A search is performed for heavy metastable particles that decay into jet pairs with a macroscopic lifetime (ctau ~ 1 cm) in ppbar collisions at sqrt{s} = 1.96 TeV using data from the CDF II detector at Fermilab corresponding to an integrated luminosity of 3.2 fb^-1. To estimate the standard model background a data-driven approach is used. Probability-density functions are constructed to model secondary vertices from known processes. No statistically significant excess is observed above the background. Limits on the production cross section in a hidden valley benchmark phenomenology are set for various Higgs boson masses as well as metastable particle masses and lifetimes.
We present a search for neutral supersymmetric Higgs bosons decaying to tau pairs produced in p-pbar collisions at sqrt(s) = 1.96 TeV. The data, corresponding to 310 pb^(-1) integrated luminosity, were collected with the CDF II detector at the Tevatron collider at Fermilab. No significant excess above the standard model backgrounds is observed. We set exclusion limits on the production cross section times branching fraction to tau pairs for Higgs masses in the range from 90 to 250 GeV/c^2.
A new heavy gauge boson, W', decaying to a muon and a neutrino, is searched for in pp collisions at a centre-of-mass of 7 TeV. The data, collected with the CMS detector at the LHC, correspond to an integrated luminosity of 36 inverse picobarns. No significant excess of events above the standard model expectation is found in the transverse mass distribution of the muon-neutrino system. Masses below 1.40 TeV are excluded at the 95% confidence level for a sequential standard-model-like W'. The W' mass lower limit increases to 1.58 TeV when the present analysis is combined with the CMS result for …
Many extensions of the Standard Model predict new resonances decaying to a $Z$, $W$, or Higgs boson and a photon. This paper presents a search for such resonances produced in $pp$ collisions at $\sqrt{s} = 13$ $\mathrm{TeV}$ using a dataset with an integrated luminosity of 36.1 fb$^{-1}$ collected by the ATLAS detector at the Large Hadron Collider. The $Z/W/H$ bosons are identified through their decays to hadrons. The data are found to be consistent with the Standard Model expectation in the entire investigated mass range. Upper limits are set on the production cross section times branching fr…
Searches for high-mass resonances decaying to pairs of standard model bosons using ATLAS and CMS detectors are presented. The searches use 15 - 36 $\textrm{fb}^{-1}$ of proton-proton collision data collected at the centre-of-mass energy of 13 TeV at the LHC. Many different final states have been considered and the results are interpreted in a range of theories beyond the standard model of particle physics, most common being heavy vector triplet and warped extra dimensions.
The high-mass spectrum of lepton and photon pairs is sensitive to a broad range of new physics. Examples are extra dimensions and new gauge bosons such as the W' and Z'. Additionally, electron compositeness would result in excited electrons that decay into an electron and a photon. We report the latest results of searches for high-mass dilepton, diphoton, and electron-photon resonances by the CDF and D0 experiments at the Tevatron.
We have used 19 pb**-1 of data collected with the Collider Detector at Fermilab to search for new particles decaying to dijets. We exclude at 95% confidence level models containing the following new particles: axigluons with mass between 200 and 870 GeV, excited quarks with mass between 80 and 570 GeV, and color octet technirhos with mass between 320 and 480 GeV.
This Letter presents a search for the production of new heavy resonances decaying into a Higgs boson and a photon using proton-proton collision data at $\sqrt{s}=13$ TeV collected by the ATLAS detector at the LHC. The data correspond to an integrated luminosity of 139 fb$^{-1}$. The analysis is performed by reconstructing hadronically decaying Higgs boson $(H\to b\bar{b})$ candidates as single large-radius jets. A novel algorithm using information about the jet constituents in the center-of-mass frame of the jet is implemented to identify the two $b$-quarks in the single jet. No significant ex…
The ATLAS detector at the LHC is used to search for high-mass states, such as heavy charged gauge bosons (W'), decaying to a charged lepton (electron or muon) and a neutrino. Results are presented based on the analysis of pp collisions at a centre-of-mass energy of 7 TeV corresponding to an integrated luminosity of 4.7 fb-1. No excess beyond Standard Model expectations is observed. A W' with Sequential Standard Model couplings is excluded at the 95% credibility level for masses up to 2.55 TeV. Excited chiral bosons (W*) with equivalent coupling strength are excluded for masses up to 2.42 TeV.
