Proc. Neutrino Astrophysics - MPP Theory Group

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24 known true source activity. The combined analysis of both series results in R = 0.93 ± 0.08, clearly demonstrating the absence of large systematic errors which could account for the observed 40% solar neutrino deficit. A similar experiment has also been performed by the Sage collaboration. They got a quantitative recovery of R = 0.95 ± 0.12 [6]. The fact that both experiments, though employing different chemistry, demonstrated in these experiments full efficiency, proves the trustworthiness of the radiochemical method and shows that the 40% solar neutrino deficit observed in the radiochemical gallium experiments cannot be ascribed to unknown systematic errors. In particular, the 51 Cr neutrino energies nicely accommodating those from the solar 7 Be-branch, the full efficiency of the gallium experiments to 7 Be-neutrinos is demonstrated. 71 As experiments However, though the 51 Cr source in Gallex did outperform the sun by more than a factor 15 after insertion into the target tank, the experiments still are low statistics, involving only several dozens of neutrino produced 71 Ge atoms. Therefore, at the very end of Gallex the collaboration has performed a large-scale test of potential effects of hot chemistry, which might lead to a different chemical behaviour of 71 Ge produced in a nuclear reaction compared to the stable Ge carrier isotope: The in-situ production of 71 Ge by β−decay of 71 As. A known quantity of 71 As (O(10 5 ) atoms) has been added to the tank (t-sample), where it decayed with T 1/2 = 2.9d to 71 Ge. Four runs have been made under different operating conditions (mixing, carrier addition, standing time), cf. table 2. For every spike a reference sample (e-sample) was kept aside, making possible to calculate the ratio of t- and e-sample which does not suffer from most of the systematic uncertainties associated with 71 Ge-counting. Table 2: Experimental conditions and results (ratio t-sample/e-sample) of the 71 As runs. run mixing conditions Ge-carrier standing result [h × m 3 /h] addition time (tank / external) A1 22 × 5.5 with As 19.9 d 1.01 ± 0.03 +0.17 × 60 A2 6 × 5.5 no Ge-carrier 19.9 d 1.00 ± 0.03 B3-1 24 × 5.5 after As 2.0 d 1.01 ± 0.03 B3-2 — after As 22.0 d 1.00 ± 0.03 In all cases a quantitative recovery of 100% was achieved. This demonstrates on a 3%-level the absence of withholding effects even under unfavourable conditions like carrier-free operation 1 . Gallium Neutrino Observatory With the 71 As-tests Gallex has completed its large-scale experimental program. However, solar neutrino measurements with a gallium target at Gran Sasso will be re-commenced in spring 1998 in the frame of the Gallium Neutrino Observatory (GNO) [2] which is designed for 1 The stable germanium carrier is not only used for determination of the extraction yield, but also plays the role of an ’insurance’ to saturate potential trace impurities which might capture 71 Ge in non-volatile complexes.
long-term operation covering at least one solar cycle. In its first phase GNO will use the 30ton target of Gallex. However, for a second phase it is planned to increase the target mass to 60tons and later to 100tons. In addition, as it is equally important to decrease the systematic uncertainty, effort is made to improve 71 Ge counting, both by improving the presently used proportional counters, and by investigating novel techniques like semiconductor devices and cryogenic detectors [1]. Acknowledgements Our contribution to Gallex and Gno is supported by grants from the german BMBF, the SFB-375, and the Beschleunigerlaboratorium Garching. References [1] M.Altmann et al., Development of cryogenic detectors for GNO, Proc. 4th Int. Solar Neutrino Conf., ed.: W. Hampel, Heidelberg, Germany, 1997. [2] E.Bellotti et al., Proposal for a permanent gallium neutrino observatory at Gran Sasso, 1996. [3] M.Cribier et al., Nucl. Inst. Meth. A 378 (1996) 233. [4] Gallex Collaboration, Phys.Lett. B 285 (1992) 376. [5] E.Henrich et al., Angew. Chem. Int. Ed. Engl. 31 (1992) 1283. [6] SAGE Collaboration, Phys. Rev. Lett. 77 (1996) 4708. [7] SAGE Collaboration, in Proc. 4th Int. Solar Neutrino Conf., ed.: W. Hampel, Heidelberg, Germany, 1997. 25
Page 1 and 2: arXiv:astro-ph/9801320v1 30 Jan 199
Page 3: Preface This was the fourth worksho
Page 6 and 7: vi S.J. Hardy Quasilinear Diffusion
Page 8 and 9: viii
Page 11 and 12: History of Neutrino Physics: Pauli
Page 13 and 14: Brief an Oskar Klein, Stockholm, vo
Page 15 and 16: Recent observations with the Hubble
Page 17 and 18: MACHO sample of ∼100,000 light cu
Page 19: Solar Neutrinos
Page 22 and 23: 14 In the depth range where an abun
Page 24 and 25: 16 as follows: (1) All the detector
Page 26 and 27: 18 [3] J.N. Bahcall and H.A. Bethe,
Page 28 and 29: 20 the opacity has a very slowly ch
Page 30 and 31: 22 Status of the Radiochemical Gall
Page 34 and 35: 26 Solar Neutrino Observation with
Page 36 and 37: 28 Events/day/kton/bin 0.3 0.25 0.2
Page 38 and 39: 30 log(Δm 2 (eV 2 log(Δm )) 2 (eV
Page 40 and 41: 32 Table 1: Neutrino event rates in
Page 42 and 43: 34 tank and sphere high purity wate
Page 44 and 45: 36 Measurements of Low Energy Nucle
Page 46 and 47: 38 Figure 1: The S(E) factor of 3 H
Page 48 and 49: 40 Solar Neutrinos: Where We Are an
Page 50 and 51: 42 [9] B. Pontecorvo, Chalk River R
Page 52 and 53: 44 Figure 2: The difference between
Page 55 and 56: Phenomenology of Supernova Explosio
