Nuclear Theory·nucl-th

Wednesday·May 5, 2021

4 papers—2 primary·2 cross-listed

01
[Submitted on 4 May 2021]
Structure of $Λ$ (1405) resonance and $γ p \to K^{+} + (π Σ)^{0}$ reaction
S. Marri🇮🇷 · M. N. Nasrabadi🇮🇷 · S. Z. Kalantari🇮🇷
Three-body calculations of $K K ˉ N$ system with quantum numbers $I = 1/2$ , $J^{π} = (\frac{1}{2})^{+}$ were performed. Using separable potentials for two-body interactions, we calculated the $π Σ$ mass spectra for the $(K ˉ N)_{I = 0} + K^{+} \to (π Σ)^{0} K^{+}$ reaction on the basis of three-body Alt-Grassberger-Sandhas equations in the momentum representation. In this regard, different types of $K ˉ N - π Σ$ potentials based on phenomenological and chiral SU(3) approach are used. The possibility to observe the trace of $Λ (1405)$ resonance in $(π Σ)^{0}$ mass spectra was studied. Using the $χ^{2}$ fitting, it was shown that the mass of $Λ$ (1405) resonance is about 1417 $MeV / c^{2}$ .
Comments:
10 pages, 6 figures, accepted for publication in PRC
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2105.01367 [pdf]
PRC(2021)·3 citations
02
[Submitted on 4 May 2021]
The impact of nuclear deformation on relativistic heavy-ion collisions: assessing consistency in nuclear physics across energy scales
Giuliano Giacalone🇩🇪 · Jiangyong Jia🇺🇸 · Chunjian Zhang🇺🇸
In the hydrodynamic framework of heavy-ion collisions, elliptic flow, $v_{2}$ , is sensitive to the quadrupole deformation, $β$ , of the colliding ions. This enables one to test whether the established knowledge on the low-energy structure of nuclei is consistent with collider data from high-energy experiments. We derive a formula based on generic scaling laws of hydrodynamics to relate the difference in $v_{2}$ measured between collision systems that are close in size to the value of $β$ of the respective species. We validate our formula in simulations of 238U+238U and 197Au+197Au collisions at top Relativistic Heavy Ion Collider (RHIC) energy, and subsequently apply it to experimental data. Using the deformation of 238U from low-energy experiments, we find that RHIC $v_{2}$ data implies $0.16 ≲ ∣ β ∣ ≲ 0.20$ for 197Au nuclei, i.e., significantly more deformed than reported in the literature, posing an interesting puzzle in nuclear phenomenology.
Comments:
6 pages and 4 figures, published version
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2105.01638 [pdf]
PRL(2021)·124 citations
03
[Submitted on 3 May 2021] (cross-list from hep-ph)
An $X (3872)$ -like peak in $B \to (J / ψ π^{+} π^{-}) K π$ due to triangle singularity
Satoshi X. Nakamura (University of Science and Technology of China)🇨🇳
Triangle mechanisms for $B^{0} \to (J / ψ π^{+} π^{-}) K^{+} π^{-}$ are studied. Experimentally, an $X (3872)$ peak has been observed in this process. When the final $(J / ψ π^{+} π^{-}) π$ invariant mass is around the $D^{*} D ˉ^{*}$ threshold, one of the triangle mechanisms causes a triangle singularity and generates a sharp $X (3872)$ -like peak in the $J / ψ π^{+} π^{-}$ invariant mass distribution. The Breit-Wigner mass and width fitted to the spectrum are 3871.68 MeV (a few keV above the $D^{* 0} D ˉ^{0}$ threshold) and $\sim$ 0.4 MeV, respectively.These Breit-Wigner parameters hardly depends on a choice of the model parameters. Comparing with the precisely measured $X (3872)$ mass and width, $3871.69 \pm 0.17$ MeV and $< 1.2$ MeV, the agreement is remarkable. When studying the $X (3872)$ signal from this process, this non-resonant contribution has to be understood in advance. We also study a charge analogous process $B^{0} \to (J / ψ π^{0} π^{-}) K^{+} π^{0}$ . A similar triangle singularity exists and generates an $X^{-} (3876)$ -like peak.
Comments:
6 pages, 4 figures, Contribution to the Proceedings for 8th Asia-Pacific Conference on Few-Body Problems in Physics (APFB2020), March 1-5 2021, Kanazawa, Japan
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2105.01118 [pdf]
Few Body Syst.(2021)·0 citations
04
[Submitted on 3 May 2021] (cross-list from hep-th)
Crystals of gauged solitons, force free plasma and resurgence
Gonzalo Barriga🇨🇱 · Fabrizio Canfora🇨🇱 · Matías Torres🇨🇱 · Aldo Vera🇨🇱
We show that the (3+1)-dimensional gauged non-linear sigma model minimally coupled to a U(1) gauge field possesses analytic solutions representing gauged solitons at finite Baryon density whose electromagnetic field is a Force Free Plasma. These gauged solitons manifest a crystalline structure and generate in a very natural way persistent currents able to support Force Free Plasma electromagnetic fields. The trajectories of charged test particles moving within these configurations can be characterized. Quite surprisingly, despite the non-integrable nature of the theory, some of the perturbations of these gauged solitons allow to identify a proper resurgent parameter. In particular, the perturbations of the solitons profile are related to the Lamé operator. On the other hand, the electromagnetic perturbations on the configurations satisfy a two-dimensional effective Schrodinger equation, where the soliton background interacts with the electromagnetic perturbations through an effective two-dimensional periodic potential. We studied numerically the band energy spectrum for different values of the free parameters of the theory and we found that bands-gaps are modulated by the potential strength. Finally we compare our crystal solutions with those of the (1+1)- dimesional Gross-Neveu model.
Comments:
New references added. 27 pages, 14 figures, version accepted for publication on PRD
Subjects:
High Energy Physics — Theory (hep-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2105.01172 [pdf]
PRD(2021)·10 citations

Affiliations

first authorsco-authorsvia INSPIRE

Structure of Λ(1405) resonance and γp→K++(πΣ)0 reaction

The impact of nuclear deformation on relativistic heavy-ion collisions: assessing consistency in nuclear physics across energy scales

An X(3872)-like peak in B→(J/ψπ+π−)Kπ due to triangle singularity

Crystals of gauged solitons, force free plasma and resurgence

Affiliations

Structure of $Λ$ (1405) resonance and $γ p \to K^{+} + (π Σ)^{0}$ reaction

An $X (3872)$ -like peak in $B \to (J / ψ π^{+} π^{-}) K π$ due to triangle singularity