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in subjects: "Mass Difference"

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A Search for New Leptons with Heavy Neutrinos in e/sup +/e/sup -/ Annihilation at. sqrt. s = 29 GeV. [None]

This thesis describes the results of a search for new leptons with associated heavy neutrinos. The search uses 68.1 pb/sup /minus/1/ of data taken with the TPC2..gamma.. detector at the PEP storage ring. New lepton pairs with charged lepton masses m/sub L/ < 12 GeV and mass differences in the approximate range 0.4 GeV < m/sub L/ /minus/ m/sub/nu/L/ < 2.5 GeV are excluded at the 99% confidence level. Results are also given of a study of search techniques for the region m/sub L/ < 12 GeV, m/sub L… more

Date: May 5, 1988

Creator: Mathis, L. G.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Recent Results From DELCO

DELCO is a magnetic spectrometer with Cerenkoc, Time-of-Flight (TOF) and shower counters for particle identification. It is located in IR8 of the PEP storage ring. Data have been obtained at a center of mass energy, ..sqrt..s, of 29 GeV. We report on: (1) the fraction of P, K, ..pi.. in hadronic events; (2) the observation of direct electron signals; and (3) the measurement of D* fragmentation function and its total cross-section. 8 references.

Date: November 1, 1983

Creator: Atwood, W. B.; Baillon, P. H.; Barish, B. C.; Bonneaud, G. R.; DeStaebler, H.; Donaldson, G. J. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Calculability of the n-p mass difference in gauge theories

The requirement of a calculable n-p mass difference leads to a consideration of unified gauge theories. Future developments in grand unified models may provide a realistic framework for the calculation of the n-p mass difference. The possibility that the relatively soft ultraviolet behavior of QCD softens the divergence in the lowest-order electromagnetic mass shift is considered in detail. It is shown that, if the bare mass and QCD coupling are constrained to be independent of the electromagne… more

Date: January 1, 1980

Creator: Kiskis, J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Effects of a new heavy neutral vector boson at SLC and LEP

Models with an extra neutral gauge boson (Z') are discussed. We constrain the Z' mass as a function of its mixing angle with the known Z/sup 0/ by requiring that the Z/sup 0/ mass not be shifted excessively by this mixing, and from the Higgs vacuum expectation value structure of the mass matrix. We compare these limits with those previously found from neutral current experiments. We discuss possible effects of non-excluded models on e/sup +/e/sup -/ physics at SLC and LEP. 8 refs., 3 figs.

Date: April 1, 1986

Creator: Franzini, P. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Neutron Production of Charm Particles in Fermilab E-400

Results are presented from Fermilab E-400 on the production of charmed baryons and mesons using incident neutrons. We show evidence for the charm-strange baryon, ..xi../sub c//sup +/, and present our measurements of its mass, width, lifetime, cross section and relative branching fractions, and the A, x/sub f/, p/sub t/, and particle/antiparticle dependence of the state. We show evidence for both the ..sigma../sub c//sup + +/ and ..sigma../sub c//sup 0/, and present measurements of three mass di… more

Date: August 20, 1987

Creator: Cumalat, J. P.; Binkley, M.; Bossi, F.; Butler, J.; Coteus, P.; DiCorato, M. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Latest results on the direct CP violation measurements:. Epsilon. prime /. epsilon

Preliminary results, based on the full data sample from Fermilab-E731 and the combined data sample from CERN-NA31, on the direct'' CP-violation measurements {epsilon}{prime}{epsilon} in neutral kaon decay have been reviewed. The E731's results if Re({epsilon}{prime}{epsilon}) = (6.0 {plus minus} 5.8(stat) {plus minus} 3.2(syst) {plus minus} 1.8(MC)) {times} 10{sup {minus}4}, which provides no evidence for direct'' CP-violation, thus supporting the Superweak model; while the NA31's combined resu… more

Date: March 1, 1992

Creator: Hsiung, Yee B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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On the n-p mass difference in QCD

