| 1. |
- Singh, B., et al.
(författare)
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Feasibility study for the measurement of pi N transition distribution amplitudes at (P)over-barANDA in (P)over-barp -> J/psi pi(0)
- 2017
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Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 95:3
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Tidskriftsartikel (refereegranskat)abstract
- The exclusive charmonium production process in (P) over barp annihilation with an associated pi 0 meson (p) over barp -> J/psi pi(0) is studied in the framework of QCD collinear factorization. The feasibility of measuring this reaction through the J/psi -> e(+) e(-) decay channel with the AntiProton ANnihilation at DArmstadt ((P) over bar ANDA) experiment is investigated. Simulations on signal reconstruction efficiency as well as the background rejection from various sources including the (P) over barp -> pi(+)pi(-)pi(0) and (p) over barp -> J/psi pi(0)pi(0) reactions are performed with PANDAROOT, the simulation and analysis software framework of the (P) over bar ANDA experiment. It is shown that the measurement can be done at (P) over bar ANDA with significant constraining power under the assumption of an integrated luminosity attainable in four to five months of data taking at the maximum design luminosity.
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| 2. |
- Singh, B., et al.
(författare)
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Study of doubly strange systems using stored antiprotons
- 2016
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Ingår i: Nuclear Physics A. - : Elsevier. - 0375-9474 .- 1873-1554. ; 954, s. 323-340
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Tidskriftsartikel (refereegranskat)abstract
- Bound nuclear systems with two units of strangeness are still poorly known despite their importance for many strong interaction phenomena. Stored antiprotons beams in the GeV range represent an unparalleled factory for various hyperon-antihyperon pairs. Their outstanding large production probability in antiproton collisions will open the floodgates for a series of new studies of systems which contain two or even more units of strangeness at the PANDA experiment at FAIR. For the first time, high resolution gamma-spectroscopy of doubly strange Lambda Lambda-hypernuclei will be performed, thus complementing measurements of ground state decays of Lambda Lambda-hypernuclei at J-PARC or possible decays of particle unstable hypernuclei in heavy ion reactions. High resolution spectroscopy of multistrange Xi(-) -atoms will be feasible and even the production of Omega(-) -atoms will be within reach. The latter might open the door to the vertical bar S vertical bar = 3 world in strangeness nuclear physics, by the study of the hadronic Omega(-) -nucleus interaction. For the first time it will be possible to study the behavior of Xi(+) in nuclear systems under well controlled conditions.
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| 3. |
- Collaboration, The PANDA, et al.
(författare)
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Feasibility studies of time-like proton electromagnetic form factors at PANDA at FAIR
- 2016
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Ingår i: European Physical Journal A. - : Springer Publishing Company. - 1434-6001 .- 1434-601X. ; 52:10
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Tidskriftsartikel (refereegranskat)abstract
- Simulation results for future measurements of electromagnetic proton form factors at P ¯ ANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel p¯ p→ e+e- is studied on the basis of two different but consistent procedures. The suppression of the main background channel, i.e.p¯ p→ π+π-, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. However, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance.
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| 4. |
- Cho, Choong-Rae, et al.
(författare)
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Na0.5K0.5NbO3 thin films for voltage controlled acoustoelectric device applications
- 2002
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 80:17, s. 3171-3173
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Tidskriftsartikel (refereegranskat)abstract
- Perovskite Na0.5K0.5NbO3 (NKN) thin films have been prepared on Y+36degrees cut single crystal quartz substrates using the pulsed laser ablation technique. X-ray diffraction theta-2theta and omega-scan data demonstrate almost perfectly c-axis oriented film textures with narrow mosaic broadening. Radio frequency dielectric spectroscopy showed that the films possess relatively high dielectric permittivities, low dielectric losses, and low frequency dispersions. Capacitance-voltage (C-V) measurements for a 2 mum slot NKN/quartz interdigital capacitor yield 23.1% tunability by applying 40 V bias at 1 MHz, while C-V hysteresis indicates polarization reversal. The considerable voltage tunability with superior crystallinity in piezoelectric NKN films on quartz substrates suggests their potential use for novel voltage tunable acoustoelectric devices.
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| 5. |
- Grishin, Michael A., et al.
(författare)
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High performance films of binary system SrTiO3-PbZr0.52Ti0.48O3 on sapphire
- 2001
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Ingår i: Integrated Ferroelectrics. - : Informa UK Limited. - 1058-4587 .- 1607-8489. ; 39:1-4, s. 351-358
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Tidskriftsartikel (refereegranskat)abstract
- Continuous series of solid solutions x.SrTiO3-(1-x).PbZr0.52Ti0.48O3 (SPZT) have been grown by pulsed laser deposition technique onto La0.7Sr0.3CoO3/Al2O3(01 (1) under bar2) single crystal. Films properties have been characterized in Au/SPZT/La0.7Sr0.3CoO3(LSCO)/Al2O3 vertical capacitive cell. X-ray diffraction shows SPZT/LSCO bilayer grows in strict epitaxial relationship with sapphire substrate: (001) SPZT parallel to (001) LSCO parallel to (01 (1) under bar2) Al2O3; [010] SPZT parallel to [010] LSCO parallel to [421] Al2O3. LSCO layer was found to be tensile strained, while SPZT film experiences tetragonal distortions c/a -1 approximate to 0.86% which are much lower than 2.73% in pure PZT ceramics. Curie temperature in SPZT film has been tailored continuously in the explored temperature range 77 K to 400 K by controlling SrTiO3:PZT ratio. Processing parameters have been optimized to get the highest tunability factor K = epsilon'(0) - epsilon'(V)/epsilon'(0) x 1/tandelta . SrTiO3:PZT=83:17 film exhibits superior properties: at I kHz maximum dielectric perinittivity and minimum loss tandelta were found to be 870 and 0.005, respectively; while K-factor exceeds value of 60 in the temperature range 280 to 350 degreesC reaching the maximum value of 64 at 325 degreesC. SPZT films can withstand prolonged pre-breakdown electric field and has resistivity as high as 3.5 10(12) Omega cm at 186 kV/cm.
