Nuclear Theory·nucl-th

Tuesday·October 31, 2023

26 papers—12 primary·14 cross-listed

01
[Submitted on 28 Oct 2023]
Uncertainty Quantification-Enabled Inversion of Nuclear Euclidean Responses
K. Raghavan · A. Lovato
Nuclear quantum many-body methods rely on integral transform techniques to infer properties of electroweak response functions from ground-state expectation values. Retrieving the energy dependence of these responses is highly non-trivial, especially for quantum Monte Carlo methods, as it requires inverting the Laplace transform -- a notoriously ill-posed problem. In this work, we propose an artificial neural network architecture suitable for accurate response function reconstruction with precise estimation of the uncertainty of the inversion. We demonstrate the capabilities of this new architecture benchmarking it against Maximum Entropy and previously developed neural network methods designed for a similar task, paying particular attention to its robustness against increasing noise in the input Euclidean responses.
Comments:
11 pages, 7 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2310.18756 [pdf]
PRC(2024)·5 citations
02
[Submitted on 29 Oct 2023]
Large-scale shell-model study of two-neutrino double-beta decay of $^{82}$ Se, $^{94}$ Zr, $^{108}$ Cd, $^{124}$ Sn, $^{128}$ Te, $^{130}$ Te, $^{136}$ Xe, and $^{150}$ Nd
Deepak Patel🇮🇳 · Praveen C. Srivastava🇮🇳 · V.K.B. Kota🇮🇳 · R. Sahu🇮🇳
Large-scale shell-model calculations have been performed for the study of two neutrino double-beta ( $2 ν β β$ ) decay in $^{82}$ Se, $^{94}$ Zr, $^{108}$ Cd, $^{124}$ Sn, $^{128}$ Te, $^{130}$ Te, $^{136}$ Xe, and $^{150}$ Nd. We have employed JUN45 interaction to calculate the nuclear matrix element (NME) for $2 ν β β$ decay in $^{82}$ Se. In the case of $^{94}$ Zr, the glekpn effective interaction is used. For $^{108}$ Cd, we have used a realistic effective interaction derived through the G-matrix approach. In the case of $^{124}$ Sn, $^{128, 130}$ Te and $^{136}$ Xe, the sn100pn effective interaction is employed. For $^{150}$ Nd, we have used KHHE effective interaction based on holes in a $^{208}$ Pb core. We have extracted the half-lives of these nuclei for the $2 ν β β$ decay with the help of calculated NME. Our results are consistent with the available experimental half-lives. The variation of cumulative $2 ν β β$ NME with respect to the excitation energy of the intermediate $1^{+}$ states is also shown, and in all cases, it is ensured that their values are almost saturated. In the present work we have calculated more intermediate $1^{+}$ states as much as possible in comparison to results available in the literature.
Comments:
17 pages, 2 figures, 2 tables
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2310.19015 [pdf]
NPA(2024)·9 citations
03
[Submitted on 30 Oct 2023]
Electromagnetic current operators for phenomenological relativistic models
Wayne Polyzou🇺🇸
Background: Phenomenological Poincaré invariant quantum mechanical models can provide an efficient description of the dynamics of strongly interacting particles that is consistent with spectral and scattering observables. These models are representation dependent and in order to apply them to reactions with electromagnetic probes it is necessary to have a consistent electromagnetic current operator. Purpose: The purpose of this work is to use local gauge invariance to construct consistent strong current operators. Method: Current operators are constructed from a model Hamiltonian by replacing momentum operators in the Weyl representation by gauge covariant derivatives. Results: The construction provides a systematic method to construct explicit expressions for current operators that are consistent with relativistic models of strong interaction dynamics.
