Showing papers by "Hyun-Chul Kim published in 1998"
University of California, Riverside1, Linfield College2, Embry–Riddle Aeronautical University3, Louisiana Tech University4, University of New Mexico5, Louisiana State University6, University of California, San Diego7, Los Alamos National Laboratory8, Temple University9, University of California, Santa Barbara10
TL;DR: In this paper, a beam-on high-energy (60-200 MeV) electron event was observed consistent with the observed oscillation probability of $(2.6\ifmmode\pm\else\textpm\fi{}1.0
Abstract: A search for ${\ensuremath{
u}}_{\ensuremath{\mu}}\ensuremath{\rightarrow}{\ensuremath{
u}}_{e}$ oscillations has been conducted with the LSND apparatus using ${\ensuremath{
u}}_{\ensuremath{\mu}}$ from ${\ensuremath{\pi}}^{+}$ decay in flight. Two analyses observe a total of 40 beam-on high-energy (60--200 MeV) electron events consistent with the ${\ensuremath{
u}}_{e}\mathrm{C}\ensuremath{\rightarrow}{e}^{\ensuremath{-}}X$ inclusive reaction. This number is significantly above the $21.9\ifmmode\pm\else\textpm\fi{}2.1$ events expected from the ${\ensuremath{
u}}_{e}$ contamination in the beam and the beam-off background. If interpreted as an oscillation signal, the observed oscillation probability of $(2.6\ifmmode\pm\else\textpm\fi{}1.0\ifmmode\pm\else\textpm\fi{}0.5)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$ is consistent with the previously reported ${\overline{\ensuremath{
u}}}_{\ensuremath{\mu}}\ensuremath{\rightarrow}{\overline{\ensuremath{
u}}}_{e}$ oscillation evidence from LSND.
468 citations
University of Naples Federico II1, University of Basilicata2, Sapienza University of Rome3, University of Pisa4, California Institute of Technology5, University of Bari6, University of Salento7, University of Turin8, Indiana University9, University of Bologna10, National Research Council11, University of Michigan12, University of L'Aquila13, Roma Tre University14, University of Trieste15, Boston University16, Drexel University17, Swarthmore College18, Pakistan Institute of Nuclear Science and Technology19, Scuola Normale Superiore di Pisa20, Texas A&M University21
TL;DR: In this article, a measurement of the flux of neutrino-induced upgoing muons ( ν >∼ 100 GeV) using the MACRO detector is presented, where the ratio of the observed to expected events integrated over all zenith angles is 0.74 ± 0.036 (stat) ±0.13 (theoretical).
260 citations
TL;DR: In this article, the decay mode B{sub c} mesons were observed in 1.8 TeV p{ovr p}collisions using the CDF detector at the Fermilab Tevatron.
Abstract: We have observed bottom-charm mesons via the decay mode B{sub c}{sup {+-}}{yields}J/{psi}{ell}{sup {+-}}v in 1.8 TeV p{ovr p}collisions using the CDF detector at the Fermilab Tevatron. A fit of background and signal contributions to the J/{psi}{ell} mass distribution yielded 20.4{sub -5.5}{sup +6.2} events from B{sub c} mesons. A fit to the same distribution with background alone was rejected at the level of 4.8 standard deviations. We measured the B{sub c}{sup +} mass to be 6.40{+-}0.39(stat){+-}0.13(syst) GeV/c{sup 2} and the B{sub c}{sup +} lifetime to be 0.46{sub -0.16}{sup +0.18}(stat){+-}0.03(syst) ps. Our measured yield (production cross section times branching ratio) for B{sub c}{sup +}{yields}J/{psi}{ell}{sup +}v relative to that for B{sup +}{yields}J/{psi} K{sup +} is 0.132{sub -0.037}{sup +0.041}(stat){+-}0.031(syst){sub -0.020}{sup +0.032}(lifetime).