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| 6. |
- Khartsev, Sergiy, et al.
(författare)
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Characterization of heteroepitaxial Na0.5K0.5NbO3/La0.5Sr0.5CoO3 electro-optical cell
- 2005
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 86:6, s. 062901-1-062901-3
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Tidskriftsartikel (refereegranskat)abstract
- Heteroepitaxial Na0.5K0.5NbO3(1.5 mum)/La0.5Sr0.5CoO3(0.5 mum) (NKN/LSCO) films were grown on an Al2O3(0112) single crystal (r-cut sapphire) by rf-magnetron sputtering (NKN) and pulsed laser deposition (LSCO) techniques. Prism coupling waveguide refractometry has been employed to characterize vertical capacitive electro-optical cells with 2 X 8 mm(2) semitransparent Au top electrodes. Fitting reflectivity spectra to Fresnel formulas yields extraordinary and ordinary refractive indices n(e) = 2.232 and n(o) = 2.234 as well as electro-optic coefficient r(13) = 17.4 pm/V. Dispersion of the refraction index follows the Sellmeier formula n(2) = 1 + 3.46/[1-(244 nm/lambda)(2)] in the range from 400 nm to 850 nm.
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| 7. |
- Khartsev, Sergiy, et al.
(författare)
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Heteroepitaxial Na0.5K0.5NbO3/La0.5Sr0.5CoO3 electro-optical cell
- 2006
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Ingår i: Integrated Ferroelectrics. - : Informa UK Limited. - 1058-4587 .- 1607-8489. ; 80, s. 133-143
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Tidskriftsartikel (refereegranskat)abstract
- We report electro-optic performance of heteroepitaxial Na0.5K0.5NbO3(1.5 mu m)/La0.5Sr0.5CoO3 (0.5 mu m) (NKN/LSCO) films grown on Al2O3(01 (1) under bar2) single crystal (r-cut sapphire) by rf-magnetron sputtering (NKN) and pulsed laser deposition (LSCO) techniques. Vertical capacitive electro-optical cells were defined by a thermal evaporation of 2 x 8 mm(2) Au electrodes through the contact mask on top the NKN film. Processing parameters have been specially optimized to obtain electrosoftNKN films with a non-linear fatigue-free P-E characteristics: low remnant P-r = 7.7 mu C/cm(2) high induced polarization P = 23 mu C/cm(2) @ 400 km/cm , and the coercive field E-c = 70 kV/cm. Electro-optical characterization of NKN films has been performed using waveguide refractometry: a prism coupling of a light beam into the thin-film waveguide modes. Intensity of TM- and TE-polarized light of 655 nm laser diode reflected from the free surface of NKN film and Au-clad NKN/LSCO waveguide was recorded at zero and 15 V (100 kV/cm) bias electric field. Fitting reflectivity spectra to Fresnel formulas yields extraordinary and ordinary refractive indices n(c) = 2.232 and n(o) = 2.234 as well as electro-optic coefficient r(13) = 17.4 pm/V. Dispersion of the refraction index follows Sellmeier formula n(2) = 1+ 3.46/[1 + (244 nm/lambda)(2)] in the range from 400 nm to 850 nm.
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| 8. |
- Khartsev, Sergiy, et al.
(författare)
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Thin PZT film pressure microsensor
- 2001
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Ingår i: Materials Research Society Symposium Proceedings. - 0272-9172 .- 1946-4274. ; 666, s. F8121-F8126
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Tidskriftsartikel (refereegranskat)abstract
- We report on a ferroelectric film pressure sensor fabricated on the top of 4 mm long and 1.4 mm in diameter Pt80Ir20 (PtIr) rod-shaped tip. It consists of a PZT(0.5 μm)/LSMO(0.1 μm) film heterostructure, deposited by pulsed laser ablation of stoichiometric ceramic targets PbZr0.52Ti0.48O3 and La0.67Sr0.33MnO3, and a circular, ∅ = 1.2 mm, Au electrode on the top of the PZT film. The Au/PZT/LSMO/PtIr thin-film capacitor demonstrates good ferroelectric properties: dielectric constant of 762 and loss tanδ =0.008 @ 5 kHz, induced polarization as high as 32 μC/cm2 at electric field of 250 kV/cm. Piezoelectric test, performed in a hydrostatic pressure chamber, exhibits the piezoelectric constant to be as high as 67 pC/N. This is 20% higher than 56 pC/N shown by a polarized bulk PZT sensor fabricated from the ceramics used as the target in the pulsed laser deposition process. Such an increase of the piezoelectric constant we attribute to the preferential (001) orientation of the PZT film grown on the PtIr bulk substrate. The resolution of the thin PZT film pressure microsensor was found to be about 1 mbar.
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