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Estimated Errors in |Vcd|/|Vcs| from semileptonic D decays

Description: We estimate statistical and systematic errors in the extraction of the CKM ratio {vert_bar}V{sub cd}{vert_bar}/{vert_bar}v{sub cs}{vert_bar} from exclusive D-meson semileptonic decays using lattice QCD and anticipated new experimental results.
Date: November 1, 1998
Creator: J.N.Simone, A.X.El-Khadra, S.Hashimoto, A.S.Kronfeld, P.B.Mackenzie, and S.M.Ryan
Partner: UNT Libraries Government Documents Department

Baryogenesis and low energy CP violation

Description: CP violation is a crucial component in the creation of the matter - anti matter asymmetry of the universe. An important open question is whether the CP violating phenomena observeable in terrestrial experiments have any relation with those responsible for baryogenesis. We discuss two mechanisms of baryogenesis where this question can be meaningfully posed: ''electroweak baryogenesis'' and ''baryogenesis via leptogenesis''. We show how these scenarios can be constrained by existing and forthcoming experimental data. We present a specific example of both these scenarios where the CP violating phase in the Cabbibo Kobayashi Maskawa matrix is related in a calculable way to the CP violating phase responsible for baryogenesis.
Date: August 19, 1999
Creator: Worah, Mihir P.
Partner: UNT Libraries Government Documents Department

Lifetime difference of B{sub s} mesons and its implications

Description: The authors discuss the calculation of the width difference {Delta}{Gamma}{sub B}, between the B{sub s} mass eigenstates to next-to-leading order in the heavy quark expansion. 1/m{sub b}-corrections are estimated to reduce the leading order result by typically 30%. The error of the present estimate ({Delta}{Gamma}/{Gamma}){sub B{sub s}} = 0.16{sub {minus}0.09}{sup +0.11} could be substantially improved by pinning down the value of <{anti B}{sub s}{vert_bar}({anti b}{sub i}s{sub i}){sub S{minus}P}({anti b}{sub j}s{sub j}){sub S{minus}P}{vert_bar}B{sub s}> and an accuracy of 10% in ({Delta}{Gamma}/{Gamma}){sub B{sub s}} should eventually be reached. They briefly mention strategies to measure ({Delta}{Gamma}/{Gamma}){sub B{sub s}}, and its implications for constraints on {Delta}M{sub B{sub s}}, CKM parameters and the observation of CP violation in untagged B{sub s} samples.
Date: August 1, 1996
Creator: Beneke, M.
Partner: UNT Libraries Government Documents Department

Quasi-degenerate neutrinos from an abelian family symmetry

Description: The authors show that models with an abelian family symmetry which accounts for the observed hierarchies of masses and mixings in the quark sector may also accommodate quasi-degeneracies in the neutrino mass spectrum. Such approximate degeneracies are, in this context, associated with large mixing angles. The parameters of this class of models are constrained. The authors discuss their phenomenological implications for present and foreseen neutrino experiments.
Date: December 31, 1996
Creator: Binetruy, P.; Lavignac, S.; Petcov, S. & Ramond, P.
Partner: UNT Libraries Government Documents Department

Measurements of the longitudinal structure function and |V{sub cs}| in the CCFR experiment

Description: Measurements of charged current neutrino and anti-neutrino nucleon interactions in the CCFR detector are used to extract the structure functions, F{sub 2}, xF{sub 3}{sup {nu}} , xF{sub 3}{sup {anti {nu}}} and R(longitudinal) in the kinematic region 0.01 < x < 0.6 and 1 < Q{sup 2} < 300 GeV{sup 2}. The new measurements of R in the x < 0.1 region provide a constraint on the level of the gluon distribution. The x and Q{sup 2} dependence of R is compared with a QCD based fit to previous data. The CKM matrix element {vert_bar}V{sub cs}{vert_bar} is extracted from a combined analysis of xF{sub 3} and dimuon data.
Date: July 1, 1998
Creator: Yang, U.K.
Partner: UNT Libraries Government Documents Department

Experimental study of sin 2 {beta} and sin 2 {alpha}

Description: Detailed measurements of CP violation in B meson decay are on the horizon. Here the author reviews the status of current measurements of sin 2{beta} made at LEP and CDF. These yield an average of sin 2{beta} = 0.82 {+-} 0.39, giving 97% confidence that {beta} is greater than 0, evidence that CP violation occurs in B decay. He reviews predictions for the precision one can expect on sin 2{beta} and sin 2{alpha} in the next few years.
Date: March 7, 2000
Creator: Truschuk, W.
Partner: UNT Libraries Government Documents Department

Measuring the CKM matrix element V{sub tb} at D-zero and CDF

Description: I present measurements by the CDF collaboration of the Standard Model three generation CKM matrix element V{sub tb} and of a special case extension with additional assumptions, using current Tevatron t{anti t} data. I then show how we can significantly improve the precision on V{sub tb} and at the same time extend the measurement so it is not constrained by Standard Model assumptions, using single top production at the upgraded Tevatron.
Date: July 1, 1997
Creator: Heinson, A.P.
Partner: UNT Libraries Government Documents Department


