Download or read book Search for the Pair Production of Scalar Top Quarks in the Acoplanar Charm Jet Final State in P Anti p Collisions at S written by and published by . This book was released on 2006 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for the pair production of scalar top quarks, {bar t}, has been performed in 360 pb−1 of data from p{bar p} collisions at a center-of-mass energy of 1.96 TeV, collected by the D0 detector at the Fermilab Tevatron collider. The {bar t} decay mode considered is {bar t} → c{bar {chi}}1°, where {bar {chi}}1° is the lightest supersymmetric particle. The topology analyzed therefore consists of a pair of acoplanar heavy-flavor jets with missing transverse energy. The data show good agreement with the standard model expectation, and a 95% C.L. exclusion domain in the (m{sub {tilde t}}, m{sub {tilde {chi}}1°}) plane has been determined, extending the domain excluded by previous experiments.

Download or read book Search for the Pair Production of Scalar Top Quarks in the Acoplanar Charm Jet Final State in P Anti p Collisions at S 1 2 written by and published by . This book was released on 2006 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for the pair production of scalar top quarks, {bar t}, has been performed in 360 pb−1 of data from p{bar p} collisions at a center-of-mass energy of 1.96 TeV, collected by the D0 detector at the Fermilab Tevatron collider. The {bar t} decay mode considered is {bar t} → c{bar {chi}}1°, where {bar {chi}}1° is the lightest supersymmetric particle. The topology analyzed therefore consists of a pair of acoplanar heavy-flavor jets with missing transverse energy. The data show good agreement with the standard model expectation, and a 95% C.L. exclusion domain in the (m{sub {tilde t}}, m{sub {tilde {chi}}1°}) plane has been determined, extending the domain excluded by previous experiments.

Download or read book Search for Scalar Top Quarks in the Acoplanar Charm Jets and Missing Transverse Energy Final State in P Anti p Collisions at S 1 2 written by and published by . This book was released on 2008 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Search for Scalar Top Quarks in the Acoplanar Charm Jets and Missing Transverse Energy Final State in P Anti p Collisions at S written by and published by . This book was released on 2008 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Search for Pair Production of Scalar Top Quarks in Jets and Missing Transverse Energy Channel with the D0 Detector written by and published by . This book was released on 2008 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation describes a search for the pair production of scalar top quarks, {tilde t}1, using a luminosity of 995 pb−1 of data collected in p{bar p} collisions with the D0 detector at the Fermilab Tevatron Collider at a center-of-mass energy (square root)s = 1.96 TeV. Both scalar top quarks are assumed to decay into a charm quark and a neutralino, {tilde {chi}}1°, where {tilde {chi}}1° is the lightest supersymmetric particle. This leads to a final state with two acoplanar charm jets and missing transverse energy. The yield of such events in data is found to be consistent with the expectations from known standard model processes. Sets of {tilde t}1 and {tilde {chi}}1° masses are excluded at the 95% confidence level that substantially extend the domain excluded by previous searches. With the theoretical uncertainty on the {tilde t}1 pair production cross section taken into account, the largest limit for m{sub {tilde t}1} is m{sub {tilde t}1}> 150 GeV, for m{sub {tilde {chi}}1°} = 65 GeV.

Download or read book Search for Scalar Charm Quark Pair Production in Pp Collisions at S written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The results of a dedicated search for pair production of scalar partners of charm quarks are reported. The search is based on an integrated luminosity of 20.3 fb-1 of pp collisions at √s=8 TeV recorded with the ATLAS detector at the LHC. The search is performed using events with large missing transverse momentum and at least two jets, where the two leading jets are each tagged as originating from c quarks. Events containing isolated electrons or muons are vetoed. In an R-parity-conserving minimal supersymmetric scenario in which a single scalar-charm state is kinematically accessible, and where it decays exclusively into a charm quark and a neutralino, 95% confidence-level upper limits are obtained in the scalar-charm-neutralino mass plane such that, neutralino masses below 200 GeV, scalar-charm masses up to 490 GeV are excluded.

Download or read book Search for Pair Production of Scalar Bottom Quarks in P Anti p Collisions at S 1 2 written by and published by . This book was released on 2006 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for direct production of scalar bottom quarks ({bar b}) is performed with 310 pb−1 of data collected by the D0 experiment in p{bar p} collisions at √s = 1.96 TeV at the Fermilab Tevatron Collider. The topology analyzed consists of two b jets and an imbalance in transverse momentum due to undetected neutralinos ({tilde {chi}}1°), with {tilde {chi}}1° assumed to be the lightest supersymmetric particle. They find the data consistent with standard model expectations, and set a 95% C.L. exclusion domain in the (m{sub {tilde b}}, m{sub {tilde {chi}}}) mass plane, improving significantly upon the results from Run I of the Tevatron.