A search for the production of neutral Higgs bosons Phi decaying into tau^+tau^- final states in p-pbar collisions at a center-of-mass energy of 1.96 TeV is presented. The data, corresponding to an integrated luminosity of up to 348 pb^-1, were collected by the D0 experiment at the Fermilab Tevatron Collider. Since no excess compared to the expectation from standard model processes is found, limits on the production cross section times branching ratio are set. The results are combined with those obtained from the D0 search for Phi b(b) to b-bbar-b(bbar) and are interpreted in the minimal super…
A search for resonances decaying to top quark-antiquark pairs is performed using a dilepton+jets data sample recorded by the CMS experiment at the LHC in pp collisions at sqrt(s) = 7 TeV corresponding to an integrated luminosity of 5.0 inverse femtobarns. No significant deviations from the standard model background are observed. Upper limits are presented for the production cross section times branching fraction of top quark-antiquark resonances for masses from 750 to 3000 GeV. In particular, the existence of a leptophobic topcolor particle Z' is excluded at the 95% confidence level for resona…
We have searched for a heavy resonance decaying into a Z+jet final state in p-pbar collisions at a center of mass energy of 1.96 TeV at the Fermilab Tevatron collider using the D0 detector. No indication for such a resonance was found in a data sample corresponding to an integrated luminosity of 370/pb. We set upper limits on the cross section times branching fraction for heavy resonance production at the 95% C.L. as a function of the resonance mass and width. The limits are interpreted within the framework of a specific model of excited quark production.
We present the results of the first search for a new particle X produced in $p\bar{p}$ collisions at \sqrt{s}=1.96 TeV and subsequently decaying to Zγ. The search uses 0.3 fb$^{-1}$ of data collected with the DØdetector at the Fermilab Tevatron Collider. We set limits on the production cross section times the branching fraction $σ(p \bar{p} \to X) \times B(X\to Zγ)$ that range from 0.4 -- 3.5 pb at the 95% C.L. for $X$ with invariant masses between 100 and 1000 GeV/$c^2$ over a wide range of $X$ decay widths.
We use 106 $\ipb$ of data collected with the Collider Detector at Fermilab to search for narrow-width, vector particles decaying to a top and an anti-top quark. Model independent upper limits on the cross section for narrow, vector resonances decaying to $\ttbar$ are presented. At the 95% confidence level, we exclude the existence of a leptophobic $\zpr$ boson in a model of topcolor-assisted technicolor with mass $M_{\zpr}$ $<$ 480 $\gev$ for natural width $Γ$ = 0.012 $M_{\zpr}$, and $M_{\zpr}$ $<$ 780 $\gev$ for $Γ$ = 0.04 $M_{\zpr}$.
We present a search for single production of heavy vector-like quarks (VLQs), carried out by the CMS collaboration analyzing LHC pp collisions at 13 TeV. The vector like quark is a massive top quark partner that is searched for in a mass range between 0.7 and 1.7 TeV and a width between $<$1\% and 30\%. Single production can be dominant over pair production, depending on the mass of the new quark. The search is performed in a variety of final states including boosted topologies that can increase the sensitivity of the analysis.
