Search results for "STATES"
showing 10 items of 1532 documents
First measurement of f′2 (1525) production in Z0 hadronic decays
1996
The inclusive production of the f(2)'(1525) in hadronic Z(0) decays has been studied in data collected by the DELPHI detector at LEP. The Ring Imaging Cherenkov detectors were important tools in the identification of the decay f(2)'(1525) --> K+K-. The average number of f(2)(')(1525) produced per hadronic Z decay, [f(2)'] = 0.020 +/- 0.005 (stat) +/- 0.006 (syst), and the momentum distribution of the f(2)'(1525) have both been measured. The mass and width of the f(2)'(1525) are found to be [M(f2)'] = 1535 +/- 5 (stat) +/- 4 (syst) MeV/c(2). [Gamma(f2)'] = 60 +/- 20 (stat) +/- 19 (syst) MeV/c(2)
Magnetic resonance imaging of (1)H long lived states derived from parahydrogen induced polarization in a clinical system.
2015
Hyperpolarization is a powerful tool to overcome the low sensitivity of nuclear magnetic resonance (NMR). However, applications are limited due to the short lifetime of this non equilibrium spin state caused by relaxation processes. This issue can be addressed by storing hyperpolarization in slowly decaying singlet spin states which was so far mostly demonstrated for non-proton spin pairs, e.g. 13C-13C. Protons hyperpolarized by parahydrogen induced polarization (PHIP) in symmetrical molecules, are very well suited for this strategy because they naturally exhibit a long-lived singlet state. The conversion of the NMR silent singlet spin state to observable magnetization can be achieved by ma…
Raman spectra of vacancy-containing LiF: Predictions from first principles
2020
Abstract The electronic structure and Raman scattering from face-centered cubic LiF with three types of vacancies — an F-center, an F ′ -center and a vacancy without electrons ( v F ) — has been calculated by means of hybrid exchange–correlation functional within density functional theory. Our modeling predicts the effective charge of 0.87 e , 1.50 e and 0.10 e on the defect, respectively. The F-center induces two in-gap energy levels for two spin states split by 3.4 eV, while the F ′ -center and the v F induce a single in-gap level 3.8 eV and 2.9 eV below the bottom of conduction band, respectively. The calculated Raman spectra are thoroughly discussed and are found to match well the earli…
Experimental program of the Super-FRS Collaboration at FAIR and developments of related instrumentation
2016
The physics program at the super-conducting fragment separator (Super-FRS) at FAIR, being operated in a multiple-stage, high-resolution spectrometer mode, is discussed. The Super-FRS will produce, separate and transport radioactive beams at high energies up to 1.5 AGeV, and it can be also used as a stand-alone experimental device together with ancillary detectors. Various combinations of the magnetic sections of the Super-FRS can be operated in dispersive, achromatic or dispersion-matched spectrometer ion-optical modes, which allow measurements of momentum distributions of secondary-reaction products with high resolution and precision. A number of unique experiments in atomic, nuclear and h…
The debye-waller factor in spincrossover molecular crystals: a mössbauer study on [FexZn1−x(ptz)6](BF4)2
1995
In a first approximation the Debye-Waller factor (DWF) of molecular crystals is factorized into a molecular and a lattice part:f=f m f l. In the case of spincrossover compounds there is the unique possibility to measure differences of both parts in the two spin states by switching the spin states with the LIESST effect. Measurements of the DWF depending on temperature, γ-ray direction and spin state were performed with57Fe-Mossbauer spectroscopy on three single crystals (R¯3) of the spincrossover system [FexZn1−x(ptz)6](BF4)2 (ptz=1-propyltetrazole), a concentrated sample withx=1 and diluted ones withx=0.30 andx=0.005. The DWF decreases from 10 to 300 K by a factor of ∼ 100 and its anisotro…
Odd parity bottom-flavored baryon resonances
2013
The LHCb Collaboration has recently observed two narrow baryon resonances with beauty. Their masses and decay modes look consistent with the quark model orbitally excited states Lambda(b)(5912) and Lambda(b)*(5920), with quantum numbers J(P) = 1/2(-) and 3/2(-), respectively. We predict the existence of these states within a unitarized meson-baryon coupled-channel dynamical model, which implements heavy-quark spin symmetry. Masses, quantum numbers and couplings of these resonances to the different meson-baryon channels are obtained. We find that the resonances Lambda(0)(b)(5912) and Lambda(0)(b)(5920) are heavy-quark spin symmetry partners, which naturally explains their approximate mass de…
S-wave Kpi scattering in chiral perturbation theory with resonances
2000
32 páginas, 6 figuras, 2 tablas.-- PACS: 11.80.Et; 12.39.Fe; 13.75.Lb; 13.85.Fb.-- arXiv:hep-ph/0006045v1
Top-quark production in proton–nucleus and nucleus–nucleus collisions at LHC energies and beyond
2015
Single and pair top-quark production in proton-lead (p-Pb) and lead-lead (Pb-Pb) collisions at the CERN Large Hadron Collider (LHC) and future circular collider (FCC) energies, are studied with next-to-leading-order perturbative QCD calculations including nuclear parton distribution functions. At the LHC, the pair-production cross sections amount to sigma(t-tbar) = 3.4 mub in Pb-Pb at sqrt(s) = 5.5 TeV, and sigma(t-tbar) = 60 nb in p-Pb at sqrt(s) = 8.8 TeV. At the FCC energies of sqrt(s) = 39 and 63 TeV, the same cross sections are factors of 90 and 55 times larger respectively. In the leptonic final-state t-tbar --> W+b W-bbar --> b bbar l+l- nu+nu-, after typical acceptance and eff…
Pion-photon transition distribution amplitudes in the Nambu-Jona-Lasinio model
2007
12 pages, 6 figures.-- PACS nrs.: 13.60.-r; 11.10.St; 12.38.Lg; 24.10.Jv.-- ISI Article Identifier: 000251327200049.-- ArXiv pre-print available at: http://arxiv.org/abs/0707.3366
Charge radii of neon isotopes across the sd neutron shell
2011
We report on the changes in mean square charge radii of unstable neon nuclei relative to the stable Ne-20, based on the measurement of optical isotope shifts. The studies were carried out using collinear laser spectroscopy on a fast beam of neutral neon atoms. High sensitivity on short-lived isotopes was achieved thanks to nonoptical detection based on optical pumping and state-selective collisional ionization, which was complemented by an accurate determination of the beam kinetic energy. The new results provide information on the structural changes in the sequence of neon isotopes all across the neutron sd shell, ranging from the proton drip line nucleus and halo candidate Ne-17 up to the…