Nuclear Theory·nucl-th

Friday·July 7, 2023

12 papers—2 primary·10 cross-listed

03
[Submitted on 2 Jul 2023] (cross-list from hep-ph)
Hidden-charm pentaquark states in a mass splitting model
Shi-Yuan Li🇨🇳 · Yan-Rui Liu🇨🇳 · Zi-Long Man🇨🇳 · Zong-Guo Si🇨🇳 · Jing Wu🇨🇳
Assuming that the $P_{c} (4312)^{+}$ is a $I (J^{P}) = \frac{1}{2} (\frac{3}{2}^{-})$ compact pentaquark, we study the mass spectrum of its S-wave hidden-charm partner states in a color-magnetic interaction model. Combining the information from their decays obtained in a simple rearrangement scheme, one finds that the quantum numbers of $P_{c} (4457)^{+}$ , $P_{c} (4440)^{+}$ , and $P_{c} (4337)^{+}$ can be assigned to be $I (J^{P}) = \frac{1}{2} (\frac{3}{2}^{-})$ , $\frac{1}{2} (\frac{1}{2}^{-})$ , and $\frac{1}{2} (\frac{1}{2}^{-})$ , respectively, while both $P_{cs} (4338)^{0}$ and $P_{cs} (4459)^{0}$ can be interpreted as $I (J^{P}) = 0 (\frac{1}{2}^{-})$ $u d sc c ˉ$ compact states. Based on the numerical results, we also find narrow pentaquarks in $ss n c c ˉ$ ( $n = u, d$ ) and $sssc c ˉ$ systems. The decay properties of the studied pentaquarks and the searching channels for them can be tested in future experiments.
Comments:
17 pages, 14 tables, 4 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2307.00539 [pdf]
PRD(2023)·24 citations
04
[Submitted on 5 Jul 2023] (cross-list from hep-ph)
Probing factorization violation with vector angularities
Pim Bijl🇳🇱 · Steven Niedenzu🇳🇱 · Wouter J. Waalewijn🇳🇱
Factorization underlies all predictions at the Large Hadron Collider, but has only been rigorously proven in a few cases. One of these cases is the Drell-Yan process, $pp \to Z / γ + X$ , in the limit of small boson transverse momentum. We introduce a one-parameter family of observables, that we call vector angularities, of which the transverse momentum is a special case. This enables the study of factorization violation, with a smooth transition to the limit for which factorization has been established. Like the angularity event shapes, vector angularities are a sum of transverse momenta weighted by rapidity, but crucially this is a vector sum rather than a sum of the magnitude of transverse momenta. We study these observables in Pythia, using the effect of multi-parton interactions (MPI) as a proxy factorization violation, finding a negligible effect in the case where factorization is established but sizable effects away from it. We also present a factorization formula for the cross section, that does not include factorization violating contributions from Glauber gluons, and thus offers a baseline for studying factorization violation experimentally using vector angularities. Our predictions at next-to-leading logarithmic accuracy (NLL $^{'}$ ) are in good in agreement with Pythia (not including MPI), and can be extended to higher order.
Comments:
8 pages, 2 figures, v2: journal version
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2307.02521 [pdf]
PRD(2024)·4 citations
05
[Submitted on 5 Jul 2023] (cross-list from quant-ph)
High-Energy Collision of Quarks and Mesons in the Schwinger Model: From Tensor Networks to Circuit QED
Ron Belyansky🇺🇸 · Seth Whitsitt🇺🇸 · Niklas Mueller🇺🇸 · Ali Fahimniya🇺🇸 · Elizabeth R. Bennewitz🇺🇸 · Zohreh Davoudi🇺🇸 · Alexey V. Gorshkov🇺🇸
With the aim of studying nonperturbative out-of-equilibrium dynamics of high-energy particle collisions on quantum simulators, we investigate the scattering dynamics of lattice quantum electrodynamics in 1+1 dimensions. Working in the bosonized formulation of the model and in the thermodynamic limit, we use uniform-matrix-product-state tensor networks to construct multi-particle wave-packet states, evolve them in time, and detect outgoing particles post collision. This facilitates the numerical simulation of scattering experiments in both confined and deconfined regimes of the model at different energies, giving rise to rich phenomenology, including inelastic production of quark and meson states, meson disintegration, and dynamical string formation and breaking. We obtain elastic and inelastic scattering cross sections, together with time-resolved momentum and position distributions of the outgoing particles. Furthermore, we propose an analog circuit-QED implementation of the scattering process that is native to the platform, requires minimal ingredients and approximations, and enables practical schemes for particle wave-packet preparation and evolution. This study highlights the role of classical and quantum simulation in enhancing our understanding of scattering processes in quantum field theories in real time.
