Download or read book Search for Resonant WW and WZ Production in Ppbar Collisions At s written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The standard model of particle physics is expected to be a low energy effective theory valid for particle interactions below the TeV scale. Above this scale, extensions to the standard model (SM) augment the existing particle content, leading to enhanced production of many final states at colliders. Specifically, the production and decay of massive charged or neutral particles can produce an excess of W boson pairs for neutral particles or W and Z boson pairs for charged particles. We search for resonant WW or WZ production using up to 5.4 fb−1 of integrated luminosity collected by the D0 experiment in Run II of the Fermilab Tevatron Collider. The data are consistent with the standard model background expectation, and we set limits on a resonance mass using the sequential standard model (SSM) W(prime) boson and the Randall-Sundrum model graviton G as benchmarks. We exclude an SSM W(prime) boson in the mass range 180-690 GeV and a Randall-Sundrum graviton in the range 300-754 GeV at 95% CL.

Download or read book Search for Massive Resonances Decaying Into WW WZ Or ZZ Bosons in Proton proton Collisions at Sqrt s written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A search is presented for new massive resonances decaying to WW, WZ or ZZ bosons in l nu quark anti-quark and quark anti-quark quark anti-quark final states. Results are based on data corresponding to an integrated luminosity of 2.3-2.7 inverse femtobarns recorded in proton-proton collisions at sqrt(s) = 13 TeV with the CMS detector at the LHC. Decays of spin-1 and spin-2 resonances into two vector bosons are sought in the mass range 0.6-4.0 TeV. No significant excess over the standard model background is observed. Combining the results of the l nu quark anti-quark and quark anti-quark quark anti-quark final states, cross section and mass exclusion limits are set for models that predict heavy spin-1 and spin-2 resonances. This is the first search for a narrow-width spin-2 resonance at sqrt(s) = 13 TeV.

Download or read book Combination of Searches for WW WZ and ZZ Resonances in Pp Collisions at written by and published by . This book was released on 2016 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this study, the ATLAS experiment at the CERN Large Hadron Collider has performed searches for new, heavy bosons decaying to WW, WZ, and ZZ final states in multiple decay channels using 20.3 fb-12 of pp collision data at √s=8 TeV. In the current study, the results of these searches are combined to provide a more stringent test of models predicting heavy resonances with couplings to vector bosons. Direct searches for a charged diboson resonance decaying to WZ in the l?l'l' (l=?,e), llqq¯,l?qq¯ and fully hadronic final states are combined and upper limits on the rate of production times branching ratio to the WZ bosons are compared with predictions of an extended gauge model with a heavy W' boson. Also, direct searches for a neutral diboson resonance decaying to WW and ZZ in the llqq¯, l?qq¯, and fully hadronic final states are combined and upper limits on the rate of production times branching ratio to the WW and ZZ bosons are compared with predictions for a heavy, spin-2 graviton in an extended Randall–Sundrum model where the Standard Model fields are allowed to propagate in the bulk of the extra dimension.

Download or read book Search for WZ Resonances in the Fully Leptonic Channel Using Pp Collisions at u221A s written by and published by . This book was released on 2014 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for resonant WZ production in the l?l'l' (l,l'=e,?) decay channel using 20.3 fb-1 of √s = 8 TeV pp collision data collected by the ATLAS experiment at LHC is presented. No significant deviation from the Standard Model prediction is observed and upper limits on the production cross sections of WZ resonances from an extended gauge model W' and from a simplified model of heavy vector triplets are derived. As a result, a corresponding observed (expected) lower mass limit of 1.52 (1.49) TeV is derived for the W' at the 95% confidence level.

Download or read book Search for Resonant t bar t Production in Proton proton Collisions at u221A s written by and published by . This book was released on 2016 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: A search is performed for the production of heavy resonances decaying into top-antitop quark pairs in proton-proton collisions at √s = 8 TeV. Data used for the analyses were collected with the CMS detector and correspond to an integrated luminosity of 19.7 fb–1. The search is performed using events with three different final states, defined by the number of leptons (electrons and muons) from the tt¯ → WbWb decay. The analyses are optimized for reconstruction of top quarks with high Lorentz boosts, where jet substructure techniques are used to enhance the sensitivity. Results are presented for all channels and a combination is performed. Furthermore, no significant excess of events relative to the expected yield from standard model processes is observed.

