A5063643284- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Black Holes and Theoretical Physics
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced Chemical Physics Studies
- Nuclear physics research studies
- Physics of Superconductivity and Magnetism
- Atomic and Subatomic Physics Research
- Superconducting Materials and Applications
- Spectroscopy and Laser Applications
- Atomic and Molecular Physics
- Quantum, superfluid, helium dynamics
- Mass Spectrometry Techniques and Applications
- Quantum optics and atomic interactions
- Laser-Matter Interactions and Applications
- Spectroscopy and Quantum Chemical Studies
- High-pressure geophysics and materials
- Geophysics and Gravity Measurements
- Particle accelerators and beam dynamics
- Cosmology and Gravitation Theories
- Computational Physics and Python Applications
- Quantum Mechanics and Applications
- Quantum chaos and dynamical systems
- Advancements in Photolithography Techniques
Vrije Universiteit Amsterdam
2012-2021
North Carolina State University
2009-2020
Kyungpook National University
2020
Institute for Theoretical and Experimental Physics
2000-2019
Universitat de València
2013
SLAC National Accelerator Laboratory
2013
University of Warsaw
2013
Thomas Jefferson National Accelerator Facility
2013
Istituto Nazionale di Fisica Nucleare, Sezione di Padova
2013
Instituto Tecnológico de Aeronáutica
2013
We present a study of the tensorial structure hadronic matrix elements angular momentum operators $\mathbit{J}$. Well known results in literature are shown to be incorrect, and we have taken pains derive correct expressions three different ways, two involving explicit physical wave packets third, totally independent, based upon rotational properties state vectors. Surprisingly it turns out that very sensitive type relativistic spin used describe motion particle, i.e., whether canonical...
Meson Green's functions and decay constants ${f}_{\ensuremath{\Gamma}}$ in different channels $\ensuremath{\Gamma}$ are calculated using the field correlator method. Both, spectrum ${f}_{\ensuremath{\Gamma}}$, appear to be expressed only through universal constants: string tension $\ensuremath{\sigma}$, ${\ensuremath{\alpha}}_{s}$, pole quark masses. For $S$-wave states masses agree with experimental numbers within $\ifmmode\pm\else\textpm\fi{}5\text{ }\text{ }\mathrm{MeV}$. $D$ ${D}_{s}$...
The masses of higher $D(nL)$ and ${D}_{s}(nL)$ excitations are shown to decrease due the string contribution, originating from rotation QCD itself: it lowers by 45 MeV for $L=2$ ($n=1$) 65 $L=3$ ($n=1$). An additional $\ensuremath{\sim}100\text{ }\text{ }\mathrm{MeV}$ takes place if current mass light (strange) quark is used in a relativistic model. For ${D}_{s}(1^{3}D_{3})$ ${D}_{s}(2{P}_{1}^{\mathrm{H}})$ calculated agree with experimental values ${D}_{s}(2860)$ ${D}_{s}(3040)$,...
Velocity distributions for the Cl(2P3/2) and Cl(2P1/2) photofragments produced by photolysis of Cl2 in region between 310 470 nm are measured using photofragment velocity mapping. Our results indicate that at short wavelengths absorption spectrum is dominated 1u(1Πu) excited electronic state which produces two ground chlorine atoms. The 0u+(B 3Πu) a spin-orbit atom becomes significant 350 dominates beyond 400 nm. Analysis angular indicates aligned magnitude alignment quantitatively...
We study the form factors of vector mesons using a covariant fermion field theory model in $(3+1)$ dimensions. Performing light-front calculation $q^+ =0$ frame parallel with manifestly calculation, we note existence nonvanishing zero-mode contribution to current $J^+$ and find way avoiding factor calculations. Upon choosing gauge ($\ep^+_{h=\pm}=0$) circular polarization spin projection $h=\uparrow\downarrow=\pm$, only helicity zero matrix element plus receives contributions. Therefore, one...
