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FAMU: study of the energy dependent transfer rate $Λ_{μp \rightarrow μO}$
Authors:
FAMU Collaboration,
E. Mocchiutti,
V. Bonvicini,
M. Danailov,
E. Furlanetto,
K. S. Gadedjisso-Tossou,
D. Guffanti,
C. Pizzolotto,
A. Rachevski,
L. Stoychev,
E. Vallazza,
G. Zampa,
J. Niemela,
K. Ishida,
A. Adamczak,
G. Baccolo,
R. Benocci,
R. Bertoni,
M. Bonesini,
F. Chignoli,
M. Clemenza,
A. Curioni,
V. Maggi,
R. Mazza,
M. Moretti
, et al. (31 additional authors not shown)
Abstract:
The main goal of the FAMU experiment is the measurement of the hyperfine splitting (hfs) in the 1S state of muonic hydrogen $ΔE_{hfs}(μ^-p)1S$. The physical process behind this experiment is the following: $μp$ are formed in a mixture of hydrogen and a higher-Z gas. When absorbing a photon at resonance-energy $ΔE_{hfs}\approx0.182$~eV, in subsequent collisions with the surrounding $H_2$ molecules,…
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The main goal of the FAMU experiment is the measurement of the hyperfine splitting (hfs) in the 1S state of muonic hydrogen $ΔE_{hfs}(μ^-p)1S$. The physical process behind this experiment is the following: $μp$ are formed in a mixture of hydrogen and a higher-Z gas. When absorbing a photon at resonance-energy $ΔE_{hfs}\approx0.182$~eV, in subsequent collisions with the surrounding $H_2$ molecules, the $μp$ is quickly de-excited and accelerated by $\sim2/3$ of the excitation energy. The observable is the time distribution of the K-lines X-rays emitted from the $μZ$ formed by muon transfer $(μp) +Z \rightarrow (μZ)^*+p$, a reaction whose rate depends on the $μp$ kinetic energy. The maximal response, to the tuned laser wavelength, of the time distribution of X-ray from K-lines of the $(μZ)^*$ cascade indicate the resonance. During the preparatory phase of the FAMU experiment, several measurements have been performed both to validate the methodology and to prepare the best configuration of target and detectors for the spectroscopic measurement. We present here the crucial study of the energy dependence of the transfer rate from muonic hydrogen to oxygen ($Λ_{μp \rightarrow μO}$), precisely measured for the first time.
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Submitted 22 January, 2019; v1 submitted 20 August, 2018;
originally announced August 2018.
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First FAMU observation of muon transfer from mu-p atoms to higher-Z elements
Authors:
FAMU Collaboration,
Emiliano Mocchiutti,
Valter Bonvicini,
Rita Carbone,
Miltcho Danailov,
Elena Furlanetto,
Komlan Segbeya Gadedjisso-Tossou,
Daniele Guffanti,
Cecilia Pizzolotto,
Alexandre Rachevski,
Lyubomir Stoychev,
Erik Silvio Vallazza,
Gianluigi Zampa,
Joseph Niemela,
Katsuhiko Ishida,
Andrzej Adamczak,
Giovanni Baccolo,
Roberto Benocci,
Roberto Bertoni,
Maurizio Bonesini,
Francesco Chignoli,
Massimiliano Clemenza,
Alessandro Curioni,
Valter Maggi,
Roberto Mazza
, et al. (32 additional authors not shown)
Abstract:
The FAMU experiment aims to accurately measure the hyperfine splitting of the ground state of the muonic hydrogen atom. A measurement of the transfer rate of muons from hydrogen to heavier gases is necessary for this purpose. In June 2014, within a preliminary experiment, a pressurized gas-target was exposed to the pulsed low-energy muon beam at the RIKEN RAL muon facility (Rutherford Appleton Lab…
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The FAMU experiment aims to accurately measure the hyperfine splitting of the ground state of the muonic hydrogen atom. A measurement of the transfer rate of muons from hydrogen to heavier gases is necessary for this purpose. In June 2014, within a preliminary experiment, a pressurized gas-target was exposed to the pulsed low-energy muon beam at the RIKEN RAL muon facility (Rutherford Appleton Laboratory, UK). The main goal of the test was the characterization of both the noise induced by the pulsed beam and the X-ray detectors. The apparatus, to some extent rudimental, has served admirably to this task. Technical results have been published that prove the validity of the choices made and pave the way for the next steps. This paper presents the results of physical relevance of measurements of the muon transfer rate to carbon dioxide, oxygen, and argon from non-thermalized excited mu-p atoms. The analysis methodology and the approach to the systematics errors are useful for the subsequent study of the transfer rate as function of the kinetic energy of the mu-p currently under way.
