Nuclear Theory·nucl-th

Friday·December 17, 2021

8 papers—4 primary·4 cross-listed

01
[Submitted on 15 Dec 2021]
Comprehensive study of muon-catalyzed nuclear reaction processes in the $d t μ$ molecule
M. Kamimura · Y. Kino · T. Yamashita
Muon catalyzed fusion ( $μ$ CF) has recently regained considerable research interest owing to several new developments and applications. In this regard, we have performed a comprehensive study of the most important fusion reaction, namely $(d t μ)_{J = v = 0} \to α$ + $n$ + $μ$ +17.6 MeV or $(α μ)_{n l}$ + $n$ +17.6 MeV. The coupled-channels Schrödinger equation for the reaction is thus solved, satisfying the boundary condition for the muonic molecule $(d t μ)_{J = v = 0}$ as the initial state and the outgoing $α n μ$ channel with the $α$ - $n$ $D$ wave. We employ the $d t μ$ - and $α n μ$ -channel coupled three-body model. All the $d$ - $t$ and $α$ - $n$ potentials, and the $d t$ - $α n$ channel-coupling nonlocal tensor potential are chosen to reproduce the observed low-energy astrophysical $S$ -factor of the reaction $d$ + $t \to α$ + $n$ +17.6 MeV, as well as the total cross section of the $α$ + $n$ reaction. The resultant $d t μ$ fusion rate is 1.15x10 $^{12}$ s $^{- 1}$ . Substituting the obtained total wave function into the $T$ matrix, we have calculated absolute values of the fusion rates going to the bound and continuum states of the outgoing $α$ - $μ$ pair. We then derived the initial $α$ - $μ$ sticking probability $ω_{S}^{0}$ =0.857%, which is $\sim$ 7% smaller than the literature values ( $≃$ 0.91-0.93%), and can explain the recent observations (2001) at high D-T densities. We also calculate the absolute values for the momentum and energy spectra of the emitted muon. The most important result is that the peak energy is 1.1 keV although the mean energy is 9.5 keV. This is an essential result for the ongoing experimental project to realize the generation of an ultra-slow negative muon beam by utilizing the $μ$ CF for various applications e.g., a scanning negative muon microscope and an injection source for the muon collider.
Comments:
21 pages, 18 figures; Fig. 18 and Tables 1, 2 added; published in Phys. Rev. C 107, 034607 (2023)
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex); Atomic Physics (physics.atom-ph); Plasma Physics (physics.plasm-ph)
arXiv:
2112.08399 [pdf]
PRC(2023)·12 citations
02
[Submitted on 16 Dec 2021]
Pairing strength in the relativistic mean-field theory determined from fission barrier heights of actinide nuclei and verified by pairing rotation and binding energies
Taiki Kouno · Chikako Ishizuka · Tsunenori Inakura · Satoshi Chiba
We have studied strength in the BCS pairing force, used as a residual interaction to the relativistic mean-field to reproduce the height of the inner fission barriers for actinide nuclei. It was found that increasing the pairing strength by about 13% makes reproduce the inner fission barriers better over a wide range of actinide nuclei. This result was verified by using the moment-of-inertia of pairing rotational energy, which was introduced to avoid mean-field and odd-mass effects in the pairing interaction to deduce purely the pairing strength. The pairing interaction thus determined could simultaneously improve the description of the binding energy of heavy nuclei as well. As a result, a consistent picture among inner fission barrier, binding energy, and pairing moment of inertia could be obtained in terms of the relativistic mean-field + BCS theory for a broad region of the actinide nuclei.
Comments:
14 pages, 9 figures, PTEP accepted
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2112.08612 [pdf]
PTEP(2022)·4 citations
03
[Submitted on 16 Dec 2021]
System dependence of away-side broadening and $α$ -clustering light nuclei structure effect in dihadron azimuthal correlations
Yuan-Zhe Wang🇨🇳 · Song Zhang🇨🇳 · Yu-Gang Ma🇨🇳
A collision system scan involving $α$ -clustered $^{12}$ C and $^{16}$ O is studied by using a multiphase transport model for central collisions at $s_{N N} = 6.37$ TeV. Background subtracted away-side dihadron azimuthal correlation is performed via the zero yield at minimum (ZYAM) method from raw signals, and the quantitative parameters, such as RMS width and Kurtosis, seem nicely follow the $A^{- 1/3}$ law of the system size if the nucleus has the normal Woods-Saxon nucleon distribution. However, for $α$ -clustering light nuclei, specifically for $^{12}$ C and $^{16}$ O, the RMS width and Kurtosis of away-side azimuthal correlation are deviated from the baseline of $A^{- 1/3}$ law. In addition, the momentum dependence of away-side broadening parameters is also presented. The results show that there is a distinction in away-side broadening parameters of dihadron correlation function between the Woods-Saxon distribution and the $α$ -clustered structures, which sheds light on that the collision system scan for dihadron azimuthal correlation as a potential probe to distinguish $α$ -clustered nuclei.
Comments:
10 pages, 6 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2112.08617 [pdf]
PLB(2022)·35 citations
04
[Submitted on 16 Dec 2021]
Surface effects on hydrodynamic evolution
Sanatan Digal🇮🇳 · P. S. Saumia🇷🇺
