We consider the flavor evolution of a dense neutrino gas by taking into account both vacuum oscillations and self-interactions neutrinos. examine system from many-body perspective as well point view an effective one-body description formulated in terms polarization vectors. show that, single angle approximation, picture one-particle possess several constants motion. write down these motion explicitly isospin operators for case vectors case. The existence is direct consequence fact that...

An algebraic approach to the neutrino propagation in dense media is presented. The Hamiltonian describing a gas of neutrinos interacting with each other and background fermions written terms appropriate SU(N) operators, where N number flavours. evolution resulting many-body problem formulated as coherent-state path integral. Some commonly used approximations are shown represent saddle-point solution integral for full system.

We study the effects of collective neutrino oscillations on $\nu p$ process nucleosynthesis in proton-rich neutrino-driven winds by including both multi-angle $3\times3$ flavor mixing and network calculation. The number flux energetic electron antineutrinos is raised a $1$D supernova model for $40 M_{\odot}$ progenitor. When gas temperature decreases down to $\sim2-3\times10^{9}$ K, increased promotes more actively, resulting enhancement $p$-nuclei. In early phase wind, blowing at $0.6$ s...

We consider the many-body system of neutrinos interacting with each other through neutral current weak force. Emerging effects in such a could play important roles some astrophysical sites as core collapse supernovae. In literature this is usually treated within mean field approximation which an effective one-body description based on omitting entangled neutrino states. paper, we original two flavor mixing scenario under single angle and present solution without using approximation. Our...

We consider collective oscillations of neutrinos, which are emergent nonlinear flavor evolution phenomena instigated by neutrino-neutrino interactions in astrophysical environments with sufficiently high neutrino densities. investigate the symmetries problem full three mixing scheme and exact many-body formulation including effects CP violation magnetic moment. show that, similar to two scheme, several dynamical exist for flavors single-angle approximation if net electron background...

Using the primordial helium abundance, an upper limit to magnetic moments for Dirac neutrinos had been provided by imposing restrictions on number of additional helicity states. Considering nonthermal photons produced in decay heavy sterile mass eigenstates due neutrino moment, we explore constraints imposed observed abundances all light elements during big-bang nucleosynthesis.

Following a recent suggestion of axion cooling photons between the nucleosynthesis and recombination epochs in Early Universe, we investigate hybrid model with both axions relic supersymmetric particles. In this demonstrate that 7Li abundance can be consistent observations without destroying important concordance deuterium abundance.

We give the exact solution of orbit dependent nuclear pairing problem between two nondegenerate energy levels using Bethe ansatz technique. Our reduces to previously solved cases in appropriate limits including Richardson's treatment reduced terms rational Gaudin algebra operators.

Tabulated rates for astrophysical photodisintegration reactions make use of Boltzmann statistics the photons involved as well interacting nuclei. Here we derive analytic corrections Planck-spectrum quantum photon energy distribution. These can be deduced directly from detailed-balance condition without assumption equilibrium long are represented by a Planck spectrum. Moreover show that these affect not only but also modify conditions nuclear statistical in Saha equation. We deduce new to...

We show that the spectral split of a neutrino ensemble, which initially consists electron type neutrinos, is analogous to Bardeen-Cooper-Schrieffer--Bose-Einstein condensate (BCS-BEC) crossover already observed in ultracold atomic gas experiments. Such ensemble mimics deleptonization burst core collapse supernova. Although these two phenomena belong very different domains physics, propagation neutrinos from highly interacting inner regions supernova vacuum reminiscent evolution Cooper pairs...

We apply the algebraic Bethe ansatz technique to nuclear pairing problem with orbit dependent coupling constants and degenerate single particle energy levels. find exact energies eigenstates. show that for a given shell, there are degeneracies between states corresponding less than more half full shell. also provide solve equations of ansatz.

Three well-known solutions of the Gaudin equation are obtained under a set standard assumptions. By relaxing one these assumptions we introduce class mutually commuting Hamiltonians based on different solution equation. Application algebraic Bethe ansatz technique to diagonalize reveals new infinite dimensional complex Lie algebra.

