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in subjects: "Weak Particle Decay"

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Top polarization at a {mu}{sup +} {mu}{sup {minus}} collider

The top quark pairs produced at a polarized muon collider are in a (nearly) pure spin configuration. This result holds for all center-of-mass energies, and is insensitive to the next-to-leading order QCD radiative corrections. The decay products of a polarized top quark show strong angular correlations. The authors describe an interesting interference effect between the left-handed and longitudinally polarized W bosons in top quark decay. This effect is easily observable in the angular distribu… more

Date: January 27, 2000

Creator: Parke, S. & Mahlon, G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Prospects for studies of ground-state proton decays with the Holifield Radioactive Ion Beam Facility

By using radioactive ions from the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory it should be possible to identify many new ground-state proton emitters in the mass region from Sn to Pb. During this production and search process the limits of stability on the proton-rich side of the nuclidic chart will be delineated for a significant fraction of medium-weight elements and our understanding of the proton-emission process will be expanded and improved.

Date: February 1, 1994

Creator: Toth, K. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Charm-studies in Experiment E687 at Fermilab

Results from analysis of data taken in 1987--88 are presented. These include branching ratios for decays of D{sup 0} and D{sub s}{sup +}, and decay fractions for the nonresonant channel and channels involving K{sup *+} and {rho}{sup 0} in the decay D{sup 0} {yields} K{sub s}{sup 0}{pi}{sup +}{pi}{sup {minus}}. An emphasis to look for the decay of P-wave D-mesons, D{sup **0} {yields} D{sup *+}{pi}{sup {minus}}, is described.

Date: May 1, 1992

Creator: Shukla, S. & Collaboration, E687

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Tests of proton structure functions using leptons at CDF and D0: W charge asymmetry and Drell-Yan production. Version 1.0

High statistics W charge asymmetry measurements at the Tevatron {bar p}p collider significantly constrain the u and d quark distributions, and specifically the slope of the d(x)/u(x) in the x range 0.007 to 0.27. The authors present measurements of lepton charge asymmetry as a function of lepton rapidity, A(y{sub l}) at {radical}s = 1.8 TeV for {vert_bar}y{sub l}{vert_bar} < 2.0, for the W decays to electrons and muons recorded by the CDF detector during the 1992-93 run ({approx} 20 pb{sup {min… more

Date: June 13, 1995

Creator: de Barbaro, P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Discovery mass reach for topgluons decaying to b{bar b} at the Tevatron

In topcolor assisted technicolor, topgluons are massive gluons which couple mainly to top and bottom quarks. We estimate the mass reach for topgluons decaying to {ital b{anti b}} at the Tevatron as a function of integrated luminosity. The mass reach for topgluons decreases with increasing topgluon width, and is 0.77-0.95 TeV for Run II (2 fb{sup -1}) and 1.0 - 1.2 TeV for TeV33 (30 fb{sup -1}).

Date: September 1, 1996

Creator: Harris, R.M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Using collider event topology in the search for the six-jet decay of top quark-antiquark pairs

The authors investigate the use of the event topology as a tool in the search for the six-jet decay of top-pair production in proton-antiproton collisions at 1.8 TeV. Modified-Fox-Wolfram shape variables, {cflx H}{sub {ell}}, are employed to help distinguish the top-pair signal from the ordinary QCD multi-jet background. The {cflx h}{sub {ell}}`s can be constructed directly from the calorimeter cells or from jets. Events are required to lie in a region of {cflx H}{sub {ell}}-space defined by L{… more

Date: November 1, 1997

Creator: Field, R.D. & Kanev, Y.A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Overview of strangeness nuclear physics

Novel as well as puzzling aspects of strangeness (S = {minus}1 and S = {minus}2) nuclear physics are highlighted. Opportunities to gain new insights into hypernuclear spectroscopy, structure, and weak decays and to contribute to the continuing effort to understand the fundamental baryon-baryon force are outlined. Connections to strangeness in heavy-ion reactions and astrophysics are noted.

