Nuclear Theory·nucl-th

Wednesday·March 9, 2022

5 papers—2 primary·3 cross-listed

01
Norm operator method for boson expansions
Kimikazu Taniguchi
We propose a new boson expansion theory that does not premise the closed-algebra approximation, indispensable for formulation until now, as an extension of the conventional practical boson expansion methods that have tried to elucidate nuclear collective motion, which is a method that allows the closed-algebra approximation not to be used or to be used appropriately, enables us to obtain the boson expansion easier, and reproduces the fermion subspace onto the boson subspace more faithfully than the conventional practical methods. The two-phonon norm matrix composed of all the phonon excitation modes is investigated in detail, which reveals the mechanism, essential for the boson expansion methods, of how we should construct the fermion subspace to be mapped from the whole fermion space. The conventional practical boson expansion methods have applied the closed-algebra approximation improperly to strengthen the effect of the Pauli principle inappropriately, which should be replaced by those that do not use that approximation or use it properly.
nucl-th0 citations
02
Status of deep subbarrier $^{12} C +^{12} C$ fusion and advancing the Trojan horse method
A. M. Mukhamedzhanov
In this paper, I will update the current status of the carbon-carbon fusion research taking into account that after the latest analysis [Beck {\it et al.} Eur. Phys. J. A {\bf 56}, 97 (2020), Letter to the Editor] new important experimental and theoretical results had been published and will discuss how to advance new THM measurements to extract the low-energy astrophysical $S$ -factors.
nucl-thastro-ph.IMastro-ph.SRnucl-exEPJA(2022)·5 citations
03
3D structure of jet-induced diffusion wake in an expanding quark-gluon plasma
Zhong Yang🇨🇳 · Tan Luo🇪🇸 · Wei Chen🇨🇳 · Long-Gang Pang🇨🇳 · Xin-Nian Wang🇨🇳
The diffusion wake accompanying the jet-induced Mach cone provides a unique probe of the properties of quark-gluon plasma in high-energy heavy-ion collisions. It can be characterized by a depletion of soft hadrons in the opposite direction of the propagating jet. We explore the 3D structure of the diffusion wake induced by $γ$ -triggered jets in Pb+Pb collisions at the LHC energy within the coupled linear Boltzmann transport and hydro model. We identify a valley structure caused by the diffusion wake on top of a ridge from the initial multiple parton interaction (MPI) in jet-hadron correlation as a function of rapidity and azimuthal angle. This leads to a double-peak structure in the rapidity distribution of soft hadrons in the opposite direction of the jets as an unambiguous signal of the diffusion wake. Using a two-Gaussian fit, we extract the diffusion wake and MPI contributions to the double peak. The diffusion wake valley is found to deepen with the jet energy loss as characterized by the $γ$ -jet asymmetry. Its sensitivity to the equation of state and shear viscosity is also studied.
↳ hep-phnucl-thPRL(2023)·70 citations
04
On Lowest Lying $\frac{1}{2}^{-}$ Octet Baryons
Chang Chen🇨🇳 · Wen-Qi Niu🇨🇳 · Han-Qing Zheng🇨🇳
The recently proposed $N^{*} (890)$ $1/ 2^{-}$ baryon is studied in a flavor $S U (3)$ scheme with $K$ matrix unitarization, by fitting to low energy cross section and phase shift data. It is found that $N^{*} (890)$ co-exists with low lying poles in other channels, which have been extensively discussed in the literature, though they belong to different octets, in the $S U (3)$ limit. Hence the existence of $N^{*} (890)$ is further verified.
↳ hep-phnucl-thCPC(2022)·5 citations
05
Linearisability of divergence-free fields along invariant 2-tori
David Perrella · David Pfefferlé · Luchezar Stoyanov
We find conditions under which the restriction of a divergence-free vector field $B$ to an invariant toroidal surface $S$ is linearisable. The main results are similar in conclusion to Arnold's Structure Theorems but require weaker assumptions than the commutation $[B, \nabla \times B] = 0$ . Relaxing the need for a first integral of $B$ (also known as a flux function), we assume the existence of a solution $u : S \to R$ to the cohomological equation $B ∣_{S} (u) = \partial_{n} B$ on a toroidal surface $S$ mutually invariant to $B$ and $\nabla \times B$ . The right hand side $\partial_{n} B$ is a normal surface derivative available to vector fields tangent to $S$ . In this situation, we show that the field $B$ on $S$ is either identically zero or nowhere vanishing with $B ∣_{S} /∥ B ∥^{2} ∣_{S}$ being linearisable. We are calling the latter the semi-linearisability of $B$ (with proportionality $∥ B ∥^{2} ∣_{S}$ ). The non-vanishing property relies on Bers' results in pseudo-analytic function theory about a generalised Laplace-Beltrami equation arising from Witten cohomology deformation. With the use of de Rham cohomology, we also point out a Diophantine integral condition where one can conclude that $B ∣_{S}$ itself is linearisable. The linearisability of $B ∣_{S}$ is fundamental to the so-called magnetic coordinates, which are central to the theory of magnetically confined plasmas.
↳ math.DGmath-phmath.MPnucl-thSN Partial Differ. Equ. Appl.(2022)·0 citations

Affiliations

first authorsco-authorsvia INSPIRE

Norm operator method for boson expansions

Status of deep subbarrier 12C+12C fusion and advancing the Trojan horse method

3D structure of jet-induced diffusion wake in an expanding quark-gluon plasma

On Lowest Lying 21​− Octet Baryons

Linearisability of divergence-free fields along invariant 2-tori

Affiliations

Status of deep subbarrier $^{12} C +^{12} C$ fusion and advancing the Trojan horse method

On Lowest Lying $\frac{1}{2}^{-}$ Octet Baryons