Nuclear Theory·nucl-th

Tuesday·March 15, 2022

10 papers—3 primary·7 cross-listed

01
Renormalization of One-Pion Exchange in Chiral Effective Field Theory for Antinucleon-Nucleon Scattering
Daren Zhou🇨🇳 · Bingwei Long🇨🇳 · R. G. E. Timmermans🇳🇱 · U. van Kolck🇫🇷
The renormalization of iterated one-pion exchange (OPE) is studied in Chiral Effective Field Theory ( $χ$ EFT) for the antinucleon-nucleon ( $N N$ ) system. The OPE potential is cut off at a certain distance and contact interactions are represented by a complex spherical well with the same radius. We investigate the dependence on the cutoff radius of the phase shifts, inelasticities, and mixing angles for the low partial waves in $N N$ scattering. We show that renormalization requires additional contact interactions compared to the expectation based on naive dimensional analysis. Results after renormalization are compared with the state-of-the-art energy-dependent partial-wave analysis of $N N$ data. We compare our conclusions with applications of $χ$ EFT to the nucleon-nucleon system.
nucl-thhep-phPRC(2022)·5 citations
02
Mapping topology of skyrmions and fractional quantum Hall droplets to nuclear EFT for ultra-dense baryonic matter
Mannque Rho🇫🇷
We describe the mapping at high density of topological structure of baryonic matter to a nuclear effective field theory that implements hidden symmetries emergent from strong nuclear correlations. The theory so constructed is found to be consistent with no conflicts with the presently available observations in both normal nuclear matter and compact-star matter. The hidden symmetries involved are "local flavor symmetry" of the vector mesons identified to be (Seiberg-)dual to the gluons of QCD and hidden "quantum scale symmetry" with an IR fixed point with a "genuine dilaton (GD)" characterized by non-vanishing pion and dilaton decay constants. Both the skyrmion topology for $N_{f} \geq 2$ baryons and the fractional quantum Hall (FQH) droplet topology for $N_{f} = 1$ baryons are unified in the "homogeneous/hidden" Wess-Zumino term in the hidden local symmetry (HLS) Lagrangian. The possible indispensable role of the FQH droplets in going beyond the density regime of compact stars approaching scale-chiral restoration is explored by moving toward the limit where both the dilaton and the pion go massless.
nucl-thastro-ph.SRhep-phSymmetry(2022)·4 citations
03
Enhancement of incoherent bremsstrahlung in proton-nucleus scattering in the $Δ$ -resonance energy region
Sergei P. Maydanyuk (1) ((1) Institute for Nuclear Research, National Academy of Sciences of Ukraine, Kyiv, 03680, Ukraine)
We investigate emission of the bremsstrahlung photons in the scattering of protons off nuclei at the $Δ$ -resonance energy region. Including properties of $Δ$ -resonance in the nucleus-target to the bremsstrahlung model, we find the following. (1) Ratio between incoherent emission and coherent emission is about $1 0^{6}$ -- $1 0^{7}$ for $p + \isotope [197] A u$ (without $Δ$ -resonance) at energy of proton beam $E_{p}$ of 190~MeV, where the calculated full bremsstrahlung spectrum is in good agreement with experimental data. This confirms importance of incoherent processes in study of $Δ$ -resonances in this reaction, which have never been studied yet. We estimate coherent and incoherent contributions, electric and magnetic contributions, full bremsstrahlung spectra for the scattering of protons on the \isotope[12]{C}, \isotope[40]{Ca}, \isotope[208]{Pb} nuclei at $E_{p} = 800$ ~MeV, we find conditions for the most intensive bremsstrahlung emission. (2) Transition $p N \to Δ^{+} N$ in the nucleus-target reinforces emission of bremsstrahlung photons in that reaction at $E_{p} = 800$ ~MeV. Difference between the spectra for normal nuclei and nuclei with included $Δ$ -resonance is larger for more light nuclei, but the spectra are larger for heavier nuclei. (3) Taking into account shortly lived state of $Δ$ -resonance, we find that the spectrum with $Δ$ -resonance in the nucleus-target is essentially larger in the high energy photon region than the spectrum without this $Δ$ -resonance (corresponding calculations for \isotope[12][\Delta]{C}, \isotope[40][\Delta]{Ca}, \isotope[208][\Delta]{Pb} in comparison with \isotope[12]{C}, \isotope[40]{Ca}, \isotope[208]{Pb} are provided). Such an aspect is recommended for registration of $Δ$ -resonances in nuclei in possible future experiments.
