The Beta Environmental Fine Structure (BEFS) effect is an oscillatory modulation on the otherwise smooth spectrum of electrons emitted by beta-decaying nuclei. The existence of this effect was theoretically proposed in 1991, for condensed emitters, in analogy with XAFS. In BEFS the electron, playing the role of the XAFS photoelectron, originates directly from the nucleus and an anti-neutrino is emitted at the same time. We present evidence for BEFS oscillations observed in Silver Perrhenate (AgReO4) low-temperature (0.1K) microbolometers, together with a XAFS-like analysis that allowed for the first time a direct measurement of the anti-neutrino angular momentum [1]. We discuss the physical analogies and differences between BEFS and XAFS and the implications for the next generation experiments aimed at measuring the neutrino mass on purely kinematic grounds. Moreover, we briefly discuss the potential and the limits of BEFS-based techniques with respect to the classical XAFS
Monfardini, A., Benedek, G., Cremonesi, O., Filipponi, A., Nucciotti, A., Sisti, M. (2007). The Beta Environmental Fine Structure (BEFS): The XAFS nuclear analogue. In X-RAY ABSORPTION FINE STRUCTURE-XAFS13 (pp.144-146). American Institute of Physics.
The Beta Environmental Fine Structure (BEFS): The XAFS nuclear analogue
BENEDEK, GIORGIO;Cremonesi, O;NUCCIOTTI, ANGELO ENRICO LODOVICO;SISTI, MONICA
2007
Abstract
The Beta Environmental Fine Structure (BEFS) effect is an oscillatory modulation on the otherwise smooth spectrum of electrons emitted by beta-decaying nuclei. The existence of this effect was theoretically proposed in 1991, for condensed emitters, in analogy with XAFS. In BEFS the electron, playing the role of the XAFS photoelectron, originates directly from the nucleus and an anti-neutrino is emitted at the same time. We present evidence for BEFS oscillations observed in Silver Perrhenate (AgReO4) low-temperature (0.1K) microbolometers, together with a XAFS-like analysis that allowed for the first time a direct measurement of the anti-neutrino angular momentum [1]. We discuss the physical analogies and differences between BEFS and XAFS and the implications for the next generation experiments aimed at measuring the neutrino mass on purely kinematic grounds. Moreover, we briefly discuss the potential and the limits of BEFS-based techniques with respect to the classical XAFSI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.