Comments:
5+12 pages, 4+6 figures, close to published version
Subjects:
Quantum Physics (quant-ph); Mesoscale and Nanoscale Physics (cond-mat.mes-hall); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2307.02522 [pdf]
PRL(2024)·97 citations
06
[Submitted on 5 Jul 2023] (cross-list from hep-ph)
A phenomenological estimate of isospin breaking in hadronic vacuum polarization
Martin Hoferichter🇨🇭 · Gilberto Colangelo🇨🇭 · Bai-Long Hoid🇨🇭 · Bastian Kubis🇩🇪 · Jacobo Ruiz de Elvira🇪🇸 · Dominic Schuh🇩🇪 · Dominik Stamen🇩🇪 · Peter Stoffer🇨🇭
Puzzles in the determination of the hadronic-vacuum-polarization contribution currently impede a conclusive interpretation of the precision measurement of the anomalous magnetic moment of the muon at the Fermilab experiment. One such puzzle concerns tensions between evaluations in lattice QCD and using $e^{+} e^{-} \to hadrons$ cross-section data. In lattice QCD, the dominant isospin-symmetric part and isospin-breaking (IB) corrections are calculated separately, with very different systematic effects. Identifying these two pieces in a data-driven approach provides an opportunity to compare them individually and trace back the source of the discrepancy. Here, we estimate the IB component of the lattice-QCD calculations from phenomenology, based on a comprehensive study of exclusive contributions that can be enhanced via infrared singularities, threshold effects, or hadronic resonances, including, for the first time, in the $e^{+} e^{-} \to 3 π$ channel. We observe sizable cancellations among different channels, with a sum that even suggests a slightly larger result for the QED correction than obtained in lattice QCD. We conclude that the tensions between lattice QCD and $e^{+} e^{-}$ data therefore cannot be explained by the IB contributions in the lattice-QCD calculations.
Comments:
7 pages, 2 figures; journal version
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2307.02532 [pdf]
PRL(2023)·56 citations
07
[Submitted on 5 Jul 2023] (cross-list from hep-ph)
Correlations of $C$ and $C P$ violation in $η \to π^{0} ℓ^{+} ℓ^{-}$ and $η^{'} \to η ℓ^{+} ℓ^{-}$
Hakan Akdag🇩🇪 · Bastian Kubis🇩🇪 · Andreas Wirzba🇩🇪
Based on recent progress in the systematic analysis of $C$ and $C P$ violation in the light-meson sector, we calculate the $C$ -odd transition amplitudes $η \to π^{0} ℓ^{+} ℓ^{-}$ and $η^{'} \to η ℓ^{+} ℓ^{-}$ . Focusing on long-distance contributions driven by the lowest-lying hadronic intermediate states, we work out the correlations between these beyond-the-Standard-Model signals and the Dalitz-plot asymmetries in $η \to π^{0} π^{+} π^{-}$ and $η^{'} \to η π^{+} π^{-}$ , using dispersion theory.
