Search for jet extinction in the inclusive jet-pT spectrum from proton-proton collisions at s=8 TeV

Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published articles title, journal citation, and DOI.The first search at the LHC for the extinction of QCD jet production is presented, using data collected with the CMS detector corresponding to an integrated luminosity of 10.7  fb−1 of proton-proton collisions at a center-of-mass energy of 8 TeV. The extinction model studied in this analysis is motivated by the search for signatures of strong gravity at the TeV scale (terascale gravity) and assumes the existence of string couplings in the strong-coupling limit. In this limit, the string model predicts the suppression of all high-transverse-momentum standard model processes, including jet production, beyond a certain energy scale. To test this prediction, the measured transverse-momentum spectrum is compared to the theoretical prediction of the standard model. No significant deficit of events is found at high transverse momentum. A 95% confidence level lower limit of 3.3 TeV is set on the extinction mass scale

Searches for electroweak neutralino and chargino production in channels with Higgs, Z, and W bosons in pp collisions at 8 TeV

Searches for supersymmetry (SUSY) are presented based on the electroweak pair production of neutralinos and charginos, leading to decay channels with Higgs, Z, and W bosons and undetected lightest SUSY particles (LSPs). The data sample corresponds to an integrated luminosity of about 19.5 fb(-1) of proton-proton collisions at a center-of-mass energy of 8 TeV collected in 2012 with the CMS detector at the LHC. The main emphasis is neutralino pair production in which each neutralino decays either to a Higgs boson (h) and an LSP or to a Z boson and an LSP, leading to hh, hZ, and ZZ states with missing transverse energy (E-T(miss)). A second aspect is chargino-neutralino pair production, leading to hW states with E-T(miss). The decays of a Higgs boson to a bottom-quark pair, to a photon pair, and to final states with leptons are considered in conjunction with hadronic and leptonic decay modes of the Z and W bosons. No evidence is found for supersymmetric particles, and 95% confidence level upper limits are evaluated for the respective pair production cross sections and for neutralino and chargino mass values

Roll-over cyclometalation: A versatile tool to enhance the catalytic activity of transition metal complexes

Roll-over cyclometalation is a special case of cyclometalation. While in classical cyclometalation, C,H-activation (deprotonation or oxidative addition) has to occur at the ligand to result in a metallacycle, in roll-over cyclometalation the ligand in principle has the chance to undergo chelating coordination without cleavage of a C-H bond (e.g. ?2-N,N?- vs. ?2-C,N-coordination at 2,2?-bipyridines). Nature thus can decide for which route shall be followed. In this review, the basic parameters for bringing a system into roll-over cyclometalation are discussed, followed by an overview on compounds that have been published in this field during the last years. The major emphasis of this review however is on applications of roll-over cyclometalation in catalysis, a rather new field in coordination and organometallic chemistry. 2018 Elsevier B.V.Our studies on roll-over cyclometalation are supported by the German research foundation DFG within the transregional collaborative research center SFB/TRR 88 Cooperative effects in homo and heterometallic complexes (3MET) and by the state research center OPTIMAS. We furthermore gratefully acknowledge the research college MAGNENZ and the state research unit NanoKat for financial support. M. L. thanks the Konrad-Adenauer-Stiftung and A.F. thanks the Cusanuswerk for a PhD grant. Dr. Kifah S. M. Salih studied chemistry at the Al-Mustansiriyah University (Baghdad, Iraq, B.Sc. 1998) and at the University of Jordan (Amman, Jordan, M.Sc. 2004), where he finished with a master thesis on Synthesis of Some New Coumarin Derivatives. After two years working as a researcher in the group of Prof. Dr. Mohammad S. Mubarak (Univ. of Jordan), he in 2006 joined the group of Prof. Dr. Lukas J. Goo?en at the Technische Universit?t Kaiserslautern for a PhD thesis supported by a DAAD scholarship. Kifah S. M. Salih finished his PhD in 2010 with a thesis on Environmentally Benign Synthesis of Enamides via Waste-Free Catalytic Addition of Amides to Terminal Alkynes. During this time, he received the award of the Karl-Ziegler-Stiftung. He then took the opportunity to work for three years as a postdoc in the group of Prof. Dr. Werner R. Thiel (TU Kaiserslautern), where he mainly focused on the synthesis of mangetic nanoparticles an their application in catalysis. From 2014 Kifah S. M. Salih was visiting lecturer at the Sultan Qaboos University (Muscat, Oman) and in 2015 he became lecturer at the Department of Chemistry and Earth Sciences of Qatar University (Doha, Qatar). Prof. Dr. Werner R. Thiel studied chemistry at the Technische Universitt Mnchen (Germany), where he received his diploma in 1987 with a thesis on Synthesis and Characterization of High Valent (? 5 -Pentamethylcyclopentadienyl)chromium Complexes carried out in the group of Prof. Dr. Wolfgang A. Herrmann. In 1990, he received his PhD with a thesis on Synthesis, Derivatization and Characterization of Chelate Complexes of 2,2?-Bipyridine: Reactivity and Structural Aspects (TU M nchen, W. A. Herrmann). Supported by a Feodor Lynen-Grant of the Alexander von Humboldt-Stiftung , Werner R. Thiel worked for one year in the group of Prof. Dr. Didier Astruc at the Universit de Bordeaux I (Bordeaux, France). After coming back to TU Mnchen in 1991 he started with own projects which were summarized in a habilitation in 1997. In 2000 he became associate professor for inorganic chemistry at the Technische Universit?t Chemnitz (Germany) and in 2004 full professor at the Technische Universit?t Kaiserslautern (Germany). Werner R. Thiel is author of about 180 publications with a focus on transition metal catalyzed reactions and their mechanisms and on the use of porous inorganic supports in catalysis