Download or read book Search for Pair Production of Scalar Bottom Quarks in P Anti p Collisions at S written by and published by . This book was released on 2006 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for direct production of scalar bottom quarks ({bar b}) is performed with 310 pb−1 of data collected by the D0 experiment in p{bar p} collisions at √s = 1.96 TeV at the Fermilab Tevatron Collider. The topology analyzed consists of two b jets and an imbalance in transverse momentum due to undetected neutralinos ({tilde {chi}}1°), with {tilde {chi}}1° assumed to be the lightest supersymmetric particle. They find the data consistent with standard model expectations, and set a 95% C.L. exclusion domain in the (m{sub {tilde b}}, m{sub {tilde {chi}}}) mass plane, improving significantly upon the results from Run I of the Tevatron.

Download or read book Search for Pair Production of Scalar Top Quarks Decaying to a Tau Lepton and a B Quark in Ppbar Collisions at Sqrt s written by and published by . This book was released on 2008 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the results of a search for pair production of scalar top quarks ({tilde t}1) in an R-parity violating supersymmetric scenario using 322 pb−1 of p{bar p} collisions at √s = 1.96 TeV collected by the upgraded Collider Detector at Fermilab. We assume each {tilde t}1 decays into a? lepton and a b quark with a branching ratio?, and that the final state contains either an electron or a muon from a leptonic? decay, a hadronically decaying? lepton, and two or more jets. Two candidate events pass our final selection criteria, consistent with the expectation from standard model processes. We present upper limits on the cross section times branching ratio squared?({tilde t}1{bar {tilde t}}1) x?2 as a function of the stop mass m({tilde t}1). Assuming? = 1, we set a 95% confidence level limit m({tilde t}1)> 153 GeV=c2 obtained using a next-to-leading order cross section. These limits are also fully applicable to the case of a pair produced third generation scalar leptoquark decaying into a? lepton and a b quark.

Download or read book Search for Scalar Charm Quark Pair Production in math Display written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The results of a dedicated search for pair production of scalar partners of charm quarks are reported. The search is based on an integrated luminosity of 20.3 fb-1 of pp collisions at √s=8 TeV recorded with the ATLAS detector at the LHC. The search is performed using events with large missing transverse momentum and at least two jets, where the two leading jets are each tagged as originating from c quarks. The events containing isolated electrons or muons are vetoed. In an R-parity-conserving minimal supersymmetric scenario in which a single scalar-charm state is kinematically accessible, and where it decays exclusively into a charm quark and a neutralino, 95% confidence-level upper limits are obtained in the scalar-charm-neutralino mass plane such that, neutralino masses below 200 GeV, scalar-charm masses up to 490 GeV are excluded.

Download or read book High Energy Physics Index written by and published by . This book was released on 1990 with total page 786 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Search for Direct Pair Production of Scalar Top Quarks in the Single and Dilepton Channels 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: Results are reported from a search for the top squark $ \tilde{t}_1 $, the lighter of the two supersymmetric partners of the top quark. The data sample corresponds to 19.7 fb$^{-1}$ of proton-proton collisions at $\sqrt{s} =$ 8 TeV collected with the CMS detector at the LHC. The search targets $ \tilde{t}_1 \to \mathrm{b} \tilde{\chi}^{\pm}_1$ and $ \tilde{t}_1 \to \mathrm{t}^{(*)} \tilde{\chi}^0_1$ decay modes, where $\tilde{\chi}^{\pm}_1$ and $\tilde{\chi}^0_1$ are the lightest chargino and neutralino, respectively. The reconstructed final state consists of jets, b jets, missing transverse energy, and either one or two leptons. Leading backgrounds are determined from data. No significant excess in data is observed above the expectation from standard model processes. The results exclude a region of the two-dimensional plane of possible $ \tilde{t}_1 $ and $\tilde{\chi}^0_1 $ masses. The highest excluded $ \tilde{t}_1 $ and $ \tilde{\chi}^0_1$ masses are about 700 GeV and 250 GeV, respectively.