254 citations
University of California, Riverside1, Linfield College2, Embry–Riddle Aeronautical University3, Louisiana Tech University4, University of New Mexico5, Louisiana State University6, University of California, San Diego7, Los Alamos National Laboratory8, Temple University9, University of California, Santa Barbara10
TL;DR: In this paper, a search for beam-related oscillations was conducted at the Los Alamos Meson Physics Facility using the LSND beam from the decay in flight, and the observed oscillation probability of $(2.6\ifmmode\pm\else\textpm\fi{}1.0
Abstract: A search for ${\ensuremath{
u}}_{\ensuremath{\mu}}\ensuremath{\rightarrow}{\ensuremath{
u}}_{e}$ oscillations has been conducted at the Los Alamos Meson Physics Facility using ${\ensuremath{
u}}_{\ensuremath{\mu}}$ from ${\ensuremath{\pi}}^{+}$ decay in flight. An excess in the number of beam-related events from the ${\ensuremath{
u}}_{e}\stackrel{\ensuremath{\rightarrow}}{C}{e}^{\ensuremath{-}}X$ inclusive reaction is observed. The excess is too large to be explained by normal ${\ensuremath{
u}}_{e}$ contamination in the beam at a confidence level greater than 99%. If interpreted as an oscillation signal, the observed oscillation probability of $(2.6\ifmmode\pm\else\textpm\fi{}1.0\ifmmode\pm\else\textpm\fi{}0.5)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$ is consistent with the previously reported ${\overline{\ensuremath{
u}}}_{\ensuremath{\mu}}\ensuremath{\rightarrow}{\overline{\ensuremath{
u}}}_{e}$ oscillation evidence from LSND.
162 citations
TL;DR: In this article, the authors search for the flavor-changing neutral current decays of the top quark and set 95% confidence level limits on the branching fractions of the decays.
Abstract: We search for the flavor-changing neutral current decays of the top quark $t\ensuremath{\rightarrow}q\ensuremath{\gamma}$ and $t\ensuremath{\rightarrow}\mathrm{qZ}$ (here $q$ represents the $c$ and $u$ quarks) in $\overline{p}p$ collisions at $\sqrt{s}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1.8\phantom{\rule{0ex}{0ex}}\mathrm{TeV}$. We use a dataset $(\ensuremath{\int}L\mathrm{dt}\ensuremath{\sim}110{\mathrm{pb}}^{\ensuremath{-}1})$ collected during the 1992--1995 run of the Collider Detector at Fermilab. We set 95% confidence level limits on the branching fractions $B(t\ensuremath{\rightarrow}q\ensuremath{\gamma})l3.2%$ and $B(t\ensuremath{\rightarrow}\mathrm{qZ})l33%$, consistent with the standard model.
106 citations
TL;DR: In this paper, bottom-charmed mesons B_c were observed in 1.8 TeV p-bar p collisions using the CDF detector at the Fermilab Tevatron and a fit to the J/psi lepton mass distribution yielded 20.4 +6.2 -5.8 standard deviations.
Abstract: We report the observation of bottom-charmed mesons B_c in 1.8 TeV p-bar p collisions using the CDF detector at the Fermilab Tevatron. The B_c mesons were found through their semileptonic decays, B_c -> J/psi lepton X. A fit to the J/psi lepton mass distribution yielded 20.4 +6.2 -5.5 events from B_c mesons. A test of the null hypothesis, i.e. an attempt to fit the data with background alone, was rejected at the level of 4.8 standard deviations. By studying the quality of the fit as a function of the assumed B_c mass, we determined M(B_c) = 6.40 +- 0.39 +- 0.13 GeV/c^2. From the distribution of trilepton intersection points in the plane transverse to the beam direction we measured the B_c lifetime to be tau(B_c) = 0.46 +0.18 -0.16 +- 0.03 ps. We also measured the ratio of production cross section times branching fraction for B_c -> J/psi lepton neutrino relative to that for B+ -> J/psi K to be: 0.132 +0.041 -0.037 (stat) +- 0.031 (syst) +0.032 -0.020 (lifetime)
82 citations
TL;DR: In this article, a new measurement of dijet production by color-singlet exchange in p{ovr p} collisions at {radical}(s)=1.8 TeV at the Fermilab Tevatron was reported.
