arXiv subjects

Adeel Mansha

Publications and source records attributed to Adeel Mansha.

13 recordsLinked to original sources

arXiv2025

Three-Family Supersymmetric Pati-Salam Flux Models from Rigid D-Branes

Intersecting D-brane model building often suffer from the unstabilized open-string moduli, leading to the unwanted massless adjoint scalars. In our previous work arXiv:2505.03664, this issue was resolved by employing the rigid D6-branes on the $\mathbb{T}^6/(\mathbb{Z}_2 \times \mathbb{Z}_2^\prime)$ orientifold with discrete torsion, where fractional cycles eliminate all adjoint scalars. In this paper, we construct new three-family flux models in the Type IIB setup on $\mathbb{T}^6/(\mathbb{Z}_2 \times \mathbb{Z}_2)$, T-dual to the Type IIA rigid D6-brane construction with discrete torsion, by introducing the quantized background $G_3$ flux that stabilizes the closed-string complex structure moduli and axio-dilaton. The resulting Pati-Salam gauge symmetry can be spontaneously broken down to the Standard Model via a supersymmetry-preserving Higgs mechanism. All the consistency conditions, including $\mathcal{N}=1$ supersymmetry, RR tadpole cancellation, and K-theory constraints, are satisfied. We present the complete particle spectra for these models and discuss how exotic states dynamically decouple through strong dynamics in the hidden sector.

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arXiv2025

Three-family supersymmetric Pati-Salam models from intersecting D6-branes on rigid cycles

Intersecting D6-brane models without discrete torsion typically suffer from unstabilized open string moduli, arising from D-brane positions and Wilson lines. These moduli generate additional massless adjoint fields, obstructing the realization of negative beta functions necessary for asymptotic freedom unless they are decoupled around string scale. A viable solution involves utilizing rigid cycles, which eliminate these unwanted adjoint fields. In this work, we for the first time present a class of consistent three-family supersymmetric Pati-Salam models from rigid intersecting D6-branes on the factorizable $\mathbb{T}^6/(\mathbb{Z}_2 \times \mathbb{Z}_2^\prime)$ orientifold with discrete torsion. These models satisfy all the known consistency conditions, including $\mathcal{N}=1$ supersymmetry, K-theory constraints, tadpole cancellation, and recent swampland bounds on the maximal gauge group rank. We provide detailed particle spectra, analyze their phenomenological implications, and discuss the decoupling of exotic states through strong dynamics in the hidden sector.

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arXiv2025

Three family supersymmetric Pati-Salam model from rigid intersecting D6-branes

We construct, for the first time, a three-family $\mathcal{N}=1$ supersymmetric Pati-Salam model from rigid intersecting D6-branes on a factorizable $\mathbb{T}^6/(\mathbb{Z}_2\times \mathbb{Z}_2')$ orientifold with discrete torsion. The factorizable geometry allows for explicit control over rigid cycles and moduli stabilization. We can break the Pati-Salam gauge symmetry down to the Standard Model (SM) gauge symmetry via the supersymmetry preserving Higgs mechanism, generate the SM fermion masses and mixings, and break the supersymmetry via gaugino condensations in the hidden sector.

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arXiv2024

Susy breaking soft terms in the supersymmetric Pati-Salam landscape from Intersecting D6-Branes

We investigate the supersymmetry breaking soft terms for all the viable models in the complete landscape of three-family supersymmetric Pati-Salam models arising from intersecting D6-branes on a $\mathbb{T}^6/(\mathbb{Z}_2\times \mathbb{Z}_2)$ orientifold in type IIA string theory. The calculations are performed in the general scenario of $u$-moduli dominance with the $s$-moduli turned on, where the soft terms remain independent of the Yukawa couplings and the Wilson lines. The results for the trilinear coupling, gaugino-masses, squared-mass parameters of squarks, sleptons and Higgs depend on the brane wrapping numbers and the susy breaking parameters. We find that unlike the Yukawa couplings which remain unchanged for the models dual under the exchange of two SU(2) sectors, the corresponding soft term parameters only match for the trilinear coupling and the mass of the gluino. This can be explained by the internal geometry where the Yukawa interactions depend only on the triangular areas of the worldsheet instantons while the soft terms have an additional dependence on the orientation-angles of D6-branes in the three two-tori. In the special limit of parameter space we find universal masses for the Higgs and the gauginos.