Download or read book Search for the Production of Scalar Bottom Quarks in p bar p Collisions at sqrt s written by and published by . This book was released on 2010 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report on a search for direct scalar bottom quark (sbottom) pair production in p{bar p} collisions at (square root)s = 1.96 TeV, in events with large missing transverse energy and two jets of hadrons in the final state, where at least one of the jets is required to be identified as originating from a b quark. The study uses a CDF Run II data sample corresponding to 2.65 fb−1 of integrated luminosity. The data are in agreement with the standard model. In an R-parity conserving minimal supersymmetric scenario, and assuming that the sbottom decays exclusively into a bottom quark and a neutralino, 95% confidence-level upper limits on the sbottom pair production cross section of 0.1 pb are obtained. For neutralino masses below 70 GeV/c2, sbottom masses up to 230 GeV/c2 are excluded at 95% confidence level.

Download or read book Search for Scalar Top Quark Production in p bar p Collisions at sqrt s written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report on a search for the supersymmetric partner of the top quark (scalar top) decaying into a charm quark and a neutralino in p{bar p} collisions at √s = 1.96 TeV. The data sample, collected by the CDF II detector at the Fermilab Tevatron, corresponds to an integrated luminosity of 2.6 fb−1. Candidate events are selected by requiring two or more jets and a large imbalance in the transverse momentum. To enhance the analysis sensitivity, at least one of the jets is required to be identified as originating from a charm quark using an algorithm specifically designed for this analysis. The selected events are in good agreement with standard model predictions. In the case of large mass splitting between the scalar top quark and the neutralino we exclude a scalar top quark mass below 180 GeV/c2 at 95% confidence level.

Download or read book Search for the Lightest Scalar Top Quark in Events with Two Leptons in P Anti p Collisions at S written by and published by . This book was released on 2007 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Data collected by the D0 detector at a p{bar p} center-of-mass energy of 1.96 TeV at the Fermilab Tevatron Collider have been used to search for pair production of the lightest supersymmetric partner of the top quark decaying into bl{bar {nu}}. The search is performed in the ll′ = e? and?? final states. No evidence for this process has been found in data samples of approximately 400 pb−1. The domain in the [M({bar t}1), M({bar {nu}})] plane excluded at the 95% C.L. is substantially extended by this search.

Download or read book Search for Pair Production of Scalar Top Quarks Decaying to A Lepton and a B Quark in 1 96 TeV P bar p Collisions written by and published by . This book was released on 2008 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: I present the results of a search for pair production of scalar top quarks ($ ilde{t}$1) in an R-parity violating supersymmetric scenario using 322 pb-1 of p{bar p} collisions at √s = 1.96 TeV collected by the upgraded Collider Detector at Fermilab. I assume each $ ilde{t}$1 decays into a ? lepton and a b quark, with branching ratio ?, and search for final states containing either an electron or a muon from a leptonic ? decay, a hadronically decaying ? lepton, and two or more jets. Two candidate events pass my final selection criteria, consistent with the expectation from standard model processes. I present upper limits on the cross section times branching ratio squared ?($ ilde{t}$1$ ilde{t}$1) x ?2 as a function of the stop mass m($ ilde{t}$1). Assuming ? = 1, I set a 95% confidence level limit m($ ilde{t}$1) > 153 GeV=c2. These limits are also fully applicable to the case of a pair produced third generation scalar leptoquark that decays into a ? lepton and a b quark.

Download or read book Search for Direct Pair Production of Supersymmetric Top Quarks Decaying to All hadronic Final States in Pp Collisions at u221A s written by and published by . This book was released on 2016 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Here, results are reported from a search for the pair production of top squarks, the supersymmetric partners of top quarks, in final states with jets and missing transverse momentum. The data sample used in this search was collected by the CMS detector and corresponds to an integrated luminosity of 18.9 fb–1 of proton-proton collisions at a centre-of-mass energy of 8 TeV produced by the LHC. The search features novel background suppression and prediction methods, including a dedicated top quark pair reconstruction algorithm. The data are found to be in agreement with the predicted backgrounds. Exclusion limits are set in simplified supersymmetry models with the top squark decaying to jets and an undetected neutralino, either via a top quark or through a bottom quark and chargino. Models with the top squark decaying via a top quark are excluded for top squark masses up to 755 GeV in the case of neutralino masses below 200 GeV. For decays via a chargino, top squark masses up to 620 GeV are excluded, depending on the masses of the chargino and neutralino.