Differential Cross Section Measurements for the Production of a W Boson in Association with Jets in Proton–Proton Collisions at $\sqrt s=7$ TeV

Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta ( pT ) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta ( HT ), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb −1 . The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa , and to next-to-leading-order calculations from BlackHat + sherpa . The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high- HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.

Combined measurements of Higgs boson couplings in proton–proton collisions at $\sqrt{s}=13\,\text {Te}\text {V} $

Muhammad Ahmad, Benjamin William Allen, Georgios Anagnostou, Konstantin Androsov, Tagir Aushev, Michele Bianco, Yixing Chen, Xin Chen, Tian Cheng, Davide Cieri, Giuseppe Codispoti, Pratyush Das, Abhisek Datta, Milos Dordevic, Dipanwita Dutta, Matthias Finger, Francesco Fiori, Daniel Gonzalez, Ruchi Gupta, Seungkyu Ha, Csaba Hajdu, Peter Hansen, Ali Harb, Miao Hu, Alexis Kalogeropoulos, Viktor Khristenko, Ji Hyun Kim, Donghyun Kim, Vineet Kumar, Sanjeev Kumar, Ajay Kumar, Ekaterina Kuznetsova, Wei Li, Jing Li, Lei Li, Ho Ling Li, Zhen Liu, Hao Liu, Werner Lustermann, Bibhuprasad Mahakud, Maren Tabea Meinhard, Thomas Muller, Ioannis Papadopoulos, Vladimir Petrov, Quentin Python, Andrea Rizzi, Paolo Ronchese, Sourav Sen, Ashish Sharma, Varun Sharma, Lesya Shchutska, Wei Shi, Kun Shi, Muhammad Shoaib, Gurpreet Singh, Jan Steggemann, Marco Trovato, Andromachi Tsirou, David Vannerom, Joao Varela, Yi Wang, Zheng Wang, Qian Wang, Siyuan Wang, Jian Wang, Mingkui Wang, Hui Wang, Xiao Wang, Muhammad Waqas, Matthias Weber, Matthias Wolf, Fan Xia, Meng Xiao, Zhirui Xu, Yong Yang

Combined measurements of the production and decay rates of the Higgs boson, as well as its couplings to vector bosons and fermions, are presented. The analysis uses the LHC proton–proton collision data set recorded with the CMS detector in 2016 at

\sqrt{s}=13\,\text {Te}\text {V}

, corresponding to an integrated luminosity of 35.9

{\,\text {fb}^{-1}}

. The combination is based on analyses targeting the five main Higgs boson production mechanisms (gluon fusion, vector boson fusion, and associated production with a

\mathrm {W}

\mathrm {Z}

boson, or a top quark-antiquark pair) and the following decay modes:

\mathrm {H} \rightarrow \gamma \gamma

\mathrm {Z}\mathrm {Z}

\mathrm {W}\mathrm {W}

\mathrm {\tau }\mathrm {\tau }

\mathrm {b} \mathrm {b}

, and

\mathrm {\mu }\mathrm {\mu }

. Searches for invisible Higgs boson decays are also considered. The best-fit ratio of the signal yield to the standard model expectation is measured to be

\mu =1.17\pm 0.10

, assuming a Higgs boson mass of

125.09\,\text {Ge}\text {V}

. Additional results are given for various assumptions on the scaling behavior of the production and decay modes, including generic parametrizations based on ratios of cross sections and branching fractions or couplings. The results are compatible with the standard model predictions in all parametrizations considered. In addition, constraints are placed on various two Higgs doublet models.