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arXiv2024

Fermion masses and mixings in the supersymmetric Pati-Salam landscape from Intersecting D6-Branes

Recently, the complete landscape of three-family supersymmetric Pati-Salam models from intersecting D6-branes on a type IIA $\mathbb{T}^6/(\mathbb{Z}_2\times \mathbb{Z}_2)$ orientifold has been enumerated consisting of 33 independent models with distinct gauge coupling relations at the string scale. Here, we study the phenomenology of all such models by providing the detailed particle spectra and the analysis of the possible 3-point and the 4-point Yukawa interactions in order to accommodate all standard-model fermion masses and mixings. We find that only 17 models contain viable Yukawa textures to explain quarks masses, charged-leptons' masses, neutrino-masses, quarks' mixings and leptons' mixings. These viable models split into four classes, viz. a single model with 3 Higgs fields from the bulk and sixteen models with either 6, 9 or 12 Higgs from the $\mathcal{N}=2$ sector. The models perform successively better with the increasing number of Higgs pairs. Remarkably, the class of models with 12 Higgs naturally predicts the Dirac-type neutrino masses in normal ordering consistent with both the experimental constraints as well as the bounds from the swampland program.

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arXiv2024

Fermion Masses and Mixings in String Theory with Dirac Neutrinos

Analyzing the supersymmetric Pati-Salam landscape on a $\mathbb{T}^6/(\mathbb{Z}_2\times \mathbb{Z}_2)$ orientifold in IIA string theory, we have found only two models that accurately account for all standard model fermion masses and mixings. The models are dual to each other under the exchange of two SU(2) sectors and feature 12 adjoint scalars, the maximum number allowed in the landscape, whose linear combination yields the two light Higgs eigenstates. Dirac neutrino-masses in normal ordering $(50.6,~10.6,~6.2)\pm 0.1$~meV satisfying both the experimental as well as swampland constraints.

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arXiv2024

Revisiting the $\mathcal{N}=1$ supersymmetric trinification models from intersecting D6-branes

We revisit the construction of the $\mathcal{N}=1$ supersymmetric trinification models with gauge group $\mathrm{U}(3)_C\times \mathrm{U}(3)_L \times \mathrm{U}(3)_R$ in Type IIA string theory on $\mathbf{T^6/(\mathbb{Z}_2\times \mathbb{Z}_2)}$ orientifold with intersecting D6-branes. The non-trivial K-theory conditions and tadpole cancellation conditions severely restrict the number of allowed models even for the case of rectangular two-tori. Using a supervised search algorithm, we find a few four-family models where the highest wrapping number is 2. For these models, we present the complete particle spectra and the gauge coupling relations at the string-scale.

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arXiv2024

Three-family supersymmetric Pati-Salam models with symplectic groups from intersecting D6-branes

We construct new three-family ${\cal N}=1$ supersymmetric Pati-Salam models from intersecting D6-branes with original gauge group ${\rm U}(4)_C \times {\rm USp}(2)_L \times {\rm U}(2)_R$ on a Type IIA $\mathbb{T}^6/(\mathbb{Z}_2\times \mathbb{Z}_2)$ orientifold. We find that replacing a ${\rm U}(2)$ with a ${\rm USp}(2)$ group severely restricts the number of three-generation supersymmetric models such that there are only five inequivalent models. Exchanging the left and right sectors, we obtain five dual models with gauge group ${\rm U}(4)_C \times {\rm U}(2)_L \times {\rm USp}(2)_R$. These ten models have different gauge coupling relations at string scale. The highest wrapping number is 4, and one of the models contains no filler O6-planes. Moreover, we discuss in detail the particle spectra, the composite particles through strong coupling dynamics, and the exotic particle decouplings. Also, we study how to realize the string-scale gauge coupling relations in some models.

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arXiv2023

The hidden sector variations in the ${\cal N}=1$ supersymmetric three-family Pati-Salam models from intersecting D6-branes

It is well-known that three-family supersymmetric Pati-Salam models from intersecting D6-branes, where either one or both of the ${\rm U}(2)$ gauge factors are replaced by a ${\rm USp}(2)$ group, are quite scarce. In order to construct all such kind of models with generic additional gauge symmetries, we fix the observable sectors and study all the possible hidden sectors. Thus, we are able to completely determine all types of such kind of the inequivalent models on a $\mathbb{T}^6/(\mathbb{Z}_2\times \mathbb{Z}_2)$ orientifold from IIA string theory. We find the gauge coupling relations to be highly sensitive to the variations in the hidden sector. One of the models exhibits the gauge coupling unification for a particular solution at the string scale. In addition, we perform scan on the hidden sector variations for the models presented in arXiv:2112.09632, whose gauge coupling relations are still preserved. Thus, we fix the gap in the previous study and complete the model building for all the inequivalent models.

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arXiv2022

The Supersymmetry Breaking Soft Terms, and Fermion Masses and Mixings in the Supersymmetric Pati-Salam Model from Intersecting D6-branes

A supersymmetric Pati-Salam model with wrapping number equal to 5 has been constructed in Type IIA orientifolds on $\mathbf{T}^6/(\mathbb{Z}_2\times \mathbb{Z}_2)$ with intersecting D6-branes recently. In particular, the string-scale gauge coupling unification can be achieved due to the intermediate-scale vector-like particles from $\mathcal{N}=2$ sector. We calculate the supersymmetry breaking soft terms, and study the Standard Model (SM) fermion masses and mixings. There are nine pairs of Higgs doublets from $\mathcal{N}=2$ sector. Interestingly, we can explain the SM quark masses and mixings, as well as the charged leptons masses from three point and four-point Yukawa interactions. Moreover, we calculate the supersymmetry breaking soft terms in a previous model with gauge coupling unification since we find a typo in the previous study.

