Nuclear Theory·nucl-th

Friday·May 6, 2022

7 papers—2 primary·5 cross-listed

03
The Four Loop QCD Rapidity Anomalous Dimension
Ian Moult🇺🇸 · Hua Xing Zhu🇨🇳 · Yu Jiao Zhu🇩🇪
The rapidity anomalous dimension controls the scaling of transverse momentum dependent observables in the Sudakov region. In a conformal theory it is equivalent to the soft anomalous dimension, but in QCD this relation is broken by anomalous terms proportional to the $β$ -function. In this paper we first give a simple proof of this relation using two different representations of the energy-energy correlator observable. We then calculate the anomalous terms to three loops by computing the three-loop fully differential soft function to $O (ϵ)$ . Combined with recent perturbative data from the study of on-shell form factors and splitting functions, this allows us to derive the four loop rapidity anomalous dimension in QCD.
↳ hep-phhep-thnucl-thJHEP(2022)·97 citations
04
Parton physics of the large- $N_{c}$ mesons
Nikhil Karthik🇺🇸 · Rajamani Narayanan🇺🇸
We initiate the studies on the structural physics of the tower of stable large- $N_{c}$ mesons through a first computation of the collinear quark-structure of a large- $N_{c}$ pion using lattice Monte-Carlo methods. We adapt the large- $N_{c}$ continuum reduction for the determination of meson correlation functions involving the spatially-extended quasi-PDF operators as a perfect strategy to concentrate only on the short perturbative length scales. We find the internal structures of pion in the large- $N_{c}$ and $N_{c} = 3$ theories to be quite similar. Interestingly, we find hints that even the observed differences could arise to a large extent via the different perturbative QCD evolution in the two theories from similar initial conditions at low factorization scales.
↳ hep-lathep-phhep-thnucl-thPRD(2022)·3 citations
05
Recollision induced nuclear excitation of $^{229}$ Th
Xu Wang
Previously we proposed a new approach of exciting the $^{229}$ Th nucleus using laser-driven electron recollision [W. Wang et al., Phys. Rev. Lett. 127, 052501 (2021)]. The current article is aimed to elaborate the method by explaining further theoretical details and presenting extended new results. The method has also been improved by adopting the electronic excitation cross sections calculated recently by Tkalya [E. V. Tkalya, Phys. Rev. Lett. 124, 242501 (2020)]. The new cross sections are obtained from Dirac distorted-wave calculations instead of from Dirac plane-wave calculations as we used previously. The distorted-wave cross sections are shown to be 5 to 6 orders of magnitude higher than the plane-wave results. With the excitation cross sections updated, the probability of isomeric excitation of $^{229}$ Th from electron recollision is calculated to be on the order of $1 0^{- 12}$ per nucleus per (femtosecond) laser pulse. Dependency of the excitation probability on various laser parameters is calculated and discussed, including the laser intensity, the laser wavelength, and the laser pulse duration.
↳ physics.atom-phnucl-thPRC(2022)·20 citations
06
Phase shifts of the light pseudoscalar meson and heavy meson scattering in heavy meson chiral perturbation theory
Bo-Lin Huang🇨🇳 · Zi-Yang Lin🇨🇳 · Kan Chen🇨🇳 · Shi-Lin Zhu🇨🇳
We calculate the complete $T$ matrices of the elastic light pseudoscalar meson and heavy meson scattering to the third order in heavy meson chiral perturbation theory. We determine the low-energy constants by fitting the phase shifts and scattering lengths from lattice QCD simulations simultaneously and predict the phase shifts at the physical meson masses. The phase shifts in the $D π (I = 1/2)$ , $D K (I = 0)$ , $D K ˉ (I = 0)$ , $D_{s} K ˉ$ , $D η$ and $D_{s} η$ $S$ waves are so strong that bound states or resonances may be generated dynamically in all these channels. The $D K (I = 0)$ channel corresponds to the well-known exotic state $D_{s 0}^{*} (2317)$ . The $D K (I = 0)$ channel corresponds to the well-known exotic state $D_{s 0}^{*} (2317)$ . The coupled-channel $D π$ , $D η$ and $D_{s} K ˉ$ scattering corresponds to $D_{0}^{*} (2400)$ . The coupled-channel $D π$ , $D η$ and $D_{s} K ˉ$ scattering corresponds to $D_{0}^{*} (2400)$ . We also predict the scattering lengths and scattering volumes and observe good convergence in the scattering volumes. Our calculations provide a possibility to accurately investigate the exotic state in the light pseudoscalar meson and heavy meson interactions.
↳ hep-phhep-exhep-latnucl-thEPJC(2023)·7 citations
07
Transverse momentum distributions of valence quark in light and heavy vector mesons
Chao Shi🇨🇳 · Jicheng Li🇨🇳 · Ming Li🇨🇳 · Xurong Chen🇨🇳 · Wenbao Jia🇨🇳
We study the leading-twist time-reversal even transverse momentum dependent parton distribution functions (TMDs) of light and heavy vector mesons, i.e., the $ρ$ , $J / ψ$ and $Υ$ . We employ the leading Fock-state light front wave functions (LF-LFWFs) of $ρ$ and $J / ψ$ from our recent study, and supplement with $Υ$ 's LF-LFWFs. These LF-LFWFs are extracted from dynamically solved Bethe-Salpeter wave functions. The vector meson TMDs are then studied with the light front overlap representation at leading Fock-state. All the obtained TMDs are non-vanishing and evolve with current quark mass, in particular the tensor polarized TMDs $f_{1 L T}$ and $f_{1 T T}$ which undergo a sign flip. The $ρ$ TMDs are compared with other model studies and agreement is found, aside from $f_{1 L T}$ and $f_{1 T T}$ . Finally, the collinear PDFs of vector mesons are studied. The $ρ$ 's valence PDFs $f_{1, v} (x)$ and $g_{1 L, v} (x)$ are evolved to the scale of 2.4 GeV, with their first three moments compared to lattice QCD prediction. The qualitative behavior of tensor polarized PDF $f_{1 LL} (x)$ in $ρ$ at large $x$ is also discussed.
↳ hep-phnucl-thPRD(2022)·20 citations

Affiliations

first authorsco-authorsvia INSPIRE

The Four Loop QCD Rapidity Anomalous Dimension

Parton physics of the large-Nc​ mesons

Recollision induced nuclear excitation of 229Th

Phase shifts of the light pseudoscalar meson and heavy meson scattering in heavy meson chiral perturbation theory

Transverse momentum distributions of valence quark in light and heavy vector mesons

Affiliations

Parton physics of the large- $N_{c}$ mesons

Recollision induced nuclear excitation of $^{229}$ Th