Download or read book Combination of Searches for Heavy Resonances Decaying to WW WZ ZZ WH and ZH Boson Pairs in Proton proton Collisions at s written by CMS Collaboration and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Search for New Resonances in W and Z Final States in Pp Collisions at u221A S written by and published by . This book was released on 2014 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Letter presents a search for new resonances decaying to final states with a vector boson produced in association with a high transverse momentum photon, V? , with V=W(→l?) or Z(→l+l-), where l=e or ?. The measurements use 20.3 fb-1 of proton–proton collision data at a center-of-mass energy of √s = 8 TeV recorded with the ATLAS detector. No deviations from the Standard Model expectations are found, and production cross section limits are set at 95% confidence level. Masses of the hypothetical aT and ?T states of a benchmark Low Scale Technicolor model are excluded in the ranges [275,960] GeV and [200,700]?[750,890] GeV, respectively. Limits at 95% confidence level on the production cross section of a singlet scalar resonance decaying to Z? final states have also been obtained for masses below 1180 GeV.

Download or read book Searches for Light and Heavy flavor Three jet Resonances in Proton proton Collisions with the CMS Detector at sqrt s written by and published by . This book was released on 2014 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for three-jet hadronic resonance production in proton-proton collisions at 8 TeV center-of-mass energy has been conducted by the CMS Collaboration at the LHC. The data set corresponds to an integrated luminosity of 19.4 fb-1. The search method is modelindependent. Events are selected that contain a large number of jets with high transverse momentum. An ensemble of jets is used to extract a new possible signal from copious QCD background. Event selection is optimized using a benchmark model where supersymmetric gluinos are pair-produced and each of the gluinos decays exclusively into three jets. Two scenarios of this decay are considered denoted by the RPV couplings [lambda]'' 112 and [lambda]'' 113 or [lambda]'' 223. The first coupling allows for gluinos to decay into only light-flavor jets, while the latter two allow decays into one heavy-flavor and two light-flavor jets. No significant deviation is found between the selected events and the expected standard model multijet and t$\bar{t}$ background. For gluinos decaying through 00 112, masses below 650 GeV are excluded at the 95% confidence level. The search including heavy-flavor jets in the final state with the couplings [lambda]'' 113 or [lambda]'' 223 is the first of its kind. Gluinos decaying into one heavy-flavor and two light-flavor jets are excluded for masses between 200 and 835 GeV.

Download or read book SEARCH FOR HIGH MASS RESONANCES DECAYING TO E mu IN Ppbar COLLISIONS AT S 1 2 written by Kristian Allan Hahn and published by . This book was released on 2006 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: We describe a general search for resonances decaying to a neutral e{mu} final state in p{bar p} collisions at a center-of-mass energy of 1.96 TeV. Using a data sample representing 344 pb{sup -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{sup 2}. Finding no significant excess (5 events observed vs. 7.7 {+-} 0.8 expected for M{sub e{mu}}> 100 GeV/c{sup 2}), we set limits on sneutrino and Z' masses as functions of lepton family number violating couplings.

Download or read book Search for Massive Resonances in Dijet Systems Containing Jets Tagged as W Or Z Boson Decays in Pp Collisions at sqrt s written by and published by . This book was released on 2014 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our search is reported for massive resonances decaying into a quark and a vector boson (W or Z), or two vector bosons (WW, WZ, or ZZ). The analysis is performed on an inclusive sample of multijet events corresponding to an integrated luminosity of 19.7 fb-1, collected in proton-proton collisions at a centre-of-mass energy of 8 TeV with the CMS detector at the LHC. We found that the search uses novel jet-substructure identification techniques that provide sensitivity to the presence of highly boosted vector bosons decaying into a pair of quarks. Exclusion limits are set at a confidence level of 95% on the production of: (i) excited quark resonances q*decaying to qW and qZ for masses less than 3.2 TeV and 2.9 TeV, respectively, (ii) a Randall-Sundrum graviton GRS decaying into WW for masses below 1.2 TeV, and (iii) a heavy partner of the W boson W' decaying into WZ for masses less than 1.7 TeV. For the first time mass limits are set on W' → WZ and GRS → WW in the all-jets final state. The mass limits on q* → qW, q* → qZ, W' → WZ, GRS → WW are the most stringent to date. A model with a "bulk" graviton Gbulk that decays into WW or ZZ bosons is also studied.

Download or read book Search for the Production of Narrow T Anti b Resonances in 1 9 Fb 1 of P Anti p Collisions at S written by and published by . This book was released on 2009 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present new limits on resonant tb production in ppbar collisions at sqrt(s) = 1.96 TeV, using 1.9 fb−1 of data recorded with the CDF II detector at the Fermilab Tevatron. We reconstruct a putative tb mass in events with a lepton, neutrino candidate, and two or three jets, and search for anomalous tb production as modeled by W′ → tb. We set a new limit on a right-handed W′ with standard model-like coupling, excluding any mass below 800 GeV at 95% C.L. For any narrow W′-like state with mass above 800 GeV, the cross-section is found to be less than 0.28 pb at 95% C.L. We also present an exclusion of the W′ coupling strength versus W′ mass.