A search for production of supersymmetric particles in final states containing jets, missing transverse momentum, and at least one hadronically decaying tau lepton is presented. The data were recorded by the ATLAS experiment in sqrt(s) = 7 TeV proton-proton collisions at the Large Hadron Collider. No excess above the Standard Model background expectation was observed in 2.05 fb-1 of data. The results are interpreted in the context of gauge mediated supersymmetry breaking models with Mmess = 250 TeV, N5 = 3, mu > 0, and Cgrav = 1. The production of supersymmetric particles is excluded at 95% C.…
We describe a general search for resonances decaying to a neutral e-mu final state in ppbar collisions at a center-of-mass energy of 1.96 TeV. Using a data sample representing 344 pb^-1 of integrated luminosity recorded by the CDF-II experiment, we compare Standard Model predictions with the number of observed events for invariant masses between 50 and 800 GeV/c^2. Finding no significant excess (5 events observed vs. 7.7 +/- 0.8 expected for e-mu invariant masses > 100 GeV/c^2), we set limits on sneutrino and Z' masses as functions of lepton family number violating couplings.
A search for narrow resonances in proton-proton collisions at sqrt(s) = 13 TeV is presented. The invariant mass distribution of the two leading jets is measured with the CMS detector using a data set corresponding to an integrated luminosity of 2.4 inverse femtobarns. The highest observed dijet mass is 6.1 TeV. The distribution is smooth and no evidence for resonant particles is observed. Upper limits at 95% confidence level are set on the production cross section for narrow resonances with masses above 1.5 TeV. When interpreted in the context of specific models, the limits exclude string reso…
This Letter presents a search for high-mass resonances decaying into tau+tau- final states using proton-proton collisions at sqrt(s) = 7 TeV produced by the Large Hadron Collider. The data were recorded with the ATLAS detector and correspond to an integrated luminosity of 4.6 inverse femtobarns. No statistically significant excess above the Standard Model expectation is observed; 95% credibility upper limits are set on the cross section times branching fraction of Z' resonances decaying into tau+tau- pairs as a function of the resonance mass. As a result, Z' bosons of the Sequential Standard M…
We present the results of a search for Wprime boson decaying to electron-neutrino pairs in pbarp collisions at a center-of-mass energy of 1.96 TeV, using a data sample corresponding to 205 pb^-1 of integrated luminosity collected by the CDF II detector at Fermilab. We observe no evidence for this decay mode and set limits on the production cross section times branching fraction, assuming the neutrinos from Wprime boson decays to be light. If we assume the manifest left-right symmetric model, we exclude a Wprime boson with mass less than 788 GeV/c^2 at the 95% confidence level.
A search for a narrow-width resonance decaying into two Higgs bosons, each decaying into a bottom quark-antiquark pair, is presented. The search is performed using proton-proton collision data corresponding to an integrated luminosity of 35.9 fb$^{-1}$ at $\sqrt{s}=$ 13 TeV recorded by the CMS detector at the LHC. No evidence for such a signal is observed. Upper limits are set on the product of the production cross section for the resonance and the branching fraction for the selected decay mode in the resonance mass range from 260 to 1200 GeV.
The ATLAS detector at the LHC is used to search for high-mass states, such as heavy charged gauge bosons (W'), decaying to a charged lepton (electron or muon) and a neutrino. Results are presented based on the analysis of pp collisions at a center-of-mass energy of 7 TeV corresponding to an integrated luminosity of 1.04 fb^-1. No excess beyond Standard Model expectations is observed. A W' with Sequential Standard Model couplings is excluded at the 95% confidence level for masses up to 2.15 TeV.
Measurements of the five most significant angular coefficients, A[0] through A[4], for Z bosons produced in pp collisions at sqrt(s) = 8 TeV and decaying to mu+mu- are presented as a function of the transverse momentum and rapidity of Z boson. The integrated luminosity of the dataset collected with the CMS detector at the LHC corresponds to 19.7 inverse femtobarns. These measurements provide comprehensive information about Z boson production mechanisms, and are compared to QCD predictions at leading order, next-to-leading order, and next-to-next-to-leading order in perturbation theory.
A search for pair-produced vector-like quarks decaying into a $Z$ boson and a third generation quark using 2015 and 2016 $pp$ collision data at $\sqrt{s}~=~13~$TeV collected by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of $36.1~$fb$^{-1}$, is presented. No significant excess over the Standard Model expectation was found so lower exclusion limits at 95% confidence level were set on the vector-like quark masses at 1030 (1210) GeV for singlet (doublet) $T$ and 1010 (1140) GeV for singlet (doublet) $B$.
