Nuclear Theory·nucl-th

Friday·July 19, 2024

6 papers—2 primary·4 cross-listed

01
An Analytic Yang-Mills Vacuum Calculation in $3 + 1 d$
Seth Grable🇺🇸
I present a novel analytic framework for $S U (N)$ Yang-Mills theory in the four-dimensional continuum. Background and effective field theory techniques are used to include non-perturbative contributions from cubic and quartic interactions. This approach is inspired by Savvidy who claims first-order contributions from quartic interactions stabilize IR divergence found at one-loop order, making possible IR finite Yang-Mills calculations. I assess the validity of this claim and discuss the implications of my findings.
nucl-thhep-th0 citations
02
Functional Renormalization Group analysis of the quark-condensation pattern on the Fermi surface: A simple effective-model approach
Kie Sang Jeong🇩🇪 · Fabrizio Murgana🇩🇪 · Ashutosh Dash🇩🇪 · Dirk H. Rischke🇩🇪
A simple effective model for the intermediate-density regime is constructed from the high-density effective theory of quantum chromodynamics (QCD). In the effective model, under a renormalization-group (RG) scaling towards low momenta, the original QCD interactions lead to four-quark contact interactions for the relevant quark and hole modes around the Fermi surface. The contact interaction in the scalar channel can be traced back to zero-sound-type collinear quark scattering near the Fermi surface in an instanton background. The quark and hole states in opposite directions of a given Fermi velocity form the collective scalar bosonic mode $σ$ . The magnitude of $σ$ is investigated via the non-perturbative Functional Renormalization Group (FRG) evolution of the effective average action from the ultraviolet (UV) to the infrared (IR). In the mean background-field approximation for $σ$ , nontrivial minima ( $σ ˉ \neq = 0$ ) are found in the IR limit of the effective average action. A nonvanishing $σ ˉ$ corresponds to condensation of quark and hole states in opposite directions of a given Fermi velocity, in a thin shell-like structure in momentum space around the Fermi surface. This looks similar to the shell-like baryon distribution in momentum space assumed in the quarkyonic-matter concept. However, when including a dynamic bosonic $σ$ -mode in the RG flow, we find that its diffusive nature destroys the quark-hole condensate, i.e., the IR potential does not show any minima beyond the trivial one.
nucl-thhep-phPRD(2025)·6 citations
03
Identifying the two-pole structure of the $Λ (1405)$ using an SU(3) flavor filter
Ying-Bo He🇨🇳 · Xiao-Hai Liu🇨🇳 · Li-Sheng Geng🇨🇳 · Feng-Kun Guo🇨🇳 · Ju-Jun Xie🇨🇳
We propose a novel method to identify the two-pole structure of the $Λ (1405)$ . The two poles owe their origin to different quark flavor irreducible representations in the meson-baryon coupled-channel interactions, thus they should be individually manifested in reactions that provide good flavor eigenstate sources. Hadronic decays of charmonia into $Λ ˉ Σ π$ and $Λ ˉ (1520) Σ π$ are such reactions, and the flavor octet and singlet poles can be approximately singled out in these two decay modes. This SU(3) flavor filter works even considering the flavor symmetry breaking. With the huge charmonium data sets collected, it is therefore promising to solve the long-standing $Λ (1405)$ puzzle employing the proposed flavor filter.
↳ hep-phhep-exnucl-thPRD(2026)·11 citations
04
Dimuon and ditau production in photon-photon collisions at next-to-leading order in QED
Hua-Sheng Shao🇫🇷 · David d'Enterria🇨🇭
Next-to-leading-order (NLO) quantum electrodynamics (QED) corrections to the production of muon and tau pairs in photon-photon collisions, $γ γ \to μ^{+} μ^{-}, τ^{+} τ^{-}$ , are calculated in the equivalent photon approximation. We mostly consider $γ γ$ processes in ultraperipheral collisions of hadrons at the LHC, but the $γ γ \to τ^{+} τ^{-}$ process in $e^{+} e^{-}$ collisions at LEP is also discussed. The NLO terms are found to modify the total fiducial cross sections by up to 5%, increasing the tails of the dilepton acoplanarity and transverse momentum distributions, and depleting by up to 15% the yields at high masses, with respect to the leading-order predictions including the very small virtuality of the colliding photons. At the LHC, the calculations obtained with the charge form factor for protons and lead ions including the NLO QED corrections improve the data--theory agreement for all measured differential distributions, and prove an indispensable ingredient for the extraction of precision quantities in photon-photon processes, such as the anomalous magnetic moment of the tau lepton.
↳ hep-phhep-exnucl-exnucl-thJHEP(2025)·22 citations
05
Systematic input scheme of many-boson Hamiltonians with applications to the two-dimensional $ϕ^{4}$ theory
Weijie Du🇺🇸 · James P. Vary🇺🇸
We develop a novel, systematic input scheme for many-boson Hamiltonians in order to solve field theory problems within the light-front Hamiltonian formalism via quantum computing. We present our discussion of this input scheme based on the light-front Hamiltonian of the two-dimensional $ϕ^{4}$ theory. In our input scheme, we employ a set of quantum registers, where each register encodes the occupation of a distinct boson mode as binaries. We squeeze the boson operators of each mode and present the Hamiltonian in terms of unique combinations of the squeezed boson operators. We design the circuit modules for these unique combinations. Based on these circuit modules, we block encode the many-boson Hamiltonian utilizing the idea of quantum walk. For demonstration purposes, we present the spectral calculations of the Hamiltonian utilizing the hybrid quantum-classical symmetry-adapted quantum Krylov subspace diagonalization algorithm based on our input scheme, where the quantum computations are performed with the IBM Qiskit quantum simulator. The results of the hybrid calculations agree with exact results.
↳ quant-phhep-thnucl-thPRD(2025)·10 citations
06
Josephson currents in neutron stars
Armen Sedrakian · Peter B. Rau
We demonstrate that the interface between $S$ -wave and $P$ -wave paired superfluids in neutron stars induces a neutron supercurrent, a charge-neutral analog of the Josephson junction effect in electronic superconductors. The proton supercurrent entrainment by the neutron superfluid generates, in addition to the neutral supercurrent, a charged current across the interface. Beyond this stationary effect, the motion of the neutron vortex lines responding to secular changes in the neutron star's rotation rate induces a time-dependent oscillating Josephson current across this interface when proton flux tubes are dragged along with them. We show that such motion produces radiation from the interface once clusters of proton flux tubes intersect the interface. The power of radiation exceeds by orders of magnitude the Ohmic dissipation of currents in neutron stars. This effect appears to be phenomenologically significant enough to heat the star and alter its cooling rate during the photon cooling era.
↳ astro-ph.HEcond-mat.supr-connucl-thPRD(2025)·9 citations

Affiliations

first authorsco-authorsvia INSPIRE

An Analytic Yang-Mills Vacuum Calculation in 3+1d

Functional Renormalization Group analysis of the quark-condensation pattern on the Fermi surface: A simple effective-model approach

Identifying the two-pole structure of the Λ(1405) using an SU(3) flavor filter

Dimuon and ditau production in photon-photon collisions at next-to-leading order in QED

Systematic input scheme of many-boson Hamiltonians with applications to the two-dimensional ϕ4 theory

Josephson currents in neutron stars

Affiliations

An Analytic Yang-Mills Vacuum Calculation in $3 + 1 d$

Identifying the two-pole structure of the $Λ (1405)$ using an SU(3) flavor filter

Systematic input scheme of many-boson Hamiltonians with applications to the two-dimensional $ϕ^{4}$ theory