Showing papers by "Hyun-Chul Kim published in 2009"
TL;DR: In this paper, the production of mesons containing strange quarks (KS, φ) and both singly and doubly strange baryons (,, and − + +) are measured at mid-rapidity in pp collisions at √ s = 0.9 TeV with the ALICE experiment at the LHC.
1,176 citations
TL;DR: In this article, the authors measured the gamma gamma* > pi0 transition form factor in the momentum transfer range from 4 to 40 GeV^2 with the BABAR detector at e+e-center-of-mass energies near 10.6 GeV.
Abstract: We study the reaction e+e- --> e+e-pi0 and measure the gamma gamma* --> pi0 transition form factor in the momentum transfer range from 4 to 40 GeV^2. The analysis is based on 442 fb^-1 of integrated luminosity collected at PEP-II with the BABAR detector at e+e- center-of-mass energies near 10.6 GeV.
297 citations
TL;DR: In this paper, the authors report the observation of single top-quark production using 3.2 fb{sup -1} of pp collision data with sq root(s)=1.96 TeV collected by the Collider Detector at Fermilab.
Abstract: We report the observation of single top-quark production using 3.2 fb{sup -1} of pp collision data with sq root(s)=1.96 TeV collected by the Collider Detector at Fermilab. The significance of the observed data is 5.0 standard deviations, and the expected sensitivity for standard model production and decay is in excess of 5.9 standard deviations. Assuming m{sub t}=175 GeV/c{sup 2}, we measure a cross section of 2.3{sub -0.5}{sup +0.6}(stat+syst) pb, extract the CKM matrix-element value |V{sub tb}|=0.91+-0.11(stat+syst)+-0.07(theory), and set the limit |V{sub tb}|>0.71 at the 95% C.L.
289 citations
TL;DR: In this paper, a precise measurement of the cross section for the process e^+e^- → K^+K^-(γ) from threshold to an energy of 5 GeV is obtained with the initial-state radiation (ISR) method using 232 fb^(-1) of data collected with the BABAR detector at energies near 10.6 GeV.
Abstract: A precise measurement of the cross section for the process e^+e^- → K^+K^-(γ) from threshold to an energy of 5 GeV is obtained with the initial-state radiation (ISR) method using 232 fb^(-1) of data collected with the BABAR detector at e^+e^- center-of-mass energies near 10.6 GeV. The measurement uses the effective ISR luminosity determined from the e^+e^- → μ^+μ^-(γ)γ_(ISR) process with the same data set. The corresponding lowest-order contribution to the hadronic vacuum polarization term in the muon magnetic anomaly is found to be a_μ^(KK,LO)=(22.93 ± 0.18_(stat) ± 0.22_(syst))×10^(-10). The charged kaon form factor is extracted and compared to previous results. Its magnitude at large energy significantly exceeds the asymptotic QCD prediction, while the measured slope is consistent with the prediction.
258 citations
TL;DR: In this paper, a search for new particles whose decays produce two jets (dijets) using proton-antiproton collision data corresponding to an integrated luminosity of 1.13 fb-1 collected with the CDF II detector is presented.
Abstract: We present a search for new particles whose decays produce two jets (dijets) using proton-antiproton collision data corresponding to an integrated luminosity of 1.13 fb-1 collected with the CDF II detector. The measured dijet mass spectrum is found to be consistent with next-to-leading-order perturbative QCD predictions, and no significant evidence of new particles is found. We set upper limits at the 95% confidence level on cross sections times the branching fraction for the production of new particles decaying into dijets with both jets having a rapidity magnitude |y| < 1. These limits are used to determine the mass exclusions for the excited quark, axigluon, flavor-universal coloron, E6 diquark, color-octet technirho, W', and Z'.
250 citations
TL;DR: In this paper, a narrow structure near the J/psi-phi threshold in exclusive B{sup +} {yields} J/{psi}{phi}K{sup+} decays produced in {bar p}p collisions at {radical}s = 1.96 TeV.
Abstract: Evidence is reported for a narrow structure near the J/{psi}{phi} threshold in exclusive B{sup +} {yields} J/{psi}{phi}K{sup +} decays produced in {bar p}p collisions at {radical}s = 1.96 TeV. A signal of 14 {+-} 5 events, with statistical significance in excess of 3.8 standard deviations, is observed in a data sample corresponding to an integrated luminosity of 2.7 fb{sup -1}, collected by the CDF II detector. The mass and natural width of the structure are measured to be 4143.0 {+-} 2.9(stat) {+-} 1.2(syst) MeV/c{sup 2} and 11.7{sub -5.0}{sup +8.3}(stat) {+-} 3.7(syst) MeV/c{sup 2}.
250 citations
TL;DR: In this article, the authors reviewed current technological developments in polarization engineering and the control of the quantum-confined Stark effect (QCSE) for InxGa1-xN-based quantum-well active regions, which are generally employed in visible LEDs for solid-state lighting applications.
