Partner
UNT Libraries Government Documents Department
13,199
UNT Libraries Special Collections
3,380
UNT Libraries
1,738
Oklahoma Historical Society
1,458
Abilene Christian University Library
393
Cross Plains Public Library
373
Sterling Municipal Library
361
National Museum of the Pacific War/Admiral Nimitz Foundation
307
San Antonio Public Library
179
Carl Albert Congressional Research and Studies Center
157
122 More
Collection
Office of Scientific & Technical Information Technical Reports
7,356
Texas Digital Newspaper Program
3,912
Congressional Research Service Reports
3,330
Oklahoma Digital Newspaper Program
1,644
Tocker Foundation Grant
1,451
Defense Base Closure and Realignment Commission
1,004
The Greensheet
882
Government Accountability Office Reports
862
KXAS-NBC 5 News Collection
744
The Black Academy of Arts and Letters Records
691
244 More
Degree Department
College of Music
49
Department of Psychology
38
Chemistry
35
Department of Counseling, Development and Higher Education
27
Libraries
27
Department of Computer Science and Engineering
25
Music
23
Computer Science and Engineering
20
Department of Teacher Education and Administration
20
Department of Technology and Cognition
17
67 More
Degree Discipline
Degree Level
Country
States
Year
Month
Language
Analysis of the quantum numbers J**PC of the X(3872)
The authors present an analysis of angular distributions and correlations of the X(3872) in the exclusive decay mode X(3872) {yields} J/{psi}{pi}{sup +}{pi}{sup -} with J/{psi} {yields} {mu}{sup +}{mu}{sup -}. They use 780 pb{sup -1} of data from p{bar p} collisions at {radical}s = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. They derive constraints on spin, parity, and charge conjugation parity of the X(3872) by comparing measured angular distributions of the decay products with predictions for different J{sup PC} hypotheses. The assignments J{sup PC} = 1{sup ++} and 2{sup -+} are the only ones consistent with the data.
Date:
December 1, 2006
Creator:
Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D. et al.
Object Type:
Article
System:
The UNT Digital Library
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 transverse energy and the number of jets in the event. The results, which use 360 pb{sup -1} of data recorded with the CDF II detector at the Fermilab Tevatron Collider, are {sigma}(t{bar t}) = 8.5{sub -2.2}{sup +2.7} pb, {sigma}(W{sup +}W{sup -}) = 16.3{sub -4.4}{sup +5.2} pb, and {sigma}(Z{sup 0} {yields} {tau}{sup +}{tau}{sup -}) = 291{sub -46}{sup +50} pb.
Date:
December 1, 2006
Creator:
Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D. et al.
Object Type:
Article
System:
The UNT Digital Library
Measurement of the B+ production cross-section in p anti-p collisions at s**(1/2) = 1960-GeV
The authors present a new measurement of the B{sup +} meson differential cross section d{sigma}/dP{sub T} at {radical}s = 1960 GeV. The data correspond to an integrated luminosity of 739 pb{sup -1} collected with the upgraded CDF detector (CDF II) at the Fermilab Tevatron collider. B{sup +} candidates are reconstructed through the decay B{sup +} {yields} J/{psi} K{sup +}, with J/{psi} {yields} {mu}{sup +}{mu}{sup -}. The integrated cross section for producing B{sup +} mesons with p{sub T} {ge} 6 GeV/c and |y| {le} 1 is measured to be 2.78 {+-} 0.24 {mu}b.
Date:
December 1, 2006
Creator:
Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D. et al.
Object Type:
Article
System:
The UNT Digital Library
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 between the momentum of the charged lepton in the W boson rest frame and the W momentum in the top quark rest frame. The cos {theta}* distribution in the data is determined by full kinematic reconstruction of the t{bar t} candidates. They find F{sub 0} = 0.85{sub -0.22}{sup +0.15}(stat){+-}0.06(syst) and F{sub +} = 0.05{sub -0.05}{sup +0.11}(stat) {+-} 0.03(syst), which is consistent with the standard model prediction. They set an upper limit on the fraction of right-handed W bosons of F{sub +} < 0.26 at the 95% confidence level.
