LARGE MIXING ANGLE STERILE NEUTRINOS AND PULSAR VELOCITIES

2009 ◽  
Vol 24 (31) ◽  
pp. 2507-2516 ◽  
Author(s):  
LEONARD S. KISSLINGER ◽  
ERNEST M. HENLEY ◽  
MIKKEL B. JOHNSON
Keyword(s):  
Magnetic Field ◽  
Sterile Neutrino ◽  
Effective Volume ◽  
Sterile Neutrinos ◽  
Mixing Angle ◽  
Lowest Landau Level ◽  
Neutrino Emissivity ◽  
Global Fit ◽  
Temperature Equilibrium ◽  
Protoneutron Star

We investigate the momentum given to a protoneutron star, the pulsar kick, during the first ten seconds after temperature equilibrium is reached. Using a model with two sterile neutrinos obtained by fits to the MiniBooNE and LSND experiments, which is consistent with a new global fit, there is a large mixing angle, and the effective volume for emission is calculated. Using formulations with neutrinos created by URCA processes in a strong magnetic field, so the lowest Landau level has a sizable probability, we find that with known parameters, the asymmetric sterile neutrino emissivity might account for large pulsar kicks.

Sterile neutrinos and Big Bang Nucleosynthesis in the 3 + 1 scheme

2014 ◽  
Vol 23 (03) ◽  
pp. 1450014 ◽  
Author(s):  
Mercedes Elisa Mosquera ◽  
Osvaldo Civitarese
Keyword(s):  
Distribution Function ◽  
Sterile Neutrino ◽  
Big Bang ◽  
Light Nuclei ◽  
Wilkinson Microwave Anisotropy Probe ◽  
Normalization Constant ◽  
Big Bang Nucleosynthesis ◽  
Sterile Neutrinos ◽  
Mixing Angle ◽  
Free Parameters

We study the effects of adding a sterile neutrino to three active neutrinos (3 + 1 scheme) in the calculation of primordial abundances. Taking the normalization constant (a) of the occupation factor of the sterile neutrino and the active-sterile mixing angle (ϕ) as free parameters, we calculate the neutrino distribution function and primordial abundances of light nuclei. We set constrains on these parameters by using the available data on the abundances of D, 4 He and 7 Li . Results are consistent with small values of a and ϕ. The extracted value of the baryon-to-photon ratio (ηB), which is constrained by the Wilkinson Microwave Anisotropy Probe (WMAP) value [Formula: see text], and Planck observations, depends strongly on the inclusion of the lithium data in the fit.

scholarly journals 7.1 keV sterile neutrino dark matter constraints from a deep Chandra X-ray observation of the Galactic bulge Limiting Window

2019 ◽  
Vol 625 ◽  
pp. L7 ◽  
Author(s):  
F. Hofmann ◽  
C. Wegg
Keyword(s):  
Dark Matter ◽  
Sterile Neutrino ◽  
Line Strength ◽  
Galactic Bulge ◽  
Sterile Neutrinos ◽  
Additional Line ◽  
Mixing Angle ◽  
X Ray ◽  
Systematic Uncertainties ◽  
Good Target

Context. An unidentified emission line at 3.55 keV was recently detected in X-ray spectra of clusters of galaxies. The line has been discussed as a possible decay signature of 7.1 keV sterile neutrinos, which have been proposed as a dark matter (DM) candidate. Aims. We aim to further constrain the line strength and its implied mixing angle under the assumption that all DM is made of sterile neutrinos. Methods. The X-ray observations of the Limiting Window (LW) towards the Galactic bulge (GB) offer a unique dataset for exploring DM lines. We characterise the systematic uncertainties of the observation and the fitted models with simulated X-ray spectra. In addition, we discuss uncertainties of indirect DM column density constraints towards the GB to understand systematic uncertainties in the assumed DM mass in the field of view of the observation. Results. We find tight constraints on the allowed flux for an additional line at 3.55 keV with a positive (∼1.5σ) best fit value FX3.55 keV ≈ (4.5 ± 3.5) × 10−7 cts cm−2 s−1. This would translate into a mixing angle of sin2(2Θ) ≈ (2.3 ± 1.8) × 10−11 which, while consistent with some recent results, is in tension with earlier detections. Conclusions. We used a very deep dataset with well understood systematic uncertainties to derive tight constraints on the mixing angle of a 7.1 keV sterile neutrino DM candidate. The results highlight that the inner Milky Way will be a good target for DM searches with upcoming missions like eROSITA, XRISM, and ATHENA.

