HEP Lattice·hep-lat

Wed·Oct 7, 2026Wednesday·October 7, 2026

6 papers—1 primary·5 cross-listed

01
Mass as pairing: an explicit Majorana mass on half of a generation does not seesaw in symmetric mass generation
Piotr S. Topa
A fermion mass pairs a field with a partner of conjugate charge: elementary (Higgs-Dirac), self-conjugate (seesaw) or a three-fermion composite (symmetric mass generation, SMG). We give half of a Spin(10)-like generation an explicit Majorana mass in a four-dimensional SMG model and ask what the other half does in a phase with no condensate. With the source on, every mass-type term of the unsourced half averages to zero under the symmetry group of the sourced action, so a light mass term, and a seesaw's light-heavy mixing, requires a spontaneously broken symmetry; exact on the lattice and a general proposition. The source is colour-democratic (a Delta_R-type mass on every flavour's right-handed taste doublet); the single-nu_R split lies outside the positivity class used but inside the symmetry statement. Measured up to 8^4: (i) in the symmetric-gap phase, with the source screened to at most 1.1% of free, the unsourced half's single-fermion readout stays at 0.3% of free while its pair susceptibility rises from 0.2% to 1.2-1.7% at h=2; on like mode sets it falls with the volume, on (4^4,8^4) no inequivalent light mass channel grows faster than free, and symmetry breaking is not resolved at L<=8; (ii) at the critical point the explicit mass collapses the critical sigma channel and moves the light half toward free as a saturating crossover, not a power law; direction tests (MIXED by their pre-registered letter) are consistent with a critical coupling rising with the mass; y_c(h) is not located. Pole versus zero of the light propagator at p->0 is not measured. The outcomes are readings after pre-registered tests that mostly returned no verdict. Also: no first-order signature of the merged transition at L<=8, a Z_4-odd response handed to a lattice composite, and flavour democracy of the positivity class. Every claim has an evidence class and a runnable check.
hep-lathep-phhep-th
02
Compositeness and decay properties of the flavor partner of $D_{s 0}^{*} (2317)$
J. Sánchez-Illana · R. Molina · Pan-Pan Shi
In view of the recent experimental finding of the heavy quark flavor partner of the $D_{s 0} (2317)$ in the bottom sector, the $B_{s 0} (5700)$ , we perform the $B^{(*)} K ˉ^{(*)}$ coupled-channel calculation in the hidden-gauge formalism. By fixing the mass of the bound state generated by the $B K ˉ$ interaction with $J^{P} = 0^{+}$ to the observed state, we also predict five new states with $J^{P} = {0, 1, 2}^{+}$ in this sector. In particular, three of them have $J^{P} = 1^{+}$ and masses $5740$ , $6005$ and $6065$ MeV, respectively. In addition, we evaluate the decay width of the $B_{s 0}$ and $B_{s 1}$ states through the isospin breaking decay mode $B_{s}^{0} π^{0}$ and $B_{s}^{* 0} π^{0}$ , respectively. We find that, because these states have large binding energies with respect to the $B^{(*)} K ˉ$ threshold, the coupling to the bare component can reduce this decay width by more than half of the decay width, from $50$ keV in the purely molecular model to $10 - 20$ keV, when the $B_{s 0}$ is coupled to the bare component. We also observe that, after considering heavy-quark-spin violating contributions, the decay width for the $B_{s 1}$ becomes smaller than for the $B_{s 0}$ .
↳ hep-phhep-exhep-lat
03
Born-Oppenheimer Effective Field Theory as a unified framework for all the XYZ exotics
Tommaso Scirpa
We discuss some recent applications of the Born-Oppenheimer effective field theory (BOEFT) formalism, directly derived from QCD and grounded in scale separation and symmetries, to hadronic systems containing two heavy quarks. This formalism provides a unified description of both ordinary and exotic quarkonium states (i.e., hybrids, tetraquarks, pentaquarks, ...) dynamics via coupled Schrödinger equations, whose potentials are computable on the lattice. The aim is to unveil the elusive pattern of the XYZ exotic hadrons. Here, we apply the BOEFT formalism to the $χ_{c 1} (3872)$ , $T_{cc} (3875)^{+}$ , and their bottom counterparts. Moreover, we assess the threshold effects on the quarkonium spectrum and discuss the inclusive production cross section for $χ_{c 1} (3872)$ .
↳ hep-phhep-exhep-latnucl-th
04
Neutral Pseudoscalar Mesons, Hadron Light-by-Light Scattering, and the Muon Anomalous Magnetic Moment
Cong-Cong Ye · Yu-Chen Hu · Minghui Ding · Craig D. Roberts
