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Properties of Exotic Charmonium-like States at CDF

Description: We report the recent evidence for a new narrow structure, Y (4140), decaying to the J/{psi}{phi} final state, in exclusive B{sup +} {yields} J/{psi}{phi}K{sup +} decays in a data sample corresponding to an integrated luminosity of 2.7 fb{sup -1} collected at the CDF II detector. This narrow structure with its mass well above open charm pairs is unlikely to be a candidate for a conventional charmonium state. From a study of the X(3872) mass and width based on the world's largest sample of X(3872) {yields} J/{psi}{pi}{sup +}{pi}{sup -} decays, we find that our X(3872) signal is consistent with a single state, and leads to the most precise measurement of the X(3872) mass.
Date: June 1, 2009
Creator: Yi, Kai & U., /Iowa
Partner: UNT Libraries Government Documents Department

Status of diffractive physics at D0 Run II

Description: The Forward Proton Detector (FPD) is a new sub-system of the D0 detector implemented for Run II at the Fermilab Tevatron which gives access to a wide range of diffractive scattering physics processes. This new detector is described and preliminary results from the diffractive program are presented.
Date: January 1, 2005
Creator: Strang, M. & /Texas U., Arlington
Partner: UNT Libraries Government Documents Department

Photon + jets at D0

Description: Photon plus jet production has been studied by the D0 experiment in Run II of the Fermilab Tevatron Collider at a centre of mass energy of {radical}s = 1.96 TeV. Measurements of the inclusive photon, inclusive photon plus jet, photon plus heavy flavour jet cross sections and double parton interactions in photon plus three jet events are presented. They are based on integrated luminosities between 0.4 fb{sup -1} and 1.0 fb{sup -1}. The results are compared to perturbative QCD calculations in various approximations.
Date: June 1, 2009
Creator: Sonnenschein, Lars & U., /RWTH Aachen
Partner: UNT Libraries Government Documents Department

Exclusive High Mass Di-leptons in CDF

Description: In the Collider Detector at Fermilab, CDF, we have measured central exclusive production, p + {bar p} {yields} p + X + {bar p}, where X is a pair of leptons or photons and nothing else. In this talk I focus on central masses M(X) > 8 GeV/c{sup 2}. We measured QED production {gamma}{gamma} {yields} e{sup +}e{sup -}, {mu}{sup +}{mu}{sup -} up to M(X) = 75 GeV/c{sup 2}, and candidates for photoproduction of Upsilons, {gamma} IP {yields} Y (1S), Y (2S), Y (3S). I report a search for exclusive photoproduction of Z-bosons, and the status of searches for exclusive two-photons: p + {bar p} {yields} p + {gamma}{gamma} + {bar p}. These measurements constrain the cross section {sigma}(p + p {yields} p + H + p) at the LHC.
Date: September 1, 2009
Creator: Albrow, Michael
Partner: UNT Libraries Government Documents Department

Measurement of y-Distributions for High Energy Antineutrino Scattering in Hydrogen-Neon

Description: Distributions in the scaling variable y are presented based on a study of approximately 700 antineutrino events in the energy range 10-200 GeV obtained using the Fermilab 15-ft bubble chamber filled with a light Hydrogen-Neon mixture. The distributions are inconsistent with a (1 -y){sup 2} form predicted by the simple quark parton model of the nucleon without antiquarks, but can be well fitted assuming a relative antiquark contribution of (10 {+-} 5)%. For small values of the Bjorken scaling variable (x < 0.1) the y-distribution can be well fitted assuming a relative antiquark contribution of (20 {+-} 5)%. For events at small x in the energy range 30-200 GeV the y-distribution is in good agreement with the results reported by the HPWF group.
Date: January 1, 1976
Creator: Berge, J.P.; DiBianca, F.A.; Hanft, R.; Nezrick, F.A.; Scott, W.G.; Smart, Wesley M. et al.
Partner: UNT Libraries Government Documents Department

Model independent measurement of S-wave K- pi+ systems using D+ ---> K pi pi decays from Fermilab E791