Comments:
31 pages, contribution to 25-th European Conference on Few Body Problems Physics, Mainz
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2310.19243 [pdf]
Few Body Syst.(2024)·2 citations
04
[Submitted on 30 Oct 2023]
Hartree-Fock Formulation of the QMC Model at Finite Temperature
P A M Guichon🇫🇷 · J R Stone🇺🇸 · A W Thomas🇦🇺
We present, for the first time, a detailed theory of high density matter including the entire baryon octet at finite temperature, based on a fully relativistic mean field model with a consistent treatment of exchange (Fock) terms, using the quark-meson-coupling model (QMC). It has been already demonstrated that the QMC equation of state is applicable in thermodynamic scenarios in stationary and rotating isentropic proto-neutron stars, producing results in agreement with recent observation. It is also suitable for the simulation of the behavior following a binary neutron star merger [1]; https://compose.obspm.fr/eos/205. We develop a comprehensive demonstration of the impact of the Fock terms in the QMC energy density functional on properties of neutrinoless proto-neutron stars with cores containing the full hyperon octet with constant entropy, S/A=2kB. Given the interest in the properties of the proto-neutron star remaining after either a supernova explosion or the merger of two neutron stars, it is vital to develop modern equations of state at finite temperature. While much attention has been paid to relativistic mean-field calculations at finite temperature, it is crucial to explore the consequences of a consistent treatment of the Fock terms.
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2310.19262 [pdf]
PRD(2024)·6 citations
05
[Submitted on 30 Oct 2023]
Eigenvector Continuation and Projection-Based Emulators
Thomas Duguet🇫🇷 · Andreas Ekström🇸🇪 · Richard J. Furnstahl🇺🇸 · Sebastian König🇺🇸 · Dean Lee🇺🇸
Eigenvector continuation is a computational method for parametric eigenvalue problems that uses subspace projection with a basis derived from eigenvector snapshots from different parameter sets. It is part of a broader class of subspace-projection techniques called reduced-basis methods. In this colloquium article, we present the development, theory, and applications of eigenvector continuation and projection-based emulators. We introduce the basic concepts, discuss the underlying theory and convergence properties, and present recent applications for quantum systems and future prospects.
Comments:
Final version to appear as colloquium article in Rev. Mod. Phys., 22 pages, 17 figures
Subjects:
Nuclear Theory (nucl-th); Quantum Gases (cond-mat.quant-gas); cs.NA (cs.NA); math.NA (math.NA); Nuclear Experiment (nucl-ex); Quantum Physics (quant-ph)
arXiv:
2310.19419 [pdf]
RMP(2024)·84 citations
06
[Submitted on 30 Oct 2023]
Revision of Analytical Properties of Reaction Amplitude near Thresholds Using the Example of Muon-Induced Prompt Fission
F.F. Karpeshin
Experimental data on the muon-induced prompt fission are analyzed and compared to theory. Good agreement is observed for the 2p to 1s and 3d to 1s transitions. Anomalously big nonradiative width in the case of 3d to 1s transition is surprised. Ways of resolving this puzzle are discussed.
Comments:
6 pages. To be published in ISINN-29 Proceedings
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2310.19421 [pdf]
1 citation
07
[Submitted on 30 Oct 2023]
Intersections of ultracold atomic polarons and nuclear clusters: How is a chart of nuclides modified in dilute neutron matter?
Hiroyuki Tajima · Hajime Moriya · Wataru Horiuchi · Eiji Nakano · Kei Iida
Neutron star observations, as well as experiments on neutron-rich nuclei, used to motivate one to look at degenerate nuclear matter from its extreme, namely, pure neutron matter. As an important next step, impurities and clusters in dilute neutron matter have attracted special attention. In this paper, we review in-medium properties of these objects on the basis of the physics of polarons, which have been recently realized in ultracold atomic experiments. We discuss how such atomic and nuclear systems are related to each other in terms of polarons. In addition to the interdisciplinary understanding of in-medium nuclear clusters, it is shown that the quasiparticle energy of a single proton in neutron matter is associated with the symmetry energy, implying a novel route toward the nuclear equation of state from the neutron-rich side.
Comments:
28 pages, 2 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Quantum Gases (cond-mat.quant-gas)
arXiv:
2310.19422 [pdf]
AAPPS Bull.(2025)·10 citations
08
[Submitted on 30 Oct 2023]
At the edge of shape coexistence in the Z=40 region
Esperanza Maya-Barbecho · Samira Baid · José-Manuel Arias · José-Enrique García-Ramos
In this contribution, the shape coexistence phenomenon near the proton sub-shell closure at Z=40 is analyzed. Particular emphasis is placed on extracting the nuclear deformation values by examining experimental B(E2) transition rates and observing how the kinematic moment of inertia evolves in these nuclei. Based on the analysis of these two observables, we arrive at the conclusion that the notable effects of shape coexistence at approximately Z=40 are largely diminished in Mo isotopes and are scarcely detectable in Ru isotopes.
