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in subjects: "Transverse Energy"

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A Search for scalar bottom quarks from gluino decays in anti-p p collisions at s**(1/2) = 1.96-TeV

We searched for scalar bottom quarks in 156 pb{sup -1} of {bar p}p collisions at {radical}s = 1.96 TeV recorded by the CDF II experiment at the Tevatron. Scalar bottom quarks can be produced from gluino decays in R-parity conserving models of supersymmetry when the mass of the gluino exceeds that of the scalar bottom quark. Then, a scalar bottom quark can decay into a bottom quark and a neutralino. To search for this scenario, we investigated events with large missing transverse energy and at l… more

Date: December 1, 2005

Creator: Abulencia, A.; Acosta, D.; Adelman, Jahred A.; Affolder, T.; Akimoto, T.; Albrow, M.G. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Search for heavy, long-lived particles that decay to photons at CDF II

The authors present the first search for heavy, long-lived particles that decay to photons at a hadron collider. They use a sample of {gamma} + jet + missing transverse energy events in p{bar p} collisions at {radical}s = 1.96 TeV taken with the CDF II detector. Candidate events are selected based on the arrival time of the photon at the detector. Using an integrated luminosity of 570 pb{sup -1} of collision data, they observe 2 events, consistent with the background estimate of 1.3 {+-} 0.7 ev… more

Date: April 1, 2007

Creator: Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M. G.; Amerio, S. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Cross Section Measurements of High-p(T) Dilepton Final-State Processes Using a Global Fitting Method

The authors present a new method for studying high-p{sub T} dilepton events (e{sup {+-}}e{sup {-+}}, {mu}{sup {+-}}{mu}{sup {-+}}, e{sup {+-}}{mu}{sup {-+}}) and simultaneously extracting the production cross sections of p{bar p} {yields} t{bar t}, p{bar p} {yields} W{sup +}W{sup -}, and p{bar p} {yields} Z{sup 0} {yields} {tau}{sup +}{tau}{sup -} at a center-of-mass energy of {radical}s = 1.96 TeV. They perform a likelihood fit to the dilepton data in a parameter space defined by the missing t… more

Date: December 1, 2006

Creator: Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Measurement of the helicity fractions of W bosons from top quark decays using fully reconstructed t anti-t events with CDF II

The authors present a measurement of the fractions F{sub 0} and F{sub +} of longitudinally polarized and right-handed W bosons in top quark decays using data collected with the CDF II detector. The data set used in the analysis corresponds to an integrated luminosity of approximately 318 pb{sup -1}. They select t{bar t} candidate events with one lepton, at least four jets, and missing transverse energy. The helicity measurement uses the decay angle {theta}*, which is defined as the angle betwee… more

Date: December 1, 2006

Creator: Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Measurement of the Top Quark Mass in p anti-p Collisions at s**(1/2) = 1.96-TeV using the Decay Length Technique

We report the first measurement of the top quark mass using the decay length technique in p{bar p} collisions at a center-of-mass energy of 1.96 TeV. This technique uses the measured flight distance of the b hadron to infer the mass of the top quark in lepton plus jets events with missing transverse energy. It relies solely on tracking and avoids the jet energy scale uncertainty that is common to all other methods used so far. We apply our novel method to a 695 pb{sup -1} data sample recorded b… more

Date: December 1, 2006

Creator: Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Observation of Exclusive Electron-Positron Production in Hadron-Hadron Collisions

We present the first observation of exclusive e{sup +}e{sup -} production in hadron-hadron collisions, using p{bar p} collision data at {radical}s = 1.96 TeV taken by the Run II Collider Detector at Fermilab, and corresponding to an integrated luminosity of 532 pb{sup -1}. We require the absence of any particle signatures in the detector except for an electron and a positron candidate, each with transverse energy E{sub T} > 5 GeV and pseudorapidity |{eta}| < 2. With these criteria, 16 eve… more

Date: November 1, 2006

Creator: Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Electroweak physics: measurement of the forward-backward charge asymmetry of electron-positron pairs in p anti-p collisions at s**(1/2) = 1.96 tev

We report a measurement of the forward-backward charge asymmetry of electrons from W boson decays in p{bar p} collisions at {radical}s = 1.96 TeV using a data sample of 170 pb{sup -1} collected by the Collider Detector at Fermilab. The asymmetry is measured as a function of electron rapidity and transverse energy and provides new input on the momentum fraction dependence of the u and d quark parton distribution functions within the proton.