Description: A model-independent partial-wave analysis of the S-wave component of the K{pi} system from decays of D{sup +} mesons to the three-body K{sup -}{pi}{sup +}{pi}{sup +} final state is described. Data come from the Fermilab E791 experiment. Amplitude measurements are made independently for ranges of K{sup -}{pi}{sup +} invariant mass, and results are obtained below 825 MeV/c{sup 2}, where previous measurements exist only in two mass bins. This method of parametrizing a three-body decay amplitude represents a new approach to analyzing such decays. Though no model is required for the S-wave, a parametrization of the relatively well-known reference P- and D-waves, optimized to describe the data used, is required. The observed phase variation for the S-, P- and D-waves do not match existing measurements of I = 1/2 K{sup -} {pi}{sup +} scattering in the invariant mass range in which scattering is predominantly elastic. If the data are mostly I = 1/2, this observation indicates that the Watson theorem, which requires these phases to have the same dependence on invariant mass, does not apply to these decays. The production rate of K{sup -}{pi}{sup +} from these decays, if assumed to be predominantly I = 1/2, is also found to have a significant dependence on invariant mass in the region above 1.25 GeV/c{sup 2}. These measurements can provide a relatively model-free basis for future attempts to determine which strange scalar amplitudes contribute to the decays.
Date: July 1, 2005
Creator: Aitala, E.M.; Amato, S.; Anjos, J.C.; Appel, J.A.; Ashery, D.; Banerjee, S. et al.
Partner: UNT Libraries Government Documents Department

Study of the S-wave K(pi) --> Amplitude Using the Decay D+ --> K-pi+pi+

Description: In this work the S-wave component of the K{pi} amplitude from decay of D{sup +} {yields} K{sup -}{pi}{sup +}{pi}{sup +} it is directly measured. The data come from the Fermilab E831/FOCUS experiment. The amplitude measurement is made using the partial wave analysis without any preliminary assumption about the nature of the S-wave component of the K{pi} system. The phase and magnitude of the S-wave amplitude are generic functions to be determined directly through the Dalitz plot fit. For the sake of comparison, our results the same decay is analyzed using the isobar model, which is the standard way to analyze the Dalitz plot. The data fit obtained with the partial wave analysis is better than the data fit from the isobar model. The phase variation with respect to the invariant mass K{pi} is compared with the measurement of the phase {delta}{sub I=1/2}{sup 0} (m{sub K{pi}}) from K{pi} {yields} K{pi} scattering. The difference between both analysis is discussed considering: a difference in the composition of the isospin components I = 1/2 and I = 3/2 of the K{pi} system between D{sup +} decay and the K{pi} {yields} K{pi} scattering; and the final state interaction involving all particles from decay.
Date: February 1, 2007
Creator: Machado, Ana Amelia Bergamini
Partner: UNT Libraries Government Documents Department

Amplitude Analysis of the Decay $D_s^+ \to \pi^+ \pi^- \pi^+$ in the Experiment E831/FOCUS

Description: We present in this thesis the Dalitz Plot analysis of the D{sub s}{sup +} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup +} decay, with the data of the E831/FOCUS, that took data in 1996 and 1997. The masses and widhts of f{sub 0}(980) and f{sub 0}(1370) are free parametres of the fit on Dalitz Plot, objectiving to study in detail these resonances. After this analysis we present the Spectator Model study on the S wave in this decay. For this study we used the formalism developed by M. Svec [2] for scattering. We present the comparison between the Isobar Model, frequently used in Dalitz Plot analysis, and this formalism.
Date: January 1, 2005
Creator: Schilithz, Anderson Correa
Partner: UNT Libraries Government Documents Department

Neutrino scattering physics and experiments at super beams and neutrino factories