We study the effect of surface tension of the phase boundary in the dynamics of an expanding fluid. A fluid at local thermal equilibrium, but has a slowly varying temperature profile, like the plasma formed in heavy ion collisions, will have rapidly varying order parameter field at the edge of the plasma where the temperature falls below the transition temperature. In the case where the free energy admits a first order transition, the gradient energy of this field will act as surface tension. We couple hydrodynamics and order parameter field evolutions to study the effect of this surface in the expansion of the plasma. We see that the surface slows down the expansion which reflects in the development of radial flow and momentum anisotropy.
Comments:
18 pages, 6 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2112.08857 [pdf]
0 citations
05
[Submitted on 15 Dec 2021] (cross-list from hep-th)
Holographic approach to compact stars and their binary mergers
Carlos Hoyos🇪🇸 · Niko Jokela🇫🇮 · Aleksi Vuorinen🇫🇮
In this review article, we describe the role of holography in deciphering the physics of dense QCD matter, relevant for the description of compact stars and their binary mergers. We review the strengths and limitations of the holographic duality in describing strongly interacting matter at large baryon density, walk the reader through the most important results derived using the holographic approach so far, and highlight a number of outstanding open problems in the field. Finally, we discuss how we foresee holography contributing to compact-star physics in the coming years.
Comments:
86 pages, 19 figures; invited review article; v2: revised and published version
Subjects:
High Energy Physics — Theory (hep-th); High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2112.08422 [pdf]
PPNP(2022)·64 citations
06
[Submitted on 16 Dec 2021] (cross-list from hep-ph)
Deep Inelastic Scattering in the Dipole Picture at Next-to-Leading Order
H. Hänninen🇫🇮
This thesis studies gluon saturation in hadronic matter at high energy by calculating next-to-leading order (NLO) corrections to inclusive and diffractive deep inelastic scattering cross sections in the Color Glass Condensate (CGC) effective field theory. We demonstrate that the large soft gluon logarithm is correctly factorized into the Balitsky-Kovchegov (BK) renormalization group equation by accurately connecting the NLO scattering kinematics to the rapidity scale of the dipole amplitude in the scattering. This brings the perturbative expansion under control and enables us to do precision comparisons between theory and data. We fit the initial condition of the BK evolution equation to HERA inclusive deep inelastic scattering data by combining the NLO accuracy inclusive cross sections with beyond leading order BK evolution prescriptions. This results in the state-of-the-art accuracy comparison between CGC theory and HERA data, and determination of the dipole amplitude initial shape which is a necessary input for all NLO CGC phenomenology. In this introductory part, the effect of the NLO BK equation on the fits is assessed, and an alternative form for the NLO loop correction to the inclusive cross sections is derived which enables the consistent setting of the dipole amplitude rapidity scale in the NLO corrections. Diffraction is studied in this thesis in the CGC formalism, and we calculate the tree-level $q q ˉ g$ NLO contribution to the diffractive deep inelastic scattering structure functions where the $q q ˉ g$ Fock state scatters off the target and becomes the diffractively produced system. This contribution has previously been known in the literature only in leading $lo g (Q^{2})$ accuracy valid at large $Q^{2}$ , and only for the structure function $F_{T}^{D}$ . The $q q ˉ g$ contribution to both structure functions $F_{T}^{D}$ and $F_{L}^{D}$ are presented in full NLO accuracy.
Comments:
PhD thesis, introductory part
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2112.08818 [pdf]
JYU Dissertations 444, 2021, ISBN:978-951…·9 citations
07
[Submitted on 16 Dec 2021] (cross-list from hep-lat)
Hadron spin structure from lattice QCD
Constantia Alexandrou (Univ. of Cyprus and The Cyprus Inst.)🇨🇾
We present results on the spin carried by quarks and gluons in the nucleon using lattice QCD simulations with physical values of the light, strange and charm quark masses. We also discuss selective results on the x-dependence of parton distribution functions computed in lattice QCD employing the quasi-parton distribution approach and the large momentum effective theory.
Comments:
10 pages, 6 figures. Invited talk, 24th International Spin Symposium, Matsue, Japan, 18-22 Oct. 2021
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2112.09038 [pdf]
1 citation
08
[Submitted on 16 Dec 2021] (cross-list from quant-ph)
Preparation of the SU(3) Lattice Yang-Mills Vacuum with Variational Quantum Methods
Anthony N Ciavarella🇺🇸 · Ivan A Chernyshev🇺🇸
Studying QCD and other gauge theories on quantum hardware requires the preparation of physically interesting states. The Variational Quantum Eigensolver (VQE) provides a way of performing vacuum state preparation on quantum hardware. In this work, VQE is applied to pure SU(3) lattice Yang-Mills on a single plaquette and one dimensional plaquette chains. Bayesian optimization and gradient descent were investigated for performing the classical optimization. Ansatz states for plaquette chains are constructed in a scalable manner from smaller systems using domain decomposition and a stitching procedure analogous to the Density Matrix Renormalization Group (DMRG). Small examples are performed on IBM's superconducting Manila processor.
Comments:
23 pages, 16 figures, 4 tables
Subjects:
Quantum Physics (quant-ph); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2112.09083 [pdf]
PRD(2022)·120 citations

Affiliations

first authorsco-authorsvia INSPIRE