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Studies of the Resonance Integrals of Re and Tm. Monthly Progress Report, May 1, 1963-May 31, 1963

Description: The branching ratio for the beta decay of Tm/sup 170/ was determined to be 0.22 with an uncertainty of 2%, and the internal conversion coefficient of Yb/ sup 170/ was determined by two different methods to be 7.27 and 8.8 plus or minus 0.5, respectively. Preliminary work on resonance integral and reactivity measured is described. (D.C.W.)
Date: June 1, 1963
Creator: Zagotta, W. E.
Partner: UNT Libraries Government Documents Department

Two RICH detectors as velocity spectrometers in the CKM experiment

Description: We present the design of two velocity spectrometers, to be used in the recently approved CKM experiment. CKM's main goal is the measurement of the branching ratio of K{sup +} {yields} {pi}{sup +} {nu}{bar {nu}} with a precision of 10%, via decays in flight of the K{sup +}. The design of both RICH detectors is based on the SELEX Phototube RICH. We will discuss the design and the expected performance, based on studies with SELEX data and Monte Carlo Simulations.
Date: September 4, 2002
Creator: al., Jurgen Engelfried et
Partner: UNT Libraries Government Documents Department

A high energy physics perspective

Description: The status of the Standard model and role of symmetry in its development are reviewed. Some outstanding problems are surveyed and possible solutions in the form of additional {open_quotes}Hidden Symmetries {close_quotes} are discussed. Experimental approaches to uncover {open_quotes}New Physics{close_quotes} associated with those symmetries are described with emphasis on high energy colliders. An outlook for the future is given.
Date: January 13, 1997
Creator: Marciano, W. J.
Partner: UNT Libraries Government Documents Department

{epsilon}{prime}/{epsilon} and rare KL decays from KTeV Experiment

Description: The authors update the current status for the measurement of the direct-CP violation parameters {epsilon}{prime}/{epsilon} in the KTeV experiment at Fermilab. Substantial statistics have been accumulated during the 1996-7 run and 1999 run for both {epsilon}{prime}/{epsilon} and rare K{sub L} decay searches. The first KTeV result on {epsilon}{prime}/{epsilon} published last year was Re({epsilon}{prime}/{epsilon}) = (28.0 {+-} 4.1) x 10{sup {minus}4} based on the 23% data from 1996-7 run. Combining with the previous E731, NA31 and the recent preliminary NA48 results, the grand average is Re({epsilon}{prime}/{epsilon}) = (19.3 {+-} 3.6) x 10{sup {minus}4} (with S = 1:49), more than 5{sigma} above zero. More data from both KTeV and NA48 after completing the analysis will further improve the precision of this measurement in the near future and hopefully further improve the agreement. New results on the branching ratio and form factor measurements of K{sub L} {r_arrow} {mu}{sup +} {mu}{sup {minus}} {gamma} using 1997 data are also presented. We find that BR(K{sub L} {r_arrow} {mu}{sup +} {mu}{sup {minus}} {gamma}) = (3.66 {+-} 0.04{sub stat} {+-} 0.07{sub syst}) x 10{sup {minus}7}. The form factor parameter {alpha}{sub K}* is measured to be {alpha}{sub K}* = {minus}0.157{sub {minus}0.027}{sup +0.025}. We make the first measurement of the parameter {alpha} from the D'Ambrosio, Isidori, and Portoles form factor, finding {alpha} = {minus}1.53 {+-} 0.09. This measurement of {alpha} limits the CKM parameter {rho} > {minus}0.2.
Date: January 16, 2001
Creator: Hsiung, Yee Bob
Partner: UNT Libraries Government Documents Department

MEASUREMENT OF B(K{sup +} {yields} {pi}{sup +} {nu}{bar {nu}})

Description: The experimental measurement of K{sup +} {yields} {pi}{sup +} {nu}{bar {nu}} is reviewed. New results from experiment E787 at BNL are presented: with data from 1995-97 the branching ratio has been measured to be B(K{sup +} {yields} {pi}{sup +} {nu}{bar {nu}}) = (1.5{sub {minus}1.2}{sup +3.4}) x 10{sup {minus}10}. The future prospects for additional data in this mode are examined.
Date: May 22, 2000
Creator: KETTELL,S.H.
Partner: UNT Libraries Government Documents Department