Page 57 and 58: Figure 2: Theoretical classificatio
Page 59 and 60: Supernova Rates Bruno Leibundgut Eu
Page 61 and 62: galaxies, however, and the statisti
Page 63 and 64: Figure 1: The motions of pulsars re
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Page 73 and 74: [9] G.S. Bisnovatyi-Kogan, Astron.
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Quasilinear Diffusion of Neutrinos
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Assuming a saturated thermal distri
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Anisotropic Neutrino Propagation in
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So far the damping rate corresponds
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Cherenkov Radiation by Massless Neu
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on ω so that they are well approxi
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2 2 / meff,e m eff 1.0 0.5 0.0 elec
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Gamma-Ray Burst Observations D.H. H
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Figure 1: The cumulative distributi
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[7] Lilly, S., in Critical Dialogue
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) Phase Transitions in Neutron Star
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after the collapse began (nb., no e
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Models of Coalescing Neutron Stars
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Figure 2: Contour plots of the mass
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From our torus models we find that
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High-Energy Neutrinos
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110 in gamma-rays. However, the acc
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112 Atmospheric Muons and Neutrinos
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114 Today, however, charm productio
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116 Atmospheric Neutrinos in Super-
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118 number of events 300 200 100 (a
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120 Acknowledgements D.K. is suppor
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122 Key signatures for νµ nucleon
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124 (a.u) 0.5 0.4 0.3 0.2 0.1 0 0 1
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126 However, in order to operate th
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128 could be gravitationally captur
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130 Ground-Based Observation of Gam
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132 Figure 2: Sensitivities in unit
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134 Crab flux Figure 4: Gamma-ray f
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136
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Helium Absorption and Cosmic Reioni
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Non-Standard Big Bang Nucleosynthes
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) Non-standard Neutrino Properties
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some heating of the plasma. In cont
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Big Bang Nucleosynthesis With Small
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Neutrinos and Structure Formation i
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Photon and Neutrino Backgrounds The
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The (photon) temperature at aeq is
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spectrum has therefore changed to 1
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Figure 4: Growth of structure in CD
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Future Prospects
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162 Figure 1: Calorimetric β − s
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164 References [1] F. Gatti: Procee
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166 The frequency of Galactic super
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168 Table 1: Comparison of proposed
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170 Neutrinos in Astrophysics José
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172 N eq 7 6.5 6 5.5 5 4.5 4 3.5 3
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174 Figure 4: SN 1987A bounds on FC
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176 [5] A. Joshipura and J. W. F. V
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178 Some Neutrino Events of the 21s
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180 2099: Relic Neutrinos And last
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182
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184 Tuesday, Oct. 21: Supernova Neu
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186 Michael Altmann Technische Univ
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188 Paolo Gondolo Max-Planck-Instit
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190 Patrizia Meunier Max-Planck-Ins
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192 Torsten Soldner Technische Univ
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194 A Experimental Particle Physics
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196 C Astrophysics and Cosmology C1
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