Nuclear Theory·nucl-th

Wednesday·July 27, 2022

16 papers—8 primary·8 cross-listed

09
[Submitted on 25 Jul 2022] (cross-list from quant-ph)
Parallelization techniques for quantum simulation of fermionic systems
Jacob Bringewatt🇺🇸 · Zohreh Davoudi🇺🇸
Mapping fermionic operators to qubit operators is an essential step for simulating fermionic systems on a quantum computer. We investigate how the choice of such a mapping interacts with the underlying qubit connectivity of the quantum processor to enable (or impede) parallelization of the resulting Hamiltonian-simulation algorithm. It is shown that this problem can be mapped to a path coloring problem on a graph constructed from the particular choice of encoding fermions onto qubits and the fermionic interactions onto paths. The basic version of this problem is called the weak coloring problem. Taking into account the fine-grained details of the mapping yields what is called the strong coloring problem, which leads to improved parallelization performance. A variety of illustrative analytical and numerical examples are presented to demonstrate the amount of improvement for both weak and strong coloring-based parallelizations. Our results are particularly important for implementation on near-term quantum processors where minimizing circuit depth is necessary for algorithmic feasibility.
Comments:
27 pages, 12 figures; (v2) corrected a misplaced figure; (v3) updated for publication with minor changes
Subjects:
Quantum Physics (quant-ph); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2207.12470 [pdf]
Quantum(2023)·15 citations
10
[Submitted on 25 Jul 2022] (cross-list from hep-ph)
Jet-medium photons as a probe of parton dynamics
Rouzbeh Modarresi Yazdi🇨🇦 · Shuzhe Shi🇺🇸 · Charles Gale🇨🇦 · Sangyong Jeon🇨🇦
Photons resulting from jet-medium interactions offer the opportunity of studying the evolving quark distribution in a heavy ion collision. The spectra of jet-medium photons is presented within the JETSCAPE framework for two different energy loss models, MARTINI and CUJET. Jet-medium photons can contribute significantly to the spectrum of direct photons in the intermediate $p_{T}$ range.
Comments:
Presented at the XXIXth International Conference on Ultra-relativistic Nucleus-Nucleus Collisions (Quark Matter 2022)
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2207.12513 [pdf]
Acta Phys.Polon.Supp.(2023)·7 citations
11
[Submitted on 25 Jul 2022] (cross-list from hep-ph)
Neutrino-induced single pion production and the reanalyzed bubble chamber data
D.F. Tamayo Agudelo🇦🇷 · A. Mariano🇦🇷 · D.E. Jaramillo Arango🇨🇴
In this work we report the calculation of the charged current total and differential cross sections for weak pion-production with neutrinos and antineutrinos, with the final pion-nucleon pair invariant mass $W_{π N} ≲ 2$ GeV. Our results are compared with the recent reanalyzed data from the old bubble chamber experiments, that solved the discrepancy between the ANL and BNL data. We implement a model previously tested for the cuts $W_{π N} < 1.4, 1.6$ Gev which includes explicitly resonances in the first and second resonance regions, within different approaches for the resonances self energy and $\frac{3}{2}$ -vertexes and propagators, a fact not usually analyzed. Our model leans on consistent effective Lagrangians that generate resonant amplitudes together non resonant plus resonant backgrounds. Effects of hadrons finite extension and more energetic resonances corresponding to the emitted pion-nucleon invariant mass in the $1.6 < W_{π N} < 2$ GeV region, are taking into account using appropiate form factors in consistency with previous results on neutral current pion production calculations. Our results reproduce well the reanalysed data without cuts and are compared with another models.
Comments:
Manuscript has been accepted for publication as a Regular Article in Physical Review D. arXiv admin note: text overlap with arXiv:1601.01888 by other authors
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2207.12549 [pdf]
PRD(2022)·2 citations
12
[Submitted on 26 Jul 2022] (cross-list from hep-th)
New developments in relativistic magnetohydrodynamics
Koichi Hattori🇨🇳 · Masaru Hongo🇯🇵 · Xu-Guang Huang🇨🇳
Relativistic magnetohydrodynamics (RMHD) provides an extremely useful description of the low-energy long-wavelength phenomena in a variety of physical systems from quark-gluon plasma in heavy-ion collisions to matters in supernovas, compact stars, and early universe. We review the recent theoretical progresses of RMHD, such as a formulation of RMHD from the perspective of magnetic flux conservation using the entropy-current analysis, the nonequilibrium statistical operator approach applied to quantum electrodynamics, and the relativistic kinetic theory. We discuss how the transport coefficients in RMHD are computed in kinetic theory and perturbative quantum field theories. We also explore the collective modes and instabilities in RMHD with a special emphasis on the role of chirality in a parity-odd plasma. We also give some future prospects of RMHD, including the interaction with spin hydrodynamics and the new kinetic framework with magnetic flux conservation.
Comments:
103 pages, 9 figures. Invited review for Symmetry
Subjects:
High Energy Physics — Theory (hep-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th); Plasma Physics (physics.plasm-ph)
arXiv:
2207.12794 [pdf]
Symmetry(2022)·53 citations
13
[Submitted on 11 Jul 2022] (cross-list from cs.LG)
Efficient Learning of Accurate Surrogates for Simulations of Complex Systems