Springer2019

Measurement of the ratio $\mathcal B(t \to Wb)/\mathcal B(t \to Wq)$ in pp collisions at $\sqrt{s}$ = 8 TeV

Muhammad Ahmad, Georgios Anagnostou, Konstantin Androsov, Alexandre Aubin, Giovanni Bianchi, Roberto Castello, Yixing Chen, Tian Cheng, Giuseppe Codispoti, Alessandro Degano, Charles Dietz, Milos Dordevic, Dipanwita Dutta, Matthias Finger, Francesco Fiori, Yifei Guo, Ruchi Gupta, Csaba Hajdu, Alexis Kalogeropoulos, Ji Hyun Kim, Donghyun Kim, Vineet Kumar, Ajay Kumar, Sanjeev Kumar, Ekaterina Kuznetsova, Wei Li, Ho Ling Li, Shuai Liu, Hao Liu, Werner Lustermann, Matteo Marone, Thomas Muller, Ioannis Papadopoulos, Vladimir Petrov, Quentin Python, Andrea Rizzi, Paolo Ronchese, Sourav Sen, Ashish Sharma, Varun Sharma, Lesya Shchutska, Muhammad Shoaib, Michal Simon, Gurpreet Singh, Jan Steggemann, Wei Sun, Andromachi Tsirou, Paul Turner, Joao Varela, Zheng Wang, Xiao Wang, Jian Wang, Qian Wang, Matthias Weber, Matthias Wolf, Fan Yang, Yong Yang, Kai Yi, Lei Zhang, Yu Zheng

The ratio of the top-quark branching fractions R=B(t→Wb)/B(t→Wq) , where the denominator includes the sum over all down-type quarks ( q=b,s,d ), is measured in the tt¯ dilepton final state with proton–proton collision data at s=8 TeV from an integrated luminosity of 19.7 fb −1 , collected with the CMS detector. In order to quantify the purity of the signal sample, the cross section is measured by fitting the observed jet multiplicity, thereby constraining the signal and background contributions. By counting the number of b jets per event, an unconstrained value of R=1.014±0.003(stat.)±0.032(syst.) is measured, in a good agreement with current precision measurements in electroweak and flavour sectors. A lower limit R>0.955 at the 95% confidence level is obtained after requiring R≤1 , and a lower limit on the Cabibbo–Kobayashi–Maskawa matrix element |Vtb|>0.975 is set at 95% confidence level. The result is combined with a previous CMS measurement of the t -channel single-top-quark cross section to determine the top-quark total decay width, Γt=1.36±0.02(stat.)−0.11+0.14(syst.) GeV .

2014

Combined measurements of Higgs boson couplings in proton–proton collisions at $\sqrt{s}=13\,\text {Te}\text {V} $

\sqrt{s}=13\,\text {Te}\text {V}

, corresponding to an integrated luminosity of 35.9

{\,\text {fb}^{-1}}

. The combination is based on analyses targeting the five main Higgs boson production mechanisms (gluon fusion, vector boson fusion, and associated production with a

\mathrm {W}

\mathrm {Z}

boson, or a top quark-antiquark pair) and the following decay modes:

\mathrm {H} \rightarrow \gamma \gamma

\mathrm {Z}\mathrm {Z}

\mathrm {W}\mathrm {W}

\mathrm {\tau }\mathrm {\tau }

\mathrm {b} \mathrm {b}

, and

\mathrm {\mu }\mathrm {\mu }

. Searches for invisible Higgs boson decays are also considered. The best-fit ratio of the signal yield to the standard model expectation is measured to be

\mu =1.17\pm 0.10

, assuming a Higgs boson mass of

125.09\,\text {Ge}\text {V}

Springer2019

Differential Cross Section Measurements for the Production of a W Boson in Association with Jets in Proton–Proton Collisions at $\sqrt s=7$ TeV

Combined measurements of Higgs boson couplings in proton–proton collisions at $\sqrt{s}=13\,\text {Te}\text {V} $

Measurement of the ratio $\mathcal B(t \to Wb)/\mathcal B(t \to Wq)$ in pp collisions at $\sqrt{s}$ = 8 TeV

Observation of the Higgs boson decay to a pair of $\tau$ leptons with the CMS detector

Measurement of the ratio $\mathcal B(t \to Wb)/\mathcal B(t \to Wq)$ in pp collisions at $\sqrt{s}$ = 8 TeV

Observation of the Higgs boson decay to a pair of $\tau$ leptons with the CMS detector

Combined measurements of Higgs boson couplings in proton–proton collisions at $\sqrt{s}=13\,\text {Te}\text {V} $