T., Okumura, A., Orienti, M., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Panetta, J. H., Parent, D., Pelassa, V., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Razzano, M., Reimer, A., Reimer, O., Roth, M., Sadrozinski, H. F. -W, Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Strong, A. W., Takahashi, H., Takahashi, T., Tanaka, T., Thayer, J. G., Thayer, J. B., Tibolla, O., Tinivella, M., Torres, D. F., Tramacere, A., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yang, Zhaoyu, Zimmer, Stephan, Ackermann, M., Ajello, M., Allafort, A., Antolini, E., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Chekhtman, A., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Enoto, T., Falletti, L., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Fukazawa, Y., Fukui, Y., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hayashi, K., Horan, D., Hou, X., Hughes, R. E., Jackson, M. S., Johannesson, G., Johnson, A. S., Kamae, T., Katagiri, H., Kataoka, J., Kerr, M., Knodlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Lee, S. -H, Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Makishima, K., Mazziotta, M. N., Mehault, J., Mitthumsiri, W., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Naumann-Godo, M., Nishino, S., Norris, J. P., Nuss, E., Ohno, M., Ohsugi, T., Okumura, A., Orienti, M., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Panetta, J. H., Parent, D., Pelassa, V., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Razzano, M., Reimer, A., Reimer, O., Roth, M., Sadrozinski, H. F. -W, Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Strong, A. W., Takahashi, H., Takahashi, T., Tanaka, T., Thayer, J. G., Thayer, J. B., Tibolla, O., Tinivella, M., Torres, D. F., Tramacere, A., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yang, Zhaoyu, and Zimmer, Stephan
Abstract: We report on the gamma-ray observations of giant molecular clouds Orion A and B with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. The gamma-ray emission in the energy band between similar to 100 MeV and similar to 100 GeV is predicted to trace the gas mass distribution in the clouds through nuclear interactions between the Galactic cosmic rays (CRs) and interstellar gas. The gamma-ray production cross-section for the nuclear interaction is known to similar to 10% precision which makes the LAT a powerful tool to measure the gas mass column density distribution of molecular clouds for a known CR intensity. We present here such distributions for Orion A and B, and correlate them with those of the velocity-integrated CO intensity (W-CO) at a 1 degrees x 1 degrees pixel level. The correlation is found to be linear over a W-CO range of similar to 10-fold when divided in three regions, suggesting penetration of nuclear CRs to most of the cloud volumes. The W-CO-to-mass conversion factor, X-CO, is found to be similar to 2.3 x 10(20) cm(-2) (K km s(-1))(-1) for the high-longitude part of Orion A (l > 212 degrees), similar to 1.7 times higher than similar to 1.3 x 10(20) found for the rest of Orion A and B. We interpret the apparent high XCO in the high-longitude region of Orion A in the light of recent works proposing a nonlinear relation between H-2 and CO densities in the diffuse molecular gas. W-CO decreases faster than the H-2 column density in the region making the gas darker to W-CO., AuthorCount:145
Published: 2012
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32. FERMI OBSERVATIONS OF gamma-RAY EMISSION FROM THE MOON

Author: Abdo, A. A., Ackermann, M., Ajello, M., Atwoo, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bonamente, E., Borgland, A. W., Bottacini, E., Bouvier, A., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Digel, S. W., Silva, E. do Couto E, Drell, P. S., Drlica-Wagner, A., Dubois, R., Favuzzi, C., Fegan, S. J., Focke, W. B., Fortin, P., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gehrels, N., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Grove, J. E., Guiriec, S., Hadasch, D., Hays, E., Hill, A. B., Horan, D., Hou, X., Hughes, R. E., Iafrate, G., Jackson, M. S., Johannesson, G., Johnson, A. S., Kamae, T., Katagiri, H., Kataoka, J., Knoedlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Naumann-Godo, M., Nolan, P. L., Norris, J. P., Nuss, E., Ohno, M., Ohsugi, T., Okumura, A., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Panetta, J. H., Parent, D., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Poon, H., Porter, T. A., Prokhorov, D., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Rochester, L. S., Roth, M., Sadrozinski, H. F. -W, Sanchez, D. A., Sbarra, C., Schalk, T. L., Sgro, C., Share, G. H., Siskind, E. J., Spandre, G., Spinelli, P., Stawarz, L., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, D. L., Wood, K. S., Yang, Zhaoyu, Zimmer, Stephan, Abdo, A. A., Ackermann, M., Ajello, M., Atwoo, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bonamente, E., Borgland, A. W., Bottacini, E., Bouvier, A., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Digel, S. W., Silva, E. do Couto E, Drell, P. S., Drlica-Wagner, A., Dubois, R., Favuzzi, C., Fegan, S. J., Focke, W. B., Fortin, P., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gehrels, N., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Grove, J. E., Guiriec, S., Hadasch, D., Hays, E., Hill, A. B., Horan, D., Hou, X., Hughes, R. E., Iafrate, G., Jackson, M. S., Johannesson, G., Johnson, A. S., Kamae, T., Katagiri, H., Kataoka, J., Knoedlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Naumann-Godo, M., Nolan, P. L., Norris, J. P., Nuss, E., Ohno, M., Ohsugi, T., Okumura, A., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Panetta, J. H., Parent, D., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Poon, H., Porter, T. A., Prokhorov, D., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Rochester, L. S., Roth, M., Sadrozinski, H. F. -W, Sanchez, D. A., Sbarra, C., Schalk, T. L., Sgro, C., Share, G. H., Siskind, E. J., Spandre, G., Spinelli, P., Stawarz, L., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, D. L., Wood, K. S., Yang, Zhaoyu, and Zimmer, Stephan
Abstract: We report on the detection of high-energy gamma-ray emission from the Moon during the first 24 months of observations by the Fermi Large Area Telescope (LAT). This emission comes from particle cascades produced by cosmic-ray (CR) nuclei and electrons interacting with the lunar surface. The differential spectrum of the Moon is soft and can be described as a log-parabolic function with an effective cutoff at 2-3 GeV, while the average integral flux measured with the LAT from the beginning of observations in 2008 August to the end of 2010 August is F(> 100 MeV) = (1.04 +/- 0.01 [statistical error] +/- 0.1 [systematic error]) x 10(-6) cm(-2) s(-1). This flux is about a factor 2-3 higher than that observed between 1991 and 1994 by the EGRET experiment on board the Compton Gamma Ray Observatory, F(> 100 MeV) approximate to 5 x 10(-7) cm-2 s-1, when solar activity was relatively high. The higher gamma-ray flux measured by Fermi is consistent with the deep solar minimum conditions during the first 24 months of the mission, which reduced effects of heliospheric modulation, and thus increased the heliospheric flux of Galactic CRs. A detailed comparison of the light curve with McMurdo Neutron Monitor rates suggests a correlation of the trends. The Moon and the Sun are so far the only known bright emitters of gamma-rays with fast celestial motion. Their paths across the sky are projected onto the Galactic center and high Galactic latitudes as well as onto other areas crowded with high-energy gamma-ray sources. Analysis of the lunar and solar emission may thus be important for studies of weak and transient sources near the ecliptic., AuthorCount:163
Published: 2012
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33. SEARCH FOR GAMMA-RAY EMISSION FROM X-RAY-SELECTED SEYFERT GALAXIES WITH FERMI-LAT

