Forecasting neutrino masses from combining KATRIN and the CMB: Frequentist and Bayesian analyses

Abstract

We present a showcase for deriving bounds on the neutrino masses from laboratory experiments and cosmological observations. We compare the frequentist and Bayesian bounds on the effective electron neutrino mass m_beta which the KATRIN neutrino mass experiment is expected to obtain, using both an analytical likelihood function and Monte Carlo simulations of KATRIN. Assuming a uniform prior in m_beta, we find that a null result yields an upper bound of about 0.17 eV at 90% confidence in the Bayesian analysis, to be compared with the frequentist KATRIN reference value of 0.20 eV. This is a significant difference when judged relative to the systematic and statistical uncertainties of the experiment. On the other hand, an input m_beta=0.35 eV, which is the KATRIN 5sigma detection threshold, would be detected at virtually the same level. Finally, we combine the simulated KATRIN results with cosmological data in the form of present (post-WMAP) and future (simulated Planck) observations. If an input of m_beta=0.2 eV is assumed in our simulations, KATRIN alone excludes a zero neutrino mass at 2.2sigma. Adding Planck data increases the probability of detection to a median 2.7sigma. The analysis highlights the importance of combining cosmological and laboratory data on an equal footing.

8 pages, 7 figures, uses Revtex. Submitted to PRD

References in corpus (8)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• Observational Constraints on the Nature of the Dark Energy: First Cosmological Results from the ESSENCE Supernova Survey
• Cosmological parameters from combining the Lyman-alpha forest with CMB, galaxy clustering and SN constraints
• The neutrino mass bound from WMAP-3, the baryon acoustic peak, the SNLS supernovae and the Lyman-alpha forest
• Observables sensitive to absolute neutrino masses: A reappraisal after WMAP-3y and first MINOS results
• Limit on the Neutrino Mass from the WMAP Three Year Data
• Using the cluster mass function from weak lensing to constrain neutrino masses
• Sub-eV upper limits on neutrino masses from cosmology

Cited by in corpus (4)

• X-ray Group and cluster mass profiles in MOND: Unexplained mass on the group scale
• Statistical Analysis of future Neutrino Mass Experiments including Neutrino-less Double Beta Decay
• Global neutrino parameter estimation using Markov Chain Monte Carlo
• Phenomenology of Discrete Flavour Symmetries