Date:
December 1, 2006
Creator:
Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D. et al.
Object Type:
Article
System:
The UNT Digital Library
Measurement of the Lambda0(b) Lifetime in Lambda0(b) ---> J/psi Lambda0 in p anti-p Collisions at s**(1/2) = 1.96-TeV
The authors report a measurement of the {Lambda}{sub b}{sup 0} lifetime in the exclusive decay {Lambda}{sub b}{sup 0} {yields} J/{psi}{Lambda}{sup 0} in p{bar p} collisions at {radical}s = 1.96 TeV using an integrated luminosity of 1.0 fb{sup -1} of data collected by the CDF II detector at the Fermilab Tevatron. Using fully reconstructed decays, they measure {tau}({Lambda}{sub b}{sup 0}) = 1.593{sub -0.078}{sup +0.083}(stat.) {+-} 0.033(syst.) ps. This is the single most precise measurement of {tau}({Lambda}{sub b}{sup 0}) and is 3.2 {sigma} higher than the current world average.
Date:
September 1, 2006
Creator:
Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D. et al.
Object Type:
Article
System:
The UNT Digital Library
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 by the CDF II detector at Fermilab and extract a measurement of m{sub t} = 180.7{sub -13.4}{sup +15.5}(stat.) {+-} 8.6 (syst.) GeV/c{sup 2}. While the uncertainty of this result is larger than that of other measurements, the dominant uncertainties in the decay length technique are uncorrelated with those in other methods. This result can help reduce the overall uncertainty when combined with other existing measurements of the top quark mass.
Date:
December 1, 2006
Creator:
Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D. et al.
Object Type:
Article
System:
The UNT Digital Library
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 events are observed compared to a background expectation of 1.9 {+-} 0.3 events. These events are consistent in cross section and properties with the QED process p{bar p} {yields} p + e{sup +}e{sup -} + {bar p} through two-photon exchange. The measured cross section is 1.6{sub -0.3}{sup +0.5}(stat) {+-} 0.3(syst) pb. This agrees with the theoretical prediction of 1.71 {+-} 0.01 pb.
Date:
November 1, 2006
Creator:
Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D. et al.
Object Type:
Article
System:
The UNT Digital Library
Precision measurement of the top quark mass from dilepton events at CDF II
We report a measurement of the top quark mass, M{sub t}, in the dilepton decay channel of t{bar t} {yields} b{ell}{prime}{sup +} {nu}{sub {ell}}, {bar b}{ell}{sup -}{bar {nu}}{sub {ell}} using an integrated luminosity of 1.0 fb{sup -1} of p{bar p} collisions collected with the CDF II detector. We apply a method that convolutes a leading-order matrix element with detector resolution functions to form event-by-event likelihoods; we have enhanced the leading-order description to describe the effects of initial-state radiation. The joint likelihood is the product of the likelihoods from 78 candidate events in this sample, which yields a measurement of M{sub t} = 164.5 {+-} 3.9(stat.) {+-} 3.9(syst.) GeV/c{sup 2}, the most precise measurement of M{sub t} in the dilepton channel.
Date:
December 1, 2006
Creator:
Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D. et al.
Object Type:
Article
System:
The UNT Digital Library
Search for Exotic S=-2 Baryons in proton-antiproton Collisions at sqrt(s) = 1.96 TeV
A search for a manifestly exotic S = -2 baryon state decaying to {Xi}{sup -}{pi}{sup -}, and its neutral partner decaying to {Xi}{sup -}{pi}{sup +}, has been performed using 220 pb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV collected by the Collider Detector at Fermilab. The {Xi}{sup -} trajectories were measured in a silicon tracker before their decay, resulting in a sample with low background and excellent position resolution. No evidence was found for S = -2 pentaquark candidates in the invariant mass range of 1600-2100 MeV/c{sup 2}. Upper limits on the product of pentaquark production cross section times its branching fraction to {Xi}{sup -}{pi}{sup +,-}, relative to the cross section of the well established {Xi}(1530) resonance, are presented for neutral and doubly negative candidates with p{sub T} > 2 GeV/c and |y| < 1 as a function of pentaquark mass. At 1862 MeV/c{sup 2}, these upper limits for neutral and doubly negative final states were found to be 3.2% and 1.7% at the 90% confidence level, respectively.