Author: Ackermann, M., Ajello, M., Allafort, A., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Bloom, E. D., Bonamente, E., Borgland, A. W., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Enoto, T., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Fortin, P., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Godfrey, G., Grove, J. E., Guiriec, S., Hadasch, D., Hayashida, M., Hays, E., Hughes, R. E., Johannesson, G., Johnson, A. S., Kamae, T., Katagiri, H., Kataoka, J., Knoedlseder, J., Kuss, M., Lande, J., Garde, Maja Llena, Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Mazziotta, M. N., Michelson, P. F., Mizuno, T., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nishino, S., Norris, J. P., Nuss, E., Ohno, M., Ohsugi, T., Okumura, A., Orlando, E., Ozaki, M., Paneque, D., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Ritz, S., Roth, M., Sanchez, D. A., Sbarra, C., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Stawarz, L., Strong, A. W., Takahashi, H., Takahashi, T., Tanaka, T., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Winer, B. L., Wood, K. S., Wood, M., Yang, Zhaoyu, Zimmer, Stephan, Ackermann, M., Ajello, M., Allafort, A., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Bloom, E. D., Bonamente, E., Borgland, A. W., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Enoto, T., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Fortin, P., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Godfrey, G., Grove, J. E., Guiriec, S., Hadasch, D., Hayashida, M., Hays, E., Hughes, R. E., Johannesson, G., Johnson, A. S., Kamae, T., Katagiri, H., Kataoka, J., Knoedlseder, J., Kuss, M., Lande, J., Garde, Maja Llena, Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Mazziotta, M. N., Michelson, P. F., Mizuno, T., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nishino, S., Norris, J. P., Nuss, E., Ohno, M., Ohsugi, T., Okumura, A., Orlando, E., Ozaki, M., Paneque, D., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Ritz, S., Roth, M., Sanchez, D. A., Sbarra, C., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Stawarz, L., Strong, A. W., Takahashi, H., Takahashi, T., Tanaka, T., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Winer, B. L., Wood, K. S., Wood, M., Yang, Zhaoyu, and Zimmer, Stephan
Abstract: We report on a systematic investigation of the gamma-ray properties of 120 hard X-ray-selected Seyfert galaxies classified as radio-quiet objects, utilizing the three-year accumulation of Fermi Large Area Telescope (LAT) data. Our sample of Seyfert galaxies is selected using the Swift Burst Alert Telescope 58 month catalog, restricting the analysis to the bright sources with average hard X-ray fluxes F14-195 keV >= 2.5 x 10(-11) erg cm(-2) s(-1) at high Galactic latitudes (|b| > 10 degrees). In order to remove radio-loud objects from the sample, we use the hard X-ray radio loudness parameter, RrX, defined as the ratio of the total 1.4 GHz radio to 14-195 keV hard X-ray energy fluxes. Among 120 X-ray bright Seyfert galaxies with RrX < 10(-4), we did not find a statistically significant g-ray excess (TS > 25) positionally coincident with any target Seyferts, with possible exceptions of ESO 323-G077 and NGC 6814. The mean value of the 95% confidence level gamma-ray upper limit for the integrated photon flux above 100 MeV from the analyzed Seyferts is similar or equal to 4 x 10(-9) photons cm(-2) s(-1), and the upper limits derived for several objects reach similar or equal to 1 x 10(-9) photons cm(-2) s(-1). Our results indicate that no prominent gamma-ray emission component related to active galactic nucleus activity is present in the spectra of Seyferts around GeV energies. The Fermi-LAT upper limits derived for our sample probe the ratio of gamma-ray to X-ray luminosities L-gamma/L-X < 0.1, and even <0.01 in some cases. The obtained results impose novel constraints on the models for high-energy radiation of radio-quiet Seyfert galaxies., AuthorCount:136
Published: 2012
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34. FERMI LARGE AREA TELESCOPE OBSERVATIONS OF THE SUPERNOVA REMNANT G8.7-0.1

Author: Ajello, M., Allafort, A., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Charles, E., Chekhtman, A., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cutini, S., de Angelis, A., de Palma, F., Dermer, C. D., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Dubois, R., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Frailis, M., Fukazawa, Y., Fukui, Y., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grove, J. E., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashi, K., Hays, E., Itoh, R., Johannesson, G., Johnson, A. S., Kamae, T., Katagiri, H., Kataoka, J., Knoedlseder, J., Kubo, H., Kuss, M., Lande, J., Latronico, L., Lee, S. -H, Lionetto, A. M., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Mazziotta, M. N., Mehault, J., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Naumann-Godo, M., Nishino, S., Nolan, P. L., Norris, J. P., Nuss, E., Ohno, M., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Ormes, J. F., Paneque, D., Parent, D., Pelassa, V., Pesce-Rollins, M., Pierbattista, M., Piron, F., Porter, T. A., Raino, S., Rando, R., Reimer, A., Reimer, O., Reposeur, T., Roth, M., Sadrozinski, H. F. -W, Sgro, C., Siskind, E. J., Smith, P. D., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Tibaldo, L., Tibolla, O., Torres, D. F., Tosti, G., Tramacere, A., Troja, E., Uchiyama, Y., Uehara, T., Usher, T. L., Vandenbroucke, J., Van Etten, A., Vasileiou, V., Vianello, G., Vilchez, N., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yamamoto, H., Yamazaki, R., Yang, Zhaoyu, Yasuda, H., Ziegler, M., Zimmer, Stefan, Ajello, M., Allafort, A., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Charles, E., Chekhtman, A., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cutini, S., de Angelis, A., de Palma, F., Dermer, C. D., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Dubois, R., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Frailis, M., Fukazawa, Y., Fukui, Y., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grove, J. E., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashi, K., Hays, E., Itoh, R., Johannesson, G., Johnson, A. S., Kamae, T., Katagiri, H., Kataoka, J., Knoedlseder, J., Kubo, H., Kuss, M., Lande, J., Latronico, L., Lee, S. -H, Lionetto, A. M., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Mazziotta, M. N., Mehault, J., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Naumann-Godo, M., Nishino, S., Nolan, P. L., Norris, J. P., Nuss, E., Ohno, M., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Ormes, J. F., Paneque, D., Parent, D., Pelassa, V., Pesce-Rollins, M., Pierbattista, M., Piron, F., Porter, T. A., Raino, S., Rando, R., Reimer, A., Reimer, O., Reposeur, T., Roth, M., Sadrozinski, H. F. -W, Sgro, C., Siskind, E. J., Smith, P. D., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Tibaldo, L., Tibolla, O., Torres, D. F., Tosti, G., Tramacere, A., Troja, E., Uchiyama, Y., Uehara, T., Usher, T. L., Vandenbroucke, J., Van Etten, A., Vasileiou, V., Vianello, G., Vilchez, N., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yamamoto, H., Yamazaki, R., Yang, Zhaoyu, Yasuda, H., Ziegler, M., and Zimmer, Stefan
Abstract: We present a detailed analysis of the GeV gamma-ray emission toward the supernova remnant (SNR) G8.7-0.1 with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. An investigation of the relationship between G8.7-0.1 and the TeV unidentified source HESS J1804-216 provides us with an important clue on diffusion process of cosmic rays if particle acceleration operates in the SNR. The GeV gamma-ray emission is extended with most of the emission in positional coincidence with the SNR G8.7-0.1 and a lesser part located outside the western boundary of G8.7-0.1. The region of the gamma-ray emission overlaps spatially connected molecular clouds, implying a physical connection for the gamma-ray structure. The total gamma-ray spectrum measured with LAT from 200 MeV-100 GeV can be described by a broken power-law function with a break of 2.4 +/- 0.6 (stat) +/- 1.2 (sys) GeV, and photon indices of 2.10 +/- 0.06 (stat) +/- 0.10 (sys) below the break and 2.70 +/- 0.12 (stat) +/- 0.14 (sys) above the break. Given the spatial association among the gamma rays, the radio emission of G8.7-0.1, and the molecular clouds, the decay of pi(0)s produced by particles accelerated in the SNR and hitting the molecular clouds naturally explains the GeV gamma-ray spectrum. We also find that the GeV morphology is not well represented by the TeV emission from HESS J1804-216 and that the spectrum in the GeV band is not consistent with the extrapolation of the TeV gamma-ray spectrum. The spectral index of the TeV emission is consistent with the particle spectral index predicted by a theory that assumes energy-dependent diffusion of particles accelerated in an SNR. We discuss the possibility that the TeV spectrum originates from the interaction of particles accelerated in G8.7-0.1 with molecular clouds, and we constrain the diffusion coefficient of the particles., 147
Published: 2012
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35. SEARCH FOR DARK MATTER SATELLITES USING FERMI-LAT

