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CP violation at CDF

Description: A major goal of experimental particle physics over the next decade is to measure the sides and angles of the Unitarity triangle redundantly, and as precisely as possible. Overconstraining the triangle will test the Cabbibo-Kobayashi-Maskawa model of quark mixing. The CDF collaboration, due to begin a second run in March 2001 with major upgrades to both the accelerator and the detector, will study the angle {beta} using B{sup 0} decays, the angle {gamma} using B{sup 0} and B{sub s}{sup 0} decays, and a side of the triangle through the observation of B{sub s}{sup 0}--{bar B}{sub s}{sup 0} mixing. Projected sensitivities are driven mostly by previous measurements using data from the first run. One highlight of the Run I B physics program is a measurement of the CP violating parameter sin 2{beta} = 0.79{sub {minus}0.44}{sup +0.41}, based on a tagged sample of 400 B{sup 0} decays in the mode B{sub 0}/{bar B}{sup 0} {r_arrow} J/{psi}K{sub s}{sup 0}. The technology of flavor tagging, used here as well as in numerous B{sup 0}-{bar B}{sup 0} mixing analyses in run I, is crucial and will be augmented in Run II with better particle identification capabilities. Exclusive all-hadronic final states will enter the data sample in Run II through a new displaced track trigger.
Date: April 16, 2001
Creator: Boudreau, J.
Partner: UNT Libraries Government Documents Department

CP VIOLATION IN K DECAY FROM LATTICE QCD, RIKEN BNL RESEARCH CENTER, RBRC AND PARTICLE PHYSICS SEMINAR, BROOKHAVEN NATIONAL LABORATORY, UPTON, N.Y., JULY 26, 2001.

Description: The entire history of the discoveries of K{sub L}{sup o} and violations of T and CP began at Brookhaven. It is most appropriate for us to hold today's special seminar on CP Violation in K decay in this laboratory. Forty-five years ago, in the same paper on parity nonconservation, it was also pointed out that there is no proof of T symmetry in the weak interaction, nor of C invariance. That paper was submitted to the Physical Review (then, also located at BNL) on June 22, 1956. A month later, Lederman and his collaborators discovered a long-lived neutral V particle (now called K{sub L}{sup o}) at the Cosmotron using the cloud chamber. This discovery was presented as a rigorous proof of C symmetry. In the same summer at Brookhaven, in collaboration with Oehme and Yang, I did the analysis on the neutral kaon system, assuming T, C and CP violations (but based on CPT symmetry). In that work, the two non-orthogonal eigen-states {psi}{sub +} and {psi}{sub -} (now K{sub S}{sup o} and K{sub L}{sup o}) were characterized by a non-orthogonality parameter {alpha} ({approx_equal} 2 Re{epsilon} in today's notation), which was shown to be small, because of unitarity. We then went on to discuss the various decay modes of the long-lived and short-lived neutral kaons as tests of possible T and CP violations. The paper was completed in December 1956, before parity-nonconservation was experimentally established. Eight years later, the important discovery of CP violation was made by Christenson, Cronin, Fitch and Turlay at BNL.
Date: July 26, 2001
Creator: Blum, T. & Mawhinney, R.
Partner: UNT Libraries Government Documents Department

A dedicated LHC collider Beauty experiment for precision measurements of CP-violation. LHC-B letter of intent

Description: The LHC-B Collaboration proposes to build a forward collider detector dedicated to the study of CP violation and other rare phenomena in the decays of Beauty particles. The forward geometry results in an average 80 GeV momentum of reconstructed B-mesons and, with multiple, efficient and redundant triggers, yields large event samples. B-hadron decay products are efficiently identified by Ring-Imaging Cerenkov Counters, rendering a wide range of multi-particle final states accessible and providing precise measurements of all angles, {alpha}, {beta} and {gamma} of the unitarity triangle. The LHC-B microvertex detector capabilities facilitate multi-vertex event reconstruction and proper-time measurements with an expected few-percent uncertainty, permitting measurements of B{sub s}-mixing well beyond the largest conceivable values of x{sub S}. LHC-B would be fully operational at the startup of LHC and requires only a modest luminosity to reveal its full performance potential.
Date: March 28, 1996
Creator: Crosetto, Dario B.
Partner: UNT Libraries Government Documents Department

Prospects for measuring K{sup +} {r_arrow} {pi}{sup +} {nu}{bar {nu}} and K{sub L}{sup 0} {r_arrow} {pi}{sup 0} {nu}{bar {nu}} at BNL