Description: A careful study of neutrino scattering physics is an essential part of the program to answer many open questions being addressed by several different physics communities. A deeper understanding of nuclear effects induced by neutrinos and considerably more accurate measurements of neutrino exclusive cross sections is crucial for minimizing systematics of neutrino oscillation experiments. In addition, the knowledge gained by neutrino scattering experiments is important to the Nuclear Physics and Astro-Particle physics communities as well. A review of where we expect to be in the study of neutrino scattering physics at the start of a Super Neutrino Beam Facility as well as the types of beams and detectors needed at such a facility are discussed.
Date: January 1, 2006
Creator: Morfin, J.G.
Partner: UNT Libraries Government Documents Department

The MINERvA Experiment

Description: The MINERvA experiment is a dedicated cross-section experiment whose aim is to measure neutrino cross sections for inclusive and exclusive final states on several nuclei. The detector is fully commissioned and began running in March 2010. As a dedicated cross-section experiment, MINERvA has a particular need to know the incident neutrino flux: both the absolute level and the energy dependence. In these proceedings we describe the MINERvA detector, give an update on the experimental status, and discuss the means to determine the neutrino flux. The MINERvA experiment is now running and has completed 25% of its full Low Energy run. There are various techniques planned for understanding the flux, including taking neutrino data at several different beam configurations. The experiment has gotten a first glimpse of two of the six configurations, and completed four horn current scans. Because of its exclusive final state reconstruction capabilities MINERvA can provide the much needed input for current and future oscillation experiments. The inclusive final state measurements and comparisons of nuclear effects across as many states as possible will provide new insights into neutrino-nucleus scattering.
Date: March 18, 2011
Creator: Harris, Deborah A. & Kopp, Sacha
Partner: UNT Libraries Government Documents Department

Search for New Physics in the B(s) Sector at the Tevatron

Description: While B{sup 0} and B{sup +} mesons are well studied at B-factories, large samples of B{sub s}{sup 0} mesons are only available at the Tevatron so far. Since the B{sub s}{sup 0} meson consists of quarks of the second and third generation it provides a complementary probe for searches for new physics effects. Results of the CDF and D0 experiments on the decays B{sub s}{sup 0} {yields} {mu}{sup +}{mu}{sup -} and B{sub s}{sup 0} {yields} {mu}{sup +}{mu}{sup -}{phi} as well as on CP violation in B{sub s}{sup 0} mixing and in interference between mixing and decay are presented.
Date: July 1, 2009
Creator: Kuhr, Thomas
Partner: UNT Libraries Government Documents Department

Measurement of the differential cross section $d\sigma/dt$ in elastic $p\bar{p}$ scattering at $\sqrt{s}=1.96$ TeV

Description: We present a measurement of the elastic differential cross section differential cross section d{sigma}(p{bar p}{yields}p{bar p})/dt as a function of the four-momentum-transfer squared t. The data sample corresponds to an integrated luminosity of {approx}31 nb{sup -1} collected with the D0 detector using dedicated Tevatron p{bar p} Collider operating conditions at {radical}s = 1.96 TeV and covers the range 0.26 < |t| < 1.2 GeV{sup 2}. For |t| < 0.6 GeV{sup 2}, d{sigma}/dt is described by an exponential function of the form Ae{sup -b|t|} with a slope parameter b = 16.86 {+-} 0.10 (stat) {+-} 0.20 (syst) GeV{sup -2}. A change in slope is observed at |t| {approx} 0.6 GeV{sup 2}, followed by a more gradual |t| dependence with increasing values of |t|.
Date: June 1, 2012
Creator: Abazov, V.M.; Abazov, V.M.; Abbott, B.; Acharya, B.S.; Adams, M.; Adams, T. et al.
Partner: UNT Libraries Government Documents Department

D^* production in deep-inelastic scattering at low Q^2

Description: Inclusive production of D* mesons in deep-inelastic scattering at HERA is studied in the range 5 < Q{sup 2} < 100 GeV{sup 2} of the photon virtuality and 0.02 < y < 0.70 of the inelasticity of the scattering process. The visible range for the D* meson is p{sub T} (D*) > 1.25 GeV and |{eta}(D*)| < 1.8. The data were taken with the H1 detector in the years 2004 to 2007 and correspond to an integrated luminosity of 347 pb{sup -1}. Single and double differential cross sections are measured. The results are compared to QCD predictions.
Date: July 1, 2011
Creator: Jung, Andreas W.
Partner: UNT Libraries Government Documents Department

