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Multi-GeV neutrinos due to neutro anti-neutron oscillation in Gamma-Ray Burst Fireballs
Sahu, Sarira
High Energy Physics - Phenomenology , 2007, DOI: 10.1142/S021773230702378X
Abstract: The long and short gamma-ray bursts are believed to be produced due to collapse of massive stars and merger of compact binaries respectively. All these objects are rich in neutron and the jet outflow from these objects must have a neutron component in it. By postulating the neutron anti-neutron oscillation in the gamma-ray burst fireball, we show that, 19-38 GeV neutrinos and anti-neutrinos can be produced due to annihilation of anti-neutrons with the background neutrons. These neutrinos and anti-neutrinos will be produced before the 5-10 GeV neutrinos due to dynamical decoupling of neutrons from the rest of the fireball. Observation of these neutrinos will shed more light on the nature of the GRB progenitors and also be a unique signature of physics beyond the standard model. A possible way of detecting these neutrinos in future is also discussed.
Effects of conversions for high energy neutrinos originating from cosmological gamma-ray burst fireballs  [PDF]
H. Athar
Physics , 1999,
Abstract: We study neutrino conversions in the recently envisaged source of high energy ($E \geq 10^{6}$ GeV) neutrinos, that is, in the vicinity of cosmological gamma-ray burst fireballs (GRB). We consider mainly the possibility of neutrino conversions due to an interplay of neutrino transition magnetic moment, $\mu$, and the violation of equivalence principle (VEP), parameterized by $\Delta f$, in a reasonable strength of magnetic field in the vicinity of the GRB. We point out that for $\Delta f \sim 10^{-25}(\delta m^2/1 {eV}^2)$, a resonant spin-flavour precession between $\bar{\nu}_{\mu}$ and $\nu_{\tau}$ may occur in the vicinity of GRB for $\mu \sim 10^{-12} \mu_{B}$ ($\mu_{B}$ is Bohr magneton), thus enhancing the expected high energy $\nu_{\tau}$ flux from GRBs.
Neutrino conversions in cosmological gamma-ray burst fireballs  [PDF]
H. Athar
Physics , 2000, DOI: 10.1016/S0927-6505(00)00116-X
Abstract: We study neutrino conversions in a recently envisaged source of high-energy neutrinos (E \geq 10^6 GeV), that is, in the vicinity of cosmological Gamma-Ray Burst fireballs (GRB). We consider the effects of flavor and spin-flavor conversions and point out that in both situations, a some what higher than estimated high energy tau neutrino flux from GRBs is expected in new km^2 surface area under water/ice neutrino telescopes.
High Energy Neutrinos from Cosmological Gamma-Ray Burst Fireballs  [PDF]
Eli Waxman,John Bahcall
Physics , 1997, DOI: 10.1103/PhysRevLett.78.2292
Abstract: Observations suggest that $\gamma$-ray bursts (GRBs) are produced by the dissipation of the kinetic energy of a relativistic fireball. We show that a large fraction, $\ge 10%$, of the fireball energy is expected to be converted by photo-meson production to a burst of $\sim10^{14} eV$ neutrinos. A km^2 neutrino detector would observe at least several tens of events per year correlated with GRBs, and test for neutrino properties (e.g. flavor oscillations, for which upward moving $\tau$'s would be a unique signature, and coupling to gravity) with an accuracy many orders of magnitude better than is currently possible.
High energy cosmic-rays and neutrinos from cosmological gamma-ray burst fireballs  [PDF]
E. Waxman
Physics , 1999, DOI: 10.1238/Physica.Topical.085a00117
Abstract: The recent detection of delayed, low energy emission from Gamma-Ray Burst (GRB) sources confirmed the cosmological origin of the bursts and provided support for models where GRBs are produced by the dissipation of the kinetic energy of relativistic fireballs. In this review, ultra high energy, >10^{19} eV, cosmic-ray and high energy, 100 TeV, neutrino production in GRBs is discussed in the light of recent GRB and cosmic-ray observations. Emphasis is put on model predictions that can be tested with operating and planned cosmic-ray and neutrino detectors. The predicted neutrino intensity, E^2 dN/dE=3\times 10^{-9} GeV/(cm^2 s sr) for 10^{14} eV
Diffuse emission of high-energy neutrinos from gamma-ray burst fireballs  [PDF]
Irene Tamborra,Shin'ichiro Ando
Physics , 2015, DOI: 10.1088/1475-7516/2015/09/036
Abstract: Gamma-ray bursts (GRBs) have been suggested as possible sources of the high-energy neutrino flux recently detected by the IceCube telescope. We revisit the fireball emission model and elaborate an analytical prescription to estimate the high-energy neutrino prompt emission from pion and kaon decays, assuming that the leading mechanism for the neutrino production is lepto-hadronic. To this purpose, we include hadronic, radiative and adiabatic cooling effects and discuss their relevance for long- (including high- and low-luminosity) and short-duration GRBs. The expected diffuse neutrino background is derived, by requiring that the GRB high-energy neutrino counterparts follow up-to-date gamma-ray luminosity functions and redshift evolutions of the long and short GRBs. Although dedicated stacking searches have been unsuccessful up to now, we find that GRBs could contribute up to a few % to the observed IceCube high-energy neutrino flux for sub-PeV energies, assuming that the latter has a diffuse origin. Gamma-ray bursts, especially low-luminosity ones, could however be the main sources of the IceCube high-energy neutrino flux in the PeV range. While high-luminosity and low-luminosity GRBs have comparable intensities, the contribution from the short-duration component is significantly smaller. Our findings confirm the most-recent IceCube results on the GRB searches and suggest that larger exposure is mandatory to detect high-energy neutrinos from high-luminosity GRBs in the near future.
