Dark matter detection

This paper reviews recent experiments on tritium β-spectroscopy searching for the absolute value of the electron neutrino mass m(νe). By the use of dedicated electrostatic filters with high acceptance and resolution, the uncertainty on the observable m2(νe) has been pushed down to about 3 eV2. The new upper limit of the mass is m(νe) < 2 eV at 95% C.L. In view of erroneous and unphysical mass results obtained by some earlier experiments in β decay, particular attention is paid to systematic effects. The mass limit is discussed in the context of current neutrino research in particle- and astrophysics. A preview is given of the next generation of β-spectroscopy experiments currently under development and construction; they aim at lowering the m2(νe) uncertainty by another factor of 100, reaching a sensitivity limit m(νe) < 0.2 eV.

https://iopscience.iop.org/article/10.1088/0034-4885/71/8/086201/pdf

Neutrino mass limit from tritium β decay

In this contribution, we review the status and perspectives of direct 
			neutrino mass experiments, which investigate the kinematics of <path id="x1D6FD" d="M558 587q0 -32 -14 -61t-40 -53.5t-48.5 -41t-54.5 -36.5q144 -51 144 -174q0 -55 -43.5 -108t-104.5 -87q-77 -42 -131 -42q-31 0 -54 20t-31 47l11 18q48 -29 108 -29q79 0 119.5 43t40.5 109t-44.5 107.5t-119.5 50.5l22 47q34 1 65 21q96 61 96 157q0 42 -24 67.5
t-62 25.5q-24 0 -43.5 -9t-35 -29.5t-27 -44t-22.5 -63t-19.5 -75.5t-18.5 -91q-57 -294 -68 -380q-26 -190 -35 -200q-26 -31 -97 -37l-4 26q19 9 48 170l77 413q23 121 52.5 187.5t83.5 114.5q70 62 148 62q51 0 88.5 -34t37.5 -91z" /> -decays of specific isotopes ( 3H, 187Re, 163Ho)
			 to derive model-independent information on the averaged electron
			 (anti)neutrino mass. After discussing the kinematics of -decay
			 and the determination of the neutrino mass, we give a brief overview
			 of past neutrino mass measurements (SN1987a-ToF studies, Mainz and
			 Troitsk experiments for 3H, cryobolometers for 187Re). We then
			 describe the Karlsruhe Tritium Neutrino (KATRIN) experiment currently under construction at Karlsruhe Institute of Technology, which will use
			 the MAC-E-Filter principle to push the sensitivity down to a value of 200 meV (90% C.L.). To do so, many technological challenges have
			 to be solved related to source intensity and stability, as well as precision
			 energy analysis and low background rate close to the kinematic endpoint
			 of tritium -decay at 18.6 keV. We then review new approaches such as the MARE, ECHO, and Project8 experiments, which offer the promise
			 to perform an independent measurement of the neutrino mass in the sub-eV region. Altogether, the novel methods developed in direct neutrino mass experiments will provide vital information on the absolute mass scale of neutrinos.

/pdf/current-direct-neutrino-mass-experiments-561nte8tso.pdf

Current Direct Neutrino Mass Experiments

In this contribution we review the status and perspectives of direct neutrino mass experiments. These experiments investigate the kinematics of $\beta$-decays of specific isotopes ($^3$H, $^{187}$Re, $^{163}$Ho) to derive model-independent information on the averaged electron (anti-) neutrino mass, which is formed by the incoherent sum of the neutrino mass eigenstates contributing to the electron neutrino. We first review the kinematics of $\beta$-decay and the determination of the neutrino mass, before giving a brief overview of past neutrino mass measurements (SN1987a-ToF studies, Mainz and Troitsk experiments for $^3$H, cryo-bolometers for $^{187}$Re). We then describe the Karlsruhe Tritium Neutrino (KATRIN) experiment which is currently under construction at Karlsruhe Institute of Technology. The large-scale setup will use the MAC-E-Filter principle pioneered earlier to push the sensitivity down to a value of 200 meV(90% C.L.). KATRIN faces many technological challenges that have to be resolved with regard to source intensity and stability, as well as precision energy analysis and low background rate close to the kinematic endpoint of tritium $\beta$-decay at 18.6 keV. We then review new experimental approaches such as the MARE, ECHO and Project8 experiments, which offer the promise to perform an independent measurement of the neutrino mass in the sub-eV region. This variety of methods and the novel technologies developed in all present and future experiments demonstrate the great potential of direct neutrino mass experiments in providing vital information on the absolute mass scale of neutrinos.

The Neutrino mass and family, Lepton and Baryon number non-conservation in gauge theories

The data from the spectrum measurement of the tritium decay in a valine molecule carried out in a wide energy range (3.4 keV) with the Institute of Theoretical and Experimental Physics spectrometer are analyzed. The combined analysis of both these data and the data of the previous cycle gives the neutrino mass ${30.3}_{\ensuremath{-}8}^{+2}$ eV. The model-independent mass interval $17l{M}_{\ensuremath{\nu}}l40$ eV is derived from the mass difference of the doublet $^{3}\mathrm{H}$-$^{3}\mathrm{He}$.

A. Golutvin

Papers

Neutrino mass from the beta spectrum in the decay of tritium.

The neutrino mass from the tritium beta spectrum in valine

Erratum: Neutrino mass from the beta spectrum in the decay of tritium [Phys. Rev. Lett. 58, 2019 (1987)]