Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 21Citation - Scopus: 20Search for Neutral Mssm Higgs Bosons Decaying To Μ+µ- in Pp Collisions at S=7 and 8 Tev(Elsevier Ltd., 2016) Karapınar, GülerA search for neutral Higgs bosons predicted in the minimal supersymmetric standard model (MSSM) for μ+μ- decay channels is presented. The analysis uses data collected by the CMS experiment at the LHC in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV, corresponding to integrated luminosities of 5.1 and 19.3 fb-1, respectively. The search is sensitive to Higgs bosons produced either through the gluon fusion process or in association with a bb quark pair. No statistically significant excess is observed in the μ+μ- mass spectrum. Results are interpreted in the framework of several benchmark scenarios, and the data are used to set an upper limit on the MSSM parameter tanβ as a function of the mass of the pseudoscalar A boson in the range from 115 to 300 GeV. Model independent upper limits are given for the product of the cross section and branching fraction for gluon fusion and b quark associated production at s=8 TeV. They are the most stringent limits obtained to date in this channel. © 2015 The Authors.Article Citation - WoS: 59Citation - Scopus: 52Search for Neutral Mssm Higgs Bosons Decaying Into a Pair of Bottom Quarks(Springer Verlag, 2015) CMS Collaboration; Karapınar, GülerA search for neutral Higgs bosons decaying into a bb¯$$ \mathrm{b}\overline{\mathrm{b}} $$ quark pair and produced in association with at least one additional b quark is presented. This signature is sensitive to the Higgs sector of the minimal supersymmetric standard model (MSSM) with large values of the parameter tan β. The analysis is based on data from proton-proton collisions at a center-of-mass energy of 8 TeV collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 19.7 fb−1. The results are combined with a previous analysis based on 7 TeV data. No signal is observed. Stringent upper limits on the cross section times branching fraction are derived for Higgs bosons with masses up to 900 GeV, and the results are interpreted within different MSSM benchmark scenarios, mh max, mh mod +, mh mod −, light-stau and light-stop. Observed 95% confidence level upper limits on tan β, ranging from 14 to 50, are obtained in the mh mod + benchmark scenario.[Figure not available: see fulltext.] © 2015, The Author(s).Article Citation - WoS: 7Citation - Scopus: 8Search for Gauge Extensions of the Mssm at the Lhc(American Physical Society, 2009) Ahmed, Ali; Demir, Durmuş Ali; Frank, Mariana; Turan, İsmailThe extensions of the minimal supersymmetric model (MSSM), driving mainly from the need to solve the μ problem, involve novel matter species and gauge groups. These extended MSSM models can be searched for at the LHC via the effects of the gauge and Higgs bosons or their fermionic partners. Traditionally, the focus has been on the study of the extra forces induced by the new gauge and Higgs bosons present in such models. An alternative way of studying such effects is through the superpartners of matter species and the gauge forces. We thus consider a U(1)′ gauge extension of the MSSM, and perform an extensive study of the signatures of the model through the production and decays of the scalar quarks and gluino, which are expected to be produced copiously at the LHC. After a detailed study of the distinctive features of such models with regard to the signatures at the LHC, we carry out a detailed Monte-Carlo analysis of the signals from the process pp→nleptons+mjets+E T, and compare the resulting distributions with those predicted by the MSSM. Our results show that the searches for the extra gauge interactions in the supersymmetric framework can proceed not only through the forces mediated by the gauge and Higgs bosons but also through the superpartner forces mediated by the gauge and Higgs fermions. Analysis of the events induced by the squark/gluino decays presented here is complementary to the direct Z′ searches at the LHC.Article Citation - WoS: 13Citation - Scopus: 13Higgs Boson Masses in the Mssm With General Soft Breaking(Elsevier Ltd., 2008) Sabancı, Aslı; Hayreter, Alper; Solmaz, LeventThe operators that break supersymmetry can be holomorphic or non-holomorphic in structure. The latter do not pose any problem for gauge hierarchy and are soft provided that the particle spectrum does not contain any gauge singlets. In minimal supersymmetric model (MSSM) we discuss the impact of non-holomorphic soft-breaking terms on the Higgs sector. We find that non-holomorphic operators can cause significant changes as are best exhibited by the correlation between the masses of the charginos and Higgs bosonsArticle Citation - WoS: 6Citation - Scopus: 6Dilepton Signatures of Family Non-Universal U (1)'(Elsevier Ltd., 2007) Hayreter, AlperThe supersymmetric models extending the minimal supersymmetric Standard Model (MSSM) by an additional Abelian gauge factor U (1)′ in order to solve the μ problem do generically suffer from anomalies disrupting the gauge coupling unification found in the MSSM. The anomalies are absent if the minimal matter content necessitated by the μ problem is augmented with exotic matter species having appropriate quantum numbers. Recently, it has been shown that anomaly cancellation can also be accomplished by introducing family non-universal U (1)′ charges and non-holomorphic soft-breaking terms [D.A. Demir, G.L. Kane, T.T. Wang, Phys. Rev. D 72 (2005) 015012, hep-ph/0503290]. We discuss collider signatures of anomaly-free family non-universal U (1)′ model by analyzing dilepton production in future colliders. We find that, both at LHC and NLC, one can establish existence/absence of such a Z′ boson by simply comparing the number of dilepton production events for electron, muon and tau lepton. The signal is free of the SM background.Article Citation - WoS: 3Citation - Scopus: 3Electric Dipole Moments in U(1)' Models(American Physical Society, 2008) Hayreter, Alper; Sabancı, Aslı; Solmaz, Levent; Solmaz, SaimeWe study electric dipole moments of electrons and protons in E(6)-inspired supersymmetric models with an extra U(1) invariance. Compared to the Minimal Supersymmetric Standard Model, in addition to offering a natural solution to the μ problem and predicting a larger mass for the lightest Higgs boson, these models are found to yield suppressed electric dipole moments. © 2008 The American Physical Society.Article Citation - WoS: 78Citation - Scopus: 79Minimal U(1)' Extension of the Minimal Supersymmetric Standard Model(American Physical Society, 2005) Demir, Durmuş Ali; Kane, Gordon L.; Wang, Ting T.Motivated by the apparent need for extending the minimal supersymmetric standard model (MSSM) and perhaps mitigating naturalness problems associated with the μ parameter and fine-tuning of the soft masses, we augment the MSSM spectrum by a SM gauge singlet chiral superfield, and enlarge the gauge structure by an additional U(1)′ invariance, so that the gauge and Higgs sectors are relatively secluded. One crucial aspect of U(1)′ models is the existence of anomalies, the cancellation of which may require the inclusion of exotic matter which in turn disrupts the unification of the gauge couplings. In this work we pursue the question of canceling the anomalies with a minimal matter spectrum and no exotics. This can indeed be realized provided that U(1)′ charges are family dependent and the soft-breaking sector includes nonholomorphic operators for generating the fermion masses. We provide the most general solutions for U(1)′ charges by taking into account all constraints from gauge invariance and anomaly cancellation. We analyze various laboratory and astrophysical bounds ranging from fermion masses to relic density, for an illustrative set of parameters. The U(1)′ charges admit patterns of values for which family nonuniversality resides solely in the lepton sector, though this does not generate leptonic flavor-changing neutral currents due to the U(1)′ gauge invariance.