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Sep 20, 2013
09/13
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F. Halzen
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This superbly organized workshop invited the participants to focus on four outstanding questions in weak interactions: i) is the electroweak model correct at the quantum level? ii)supersymmetry? iii) neutrino mass? iv) what is the nature of CP-violation? The meeting demonstrated how weak-interaction physics has become a terrain successfully covered by accelerator and non-accelerator experiments in a very complimentary way.
Source: http://arxiv.org/abs/hep-ph/9308375v1
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Sep 23, 2013
09/13
by
F. Halzen
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Although high energy neutrino astronomy is a multidisciplinary science, gamma ray bursts have become the theoretical focus since recent astronomical observations revealed their potential as cosmic particle accelerators. This spotlight is shared with investigations of the potential of high energy telescopes to observe oscillating atmospheric neutrinos. The Superkamiokande results have boosted atmospheric neutrinos from a calibration tool and a background for doing astronomy, to an opportunity to...
Source: http://arxiv.org/abs/astro-ph/9904216v1
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Sep 22, 2013
09/13
by
F. Halzen
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Kilometer-scale neutrino detectors such as IceCube are discovery instruments covering nuclear and particle physics, cosmology and astronomy. Examples of their multidisciplinary missions include the search for the particle nature of dark matter and for additional small dimensions of space. In the end, their conceptual design is very much anchored to the observational fact that Nature accelerates protons and photons to energies in excess of 10^{20} and 10^{13} eV, respectively. The cosmic ray...
Source: http://arxiv.org/abs/astro-ph/0501593v1
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Sep 19, 2013
09/13
by
F. Halzen
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Although we have a theory of strong interactions, its implications for the physics of average hadron collisions, which is the focus of this series of conferences, are far from obvious. QCD has nevertheless been a very powerful guide and I will argue that a consensus description of ``soft" hadronic physics is emerging at least at the phenomenological level, even though the message is hidden by a myriad of competing models such as the Lipatov Pomeron, the jet model, dual topological...
Source: http://arxiv.org/abs/hep-ph/9307237v1
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Sep 19, 2013
09/13
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F. Halzen
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We introduce neutrino astronomy from the observational fact that Nature accelerates protons and photons to energies in excess of 10^{20} and 10^{13} eV, respectively. Although the discovery of cosmic rays dates back close to a century, we do not know how and where they are accelerated. We review the facts as well as the speculations about the sources. Among these gamma ray bursts and active galaxies represent well-motivated speculations because these are also the sources of the highest energy...
Source: http://arxiv.org/abs/astro-ph/0206268v1
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Sep 20, 2013
09/13
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F. Halzen
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Initial deployment of optical modules near 1 and 2 kilometer depth indicate that deep polar ice is the most transparent known natural solid. Experience with early data has revealed that a detector, conceived to measure muons tracks, can also measure energy of high energy neutrinos as well as bursts of MeV neutrinos, e.g. produced by supernovae and gamma ray bursts. We plan to complete AMANDA this austral summer to form a detector of 11 deep strings instrumented over 400 meters height with 300...
Source: http://arxiv.org/abs/hep-ex/9611014v1
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Sep 22, 2013
09/13
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F. Halzen
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Although cosmic rays were discovered 90 years ago, we do not know how and where they are accelerated. There is compelling evidence that the highest energy cosmic rays are extra-galactic -- they cannot be contained by our galaxy's magnetic field anyway because their gyroradius exceeds its dimensions. Elementary elementary-particle physics dictates a universal upper limit on their energy of $5\times10^{19}$ eV, the so-called Greisen-Kuzmin-Zatsepin cutoff; however, particles in excess of this...
Source: http://arxiv.org/abs/astro-ph/0111059v1
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Sep 19, 2013
09/13
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F. Halzen
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An ever-increasing body of evidence suggests that weakly interacting massive particles (WIMPs) constitute the bulk of the matter in the Universe. Experimental data, dimensional analysis and Standard Model particle physics are sufficient to evaluate and compare the performance of detectors searching for such particles either directly (e.g.\ by their scattering in germanium detectors), or indirectly (e.g.\ by observing their annihilation into neutrinos in underground detectors). We conclude that...