A search is performed in pp collisions at sqrt(s) = 7 TeV for exotic particles decaying via WZ to final states with electrons and muons. The data sample corresponds to an integrated luminosity of approximately 5 inverse femtobarns. No significant excess is observed in the data above the expected standard model background. Upper bounds at 95% confidence level are set on the production cross section of the W' boson described by the sequential standard model and on the W'WZ coupling. W' bosons with masses below 1143 GeV are excluded. Limits are also set in the context of low-scale technicolor mod…
Results are reported from a search for the anomalous production of highly boosted Z bosons with large transverse momentum and decaying to dimuons. Such Z bosons may be produced in the decays of new heavy particles. The search uses pp collision data at sqrt(s) = 7 TeV, corresponding to an integrated luminosity of 5.0 inverse femtobarns recorded with the CMS detector. The shape of the observed transverse-momentum distribution of Z bosons is consistent with standard model expectations. Constraints are obtained on models predicting the production of excited quarks decaying via electroweak processe…
We present a search for new high mass phenomena using the latest data collected by the ATLAS detector at the LHC, corresponding to 36.1 fb$^{-1}$ at $\sqrt{s}$ = 13 TeV. The search is conducted for both resonant and non-resonant new phenomena in dimuon final states. The dimuon invariant mass spectrum is the discriminating variable used in the search. No significant deviations from the Standard Model expectation are observed. Lower limits are set on the signal parameters of interest at 95% credibility level, using a Bayesian interpretation. In particular, a Sequential Standard Model Z' resonanc…
Using data corresponding to an integrated luminosity of 1.3 fb^-1, we observe a narrow mass state decaying into Upsilon(1S)+gamma, where the Upsilon(1S) meson is detected by its decay into a pair of oppositely charged muons, and the photon is identified through its conversion into an electron-positron pair. The significance of this observation is 5.6 standard deviations. The mass of the state is centered at 10.551 \pm 0.014 (stat.) \pm 0.017 (syst.) GeV/c^2, which is consistent with that of the state recently observed by the ATLAS Collaboration.
We present a new search for $H^{0}V$ production, where $H^0$ is a scalar Higgs boson decaying into $b\bar{b}$ with branching ratio $β$, and $V$ is a $Z^{0}$ boson decaying into $e^{+}e^{-}$, $μ^{+}μ^{-}$, or $ν\barν$. This search is then combined with previous searches for $H^{0}V$ where $V$ is a $W^{\pm}$ boson or a hadronically decaying $Z^{0}$. The data sample consists of $106 \pm 4$ pb$^{-1}$ of $p\bar{p}$ collisions at $\sqrt{s}=1.8$ TeV accumulated by the Collider Detector at Fermilab. Observing no evidence of a signal, we set 95% Bayesian credibility level upper limits on $σ(p\bar{p}\to…
A search is performed in proton-proton collisions at sqrt(s) = 8 TeV for exotic particles decaying via WZ to fully leptonic final states with electrons, muons, and neutrinos. The data set corresponds to an integrated luminosity of 19.5 inverse femtobarns. No significant excess is observed above the expected standard model background. Upper bounds at 95% confidence level are set on the production cross section of a W' boson as predicted by an extended gauge model, and on the W'WZ coupling. The expected and observed mass limits for a W' boson, as predicted by this model, are 1.55 and 1.47 TeV, r…
A search for single production of vector-like quarks, T and B, decaying into a Z boson and a top or a bottom quark, respectively, is presented. The search is performed using data collected by the CMS experiment at the LHC in proton-proton collisions at sqrt(s) = 13 TeV, corresponding to an integrated luminosity of 2.3 inverse femtobarns. An exotic T quark production mode through the decay of a heavy Z' resonance is also considered. The search is performed in events with a Z boson decaying leptonically, accompanied by a bottom or a top quark decaying hadronically. No excess of events is observe…
