Browsing by Author "Cici, Ali"

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Light Higgs bosons and muon g-2 in THDM
(Amer Inst Physics, 2017) Akkuş, B.; Öktem, Y.; Doğan, G. S.; Güzelçimen, F.; Niş, Büşra; Cici, Ali; Ün, Cem Salih; Kırca, Zerrin; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Fizik Bölümü.; 0000-0002-0595-8803; 0000-0001-5217-9290; AAH-8661-2021; N-3421-2014; 57193708148; 57193713979; 55325758100; 6508185203
As well as having a significant impact on models beyond the Standard Model, the Higgs boson discovery has opened a new era in both experimental and phenomenological searches. For instance, observed anomalies in Higgs decays into two photons and four leptons and muon anomalous magnetic moment (muon g - 2) may imply more Higgs-like scalars. In this work, we study Two Higgs Doublet Model-TypeIII, in which one Higgs doublet develops a zero vacuum expectation value. we find the mass spectrum include five Higgs bosons each of which is lighter than about 350 GeV. We consider the contributions to muon g - 2 from these light extra Higgs bosons, and we find that the discrepancy between the SM and the experimental measurements can be resolved if m(H), m(A), m(H perpendicular to) less than or similar to 150 GeV.
Light stops and fine-tuning in MSSM
(Springer, 2018-01-13) Cici, Ali; Kırca, Zerrin; Ün, Cem Salih; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Fizik Bölümü.; 0000-0002-0595-8803; 0000-0001-5217-9290; AAH-8661-2021; N-3421-2014; 57193713979; 6508185203; 55325758100
We discuss the fine-tuning issue within the MSSM framework. Following the idea that the fine-tuning can measure effects of some missing mechanism, we impose non-universal gaugino masses at the GUT scale, and explore the low scale implications. We realize that the fine-tuning parametrized with Δ EW can be as low as zero. We consider the stop mass with a special importance and focus on the mass scales as mt~≤ 700 GeV, which are excluded by the current experiments when the stop decays into a neutralino along with a top quark or a chargino along with a bottom quark. We find that the stop mass can be as low as about 250 GeV with Δ EW∼ 50. We find that the solutions in this region can be exluded only up to 60 % when stop decays into a neutralino-top quark, and 50 % when it decays into a chargino-b quark. Setting 65 % CL to be potential exclusion and 95 % to be pure exclusion limit such solutions will be tested in near future experiments, which are conducted with higher luminosity. In addition to stop, the region with low fine-tuning and light stops predicts masses for the other supersymmetric particles such as mb~≳ 700 GeV, mτ~≳ 1 TeV, mχ~1±≳120 GeV. The details for the mass scales and decay rates are also provided by tables of benchmark points.
The 28 gev dimuon excess in lepton specific thdm
(Elsevier, 2022-03-18) Khalil, Shaaban; Cici, Ali; Nis, Büşra; Ün, Cem Salih; ÜN, CEM SALİH; Bursa Uludağ Üniversitesi/Fen Edebiyat Fakültesi/Fizik Bölümü.; 0000-0002-0595-8803; N-3421-2014
We explore the Higgs mass spectrum in a class of Two Higgs Doublet Models (THDMs) in which a scalar SU (2)(L) doublet interacts only with quarks, while the second one interacts only with leptons. The spectrum includes two CP-even Higgs bosons, either of which can account for the SM-like Higgs boson, and the spectra involving light Higgs bosons receive strong impacts from the LEP results and the current collider analyses. We find that a consistent spectrum can involve a CP-odd Higgs boson as light as about 10 GeV, while the lightest CP-even Higgs boson cannot be lighter than about 55 GeV when m(A) similar to 28 GeV. These analyses can rather bound the low tan beta region which can also accommodate an observed excess in dimuon events at m(mu mu) similar to 28 GeV. A lepton-specific class of THDMs (LS-THDM) can predict such an excess through A -> mu mu decays, while the solutions can be constrained by the A -> tau tau mode. After constraining the solutions with the consistent ranges of sigma(pp -> bbA -> bb tau tau), a largest excess at about 1.5 sigma at 8 TeV center of mass (COM) energy and 2 sigma at 13 TeV COM is observed for tan beta similar to 12 and m(A) similar to 28 GeV in the sigma(pp -> bbA -> bb mu mu) events.