On the Hypothesis of Exact Conservation of Charged Weak Hadronic Vector Current in the Standard Model
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe authors estimate the effect of a term in the phenomenological parametrization of the hadronic current used in neutron decay, calling it the CVC effect.
The calculations are done accurately and described well.
But the method is not clean in the sense that C. Giunti pointed out in arXiv:1602.00215v1 as a response to Artur M. Ankowski in arXiv:1601.06169v1. The authors also cite both papers, but do not comment on the discrepancy.
I will try to illustrate the inconsistency in estimating the CVC effect, based on the term the authors attribute to the effect, i.e. the term that guarantees the "conservation" of the hadronic current.
As far as I can see all experimental papers, including Hartmut Abele in PPNP_60, use the simple theoretically motivated form for the hadronic current, that treats proton and neutron as an iso-doublet. The parameters obtained from these experimental papers have to be used in the way they were obtained, i.e. in the form of the theoretically motivated conserved iso-current.
Changing the parametrization of the current to a (maybe) more convenient phenomenological one, like the one used for virtual transitions, that include the conservation properties for different masses of the nucleon, which is done by Ankovski and then also the authors of this paper, would require to re-evaluate ALL measurements with the new current in order to find the correct parameter values, not the ones cited from the literature!
Another solution would be to directly address this point and explain the discrepancy between Ankowski and Giunti. That way it would be more clear to the reader, what message the authors want to give.
Additionally: eq.(7) together with the consequences written in the paragraph after the equation seem to not correctly phrase the chain of references (PhysRevD88 and PhysRevC80) that indicated that the neutron life time in the SM agrees with the experimental measurements.
The last sentence in the conclusions, lines 137 to 140, are written in a very complicated way. Using simpler words (simpler than "induces irresistible problems") and more concrete statements (more concrete than "... is not acceptable, one may conclude that ...") would help to understand better what the authors want to tell us!
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Remark on a typo in line 103: the references are given two times: first without hyperref, then with a hyperref.
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With a "low quality of presentation" I mean, that the message is not fully clear.
Comments on the Quality of English LanguageThe English language uses complicated words and formulations, which sometimes obscure the message of the authors.
Simple English is better for scientific articles, even if it goes against the style liked by people educated in the former Soviet Union. And active language is better than passive.
Author Response
Thank you for your detailed review and for recognizing the importance of the problem we address in our manuscript . We appreciate the opportunity and the chance to revise our work and respond to your concerns.
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Comment: But the method is not clean in the sense that C. Giunti pointed out in arXiv:1602.00215v1 as a response to Artur M. Ankowski in arXiv:1601.06169v1. The authors also cite both papers, but do not comment on the discrepancy...
Answer: We comment on the discrepancy at the end of the introduction. We extend this discussion to clarify our motivation. The criticism of Giunti does not apply to our approach since we don’t use the exact validity of the trivial current conservation relation (5) of Ref.[10]. We indeed take a more conventional current conservation approach, by taking into account the broken isospin symmetry and resulting mass difference of the u and d quarks, respectively proton and neutron.
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Comment: Additionally: eq.(7) together with the consequences written in the paragraph after the equation seem to not correctly phrase the chain of references (PhysRevD88 and PhysRevC80) that indicated that the neutron life time in the SM agrees with the experi- mental measurements.
Answer: The analysis in PRD88 and PRC80 does not include the broken isospin symmetry and resulting mass difference. Equation(7) reflects the theoretical prediction of neutron beta decay in the Standard Model. The agreement with experimental measurements of the neutron lifetime, comes from a precise treatment of radiative corrections and the accurate determination of axial coupling constants. The agree- ment, as shown in these studies depends on the precise determination of the axial coupling constant. As mention in the last paragraph after Eq 7: ”the contribution from the CVC effect and the Fierz interference term can be maintained at the required level of 1.2 × 10−4, provided that the Fierz interference term is set to bF = 0.12189”. ————————————————————————————————————————–
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Comment: The last sentence in the conclusions, lines 137 to 140, are written in a very complicated way. Using simpler words (simpler than ”induces irresistible problems”) and more concrete statements (more concrete than ”... is not acceptable, one may conclude that...”) would help to understand better what the authors want to tell us!
Answer: We have revised the wording to use simpler language and more direct statements.
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5. Comment: Remark on a typo in line 103: the references are given two times: first without hyperref, then with a hyperref.
Answer: We have corrected this duplication to ensure clarity and consistency in the reference formatting.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors examine the validity of the vector current (CV) hypothesis in neutron decay. They computed the neutron lifetime contribution of the phenomenological factor that causes the CVC in the hadronic current of the neutron β- decay (also known as the CVC effect). They demonstrate that the CVC effect contributes 8.684 × 10−2 to the increase in neutron lifetime. As a result, the neutron lifespan is increased by 76.4 s in comparison to the global average of τn = 880.2 (1.0) s. They demonstrate that since there are no interactions in the Standard Model (SM) that can counteract such a significant rise in the neutron lifetime, they must look to interactions outside of the SM. The contribution to the neutron lifetime is reduced to the Fierz interference term (bF) alone. When the CVC effect is eliminated at the experimental accuracy level, bF = 0.1219 (12) is obtained. The CVC effect creates unavoidable issues for the explanation and comprehension of neutron β-decay if this value for the Fierz interference term cannot be accepted.
The Beyond the Standard Model (BSM) hypothesis is supported by this significant research study, which is presented in an organized, comprehensible, and field-relevant manner. The majority of the mentioned works are recent, the text is scientifically good, and the experimental design is suitable for testing the Beyond the Standard Model (BSM) theoretical framework. The results are in line with the arguments and supporting data. The article should be published exactly as it is.
Author Response
We sincerely thank the reviewer for his encouraging comments and for recognizing the clarity, relevance, and scientific quality of our work. We appreciate the recommendation for publication.
