Prof Subir Sarkar: Publications

IceCube

IceCube at Oxford

I am a member since 2004 of the IceCube collaboration which discovered cosmic high energy neutrinos and identified some of their astrophysical sources.

IceCube @ Oxford

Upper Limit on the Diffuse Flux of Ultrahigh Energy Tau Neutrinos from the Pierre Auger Observatory

Physical Review Letters 100:21 (2008)

Authors:

J Abraham, P Abreu, M Aglietta, C Aguirre, D Allard, I Allekotte, J Allen, P Allison, J Alvarez-Muñiz, M Ambrosio, L Anchordoqui, S Andringa, A Anzalone, C Aramo, S Argirò, K Arisaka, E Armengaud, F Arneodo, F Arqueros, T Asch, H Asorey, P Assis, BS Atulugama, J Aublin, M Ave, G Avila, T Bäcker, D Badagnani, AF Barbosa, D Barnhill, SLC Barroso, P Bauleo, JJ Beatty, T Beau, BR Becker, KH Becker, JA Bellido, S Benzvi, C Berat, T Bergmann, P Bernardini, X Bertou, PL Biermann, P Billoir, O Blanch-Bigas, F Blanco, P Blasi, C Bleve, H Blümer, M Boháčová, C Bonifazi, R Bonino, M Boratav, J Brack, P Brogueira, WC Brown, P Buchholz, A Bueno, RE Burton, NG Busca, KS Caballero-Mora, B Cai, DV Camin, L Caramete, R Caruso, W Carvalho, A Castellina, O Catalano, G Cataldi, L Cazon, R Cester, J Chauvin, A Chiavassa, JA Chinellato, A Chou, J Chye, PDJ Clark, RW Clay, E Colombo, R Conceição, B Connolly, F Contreras, J Coppens, A Cordier, U Cotti, S Coutu, CE Covault, A Creusot, A Criss, J Cronin, A Curutiu, S Dagoret-Campagne, K Daumiller, BR Dawson, RM De Almeida, C De Donato, SJ De Jong, G De La Vega, WJM De Mello Junior, JRT De Mello Neto

Abstract:

The surface detector array of the Pierre Auger Observatory is sensitive to Earth-skimming tau neutrinos that interact in Earth's crust. Tau leptons from ντ charged-current interactions can emerge and decay in the atmosphere to produce a nearly horizontal shower with a significant electromagnetic component. The data collected between 1 January2004 and 31 August 2007 are used to place an upper limit on the diffuse flux of ντ at EeV energies. Assuming an Eν-2 differential energy spectrum the limit set at 90% C.L. is Eν2dNντ/dEν<1.3×10-7GeVcm-2s-1sr-1 in the energy range 2×1017eV

Intergalactic propagation of ultrahigh energy cosmic ray nuclei: An analytic approach

Physical Review D Particles Fields Gravitation and Cosmology 77:10 (2008)

Authors:

D Hooper, S Sarkar, AM Taylor

Abstract:

It is likely that ultrahigh energy cosmic rays contain a significant component of heavy or intermediate mass nuclei. The propagation of ultrahigh energy nuclei through cosmic radiation backgrounds is more complicated than that of protons and its study has required the use of Monte Carlo techniques. We present an analytic method for calculating the spectrum and the composition at Earth of ultrahigh energy cosmic rays which start out as heavy nuclei from their extragalactic sources. The results obtained are in good agreement with those obtained using numerical methods. © 2008 The American Physical Society.

Fine tuning and the ratio of tensor to scalar density fluctuations from cosmological inflation

(2008)

Authors:

Shaun Hotchkiss, Gabriel German, Graham G Ross, Subir Sarkar

Erratum: Multiyear search for a diffuse flux of muon neutrinos with AMANDA-II [Phys. Rev. D 76, 042008 (2007)]

Physical Review D American Physical Society (APS) 77:8 (2008) 089904

Authors:

A Achterberg, M Ackermann, J Adams, J Ahrens, K Andeen, J Auffenberg, X Bai, B Baret, SW Barwick, R Bay, K Beattie, T Becka, JK Becker, K-H Becker, P Berghaus, D Berley, E Bernardini, D Bertrand, DZ Besson, E Blaufuss, DJ Boersma, C Bohm, J Bolmont, S Böser, O Botner, A Bouchta, J Braun, T Burgess, T Castermans, D Chirkin, B Christy, J Clem, DF Cowen, MV D’Agostino, A Davour, CT Day, C De Clercq, L Demirörs, F Descamps, P Desiati, T DeYoung, JC Diaz-Velez, J Dreyer, JP Dumm, MR Duvoort, WR Edwards, R Ehrlich, J Eisch, RW Ellsworth, PA Evenson, O Fadiran, AR Fazely, K Filimonov, C Finley, MM Foerster, BD Fox, A Franckowiak, R Franke, TK Gaisser, J Gallagher, R Ganugapati, H Geenen, L Gerhardt, A Goldschmidt, JA Goodman, R Gozzini, T Griesel, A Groß, S Grullon, RM Gunasingha, M Gurtner, C Ha, A Hallgren, F Halzen, K Han, K Hanson, D Hardtke, R Hardtke, JE Hart, Y Hasegawa, T Hauschildt, D Hays, J Heise, K Helbing, M Hellwig, P Herquet, GC Hill, J Hodges, KD Hoffman, B Hommez, K Hoshina, D Hubert, B Hughey, J-P Hülß, PO Hulth, K Hultqvist, S Hundertmark, M Inaba, A Ishihara, J Jacobsen, GS Japaridze, H Johansson, A Jones, JM Joseph, K-H Kampert, A Kappes, T Karg, A Karle, H Kawai, JL Kelley, F Kislat, N Kitamura, SR Klein, S Klepser, G Kohnen, H Kolanoski, L Köpke, M Kowalski, T Kowarik, M Krasberg, K Kuehn, M Labare, H Landsman, R Lauer, H Leich, D Leier, I Liubarsky, J Lundberg, J Lünemann, J Madsen, R Maruyama, K Mase, HS Matis, T McCauley, CP McParland, A Meli, T Messarius, P Mészáros, H Miyamoto, A Mokhtarani, T Montaruli, A Morey, R Morse, SM Movit, K Münich, R Nahnhauer, JW Nam, P Nießen, DR Nygren, H Ögelman, A Olivas, S Patton, C Peña-Garay, C Pérez de los Heros, A Piegsa, D Pieloth, AC Pohl, R Porrata, J Pretz, PB Price, GT Przybylski, K Rawlins, S Razzaque, E Resconi, W Rhode, M Ribordy, A Rizzo, S Robbins, P Roth, F Rothmaier, C Rott, D Rutledge, D Ryckbosch, H-G Sander, S Sarkar, K Satalecka, S Schlenstedt, T Schmidt, D Schneider, D Seckel, B Semburg, SH Seo, Y Sestayo, S Seunarine, A Silvestri, AJ Smith, M Solarz, C Song, JE Sopher, GM Spiczak, C Spiering, M Stamatikos, T Stanev, T Stezelberger, RG Stokstad, MC Stoufer, S Stoyanov, EA Strahler, T Straszheim, K-H Sulanke, GW Sullivan, TJ Sumner, I Taboada, O Tarasova, A Tepe, L Thollander, S Tilav, M Tluczykont, PA Toale, D Tosi, D Turčan, N van Eijndhoven, J Vandenbroucke, A Van Overloop, V Viscomi, B Voigt, W Wagner, C Walck, H Waldmann, M Walter, Y-R Wang, C Wendt, CH Wiebusch, C Wiedemann, G Wikström, DR Williams, R Wischnewski, H Wissing, K Woschnagg, XW Xu, G Yodh, S Yoshida, JD Zornoza

Search for ultra-high-energy neutrinos with AMANDA-II

Astrophysical Journal 675:2 (2008) 1014-1024

Authors:

M Ackermann, J Adams, J Ahrens, K Andeen, J Auffenberg, X Bai, B Baret, SW Barwick, R Bay, K Beattie, T Becka, JK Becker, KH Becker, M Beimforde, P Berghaus, D Berley, E Bernardini, D Bertrand, DZ Besson, E Blaufuss, DJ Boersma, C Bohm, J Bolmont, S Böser, O Botner, A Bouchta, J Braun, T Burgess, T Castermans, D Chirkin, B Christy, J Clem, DF Cowen, MV D'Agostino, A Davour, CT Day, C De Clercq, L Demirörs, F Descamps, P Desiati, G De Vries-Uiterweerd, T De Young, JC Diaz-Velez, J Dreyer, JP Dumm, MR Duvoort, WR Edwards, R Ehrlich, J Eisch, RW Ellsworth, PA Evenson, O Fadiran, AR Fazely, K Filimonov, C Finley, MM Foerster, BD Fox, A Franckowiak, R Franke, TK Gaisser, J Gallagher, R Ganugapati, H Geenen, L Gerhardt, A Goldschmidt, JA Goodman, R Gozzini, T Griesel, A Grob, S Grullon, RM Gunasingha, M Gurtner, C Ha, A Halloren, F Halzen, K Han, K Hanson, D Hardtke, R Hardtke, Y Hasegawa, T Hauschildt, J Heise, K Helbing, M Hellwig, P Herquet, GC Hill, J Hodges, KD Hoffman, B Hommez, K Hoshina, D Hubert, B Hughey, JP Hülß, PO Hulth, K Hultqvist, S Hundertmark, M Inaba, A Ishihara, J Jacobsen, GS Japaridze

Abstract:

A search for diffuse neutrinos with energies in excess of 105 GeV is conducted with AMANDA-II data recorded between 2000 and 2002. Above 107 GeV, the Earth is essentially opaque to neutrinos. This fact, combined with the limited overburden of the AMANDA-II detector (roughly 1.5 km), concentrates these ultra-high-energy neutrinos at the horizon. The primary background for this analysis is bundles of downgoing, high-energy muons from the interaction of cosmic rays in the atmosphere. No statistically significant excess above the expected background is seen in the data, and an upper limit is set on the diffuse all-flavor neutrino flux of E2Φ 90%Cl < 2.7 × 10-7 GeV cm-2 s -1 sr-1 valid over the energy range of 2 × 10 5 to 109 GeV. A number of models that predict neutrino fluxes from active galactic nuclei are excluded at the 90% confidence level. © 2008. The American Astronomical Society. All rights reserved.

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