Date: February 23, 2005

Creator: Acosta, D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Electroweak physics: measurement of w gamma and z gamma production in pp-bar collisions at s**(1/2) = 1.96 tev

The Standard Model predictions for W{gamma} and Z{gamma} production are tested using an integrated luminosity of 200 pb{sup -1} of p{bar p} collision data collected at the Collider Detector at Fermilab. The cross sections are measured by selecting leptonic decays of the W and Z bosons, and photons with transverse energy E{sub T} > 7 GeV that are well separated from leptons. The production cross sections and kinematic distributions for the W{gamma} and Z{gamma} data are compared to SM predict… more

Date: February 2, 2005

Creator: Acosta, D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Exotic physics: search for scalar leptoquark pairs decaying to nu nu-bar qq-bar in p anti-p collisions at s**(1/2) = 1.96 tev

We report on a search for the pair production of scalar leptoquarks, LQ, using 191 pb{sup -1} of proton-antiproton collision data recorded by the CDF experiment during Run II of the Tevatron. The leptoquarks are sought via their decay into a neutrino and quark yielding missing transverse energy and several jets of large transverse energy. No evidence for leptoquark production is observed, and limits are set on {sigma}(p{bar p} {yields} LQ{ovr OQ}X {yields} v{bar v}q{bar q}X). Using a next-to-le… more

Date: October 25, 2004

Creator: Acosta, D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Top physics: measurement of the cross section for ttbar production in ppbar collisions using the kinematics of lepton + jets events

We present a measurement of the top pair production cross section in p{bar p} collisions at {radical}s = 1.96 TeV. We collect a data sample with an integrated luminosity of 194 {+-} 11 pb{sup -1} with the CDF II detector at the Fermilab Tevatron. We use an artificial neural network technique to discriminate between top pair production and background processes in a sample of 519 lepton+jets events, which have one isolated energetic charged lepton, large missing transverse energy and at least thr… more

Date: April 27, 2005

Creator: Acosta, D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Top physics: measurement of the tt-bar production cross section in pp-bar collisions at s**(1/2) = 1.96 tev using dilepton event

We report a measurement of the t{bar t} production cross section using dilepton events with jets and missing transverse energy in p{bar p} collisions at a center-of-mass energy of 1.96 TeV. Using a 197 {+-} 12 pb{sup -1} data sample recorded by the upgraded Collider Detector at Fermilab, we use two complementary techniques to select candidate events. We compare the number of observed events and selected kinematical distributions with the predictions of the standard model and find good agreement… more

Date: October 14, 2004

Creator: Acosta, D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

# top physics: measurement of the ttbar production cross section in pp-bar collisions at sqrt s = 1.96 tev using lepton plus jets events with semileptonic b decays to muons

We present a measurement of the t{bar t} production cross section using 194 pb{sup -1} of CDF II data using events with a high transverse momentum electron or muon, three or more jets, and missing transverse energy. The measurement assumes 100% t {yields} Wb branching fraction. Events consistent with t{bar t} decay are found by identifying jets containing heavy flavor semileptonic decays to muons. The dominant backgrounds are evaluated directly from the data. Based on 20 candidate events and an… more

Date: June 1, 2005

Creator: Acosta, D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Measurement of the cross section for t anti-t production in p anti-p collisions using the kinematics of lepton + jets events

The authors present a measurement of the top pair production cross section in p{bar p} collisions at {radical}s = 1.96 TeV. We collect a data sample with an integrated luminosity of 194 {+-} 11 pb{sup -1} with the CDF II detector at the Fermilab Tevatron. We use an artificial neural network technique to discriminate between top pair production and background processes in a sample of 519 lepton + jets events, which have one isolated energetic charged lepton, large missing transverse energy and a… more

Date: April 1, 2005

Creator: Acosta, D.; Adelman, J.; Affolder, Anthony A.; Akimoto, T.; Albrow, M. G.; Ambrose, D. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Measurements of Transverse Energy Distributions in Au+Au Collisions at {radical}s{sub NN} = 200 GeV

Transverse energy (E{sub T}) distributions have been measured for Au+Au collisions at {radical}s{sub NN} = 200 GeV by the STAR collaboration at RHIC. E{sub T} is constructed from its hadronic and electromagnetic components, which have been measured separately. E{sub T} production for the most central collisions is well described by several theoretical models whose common feature is large energy density achieved early in the fireball evolution. The magnitude and centrality dependence of E{sub T}… more

Date: July 2, 2004

Creator: Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D.; Arkhipkin, D. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

QCD in hadron-hadron collisions

Quantum Chromodynamics provides a good description of many aspects of high energy hadron-hadron collisions, and this will be described, along with some aspects that are not yet understood in QCD. Topics include high E{sub T} jet production, direct photon, W, Z and heavy flavor production, rapidity gaps and hard diffraction.