A search for a new heavy particle decaying to a pair of vector bosons (WW or WZ) is presented using data from the CMS detector corresponding to an integrated luminosity of 35.9/fb collected in proton-proton collisions at a centre-of-mass energy of 13 TeV in 2016. One of the bosons is required to be a W boson decaying to eν or μν, while the other boson is required to be reconstructed as a single massive jet with substructure compatible with that of a highly-energetic quark pair from a W or Z boson decay. The search is performed in the resonance mass range between 1.0 and 4.5 TeV. The largest de…
A search for high-mass resonances decaying into tau-lepton pairs is performed using a data sample of pp collisions at sqrt(s) = 7 TeV. The data were collected with the CMS detector at the LHC and correspond to an integrated luminosity of 4.9 inverse femtobarns. The number of observed events is in agreement with the standard model prediction. An upper limit on the product of the resonance cross section and branching fraction into tau-lepton pairs is calculated as a function of the resonance mass. Using the sequential standard model resonance Z'(SSM) and the superstring-inspired E(6) model with …
A search for the standard model Higgs boson decaying to W+W- in pp collisions at sqrt(s) = 7 TeV is reported. The data are collected at the LHC with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. The W+W- candidates are selected in events with two charged leptons and large missing transverse energy. No significant excess of events above the standard model background expectations is observed, and upper limits on the Higgs boson production relative to the standard model Higgs expectation are derived. The standard model Higgs boson is excluded in the mass …
A search for new particles (X) that decay to electron or muon pairs has been performed using approximately 200 pb**(-1) of pbarp collision data at sqrt(s)=1.96 TeV collected by the CDF II experiment at the Fermilab Tevatron. Limits on sigma(ppbar -> X)*BR(X -> ll) are presented as a function of dilepton invariant mass m(ll) > 150 GeV/c**2, for different spin hypotheses (0, 1, or 2). The limits are approximately 25 fb for m(ll) > 600 GeV/c**2. Lower mass bounds for X from representative models beyond the Standard Model including heavy neutral gauge bosons are presented.
A search for dark-matter particles in events with large missing transverse momentum and a Higgs boson candidate decaying into two photons is reported. The search uses $139$ fb$^{-1}$ of proton-proton collision data collected at $\sqrt{s}=13$ TeV with the ATLAS detector at the CERN LHC between 2015 and 2018. No significant excess of events over the Standard Model predictions is observed. The results are interpreted by extracting limits on three simplified models that include either vector or pseudoscalar mediators and predict a final state with a pair of dark-matter candidates and a Higgs boson…
A model-independent search for a narrow resonance produced in proton-proton collisions at sqrt(s) = 8 TeV and decaying to a pair of 125 GeV Higgs bosons that in turn each decays into bottom quark-antiquark pairs is performed by the CMS experiment at the LHC. The analyzed data correspond to an integrated luminosity of 17.9 inverse femtobarns. No evidence for a signal is observed. Upper limits at a 95% confidence level on the production cross section for such a resonance, in the mass range from 270 to 1100 GeV, are reported. Using these results, a radion with decay constant of 1 TeV and mass fro…
A search for supersymmetric partners of quarks is performed in the topology of multijet events accompanied by at least one tau lepton decaying hadronically and large missing transverse energy. Approximately 1 fb-1 of ppbar collision data from the Fermilab Tevatron Collider at a center of mass energy of 1.96 TeV recorded by the D0 detector is analyzed. Results are combined with the previously published D0 inclusive search for squarks and gluinos. No evidence of physics beyond the standard model is found and lower limits on the squark mass up to 410 GeV are derived in the framework of minimal su…
This letter presents the results of a search for a heavy particle decaying into an e mu, e tau, or mu tau final state in pp collisions at sqrt(s) = 7 TeV. The data were recorded with the ATLAS detector at the LHC during 2011 and correspond to an integrated luminosity of 4.6/fb. No significant excess above the Standard Model expectation is observed, and exclusions at 95% confidence level are placed on the cross section times branching ratio for the production of an R-parity-violating supersymmetric tau sneutrino. These results considerably extend constraints from Tevatron experiments.