Description: Rare kaon decay experiments underway or planned for the BNL AGS will yield new and independent determinations of V*{sub ts}V{sub td}. A measurement of B(K{sub L}{sup 0} {r_arrow} {pi}{sup 0} {nu}{bar {nu}}) allows a determination of the imaginary part of this quantity, which is the fundamental CP-violating parameter of the Standard Model, in a uniquely clean manner. Since the measurement of B(K{sup +} {r_arrow} {pi}{sup +} {nu}{bar {nu}}) determines {vert_bar}V*{sub ts}V{sub td}, a complete derivation of the unitarity triangle is facilitated. These results can be compared to high precision data expected to come from the B sector in a number of ways, allowing for unique tests of new physics.
Date: September 18, 2000
Creator: Bryman, D.A. & Littenberg, L.
Partner: UNT Libraries Government Documents Department

Lattice QCD and the unitarity triangle

Description: Theoretical and computational advances in lattice calculations are reviewed, with focus on examples relevant to the unitarity triangle of the CKM matrix. Recent progress in semi-leptonic form factors for B {yields} {pi}/v and B {yields} D*lv, as well as the parameter {zeta} in B{sup 0}-{bar B}{sup 0} mixing, are highlighted.
Date: December 3, 2001
Creator: Kronfeld, Andreas S
Partner: UNT Libraries Government Documents Department

A New Approach to Measuring the Neutron Decay Correlations with Cold Neutrons at LANSCE

Description: Precision measurements of the neutron beta-decay correlations A, B, a, and b provide important tests of the standard model of electroweak interactions: a test of the unitarity of the first row of the CKM matrix, a search for new weak interactions, a test of the theory of nuclear beta decays, and a test of the conserved-vector-current hypothesis. The authors are designing an experiment at the LANSCE short-pulse spallation source to measure all four correlations to an order of magnitude better accuracy than the existing measurements. The accuracy of the previous measurements was limited by systematics. The design of the proposed experiment makes use of the pulsed nature of the LANSCE source to reduce systematic errors associated with the measurement of the neutron polarization as well as other systematic errors. In addition, the authors are developing silicon strip detectors for detecting both the proton and electron from the neutron decay.
Date: June 8, 1999
Creator: Wilburn, W.S.; Bowman, J.D.; Greene, G.L.; Jones, G.L.; Kapustinsky, J.S. & Penttila, S.I.
Partner: UNT Libraries Government Documents Department

Strangeness in the Nucleon or the quark model beyond the valence approximation

Description: Simple arguments based on unitarity indicate that meson loops diagrams, induced by an underlying qq pair creation process, should badly disturb the phenomenologically successful spectroscopy and dynamics of the valence quark model, including such simple but mysterious regularities as the OZI rule. The author discusses some recent progress in adding pair creation to the valence quark model in a way which provides rationale for the quark model's success.
Date: January 1, 1999
Creator: Isgur, Nathan
Partner: UNT Libraries Government Documents Department

CP and B Physics: Progress and prospects

Description: This summary of the 2nd International Conference on B Physics and CP Violation (Honolulu, 24--27 March, 1997) contains, in addition to what is implied in the title, some extended remarks on the limitations of theory as well as speculations regarding nonperturbative enhancement of decay modes of the class b {yields} s+ charmless hadrons.
Date: June 1, 1997
Creator: Bjorken, J.D.
Partner: UNT Libraries Government Documents Department

The VIIth Blois workshop: Theory summary and factorization issues

Description: Theory presentations at this workshop have covered a wide range of topics. In addition to the traditional topics of elastic and diffractive scattering, the workshop has had a variety of interesting talks coming under the broad umbrella of ``Recent Advances in Hadron Physics.`` These have included review talks on lattice gauge theory, techniques for high-order perturbative QCD calculations, strong interaction effective field theories, the current status of QED and the construction of theories beyond the Standard Model. While the author briefly describes some topics covered, a ``review of reviews`` is in no way a substitute for the original reviews which also appear, of course, in this same volume. Among the more traditional topics covered are: BFKL physics -- higher-order corrections and jet cross-sections; unitarity and eikonal screening -- mainly in deep-inelastic diffraction but also in soft diffraction; elastic scattering phenomenology -- including real parts, the pomeron intercept and small-t oscillations. Also discussed is the role of factorization, i.e. both Regge pole factorization and perturbative QCD factorization theorems in the definition of a pomeron structure function and in the formulation of a parton model description of diffractive hard physics. The author focuses on one gluon versus two gluons as illustrating the issues involved.
Date: September 17, 1997
Creator: White, A.R.
Partner: UNT Libraries Government Documents Department

