Bottom-up approach to moduli dynamics in heavy gravitino scenario: Superpotential, soft terms, and sparticle mass spectrum

Abstract

The physics of moduli fields is examined in the scenario where the gravitino is relatively heavy with mass of order 10 TeV, which is favored in view of the severe gravitino problem. The form of the moduli superpotential is shown to be determined, if one imposes a phenomenological requirement that no physical CP phase arise in gaugino masses from conformal anomaly mediation. This bottom-up approach allows only two types of superpotential, each of which can have its origins in a fundamental underlying theory such as superstring. One superpotential is the sum of an exponential and a constant, which is identical to that obtained by Kachru et al. (KKLT), and the other is the racetrack superpotential with two exponentials. The general form of soft supersymmetry breaking masses is derived, and the pattern of the superparticle mass spectrum in the minimal supersymmetric standard model is discussed with the KKLT-type superpotential. It is shown that the moduli mediation and the anomaly mediation make comparable contributions to the soft masses. At the weak scale, the gaugino masses are rather degenerate compared to the minimal supergravity, which bring characteristic features on the superparticle masses. In particular, the lightest neutralino, which often constitutes the lightest superparticle and thus a dark matter candidate, is a considerable admixture of gauginos and higgsinos. We also find a small mass hierarchy among the moduli, gravitino, and superpartners of the standardmodel fields. Cosmological implications of the scenario are briefly described.

String theoretic QCD axion with stabilized saxion and the pattern of supersymmetry breaking

“…As a result, the soft SUSY breaking terms of visible fields receive comparable contributions from moduli mediation and anomaly mediation [16], leading to the mirage mediation pattern of superparticle masses discussed in [20,21,22,23]. We also find the modulino and axino masses are given by…”

“…Quite interestingly, although some details of moduli stabilization are different from the original KKLT scenario, the resulting soft SUSY breaking terms still receive comparable contributions from moduli mediation (including the saxion mediation) [18] and anomaly mediation [19], thereby take the mirage mediation pattern [16,20,21,22,23,24] as in the KKLT case * . Furthermore, the soft terms naturally preserve flavor and CP as a consequence of approximate scaling and axionic-shift symmetries of the underlying string compactification, independently of the detailed forms of moduli Kähler potential and matter Kähler metric.…”

Moduli stabilisation and applications in IIB string theory

“…This small hierarchy was first identified in single-modulus KKLT models [92] (with a twomodulus example also studied in [116]). For the KKLT case this suppression of M a leads to mixed modulus-anomaly mediation and the phenomenology of this scenario has been analysed in [117,118,119,120,121,122,123,124,125,126,127]. 3 Here we show this relation to be a truly generic feature of the landscape, by showing it to hold for arbitrary multi-modulus models and to be independent of the precise details of the scenario used to stabilise the moduli.…”

“…TeV-scale soft terms require hierarchically small W 0 . For the (gravity-mediated) case studied in [117,118,119], this required W 0 ∼ 10 −13 , with…”

Moduli-induced baryogenesis

“…Let us continue to examine how the SUSY breaking is mediated to the visible sector. The soft SUSY breaking terms receive contributions from both modulus mediation and anomaly mediation [44][45][46][47], 8) where φ i denotes the scalar component of the visible sector chiral superfield Φ i , λ a is the gaugino, and y ijk is the Yukawa coupling for the superpotential term Φ i Φ j Φ k . Here i, j, k are the indices of matter fields, and a = 1, 2, 3 corresponds to the U(1) Y , SU(2) L , SU(3) C gauge group, respectively.…”