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arXiv2020

Revisiting the Supersymmetric Pati-Salam Models from Intersecting D6-branes

Employing new scanning methods, we revisit the systematic construction of three-family $N=1$ supersymmetric Pati-Salam models in Type IIA orientifolds on ${\bf T}^6/(\mathbb Z_2\times \mathbb Z_2)$ with intersecting D6-branes. Arising from the stacks of D6-branes with $U(n)$ gauge symmetries, the Pati-Salam gauge symmetries $SU(4)_C\times SU(2)_L \times SU(2)_R$ can be broken down to the Standard Model via D-brane splitting as well as D- and F-flatness preserving Higgs mechanism. Also, the hidden sector contains $USp(n)$ branes, which are parallel with the orientifold planes or their ${\mathbb Z_2}$ images. We find that the Type II T-duality in the previous study is not an equivalent relation in Pati-Salam model building if the model is not invariant under $SU(2)_L$ and $SU(2)_R$ exchange, and provides a way to obtain new models. We systematically construct the new models with three families, which usually do not have gauge coupling unification at the string scale. We for the first time construct the Pati-Salam models with one wrapping number equal to $5$. In particular, we find that these models carry more refined gauge couplings, and thus with more possibility to have approximate gauge coupling unification.

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arXiv2020

Generalized Supersymmetric Pati-Salam Models from Intersecting D6-branes

Following the scanning methods of arXiv:1910.04530, we for the first time systematically construct the $N=1$ supersymmetric $SU(12)_C\times SU(2)_L\times SU(2)_R$ models, $SU(4)_C\times SU(6)_L\times SU(2)_R$ models, and $SU(4)_C\times SU(2)_L\times SU(6)_R$ models from the Type IIA orientifolds on $\bf T^6/(\mathbb Z_2\times \mathbb Z_2)$ with intersecting D6-branes. These gauge symmetries can be broken down to the Pati-Salam gauge symmetry $SU(4)_C\times SU(2)_L \times SU(2)_R$ via three $SU(12)_C/SU(6)_L/SU(6)_R$ adjoint representation Higgs fields, and further down to the Standard Model (SM) via the D-brane splitting and Higgs mechanism. Also, we obtain three families of the SM fermions, and have the left-handed and right-handed three-family SM fermion unification in the $SU(12)_C\times SU(2)_L\times SU(2)_R$ models, the left-handed three-family SM fermion unification in the $SU(4)_C\times SU(6)_L\times SU(2)_R$ models, and the right-handed three-family SM fermion unification in the $SU(4)_C\times SU(2)_L\times SU(6)_R$ models. Moreover, the $SU(4)_C\times SU(6)_L\times SU(2)_R$ models and $SU(4)_C\times SU(2)_L\times SU(6)_R$ models are related by the left and right gauge symmetry exchanging, as well as a variation of type II T-duality. Furthermore, the hidden sector contains $USp(n)$ branes, which are parallel with the orientifold planes or their $Z_2$ images and might break the supersymmetry via gaugino condensations.

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arXiv2019

The PeV-Scale Split Supersymmetry from Higgs Mass and Electroweak Vacuum Stability

The null results of the LHC searches have put strong bounds on new physics scenario such as supersymmetry (SUSY). With the latest values of top quark mass and strong coupling, we study the upper bounds on the sfermion masses in Split-SUSY from the observed Higgs boson mass and electroweak (EW) vacuum stability. To be consistent with the observed Higgs mass, we find that the largest value of supersymmetry breaking scales $M_{S}$ for $\tanβ=2$ and $\tanβ=4$ are $\mathcal{O} (10^{3}\, {\rm TeV})$ and $\mathcal{O} (10^{1.5}\, {\rm TeV})$ respectively, thus putting an upper bound on the sfermion masses around $10^{3}\, {\rm TeV}$. In addition, the Higgs quartic coupling becomes negative at much lower scale than the Standard Model (SM), and we extract the upper bound of $\mathcal{O}(10^{4}\, {\rm TeV})$ on the sfermion masses from EW vacuum stability. Therefore, we obtain the PeV-Scale Split-SUSY. The key point is the extra contributions to the Renormalization Group Equation (RGE) running from the couplings among Higgs boson, Higgsinos, and gauginos. We briefly comment on the lifetime of gluinos in our study and compare it with current LHC observations. Additionally, we comment on the prospects of discovery of prompt gluinos in a 100 TeV proton-propton collider.

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