Comments:
To appear in the CGS-17 2023 proceedings, 3 pages
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2310.19458 [pdf]
EPJ Web Conf.(2025)·0 citations
09
[Submitted on 30 Oct 2023]
The 5-dimensional Langevin approach to fission of atomic nuclei
F.A.Ivanyuk · C.Ishizuka · S.Chiba
We have generalized the four-dimensional Langevin approach used in our previous works for the description of fission process to the five-dimensional by considering the neck parameter $\eps$ in the two-center shell model shape parametrization as an independent dynamical variable. The calculated results for the mass distribution of fission fragments are in better agreement with the available experimental data. In particular, the transition from the mass-symmetric to mass-asymmetric fission via the triple-humped distribution in fission of Thorium isotopes is well reproduced.
Comments:
9 pages, 11 figures, submitted to PRC
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2310.19466 [pdf]
PRC(2024)·15 citations
10
[Submitted on 30 Oct 2023]
First-forbidden transition of nuclear $β$ decay by projected shell model
Bin-Lei Wang · Long-Jun Wang
The first-forbidden transition of nuclear $β$ decay is expected to play crucial roles in many aspects in nuclear physics, nuclear astrophysics and particle physics such as the stellar $β$ -decay rates and the reactor anti-neutrino spectra. In this work we develop the projected shell model (PSM) for description of first-forbidden transition of nuclear $β$ decay for the first time. Detailed theoretical framework and logics are provided, and 35 dominant first-forbidden transitions that are expected to be important for the reactor anti-neutrino spectra problems are calculated and compared systematically with the data to test the new development of the PSM. The corresponding experimental Log $f_{0} t$ values are described reasonably, and the quenching factors of nuclear matrix elements are found to affect the Log $f_{0} t$ values as well as the related shape factors, which may be helpful for better understanding of the reactor anti-neutrino spectra problems.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2310.19523 [pdf]
PLB(2024)·16 citations
11
[Submitted on 30 Oct 2023]
Scalar field, nucleon structure and relativistic chiral theory for nuclear matter
Guy Chanfray🇫🇷
The work that Peter Schuck and I carried out during the nineties in collaboration with the Lyon and Darmstadt theory groups is summarized. I retrace how our theoretical developments combined with experimental results concerning the in-medium modification of the pion-pion interaction allowed a clarification of the chiral status of the sigma meson introduced in relativistic theories of nuclear matter. This enabled us to build a relativistic chiral theory, now called the chiral confining model of nuclear matter, which includes the effect of the nucleon substructure, namely the response of the nucleon to the nuclear scalar field generating an efficient and natural contribution to the saturation mechanism. Using parameters from a QCD-connected version of the chiral confining model, I describe the relative roles of the chiral scalar field and two-pion (or two-rho) exchange for the in-medium $N N$ attractive interaction and the associated sources of three-body interactions needed for the saturation mechanism.
Comments:
16 pages, 8 figures. arXiv admin note: text overlap with arXiv:2307.03484
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2310.19532 [pdf]
EPJA(2024)·10 citations
12
[Submitted on 30 Oct 2023]
Expansion of one-, two- and three-body matrix elements on a generic spherical basis for nuclear ab initio calculations
Alberto Scalesi🇫🇷 · Carlo Barbieri🇮🇹 · Enrico Vigezzi🇮🇹
Ab initio studies of atomic nuclei are based on Hamiltonians including one-, two- and three-body operators with very complicated structures. Traditionally, matrix elements of such operators are expanded on a Harmonic Oscillator single-particle basis, which allows for a simple separation of the center-of-mass motion from the intrinsic one. A few recent investigations have showed that the use of different single-particle bases can bring significant advantages to numerical nuclear structure computations. In this work, the complete analytical expression of the Hamiltonian matrix elements expanded on a generic spherical basis is presented for the first time. This will allow systematic studies aimed at the determination of optimal nuclear bases.