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Submitted 15 December, 2017; v1 submitted 10 August, 2017;
originally announced August 2017.
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Experimental method for measuring classical concurrence of generic beam shapes
Authors:
E. Roccia,
I. Gianani,
L. Mancino,
M. Sbroscia,
I. Miatka,
F. Somma,
M. Barbieri
Abstract:
Classical entanglement is a powerful tool which provides a neat numerical estimate for the study of classical correlations. Its experimental investigation, however, has been limited to special cases. Here, we demonstrate that the experimental quantification of the level of classical entanglement can be carried out in more general instances. Our approach enables the extension to arbitrarily shaped…
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Classical entanglement is a powerful tool which provides a neat numerical estimate for the study of classical correlations. Its experimental investigation, however, has been limited to special cases. Here, we demonstrate that the experimental quantification of the level of classical entanglement can be carried out in more general instances. Our approach enables the extension to arbitrarily shaped transverse modes and hence delivering a suitable quantification tool to describe concisely the modal structure.
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Submitted 12 December, 2016;
originally announced December 2016.
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Steps towards the hyperfine splitting measurement of the muonic hydrogen ground state: pulsed muon beam and detection system characterization
Authors:
A. Adamczak,
G. Baccolo,
D. Bakalov,
G. Baldazzi,
R. Bertoni,
M. Bonesini,
V. Bonvicini,
R. Campana,
R. Carbone,
T. Cervi,
F. Chignoli,
M. Clemenza,
L. Colace,
A. Curioni,
M. Danailov,
P. Danev,
I. D'Antone,
A. De,
C. De,
M. De,
M. Furini,
F. Fuschino,
K. Gadejisso-Tossou,
D. Guffanti,
A. Iaciofano
, et al. (30 additional authors not shown)
Abstract:
The high precision measurement of the hyperfine splitting of the muonic-hydrogen atom ground state with pulsed and intense muon beam requires careful technological choices both in the construction of a gas target and of the detectors. In June 2014, the pressurized gas target of the FAMU experiment was exposed to the low energy pulsed muon beam at the RIKEN RAL muon facility. The objectives of the…
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The high precision measurement of the hyperfine splitting of the muonic-hydrogen atom ground state with pulsed and intense muon beam requires careful technological choices both in the construction of a gas target and of the detectors. In June 2014, the pressurized gas target of the FAMU experiment was exposed to the low energy pulsed muon beam at the RIKEN RAL muon facility. The objectives of the test were the characterization of the target, the hodoscope and the X-ray detectors. The apparatus consisted of a beam hodoscope and X-rays detectors made with high purity Germanium and Lanthanum Bromide crystals. In this paper the experimental setup is described and the results of the detector characterization are presented.
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Submitted 21 June, 2016; v1 submitted 6 April, 2016;
originally announced April 2016.
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Metrology with Unknown Detectors
Authors:
Matteo Altorio,
Marco G. Genoni,
Fabrizia Somma,
Marco Barbieri
Abstract:
The best possible precision is one of the key figures in metrology, but this is established by the exact response of the detection apparatus, which is often unknown. There exist techniques for detector characterisation, that have been introduced in the context of quantum technologies, but apply as well for ordinary classical coherence; these techniques, though, rely on intense data processing. Her…
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The best possible precision is one of the key figures in metrology, but this is established by the exact response of the detection apparatus, which is often unknown. There exist techniques for detector characterisation, that have been introduced in the context of quantum technologies, but apply as well for ordinary classical coherence; these techniques, though, rely on intense data processing. Here we show that one can make use of the simpler approach of data fitting patterns in order to obtain an estimate of the Cramér-Rao bound allowed by an unknown detector, and present applications in polarimetry. Further, we show how this formalism provide a useful calculation tool in an estimation problem involving a continuous-variable quantum state, i.e. a quantum harmonic oscillator.
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Submitted 23 November, 2015;
originally announced November 2015.