nucl-thhep-phnucl-exPRC(2023)·7 citations
04
Helicity-dependent distribution of strange quarks in the proton from nonlocal chiral effective theory
Fangcheng He🇨🇳 · Chueng-Ryong Ji🇺🇸 · W. Melnitchouk🇺🇸 · Y. Salamu🇨🇳 · A. W. Thomas🇦🇺 · P. Wang🇨🇳 · X. G. Wang🇦🇺
The helicity-dependent strange quark distribution in the proton, $Δ s$ , is calculated in a nonlocal chiral SU(3) effective field theory. The hadronic proton to meson plus octet or decuplet baryon splitting functions are derived at the one-loop level, with loop integrals rendered finite by correlation functions introduced in the nonlocal Lagrangian. Within the convolution framework, the proton strange helicity distribution is obtained using spin-flavor symmetry to constrain the input valence quark distributions in the hadronic intermediate states. The polarized strange quark distribution is found to be quite small, with the lowest moment of $Δ s$ negative, but consistent with recent global QCD analyses.
↳ hep-phhep-latnucl-thPRD(2022)·9 citations
05
Understanding mass hierarchy in collisional energy loss through heavy flavor data
Bojana Ilic🇷🇸 · Magdalena Djordjevic🇷🇸
While experimental observations, such as the mass hierarchy effect, are attributed and analyzed within radiative models, their interpretation crucially depends on collisional energy loss contribution, which is often neglected in such analyses. To our knowledge, neither a (direct) simple relation between collisional energy loss and heavy quark mass is established, nor an observable that quantifies this effect. On the other hand, the upcoming high-luminosity measurements at RHIC and LHC will generate heavy flavor data with unprecedented precision, providing an opportunity to utilize high-pT heavy flavor data to analyze the interaction mechanisms in the quark-gluon plasma. To this end, we employ a recently developed DREENA framework based on our dynamical energy loss formalism to study the mass hierarchy in heavy flavor suppression. We present i) Analytical derivation of a direct relation between collisional suppression/energy loss and heavy quark mass. ii) A novel observable sensitive only to the collisional energy loss mechanism to be tested by future high-precision experiments. iii) Analytical and numerical extraction of the mass hierarchy in collisional energy losses through this observable.
↳ hep-phnucl-thPRC(2022)·3 citations
06
Memory effects on energy loss and diffusion of heavy quarks in the quark-gluon plasma
Marco Ruggieri🇨🇳 · Pooja🇮🇳 · Jai Prakash🇮🇳 · Santosh K. Das🇮🇳
We study the dynamics of heavy quarks in a thermalized quark-gluon plasma with a time-correlated thermal noise, $η$ . In this case it is said that $η$ has memory. We use an integro-differential Langevin equation in which the memory enters via the thermal noise and the dissipative force. We assume that the time correlations of the noise decay exponentially on a time scale, $τ$ , that we treat as a free parameter. We compute the effects of $τ \neq = 0$ on the thermalization time of the heavy quarks, on their momentum broadening and on the nuclear modification factor. We find that overall memory slows down the momentum evolution of heavy quarks: in fact, transverse momentum broadening and the formation of $R_{AA}$ are slowed down by memory and the thermalization time of the heavy quarks become larger. The potential impact on other observables is discussed briefly.
↳ hep-phnucl-thPRD(2022)·51 citations
07
Nuclei with enhanced Schiff moments in practical elements for atomic and molecular EDM measurements
J.A. Behr
