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• 1. Abbasi, R.
Högskolan i Kalmar, Naturvetenskapliga institutionen.
Extending the Search for Neutrino Point Sources with IceCube above the Horizon2009Ingår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 103, nr 22, s. Article ID: 221102-Artikel i tidskrift (Refereegranskat)

Point source searches with the IceCube neutrino telescope have been restricted to one hemisphere, due to the exclusive selection of upward going events as a way of rejecting the atmospheric muon background. We show that the region above the horizon can be included by suppressing the background through energy-sensitive cuts. This improves the sensitivity above PeV energies, previously not accessible for declinations of more than a few degrees below the horizon due to the absorption of neutrinos in Earth. We present results based on data collected with 22 strings of IceCube, extending its field of view and energy reach for point source searches. No significant excess above the atmospheric background is observed in a sky scan and in tests of source candidates. Upper limits are reported, which for the first time cover point sources in the southern sky up to EeV energies.

• 2. Abbasi, R.
Högskolan i Kalmar, Naturvetenskapliga institutionen.
First Neutrino Point-Source Results from the 22 String Icecube Detector2009Ingår i: The Astrophysical Journal Letters, ISSN 2041-8205, Vol. 701, nr 1, s. L47-L51Artikel i tidskrift (Refereegranskat)

We present new results of searches for neutrino point sources in the northern sky, using data recorded in 2007-2008 with 22 strings of the IceCube detector (approximately one-fourth of the planned total) and 275.7 days of live time. The final sample of 5114 neutrino candidate events agrees well with the expected background of atmospheric muon neutrinos and a small component of atmospheric muons. No evidence of a point source is found, with the most significant excess of events in the sky at 2.2Ïƒ after accounting for all trials. The average upper limit over the northern sky for point sources of muon-neutrinos with E â€“2 spectrum is ##IMG## [http://ej.iop.org/images/1538-4357/701/1/L47/apjl318527ieqn1.gif] $E^2\,Φ _ν _μ < 1.4 \,\,\times\,\, 10^-11\; \mathrmTeV\;cm^-2\;\mathrms^-1$ , in the energy range from 3Â TeV to 3Â PeV, improving the previous best average upper limit by the AMANDA-II detector by a factor of 2.

• 3. Abbasi, R.
Högskolan i Kalmar, Naturvetenskapliga institutionen.
Limits on a Muon Flux from Neutralino Annihilations in the Sun with the IceCube 22-String Detector2009Ingår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 102, nr 20, s. Article ID: 201302-Artikel i tidskrift (Refereegranskat)

A search for muon neutrinos from neutralino annihilations in the Sun has been performed with the IceCube 22-string neutrino detector using data collected in 104.3 days of live time in 2007. No excess over the expected atmospheric background has been observed. Upper limits have been obtained on the annihilation rate of captured neutralinos in the Sun and converted to limits on the weakly interacting massive particle (WIMP) proton cross sections for WIMP masses in the range 250-5000 GeV. These results are the most stringent limits to date on neutralino annihilation in the Sun.

• 4. Abbasi, R.
Högskolan i Kalmar, Naturvetenskapliga institutionen.
Determination of the atmospheric neutrino flux and searches for new physics with AMANDA-II2009Ingår i: Physical Review D, ISSN 1550-7998, E-ISSN 1550-2368, Vol. 79, nr 10, s. Article ID: 102005-Artikel i tidskrift (Refereegranskat)

The AMANDA-II detector, operating since 2000 in the deep ice at the geographic South Pole, has accumulated a large sample of atmospheric muon neutrinos in the 100 GeV to 10 TeV energy range. The zenith angle and energy distribution of these events can be used to search for various phenomenological signatures of quantum gravity in the neutrino sector, such as violation of Lorentz invariance or quantum decoherence. Analyzing a set of 5511 candidate neutrino events collected during 1387 days of livetime from 2000 to 2006, we find no evidence for such effects and set upper limits on violation of Lorentz invariance and quantum decoherence parameters using a maximum likelihood method. Given the absence of evidence for new flavor-changing physics, we use the same methodology to determine the conventional atmospheric muon neutrino flux above 100 GeV.

