scholarly journals Search for chargino-neutralino production in events with Higgs and W bosons using 137 fb−1 of proton-proton collisions at $$ \sqrt{s} $$ = 13 TeV

2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
◽  
A. Tumasyan ◽  
W. Adam ◽  
J. W. Andrejkovic ◽  
T. Bergauer ◽  
...  
Keyword(s):  
Higgs Boson ◽  
W Boson ◽  
Center Of Mass ◽  
W Bosons ◽  
Proton Proton ◽  
Proton Collisions ◽  
Center Of Mass Energy ◽  
Missing Transverse Momentum ◽  
The Masses ◽  
Proton Proton Collisions

Abstract A search for electroweak production of supersymmetric (SUSY) particles in final states with one lepton, a Higgs boson decaying to a pair of bottom quarks, and large missing transverse momentum is presented. The search uses data from proton-proton collisions at a center-of-mass energy of 13 TeV collected using the CMS detector at the LHC, corresponding to an integrated luminosity of 137 fb−1. The observed yields are consistent with backgrounds expected from the standard model. The results are interpreted in the context of a simplified SUSY model of chargino-neutralino production, with the chargino decaying to a W boson and the lightest SUSY particle (LSP) and the neutralino decaying to a Higgs boson and the LSP. Charginos and neutralinos with masses up to 820 GeV are excluded at 95% confidence level when the LSP mass is small, and LSPs with mass up to 350 GeV are excluded when the masses of the chargino and neutralino are approximately 700 GeV.

Implementation of the CMS-HIG-18-011 analysis in the MadAnalysis 5 framework (exotic Higgs decays via two pseudoscalars with two muons and two b-jets; 35.9 fb−1)

2020 ◽  
pp. 2141003
Author(s):  
Joon-Bin Lee ◽  
Jehyun Lee
Keyword(s):  
Higgs Boson ◽  
Center Of Mass ◽  
Final State ◽  
Proton Proton ◽  
Proton Collisions ◽  
Center Of Mass Energy ◽  
Cms Experiment ◽  
The Standard Model ◽  
Proton Proton Collisions ◽  
Selection Of

We present the implementation in the MadAnalysis 5 framework of the CMS-HIG-18-011 search for exotic decays of the Standard Model Higgs boson, in which the Higgs boson is assumed to decay into a pair of light pseudoscalar [Formula: see text], that then further decay into a di-muon and di-[Formula: see text]-jet final state. This analysis considers proton-proton collisions at a center-of-mass energy of 13 TeV and data collected by the CMS experiment in 2016, with an integrated luminosity of 35.9 fb[Formula: see text]. We present a selection of recast predictions, obtained with MadAnalysis 5 and Delphes 3, that include a few differential distributions, yields, and efficiencies. We show that they agree at a level of a few percent with public CMS results.

scholarly journals Search for production of four top quarks in final states with same-sign or multiple leptons in proton–proton collisions at $$\sqrt{s}=13$$ $$\,\text {TeV}$$

2020 ◽  
Vol 80 (2) ◽  
Author(s):  
A. M. Sirunyan ◽  
◽  
A. Tumasyan ◽  
W. Adam ◽  
F. Ambrogi ◽  
...  
Keyword(s):  
Higgs Boson ◽  
Top Quark ◽  
Center Of Mass ◽  
Top Quarks ◽  
Higgs Doublet ◽  
Effective Field ◽  
Proton Proton ◽  
Proton Collisions ◽  
Center Of Mass Energy ◽  
Proton Proton Collisions

Abstract The standard model (SM) production of four top quarks ($$\text {t} {}{\overline{\text {t}}} \text {t} {}{\overline{\text {t}}} $$tt¯tt¯) in proton–proton collisions is studied by the CMS Collaboration. The data sample, collected during the 2016–2018 data taking of the LHC, corresponds to an integrated luminosity of 137$$\,\text {fb}^{-1}$$fb-1 at a center-of-mass energy of 13$$\,\text {TeV}$$TeV. The events are required to contain two same-sign charged leptons (electrons or muons) or at least three leptons, and jets. The observed and expected significances for the $$\text {t} {}{\overline{\text {t}}} \text {t} {}{\overline{\text {t}}} $$tt¯tt¯ signal are respectively 2.6 and 2.7 standard deviations, and the $$\text {t} {}{\overline{\text {t}}} \text {t} {}{\overline{\text {t}}} $$tt¯tt¯ cross section is measured to be $$12.6^{+5.8}_{-5.2}\,\text {fb} $$12.6-5.2+5.8fb. The results are used to constrain the Yukawa coupling of the top quark to the Higgs boson, $$y_{\text {t}}$$yt, yielding a limit of $$|y_{\text {t}}/y_{\text {t}}^{\mathrm {SM}} | < 1.7$$|yt/ytSM|<1.7 at $$95\%$$95% confidence level, where $$y_{\text {t}}^{\mathrm {SM}}$$ytSM is the SM value of $$y_{\text {t}}$$yt. They are also used to constrain the oblique parameter of the Higgs boson in an effective field theory framework, $$\hat{H}<0.12$$H^<0.12. Limits are set on the production of a heavy scalar or pseudoscalar boson in Type-II two-Higgs-doublet and simplified dark matter models, with exclusion limits reaching 350–470$$\,\text {GeV}$$GeV and 350–550$$\,\text {GeV}$$GeV for scalar and pseudoscalar bosons, respectively. Upper bounds are also set on couplings of the top quark to new light particles.