This is a resource paper concerning enhancement of observable time-reversal breaking effects by nuclear structure, aimed at AMO experimentalists. It's intended to support a white paper by providing some orientation on what can be said about some particular isotopes. Any conclusions are qualitative, and the reader should consult and cite the primary references and reviews rather than this arXiv alone.
↳ nucl-exnucl-th5 citations
08
Electron Scattering and Neutrino Physics
A. M. Ankowski🇺🇸 · A. Ashkenazi🇮🇱 · S. Bacca🇩🇪 · J. L. Barrow🇮🇱 · M. Betancourt🇺🇸 · A. Bodek🇺🇸 · M. E. Christy🇺🇸 · L. Doria. S. Dytman🇺🇸 · A. Friedland🇺🇸 · O. Hen🇺🇸 · C. J. Horowitz🇺🇸 · N. Jachowicz🇧🇪 and 41 other authors
A thorough understanding of neutrino-nucleus scattering physics is crucial for the successful execution of the entire US neutrino physics program. Neutrino-nucleus interaction constitutes one of the biggest systematic uncertainties in neutrino experiments - both at intermediate energies affecting long-baseline Deep Underground Neutrino Experiment (DUNE), as well as at low energies affecting coherent scattering neutrino program - and could well be the difference between achieving or missing discovery level precision. To this end, electron-nucleus scattering experiments provide vital information to test, assess and validate different nuclear models and event generators intended to be used in neutrino experiments. In this white paper, we highlight connections between electron- and neutrino-nucleus scattering physics at energies ranging from 10s of MeV to a few GeV, review the status of ongoing and planned electron scattering experiments, identify gaps, and layout a path forward that benefits the neutrino community. We also highlight the systemic challenges with respect to the divide between the nuclear and high-energy physics communities and funding that presents additional hurdle in mobilizing these connections to the benefit of neutrino programs.
↳ hep-exhep-phnucl-exnucl-thJ.Phys.G(2023)·49 citations
09
Contribution of the Weinberg-type Operator to atomic and nuclear electric dipole moments
Naohiro Osamura🇯🇵 · Philipp Gubler🇯🇵 · Nodoka Yamanaka🇯🇵
The contribution of the CP violating three-gluon Weinberg operator, $\frac{1}{3 !} w f^{ab c} ϵ^{ν ρ α β} G_{μν}^{a} G_{α β}^{b} G_{ρ}^{c μ}$ , to the atomic and nuclear EDMs is estimated using QCD sum rules. After calculating the transition matrix element between the pion and the vacuum through the Weinberg operator, we obtain the long-range CP-odd nuclear force by determining the isovector CP-odd pion-nucleon vertex, using chiral perturbation theory at NLO. The EDMs of $^{199}$ Hg, $^{129}$ Xe, $^{225}$ Ra, $^{2}$ H, and $^{3}$ He are finally given including comprehensive uncertainty analysis. While the leading contribution of the $^{199}$ Hg EDM is given by the intrinsic nucleon EDM, that of $^{129}$ Xe atom may be dominated by the one-pion exchange CP-odd nuclear force generated by the Weinberg operator. From current experimental data of the $^{199}$ Hg atomic EDM, we obtain an upper limit on the Weinberg operator magnitude of $∣ w ∣ < 4 \times 1 0^{- 10} GeV^{- 2}$ if we assume that it is the only source of CP violation at the scale $μ = 1$ TeV.
↳ hep-phhep-exnucl-thphysics.atom-phJHEP(2022)·15 citations
10
Energy-Energy Correlators for Precision QCD
Duff Neill🇺🇸 · Gherardo Vita🇺🇸 · Ivan Vitev🇺🇸 · Hua Xing Zhu🇨🇳
In this contribution to the Proceedings of the US Community Study on the Future of Particle Physics (Snowmass 2021) we review recent progress in the evaluation and application of the Energy-Energy Correlator (EEC) event shape observable in $e^{+} e^{-}$ annihilation, hadronic collisions, and deep inelastic scattering. The importance of EEC as a precision probe of the perturbative and non perturbative aspects of QCD dynamics is emphasized. It can be used to extract the strong coupling constant and to constrain TMD distribution functions. Closely related energy-correlation shape variables have also been used to tag boosted objects produced in high energy collisions. The opportunities to study EEC at the future Electron-Ion Collider are also highlighted.
↳ hep-phnucl-th27 citations

Affiliations

first authorsco-authorsvia INSPIRE