arXiv subjects

V. Suryanarayana Mummidi

Publications and source records attributed to V. Suryanarayana Mummidi.

11 recordsLinked to original sources

arXiv2026

Low scale leptogenesis and $TM_1$ mixing in neutrinophillic two Higgs doublet model($ν$2HDM) with S4 flavor symmetry

We study a modified version of the Standard Model that includes a scalar doublet and two right-handed neutrinos, forming the neutrinophillic two higgs doublet ($ν\text{2HDM}$) framework. For the two Higgs-doublet vacuum expectation values satisfying $\text{v}_2 << \text{v}_1$, this model operates at a TeV scale, bringing the RHNs within experimental reach. To further enhance its predictive power, we introduce an $S_4 \times Z_4$ flavor symmetry with five flavons, resulting in mass matrices that realize the so-called Trimaximal $\text{TM}_1$ mixing scheme. The model effectively explains lepton masses and flavor mixing under the normal ordering of neutrino masses, predicting that the effective neutrino mass in 0$νββ$ decay lies between [4 - 5] meV, significantly lower than the sensitivity limits of current experiments. We also investigate how this framework could support low-scale leptogenesis as a natural way to explain the observed imbalance between matter and antimatter in the Universe. This work explores how neutrino physics, flavor symmetry and baryon asymmetry are connected, providing a clear framework that links theoretical predictions with experimental possibilities.

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arXiv2026

Resonant leptogenesis in inverse see-saw framework with modular $S_4$ symmetry

We introduce a lepton mass generation and flavor mixing model, realized through a (2,3) inverse seesaw structure based on modular $ S_4 $ symmetry. The model employs modular forms to construct the lepton Yukawa couplings, significantly simplifying the framework by reducing redundant parameters. A detailed numerical analysis demonstrates consistency with current neutrino oscillation data, yielding specific outputs for the mixing angles and CP-violating phases. The Dirac CP phase is predicted to lie near $δ_{\rm CP} \approx \pm 90^\circ$, corresponding to near-maximal leptonic CP violation. The total neutrino mass lies within $\sum m_ν\approx 0.0587\text{--}0.0924$ eV, and the effective Majorana mass $|m_{ee}| \approx (0.002\text{--}0.02)$ eV, within reach of upcoming neutrinoless double beta decay experiments such as nEXO and AMoRE-II. The model also remains consistent with current bounds on charged lepton flavor violating processes from MEG and BaBar. We further explore resonant leptogenesis enabled by quasi-degenerate heavy neutrino states and show that the observed baryon asymmetry of the universe can be successfully generated in this scenario. The combined treatment of low-energy observables and high-scale baryogenesis demonstrates the predictivity and testability of the modular $ S_4 $-based ISS(2,3) framework.

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arXiv2026

Modular $S_4$ Scotogenic Model with Flavored Resonant Leptogenesis

We construct a radiative neutrino mass model that combines the scotogenic mechanism with modular $S_4$ flavour symmetry. The entire lepton flavour structure is governed by holomorphic modular forms of a single complex modulus $τ$, eliminating the need for flavon fields. Beyond the Standard Model, the particle content consists of two right-handed Majorana fermions assigned to the $S_4$ doublet representation and an inert scalar doublet odd under a $\mathbb{Z}_2$ parity. Neutrino masses emerge at one loop through the scotogenic mechanism, and the lightest $\mathbb{Z}_2$-odd state serves as a dark matter candidate. A comprehensive scan of the parameter space demonstrates consistency with all five neutrino oscillation observables at the $3σ$ level. Having exactly two right-handed neutrinos forces the light neutrino mass matrix to rank two, leaving one neutrino massless and selecting normal ordering as the only viable option. The framework predicts a total neutrino mass in the narrow window $Σm_ν\simeq 0.059$--$0.06\,\mathrm{eV}$, well within current cosmological bounds, and an effective Majorana mass $m_{ββ} \simeq (1.3$--$3.5)\times 10^{-3}\,\mathrm{eV}$ relevant for neutrinoless double beta decay searches. The modular structure of the right-handed Majorana mass matrix intrinsically produces a quasi-degenerate heavy neutrino spectrum, enabling flavoured resonant leptogenesis at $M_1 \sim 10^5\,\mathrm{GeV}$ without any fine-tuning. Integration of the full three-flavour Boltzmann equations confirms that the observed baryon asymmetry is reproduced, establishing that neutrino masses, leptonic mixing, and the baryon asymmetry of the Universe all find a common explanation within this framework.

