Proc. Neutrino Astrophysics - MPP Theory Group

More documents

Recommendations

Info

72 Figure 4: Expected event rates at the Superkamiokande (SK) detector for various cosmological models, as a function of kinetic energy of positrons produced by the reaction ¯νep → e + n. This figure corresponds to Figure 3 of the SRN spectrum. The thick lines show the event rate for a low-density, flat universe with Ω0 = 0.2, λ0 = 0.8, and three different values of the Hubble constant; h = 0.5 (bottom line), h = 0.8 (middle line), and h = 1.0 (top line). The dashed line shows the event rate for a low-density, open universe with Ω0 = 0.2, λ0 = 0.0, and h = 0.8, and the dot-dashed line for an Einstein-de Sitter universe with Ω0 = 1.0, λ0 = 0.0, and h = 0.5. The S1 model is used to represent the evolution of spiral galaxies, and the standard SFR model for elliptical galaxies. The epoch of galaxy formation is set to be zF = 5. For an illustrative purpose of comparison, two event rate curves based on a model with a constant supernova rate are also shown by the two dotted lines. The used rates of supernovae are the same with those used in Fig. 3.
Supernova <strong>Neutrino</strong> Opacities G.G. Raffelt Max-Planck-Institut für Physik (Werner-Heisenberg-Institut) Föhringer Ring 6, 80805 München, Germany The collapsed cores of supernovae are so dense and hot that neutrinos are trapped. Therefore, the transport of energy and lepton number is governed by the neutrino transport coefficients, i.e. by their effective scattering and absorption cross sections. While electrons cannot be entirely ignored, it is the interaction with nucleons which is thought to dominate the neutrino opacities. The cross sections can be dramatically modified by medium effects; strong magnetic fields which can also be important will not be considered here. Final-state blocking by degenerate nucleons is one obvious modification of the vacuum cross sections [1]. Even this trivial effect depends sensitively on the nucleon dispersion relation; a reduced effective nucleon mass increases the degree of degeneracy. Moreover, depending on the equation of state the composition may deviate from a naive proton-neutron mixture in that there may be a significant fraction of hyperons. Studies of opacities with self-consistent compositions and dispersion relations reveal large modifications [2]. The neutrino interaction with nucleons is dominated by the axial vector current, i.e. it is a spin-dependent phenomenon. At supernuclear densities one thus expects a dominant role for spin-spin correlations [3]; the use of uncorrelated single-particle states for an opacity calculation amounts to an uncontrolled approximation. A less intuitive effect is the cross-section reduction by the nucleon spin fluctuations which are described by the dynamical dependence of the spin-density structure function [4, 5, 6]. In Fig. 1 the reduction of the average neutrino-nucleon axial-vector cross section is shown as a function of the assumed nucleon spin fluctuation rate Γσ. A perturbative calculation yields Γσ/T ≈ 20–50 for a SN core, but the true value is not known. Still, spin fluctuations (dynamical correlations) certainly have a significant impact on the neutrino opacities. Figure 1: Variation of the thermally averaged axial-current neutrino scattering cross section on nucleons as a function of the nucleon spin-fluctuation rate. The curve marked “Lorentzian” is obtained from a “resummed” dynamical structure function [6]. 73
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 32 and 33: 24 known true source activity. The
