Precise Neutron Lifetime Measurement with a Solenoidal Coil

The neutron lifetime, \(\tau\) = 880.2 \(\pm\) 1.0 sec , is an important parameter for particle physics and cosmology. There is, however, an 8.4 sec (4.0\(\,\sigma\)) deviation between the measured value of the neutron lifetime using two methods : one method counts neutrons that survive after some t...

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Bibliographic Details
Published inarXiv.org
Main Authors Sumi, Naoyuki, Otono, Hidetoshi, Yoshioka, Tamaki, Mishima, Kenji, Makida, Yasuhiro
Format Paper
LanguageEnglish
Published Ithaca Cornell University Library, arXiv.org 13.01.2018
Subjects
Beta decay
Coils
Cold neutrons
Cosmology
Drift
Neutron beams
Neutron flux
Neutrons
Particle physics
Proton accelerators
Radiation counters
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Summary:The neutron lifetime, \(\tau\) = 880.2 \(\pm\) 1.0 sec , is an important parameter for particle physics and cosmology. There is, however, an 8.4 sec (4.0\(\,\sigma\)) deviation between the measured value of the neutron lifetime using two methods : one method counts neutrons that survive after some time, while the other counts protons resulting from neutron beta decay. A new method is being implemented at J-PARC / MLF / BL05 using a pulsed cold neutron beam. A Time Projection Chamber (TPC) records both the electrons from neutron beta decay and protons from the neutron-\(^3\)He capture reactions in order to estimate the neutron flux. Electron background signals require the largest correction and are source of uncertainty for this experiment. A solenoidal magnetic field can greatly reduce this background. The TPC drift region must be divided into three region in this case. A prototype detector was developed to study the multi drift layer TPC. The status of a study using a prototype detector is reported in this paper.
ISSN:2331-8422