We introduce a class of exactly solvable boson models. give explicit analytic expressions for energy eigenvalues and eigenvectors an sd-boson Hamiltonian, which is related to the SO(6) chain Interacting Boson Model Hamiltonian.

We show that nuclear pairing Hamiltonian exhibits supersymmetry in the strong-coupling limit. The underlying supersymmetric quantum mechanical structure explains degeneracies between energies of N and Nmax-N+1 pair eigenstates. transformations connecting these states are given.

We introduce a new class of exactly solvable boson pairing models using the technique Richardson and Gaudin. Analytical expressions for all energy eigenvalues first few eigenstates are given. In addition, another solution to Gaudin's equation is also mentioned. A relation with Calogero-Sutherland model suggested.

Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation Y. Pehlivan, Toshitaka Kajino, A. B. Balantekin, Takashi Yoshida, Tomoyuki Maruyama; On the Neutrino Self Refraction Problem from a Many‐Body Perspective. AIP Conf. Proc. 12 August 2010; 1269 (1): 189–194. https://doi.org/10.1063/1.3485133 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends...

Collective neutrino oscillations in a core collapse supernova is many-body phenomenon which can transform the energy spectra through emergent effects. One example of this behavior spectral swaps neutrinos different flavors partially or completely exchange their spectra. In talk, we address question how model dependent is. particular, demonstrate that these may be independent mean field approximation typically employed numerical treatments by showing an swap exact picture.

Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation T. Kajino, W. Aoki, A. B. Balantekin, M.-K. Cheoun, Hayakawa, J. Hidaka, Y. Hirai, M. Kusakabe, G. Mathews, K. Nakamura, Pehlivan, S. Shibagaki, Suzuki; Cosmological supernova neutrinos. AIP Conf. Proc. 24 June 2014; 1604 (1): 193–200. https://doi.org/10.1063/1.4883430 Download citation file: Ris (Zotero)...

We calculate the response of a lead-based detector, such as Helium and Lead Observatory (HALO) or its planned upgrade HALO-1kt to Galactic core-collapse supernova. pay particular attention time dependence reaction rates. All rates decrease neutrino luminosity exponentially drops during cooling period, but ratio one-neutron (1n) two-neutron (2n) event in HALO is independent this overall decrease. Nevertheless, we find that still changes with due changing character flavor transformations...

Quantum invariants of the orbit dependent pairing problem are identified in limit where orbits become degenerate. These quantum simultaneously diagonalized with help Bethe ansatz method and a symmetry their spectra relating eigenvalues corresponding to different number pairs is discussed. analogous well known rational Gaudin magnet Hamiltonians which play same role reduced case (i.e., independent non degenerate energy levels). It pointed out that although cases opposite each other,...

We study the phase effects driven by neutrino magnetic moment for Majorana neutrinos in a core collapse supernova. A with large is emitted superposition of energy eigenstates from neutrinosphere. These can interfere to create effect at partially adiabatic spin flavor precession (SFP) resonance. examine dependence SFP on size as well its variation post bounce time. In particular, late post-bounce times resonance becomes wider and eventually overlaps Mikheev-Smirnov-Wolfenstein (MSW) At this...

Pairing plays a crucial role in nuclear spectra and attempts to describe it has long history physics. The limiting case which all single particle states are degenerate, but with different s-wave pairing strengths was only recently solved. In this strong coupling limit the Hamiltonian also exhibits supersymmetry. Another solution away from those limits, namely two non-degenerate strengths, given. contribution these developments summarized difficulties possible generalizations more d-wave discussed.

A simple model of nucleons coupled to angular momentum zero (s‐pairs) occupying the valance shell a semi‐magic nuclei is considered. The has separable, orbit dependent pairing interaction which dominates over kinetic term. It shown that such an leads exactly solvable whose (0+) eigenstates and energies can be computed very easily with help algebraic Bethe ansatz method. also supersymmetry connects spectra some semimagic nuclei. results obtained from this for Ni isotopes 58Ni 68Ni are given....

Interpolation of two adjacent Hamiltonians in SUSY quantum mechanics is discussed together with related operators. For a wide variety shape-invariant degree-one and their 'discrete' counterparts, the interpolation Hamiltonian also shape-invariant, that is, it takes same form as original shifted coupling constant(s).