Comments:
35 pages, 7 figures, 3 tables; v2: section 5 revised, discussion extended, version published in JHEP
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2307.02533 [pdf]
JHEP(2024)·10 citations
08
[Submitted on 5 Jul 2023] (cross-list from hep-ph)
Isospin-breaking effects in the three-pion contribution to hadronic vacuum polarization
Martin Hoferichter🇨🇭 · Bai-Long Hoid🇨🇭 · Bastian Kubis🇩🇪 · Dominic Schuh🇩🇪
Isospin-breaking (IB) effects are required for an evaluation of hadronic vacuum polarization at subpercent precision. While the dominant contributions arise from the $e^{+} e^{-} \to π^{+} π^{-}$ channel, also IB in the subleading channels can become relevant for a detailed understanding, e.g., of the comparison to lattice QCD. Here, we provide such an analysis for $e^{+} e^{-} \to 3 π$ by extending our dispersive description of the process, including estimates of final-state radiation (FSR) and $ρ$ - $ω$ mixing. In particular, we develop a formalism to capture the leading infrared-enhanced effects in terms of a correction factor $η_{3 π}$ that generalizes the analog treatment of virtual and final-state photons in the $2 π$ case. The global fit to the $e^{+} e^{-} \to 3 π$ data base, subject to constraints from analyticity, unitarity, and the chiral anomaly, gives $a_{μ}^{3 π} ∣_{\leq 1.8 GeV} = 45.91 (53) \times 1 0^{- 10}$ for the total $3 π$ contribution to the anomalous magnetic moment of the muon, of which $a_{μ}^{FSR} [3 π] = 0.51 (1) \times 1 0^{- 10}$ and $a_{μ}^{ρ - ω} [3 π] = - 2.68 (70) \times 1 0^{- 10}$ can be ascribed to IB. We argue that the resulting cancellation with $ρ$ - $ω$ mixing in $e^{+} e^{-} \to 2 π$ can be understood from a narrow-resonance picture, and provide updated values for the vacuum-polarization-subtracted vector-meson parameters $M_{ω} = 782.70 (3) MeV$ , $M_{ϕ} = 1019.21 (2) MeV$ , $Γ_{ω} = 8.71 (3) MeV$ , and $Γ_{ϕ} = 4.27 (1) MeV$ .
Comments:
29 pages, 4 figures, result for $η ˉ_{3 π}$ included as supplementary material; journal version
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2307.02546 [pdf]
JHEP(2023)·52 citations
09
[Submitted on 5 Jul 2023] (cross-list from astro-ph.HE)
Viscous hydrodynamic evolution of neutron star merger accretion disks: a code comparison
Rodrigo Fernández · Oliver Just · Zewei Xiong · Gabriel Martínez-Pinedo
The accretion disk formed after a neutron star merger is an important contributor to the total ejecta from the merger, and hence to the kilonova and the $r$ -process yields of each event. Axisymmetric viscous hydrodynamic simulations of these disks can capture thermal mass ejection due to neutrino absorption and in the advective phase -- after neutrino cooling has subsided -- and are thus likely to provide a lower-limit to the total disk ejecta relative to MHD evolution. Here we present a comparison between two viscous hydrodynamic codes that have been used extensively on this problem over the past decade: ALCAR and FLASH. We choose a representative setup with a black hole at the center, and vary the treatment of viscosity and neutrino transport. We find good overall agreement ( $\sim 10%$ level) in most quantities. The average outflow velocity is sensitive to the treatment of the nuclear binding energy of heavy nuclei, showing a larger variation than other quantities. We post-process trajectories from both codes with the same nuclear network, and explore the effects of code differences on nucleosynthesis yields, heating rates, and kilonova light curves. For the latter, we also assess the effect of varying the number of tracer particles in reconstructing the spatial abundance distribution for kilonova light curve production.
Comments:
Accepted by PRD. Tracked down small initial difference in degeneracy parameter to differences in the entropy of ions in each EOS. Minor changes otherwise
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
arXiv:
2307.02554 [pdf]
PRD(2024)·9 citations
10
[Submitted on 3 Jul 2023] (cross-list from hep-ph)
Resonant screening in dense and magnetized QCD matter
Guojun Huang🇨🇳 · Jiaxing Zhao🇫🇷 · Pengfei Zhuang🇨🇳
We calculate the Debye screening mass in thermal, dense and magnetized QCD matter in the frame of resummed perturbation theory. In the limit of zero temperature, when the Landau energy level and Fermi surface of quarks match each other $μ_{q}^{2} = 2 n ∣ q B ∣$ , where $q$ , $μ_{q}$ and $B$ are respectively the quark electric charge, chemical potential and external magnetic field, the screening mass diverges and the system is in the state of weakly interacting parton gas, which is very different from the known result of strongly interacting quark-gluon plasma at high temperature. The divergence disappears in thermal medium, but the screening mass oscillates with clear peaks at the matched magnetic field.