• 5. Abbasi, R.
Högskolan i Kalmar, Naturvetenskapliga institutionen.
Search for point sources of high energy neutrinos with final data from AMANDA-II2009Ingår i: Physical Review D, ISSN 1550-7998, E-ISSN 1550-2368, Vol. 79, nr 6, s. Article ID: 062001-Artikel i tidskrift (Refereegranskat)

We present a search for point sources of high energy neutrinos using 3.8 yr of data recorded by AMANDA-II during 2000-2006. After reconstructing muon tracks and applying selection criteria designed to optimally retain neutrino-induced events originating in the northern sky, we arrive at a sample of 6595 candidate events, predominantly from atmospheric neutrinos with primary energy 100 GeV to 8 TeV. Our search of this sample reveals no indications of a neutrino point source. We place the most stringent limits to date on E(-2) neutrino fluxes from points in the northern sky, with an average upper limit of E(2)Phi(nu mu)+nu(tau)<= 5.2x10(-11) TeV cm(-2) s(-1) on the sum of nu(mu) and nu(tau) fluxes, assumed equal, over the energy range from 1.9 TeV to 2.5 PeV.

• 6. Abbasi, R.
Högskolan i Kalmar, Naturvetenskapliga institutionen.
Solar Energetic Particle Spectrum on 2006 December 13 Determined by IceTop2008Ingår i: The Astrophysical Journal Letters, Vol. 689, nr 1, s. L65-L68Artikel i tidskrift (Refereegranskat)

On 2006 December 13 the IceTop air shower array at the South Pole detected a major solar particle event. By numerically simulating the response of the IceTop tanks, which are thick Cerenkov detectors with multiple thresholds deployed at high altitude with no geomagnetic cutoff, we determined the particle energy spectrum in the energy range 0.6-7.6 GeV. This is the first such spectral measurement using a single instrument with a well-defined viewing direction. We compare the IceTop spectrum and its time evolution with previously published results and outline plans for improved resolution of future solar particle spectra.

• 7. Abbasi, R.
Högskolan i Kalmar, Naturvetenskapliga institutionen.
The IceCube data acquisition system: Signal capture, digitization, and timestamping2009Ingår i: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 601, nr 3, s. 294-316Artikel i tidskrift (Refereegranskat)

IceCube is a km-scale neutrino observatory under construction at the South Pole with sensors both in the deep ice (InIce) and on the surface (IceTop). The sensors, called Digital Optical Modules (DOMs). detect, digitize and timestamp the signals from optical Cherenkov-radiation photons. The DOM Main Board (MB) data acquisition subsystem is connected to the central DAQ in the IceCube Laboratory (ICL) by a single twisted copper wire-pair and transmits packetized data on demand. Time calibration is maintained throughout the array by regular transmission to the DOMs of precisely timed analog signals, synchronized to a central GPS-disciplined clock. The design goals and consequent features, functional capabilities, and initial performance of the DOM MB, and the operation of a combined array of DOMs as a system, are described here. Experience with the first InIce strings and the IceTop stations indicates that the system design and performance goals have been achieved. (c) 2009 Elsevier B.V. All rights reserved.