We report the results of a search for the anomalous production of a massive particle decaying to four electrons via two Z^0 bosons in 1.1 fb^{-1} of p-pbar collisions at sqrt(s)=1.96 TeV collected by the CDF II detector at Fermilab. We employ optimized electron identification criteria to maximize acceptance and efficiency. We estimate the backgrounds in the invariant mass range 500 - 1000 GeV/c^2 to be 0.028 +/- 0.009 (stat) +/- 0.011 (syst) events. We observe zero events in this search region. Assuming a Randall-Sundrum graviton production model, we set 95% CL limits on σtimes BF(G -> Z^0 Z^0…
This Letter presents the first search for a heavy particle decaying into an eμfinal state in sqrt(s)=7 TeV pp collisions at the LHC. The data were recorded by the ATLAS detector during 2010 and correspond to a total integrated luminosity of 35/pb. No excess above the Standard Model background expectation is observed. Exclusions at 95% confidence level are placed on two representative models. In an R-parity violating supersymmetric model, tau sneutrinos with a mass below 0.75 TeV are excluded, assuming single coupling dominance and the couplings lambda'_{311}=0.11, lambda_{312}=0.07. In a lepto…
This Letter reports a search for non standard model topquark resonances, $Z'$, decaying to $t\bar{t} \rightarrow W^+b W^-\bar{b}$ %\rightarrow qq'b qq' \bar{b}$, where both $W$ decay to quarks. We examine the top-antitop quark invariant mass spectrum for the presence of narrow resonant states. The search uses a data sample of $\ppb$ collisions at a center of mass energy of 1.96 TeV collected by the CDF II detector at the Fermilab Tevatron, with an integrated luminosity of 2.8 fb$^{-1}$. No evidence for top-antitop quark resonant production is found. We place upper limits on the production cros…
We present a search for a narrow scalar or vector resonance decaying into Zgamma with a subsequent Z decay into a pair of electrons or muons. The data for this search were collected with the D0 detector at the Fermilab Tevatron ppbar collider at a center of mass energy sqrt(s) = 1.96 TeV. Using 1.1 (1.0) fb-1 of data, we observe 49 (50) candidate events in the electron (muon) channel, in good agreement with the standard model prediction. From the combination of both channels, we derive 95% C.L. upper limits on the cross section times branching fraction (sigma x B) into Zgamma. These limits ran…
A search for neutral MSSM Higgs bosons in pp collisions at the LHC at a center-of-mass energy of 7 TeV is presented. The results are based on a data sample corresponding to an integrated luminosity of 36 inverse picobarns recorded by the CMS experiment. The search uses decays of the Higgs bosons to tau pairs. No excess is observed in the tau-pair invariant-mass spectrum. The resulting upper limits on the Higgs boson production cross section times branching fraction to tau pairs, as a function of the pseudoscalar Higgs boson mass, yield stringent new bounds in the MSSM parameter space.
A search for high-mass resonances decaying to $τν$ using proton-proton collisions at $\sqrt{s}$ = 13 TeV produced by the Large Hadron Collider is presented. Only $τ$-lepton decays with hadrons in the final state are considered. The data were recorded with the ATLAS detector and correspond to an integrated luminosity of 36.1 fb$^{-1}$. No statistically significant excess above the Standard Model expectation is observed; model-independent upper limits are set on the visible $τν$ production cross section. Heavy $W^{\prime}$ bosons with masses less than 3.7 TeV in the Sequential Standard Model and…
We present a search for a neutral particle, pair-produced in p-pbar collisions at sqrt(s)=1.96 TeV, which decays into two muons and lives long enough to travel at least 5 cm before decaying. The analysis uses ~380 pb^-1 of data recorded with the D0 detector. The background is estimated to be about one event. No candidates are observed, and limits are set on the pair production cross section times branching fraction into dimuons + X for such particles. For a mass of 10 GeV and lifetime of 4x10^-11 s, we exclude values greater than 0.14 pb (95% C.L.). These results are used to limit the interpre…
A search is presented for dark matter produced in association with a hadronically decaying W or Z boson using 3.2 /fb of pp collisions at $\sqrt{s}$=13 TeV recorded by the ATLAS detector at the Large Hadron Collider. Events with a hadronic jet compatible with a W or Z boson and with large missing transverse momentum are analysed. The data are consistent with the Standard Model predictions and are interpreted in terms of both an effective field theory and a simplified model containing dark matter.