Author: Ackermann, M., Albert, A., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Burnett, T. H., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Charles, E., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., de Palma, F., Dermer, C. D., Digel, S. W., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Essig, R., Falletti, L., Favuzzi, C., Fegan, S. J., Focke, W. B., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Guiriec, S., Gustafsson, M., Hadasch, D., Hayashida, M., Hou, X., Hughes, R. E., Johnson, R. P., Johnson, A. S., Kamae, T., Katagiri, H., Kataoka, J., Knoedlseder, J., Kuss, M., Lande, J., Latronico, L., Lee, S. -H, Lionetto, A. M., Garde, Maja Llena, Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Naumann-Godo, M., Norris, J. P., Nuss, E., Ohsugi, T., Okumura, A., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Pelassa, V., Pierbattista, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Ritz, S., Sadrozinski, H. F. -W, Sehgal, N., Sgro, C., Siskind, E. J., Spinelli, P., Strigari, L., Suson, D. J., Tajima, H., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Tibaldo, L., Tinivella, M., Torres, D. F., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yang, Zhaoyu, Zalewski, S., Zimmer, Stephan, Ackermann, M., Albert, A., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Burnett, T. H., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Charles, E., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., de Palma, F., Dermer, C. D., Digel, S. W., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Essig, R., Falletti, L., Favuzzi, C., Fegan, S. J., Focke, W. B., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Guiriec, S., Gustafsson, M., Hadasch, D., Hayashida, M., Hou, X., Hughes, R. E., Johnson, R. P., Johnson, A. S., Kamae, T., Katagiri, H., Kataoka, J., Knoedlseder, J., Kuss, M., Lande, J., Latronico, L., Lee, S. -H, Lionetto, A. M., Garde, Maja Llena, Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Naumann-Godo, M., Norris, J. P., Nuss, E., Ohsugi, T., Okumura, A., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Pelassa, V., Pierbattista, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Ritz, S., Sadrozinski, H. F. -W, Sehgal, N., Sgro, C., Siskind, E. J., Spinelli, P., Strigari, L., Suson, D. J., Tajima, H., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Tibaldo, L., Tinivella, M., Torres, D. F., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yang, Zhaoyu, Zalewski, S., and Zimmer, Stephan
Abstract: Numerical simulations based on the ACDM model of cosmology predict a large number of as yet unobserved Galactic dark matter satellites. We report the results of a Large Area Telescope (LAT) search for these satellites via the gamma-ray emission expected from the annihilation of weakly interacting massive particle (WIMP) dark matter. Some dark matter satellites are expected to have hard gamma-ray spectra, finite angular extents, and a lack of counterparts at other wavelengths. We sought to identify LAT sources with these characteristics, focusing on gamma-ray spectra consistent with WIMP annihilation through the b (b) over bar channel. We found no viable dark matter satellite candidates using one year of data, and we present a framework for interpreting this result in the context of numerical simulations to constrain the velocity-averaged annihilation cross section for a conventional 100 GeV WIMP annihilating through the b (b) over bar channel., AuthorCount:135
Published: 2012
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36. FERMI LARGE AREA TELESCOPE SECOND SOURCE CATALOG

