Fizik Mühendisliği Bölümü Makale Koleksiyonuhttps://hdl.handle.net/11655/4312024-03-29T05:40:01Z2024-03-29T05:40:01ZSearch For New Physics In Final States With A Single Photon And Missing Transverse Momentum In Proton-Proton Collisions At <Mml:Msqrt>S</Mml:Msqrt>=13 TevThe CMS CollaborationSen,S.https://hdl.handle.net/11655/245202021-06-04T07:38:08Z2019-01-01T00:00:00ZSearch For New Physics In Final States With A Single Photon And Missing Transverse Momentum In Proton-Proton Collisions At <Mml:Msqrt>S</Mml:Msqrt>=13 Tev
The CMS Collaboration; Sen,S.
A search is conducted for new physics in final states containing a photon and missing transverse momentum in proton-proton collisions at <mml:msqrt>s</mml:msqrt>=13 TeV, using the data collected in 2016 by the CMS experiment at the LHC, corresponding to an integrated luminosity of 35.9 fb(-1). No deviations from the predictions of the standard model are observed. The results are interpreted in the context of dark matter production and models containing extra spatial dimensions, and limits on new physics parameters are calculated at 95% confidence level. For the two simplified dark matter production models considered, the observed (expected) lower limits on the mediator masses are both 950 (1150) GeV for 1 GeV dark matter mass. For an effective electroweak-dark matter contact interaction, the observed (expected) lower limit on the suppression parameter is 850 (950) GeV. Values of the effective Planck scale up to 2.85-2.90 TeV are excluded for between 3 and 6 extra spatial dimensions.
2019-01-01T00:00:00ZSearch For New Particles Decaying To A Jet And An Emerging JetThe CMS CollaborationSen,S.https://hdl.handle.net/11655/245192021-06-03T09:15:18Z2019-01-01T00:00:00ZSearch For New Particles Decaying To A Jet And An Emerging Jet
The CMS Collaboration; Sen,S.
A search is performed for events consistent with the pair production of a new heavy particle that acts as a mediator between a dark sector and normal matter, and that decays to a light quark and a new fermion called a dark quark. The search is based on data corresponding to an integrated luminosity of 16.1 fb(-1) from proton-proton collisions at =13 TeV collected by the CMS experiment at the LHC in 2016. The dark quark is charged only under a new quantum-chromodynamics-like force, and forms an emerging jet via a parton shower, containing long-lived dark hadrons that give rise to displaced vertices when decaying to standard model hadrons. The data are consistent with the expectation from standard model processes. Limits are set at 95% confidence level excluding dark pion decay lengths between 5 and 225 mm for dark mediators with masses between 400 and 1250 GeV. Decay lengths smaller than 5 and greater than 225 mm are also excluded in the lower part of this mass range. The dependence of the limit on the dark pion mass is weak for masses between 1 and 10 GeV. This analysis is the first dedicated search for the pair production of a new particle that decays to a jet and an emerging jet.
2019-01-01T00:00:00ZSearch For Narrow H Gamma Resonances In Proton-Proton Collisions At Root S=13 TevThe CMS CollaborationSen,S.https://hdl.handle.net/11655/245182021-06-04T07:13:45Z2019-01-01T00:00:00ZSearch For Narrow H Gamma Resonances In Proton-Proton Collisions At Root S=13 Tev
The CMS Collaboration; Sen,S.
A search for heavy, narrow resonances decaying to a Higgs boson and a photon (Hy) has been performed in proton-proton collision data at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb-1 collected with the CMS detector at the LHC in 2016. Events containing a photon and a Lorentz-boosted hadronically decaying Higgs boson reconstructed as a single, large-radius jet are considered, and the y jet invariant mass spectrum is analyzed for the presence of narrow resonances. To increase the sensitivity of the search, events are categorized depending on whether or not the large-radius jet can be identified as a result of the merging of two jets originating from b quarks. Results in both categories are found to agree with the predictions of the standard model. Upper limits on the production rate of Hy resonances are sct as a function of their mass in the range of 720-3250 GeV, representing thc most stringent constraints to date.
2019-01-01T00:00:00ZSearch For New Physics In Top Quark Production In Dilepton Final States In Proton-Proton Collisions At Root S=13 TevThe CMS CollaborationSen,S.https://hdl.handle.net/11655/245212021-06-03T09:15:18Z2019-01-01T00:00:00ZSearch For New Physics In Top Quark Production In Dilepton Final States In Proton-Proton Collisions At Root S=13 Tev
The CMS Collaboration; Sen,S.
A search for new physics in top quark production is performed in proton-proton collisions at 13 TeV. The data set corresponds to an integrated luminosity of 35.9 fb(-1) collected in 2016 with the CMS detector. Events with two opposite-sign isolated leptons (electrons or muons), and b quark jets in the final state are selected. The search is sensitive to new physics in top quark pair production and in single top quark production in association with a W boson. No significant deviation from the standard model expectation is observed. Results are interpreted in the framework of effective field theory and constraints on the relevant effective couplings are set, one at a time, using a dedicated multivariate analysis. This analysis differs from previous searches for new physics in the top quark sector by explicitly separating tW from t (t) over bar events and exploiting the specific sensitivity of the tW process to new physics.
2019-01-01T00:00:00Z