Source: http://arxiv.org/abs/hep-ph/9506304v1
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Sep 19, 2013
09/13
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F. Halzen
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With an effective telescope area of order 10^4 m^2, a threshold of ~50 GeV and a pointing accuracy of 2.5 degrees, the AMANDA detector represents the first of a new generation of high energy neutrino telescopes, reaching a scale envisaged over 25 years ago. We describe its performance, focussing on the capability to detect halo dark matter particles via their annihilation into neutrinos.
Source: http://arxiv.org/abs/hep-ex/9804007v1
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Sep 20, 2013
09/13
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F. Halzen
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We introduce neutrino astronomy starting from the observational fact that Nature accelerates protons and photons to energies in excess of 10^{20} and 10^{13} eV, respectively. Although the discovery of cosmic rays dates back a century, we do not know how and where they are accelerated. We review the observations as well as speculations about the sources. Among these gamma ray bursts and active galaxies represent well-motivated speculations because these are also the sources of the highest...
Source: http://arxiv.org/abs/astro-ph/0301143v1
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Sep 19, 2013
09/13
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F. Halzen
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This is the summary of a week of very informative presentations on new ways to probe the Universe using gravitational detectors, space and ground based gamma ray telescopes, EeV air shower detectors and neutrino telescopes. Gamma ray bursts and active galaxies were hot theoretical themes in the multi-wavelength discussions.
Source: http://arxiv.org/abs/astro-ph/9703004v1
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Sep 21, 2013
09/13
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F. Halzen
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Kilometer-scale neutrino detectors such as IceCube are discovery instruments covering nuclear and particle physics, cosmology and astronomy. Examples of their multidisciplinary missions include the search for the particle nature of dark matter and for additional small dimensions of space. In the end, their conceptual design is very much anchored to the observational fact that Nature accelerates protons and photons to energies in excess of 10^{20} and 10^{13} eV, respectively. The cosmic ray...
Source: http://arxiv.org/abs/astro-ph/0311004v1
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Sep 20, 2013
09/13
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F. Halzen
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Kilometer-scale neutrino detectors such as IceCube are discovery instruments covering nuclear and partile physics, cosmology and astronomy. Examples of their multidisciplinary mission include the search for the particle nature of dark matter and for additional small dimensions of space. In these lectures, we discuss the nature of cosmic neutrinos and their sources, the need for kilometer-scale detectors and the status and methodologies of current detectors.
Source: http://arxiv.org/abs/astro-ph/0506248v1
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Sep 21, 2013
09/13
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F. Halzen
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Kilometer-scale neutrino detectors such as IceCube are discovery instruments covering nuclear and particle physics, cosmology and astronomy. Examples of their multidisciplinary missions include the search for the particle nature of dark matter and for additional small dimensions of space. In the end, their conceptual design is very much anchored to the observational fact that Nature accelerates protons and photons to energies in excess of $10^{20}$ and $10^{13}$ eV, respectively. The cosmic ray...
Source: http://arxiv.org/abs/astro-ph/0402083v1
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Sep 21, 2013
09/13
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F. Halzen
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An ever-increasing body of evidence suggests that weakly interacting massive particles (WIMPs) constitute the bulk of the matter in the Universe. We illustrate how experimental data, dimensional analysis and Standard Model particle physics are sufficient to evaluate and compare the potential of detectors searching for such particles either directly (e.g.\ by their scattering in germanium detectors), or indirectly (e.g.\ by observing their annihilation into neutrinos in underground detectors).