High Energy Neutrinos from Gamma-Ray Bursts  [PDF]
Eli Waxman
Physics , 2000, DOI: 10.1016/S0920-5632(00)00980-4
Abstract: Observations suggest that gamma-ray bursts (GRBs) are produced by the dissipation of the kinetic energy of a relativistic fireball. In this talk, recent work on the production of high energy neutrinos by GRB fireballs is reviewed. A significant fraction of GRB energy is expected to be converted to an accompanying burst of high energy neutrinos. Photomeson interactions produce a burst of ~100 TeV neutrinos in coincidence with the GRB, and a burst of \~10^18 eV neutrinos following the GRB on a time scale of 10 s. Inelastic p-n nuclear collisions result in the production of a burst of ~10 GeV neutrinos in coincidence with the GRB. Planned 1 km^3 neutrino telescopes are expected to detect tens of 100 TeV neutrino events, and several 10^18 eV events, correlated with GRBs per year. A suitably densely spaced detector may allow the detection of several 10 GeV events per year. The detection of high-energy neutrino events correlated with GRBs will allow to constrain GRB progenitor models and to test the suggestion that GRBs accelerate protons to >10^20 eV. Moreover, such detection will allow to test for neutrino properties, e.g. flavor oscillations (for which upward moving tau's would be a unique signature) and coupling to gravity, with an accuracy many orders of magnitude better than is currently possible.
Resonant oscillations of GeV - TeV neutrinos in internal shocks from gamma-ray burst jets inside the stars  [PDF]
Nissim Fraija
Physics , 2015, DOI: 10.1093/mnras/stv737
Abstract: High-energy neutrinos generated in collimated jets inside the progenitors of gamma-ray bursts (GRBs) have been related with the events detected by IceCube. These neutrinos, produced by hadronic interactions of Fermi-accelerated protons with thermal photons and hadrons in internal shocks, are the only signature when jet has not broken out or failed. Taking into account that the photon field is thermalized at keV energies and the standard assumption that the magnetic field maintains a steady value throughout the shock region (with a width of $10^{10} - 10^{11}$ cm in the observed frame), we study the effect of thermal and magnetized plasma generated in internal shocks on the neutrino oscillations. We calculate the neutrino effective potential generated by this plasma, the effects of the envelope of the star, and the vacuum on the path to Earth. By considering these three effects, the two (solar, atmospheric and accelerator parameters) and three neutrino mixing, we show that although GeV - TeV neutrinos can oscillate resonantly from one flavor to another, a nonsignificant deviation of the standard flavor ratio (1:1:1) could be expected on Earth.
Very High Lorentz Factor Fireballs and Gamma-Ray Burst Spectra  [PDF]
Kunihito Ioka
Physics , 2010, DOI: 10.1143/PTP.124.667
Abstract: Collisionless entrainment of the surrounding matter imports the relativistic baryon component in the Gamma-Ray Burst (GRB) fireball frame. We show that half the fireball energy can be transferred from radiation to the comoving hot motions of baryons under the photosphere. The yet baryon-poor fireball can reexpand to a very high Lorentz factor (VHLF) \Gamma ~ 10^3-10^6 by its own relativistic collisionless pressure beyond the photosphere (so-called collisionless bulk acceleration), leading to internal and external shocks. A simple synchrotron emission from the VHLF internal shocks produces (i) the extra power-law spectral component with variability observed in the Fermi GeV bursts, up to the TeV range for the future Cherenkov Telescope Array (CTA), (ii) the GeV onset delay with a weak luminosity dependence t_{delay} ~ L^{-1/5}, and (iii) the spectral break of GRB 090926 by the synchrotron cooling break or the maximum synchrotron cutoff limited by the dynamical time, not by the e+- creation cutoff. The relativistic baryon component could also heat the photospheric thermal photons into the main GRB Band spectrum via pp, p\gamma (Bethe-Heitler and photomeson), and Coulomb thermalization processes. In this hot photosphere-internal-external shock model, we can predict the anticorrelation of ~TeV neutrinos and GeV gamma-rays, which may be detectable using IceCube. The spectral peak and luminosity (Yonetoku) relation is also reproduced if the progenitor stars are nearly identical. We also discuss the steep/shallow decay of early X-ray afterglows and short GRBs.
Nuclear Composition of Gamma-Ray Burst Fireballs  [PDF]
Andrei M. Beloborodov
Physics , 2002, DOI: 10.1086/374217
Abstract: We study three processes that shape the nuclear composition of GRB fireballs: (1) neutronization in the central engine, (2) nucleosynthesis in the fireball as it expands and cools, and (3) spallation of nuclei in subsequent internal shocks. The fireballs are found to have a neutron excess and a marginally successful nucleosynthesis. They are composed of free nucleons, alpha-particles, and deuterium. A robust result is the survival of a significant neutron component, which has important implications. First, as shown in previous works, neutrons can lead to observable multi-GeV neutrino emission. Second, as we show in an accompanying paper, neutrons impact the explosion dynamics at radii up to 10^{17} cm and change the mechanism of the GRB afterglow emission.
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