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An Integrated Front-End Readout And Feature Extraction System for the BaBar Drift Chamber

Description: The BABAR experiment has been operating at SLAC's PEP-II asymmetric B-Factory since 1999. The accelerator has achieved more than three times its original design luminosity of 3 x 10{sup 33} cm{sup -2} s{sup -1}, with plans for an additional factor of three in the next two years. To meet the experiment's performance requirements in the face of significantly higher trigger and background rates, the drift chamber's front-end readout system has been redesigned around the Xilinx Spartan 3 FPGA. The new system implements analysis and feature-extraction of digitized waveforms in the front-end, reducing the data bandwidth required by a factor of four.
Date: August 10, 2006
Creator: Zhang, Jinlong & U., /Colorado
Partner: UNT Libraries Government Documents Department

A Measurement of Neutrino-Induced Charged-Current Neutral Pion Production

Description: This work presents the first comprehensive measurement of neutrino-induced charged-current neutral pion production (CC{pi}{sup 0}) off a nuclear target. The Mini Booster Neutrino Experiment (MiniBooNE) and Booster Neutrino Beam (BNB) are discussed in detail. MiniBooNE is a high-statistics ({approx} 1,000,000 interactions) low-energy (E{sub {nu}} {element_of} 0.5-2.0 GeV) neutrino experiment located at Fermilab. The method for selecting and reconstructing CC{pi}{sup 0} events is presented. The {pi}{sup 0} and {mu}{sup -} are fully reconstructed in the final state allowing for the measurement of, among other things, the neutrino energy. The total observable CC{pi}{sup 0} cross-section is presented as a function of neutrino energy, along with five differential cross-sections in terms of the final state kinematics and Q{sup 2}. The results are combined to yield a flux-averaged total cross-section of <{sigma}>{sub {Phi}} = (9.2 {+-} 0.3{sub stat.} {+-} 1.5{sub syst}.) x 10{sup -39} cm{sup 2}/CH{sub 2} at energy 965 MeV. These measurements will aid future neutrino experiments with the prediction of their neutrino interaction rates.
Date: April 1, 2010
Creator: Nelson, Robert H. & U., /Colorado
Partner: UNT Libraries Government Documents Department

Measuring the branching ratio of the rare decay pi0 --> e+ e-

Description: A precise branching ratio measurement of the rare decay {pi}{sup 0} {yields} e{sup +}e{sup -} has been made. The measurement was made with the rare kaon decay experiment KTeV at Fermilab where the source of {pi}{sup 0}s was K{sub L} {yields} {pi}{sup 0}{pi}{sup 0}{pi}{sup 0} decaying in flight. A total of 794 fully reconstructed K{sub L} {yields} 3{pi}{sup 0} events consistent with two of the intermediate {pi}{sup 0}s decaying into {gamma}{gamma} and one into e{sup +}e{sup -} were collected. An estimated 53.2 {+-} 11.0 of these events were expected to be background. Normalizing to the {pi}{sup 0} Dalitz decay they found Br({pi}{sup 0} {yields} e{sup +}e{sup -}, (m{sub e{sup +}e{sup -}}/m{sub {pi}{sup 0}}){sup 2} > 0.95) = (6.44 {+-} 0.25(stat) {+-} 0.22(syst)) x 10{sup -8} where internal radiation, {pi}{sup 0} {yields} e{sup +}e{sup -}({gamma}), was limited by the requirement (m{sub e{sup +}e{sup -}}/m{sub {pi}{sup 0}}){sup 2} > 0.95 which separated it from the tree level Dalitz decay, {pi}{sup 0} {yields} e{sup +}e{sup -}P{gamma}.
Date: February 1, 2006
Creator: Niclasen, Rune & U., /Colorado
Partner: UNT Libraries Government Documents Department

Measurement of the B0 ---> Psi (2S) Lambda0 Branching Fraction on BaBar at the Stanford Linear Accelerator Center (Abstract Only)