Author: Nolan, P. L., Abdo, A. A., Ackermann, M., Ajello, M., Allafort, A., Antolini, E., Atwood, W. B., Axelsson, Magnus, Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Belfiore, A., Bellazzini, R., Berenji, B., Bignami, G. F., Blandford, R. D., Bloom, E. D., Bonamente, E., Bonnell, J., Borgland, A. W., Bottacini, E., Bouvier, A., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Burnett, T. H., Buson, S., Caliandro, G. A., Cameron, R. A., Campana, R., Canadas, B., Cannon, A., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Ceccanti, M., Cecchi, C., Celik, Oe, Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Chipaux, R., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, Corbet, R., Cutini, S., D'Ammando, F., Davis, D. S., de Angelis, A., DeCesar, M. E., DeKlotz, M., De Luca, A., den Hartog, P. R., de Palma, F., Dermer, C. D., Digel, S. W., Do Couto E Silva, E., Drell, P. S., Drlica-Wagner, A., Dubois, R., Dumora, D., Enoto, T., Escande, L., Fabiani, D., Falletti, L., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Fortin, P., Frailis, M., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giebels, B., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grondin, M. -H, Grove, J. E., Guillemot, L., Guiriec, S., Gustafsson, M., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hays, E., Hill, A. B., Horan, D., Hou, X., Hughes, R. E., Iafrate, G., Itoh, R., Johannesson, G., Johnson, R. P., Johnson, T. E., Johnson, A. S., Johnson, T. J., Kamae, T., Katagiri, H., Kataoka, J., Katsuta, J., Kawai, N., Kerr, M., Knoedlseder, J., Kocevski, D., Kuss, M., Lande, J., Landriu, D., Latronico, L., Lemoine-Goumard, M., Lionetto, A. M., Garde, Maja Llena, Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Marelli, M., Massaro, E., Mazziotta, M. N., McConville, W., McEnery, J. E., Mehault, J., Michelson, P. F., Minuti, M., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Mongelli, M., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Naumann-Godo, M., Norris, J. P., Nuss, E., Nymark, T., Ohno, M., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Panetta, J. H., Parent, D., Perkins, J. S., Pesce-Rollins, M., Pierbattista, M., Pinchera, M., Piron, F., Pivato, G., Porter, T. A., Racusin, J. L., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Ritz, S., Rochester, L. S., Romani, R. W., Roth, M., Rousseau, R., Ryde, F., Sadrozinski, H. F. -W, Salvetti, D., Sanchez, D. A., Parkinson, P. M. Saz, Sbarra, C., Scargle, J. D., Schalk, T. L., Sgro, C., Shaw, M. S., Shrader, C., Siskind, E. J., Smith, D. A., Spandre, G., Spinelli, P., Stephens, T. E., Strickman, M. S., Suson, D. J., Tajima, H., Takahashi, H., Takahashi, T., Tanaka, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tibolla, O., Tinebra, F., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Vandenbroucke, J., Van Etten, A., Van Klaveren, B., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Wallace, E., Wang, P., Werner, M., Winer, B. L., Wood, D. L., Wood, K. S., Wood, M., Yang, Zhaoyu, Zimmer, Stephan, Nolan, P. L., Abdo, A. A., Ackermann, M., Ajello, M., Allafort, A., Antolini, E., Atwood, W. B., Axelsson, Magnus, Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Belfiore, A., Bellazzini, R., Berenji, B., Bignami, G. F., Blandford, R. D., Bloom, E. D., Bonamente, E., Bonnell, J., Borgland, A. W., Bottacini, E., Bouvier, A., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Burnett, T. H., Buson, S., Caliandro, G. A., Cameron, R. A., Campana, R., Canadas, B., Cannon, A., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Ceccanti, M., Cecchi, C., Celik, Oe, Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Chipaux, R., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, Corbet, R., Cutini, S., D'Ammando, F., Davis, D. S., de Angelis, A., DeCesar, M. E., DeKlotz, M., De Luca, A., den Hartog, P. R., de Palma, F., Dermer, C. D., Digel, S. W., Do Couto E Silva, E., Drell, P. S., Drlica-Wagner, A., Dubois, R., Dumora, D., Enoto, T., Escande, L., Fabiani, D., Falletti, L., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Fortin, P., Frailis, M., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giebels, B., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grondin, M. -H, Grove, J. E., Guillemot, L., Guiriec, S., Gustafsson, M., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hays, E., Hill, A. B., Horan, D., Hou, X., Hughes, R. E., Iafrate, G., Itoh, R., Johannesson, G., Johnson, R. P., Johnson, T. E., Johnson, A. S., Johnson, T. J., Kamae, T., Katagiri, H., Kataoka, J., Katsuta, J., Kawai, N., Kerr, M., Knoedlseder, J., Kocevski, D., Kuss, M., Lande, J., Landriu, D., Latronico, L., Lemoine-Goumard, M., Lionetto, A. M., Garde, Maja Llena, Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Marelli, M., Massaro, E., Mazziotta, M. N., McConville, W., McEnery, J. E., Mehault, J., Michelson, P. F., Minuti, M., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Mongelli, M., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Naumann-Godo, M., Norris, J. P., Nuss, E., Nymark, T., Ohno, M., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Panetta, J. H., Parent, D., Perkins, J. S., Pesce-Rollins, M., Pierbattista, M., Pinchera, M., Piron, F., Pivato, G., Porter, T. A., Racusin, J. L., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Ritz, S., Rochester, L. S., Romani, R. W., Roth, M., Rousseau, R., Ryde, F., Sadrozinski, H. F. -W, Salvetti, D., Sanchez, D. A., Parkinson, P. M. Saz, Sbarra, C., Scargle, J. D., Schalk, T. L., Sgro, C., Shaw, M. S., Shrader, C., Siskind, E. J., Smith, D. A., Spandre, G., Spinelli, P., Stephens, T. E., Strickman, M. S., Suson, D. J., Tajima, H., Takahashi, H., Takahashi, T., Tanaka, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tibolla, O., Tinebra, F., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Vandenbroucke, J., Van Etten, A., Van Klaveren, B., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Wallace, E., Wang, P., Werner, M., Winer, B. L., Wood, D. L., Wood, K. S., Wood, M., Yang, Zhaoyu, and Zimmer, Stephan
Abstract: We present the second catalog of high-energy gamma-ray sources detected by the Large Area Telescope (LAT), the primary science instrument on the Fermi Gamma-ray Space Telescope (Fermi), derived from data taken during the first 24 months of the science phase of the mission, which began on 2008 August 4. Source detection is based on the average flux over the 24 month period. The second Fermi-LAT catalog (2FGL) includes source location regions, defined in terms of elliptical fits to the 95% confidence regions and spectral fits in terms of power-law, exponentially cutoff power-law, or log-normal forms. Also included are flux measurements in five energy bands and light curves on monthly intervals for each source. Twelve sources in the catalog are modeled as spatially extended. We provide a detailed comparison of the results from this catalog with those from the first Fermi-LAT catalog (1FGL). Although the diffuse Galactic and isotropic models used in the 2FGL analysis are improved compared to the 1FGL catalog, we attach caution flags to 162 of the sources to indicate possible confusion with residual imperfections in the diffuse model. The 2FGL catalog contains 1873 sources detected and characterized in the 100 MeV to 100 GeV range of which we consider 127 as being firmly identified and 1171 as being reliably associated with counterparts of known or likely gamma-ray-producing source classes., AuthorCount:237
Published: 2012
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37. A STATISTICAL APPROACH TO RECOGNIZING SOURCE CLASSES FOR UNASSOCIATED SOURCES IN THE FIRST FERMI-LAT CATALOG

Author: Ackermann, M., Ajello, M., Allafort, A., Antolini, E., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bouvier, A., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Burnett, T. H., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Celik, O., Charles, E., Chekhtman, A., Chen, A. W., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., de Angelis, A., DeCesar, M. E., De Luca, A., de Palma, F., Dermer, C. D., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Dubois, R., Enoto, T., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Fortin, P., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grondin, M. -H, Grove, J. E., Guillemot, L., Guiriec, S., Gustafsson, M., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hays, E., Healey, S. E., Hill, A. B., Horan, D., Hou, X., Johannesson, G., Johnson, A. S., Johnson, T. J., Kamae, T., Katagiri, H., Kataoka, J., Kerr, M., Knoedlseder, J., Kuss, M., Lande, J., Latronico, L., Lee, S. -H, Lemoine-Goumard, M., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mignani, R. P., Mitthumsiri, W., Mizuno, T., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Naumann-Godo, M., Nolan, P. L., Norris, J. P., Nuss, E., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Panetta, J. H., Parent, D., Pelassa, V., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Ray, P. S., Razzano, M., Reimer, A., Reimer, O., Reposeur, T., Romani, R. W., Sadrozinski, H. F. -W, Salvetti, D., Parkinson, P. M. Saz, Schalk, T. L., Sgro, C., Shaw, M. S., Siskind, E. J., Smith, P. D., Spandre, G., Spinelli, P., Suson, D. J., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tibolla, O., Torres, D. F., Tosti, G., Tramacere, A., Troja, E., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vilchez, N., Vitale, V., Waite, A. P., Wallace, E., Wang, P., Winer, B. L., Wolff, M. T., Wood, D. L., Wood, K. S., Yang, Zhaoyu, Zimmer, Stephan, Ackermann, M., Ajello, M., Allafort, A., Antolini, E., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bouvier, A., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Burnett, T. H., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Celik, O., Charles, E., Chekhtman, A., Chen, A. W., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., de Angelis, A., DeCesar, M. E., De Luca, A., de Palma, F., Dermer, C. D., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Dubois, R., Enoto, T., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Fortin, P., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grondin, M. -H, Grove, J. E., Guillemot, L., Guiriec, S., Gustafsson, M., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hays, E., Healey, S. E., Hill, A. B., Horan, D., Hou, X., Johannesson, G., Johnson, A. S., Johnson, T. J., Kamae, T., Katagiri, H., Kataoka, J., Kerr, M., Knoedlseder, J., Kuss, M., Lande, J., Latronico, L., Lee, S. -H, Lemoine-Goumard, M., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mignani, R. P., Mitthumsiri, W., Mizuno, T., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Naumann-Godo, M., Nolan, P. L., Norris, J. P., Nuss, E., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Panetta, J. H., Parent, D., Pelassa, V., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Ray, P. S., Razzano, M., Reimer, A., Reimer, O., Reposeur, T., Romani, R. W., Sadrozinski, H. F. -W, Salvetti, D., Parkinson, P. M. Saz, Schalk, T. L., Sgro, C., Shaw, M. S., Siskind, E. J., Smith, P. D., Spandre, G., Spinelli, P., Suson, D. J., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tibolla, O., Torres, D. F., Tosti, G., Tramacere, A., Troja, E., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vilchez, N., Vitale, V., Waite, A. P., Wallace, E., Wang, P., Winer, B. L., Wolff, M. T., Wood, D. L., Wood, K. S., Yang, Zhaoyu, and Zimmer, Stephan
Abstract: The Fermi Large Area Telescope (LAT) First Source Catalog (1FGL) provided spatial, spectral, and temporal properties for a large number of gamma-ray sources using a uniform analysis method. After correlating with the most-complete catalogs of source types known to emit gamma rays, 630 of these sources are unassociated (i.e., have no obvious counterparts at other wavelengths). Here, we employ two statistical analyses of the primary gamma-ray characteristics for these unassociated sources in an effort to correlate their gamma-ray properties with the active galactic nucleus (AGN) and pulsar populations in 1FGL. Based on the correlation results, we classify 221 AGN-like and 134 pulsar-like sources in the 1FGL unassociated sources. The results of these source classifications appear to match the expected source distributions, especially at high Galactic latitudes. While useful for planning future multiwavelength follow-up observations, these analyses use limited inputs, and their predictions should not be considered equivalent to probable source classes for these sources. We discuss multiwavelength results and catalog cross-correlations to date, and provide new source associations for 229 Fermi-LAT sources that had no association listed in the 1FGL catalog. By validating the source classifications against these new associations, we find that the new association matches the predicted source class in similar to 80% of the sources., AuthorCount:177
Published: 2012
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38. FERMI-LAT OBSERVATIONS OF THE DIFFUSE gamma-RAY EMISSION : IMPLICATIONS FORCOSMIC RAYS AND THE INTERSTELLAR MEDIUM

