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Publication

Search for Supersymmetry Using Razor Variables in Events with $b$-Tagged Jets in $pp$ Collisions at $\sqrt{s} =$ 8 TeV

An inclusive search for supersymmetry in events with at least one b-tagged jet is performed using proton-proton collision data collected by the CMS experiment in 2012 at a center-of-mass energy of 8 TeV. The data set size corresponds to an integrated luminosity of 19.3 fb−1. The two-dimensional distribution of the razor variables R2 and MR is studied in events with and without leptons. The data are found to be consistent with the expected background, which is modeled with an empirical function. Exclusion limits on supersymmetric particle masses at a 95% confidence level are derived in several simplified supersymmetric scenarios for several choices of the branching fractions. By combining the likelihoods of a search in events without leptons and a search that requires a single lepton (electron or muon), an improved bound on the top-squark mass is obtained. Assuming the lightest supersymmetric particle to be stable and weakly interacting, and to have a mass of 100 GeV, the branching-fraction-dependent (-independent) production of gluinos is excluded for gluino masses up to 1310 (1175) GeV. The corresponding limit for top-squark pair production is 730 (645) GeV.

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Muhammad Ahmad, Georgios Anagnostou, Konstantin Androsov, Alexandre Aubin, Roberto Castello, Yixing Chen, Tian Cheng, Giuseppe Codispoti, Alessandro Degano, Charles Dietz, Milos Dordevic, Dipanwita Dutta, Matthias Finger, Francesco Fiori, Ruchi Gupta, Csaba Hajdu, Alexis Kalogeropoulos, Donghyun Kim, Ji Hyun Kim, Vineet Kumar, Ajay Kumar, Sanjeev Kumar, Ekaterina Kuznetsova, Ho Ling Li, Wei Li, Hao Liu, Shuai 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, Jian Wang, Rui Wang, Qian Wang, Matthias Weber, Matthias Wolf, Zhirui Xu, Fan Yang, Yong Yang, Kai Yi
2015
Article

Résumé

Official source

https://infoscience.epfl.ch/record/274730?ln=fr

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Concepts associés (15)

Concepts associés

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Publications associées (109)

Publications associées

Chargement

Luminosité

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Intervalle de confiance

vignette|Chaque ligne montre 20 échantillons tirés selon la loi normale de moyenne μ. On y montre l'intervalle de confiance de niveau 50% pour la moyenne correspondante aux 20 échantillons, marquée pa

Donnée

Une donnée est ce qui est connu et qui sert de point de départ à un raisonnement ayant pour objet la détermination d'une solution à un problème en relation avec cette donnée. Cela peut être une descr

Search for additional neutral MSSM Higgs bosons in the $\tau\tau$ final state in proton-proton collisions at $\sqrt{s}=$ 13 TeV

Muhammad Ahmad, Benjamin William Allen, Georgios Anagnostou, Konstantin Androsov, Tagir Aushev, Michele Bianco, Roberto Castello, Xin Chen, Yixing Chen, Tian Cheng, Davide Cieri, Giuseppe Codispoti, Pratyush Das, Abhisek Datta, Alessandro Degano, 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, Ajay Kumar, Sanjeev Kumar, Vineet Kumar, Ekaterina Kuznetsova, Wei Li, Ho Ling Li, Jing Li, Shuai Liu, Zhen Liu, Hao Liu, Werner Lustermann, Bibhuprasad Mahakud, Maren Tabea Meinhard, Amr Mohamed, Thomas Muller, Ioannis Papadopoulos, Vladimir Petrov, Quentin Python, Andrea Rizzi, Paolo Ronchese, Ashish Sharma, Varun Sharma, Lesya Shchutska, Wei Shi, Kun Shi, Muhammad Shoaib, Gurpreet Singh, Jan Steggemann, Marco Trovato, Andromachi Tsirou, David Vannerom, Joao Varela, Hui Wang, Qian Wang, Mingkui Wang, Zheng Wang, Yi Wang, Siyuan Wang, Jian Wang, Muhammad Waqas, Matthias Weber, Matthias Wolf, Wenjing Wu, Fan Xia, Meng Xiao, Zhirui Xu, Yong Yang, Kai Yi

A search is presented for additional neutral Higgs bosons in the τ τ final state in proton-proton collisions at the LHC. The search is performed in the context of the minimal supersymmetric extension of the standard model (MSSM), using the data collected with the CMS detector in 2016 at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb

^{−1}

. To enhance the sensitivity to neutral MSSM Higgs bosons, the search includes production of the Higgs boson in association with b quarks. No significant deviation above the expected background is observed. Model-independent limits at 95% confidence level (CL) are set on the product of the branching fraction for the decay into τ leptons and the cross section for the production via gluon fusion or in association with b quarks. These limits range from 18 pb at 90 GeV to 3.5 fb at 3.2 TeV for gluon fusion and from 15 pb (at 90 GeV) to 2.5 fb (at 3.2 TeV) for production in association with b quarks, assuming a narrow width resonance. In the m

_{h}^{hod +}

scenario these limits translate into a 95% CL exclusion of tan β > 6 for neutral Higgs boson masses below 250 GeV, where tan β is the ratio of the vacuum expectation values of the neutral components of the two Higgs doublets. The 95% CL exclusion contour reaches 1.6 TeV for tan β = 60.

