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Thermal modification of K1(1270)→π+π−K+ in a hot hadronic medium

Seung-il Nam*

  • *Contact author: sinam@pknu.ac.kr
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Phys. Rev. C 114, 014918 – Published 28 July, 2026

DOI: https://doi.org/10.1103/jsq7-hxsj

Abstract

The thermal modification of the exclusive decay K1+(1270)→π+π−K+ in a hot hadronic medium is studied. The decay amplitude is constructed from effective hadronic interactions dominated by the ρ- and K*-pole contributions, thereby enabling a Dalitz-level analysis of the three-body decay in the medium. Thermal effects associated with partial chiral-symmetry restoration are incorporated through a phenomenological interpolation toward vector–axial-vector degeneracy near the chiral crossover. As the temperature increases, the reduction of the parent K1 mass strongly compresses the available three-body phase space, leading to substantial deformation of the Dalitz distribution and invariant-mass spectra, as well as to a pronounced suppression of ΓK1→π+π−K+(T). As a further step toward future transport-based phenomenological comparisons, Normalized shape observables are introduced to quantify the thermal evolution of the K*-dominated πK region, the upper-edge weight of the ππ spectrum, and the compactification of the Dalitz population. The dominant effect identified in the present framework is therefore kinematic: thermal phase-space reduction in the strange axial-vector channel. These results suggest that the exclusive K1(1270) channel may provide a useful qualitative probe of in-medium strange axial-vector dynamics near the pseudocritical region.

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Phys. Rev. C 114, 014918– Published 28 July, 2026
  • Received 30 March 2026
  • Revised 8 June 2026
  • Accepted 26 June 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.

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