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arXiv2026

SIMPonium bound states of complex scalar dark matter: Relic density and astrophysical signatures

We study a strongly interacting complex scalar dark matter candidate $(χ)$, subject to an attractive potential mediated by a vector boson $A^μ$. Such interactions allow $χ$ to form bound states: SIMPonium. In this work, we systematically investigate the bound state dynamics of our dark sector, including the formation and decay of SIMPonium and it's influence on the thermal history. Our analysis shows in absence of any bound state formation $χ$ freezes out at $x\approx 16$ and the presence of SIMPonium in the thermal bath slightly modifies the freeze out behaviour of the free $χ$ particles, which freezes out at $x \approx 20$. While the bound state itself remains in chemical equilibrium for a longer duration and freezes out at a significantly later time, $x \approx 250$. We compute the indirect energy spectra arising from free dark matter annihilation and SIMPonium decay, where the resulting Standard Model particles subsequently produce both final state radiation and radiative decay spectra. We find that the total differential photon flux from dark matter with mass $m_χ= 150\,\mathrm{MeV}$ lies in the range $E_γ^2 \frac{dϕ}{dΩ\, dE_γ} \in [10^{-27},\,10^{-17}] \,\mathrm{MeV\,cm^{-2}\,s^{-1}\,sr^{-1}}$ , for photon energies in the interval $E_γ\in [10^{-3},\,10^{2}] \,\mathrm{MeV}$. The predicted signal is therefore exceedingly feeble and remains well below the sensitivity of current experimental facilities.

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arXiv2026

Asymmetric dark matter from leptogenesis in type-III seesaw framework with modular $S_4$ symmetry

We present a unified framework for neutrino masses, baryogenesis, and dark matter based on a modular $S_4$ symmetry combined with a type-III seesaw mechanism. All Yukawa couplings, CP phases, and flavor textures originate from a single complex modulus $τ$, whose vacuum expectation value controls both visible and dark sector dynamics. The same modular parameter fixes the neutrino mass matrix, determines the CP asymmetries driving resonant leptogenesis, and correlates the resulting baryon and dark matter abundances. A detailed numerical analysis shows that the model reproduces all neutrino oscillation data within the $3σ$ NuFIT~5.2 (2024) ranges for normal ordering, predicting $δ_{\rm CP} \simeq \pm (150^\circ-180^\circ)$, $\sum m_ν\simeq(0.06-0.08)~\mathrm{eV}$, and an effective Majorana mass $m_{ββ} \simeq (8 - 18)\times 10^{-3}~\mathrm{eV}$, testable in next-generation neutrinoless double-beta decay experiments. The same modular Yukawas yield resonantly enhanced CP asymmetries $|ε_{L,χ}| \sim 10^{-9}-10^{-6}$ at $M_Σ\sim 10^{7}~\mathrm{GeV}$, successfully generating the observed baryon asymmetry $η_B\simeq6\times10^{-10}$ and dark relic density $Ω_χh^2\simeq0.12$ without additional free parameters. The predicted correlation $Ω_χ/Ω_B\simeq5.4$ fixes the dark matter mass to $m_χ\simeq0.1-2~\mathrm{GeV}$, consistent with all current constraints. This framework therefore realizes a fully predictive baryon$-$dark matter co-genesis, where the geometry of the modular symmetry links the origin of flavor, CP violation, and the cosmic matter asymmetry.

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arXiv2023

Supersymmetry : A decade after Higgs discovery

Supersymmetric extensions of the Standard Model have been in vogue for over half a century. They have many interesting theoretical properties like calculability, absence of quadratic divergences, and phenomenologically impactful features like gauge coupling unification, dark matter candidates, signatures at present and future colliders, etc. A defining feature of these models is the calculability of Higgs mass in terms of a few parameters. The discovery of a Higgs particle with a mass of around 125 GeV thus has significant implications. The null results for the searches of superpartners at LHC has also put further constraints. Taken together with direct detection limits on WIMP (Weakly Interacting Massive Particle) dark matter, it appears that TeV scale supersymmetry is not realised in Nature and the theoretical expectations have reached a turning point. The present onslaught from the experiments suggests that supersymmetric models need a more complex particle structure, lagrangian and breaking patterns to be a natural solution to the hierarchy problem. We review existing models and discuss their feasibility in the current and future experimental programs.