• 8. AMANDA Collaboration, -
Högskolan i Kalmar, Naturvetenskapliga institutionen.
Flux limits on ultra high energy neutrinos with AMANDA-B102005Ingår i: Astroparticle physics, ISSN 0927-6505, E-ISSN 1873-2852, Vol. 22, nr 5-6, s. 339-353Artikel i tidskrift (Refereegranskat)

Data taken during 1997 with the AMANDA-B10 detector are searched for a diffuse flux of neutrinos of all flavors with energies above 10(16) eV. At these energies the Earth is opaque to neutrinos, and thus neutrino induced events are concentrated at the horizon. The background are large muon bundles from down-going atmospheric air shower events. No excess events above the background expectation are observed and a neutrino flux following E-2, with an equal mix of all flavors, is limited to E(2)Phi(10(15) eV < E < 3 x 10(18) eV) less than or equal to 0.99 x 10(-6) GeV cm(-2) s(-1) sr(-1) at 90% confidence level. This is the most restrictive experimental bound placed by any neutrino detector at these energies. Bounds to specific extraterrestrial neutrino flux predictions are also presented.

• 9. AMANDA Collaboration, -
Högskolan i Kalmar, Naturvetenskapliga institutionen.
Limits to the muon flux from neutralino annihilations at the Center of the Earth with AMANDA2006Ingår i: Astroparticle physics, ISSN 0927-6505, E-ISSN 1873-2852, Vol. 26, nr 2, s. 129-139Artikel i tidskrift (Refereegranskat)

A search has been performed for nearly vertically upgoing neutrino-induced muons with the Antarctic Muon And Neutrino DetectorArray (AMANDA), using data taken over the three year period 1997–99. No excess above the expected atmospheric neutrino backgroundhas been found. Upper limits at 90% confidence level have been set on the annihilation rate of neutralinos at the center ofthe Earth, as well as on the muon flux at AMANDA induced by neutrinos created by the annihilation products.

• 10. AMANDA Collaboration, -
Högskolan i Kalmar, Naturvetenskapliga institutionen.
Limits to the muon flux from neutralino annihilations in the Sun with the AMANDA detector2006Ingår i: Astroparticle physics, ISSN 0927-6505, E-ISSN 1873-2852, Vol. 24, nr 6, s. 459-466Artikel i tidskrift (Refereegranskat)

A search for an excess of muon-neutrinos from neutralino annihilations in the Sun has been performed with the AMANDA-II neutrino detector using data collected in 143.7 days of live-time in 2001. No excess over the expected atmospheric neutrino background has been observed. An upper limit at 90% confidence level has been obtained on the annihilation rate of captured neutralinos in the Sun, as well as the corresponding muon flux limit at the Earth, both as functions of the neutralino mass in the range 100-5000 GeV.

• 11. AMANDA Collaboration, -
Högskolan i Kalmar, Naturvetenskapliga institutionen.
Search for extraterrestrial point sources of high energy neutrinos with AMANDA-II using data collected in 2000-20022005Ingår i: Physical Review D. Particles and fields, ISSN 0556-2821, E-ISSN 1089-4918, Vol. 71, nr 7, s. 077102-Artikel i tidskrift (Refereegranskat)

The results of a search for point sources of high energy neutrinos in the northern hemisphere using data collected by AMANDA-II in the years 2000, 2001, and 2002 are presented. In particular, a comparison with the single-year result previously published shows that the sensitivity was improved by a factor of 2.2. The muon neutrino flux upper limits on selected candidate sources, corresponding to an E-nu(-2) neutrino energy spectrum, are included. Sky grids were used to search for possible excesses above the background of cosmic ray induced atmospheric neutrinos. This search reveals no statistically significant excess for the three years considered.

• 12. AMANDA Collaboration, -
Högskolan i Kalmar, Naturvetenskapliga institutionen.
The ICECUBE prototype string in AMANDA2006Ingår i: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 556, nr 1, s. 169-181Artikel i tidskrift (Refereegranskat)

The Antarctic Muon And Neutrino Detector Array (AMANDA) is a high-energy neutrino telescope. It is a lattice of optical modules (OM) installed in the clear ice below the South Pole Station. Each OM contains a photomultiplier tube (PMT) that detects photons of Cherenkov light generated in the ice by muons and electrons. ICECUBE is a cubic-kilometer-sized expansion of AMANDA currently being built at the South Pole. In ICECUBE the PMT signals are digitized already in the optical modules and transmitted to the surface. A prototype string of 41 OMs equipped with this new all-digital technology was deployed in the AMANDA array in the year 2000. In this paper we describe the technology and demonstrate that this string serves as a proof of concept for the ICECUBE array. Our investigations show that the OM timing accuracy is 5 ns. Atmospheric muons are detected in excellent agreement with expectations with respect to both angular distribution and absolute rate.

