Two-loop scale-invariant scalar potential and quantum effective operators
Two-loop scale-invariant scalar potential and quantum effective operators
复制标题
二环尺度不变标量势和量子有效算子
DOI:
--
复制
发表时间:
2016
期刊:
影响因子:
--
通讯作者:
P. Olszewski
中科院分区:
文献类型:
--
作者:
D. Ghilencea;Z. Lalak;P. Olszewski
Spontaneous breaking of quantum scale invariance may provide a solution to the hierarchy and cosmological constant problems. In a scale-invariant regularization, we compute the two-loop potential of a Higgs-like scalar $$phi $$ϕ in theories in which scale symmetry is broken only spontaneously by the dilaton ($$sigma $$σ). Its VEV $$langle sigma
angle $$⟨σ⟩ generates the DR subtraction scale ($$mu sim langle sigma
angle $$μ∼⟨σ⟩), which avoids the explicit scale symmetry breaking by traditional regularizations (where $$mu $$μ$$=$$= fixed scale). The two-loop potential contains effective operators of non-polynomial nature as well as new corrections, beyond those obtained with explicit breaking ($$mu $$μ$$=$$= fixed scale). These operators have the form $$phi ^6/sigma ^2$$ϕ6/σ2, $$phi ^8/sigma ^4$$ϕ8/σ4, etc., which generate an infinite series of higher dimensional polynomial operators upon expansion about $$langle sigma
angle gg langle phi
angle $$⟨σ⟩≫⟨ϕ⟩, where such hierarchy is arranged by one initial, classical tuning. These operators emerge at the quantum level from evanescent interactions ($$propto epsilon $$∝ϵ) between $$sigma $$σ and $$phi $$ϕ that vanish in $$d=4$$d=4 but are required by classical scale invariance in $$d=4-2epsilon $$d=4-2ϵ. The Callan–Symanzik equation of the two-loop potential is respected and the two-loop beta functions of the couplings differ from those of the same theory regularized with $$mu =$$μ= fixed scale. Therefore the running of the couplings enables one to distinguish between spontaneous and explicit scale symmetry breaking.