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
Page 65 and 66: Convection in Newly Born Neutron St
Page 67 and 68: a b Figure 2: Panel a shows the rec
Page 69 and 70: ference). The angular variations of
Page 71 and 72: Figure 1: Neutrino luminosity and e
Page 73 and 74: [9] G.S. Bisnovatyi-Kogan, Astron.
Page 75 and 76: and the mass-to-luminosity ratio of
Page 77 and 78: Figure 1: Time variation of superno
Page 79: Figure 3: Energy spectra of the sup
Page 83 and 84: Quasilinear Diffusion of Neutrinos
Page 85 and 86: Assuming a saturated thermal distri
Page 87 and 88: Anisotropic Neutrino Propagation in
Page 89 and 90: So far the damping rate corresponds
Page 91 and 92: Cherenkov Radiation by Massless Neu
Page 93 and 94: on ω so that they are well approxi
Page 95: 2 2 / meff,e m eff 1.0 0.5 0.0 elec
Page 99 and 100: Gamma-Ray Burst Observations D.H. H
Page 101 and 102: Figure 1: The cumulative distributi
Page 103 and 104: [7] Lilly, S., in Critical Dialogue
Page 105 and 106: ) Phase Transitions in Neutron Star
Page 107 and 108: after the collapse began (nb., no e
Page 109 and 110: Models of Coalescing Neutron Stars
Page 111 and 112: Figure 2: Contour plots of the mass
Page 113 and 114: From our torus models we find that
Page 115: High-Energy Neutrinos
Page 118 and 119: 110 in gamma-rays. However, the acc
Page 120 and 121: 112 Atmospheric Muons and Neutrinos
Page 122 and 123: 114 Today, however, charm productio
Page 124 and 125: 116 Atmospheric Neutrinos in Super-
Page 126 and 127: 118 number of events 300 200 100 (a
Page 128 and 129: 120 Acknowledgements D.K. is suppor
Page 130 and 131:
122 Key signatures for νµ nucleon
Page 132 and 133:
124 (a.u) 0.5 0.4 0.3 0.2 0.1 0 0 1
Page 134 and 135:
126 However, in order to operate th
Page 136 and 137:
128 could be gravitationally captur
Page 138 and 139:
130 Ground-Based Observation of Gam
Page 140 and 141:
132 Figure 2: Sensitivities in unit
Page 142 and 143:
134 Crab flux Figure 4: Gamma-ray f
Page 144 and 145:
136
Page 147 and 148:
Helium Absorption and Cosmic Reioni
Page 149 and 150:
Non-Standard Big Bang Nucleosynthes
Page 151 and 152:
) Non-standard Neutrino Properties
Page 153 and 154:
some heating of the plasma. In cont
Page 155 and 156:
Big Bang Nucleosynthesis With Small
Page 157 and 158:
Neutrinos and Structure Formation i
Page 159 and 160:
Photon and Neutrino Backgrounds The
Page 161 and 162:
The (photon) temperature at aeq is
Page 163 and 164:
spectrum has therefore changed to 1
Page 165 and 166:
Figure 4: Growth of structure in CD
Page 167:
Future Prospects
Page 170 and 171:
162 Figure 1: Calorimetric β − s
Page 172 and 173:
164 References [1] F. Gatti: Procee
Page 174 and 175:
166 The frequency of Galactic super
Page 176 and 177:
168 Table 1: Comparison of proposed
Page 178 and 179:
170 Neutrinos in Astrophysics José
Page 180 and 181:
172 N eq 7 6.5 6 5.5 5 4.5 4 3.5 3
Page 182 and 183:
174 Figure 4: SN 1987A bounds on FC
Page 184 and 185:
176 [5] A. Joshipura and J. W. F. V
Page 186 and 187:
178 Some Neutrino Events of the 21s
Page 188 and 189:
180 2099: Relic Neutrinos And last
Page 190 and 191:
182
Page 192 and 193:
184 Tuesday, Oct. 21: Supernova Neu
Page 194 and 195:
186 Michael Altmann Technische Univ
Page 196 and 197:
188 Paolo Gondolo Max-Planck-Instit
Page 198 and 199:
190 Patrizia Meunier Max-Planck-Ins
Page 200 and 201:
192 Torsten Soldner Technische Univ
Page 202 and 203:
194 A Experimental Particle Physics
Page 204:
196 C Astrophysics and Cosmology C1
show all

Proc. Neutrino Astrophysics - MPP Theory Group

Create successful ePaper yourself

Delete template?

Save as template?