Comments:
42 pages, 1 figure
Subjects:
Nuclear Theory (nucl-th); Mathematical Physics (math-ph); math.MP (math.MP); Quantum Physics (quant-ph)
arXiv:
2310.19547 [pdf]
Annals Phys.(2024)·2 citations
13
[Submitted on 18 Oct 2023] (cross-list from cond-mat.stat-mech)
Translation-invariant relativistic Langevin equation derived from first principles
Filippo Emanuele Zadra🇮🇹 · Aleksandr Petrosyan🇬🇧 · Alessio Zaccone🇮🇹
The relativistic Langevin equation poses a number of technical and conceptual problems related to its derivation and underlying physical assumptions. Recently, a method has been proposed in [A. Petrosyan and A. Zaccone, J. Phys. A: Math. Theor. 55 015001 (2022)] to derive the relativistic Langevin equation from a first-principles particle-bath Lagrangian. As a result of the particle-bath coupling, a new ``restoring force'' term appeared, which breaks translation symmetry. Here we revisit this problem aiming at deriving a fully translation-invariant relativistic Langevin equation. We successfully do this by adopting the renormalization potential protocol originally suggested by Caldeira and Leggett. The relativistic renormalization potential is derived here and shown to reduce to Caldeira and Leggett's form in the non-relativistic limit. The introduction of this renormalization potential successfully removes the restoring force and a fully translation-invariant relativistic Langevin equation is derived for the first time. The physically necessary character of the renormalization potential is discussed in analogy with non-relativistic systems, where it emerges due to the renormalization of the tagged particle dynamics due to its interaction with the bath oscillators (a phenomenon akin to level-repulsion or avoided-crossing in condensed matter). We discuss the properties that the corresponding non-Markovian friction kernel has to satisfy, with implications ranging from transport models of the quark-gluon plasma, to relativistic viscous hydrodynamic simulations, and to electrons in graphene.
Subjects:
Statistical Mechanics (cond-mat.stat-mech); Strongly Correlated Electrons (cond-mat.str-el); High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2310.18327 [pdf]
PRD(2023)·4 citations
14
[Submitted on 27 Oct 2023] (cross-list from hep-ph)
QCD equation of state and thermodynamic observables from computationally minimal Dyson-Schwinger Equations
Yi Lu🇨🇳 · Fei Gao🇨🇳 · Yu-Xin Liu🇨🇳 · Jan M. Pawlowski🇩🇪
We study the QCD equation of state and other thermodynamic observables including the isentropic trajectories and the speed of sound. These observables are of eminent importance for the understanding of experimental results in heavy ion collisions and also provide a QCD input for studies of the timeline of heavy-ion-collisions with hydrodynamical simulations. They can be derived from the quark propagator whose gap equation is solved within a minimal approximation to the Dyson-Schwinger equations of QCD at finite temperature and density. This minimal approximation aims at a combination of computational efficiency and simplification of the truncation scheme while maintaining quantitative precision. This minimal DSE scheme is confronted and benchmarked with results for correlation functions and observables from first principles QCD lattice at vanishing density and quantitative functional approaches at finite density.
Comments:
14 pages, 13 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2310.18383 [pdf]
PRD(2024)·34 citations
15
[Submitted on 27 Oct 2023] (cross-list from hep-ph)
Orbital Angular Momentum at Small $x$ Revisited
Yuri V. Kovchegov🇺🇸 · Brandon Manley🇺🇸
We revisit the problem of the small Bjorken- $x$ asymptotics of the quark and gluon orbital angular momentum (OAM) distributions in the proton utilizing the revised small- $x$ helicity evolution derived recently. We relate the quark and gluon OAM distributions at small $x$ to the polarized dipole amplitudes and their (first) impact-parameter moments. To obtain the OAM distributions, we derive novel small- $x$ evolution equations for the impact-parameter moments of the polarized dipole amplitudes in the double-logarithmic approximation (summing powers of $α_{s} ln^{2} (1/ x)$ with $α_{s}$ the strong coupling constant). We solve these evolution equations numerically and extract the leading large- $N_{c}$ , small- $x$ asymptotics of the quark and gluon OAM distributions, which we determine to be \begin{align} L_{q+\bar{q}}(x, Q^2) \sim L_{G}(x,Q^2) \sim \Delta \Sigma(x, Q^2) \sim \Delta G(x,Q^2) \sim \left(\frac{1}{x}\right)^{3.66 \, \sqrt{\frac{\alpha_s N_c}{2\pi}}}, \notag \end{align} in agreement with the existing results in the literature within the precision of our numerical evaluation. (Here $N_{c}$ is the number of quark colors.) We also investigate the ratios of the quark and gluon OAM distributions to their helicity distribution counterparts in the small- $x$ region.
