相关论文: Constraints on Dirac Neutrinos from SN 1987A
The duration of the neutrino burst from the supernova event SN 1987A is known to be sensitive to exotic sources of cooling, such as axions radiated from the dense and hot hadronic matter thought to constitute the inner core of the…
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…
Theory of nuclear magnetic resonance (NMR) in graphene is presented. The canonical form of the electron-nucleus hyperfine interaction is strongly modified by the linear electronic dispersion. The NMR shift and spin-lattice relaxation time…
We analyze the influence of neutrino helicity conversion, $\nu_L \to \nu_R$, on the neutrino flux from a supernova caused by the interaction of the Dirac neutrino magnetic moment with a magnetic field. We show that if the neutrino has a…
We consider nucleosynthesis constraints on models which use chiral symmetry breaking as a basis for understanding very small Dirac neutrino masses. We show that present big-bang nucleosynthesis constraints impose a well-defined upper bound…
The existence of bulk sterile neutrinos in theories with large extra dimensions can naturally explain small 4-dimensional Dirac masses for the active neutrinos. We study a model with 3 bulk neutrinos and derive various constraints on the…
It is known that if neutrino is a Dirac fermion with magnetic moment, then \nu_L -> \nu_R -> \nu_L transition of supernova neutrinos may occur. The first stage of such transition is due to the neutrino spin flip inside the hot dense…
The neutrino-heating mechanism remains a viable possibility for the cause of the explosion in a wide mass range of supernova progenitors. This is demonstrated by recent two-dimensional hydrodynamic simulations with detailed,…
The gauge-singlet right-handed neutrinos would be essential to explain the tiny masses of active neutrinos. We consider the effective field theory of the Standard Model extended with these fields under the assumption that neutrinos are…
I calculate the diffuse flux of electron antineutrinos from all supernovae using the information on the neutrino spectrum from SN987A and the information on the rate of supernovae from direct supernova observations. The interval of flux…
Neutrino emissivities due to direct Urca processes of several spin-one color-superconducting phases of dense quark matter are calculated. In particular, the role of anisotropies and nodes of the gap functions is analyzed. Results for the…
We discuss the phenomenology of neutrino mixing with bulk fermions in the context of supernova physics. The constraints on the parameter space following from the usual energy loss argument can be relaxed by four orders of magnitude due to a…
The presence of narrow high-temperature emission lines from nitrogen-rich gas close to SN 1987A has been the principal observational constraint on the evolu- tionary status of the supernova's progenitor. A new analysis of the complete…
Neutrinos are among the most mysterious particles in nature. Their mass hierarchy and oscillations, as well as their antiparticle properties, are being intensively studied in experiments around the world. Moreover, in many models of physics…
Beyond-the-Standard-Model interactions of neutrinos among themselves -- {\it secret interactions} -- in the supernova core may prevent the shock revival, halting the supernova explosion. Besides, if supernova neutrinos en route to Earth…
Weak interactions in neutron $\beta$-decay exhibit parity violation through the preferential emission of right-handed antineutrinos. We identify this symmetry breaking with a reduction of phase space due to the small neutrino mass. During a…
The observation of neutrinos from Supernova~1987A has confirmed the theoretical conjecture that these particles play a crucial role during the collapse of the core of a massive star. Only one per cent of the energy they carry away from the…
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…
We consider right handed neutrino emission from charged and neutral pion condensate matter likely to be present in the supernova core associated with SN 1987 A. This is used to constrain the strength of right handed interaction and we get…
We perform general relativistic one-dimensional supernova (SN) simulations to identify observable signatures of enhanced axion emission from the pion-induced reaction $\pi^- + p \rightarrow n + a$ inside a newly born protoneutron star…