In: Physics Procedia, 2011, vol. 17, p. 159-167
The measurement of the neutron electric dipole moment (nEDM) constrains the contribution of CP-violating terms within both the Standard Model and its extensions. The experiment uses ultracold neutrons (UCN) stored in vacuum at room temperature. This technique provided the last (and best) limit by the RAL/Sussex/ILL collaboration in 2006: dn < 2:9 × 10⁻²⁶ e cm (90% C.L.). We aim to improve...
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In: Physics Procedia, 2011, vol. 17, p. 259-267
The nEDM experiment hosted at the Paul Scherrer Institute is the flagship project at the new ultracold neutron facility. Estimations of systematic effects for the determination of the neutron electric dipole moment play an important role in this project. Experimental studies are supported by Monte Carlo simulations using the MCUCN code. Here we briefly present first results on the experimental...
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In: Physical Review Letters, 2009, vol. 103, no. 8, p. 081602
A clock comparison experiment, analyzing the ratio of spin precession frequencies of stored ultracold neutrons and ¹⁹⁹Hg atoms, is reported. No daily variation of this ratio could be found, from which is set an upper limit on the Lorentz invariance violating cosmic anisotropy field b⊥<2×10⁻²⁰ eV (95% C.L.). This is the first limit for the free neutron. This result...
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In: Physical Review D, 2009, vol. 80, no. 3, p. 032003
We performed ultracold neutron storage measurements to search for additional losses due to neutron (n) to mirror-neutron (n') oscillations as a function of an applied magnetic field B. In the presence of a mirror magnetic field B', ultracold neutron losses would be maximal for B~B'. We did not observe any indication for...
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In: Nuclear Instruments and Methods in Physics Research Section A, 2009, p. -
The effort towards a new measurement of the neutron electric dipole moment (nEDM) at the Paul Scherrer Institut's (PSI) new high intensity source of ultracold neutrons (UCN) is described. The experimental technique relies on Ramsey's method of separated oscillatory fields, using UCN in vacuum with the apparatus at ambient temperature. In the first phase, R&D towards the upgrade of the...
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In: Nuclear Instruments and Methods in Physics Research Section A, 2009///doi: 10.1016/j.nima.2009.07.047
The existence of a mirror world holding a copy of our ordinary particle spectrum could lead to oscillations between the neutron (n) and its mirror partner (n′). Such oscillations could manifest themselves in storage experiments with ultracold neutrons whose storage lifetime would depend on the applied magnetic field. Here, extended details and measurements from the first dedicated experimental...
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In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2006, vol. 556(2), p. 509-515
The analysis method developed for kaonic nitrogen X-ray data obtained at the DAΦNE electron–positron collider of Frascati National Laboratories using Charge-Coupled Devices (CCDs) in the DEAR experimental setup is described. Background events could be highly rejected by this analysis procedure. Three sequential X-ray lines from kaonic nitrogen transitions, showing good energy resolution, could...
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In: Physical Review Letters, 2005, vol. 94, p. 212302
The DEAR (DAΦNE exotic atom research) experiment measured the energy of x rays emitted in the transitions to the ground state of kaonic hydrogen. The measured values for the shift ε and the width Γ of the 1s state due to the K⁻p strong interaction are ε1s=-193±37 (stat) ±6 (syst) eV and Γ1s=249±111 (stat) ±30 (syst) eV, the most...
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In: Nuclear Physics A, 2005, vol. 754, p. 369-374
The goal of the DEAR (DAΦNE exotic atom research) experiment is the precise determination of the isospin dependent antikaon–nucleon scattering lengths. The experiment accurately measures the Kα line shift and broadening, due to the strong interaction, in kaonic hydrogen and, for the first time, in kaonic deuterium. A precision measurement of kaonic hydrogen tests chiral symmetry...
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In: Physics Letters B, 2004, vol. 593, p. 48-54
The first measurement of the yields of three kaonic nitrogen X-ray transitions, using the DEAR (DAΦNE Exotic Atom Research) setup at the DAΦNE collider of Frascati, is reported. The yields are 41.5±8.7(stat.)±4.1(sys.)% for the n=7→6 transition, 55.0±3.9(stat.)±5.5(sys.)% for the n=6→5 transition and 57.4±15.2(stat.)±5.7(sys.)% for the n=5→4 transition at a density ρ=3.4ρNTP. By...
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