From AMANDA to IceCube

The first string of the neoteric high-energy neutrino telescope IceCube successfully began operating in January 2005. It is anticipated that, upon completion, the new detector will vastly increase the sensitivity and extend the reach of AMANDA to higher energies. A discussion of the IceCube’s discovery potential for extraterrestrial neutrinos, together with the prospects of new physics derived from the ongoing AMANDA research, will be the focus of this paper. Preliminary results of the first antarctic high-energy neutrino telescope AMANDA searching in the muon-neutrino channel for localized and diffuse excess of extraterrestrial neutrinos will be reviewed using data collected between 2000 and 2003. Neutrino flux limits obtained with the all-flavor dedicated ultrahigh energy and cascade analyses will be described. A first neutrino spectrum above 1 TeV in agreement with atmospheric neutrino flux expectations and no extraterrestrial contribution will be presented, followed by a discussion of a limit for neutralino cold dark matter candidates annihilating in the center of the Sun. on behalf of the IceCube Collaboration The text was submitted by the author in English.     

Astroparticle physics with AMS-02

The main physics goals of the AMS-02 experiment in the astroparticle domain are searches for antimatter and dark matter. The discovery potential of primordial antimatter by AMS-02 is presented, emphasizing the completeness of the AMS-02 detector for these searches. Meanwhile, antiproton detection suffers from a large secondary interaction background; the anti-⁴He or anti-³He signal would allow one to probe the Universe for existence of antimatter. The expected signal in AMS-02 is presented and compared to results from present experiments. The e⁺ and antiproton channels will contribute to the dark matter detection studies. A SUSY neutralino candidate is considered. The expected flux sensitivities in a three-year exposure for the e⁺/e^? ratio and antiproton yields as a function of energy are presented and compared to other direct and indirect searches.     

Astroparticle physics: Working group report

The astroparticle physics working group witnessed intense discussion and activity covering a broad range of topics ranging from supergravity and baryogenesis to compact stars and the large scale structure of the Universe. A summary of some of the subject areas in which collaborations were initiated during WHEPP-5 is presented below.     

Very high energy neutrinos

A sky survey with neutrinos may considerably extend our understanding of cosmic phenomena. Due to the low interaction cross section of neutrinos with matter and due to the high cosmic ray background the detector must be very large (of the order of 1 km³) and must be shielded. These new devices consist of a network of photo-tubes which are deployed in the depth of the ocean, of a lake or of the ice of South Pole. The detection of the Cherenkov light emitted by muons produced in muon neutrino interactions with the matter surrounding the detector will allow the reconstruction of the neutrino direction with an angular resolution of the order or lower than one degree. Several projects are underway. Their status will be reviewed in this paper.     

Working group report: Astroparticle and neutrino physics

The working group on astroparticle and neutrino physics at WHEPP-9 covered a wide range of topics. The main topics were neutrino physics at INO, neutrino astronomy and recent constraints on dark energy coming from cosmological observations of large scale structure and CMB anisotropy.     

Liquid scintillation detectors for high energy neutrinos

Large liquid scintillation detectors have been generally used for low energy neutrino measurements, in the MeV energy region. We describe the potential employment of large detectors (>1 kiloton) for studies of higher energy neutrino interactions, such as cosmic rays and long baseline experiments. When considering the physics potential of new large instruments the possibility of doing useful measurements with higher energy neutrino interactions has been overlooked. Here we take into account Fermat’s principle, which states that the first light to reach each PMT will follow the shortest path between that PMT and the point of origin. We describe the geometry of this process, and the resulting wavefront, which we call the “Fermat surface”, and discuss methods of using this surface to extract directional track information and particle identification. This capability may be demonstrated in the new long baseline neutrino beam from Jaeri accelerator to the KamLAND detector in Japan. Other exciting applications include the use of Hanohano as a movable long baseline detector in this same beam, and LENA in Europe for future long baseline neutrino beams from CERN. Also, this methodology opens up the question as to whether a large liquid scintillator detector should be given consideration for use in a future long baseline experiment from Fermilab to the DUSEL underground laboratory at Homestake.     

Probing new physics scale with high-energy neutrinos

Motivated by the new physics beyond the Standard Model through the scale at which neutrino mass has origin, we investigate its possible manifestation at low energy within the corresponding propagation of the energetic neutrino. Then, we consider the SN1987A and base on the recorded neutrino data to explore the scale range of the new physics.     

Polarization of baryons produced by high energy neutrinos

Zeitschrift für Physik C Particles and Fields - It is shown that a measurement of the baryon polarization in the reaction $$\mathop v\limits^{( - )} + N \to \mu + B + X$$ gives information on...     