Comments:
36 pages, 6 figures; v2: typos corrected, references added; v3: several signs corrected
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2310.18404 [pdf]
JHEP(2024)·29 citations
16
[Submitted on 27 Oct 2023] (cross-list from hep-th)
A loophole in the proofs of asymptotic freedom and quantum triviality
Paul Romatschke🇺🇸
In 1973, Coleman and Gross proved that in four dimensions, only non-abelian gauge theories can have asymptotic freedom. More recently, Aizenman and Duminil-Copin proved that four dimensional scalar field theories are quantum trivial in the continuum. Both of these proofs have a loophole, and it is the same loophole in both proofs: The proofs assume that the scalar self-coupling in the UV is positive definite. While this is a perfectly reasonable and classically very intuitive assumption, it is an assumption nevertheless. In this work, I show that the assumption of coupling positivity is violated in a concrete quantum field theory, the O(N) model, in the large N limit. Surprisingly, despite the classically nonsensical unbounded potential, the negative coupling has no pathological consequence for propagators, the free energy or cross sections. This suggests that interacting scalar field theories with asymptotic freedom in four dimensions are possible, despite long-held opinions to the contrary.
Comments:
10 pages, talk contribution to EPS-HEP 2023 conference
Subjects:
High Energy Physics — Theory (hep-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2310.18414 [pdf]
PoS(2024)·6 citations
17
[Submitted on 28 Oct 2023] (cross-list from hep-ph)
On the Fractional Quark-Antiquark Confinement and Symplectic Quantum Mechanics
M. Abu-Shady🇪🇬 · R. R. Luz🇧🇷 · G. X. A. Petronilo🇧🇷 · A. E. Santana🇧🇷 · R. G. G. Amorim🇧🇷
Using the formalism of generalized fractional derivatives, a two-dimensional non-relativistic meson system is studied. The mesons are interacting by a Cornell potential. The system is formulated in the domain of the symplectic quantum mechanics by means of the generalized fractional Nikiforov-Uvarov method. The corresponding Wigner function and the energy eigenvalues are then derived. The effect of fractional parameters $α$ and $β$ with the ground state solution is analyzed through the Wigner function for the charm-anticharm, bottom-antibottom and $b c$ mesons. One of the fundamental achievements of such Cornell model is the determination of heavy quarkonia mass spectra. We have computed these masses and the
Comments:
11 pages, 3 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2310.18810 [pdf]
Int.J.Mod.Phys.A(2024)·3 citations
18
[Submitted on 28 Oct 2023] (cross-list from physics.comp-ph)
A thousand fermions in a 3D harmonic trap via Monte Carlo simulations
Siu A. Chin
By use of a special wave function derived from similarly transformed propagators, this work shows that the energy of a thousand spin-balanced fermions in a three-dimensional harmonic potential can be accurately computed using the Monte Carlo method.
Comments:
18 pages with 6 figures
Subjects:
Computational Physics (physics.comp-ph); Statistical Mechanics (cond-mat.stat-mech); Nuclear Theory (nucl-th)
arXiv:
2310.18818 [pdf]
0 citations
19
[Submitted on 29 Oct 2023] (cross-list from hep-lat)
$T$ -matrix Analysis of Static Wilson Line Correlators from Lattice QCD at Finite Temperature
Zhanduo Tang🇺🇸 · Swagato Mukherjee🇺🇸 · Peter Petreczky🇺🇸 · Ralf Rapp🇺🇸
We utilize a previously constructed thermodynamic $T$ -matrix approach to the quark-gluon plasma (QGP) to calculate Wilson line correlators (WLCs) of a static quark-antiquark pair and apply them to the results from 2+1-flavor lattice-QCD (lQCD) computations with realistic pion mass. The self-consistent $T$ -matrix results, which include constraints from the lQCD equation of state in the light-parton sector, can describe the lQCD data for WLCs fairly well once refinements of the input parameters are implemented. In particular, the input potential requires less screening than used in previous $T$ -matrix analyses. Pertinent predictions for the spectral and transport properties of the QGP are discussed, including the spatial diffusion coefficient for heavy quarks which turns out to have a rather weak temperature dependence, in approximate agreement with recent lQCD results.
