scholarly journals A Model of Bulk Supersymmetry in Warped Spacetime

2016 ◽  
Vol 26 (2) ◽  
pp. 111
Author(s):  
Tran Minh Hieu
Keyword(s):  
Supersymmetry Breaking ◽  
Mass Parameter ◽  
Brane World ◽  
Hierarchy Problem ◽  
Geometrical Properties ◽  
Yukawa Couplings ◽  
Hidden Sector ◽  
The Standard Model ◽  
Soft Supersymmetry Breaking

The Randall-Sundrum solution to the hierarchy problem in the brane-world scenario has made a significant impact on the development of model building.We investigate in this paper a model of supersymmetry in a 5D spacetime with the Randal-Sundrum warped metric.The minimal supersymmetric extension of the standard model (MSSM) superfields propagate in the bulk between the UV and IR branes at separated orbifold fixed points, while the hidden sector in charge of supersymmetry breaking is confined on the UV brane.We derive the 4D effective action from the original 5D action of the underlying theory.The effective 4D Yukawa couplings and all the soft supersymmetry breaking terms are calculated in terms of the 5D theory's coefficients. We comment on the important role of the bulk mass parameter in the relation with the geometrical properties of particles.

scholarly journals Explicit soft supersymmetry breaking in the heterotic M-theory B − L MSSM

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Anthony Ashmore ◽  
Sebastian Dumitru ◽  
Burt A. Ovrut
Keyword(s):  
Line Bundle ◽  
Supersymmetry Breaking ◽  
Moduli Space ◽  
Initial Conditions ◽  
Low Energy ◽  
Strongly Coupled ◽  
Hidden Sector ◽  
Effective Lagrangian ◽  
Soft Supersymmetry Breaking ◽  
M Theory

Abstract The strongly coupled heterotic M-theory vacuum for both the observable and hidden sectors of the B − L MSSM theory is reviewed, including a discussion of the “bundle” constraints that both the observable sector SU(4) vector bundle and the hidden sector bundle induced from a single line bundle must satisfy. Gaugino condensation is then introduced within this context, and the hidden sector bundles that exhibit gaugino condensation are presented. The condensation scale is computed, singling out one line bundle whose associated condensation scale is low enough to be compatible with the energy scales available at the LHC. The corresponding region of Kähler moduli space where all bundle constraints are satisfied is presented. The generic form of the moduli dependent F-terms due to a gaugino superpotential — which spontaneously break N = 1 supersymmetry in this sector — is presented and then given explicitly for the unique line bundle associated with the low condensation scale. The moduli-dependent coefficients for each of the gaugino and scalar field soft supersymmetry breaking terms are computed leading to a low-energy effective Lagrangian for the observable sector matter fields. We then show that at a large number of points in Kähler moduli space that satisfy all “bundle” constraints, these coefficients are initial conditions for the renormalization group equations which, at low energy, lead to completely realistic physics satisfying all phenomenological constraints. Finally, we show that a substantial number of these initial points also satisfy a final constraint arising from the quadratic Higgs-Higgs conjugate soft supersymmetry breaking term.

scholarly journals LEPTONIC CUSTODIAL SYMMETRY, QUANTIZATION OF THE ELECTRIC CHARGE AND THE NEUTRINO IN THE STANDARD MODEL

1996 ◽  
Vol 11 (28) ◽  
pp. 2297-2307
Author(s):  
B. MACHET
Keyword(s):  
Standard Model ◽  
Electric Charge ◽  
Majorana Neutrino ◽  
Hidden Sector ◽  
Majorana Particle ◽  
Leptonic Sector ◽  
The Standard Model ◽  
Custodial Symmetry ◽  
Vectorial Model

I study, in the leptonic sector, the role of the SU (2)v custodial symmetry [Formula: see text] which was shown in Ref. 1 to control the quantization of the electric charge in the J=0 mesonic sector. The electroweak theory is considered, according to Ref. 2, as a purely vectorial model which interacts with a “hidden” sector of composite scalars. [Formula: see text] can only be a symmetry of the former if the neutrino is a Majorana particle; the latter provides a dynamical modification of the leptonic weak couplings, reconstructing those of the standard model with a massless Majorana neutrino.

scholarly journals Flipped $$\mathbf {g_\mu - 2}$$

2021 ◽  
Vol 81 (12) ◽  
Author(s):  
John Ellis ◽  
Jason L. Evans ◽  
Natsumi Nagata ◽  
Dimitri V. Nanopoulos ◽  
Keith A. Olive
Keyword(s):  
Standard Model ◽  
Supersymmetry Breaking ◽  
Model Calculation ◽  
Experimental Measurement ◽  
The Other ◽  
Gaugino Mass ◽  
The Standard Model ◽  
Soft Supersymmetry Breaking ◽  
The Right