Download or read book Search for Anomalous WW and WZ Production at written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a preliminary result from a search for anomalous WW and WZ production in p[bar p] collisions at[radical]s= 1.8 TeV using p[bar p][yields] e[nu]jj events observed during the 1992-1993 run of the Fermilab Tevatron collider. A fit to the p[sub T] spectrum of W(e[nu]) yields direct limits on the CP-conserving anomalous WW[gamma] and WWZ coupling parameters of -0.89

Download or read book WW and WZ Production at the Tevatron written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Direct limits are set on WWZ and WW[gamma] three-boson couplings in a search for WW and WZ production in p[bar p] collisions at[radical]s= 1.8 TeV using the D(0) and CDF detectors at the Fermilab Tevatron.

Download or read book Search for a Dijet Resonance in Events with Jets and Missing Transverse Energy in Pp over Collisions at Sqrt s written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report on a search for a dijet resonance in events with only two or three jets and large imbalance in the total event transverse momentum. This search is sensitive to the possible production of a new particle in association with a W or Z boson, where the boson decays leptonically with one or more neutrinos in the final state. We use the full data set collected by the CDF II detector at the Tevatron collider at a proton-antiproton center-of-mass energy of 1.96 TeV. These data correspond to an integrated luminosity of 9.1 fb{̂-1}. We study the invariant mass distribution of the two jets with highest transverse energy. We find good agreement between data and standard model background expectations and measure the combined cross section for WW, WZ, and ZZ production to be 13.8{̂+3.0}_{-2.7} pb. No significant anomalies are observed in the mass spectrum and 95% credibility level upper limits are set on the production rates of a potential new particle in association with a W or Z boson.

Download or read book Measurement of WZ and ZZ Production in Pp Collisions at sqrt s written by and published by . This book was released on 2014 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements are reported of the WZ and ZZ production cross sections in proton-proton collisions at $\sqrt{s}$ = 8 TeV in final states where one Z boson decays to b-tagged jets. The other gauge boson, either W or Z, is detected through its leptonic decay (either $W \to e\nu, \mu\nu$ or $Z \to e^+ e^-, \mu^+ \mu^-$, or $\nu\bar{\nu})$. The results are based on data corresponding to an integrated luminosity of 18.9 inverse-femtobarns collected with the CMS detector at the Large Hadron Collider. The measured cross sections, $\sigma(pp \to WZ)$ = 30.7 $\pm$ 9.3 (stat.) $\pm$ 7.1 (syst.) $\pm$ 4.1 (th.) $\pm$ 1.0 (lum.) pb and $\sigma(pp \to ZZ)$ = 6.5 $\pm$ 1.7 (stat.) $\pm$ 1.0 (syst.) $\pm$ 0.9 (th.) $\pm$ 0.2 (lum.) pb, are consistent with next-to-leading order quantum chromodynamics calculations.

Download or read book Search for Resonant Production of Tt Decaying to Jets in Pp Collisions at u221A s written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This Letter reports a search for non-standard model topquark resonances, Z', decaying to ttMs; →W+bW-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 p{bar p} 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 cross section times branching ratio for a specific topcolor assisted technicolor model with width of ?Z' = 0.012 MZ'. Within this model, we exclude Z' boson with masses below 805 GeV/c2 at the 95% confidence level.

Download or read book Searches for Light and Heavy flavour Three jet Resonances in Pp Collisions at sqrt s written by and published by . This book was released on 2014 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for three-jet hadronic resonance production in pp collisions at a centre-of-mass energy of 8 TeV has been conducted by the CMS Collaboration at the LHC with a data sample corresponding to an integrated luminosity of 19.4 inverse femtobarns. The search method is model independent, and events are selected that have high jet multiplicity and large values of jet transverse momenta. The signal models explored assume R-parity-violating supersymmetric gluino pair production and have final states with either only light-flavour jets or both light- and heavy-flavour jets. No significant deviation is found between the selected events and the expected standard model multijet and t t-bar quark background. For a gluino decaying into light-flavour jets, a lower limit of 650 GeV on the gluino mass is set at a 95% confidence level, and for a gluino decaying into one heavy- and two light-flavour jets, gluino masses between 200 and 835 GeV are, for the first time, likewise excluded.