Date:
December 1, 2006
Creator:
Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D. et al.
Object Type:
Article
System:
The UNT Digital Library
Search for V+A current in top quark decay in p anti-p collisions at s**(1/2) = 1.96-TeV
The authors report an upper limit on the fraction of V + A current, f{sub V+A}, in top quark decays, using approximately 700 pb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV acquired by the upgraded Collider Detector at Fermilab. For the decay t {yields} wb {yields} {ell}vb (where {ell} = e or {mu}), the invariant mass of the charged lepton and the bottom quark jet is sensitive to the polarization of the W boson. They determine f{sub V+A} = -0.06 {+-} 0.25 given a top quark mass of 175 GeV/c{sup 2}. They set an upper limit on f{sub V+A} of 0.29 at the 95% confidence level, which represents an improvement by a factor of two on the previous best direct limit.
Date:
August 1, 2006
Creator:
Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D. et al.
Object Type:
Article
System:
The UNT Digital Library
Search for V + A current in top quark decay in p anti-p collisions at s**(1/2) = 1.96 TeV
The authors report an upper limit on the fraction of V + A current, f{sub V+A}, in top quark decays, using approximately 700 pb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV acquired by the upgraded Collider Detector at Fermilab. For the decay t {yields} Wb {yields} {ell}{nu}b (where {ell} = e or {mu}), the invariant mass of the charged lepton and the bottom quark jet is sensitive to the polarization of the W boson. They determine f{sub V+A} = -0.06 {+-} 0.25 given a top quark mass of 175 GeV/c{sup 2}. They set an upper limit on f{sub V+A} of 0.29 at the 95% confidence level, which represents an improvement by a factor of two on the previous best direct limit.
Date:
September 1, 2006
Creator:
Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D. et al.
Object Type:
Article
System:
The UNT Digital Library
Search for W-prime boson decaying to electron-neutrino pairs in p anti-p collisions at s**(1/2) = 1.96-TeV
The authors present the results of a search for W{prime} boson decaying to electron-neutrino pairs in p{bar p} collisions at a center-of-mass energy of 1.96 TeV, using a data sample corresponding to 205 pb{sup -1} of integrated luminosity collected by the CDF II detector at Fermilab. They observe no evidence for this decay mode and set limits on the production cross section times branching fraction, assuming the neutrinos from W{prime} boson decays to be light. If they assume the manifest left-right symmetric model, they exclude a W{prime} boson with mass less than 788 GeV/c{sup 2} at the 95% confidence level.
Date:
November 1, 2006
Creator:
Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D. et al.
Object Type:
Article
System:
The UNT Digital Library
Measurement of the t anti-t Production Cross Section in p anti-p collisions at s**(1/2) = 1.96-TeV in the All Hadronic Decay Mode
The authors report a measurement of the t{bar t} production cross section using the CDF II detector at the Fermilab Tevatron. The analysis is performed using 311 pb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV. The data consist of events selected with six or more hadronic jets with additional kinematic requirements. At least one of these jets must be identified as a b-quark jet by the reconstruction of a secondary vertex. The cross section is measured to be {sigma}{sub t{bar t}} = 7.5 {+-} 2.1(stat.){sub -2.2}{sup +3.3}(syst.){sub -0.4}{sup +0.5}(lumi.) pb, which is consistent with the standard model prediction.
Date:
July 1, 2006
Creator:
Abulencia, A.; Adelman, Jahred A.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D. et al.