A. Diaw · M. McKerns · I. Sagert · L. G. Stanton · M. S. Murillo
Machine learning methods are increasingly used to build computationally inexpensive surrogates for complex physical models. The predictive capability of these surrogates suffers when data are noisy, sparse, or time-dependent. As we are interested in finding a surrogate that provides valid predictions of any potential future model evaluations, we introduce an online learning method empowered by optimizer-driven sampling. The method has two advantages over current approaches. First, it ensures that all turning points on the model response surface are included in the training data. Second, after any new model evaluations, surrogates are tested and "retrained" (updated) if the "score" drops below a validity threshold. Tests on benchmark functions reveal that optimizer-directed sampling generally outperforms traditional sampling methods in terms of accuracy around local extrema, even when the scoring metric favors overall accuracy. We apply our method to simulations of nuclear matter to demonstrate that highly accurate surrogates for the nuclear equation of state can be reliably auto-generated from expensive calculations using a few model evaluations.
Comments:
13 pages, 6 figures, submitted to Nature Machine Intelligence
Subjects:
Machine Learning (cs.LG); Nuclear Theory (nucl-th); Computational Physics (physics.comp-ph); Data Analysis, Statistics and Probability (physics.data-an); Plasma Physics (physics.plasm-ph)
arXiv:
2207.12855 [pdf]
1 citation
14
[Submitted on 26 Jul 2022] (cross-list from hep-ph)
$X$ and $Z_{cs}$ in $B^{+} \to J / ψ ϕ K^{+}$ as $s$ -wave threshold cusps and alternative spin-parity assignments to $X (4274)$ and $X (4500)$
Xuan Luo (Anhui University)🇨🇳 · Satoshi X. Nakamura (Univ. of Science and Technology of China)🇨🇳
Recent LHCb's amplitude analysis on $B^{+} \to J / ψ ϕ K^{+}$ suggests the existence of exotic $X$ and $Z_{cs}$ hadrons, based on an assumption that Breit-Wigner resonances describe all the peak structures. However, all the peaks and also dips in the spectra are located at relevant meson-meson thresholds where threshold kinematical cusps might cause such structures. This points to the importance of an independent amplitude analysis with due consideration of the kinematical effects, and this is what we do in this work. Our model fits well $J / ψ ϕ$ , $J / ψ K^{+}$ , and $K^{+} ϕ$ invariant mass distributions simultaneously, demonstrating that all the $X$ , $Z_{cs}$ , and dip structures can be well described with the ordinary $s$ -wave threshold cusps. Spin-parity of the $X (4274)$ and $X (4500)$ structures are respectively $0^{-}$ and $1^{-}$ from our model, as opposed to $1^{+}$ and $0^{+}$ from the LHCb's. With all relevant threshold cusps considered, the number of fitting parameters seems to be significantly reduced. The LHCb data requires $D_{s}^{(*)} D ˉ^{*}$ scattering lengths in our model to be consistent with zero, disfavoring $D_{s}^{(*)} D ˉ^{*}$ molecule interpretations of $Z_{cs} (4000)$ and $Z_{cs} (4220)$ and, via the SU(3) relation, being consistent with previous lattice QCD results.
Comments:
10 pages, 6 figures, 1 table; v3: minor corrections, matches published version
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2207.12875 [pdf]
PRD(2023)·9 citations
15
[Submitted on 26 Jul 2022] (cross-list from gr-qc)
Charged quark stars in $f (R, T)$ gravity
Juan M. Z. Pretel🇧🇷 · Takol Tangphati🇹🇭 · Ayan Banerjee🇿🇦 · Anirudh Pradhan🇮🇳
Recent advances in nuclear theory combined with new astrophysical observations have led to the need for specific theoretical models that actually apply to phenomena on dense-matter physics. At the same time, quantum chromodynamics (QCD) predicts the existence of non-nucleonic degrees of freedom at high densities in neutron-star matter, such as quark matter. Within a confining quark matter model, which consists of homogeneous, neutral 3-flavor interacting quark matter with $O (m_{s}^{4})$ corrections, we study the structure of compact stars made of a charged perfect fluid in the context of $f (R, T)$ gravity. The system of differential equations that describe the structure of charged compact stars have been derived and solved numerically for a gravity model with $f (R, T) = R + 2 β T$ . For simplicity, we assume that the charge density is proportional to the energy density, namely, $ρ_{ch} = α ρ$ . It is demonstrated that matter-geometry coupling constant $β$ and the charge parameter $α$ affect the total gravitational mass and the radius of the star.
Comments:
10 pages, 6 figures. To appear in Chinese Physics C
Subjects:
General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
2207.12947 [pdf]
CPC(2022)·46 citations
16
[Submitted on 26 Jul 2022] (cross-list from hep-ph)
Compton scattering for photon and gluon in fixed-target collisions at AFTER@LHC
Gongming Yu🇨🇳 · Runlong Liu🇨🇳 · Yanbing Cai🇨🇳 · Quangui Gao🇨🇳 · Qiang Hu🇨🇳
We calculate the Compton scattering for photon and gluon with the Klein-Nishina formula in fixed-target collisions by using the proton and lead beams at AFTER@LHC. In these collisions, we can investigate the particular case of Compton scattering at the partonic level, such as $γ q \to q γ$ , $γ q \to q g$ , $g q \to q γ$ , and $g q \to q g$ , that can help to check of the equivalent-photon approximation and understand the dynamics of hadron collisions at high energies, as well as probe the inner hadron structure.
Comments:
5 pages, 2 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2207.13089 [pdf]
0 citations

Affiliations

first authorsco-authorsvia INSPIRE