Zobrazeno 1 - 10
of 87
pro vyhledávání: '"Riccardo Giachetti"'
Autor:
Emanuele Sorace, Riccardo Giachetti
Publikováno v:
Annals of Physics. 401:202-223
The relativistic quantum mechanics of two interacting particles is considered. We first present a covariant formulation of kinematics and of reduced phase space, giving a short outline of the classical results. We then quantize the systems for the sc
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e198929dc66612d368fedf3efc3e7670
https://doi.org/10.1016/j.aop.2019.01.005
https://doi.org/10.1016/j.aop.2019.01.005
Publikováno v:
EPJ Web of Conferences, Vol 137, p 06024 (2017)
We calculate some radiative decays of Bottomonium in a covariant scheme for two interacting fermions. We present their branching ratios and their absolute widths. A comparison with experimental data shows a good agreement with our results. Some decay
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::912df5899452369335e69fca4c0f8162
http://hdl.handle.net/2158/1090759
http://hdl.handle.net/2158/1090759
Autor:
Riccardo Giachetti
Publikováno v:
Applied Numerical Mathematics. 62:1119-1125
We study by numerical methods the Dirac equation in linear and quadratic potentials with pure vector coupling. We determine the spectral concentration of the continuous spectrum and we prove that it is well described by a sum of Breit-Wigner lines. T
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::e4519a51ad73c4d4d71e16c2d9dc1780
https://doi.org/10.1016/j.apnum.2011.03.010
https://doi.org/10.1016/j.apnum.2011.03.010
Publikováno v:
The European Physical Journal C. 70:445-450
In this paper we evaluate the expression for the Green function of a pseudo-classical spinning particle interacting with constant electromagnetic external fields by taking into account the anomalous magnetic and electric moments of the particle. The
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::3ddf5d665bb281fcf701ebd93236a59e
https://doi.org/10.1140/epjc/s10052-010-1472-6
https://doi.org/10.1140/epjc/s10052-010-1472-6
Autor:
Vincenzo Grecchi, Riccardo Giachetti
We consider a \textit{PT}-symmetric cubic oscillator with an imaginary double well. We prove the existence of an infinite number of level crossings with a definite selection rule. Decreasing the positive parameter $\hbar$ from large values, at a valu
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8501a71c90d4e07cc75783248b9bfead
Autor:
Riccardo Giachetti, Emanuele Sorace
Publikováno v:
Journal of Physics A: Mathematical and General. 39:15207-15223
We discuss the hyperfine shifts of the Positronium levels in a relativistic framework, starting from a two fermion wave equation where, in addition to the Coulomb potential, the magnetic interaction between spins is described by a Breit term. We writ
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::91dfcfcc0e5c42ada684c9418056c1c5
https://doi.org/10.1088/0305-4470/39/49/009
https://doi.org/10.1088/0305-4470/39/49/009
Autor:
Andrea Barducci, Riccardo Giachetti
Publikováno v:
Journal of Physics A: Mathematical and General. 36:8129-8140
We study the quantization problem of relativistic scalar and spinning particles interacting with a radiation electromagnetic field by using the path integral and the external source method. The spin degrees of freedom are described in terms of Grassm
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ccafe60974b25ae655fe62b49a37d592
https://doi.org/10.1088/0305-4470/36/29/317
https://doi.org/10.1088/0305-4470/36/29/317
Autor:
Riccardo Giachetti, Vincenzo Grecchi
We make a nodal analysis of the processes of level crossings in a model of quantum mechanics with a PT-symmetric double well. We prove the existence of infinite crossings with their selection rules. At the crossing, before the PT-symmetry breaking an
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0cbf890789d44cd9803de0fb2928d18e
http://arxiv.org/abs/1410.8460
http://arxiv.org/abs/1410.8460
A system of two fermions with different masses and interacting by the Coulomb potential is presented in a completely covariant framework. The spin-spin interaction, including the anomalous magnetic moments of the two fermions, is added by means of a
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2ded33d94a24b5ff3abf293bc81b898b
Autor:
Vincenzo Grecchi, Riccardo Giachetti
Publikováno v:
Journal of Mathematical Physics. 57:122109
We consider the properties of the family of double well quantum Hamiltonians Hħ = − ħ2 (d2/dx2) + i(x3 − x), x ∈ ℝ, ħ > 0, starting from the resonances of the cubic oscillator Hϵ = − (d2/dx2) + x2 + ϵx3, ϵ > 0, and studying their anal
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b822395e3970648b76e94abd20b83dbf
https://doi.org/10.1063/1.4972290
https://doi.org/10.1063/1.4972290