Search results for "Number"
showing 10 items of 3939 documents
The baryonic spectrum of QCD 2 in the chiral limit
1991
Abstract A description of the baryonic spectrum of quantum chromodynamics in one-space-one-time dimensions for massless quarks is presented. The theory has been studied in the equivalent non-abelian bosonic representation, and four-point functions of the colored meson fields under the simplifying assumption of two colors have been calculated. The crucial role of the chiral sector in providing baryon number has been unveiled. Excited baryon states appear as pseudomesonic excitations on top of the massless baryons associated with the chiral fields.
Resonances in QCD
2015
We report on the EMMI Rapid Reaction Task Force meeting 'Resonances in QCD', which took place at GSI October 12-14, 2015. A group of 26 people met to discuss the physics of resonances in QCD. The aim of the meeting was defined by the following three key questions: What is needed to understand the physics of resonances in QCD? Where does QCD lead us to expect resonances with exotic quantum numbers? What experimental efforts are required to arrive at a coherent picture? For light mesons and baryons only those with ${\it up}$, ${\it down}$ and ${\it strange}$ quark content were considered. For heavy-light and heavy-heavy meson systems, those with ${\it charm}$ quarks were the focus. This docum…
Study of resonance interactions in polyatomic molecules on the basis of highly accurate experimental data: Set of strongly interacting Bands ν10(B1),…
2016
Abstract The highly accurate (experimental accuracy in line positions ~ ( 1 − 3 ) × 10 − 4 cm − 1 ) FTIR ro-vibrational spectra of CH2=CD2 in the region of 600–1300 cm−1, where the fundamental bands ν10, ν7, ν4, ν8, ν3, and ν6 are located, were recorded and analyzed with the Hamiltonian model which takes into account resonance interactions between all six studied bands. About 12 200 ro-vibrational transitions belonging to these bands (that is considerably more than it was made in the preceding studies for the bands ν10, ν7, ν8, ν3 and ν6; transitions belonging to the ν4 band were assigned for the first time) were assigned in the experimental spectra with the maximum values of quantum number…
High resolution analysis of the SO2 spectrum in the 2600–2900cm−1 region: 2ν3, ν2+2ν3−ν2 and 2ν1+ν2 bands
2012
Abstract Infrared spectrum of the SO 2 molecule was recorded with high resolution in the 2600– 2900 cm − 1 region. Spectrum was recorded with the Fourier transform interferometer Bruker IFS-120 HR in Oulu (Finland) with the pressure of 111 Pa and the absorption path length of 163.2 m that allowed us to record 2 ν 3 and 2 ν 1 + ν 2 weak bands. The 2 ν 3 band discussed earlier by Lafferty et al., was re-analyzed, and considerably more information was extracted from the spectrum (more than 3800 transitions of the 2 ν 3 band were assigned in the experimental spectrum with maximum values of quantum numbers, J max . = 76 and K a max . = 26 ). On the basis of the procedure discussed in Ulenikov et…
A direct study of the vibrational bending effect in line mixing: The hot degenerate 1110 ← 0110 transition of CO2
1997
Abstract The study of the isotropiv Raman Q -branch of a hot band Π ← Π allows one to establish a direct connection between the vibration-rotation angular momentum coupling and the resulting spectra. Due to the l -doubling, the Q -branch is split into two subbranches characterized by either even or odd rotational quantum number j . The vibrational bending reduces the rotational transfer rates inside each of these subbranches by a factor of about two and induces an inter-subbranch coupling. The expected propensity rule towards conservation of the parity index for high rotational levels is well observed. Calculated spectra are in excellent agreement with CARS experiments for the v 1 + v 2 ← v…
Evaluation using m.c.n.p. code of the bremsstrahlung energy spectrum produced by interactions between structural materials and accelerated electrons
2004
Abstract In order to design the biological shield of industrial accelerator plants, it is needed to have a good knowledge of the bremsstrahlung energy spectrum and the intensity of the bremsstrahlung produced by electron interactions with both products (usually water equivalent) and structural materials such as concrete, iron, aluminium. Using the MCNP code, a normalized bremsstrahlung energy spectrum was obtained for materials with average atomic number lower than or equal to 13 and irradiated with 5 and 10 Mev electrons, respectively; multiplying the spectrum by suitable coefficients, it was possible to obtain the real spectrum for materials such as water, concrete, aluminium and iron. Th…
Experimental Constraint on Axionlike Particles over Seven Orders of Magnitude in Mass
2021
We use our recent electric dipole moment (EDM) measurement data to constrain the possibility that the HfF+ EDM oscillates in time due to interactions with candidate dark matter axionlike particles (ALPs). We employ a Bayesian analysis method which accounts for both the look-elsewhere effect and the uncertainties associated with stochastic density fluctuations in the ALP field. We find no evidence of an oscillating EDM over a range spanning from 27 nHz to 400 mHz, and we use this result to constrain the ALP-gluon coupling over the mass range 10-22-10-15 eV. This is the first laboratory constraint on the ALP-gluon coupling in the 10-17-10-15 eV range, and the first laboratory constraint to pr…
FITTING LAW FOR THE DENSITY SHIFT OF Q(J) TRANSITIONS OF H2 IN H2–X (X: H2, He, N2) MIXTURES
1998
Abstract A variety of fitting laws have been developed for the purpose of modelling broadening effects in collisional processes, but only a few have been proposed for modelling collision-induced lineshifts in molecules. We analysed accurate stimulated Raman data obtained in several H2–X mixtures (X: H2, He and N2). For the first time, we show that an empirical law provides a very good representation of collisional lineshift coefficients in the range 300–1200 K and for J quantum number up to 9.
Direct time delay computation applied to the O + O2 exchange reaction at low energy: Lifetime spectrum of O3* species
2021
We report full quantum dynamical calculations for lifetimes of scattering resonances, among which are true metastable states, of the intermediate heavy ozone complex 50O3* of the 18O + 16O16O reaction, for any value of the total angular momentum quantum number J. We show that computations for nonzero values of J are mandatory in order to properly analyze resonances and time delays, with a view to establish a somewhat comprehensive eigenlife spectrum of the complex O3*. Calculations have been performed in a given low to moderate energy range, including the interval between zero-point energies (ZPEs) of reagents and product species. Quasi-bound states tend to be more numerous, and eigenlifeti…
The Stochastic Limit of the Fröhlich Hamiltonian: Relations with the Quantum Hall Effect
2003
We propose a model of an approximatively two-dimensional electron gas in a uniform electric and magnetic field and interacting with a positive background through the Fröhlich Hamiltonian. We consider the stochastic limit of this model and we find the quantum Langevin equation and the generator of the master equation. This allows us to calculate the explicit form of the conductivity and the resistivity tensors and to deduce a fine tuning condition (FTC) between the electric and the magnetic fields. This condition shows that the x-component of the current is zero unless a certain quotient, involving the physical parameters, takes values in a finite set of physically meaningful rational number…