arXiv subjects

Syed Adil Pasha

Publications and source records attributed to Syed Adil Pasha.

6 recordsLinked to original sources

arXiv2026

Radiative Corrections to the Direct Detection of Inelastic Scattering of Higgsino-like Neutralino Dark Matter

The direct detection (DD) of Higgsino-like dark matter (DM) through inelastic scattering processes may provide a promising avenue, along with the elastic scattering, when the mass splitting between the neutral Higgsino pairs is extremely tiny. The mass splitting can be reduced further by adopting the on-shell renormalization for the neutral and charged Higgsinos in the MSSM. Moreover, all the one-loop electroweak (EW) corrections to the three-point vertices for the neutralino(s)-Higgs interactions have been considered, while both elastic and inelastic DM-nucleon scattering cross-sections have been calculated primarily through Higgs exchange. Subsequently, the expected number of scattering events in the latest LUX-ZEPLIN (LZ) DD experiment are also computed. Our results highlight a few scenarios in which the inelastic component may exceed the corresponding elastic component, leading to enhanced direct detection scattering rates.

hep-ph↗

arXiv2026

Unveiling the Vanishing Higgsino-Nucleon Scattering in the MSSM at Next-to-Leading Order

Higgsino dark matter (DM) is considered one of the most well-motivated and minimal DM scenarios arising from supersymmetric extensions of the Standard Model. Motivated by the requirement of electroweak naturalness, Higgsinos are expected to be relatively light, with masses close to the weak scale. While a pure Higgsino state typically evades current direct detection limits, next-to-leading (NLO) order radiative corrections may bring it within the sensitivity of upcoming experiments. On the contrary, a more important consequence, observed specifically near the kinematic threshold for the production of two particles, is that the NLO corrections lower the DM-nucleon cross section below the neutrino floor. We explicitly examine the cancellation mechanism responsible for suppressed Higgsino-nucleon scattering and identify regions of MSSM parameter space where spin-independent cross-sections may vanish.

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arXiv2025

Radiative corrections to the direct detection of the Higgsino-(and Wino-)like neutralino dark matter: Spin-dependent interactions

The lightest neutralino ($\tildeχ_1^0$) is a promising dark matter (DM) candidate in the R-parity conserving minimal supersymmetric standard model (MSSM). In this work, we focus on dominantly Higgsino-like and Wino-like $\tildeχ_1^0$ DM, with small admixtures of gauginos and Higgsinos, respectively. In particular, we explore large one-loop corrections to the $\tildeχ_1^0 \tildeχ_1^0Z$ vertex, which can significantly affect the estimation of the spin-dependent $\tildeχ_1^0$-nucleon scattering cross-section in the regions where such DM candidates are viable. We have used the on-shell renormalization scheme to estimate the relevant counterterm contributions. In the parameter region where $\tildeχ_1^0$ is dominantly Higgsino-like, the radiative corrections (including the contributions from the respective counterterms) are substantial and can enhance the $\tildeχ_1^0\tildeχ_1^0Z$ vertex by up to $\sim 120\%$ for the benchmark scenarios we have considered. Further, for an almost pure Wino-like $\tildeχ_1^0$, the increment in the $\tildeχ_1^0\tildeχ_1^0Z$ vertex is up to $15\%$. The corresponding cross-sections with the proton and the neutron can be changed by up to about $50\%$. In addition, including the electroweak box diagrams, the cross-sections can be significantly enhanced, in particular, for the Wino-like $\tildeχ_1^0$.

hep-ph↗

arXiv2025

Electroweak renormalization of neutralino-Higgs interactions at one-loop and its impacts on spin-independent direct detection of Wino-like dark matter

A Wino-like neutralino dark matter (DM) in the form of the lightest supersymmetric particle (LSP) has been considered one of the popular paradigms that can naturally accommodate {\it new physics} at a relatively higher scale, typically beyond the reach of the LHC. The constraint on the DM relic density typically implies a lightest neutralino mass $\simeq 2$ TeV. Its observational signature through nuclear recoil experiments, specifically involving DM-nucleon spin-independent (SI) scattering, is not impressive, following its high masses and tiny Higgsino fractions. The theoretical calculations can be improved when we compute all the one-loop electroweak (EW) corrections to the three-point vertices for the neutralino (Wino)-Higgs interactions, which in turn boosts the DM-nucleon scattering cross-sections through the SM-like Higgs exchange. Importantly, we include the counterterm contributions. In addition, we incorporate the other next-to-leading order (NLO) EW DM-quark and DM-gluon interactions present in the literature to calculate the DM-nucleon cross-sections. With the improved and precise theoretical estimates, DM-nucleon scattering cross-sections may increase or decrease significantly by more than $100\%$ compared to leading order (LO) cross-sections in different parts of the parameter space.

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arXiv2024

Radiative Corrections to Aid the Direct Detection of the Higgsino-like Neutralino Dark Matter: Spin-Independent Interactions

The lightest neutralino ($\tildeχ_1^0$) is a good Dark Matter (DM) candidate in the R-parity conserving Minimal Supersymmetric Standard Model (MSSM). In this work, we consider the light higgsino-like neutralino as the Lightest Stable Particle (LSP), thanks to rather small higgsino mass parameter $μ$. We then estimate the prominent radiative corrections to the neutralino-neutralino-Higgs boson vertices. We show that for higgsino-like $\tildeχ_1^0$, these corrections can significantly influence the spin-independent direct detection cross-section, even contributing close to 100\% in certain regions of the parameter space. These corrections, therefore, play an important role in deducing constraints on the mass of the higgsino-like lightest neutralino DM, and thus the $μ$ parameter.

hep-ph↗

arXiv2024

Confronting electroweak MSSM through one-loop renormalized neutralino-Higgs interactions for dark matter direct detection and muon $(g-2)$

We compute the next-to-leading order (NLO) corrections to the vertices where a pair of the lightest neutralino couples to CP-even (light or heavy) Higgs scalars. In particular, the lightest neutralino is assumed to be a dominantly Bino-like mixed state, composed of Bino and Higgsino or Bino, Wino, and Higgsino. After computing all the three-point functions in the electroweak MSSM, we detail the contributions from the counterterms that arise in renormalizing these vertices in one-loop order. The amendment of the renormalized vertices impacts the spin-independent direct detection cross-sections of the scattering of nucleons with dark matter. We perform a comprehensive numerical scan over the parameter space where all the points satisfy the present B-physics constraints and accommodate the muon's anomalous magnetic moment. Finally, we exemplify a few benchmark points, which indulge the present searches of supersymmetric particles. After including the renormalized one-loop vertices, the spin-independent DM-nucleon cross-sections may be enhanced up to $20\%$ compared to its tree-level results. Finally, with the NLO cross-section, we use the recent LUX-ZEPLIN (LZ) results on the neutralino-nucleon scattering to display the relative rise in the lowest allowed band of the Higgsino mass parameter in the $M_1-μ$ plane of the electroweak MSSM.

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