Quantum groups, roots of unity and particles on quantized Anti-de Sitter space

Description: Quantum groups in general and the quantum Anti-de Sitter group U{sub q}(so(2,3)) in particular are studied from the point of view of quantum field theory. The author shows that if q is a suitable root of unity, there exist finite-dimensional, unitary representations corresponding to essentially all the classical one-particle representations with (half) integer spin, with the same structure at low energies as in the classical case. In the massless case for spin {ge} 1, {open_quotes}naive{close_quotes} representations are unitarizable only after factoring out a subspace of {open_quotes}pure gauges{close_quotes}, as classically. Unitary many-particle representations are defined, with the correct classical limit. Furthermore, the author identifies a remarkable element Q in the center of U{sub q}(g), which plays the role of a BRST operator in the case of U{sub q}(so(2,3)) at roots of unity, for any spin {ge} 1. The associated ghosts are an intrinsic part of the indecomposable representations. The author shows how to define an involution on algebras of creation and anihilation operators at roots of unity, in an example corresponding to non-identical particles. It is shown how nonabelian gauge fields appear naturally in this framework, without having to define connections on fiber bundles. Integration on Quantum Euclidean space and sphere and on Anti-de Sitter space is studied as well. The author gives a conjecture how Q can be used in general to analyze the structure of indecomposable representations, and to define a new, completely reducible associative (tensor) product of representations at roots of unity, which generalizes the standard {open_quotes}truncated{close_quotes} tensor product as well as many-particle representations.
Date: May 23, 1997
Creator: Steinacker, H.
Partner: UNT Libraries Government Documents Department

NLO conformal symmetry in the Regge limit of QCD

Description: The authors show that a scale invariant approximation to the next-to-leading order BFKL kernel, constructed via transverse momentum diagrams, has a simple conformally invariant representation in impact parameter space. That a conformally invariant representation exists is shown first by relating the kernel directly to Feynman diagrams contributing to two photon diffractive dissociation.
Date: September 18, 1996
Creator: Coriano, C.; White, A. R. & Wuesthoff, M.
Partner: UNT Libraries Government Documents Department

Group representations, error bases and quantum

Description: This report continues the discussion of unitary error bases and quantum codes. Nice error bases are characterized in terms of the existence of certain characters in a group. A general construction for error bases which are non-abelian over the center is given. The method for obtaining codes due to Calderbank et al. is generalized and expressed purely in representation theoretic terms. The significance of the inertia subgroup both for constructing codes and obtaining the set of transversally implementable operations is demonstrated.
Date: September 1, 1996
Creator: Knill, E.
Partner: UNT Libraries Government Documents Department

t-Channel unitarity construction of small-x kernels

Description: In the leading-log approximation, the small-x behavior of parton distributions in QCD is derived from the BFKL evolution equation. The authors describe the ion as a reggeon Bethe-Salpeter equation and discuss the use of reggeon diagrams to obtain 2-2 and 2-4 reggeon interactions at O(g{sup 4}). They then outline the dispersion theory basis of multiparticle j-plane analysis and describe how a gauge theory can be studied by combining Ward identity constraints with the group structure of reggeon interactions. Gluon reggeization, the O(g{sup 2}) BFKL kernel and O(g{sup 4}) corrections to it, are derived within this formalism. They give an explicit expression for the O(g{sup 4}) forward ``parton`` kernel in terms of logarithms and evaluate the eigenvalues. A separately infra-red finite component with a holomorphically factorizable spectrum is shown to be present and conjectured to be a new leading-order partial-wave amplitude. A comparison is made with Kirschner`s discussion of O(g{sup 4}) contributions from the multi-Regge effective action.
Date: 1994-12~
Creator: Coriano, C. & White, A. R.
Partner: UNT Libraries Government Documents Department

The investigation of CP violation through the decay of polarized tau leptons

Description: Under the assumption that CP violation is caused by exchange of a new boson, the author proposes to measure the magnitudes and CP-violating phases of the coupling constants of this boson to five different vertices in tau decay. This can be accomplished by studying the decays of polarized tau leptons produced at an e{sup +} e{sup {minus}} collider whose beams are polarized. He points out that CP violation in the tau decay tests most directly the assumption in the standard theory that the imaginary numbers in the mass matrix is the sole cause of CP violation.
Date: March 1, 1996
Creator: Tsai, Y.S.
Partner: UNT Libraries Government Documents Department