The CKM Experiment

Description: I describe the CKM experiment, a new initiative using the Fermilab Main Injector to obtain {approx} 100 events of the ultra-rare decay mode K{sup +} {yields} {pi}{sup +}{nu}{bar {nu}}. The branching ratio will be used to extract |V*{sub ts}V{sub td}|. Due to the decay mode's theoretical cleanliness, it plays a key role in over-constraining the Standard Model description of CP violation.
Date: October 25, 2002
Creator: Nguyen, Hogan H.
Partner: UNT Libraries Government Documents Department

Branching ratios from B{sub s} and {Lambda}{sub b}{sup 0}

Description: CDF Run II relative branching ratio measurements for 65 pb{sup -1} of data in the channels B{sub s} {yields} D{sub s}{sup {-+}}{pi}{sup {-+}}, {Lambda} {sub b}{sup 0} {yields} {Lambda}{sub c}{sup {+-}}{pi}{sup {-+}} and B {yields} h{sup +}h{sup -} are presented. Further, an observation of B{sub s} {yields} K{sup {+-}} K{sup {-+}} and a measurement of A{sub CP} are presented.
Date: May 28, 2004
Creator: Martin, Matthew S.
Partner: UNT Libraries Government Documents Department

Rare kaon decays

Description: The phenomenology of rare kaon decays is reviewed, with emphasis on tests of standard model flavordynamics.
Date: January 1, 1997
Creator: Buchalla, G.
Partner: UNT Libraries Government Documents Department

Review of alpha-decay data from doubly-even nuclei

Description: Alpha-decay data from doubly-even nuclei throughout the periodic table are reviewed and evaluated. From these data, nuclear radius parameters are calculated by using the Preston formula for {alpha}- decay probabilities. The radius parameters for each element behave rather regularly as a function of neutron number. The show minima at the major closed shells, increase sharply for parents just above the closed shells, and decrease smoothly toward the next shell closure. The same trend is observed for {alpha} reduced widths calculated using the Rasmussen formalism. Any irregularity or large departure from this behavior indicates probable incorrect input data. This systematic behavior can also be utilized to estimate partial half- lives.
Date: September 1, 1996
Creator: Akovali, Y.A.
Partner: UNT Libraries Government Documents Department

Towards a next-to-leading logarithmic result in B {r_arrow} X{sub s}{gamma}

Description: The calculation of the O ({alpha}{sub s}) virtual corrections to the matrix element of the inclusive decay b {r_arrow} s{gamma} is reported. These contributions drastically reduce the large renormalization scale dependence of the leading logarithmic calculation. Combining these results with the preliminary result for the Wilson coefficient C{sub {gamma}} (m{sub b}) calculated recently by Chetyrkin, Misiak, and Muenz, we estimate the branching ratio to be BR(B {r_arrow} X{sub s} {gamma}) = (3.25 {plus_minus} 0.50) x 10{sup {minus}4}.
Date: August 1, 1996
Creator: Greub, C. & Hurth, T.
Partner: UNT Libraries Government Documents Department

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

Description: The first observation of the decay {Kappa}{sup +} {r_arrow} {pi}{sup +}{nu}{anti {nu}} has been reported. The E787 experiment presented evidence for the {Kappa}{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, {Beta}({Kappa}{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--98 runs, should reach a sensitivity of about five times that of the 1995 run alone. A new experiment, E949, has been given scientific approval and should start data collection in 2001. It 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.
Partner: UNT Libraries Government Documents Department

Charm physics at CDF II

Description: The CDF II detector has the capability of triggering on displaced tracks. Because of this ability, CDF II has accrued large samples of charged meson decays to fully hadronic final states in 64 pb{sup -1} of p{bar p} collision data gathered at {radical}s = 1.96 TeV. Using initial Run II data samples, the production cross sections for J/{psi}, D{sup 0}, D{sup +}, D*{sup +} and D{sub s}{sup +} mesons have been measured. Ratios of branching ratios for Cabibbo suppressed final states and CP asymmetries in D{sup 0} meson decays have been studied. A measurement of the mass difference m(D{sub s}{sup +}) -m(D{sup +}) has been done, and a limit for the branching fraction of the FCNC D{sup 0} {yields} {mu}{sup +}{mu}{sup -} decays has been set.
Date: October 28, 2003
Creator: Furic, I.
Partner: UNT Libraries Government Documents Department

