Nuclear Theory·nucl-th

Monday·May 5, 2025

11 papers—8 primary·3 cross-listed

09
[Submitted on 1 May 2025] (cross-list from hep-ph)
Study of electron-positron annihilation into four pions within chiral effective field theory in the low energy region
Jia-Yu Zhou🇨🇳 · Hao-Xiang Pan🇨🇳 · Ling-Yun Dai🇨🇳
In this paper, we employ chiral effective field theory to study the process of electron-positron annihilation into four pions in the low energy region within $E_{c . m .} \leq 0.6$ GeV. The prediction of the cross section is obtained through $S U (3)$ chiral perturbation theory up to the next-to-leading order, which is smaller than the experimental data in the energy region [0.6-0.65] GeV, though the data has only a few points and poor statistics. Then, the resonance chiral theory is applied to include the resonance contribution, with the lightest scalars and vectors written in the effective Lagrangians. A series of relevant decay widths and the masses of the vectors are studied to fix the unknown couplings. The resonance contribution should be one order larger than that of the chiral perturbation theory but still one to two orders smaller than the data. The significant discrepancy urged the new experimental measurements to give more guidance. We also compute the leading order hadronic vacuum polarization contribution from the four pion channels to the anomalous magnetic moment of the muon, $(g - 2)_{μ}$ . In the energy range from threshold up to 0.6 GeV within resonance chiral theory, the contributions are $a_{μ} = (0.680 \pm 0.062) \times 1 0^{- 16}$ and $a_{μ} = (0.597 \pm 0.058) \times 1 0^{- 16}$ for the processes of $e^{+} e^{-} \to π^{+} π^{+} π^{-} π^{-}$ , $π^{0} π^{0} π^{+} π^{-}$ , respectively.
Comments:
23 pages, 8 figures, to be the same as the published version and correct a few typos
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2505.00770 [pdf]
PRD(2026)·2 citations
10
[Submitted on 1 May 2025] (cross-list from hep-ph)
Holographic Heavy Quark Energy Loss in the Hybrid Model
Jean F. Du Plessis🇺🇸 · Daniel Pablos🇪🇸 · Krishna Rajagopal🇺🇸
To date, holographic calculations in strongly coupled plasma have provided separate descriptions for the rates of energy loss either for ultrarelativistic massless quarks and gluons or for infinitely massive quarks, with the latter calculation valid for $γ < M / (λ T)$ , where $γ$ is the Lorentz boost factor for a heavy quark with velocity $v$ and mass $M$ moving through plasma with 't Hooft coupling $λ$ and temperature $T$ . These two calculations should apply sequentially in the description of the energy loss of a heavy quark that starts out ultrarelativistic, loses energy, slows down, becomes non-relativistic at later times, and ultimately comes to rest and diffuses in the strongly coupled plasma. We provide an ansatz for uniquely incorporating both regimes to give an approximate but unified description of how a heavy quark that is initially ultrarelativistic loses energy all the way until it comes to rest. We implement this ansatz in the Hybrid Strong/Weak Coupling Model. With this new, consistent, treatment of heavy quark energy loss at strong coupling, we confront our predictions for the suppression and azimuthal anisotropies of D- and B-mesons, as well as B-tagged jets, with available experimental data.
Comments:
7 pages, 4 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2505.00863 [pdf]
EPJ Web Conf.(2025)·0 citations
11
[Submitted on 1 May 2025] (cross-list from hep-ph)
Entanglement Maximization and Mirror Symmetry in Two-Higgs-Doublet Models
Marcela Carena🇨🇦 · Guglielmo Coloretti🇨🇭 · Wanqiang Liu🇺🇸 · Mira Littmann🇺🇸 · Ian Low🇺🇸 · Carlos E. M. Wagner🇨🇦
We consider 2-to-2 scatterings of Higgs bosons in a CP-conserving two-Higgs-doublet model (2HDM) and study the implication of maximizing the entanglement in the flavor space, where the two doublets $Φ_{a}$ , $a = 1, 2$ , can be viewed as a qubit: $Φ_{1} = ∣0 ⟩$ and $Φ_{2} = ∣1 ⟩$ . More specifically, we compute the scattering amplitudes for $Φ_{a} Φ_{b} \to Φ_{c} Φ_{d}$ and require the outgoing flavor entanglement to be maximal for a full product basis such as the computational basis, which consists of ${∣00 ⟩, ∣01 ⟩, ∣10 ⟩, ∣11 ⟩}$ . In the unbroken phase and turning off the gauge interactions, entanglement maximization results in the appearance of an $U (2) \times U (2)$ global symmetry among the quartic couplings, which in general is broken softly by the mass terms. Interestingly, once the Higgs bosons acquire vacuum expectation values, maximal entanglement enforces an exact $U (2) \times U (2)$ symmetry, which is spontaneously broken to $U (1) \times U (1)$ . As a byproduct, this gives rise to Higgs alignment as well as to the existence of 6 massless Nambu-Goldstone bosons. The $U (2) \times U (2)$ symmetry can be gauged to lift the massless Goldstones, while maintaining maximal entanglement demands the presence of a discrete $Z_{2}$ symmetry interchanging the two gauge sectors. The model is custodially invariant in the scalar sector, and the inclusion of fermions requires a mirror dark sector, related to the standard one by the $Z_{2}$ symmetry.
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
arXiv:
2505.00873 [pdf]
JHEP(2025)·29 citations

Affiliations

first authorsco-authorsvia INSPIRE

Study of electron-positron annihilation into four pions within chiral effective field theory in the low energy region

Holographic Heavy Quark Energy Loss in the Hybrid Model

Entanglement Maximization and Mirror Symmetry in Two-Higgs-Doublet Models

Affiliations