Abstract: We report a new measurement of dijet production by color-singlet exchange in p{ovr p} collisions at {radical}(s)=1.8 TeV at the Fermilab Tevatron. In a sample of events with two jets of transverse energy E{sup jet}{sub T}{gt}20 GeV , pseudorapidity in the range 1.8{lt}{vert_bar}{eta}{sup jet}{vert_bar}{lt}3.5 , and {eta}{sub 1}{eta}{sub 2}{lt}0 , we find that a fraction R=[1.13{plus_minus}0.12(stat){plus_minus} 0.11(syst)]{percent} has a pseudorapidity gap within {vert_bar}{eta}{vert_bar}{lt}1 between the jets that can be attributed to color-singlet exchnage. The fraction R shows no significant dependence on E{sup jet}{sub T} or on the pseudorapidity separation between the jets. {copyright} {ital 1998} {ital The American Physical Society}
79 citations
TL;DR: In this article, the authors describe a measurement of the charge asymmetry of leptons from W -boson decays in the rapidity range 0.006 to 0.34 at Q{sup 2,rox}M{sup n 2,sub W}.
Abstract: We describe a measurement of the charge asymmetry of leptons from W -boson decays in the rapidity range 0{lt}{vert_bar}y{sub l}{vert_bar}{lt}2.5 using W{r_arrow}e{nu},thinsp{mu}{nu} events from 110{plus_minus}7 pb{sup {minus}1} of data collected by the CDF detector during 1992{endash}1995. The asymmetry data constrain the ratio of d and u quark momentum distributions in the proton over the x range of 0.006 to 0.34 at Q{sup 2}{approx}M{sup 2}{sub W} . The asymmetry predictions that use parton distribution functions obtained from previously published CDF data in the central rapidity region (0.0{lt}{vert_bar}y{sub l}{vert_bar}{lt}1.1 ) do not agree with the new data in the large rapidity region ({vert_bar}y{sub l}{vert_bar}{gt}1.1 ). {copyright} {ital 1998} {ital The American Physical Society}
77 citations
TL;DR: In this paper, the authors report on the most recent measurements of the top quark mass, performed by the CDF and D0 collaborations at the Fermilab Tevatron.
Abstract: The first evidence and subsequent discovery of the top quark was reported nearly 4 years ago. Since then, CDF and D0 have analyzed their full Run 1 data samples, and analysis techniques have been refined to make optimal use of the information. In this paper, we report on the most recent measurements of the top quark mass, performed by the CDF and D0 collaborations at the Fermilab Tevatron. The CDF collaboration has performed measurements of the top quark mass in three decay channels from which the top quark mass is measured to be 175.5 {+-} 6.9 GeV=c{sup 2}. The D0 collaboration combines measurements from two decay channels to obtain a top quark mass of 172.1 {+-} 7.1 GeV/c{sup 2}. Combining the measurements from the two experiments, assuming a 2 GeV GeV/c{sup 2} correlated systematic uncertainty, the measurement of the top quark mass at the Tevatron is 173.9 {+-} 5.2 GeV/c{sup 2}. This report presents the measurements of the top quark mass from each of the decay channels which contribute to this measurement.
68 citations
TL;DR: Measurements show that single event transient cross sections and transient propagation varies with circuit filtering, and the idea that two mechanisms exist for inducing transients on the optocoupler output is discussed.
Abstract: Radiation-induced permanent degradation and single event transient effects for optocouplers are discussed in this paper. These two effects are independent to the first order and will be addressed separately. Displacement damage-induced degradation of optocoupler current transfer ratio is reviewed. New data are presented that show the importance of application specific testing and that generalized quantification of optocoupler CTR degradation can lead to incorrect predictions of actual circuit performance in a radiation environment. Data are given for various circuit loading and drive current parameters. Previous work that introduces the idea that two mechanisms exist for inducing transients on the optocoupler output is discussed. New data are presented that extends the evidence of this dual mechanism hypothesis. In this work measurements show that single event transient cross sections and transient propagation varies with circuit filtering. Finally, we discuss utilization of the optocouplers in the space environment. New data are applied to two examples: one on permanent degradation and the other on single event transient rates in high bandwidth applications.
59 citations
TL;DR: In this article, the W boson mass was measured using data collected with the CDF detector during the 1994-1995 collider run at the Fermilab Tevatron, and a fit to the transverse mass spectrum of a sample of 30115 W --> ev events recorded in an integrated luminosity of 84 pb(-1) gave a mass M-W=80.473 +/- 0.100(stat)+/-0.103(syst) Ge V/c(2).
