Q. Shafi

activity

19922026

most citedInflation and Monopoles in Supersymmetric SU(4)_c x SU(2)_L x SU(2)_R

162 citations · 1.2k across the 52 of their papers we have counts for

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51 papers · 1 filter

hep-ph2026

Monopoles, Strings, Walls and Gravitational waves

Rinku Maji, Qaisar Shafi

The gauge symmetry breaking $S U (2) \to U (1) \to Z_{2} \to 1$ successively produces monopoles, strings and domain walls bounded by strings (WBS), with the elementary monopole carrying…

hep-ph2025

Neutrino masses, $δ_{PMNS}$ , and $m_{β β}$ in SO(10)

Shaikh Saad, Qaisar Shafi

We explore the leptonic sector of a recently proposed supersymmetric SO(10) model with supersymmetry breaking in the 3-10 TeV range. A new ingredient in this work is the requiremen…

hep-ph2025

Superconducting Strings in $E_{6}$

Rinku Maji, Qaisar Shafi

We discuss the appearance of superconducting strings in $E_{6}$ grand unification, keeping track of the magnetic monopole flux that precedes the formation of the string flux tube. Th…

hep-ph2025

Split supersymmetry and hybrid inflation in light of Atacama Cosmology Telescope DR6 data

Nobuchika Okada, Qaisar Shafi

Inspired by the recent measurement of the scalar spectral index, $n_{s} = 0.9743 \pm 0.0034$ , by the Atacama Cosmology Telescope (ACT) DR6 data, we present an update on the split sup…

hep-ph2025

Waterfall phase in supersymmetric hybrid inflation

Ahmad Moursy, Qaisar Shafi

We explore a class of realistic supersymmetric hybrid inflation models with a predicted scalar spectral index $n_{s} \approx 0.97 - 0.978$ , which is in good agreement with the recent A…

hep-ph2025

Fermion masses and mixings in supersymmetric SO(10) with third-generation quasi-Yukawa unification

Shaikh Saad, Qaisar Shafi

We discuss the charged and neutral fermion masses and mixings in a supersymmetric SO(10) model with a minimal Higgs sector consisting of the multiplets $1 0_{H}$ , $4 5_{H}$ , and $16_H +…

hep-ph2025★ 10 cited

Superheavy Metastable Strings in SO(10)

Rinku Maji, Qaisar Shafi

The spontaneous breaking of $S O (10)$ grand unified symmetry to $S U (3)_{c} \times S U (2)_{L} \times U (1)_{Y} \times U (1)_{χ}$ yields the GUT monopole as well as a comparably heavy $U (1)_{χ}$ m…

hep-ph2025

Magnetic Monopoles and Exotic States in $S U (4)_{c} \times S U (2)_{L} \times S U (2)_{R}$

Thomas W. Kephart, Qaisar Shafi

In the Pati-Salam gauge symmetry $S U (4)_{c} \times S U (2)_{L} \times S U (2)_{R}$ (4-2-2, for short), the observed quarks and leptons of each family reside in the bi-fundamental representat…

hep-ph2025★ 8 cited

C-parity, magnetic monopoles and higher frequency gravitational waves

Rinku Maji, Qaisar Shafi

We consider the spontaneous breaking of $S O (10)$ grand unified symmetry to the left-right symmetric model $S U (3)_{c} \times S U (3)_{L} \times S U (2)_{R} \times U (1)_{B - L}$ with C-parity al…

hep-ph2025★ 9 cited

$μ$ -Hybrid Inflation and Metastable Cosmic Strings in $SU (3)_{c} \times SU (2)_{L} \times SU (2)_{R} \times U (1)_{B - L}$

Muhammad Nadeem Ahmad, Maria Mehmood, Mansoor Ur Rehman +1

We develop a scenario based on $μ$ -hybrid inflation within the framework of a left-right symmetric model defined by the gauge symmetry group $G_{3221} = SU(3)_c \times SU(2)_L \tim…

hep-ph2024

Induced gravitational waves, metastable cosmic strings and primordial black holes in GUTs