The divergences appearing in the 3+1 dimensional fermion-loop calculations are often regulated by smearing vertices a covariant manner. Performing parallel light-front calculation, we corroborate similarity between vertex-smearing-technique and Pauli-Villars regularization. In calculation of electromagnetic meson current, find that persistent end-point singularity appears case point is removed even if smeared-vertex taken to limit point-vertex. Recapitulating current conservation,...
The hyperfine splitting for the $2S$ charmonium state is calculated and predicted number ${\ensuremath{\Delta}}_{\mathrm{HF}}(2S)=57\ifmmode\pm\else\textpm\fi{}8\mathrm{MeV},$ being by derivation lower bound of this splitting. It results in $M({\ensuremath{\eta}}_{c}(2S))=3630\ifmmode\pm\else\textpm\fi{}8\mathrm{MeV},$ which smaller two standard deviations than found Belle experiment, but close to ${\ensuremath{\eta}}_{c}(2S)$ mass observed same group experiment...
A new physical mechanism is suggested to explain the universal depletion of high meson excitations. It takes into account appearance holes inside string world sheet due $q\overline{q}$ pair creation when length exceeds critical value ${R}_{1}\ensuremath{\simeq}1.4 \mathrm{fm}$. argued that a delicate balance between large ${N}_{c}$ loop suppression and favorable gain in action, produced by holes, creates metastable (predecay) stage with renormalized tension which now depends on separation r....
The $b\overline{b}$ spectrum is calculated with the use of a relativistic Hamiltonian where gluon-exchange potential between quark and an antiquark taken as in background perturbation theory. We observed that splittings ${\ensuremath{\Delta}}_{1}=\ensuremath{\Upsilon}(1\mathrm{D})\ensuremath{-}{\ensuremath{\chi}}_{b}(1\mathrm{P})$ other low-lying states are very sensitive to QCD constant ${\ensuremath{\Lambda}}_{\mathrm{V}}{(n}_{\mathrm{f}})$ which occurs vector scheme, good agreement...
Radiative decays of $X(3872)$ with ${J}^{\mathrm{PC}}={1}^{++}$ are studied in the coupled-channel approach, where $c\overline{c}$ states described by relativistic string Hamiltonian, while for decay channels $D{D}^{*}$ a string-breaking mechanism is used. Within this method sharp peak and correct mass shift $2^{3}P_{1}$ charmonium state just to ${D}^{0}{D}^{*0}$ threshold was already obtained prescribed channel coupling channels. For same value normalized wave function (w.f.) acquires...
In the framework of QCD string approach it is shown that spin-averaged masses $\overline{M}(\mathrm{nL})$ all low-lying light mesons are well described using tension $\ensuremath{\sigma}$ as only parameter. The Regge slope ${\ensuremath{\alpha}}_{L}^{\ensuremath{'}}$ and intercept ${\ensuremath{\alpha}}_{L}(0)$ L trajectory for calculated analytically turn out to be ${\ensuremath{\alpha}}_{L}^{\ensuremath{'}}=0.80 {\mathrm{GeV}}^{\ensuremath{-}2}$ (for $L<~4)$...
In this paper we discuss the relation between standard covariant quantum field theory and light-front theory. We define by its Feynman diagrams, whereas is defined in terms of light-cone time-ordered diagrams. A general algorithm proposed that produces latter from any diagram. The procedure illustrated several cases. Technical problems occur formulation have no counterpart are identified solved.
We study the transition form factors between pseudoscalar and vector mesons using a covariant fermion field theory model in $3+1$ dimensions. Performing light-front calculation ${q}^{+}=0$ frame parallel with manifestly calculation, we note that suspected nonvanishing zero-mode contribution to current ${J}^{+}$ does not exist our analysis of factors. also perform purely longitudinal ${q}^{+}>0$ confirm obtained directly from timelike region are identical ones by analytic continuation...