Abstract: We present a measurement of the W boson mass using data collected with the CDF detector during the 1994-1995 collider run at the Fermilab Tevatron. A fit to the transverse mass spectrum of a sample of 30115 W --> ev events recorded in an integrated luminosity of 84 pb(-1) gives a mass M-W=80.473 +/-0.065(stat) +/-0.092(syst) GeV/c(2). A fit to the transverse mass spectrum of a sample of 14740 W --> muv events from 80 pb(-1) gives a mass M-W=80,465 +/-0.100(stat)+/-0.103(syst) Ge V/c(2) The dominant contributions to the systematic uncertainties are the uncertainties in the electron energy scale and the muon momentum scale, 0.075 GeV/c(2) and 0.085 GeV/c(2), respectively. The combined value for the electron and muon channel is M-W=80.470 +/-0.089-GeV/c(2). When combined with previously published CDF measurements, we obtain M-W=80.433 +/-0.079 GeV/c(2).
TL;DR: In this paper, the authors present an analysis of dilepton events originating from $t\overline{t}$ production in $p/overline p$ collisions at the Fermilab Tevatron Collider.
Abstract: We present an analysis of dilepton events originating from $t\overline{t}$ production in $p\overline{p}$ collisions at $\sqrt{s}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1.8\phantom{\rule{0ex}{0ex}}\mathrm{TeV}$ at the Fermilab Tevatron Collider. The sample corresponds to an integrated luminosity of $109\ifmmode\pm\else\textpm\fi{}7{\mathrm{pb}}^{\ensuremath{-}1}$. We observe nine candidate events, with an estimated background of $2.4\ifmmode\pm\else\textpm\fi{}0.5$ events. We determine the mass of the top quark to be ${M}_{\mathrm{top}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}161\ifmmode\pm\else\textpm\fi{}17(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}10(\mathrm{syst})\phantom{\rule{0ex}{0ex}}\mathrm{GeV}{/c}^{2}$. In addition, we measure a $t\overline{t}$ production cross section of ${8.2}_{\ensuremath{-}3.4}^{+4.4}\phantom{\rule{0ex}{0ex}}\mathrm{pb}$ (where ${M}_{\mathrm{top}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}175\phantom{\rule{0ex}{0ex}}\mathrm{GeV}{/c}^{2}$ has been assumed for the acceptance estimate).
TL;DR: In this paper, the magnetic moments of baryons were studied within the chiral quark soliton model with special emphasis on the decuplet of the baryon.
Abstract: Magnetic moments of baryons are studied within the chiral quark soliton model with special emphasis on the decuplet of baryons. The model is used to identify all symmetry breaking terms proportional to $m_{\rm s}$. Sum rules for the magnetic moments are derived. A ``model-independent'' analysis of the symmetry breaking terms is performed and finally model calculations are presented, which show the importance of the rotational $1/N_{\rm c}$ corrections for cranking of the soliton.
TL;DR: In this paper, the authors present a search for the flavor-changing neutral current decays B{sub d{sup 0}{yields}{mu}{sup +}{mu-sup +} and B {sub s}{sup 0} in p{ovr p} collisions at sqrt[s] = 1.8 TeV, using 98 pp{sup -1} of data collected at the Collider Detector at Fermilab.
Abstract: We present a search for the flavor-changing neutral current decays B{sub d}{sup 0}{yields}{mu}{sup +}{mu}{sup -} and B{sub s}{sup 0}{yields}{mu}{sup +}{mu}{sup -} in p{ovr p} collisions at sqrt[s] = 1.8 TeV, using 98 pp{sup -1} of data collected at the Collider Detector at Fermilab. We find one candidate event for these decays, which is consistent with the background estimates, and set upper limits on the branching fractions of B(B{sub d}{sup 0}{yields}{mu}{sup +}{mu}{sup -})<8.6 x 10{sup -7} and B(B{sub s}{sup 0}{yields}{mu}{sup +}{mu}{sup -}) < 2.6 x 10{sup -6} at 95% confidence level.
TL;DR: In this article, a simple Disoriented Chiral Condensates (DCC) model was used to measure charged and photon multiplicities in the central region of 158 AGeV Pb+Pb collisions at the CERN SPS.
TL;DR: In this article, a self-tagged sample of partially reconstructed $B$ mesons decaying into a lepton and a charmed meson collected in $p\overline{p}$ collisions was used to detect the correlation between the flavor of mesons and the charge of a nearby particle.
