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in subjects: "Unitarity"  
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Measurement of Sin(2beta) in Tree Dominated B0 Decays And Ambiguity Removal

Description: The most recent results from the B-factories on the time-dependent CP asymmetries measured in B{sup 0}-decays mediated by b {yields} c{bar c}s quark-transitions are reviewed. The Standard Model interpretation of the results in terms of the parameter sin 2{beta} leads to a four-fold ambiguity on the unitarity triangle {beta} which can be reduced to a two-fold ambiguity by measuring the sign of the parameter cos 2{beta}. The results on cos2{beta} obtained so far are reviewed.
Date: November 20, 2007
Creator: Lacker, H.
Partner: UNT Libraries Government Documents Department
open access

MATRIX N/D METHOD WITH ABSORPTION AND THE UNITARITY PROBLEM IN COUPLED-CHANNEL REGGE THEORY

Description: In a crossing-symmetric Regge theory with several coupled two-particle channels, there are many-particle absorptive effects due to crossed two-particle processes. Also, some of the partial-wave amplitudes have overlapping left-hand and right-hand cuts in the s-plane, To enforce unitarity in such a theory, one needs a coupled-channel N/D method allowing arbitrary absorption parameters and overlapping cuts. These requirements lead to a nonlinear marginally singular N/D equation, which is proposed… more
Date: November 1, 1979
Creator: Warnock, Robert Lee
Partner: UNT Libraries Government Documents Department
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Update on Angles and Sides of the CKM Unitarity Triangle from BaBar

Description: We report several recent updates from the BABAR Collaboration on the matrix elements |V{sub cb}|, |V{sub ub}|, and |V{sub td}| of the Cabibbo-Kobayashi-Maskawa (CKM) quark-mixing matrix, and the angles {beta} and {alpha} of the unitarity triangle. Most results presented here are using the full BABAR {Upsilon}(4S) data set.
Date: November 14, 2011
Creator: Cheng, Chih-hsiang & /Caltech
Partner: UNT Libraries Government Documents Department
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Semileptonic B to D Decays at Nonzero Recoil with 2+1 Flavors of Improved Staggered Quarks

Description: The Fermilab Lattice-MILC collaboration is completing a comprehensive program of heavy-light physics on the MILC (2+1)-flavor asqtad ensembles with lattice spacings as small as 0.045 fm and light-to-strange-quark mass ratios as low as 1/20. We use the Fermilab interpretation of the clover action for heavy valence quarks and the asqtad action for light valence quarks. The central goal of the program is to provide ever more exacting tests of the unitarity of the CKM matrix. We give a progress rep… more
Date: November 1, 2011
Creator: Qiu, Si-Wei; DeTar, Carleton; Du, Daping; Kronfeld, Andreas S.; Laiho, Jack & Van de Water, Ruth S.
Partner: UNT Libraries Government Documents Department
open access

CP Violation at BaBar

Description: We report recent measurements of the three CKM angles of the Unitarity Triangle using about 383 millions b{bar b} pairs collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. The results of the angles ({beta}, {alpha}, {gamma}) of the unitarity triangle are consistent with Belle results, and with other CKM constraints such as the measurement of {epsilon}{sub K}, the length of the sides of the unitarity triangle determined from the measurements of {Delta}m{sub d}, {… more
Date: November 15, 2011
Creator: Yeche, Christophe
Partner: UNT Libraries Government Documents Department
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Amplitude Analysis of B0 to K^ pi^-pi^0 and Evidence of Direct CP Violation in B to K^* pi decays

Description: We analyze the decay B{sup 0} {yields} K{sup +} {pi}{sup -} {pi}{sup 0} with a sample of 454 million B{bar B} events collected by the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC, and extract the complex amplitudes of seven interfering resonances over the Dalitz plot. These results are combined with amplitudes measured in B{sup 0} {yields} K{sup 0}{sub s}{pi}{sup +}{pi}{sup -} decays to construct isospin amplitudes from B{sup 0} {yields} K{sup *}{pi} and B{sup 0} {yields} {r… more
Date: November 4, 2011
Creator: Lees, J. P.
Partner: UNT Libraries Government Documents Department
open access