Description: The decays of B{sup 0} mesons to hadronic final states remains a rich area of physics on BaBar. Not only do the c{bar c}-K final states (e.g. B{sup 0} {yields} {psi}(2S)K{sup 0}) allow for the measurement of CP Violation, but the branching fractions provide a sensitive test of the theoretical methods used to account for low energy non-perturbative QCD effects. They present the measurement of the branching fraction for the decay B{sup 0} {yields} {psi}(2S)K{sub s}. The data set consists of 88.8 {+-} 1.0 x 10{sup 6} B{bar b} pairs collected on the e{sup +}e{sup -} {yields} {Upsilon}(4S) resonance on BaBar/PEP-II at the Stanford Linear Accelerator Center (SLAC). This analysis features a modification of present cuts, with respect to those published so far on BaBar, on the K{sub S} {yields} {pi}{sup +}{pi}{sup -} and {psi}(2S) {yields} J/{psi}{pi}{sup +}{pi}{sup -} which aim at reducing the background while keeping the signal intact. Various data selection criteria are studied for the lepton modes (e{sup +}e{sup -} and {mu}{sup +}{mu}{sup -}) of the J/{psi} and {psi}(2S) to improve signal purity as well as study the stability of the resultant branching fractions.
Date: November 16, 2005
Creator: Olivas, Alexander Raymond, Jr. & U., /Colorado
Partner: UNT Libraries Government Documents Department

Chamonium Spectroscopy at BaBar

Description: The charmonium-like states, Y(4260), Y(4350), produced via initial state radiation, as well as the X(3872), and Y(3940), produced in B meson decays from the BABAR B-factory are reviewed. These mesons do not seem consistent with conventional charmonium models, and several alternate hypotheses have been proposed to explain these new discoveries.
Date: January 14, 2008
Creator: Mokhtar, Arafat Gabareen & U., /Colorado State
Partner: UNT Libraries Government Documents Department

CCpi0 Event Reconstruction at MiniBooNE

Description: We describe the development of a fitter to reconstruct {nu}{sub {mu}} induced Charged-Current single {pi}{sup 0} (CC{pi}{sup 0}) events in an oil Cerenkov detector (CH{sub 2}). These events are fit using a generic muon and two photon extended track hypothesis from a common event vertex. The development of ring finding and particle identification are described. Comparisons between data and Monte Carlo are presented for a few kinematic distributions.
Date: September 1, 2009
Creator: Nelson, Robert H. & U., /Colorado
Partner: UNT Libraries Government Documents Department

Branching Ratio Measurements of B ---> J/psi eta K and B+- ---> D0 K+- with D0 ---> pi+ pi- pi0

Description: Results are presented for the decays of B {yields} J/{psi}{eta}K and B{sup {+-}} {yields} DK{sup {+-}}, respectively, with experimental data collected with BABAR detector at PEP-II, located at Stanford Linear Accelerator Center (SLAC). With 90 x 10{sup 6} B{bar B} events at the {Upsilon}(4S) resonance, we obtained branching fractions of {Beta}(B{sup {+-}} {yields} J/{psi}{eta}K{sup {+-}}) = [10.8 {+-} 2.3(stat) {+-} 2.4(syst)] x 10{sup -5} and {Beta}(B{sup 0} {yields} J/{psi}{eta}K{sub S}{sup 0}) = [8.4 {+-} 2.6(stat) {+-} 2.7(syst)] x 10{sup -5}; and we set an upper limit of {Beta}[B{sup {+-}} {yields} X(3872)K{sup {+-}} {yields} J/{psi}{eta}K{sup {+-}}] < 7.7 x 10{sup -6} at 90% confidence level. The branching fraction of decay chain {Beta}(B{sup {+-}} {yields} DK{sup {+-}} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup 0}K{sup {+-}}) = [5.5 {+-} 1.0(stat) {+-} 0.7(syst)] x 10{sup -6} with 229 x 10{sup 6} B{bar B} events at {Upsilon}(4S) resonance, here D represents the neutral D meson. The decay rate asymmetry is A = 0.02 {+-} 0.16(stat) {+-} 0.03(syst) for this full decay chain. This decay can be used to extract the unitarity angle {gamma}, a weak CP violation phase, through the interference of decay production of D{sup 0} and {bar D}{sup 0} to {pi}{sup +}{pi}{sup -}{pi}{sup 0}.
Date: March 8, 2006
Creator: Zeng, Qinglin & U., /Colorado State
Partner: UNT Libraries Government Documents Department

Measurements of CKM Angle Beta from BaBar

Description: We present recent results of hadronic B meson decays related to the CKM angle beta. The data used were collected by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider operating at the Upsilon(4S) resonance located at the Stanford Linear Accelerator Center.
Date: May 23, 2007
Creator: Ulmer, Keith A. & U., /Colorado
Partner: UNT Libraries Government Documents Department