Source: http://arxiv.org/abs/astro-ph/9508020v1
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Sep 24, 2013
09/13
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F. Halzen
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Of all high-energy particles, only neutrinos can directly convey astronomical information from the edge of the universe---and from deep inside the most cataclysmic high-energy processes. Copiously produced in high-energy collisions, travelling at the velocity of light, and not deflected by magnetic fields, neutrinos meet the basic requirements for astronomy. Their unique advantage arises from a fundamental property: they are affected only by the weakest of nature's forces (but for gravity) and...
Source: http://arxiv.org/abs/astro-ph/0103195v1
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Sep 19, 2013
09/13
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F. Halzen
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In this review we first address two questions: 1. Why do we need kilometer-scale muon and neutrino detectors? 2. What do we learn from the operating Baikal and AMANDA detectors about the construction of kilometer-scale detectors? I will subsequently discuss the challenges for building the next-generation detectors. The main message is that these are different, in fact less ominous, than for commissioning the present, relatively small, detectors which must reconstruct events far outside their...
Source: http://arxiv.org/abs/hep-ex/9801009v1
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Sep 23, 2013
09/13
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F. Halzen
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We present the theoretical arguments and describe the accumulating experimental evidence that jets, powered by supermassive black holes, are true cosmic accelerators. They produce photons of TeV energy, possible higher, and may be the enigmatic source of the highest energy cosmic rays. The features of the multi-wavelength emission spectrum are dictated by the interactions of electrons and protons, accelerated in the vicinity of the black hole, with the ambient light in the galaxy....
Source: http://arxiv.org/abs/astro-ph/9608185v1
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Sep 22, 2013
09/13
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F. Halzen
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Doing astronomy with photons of energies in excess of a GeV has turned out to be extremely challenging. Efforts are underway to develop instruments that may push astronomy to wavelengths smaller than $10^{-14}$~cm by mapping the sky in high energy neutrinos instead. Neutrino astronomy, born with the identification of thermonuclear fusion in the sun and the particle processes controlling the fate of a nearby supernova, will reach outside the galaxy and make measurements relevant to cosmology....
Source: http://arxiv.org/abs/hep-ph/9410386v1
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Sep 18, 2013
09/13
by
F. Halzen
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The objective of neutrino astronomy, born with the identification of thermonuclear fusion in the sun and the particle processes controlling the fate of a nearby supernova, is to build instruments which reach throughout and far beyond our Galaxy and make measurements relevant to cosmology, astrophysics, cosmic-ray and particle physics. These telescopes will push astronomy to wavelengths smaller than $10^{-14}$~cm by mapping the sky in high-energy neutrinos instead of high-energy photons to which...
Source: http://arxiv.org/abs/astro-ph/9605014v1
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Sep 22, 2013
09/13
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F. Halzen
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Active galaxies and gamma ray bursts are the sources of the highest energy photons detected by astronomical telescopes. We speculate that they may be the sources of the highest energy cosmic rays. This makes them true proton accelerators, where the highest energy photons are the decay products of neutral pions photoproduced when the proton beams interacts with ambient radiation. Neutrinos from the decay of charged pions represent an incontrovertible signature for proton acceleration. A main...
Source: http://arxiv.org/abs/astro-ph/9704020v1
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Sep 20, 2013
09/13
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F. Halzen
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The first optical modules of the Baikal high energy neutrino telescope have recently been deployed. Commissioning of the AMANDA, DUMAND and NESTOR detectors will follow soon. Before discussing the detectors we review the arguments that pinpoint $0.1\rm~km^2$ as the natural scale of a neutrino telescope. Though present detectors do not quite reach this goal, their techniques, if successful, can be exploited to build km$^2$ detectors for a cost not exceeding one hundred million dollars....
Source: http://arxiv.org/abs/hep-ph/9308373v1
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Jul 20, 2013
07/13
by
F. Halzen
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Surrounded by stunning Algarve landscapes not far from where Henry the Navigator organized the voyages that mapped the Earth, particle astrophysicists discussed new initiatives to explore the cosmos. While first generation experiments opened new voyages of the mind with evidence for neutrino mass and a cosmological constant, much of the discussion focussed on novel experimental assaults on the secrets of the Universe. While "big-time" particle physics entered space with AMS and high...
