Nuclear Theory·nucl-th

Monday·May 22, 2017

5 papers—3 primary·2 cross-listed

01
[Submitted on 19 May 2017]
Constraining the $K ˉ N$ interaction from the $1 S$ level shift of kaonic deuterium
Tsubasa Hoshino🇯🇵 · Shota Ohnishi🇯🇵 · Wataru Horiuchi🇯🇵 · Tetsuo Hyodo🇯🇵 · Wolfram Weise🇯🇵
Motivated by the precise measurement of the $1 S$ level shift of kaonic hydrogen, we perform accurate three-body calculations for the spectrum of kaonic deuterium using a realistic antikaon-nucleon ( $K N$ ) interaction. In order to describe both short- and long-range behavior of the kaonic atomic states, we solve the three-body Schrödinger equation with a superposition of a large number of correlated Gaussian basis functions covering distances up to several hundreds of fm. Transition energies between $1 S$ , $2 P$ and $2 S$ states are determined with high precision. The complex energy shift of the $1 S$ level of kaonic deuterium is found to be $670 - i 508$ eV. The sensitivity of this level shift with respect to the isospin $I = 1$ component of the $K N$ interaction is examined. It is pointed out that an experimental determination of the kaonic deuterium level shift within an uncertainty of 25\% will provide a constraint for the $I = 1$ component of the $K N$ interaction significantly stronger than that from kaonic hydrogen.
Comments:
11 pages, no figure
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1705.06857 [pdf]
PRC(2017)·47 citations
02
[Submitted on 19 May 2017]
Integrated cross sections of high-energy $e^{+} e^{-}$ electroproduction by an electron in an atomic field
P.A. Krachkov · A.I. Milstein
The integrated cross sections of high-energy $e^{+} e^{-}$ electroproduction by an electron in an atomic field is studied. Importance of various contributions to these cross sections is discussed. It is shown that the Coulomb corrections are very important both for the differential cross section and for the integrated cross sections even for moderate values of the atomic charge number. This effect is mainly related to the interaction of the produced $e^{+} e^{-}$ pair with the atomic field. For the cross section differential over the electron transverse momentum the account for the interference of the amplitudes and the contribution of virtual bremsstrahlung is noticeable. The Coulomb corrections to scattering is larger than these two effects but essentially smaller than the Coulomb corrections to the amplitude of pair photoproduction by a virtual photon. However, in the cross section differential over the positron transverse momentum, there is a strong suppression of the effect of the Coulomb corrections to scattering.
Comments:
12 pages, 5 figures
Subjects:
Nuclear Theory (nucl-th); Atomic Physics (physics.atom-ph)
arXiv:
1705.06906 [pdf]
Zh.Eksp.Teor.Fiz.(2018)·2 citations
03
[Submitted on 19 May 2017]
The relationship between undularity and L dependence of the nuclear optical model potential
R. S. Mackintosh
The contribution of collective or reaction channels to a local optical model potential, OMP, can be readily calculated as a dynamical polarization potential, DPP. The resulting local DPPs commonly have undulatory (`wavy') features, often including local regions of emissivity in the imaginary component. We show here that this undularity arises from $l$ -dependence of the underlying formal non-local and $l$ -dependent DPP. The $l$ -independent proton OMPs, that have the same $S$ -matrix $S_{l j}$ as phenomenological $l$ -dependent potentials, exhibit undulations that are qualitatively similar to undulations of local DPPs generated by channel coupling. The $l$ -dependent phenomenological potentials studied are the potentials that give the best existing fits to the relevant elastic scattering data and the undulatory potentials presented here, being $S$ -matrix equivalent (i.e.\ having the same $S$ -matrix, $S_{l j}$ ) give exactly the same scattering. In addition, we present calculations strongly suggesting that undularity (`waviness') is a generic property of $l$ -independent potentials that are $S$ -matrix equivalent to $l$ -dependent potentials. Implications for the validity of folding models based on a local density model are noted.
Comments:
29 pages, 13 figures, improved abstract, much text thoroughly revised, typos corrected, new references
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1705.07003 [pdf]
2 citations

Affiliations

first authorsco-authorsvia INSPIRE

Constraining the KˉN interaction from the 1S level shift of kaonic deuterium

Integrated cross sections of high-energy e+e− electroproduction by an electron in an atomic field

The relationship between undularity and L dependence of the nuclear optical model potential

Affiliations

Constraining the $K ˉ N$ interaction from the $1 S$ level shift of kaonic deuterium

Integrated cross sections of high-energy $e^{+} e^{-}$ electroproduction by an electron in an atomic field