Description: Recent highlights in CP violation phenomena, are reviewed. B-factory results imply that, CP-violation phase in the CKM matrix is the dominant contributor to the observed CP violation in K and B-physics. Deviations from the predictions of the CKM-paradigm due to beyond the Standard Model CP-odd phase are likely to be a small perturbation. Therefore, large data sample of clean B's will be needed. Precise determination of the unitarity triangle, along with time dependent CP in penguin dominated hadronic and radiative modes are discussed. Null tests in B, K and top-physics and separate determination of the K-unitarity triangle are also emphasized.
Date: February 27, 2005
Creator: A., SONI
Partner: UNT Libraries Government Documents Department

Heavy Quark Symmetry

Description: New symmetries of the strong interactions appear in heavy quark physics. They can be used to predict many properties of hadrons containing a single heavy quark. Some of these predictions are expected to play an important role in determining the values of elements of the Cabibbo-Kobayashi-Maskawa matrix.
Date: June 1, 1992
Creator: Wise, Mark & Isgur, Nathan
Partner: UNT Libraries Government Documents Department

Evidence for K{sup +} {r_arrow} {pi}{sup +} {nu}{anti {nu}}

Description: The decay K{sup +} {r_arrow} {pi}{sup +}{nu}{anti {nu}} has been observed for the first time. The E787 experiment has presented evidence for the K{sup +} {r_arrow} {pi}{sup +}{nu}{anti {nu}} decay, based on the observation of a single clean event from data collected during the 1995 run of the AGS (Alternating Gradient Synchrotron at Brookhaven National Laboratory). The branching ratio indicated by this observation, B(K{sup +} {r_arrow} {pi}{sup +}{nu}{anti {nu}}) = 4.2{sub {minus}3.5}{sup +9.7} {times} 10{sup {minus}10}, is consistent with the Standard Model expectation although the central experimental value is four times larger. The final E787 data sample, from the 1995--99 runs, should reach a sensitivity of about eight times that of the 1995 run alone. A new experiment, E949, has been approved to run, starting in the year 2000, and is expected to achieve a sensitivity of more than an order of magnitude below the prediction of the Standard Model.
Date: December 31, 1998
Creator: Kettell, S.; Collaboration, E787 & Collaboration, E949
Partner: UNT Libraries Government Documents Department

Search for T-violation in K{sub {mu}3} decay

Description: We have designed a new experiment (E923) at the BNL-AGS to search for the T-violating polarization of the muon normal to the decay plane of the K{sup +} {yields} {mu}{sup +}{pi}{sup 0}{nu} decay. The experiment aims to search for T-violation beyond the Standard Model; such a search is motivated by the need for a stronger CP violation source to account for the baryon asymmetry of the Universe. The experiment will be performed with in-flight decays from an intense (2 x 10{sub 7} K{sup +}/sec) 2 GeV/c separated K{sup +} beam in an existing beam-line at the AGS. We expect to analyze more than 10{sup 9} events to obtain the sensitivity of {delta}P{sub 2} = {+-} 0.00013 at 1 {sigma}, corresponding to the sensitivity of {+-}0.0007 to Im{xi}, an improvement by 40 over the present limit on the same measurement.
Date: January 8, 1998
Creator: Diwan, M.V.
Partner: UNT Libraries Government Documents Department

Beautiful CP violation

Description: CP violation is observed to date only in K{sup 0} decays and is parameterizable by a single quantity {epsilon}. Because it is one of the least understood phenomena in the Standard Model and holds a clue to baryogenesis, it must be investigated further. Highly specialized searches in K{sup 0} decays are possible. Effects in B decays are much larger. In addition to the traditional B{sub d} {yields} J/{psi}K{sub S}, {pi}{sup +}{pi}{sup {minus}} asymmetries, CP violation could be searched for in already existing inclusive B data samples. The rapid B{sub s}--{anti B}{sub s} oscillations cancel in untagged B{sub s} data samples, which therefore allow feasibility studies for the observation of CP violation and the extraction of CKM elements with present vertex detectors. The favored method for the extraction of the CKM angle {gamma} is shown to be unfeasible and a solution is presented involving striking direct CP violation in charged B decays. Novel methods for determining the B{sub s} mixing parameter {Delta}m are described without the traditional requirement of flavor-specific final states.
Date: September 24, 1997
Creator: Dunietz, I.
Partner: UNT Libraries Government Documents Department

Rare and forbidden kaon decays at the AGS

Description: An overview of the Rare Kaon Decay program at the AGS is presented, with particular emphasis on the three major experiments currently running and analyzing data. A brief overview of earlier kaon decay experiments and of the AGs performance improvements is also provided. This review concludes with a discussion of proposed and developing experiments planned to run in the year 2000 and beyond (AGS-2000).
Date: December 9, 1997
Creator: Kettell, S.
Partner: UNT Libraries Government Documents Department