Abstract: ${B}_{d}^{0}\ensuremath{-}{B}_{d}^{0}$ oscillations are observed in ``self-tagged'' samples of partially reconstructed $B$ mesons decaying into a lepton and a charmed meson collected in $p\overline{p}$ collisions at $\sqrt{s}=18\mathrm{TeV}$ A flavor tagging technique is employed which relies upon the correlation between the flavor of $B$ mesons and the charge of a nearby particle We measure the flavor oscillation frequency to be $\ensuremath{\Delta}{m}_{d}{=0471}_{\ensuremath{-}0068}^{+0078}\ifmmode\pm\else\textpm\fi{}0034{\mathrm{ps}}^{\mathrm{\ensuremath{-}}1}$ The tagging method is also demonstrated in exclusive samples of ${B}_{u}^{+}\ensuremath{\rightarrow}J/\ensuremath{\psi}{K}^{+}$ and ${B}_{d}^{0}\ensuremath{\rightarrow}J/\ensuremath{\psi}{K}^{*0}(892),$ where similar flavor-charge correlations are observed The tagging characteristics of the various samples are compared with each other, and with Monte Carlo simulations
TL;DR: In this article, the centrality dependence of the neutral pion spectral shape and yield was investigated in the WA98 experiment at the CERN Super Proton Synchrotron (SPS).
Abstract: The production of neutral pions in 158A GeV {sup 208}Pb+ {sup 208}Pb collisions has been studied in the WA98 experiment at the CERN Super Proton Synchrotron (SPS). Transverse momentum spectra are studied for the range 0.3{le}m{sub T}{minus}m{sub 0}{le}4.0 GeV /c . The results for central collisions are compared to various models. The centrality dependence of the neutral pion spectral shape and yield is investigated. An invariance of the spectral shape and a simple scaling of the yield with the number of participating nucleons is observed for centralities with greater than about 30thinspthinspparticipating nucleons. This is most naturally explained by assuming an equilibrated system. {copyright} {ital 1998} {ital The American Physical Society }
01 Oct 1998
TL;DR: Ground test and space flight data is presented describing a single event anomaly that affects multiple bytes in a stacked DRAM module that experiences the anomalies at a rate requiring testing of a large sample set of these modules.
Abstract: We present ground test and space flight data describing a single event anomaly that affects multiple bytes in a stacked DRAM module. A 12 Gbit solid state recorder containing 1,440 DRAM die experiences the anomalous events at a rate requiring testing of a large sample set of these modules.
TL;DR: In this article, a measurement of the B{sup 0} oscillation frequency using a flavor tagging method based on correlations of B meson flavor with the charge of other particles produced in p{ovr p} collisions at sqrt[s] = 1.8 TeV is presented.
Abstract: We present a measurement of the B{sup 0}{leftrightarrow}{ovr B}{sup 0} 0 oscillation frequency using a flavor tagging method based on correlations of B meson flavor with the charge of other particles produced in p{ovr p} collisions at sqrt[s] = 1.8 TeV. Such correlations are expected to arise from b quark hadronization and from B** decays. We partially reconstruct B mesons using the semileptonic decays B{sup 0}{yields}l{sup +}D{sup (*)-}X and B{sup +}{yields}l{sup +}{ovr D}{sup 0}X. From the oscillation frequency, we obtain the mass difference between the two B{sup 0} mass eigenstates, {Delta}m{sub d} = 0.471{sub -0.068}{sup +0.078}(stat){+-}0.034(syst){Dirac_h} ps{sup -1}, and measure the efficiency and purity of this flavor tagging method for both charged and neutral B mesons.
TL;DR: In this paper, the authors measured the t (t) over bar production cross section in p (p)-over bar collisions at root s = 1.96 TeV in the lepton + jets channel, assuming the current world average m(t) = 172.6 GeV.
Abstract: We measure the t (t) over bar production cross section in p (p) over bar collisions at root s = 1.96 TeV in the lepton + jets channel. Two complementary methods discriminate between signal and background: b tagging and a kinematic likelihood discriminant. Based on 0.9 fb(-1) of data collected by the D0 detector at the Fermilab Tevatron Collider, we measure sigma(t (t) over bar) = 7.62 +/- 0.85 pb, assuming the current world average m(t) = 172.6 GeV. We compare our cross section measurement with theory predictions to determine a value for the top-quark mass of 170 +/- 7 GeV.