Fluctuations and anomalous dimensions in QCD cascades1991Ingår i: Z. Phys. C - Particles and Fields, ISSN 0170-9739, Vol. 49, nr 1, s. 79-89Artikel i tidskrift (Refereegranskat)
Comparison of the dipole cascade model versus O(aS2) matrix elements and colour interference  in  e+ e- annihilation1992Ingår i: Nuclear Physics B, ISSN 0550-3213, E-ISSN 1873-1562, Vol. 380, nr 3, s. 391-407Artikel i tidskrift (Refereegranskat)
Prompt photon production in e+ e- annihilation1992Ingår i: Nuclear Physics B, ISSN 0550-3213, E-ISSN 1873-1562, Vol. 380, nr 3, s. 408-422Artikel i tidskrift (Refereegranskat)
LNU.
Prompt photons in e+ e- annihilation reactions1992Ingår i: Proceedings of Workshop on photon radiation from quarks / [ed] S. Cartwright, CERN , 1992, s. 74-88Konferensbidrag (Övrigt vetenskapligt)
• 17. Gustafson, G.
LNU.
Intermittency in e+ e- annihilation at PEP-PETRA energies1990Ingår i: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 248, nr 3, 4, s. 430-436Artikel i tidskrift (Refereegranskat)
• 18. IceCube Collaboration, -
Högskolan i Kalmar, Naturvetenskapliga institutionen.
Detection of Atmospheric Muon Neutrinos with the IceCube 9-String Detector2007Ingår i: Physical Review D. Particles and fields, ISSN 0556-2821, E-ISSN 1089-4918, Vol. 76, nr 2, s. 027101-Artikel i tidskrift (Refereegranskat)

The IceCube neutrino detector is a cubic kilometer TeV to PeV neutrino detector under construction at the geographic South Pole. The dominant population of neutrinos detected in IceCube is due to meson decay in cosmic-ray air showers. These atmospheric neutrinos are relatively well understood and serve as a calibration and verification tool for the new detector. In 2006, the detector was approximately 10% completed, and we report on data acquired from the detector in this configuration. We observe an atmospheric neutrino signal consistent with expectations, demonstrating that the IceCube detector is capable of identifying neutrino events. In the first 137.4 days of live time, 234 neutrino candidates were selected with an expectation of 211 +/- 76.1(syst)+/- 14.5(stat) events from atmospheric neutrinos.

• 19. IceCube Collaboration, -
Högskolan i Kalmar, Naturvetenskapliga institutionen.
First year performance of the IceCube neutrino telescope2006Ingår i: Astroparticle physics, ISSN 0927-6505, E-ISSN 1873-2852, Vol. 26, nr 3, s. 155-173Artikel i tidskrift (Refereegranskat)

The first sensors of the IceCube neutrino observatory were deployed at the South Pole during the austral summer of 2004-2005 and have been producing data since February 2005. One string of 60 sensors buried in the ice and a surface array of eight ice Cherenkov tanks took data until December 2005 when deployment of the next set of strings and tanks began. We have analyzed these data, demonstrating that the performance of the system meets or exceeds design requirements. Times are determined across the whole array to a relative precision of better than 3 ns, allowing reconstruction of muon tracks and light bursts in the ice, of air-showers in the surface array and of events seen in coincidence by surface and deep-ice detectors separated by up to 2.5 km.