AbstractWe analyze the possible magnitude of the supersymmetric contribution to $$g_\mu - 2$$ g μ - 2 in a flipped SU(5) GUT model. Unlike other GUT models which are severely constrained by universality relations, in flipped SU(5) the U(1) gaugino mass and the soft supersymmetry-breaking masses of right-handed sleptons are unrelated to the other gaugino, slepton and squark masses. Consequently, the lightest neutralino and the right-handed smuon may be light enough to mitigate the discrepancy between the experimental measurement of $$g_\mu - 2$$ g μ - 2 and the Standard Model calculation, in which case they may be detectable at the LHC and/or a 250 GeV $$e^+ e^-$$ e + e - collider, whereas the other gauginos and sfermions are heavy enough to escape detection at the LHC.

scholarly journals Possible Approach to Dynamical Supersymmetry Breaking via Nambu-Jona-Lasinio Model

2018 ◽  
Vol 182 ◽  
pp. 03002
Author(s):  
Yifan Cheng
Keyword(s):  
Standard Model ◽  
Supersymmetry Breaking ◽  
Type Model ◽  
Beyond The Standard Model ◽  
Nontrivial Solutions ◽  
Vacuum Condensate ◽  
Njl Model ◽  
The Standard Model ◽  
Interaction Term ◽  
Soft Supersymmetry Breaking

Supersymmetry is undoubtedly a popular candidate for physics beyond the Standard Model. However, the origin of soft supersymmetry breaking masses has been usually depicted intricately in the literature via extra hidden/mediating sectors. Thus, a simple theory for the generation of the soft masses would be more compelling. Here we discuss a possible approach to dynamical supersymmetry breaking via Nambu-Jona- Lasinio (NJL) Model, which has been missed since the first investigation of supersymmetric NJL model. We introduce a four-superfield interaction term that induces a real two-superfield composite with vacuum condensate. The latter has supersymmetry breaking parts, which we show to bear nontrivial solutions following a standard nonperturbative analysis for a NJL type model. The presence of the expected Goldstino state along with the supersymmetry breaking, is also verified. Moreover, the model gives rise to a composite spin one field, as its important characteristic.

EXPERIMENTAL SIGNATURES OF STRINGS AND BRANES

2006 ◽  
Vol 21 (08n09) ◽  
pp. 1657-1669 ◽  
Author(s):  
IGNATIOS ANTONIADIS
Keyword(s):  
Gauge Coupling ◽  
Brane World ◽  
Type I ◽  
Mass Hierarchy ◽  
Beyond The Standard Model ◽  
Hierarchy Problem ◽  
The Standard Model ◽  
Concrete Realization ◽  
Strings And Branes ◽  
Split Supersymmetry

Type I string theory provides a D-brane world description of our universe and leads to two new scenaria for physics beyond the Standard Model: low string scale and split supersymmetry. Lowering the string scale in the TeV region provides a theoretical framework for solving the mass hierarchy problem and unifying all interactions. The apparent weakness of gravity can then be accounted by the existence of large internal dimensions, in the submillimeter region, and transverse to a braneworld where we must be confined. I review the main properties of this scenario and its implications for observations at both particle colliders, and in non-accelerator gravity experiments. I also present a concrete realization of split supersymmetry which guarantees gauge coupling unification at the conventional scale M GUT ≃ 2 × 1016 GeV .

scholarly journals Flipped SU(5) GUT phenomenology: proton decay and $$\mathbf {g_\mu - 2}$$

2021 ◽  
Vol 81 (12) ◽  
Author(s):  
John Ellis ◽  
Jason L. Evans ◽  
Natsumi Nagata ◽  
Dimitri V. Nanopoulos ◽  
Keith A. Olive
Keyword(s):  
Supersymmetry Breaking ◽  
Proton Decay ◽  
Data Driven ◽  
Substantial Contribution ◽  
Foreseeable Future ◽  
High Scale ◽  
The Standard Model ◽  
Proton Lifetime ◽  
Soft Supersymmetry Breaking ◽  
Under Construction

AbstractWe consider proton decay and $$g_\mu - 2$$ g μ - 2 in flipped SU(5) GUT models. We first study scenarios in which the soft supersymmetry-breaking parameters are constrained to be universal at some high scale $$M_{in}$$ M in above the standard GUT scale where the QCD and electroweak SU(2) couplings unify. In this case the proton lifetime is typically $$ > rsim 10^{36}$$ ≳ 10 36  years, too long to be detected in the foreseeable future, and the supersymmetric contribution to $$g_\mu - 2$$ g μ - 2 is too small to contribute significantly to resolving the discrepancy between the experimental measurement and data-driven calculations within the Standard Model. However, we identify a region of the constrained flipped SU(5) parameter space with large couplings between the 10- and 5-dimensional GUT Higgs representations where $$p \rightarrow e^+ \pi ^0$$ p → e + π 0 decay may be detectable in the Hyper-Kamiokande experiment now under construction, though the contribution to $$g_\mu -2$$ g μ - 2 is still small. A substantial contribution to $$g_\mu - 2$$ g μ - 2 is possible, however, if the universality constraints on the soft supersymmetry-breaking masses are relaxed. We find a ‘quadrifecta’ region where observable proton decay co-exists with a (partial) supersymmetric resolution of the $$g_\mu - 2$$ g μ - 2 discrepancy and acceptable values of $$m_h$$ m h and the relic LSP density.