Date: March 1, 1997

Creator: Albrow, M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Diffractive dijet production in CDF

We have studied events with a high-x{sub F} antiproton and two central jets in CDF, with p{anti p} collisions at {radical}s = 630 and 1800 GeV. These events are expected to be dominated by diffraction (pomeron exchange). The jet E{sub T} spectra are very similar to those of non-diffractively produced jets but slightly steeper; their azimuthal difference {Delta}{phi} is more peaked at 180{degree}.

Date: April 17, 1998

Creator: Albrow, M.G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Pion production in relativistic collisions of nuclear drops

In a continuation of the long-standing effort of the nuclear physics community to model atomic nuclei as droplets of a specialized nuclear fluid, we have developed a hydrodynamic model for simulating the collisions of heavy nuclei at relativistic speeds. Our model couples ideal relativistic hydrodynamics with a new Monte Carlo treatment of dynamic pion production and tracking. The collective flow for low-energy (200 MeV/N) collisions predicted by this model compares favorably with results from … more

Date: September 1, 1988

Creator: Alonso, C. T.; Wilson, J. R.; McAbee, T. L. & Zingman, J. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Reach the Bottom Line of the Sbottom Search

We propose a new search strategy for directly-produced sbottoms at the LHC with a small mass splitting between the sbottom and its decayed stable neutralino. Our search strategy is based on boosting sbottoms through an energetic initial state radiation jet. In the final state, we require a large missing transverse energy and one or two b-jets besides the initial state radiation jet. We also define a few kinematic variables to further increase the discovery reach. For the case that the sbottom m… more

Date: May 22, 2012

Creator: Alvarez, Ezequiel & Bai, Yang

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

It's On: Early Interpretations of ATLAS Results in Jets and Missing Energy

The first search for supersymmetry from ATLAS with 70 nb{sup -1} of integrated luminosity extends the Tevatron's reach for colored particles that decay into jets plus missing transverse energy. For gluinos that decay directly or through a one step cascade into the LSP and two jets, the mass range m{sub {bar g}} {le} 205 GeV is disfavored by the ATLAS searches, regardless of the mass of the LSP. In some cases the coverage extends up to m{sub {bar g}} {approx_equal} 295 GeV, already surpassing th… more

Date: August 12, 2011

Creator: Alves, Daniele S. M.; Izaguirre, Eder & Wacker, Jay G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Fermilab E791

Fermilab E791, a very high statistics charm particle experiment, recently completed its data taking at Fermilab`s Tagged Photon Laboratory. Over 20 billionevents were recorded through a loose transverse energy trigger and written to 8mm tape in the 1991--92 fixed target run at Fermilab. This unprecedented data sample containing charm is being analysis on many-thousand MIP RISC computing farms set up at sites in the collaboration. A glimpse of the data taking and analysis effort is presented. We… more

Date: October 1, 1992

Creator: Amato, S.; Anjos, J. C.; Bediaga, I.; Costa, I.; de Mello Neto, J. R. T.; de Miranda, J. M. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Fermilab E791

Fermilab E791, a very high statistics charm particle experiment, recently completed its data taking at Fermilab's Tagged Photon Laboratory. Over 20 billionevents were recorded through a loose transverse energy trigger and written to 8mm tape in the 1991--92 fixed target run at Fermilab. This unprecedented data sample containing charm is being analysis on many-thousand MIP RISC computing farms set up at sites in the collaboration. A glimpse of the data taking and analysis effort is presented. We… more

Date: October 1, 1992

Creator: Amato, S.; Anjos, J. C.; Bediaga, I.; Costa, I.; de Mello Neto, J. R. T.; de Miranda, J. M. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

New shower maximum trigger for electrons and photons at CDF

For the 1994 Tevatron collider run, CDF has upgraded the electron and photo trigger hardware to make use of shower position and size information from the central shower maximum detector. For electrons, the upgrade has resulted in a 50% reduction in backgrounds while retaining approximately 90% of the signal. The new trigger also eliminates the background to photon triggers from single-phototube spikes.

Date: July 28, 1994

Creator: Amidei, D.; Burkett, K.; Gerdes, D.; Miao, C.; Wolinski, D.; Byrum, K. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Status and Future Prospects for Supersymmetry at the Tevatron

We investigate the potential for discovery of super-symmetry during the next Tevatron Collider run in the light of new results fro LEP and CDF.

Date: January 1, 1990

Creator: Amos, N.; De, K.; White, A & Yamin, P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Status and Future Prospects for Supersymmetry at the Tevatron

We investigate the potential for discovery of super-symmetry during the next Tevatron Collider run in the light of new results fro LEP and CDF.

Date: December 31, 1990

Creator: Amos, N.; De, K.; White, A. & Yamin, P.

Item Type: Article

Partner: UNT Libraries Government Documents Department