相关论文: SN1987A - a Testing Ground for the KARMEN Anomaly
Constraints on the lifetime of the heavy sterile neutrino, that was proposed as a possible interpretation of the KARMEN anomaly, are derived from primordial nucleosynthesis and SN 1987A. Together with the recent experimental bounds on the…
A recently reported anomaly in the time structure of signals in the KARMEN neutrino detector suggests the decay of a new particle $x$, produced in $\pi^+ \to \mu^+ x$ with mass $m_x=33.9$ MeV. We discuss the constraints and difficulties in…
We consider the hypothesis that the recently reported anomaly in the time structure of signals in the KARMEN experiment is due to the production of a light photino (or Zino) which decays radiatively due to violation of $R$-parity. Such a…
The KARMEN experiment observes a time anomaly in events induced by pion decay at rest. This anomaly can be ascribed to the production of a new weakly interacting particle X with mass m_X\sim 34 MeV. We show that a recently proposed…
What did we learn out of SN1987A neutrino observations? What do we still need for a full understanding? We select important issues debated in the literature on SN1987A. We focus the discussion mostly on the relevance of certain data…
Motivated by the anomaly in the KARMEN experiment, we study new possibilities for brane-world models of neutrino masses. We show that the KARMEN anomaly can be understood in the context of a six-dimensional brane-world model. The…
Evidence was previously reported for an 8 MeV neutrino line associated with SN 1987A based on an analysis of 997 events recorded in the Kamiokande-II detector on the day of the supernova. That claimed line, however, occurred at the peak of…
An anomaly in the time behaviour of the signals observed by the KARMEN Collaboration may be interpreted as the possible decay signature of a 33.9 MeV/c$^2$ mainly sterile neutrino. This note discusses the parameter space still open for the…
We obtain stringent bounds on neutrino quantum decoherence from the analysis of SN1987A data. We show that for the decoherence model considered here, which allows for neutrino-loss along the trajectory, the bounds are many orders of…
The SN1987A detection through neutrinos was an event of great importance in neutrino physics, being the first detection of neutrinos created outside our solar system, and then inaugurating the era of experimental neutrino astronomy. The…
The neutrino signal from SN~1987A provides an excellent opportunity to constrain physical theories for matter at extreme conditions and properties of particles that are produced in supernova (SN) cores. Phase transitions in the supranuclear…
The standard model for Type II supernovae explosion, confirmed by the detection of the neutrinos emitted during the supernova explosion, predicts the formation of a compact object, usually assumed to be a neutron star. However, the lack of…
We analyze the possibility of superluminal neutrino propagation delta v = (v - c)/c > 0 as indicated by OPERA data, in view of previous phenomenological constraints from supernova SN1987a and gravitational Cerenkov radiation. We argue that…
The neutrino experiment KARMEN is situated at the beam stop neutrino source ISIS. It provides nu_mu's, nu_e's and nu_mu_bar's in equal intensities from the pi+ mu+ decay at rest. The oscillation channels nu_mu->nu_e and nu_mu_bar->nu_e_bar…
Several possible statistical interpretations of the null result of the KARMEN 2 neutrino oscillation experiment are discussed with the aim of clarifying the implications of the fact that KARMEN 2 did not observe any of the expected…
Neutrino astronomy offers the prospect to be able to look into the interior of compact astrophysical objects which may be the sources of cosmic radiation. This paper describes the results on neutrino observations from the sun and the…
We derive the event-by-event likelihood that allows to extract the complete information contained in the energy, time and direction of supernova neutrinos, and specify it in the case of SN1987A data. We resolve discrepancies in the previous…
The Karmen anomaly can be interpreted as being due to a heavy neutrino of mass around 137 MeV produced in $\pi_{e 2}$ decays. This interpretation is consistent with the present limits on the couplings of such an object.
Supernova neutrinos are of considerable importance for ongoing research in astrophysics, nuclear and particle physics. Existing simulations of this complex event are increasingly sophisticated, but the accuracy with which they describe the…
The remnant of SN 1987A is the best-studied object of its kind. The rich data-set of its thermal and non-thermal emission across the electromagnetic spectrum poses a unique testbed for the elaboration of particle-acceleration theory. We use…