Source: http://arxiv.org/abs/astro-ph/9902041v1
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Sep 20, 2013
09/13
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F. Halzen
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1. Overview of neutrino astronomy: multidisciplinary science. 2. Cosmic accelerators: the highest energy cosmic rays. 3. Neutrino beam dumps: supermassive black holes and gamma ray bursts. 4. Neutrino telescopes: water and ice. 5. Indirect dark matter detection. 6. Towards kilometer-scale detectors.
Source: http://arxiv.org/abs/astro-ph/9810368v1
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Sep 19, 2013
09/13
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F. Halzen
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Although cosmic rays were discovered a century ago, we do not know where or how they are accelerated. There is a realistic hope that the oldest problem in astronomy will be solved soon by ambitious experimentation: air shower arrays of 10,000 kilometer-square area, arrays of air Cerenkov telescopes and kilometer- scale neutrino observatories. Their predecessors are producing science. We will review the highlights: - Cosmic rays: the highest energy particles and the GZK cutoff, the search for...
Source: http://arxiv.org/abs/astro-ph/0302489v1
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Sep 22, 2013
09/13
by
F. Halzen; G. Jaczko
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We show that the detection of neutrinos from a typical gamma ray burst requires a kilometer-scale detector. We argue that large bursts should be visible with the neutrino telescopes under construction. We emphasize the 3 techniques by which neutrino telescopes can perform this search: by triggering on i) bursts of muons from muon neutrinos, ii) muons from air cascades initiated by high energy gamma rays and iii) showers made by relatively low energy ($\simeq 100\,\mev$) electron neutrinos....
Source: http://arxiv.org/abs/astro-ph/9602038v1
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Sep 20, 2013
09/13
by
F. Halzen; T. Stanev
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Underground detectors measure the directions of up-coming muons of neutrino origin. They can also observe down-going muons made by gamma rays in the Earth's atmosphere. Although gamma ray showers are muon-poor, they produce a sufficient number of muons to detect the sources observed by GeV and TeV telescopes. With a threshold higher by one hundred and a probability of muon production of about $1\%$ for the shallower AMANDA and Lake Baikal detectors, these instruments can, for a typical GRO...
Source: http://arxiv.org/abs/hep-ph/9507362v1
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Jul 22, 2013
07/13
by
F. Halzen; E. Zas
texts
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There are tantalizing hints that jets, powered by supermassive black holes at the center of active galaxies, are true cosmic proton accelerators. They produce photons of TeV energy, possible higher, and may be the enigmatic source of the highest energy cosmic rays. Photoproduction of neutral pions by accelerated protons on UV light is the source of the highest energy photons, in which most of the bolometric luminosity of the galaxy may be emitted. The case that proton beams power active...
Source: http://arxiv.org/abs/astro-ph/9702193v1
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Sep 23, 2013
09/13
by
M. M. Block; F. Halzen
texts
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It is well known that high energy data alone do not discriminate between asymptotic $\ln s$ and $\ln^2s$ behavior of $pp$ and $\bar pp$ cross sections. By exploiting high quality low energy data, analyticity resolves this ambiguity in favor of cross sections that grow asymptotically as $\ln^2s$. We here show that two methods for incorporating the low energy data into the high energy fits give numerically identical results and yield essentially identical tightly constrained values for the LHC...
Source: http://arxiv.org/abs/hep-ph/0510238v2
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Jul 20, 2013
07/13
by
J. Alvarez-Muniz; F. Halzen
texts
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Because of the limited size of the satellite-borne instruments, it has not been possible to observe the flux of gamma ray bursts (GRB) beyond GeV energy. We here show that it is possible to detect the GRB radiation of TeV energy and above, by detecting the muon secondaries produced when the gamma rays shower in the Earth's atmosphere. Observation is made possible by the recent commissioning of underground detectors (AMANDA, the Lake Baikal detector and MILAGRO) which combine a low muon...