Comments:
7 pages, 2 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2307.02608 [pdf]
PRD(2023)·3 citations
11
[Submitted on 6 Jul 2023] (cross-list from astro-ph.HE)
Effects of Hoyle state de-excitation on $ν p$ -process nucleosynthesis and Galactic chemical evolution
Hirokazu Sasaki · Yuta Yamazaki · Toshitaka Kajino · Grant J. Mathews
The partcle-induced hadronic de-excitation of the Hoyle state in $^{12}$ C induced by inelastic scattering in a hot and dense plasma can enhance the triple-alpha reaction rate. This prevents the production of heavy nuclei within the neutrino-driven winds of core-collapse supernovae and raises a question as to the contribution of proton-rich neutrino-driven winds as the origin of $p$ -nuclei in the solar system abundances. Here we study $ν p$ -process nucleosynthesis in proton-rich neutrino-driven winds relevant to the production of $^{92, 94} Mo$ and $^{96, 98} Ru$ by considering such particle-induced de-excitation. We show that the enhancement of the triple-alpha reaction rate induced by neutron inelastic scattering hardly affects the $ν p$ -process, while the proton scattering contributes to the nucleosynthesis in proton-rich neutrino-driven winds at low temperature. The associated enhanced triple-alpha reaction rate decreases the production of $^{92, 94} Mo$ and $^{96, 98} Ru$ in a wind model of ordinary core-collapse supernovae. On the other hand, the abundances of these $p$ -nuclei increase in an energetic hypernova wind model. Hence, we calculate the galactic chemical evolution of $^{92, 94} Mo$ and $^{96, 98} Ru$ by taking account of both contributions from core-collapse supernovae and hypernovae. We show that the hypernova $ν p$ -process can enhance the calculated solar isotopic fractions of $^{92, 94} Mo$ and $^{96, 98} Ru$ and make a significant impact on the GCE of $p$ -nuclei regardless of the particle-induced Hoyle state de-excitation.
Comments:
16 pages, 7 figures
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Astrophysics of Galaxies (astro-ph.GA); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2307.02785 [pdf]
PLB(2024)·6 citations
12
[Submitted on 6 Jul 2023] (cross-list from hep-ph)
Quarkyonic matter and quarkyonic stars in an extended RMF model
Cheng-Jun Xia🇨🇳 · Hao-Miao Jin🇨🇳 · Ting-Ting Sun🇨🇳
By combining RMF models and equivparticle models with density-dependent quark masses, we construct explicitly ``a quark Fermi Sea'' and ``a baryonic Fermi surface'' to model the quarkyonic phase, where baryons with momentums ranging from zero to Fermi momentums are included. The properties of nuclear matter, quark matter, and quarkyonic matter are then investigated in a unified manner, where quarkyonic matter is more stable and energy minimization is still applicable to obtain the microscopic properties of dense matter. Three different covariant density functionals TW99, PKDD, and DD-ME2 are adopted in our work, where TW99 gives satisfactory predictions for the properties of nuclear matter both in neutron stars and heavy-ion collisions and quarkyonic transition is unfavorable. Nevertheless, if PKDD with larger slope of symmetry energy $L$ or DD-ME2 with larger skewness coefficient $J$ are adopted, the corresponding EOSs are too stiff according to both experimental and astrophysical constraints. The situation is improved if quarkyonic transition takes place, where the EOSs become softer and can accommodate various experimental and astrophysical constraints.
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2307.03032 [pdf]
PRD(2023)·17 citations

Affiliations

first authorsco-authorsvia INSPIRE