A search for new exotic particles decaying to the VZ final state is performed, where V is either a W or a Z boson decaying into two overlapping jets and the Z decays into a pair of electrons, muons or neutrinos. The analysis uses a data sample of pp collisions corresponding to an integrated luminosity of 5 inverse femtobarns collected by the CMS experiment at the LHC at sqrt(s) = 7 TeV in 2011. No significant excess is observed in the mass distribution of the VZ candidates compared with the background expectation from standard model processes. Model-dependent upper limits at the 95% confidence…
Several theories beyond the Standard Model predict the existence of new heavy neutral bosons. Such particles could be produced in significant amounts at the LHC and their decay into a dilepton pair provides a clean signature with low background contamination. The results of the analysis of the whole 2012 dataset collected by the CMS experiment at a center of mass energy of 8 TeV are presented. No evidence for new physics is seen and upper limits on the cross section production of such particles are extracted. These results can be turned into lower limits on the mass of the heavy bosons, reachi…
A search for a new high-mass resonance decaying to a tau lepton and a neutrino is reported. The analysis uses proton-proton collision data collected by the CMS experiment at the LHC at $\sqrt{s} =$ 13 TeV, corresponding to an integrated luminosity of 35.9 fb$^{-1}$. The search utilizes hadronically decaying tau leptons. No excess in the event yield is observed at high transverse masses of the $τ$ and missing transverse momentum. An interpretation of results within the sequential standard model excludes W' boson masses below 4.0 TeV at 95% confidence level. Existing limits are also improved on …
Using data from 2.9/fb of integrated luminosity collected with the CDF II detector at the Tevatron, we search for resonances decaying into a pair of on-shell gauge bosons, WW or WZ, where one W decays into an electron and a neutrino, and the other boson decays into two jets. We observed no statistically significant excess above the expected standard model background, and we set cross section limits at 95% confidence level on G*(Randall-Sundrum graviton), Z', and W' bosons. By comparing these limits to theoretical cross sections, mass exclusion regions for the three particles are derived. The m…
A search for the standard model Higgs boson in the rare mu+mu- decay channel is presented. The data samples, recorded by the CMS experiment at the LHC, correspond to integrated luminosities of 5.0 +/- 0.1 inverse femtobarns at 7 TeV center-of-mass energy and of 19.7 +/- 0.5 inverse femtobarns at 8 TeV. To enhance the Higgs signal over the dominant Drell-Yan background, the events are categorized by topologies corresponding to different production processes. Upper limits on the production rate, with respect to the Standard Model prediction, are reported at the 95% confidence level for Higgs bos…
A search for heavy neutral Higgs bosons is performed using the LHC Run 2 data, corresponding to an integrated luminosity of 139 fb$^{-1}$ of proton-proton collisions at $\sqrt{s}=13$ TeV recorded with the ATLAS detector. The search for heavy resonances is performed over the mass range 0.2-2.5 TeV for the $τ^+τ^-$ decay with at least one $τ$-lepton decaying into final states with hadrons. The data are in good agreement with the background prediction of the Standard Model. In the $M_{h}^{125}$ scenario of the Minimal Supersymmetric Standard Model, values of $\tanβ>8$ and $\tanβ>21$ are excluded …
A search for heavy narrow resonances decaying into four-lepton final states from cascade decays of a Z' boson has been performed using proton-proton collision data at sqrt(s) = 8 TeV collected by the CMS experiment, corresponding to an integrated luminosity of 19.7 inverse femtobarns. No excess of events over the standard model background expectation is observed. Upper limits for a benchmark model on the product of cross section and branching fraction for the production of these heavy narrow resonances are presented. The limit excludes leptophobic Z' bosons with masses below 2.5 TeV within the…
