Nuclear Theory·nucl-th

Friday·January 31, 2025

13 papers—6 primary·7 cross-listed

07
The Fermi function and the neutron's lifetime
Peter Vander Griend🇺🇸 · Zehua Cao🇺🇸 · Richard Hill🇺🇸 · Ryan Plestid🇺🇸
The traditional Fermi function ansatz for nuclear beta decay describes enhanced perturbative effects in the limit of large nuclear charge $Z$ and/or small electron velocity $β$ . We define and compute the quantum field theory object that replaces this ansatz for neutron beta decay, where neither of these limits hold. We present a new factorization formula that applies in the limit of small electron mass, analyze the components of this formula through two loop order, and resum perturbative corrections that are enhanced by large logarithms. We apply our results to the neutron lifetime, supplying the first two-loop input to the long-distance corrections. Our result can be summarized as \begin{equation*} \tau_n \times |V_{ud}|^2\big[1+3\lambda^2\big]\big[1+\Delta_R\big] = \frac{5263.284(17)\,{\rm s}} {1 + 27.04(7)\times 10^{-3} }~, \end{equation*} with $∣ V_{u d} ∣$ the up-down quark mixing parameter, $τ_{n}$ the neutron's lifetime, $λ$ the ratio of axial to vector charge, and $Δ_{R}$ the short-distance matching correction. We find a shift in the long-distance radiative corrections compared to previous work, and discuss implications for extractions of $∣ V_{u d} ∣$ and tests of the Standard Model.
↳ hep-phnucl-exnucl-thPLB(2025)·15 citations
08
The spatial string tension and its effects on screening correlators in a thermal QCD plasma
Dibyendu Bala🇩🇪 · Olaf Kaczmarek🇩🇪 · Peter Petreczky🇺🇸 · Sayantan Sharma🇮🇳 · Swagatam Tah🇮🇳
We calculate the spatial Wilson line correlator for 2+1 flavor QCD using highly improved staggered quark discretization for fermions and in quenched QCD for a wide range of temperatures, from the chiral crossover temperature $T_{pc} ≃ 156$ MeV or the deconfinement temperature $≃ 300$ MeV respectively, up to $2$ GeV. Extracting the spatial string tension for different lattice cut-offs and by performing a continuum extrapolation of this observable, we show that the soft (magnetic) gluons interact non-perturbatively even at temperatures $≳ 1$ GeV. We provide incriminating evidences to demonstrate that dimensionally reduced effective theories can describe these soft quark and gluon quasi-particles for both quenched and $2 + 1$ flavor QCD, at temperatures $T ≳ 5 T_{pc}$ . We also show for the first time the imprints of the non-perturbative pseudo-potential in the properties of mesonic screening masses for temperatures ranging from $0.8$ - $164$ GeV in the quark-gluon plasma.
↳ hep-lathep-phnucl-thPRL(2025)·16 citations
09
Spectral-statistics properties of the experimental and theoretical light baryon and meson spectra
L. Muñoz🇪🇸 · A. Relaño🇪🇸
We compare the statistical fluctuation properties of the baryon and meson experimental mass spectra with those obtained from theoretical models (quark models and lattice QCD). We find that for the experimental spectra the statistical properties are close to those predicted by Random Matrix Theory for chaotic systems, while for the theoretical ones they are in general closer to those predicted for integrable systems and safely incompatible with those of chaotic systems. We stress the importance of the agreement of the fluctuation properties between experiment and theoretical models, as they determine the dynamical regime and the complexity of the real interactions. We emphasize the new statistical method we use, adapted for properly analyzing the fluctuation properties for very short spectral sequences.
↳ hep-phnlin.CDnucl-thPRC(2015)·1 citation
10
Recent open heavy flavor studies for the Electron-Ion Collider
Xuan Li🇺🇸
The future Electron-Ion Collider (EIC) will operate a series of high-luminosity high-energy electron+proton ( $e + p$ ) and electron+nucleus ( $e + A$ ) collisions to study several fundamental questions in the high energy and nuclear physics field. Heavy flavor hadron and jet production at the EIC plays an important role in exploring both potential modification on the initial-state nuclear parton distribution functions (nPDFs) and final-state parton propagation and hadronization processes under different nuclear medium conditions. The current design of the EIC ePIC detector has good performance of vertex and track reconstruction, particle identification and energy determination in the pseudorapidity region of $- 3.5 < η < 3.5$ , which will enable a series of high precision heavy flavor hadron and jet measurements. Latest simulation studies of the projected nuclear modification factor $R_{e A}$ of heavy flavor jets and heavy flavor hadron inside jets in $e + p$ and $e + Au$ collisions at $s =$ 28.6 GeV and 63.2 GeV as well as the projected statistical accuracy of inclusive and differential charm baryon over meson ratio measurements in $e + p$ collisions will be presented. The impacts of these proposed EIC measurements on constraining the heavy quark propagation properties in cold nuclear medium and exploring the heavy quark hadronization process will be discussed.