TL;DR: In this article, the authors search for anomalous production of missing E{sub T} (E{ sub T}), jets, leptons (e,mu,{tau}), b quarks, or additional photons in events containing two isolated, central (|{eta| 12 GeV).
Abstract: We have searched for anomalous production of missing E{sub T} (E{sub T}), jets, leptons (e,{mu},{tau}), b quarks, or additional photons in events containing two isolated, central (|{eta}| 12 GeV. The results are consistent with standard model expectations, with the possible exception of one event that has in addition to the two photons a central electron, a high-E{sub T} electromagnetic cluster, and large E{sub T}. We set limits using two specific supersymmetry scenarios for production of diphoton events with E{sub T}.
TL;DR: In this paper, a measurement of the time-dependent asymmetry in the rate for {ovr B} versus B{sub d} decays to J/{psi}K{sub s}{sup 0}.
Abstract: We present a measurement of the time-dependent asymmetry in the rate for {ovr B}{sub d}{sup 0} versus B{sub d}{sup 0} decays to J/{psi}K{sub s}{sup 0}. A nonzero asymmetry would be an indication of CP violation, and within the standard model this may be used to measure the CP-violation parameter sin(2{beta}). A total of 198{+-}17 B{sub d}{sup 0}/{ovr B}{sub d}{sup 0} decays were observed in p{ovr p} collisions at sqrt[s] = 1.8 TeV by the CDF detector at the Fermilab Tevatron. B{sub d}{sup 0} and {ovr B}{sub d}{sup 0} are distinguished by a technique based on charge correlations from hadronization of the b quark. Our analysis results in sin(2{beta}) = 1.8{+-}1.1(stat){+-}0.3(syst).
TL;DR: In this article, it was shown that trilepton events from chargino-neutralino ( (+/-)(1) (0)(2) pair production, with subsequent decay into leptons, do not exist in the standard model.
Abstract: We have searched in p (p) over bar collisions at root s = 1.8 TeV for events with three charged leptons and missing transverse energy. In the minimal supersymmetric standard model, we expect trilepton events from chargino-neutralino ( (+/-)(1) (0)(2) pair production, with subsequent decay into leptons. We observe no candidate e(+)e(-)e(+/-), e(+)e(-)mu(+/-), e(+/-)mu(+)mu(-), or mu(+)mu(-)mu(+/-) events in 106 pb(-1) integrated luminosity. We present limits on the sum of the branching ratios times cross section for the four channels: sigma( 1)(+/-)( 2)B-0( (+/-)(1) (0)(2) --> 3l + X) 1)(+/-) > 81.5 GeV/c(2), and M( 2)(0) > 82.2 GeV/c(2) for tan beta = 2, mu = -600 GeV/c(2), and M-(q over tilde) = M-(g over tilde).
TL;DR: The average bottom-hadron and individual B{sup +, B{sub s} meson lifetimes have been determined using decays with a J/{psi}{r_arrow}+X in the final state as mentioned in this paper.
Abstract: The average bottom-hadron and individual B{sup +}, B{sup 0}, and B{sub s}{sup 0} meson lifetimes have been determined using decays with a J/{psi}{r_arrow}{mu}{sup +}{mu}{sup {minus}} in the final state. The data sample consists of 110 pb{sup {minus}1} of {bar p}p collisions at {radical} (s) =1.8 TeV collected by the CDF detector at the Fermilab Tevatron collider during 1992{endash}1995. For the average lifetime of B hadrons decaying into J/{psi}+X, we obtain {l_angle}{tau}{sub b}{r_angle}=1.533{plus_minus}0.015(stat){sub {minus}0.031}{sup +0.035}(syst)ps. For the B{sup +} and B{sup 0} meson lifetimes, we determine {tau}(B{sup +})=1.68{plus_minus}0.07(stat){plus_minus}0.02(syst)ps, {tau}(B{sup 0})=1.58{plus_minus}0.09(stat){plus_minus}0.02(syst)ps, and {tau}(B{sup +})/{tau}(B{sup 0})=1.06{plus_minus}0.07(stat){plus_minus}0.02(syst). For the B{sub s}{sup 0} meson lifetime, we find {tau}(B{sub s}{sup 0})=1.34{sub {minus}0.19}{sup +0.23}(stat){plus_minus}0.05(syst) ps. {copyright} {ital 1998} {ital The American Physical Society}
TL;DR: In this paper, the authors used the chiral quark-soliton model to identify all symmetry breaking terms linear in $m s and investigate the strange magnetic moment in a ''model-independent'' way.