A search for high-mass resonances decaying into $τ^{+}τ^{-}$ final states using proton-proton collisions at $\sqrt{s}= 8$ TeV produced by the Large Hadron Collider is presented. The data were recorded with the ATLAS detector and correspond to an integrated luminosity of 19.5-20.3 fb$^{-1}$. No statistically significant excess above the Standard Model expectation is observed; 95% credibility upper limits are set on the cross section times branching fraction of $Z^{\prime}$ resonances decaying into $τ^+τ^-$ pairs as a function of the resonance mass. As a result, $Z^{\prime}$ bosons of the Sequen…
A search for heavy resonances decaying to a $W$ or $Z$ boson and a Higgs boson in the $q\bar{q}^{(\prime)}b\bar{b}$ final state is described. The search uses 36.1 fb$^{-1}$ of proton-proton collision data at $\sqrt{s} =$ 13 TeV collected by the ATLAS detector at the CERN Large Hadron Collider in 2015 and 2016. The data are in agreement with the Standard Model expectations, with the largest excess found at a resonance mass of 3.0 TeV with a local (global) significance of 3.3 (2.1) $σ$. The results are presented in terms of constraints on a simplified model with a heavy vector triplet. Upper lim…
We search for pair production of supersymmetric top quarks (~t_1), followed by R-parity violating decay ~t_1 -> tau b with a branching ratio beta, using 322 pb^-1 of ppbar collisions at sqrt{s}=1.96 TeV collected by the CDF II detector at Fermilab. Two candidate events pass our final selection criteria, consistent with the standard model expectation. We set upper limits on the cross section sigma(~t_1 ~tbar_1)*beta^2 as a function of the stop mass m(~t_1). Assuming beta=1, we set a 95% confidence level limit m(~t_1)>153 GeV/c^2. The limits are also applicable to the case of a third generation …
We report results from a search for neutral Higgs bosons produced in association with b quarks using data recorded by the D0 experiment at the Fermilab Tevatron Collider and corresponding to an integrated luminosity of 7.3 fb-1. This production mode can be enhanced in several extensions of the standard model (SM) such as in its minimal supersymmetric extension (MSSM) at high tanBeta. We search for Higgs bosons decaying to tau pairs with one tau decaying to a muon and neutrinos and the other to hadrons. The data are found to be consistent with SM expectations, and we set upper limits on the cro…
A search for Supersymmetry involving the pair production of gluinos decaying via third-generation squarks to the lightest neutralino is reported. It uses an LHC proton--proton dataset at a center-of-mass energy $\sqrt{s} = 13$ TeV with an integrated luminosity of 3.2 fb$^{-1}$ collected with the ATLAS detector in 2015. The signal is searched for in events containing several energetic jets, of which at least three must be identified as $b$-jets, large missing transverse momentum and, potentially, isolated electrons or muons. Large-radius jets with a high mass are also used to identify highly bo…
We report on a first search for resonant pair production of neutral long-lived particles (NLLP) which each decay to a bbbar pair, using 3.6 fb^-1 of data recorded with the D0 detector at the Fermilab Tevatron collider. We search for pairs of displaced vertices in the tracking detector at radii in the range 1.6--20 cm from the beam axis. No significant excess is observed above background, and upper limits are set on the production rate in a hidden-valley benchmark model for a range of Higgs boson masses and NLLP masses and lifetimes.
A search is performed for WH production with a light Higgs boson decaying to hidden-sector particles resulting in clusters of collimated electrons, known as electron-jets. The search is performed with 2.04 fb-1 of data collected in 2011 with the ATLAS detector at the LHC in proton-proton collisions at sqrt(s)=7 TeV. One event satisfying the signal selection criteria is observed, which is consistent with the expected background rate. Limits on the product of the WH production cross section and the branching ratio of a Higgs boson decaying to prompt electron-jets are calculated as a function of …