High energy neutrinos from galactic sources

Analytical expressions are derived which allow to calculate flux densities of energetic neutrinos from hypothetical galactic sources, consisting of a proton accelerator and a dilute gas beam dump. The same formalism is used to calculate atmospheric muon and μ-neutrino fluxes. From the results, rates of upward going muons, both from the atmosphere and galactic sources, are computed and detection limits for neutrino emitters in the sky are established. Finally, the background in a surface detector, caused by scattered muons and charm decays in the rock, is estimated for the case of a flat surrounding.     

Medium energy neutrinos from solar flares

The production of neutrinos with energies higher than 0.1 GeV in the solar atmosphere during solar flares is discussed. Neutrinos and muons are generated in decays of π^+- mesons produced in nuclear interactions of accelerated solar flare protons with matter of the Sun. Muons themselves decay yielding neutrinos. These neutrinos could come to the Earth and be detected with neutrino telescopes. Estimations of fluxes of such neutrinos are given.     

From high energy supersymmetry breaking to low energy physics through decoupling

We reconsider a realistic model of electroweak and strong interactions with calculable mass spectrum at the tree level in which supersymmetry and an extra gauge group factor ?(1) beyond SU(3) × SU(2) × U(1) are both broken at very high energies: $\text{M}{}_{\mathrm{<mtext>SUSY</mtext>}}\text{?(M}{}_{\mathrm{<mtext>W</mtext>}}\text{M)}{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$, $\text{M}{}_{\mathrm{<mtext>U</mtext><mtext>?</mtext><mtext>(1)</mtext>}}\text{?M}\text{with}\text{M?M}{}_{\mathrm{<mtext>W</mtext>}}$. In spite of these high-energy scales, especially the large scale of supersymmetry breaking, the low energy spectrum - including the relevant Higgs boson - is decoupled from the heavy degrees of freedom. Due to the “non-renormalization” theorems this decoupling persists to all orders in perturbation theory.     

Cosmology with massive neutrinos coupled to dark energy

Cosmological consequences of a coupling between massive neutrinos and dark energy are investigated. In such models, the neutrino mass is a function of a scalar field, which plays the role of dark energy. The evolution of the background and cosmological perturbations are discussed. We find that mass-varying neutrinos can leave a significant imprint on the anisotropies in the cosmic microwave background and even lead to a reduction of power on large angular scales.     

High energy neutrinos from gamma-ray bursts with precursor supernovae

The high energy neutrino signature from proton-proton and photo-meson interactions in a supernova remnant shell ejected prior to a gamma-ray burst provides a test for the precursor supernova, or supranova, model of gamma-ray bursts. Protons in the supernova remnant shell and photons entrapped from a supernova explosion or a pulsar wind from a fast-rotating neutron star remnant provide ample targets for protons escaping the internal shocks of the gamma-ray burst to interact and produce high energy neutrinos. We calculate the expected neutrino fluxes, which can be detected by current and future experiments.     

Universal multifractal approach to intermittency in high energy physics

A new stochastic approach to intermittency in high energy physics is proposed. It yields to intermittency exponents defined independently of phase-space dimensions; their role in the calculation of generalized moments is discussed. A straightforward application of universal multifractals is suggested and a new parametric technique for phase-space analysis is provided.     

IceCube Neutrinos: from Oscillations to PeV-Energy Events

With IceCube and its low-energy extension DeepCore, a neutrino detector with an energy reach from tens of gigaelectronvolt to exaelectronvolt has been commissioned. It measures the atmospheric neutrino spectrum from the lower energies where neutrinos oscillate to energies as large as 100 TeV with a statistic of more than 100,000 events per year. The initial results suggest that IceCube can measure the oscillation parameters in an energy range that exceeds existing observations by 1 order of magnitude, thus opening a new window on neutrino physics. We emphasize the search for sterile neutrinos particularly relevant to cosmology. We also discuss the first observation of (PEV) petaelectronvolt-Energy events that cannot be accommodated by the flux anticipated by extrapolation of the present atmospheric neutrino measurements.     

Number theory meets high energy physics

Feynman amplitudes in perturbative quantum field theory are being expressed in terms of an algebra of functions, extending the familiar logarithms, and associated numbers—periods. The study of these functions (including hyperlogarithms) and numbers (like the multiple zeta values), that dates back to Leibniz and Euler, has attracted anew the interest of algebraic geometers and number theorists during the last decades. The two originally independent developments are recently coming together in an unlikely collaboration between particle physics and what were regarded as the most abstruse branches of mathematics.