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arXiv2021

Leptogenesis and fermion mass fit in a renormalizable $SO(10)$ model

A non-supersymmetric renormalizable $SO(10)$ model is investigated for its viability in explaining the observed fermion masses and mixing parameters along with the baryon asymmetry produced via thermal leptogenesis. The Yukawa sector of the model consists of complex $10_H$ and $\overline{126}_H$ scalars with a Peccei-Quinn like symmetry and it leads to strong correlations among the Yukawa couplings of all the standard model fermions including the couplings and masses of the right-handed (RH) neutrinos. The latter implies the necessity to include the second lightest RH neutrino and flavor effects for the precision computation of leptogenesis. We use the most general density matrix equations to calculate the temperature evolution of flavoured leptonic asymmetry. A simplified analytical solution of these equations, applicable to the RH neutrino spectrum predicted in the model, is also obtained which allows one to fit the observed baryon to photon ratio along with the other fermion mass observables in a numerically efficient way. The analytical and numerical solutions are found to be in agreement within a factor of ${\cal O}(1)$. We find that the successful leptogenesis in this model does not prefer any particular value for leptonic Dirac and Majorana CP phases and the entire range of values of these observables is found to be consistent. The model specifically predicts (a) the lightest neutrino mass $m_{ν_1}$ between 2-8 meV, (b) the effective mass of neutrinoless double beta decay $m_{ββ}$ between 4-10 meV, and (c) a particular correlation between the Dirac and one of the Majorana CP phases.

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arXiv2020

Precision unification and Higgsino dark matter in GUT scale supersymmetry

Even if the concerns related to the naturalness of the electroweak scale are repressed, the Higgs mass and stability of the electroweak vacuum do not allow arbitrarily large supersymmetry breaking scale, $M_S$, in the minimal models with split or high-scale supersymmetry. We show that $M_S$ can be raised to the GUT scale if the theory below $M_S$ contains a Higgs doublet, a pair of TeV scale Higgsino and widely separated gauginos in addition to the Standard Model particles. The presence of wino and gluino below ${\cal O}(100)$ TeV leads to precision unification of the gauge couplings consistent with the current limits on the proton lifetime. Wino, at this scale, renders the Higgsino as pseudo-Dirac dark matter which in turn evades the existing constraints from the direct detection experiments. Bino mass scale is required to be $\gtrsim 10^{10}$ GeV to get the observed Higgs mass respecting the current limit on the charged Higgs mass. The framework predicts, $1 \lesssim \tanβ\lesssim 2.2$ and $τ[p\to e^+\, π^0] < 7 \times 10^{35}$ years, almost independent of values of the other parameters. The electroweak vacuum is found to be stable or metastable. The underlying framework provides an example of a viable sub-GUT scale theory of supersymmetric grand unified theory in which supersymmetry and unified gauge symmetry are broken at a common scale.

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arXiv2014

Neutralino-Neutralino pair annihilation crosssections with flavour violation

We present the first exact and most general neutralino-neutralino annihilation cross sections in the presence of flavor violation. The existing set of calculations in literature do not include flavour violation. These calculations are important for the calculation of relic density and indirect detection of dark matter in various experiments.

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arXiv2014

Anatomy of Higgs mass in Supersymmetric Inverse Seesaw Models

We compute the one loop corrections to the CP even Higgs mass matrix in the supersymmetric inverse seesaw model to single out the different cases where the radiative corrections from the neutrino sector could become important. It is found that there could be a significant enhancement in the Higgs mass even for Dirac neutrino masses of $\mathcal{O}$(30) GeV if the left-handed sneutrino soft mass is comparable or larger than the right-handed neutrino mass. In the case where right-handed neutrino masses are significantly larger than the supersymmety breaking scale, the corrections can utmost account to an upward shift of 3 GeV. For very heavy multi TeV sneutrinos, the corrections replicate the stop corrections at 1-loop. We further show that general gauge mediation with inverse seesaw model naturally accommodates a 125 GeV Higgs with TeV scale stops.

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arXiv2014

A little more Gauge Mediation and the light Higgs mass

We consider minimal models of gauge mediated supersymmetry breaking with an extra $U(1)$ factor in addition to the Standard Model gauge group. A $U(1)$ charged, Standard Model singlet is assumed to be present which allows for an additional NMSSM like coupling, $λH_u H_d S$. The U(1) is assumed to be flavour universal. Anomaly cancellation in the MSSM sector requires additional coloured degrees of freedom. The $S$ field can get a large vacuum expectation value along with consistent electroweak symmetry breaking. It is shown that the lightest CP even Higgs boson can attain mass of the order of 125 GeV.

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