Date: December 1998

Creator: Gibson, B. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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CP violation

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.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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General results for the decays D {yields} {pi}{ell}{nu} and B {yields} {pi}{ell}{nu}

Results are given for the two form factors for D {yields} {pi}{ell}{nu} and B {yields} {pi}{ell}{nu} at the soft pion limit. The deriviation depends only on pion PCAC and heavy quark spin symmetry. The usefulness of these results is discussed.

Date: September 1, 1992

Creator: Wolfenstein, L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Rare decays experimental summary and prospects

I review the status and future prospects of searches for forbidden and highly kaon suppressed decays. This workshop comes as we are poised at the threshold of a new generation of rare K decay experiments. There are new experiments running or about to run at KEK, BNL, FNAL, and CERN. In another year or so these will be joined by the KLOE experiment at DA{Phi}NE. The good news is that it`s a very exciting time. The bad news, at least for a reviewer, is that there aren`t too many new results. Thus… more

Date: December 31, 1996

Creator: Littenberg, L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Search for leptoquarks at CDF

We present the result of direct leptoquark searches based on 110 pb{sup -1} of integrated luminosity collected by the Collider Detector at Fermilab during the 1992-93 and 1994-95 Tevatron runs at {radical}s = 1.8 TeV. We present upper limits on the production cross sections as a function of the leptoquark mass. Using the NLO calculation of the leptoquark-pair production cross sections we extract lower-mass limits for 1{sup st}, 2{sup nd}, and 3{sup d} generation leptoquarks. We also present the… more

Date: July 1, 1997

Creator: Kambara, H. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Jet angular decorrelation and color coherence in p{bar p} collisions at {radical}s = 1.8 TeV

We present three QCD studies based on data collected by the d{O} detector during the 1992-1993 and 1994-1995 runs at the Fermilab Tevatron collider at center of mass energy {radical}s = 1.8 TeV. The first study is an analysis of jet-jet azimuthal decorrelation as a function of jet rapidity separation. The second and third studies are probes of color coherence effects in hadronic collisions - one using multi-jet events and the other using W+jet events.

Date: August 1, 1996

Creator: Jaques, J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Top quark measurements at the Tevatron

The authors present top physics results from the CDF and D0 collaborations. The data were collected at the Fermilab Tevatron over the years 1992--1995 and correspond to approximately 110 pb{sup {minus}1} of p{anti p} collisions. Both experiments present determination of the t{anti t} production cross section using a variety of top decay channels, and refined measurements of the top mass.

Date: January 1, 1997

Creator: Kestenbaum, D. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

CP and B Physics: Progress and prospects

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.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Pentaquark phenomenology

Heavy flavor hadron scattering and bound states give experimental information otherwise unobtainable on effective (qq){sub 6} and ({anti q}q){sub 8} interactions. All constituent quark model successes in (uds) hadron spectroscopy depend only on (qq){sub 3*} and ({anti q}q){sub 1} interactions. Reliable vertex detectors open new pentaquark search directions. Any event in with a proton emitted from a secondary vertex indicates a particle decaying weakly by proton emission and the discovery of a n… more

Date: September 1, 1997

Creator: Lipkin, Harry J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

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

Under the assumption that CP violation is caused by exchange of anew boson, the authors propose 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 decay of polarized tau leptons produced at an e{sup +}e{sup {minus}} collider whose beams are polarized. These five coupling constants could be used to construct a future theory of CP violation. If CP is violated in any channel of … more

Date: May 1, 1996

Creator: Tsai, Y.S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

CP violation in top physics at the NLC

Top quark is extremely sensitive to non-standard CP violating phases. General strategies for exposing different types of phases at the NLC are outlined. SUSY phase(s) cause PRA in t {r_arrow} Wb. The transverse polarization of the {tau} in the reaction t {r_arrow} b{tau}{nu} is extremely sensitive to a phase from the charged Higgs sector. Phase(s) from the neutral Higgs sector cause appreciable dipole moment effects and lead to sizable asymmetries in e{sup +}e{sup {minus}} {r_arrow} t{anti t}H{… more

Date: September 1, 1996

Creator: Atwood, D. & Soni, A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