Author: Ackermann, M., Ajello, M., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., de Angelis, A., de Palma, F., Dermer, C. D., Digel, S. W., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Falletti, L., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Fortin, P., Fukazawa, Y., Funk, S., Fusco, P., Gaggero, D., Gargano, F., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grove, J. E., Guiriec, S., Gustafsson, M., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hays, E., Horan, D., Hou, X., Hughes, R. E., Johannesson, G., Johnson, A. S., Johnson, R. P., Kamae, T., Katagiri, H., Kataoka, J., Knoedlseder, J., Kuss, M., Lande, J., Latronico, L., Lee, S. -H, Lemoine-Goumard, M., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Naumann-Godo, M., Norris, J. P., Nuss, E., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Parent, D., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Sadrozinski, H. F. -W, Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Strong, A. W., Suson, D. J., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Wood, M., Yang, Zhaoyu, Ziegler, M., Zimmer, Stephen, Ackermann, M., Ajello, M., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., de Angelis, A., de Palma, F., Dermer, C. D., Digel, S. W., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Falletti, L., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Fortin, P., Fukazawa, Y., Funk, S., Fusco, P., Gaggero, D., Gargano, F., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grove, J. E., Guiriec, S., Gustafsson, M., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hays, E., Horan, D., Hou, X., Hughes, R. E., Johannesson, G., Johnson, A. S., Johnson, R. P., Kamae, T., Katagiri, H., Kataoka, J., Knoedlseder, J., Kuss, M., Lande, J., Latronico, L., Lee, S. -H, Lemoine-Goumard, M., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Naumann-Godo, M., Norris, J. P., Nuss, E., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Parent, D., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Sadrozinski, H. F. -W, Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Strong, A. W., Suson, D. J., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Wood, M., Yang, Zhaoyu, Ziegler, M., and Zimmer, Stephen
Abstract: The gamma-ray sky >100MeVis dominated by the diffuse emissions from interactions of cosmic rays with the interstellar gas and radiation fields of the Milky Way. Observations of these diffuse emissions provide a tool to study cosmic-ray origin and propagation, and the interstellar medium. We present measurements from the first 21 months of the Fermi Large Area Telescope (Fermi-LAT) mission and compare with models of the diffuse gamma-ray emission generated using the GALPROP code. The models are fitted to cosmic-ray data and incorporate astrophysical input for the distribution of cosmic-ray sources, interstellar gas, and radiation fields. To assess uncertainties associated with the astrophysical input, a grid of models is created by varying within observational limits the distribution of cosmic-ray sources, the size of the cosmic-ray confinement volume (halo), and the distribution of interstellar gas. An all-sky maximum-likelihood fit is used to determine the X-CO factor, the ratio between integrated CO-line intensity and H-2 column density, the fluxes and spectra of the gamma-ray point sources from the first Fermi-LAT catalog, and the intensity and spectrum of the isotropic background including residual cosmic rays that were misclassified as gamma-rays, all of which have some dependency on the assumed diffuse emission model. The models are compared on the basis of their maximum-likelihood ratios as well as spectra, longitude, and latitude profiles. We also provide residual maps for the data following subtraction of the diffuse emission models. The models are consistent with the data at high and intermediate latitudes but underpredict the data in the inner Galaxy for energies above a few GeV. Possible explanations for this discrepancy are discussed, including the contribution by undetected point-source populations and spectral variations of cosmic rays throughout the Galaxy. In the outer Galaxy, we find that the data prefer models with a flatter distribution of cos, AuthorCount:147
Published: 2012
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39. The cosmic-ray and gas content of the Cygnus region as measured in gamma-rays by the Fermi Large Area Telescope

