3,216 Matching Results

Search Results

Advanced search parameters have been applied.

Observation of Mesons Produced by the 184-inch Cyclotron

Description: The following report presents the study of meson tracks produced by a cyclotron of 184-inches, and prompting the question of whether the light mesons all come from decays of heavy mesons, or whether they are produced in a primary process at the target.
Date: 1948
Creator: Lattes, César & Gardner, Eugene
Partner: UNT Libraries Government Documents Department

The Supersymmetric Fat Higgs

Description: Supersymmetric models have traditionally been assumed to be perturbative up to high scales due to the requirement of calculable unification. In this note I review the recently proposed `Fat Higgs' model which relaxes the requirement of perturbativity. In this framework, an NMSSM-like trilinear coupling becomes strong at some intermediate scale. The NMSSM Higgses are meson composites of an asymptotically-free gauge theory. This allows us to raise the mass of the Higgs, thus alleviating the MSSM of its fine tuning problem. Despite the strong coupling at an intermediate scale, the UV completion allows us to maintain gauge coupling unification.
Date: October 27, 2004
Creator: Harnik, Roni
Partner: UNT Libraries Government Documents Department

Compton Scattering on Nucleons

Description: From introduction: "The present paper deals with a classical calculation in which some of the meson effects can be included to all orders in the meson-nucleon coupling coupling constant, in particular those having to do with the gyration of the nucleon spin and isotopic spin. Such a treatment leads to results qualitatively different from the weak coupling calculations."
Date: May 24, 1954
Creator: Huddlestone, Richard Harold
Partner: UNT Libraries Government Documents Department

The Method of Moments in Quantum Mechanics ; The [Pi]-Mesic Disintegration of the Deuteron

Description: The following report contains two reports to summarize a thesis: first, a report describing the classical moment techniques of Tchebycheff, Markov, and Stieltjes that have been applied to the problem of diagonalizing the Hamiltonian operator; and the second report describes an investigation of the higher-order corrections to the mesic disintegration of deuterons that is considered.
Date: March 18, 1957
Creator: Halpern, Francis Robert, {}
Partner: UNT Libraries Government Documents Department

Properties of Negtive K Mesons

Description: Report discussing interactions of 420-Mev/c K- mesons incident on a nuclear emulsion stack. Information on the differential scattering, elastic scattering, absorption events, and inelastic scattering of the mesons is provided. Additionally, the ratio of Λ to Σ hyperons produced in the primary interaction is calculated.
Date: September 1, 1957
Creator: Webb, Francis M.; Hoff, Edwin L.; Featherston, Frank Hunter; Chupp, Warren W.; Goldhaber, Gerson & Goldhaber, Sulamith
Partner: UNT Libraries Government Documents Department

Rare and forbidden decays of D Mesons

Description: The authors summarize the results of two recent searches for flavor-changing neutral current, lepton-flavor violating, and lepton-number violating decays of D{sup +}, D{sub s}{sup +}, and D{sup 0} mesons (and their antiparticles) into modes containing muons and electrons. using data from Fermilab charm hadroproduction experiment E791, they examined D{sup +} and D{sub s}{sup +} {pi}{ell}{ell} and {Kappa}{ell}{ell} decay modes and the D{sup 0} dilepton decay modes containing either {ell}{sup +}{ell}{sup {minus}}, a {rho}{sup 0}, {bar {Kappa}}*{sup 0}, or {phi} vector meson, or a non-resonant {pi}{pi}, {Kappa}{pi}, or {Kappa}{Kappa} pair of pseudoscalar mesons. No evidence for any of these decays was found. Therefore, the authors presented branching-fraction upper limits at 90% confidence level for the 51 decay modes examined. Twenty-six of these modes had no previously reported limits, and eighteen of the remainder were reported with significant improvements over previously published results.
Date: May 23, 2001
Creator: al., David A. Sanders et
Partner: UNT Libraries Government Documents Department

Measurement of A{sub c} with charmed mesons at SLD

Description: We present a direct measurement of the parity-violation parameter A{sub c}. The measurement is based on 550k Z{sup 0} decays collected by the SLD detector. The mean electron-beam polarization is |P{sub e}| = 73%. The tagging of c-quark events was performed using two methods: The exclusive reconstruction of D*{sup +}, D{sup +}, and D{sup 0} mesons, and the inclusive P{sub T} spectrum of soft-pions ({pi}{sub s}) in the decay of D*{sup +} {yields} D{sup 0}{pi}{sub s}{sup +}. The results of these two methods are combined to give A{sub c} = 0.688 {+-} 0.035(stat.) {+-} 0.025(sys.) (preliminary).
Date: July 16, 1999
Creator: Iwasaki, Masako
Partner: UNT Libraries Government Documents Department