Gauge theory high-energy behavior from J-plane unitarity

Description: In a non-abelian gauge theory the t-channel multiparticle unitarity equations continued in the complex j-plane can be systematically expanded around j = 1. The combination of Ward identity constraints with unitarity is sufficient to produce directly many results obtained by Regge limit leading-log and next-to-leading log momentum space calculations. The O(g{sup 2}) BFKL kernel is completely determined. O(g{sup 4}) contributions to the kernel are also determined, including the leading contribution of a new partial-wave amplitude--previously identified as a separate forward component with a holomorphically factorizable spectrum. For this amplitude the only scale ambiguity is the overall normalization and it is anticipated to be a new conformally invariant kernel. The results suggest that all conformally invariant reggeon interactions are determined by t-channel unitarity.
Date: December 31, 1995
Creator: Coriano, C. & White, A.R.
Partner: UNT Libraries Government Documents Department

Higher-order corrections to BFKL evolution from t-channel unitarity

Description: Using reggeon diagrams as a partial implementation of t-channel unitarity, O(g{sup 4}) corrections to the BFKL evolution equation have been obtained. We describe the spectrum and holomorphic factorization properties of the resulting scale-invariant kernel. For a gauge theory, t-channel unitarity can be studied directly in the complex j-plane by implementing Ward identity constraints together with the group structure of reggeon interactions. We discuss how both the O(g{sup 2}) BFKL kernel and the O(g{sup 4}) corrections can then be derived.
Date: 1994-12~
Creator: Coriano, C. & White, A. R.
Partner: UNT Libraries Government Documents Department

t-Channel unitarity construction of small-x kernels

Description: The authors present the BFKL equation as a reggeon Bethe-Salpeter equation and discuss the use of reggeon diagrams to obtain 2-2 and 2-4 reggeon interactions at O(g{sup 4}). They then outline the dispersion theory basis of multiparticle j-plane analysis and describe how a gauge theory can be studied by combining Ward identity constraints with the group structure of reggeon interactions. The derivation of gluon reggeization, the O(g{sup 2}) BFKL kernel, and O(g{sup 4}) corrections, is described within this formalism. They give an explicit expression for the O(g{sup 4}) forward ``parton`` kernel in terms of logarithms and evaluate the eigenvalues. A separately infra-red finite component with a holomorphically factorizable spectrum is shown to be present and conjectured to be a new leading-order partial-wave amplitude. A comparison is made with Kirschner`s discussion of O(g{sup 4}) contributions from the multi-Regge effective action.
Date: December 1995
Creator: Coriano, C. & White, A. R.
Partner: UNT Libraries Government Documents Department

Weak interaction studies with an on-line Penning trap mass spectrometer.

Description: Superallowed {beta}-decays are a sensitive probe of the fundamental aspects of the weak interaction. Such decays are used to stringently test the CVC hypothesis, deduce a precise value of the weak vector coupling constant, test the unitarity of the CKM matrix and look for deviation from the V-A structure for the weak interaction. The ability to efficiently capture and store short-lived superallowed beta-emitters in ion traps will help to elucidate discrepancies in the most precise unitarity test of the CKM matrix and tighten the present limits on interactions outside the standard V-A form.
Date: March 10, 1999
Creator: Barber, R. C.; Buchinger, F.; Crawford, J. E.; Feng, X.; Gulick, S.; Hackman, G. et al.
Partner: UNT Libraries Government Documents Department

One-loop corrections to the D3 brane action.

Description: We calculate one-loop corrections to the effective Lagrangian for the D3 brane. We perform the gauge-fixing of the {kappa}-symmetric Born-Infeld D3 brane action in the flat background using Killing gauge. The linearized supersymmetry of the gauge-fixed action coincides with that of the N = 4 Yang-Mills theory. We use the helicity amplitude and unitarity technique to calculate the one-loop amplitudes at order {alpha}{sup 4}. The counterterms and the finite 1-loop corrections are of the form ({partial_derivative}F){sup 4} and their supersymmetric generalization. This is to be contrasted with the Born-Infeld action which contains (F){sup 4} and other terms which do not depend on derivatives of the vector field strength.
Date: June 30, 1999
Creator: Shmakova, Marina
Partner: UNT Libraries Government Documents Department