Author: Ackermann, M., Ajello, M., Allafort, A., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Belfiore, A., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bottacini, E., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Chekhtman, A., Ciprini, S., Claus, R., Cohen-Tanugi, J., de Angelis, A., de Palma, F., Dermer, C. D., do Couto e Silva, E., Drell, P. S., Dumora, D., Favuzzi, C., Fegan, S. J., Focke, W. B., Fortin, P., Fukazawa, Y., Fusco, P., Gargano, F., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Guillemot, L., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hayashi, K., Hays, E., Johannesson, G., Johnson, A. S., Kamae, T., Katagiri, H., Kataoka, J., Kerr, M., Knoedlseder, J., Kuss, M., Lande, J., Latronico, L., Lee, S. -H, Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Martin, P., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Naumann-Godo, M., Nolan, P. L., Norris, J. P., Nuss, E., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Parent, D., Pesce-Rollins, M., Pierbattista, M., Piron, F., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, O., Reposeur, T., Ritz, S., Parkinson, P. M. Saz, Sgro, C., Siskind, E. J., Smith, P. D., Spinelli, P., Strong, A. W., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Torres, D. F., Tosti, G., Tramacere, A., Troja, E., Uchiyama, Y., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yang, Zhaoyu, Zimmer, Stephan, Bontemps, S., Ackermann, M., Ajello, M., Allafort, A., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Belfiore, A., Bellazzini, R., Berenji, B., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bottacini, E., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Chekhtman, A., Ciprini, S., Claus, R., Cohen-Tanugi, J., de Angelis, A., de Palma, F., Dermer, C. D., do Couto e Silva, E., Drell, P. S., Dumora, D., Favuzzi, C., Fegan, S. J., Focke, W. B., Fortin, P., Fukazawa, Y., Fusco, P., Gargano, F., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Guillemot, L., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hayashi, K., Hays, E., Johannesson, G., Johnson, A. S., Kamae, T., Katagiri, H., Kataoka, J., Kerr, M., Knoedlseder, J., Kuss, M., Lande, J., Latronico, L., Lee, S. -H, Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Martin, P., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Naumann-Godo, M., Nolan, P. L., Norris, J. P., Nuss, E., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Parent, D., Pesce-Rollins, M., Pierbattista, M., Piron, F., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, O., Reposeur, T., Ritz, S., Parkinson, P. M. Saz, Sgro, C., Siskind, E. J., Smith, P. D., Spinelli, P., Strong, A. W., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Torres, D. F., Tosti, G., Tramacere, A., Troja, E., Uchiyama, Y., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yang, Zhaoyu, Zimmer, Stephan, and Bontemps, S.
Abstract: Context. The Cygnus region hosts a giant molecular-cloud complex that actively forms massive stars. Interactions of cosmic rays with interstellar gas and radiation fields make it shine at gamma-ray energies. Several gamma-ray pulsars and other energetic sources are seen in this direction. Aims. In this paper we analyze the gamma-ray emission measured by the Fermi Large Area Telescope (LAT) in the energy range from 100 MeV to 100 GeV in order to probe the gas and cosmic-ray content on the scale of the whole Cygnus complex. The gamma-ray emission on the scale of the central massive stellar clusters and from individual sources is addressed elsewhere. Methods. The signal from bright pulsars is greatly reduced by selecting photons in their off-pulse phase intervals. We compare the diffuse gamma-ray emission with interstellar gas maps derived from radio/mm-wave lines and visual extinction data. A general model of the region, including other pulsars and gamma-ray sources, is sought. Results. The integral HI emissivity above 100 MeV averaged over the whole Cygnus complex amounts to [2.06 +/- 0.11 (stat.) (+0.15)(-0.84) (syst.)] x 10(-26) photons s(-1) sr(-1) H-atom(-1), where the systematic error is dominated by the uncertainty on the HI opacity to calculate its column densities. The integral emissivity and its spectral energy distribution are both consistent within the systematics with LAT measurements in the interstellar space near the solar system. The average X-CO = N(H-2)/W-CO ratio is found to be [1.68 +/- 0.05 (stat.) (+0.87)(-0.10) (H I opacity)] x 10(20) molecules cm(-2) (K km s(-1))(-1), consistent with other LAT measurements in the Local Arm. We detect significant gamma-ray emission from dark neutral gas for a mass corresponding to similar to 40% of what is traced by CO. The total interstellar mass in the Cygnus complex inferred from its gamma-ray emission amounts to 8 (+5)(-1) x 10(6) M-circle dot at a distance of 1.4 kpc. Conclusions. Despite the conspicuous st, 135
Published: 2012
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40. Performance of the ATLAS Trigger System in 2010

Author: Åsman, Barbro, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Hidvégi, Attila, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, Erik, Jon-And, Kerstin, Lesser, Jonas, Lundberg, Johan, Milstead, David, Moa, Torbjörn, Nordkvist, Björn, Ohm, Christian, Papadelis, Aras, Ramstedt, Magnus, Selldén, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Åsman, Barbro, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Hidvégi, Attila, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, Erik, Jon-And, Kerstin, Lesser, Jonas, Lundberg, Johan, Milstead, David, Moa, Torbjörn, Nordkvist, Björn, Ohm, Christian, Papadelis, Aras, Ramstedt, Magnus, Selldén, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: Proton–proton collisions at Ös=7s=7 TeV and heavy ion collisions at Ö{sNN}=2.76sNN=276 TeV were produced by the LHC and recorded using the ATLAS experiment’s trigger system in 2010. The LHC is designed with a maximum bunch crossing rate of 40 MHz and the ATLAS trigger system is designed to record approximately 200 of these per second. The trigger system selects events by rapidly identifying signatures of muon, electron, photon, tau lepton, jet, and B meson candidates, as well as using global event signatures, such as missing transverse energy. An overview of the ATLAS trigger system, the evolution of the system during 2010 and the performance of the trigger system components and selections based on the 2010 collision data are shown. A brief outline of plans for the trigger system in 2011 is presented., 3049, Atlas
Published: 2012
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41. Search for a Heavy Standard Model Higgs Boson in the Channel $H\to ZZ\to \ell^+\ell^-q\bar{q}$ Using the ATLAS Detector

Author: Åsman, Barbro, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Hidvégi, Attila, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, Erik, Jon-And, Kerstin, Lesser, Jonas, Lundberg, Johan, Milstead, David, Moa, Torbjörn, Nordkvist, Björn, Ohm, Christian, Papadelis, Aras, Ramstedt, Magnus, Selldén, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Åsman, Barbro, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Hidvégi, Attila, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, Erik, Jon-And, Kerstin, Lesser, Jonas, Lundberg, Johan, Milstead, David, Moa, Torbjörn, Nordkvist, Björn, Ohm, Christian, Papadelis, Aras, Ramstedt, Magnus, Selldén, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: Publikationen har totalt 3025 författare, G. Aad et al., Atlas
Published: 2012
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42. Performance of Missing Transverse Momentum Reconstruction in Proton-Proton Collisions at 7 TeV with ATLAS

Author: Åsman, Barbro, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Hidvégi, Attila, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, Erik, Jon-And, Kerstin, Lesser, Jonas, Lundberg, Johan, Milstead, David, Moa, Torbjörn, Nordkvist, Björn, Ohm, Christian, Papadelis, Aras, Ramstedt, Magnus, Selldén, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Åsman, Barbro, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Hidvégi, Attila, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, Erik, Jon-And, Kerstin, Lesser, Jonas, Lundberg, Johan, Milstead, David, Moa, Torbjörn, Nordkvist, Björn, Ohm, Christian, Papadelis, Aras, Ramstedt, Magnus, Selldén, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: The measurement of missing transverse momentum in the ATLAS detector, described in this paper, makes use of the full event reconstruction and a calibration based on reconstructed physics objects. The performance of the missing transverse momentum reconstruction is evaluated using data collected in pp collisions at a centre-of-mass energy of 7 TeV in 2010. Minimum bias events and events with jets of hadrons are used from data samples corresponding to an integrated luminosity of about 0.3 nb−1 and 600 nb−1 respectively, together with events containing a Z boson decaying to two leptons (electrons or muons) or a W boson decaying to a lepton (electron or muon) and a neutrino, from a data sample corresponding to an integrated luminosity of about 36 pb−1. An estimate of the systematic uncertainty on the missing transverse momentum scale is presented., 3031, Atlas
Published: 2012
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43. Measurement of the pseudorapidity and transverse momentum dependence of the elliptic flow of charged particles in lead-lead collisions at root s(NN)=2.76 TeV with the ATLAS detector