Object Type:
Article
System:
The UNT Digital Library
Observation of B0(s) - anti-B0(s) Oscillations
The authors report the observation of B{sub s}{sup 0}-{bar B}{sub s}{sup 0} oscillations from a time-dependent measurement of the B{sub s}{sup 0}-{bar B}{sub s}{sup 0} oscillation frequency {Delta}m{sub s}. Using a data sample of 1 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron, they find signals of 5600 fully reconstructed hadronic B{sub s} decays, 3100 partially reconstructed hadronic B{sub s} decays, and 61,500 partially reconstructed semileptonic B{sub s} decays. They measure the probability as a function of proper decay time that the B{sub s} decays with the same, or opposite, flavor as the flavor at production, and they find a signal for B{sub s}{sup 0}-{bar B}{sub s}{sup 0} oscillations. The probability that random fluctuations could produce a comparable signal is 8 x 10{sup -8}, which exceeds 5{sigma} significance. They measure {Delta}m{sub s} = 17.77 {+-} 0.10(stat) {+-} 0.07(syst) ps{sup -1} and extract |V{sub td}/V{sub ts}| = 0.2050 {+-} 0.0007(exp{sub -0.0060}{sup +0.0081})(theor).
Date:
September 1, 2006
Creator:
Abulencia, A.; Adelman, Jahred A.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D. et al.
Object Type:
Article
System:
The UNT Digital Library
The CDF II eXtremely fast tracker upgrade
The CDF II Extremely Fast Tracker is the trigger track processor which reconstructs charged particle tracks in the transverse plane of the CDF II central outer tracking chamber. The system is now being upgraded to perform a three dimensional track reconstruction. A review of the upgrade is presented here.
Date:
September 1, 2006
Creator:
Abulencia, A.; Azzurri, P.; Cochran, E.; Dittmann, J.; Donati, S.; Efron, J. et al.
Object Type:
Article
System:
The UNT Digital Library
Fast Prediction of HCCI Combustion with an Artificial Neural Network Linked to a Fluid Mechanics Code
We have developed an artificial neural network (ANN) based combustion model and have integrated it into a fluid mechanics code (KIVA3V) to produce a new analysis tool (titled KIVA3V-ANN) that can yield accurate HCCI predictions at very low computational cost. The neural network predicts ignition delay as a function of operating parameters (temperature, pressure, equivalence ratio and residual gas fraction). KIVA3V-ANN keeps track of the time history of the ignition delay during the engine cycle to evaluate the ignition integral and predict ignition for each computational cell. After a cell ignites, chemistry becomes active, and a two-step chemical kinetic mechanism predicts composition and heat generation in the ignited cells. KIVA3V-ANN has been validated by comparison with isooctane HCCI experiments in two different engines. The neural network provides reasonable predictions for HCCI combustion and emissions that, although typically not as good as obtained with the more physically representative multi-zone model, are obtained at a much reduced computational cost. KIVA3V-ANN can perform reasonably accurate HCCI calculations while requiring only 10% more computational effort than a motored KIVA3V run. It is therefore considered a valuable tool for evaluation of engine maps or other performance analysis tasks requiring multiple individual runs.
Date:
August 29, 2006
Creator:
Aceves, S M; Flowers, D L; Chen, J & Babaimopoulos, A
Object Type:
Article
System:
The UNT Digital Library
Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Juveniles, 2004-2005 Annual Report.
