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Title: A Bottom-Up Approach to Moduli Dynamics in Heavy Gravitino Scenario

Abstract

Moduli dynamics is discussed in the scenario where gravitino is relatively heavy with mass of the order of 10 TeV, which is favored to relax the gravitino problem. Imposing a phenomenological requirement that CP phases in the gaugino masses do not arise from the conformal anomaly mediation, we find that the form of the superpotential for the modulus field is determined. Interestingly one solution is the sum of an exponential and a constant, which is identical to the one recently obtained by Kachru et al (KKLT). Supersymmetry breaking is discussed with this superpotential. In particular, it is shown that the soft supersymmetry breaking masses are admixture of the modulus mediation and the conformal anomaly mediation of supersymmetry breaking. The resulting mass spectrum is very characteristic. It is rather compact compared to the minimal supergravity or to the pure anomaly mediation, which is testable at future collider experiments. The higgsino mass parameter is expected to be small, and hence the lightest of the neutralinos, which is a candidate for dark matter of the universe, is an admixture of the gauinos and higgsinos. This has some impacts on dark matter searches. This talk is based on the work with Motoi Endo andmore » Koichi Yoshioka.« less

Authors:
 [1]
  1. Department of Physics, Tohoku University, Sendai 980-8578 (Japan)
Publication Date:
OSTI Identifier:
20729212
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 805; Journal Issue: 1; Conference: PASCOS 2005: 11. international symposium on particles, strings, and cosmology, Gyeongju (Korea, Republic of), 30 May - 4 Jun 2005; Other Information: DOI: 10.1063/1.2149674; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; MASS SPECTRA; MATHEMATICAL SOLUTIONS; NONLUMINOUS MATTER; POTENTIALS; REST MASS; SPARTICLES; SUPERGRAVITY; SYMMETRY BREAKING; TEV RANGE; UNIVERSE

Citation Formats

Yamaguchi, Masahiro. A Bottom-Up Approach to Moduli Dynamics in Heavy Gravitino Scenario. United States: N. p., 2005. Web. doi:10.1063/1.2149674.
Yamaguchi, Masahiro. A Bottom-Up Approach to Moduli Dynamics in Heavy Gravitino Scenario. United States. doi:10.1063/1.2149674.
Yamaguchi, Masahiro. Fri . "A Bottom-Up Approach to Moduli Dynamics in Heavy Gravitino Scenario". United States. doi:10.1063/1.2149674.
@article{osti_20729212,
title = {A Bottom-Up Approach to Moduli Dynamics in Heavy Gravitino Scenario},
author = {Yamaguchi, Masahiro},
abstractNote = {Moduli dynamics is discussed in the scenario where gravitino is relatively heavy with mass of the order of 10 TeV, which is favored to relax the gravitino problem. Imposing a phenomenological requirement that CP phases in the gaugino masses do not arise from the conformal anomaly mediation, we find that the form of the superpotential for the modulus field is determined. Interestingly one solution is the sum of an exponential and a constant, which is identical to the one recently obtained by Kachru et al (KKLT). Supersymmetry breaking is discussed with this superpotential. In particular, it is shown that the soft supersymmetry breaking masses are admixture of the modulus mediation and the conformal anomaly mediation of supersymmetry breaking. The resulting mass spectrum is very characteristic. It is rather compact compared to the minimal supergravity or to the pure anomaly mediation, which is testable at future collider experiments. The higgsino mass parameter is expected to be small, and hence the lightest of the neutralinos, which is a candidate for dark matter of the universe, is an admixture of the gauinos and higgsinos. This has some impacts on dark matter searches. This talk is based on the work with Motoi Endo and Koichi Yoshioka.},
doi = {10.1063/1.2149674},
journal = {AIP Conference Proceedings},
number = 1,
volume = 805,
place = {United States},
year = {Fri Dec 02 00:00:00 EST 2005},
month = {Fri Dec 02 00:00:00 EST 2005}
}
  • 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 identicalmore » 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 standard-model fields. Cosmological implications of the scenario are briefly described.« less
  • We present a thermal inflation model that incorporates the Affleck-Dine leptogenesis in heavy gravitino/moduli scenario, which solves the moduli-induced gravitino problem while producing a correct amount of baryon asymmetry and relic dark matter density. The model involves two singlet flat directions stabilized by radiative corrections associated with supersymmetry breaking, one direction that generates the Higgs μ and B parameters, and the other direction that generates the scale of spontaneous lepton number violation. The dark matter is provided by the lightest flatino which might be identified as the axino if the model is assumed to have a U(1){sub PQ} symmetry tomore » solve the strong CP problem. We derive the conditions for the model to satisfy various cosmological constraints coming from the Big-Bang nucleosynthesis and the dark matter abundance.« less
  • In some models of supersymmetry breaking, modulus fields are heavy enough to decay before big bang nucleosynthesis. But the large entropy produced via moduli decay significantly dilutes the preexisting baryon asymmetry of the Universe. We study whether the Affleck-Dine mechanism can provide enough baryon asymmetry which survives the dilution, and find several situations in which a desirable amount of baryon number remains after the dilution. The possibility of nonthermal dark matter is also discussed. This provides the realistic cosmological scenario with heavy moduli.
  • In gravity mediated models and in particular in models with strongly stabilized moduli, there is a natural hierarchy between gaugino masses, the gravitino mass and moduli masses: m{sub 1/2} << m{sub 3/2} << m{sub φ}. Given this hierarchy, we show that 1) moduli problems associated with excess entropy production from moduli decay and 2) problems associated with moduli/gravitino decays to neutralinos are non-existent. Placed in an inflationary context, we show that the amplitude of moduli oscillations are severely limited by strong stabilization. Moduli oscillations may then never come to dominate the energy density of the Universe. As a consequence, modulimore » decay to gravitinos and their subsequent decay to neutralinos need not overpopulate the cold dark matter density.« less
  • We investigate the cosmological moduli problem by studying a modulus decay in detail and find that the branching ratio of the gravitino production is generically of O(0.01-1), which causes another cosmological disaster. Consequently, the cosmological moduli problem cannot be solved simply by making the modulus mass heavier than 100 TeV. We also illustrate our results by explicitly calculating the branching ratio into the gravitinos in the mixed modulus-anomaly model.