• 20. IceCube Collaboration, -
Högskolan i Kalmar, Naturvetenskapliga institutionen.
Five Years of Searches for Point Sources of Astrophysical Neutrinos with the AMANDA-II Neutrino Telescope2007Ingår i: Physical Review D. Particles and fields, ISSN 0556-2821, E-ISSN 1089-4918, Vol. 75, nr 10, s. 102001-Artikel i tidskrift (Refereegranskat)

We report the results of a five-year survey of the northern sky to search for point sources of high energy neutrinos. The search was performed on the data collected with the AMANDA-II neutrino telescope in the years 2000 to 2004, with a live time of 1001 days. The sample of selected events consists of 4282 upward going muon tracks with high reconstruction quality and an energy larger than about 100 GeV. We found no indication of point sources of neutrinos and set 90% confidence level flux upper limits for an all-sky search and also for a catalog of 32 selected sources. For the all-sky search, our average (over declination and right ascension) experimentally observed upper limit Phi(0)=(E/1 TeV)(gamma)center dot d Phi/dE to a point source flux of muon and tau neutrino (detected as muons arising from taus) is Phi(nu mu)+nu(0)(mu)+Phi(nu tau)+nu(0)(tau)=11.1x 10(-11) TeV-1 cm(-2) s(-1), in the energy range between 1.6 TeV and 2.5 PeV for a flavor ratio Phi(nu mu)+nu(0)(mu)/Phi(nu tau)+nu(0)(tau)=1 and assuming a spectral index gamma=2. It should be noticed that this is the first time we set upper limits to the flux of muon and tau neutrinos. In previous papers we provided muon neutrino upper limits only neglecting the sensitivity to a signal from tau neutrinos, which improves the limits by 10% to 16%. The value of the average upper limit presented in this work corresponds to twice the limit on the muon neutrino flux Phi(nu mu)+nu(0)(mu)=5.5x10(-11) TeV-1 cm(-2) s(-1). A stacking analysis for preselected active galactic nuclei and a search based on the angular separation of the events were also performed. We report the most stringent flux upper limits to date, including the results of a detailed assessment of systematic uncertainties.

• 21. IceCube Collaboration, -
Högskolan i Kalmar, Naturvetenskapliga institutionen.
Limits on the High-Energy Gamma and Neutrino Fluxes from the SGR 1806-20 Giant Flare of 27 December 2004 with the AMANDA-II Detector2006Ingår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 97, nr 22, s. 221101-Artikel i tidskrift (Refereegranskat)

On 27 December 2004, a giant gamma flare from the Soft Gamma-Ray Repeater 1806-20 saturated many satellite gamma-ray detectors, being the brightest transient event ever observed in the Galaxy. AMANDA-II was used to search for down-going muons indicative of high-energy gammas and/or neutrinos from this object. The data revealed no significant signal, so upper limits (at 90% C.L.) on the normalization constant were set: 0.05(0.5) TeV-1 m(-2) s(-1) for gamma=-1.47 (-2) in the gamma flux and 0.4(6.1) TeV-1 m(-2) s(-1) for gamma=-1.47 (-2) in the high-energy neutrino flux.

• 22. IceCube Collaboration, -
Högskolan i Kalmar, Naturvetenskapliga institutionen.
Multiyear Search for a Diffuse Flux of Muon Neutrinos with AMANDA-II2007Ingår i: Physical Review D. Particles and fields, ISSN 0556-2821, E-ISSN 1089-4918, Vol. 76, nr 4, s. 042008-Artikel i tidskrift (Refereegranskat)

A search for TeV-PeV muon neutrinos from unresolved sources was performed on AMANDA-II data collected between 2000 and 2003 with an equivalent live time of 807 days. This diffuse analysis sought to find an extraterrestrial neutrino flux from sources with nonthermal components. The signal is expected to have a harder spectrum than the atmospheric muon and neutrino backgrounds. Since no excess of events was seen in the data over the expected background, an upper limit of E-2 Phi(90%C.L.)< 7.4x10(-8) GeV cm(-2) s(-1) sr(-1) is placed on the diffuse flux of muon neutrinos with a Phi proportional to E-2 spectrum in the energy range 16 TeV to 2.5 PeV. This is currently the most sensitive Phi proportional to E-2 diffuse astrophysical neutrino limit. We also set upper limits for astrophysical and prompt neutrino models, all of which have spectra different from Phi proportional to E-2.