Rinku Maji, Ahmad Moursy, Qaisar Shafi

We explore the cosmological and astrophysical implications of a realistic hybrid inflation model based on flipped $S U (5)$ . The model contains superheavy metastable cosmic strings a…

hep-ph2024★ 10 cited

Kinetic Mixing, Proton Decay and Gravitational Waves in SO(10)

Rinku Maji, Qaisar Shafi

We present an $S O (10)$ model in which a dimension five operator induces kinetic mixing at the GUT scale between the abelian subgroups $U (1)_{B - L}$ and $U (1)_{R}$ . We discuss in this…

hep-ph2024★ 13 cited

Topological structures, dark matter and gravitational waves in $E_{6}$

Rinku Maji, Qaisar Shafi, Amit Tiwari

We discuss the appearance of topological structures from the spontaneous breaking of $E_{6}$ to the Standard Model via its maximal subgroup $S O (10) \times U (1)_{ψ}$ . They include dumbb…

hep-ph2024

Primordial monopoles, black holes and gravitational waves

Ahmad Moursy, Qaisar Shafi

We show how topologically stable superheavy magnetic monopoles and primordial black holes can be generated at observable levels by the waterfall field in hybrid inflation models ba…

hep-ph2024

Muon g-2 and lepton flavor violation in supersymmetric GUTs

Mario E. Gomez, Smaragda Lola, Qaisar Shafi +1

We present a class of supersymmetric (SUSY) GUT models that can explain the apparent discrepancy between the SM predictions and experimental values of muon g-2 while providing test…

hep-ph2024★ 13 cited

Quantum tunneling in the early universe: Stable magnetic monopoles from metastable cosmic strings

George Lazarides, Rinku Maji, Qaisar Shafi

We present a novel mechanism for producing topologically stable monopoles (TSMs) from the quantum mechanical decay of metastable cosmic strings in the early universe. In an $SO(10)…

hep-ph2023★ 25 cited

Gravitational wave emission from metastable current-carrying strings in $E_{6}$

Adeela Afzal, Qaisar Shafi, Amit Tiwari

We discuss $E_{6}$ based extensions of the Standard Model (SM) containing two varieties of superheavy metastable cosmic strings (CSs) that respectively have neutral and electrically…

hep-ph2023

Muon $g - 2$ and dark matter in Supersymmetric $S U (4)_{c} \times S U (2)_{L} \times S U (2)_{R}$

Qaisar Shafi, Amit Tiwari, Cem Salih Un

The latest FermiLab muon $g - 2$ result shows a $5 σ$ discrepancy with a ``widely advertised" Standard Model prediction. We consider a supersymmetric $SU(4)_c \times SU(2)_L \times SU…

hep-ph2023★ 32 cited

Inflation, superheavy metastable strings and gravitational waves in non-supersymmetric flipped SU(5)

George Lazarides, Rinku Maji, Ahmad Moursy +1

Motivated by the NANOGrav 15 year data and other recent investigations of stochastic gravitational background radiation based on pulsar timing arrays, we show how superheavy string…

hep-ph2023★ 1 cited

Standard Model Higgs inflation supplemented by minimal dark matter

Shinsuke Kawai, Nobuchika Okada, Qaisar Shafi

Renormalisation group analysis with the present measurements of the top quark mass $m_{t} = 172.69 \pm 0.30$ GeV indicates that the Standard Model (SM) Higgs potential becomes unstabl…

hep-ph2023★ 21 cited

Gravitational waves from walls bounded by strings in $S O (10)$ model of pseudo-Goldstone dark matter