None
Date:
May 1, 2006
Creator:
Achrod, Stephen; Sandford, Benjamin P. & Hockersmith, Eric E. (National Marine Fisheries Services, Northwest Fisheries Science Center, Fish Ecology Division, Seattle, WA)
Object Type:
Report
System:
The UNT Digital Library
Assessing Terrorist Motivations for Attacking Critical Infrastructure
Certain types of infrastructure--critical infrastructure (CI)--play vital roles in underpinning our economy, security and way of life. These complex and often interconnected systems have become so ubiquitous and essential to day-to-day life that they are easily taken for granted. Often it is only when the important services provided by such infrastructure are interrupted--when we lose easy access to electricity, health care, telecommunications, transportation or water, for example--that we are conscious of our great dependence on these networks and of the vulnerabilities that stem from such dependence. Unfortunately, it must be assumed that many terrorists are all too aware that CI facilities pose high-value targets that, if successfully attacked, have the potential to dramatically disrupt the normal rhythm of society, cause public fear and intimidation, and generate significant publicity. Indeed, revelations emerging at the time of this writing about Al Qaida's efforts to prepare for possible attacks on major financial facilities in New York, New Jersey, and the District of Columbia remind us just how real and immediate such threats to CI may be. Simply being aware that our nation's critical infrastructure presents terrorists with a plethora of targets, however, does little to mitigate the dangers of CI attacks. In order …
Date:
December 4, 2006
Creator:
Ackerman, G.; Abhayaratne, P.; Bale, J.; Bhattacharjee, A.; Blair, C.; Hansell, L. et al.
Object Type:
Report
System:
The UNT Digital Library
The Jericho Option: Al-Qa'ida and Attacks on Critical Infrastructure
There is no doubt that al-Qaida and its affiliates have displayed, and continue to display, an acute interest in attacking targets that are considered to be important components of the infrastructure of the United States. What has not thus far been carried out, however, is an in-depth examination of the basic nature, historical evolution, and present scope of the organization's objectives that might help government personnel develop sound policy recommendations and analytical indicators to assist in detecting and interdicting plots of this nature. This study was completed with the financial support of the Lawrence Livermore National Laboratory, through a project sponsored by the U.S. Department of Homeland Security, Science and Technology Directorate. It is specifically intended to increase counterterrorism analysts understanding of certain features of al-Qaida's strategy and operations in order to facilitate the anticipation and prevention of attacks directed against our most critical infrastructures. The procedure adopted herein has involved consulting a wide variety of source materials that bear on the topic, ranging from sacred religious texts and historical accounts to al-Qaida-linked materials and the firsthand testimony of captured members of the group. It has also intentionally combined multiple approaches, including exploring the more esoteric religion-historical referents that have …
Date:
August 28, 2006
Creator:
Ackerman, G.; Blair, C.; Bale, J.; Hahn, G.; DiLorenzo, E.; Vadlamudi, S. et al.
Object Type:
Report
System:
The UNT Digital Library
Phase Change Enthalpies and Entropies of Liquid Crystals
Article on phase change enthalpies and entropies of liquid crystals.
Date:
July 17, 2006
Creator:
Acree, William E. (William Eugene) & Chickos, James S.
Object Type:
Article
System:
The UNT Digital Library
[Chrystalyn booth at Craft Mafia exhibition]
Photograph of a necklace display at Denton Craft Mafia's annual exhibition and sale at Art Six Coffee House. The necklaces, made of various shapes of beads, hang on metal racks and sit on a tabletop. A sheet of paper visible in the foreground reads, "Chrystalyn email list."
Date:
April 2006
Creator:
Adair, Nikki
Object Type:
Photograph
System:
The UNT Digital Library
[Necklaces on display at Craft Mafia exhibition]
Photograph of a necklace display at Denton Craft Mafia's annual exhibition and sale at Art Six Coffee House. The necklaces, made of square-shaped charms on ball chains, can be seen hanging in a row, receding into the background.
Date:
April 2006
Creator:
Adair, Nikki
Object Type:
Photograph
System:
The UNT Digital Library
[Wrist cuffs on display at Craft Mafia exhibition]
Photograph of a wrist cuff display at Denton Craft Mafia's annual exhibition and sale at Art Six Coffee House. The cuffs, made of floral and abstract patterned fabric, are being displayed on a wooden shelf.
Date:
April 2006
Creator:
Adair, Nikki
Object Type:
Photograph
System:
The UNT Digital Library
Radiation hard diamond sensors for future tracking applications
None
Date:
January 1, 2006
Creator:
Adam, W.; de Boer, W.; Borchi, E.; Bruzzi, M.; Colledani, C.; D'Angelo, P. et al.
Object Type:
Article
System:
The UNT Digital Library