scholarly journals Vacuum Constraints for Realistic Strongly Coupled Heterotic M-Theories

Symmetry ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 723
Author(s):  
Burt Ovrut

The compactification from the 11-dimensional Horava-Witten orbifold to 5-dimensional heterotic M-theory on a Schoen Calabi-Yau threefold is reviewed, as is the specific S U ( 4 ) vector bundle leading to the “heterotic standard model” in the observable sector. A generic formalism for a consistent hidden sector gauge bundle, within the context of strongly coupled heterotic M-theory, is presented. Anomaly cancellation and the associated bulk space 5-branes are discussed in this context. The further compactification to a 4-dimensional effective field theory on a linearized BPS double domain wall is then presented to order κ 11 4 / 3 . Specifically, the generic constraints required for anomaly cancellation and by the linearized domain wall solution, restrictions imposed by the vanishing of the D-terms and, finally, the constraints imposed by the necessity for positive, perturbative squared gauge couplings to this order are presented in detail.

2000 ◽  
Vol 15 (18) ◽  
pp. 1191-1202 ◽  
Author(s):  
G. B. CLEAVER ◽  
D. V. NANOPOULOS ◽  
J. W. WALKER ◽  
A. E. FARAGGI

Recently, by studying exact flat directions of non-Abelian singlet fields, we demonstrated the existence of free fermionic heterotic-string models in which the SU (3)C× SU (2)L×U(1)Y-charged matter spectrum reduces to that of the MSSM in the effective field theory. In this letter we generalize the analysis to include vevs of non-Abelian fields. We find MSSM-producing, exact non-Abelian flat directions, which are the first such examples in the literature. We examine the possibility that hidden sector condensates lift the flat directions.


2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Mason Acevedo ◽  
Albany Blackburn ◽  
Nikita Blinov ◽  
Brian Shuve ◽  
Mavis Stone

Abstract We propose a program at B-factories of inclusive, multi-track displaced vertex searches, which are expected to be low background and give excellent sensitivity to non-minimal hidden sectors. Multi-particle hidden sectors often include long-lived particles (LLPs) which result from approximate symmetries, and we classify the possible decays of GeV-scale LLPs in an effective field theory framework. Considering several LLP production modes, including dark photons and dark Higgs bosons, we study the sensitivity of LLP searches with different number of displaced vertices per event and track requirements per displaced vertex, showing that inclusive searches can have sensitivity to a large range of hidden sector models that are otherwise unconstrained by current or planned searches.


2016 ◽  
Vol 31 (19) ◽  
pp. 1630026
Author(s):  
Thomas Flacke

Composite Higgs models have the potential to provide a solution to the hierarchy problem and a dynamical explanation for the generation of the Higgs potential. They can be tested at the LHC as the new sector which underlies electroweak symmetry breaking must become strong in the TeV regime, which implies additional bound states beyond the Higgs. In this paper, we first discuss prospects and search strategies for top partners (and other quark partners) in the strongly coupled sector, which we study in an effective field theory setup. In the second part of the proceedings, we go beyond the effective field theory approach. We discuss potential UV embeddings for composite Higgs models which contain a Higgs as well as top partners. We show that in all of these models, additional pseudo-Nambu–Goldstone bosons beyond the Higgs are present. In particular, all of the models contain a pseudoscalar which couples to the Standard Model gauge fields through Wess–Zumino–Witten terms, providing a prime candidate for a di-boson (including a di-photon) resonance. The models also contain colored pNGBs which can be searched for at the LHC.


2015 ◽  
Vol 30 (24) ◽  
pp. 1550155
Author(s):  
Yu Nakayama

Gauging extra matter is a common way to couple two CFTs discontinuously. We may consider gauging matter by strongly coupled gauge theories at criticality rather than by weakly coupled (asymptotic free) gauge theories. It often triggers relevant deformations and possibly leads to a nontrivial fixed point. In many examples such as the IR limit of SQCDs (and their variants), the relevant RG flow induced by this strong gauging makes the total central charge [Formula: see text] increase rather than decrease compared with the sum of the original decoupled CFTs. The dilaton effective field theory argument given by Komargodski and Schwimmer does not apply because strong gauging is not a simple deformation by operators in the original two decoupled CFTs and it may not be UV complete. When the added matter is vector-like, one may emulate strong gauging in a UV completed manner by decoupling of ghost matter. While the UV completed description makes the dilaton effective field theory argument possible, due to the nonunitarity, we cannot conclude the positivity of the central charge difference in accordance with the observations in various examples that show the contrary.


Effective field theory (EFT) is a general method for describing quantum systems with multiple-length scales in a tractable fashion. It allows us to perform precise calculations in established models (such as the standard models of particle physics and cosmology), as well as to concisely parametrize possible effects from physics beyond the standard models. EFTs have become key tools in the theoretical analysis of particle physics experiments and cosmological observations, despite being absent from many textbooks. This volume aims to provide a comprehensive introduction to many of the EFTs in use today, and covers topics that include large-scale structure, WIMPs, dark matter, heavy quark effective theory, flavour physics, soft-collinear effective theory, and more.


2008 ◽  
Author(s):  
Ulf-G. Meiβner ◽  
Hideyuki Sakai ◽  
Kimiko Sekiguchi ◽  
Benjamin F. Gibson

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