Implementation of the CMS-EXO-17-015 analysis in the MadAnalysis 5 framework (leptoquark and dark matter with one muon, one jet and missing transverse energy; 77.4 fb−1)

2020 ◽  
pp. 2141002
Author(s):  
Benjamin Fuks ◽  
Adil Jueid
Keyword(s):  
Dark Matter ◽  
Transverse Energy ◽  
Center Of Mass ◽  
Missing Transverse Energy ◽  
Final State ◽  
Proton Proton ◽  
Proton Collisions ◽  
Center Of Mass Energy ◽  
Scalar Leptoquarks ◽  
Proton Proton Collisions

We present an implementation of the CMS-EXO-17-015 analysis in the MadAnalysis 5 framework. The analysis targets a search for dark matter in a channel in which it originates from the production and decay of a pair of scalar leptoquarks. This search considers a luminosity [Formula: see text] of CMS data collected in 2016 and 2017, in proton-proton collisions at a center-of-mass energy of 13 TeV. The final state signature is comprised of one isolated highly-energetic muon, one jet with a large transverse momentum and a significant amount of missing transverse energy. We validate our implementation in MadAnalysis 5 for a specific leptoquark/dark matter benchmark scenario. In particular, we compare predictions obtained with MadAnalysis 5 with the official CMS results for various kinematical distributions relevant for the CMS-EXO-17-015 analysis, as well as detailed cut-flow tables. We have found an excellent agreement.

scholarly journals Gaugino production in proton-proton collisions at a center-of-mass energy of 8 TeV

2012 ◽  
Vol 2012 (10) ◽  
Author(s):  
Benjamin Fuks ◽  
Michael Klasen ◽  
David R. Lamprea ◽  
Marcel Rothering
Keyword(s):  
Center Of Mass ◽  
Mass Energy ◽  
Proton Proton ◽  
Proton Collisions ◽  
Center Of Mass Energy ◽  
8 Tev ◽  
Proton Proton Collisions

scholarly journals Search for physics beyond the standard model in events with jets and two same-sign or at least three charged leptons in proton-proton collisions at $$\sqrt{s}=13\,{\text {TeV}} $$

2020 ◽  
Vol 80 (8) ◽  
Author(s):  
A. M. Sirunyan ◽  
◽  
A. Tumasyan ◽  
W. Adam ◽  
F. Ambrogi ◽  
...  
Keyword(s):  
Standard Model ◽  
Cross Sections ◽  
Center Of Mass ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Proton Proton ◽  
Proton Collisions ◽  
Center Of Mass Energy ◽  
Charged Leptons ◽  
Proton Proton Collisions

Abstract A data sample of events from proton-proton collisions with at least two jets, and two isolated same-sign or three or more charged leptons, is studied in a search for signatures of new physics phenomena. The data correspond to an integrated luminosity of $$137{\,{\text {fb}}^{-1}} $$137fb-1 at a center-of-mass energy of $$13\,{\text {TeV}} $$13TeV, collected in 2016–2018 by the CMS experiment at the LHC. The search is performed using a total of 168 signal regions defined using several kinematic variables. The properties of the events are found to be consistent with the expectations from standard model processes. Exclusion limits at 95% confidence level are set on cross sections for the pair production of gluinos or squarks for various decay scenarios in the context of supersymmetric models conserving or violating R parity. The observed lower mass limits are as large as $$2.1\,{\text {TeV}} $$2.1TeV for gluinos and $$0.9\,{\text {TeV}} $$0.9TeV for top and bottom squarks. To facilitate reinterpretations, model-independent limits are provided in a set of simplified signal regions.

Production of a light top-squark pair in association with a light non-SM Higgs boson within the NMSSM from proton–proton collisions at s = 13 TeV and 33 TeV

2019 ◽  
Vol 34 (22) ◽  
pp. 1950125
Author(s):  
Siba P. Das ◽  
Jorge F. Fraga ◽  
Carlos Avila
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Cross Sections ◽  
Center Of Mass ◽  
Top Squark ◽  
Proton Proton ◽  
Proton Collisions ◽  
Physical Constraints ◽  
Leptonic Decays ◽  
Proton Proton Collisions

We study the production of a light top-squark pair in association with the lightest Higgs boson [Formula: see text], as predicted by the Next-to-Minimal Supersymmetric Standard Model (NMSSM) in proton–proton collisions at center-of-mass energies of 13 TeV and 33 TeV. We scan randomly about 10 million points of the NMSSM parameter space, allowing all possible decays of the lightest top-squark and lightest Higgs boson, with no further assumptions, except for known physical constraints such as perturbative bounds, dark matter relic density consistent with recent Planck experiment measurements, Higgs mass bounds on the next to lightest Higgs boson, [Formula: see text], assuming it is consistent with LHC measurements for the Standard Model Higgs boson, LEP bounds for the chargino mass and [Formula: see text] invisible width, experimental bounds on [Formula: see text] meson rare decays and some LHC experimental bounds on SUSY particle spectra different to the particles involved in our analysis. We find that for low mass top-squark, the dominating decay mode is [Formula: see text] with [Formula: see text]. We use three benchmark points with the highest cross-sections, which naturally fall within the compressed spectra of the top-squark, and make a phenomenological analysis to determine the optimal event selection that maximizes the signal significance over backgrounds. We focus on the leptonic decays of both [Formula: see text]’s and the decay of the lightest Higgs boson into [Formula: see text]-quarks [Formula: see text]. Our results show that the high luminosity LHC will have limitations to observe the studied SUSY scenario and only a proton collider with a collision energy above 33 TeV will be able to observe this signal with more than three standard deviations over background, albeit for stop masses below 300 GeV.

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