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arxiv: 2606.31107 · v1 · pith:IT3XLHZ4new · submitted 2026-06-30 · ⚛️ nucl-th

Exact Calculation of Two-neutrino Double Beta Decay Rate

Stefan-Alexandru Ghinescu , Andrei Neacsu , Sabin Stoica This is my paper

Pith reviewed 2026-07-01 03:31 UTC · model grok-4.3

classification ⚛️ nucl-th
keywords two-neutrino double beta decaynuclear structurelepton kinematicsclosure approximation82Se136Xedecay rate calculation
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0 comments X

The pith

A new calculation of two-neutrino double beta decay rates keeps nuclear structure and lepton kinematics fully coupled instead of decoupling them.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper presents an approach to two-neutrino double-beta decay that treats nuclear structure and the kinematics of the emitted electrons and neutrinos as interdependent rather than separate. Traditional calculations have used closure, non-closure, or Taylor expansions that break this link. The new method is applied to 82Se and 136Xe and produces different decay rates and electron spectra from those approximations. A reader would care because double-beta decay rates enter searches for neutrino mass and other beyond-standard-model physics. The authors state that the change yields a more realistic description and opens further work on nuclear and atomic effects.

Core claim

By incorporating the full interdependence between nuclear structure and lepton kinematics, the calculation deviates from the rates and spectra obtained with closure, non-closure, and Taylor expansion approximations for the isotopes 82Se and 136Xe, providing a more realistic description of the two-neutrino double-beta decay process.

What carries the argument

The approach that keeps nuclear structure and lepton kinematics interdependent without the usual decoupling approximations.

If this is right

  • Decay rates and electron spectra for 82Se and 136Xe differ from those given by closure, non-closure, and Taylor expansion methods.
  • The calculation supplies a more realistic description of the two-neutrino double-beta decay process.
  • The framework can be extended to additional isotopes and to neutrinoless double-beta decay.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Nuclear matrix elements extracted from experiment may shift once spectra are analyzed with the coupled treatment.
  • Atomic effects that were previously averaged out could become visible in high-statistics data.
  • The same interdependence might alter limits placed on neutrino mass from neutrinoless searches.

Load-bearing premise

The method captures the full interdependence between nuclear structure and lepton kinematics without adding new uncontrolled approximations or model dependencies.

What would settle it

High-precision measurement of the electron energy spectrum or total decay rate for 82Se or 136Xe that either matches or clearly disagrees with the deviations predicted by the coupled calculation.

read the original abstract

The calculation of the two-neutrino double-beta decay (DBD) rates has relied so far on approximations that decouple the nuclear and atomic parts. To provide a more rigorous treatment, we propose an approach which incorporates the full interdependence between nuclear structure and lepton kinematics. Deviations of the decay rates and electron spectra from the traditional methods, such as closure, non-closure and Taylor expansion approximation, are presented and discussed for the isotopes $^{82}$Se and $^{136}$Xe. Our approach gives a more realistic description of the DBD process, and opens the avenue of additional, new theoretical and experimental investigations into nuclear and atomic effects in the process. Extensions of this framework to other isotopes and to neutrinoless double-beta decay are currently underway.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

1 major / 0 minor

Summary. The manuscript proposes an approach to calculate two-neutrino double-beta decay (2νDBD) rates that retains the full interdependence between nuclear structure and lepton kinematics, thereby avoiding the decoupling inherent in the closure, non-closure, and Taylor-expansion approximations used in prior work. Deviations in decay rates and electron spectra relative to those traditional methods are presented for 82Se and 136Xe; the authors conclude that the new treatment supplies a more realistic description and opens avenues for further nuclear and atomic investigations, with extensions to other isotopes and to 0νDBD noted as in progress.

Significance. If the central claim of an exact, approximation-free treatment holds and is accompanied by reproducible numerical results, the work would address a long-standing limitation in 2νDBD calculations and could improve the reliability of nuclear matrix elements and spectral shapes used in neutrino-physics analyses. The explicit avoidance of decoupling approximations is a methodological strength worth crediting.

major comments (1)
  1. [Abstract] Abstract: the claim that the proposed method 'incorporates the full interdependence between nuclear structure and lepton kinematics without introducing new uncontrolled approximations' cannot be evaluated because the abstract supplies no equations, integration procedure, numerical results, error estimates, or direct comparison with experimental half-lives or spectra.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for their review. We address the single major comment below.

read point-by-point responses

  1. Referee: [Abstract] Abstract: the claim that the proposed method 'incorporates the full interdependence between nuclear structure and lepton kinematics without introducing new uncontrolled approximations' cannot be evaluated because the abstract supplies no equations, integration procedure, numerical results, error estimates, or direct comparison with experimental half-lives or spectra.

    Authors: We agree that the abstract, as written, is too concise to permit direct evaluation of the central claim and contains none of the requested technical elements. The full manuscript supplies the integration procedure, numerical results for 82Se and 136Xe, and comparisons with closure, non-closure, and Taylor approximations. To address the concern we will revise the abstract to include a brief statement of the method and the principal numerical findings. revision: yes

Circularity Check

0 steps flagged

No significant circularity identified

full rationale

The paper's central claim is that an exact integration retains the full nuclear-lepton interdependence, avoiding the decoupling of prior approximations (closure, non-closure, Taylor expansion). This is presented as a direct computational method whose output (rates and spectra for 82Se and 136Xe) is compared to those approximations. No equations or steps in the abstract or description reduce by construction to fitted inputs, self-definitions, or load-bearing self-citations; the deviations are offered as external validation rather than tautological predictions. The derivation chain is therefore self-contained against the stated benchmarks.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

Only the abstract is available; the ledger is therefore limited to the explicit domain assumption stated in the abstract. No free parameters, invented entities, or additional axioms are identifiable from the provided text.

axioms (1)
  • domain assumption Nuclear structure and lepton kinematics can be treated with full interdependence in a computationally tractable exact framework
    This is the central premise of the proposed approach as described in the abstract.

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discussion (0)

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Reference graph

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