↳ nucl-exhep-exnucl-thphysics.ins-detPoS(2025)·3 citations
11
Baryon Construction with $η^{'}$ Meson Field
Fan Lin🇨🇳 · Yong-Liang Ma🇨🇳
In the low-energy regime, baryons with $N_{f} \geq 2$ have long been constructed as skyrmions or through bag models, but such constructions for $N_{f} = 1$ are hindered by the trivial topological structure of the meson field. Recent proposals suggest that one-flavor baryons can instead be interpreted as quantum Hall droplets on the $η^{'}$ domain wall, providing a potential link to quark--hadron continuity at high density. In retrospect, the qualitative or semi-qualitative construction of one-flavor baryons on the $η^{'}$ domain wall reveals that these baryons can be described as quantum Hall droplets, resembling topological solitons akin to skyrmions. Using an effective theory on the $η^{'}$ domain wall, which is conjectured to be the Chern--Simons--Higgs theory, it is discussed that its vortex solution with unit baryon numbers naturally has a spin of $N_{c} /2$ , and thus can be interpreted as a baryon or multi-baryon structure. The particle--vortex duality suggests that quarks carry a fractional topological charge of $1/ N_{c}$ and obey fractional statistics. In terms of chiral bag models, confinement can be attributed to the monopoles confined within the bag, and the vector meson fields on the bag surface are essential for ensuring the correct baryon number in the chiral bag framework, thereby providing deeper insights into baryons as non-trivial topological structures of the meson field. In this paper, we review the progress in this development, with a special focus on the $η^{'}$ domain wall dynamics. Naive extensions to $N_{f} \geq 2$ are also discussed.
↳ hep-phhep-thnucl-thSymmetry(2025)·1 citation
12
Spacetime profile of electromagnetic fields in intermediate-energy heavy-ion collisions
Hidetoshi Taya🇯🇵
I numerically estimate the spacetime profile of the electromagnetic fields produced in intermediate-energy heavy-ion collisions at $\sqsNN = 2.4 \mathchar ‘ - 7.7 GeV$ for a wide range of impact parameters $b = 0 \mathchar ‘ - 9 fm$ , using a hadronic cascade model, JAM (Jet AA Microscopic transport model). I demonstrate that (1) the produced electromagnetic fields are as strong as $e E, e B = O ((50 MeV)^{2})$ ; (2) that the produced fields extend in spacetime about $V_{4} = O ((10 fm)^{4})$ ; (3) that the magnetic field dominates around the collision point, while the other broad regions of spacetime are dominated by the electric field; and (4) that a topological electromagnetic-field configuration such that $E \cdot B \neq = 0$ is realized.
↳ hep-phnucl-thPRC(2025)·4 citations
13
't Hooft model in the temporal gauge
Paul Hoyer🇫🇮
I consider QCD $_{2}$ in the $N_{c} \to \infty$ limit at fixed $g^{2} N_{c}$ . The derivation starts from equal-time $q q ˉ$ bound states in coordinate space and temporal ( $A^{0} = 0$ ) gauge, avoiding the use of quark and gluon propagators. The wave function is given analytically by a $_{1} F_{1}$ function with an explicit frame dependence. In the infinite momentum frame the Fourier transformed wave function satisfies the 't~Hooft equation, however with contributions also from quarks with negative kinetic energy. Such contributions are present also in the rest frame, and do not vanish under boosts.
↳ hep-phnucl-thPRD(2025)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE

The Fermi function and the neutron's lifetime

The spatial string tension and its effects on screening correlators in a thermal QCD plasma

Spectral-statistics properties of the experimental and theoretical light baryon and meson spectra

Recent open heavy flavor studies for the Electron-Ion Collider

Baryon Construction with η′ Meson Field

Spacetime profile of electromagnetic fields in intermediate-energy heavy-ion collisions

't Hooft model in the temporal gauge

Affiliations

Baryon Construction with $η^{'}$ Meson Field