scholarly journals keV sterile neutrino with large mixing angle is still alive

2018 ◽  
Vol 191 ◽  
pp. 08003
Author(s):  
Anton Chudaykin
Keyword(s):  
Sterile Neutrino ◽  
Sterile Neutrinos ◽  
Mixing Angle ◽  
Mixing Angles ◽  
Hidden Sector ◽  
The Standard Model ◽  
Neutrino Experiments ◽  
Active Mixing ◽  
Neutrino Decay ◽  
Made In

We study production of keV scale sterile neutrinos with large mixing with the Standard Model sector [1]. Conventional mechanism of sterile neutrino generation in the early Universe leads to overproduction of the Dark Matter and strong X-ray signal from sterile neutrino decay. It makes anticipated groundbased experiments on direct searches of sterile-active mixing unfeasible. We argue that for models with a hidden sector coupled to the sterile neutrinos cosmological and astrophysical constraints can be significantly alleviated. In developed scenario a phase transition in the hidden sector modifies the standard oscillation picture and leads to significantly larger mixing angles, thus opening new perspectives for future neutrino experiments such as Troitsk v-mass and KATRIN. This work was made in collaboration with Fedor Bezrukov and Dmitry Gorbunov.

scholarly journals STERILE NEUTRINOS AND PULSAR VELOCITIES REVISITED

2012 ◽  
Vol 27 (37) ◽  
pp. 1250215 ◽  
Author(s):  
LEONARD S. KISSLINGER ◽  
MIKKEL B. JOHNSON
Keyword(s):  
Neutron Star ◽  
Sterile Neutrinos ◽  
Mixing Angle ◽  
Mixing Angles ◽  
Wide Range ◽  
Temperature Equilibrium ◽  
Proto Neutron Star

We calculate the momentum given to a proto-neutron star during the first 10 s after temperature equilibrium is reached, using recent evidence of sterile neutrinos and a measurement of the mixing angle. This is a continuation of an earlier estimate with a wide range of possible mixing angles. Using the new mixing angle we find that sterile neutrinos can account for the observed pulsar velocities.

scholarly journals Viable production mechanism of keV sterile neutrino with large mixing angle

2018 ◽  
Vol 182 ◽  
pp. 02032
Author(s):  
A. Chudaykin
Keyword(s):  
Phase Transition ◽  
Sterile Neutrino ◽  
Production Mechanism ◽  
Sterile Neutrinos ◽  
Mixing Angle ◽  
Hidden Sector

We study a model with a hidden sector coupled to keV scale sterile neutrinos. Due to nontrivial dynamics of this sector, the initially massless sterile neutrino acquires a nonzero mass at some temperature corresponding to the phase transition in the hidden sector. It shifts the onset of oscillations in plasma to later times, so that the final abundance of sterile neutrinos is strongly suppressed. We argue that in this model various cosmological and astrophysical bounds can be significantly alleviated opening new perspectives for ground-based experiments such as Troitsk ν-mass and KATRIN in the large mixing region.

scholarly journals Sterile Neutrino Fits to Short-Baseline Neutrino Oscillation Measurements