Rare B Meson Decays With Omega Mesons

Description: Rare charmless hadronic B decays are particularly interesting because of their importance in understanding the CP violation, which is essential to explain the matter-antimatter asymmetry in our universe, and of their roles in testing the ''effective'' theory of B physics. The study has been done with the BABAR experiment, which is mainly designed for the study of CP violation in the decays of neutral B mesons, and secondarily for rare processes that become accessible with the high luminosity of the PEP-II B Factory. In a sample of 89 million produced B{bar B} pairs on the BABAR experiment, we observed the decays B{sup 0} {yields} {omega}K{sup 0} and B{sup +} {yields} {omega}{rho}{sup +} for the first time, made more precise measurements for B{sup +} {yields} {omega}h{sup +} and reported tighter upper limits for B {yields} {omega}K* and B{sup 0} {yields} {omega}{rho}{sup 0}.
Date: April 24, 2006
Creator: Zhang, Lei & U., /Colorado
Partner: UNT Libraries Government Documents Department

Measurement of the Decay B to Omega L Nu with the BaBar Detector and Determination of V_Ub

Description: We measure the branching fraction of the exclusive charmless semileptonic decay B {yields} {omega}{ell}{nu}{sub {ell}}, where {ell} is either an electron or a muon, with the charged B meson recoiling against a tag B meson decaying in the charmed semileptonic modes B {yields} D{ell}{nu}{sub {ell}} or B {yields} D*{ell}{nu}{sub {nu}}. The measurement is based on a dataset of 426.1 fb{sup -1} of e{sup +}e{sup -} collisions at a CM energy of 10.58 GeV recorded with the BABAR detector at the PEP-II asymmetric B Factory located at the SLAC National Accelerator Laboratory. We also calculate the relevant B {yields} {omega} hadronic form factors to determine the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element |V{sub ub}|.
Date: September 10, 2010
Creator: Nagel, Martin; U., /Colorado & ,
Partner: UNT Libraries Government Documents Department

Validation of Broadly Filtered Diagonalization Method for Extracting Frequencies and Modes from High-Performance Computations

Description: Recent developments have shown that one can get around the difficulties of finding the eigenvalues and eigenmodes of the large systems studied with high performance computation by using broadly filtered diagonalization [G. R. Werner and J. R. Cary, J. Compo Phys. 227, 5200 (2008)]. This method can be used in conjunction with any time-domain computation, in particular those that scale very well up to 10000s of processors and beyond. Here we present results that show that this method accurately obtains both modes and frequencies of electromagnetic cavities, even when frequencies are nearly degenerate. The application was to a well-characterized Kaon separator cavity, the A15. The computations are shown to have a precision to a few parts in 10{sup 5}. Because the computed frequency differed from the measured frequency by more than this amount, a careful validation study to determine all sources of difference was undertaken. Ultimately, more precise measurements of the cavity showed that the computations were correct, with remaining differences accounted for by uncertainties in cavity dimensions and atmospheric and thermal conditions. Thus, not only was the method validated, but it was shown to have the ability to predict differences in cavity dimensions from fabrication specifications.
Date: June 1, 2009
Creator: Austin, T.M.; Cary, J.R.; U., /Colorado; Werner, G.R.; U., /Colorado; Bellantoni, L. et al.
Partner: UNT Libraries Government Documents Department

Low scale seesaw, electron EDM and leptogenesis in a model with spontaneous CP violation

Description: Strong correlations between leptogenesis and low energy CP violating leptonic processes have been shown by us to exist fin the minimal left-right symmetric model with spontaneous CP violation. In this note, they investigate the implications of this model for the electric dipole moment of the electron. With an additional broken U(1){sub H} symmetry, the seesaw scale can be lowered to close to the electroweak scale. This additional symmetry also makes the connection between CP violation in quark sector to that in the lepton sector possible.
Date: September 1, 2006
Creator: Chen, Mu-Chun; /Fermilab /UC, Irvine; Mahanthappa, K.T. & U., /Colorado
Partner: UNT Libraries Government Documents Department


