The energy spectrum of atmospheric neutrinos between 2 and 200 TeV with the AMANDA-II detector
Astroparticle Physics 34:1 (2010) 48-58
Abstract:
The muon and anti-muon neutrino energy spectrum is determined from 2000-2003 AMANDA telescope data using regularised unfolding. This is the first measurement of atmospheric neutrinos in the energy range 2-200 TeV. The result is compared to different atmospheric neutrino models and it is compatible with the atmospheric neutrinos from pion and kaon decays. No significant contribution from charm hadron decays or extraterrestrial neutrinos is detected. The capabilities to improve the measurement of the neutrino spectrum with the successor experiment IceCube are discussed.The goldstini variations
Journal of High Energy Physics 2010:10 (2010)
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. © SISSA 2010.Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter
Astroparticle Physics 34:5 (2010) 314-326
Abstract:
Data collected by the Pierre Auger Observatory through 31 August 2007 showed evidence for anisotropy in the arrival directions of cosmic rays above the Greisen-Zatsepin-Kuz'min energy threshold, 6 × 1019 eV. The anisotropy was measured by the fraction of arrival directions that are less than 3.1° from the position of an active galactic nucleus within 75 Mpc (using the Véron-Cetty and Véron 12th catalog). An updated measurement of this fraction is reported here using the arrival directions of cosmic rays recorded above the same energy threshold through 31 December 2009. The number of arrival directions has increased from 27 to 69, allowing a more precise measurement. The correlating fraction is 38-6+7%, compared with 21% expected for isotropic cosmic rays. This is down from the early estimate of 69-13+11%. The enlarged set of arrival directions is examined also in relation to other populations of nearby extragalactic objects: galaxies in the 2 Microns All Sky Survey and active galactic nuclei detected in hard X-rays by the Swift Burst Alert Telescope. A celestial region around the position of the radiogalaxy Cen A has the largest excess of arrival directions relative to isotropic expectations. The 2-point autocorrelation function is shown for the enlarged set of arrival directions and compared to the isotropic expectation. © 2010 Elsevier B.V. All rights reserved.Atmospheric effects on extensive air showers observed with the surface detector of the Pierre Auger observatory (vol 32, pg 89, 2009)
ASTROPARTICLE PHYSICS 33:1 (2010) 65-67
Exploring positive monad bundles and a new heterotic standard model
JOURNAL OF HIGH ENERGY PHYSICS (2010) ARTN 054