Nuclear Theory·nucl-th

Friday·December 6, 2019

6 papers—3 primary·3 cross-listed

01
[Submitted on 4 Dec 2019]
Ab initio models of atomic nuclei: challenges and new ideas
Andreas Ekström🇸🇪
This review presents some of the challenges in constructing models of atomic nuclei starting from theoretical descriptions of the strong interaction between nucleons. The focus is on statistical computing and methods for analyzing the link between bulk properties of atomic nuclei, such as radii and binding energies, and the underlying microscopic description of the nuclear interaction. The importance of careful model calibration and uncertainty quantification of theoretical predictions is highlighted.
Comments:
25 pages, 5 figures, Submitted to Frontiers in Physics (Research topic) The Long-Lasting Quest for Nuclear Interactions: The Past, the Present and the Future
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1912.02227 [pdf]
4 citations
02
[Submitted on 5 Dec 2019]
Description of proton-rich nuclei in the $A \sim 20$ region with the Gamow shell model
Nicolas Michel · Jian Guo Li · Fu Rong Xu · Wei Zuo
The Gamow shell model is utilized to describe nuclear observables of the weakly bound and resonance isotonic states of $^{16}$ O at proton drip-line. It is hereby shown that the presence of continuum coupling leads to complex Coulomb contributions in the spectrum of these isotones. The necessity to include the effects of three-body forces, either by a direct calculation or by adding an $A$ -dependence to the nucleon-nucleon interaction, already noticed in other theoretical models, is pointed out. It is also demonstrated that our approach is predictive for reaction observables.
Comments:
12 pages, 10 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1912.02364 [pdf]
PRC(2019)·25 citations
03
[Submitted on 5 Dec 2019]
Transverse wobbling in an even-even nucleus
Q. B. Chen🇩🇪 · S. Frauendorf🇺🇸 · C. M. Petrache🇫🇷
Two new bands built on the two-quasiparticle $π (h_{11/2})^{2}$ configuration of the even-even nucleus $^{130}$ Ba are investigated using constrained triaxial covariant density functional theory combined with quantum particle rotor model calculations. The energy difference between the two bands, as well as the available electromagnetic transition probabilities $B (M 1)_{out} / B (E 2)_{in}$ and $B (E 2)_{out} / B (E 2)_{in}$ , are well reproduced. The analysis of the angular momentum geometry reveals that the higher band represents transverse wobbling motion of a two-quasiparticle configuration. This is the first example of two-quasiparticle wobbling bands in an even-even nucleus.
Comments:
5 pages, 4 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
1912.02756 [pdf]
PRC(2019)·51 citations
04
[Submitted on 4 Dec 2019] (cross-list from hep-ph)
Heavy Quarkonium in Extreme Conditions
Alexander Rothkopf🇳🇴
In this report we review recent progress achieved in the understanding of heavy quarkonium under extreme conditions from a theory perspective. Its focus lies both on quarkonium properties in thermal equilibrium, as well as recent developments towards a genuine real-time description, valid also out-of-equilibrium. We will give an overview of the theory tools developed and deployed over the last decade, including effective field theories, lattice field theory simulations, modern methods for spectral reconstructions and the the open-quantum systems paradigm. The report will discuss in detail the concept of quarkonium melting, providing the reader with a contemporary perspective. In order to judge where future progress is needed we will also discuss recent results from experiments and phenomenological modeling of quarkonium in relativistic heavy-ion collisions.
Comments:
129 pages, 55 figures, submitted to Physics Reports on July 23rd 2019
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
1912.02253 [pdf]
Phys.Rept.(2020)·254 citations
05
[Submitted on 5 Dec 2019] (cross-list from hep-ph)
Double parton scattering in pA collisions at the LHC revisited
B.Blok🇮🇱 · F.A. Ceccopieri🇮🇱
We consider the production of $W$ -boson plus dijet, $W$ -boson plus b-jets and same sign $W W$ via double parton scattering (DPS) in $p A$ collisions at the LHC and evaluate the corresponding cross sections. The impact of a novel DPS contribution pertinent to $p A$ collisions is quantified. Exploiting the experimental capability of performing measurements differential in the impact parameter in $p A$ collisions, we discuss a method to single out this novel DPS contribution. The method allows the subtraction of the leading twist (LT) single parton scattering background and it gives access in a very clean way to double parton distribution functions in the proton. We calculate leading twist and DPS cross sections and study the dependence of the observables on the cuts in the jets phase space. In the $W j j$ channel the observation of DPS is possible with data already accumulated in $p A$ runs and the situation will greatly improve for the next high luminosity runs. For the $W b b ˉ$ final state, the statistics within the current data is too low, but there is possibility to observe DPS in this channel in future runs, albeit with much reduced sensitivity than in $W j j$ final state. Finally the DPS observation in the same sign $W W$ channel will require either significant increase of integrated luminosity beyond that foreseen in next $p A$ runs or improved methods for $W$ reconstruction, along with its charge, in hadronic decay channels.
Comments:
15 pages,8 figures and 3 tables; significant changes are made, in particular basic observables where changed to minimize systematic errors, leading twist contributions were calculated, and systematic error in DPS determination was estimated, permitting to find at what kinematic constraints DPS contribution to W jj ,Wbb ,WW final states can be separated
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1912.02508 [pdf]
EPJC(2020)·8 citations
06
[Submitted on 5 Dec 2019] (cross-list from hep-ph)
Understanding $X (3872)$ and its decays in the extended Friedrichs scheme
Meng-Ting Yu🇨🇳 · Zhi-Yong Zhou🇨🇳 · Zhiguang Xiao🇨🇳
We present that the $X (3872)$ could be represented as a dynamically generated state in the extended Friedrichs scheme, in which the ratio of "elementariness" and "compositeness" of the different components in the $X (3872)$ is about $Z_{c c ˉ} : X_{D ˉ^{0} D^{0 *}} : X_{D^{+} D^{-*}} : X_{D ˉ^{*} D^{*}}$ $= 1 : (2.67 \sim 8.85) : (0.45 \sim 0.46) : 0.04$ . Furthermore, its decays to $π^{0}$ and a $P$ -wave charmonium $χ_{c J}$ state with $J = 0, 1$ , or $2$ , $J / ψ π^{+} π^{-}$ , and $J / ψ π^{+} π^{-} π^{0}$ could be calculated out with the help of Barnes-Swanson model. The isospin breaking effects is easily understood in this scheme. This calculation also shows that the decay rate of $X (3872)$ to $χ_{c 1} π^{0}$ is much smaller than its decay rate to $J / ψ π^{+} π^{-}$ .
Comments:
5 pages, proceedings for the 18th International Conference on Hadron Spectroscopy and Structure (Hadron 2019)
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
1912.02542 [pdf]
0 citations

Affiliations

first authorsco-authorsvia INSPIRE

Ab initio models of atomic nuclei: challenges and new ideas

Description of proton-rich nuclei in the A∼20 region with the Gamow shell model

Transverse wobbling in an even-even nucleus

Heavy Quarkonium in Extreme Conditions

Double parton scattering in pA collisions at the LHC revisited

Understanding X(3872) and its decays in the extended Friedrichs scheme

Affiliations

Description of proton-rich nuclei in the $A \sim 20$ region with the Gamow shell model

Understanding $X (3872)$ and its decays in the extended Friedrichs scheme