Nuclear Theory·nucl-th

Monday·August 26, 2024

11 papers—6 primary·5 cross-listed

07
[Submitted on 21 Aug 2024] (cross-list from hep-ph)
$ϕ$ - $p$ bound state and completeness of quantum states
Arkadiusz Kuros🇵🇱 · Radoslaw Maj🇵🇱 · Stanislaw Mrowczynski🇵🇱
The existence of a bound state of a $ϕ$ meson and proton has been recently indicated on the basis of a combined analysis of the measured $ϕ$ - $p$ correlation function and the QCD lattice calculations of $ϕ$ - $p$ interaction in the spin 1/2 and 3/2 channels. We check whether the correlation functions and bound state formation rate satisfy the sum rule which follows from the completeness of quantum states. The sum rule is not satisfied but it is close to it, suggesting that the inferred scattering parameters, which determine the correlation functions, are not fully consistent with the potential responsible for the bound state existence.
Comments:
6 pages, 4 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2408.11941 [pdf]
2 citations
08
[Submitted on 22 Aug 2024] (cross-list from hep-ph)
Heavy-quark diffusion in 2+1D and Glasma-like plasmas: evidence of a transport peak
Liane Backfried🇦🇹 · Kirill Boguslavski🇦🇹 · Paul Hotzy🇦🇹
We examine how plasma excitations affect the heavy-quark diffusion coefficient in 2+1 dimensional and Glasma-like plasmas, akin to the pre-equilibrium matter describing relativistic heavy-ion collisions at early times. We find that the transport coefficient $2 κ$ transverse to and $κ_{z}$ along the beam direction display a qualitatively different evolution. We attribute this to the underlying excitation spectra of these systems, thus providing evidence for the existence of non-perturbative properties in the spectrum. This is accomplished by first reconstructing the diffusion coefficients using gauge-fixed correlation functions, which accurately reproduces the time evolution of $2 κ$ and $κ_{z}$ . We then modify these excitation spectra to study the impact of their non-perturbative features on the transport coefficients. In particular, we find evidence for a novel transport peak in the low-frequency spectrum that is crucial for heavy-quark diffusion. We also demonstrate that gluonic excitations are broad while scalar excitations associated with $κ_{z}$ are narrow and strongly enhanced at low momenta. Our findings indicate that the large values and dynamical properties of transport coefficients in the Glasma could originate from genuinely non-perturbative features in the spectrum.
Comments:
21 pages, 12 figures, 1 table; v2: minor revision, published version, data and plot files available under reference [49] (https://zenodo.org/records/14039178)
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2408.12646 [pdf]
PRD(2024)·9 citations
09
[Submitted on 23 Aug 2024] (cross-list from hep-lat)
Parton Distribution Function of a Deuteron-like Dibaryon System from Lattice QCD
Chen Chen🇨🇳 · Liuming Liu🇨🇳 · Peng Sun🇨🇳 · Yi-Bo Yang🇨🇳 · Yiqi Geng🇨🇳 · Fei Yao🇨🇳 · Jian-Hui Zhang🇨🇳 · Kuan Zhang🇨🇳
We report a lattice QCD calculation of the parton distribution function (PDF) of a deuteron-like dibaryon system using large-momentum effective theory. The calculation is done on three Wilson Clover ensembles with a fixed lattice spacing a=0.105 fm and two pion masses. The lattice matrix elements are computed at proton momenta up to 2.46 GeV with the signal of high momentum modes being improved by applying the momentum smearing technique. The state-of-the-art renormalization, matching and extrapolation are then applied to obtain the final result of the light-cone PDF. A comparison between the result of the dibaryon system and the sum of the proton and neutron PDFs is also given.
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2408.12819 [pdf]
PRD(2025)·21 citations
10
[Submitted on 23 Aug 2024] (cross-list from hep-ph)
Search for the $Σ (1380) 1/ 2^{-}$ state in $Λ_{c}^{+} \to γ π^{+} Λ$ decay by triangle singularity
Ke Wang🇨🇳 · Yu-Fei Wang🇨🇳 · Bo-Chao Liu🇨🇳 · Fei Huang🇨🇳
In this work, we investigate the resonance production in $Λ_{c}^{+} \to γ π^{+} Λ$ decay through the triangle singularity (TS) mechanism, within an effective Lagrangian approach. We find that the appropriate loop decay process could develop a triangle singularity in the invariant mass $M_{π Λ}$ around $1.35$ GeV, with the shape depending on the quantum numbers of $Σ^{*}$ states that couple to the final $π Λ$ system. Especially, the $Σ (1380) 1/ 2^{-}$ state newly predicted in the pentaquark model, if exists, significantly enhances the TS contribution and sharpens the TS peak due to the $S$ -wave $Σ^{*} π Σ$ vertex in the loop. Therefore, the existence of the $Σ (1380) 1/ 2^{-}$ state can be examined by measuring the TS signal in $Λ_{c}^{+} \to γ π^{+} Λ$ . Considering also possible tree-level diagrams, we additionally obtain the branching ratio $Br (Λ_{c}^{+} \to γ π^{+} Λ) ≃ 1.5 \times 1 0^{- 5}$ . We suggest the investigation of this reaction by future BESIII, LHCb, and Belle experiments.
Comments:
8 pages, 6 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2408.12965 [pdf]
PRD(2024)·9 citations
11
[Submitted on 23 Aug 2024] (cross-list from astro-ph.HE)
Generating ultra-compact neutron stars with bosonic dark matter
Sarah Louisa Pitz🇩🇪 · Jürgen Schaffner-Bielich🇩🇪
In this work we investigate the properties of neutron stars admixed with selfinteracting scalar bosonic dark matter. The dark matter interaction is described by a generalized $ϕ^{n}$ power-law potential. We perform a stability analysis of these two-fluid objects by studying the onset of the unstable radial modes. We find ultra-compact neutron star-dark matter configurations where the neutron star matter is confined to a core radius of values below $7$ km which is unreachable for pure neutron stars. The total gravitational maximum mass of these ultra-compact configurations can have values of $3.4 M_{⊙}$ . With our general ansatz of the power-law potential we show that the compactness of these solutions can be extreme, i.e. the compactness is $C = 1/3$ or even larger, making them compact enough to have a light-ring mimicking black holes. These ultra-compact objects are stable and possess a dark matter halo while having a hadronic matter core. With the addition of dark matter to neutron stars recent unusual mass-radius measurements of compact stars can be explained. We conclude that apparently contradictory measurements of neutron star masses and radii could be not only an indication of the presence of dark matter around a the hadronic matter core which is stabilized by the gravitational potential of dark matter but could also serve to disentangle the selfinteraction strength of dark matter. Our work points to a stiff equation of state for the dark matter fluid, rather than a soft one.
Comments:
12 pages, 5 figures, accepted for publication in PRD
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
2408.13157 [pdf]
PRD(2025)·43 citations

Affiliations

first authorsco-authorsvia INSPIRE

ϕ-p bound state and completeness of quantum states

Heavy-quark diffusion in 2+1D and Glasma-like plasmas: evidence of a transport peak

Parton Distribution Function of a Deuteron-like Dibaryon System from Lattice QCD

Search for the Σ(1380)1/2− state in Λc+​→γπ+Λ decay by triangle singularity

Generating ultra-compact neutron stars with bosonic dark matter

Affiliations

$ϕ$ - $p$ bound state and completeness of quantum states

Search for the $Σ (1380) 1/ 2^{-}$ state in $Λ_{c}^{+} \to γ π^{+} Λ$ decay by triangle singularity