CDF top quark production and mass

The top search in the dilepton and lepton plus jets channels with the Collider Detector at Fermilab is presented. The analysis uses a 67 pb{sup {minus}1} sample of p{bar p} collisions at 1.8 TeV. A 4.8{sigma} excess of candidate events establishes the existence of the top quark. The t{bar t} production cross section is measured to be {sigma}{sub t{bar t}} = 7.6{sub {minus}2.0}{sup +2.4} pb with branching Br(t {yields} Wb) = 0.87{sub {minus}0.30}{sup +0.13}(stat) {sub {minus}0.11}{sup +0.13}(sys… more

Date: July 18, 1995

Creator: Incandela, J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Spin correlation in t{anti t} production from p{anti p} collisions at {radical}s = 1.8 TeV

The Standard Model predicts that the lifetime of the top quark is shorter than the typical time scale at which hadronization process occurs, and the spin information at its production is preserved. Spin correlation of the t{anti t} system from p{anti p} collisions at the Tevatron is analyzed using 6 events in the dilepton channels collected using the D0 detector. Spin correlation factor of {kappa} > {minus} 0.25 at 68% CL is obtained from the data.

Date: June 15, 2000

Creator: Choi, Suyong

Item Type: Thesis or Dissertation

Partner: UNT Libraries Government Documents Department

open access

Search for anomalous couplings in the decay of polarized Z bosons to tau lepton pairs

Using a sample of 4,500 polarized Z decays to {tau} lepton pairs accumulated with the SLD detector at the SLAC Linear Collider (SLC) in 1993-95, a search has been made for anomalous couplings in the neutral current reaction e{sup +}e{sup {minus}}{yields}{tau}{sup +}{tau}{sup {minus}}. A measurement of the CP violating Weak Electric Dipole Moment (WEDM) and the CP conserving Weak Magnetic Dipole Moment (WMDM) of the {tau} lepton has been performed by considering the transverse spin polarization … more

Date: June 1, 1997

Creator: Torrence, E.C.

Item Type: Thesis or Dissertation

Partner: UNT Libraries Government Documents Department

open access

Rare and forbidden kaon decays at the AGS

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.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The {pi}{sup +}-emission puzzle in 4 over Lambda He decay

The observed {pi}{sup +} emission from the weak decay of 4 over {Lambda} He has long been an intriguing puzzle. Experimentally, the {pi}{sup +} to {pi}{sup {minus}} ratio for 4 over {Lambda} He decay is about 5%. Because mesonic decay modes of the free {Lambda} ({yields} p + {pi}{sup {minus}}, n + {pi}{sup 0}) produce no {pi}{sup +}s, more complicated mechanisms must be responsible for the {pi}{sup +} decay of 4 over {Lambda} He. Dalitz and von Hippel explored two-body decay processes of the ty… more

Date: October 1, 1997

Creator: Gibson, B. F. & Timmermans, R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

High intensity performance of the Brookhaven AGS

Experience and results from recent high intensity proton running periods of the Brookhaven AGS, during which a record intensity for a proton synchrotron of 6.3 x 10{sup 13} protons/pulse was reached, is presented. This high beam intensity allowed for the simultaneous operation of three high precision rare kaon decay experiments. The record beam intensities were achieved after the 1.5 GeV Booster was commissioned and a transition jump system, a powerful transverse damper, and an rf upgrade in th… more

Date: July 1, 1996

Creator: Brennan, J. M. & Roser, T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

L3 physics at the Z resonance and a search for the Higgs particle

This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory. Electroweak interactions were studied using the L3 Detector on the Large Electron-Positron Collider (LEP) at the European Center for Nuclear Study (CERN). The specific physics studied utilized the Silicon Microvertex Detector (SMD) of L3, which Los Alamos had previously played a major role in proposing, designing, constructing, and commissioning. This dete… more

Date: July 1, 1997

Creator: Coan, T.A.; Kinnison, W.W.; Kapustinsky, J. & Shukla, J.

Item Type: Report

Partner: UNT Libraries Government Documents Department