Author: Åsman, Barbro, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Hidvégi, Attila, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, Erik, Jon-And, Kerstin, Lesser, Jonas, Lundberg, Johan, Milstead, David, Moa, Torbjörn, Nordkvist, Björn, Ohm, Christian, Papadelis, Aras, Ramstedt, Magnus, Selldén, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Åsman, Barbro, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Hidvégi, Attila, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, Erik, Jon-And, Kerstin, Lesser, Jonas, Lundberg, Johan, Milstead, David, Moa, Torbjörn, Nordkvist, Björn, Ohm, Christian, Papadelis, Aras, Ramstedt, Magnus, Selldén, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: This Letter describes the measurement of elliptic flow of charged particles in lead-lead collisions at root s(NN) = 2.76 TeV using the ATLAS detector at the Large Hadron Collider (LHC). The results are based on an integrated luminosity of approximately 7 mu b(-1). Elliptic flow is measured over a wide region in pseudorapidity, vertical bar eta vertical bar < 2.5, and over a broad range in transverse momentum, 0.5 < p(T) < 20 GeV. The elliptic flow parameter nu(2) is obtained by correlating individual tracks with the event plane measured using energy deposited in the forward calorimeters. As a function of transverse momentum, nu(2)(p(T)) reaches a maximum at p(T) of about 3 GeV. then decreases and becomes weakly dependent on p(T) above 7-8 GeV. Over the measured pseudorapidity region, nu(2) is found to be only weakly dependent on eta, with less variation than observed at lower beam energies. The results are discussed in the context of previous measurements at lower collision energies, as well as recent results from the LHC., Publikationen har totalt 3031 författare, G. Aad et al., Atlas
Published: 2012
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44. FERMI DETECTION OF gamma-RAY EMISSION FROM THE M2 SOFT X-RAY FLARE ON 2010 JUNE 12f

Author: Ackermann, M., Ajello, M., Allafort, A., Atwood, W. B., Baldini, L., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bhat, P. N., Blandford, R. D., Bonamente, E., Borgland, A. W., Bregeon, J., Briggs, M. S., Brigida, M., Bruel, P., Buehler, R., Burgess, J. M., Buson, S., Caliandro, G. A., Cameron, R. A., Casandjian, J. M., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Connaughton, V., Conrad, Jan, Cutini, S., Dennis, B. R., de Palma, F., Dermer, C. D., Digel, S. W., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Dubois, R., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Fortin, P., Fukazawa, Y., Fusco, P., Gargano, F., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grillo, L., Grove, J. E., Gruber, D., Guiriec, S., Hadasch, D., Hayashida, M., Hays, E., Horan, D., Iafrate, G., Johannesson, G., Johnson, A. S., Johnson, W. N., Kamae, T., Kippen, R. M., Knoedlseder, J., Kuss, M., Lande, J., Latronico, L., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Mazziotta, M. N., McEnery, J. E., Meegan, C., Mehault, J., Michelson, P. F., Mitthumsiri, W., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Murphy, R., Naumann-Godo, M., Nuss, E., Nymark, T., Ohno, M., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Paciesas, W. S., Panetta, J. H., Parent, D., Pesce-Rollins, M., Petrosian, V., Pierbattista, M., Piron, F., Pivato, G., Poon, H., Porter, T. A., Preece, R., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Ritz, S., Sbarra, C., Schwartz, R. A., Sgro, C., Share, G. H., Siskind, E. J., Spinelli, P., Takahashi, H., Tanaka, T., Tanaka, Y., Thayer, J. B., Tibaldo, L., Tinivella, M., Tolbert, A. K., Tosti, G., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., von Kienlin, A., Waite, A. P., Wilson-Hodge, C., Wood, D. L., Wood, K. S., Yang, Zhaoyu, Ackermann, M., Ajello, M., Allafort, A., Atwood, W. B., Baldini, L., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bhat, P. N., Blandford, R. D., Bonamente, E., Borgland, A. W., Bregeon, J., Briggs, M. S., Brigida, M., Bruel, P., Buehler, R., Burgess, J. M., Buson, S., Caliandro, G. A., Cameron, R. A., Casandjian, J. M., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Connaughton, V., Conrad, Jan, Cutini, S., Dennis, B. R., de Palma, F., Dermer, C. D., Digel, S. W., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Dubois, R., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Fortin, P., Fukazawa, Y., Fusco, P., Gargano, F., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grillo, L., Grove, J. E., Gruber, D., Guiriec, S., Hadasch, D., Hayashida, M., Hays, E., Horan, D., Iafrate, G., Johannesson, G., Johnson, A. S., Johnson, W. N., Kamae, T., Kippen, R. M., Knoedlseder, J., Kuss, M., Lande, J., Latronico, L., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Mazziotta, M. N., McEnery, J. E., Meegan, C., Mehault, J., Michelson, P. F., Mitthumsiri, W., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Murphy, R., Naumann-Godo, M., Nuss, E., Nymark, T., Ohno, M., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Paciesas, W. S., Panetta, J. H., Parent, D., Pesce-Rollins, M., Petrosian, V., Pierbattista, M., Piron, F., Pivato, G., Poon, H., Porter, T. A., Preece, R., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Ritz, S., Sbarra, C., Schwartz, R. A., Sgro, C., Share, G. H., Siskind, E. J., Spinelli, P., Takahashi, H., Tanaka, T., Tanaka, Y., Thayer, J. B., Tibaldo, L., Tinivella, M., Tolbert, A. K., Tosti, G., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., von Kienlin, A., Waite, A. P., Wilson-Hodge, C., Wood, D. L., Wood, K. S., and Yang, Zhaoyu
Abstract: The Geostationary Operational Environmental Satellite (GOES) M2-class solar flare, SOL2010-06-12T00: 57, was modest in many respects yet exhibited remarkable acceleration of energetic particles. The flare produced an similar to 50 s impulsive burst of hard X-and gamma-ray emission up to at least 400 MeV observed by the Fermi Gamma-ray Burst Monitor and Large Area Telescope experiments. The remarkably similar hard X-ray and high-energy gamma-ray time profiles suggest that most of the particles were accelerated to energies greater than or similar to 300 MeV with a delay of similar to 10 s from mildly relativistic electrons, but some reached these energies in as little as similar to 3 s. The gamma-ray line fluence from this flare was about 10 times higher than that typically observed from this modest GOES class of X-ray flare. There is no evidence for time-extended >100 MeV emission as has been found for other flares with high-energy gamma-rays., 142
Published: 2012
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45. Measurement of the cross section for the production of a W boson in association with b-jets in pp collisions at root s=7 TeV with the ATLAS detector

Author: Åsman, Barbro, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Hidvégi, Attila, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Lesser, Jonas, Lundberg, Johan, Milstead, David A., Moa, Torbjörn, Nordkvist, Björn, Ohm, Christian C., Papadelis, Aras, Ramstedt, Magnus, Selldén, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Åsman, Barbro, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Hidvégi, Attila, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, K. Erik, Jon-And, Kerstin, Lesser, Jonas, Lundberg, Johan, Milstead, David A., Moa, Torbjörn, Nordkvist, Björn, Ohm, Christian C., Papadelis, Aras, Ramstedt, Magnus, Selldén, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: A measurement is presented of the cross section for the production of a W boson with one or two jets, of which at least one must be a b-jet, in pp collisions at root s = 7 TeV. Production via top decay is not included in the signal definition. The measurement is based on 35 pb(-1) of data collected with the ATLAS detector at the LHC. The W + b-jet cross section is defined for jets reconstructed with the anti-k(t) clustering algorithm with transverse momentum above 25 GeV and rapidity within +/-2.1. The b-jets are identified by reconstructing secondary vertices. The fiducial cross section is measured both for the electron and muon decay channel of the W boson and is found to be 10.2 +/- 1.9(stat) +/- 2.6(syst) pb for one lepton flavour. The results are compared with next-to-leading order QCD calculations, which predict a cross section smaller than, though consistent with, the measured value., Publikationen har totalt 3024 författare, G. Aad et al., Atlas
Published: 2012
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46. Search for supersymmetry in final states with jets, missing transverse momentum and one isolated lepton in √s=7 TeV pp collisions using 1 fb-1 of ATLAS data