2018

Chargement

Searches for $R$-parity-violating supersymmetry in $pp $collisions at $\sqrt(s) =$ 8 TeV in final states with 0-4 leptons

Muhammad Ahmad, Georgios Anagnostou, Konstantin Androsov, Alexandre Aubin, Roberto Castello, Juan Ramon Castiñeiras De Saa, Yixing Chen, Tian Cheng, Davide Cieri, Giuseppe Codispoti, Alessandro Degano, Charles Dietz, Milos Dordevic, Dipanwita Dutta, Matthias Finger, Francesco Fiori, Daniel Gonzalez, Ruchi Gupta, Csaba Hajdu, Peter Hansen, Ali Harb, Alexis Kalogeropoulos, Viktor Khristenko, Donghyun Kim, Ji Hyun Kim, Sanjeev Kumar, Ajay Kumar, Vineet Kumar, Ekaterina Kuznetsova, Wei Li, Ho Ling Li, Hao Liu, Shuai 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, Muhammad Shoaib, Michal Simon, Gurpreet Singh, Jan Steggemann, Xin Sun, Wei Sun, Marco Trovato, Andromachi Tsirou, Paul Turner, Joao Varela, Jian Wang, Qian Wang, Yi Wang, Rui Wang, Zheng Wang, Mingkui Wang, Siyuan Wang, Muhammad Waqas, Matthias Weber, Matthias Wolf, Fan Xia, Meng Xiao, Zhirui Xu, Yong Yang, Kai Yi

Results are presented from searches for R-parity-violating supersymmetry in events produced in pp collisions at s=8 TeV at the LHC. Final states with 0, 1, 2, or multiple leptons are considered independently. The analysis is performed on data collected by the CMS experiment corresponding to an integrated luminosity of 19.5 fb-1. No excesses of events above the standard model expectations are observed, and 95% confidence level limits are set on supersymmetric particle masses and production cross sections. The results are interpreted in models featuring R-parity-violating decays of the lightest supersymmetric particle, which in the studied scenarios can be either the gluino, a bottom squark, or a neutralino. In a gluino pair production model with baryon number violation, gluinos with a mass less than 0.98 and 1.03 TeV are excluded, by analyses in a fully hadronic and one-lepton final state, respectively. An analysis in a dilepton final state is used to exclude bottom squarks with masses less than 307 GeV in a model considering bottom squark pair production. Multilepton final states are considered in the context of either strong or electroweak production of superpartners and are used to set limits on the masses of the lightest supersymmetric particles. These limits range from 300 to 900 GeV in models with leptonic and up to approximately 700 GeV in models with semileptonic R-parity-violating couplings.

2016

Chargement

Search for supersymmetry with a compressed mass spectrum in events with a soft $\tau$ lepton, a highly energetic jet, and large missing transverse momentum in proton-proton collisions at $\sqrt{s}=$ 13 TeV

Muhammad Ahmad, Benjamin William Allen, Georgios Anagnostou, Konstantin Androsov, Tagir Aushev, Thomas Berger, Michele Bianco, Alessandro Caratelli, Xin Chen, Yixing Chen, Tian Cheng, Giuseppe Codispoti, Pratyush Das, Abhisek Datta, Milos Dordevic, Dipanwita Dutta, Matthias Finger, Francesco Fiori, Sebastiana Gianì, 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, Ajay Kumar, Sanjeev Kumar, Ekaterina Kuznetsova, Federica Legger, Wei Li, Lei Li, Yiming Li, Jing Li, Zhen Liu, Werner Lustermann, Bibhuprasad Mahakud, Maren Tabea Meinhard, Amr Mohamed, Thomas Muller, Ioannis Papadopoulos, Vladimir Petrov, Jessica Prisciandaro, Quentin Python, Andrea Rizzi, Paolo Ronchese, Valérie Scheurer, Sourav Sen, Varun Sharma, Ashish Sharma, Lesya Shchutska, Wei Shi, Kun Shi, Muhammad Shoaib, Jan Steggemann, Marco Trovato, Andromachi Tsirou, David Vannerom, Joao Varela, Jian Wang, Qian Wang, Siyuan Wang, Xiao Wang, Hui Wang, Mingkui Wang, Zheng Wang, Yi Wang, Muhammad Waqas, Matthias Weber, Matthias Wolf, Fan Xia, Meng Xiao, Yong Yang, Yi Zhang

The first search for supersymmetry in events with an experimental signature of one soft, hadronically decaying

\tau

lepton, one energetic jet from initial-state radiation, and large transverse momentum imbalance is presented. These event signatures are consistent with direct or indirect production of scalar

\tau

leptons (

\tilde{\tau}

) in supersymmetric models that exhibit coannihilation between the

\tilde{\tau}

and the lightest neutralino (

\tilde{\chi}^0_1

), and that could generate the observed relic density of dark matter. The data correspond to an integrated luminosity of 77.2 fb

^{-1}

of proton-proton collisions at

\sqrt{s}=

13 TeV collected with the CMS detector at the LHC in 2016 and 2017. The results are interpreted in a supersymmetric scenario with a small mass difference (

\Delta m

) between the chargino (

\tilde{\chi}^\pm_1

) or next-to-lightest neutralino (

\tilde{\chi}^0_2

), and the

\tilde{\chi}^0_1

. The mass of the

\tilde{\tau}

is assumed to be the average of the

\tilde{\chi}^\pm_1

and

\tilde{\chi}^0_1

masses. The data are consistent with standard model background predictions. Upper limits at 95% confidence level are set on the sum of the

\tilde{\chi}^\pm_1

\tilde{\chi}^0_2

, and

\tilde{\tau}

production cross sections for

\Delta m(\tilde{\chi}^\pm_1, \tilde{\chi}^0_1) =

50 GeV, resulting in a lower limit of 290 GeV on the mass of the

\tilde{\chi}^\pm_1

, which is the most stringent to date and surpasses the bounds from the LEP experiments.

2019

Chargement