Source: http://arxiv.org/abs/astro-ph/9902039v1
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Sep 17, 2013
09/13
by
J. Alvarez-Muniz; F. Halzen
texts
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We show that a kilometer-scale neutrino observatory, though optimized for TeV to PeV energy, is sensitive to the neutrinos associated with super-EeV sources. These include super-heavy relics, neutrinos associated with the Greisen cutoff, and topological defects which are remnant cosmic structures associated with phase transitions in grand unified gauge theories. It is a misconception that new instruments optimized to EeV energy are required to do this important science. Because kilometer-scale...
Source: http://arxiv.org/abs/astro-ph/0007329v3
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Sep 18, 2013
09/13
by
M. M. Block; F. Halzen
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Using an eikonal analysis, we simultaneously fit a QCD-inspired parameterization of all accelerator data on forward proton-proton and antiproton-proton scattering amplitudes, together with cosmic ray data (using Glauber theory), to predict proton-air and proton-proton cross sections at energies near \sqrt s \approx 30 TeV. The p-air cosmic ray measurements greatly reduce the errors in the high energy proton-proton and proton-air cross section predictions--in turn, greatly reducing the errors in...
Source: http://arxiv.org/abs/hep-ph/0101022v1
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Sep 21, 2013
09/13
by
F. Halzen; J. E Jacobsen
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High energy particles are produced by the annihilation of dark matter particles in our galaxy. These are presently searched for using balloon-borne antiproton and positron detectors and large area, deep underground neutrino telescopes. Dark matter particles, trapped inside the sun, are an abundant source of such neutrinos. From both the cosmological and particle physics points of view the lightest, stable supersymmetric particle or neutralino is arguably the leading dark matter candidate. Its...
Source: http://arxiv.org/abs/hep-ph/9404252v1
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Sep 20, 2013
09/13
by
M. M. Block; F. Halzen
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It is well known that fits to high energy data cannot discriminate between asymptotic ln(s) and ln^2(s) behavior of total cross section. We show that this is no longer the case when we impose the condition that the amplitudes also describe, on average, low energy data dominated by resonances. We demonstrate this by fitting real analytic amplitudes to high energy measurements of the gamma p total cross section, for sqrt(s) > 4 GeV. We subsequently require that the asymptotic fit smoothly join...
Source: http://arxiv.org/abs/hep-ph/0405174v1
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Sep 18, 2013
09/13
by
M. M. Block; F. Halzen
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Landshoff and Donnachie[hep-ph/0509240, (2005)] parametrize the energy behavior of pp and p\bar p scattering cross sections with five parameters, using: \sigma^+=56.08 s^{-0.4525}+21.70s^{0.0808} for pp, \sigma^-=98.39 s^{-0.4525}+21.70s^{0.0808} for p\bar p. Using the 4 analyticity constraints of Block and Halzen[M. M. Block and F. Halzen, Phys. Rev. D {\bf 72}, 036006 (2005)], we simultaneously fit the Landshoff-Donnachie form to the same ``sieved'' set of pp and p\bar p cross section and...
Source: http://arxiv.org/abs/hep-ph/0605216v1
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Sep 19, 2013
09/13
by
J. Alvarez-Muniz; F. Halzen
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We show that a kilometer-scale neutrino observatory, though optimized for detecting neutrinos of TeV to PeV energy, can reveal the science associated with the enigmatic super-EeV radiation in the Universe. Speculations regarding its origin include heavy relics from the early Universe, particle interactions associated with the Greisen cutoff, and topological defects which are remnant cosmic structures associated with phase transitions in grand unified gauge theories. We show that it is a...
