[en] Current research falls into the following five principal areas: (1) relativistic heavy ion research (DOE support); (2) search for highly ionizing particles in e⁺e^- annihilation (PEP-2 experiment, supported by NSF) and in pp anti annihilation (NSF support); (3) cosmic-ray astrophysics (NASA and NSF support); (4) new detectors (NASA support); and (5) search for grand-unification magnetic monopoles (NSF and Calspace support). Among the experiments in progress or planned for the next two years at the Bevalac are a high-energy gamma-ray experiment with 100 times higher collecting power; detection of many new nuclides delineating the neutron dripline; hadron calorimetry with large solid angle; search for Lee-Wick matter in U-U collisons; measurement of higher order electrodynamics in dE/dx and Cerenkov radiation by ions up to U; detailed studies of anomalons, including measurement of lifetimes, with detectors capable of resolving nonintegral charge; and determination of the response of plastic track detectors to relativistic ions up to U (the latter being of crucial importance for the proof that cosmic rays come from freshly synthesized supernova debris)

[en] Current research falls into the following six principal areas: (1) relativistic heavy ion research (DOE support); (2) exotic radioactive decay modes such as ¹⁴C emission (DOE support); (3) search for highly ionizing particles in e⁺e^- annihilation (TRISTAN experiment, supported by NSF) and in anti-ppannihilation (NSF support); (4) cosmic-ray astrophysics (NASA and NSF support); (5) search for grand-unification magnetic monopoles (NSF support); and (6) ultrarelativistic nucleus-nucleus collisions (DOE support) (1986)

[en] We describe the results of a balloon-borne apparatus searching for low-energy antiprotons in the Galactic cosmic rays. For energies less than 640 MeV at the top of the atmosphere, no cosmic-ray antiprotons were observed. This yields an upper limit to the p-bar/p ratio of 4.6 x 10/sup -5/ at the 85% confidence level

[en] The measurement of ultra-high energy (UHE) neutrinos (E > 10¹⁶ eV) opens a new field of astronomy with the potential to reveal the sources of ultra-high energy cosmic rays especially if combined with observations in the electromagnetic spectrum and gravitational waves. The ARIANNA pilot detector explores the detection of UHE neutrinos with a surface array of independent radio detector stations in Antarctica which allows for a cost-effective instrumentation of large volumes. Twelve stations are currently operating successfully at the Moore's Bay site (Ross Ice Shelf) in Antarctica and at the South Pole. In this work, we will review the current state of ARIANNA and its main results. We report on a newly developed wind generator that successfully operates in the harsh Antarctic conditions and powers the station for a substantial time during the dark winter months. The robust ARIANNA surface architecture, combined with environmentally friendly solar and wind power generators, can be installed at any deep ice location on the planet and operated autonomously. We discuss the detector capabilities to determine the neutrino direction by reconstructing the signal arrival direction of a 800 m deep calibration pulser, and the reconstruction of the signal polarization using the more abundant cosmic-ray air showers. Lastly, we describe a large-scale design – ARIA – that capitalizes on the successful experience of the ARIANNA operation and is designed sensitive enough to discover the first UHE neutrino.

No abstract available

No abstract available

[en] The IceCube neutrino observatory pursues a follow-up program selecting interesting neutrino events in real-time and issuing alerts for electromagnetic follow-up observations. In 2012 March, the most significant neutrino alert during the first three years of operation was issued by IceCube. In the follow-up observations performed by the Palomar Transient Factory (PTF), a Type IIn supernova (SN IIn) PTF12csy was found 0.°2 away from the neutrino alert direction, with an error radius of 0.°54. It has a redshift of z = 0.0684, corresponding to a luminosity distance of about 300 Mpc and the Pan-STARRS1 survey shows that its explosion time was at least 158 days (in host galaxy rest frame) before the neutrino alert, so that a causal connection is unlikely. The a posteriori significance of the chance detection of both the neutrinos and the SN at any epoch is 2.2σ within IceCube's 2011/12 data acquisition season. Also, a complementary neutrino analysis reveals no long-term signal over the course of one year. Therefore, we consider the SN detection coincidental and the neutrinos uncorrelated to the SN. However, the SN is unusual and interesting by itself: it is luminous and energetic, bearing strong resemblance to the SN IIn 2010jl, and shows signs of interaction of the SN ejecta with a dense circumstellar medium. High-energy neutrino emission is expected in models of diffusive shock acceleration, but at a low, non-detectable level for this specific SN. In this paper, we describe the SN PTF12csy and present both the neutrino and electromagnetic data, as well as their analysis

[en] We describe a prototype water Cherenkov counter which has been built and tested with relativistic cosmic ray muons. An analysis of the expected photoelectron yield is described. The predicted result of 315±31 photoelectrons is compared with the experimental result of 272±30 photoelectrons. We find that over 70% of the Cherenkov photons detected have wavelengths less than 400 nm. (orig.)

[en] Kinematics predicts the severe suppression of low-energy (<1 GeV) secondary antiprotons in the Galactic cosmic rays. Thus the observation several years ago of a finite flux of low-energy antiprotons could not be explained with existing models of cosmic ray propagation, which led to a plethora of theoretical speculation. We have recently flown a balloon-borne instrument to measure the energy spectrum of cosmic-ray anti p's, and have found no antiprotons in the energy interval 200-640 MeV (corrected to the top of the atmosphere). This yields an upper limit to the anti p/p ratio of 5.5x10^-5 (90% confidence level), well below and hence contradicting the earlier result. (orig.)

[en] We report on observations of coherent, impulsive radio Cherenkov radiation from electromagnetic showers in solid ice. This is the first observation of the Askaryan effect in ice. As part of the complete validation process for the ANITA experiment, we performed an experiment at the Stanford Linear Accelerator Center in June 2006 using a 7.5 metric ton ice target. We measure for the first time the large-scale angular dependence of the radiation pattern, a major factor in determining the solid-angle acceptance of ultrahigh-energy neutrino detectors