Abstract: We use the chiral quark-soliton model to identify all symmetry breaking terms linear in $m_{s}$ and investigate the strange magnetic moment in a ``model-independent'' way. Assuming hedgehog symmetry and employing the collective quantization, we obtain the most general expression for the flavor-singlet and flavor-octet magnetic moments in terms of seven independent parameters. Having fitted these parameters to the experimental magnetic moments of the octet baryons, we show that the strange magnetic moment turns out to be positive. The best fit obtained by minimizing $\chi^2$ assuming 15% theoretical accuracy yields: $\mu^{({\rm s})}_{N} = (0.41 \pm 0.18) \mu_{N}$.
University of Naples Federico II1, Sapienza University of Rome2, University of Basilicata3, University of Pisa4, California Institute of Technology5, University of Bari6, University of Salento7, University of Turin8, Indiana University9, University of Bologna10, University of Michigan11, Pennsylvania State University12, University of L'Aquila13, Roma Tre University14, University of Trieste15, Boston University16, Drexel University17, Swarthmore College18, Pakistan Institute of Nuclear Science and Technology19, Scuola Normale Superiore di Pisa20, Texas A&M University21
TL;DR: In this paper, the shadow of the Moon in the underground cosmic ray flux with a significance of 3.6σ was detected by an underground detector, which is the first detection of the shadowing effect by a muon telescope.
Abstract: Using data collected by the MACRO experiment during the years 1989--1996, we show evidence for the shadow of the Moon in the underground cosmic ray flux with a significance of 3.6\ensuremath{\sigma}. This detection of the shadowing effect is the first by an underground detector. A maximum-likelihood analysis is used to determine that the angular resolution of the apparatus is $0.9\ifmmode^\circ\else\textdegree\fi{}\ifmmode\pm\else\textpm\fi{}0.3\ifmmode^\circ\else\textdegree\fi{}.$ These results demonstrate MACRO's capabilities as a muon telescope by confirming its absolute pointing ability and quantifying its angular resolution.
TL;DR: In this paper, the authors search for new long-lived particles which decay to Z{sup 0} bosons by looking for Z {sup 0}{yields}e{sup +} e{sup -} decays with displaced vertices.
Abstract: We search for new long-lived particles which decay to Z{sup 0} bosons by looking for Z{sup 0}{yields}e{sup +}e{sup -} decays with displaced vertices. We find no evidence for parent particles of the Z{sup 0} with long lifetimes in 90 pb{sup -1} of data from the CDF experiment at Fermilab. We set a cross section limit as a function of the lifetime of the parent particle for both a generic Z{sup 0} parent and a fourth-generation, charge -1/3 quark that decays into Z{sup 0}b.
TL;DR: In this article, the authors investigated the baryon semileptonic decay constants (f{sub 1, f{sub 2, f {sub 2}/f {sub 1} and g{sub A}{sup (3)} in the chiral quark-soliton model and found that the value predicted by the present model naturally lies between the Skyrme model and that of the nonrelativistic quark model.
Abstract: Based on the recent study of the magnetic moments and axial-vector constants within the framework of the chiral quark-soliton model, we investigate the baryon semileptonic decay constants (f{sub 1},f{sub 2}) and (g{sub 1},g{sub 2}). Employing the relations between the diagonal transition matrix elements and off-diagonal ones in the vector and axial-vector channels, we obtain the ratios of baryon semileptonic decay constants f{sub 2}/f{sub 1} and g{sub 1}/f{sub 1}. The F/D ratio is also discussed and found that the value predicted by the present model naturally lies between that of the Skyrme model and that of the nonrelativistic quark model. The singlet axial-vector constant g{sub A}{sup (0)} can be expressed in terms of the F/D ratio and g{sub A}{sup (3)} in the present model and turns out to be small. The results are compared with available experimental data and found to be in good agreement with them. In addition, the induced pseudotensor coupling constants g{sub 2}/f{sub 1} are calculated, the SU(3) symmetry breaking being considered. The results indicate that the effect of SU(3) symmetry breaking might play an important role for some decay modes in hyperon semileptonic decay. {copyright} {ital 1997} {ital The American Physical Society}