Source: http://arxiv.org/abs/astro-ph/0102106v2
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Sep 23, 2013
09/13
by
F. Halzen; J. E. Jacobsen
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High energy neutrinos are produced by the annihilation of dark matter particles in our galaxy. These are presently searched for with large area, deep underground neutrino telescopes. Cold dark matter particles, trapped inside the sun, are an abundant source of such neutrinos. Back-of-the-envelope calculations are sufficient to demonstrate how neutrino telescopes are competitive with existing and future particle colliders such as the LHC in the search for weakly interacting massive cold dark...
Source: http://arxiv.org/abs/hep-ph/9406309v1
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Sep 23, 2013
09/13
by
F. Halzen; D. W. Hooper
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We recalculate the diffuse flux of high energy neutrinos produced by Gamma Ray Bursts (GRB) in the relativistic fireball model. Although we confirm that the average single burst produces only ~10^{-2} high energy neutrino events in a detector with 1 km^2 effective area, i.e. about 10 events per year, we show that the observed rate is dominated by burst-to-burst fluctuations which are very large. We find event rates that are expected to be larger by one order of magnitude, likely more, which are...
Source: http://arxiv.org/abs/astro-ph/9908138v3
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Sep 20, 2013
09/13
by
M. M. Block; F. Halzen
texts
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Fits to high energy data alone cannot cleanly discriminate between asymptotic $\ln s$ and $\ln^2s$ behavior of total hadronic cross sections. We demonstrate that this is no longer true when we require that these amplitudes also describe, on average, low energy data dominated by resonances.
Source: http://arxiv.org/abs/hep-ph/0506031v2
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Sep 18, 2013
09/13
by
M. C. Gonzalez-Garcia; F. Halzen
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Very high energy, short wavelength, neutrinos may interact with the space-time foam predicted by theories of quantum gravity. They would propagate like light through a crystal lattice and be delayed, with the delay depending on the energy. This will appear to the observer as a violation of Lorenz invariance. Back of the envelope calculations imply that observations of neutrinos produced by gamma ray bursts may reach Planck-scale sensitivity. We revisit the problem considering two essential...
Source: http://arxiv.org/abs/hep-ph/0611359v1
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Sep 23, 2013
09/13
by
M. M. Block; F. Halzen; T. Stanev
texts
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We use the high energy predictions of a QCD-inspired parameterization of all accelerator data on forward proton-proton and antiproton-proton scattering amplitudes, along with Glauber theory, to predict proton-air cross sections at energies near \sqrt s \approx 30 TeV. The parameterization of the proton-proton cross section incorporates analyticity and unitarity, and demands that the asymptotic proton is a black disk of soft partons. By comparing with the p-air cosmic ray measurements, our...
Source: http://arxiv.org/abs/hep-ph/9908222v2
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Sep 23, 2013
09/13
by
S. Barwick; F. Halzen; P. B. Price
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The hope is that in the near future neutrino astronomy, born with the identification of thermonuclear fusion in the sun and the particle processes controlling the fate of a nearby supernova, will reach throughout and beyond our Galaxy and make measurements relevant to cosmology, astrophysics, cosmic-ray and particle physics. The construction of a high-energy neutrino telescope requires a huge volume of very transparent, deeply buried material such as ocean water or ice, which acts as the medium...
Source: http://arxiv.org/abs/astro-ph/9512079v1
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Sep 19, 2013
09/13
by
G. Burdman; F. Halzen; R. Gandhi
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It has been argued that the observations of cosmic particles with energies in excess of $10^8$ TeV represent a puzzle. Its solution requires new astrophysics or new particle physics. We show that the latter is unlikely given that the scale associated with a new particle physics threshold must be of order 1 GeV, not TeV and above, in order to resolve the problem. In most cases such new physics should have been revealed by accelerator experiments. We examine the possibility that the highest...
