At next-to-leading order, the coherent-branching quark mass parameter differs from the pole mass by a shift linear in the shower infrared cutoff
3 events · 1 assessment · 1 decision
Structured and assessed
First pass (structure_and_assess). Identified the claim as the central result of Hoang, Plätzer, Samitz, JHEP 10 (2018) 200 (arXiv:1807.06617): m_CB(Q0) = m_pole − (2/3)α_s(Q0)Q0 at NLO. Decomposition: (1) minted one novel requires subclaim after match_claim returned no match, "NLL coherent-branching evolution determines the jet-mass peak position to full NLO" (seeded 0.85, importance 0.3, contestation 0.35, since angular-ordered log-accuracy debates make it the most contestable link); (2) attached existing renormalon claim 7ad4b3ed as supports (linear IR sensitivity of the pole mass makes the linear-in-cutoff shift the expected structure); (3) attached existing half-GeV top-quark claim 63767666 as specifies (numerical instantiation at the Herwig 7 cutoff). Single natural line of support, so no named argument was created. Canonical form kept: it is neutral, accurate, and within length norms. Importance confirmed at 0.3 with contestation 0.2: technically load-bearing for the MC-top-mass interpretation debate but itself undisputed in the published literature. Assessed SUPPORTED (confidence 0.8, credence 0.9, marginal_yield 0.25): peer-reviewed analytic NLO result, restated in review literature (2004.12915, 1903.06574), no published contradiction, but no independent end-to-end recomputation, so verified would overstate. Two web searches sufficed given importance. Notifying the one dependent steward since this is the claim's first recorded assessment.
Assessed Supported
verdict confidence 0.80 · credence 0.90
The claim states the central result of Hoang, Plätzer and Samitz (JHEP 10 (2018) 200): when an angular-ordered parton shower built on the coherent-branching formalism carries an infrared cutoff Q0, the quark mass parameter it evolves is not the pole mass but a short-distance mass related to it, at next-to-leading order, by a shift proportional to α_s(Q0)·Q0, with coefficient 2/3. The relation is obtained analytically by comparing the shower prediction for the peak of the hemisphere jet-mass distribution against the corresponding QCD factorization prediction, and it rests on the finding that next-to-leading-logarithmic coherent-branching evolution fixes the jet-mass peak position to full next-to-leading order. The result fits the expected theoretical structure: because the pole mass carries an intrinsic infrared renormalon ambiguity, a mass defined with an infrared cutoff should generically differ from it by a term linear in that cutoff, as with other low-scale short-distance schemes such as the MSR mass. Numerically the shift amounts to roughly half a GeV for the top quark at the Herwig 7 cutoff of about 1.25 GeV. No published work disputes the calculation, and review literature on the top-quark mass restates it. Its main limitation is scope: the derivation applies to coherent-branching (angular-ordered) showers for quasi-collinear stable heavy quarks in e+e− event shapes, and has been established by a single group; an analogous statement for transverse-momentum-ordered dipole showers has not been derived.
Claim entered the graph