On the origin of transient effects in the solar neutrino experiment

Correlation studies of the pattern of time variation of the recorded solar neutrino flux monitored through the reaction Cl³⁷ → Ar³⁷ with various parameters of solar activity is suggestive of possible emission of a penetrating neutral particle from the sun influencing directly or indirectly the transformation Cl³⁷ → Ar³⁷ deep underground at the required rates. This possibility has to be invoked in view of the difficulties in generating the observed pattern of variations through a large modulatory mechanism involving the electron neutrino. The prediction that follows is the possible existence of a time varying component (diurnal) in the rate of some nuclear transmutations deep underground caused by an unknown neutral radiation having an interaction cross section with matter probably much larger than the canonical value of 10^-36 cm² per nucleon speculated upon by some authors in the WIMP scenario for the sun.     

The LMC supernova (SN 1987 A) as a probe for the outcome of stellar collapse

Implications from the available information on the supernova SN 1987 A are discussed for the supernova models. We derive an upper bound of 10–25 eV for the neutrino rest mass.     

Cosmic thermal neutrino background: Can it be detected?

The detection of the Cosmic Thermal Neutrino Background (CTNB) would provide the “cleanest” evidence for the hot big bang model of the early Universe. I discuss some recent thoughts on the possibility of detecting the CTNB (especially if neutrinos have a small mass of ~ few eV) by looking for certain CTNB-induced features in the extremely high energy (E ≳ 10²⁰ eV) cosmic neutrino spectrum that may become measurable in the future by some of the large-area extensive air-shower detectors being built for detecting extremely high energy cosmic rays. NAS/NRC Senior Research Associate on sabbatical leave from Indian Institute of Astrophysics, Bangalore 560 034, India.     

Influence of a strong magnetic field on the neutrino heating of a supernova shock

Based on the magnetorotational model of a supernova explosion with core collapse, we investigate the significant processes of neutrino heating of the supernova shock. These processes should be taken into account in self-consistent modeling, since the neutrino heating mechanism is capable of increasing the explosion efficiency. We show that, even in the presence of a strong magnetic field (B ～ 10¹⁵ G) in the shock formation region, the heating rate is determined with good accuracy by the absorption and emission of neutrinos in direct URCA processes. Moreover, the influence on them of a magnetic field is reduced to insignificant corrections.     

Scintillating Oils and Compatible Materials for Next Generation of Electron Anti-neutrino Detectors, After Double Chooz

The Double Chooz reactor neutrino experiment will be built in the forthcoming years. Eventhough not dedicated to geo-neutrino detection, it is based on similar experimental methods. By pushing current technology to the limits an unprecedented precision will be reached due to careful reduction and control of systematic errors below the percent level. The experience and technical innovation achieved by this project could be valuable for future geo-neutrino experiments. After discussing the Double Chooz detector design we focus on progress achieved on scintillating oils and compatible materials.     

Detection potential to point-like neutrino sources with the NEMO-km3 telescope

The NEMO Collaboration is conducting an R&D activity towards the construction of a Mediterranean km³ neutrino telescope. In this work, we present the results of Monte Carlo simulation studies on the capability of the proposed NEMO telescope to detect and identify point-like sources of high energy muon neutrinos. C. Distefano for the NEMO Collaboration.     

UHE and EHE neutrino induced taus inside the Earth

Tau neutrinos interacting inside the Earth produce τ leptons which thereafter can decay inside the atmosphere. The propagation of extremely energetic ν_τ’s and τ’s through the Earth is studied by means of a detailed Monte Carlo simulation, taking into account all major mechanisms of ν_τ interactions and τ energy loss as well as decay modes. The rates of τ’s emerging from the Earth are determined as a function of τ’s energy for several cosmic neutrino models.     

Problems of the detection of neutrino radiation from SN 1987A: Twenty years after

Basic characteristics of the “response” of underground neutrino detectors to the explosion of SN 1987A occurred on February 23, 1987, are presented. We discuss the evolution of our viewpoint on the interpretation of the results concerning the detection of neutrino radiation from the supernova over the past 20 years.     

超新星坍缩与中微子泄漏

本文用简化的中微子泄漏模式代替输运方程，计算超新星坍缩过程中的中微子变化，通过调节模式中的参数可改变中微子的俘陷密度，使之达到较为合适的值，还讨论了在中微子俘陷密度到达之前，特定密度区段（10~(-10)－5×10~(11)g／cm~3）内使电子俘获率有显著变化的一种参数方法及研究结果。     

The neutrino in the primordial magnetic field

We discuss the evolution of the massive Dirac particle in the cosmic magnetic field. The magnetic field makes the space metric anisotropic. By solving the Dirac equation we obtain the apparent magnetic moment of the neutrino in the cosmic magnetic field.