• 23. IceCube Collaboration, -
Högskolan i Kalmar, Naturvetenskapliga institutionen.
On the selection of AGN neutrino source candidates for a source stacking analysis with neutrino telescopes2006Ingår i: Astroparticle physics, ISSN 0927-6505, E-ISSN 1873-2852, Vol. 26, nr 4-5, s. 282-300Artikel i tidskrift (Refereegranskat)

The sensitivity of a search for sources of TeV neutrinos can be improved by grouping potential sources together into generic classes in a procedure that is known as source stacking. In this paper, we define catalogs of Active Galactic Nuclei (AGN) and use them to perform a source stacking analysis. The grouping of AGN into classes is done in two steps: first, AGN classes are defined, then, sources to be stacked are selected assuming that a potential neutrino flux is linearly correlated with the photon luminosity in a certain energy band (radio, IR, optical, keV, GeV, TeV). Lacking any secure detailed knowledge on neutrino production in AGN, this correlation is motivated by hadronic AGN models, as briefly reviewed in this paper.The source stacking search for neutrinos from generic AGN classes is illustrated using the data collected by the AMANDA-II highenergy neutrino detector during the year 2000. No significant excess for any of the suggested groups was found. (c) 2006 Elsevier B.V. All rights reserved.

• 24. IceCube Collaboration, -
Högskolan i Kalmar, Naturvetenskapliga institutionen.
Search for Neutrino-Induced Cascades From Gamma-Ray Bursts with AMANDA2007Ingår i: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 664, nr 1, s. 397-410Artikel i tidskrift (Refereegranskat)

Using the neutrino telescope AMANDA-II, we have conducted two analyses searching for neutrino-induced cascades fromgamma-ray bursts. No evidence of astrophysical neutrinos was found, and limits are presented for several models. We also present neutrino effective areas which allow the calculation of limits for any neutrino production model. The first analysis looked for a statistical excess of events within a sliding window of 1 or 100 s ( for short and long burst classes, respectively) during the years 2001-2003. The resulting upper limit on the diffuse flux normalization times E-2 for the Waxman-Bahcall model at 1 PeV is 1.6 x 10(-6) GeVcm(-2) s(-1) sr(-1) (a factor of 120 above the theoretical prediction). For this search 90% of the neutrinos would fall in the energy range 50 TeV to 7 PeV. The second analysis looked for neutrino-induced cascades in coincidence with 73 bursts detected by BATSE in the year 2000. The resulting upper limit on the diffuse flux normalization times E-2, also at 1 PeV is 1.5 x 10(-6) GeV cm(-2) s(-1) sr(-1) (a factor of 110 above the theoretical prediction) for the same energy range. The neutrino-induced cascade channel is complementary to the up-going muon channel. We comment on its advantages for searches of neutrinos from GRBs and its future use with IceCube.

• 25. IceCube Collaboration and InterPlanetary Network, -
Högskolan i Kalmar, Naturvetenskapliga institutionen.
The Search for Muon Neutrinos from Northern Hemisphere Gamma-Ray Bursts with AMANDA2008Ingår i: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 674, nr 1, s. 357-370Artikel i tidskrift (Refereegranskat)