Author: Åsman, Barbro, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Hidvégi, Attila, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, Erik, Jon-And, Kerstin, Lesser, Jonas, Lundberg, Johan, Milstead, David, Moa, Torbjörn, Nordkvist, Björn, Ohm, Christian, Papadelis, Aras, Ramstedt, Magnus, Selldén, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Åsman, Barbro, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Hidvégi, Attila, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, Erik, Jon-And, Kerstin, Lesser, Jonas, Lundberg, Johan, Milstead, David, Moa, Torbjörn, Nordkvist, Björn, Ohm, Christian, Papadelis, Aras, Ramstedt, Magnus, Selldén, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: We present an update of a search for supersymmetry in final states containing jets, missing transverse momentum, and one isolated electron or muon, using 1.04 fb-1 of proton-proton collision data at √s=7 TeV recorded by the ATLAS experiment at the LHC in the first half of 2011. The analysis is carried out in four distinct signal regions with either three or four jets and variations on the (missing) transverse momentum cuts, resulting in optimized limits for various supersymmetry models. No excess above the standard model background expectation is observed. Limits are set on the visible cross section of new physics within the kinematic requirements of the search. The results are interpreted as limits on the parameters of the minimal supergravity framework, limits on cross sections of simplified models with specific squark and gluino decay modes, and limits on parameters of a model with bilinear R-parity violation., 3007, Atlas
Published: 2012
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47. A Measurement of the Ratio of the W and Z Cross Sections with Exactly one Associated jet in pp Collisions at $\sqrt{s}=7$ TeV with ATLAS

Author: Åsman, Barbro, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Hidvégi, Attila, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, Erik, Jon-And, Kerstin, Lesser, Jonas, Lundberg, Johan, Milstead, David, Moa, Torbjörn, Nordkvist, Björn, Ohm, Christian, Papadelis, Aras, Ramstedt, Magnus, Selldén, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Åsman, Barbro, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Hidvégi, Attila, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, Erik, Jon-And, Kerstin, Lesser, Jonas, Lundberg, Johan, Milstead, David, Moa, Torbjörn, Nordkvist, Björn, Ohm, Christian, Papadelis, Aras, Ramstedt, Magnus, Selldén, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: The ratio of production cross sections of the W and Z bosons with exactly one associated jet is presented as a function of jet transverse momentum threshold. The measurement has been designed to maximise cancellation of experimental and theoretical uncertainties, and is reported both within a particle-level kinematic range corresponding to the detector acceptance and as a total cross-section ratio. Results are obtained with the ATLAS detector at the LHC in pp collisions at a centre-of-mass energy of 7 TeV using an integrated luminosity of 33 pb−1. The results are compared with perturbative leading-order, leading-log, and next-to-leading-order QCD predictions, and are found to agree within experimental and theoretical uncertainties. The ratio is measured for events with a single jet with pT>30 GeV to be 8.73±0.30(stat)±0.40(syst) in the electron channel, and 8.49±0.23(stat)±0.33(syst) in the muon channel., Publikationen har totalt 3024 författare, G. Aad et al., Atlas
Published: 2012
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48. Search for New Physics in the Dijet Mass Distribution using 1 fb-1 of pp Collision Data at $\sqrt{s}=7$ TeV Collected by the ATLAS Detector

Author: Åsman, Barbro, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Hidvégi, Attila, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, Erik, Jon-And, Kerstin, Lesser, Jonas, Lundberg, Johan, Milstead, David, Moa, Torbjörn, Nordkvist, Björn, Ohm, Christian, Papadelis, Aras, Ramstedt, Magnus, Selldén, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Åsman, Barbro, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Hidvégi, Attila, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, Erik, Jon-And, Kerstin, Lesser, Jonas, Lundberg, Johan, Milstead, David, Moa, Torbjörn, Nordkvist, Björn, Ohm, Christian, Papadelis, Aras, Ramstedt, Magnus, Selldén, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: Invariant mass distributions of jet pairs (dijets) produced in LHC proton–proton collisions at a centre-of-mass energy TeV have been studied using a data set corresponding to an integrated luminosity of 1.0 fb-1 recorded in 2011 by ATLAS. Dijet masses up to ∼4 TeV are observed in the data, and no evidence of resonance production over background is found. Limits are set at 95% C.L. for several new physics hypotheses: excited quarks are excluded for masses below 299 TeV, axigluons are excluded for masses below 3.32 TeV, and colour octet scalar resonances are excluded for masses below 1.92 TeV., Publikationen har totalt 3024 författare, G. Aad et al., Atlas
Published: 2012
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49. Measurement of the Top Quark Pair Production Cross Section in pp Collisions at $\sqrt{s}=7$ TeV in Dilepton Final States with ATLAS

Author: Åsman, Barbro, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Hidvégi, Attila, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, Erik, Jon-And, Kerstin, Lesser, Jonas, Lundberg, Johan, Milstead, David, Moa, Torbjörn, Nordkvist, Björn, Ohm, Christian, Papadelis, Aras, Ramstedt, Magnus, Selldén, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Åsman, Barbro, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Hidvégi, Attila, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, Erik, Jon-And, Kerstin, Lesser, Jonas, Lundberg, Johan, Milstead, David, Moa, Torbjörn, Nordkvist, Björn, Ohm, Christian, Papadelis, Aras, Ramstedt, Magnus, Selldén, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: A measurement of the production cross section of top quark pairs () in proton–proton collisions at a center-of-mass energy of 7 TeV recorded with the ATLAS detector at the Large Hadron Collider is reported. Candidate events are selected in the dilepton topology with large missing transverse energy and at least two jets. Using a data sample corresponding to an integrated luminosity of 35 pb−1, a production cross section is measured for an assumed top quark mass of mt=172.5 GeV. A second measurement requiring at least one jet identified as coming from a b quark yields a comparable result, demonstrating that the dilepton final states are consistent with being accompanied by b-quark jets. These measurements are in good agreement with Standard Model predictions., Publikationen har totalt 3035 författare, G. Aad et al., Atlas
Published: 2012
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50. Search for Displaced Vertices arising from Decays of New Heavy Particles in 7 TeV pp Collisions at ATLAS

Author: Åsman, Barbro, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Hidvégi, Attila, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, Erik, Jon-And, Kerstin, Lesser, Jonas, Lundberg, Johan, Milstead, David, Moa, Torbjörn, Nordkvist, Björn, Ohm, Christian, Papadelis, Aras, Ramstedt, Magnus, Selldén, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, Yang, Zhaoyu, Åsman, Barbro, Bohm, Christian, Clément, Christophe, Eriksson, Daniel, Gellerstedt, Karl, Hellman, Sten, Hidvégi, Attila, Holmgren, Sven-Olof, Johansen, Marianne, Johansson, Erik, Jon-And, Kerstin, Lesser, Jonas, Lundberg, Johan, Milstead, David, Moa, Torbjörn, Nordkvist, Björn, Ohm, Christian, Papadelis, Aras, Ramstedt, Magnus, Selldén, Björn, Silverstein, Samuel, Sjölin, Jörgen, Strandberg, Sara, Tylmad, Maja, and Yang, Zhaoyu
Abstract: We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb−1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models, Publikationen har totalt 3024 författare, G. Aad et al., Atlas
Published: 2012
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