Cosmological upper limit to neutrino magnetic moments

Morgan, J. A.

doi:10.1016/0370-2693(81)90868-6

Cited by 87 publications

(30 citation statements)

References 14 publications

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“…The treatment of the divergent behavior of the scattering cross section σ ∝ ln q 2 max /q 2 min is what led to the reexamination of the result of Morgan [8] in Refs. [9][10][11].…”

Section: Low Temperature Enhancement To Magnetic Scatteringmentioning

confidence: 95%

“…The higher energy density would increase N eff (the so-called effective number of relativistic degrees of freedom measured by cosmic microwave background (CMB) experiments) from ∼ 3 to ∼ 6 which is in disagreement with current observations [7]. This has lead many authors to examine limits on the magnetic moments of Dirac neutrinos by constraining the production of right-handed states during times earlier than BBN such as the QCD epoch [8][9][10][11]. Morgan [8] and Fukugita et al [9] use an approximate neutrino-electron scattering cross section to quantify the production of these helicity states.…”

Section: Introductionmentioning

confidence: 97%

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Majorana neutrino magnetic moment and neutrino decoupling in big bang nucleosynthesis

et al. 2015

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We examine the physics of the early universe when Majorana neutrinos (νe, νµ, ντ ) possess transition magnetic moments. These extra couplings beyond the usual weak interaction couplings alter the way neutrinos decouple from the plasma of electrons/positrons and photons. We calculate how transition magnetic moment couplings modify neutrino decoupling temperatures, and then use a full weak, strong, and electromagnetic reaction network to compute corresponding changes in Big Bang Nucleosynthesis abundance yields. We find that light element abundances and other cosmological parameters are sensitive to magnetic couplings on the order of 10 −10 µB. Given the recent analysis of sub-MeV Borexino data which constrains Majorana moments to the order of 10 −11 µB or less, we find that changes in cosmological parameters from magnetic contributions to neutrino decoupling temperatures are below the level of upcoming precision observations.

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“…The treatment of the divergent behavior of the scattering cross section σ ∝ ln q 2 max /q 2 min is what led to the reexamination of the result of Morgan [8] in Refs. [9][10][11].…”

Section: Low Temperature Enhancement To Magnetic Scatteringmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 97%

Majorana neutrino magnetic moment and neutrino decoupling in big bang nucleosynthesis

et al. 2015

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“…In particular, a re-analysis [17] of the Savannah River results [8], based on an improved reactor neutrino spectrum and the Standard Model sin 2 θ W value, suggested that the measured (ν e e) crosssections at 1.5-3.0 MeV and 3.0-4.5 MeV are 1.35±0.4 and 2.0±0.5 times, respectively, larger than the expected values, and can be interpreted to be consistent with a µ ν at the range of (2-4)X10 −10 µ B . Various astrophysics considerations from the time duration of the supernova SN1987A burst [23], stellar cooling [24] and Big Bang Nucleosynthesis [25] provide more stringent bounds on µ ν to the 10 −11 − 10 13 µ B level, but these are model-dependent. An anomalous neutrino magnetic moment of range µ ν ∼ 10 −10 µ B has been considered as a solution to the Solar Neutrino Puzzle [26].…”

Section: Neutrino-electron Scatteringmentioning

confidence: 99%

A CsI(Tl) scintillating crystal detector for the studies of low-energy neutrino interactions

Liu

et al. 2001

Nuclear Instruments and Methods in Physics Research Section A:

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Scintillating crystal detector may offer some potential advantages in the low-energy, low-background experiments. A 500 kg CsI(Tl) detector to be placed near the core of Nuclear Power Station II in Taiwan is being constructed for the studies of electron-neutrino scatterings and other keV−MeV range neutrino interactions. The motivations of this detector approach, the physics to be addressed, the basic experimental design, and the characteristic performance of prototype modules are described. The expected background channels and their experimental handles are discussed.

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“…For both cases of neutrino oscillations (magnetically induced and active-sterile), we find, with the aid of Eqs. (17) and (18), that However, for a nondiagonal p, connecting only active species, we should identify UR = ( u~)~( , , , ) . Now, TR = TL and also the supernova bound (10) is no longer operative.…”

Section: (4)mentioning

confidence: 99%

Magnetic-moment contributions to the neutrino index of refraction in the early Universe

Horvat

1995

Phys. Rev. D

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The existence of anomalous magnetic dipole moments for neutrinos can affect neutrino oscillations in the early Universe through previously ignored refractive effects. Using the real-time approach of finite-temperature field theory, we have calculated the effective potential for neutrinos due to their magnetic moments and compared it to the standard model value, in view of the astrophysical and laboratory constraints. PACS number(s): 13.10.+q, 13.15.+g, 98.80.Cq The effect of neutrino oscillations in big-bang nucleosynthesis has recently received much attention [I-61. The constraints on mixings between active (v,, v,, v,) and sterile (v,) neutrinos [2,5] from the present observation of the primordial helium abundance are such that excluded regions include the large angle v,-v, Mikheyev-Smirnov-Wolfenstein (MSW) solution [7] as well as the v,-v, mixing solution [8] to the atmospheric neutrino problem. On the other hand, oscillations between ordinary (active) neutrinos would not have any obvious consequences for the early Universe as the abundances of these states are practically equal [9]. For Dirac neutrinos endowed with anomalous magnetic dipole moments (MDM's) the magnetically induced neutrino oscillations in the early Universe may occur [1,10]. In such oscillations between left-handed (vL) and right-handed (vR) states the nucleosynthesis arguments constrain the product of neutrino MDM's and a present-day intergalactic field strength.In all the above examples of neutrino oscillations in the early Universe the neutrino refractive effects are of crucial importance. In terms of standard electroweak interactions the almost C P symmetry of the medium implies that the lowest order refractive effects, which dominate in stars, nearly cancel. Indeed, previous calculations [11,12] have shown that the only nonzero result arises from higher order effects (such as an expansion of gauge-boson propagators and iadiative corrections). However, the CP-symmetric contributions turn out to be suppressed by a very small factor of order T 2 / M & , where the temperature T in the epoch of interest T N 0.1-10 MeV.For neutrinos with MDM's the vR'S (uL'S) and photons of the heat bath will affect vL7S (vR7S) propagation through the coherent forward-scattering amplitude in the lowest order. In addition to the asymmetry term which is probably at the level of 10-lo, as the baryon to photon ratio is, there is a nonvanishing CP-symmetric contribution in the lowest order, as opposed to the case of standard interactions. This motivates us to study the precise temperature dependence of the effect and to compare new contributions to the standard model value in the temperature range of interest (the central discussion goes with the strongest astrophysical bounds on neutrino MDM's).In the application to the early Universe, we consider an ordinary light neutrino v~ (mu, 5 10 eV) in the radiation-dominated epoch with temperatures T -0.1-10 MeV. So. in the calculation of refractive effects its rest mass can always be neglected. In addition, this al...

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Cosmological upper limit to neutrino magnetic moments

Cited by 87 publications

References 14 publications

Majorana neutrino magnetic moment and neutrino decoupling in big bang nucleosynthesis

Majorana neutrino magnetic moment and neutrino decoupling in big bang nucleosynthesis

A CsI(Tl) scintillating crystal detector for the studies of low-energy neutrino interactions

Magnetic-moment contributions to the neutrino index of refraction in the early Universe

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