The radiative contribution to ..delta..m, the n-p mass difference, is discussed in terms of dynamical symmetry breaking and gauge boson radiative corrections. (GHT)

Date: January 1, 1980

Creator: West, G.B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Measurement of Resonance Parameters of Orbitally Excited Narrow B^0 Mesons

The authors report a measurement of resonance parameters of the orbitally excited (L = 1) narrow B{sup 0} mesons in decays to B{sup (*)+}{pi}{sup -} using 1.7 fb{sup -1} of data collected by the CDF II detector at the Fermilab Tevatron. The mass and width of the B*{sub 2}{sup 0} state are measured to be m(B*{sub 2}{sup 0}) = 5740.2{sub -1.8}{sup +1.7}(stat.){sub -0.8}{sup +0.9}(syst.) MeV/c{sup 2} and {Lambda}(B*{sub 2}{sup 0}) = 22.7{sub -3.2}{sup +3.8}(stat.){sub -10.2}{sup +3.2}(syst.) MeV/c… more

Date: September 1, 2008

Creator: Aaltonen, : T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Precision measurement of a particle mass at the linear collider

Precision measurement of the stop mass at the ILC is done in a method based on cross-sections measurements at two different center-of-mass energies. This allows to minimize both the statistical and systematic errors. In the framework of the MSSM, a light stop, compatible with electro-weak baryogenesis, is studied in its decay into a charm jet and neutralino, the Lightest Supersymmetric Particle (LSP), as a candidate of dark matter. This takes place for a small stop-neutralino mass difference.

Date: June 1, 2007

Creator: Milstene, C.; Freitas, A.; Schmitt, M. & Sopczak, A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Hadronic B Decays to Charm and Charmonium With the BaBar Experiment

The BABAR experiment has recorded the decays of more than 465 x 10{sup 6} B{bar B} pairs since 1999, and is reaching an unprecedented precision in the measurement of hadronic B decays. The following results are presented: tests of QCD factorization with the decays B {yields} {chi}{sub c0}K*, B {yields} {chi}{sub c1,2}K{sup (*)}, and {bar B}{sup 0} {yields} D{sup (*)0}h{sup 0}, h{sup 0} = {pi}{sup 0}, {eta}, {omega}, {eta}{prime}, study of the decays to charmonium B {yields} {eta}{sub c}K{sup (*… more

Date: September 18, 2008

Creator: Prudent, Xavier

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Measurement of the Branching Fractions of Bbar -> D** l^- nubar_l Decays in Events Tagged by a Fully Reconstructed B Meson

We report a measurement of the branching fractions of {bar B} {yields} D** {ell}{sup -}{bar {nu}}{sub {ell}} decays based on 417 fb{sup -1} of data collected at the {Upsilon}(4S) resonance with the BABAR detector at the PEP-II e{sup +}e{sup -} storage rings. Events are selected by fully reconstructing one of the B mesons in a hadronic decay mode. A fit to the invariant mass differences m(D{sup (*)})-m(D{sup (*)}) is performed to extract the signal yields of the different D** states. We observe … more

Date: November 5, 2008

Creator: Aubert, Bernard; Bona, M.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Measurement of the Mass Difference m(B0) - m(B+)

Using 230 million B{bar B} events recorded with the BABAR detector at the e{sup +}e{sup -} storage rings PEP-II, they reconstruct approximately 4100 B{sup 0} {yields} J/{psi} K{sup +}{pi}{sup -} and 9930 B{sup +} {yields} J/{psi}K{sup +} decays with J/{psi} {yields} {mu}{sup +}{mu}{sup -} and e{sup +} e{sup -}. From the measured B-momentum distributions in the e{sup +}e{sup -} rest frame, they determine the mass difference m(B{sup 0}) - m(B{sup +}) = (+0.33 {+-} 0.05 {+-} 0.03) MeV/c{sup 2}.

