2010 Fall Meeting of the APS Division of Nuclear Physics
Volume 55, Number 14
Tuesday–Saturday, November 2–6, 2010;
Santa Fe, New Mexico
Session 1WA: Neutrinos and Fundamental Symmetries I
3:00 PM–7:00 PM,
Tuesday, November 2, 2010
Hilton Hotel
Room: Mesa A
Chair: Vincenzo Cirigliano, Los Alamos National Laboratory
Abstract ID: BAPS.2010.DNP.1WA.6
Abstract: 1WA.00006 : Neutron Lifetime*
5:30 PM–6:00 PM
Preview Abstract
Abstract
Author:
Anatolii Serebrov
(PNPI, Petersburg Nuclear Physics Institute, Russian Academy of Sciences, RU-188300 Gatchina, Leningrad District, Russia)
The recent neutron lifetime experiment [1] has provided the value
878.5 $\pm
$ 0.8 s. It differs by 6.5 standard deviations from the world
average value
885.7 $\pm $ 0.8 s quoted by the particle data group (PDG) in
2006 [2]. In
determination of the world average value of the neutron lifetime
there is
rather dramatic situation. On the one hand a new value of neutron
lifetime
from work [1] cannot be included in the world average value
because of the
big difference of results. On the other hand until this major
disagreement
is understood the present world average value for the neutron
lifetime must
be suspect. So the situation on PDG page devoted to the neutron
lifetime is
formulated [2] in view of this controversy. The only way out of
the present
situation is to carry out new more precise experiments. More
detailed
analysis of the previous experiments and search of possible
systematic error
is also reasonable. In this connection the analysis and Monte Carlo
simulation of experiments [3] and [4] is carried out. Systematic
errors of
about -6~s are found in each of the experiments. The summary
table for the
neutron lifetime measurements after corrections and additions is
given. A
new world average value for the neutron lifetime 879.9 $\pm $
0.9~s is
presented. The value $\vert $V$_{ud}\vert $ = 09743(7),
calculated for the
new world average value for the neutron lifetime 879.9(9)~s and
g$_{A}$ =
12750(9) [5], agrees with both $\vert $V$_{ud}\vert $ =
097419(22) from
the unitarity of the CKM matrix elements [2] and $\vert
$V$_{ud}\vert $ =
097425(22), measured from the superallowed 0$^{+} \quad \to $
0$^{+}$ nuclear
$\beta $-decays, caused by pure Fermi transitions only [5,6]. The
analysis
of neutron $\beta $-decay with new world average neutron lifetime
demonstrates reasonable agreement in frame of Standard Model.
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[1] A. Serebrov et al., Phys. Lett. B 605, 72 (2005); A.P.
Serebrov et al., Phys. Rev. C 78, 035505 (2008).
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[2] C.~Amsler et al. (Particle Data Group), Phys. Lett. B 667, 1
(2008).
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[3] S.~Arzumanov et al., Phys. Lett. B 483, 15 (2000).
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[4] W. Mampe et al., Phys. Rev. Lett. 63, 593 (1989).
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[5] H. Abele, Prog. Part. Nucl. Phys. 60, 1 (2008).
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[6] J. C. Hardy, I.S. Towner, Phys. Rev. C 79, 055502 (2009).
*This visit is supported by LANL.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2010.DNP.1WA.6