Scale-anomaly-induced binding pressure in hadrons

Fujii, Daisuke; Tanaka, Mitsuru*

Physics Letters B, 870, p.139872_1 - 139872_7, 2025/11

https://doi.org/10.1016/j.physletb.2025.139872

We investigate how the QCD scale anomaly contributes to the internal pressure structure of hadrons, employing the decomposition of the energy-momentum tensor into its trace and traceless parts. By utilizing recent model-independent results for gravitational form factors, we analyze the pressure distributions of both pions and nucleons in the instant form and the light-front form. Our analysis reveals that, in all examined cases, the confining pressure is predominantly driven by the scale anomaly. This indicates that the dominance of the scale anomaly in generating internal pressure is a robust and universal feature, regardless of the specific hadron, theoretical model, or form used in the analysis.

Lifshitz formulas for finite-density Casimir effect

Fujii, Daisuke; Nakayama, Katsumasa*; Suzuki, Kei

Physics Letters B, 868, p.139758_1 - 139758_6, 2025/09

https://doi.org/10.1016/j.physletb.2025.139758

The Lifshitz formula has long served as a foundational framework for analyzing the Casimir effect under finite-temperature conditions. In this work, we extend its applicability to situations involving finite chemical potential, thereby incorporating quantum field contributions beyond thermal effects. We illustrate the broad utility of the resulting generalized formula by exploring characteristic features of the Casimir effect across a variety of setups, including different boundary conditions, temperature regimes, spatial dimensionalities, and chemical potential imbalances. This extended framework is particularly relevant to systems such as dense quark matter and Dirac/Weyl semimetals, where the chemical potential functions as a tunable parameter that influences the Casimir force.

Dominance of gluonic scale anomaly in confining pressure inside nucleon and D-term

Fujii, Daisuke; Kawaguchi, Mamiya*; Tanaka, Mitsuru*

Physics Letters B, 866, p.139559_1 - 139559_7, 2025/07

https://doi.org/10.1016/j.physletb.2025.139559

We investigate the confining pressure inside the nucleon and the associated gravitational form factor, known as the D-term, within a skyrmion based on the scale-invariant chiral perturbation theory. In this approach, the effects of scale symmetry breaking are incorporated through the coupling of a scalar meson field to the scale anomaly, following the low-energy theorem. Utilizing the decomposition of the nucleon's energy-momentum tensor, we clarify how the scale anomaly components contribute to the internal pressure. Our analysis reveals that the gluon-induced scale anomaly predominantly governs the confining pressure. Compared to the result in the chiral limit of conventional chiral perturbation theory, this approach yields a total pressure profile more consistent with lattice QCD data. Furthermore, the pressure due to the gluonic anomaly extends over a wide spatial region, leading to a significant contribution to the D-term.

A Study of the correlation function

Abreu, L. M.*; Gubler, P.; Khemchandani, K. P.*; Martnez Torres, A.*; Hosaka, Atsushi

Physics Letters B, 860, p.139175_1 - 139175_7, 2025/01

https://doi.org/10.1016/j.physletb.2024.139175

Search for the 6 condensed state in Mg using the C+C scattering

Fujikawa, Y.*; Kawabata, T.*; Adachi, S.*; Hirose, Kentaro; Makii, Hiroyuki; Nishio, Katsuhisa; Orlandi, R.; Suzaki, Fumi; 13 of others*

Physics Letters B, 848, p.138384_1 - 138384_6, 2024/01

https://doi.org/10.1016/j.physletb.2023.138384

Doubly heavy tetraquarks including one-pion exchange potential

Meng, Q.*; Hiyama, Emiko*; Oka, Makoto*; Hosaka, Atsushi; Xu, C.*

Physics Letters B, 846, p.138221_1 - 138221_6, 2023/11

https://doi.org/10.1016/j.physletb.2023.138221

no abstracts in English

Level structures of Ca cast doubt on a doubly magic Ca

Chen, S.*; Browne, F.*; Doornenbal, P.*; Lee, J.*; Obertelli, A.*; Tsunoda, Yusuke*; Otsuka, Takaharu*; Chazono, Yoshiki*; Hagen, G.*; Holt, J. D.*; et al.

Physics Letters B, 843, p.138025_1 - 138025_7, 2023/08

https://doi.org/10.1016/j.physletb.2023.138025

Gamma decays were observed in Ca and Ca following quasi-free one-proton knockout reactions from Sc. For Ca, a ray transition was measured to be 1456(12) keV, while for Ca an indication for a transition was observed at 1115(34) keV. Both transitions were tentatively assigned as the decays. A shell-model calculation in a wide model space with a marginally modified effective nucleon-nucleon interaction depicts excellent agreement with experiment for level energies, two-neutron separation energies, and reaction cross sections, corroborating the formation of a new nuclear shell above the N = 34 shell. Its constituents, the and orbitals, are almost degenerate. This degeneracy precludes the possibility for a doubly magic Ca and potentially drives the dripline of Ca isotopes to Ca or even beyond.

Dirac/Weyl-node-induced oscillating Casimir effect

Nakayama, Katsumasa*; Suzuki, Kei

Physics Letters B, 843, p.138017_1 - 138017_7, 2023/08

https://doi.org/10.1016/j.physletb.2023.138017

The Casimir effect is a quantum phenomenon induced by the zero-point energy of relativistic fields confined in a finite-size system. This effect for photon fields has been studied for a long time, while the realization of counterparts for fermion fields in Dirac/Weyl semimetals is an open question. We theoretically demonstrate the typical properties of the Casimir effect for relativistic electron fields in Dirac/Weyl semimetals and show the results from an effective Hamiltonian for realistic materials such as CdAs and NaBi. We find an oscillation of the Casimir energy as a function of the thickness of the thin film, which stems from the existence of Dirac/Weyl nodes in momentum space. Experimentally, such an effect can be observed in thin films of semimetals, where the thickness dependence of thermodynamic quantities is affected by the Casimir energy.

Elastic properties of nuclear pasta in a fully three-dimensional geometry

Xia, C.-J.*; Maruyama, Toshiki; Yasutake, Nobutoshi*; Tatsumi, Toshitaka*; Zhang, Y.-X.*

Physics Letters B, 839, p.137769_1 - 137769_5, 2023/04

https://doi.org/10.1016/j.physletb.2023.137769

Pole position of measured in reactions

Aikawa, Shu*; Hashimoto, Tadashi; Tanida, Kiyoshi; 73 of others*

Physics Letters B, 837, p.137637_1 - 137637_8, 2023/02

https://doi.org/10.1016/j.physletb.2022.137637