Comments:
11 pages, 10 figures
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2310.18864 [pdf]
EPJA(2024)·37 citations
20
[Submitted on 29 Oct 2023] (cross-list from hep-ph)
Impact of Medium Anisotropy on Quarkonium Dissociation and Regeneration
Captain R. Singh🇮🇳 · Mohammad Yousuf Jamal🇮🇳 · Raghunath Sahoo🇮🇳
Quarkonium production in ultra-relativistic collisions plays a crucial role in probing the existence of hot QCD matter. This study explores quarkonia states dissociation and regeneration in the hot QCD medium while considering momentum anisotropy. The net quarkonia decay width ( $Γ_{D}$ ) arises from two essential processes: collisional damping and gluonic dissociation. The quarkonia regeneration includes the transition from octet to singlet states within the anisotropic medium. Our study utilizes a medium-modified potential that incorporates anisotropy via particle distribution functions. This modified potential gives rise to collisional damping for quarkonia due to the surrounding medium, as well as the transition of quarkonia from singlet to octet states due to interactions with gluons. Furthermore, we employ the detailed balance approach to investigate the regeneration of quarkonia within this medium. Our comprehensive analysis spans various temperature settings, transverse momentum values, and anisotropic strengths. Notably, we find that, in addition to medium temperatures and heavy quark transverse momentum, anisotropy significantly influences the dissociation and regeneration of various quarkonia states.
Comments:
11 pages and 4 captioned figures, same as the published version in EPJC
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2310.18909 [pdf]
EPJC(2024)·9 citations
21
[Submitted on 29 Oct 2023] (cross-list from hep-ph)
Towards higher-order collinear splittings with massive partons
Prasanna K. Dhani🇪🇸 · Germán Rodrigo🇪🇸 · German F. R. Sborlini🇪🇸
The singularities associated with QCD factorization in the collinear limit are key ingredients for high-precision theoretical predictions in particle physics. They govern the collinear behaviour of scattering amplitudes, as well as the perturbative energy evolution of parton densities (PDFs) and fragmentation functions (FFs). In this talk, we present the computation of multiple collinear and higher-order QCD splittings with massive partons. Our results are highly-relevant for the consistent introduction of mass effects in the subtraction formalism and PDF/FF evolution.
Comments:
6 pages. Contribution to the Proceedings of the EPS-HEP 2023 Conference
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2310.18972 [pdf]
PoS(2024)·0 citations
22
[Submitted on 29 Oct 2023] (cross-list from hep-ph)
Studying the production mechanisms of light meson resonances in two-pion photoproduction: a Regge approach
Łukasz Bibrzycki🇵🇱 · Nadine Hammoud🇵🇱 · Vincent Mathieu🇪🇸 · Robert J. Perry🇪🇸 · Adam P. Szczepaniak🇺🇸
A calculation of the angular moments of two-pion photoproduction is presented. The underlying theoretical model encodes the prominent $ρ (770)$ resonance and the expected leading background contribution coming from the Deck mechanism. The model contains a number of free parameters which are fit to experimental data. A good description of the angular moments is obtained.
Comments:
5 pages, 3 figures. Prepared as proceedings contribution for the 20th International Conference on Hadron Spectroscopy and Structure (HADRON 2023), Genova, Italy, 5-9/6/2023
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2310.18990 [pdf]
Nuovo Cim.C(2024)·0 citations
23
[Submitted on 29 Oct 2023] (cross-list from hep-ph)
Nonperturbative photon $q q ˉ$ light front wave functions from a contact interaction model
Chao Shi🇨🇳 · Zhongtian Yang🇨🇳 · Xurong Chen🇨🇳 · Wenbao Jia🇨🇳 · Cuibai Luo🇨🇳 · Wenchang Xiang🇨🇳
We propose a method to calculate the $q q ˉ$ light front wave functions (LFWFs) of photon at low-virtuality, i.e., the light front amplitude of $γ^{*} \to q q ˉ$ at low $Q^{2}$ , based on a light front projection approach. We exemplify this method using a contact interaction model within Dyson-Schwinger equations formalism and obtain the nonperturbative photon $q q ˉ$ LFWFs. In this case, we find the nonperturbative effects are encoded in the enhanced quark mass and a dressing function of covariant quark-photon vertex, as compared to the leading order quantum electrodynamics photon $q q ˉ$ LFWFs. We then use nonperturbative-effect modified photon $q q ˉ$ LFWFs to study the inclusive deep inelastic scattering HERA data in the framework of the color dipole model. The results demonstrate that the theoretical description of data at low $Q^{2}$ can be significantly improved once the nonperturbative corrections are included in the photon LFWFs.
