While the international nEDM collaboration at the Paul Scherrer Institut (PSI) took data in 2017 that covered a considerable fraction of the parameter space of claimed potential signals of ...hypothetical neutron (n) to mirror-neutron (n′) transitions, it could not test all claimed signal regions at various mirror magnetic fields. Therefore, a new study of n−n′ oscillations using stored ultracold neutrons (UCNs) is underway at PSI, considerably expanding the reach in parameter space of mirror magnetic fields (B′) and oscillation time constants (τnn′). The new apparatus is designed to test for the anomalous loss of stored ultracold neutrons as a function of an applied magnetic field. The experiment is distinguished from its predecessors by its very large storage vessel (1.47 m3), enhancing its statistical sensitivity. In a test experiment in 2020 we have demonstrated the capabilities of our apparatus. However, the full analysis of our recent data is still pending. Based on already demonstrated performance, we will reach sensitivity to oscillation times τnn′/cos(β) well above a hundred seconds, with β being the angle between B′ and the applied magnetic field B. The scan of B will allow the finding or the comprehensive exclusion of potential signals reported in the analysis of previous experiments and suggested to be consistent with neutron to mirror-neutron oscillations.
The mass of the $\pi^- Daum, Manfred; Gotta, Detlev
SciPost physics proceedings,
09/2021
5
Journal Article
Recenzirano
Odprti dostop
The most precise values of the mass of the negatively charged pion
have been determined from several measurements of X-ray wavelengths for
transitions in pionic atoms at PSI. The Particle Data Group ...gives the
average
m_{\pi^-}
m
π
−
= (139.570 61
\pm
±
0.000 24) MeV/c
^2
2
.
The mass of the 4\pi Daum, Manfred; Kettle, Peter-R.
SciPost physics proceedings,
09/2021
5
Journal Article
Recenzirano
Odprti dostop
The most precise value for the pion mass was determined from a
precision measurement at PSI of the muon momentum in pion decay at rest,
\pi^+ \rightarrow \mu^+ + \nu_{\mu}
π
+
→
μ
+
+
ν
μ
.
The ...result is
m_{\pi^+} = 139.570\,21(14)
m
π
+
=
139.570
21
(
14
)
~MeV/c
^2
2
.
This value is more precise, however, in agreement with the recent
compilation of the Particle Data Group for
m_{\pi^-}
m
π
−
.
The agreement of
m_{\pi^+}
m
π
+
with the recent measurement. This yields a new quantitative measure of
CPT invariance in the pion sector:
(m_{\pi^+} - m_{\pi^-})/m_{\pi}(\mbox{av}) = (-2.9 \pm 2.0)\cdot 10^{-6}
(
m
π
+
−
m
π
−
)
/
m
π
(
av
)
=
(
−
2.9
±
2.0
)
⋅
10
−
6
,
an improvement by two orders of magnitude.
The most precise value for the
\pi^0
π
0
mass was obtained from the measurement of the mass difference
m_{\pi^-}-m_{\pi^0} = 4.593\,64(48)
m
π
−
−
m
π
0
=
4.593
64
(
48
)
,MeV/c
^2
2
in the charge ...exchange reaction
\pi^-
π
−
p
\rightarrow \pi^0
→
π
0
n
at PSI. With the most precise charged pion mass value,
m_{\pi^+} = 139.570\,21(14)
m
π
+
=
139.570
21
(
14
)
,MeV/c
^2
2
and the validity of the CPT theorem (
m_{\pi^-} = m_{\pi^+}
m
π
−
=
m
π
+
),
a value
m_{\pi^0} = 134.976\,57(50)
m
π
0
=
134.976
57
(
50
)
,MeV/c
^2
2
is obtained. The measurements also revealed, for the first time,
evidence of an unexpectedly large contribution from Coulomb
de-excitation states during the pionic atom cascade.
The contract is one of the most used documents in any language within the legal field. It is therefore of interest for the study of microfunctions in this genre of text in order to determine ...linguistic functions and to advance in the detection of nuances of languages. For this reason, this paper proposes the analysis of a subgenre of contract, the lease, focusing the study on one of the most characteristic microfunctions of this genre, the temporal microfunctions. In a comparative corpus, the temporal microfunctions are analyzed using a contrastive methodology for the German and Spanish texts.
The contract is one of the most used documents in any language within the legal field. It is therefore of interest for the study of microfunctions in this genre of text in order to determine ...linguistic functions and to advance in the detection of nuances of languages. For this reason, this paper proposes the analysis of a subgenre of contract, the lease, focusing the study on one of the most characteristic microfunctions of this genre, the temporal microfunctions. In a comparative corpus, the temporal microfunctions are analyzed using a contrastive methodology for the German and Spanish texts.
We have developed a highly sensitive
3
He magnetometer for the accurate measurement of the magnetic field in an experiment searching for an electric dipole moment of the neutron. By measuring the ...Larmor frequency of nuclear spin polarized
3
He atoms a sensitivity on the femto-Tesla scale can be achieved. A
3
He/Cs-test facility was established at the Institute of Physics of the Johannes Gutenberg University in Mainz to investigate the readout of
3
He free induction decay with a lamp-pumped Cs magnetometer. For this we designed and built an ultra-compact and transportable polarizer unit which polarizes
3
He gas up to 55% by metastability exchange optical pumping. The polarized
3
He was successfully transfered from the polarizer into a glass cell mounted in a magnetic shield and the
3
He free induction decay was detected by a lamp-pumped Cs magnetometer.
PACS numbers
07.55.Ge Magnetometers for magnetic field measurements; 13.40 Electric and magnetic moments; 14.20 Protons and neutrons
Abstract We have developed a highly sensitive ^sup 3^He magnetometer for the accurate measurement of the magnetic field in an experiment searching for an electric dipole moment of the neutron. By ...measuring the Larmor frequency of nuclear spin polarized ^sup 3^He atoms a sensitivity on the femto-Tesla scale can be achieved. A ^sup 3^He/Cs-test facility was established at the Institute of Physics of the Johannes Gutenberg University in Mainz to investigate the readout of ^sup 3^He free induction decay with a lamp-pumped Cs magnetometer. For this we designed and built an ultra-compact and transportable polarizer unit which polarizes ^sup 3^He gas up to 55% by metastability exchange optical pumping. The polarized ^sup 3^He was successfully transfered from the polarizer into a glass cell mounted in a magnetic shield and the ^sup 3^He free induction decay was detected by a lamp-pumped Cs magnetometer. PACS numbers 07.55.Ge Magnetometers for magnetic field measurements; 13.40 Electric and magnetic moments; 14.20 Protons and neutrons
The search for a permanent electric dipole moment (EDM) of the muon is an excellent probe for physics beyond the Standard Model of particle physics. We propose the first dedicated muon EDM search ...employing the frozen-spin technique at the Paul Scherrer Institute (PSI), Switzerland, with a sensitivity of \(6 \times 10^{-23}~e\!\cdot\!\mathrm{cm}\), improving the current best limit set by the E821 experiment at Brookhaven National Laboratory by more than three orders of magnitude. In preparation for a high precision experiment to measure the muon EDM, several R&D studies have been performed at PSI: the characterisation of a possible beamline to host the experiment for the muon beam injection study and the measurement of the multiple Coulomb scattering of positrons in potential detector materials at low momenta for the positron tracking scheme development. This paper discusses experimental concepts and the current status of the muEDM experiment at PSI.
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