Description: We propose to design, build and use a tertiary K{sub L}{sup 0} beam produced using the high intensity pion beam being built in the proton area. The main advantage of this beam over previous beam is the low neutron background (K{sub L}/n > 3). We propose to study the large transverse momentum dependence of the particles produced in the strong interactions of a K{sub L}{sup 0} beam, and also the production of leptons, and lepton pairs.
Date: October 1, 1974
Creator: Bartlett, D.; Morse, R.; McQuate, D.; Mugge, M.; Nauenberg, U. & U., /Colorado
Partner: UNT Libraries Government Documents Department

A Gravity Dual of Metastable Dynamical Supersymmetry Breaking

Description: Metastable, supersymmetry-breaking configurations can be created in flux geometries by placing antibranes in warped throats. Via gauge/gravity duality, such configurations should have an interpretation as supersymmetry-breaking states in the dual field theory. In this paper, we perturbatively determine the asymptotic supergravity solutions corresponding to D3-brane probes placed at the tip of the cascading warped deformed conifold geometry, which is dual to an SU(N+M) x SU(N) gauge theory. The backreaction of the antibranes has the effect of introducing imaginary anti-self-dual flux, squashing the compact part of the space and forcing the dilaton to run. Using the generalization of holographic renormalization to cascading geometries, we determine the expectation values of operators in the dual field theory in terms of the asymptotic values of the supergravity fields.
Date: February 4, 2008
Creator: DeWolfe, Oliver; U., /Colorado; Kachru, Shamit; Mulligan, Michael & /Stanford U., Phys. Dept. /SLAC
Partner: UNT Libraries Government Documents Department

Search for Monopoles Above the 15-Foot Bubble Chamber

Description: Magnetic monopoles having energies less than about 40 TeV will be slowed to their terminal velocity by the earth's atmosphere. They may then be gathered by the fringing magnetic field of the 15-foot bubble chamber. We propose placing detectors of Lexan and nuclear emulsion at convenient locations above and below the bubble chamber. Such a systom would be sensitive to monopole masses between 10 GeV and 100 TeV and to monopole charges between {approx}0.7 and 10 hc/2e. The experiment would require the construction of a special light roof and would run for 5 weeks during a time when the bubble chamber is filled with air and not in use for other experiments. This study would lower the existing limit on in-flight detection of monopoles (at the earth's surface) by a factor of 20.
Date: January 1, 1976
Creator: Bartlett, D.F.; Soo, Daniel; U., /Colorado; Fleischer, Robert L.; Hart Jr., Howard R.; Mogro-Campero, Antonio et al.
Partner: UNT Libraries Government Documents Department

Observation of Two-Neutrino Double-Beta Decay in Xe-136 with EXO-200

Description: We report the observation of two-neutrino double-beta decay in {sup 136}Xe with T{sub 1/2} = 2.11 {+-} 0.04(stat) {+-} 0.21(syst) x 10{sup 21} yr. This second-order process, predicted by the standard model, has been observed for several nuclei but not for {sup 136}Xe. The observed decay rate provides new input to matrix element calculations and to the search for the more interesting neutrinoless double-beta decay, the most sensitive probe for the existence of Majorana particles and the measurement of the neutrino mass scale.
Date: September 14, 2012
Creator: Ackerman, N.; /SLAC; Aharmim, B.; U., /Laurentian; Auger, M.; U., /Bern et al.
Partner: UNT Libraries Government Documents Department

Final Results from the KTeV Experiment on the Decay K(L) ---> pi0 gamma gamma

Description: The authors report on a new measurement of the branching ratio B(K{sub L} {yields} {pi}{sup 0}{gamma}{gamma}) using the KTeV detector. They reconstruct 1982 events with an estimated background of 608, that results in B(K{sub L} {yields} {pi}{sup 0}{Gamma}{gamma}) = (1.29 {+-} 0.03{sub stat} {+-} 0.05{sub syst}) x 10{sup -6}. They also measure the parameter, a{sub V}, which characterizes the strength of vector meson exchange terms in this decay. They find a{sub V} = -0.31 {+-} 0.05{sub stat} {+-} 0.07{sub syst}. These results utilize the full KTeV data set collected from 1997 to 2000 and supersede earlier KTeV measurements of the branching ratio and a{sub V}.
Date: May 1, 2008
Creator: Abouzaid, E.; /Illinois U., Chicago; Arenton, M.; U., /Virginia; Barker, A.R.; U., /Colorado et al.
Partner: UNT Libraries Government Documents Department