Date: May 19, 2008

Creator: Aubert, B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Study of Charmed Baryon Sigma(C)(2800) Production at the BaBar Experiment

This dissertation reports on a study of search for an orbitally excited state of charmed baryons {Sigma}{sub c}{sup 0}(2800) and {Sigma}{sub c}{sup ++}(2800). They measure the widths, momentum spectrum and production cross-section for these states decaying into a {Lambda}{sub c}{sup +} and a charged {pi}. The analysis uses 230 fb{sup -1} of data collected at BABAR detector operating at PEP-II collider at Stanford Linear Accelerator Center. The data is collected in the region of {Upsilon}(4S) an… more

Date: February 29, 2008

Creator: Ahmded, Shamona

Item Type: Thesis or Dissertation

Partner: UNT Libraries Government Documents Department

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Measurement of Semileptonic B Decays Into Orbitally-Excited Charm Mesons

The authors present a study of B decays into semileptonic final states containing charged and neutral D{sub 1}(2420) and D*{sub 2}(2460). The analysis is based on a data sample of 208 fb{sup -1} collected at the {Upsilon}(4S) resonance with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. With a simultaneous fit to four different decay chains, the semileptonic branching fractions are extracted from measurements of the mass difference {Delta}m = m(D**)-m(D) distributions. Pr… more

Date: August 7, 2008

Creator: Aubert, Bernard; Bona, M.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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'Fission' of Medium Weight Elements

The fission reaction has been observed with high energy accelerator projectiles for elements as light as tantalum but has not been reported for medium weight elements. The present note presents evidence for the occurrence of reactions which are probably most properly described by the term 'fission' and which seem to occur with very small yield throughout the region where this type of reaction is only slightly exoergic or even endoergic with respect to mass balance. In the course of detailed inv… more

Date: May 29, 1950

Creator: Batzel, Roger T. & Seaborg, G. T.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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New Quarkonium Results from the BABAR experiment

New BABAR results on B mesons and quarkonia are presented: an analysis of B{sup +} {yields} X(3872)K{sup +} and B{sup 0} {yields} X(3872)K{sup 0} decays with X(3872) {yields} J/{psi}{pi}{sup +}{pi}{sup -}, a precise measurement of the B mass difference {Delta}m{sub B} = m(B{sup 0}) -m(B{sup +}) and a study of hadronic transition between {Upsilon} mesons.

Date: May 21, 2008

Creator: Arnaud, Nicolas & Collaboration, representing the BABAR

Item Type: Article

Partner: UNT Libraries Government Documents Department

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First Observation of An Excited Charm Baryon Decaying to Omega Charm Baryon at the BaBar Experiment

We have carried out a search for a charmed baryon {Omega}{sup *}{sub c} decaying to {Omega}{sup 0}{sub c} and a {gamma} where {Omega}{sub c} candidates are reconstructed using decay modes {Omega}{sup -}{pi}{sup +}(c1), {Omega}{sup -}{pi}{sup +}{pi}{sup 0}(c2), {Omega}{sup -}{pi}{sup +}{pi}{sup -}{pi}{sup +}(c3) and {Xi}{sup -}K{sup -}{pi}{sup +}{pi}{sup +}(c4). This search is performed by analyzing integrated luminosity of 230.7 fb{sup -1} data collected by the BABAR detector at the Stanford Li… more

Date: November 26, 2007

Creator: Bula, Rahmi & /SUNY, Albany

Item Type: Thesis or Dissertation

Partner: UNT Libraries Government Documents Department

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A search for close-mass lepton doublet

Described is a search for a heavy charged lepton with an associated neutrino of nearly the same mass, together known as a close-mass lepton doublet. The search is conducted in e/sup +/e/sup/minus// annihilation data taken with the Mark II detector at a center-of-mass energy of 29 GeV. In order to suppress contamination from conventional two-photon reactions, the search applies a novel, radiative-tagging technique. Requiring the presence of an isolated, energetic photon allows exploration for le… more

Date: April 1, 1989

Creator: Riles, J.K.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Some aspects of quark fragmentation: comparison of heavy (c) and light quarks (u,d,s)