B physics at the tevatron

Description: Precision B-physics results from the CDF and D0 Collaborations based on data collected during the Tevatron 1992-96 run are presented. In particular we discuss the measurement of the B{sub s} meson lifetime, B{sub c} meson observation, and B{sup 0} - {anti B}{sup 0} mixing results obtained using time-evolution analyses. Prospects for the next Tevatron run, starting in 1999, are also reported.
Date: July 1, 1998
Partner: UNT Libraries Government Documents Department

Production of Neutral Photopions as a Function of Atomic Weight

Description: Thesis discussing the relative yield of neutral pions from elements in a reaction "as a function of the quantum-limit energy (the maximum energy of the quanta in the bremsstrahlung beam) of the Berkeley synchrotron." Interpretation of the results leads to values for the mean free path for absorption of the neutral pions in nuclear matter.
Date: May 28, 1956
Creator: Anderson, John David
Partner: UNT Libraries Government Documents Department

Electromagnetic Mass Splittings in Heavy Mesons

Description: The electromagnetic contribution to the isomultiplet mass splittings of heavy mesons is reanalyzed within the framework of the heavy mass expansion. It is shown that the leading term in the expansion is given to a good approximation by the elastic term. 1/mQ-corrections can only be estimated, the main source of uncertainty now being inelastic contributions. The 1/mQ-corrections to the elastic term turn out to be relatively small in both D and B mesons.
Date: November 1, 1992
Creator: Goity, Jose
Partner: UNT Libraries Government Documents Department

New puzzles in nonleptonic B and D decays

Description: Exclusive charged B decays show an unexplained enhancement in low-lying channels which must be reversed in other channels to equalise charged and neutral lifetimes. One suggested explanation involves decay modes with excited mesons like the a{sub 1}. The anomalous behavior of decay modes of D and B mesons into final states containing the {eta} and {eta}{prime} mesons is discussed.
Date: September 1, 1997
Creator: Lipkin, H.J.
Partner: UNT Libraries Government Documents Department

Search for rare 3 and 4-body D0 decays at FNAL E791

Description: Limits at the 10{sup -4} level are reported for rare and forbidden decays of the D{sup 0} charm meson to a pair of leptons and either a vector meson or two pseudoscalar mesons. Of these searches, 18 are investigations of decays without previous published results; several others have significantly improved sensitivity over previous results.
Date: June 12, 2001
Creator: Summers, Donald J.
Partner: UNT Libraries Government Documents Department

On constraints for heavy-meson form factors

Description: We examine the recent work of de Rafael and Taron where model-independent bounds on the Isgur-Wise function are presented. We first argue that the bounds cannot hold in as much generality as implied. We show that the effects of resonances omitted in their discussion (such as heavy-heavy ``onium`` states below threshold) modify the bound. The resulting bound is much weaker but may be useful where the size of the additional contribution may be computed or estimated.
Date: November 1, 1992
Creator: Grinstein, B. & Mende, P.F.
Partner: UNT Libraries Government Documents Department

Time dependent B{sup 0} {anti B}{sup 0} mixing at CDF

Description: WE describe two measurements of {Delta}{ital m}{sub d}. The first uses {ital B} {r_arrow} {ital vlD}{sup (*)} events and a same-side flavor tagging algorithm. the second uses dilepton events. From the average of these two measurements we find {Delta}{ital m}{sub d} = 0. 466 {+-}0.037{+-} 0.031 ps{sup -1}.
Date: November 1, 1996
Creator: CDF Collaboration
Partner: UNT Libraries Government Documents Department

Hot Topics from the BABAR Experiment

Description: With a sample of about 384 million B{bar B} pairs recorded with the BABAR detector, we search for the flavor-changing charged current transition B{sup {+-}} {yields} {tau}{+-}{upsilon} and perform an amplitude analysis of the effective flavor-changing neutral current transition B{sup {+-}} {yields} {var_phi}(1020)K*(892){+-}. We also extend our search for other K* final states in the decay B{sup 0} {yields} {var_phi}(1020)K*0 with a large K*0 {yields} K{sup +}{pi}{sup -} invariant mass. Two samples of events with one reconstructed hadronic B decay or one reconstructed semileptonic B decay are selected, and in the recoil a search for B{sup {+-}} {yields} {tau}{+-}{upsilon} is performed. We find a 2.6 {sigma} (3.2 {sigma} not including expected background uncertainty) excess in data which can be converted to a preliminary branching fraction central value of {beta}(B{sup {+-}} {yields} {tau}{+-}{upsilon}) = (1.20{sup +0.40+0.29}{sub -0.38-0.30} {+-} 0.22) x 10{sup -4}. With the decay B{sup {+-}} {yields} {var_phi}(1020)K*(892){sup {+-}}, twelve parameters are measured, where our measurements of f{sub L} = 0.49 {+-} 0.05 {+-} 0.03, f{sub {perpendicular}} = 0.21 {+-} 0.05 {+-} 0.02, and the strong phases point to the presence of a substantial helicity-plus amplitude from a presently unknown source.
Date: June 15, 2007
Creator: Gritsan, A.V. & U., /Johns Hopkins
Partner: UNT Libraries Government Documents Department