Perspective on the weakly coupled heterotic string

2015 ◽  
Vol 30 (08) ◽  
pp. 1530005 ◽  
Author(s):  
Mary K. Gaillard
Keyword(s):  
String Theory ◽  
Standard Model ◽  
Supersymmetry Breaking ◽  
Heterotic String ◽  
Particle Spectrum ◽  
Promising Candidate ◽  
Heterotic String Theory ◽  
Hidden Sector ◽  
Weakly Coupled ◽  
The Standard Model

Since the first "string revolution" of 1984, the weakly coupled E8⊗E8 heterotic string theory has been a promising candidate for the underlying theory of the Standard Model. The particle spectrum and the issue of dilaton stabilization are reviewed. Specific models for hidden sector condensation and supersymmetry breaking are described and their phenomenological and cosmological implications are discussed. The importance of T-duality is emphasized. Theoretical challenges to finding a satisfactory vacuum, as well as constraints from LHC data are addressed.

scholarly journals Gravitational rescue of minimal gauge mediation

2016 ◽  
Vol 31 (10) ◽  
pp. 1650045 ◽  
Author(s):  
Abhishek M. Iyer ◽  
V. Suryanarayana Mummidi ◽  
Sudhir K. Vempati
Keyword(s):  
Supersymmetry Breaking ◽  
Higgs Mass ◽  
Vacuum Expectation ◽  
Gauge Mediation ◽  
Expectation Values ◽  
Hidden Sector ◽  
Mixing Parameter ◽  
Renormalization Group Equations ◽  
Soft Supersymmetry Breaking ◽  
Gravitational Contribution

Gravity mediated supersymmetry breaking becomes comparable to gauge mediated supersymmetry breaking contributions when messenger masses are close to the GUT scale. By suitably arranging the gravity contributions, one can modify the soft supersymmetry breaking sector to generate a large stop mixing parameter and a light Higgs mass of 125 GeV. In this kind of hybrid models, however, the nice features of gauge mediation like flavor conservation, etc. are lost. To preserve the nice features, gravitational contributions should become important for lighter messenger masses and should be important only for certain fields. This is possible when the hidden sector contains multiple (at least two) spurions with hierarchical vacuum expectation values. In this case, the gravitational contributions can be organized to be “just right.” We present a complete model with two spurion hidden sector where the gravitational contribution is from a warped flavor model in a Randall–Sundrum setting. Along the way, we present simple expressions to handle renormalization group equations when supersymmetry is broken by two different sectors at two different scales.

scholarly journals Left–left squark mixing, $K^+\rightarrow \pi^+\nu\bar{\nu}$ and minimal supersymmetry with largetanβ

2014 ◽  
Vol 29 (27) ◽  
pp. 1450162 ◽  
Author(s):  
Tomáš Blažek ◽  
Peter Maták
Keyword(s):  
Higgs Boson ◽  
Decay Rate ◽  
Supersymmetry Breaking ◽  
Mass Matrix ◽  
Boson Mass ◽  
Higgs Boson Mass ◽  
Squark Mass ◽  
Flavor Changing ◽  
Soft Supersymmetry Breaking

We analyze the role of the left–left squark mixing in the rare [Formula: see text] decay within the minimal supersymmetry with a large tan β. A Higgs boson mass of 125 GeV has been taken into account leading to correlation between stop masses and trilinear soft supersymmetry breaking coupling [Formula: see text]. We find that measurable effects, similar to that of the well known LR squark mixing terms, are possible for large [Formula: see text] combined with the off-diagonal LL-insertions. Precise measurements of the decay rate are expected from the ongoing NA62 experiment at CERN. We emphasize that the effect we present can put certain limits on the left–left flavor changing structure of the squark mass matrix.

scholarly journals PREDICTED SIGNATURES AT THE LHC FROM U(1) EXTENSIONS OF THE STANDARD MODEL

2010 ◽  
Vol 25 (36) ◽  
pp. 3003-3016 ◽  
Author(s):  
PRAN NATH
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Vector Boson ◽  
Hadron Collider ◽  
Mass Growth ◽  
Hidden Sector ◽  
Quantum Numbers ◽  
The Standard Model ◽  
Vector Bosons

We discuss the U (1)X extensions of the standard model with focus on the Stueckelberg mechanism for mass growth for the extra U (1)X gauge boson. The assumption of an axionic connector field which carries dual U(1) quantum numbers, i.e. quantum numbers for the hypercharge U(1) Y and for the hidden sector gauge group U (1)X, allows a nontrivial mixing between the mass growth for the neutral gauge vector bosons in the SU(2) L × U (1)Y sector and the mass growth for the vector boson by the Stueckelberg mechanism in the U (1)X sector. This results in an extra Z′ which can be very narrow, but still detectable at the Large Hadron Collider (LHC). The U (1)X extension of the minimal supersymmetric standard model is also considered and the role of the Fayet–Illiopoulos term in such an extension discussed. The U (1)X extensions of the SM and of the MSSM lead to new candidates for dark matter.

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