The data that the author presents come from the first two years of operation of the High Resolution Spectrometer (HRS) at PEP, and correspond to an integrated luminosity of 106 +- 5 pb/sup -1/ (20 pb/sup -1/ from the first year and 86 pb/sup -1/ from the second year's running). Since the quark-meson transitions may have a particularly simple form at the values of the momentum fraction Z = 2p/sub meson//..sqrt..s, we emphasize this aspect of the data, and show how a sample of e/sup +/e/sup -/ ..… more

Date: January 1, 1984

Creator: Derrick, M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Search for D/sup *//sup 0/. -->. D/sup +/. pi. /sup -/

We report on a search for the decay mode D/sup *//sup 0/(2007) ..-->.. D/sup +/..pi../sup -/ using the High Resolution Spectrometer at PEP. Although this decay is kinematically forbidden for the central mass value, it can occur through the natural width of the D/sup *//sup 0/. The D/sup +/ was reconstructed in the K/sup -/..pi../sup +/..pi../sup +/ decay mode. The mass difference distribution (K/sup -/..pi../sup +/..pi../sup +/..pi../sup +/) - (K/sup -/..pi../sup +/..pi../sup -/), which shows n… more

Date: January 1, 1987

Creator: Abachi, S.; Akerlof, C.; Baringer, P.; Blockus, D.; Brabson, B.; Brom, J.M. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Neutrino oscillation searches at the AGS. [Feasibility studies, upper limit]

A feasibility study of the time evolution of a long-lived ..nu../sub ..mu../ beam was performed. The proton momentum (1.5 GeV/c) was chosen to concentrate the ..nu../sub ..mu../ flux at very low energy where all background reactions are kinematically suppressed. Sensitivity to oscillations at large proper times tau Varies as l/p (where l is the flight length and p is the momentum of the neutrino) is greatly enhanced by the resulting low neutrino momentum. Possible transformations ..nu../sub ..m… more

Date: January 1, 1978

Creator: Soukas, A.; Bregman, M. & Galik, R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Fermion masses and neutrino mixing in an SU(5)/sub GUT/ x SU(8)/sub ETC/ model

We extend the SU(3) x SU(2) x U(1) model without scalars to SU(5)/sub GUT/ x SU(8)/sub ETC/. In our model, the mixing in the leptons is identical to that for the quarks, so that the Cabibbo angle determines the mixing of nu/sub e/ and nu/sub ..mu../. The quark masses and mixing angles are studied for two and three generations of quarks.

Date: January 1, 1983

Creator: Aubrecht, G. J., II; Matsuki, T. & Tanaka, K.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Search for Neutrino Oscillations at the Brookhaven AGS

We report on a search for neutrino oscillations of the type nu/sub ..mu../ ..-->.. nu/sub e/ in a detector located an effective distance of 96m from the neutrino source in the wide band neutrino beam at the Brookhaven AGS. No excess of electron events was observed. The resulting upper limit on the strength of the mixing between nu/sub ..mu../ and nu/sub e/ in the case of large mass difference ..delta..m/sup 2/ = absolute value m/sub 1//sup 2/ - m/sub 2//sup 2/ between the neutrino mass eigensta… more

Date: February 20, 1985

Creator: Ahrens, L. A.; Aronson, S. H.; Connolly, P. L.; Gibbard, B. G.; Murtagh, M. J.; Murtagh, S. J. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Neutrino mass experiments

The current status of the experimental search for neutrino mass is reviewed, with emphasis on direct kinematic methods. Simpson and Hime report finding new evidence for a 17-keV neutrino in the ..beta.. decay of /sup 3/H and /sup 35/S. The situation concerning the electron neutrino mass as measured in tritium beta decay has not changed significantly in the last two years. We discuss the ''model independent'' lower limit of 17 eV obtained by the ITEP group in light of existing data on the /sup 3… more

Date: January 1, 1989

Creator: Robertson, R.G.H.

Item Type: Article

Partner: UNT Libraries Government Documents Department