A5064790939- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Nuclear physics research studies
- Cold Atom Physics and Bose-Einstein Condensates
- Atomic and Molecular Physics
- Advanced Chemical Physics Studies
- Black Holes and Theoretical Physics
- Quantum, superfluid, helium dynamics
- Atomic and Subatomic Physics Research
- Quantum chaos and dynamical systems
- Nuclear Physics and Applications
- Physics of Superconductivity and Magnetism
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Spectral Theory in Mathematical Physics
- Superconducting Materials and Applications
- Quantum Mechanics and Non-Hermitian Physics
- Particle accelerators and beam dynamics
- Cosmology and Gravitation Theories
- Advanced Physical and Chemical Molecular Interactions
- Advanced NMR Techniques and Applications
- Quantum Computing Algorithms and Architecture
- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
Université Claude Bernard Lyon 1
2015-2024
Centre National de la Recherche Scientifique
2015-2024
Institut de Physique des 2 Infinis de Lyon
2020-2024
Institut National de Physique Nucléaire et de Physique des Particules
2015-2024
Institute of Nuclear Physics of Lyon
2013-2024
Institut de Physique
1982-2024
European Organization for Nuclear Research
1981-2020
Université Joseph Fourier
2002-2013
University of Bonn
1996-2010
Université des Sciences et de la Technologie d'Oran Mohamed Boudiaf
2000-2009
About 120 baryons and baryon resonances are known, from the abundant nucleon with $u$ $d$ light-quark constituents up to recently discovered $\Omega_b^-=bss$, $\Xi_b^-=bsd$ which contains one quark of each generation. In spite this impressively large number states, underlying mechanisms leading excitation spectrum not yet understood. Heavy-quark suffer a lack known spin-parities. sector, quark-model calculations have met considerable success in explaining low-mass excitations but some...
We discuss the existence of states made four heavy quarks in context potential models already used study mesons and baryons. first consider situation where have same mass interact through a two-body due to color-octet exchange. In this case, we show that for any reasonable confining there is no state below threshold corresponding spontaneous dissociation into two mesons. investigate detail different possibilities modifying negative result. This concerns effect hyperfine corrections, case...
We use QCD spectral sum rules to test the nature of meson $X(3872)$, assumed be an exotic four-quark ($c\overline{c}q\overline{q}$) state with ${J}^{\mathrm{PC}}={1}^{++}$. For definiteness, we work diquark-antidiquark current proposed recently, at leading order in ${\ensuremath{\alpha}}_{s}$, consider contributions higher dimension condensates and keep terms which are linear light quark mass ${m}_{q}$. find ${M}_{X}=(3925\ifmmode\pm\else\textpm\fi{}127)\text{ }\text{ }\mathrm{MeV}$ is...
The two-pion exchange contributions to nucleon-nucleon forces are calculated from our knowledge of pion-nucleon phase shifts and pion-pion interaction which used as input into dispersion relations with the subtractions required by Regge asymptotic behavior. At low energies, potentials derived, which, addition $\ensuremath{\pi}$-meson $\ensuremath{\omega}$-meson exchange, explain many features phenomenological without any adjustable parameter. However, spin-orbit central have significant...
The optical model of antiproton-proton scattering is examined critically. We show that the addition an attractive real part to annihilation potential allows one reduce imaginary and improve fit data. However, absorptive component must be still rather strong also have a fairly large range. Such features are difficult understand in terms naive direct channel meson exchange processes. confirm local no narrow structures can survive annihilation, unless they lie very close threshold. we propose,...
Multiquark states have been advocated to explain recent experimental data in the heavy-light sector, and there are already speculations about multiquarks containing only heavy quarks antiquarks. With a rigorous treatment of four-body problem current quark models, full-charm $(cc\overline{c}\overline{c})$ full-beauty $(bb\overline{b}\overline{b})$ tetraquarks found be unbound. Thus their stability should rely on more subtle effects that not included simple picture constituent quarks. The case...
We discuss the adequate treatment of three- and four-body dynamics for quark model picture double-charm baryons tetraquarks. stress that variational Born-Oppenheimer approximations give energies very close to exact ones, while diquark approximation might be somewhat misleading. The Hall-Post inequalities also provide useful lower bounds exclude possibility stable tetraquarks some mass ratios color wave functions.
A nucleon-nucleon potential is constructed which possesses fundamental theoretical long- and medium-range parts. The short-range part determined phenomenologically by fitting the phase parameters as well deuteron properties. Although number of free small (six in each isospin state) quality fit very good.
We present the first full-fledged study of flavor-exotic isoscalar $T_{bb}^-\equiv b \bar u d$ tetraquark with spin and parity $J^P=1^+$. report accurate solutions four-body problem in a quark model, characterizing structure state as function ratio $M_Q/m_q$ heavy to light masses. For such standard constituent $T_{bb}^-$ lies approximately 150 MeV below strong decay threshold $B^-\bar {B^*}^{0}$ 105 electromagnetic $B^- B^0 \gamma$. evaluate lifetime $T_{bb}^-$, identifying promising modes...
A simple string model inspired by the strong-coupling regime of quantum chromodynamics is used as a potential for studying spectrum multiquark systems with two quarks and antiquarks, careful treatment four-body problem. It found that ground state stable, lying below threshold dissociation into isolated mesons.
We use potential models and several versions of the bag model to calculate mass spectrum baryons with two charmed quarks surrounded by an ordinary or strange quark. Such a system is conveniently described in Born-Oppenheimer approximation, where light quark dynamics provides effective which heavy move non-relativistically. survey briefly possibilities producing such discuss their decay properties.
The chromomagnetic interaction, with proper account for flavor-symmetry breaking, is shown to explain the mass and coupling properties of X(3872) resonance as a ${J}^{PC}={1}^{++}$ state consisting heavy quark-antiquark pair light one. It crucial introduce all spin-color configurations compatible these quantum numbers diagonalize interaction in this basis. This approach thus differs from molecular picture $\mathrm{D}{\overline{\mathrm{D}}}^{*}$ diquark--anti-diquark picture.
We present calculations of the neutron-antineutron ($n\ensuremath{-}\overline{n}$) annihilation lifetime $T$ in deuterium, $^{16}\mathrm{O}$, and $^{56}\mathrm{Fe}$ terms free-space oscillation time ${T}_{n\overline{n}}$. The coupled Schr\"odinger equations for $n$ $\overline{n}$ wave functions a nucleus are solved numerically, using realistic shell-model potential which fits empirical binding energies neutron orbits, complex $\overline{n}$-nucleus optical obtained from to...