The spectra of heavy quarkonia are studied in two approaches: with the use Afonin-Pusenkov representation Regge trajectories for squared excitation energy ${E}^{2}(nl)$ (ERT) and using relativistic Hamiltonian universal interaction. parameters ERTs extracted from experimental masses both cases, bottomonium charmonium, value radial slope ${b}_{n}(Q\overline{Q})$ appears to be $\ensuremath{\sim}40%$ larger than orbital ${b}_{l}(Q\overline{Q})$: particular ${b}_{l}(b\overline{b})=0.50(1)\text{...
We discuss a treacherous point in light-front dynamics (LFD) which should be taken into account to restore complete equivalence with the manifestly covariant formalism. present examples that require an inclusion of arc contribution energy contour integration order achieve between LFD result and result.
A universal description of the hyperfine splittings (HFS) in bottomonium and ${B}_{q}$ ($q=n$, $s$, $c$) mesons is obtained with a strong coupling constant ${\ensuremath{\alpha}}_{s}(\ensuremath{\mu})=0.310$ spin-spin potential. Other characteristics are calculated within field correlator method, taking freezing value independent ${n}_{f}$. The HFS $M({B}^{*})\ensuremath{-}M(B)=45.5(1)\text{ }\text{ }\mathrm{MeV}$, $M({B}_{s}^{*})\ensuremath{-}M({B}_{s})=46.2(1)\text{ }\mathrm{MeV}$ full...
The possibility to observe new bottomonium states with ${J}^{PC}={1}^{--}$ in the region 10.7--11.1 GeV is discussed. analysis of dielectron widths shows that $(n+1)^{3}S_{1}$ and $n^{3}D_{1}$ ($n\ensuremath{\ge}3$) may be mixed a rather large mixing angle, $\ensuremath{\theta}\ensuremath{\approx}30\ifmmode^\circ\else\textdegree\fi{}$, this effect provides correct values ${\ensuremath{\Gamma}}_{ee}(\ensuremath{\Upsilon}(10580))$ ${\ensuremath{\Gamma}}_{ee}(\ensuremath{\Upsilon}(11020))$. On...
We review the interface between current theoretical framework based on generalized parton distributions (GPDs) and experimental measurements of deeply virtual Compton scattering (DVCS) observables. find that present needs to be extended cover future DVCS experiments. The formulation is quantum chromodynamics factorization handbag diagrams, relying dominance. Our examination reveals diagrams by themselves do not satisfy electromagnetic gauge invariance. numerical estimates amplitudes in a...
Multiphoton processes following the excitation of methyl iodide to A-band continuum are studied using a pulsed laser beam 5 eV photons with pulse duration 15 ns, ps, and 500 fs. Velocity map images obtained for resulting photoelectron, I+, CH3+ fragments. Both one-photon dissociation multistep ionization observed, latter process becoming dominant at shorter duration. The photoelectron spectra (PES) from velocity imaging, which provides uniform transmittance all electron kinetic energies,...
The photodissociation of hydrogen iodide in the A-band region was investigated between 273 and 288 nm using photofragment imaging technique. At 17 wavelengths I* (2P1/2)/I(2P3/2) branching ratio measured by recording corresponding atomic fragment multiphoton ionization at 243 nm. ratios are good agreement with previous measurements confirm that four (final) states Π3(0+), 3Π(1), 3Σ(1), Π1(1) involved absorption HI those dissociate adiabatically to form H+I* H+I following parallel...
The dynamical picture of a quark-antiquark interaction in light mesons, which provides linearity radial and orbital Regge trajectories (RT), is studied with the use relativistic string Hamiltonian flattened confining potential (CP) taking into account three negative corrections: gluon-exchange, self-energy, corrections. Due to flattening effect slope ${\ensuremath{\beta}}_{n}$ ${\ensuremath{\beta}}_{l}$ decrease by $\ensuremath{\sim}30%$ as compared those linear CP, while correction...