Prospects of discovery for supersymmetry at the Tevatron

Description: We summarize a discovery potential for supersymmetric particles at the p{bar p} collider of Tevatron with center-of-mass energy {radical}s = 2 TeV and integrated luminosity {integral} L dt = 15-30 fb{sup -1}. Any direct search is kinematically limited to below 450 GeV/c{sup 2}. We, however, have a unique opportunity to test various supersymmetric scenarios by a measurement of the branching ratio for the rare decay mode B{sub s} {yields} {mu}{sup +}{mu}{sup -}. Using the background estimate in the CDF analysis of B{sub s} {yields} {mu}{sup +}{mu}{sup -} in Run I, we investigate the prospects for studying this mode in Run II. CDF would be sensitive to this decay for a branching ratio > 1.2 x 10{sup -8} with 15 fb{sup -1} (or, if a similar analysis holds for D0, > 6.5 x 10{sup -9} for the combined data). For tan {beta} > 30, the B{sub s} {yields} {mu}{sup +}{mu}{sup -} search can probe the SUSY parameter space that cannot be probed by direct production of SUSY particles at Run II. An observation of B{sub s} {yields} {mu}{sup +}{mu}{sup -} with a large branching ratio > 7(14) x 10{sup -8} (feasible with only 2 fb{sup -1}) would be sufficient to exclude the mSUGRA model for tan {beta} {le} 50(55) including other experimental constraints. For some models, the branching ratio can be large enough to be detected even for small tan {beta} and large m{sub 1/2}.
Date: January 15, 2003
Creator: Kamon, T.
Partner: UNT Libraries Government Documents Department

Observation of the Bc Meson at CDF

Description: We report on the observation of bottom-charm mesons via the decay mode B{sub c}{sup {+-}} {yields} J/{psi}l{sup {+-}}{nu} in 1.8 TeV p{anti p} collisions using the CDF detector at the Fermilab Tevatron. A fit of background and signal contributions to the J/{psi}l mass distribution yielded 20.4{sup +6.2}{sub -5.5} events from B{sub c} mesons. We measured the B{sub c}{sup +} mass to be 6.40{+-}0.39(stat.){+-}0.13(syst.)GeV/c and the B{sub c}{sup +}lifetime to be 0:46{sup +0.18}{sub -0.16}(stat.){+-} 0.03(syst.)ps. The measured production cross section times branching ratio for B{sub c}{sup +}{yields}J/{psi}l{sup +}{nu} relative to that for B{sup +}{yields}J/{psi}K{sup +} is 0.132{sup +0.041}{sub -0.037}(stat.){+-}0.031(syst.){sup +0.032}{sub -0.020}(lifetime).
Date: December 1, 1998
Creator: Papadimitriou, V.
Partner: UNT Libraries Government Documents Department

Radial and orbital q{anti q} excitations: ``Higher quarkonia``

Description: Identification of the spectrum of non-{ital q{anti q}} exotica such as glueballs, hybrids and molecules will require a detailed understanding of radially and orbitally excited quarkonia, since these states are a background to non-{ital q{anti q}} states. The data likely to become available experimentally on these higher-mass resonances are their total widths and strong branching fractions to dominant modes. We advocate the use of these branching fractions to distinguish quarkonia from exotica; in this contribution we summarize our recent detailed {sup 3}P{sub 0} decay model calculations of the 374 two-body open-flavor decay modes of the 32 lightest {ital n{anti n}} states above 1S and 1P, which should be useful for this program.
Date: December 31, 1996
Creator: Barnes, T.
Partner: UNT Libraries Government Documents Department

Susy and Such

Description: In these lectures, the author discusses the theoretical motivation for supersymmetric theories and introduce the minimal low energy effective supersymmetric theory, (MSSM). I consider only the MSSM and its simplest grand unified extension here. Some of the other possible low-energy SUSY models are summarized. The particles and their interactions are examined in detail in the next sections and a grand unified SUSY model presented which gives additional motivation for pursuing supersymmetric theories.
Date: January 13, 1997
Creator: Dawson, S.
Partner: UNT Libraries Government Documents Department

Lepton flavor violation

Description: The connection of rare decays to supersymmetric grand unification is highlighted, and a review of the status of rare decay experiments is given. Plans for future investigations of processes that violate lepton flavor are discussed. A new result from the MEGA experiment, a search for {mu}{sup +} {yields} e{sup +} {gamma}, is reported to be B.R. < 3.8 x 10{sup -11} with 90% confidence.
Date: October 1, 1997
Creator: Cooper, M.D. Brooks, M. & Hogan, G.E.
Partner: UNT Libraries Government Documents Department