Recent Results on Semileptonic Decays at Babar

Description: Some recent BABAR results on semileptonic decays are presented. They focus on the determination of the CKM matrix elements |V{sub ub}| and |V{sub cb}| in inclusive and exclusive b {yields} u{ell}v and b {yields} c{ell}v decays, and on form factors measurement in exclusive c {yields} s{ell}v decays. Semileptonic decays play a crucial role in the determination of the unitarity triangle parameters: decays of the b quark give access to the CKM matrix elements |V{sub ub}| and |V{sub cb}|, while char… more
Date: November 7, 2011
Creator: Serrano, Justine
Partner: UNT Libraries Government Documents Department
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CKM-UT Angles: Mixing And CP Violation at the B Factories

Description: We review the experimental status of the angles of the Unitarity Triangle of the CKM matrix, as measured by the BABAR and Belle experiments. The B Factories have demonstrated since the beginning of this decade that CP violation in the B meson system is consistent with the Standard Model (SM) description in terms of the complex phase in the three-by-three Cabibbo-Kobayashi-Maskawa (CKM) matrix. With one single phase, the SM predicts clear patterns for quark mixing and CP violations, to be satisf… more
Date: November 7, 2011
Creator: Finocchiaro, Giuseppe
Partner: UNT Libraries Government Documents Department
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The Four-Loop Planar Amplitude and Cusp Anomalous Dimension in Maximally Supersymmetric Yang-Mills Theory

Description: We present an expression for the leading-color (planar) four-loop four-point amplitude of N = 4 supersymmetric Yang-Mills theory in 4-2{epsilon} dimensions, in terms of eight separate integrals. The expression is based on consistency of unitarity cuts and infrared divergences. We expand the integrals around {epsilon} = 0, and obtain analytic expressions for the poles from 1/{epsilon}{sup 8} through 1/{epsilon}{sup 4}. We give numerical results for the coefficients of the 1/{epsilon}{sup 3} and … more
Date: November 15, 2006
Creator: Bern, Zvi; Czakon, Michael; Dixon, Lance J.; Kosower, David A. & Smirnov, Vladimir A.
Partner: UNT Libraries Government Documents Department
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Is N=8 Supergravity Ultraviolet Finite?

Description: Conventional wisdom holds that no four-dimensional gravity field theory can be ultraviolet finite. This understanding is based mainly on power counting. Recent studies confirm that one-loop N = 8 supergravity amplitudes satisfy the so-called 'no-triangle hypothesis', which states that triangle and bubble integrals cancel from these amplitudes. A consequence of this hypothesis is that for any number of external legs, at one loop N = 8 supergravity and N = 4 super-Yang-Mills have identical superf… more
Date: November 15, 2006
Creator: Bern, Zvi; Dixon, Lance J. & Roiban, Radu
Partner: UNT Libraries Government Documents Department
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Scale-invariant Lipatov kernels from t-channel unitarity

Description: The Lipatov equation can be regarded as a reggeon Bethe-Salpeter equation in which higher-order reggeon interactions give higher-order kernels. Infra-red singular contributions in a general kernel are produced by t-channel nonsense states and the allowed kinematic forms are determined by unitarity. Ward identity and infra-red finiteness gauge invariance constraints then determine the corresponding scale-invariant part of a general higher-order kernel.
Date: November 14, 1994
Creator: Coriano, C. & White, A. R.
Partner: UNT Libraries Government Documents Department
open access

New Measurements of the Angle Gamma at the BabarExperiment

Description: Measuring the angle {gamma} is an important part of over-constraining the Unitarity Triangle to test Standard Model predictions. There are a number of methods to measure {gamma}, and we present results on the progress made in measuring {gamma} with B meson decays, using data collected with the BABAR detector at the PEP-II asymmetric energy e{sup +}e{sup -} collider at SLAC.
Date: November 7, 2007
Creator: Orimoto, Toyoko Jennifer
Partner: UNT Libraries Government Documents Department
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