We present the results of the analysis of neutrino observations by the Antarctic Muon and Neutrino Detector Array(AMANDA) correlated with photon observations of more than 400 gamma-ray bursts (GRBs) in the northernhemisphere from 1997 to 2003. During this time period,AMANDA’s effective collection area for muon neutrinos waslarger than that of any other existing detector. After the application of various selection criteria to our data, we expect1 neutrino event and<2 background events. Based on our observations of zero events during and immediately priorto the GRBs in the data set, we set the most stringent upper limit on muon neutrino emission correlated with GRBs.Assuming a Waxman-Bahcall spectrum and incorporating all systematic uncertainties, our flux upper limit has anormalization at 1 PeVof E2 6:3 ; 109 GeV cm2 s1 sr1, with 90% of the events expected within the energyrange of 10 TeV to 3 PeV. The impact of this limit on several theoretical models of GRBs is discussed, as well asthe future potential for detection of GRBs by next-generation neutrino telescopes. Finally, we briefly describe severalmodifications to this analysis in order to apply it to other types of transient point sources.

• 26.
Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för matematik (MA).
Towards a wave resolution of the wave-particle duality2014Ingår i: International Journal of Modern Physics A, ISSN 0217-751X, E-ISSN 1793-656X, Vol. 29, nr 31, s. 1450185-Artikel i tidskrift (Refereegranskat)

We developed a purely field model of microphenomena-prequantum classical statistical field theory (PCSFT). This model reproduces important probabilistic predictions of QM including correlations for entangled systems. Hence, the wave-particle duality can be resolved in favor of a purely wave model. In PCSFT "particles" are just clicks of detectors.

• 27.
Högskolan i Kalmar, Naturvetenskapliga institutionen.
Search for Subrelativistic Particles with the AMANDA Neutrino Telescope2009Doktorsavhandling, monografi (Övrigt vetenskapligt)
• 28.
Högskolan i Kalmar, Naturvetenskapliga institutionen.
Subrelativistic Particle Searches with the AMANDA-II Detector2007Ingår i: Proceedings of the 30th International Cosmic Ray Conference: session HE3.4, Vol. 4 (HE part 1), 2007, s. 803-806Konferensbidrag (Övrigt vetenskapligt)
• 29.
Lunds Universitet.
Parton cascades and multi particle production1992Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
• 30. Tanaka, T.
Högskolan i Kalmar, Naturvetenskapliga institutionen.
Data acquisition system for the PoGOLite astronomical hard X-ray polarimeter2007Ingår i: Nuclear Science Symposium Conference Record, 2007: NSS'07. IEEE, 2007, s. 445-449Konferensbidrag (Övrigt vetenskapligt)

The PoGOLite is a new balloon-borne instrument to measure the polarization of hard X-rays/soft gamma-rays in the 25-80 keV energy range for the first time. In order to detect the polarization, PoGOLite measures the azimuthal angle asymmetry of Compton scattering and the subsequent photo-absorption in an array of detectors. This array consists of 217 well-type phoswich detector cells (PDCs) surrounded by a side anti-coincidence shield (SAS) composed of 54 segments of BGO crystals. At balloon altitude, the intensity of backgrounds due to cosmic-ray charged particles, atmospheric gamma-rays and neutrons is extremely high, typically a few hundred Hz per unit. Hence the data acquisition (DAQ) system of PoGOLite is required to handle more than 270 signals simultaneously, and detect weak signals from astrophysical objects (100mCrab, 1.5 cs(-1) in 25-80 keV) under such a severe environment. We have developed a new DAQ system consisting of front-end electronics, waveform digitizer, Field Programmable Gate Array (FPGA) and a microprocessor. In this system, all output signals of PDC / SAS are fed into individual charge-sensitive amplifier and then digitized to 12 bit accuracy at 24 MSa/s by pipelined analog to digital converters. A DAQ board for the PDC records waveforms which will be examined in an off-line analysis to distinguish signals from the background events and measure the energy spectrum and polarization of targets. A board for the SAS records hit pattern to be used for background rejection. It also continuously records a pulse-height analysis (PHA) histogram to monitor incident background flux. These basic functions of the DAQ system were verified in a series of beam tests.

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