Measurement of muon neutrino quasi-elastic scattering on carbon

Description: Low energy (200 < E{sub v} < 2000 MeV) neutrino oscillation experiments, including MiniBooNE, require a model of charged current quasi-elastic (CCQE) neutrino interactions to predict signal samples. Using a high-statistics sample of muon neutrino CCQE events, MiniBooNE finds that a simple Fermi gas model, with appropriate adjustments, accurately characterizes the CCQE events observed in a carbon-based detector. The extracted parameters include an effective axial mass, M{sub A} = 1.23 {+-} 0.20 GeV, used to describe the four-momentum dependence of the axial-vector form factor of the nucleon; and a Pauli-suppression parameter, {kappa} = 1.019 {+-} 0.011.
Date: June 1, 2007
Creator: Aguilar-Arevalo, A.A.; Bazarko, A.O.; Brice, S.J.; Brown, B.C.; Bugel, L.; Cao, J. et al.
Partner: UNT Libraries Government Documents Department

Exclusive Hadronic Final States in E+ E- Interactions at BaBar

Description: The first observation of e{sup +}e{sup -} annihilation into states of positive C parity, {rho}{sup 0}{rho}{sup 0} and {phi}{phi}{sup 0} is reported. It is shown that these final states are produced through two-virtual-photon annihilation. this is based on the distributions of cos{theta}*, where {theta}* is the center-of-mass polar angle of {phi} or {rho}{sup 0}. The cross sections for the |cos{theta}*| < 0.8 are measured. In addition, the observation of another channel, e{sup +}e{sup -} {yields} {phi}{eta} near {radical}s = 10.58 Gev with a significance of 6.5{sigma} is discussed. The cross section of the later channel for |cos{theta}*| < 0.8 is measured, where {theta}* is the center-of-mass polar angle of {phi} meson.
Date: December 5, 2007
Creator: Saremi, Sepehr & /Massachusetts U., Amherst
Partner: UNT Libraries Government Documents Department

Studying neutrino oscillations using quasi-elastic events in MINOS

Description: MINOS (Main Injector Neutrino Oscillation Search), is a long baseline neutrino experiment designed to search for neutrino oscillations using two detectors at Fermi National Accelerator Laboratory, IL (Near Detector) and Soudan, MN (Far Detector). It will study {nu}{sub {mu}} {yields} {nu}{sub {tau}} oscillations and make a measurement on the oscillation parameters, {Delta}m{sub 23}{sup 2} and sin{sup 2} 2{theta}{sub 23}, via a {nu}{sub {mu}} beam made at Fermilab. Charge current neutrino interactions in the MINOS detectors are of three types: quasi-elastic scattering (QEL), resonance scattering (RES) and deep inelastic scattering (DIS). Of these, quasi-elastic scattering leaves the cleanest signal with just one {mu} and one proton in the final state, thus rendering the reconstruction of the neutrino energy more accurate. This thesis will outline a method to separate QEL events from the others in the two detectors and perform a calculation of {Delta}m{sub 23}{sup 2} and sin{sup 2} 2{theta}{sub 23} using those events. The period under consideration was May 2005 to February 2006. The number of observed quasi-elastic events with energies below 10 GeV was 29, where the expected number was 60 {+-} 3. A fit to the energy distribution of these events gives {Delta}m{sub 23}{sup 2} = 2.91{sub -0.53}{sup +0.49}(stat){sub -0.09}{sup +0.08}(sys) x 10{sup -3} eV{sup 2} and sin{sup 2} 2{theta}{sub 23} = 0.990{sub -0.180}(stat){sub -0.030}(sys).
Date: February 1, 2008
Creator: Kumaratunga, Sujeewa Terasita & U., /Minnesota
Partner: UNT Libraries Government Documents Department

