arXiv subjects

Cem Salih Ün

Publications and source records attributed to Cem Salih Ün.

6 recordsLinked to original sources

arXiv2026

Non-Holomorphic Impact on $t-b-τ$ Yukawa Unification in minimal GMSB

We study and explore the low scale implications of Yukawa unification in the minimal gauge mediated supersymmetry breaking models. We also assume non-zero non-holomorphic terms, with which the YU solutions can be accommodated in the cases with $μ> 0$. These results can be considered a direct effect from the non-holomorphic terms, but they also lead to testable low scale implications compatible with YU. We observe abundant solutions consistent with the Higgs boson mass. This constraint leads to heavy strongly interacting supersymmetric particles, while the electroweak sector can be relatively light and they can be probed by several experiments. We find that the chargino can be lighter than 1 TeV and it is degenerate with the lightest neutralino in most of these solutions. Consistent solutions in this region can accommodate charginos as light as about 120 GeV, and they will likely be tested soon by the analyses over the compressed spectra. These solutions are also subjected in the lifetime analyses. Our analyses identify such light charginos as decaying in about $10^{-2}$ ns. Probing such points may need a slight improvement in the sensitivity of current analyses, and one can expect them to be tested very soon. In the same region, the stau is found to be another light supersymmetric particle, and some of the solutions can be inconsistently lighter. We find that it can weigh as light as about 600 GeV consistently, and it can be tested also soon over its lifetime. We summarize and also exemplify our findings with five benchmark scenarios. Furthermore, the benchmark solutions also reveal that the solutions can be tested in heavy Higgs boson searches, which shape the whole Higgs boson spectrum in models.

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arXiv2023

Mono-Photon Events with Light Higgs bosons in Secluded UMSSM

We explore the Higgs boson implications of a class of supersymmetric models, which extends the MSSM gauge group by a $U(1)^{\prime}$ symmetry, which is broken at low energy scales by VEVs of four MSSM singlet fields. These singlets also form a secluded sector, and one of them is allowed to interact with the MSSM Higgs fields directly. After the $U(1)^{\prime}$ and electroweak symmetry breaking, the low scale spectra include six CP-even and 4 CP-odd Higgs bosons, whose masses can lie from 80 GeV to 2-3 TeV. We find that the heavy CP-even Higgs bosons can be probed through their decays into a pair of SM gauge bosons currently up to about $m_{h_{i}} \simeq 1.5$ TeV, while their probe can be extended to about $m_{h_{i}} \simeq 2.5$ TeV in near future. The most interesting feature of the low scale spectra in the class of Secluded $U(1)^{\prime}$ models is to include two light CP-odd Higgs bosons whose masses are bounded at about 250 GeV by the current collider and DM experiments, when the LSP neutralino is mostly formed by the MSSM singlets. These light CP-odd Higgs bosons should be formed by the MSSM singlet scalars to be consistent with the current constraints. Despite their singlet nature, they can be traced through their associated production with photons. In our work, we consider their productions at the collider experiments together with photons, and we realize that these light Higgs bosons can potentially be probed during Run-3 experiments of LHC when they are lighter than about 100 GeV. We also show that Run-4 and HL-LHC experiments will be able to probe these light scalars up to about 250 GeV.

hep-ph↗

arXiv2022

Model Characterization and Dark Matter in the Secluded $U(1)^\prime$ Model

We consider a class of $U(1)^\prime$-extended MSSM in which the $U(1)^{\prime}$ symmetry is broken by vacuum expectation values (VEVs) of four MSSM singlet fields. While one MSSM singlet field interacts with the MSSM Higgs fields, three of them interact only with each other in forming a secluded sector. Assigning universal $U(1)^{\prime}$ charges for three families, the anomaly cancellation condition requires exotic fields which are assumed to be heavy and decoupled. We discuss a variety of $U(1)^{\prime}$ charge assignments and anomaly cancellation, $Z^{\prime}/Z$ hierarchy, neutralinos, charginos and the Higgs sector. We find that the typical spectra involve two CP-odd Higgs bosons lighter than about 200 GeV and 600 GeV respectively, which are mostly formed by the MSSM singlet fields. If the relic density of dark matter is saturated only by a neutralino, compatible solutions predict LSP neutralinos formed by the MSSM singlet fields in the mass scales below about 600 GeV, while it is possible to realize MSSM neutralino LSP above these mass scales. One can classify the implications in three scenarios. Scenario I involves NLSP charginos, while Scenario II involves charginos which do not participate coannihilation processes with the LSP neutralino. These two scenarios predict MSSM singlet LSP neutralinos, while Scenario I leads to larger scattering cross-sections of dark matter. Scenario III has the solutions in which the MSSM neutralinos are considerably involved in LSP decomposition which yields very large scattering cross-section excluded by the direct detection experiments.

hep-ph↗

arXiv2021

Electron and muon magnetic moments and implications for dark matter and model characterisation in non-universal $U(1)^\prime$ supersymmetric models

We attribute deviations of the muon and electron magnetic moments from the theoretical predictions to the presence of an additional $U(1)^\prime$ supersymmetric model. We interpret the discrepancies between the muon and electron anomalous magnetic moments to be due to the presence of non-universal $U(1)^\prime$ charges. In a minimally extended model, we show that requiring both deviations to be satisfied imposes constraints on the spectrum of the model, in particular on dark matter candidates and slepton masses and ordering. Choosing three benchmarks with distinct dark matter features, we study implications of the model at colliders, concentrating on variables that can distinguish our non-universal scenario from other $U(1)^\prime$ implementations.

hep-ph↗

arXiv2014

NLSP Gluino and NLSP Stop Scenarios from b-tau Yukawa Unification

We present a study of b-tau Yukawa unified supersymmetric SU(4)_c x SU(2)_L x SU(2)_R model (with mu > 0), which predicts the existence of gluino - neutralino and stop - neutralino coannihilation scenarios compatible with the desired relic LSP neutralino dark matter abundance and other collider constraints. The NLSP gluino or NLSP stop masses vary between 400 GeV to ~ 1 TeV. The NLSP gluinos will be accessible at the 14 TeV LHC, while we hope that the NSLP stop solutions will be probed in future LHC searches. We also identify regions of the parameter space in which the gluino and the lighter stop are closely degenerate in mass, interchangeably playing the role of NLSP and NNLSP. We also update a previous study of t-b-tau Yukawa unification and show that NLSP gluino of mass ~ 1 TeV, with a mass difference between the gluino and neutralino of less than 80 GeV, can be realized consistent with the current collider and astrophysical constraints. We present benchmark points for b-tau and t-b-tau Yukawa unification that can be accessible at the LHC.

hep-ph↗

arXiv2012

125 GeV Higgs Boson from t-b-tau Yukawa Unification

We identify a class of supersymmetric SU(4)_c x SU(2)_L x SU(2)_R models in which imposing essentially perfect t-b-tau Yukawa coupling unification at M_GUT yields a mass close to 122-126 GeV for the lightest CP-even (SM-like) Higgs boson. The squark and gluino masses in these models exceed 3 TeV, but the stau and charginos in some cases can be considerably lighter. We display some benchmark points corresponding to neutralino-stau and bino-wino coannihilations as well as A-resonance. The well-known MSSM parameter tan beta is around 46-52.

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