BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//CERN//INDICO//EN
BEGIN:VEVENT
SUMMARY:Majoron Potential by Majorana fermion Loops
DTSTART;VALUE=DATE-TIME:20260812T032000Z
DTEND;VALUE=DATE-TIME:20260812T034000Z
DTSTAMP;VALUE=DATE-TIME:20260824T154759Z
UID:indico-contribution-2704@indico.itp.ac.cn
DESCRIPTION:Speakers: Mussawir Khan (State Key Laboratory of Particle Astr
 ophysics\, Institute of High Energy Physics\, Chinese Academy of Sciences\
 , Beijing 100049\, China)\nWe present a diagrammatic framework for radiati
 ve Majoron potentials induced by an explicit Majorana mass $M$. Classifyin
 g one-loop diagrams by the number of fermion-number-violating ($N_{\\rm FN
 V}$) and fermion-number-preserving ($N_{\\rm FNP}$) propagators yields a h
 eavy-mass scaling rule: pure FNV amplitudes behave as $M^{4-n}$\, while mi
 xed diagrams receive additional suppression from momentum numerators. Afte
 r removing the dominant tadpole by a matching condition\, the bubble diagr
 am provides the leading Majoron mass $\\propto y^2M^2$. The mixed FNV/FNP 
 triangle supplies the complete next-to-leading $\\mathcal{O}(yv/M)$ correc
 tion through a $\\cos\\theta$ harmonic after vacuum alignment. We analyze 
 the one-loop Coleman-Weinberg potential for the full two-field space $V_{\
 \rm eff}(r\, \\theta)$\, derive the quantum-shifted vacuum and scalar Hess
 ian\, and identify the parameter conditions required for local stability. 
 The heavy Majorana fermion decouples from irrelevant operators but leaves 
 non-decoupling threshold corrections to relevant symmetry-breaking operato
 rs. At finite temperature\, the explicit breaking spurion $M$ induces a th
 ermal tadpole $\\propto M T^2 r \\cos\\theta$. This term prevents the orig
 in from ever being a stationary point\, ensuring that the radial vacuum ex
 pectation value remains non-zero at all temperatures. Consequently\, the s
 ystem undergoes a smooth crossover rather than a true symmetry-restoring p
 hase transition\, and the pseudo-Goldstone description remains rigorously 
 valid across all temperature regimes. The resulting effective potential is
  a periodic non-linear sigma model whose Wilson coefficients follow a two-
 parameter lattice classification.\n\nhttps://indico.itp.ac.cn/event/416/co
 ntributions/2704/
LOCATION:Conference Center (2F) Back Area
URL:https://indico.itp.ac.cn/event/416/contributions/2704/
END:VEVENT
END:VCALENDAR