Heavy quark effective theory

Description: After a brief introduction, the results of application of the heavy quark effective theory to semileptonic decays of beta mesons are discussed. A nearly-model-independent extraction of {vert_bar}V{sub cb}{vert_bar} from data is described. Application of the effective theory to inclusive semileptonic decays of heavy mesons, in semileptonic decays of heavy baryons, and to the nonleptonic decays of hadrons are outlined. The authors conclude by mentioning other areas of research in this very active field.
Date: June 1, 1994
Creator: Roberts, W.
Partner: UNT Libraries Government Documents Department

Theoretical uncertainties in {Gamma}{sub sl}(b {r_arrow} u)

Description: The author reviews the existing theoretical uncertainties in relating the semileptonic decay width in b {r_arrow} u transitions to the underlying Kobayashi-Maskawa mixing element {vert_bar}V{sub ub}{vert_bar}. The theoretical error bars are only a few percent in {vert_bar}V{sub ub}{vert_bar}, with uncertainties from the impact of the nonperturbative effects nearly negligible.
Date: May 1, 1999
Creator: Uraltsev, Nikolai
Partner: UNT Libraries Government Documents Department

Duality in inclusive semileptonic heavy quark decay

Description: The author identifies a source of Lambda{sub QCD}/m{sub Q} corrections to the assumption of quark-hadron duality in the application of heavy quark methods to inclusive heavy quark semileptonic decays Q {r_arrow} ql{anti {nu}}{sub l}. These corrections could substantially affect the accuracy of such methods in practical applications and in particular compromise their utility for the extraction of the Cabibbo-Kobayashi-Maskawa matrix element V{sub cb}.
Date: September 1, 1998
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

High Energy Physics Division semiannual report of research activities, January 1, 1999--June 30, 1999.

Description: In the period January--June 1999 accomplishments for the ANL-HEP division medium energy physics project consisted of the completion of two papers on past Saclay experiments, the beginning of analysis of recent data from the Crystal Ball measurements at the Brookhaven AGS, and preparations for a RHIC polarimeter. Two papers on Saclay pp elastic scattering data were completed by an ANL physicist, submitted and accepted in Physical Review. Results for the spin observable P - A{sub oono} = A{sub ooon} = A{sub y} at over 30 beam kinetic energies between 800 and 2,800 MeV and C.M. angles from about 70{degree}--110{degree} are described. A total of 919 new data points are presented in these articles. The energy dependence at fixed c.m. angles appears smooth, with no evidence for rapid energy-dependent structure. Work has also begun on two additional papers at Argonne and on others at Saclay.
Date: January 26, 2000
Creator: Spinka, H.; Nodulman, L.; Goodman, M.C.; Repond, J.; Proudfoot, J.; Underwood, D. et al.
Partner: UNT Libraries Government Documents Department

B{sup +} {r_arrow} D{sup *+}{sub s}{gamma} and B{sup +} {r_arrow} -&gt; D{sup *+}{gamma} as probes of V{sub ub}

Description: The decays B{sup +} {r_arrow} D{sup *+}{sub s}{gamma} and B{sup +} {r_arrow} D{sup *+}{gamma} can be used for an extraction of {vert_bar}V{sub ub}{vert_bar}. When the b and c quarks are nearly degenerate the rate for these modes can be determined in terms of other observed rates, namely B{anti B} mixing and D{sup *} {r_arrow} D{gamma} decay. To this end the authors introduce a novel application of heavy quark and flavor symmetries. Although somewhat unrealistic, this limit provides them with a first estimate of these rates.
Date: February 1, 1999
Creator: Grinstein, Benjamin & Lebed, Richard F.
Partner: UNT Libraries Government Documents Department

CP violation

Description: In this talk the author briefly reviews the cosmological importance of CP violation and the status of calculations of baryogenisis in the context of the Standard Model. The author then turns to a discussion of Standard Model Predictions for CP violation in B decays, stressing the importance of multiple measurements to overconstrain the model parameters and thus search for indications of beyond-Standard-Model physics.
Date: December 1, 1995
Creator: Quinn, H.
Partner: UNT Libraries Government Documents Department

CP violation at the Z peak

Description: Some possibilities for searches of CP-nonconservation in decays of the Z boson produced in e{sup +}e{sup {minus}} collisions are briefly reviewed. 18 refs.
Date: June 1, 1989
Creator: Bernreuther, W.
Partner: UNT Libraries Government Documents Department

A Parameterization Invariant Approach to the Statistical Estimation of the CKM Phase alpha

Description: In contrast to previous analyses, we demonstrate a Bayesian approach to the estimation of the CKM phase {alpha} that is invariant to parameterization. We also show that in addition to computing the marginal posterior in a Bayesian manner, the distribution must also be interpreted from a subjective Bayesian viewpoint. Doing so gives a very natural interpretation to the distribution. We also comment on the effect of removing information about {beta}{sup 00}.
Date: April 14, 2008
Creator: Morris, Robin D.; /RIACS, Mtn. View; Cohen-Tanugi, Johann & /SLAC
Partner: UNT Libraries Government Documents Department