Comments:
11 pages, 4 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2310.19042 [pdf]
PRD(2024)·6 citations
24
[Submitted on 29 Oct 2023] (cross-list from hep-lat)
Transversity PDFs of the proton from lattice QCD with physical quark masses
Xiang Gao🇺🇸 · Andrew D. Hanlon🇺🇸 · Swagato Mukherjee🇺🇸 · Peter Petreczky🇺🇸 · Qi Shi🇺🇸 · Sergey Syritsyn🇺🇸 · Yong Zhao🇺🇸
We present a lattice QCD calculation of the transversity isovector- and isoscalar-quark parton distribution functions (PDFs) of the proton utilizing a perturbative matching at next-to-leading-order (NLO) accuracy. Additionally, we determine the isovector and isoscalar tensor charges for the proton. In both calculations, the disconnected contributions to the isoscalar matrix elements have been ignored. The calculations are performed using a single ensemble of $N_{f} = 2 + 1$ highly-improved staggered quarks simulated with physical-mass quarks and a lattice spacing of $a = 0.076$ fm. The Wilson-clover action, with physical quark masses and smeared gauge links obtained from one iteration of hypercubic smearing, is used in the valence sector. Using the NLO operator product expansion, we extract the lowest four to six Mellin moments and the PDFs via a neural network from the matrix elements in the pseudo-PDF approach. In addition, we calculate the PDFs in the quasi-PDF approach with hybrid-scheme renormalization and the recently developed leading-renormalon resummation technique, at NLO with the resummation of leading small- $x$ logarithms.
Comments:
23 pages, 22 figures, and 2 tables; version accepted for publication in PRD
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2310.19047 [pdf]
PRD(2024)·40 citations
25
[Submitted on 30 Oct 2023] (cross-list from hep-lat)
Efficient vacuum state preparation for quantum simulation of strongly interacting local quantum field theories
Thomas D. Cohen🇺🇸 · Hyunwoo Oh🇺🇸
We present an efficient approach for preparing ground states in the context of strongly interacting local quantum field theories on quantum computers. The approach produces the vacuum state in a time proportional to the square-root of the volume, which is a square-root improvement in speed compared to traditional approaches. The approach exploits a novel method for traversing the path in parameter space in which the resources scale linearly with a path length suitably defined in parameter space. Errors due to practical limitations are controlled and do not exhibit secular growth along the path. The final accuracy can be arbitrarily improved with an additive cost, which is independent of the volume and grows slower than logarithmically with the overlap between the state produced and the exact ground state. We expect that the method could potentially hold practical value not only within the realm of quantum field theories but also in addressing other challenges involving long path lengths.
Comments:
6 pages, 3 figures
Subjects:
High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
arXiv:
2310.19229 [pdf]
PRA(2024)·12 citations
26
[Submitted on 30 Oct 2023] (cross-list from quant-ph)
Real-time Spin Systems from Lattice Field Theory
Neill C. Warrington🇺🇸
We construct a lattice field theory method for computing the real-time dynamics of spin systems in a thermal bath. This is done by building on previous work of Takano with Schwinger-Keldysh and functional differentiation techniques. We derive a Schwinger-Keldysh path integral for generic spin Hamiltonians, then demonstrate the method on a simple system. Our path integral has a sign problem, which generally requires exponential run time in the system size, but requires only linear storage. The latter may place this method at an advantage over exact diagonalization, which is exponential in both. Our path integral is amenable to contour deformations, a technique for reducing sign problems.
Comments:
7 pages, 2 figures, 1 table
Subjects:
Quantum Physics (quant-ph); Strongly Correlated Electrons (cond-mat.str-el); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2310.19761 [pdf]
JHEP(2023)·2 citations

Affiliations

first authorsco-authorsvia INSPIRE