Stabilizing the Complex Structure in Heterotic Calabi-Yau Vacua

(2010)

Authors:

Lara B Anderson, James Gray, Andre Lukas, Burt Ovrut

The goldstini variations

J HIGH ENERGY PHYS SPRINGER (2010) 095

Authors:

N Craig, J March-Russell, M McCullough

Abstract:

We study the 'goldstini' scenario of Cheung, Nomura, and Thaler, in which multiple independent supersymmetry (SUSY) breaking sectors lead to multiple would-be goldstinos, changing collider and cosmological phenomenology. In supergravity, potentially large corrections to the previous prediction of twice the gravitino mass for goldstini masses can arise when their scalar partners are stabilized far from the origin. Considerations arising from the complexity of realistic string compactifications indicate that many of the independent SUSY-breaking sectors should be conformally sequestered or situated in warped Randall-Sundrum-like throats, further changing the predicted goldstini masses. If the sequestered hidden sector is a metastable SUSY-breaking sector of the Intriligator-Seiberg-Shih (ISS) type then multiple goldstini can originate from within a single sector, along with many supplementary 'modulini', all with masses of order twice the gravitino mass. These fields can couple to the Supersymmetric Standard Model (SSM) via the 'Goldstino Portal'. Collider signatures involving SSM sparticle decays can provide strong evidence for warped-or-conformally-sequestered sectors, and of the ISS mechanism of SUSY breaking. Along with axions and photini, the Goldstino Portal gives another potential window to the hidden sectors of string theory.

Kinetic mixing of U(1)s for local string models

ArXiv 1009.238 (2010)

Authors:

Mathew Bullimore, Joseph P Conlon, Lukas T Witkowski

Abstract:

We study kinetic mixing between massless U(1)s in toroidal orbifolds with D3-branes at orbifold singularities. We focus in particular on C^3/Z_4 singularities but also study C^3/Z_6 and C^3/Z'_6 singularities. We find kinetic mixing can be present and describe the conditions for it to occur. Kinetic mixing comes from winding modes in the N=2 sector of the orbifold. If kinetic mixing is present its size depends only on the complex structure modulus of the torus and is independent of the K\"ahler moduli. We also study gauge threshold corrections for local Z_M x Z_N orbifold models finding that, consistent with previous studies, gauge couplings run from the bulk winding scale rather than the string scale.

Kinetic mixing of U(1)s for local string models

(2010)

Authors:

Mathew Bullimore, Joseph P Conlon, Lukas T Witkowski

The first search for extremely-high energy cosmogenic neutrinos with the IceCube Neutrino Observatory

ArXiv 1009.1442 (2010)

Authors:

IceCube Collaboration, R Abbasi, Y Abdou, T Abu-Zayyad, J Adams, JA Aguilar, M Ahlers, K Andeen, J Auffenberg, X Bai, M Baker, SW Barwick, R Bay, JL Bazo Alba, K Beattie, JJ Beatty, S Bechet, JK Becker, K-H Becker, ML Benabderrahmane, J Berdermann, P Berghaus, D Berley, E Bernardini, D Bertrand, DZ Besson, M Bissok, E Blaufuss, DJ Boersma, C Bohm, S Böser, O Botner, L Bradley, J Braun, S Buitink, M Carson, D Chirkin, B Christy, J Clem, F Clevermann, S Cohen, C Colnard, DF Cowen, MV D'Agostino, M Danninger, JC Davis, C De Clercq, L Demirörs, O Depaepe, F Descamps, P Desiati, G de Vries-Uiterweerd, T DeYoung, JC Díaz-Vélez, J Dreyer, JP Dumm, MR Duvoort, R Ehrlich, J Eisch, RW Ellsworth, O Engdegård, S Euler, PA Evenson, O Fadiran, AR Fazely, T Feusels, K Filimonov, C Finley, MM Foerster, BD Fox, A Franckowiak, R Franke, TK Gaisser, J Gallagher, R Ganugapati, M Geisler, L Gerhardt, L Gladstone, T Glüsenkamp, A Goldschmidt, JA Goodman, D Grant, T Griesel, A Groß, S Grullon, M Gurtner, C Ha, A Hallgren, F Halzen, K Han, K Hanson, K Helbing, P Herquet, S Hickford, GC Hill, KD Hoffman, A Homeier, K Hoshina, D Hubert, W Huelsnitz, J-P Hülß, PO Hulth, K Hultqvist, S Hussain, RL Imlay, A Ishihara, J Jacobsen, GS Japaridze, H Johansson, JM Joseph, K-H Kampert, A Kappes, T Karg, A Karle, JL Kelley, N Kemming, P Kenny, J Kiryluk, F Kislat, SR Klein, S Knops, J-H Köhne, G Kohnen, H Kolanoski, L Köpke, DJ Koskinen, M Kowalski, T Kowarik, M Krasberg, T Krings, G Kroll, K Kuehn, T Kuwabara, M Labare, S Lafebre, K Laihem, H Landsman, R Lauer, R Lehmann, D Lennarz, J Lünemann, J Madsen, P Majumdar, R Maruyama, K Mase, HS Matis, M Matusik, K Meagher, M Merck, P Mészáros, T Meures, E Middell, N Milke, J Miller, T Montaruli, R Morse, SM Movit, R Nahnhauer, JW Nam, U Naumann, P Nießen, DR Nygren, S Odrowski, A Olivas, M Olivo, S Panknin, L Paul, C Pérez de los Heros, J Petrovic, A Piegsa, D Pieloth, R Porrata, J Posselt, PB Price, M Prikockis, GT Przybylski, K Rawlins, P Redl, E Resconi, W Rhode, M Ribordy, A Rizzo, JP Rodrigues, P Roth, F Rothmaier, C Rott, C Roucelle, T Ruhe, D Rutledge, B Ruzybayev, D Ryckbosch, H-G Sander, S Sarkar, K Schatto, S Schlenstedt, T Schmidt, D Schneider, A Schukraft, A Schultes, O Schulz, M Schunck, D Seckel, B Semburg, SH Seo, Y Sestayo, S Seunarine, A Silvestri, A Slipak, GM Spiczak, C Spiering, M Stamatikos, T Stanev, G Stephens, T Stezelberger, RG Stokstad, S Stoyanov, EA Strahler, T Straszheim, GW Sullivan, Q Swillens, I Taboada, A Tamburro, O Tarasova, A Tepe, S Ter-Antonyan, S Tilav, PA Toale, D Tosi, D Turčan, N van Eijndhoven, J Vandenbroucke, A Van Overloop, J van Santen, B Voigt, C Walck, T Waldenmaier, M Wallraff, M Walter, C Wendt, S Westerhoff, N Whitehorn, K Wiebe, CH Wiebusch, G Wikström, DR Williams, R Wischnewski, H Wissing, K Woschnagg, C Xu, XW Xu, G Yodh, S Yoshida, P Zarzhitsky

Abstract:

We report on the results of the search for extremely-high energy (EHE) neutrinos with energies above $10^7$ GeV obtained with the partially ($\sim$30%) constructed IceCube in 2007. From the absence of signal events in the sample of 242.1 days of effective livetime, we derive a 90% C.L. model independent differential upper limit based on the number of signal events per energy decade at $E^2 \phi_{\nu_e+\nu_\mu+\nu_\tau}\simeq 1.4 \times 10^{-6}$ GeV cm$^{-2}$ sec$^{-1}$ sr$^{-1}$ for neutrinos in the energy range from $3\times10^7$ to $3\times10^9$ GeV.