Rinku Maji, Wan-Il Park, Qaisar Shafi

We explore the gravitational wave spectrum generated by string-wall structures in an $S O (10)$ ( $S p in (10)$ ) based scenario of pseudo-Goldstone boson dark matter (pGDM) particle. Thi…

hep-ph2023

Third family quasi-Yukawa unification: Higgsino dark matter, NLSP gluino and all that

Qaisar Shafi, Amit Tiwari, Cem Salih Un

We explore the implications of third family ( $t - b - τ$ ) quasi-Yukawa unification (QYU) for collider and dark matter (DM) searches within the framework of a supersymmetric $SU(4)_c \t…

hep-ph2023★ 32 cited

Composite Topological Structures in SO(10)

George Lazarides, Qaisar Shafi, Amit Tiwari

We explore a variety of composite topological structures that arise from the spontaneous breaking of $S O (10)$ to $S U (3)_{c} \times U (1)_{e m}$ via one of its maximal subgroups $SU(5)…

hep-ph2020★ 2 cited

Confronting Grand Unification with Lepton Flavour Violation, Dark Matter and LHC Data

J. Ellis, M. E. Gomez, S. Lola +2

We explore possible signatures for charged lepton flavour violation (LFV), sparticle discovery at the LHC and dark matter (DM) searches in grand unified theories (GUTs) based on SU…

Monopoles, Strings, Walls and Gravitational waves

Neutrino masses, δPMNS​, and mββ​ in SO(10)

Superconducting Strings in E6​

Split supersymmetry and hybrid inflation in light of Atacama Cosmology Telescope DR6 data

Waterfall phase in supersymmetric hybrid inflation

Fermion masses and mixings in supersymmetric SO(10) with third-generation quasi-Yukawa unification

Superheavy Metastable Strings in SO(10)

Magnetic Monopoles and Exotic States in SU(4)c​×SU(2)L​×SU(2)R​

C-parity, magnetic monopoles and higher frequency gravitational waves

μ-Hybrid Inflation and Metastable Cosmic Strings in SU(3)c​×SU(2)L​×SU(2)R​×U(1)B−L​

Induced gravitational waves, metastable cosmic strings and primordial black holes in GUTs

Kinetic Mixing, Proton Decay and Gravitational Waves in SO(10)

Topological structures, dark matter and gravitational waves in E6​

Primordial monopoles, black holes and gravitational waves

Muon g-2 and lepton flavor violation in supersymmetric GUTs

Quantum tunneling in the early universe: Stable magnetic monopoles from metastable cosmic strings

Gravitational wave emission from metastable current-carrying strings in E6​

Muon g−2 and dark matter in Supersymmetric SU(4)c​×SU(2)L​×SU(2)R​

Inflation, superheavy metastable strings and gravitational waves in non-supersymmetric flipped SU(5)

Standard Model Higgs inflation supplemented by minimal dark matter

Gravitational waves from walls bounded by strings in SO(10) model of pseudo-Goldstone dark matter

Third family quasi-Yukawa unification: Higgsino dark matter, NLSP gluino and all that

Composite Topological Structures in SO(10)

Confronting Grand Unification with Lepton Flavour Violation, Dark Matter and LHC Data

Neutrino masses, $δ_{PMNS}$ , and $m_{β β}$ in SO(10)

Superconducting Strings in $E_{6}$

Magnetic Monopoles and Exotic States in $S U (4)_{c} \times S U (2)_{L} \times S U (2)_{R}$

$μ$ -Hybrid Inflation and Metastable Cosmic Strings in $SU (3)_{c} \times SU (2)_{L} \times SU (2)_{R} \times U (1)_{B - L}$

Topological structures, dark matter and gravitational waves in $E_{6}$

Gravitational wave emission from metastable current-carrying strings in $E_{6}$

Muon $g - 2$ and dark matter in Supersymmetric $S U (4)_{c} \times S U (2)_{L} \times S U (2)_{R}$

Gravitational waves from walls bounded by strings in $S O (10)$ model of pseudo-Goldstone dark matter