SciNOvA: A Measurement of Neutrino-Nucleus Scattering in a Narrow-Band Beam

Description: We propose to construct and deploy a fine-grained detector in the Fermilab NOvA 2 GeV narrow-band neutrino beam. In this beam, the detector can make unique contributions to the measurement of quasi-elastic scattering, neutral-current elastic scattering, neutral-current {pi}{sup 0} production, and enhance the NOvA measurements of electron neutrino appearance. To minimize cost and risks, the proposed detector is a copy of the SciBar detector originally built for the K2K long baseline experiment and used recently in the SciBooNE experiment.
Date: October 15, 2010
Creator: Paley, J.; Djurcic, Z.; /Argonne; Harris, D.; Tesarek, R.; /Fermilab et al.
Partner: UNT Libraries Government Documents Department

Bigger, Better, Faster, More at the LHC

Description: Multijet plus missing energy searches provide universal coverage for theories that have new colored particles that decay into a dark matter candidate and jets. These signals appear at the LHC further out on the missing energy tail than two-to-two scattering indicates. The simplicity of the searches at the LHC contrasts sharply with the Tevatron where more elaborate searches are necessary to separate signal from background. The searches presented in this article effectively distinguish signal from background for any theory where the LSP is a daughter or granddaughter of the pair-produced colored parent particle without ever having to consider missing energies less than 400 GeV.
Date: August 26, 2010
Creator: Izaguirre, Eder; /SLAC; Manhart, Michael; /Rutgers U., Piscataway; Wacker, Jay G. & /SLAC
Partner: UNT Libraries Government Documents Department

Experimental probes of axions

Description: Experimental searches for axions or axion-like particles rely on semiclassical phenomena resulting from the postulated coupling of the axion to two photons. Sensitive probes of the extremely small coupling constant can be made by exploiting familiar, coherent electromagnetic laboratory techniques, including resonant enhancement of transitions using microwave and optical cavities, Bragg scattering, and coherent photon-axion oscillations. The axion beam may either be astrophysical in origin as in the case of dark matter axion searches and solar axion searches, or created in the laboratory from laser interactions with magnetic fields. This note is meant to be a sampling of recent experimental results.
Date: October 1, 2009
Creator: Chou, Aaron S.
Partner: UNT Libraries Government Documents Department

Measurement of the Cross Section for Prompt Isolated Diphoton Production in $p\bar{p}$ Collisions at \sqrt s = 1.96 TeV

Description: This article reports a measurement of the cross section of prompt isolated photon pair production in p{bar p} collisions at a total energy {radical}s = 1.96 TeV using data of 5.36 fb{sup -1} integrated luminosity collected with the CDF II detector at the Fermilab Tevatron. The measured cross section, differential in basic kinematic variables, is compared with three perturbative QCD predictions, a leading order (LO) parton shower calculation and two next-to-leading order (NLO) calculations. The NLO calculations reproduce most aspects of the data. By including photon radiation from quarks before and after hard scattering, the parton shower prediction becomes competitive with the NLO predictions.
Date: September 1, 2011
Creator: Vellidis, Costas
Partner: UNT Libraries Government Documents Department

Neutrino-nucleus interactions

Description: The study of neutrino oscillations has necessitated a new generation of neutrino experiments that are exploring neutrino-nuclear scattering processes. We focus in particular on charged-current quasi-elastic scattering, a particularly important channel that has been extensively investigated both in the bubble-chamber era and by current experiments. Recent results have led to theoretical reexamination of this process. We review the standard picture of quasi-elastic scattering as developed in electron scattering, review and discuss experimental results, and discuss additional nuclear effects such as exchange currents and short-range correlations that may play a significant role in neutrino-nucleus scattering.
Date: January 1, 2011
Creator: Gallagher, H.; U., /Tufts; Garvey, G.; Alamos, /Los; Zeller, G.P. & /Fermilab
Partner: UNT Libraries Government Documents Department