Source: http://arxiv.org/abs/hep-ph/9709399v1
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Sep 19, 2013
09/13
by
F. Halzen; J. E. Jacobsen; E. Zas
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We have simulated the response of a high energy neutrino telescope to the stream of low energy neutrinos produced by a supernova. The nominal threshold of such detectors is in the GeV energy range. The passage of a large flux of MeV neutrinos during a period of seconds will nevertheless be detected as an excess of single counting rates in all individual optical modules. Detectors under construction, which consist of roughly 200 modules, will be able to detect a galactic supernova at or above...
Source: http://arxiv.org/abs/hep-ph/9307240v1
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Sep 18, 2013
09/13
by
F. Halzen; for the AMANDA Collaboration
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With an effective telescope area of order $10^4$ m$^2$ for TeV neutrinos, a threshold near $\sim$50 GeV and a pointing accuracy of 2.5 degrees per muon track, the AMANDA detector represents the first of a new generation of high energy neutrino telescopes, reaching a scale envisaged over 25 years ago. We describe early results on the calibration of natural deep ice as a particle detector as well as on AMANDA's performance as a neutrino telescope.
Source: http://arxiv.org/abs/hep-ex/9809025v1
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Sep 22, 2013
09/13
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M. M. Block; F. Halzen; G. Pancheri
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Using an eikonal structure for the scattering amplitude, Block and Kaidalov have derived factorization theorems for nucleon-nucleon, $\gamma p$ and $\gamma\gamma$ scattering at high energies, using only some very general assumptions. We present here an analysis giving experimental confirmation for factorization of cross sections, nuclear slope parameters B and $\rho$-values (ratio of real to imaginary portion of forward scattering amplitudes), showing that: i) the three factorization theorems...
Source: http://arxiv.org/abs/hep-ph/0111046v2
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Sep 22, 2013
09/13
by
T. K. Gaisser; F. Halzen; T. Stanev
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The topic of this review is the particle astrophysics of high energy neutrinos. High energy is defined as $E_{\nu} > 100$~MeV. Main topics include: -- atmospheric neutrinos and muons from $\pi$, $K$ and charm decay. They probe uncharted territory in neutrino oscillations and constitute both the background and calibration of high energy neutrino telescopes, -- sources of high energy neutrino beams: the galactic plane, the sun, X-ray binaries, supernova remnants and interactions of...
Source: http://arxiv.org/abs/hep-ph/9410384v1
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Sep 23, 2013
09/13
by
F. Halzen; T. Stanev; G. B. Yodh
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Although gamma ray showers are muon-poor, they still produce a number of muons sufficient to make the sources observed by GeV and TeV telescopes observable also in muons. For sources with hard gamma ray spectra there is a relative `enhancement' of muons from gamma ray primaries as compared to that from nucleon primaries. All shower gamma rays above the photoproduction threshold contribute to the number of muons $N_\mu$, which is thus proportional to the primary gamma ray energy. With gamma ray...
Source: http://arxiv.org/abs/astro-ph/9608201v1
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Sep 23, 2013
09/13
by
F. Halzen; J. E. Jacobsen; E. Zas
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We have simulated the response of a high energy neutrino telescope in deep Antarctic ice to the stream of low energy neutrinos produced by a supernova. The passage of a large flux of MeV-energy neutrinos during a period of seconds will be detected as an excess of single counting rates in all individual optical modules. We update here a previous estimate of the performance of such an instrument taking into account the recent discovery of absorption lengths of several hundred meters for near-UV...
Source: http://arxiv.org/abs/astro-ph/9512080v1
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Sep 18, 2013
09/13
by
O. Eboli; F. Halzen; K. Mizukoshi
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The sources of $W + n$-jet events in hadron collisions are higher-order QCD processes, but also multiple-parton interactions. A subprocess producing a $W + k$-jet final state, followed by one producing $l$ jets in the same nucleon-nucleon interaction, will result in a $W + n$-jet event if $k + l = n$. In the simplest case a $W + 2$-jet event can be produced by a quark-antiquark annihilation into $W$ and a 2-jet event occurring in the same proton-antiproton interaction. We compute that this...
Source: http://arxiv.org/abs/hep-ph/9710443v1