Continuum Schwinger function methods\linebreak (CSM) are used to provide estimates of pseudoscalar meson pole contributions - $P = π^{0}$ , $η$ , $η^{'}$ , $η_{c}$ , $η_{b}$ - to the muon anomalous magnetic moment. The analysis framework is benchmarked via successful applications to an array of other meson and nucleon properties. It uses the leading order CSM truncation, augmented by a parametrisation of non-Abelian anomaly effects, to deliver an internally consistent treatment of all the pseudoscalar--two-photon transition form factors required to complete such a calculation. Employing those form factor predictions, the following results are obtained (units $1 0^{- 11}$ ): $a_{μ}^{π^{0}} + a_{μ}^{η} + a_{μ}^{η^{'}} = 84.3 (0.8)$ - a value lower than some other contemporary estimates; $a_{μ}^{η_{c}} = 0.82 (0.04)$ ; and a value of $a_{μ}^{η_{b}}$ that is negligible. The total contribution is $\sum_{P} a_{μ}^{P} = 85.1 (0.8) /1 0^{11}$ . Our analysis suggests that this pole contribution to $a_{μ}$ is still not known with precision better than 5\%.
↳ hep-phhep-exhep-latnucl-ex+1
05
Fully charmed tetraquarks on the Lattice with controlled errors
Zhenyu Zhang · Bing-Nan Lu · Qian Wang · Qiang Zhao
We introduce the lattice quark potential model (LQPM), which discretizes the nonrelativistic quark potential model on a periodic cubic lattice and diagonalizes the resulting many-body Hamiltonian exactly. Unlike variational approaches, which provide only upper bounds on the energy, LQPM removes this variational bias, and its remaining finite-volume uncertainty is removed by extrapolation. Formulated directly in coordinate space, the method is indifferent to the specific form of the potential and accommodates arbitrary interactions, such as including three-body forces and spin-orbit and tensor couplings, that are difficult to treat in conventional few-body approaches. As a benchmark, the charmonium and $Ω_{ccc}$ spectra are reproduced within a few MeV of experiment. For the fully charmed tetraquark $cc c ˉ c ˉ$ , we obtain a $J^{P} = 0^{+}$ ground state at $5934.8 (13) MeV$ , $33.2 (13) MeV$ below the $η_{c} η_{c}$ threshold, unambiguously identified as a deeply bound tetraquark whose existence is robust against the choice of potential. Such a state can decay into two dileption pairs $2 (e^{+} e^{-})$ via $J / ψ e^{+} e^{-}$ , with significance similar to $X (6400)$ , or about one order of magnitude smaller. Lying below the lowest strong-decay channel, it can decay only through electromagnetic and weak interactions. Our results establish exact lattice diagonalization as a controlled, systematically improvable, and broadly applicable route to multiquark spectroscopy, providing a quantitative benchmark for the strong interaction and valuable guidance for future experimental searches for exotic hadrons.
↳ hep-phhep-lat
06
Glueball gravitational form factors in dynamical holography
Kiminad A. Mamo
We present the first holographic study of gravitational form factors (GFFs) of scalar, pseudoscalar and canonical-spin-averaged tensor glueball targets. These observables test gravitational cubic couplings whose physical validity is not established by spectra and static-force calibration. We construct a dynamical Einstein--scalar--axion representation inspired by the Babington--Crooks--Evans adjoint-mass deformation of $N = 4$ super-Yang--Mills theory and its Type-IIB supergravity dual. Leading ultraviolet source data are retained, while a soft-wall-like infrared reconstruction incorporates asymptotically linear radial mass-squared trajectories. Spectra and Wilson observables fix the parameters at a common Sommer scale without GFF input. The full constrained cubic vertices fail to describe 27 correlated scalar lattice observations, giving $χ^{2} / dof = 73.60/27 = 2.73$ . We propose normalized heavy-target (HT) effective cubic couplings for pure-glue matching. HT adopts leading radial shapes suggested by infinitely heavy targets at fixed probe dynamics and normalizes their overlap weights on the physical ground states. With the background, modes and propagators unchanged, HT gives $χ^{2} / dof = 16.98/27 = 0.63$ , without numerical adjustment to GFF data. Tensor and scalar source overlaps determine $A$ and the physical normalized trace; the exact finite-mass energy--momentum-tensor relation determines $D$ . We predict the pseudoscalar and tensor form factors and three-target Breit pressure and shear profiles. On the reference infrared-decaying axion branch, the HT Breit mass radii are $0.276$ , $0.300$ and $0.311 fm$ , respectively. The results identify gravitational cubic matching as a distinct step beyond background calibration and provide a prescription for further lattice tests.
↳ hep-thhep-lathep-ph

Mass as pairing: an explicit Majorana mass on half of a generation does not seesaw in symmetric mass generation

Compositeness and decay properties of the flavor partner of Ds0∗​(2317)

Born-Oppenheimer Effective Field Theory as a unified framework for all the XYZ exotics

Neutral Pseudoscalar Mesons, Hadron Light-by-Light Scattering, and the Muon Anomalous Magnetic Moment

Fully charmed tetraquarks on the Lattice with controlled errors

Glueball gravitational form factors in dynamical holography

Compositeness and decay properties of the flavor partner of $D_{s 0}^{*} (2317)$