2013 ◽  
Vol 2013 ◽  
pp. 1-26 ◽  
Author(s):  
J. M. Conrad ◽  
C. M. Ignarra ◽  
G. Karagiorgi ◽  
M. H. Shaevitz ◽  
J. Spitz
Keyword(s):  
Neutrino Oscillation ◽  
Neutrino Mass ◽  
Goodness Of Fit ◽  
Sterile Neutrino ◽  
Low Energy ◽  
Data Sets ◽  
Sterile Neutrinos ◽  
Short Baseline ◽  
Energy Excess ◽  
Global Fit

This paper reviews short-baseline oscillation experiments as interpreted within the context of one, two, and three sterile neutrino models associated with additional neutrino mass states in the~1 eV range. Appearance and disappearance signals and limits are considered. We show that fitting short-baseline datasets to a 3 + 3 (3 + 2) model, defined by three active and three (two) sterile neutrinos, results in an overall goodness of fit of 67% (69%) and good compatibility between data sets—to be compared to a 3 + 1 model with a 55% goodness of fit. While the (3 + 3) fit yields the highest quality overall, it still finds inconsistencies with the MiniBooNE appearance datasets; in particular, the global fit fails to account for the observed MiniBooNE low-energy excess. Given the overall improvement, we recommend using the results of (3 + 2) and (3 + 3) fits, rather than (3 + 1) fits, for future neutrino oscillation phenomenology. These results motivate the pursuit of further short-baseline experiments, such as those reviewed in this paper.

scholarly journals Direct comparison of sterile neutrino constraints from cosmological data, $$\nu _{e}$$ disappearance data and $$\nu _{\mu } \rightarrow \nu _{e} $$ appearance data in a $$3+1$$ model

2020 ◽  
Vol 80 (8) ◽  
Author(s):  
Matthew Adams ◽  
Fedor Bezrukov ◽  
Jack Elvin-Poole ◽  
Justin J. Evans ◽  
Pawel Guzowski ◽  
...  
Keyword(s):  
Neutrino Oscillation ◽  
Sterile Neutrino ◽  
Cosmological Evolution ◽  
Daya Bay ◽  
Sterile Neutrinos ◽  
Planck Data ◽  
Mixing Angle ◽  
Cosmological Data ◽  
Exclusion Region

Abstract We present a quantitative, direct comparison of constraints on sterile neutrinos derived from neutrino oscillation experiments and from Planck data, interpreted assuming standard cosmological evolution. We extend a $$1+1$$1+1 model, which is used to compare exclusion contours at the 95% Cl derived from Planck data to those from $$\nu _{e}$$νe-disappearance measurements, to a $$3+1$$3+1 model. This allows us to compare the Planck constraints with those obtained through $$\nu _{\mu }\rightarrow \nu _{e}$$νμ→νe appearance searches, which are sensitive to more than one active-sterile mixing angle. We find that the cosmological data fully exclude the allowed regions published by the LSND, MiniBooNE and Neutrino-4 collaborations, and those from the gallium and rector anomalies, at the 95% Cl. Compared to the exclusion region from the Daya Bay $$\nu _{e}$$νe-disappearance search, the Planck data are more strongly excluding above $$|\Delta m^{2}_{41}|\approx 0.1\,\mathrm {eV}^{2}$$|Δm412|≈0.1eV2 and $$m_\mathrm {eff}^\mathrm {sterile}\approx 0.2\,\mathrm {eV}$$meffsterile≈0.2eV, with the Daya Bay exclusion being stronger below these values. Compared to the combined Daya Bay/Bugey/MINOS exclusion region on $$\nu _{\mu }\rightarrow \nu _{e}$$νμ→νe appearance, the Planck data is more strongly excluding above $$\Delta m^{2}_{41}\approx 5\times 10^{-2}\,\mathrm {eV}^{2}$$Δm412≈5×10-2eV2, with the exclusion strengths of the Planck data and the Daya Bay/Bugey/MINOS combination becoming comparable below this value.