919: Evidence for K{sup +} {r_arrow} {pi}{sup +} {nu}{bar {nu}} from E787

Description: A collaboration from KEK, INS, Osaka, TRIUMF, Princeton, and BNL is currently running E787 at the AGS. The experiment is designed primarily to search for the rare decay K{sup +} {yields} {pi}{sup +}{nu}{bar {nu}}, with an expected branching ratio of {approximately} 10{sup {minus}10}. The authors report evidence that they have observed this decay. They also discuss the future outlook for the experiment.
Date: December 1, 1997
Creator: Frank, J.S. & Collaboration, E787
Partner: UNT Libraries Government Documents Department

Search for heavy neutral gauge bosons at D-Zero

Description: We report preliminary results of a search for a heavy neutral gauge boson, Z`, using the decay channel Z` {yields} ee . The data were collected with the D0 detector at the Fermilab Tevatron during the 1994-1995 p{anti p} collider run at {radical}s = 1.8 TeV and correspond to an integrated luminosity of {approx} 90 pb{sup -1}. Limits are set on the cross section times branching ratio for the process {anti p}p {yields} Z` {yields} ee as a function of the Z` mass. We exclude the existence of a heavy neutral gauge boson of mass less than 660 GeV/c{sup 2} (95% CL), assuming a Z` with the same coupling strengths to quarks and leptons as the standard model Z boson. Combining this analysis with DO`s 1992-1993 data set increases the limit to m{sub Z`} > 670 GeV/c{sup 2}.
Date: October 1, 1997
Creator: Abbott, B.
Partner: UNT Libraries Government Documents Department

W and Z production cross sections at D0

Description: We present a measurement of the production cross section times branching ratio for {ital W} and {ital Z} bosons decaying to the electrons or muons in {ital p}{ital {anti p}} collisions at {radical}s = 1.8 TeV using data recorded at the Tevatron during the 1994-1995 collider run. Using the ratio of these two measurements, we derive the {ital W} leptonic branching fraction and the width of the {ital W} boson.
Date: November 1, 1996
Creator: Tarazi, J.N.
Partner: UNT Libraries Government Documents Department

The K{sub L} {yields} {pi}{sup 0}{nu}{anti {nu}} decay beyond the Standard Model

Description: The K{sub L} {yields} {pi}{sup 0}{nu}{anti {nu}} decay is analyzed in a model independent way. When lepton flavor is conserved, this decay mode is a manifestation of CP violating interference between mixing and decay. Consequently, a theoretically clean relation between the measured rate and electroweak parameters holds in any given model.
Date: April 1, 1997
Creator: Grossman, Y.
Partner: UNT Libraries Government Documents Department

MEGA -- A search for {mu} {r_arrow} e{gamma}

Description: The MEGA experiment is a search for the decay {mu} {r_arrow} e{gamma}. Even though there is no fundamental reason to expect lepton number to be a conserved quantity, processes such as {mu} {r_arrow} e{gamma} have not been observed. (The present upper limit for the branching ratio for {mu} {r_arrow} e{gamma} is 4.9 x 10{sup {minus}11}.) The minimal standard model of electroweak interactions, which is enormously successful, builds in lepton number conservation. However, the decay {mu} {r_arrow} e{gamma} is expected in many extensions to the standard model, in particular in supersymmetry models. The experimental signature for {mu} {r_arrow} e{gamma} from decays at rest is the observation of a positron and photon, each of 52.8 MeV , that are back-to-back, in time coincidence, and originate from a common spatial point. The MEGA detector consists of two spectrometers designed to measure the kinematic characteristics of positrons and photons to search for events with this signature. The primary difficulty in the analysis of these data has been the development of reconstruction algorithms that balance efficiency and resolution. Also, many calibrations and corrections are needed to get optimum resolutions. Most surviving candidate events are accidentals. Results of analysis are given.
Date: December 1, 1998
Creator: Mischke, R. E.
Partner: UNT Libraries Government Documents Department

CKM--Charged Kaons at the Main Injector

Description: The CKM experiment is a proposal to measure the branching ratio of the rare decay K{sup +} {r_arrow} {pi}{sup +} {nu}{bar {nu}} at the Main Injector at Fermilab using a decay in flight technique. The goal is to observe {approx}100 events, for a Standard Model branching ratio of 1 x 10{sup {minus}10} with a background of less than 10 events.
Date: January 16, 2001
Creator: Cooper, P.S.
Partner: UNT Libraries Government Documents Department