X-rays Help to Unfuzzy the Concept of Measurement

Curceanu, C.; Hiesmayr, Beatrix C.; Piscicchia, K.

doi:10.1166/jap.2015.1193

Cited by 53 publications

(83 citation statements)

References 11 publications

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“…Both bounds, however, are weaker than those coming from non-interferometric tests: violation of the equipartition theorem with cantilevers [18], and X-ray measurements [17]. At present, non-interferometric tests proved the strongest upper bound for the CSL parameters; what is not clear is whether these bounds are robust against changes in the collapse mechanism, while those associated to interferometric tests are [19].…”

Section: Comments and Conclusionmentioning

confidence: 78%

Entangling macroscopic diamonds at room temperature: Bounds on the continuous-spontaneous-localization parameters

et al. 2016

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A recent experiment [K. C. Lee et al., Science 334, 1253] succeeded in detecting entanglement between two macroscopic specks of diamonds, separated by a macroscopic distance, at room temperature. This impressive results is a further confirmation of the validity of quantum theory in (at least parts of) the mesoscopic and macroscopic domain, and poses a challenge to collapse models, which predict a violation of the quantum superposition principle, which is the bigger the larger the system. We analyze the experiment in the light of such models. We will show that the bounds placed by experimental data are weaker than those coming from matter-wave interferometry and non-interferometric tests of collapse models.

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Section: Comments and Conclusionmentioning

confidence: 78%

Entangling macroscopic diamonds at room temperature: Bounds on the continuous-spontaneous-localization parameters

et al. 2016

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“…To allow for a full comparison we have extended the upper limit, reported only for r C ¼ 10 −7 m in Ref. [32], to the full r C range. This is done by taking into account that CSL-induced x-ray emission scales as r −2 C .…”

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confidence: 99%

Upper Bounds on Spontaneous Wave-Function Collapse Models Using Millikelvin-Cooled Nanocantilevers

et al. 2016

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Collapse models predict a tiny violation of energy conservation, as a consequence of the spontaneous collapse of the wave function. This property allows us to set experimental bounds on their parameters. We consider an ultrasoft magnetically tipped nanocantilever cooled to millikelvin temperature. The thermal noise of the cantilever fundamental mode has been accurately estimated in the range 0.03-1 K, and any other excess noise is found to be negligible within the experimental uncertainty. From the measured data and the cantilever geometry, we estimate the upper bound on the continuous spontaneous localization collapse rate in a wide range of the correlation length r C . Our upper bound improves significantly previous constraints for r C > 10 −6 m, and partially excludes the enhanced collapse rate suggested by Adler. We discuss future improvements. DOI: 10.1103/PhysRevLett.116.090402 Spontaneous wave function collapse models [1][2][3][4] have been proposed to reconcile the linear and deterministic evolution of quantum mechanics with the nonlinear and stochastic character of the measurement process. According to such phenomenological models, random collapses occur spontaneously in any material system, leading to a spatial localization of the wave function. The collapse rate scales with the size (number of constituents) of the system, leading to rapid localization of any macroscopic system, while giving no measurable effect at the microscopic level, where conventional quantum mechanics is recovered.Here we consider the mass-proportional version of the continuous spontaneous localization (CSL) model [2], the most widely studied one, originally introduced as a refinement of the Ghirardi-Rimini-Weber (GRW) model [1]. CSL is characterized by two phenomenological constants, a collapse rate λ, and a characteristic length r C , which characterize, respectively, the intensity and the spatial resolution of the spontaneous collapse. 11AE2 times larger at r C ¼ 10 −6 m. The direct effect of collapse models like CSL is to destroy quantum superpositions, resulting in a loss of coherence in interferometric tests with matter-wave [6][7][8] or mechanical resonators [9][10][11]. Recently, noninterferometric tests have been proposed, which promise to set stronger bounds on these models [12][13][14][15][16][17][18][19]. Among such tests, the measurement of heating effects in mechanical systems, a byproduct of the collapse process, seems particularly promising [15][16][17][18]. Here, we demonstrate for the first time this method, by accurately measuring the mean energy of a nanocantilever in thermal equilibrium at millikelvin temperatures. We infer an experimental upper bound on λ, which is 2 orders of magnitude stronger than that set by matter-wave interferometry [20][21][22] for r C ¼ 10 −7 m, and the strongest one to date for r C > 10 −6 m. Theoretical model.-The detection of CSL-induced heating in realistic optomechanical systems has been extensively discussed in the recent literature [15][16][17][18][19]. Here we summarize th...

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“…The obtained M pπ − invariant mass mean value is 1115.753±0.002 MeV/c 2 (only statistical error is given, the systematics being under investigation), with a resolution of σ=0.5 MeV/c 2 . The particle identification takes advantage of both dE/dx information from the DC wires and the measurement of the energy released in the Calorimeter, as described in [1]. Σ particles are identified through their decay into Λγ or pπ as reported in [7,8].…”

Section: Particle Identificationmentioning

confidence: 99%

“…The AMADEUS (Anti-kaonic Matter At DAΦNE: An Experiment with Unraveling Spectroscopy) [1] experiment investigates the low-energy K − hadronic interaction in light nuclei (e.g. H, 4 He, 9 Be and 12 C) in order to provide experimental constraints on the non-perturbative QCD in the strangeness sector.…”

Section: Introductionmentioning

confidence: 99%

Low-energy antikaon-nuclei interactions studies by AMADEUS: from QCD with strangeness to neutron stars

et al. 2018

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Abstract. The AMADEUS collaboration aims to provide unique quality results from K − hadronic interactions in light nuclear targets, in order to solve fundamental open questions in the non-perturbative strangeness QCD sector, like the controversial nature of the Λ(1405) state, the yield of hyperon formation below threshold, the yield and shape of multi-nucleon K − absorption, processes which are intimately connected to the possible existence of exotic antikaon multi-nucleon clusters and to the role of strangeness in neutron stars. AMADEUS takes advantage of the DAΦNE collider, which provides a unique source of monochromatic low-momentum kaons and exploits the KLOE detector as an active target, in order to obtain excellent acceptance and resolution data for K − nuclear capture on H, 4 He, 9 Be and 12 C, both at-rest and in-flight.

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X-rays Help to Unfuzzy the Concept of Measurement

Cited by 53 publications

References 11 publications

Entangling macroscopic diamonds at room temperature: Bounds on the continuous-spontaneous-localization parameters

Entangling macroscopic diamonds at room temperature: Bounds on the continuous-spontaneous-localization parameters

Upper Bounds on Spontaneous Wave-Function Collapse Models Using Millikelvin-Cooled Nanocantilevers

Low-energy antikaon-nuclei interactions studies by AMADEUS: from QCD with strangeness to neutron stars

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