scholarly journals Magnetic-field effects on p-wave phase transition in Gauss–Bonnet gravity

2014 ◽  
Vol 29 (20) ◽  
pp. 1450094 ◽  
Author(s):  
Ya-Bo Wu ◽  
Jun-Wang Lu ◽  
Yong-Yi Jin ◽  
Jian-Bo Lu ◽  
Xue Zhang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
P Wave ◽  
Vector Model ◽  
Magnetic Field Effects ◽  
Complex Vector ◽  
Bonnet Gravity ◽  
Yang Mills ◽  
Wave Phase ◽  
Lowest Landau Level

In the probe limit, we study the holographic p-wave phase transition in the Gauss–Bonnet gravity via numerical and analytical methods. Concretely, we study the influences of the external magnetic field on the Maxwell complex vector model in the five-dimensional Gauss–Bonnet–AdS black hole and soliton backgrounds, respectively. For the two backgrounds, the results show that the magnetic field enhances the superconductor phase transition in the case of the lowest Landau level, while the increasing Gauss–Bonnet parameter always hinders the vector condensate. Moreover, the Maxwell complex vector model is a generalization of the SU(2) Yang–Mills model all the time. In addition, the analytical results backup the numerical results. Furthermore, this model might provide a holographic realization for the QCD vacuum instability.

scholarly journals Generalized two-point tree-level amplitude j f → j′ f′ in a magnetized medium

2015 ◽  
Vol 30 (11) ◽  
pp. 1550049 ◽  
Author(s):  
A. V. Kuznetsov ◽  
D. A. Rumyantsev ◽  
D. M. Shlenev
Keyword(s):  
Magnetic Field ◽  
Axial Vector ◽  
Field Operator ◽  
Coherent Scattering ◽  
Tree Level ◽  
Tree Level Amplitude ◽  
Photoproduction Process ◽  
Arbitrary Strength ◽  
Neutrino Emissivity ◽  
A Current

The tree-level two-point amplitudes for the transitions j f → j′ f′, where f is a fermion and j is a generalized current, in a constant uniform magnetic field of an arbitrary strength and in charged fermion plasma, for the j f f interaction vertices of the scalar, pseudoscalar, vector and axial-vector types have been calculated. The generalized current j could mean the field operator of a boson, or a current consisting of fermions, e.g. the neutrino current. The particular cases of a very strong magnetic field, and of the coherent scattering off the real fermions without change of their states (the "forward" scattering) have been analyzed. The contribution of the neutrino photoproduction process, [Formula: see text], to the neutrino emissivity has been calculated with taking account of a possible resonance on the virtual electron.

scholarly journals New results from the DANSS experiment

2020 ◽  
Vol 35 (34n35) ◽  
pp. 2044015
Author(s):  
Nataliya Skrobova
Keyword(s):  
Nuclear Power ◽  
Sterile Neutrino ◽  
Reactor Core ◽  
Detector Efficiency ◽  
Sterile Neutrinos ◽  
Inverse Beta Decay ◽  
Systematic Uncertainties ◽  
Interesting Part ◽  
Raster Scan ◽  
Kalinin Nuclear Power Plant

We present new results of the DANSS experiment on the searches for sterile neutrinos. They are based on more than 2 million of inverse beta decay events collected at 10.7 m, 11.7 m and 12.7 m from the reactor core of the 3.1 GW Kalinin Nuclear Power Plant in Russia. This data sample is 2.4 times larger than the data sample in the previous DANSS publication. The search for the sterile neutrinos is performed using the ratio of [Formula: see text] spectra at two distances. This method is very robust against systematic uncertainties in the [Formula: see text] spectrum and the detector efficiency. We do not see any statistically significant sign for the [Formula: see text] oscillations. This allows us to exclude further a large and interesting part of the sterile neutrino parameter space. A Gaussian CL[Formula: see text] method was used to obtain exclusion areas. This method is more conservative than a Raster Scan method.

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