Abstract: This paper reviews current technological developments in polarization engineering and the control of the quantum-confined Stark effect (QCSE) for InxGa1- xN-based quantum-well active regions, which are generally employed in visible LEDs for solid-state lighting applications. First, the origin of the QCSE in III-N wurtzite semiconductors is introduced, and polarization-induced internal fields are discussed in order to provide contextual background. Next, the optical and electrical properties of InxGa1- xN-based quantum wells that are affected by the QCSE are described. Finally, several methods for controlling the QCSE of InxGa1- xN-based quantum wells are discussed in the context of performance metrics of visible light emitters, considering both pros and cons. These strategies include doping control, strain/polarization field/electronic band structure control, growth direction control, and crystalline structure control.
246 citations
TL;DR: It is shown that supernumerary teeth can form from multiple regions of the jaw and that they are properly mineralized, vascularized, innervated and can start to form roots.
Abstract: The ablation of Apc function or the constitutive activation of β-catenin in embryonic mouse oral epithelium results in supernumerary tooth formation, but the underlying mechanisms and whether adult tissues retain this potential are unknown. Here we show that supernumerary teeth can form from multiple regions of the jaw and that they are properly mineralized, vascularized, innervated and can start to form roots. Even adult dental tissues can form new teeth in response to either epithelial Apc loss-of-function or β-catenin activation, and the effect of Apc deficiency is mediated by β-catenin. The formation of supernumerary teeth via Apc loss-of-function is non-cell-autonomous. A small number of Apc-deficient cells is sufficient to induce surrounding wild-type epithelial and mesenchymal cells to participate in the formation of new teeth. Strikingly, Msx1, which is necessary for endogenous tooth development, is dispensable for supernumerary tooth formation. In addition, we identify Fgf8, a known tooth initiation marker, as a direct target of Wnt/β-catenin signaling. These studies identify key mechanistic features responsible for supernumerary tooth formation.
200 citations
TL;DR: In this paper, the effect of Ta content on shape memory behavior of Ti-Ta alloys was investigated, and the shape memory effect was confirmed in Ti-(30-40)Ta alloy.
187 citations
TL;DR: In this paper, the authors search for evidence of a light scalar boson in the radiative decays of the 2S and 3S resonances and find no evidence for such processes in the mass range 0.212 and 9.3 GeV, respectively.
Abstract: We search for evidence of a light scalar boson in the radiative decays of the {Upsilon}(2S) and {Upsilon}(3S) resonances: {Upsilon}(2S, 3S) {yields} {gamma}A{sup 0}, A{sup 0} {yields} {mu}{sup +}{mu}{sup -}. Such a particle appears in extensions of the Standaard Model, where a light CP-odd Higgs boson naturally couples strongly to b-quarks. We find no evidence for such processes in the mass range 0.212 {<=} m{sub A{sup 0}} {<=} 9.3 GeV in the samples of 99 x 10{sup 6} {Upsilon}(2S) and 122 x 10{sup 6} {Upsilon}(3S) decays collected by the BABAR detector at the PEP-II B-factory and set stringent upper limits on the effective coupling of the b quark to the A{sup 0}. We also limit the dimuon branching fraction of the {eta}{sub b} meson: {Beta}({eta}{sub b} {yields} {mu}{sup +}{mu}{sup -}) < 0.9% at 90% confidence level.
154 citations
TL;DR: An upper limit is put on the cross section for Odderon exchange in exclusive J/psi production in hadron-hadron collisions and the continuum is consistent with QED.
Abstract: In CDF we have observed the reactions p + (p) over bar -> p + X + (p) over bar, with X being a centrally produced J/psi, psi(2S), or chi(c0), and gamma gamma -> mu(+)mu(-) in p (p) over bar collisions at root s = 1.96 TeV. The event signature requires two oppositely charged central muons, and either no other particles or one additional photon detected. Exclusive vector meson production is as expected for elastic photoproduction, gamma + p -> J/psi(psi(2S)) + p, observed here for the first time in hadron-hadron collisions. We also observe exclusive chi(c0) -> J/psi + gamma. The cross sections d sigma/dy vertical bar(y=0) for J/psi, psi(2S), and chi(c0) are 3.92 +/- 0: 25(stat) +/- 0.52(syst) nb, 0.53 +/- 0.09(stat) +/- 0.10(syst) nb, and 76 +/- 10(stat) +/- 10(syst) nb, respectively, and the continuum is consistent with QED. We put an upper limit on the cross section for Odderon exchange in exclusive J/psi production.
TL;DR: In this paper, the self-accommodation morphology of the α martensites in Ti-Nb shape memory alloys with Nb content ranging from 20 to 24 at% was investigated.
TL;DR: In this article, the authors investigated the modeling and simulation of EMB systems for hybrid electric vehicles (HEVs) and evaluated the control performance of the EMB system via the simulation of the regenerative braking of the HEV during various driving conditions.
Abstract: The regenerative braking system of the Hybrid Electric Vehicle (HEV) is a key technology that can improve fuel efficiency by 20∼50%, depending on motor size. In the regenerative braking system, the electronically controlled brake subsystem that directs the braking forces into four wheels independently is indispensable. This technology is currently found in the Electronic Stability Program (ESP) and in Vehicle Dynamic Control (VDC). As braking technologies progress toward brake-by-wire systems, the development of Electro-Mechanical Brake (EMB) systems will be very important in the improvement of both fuel consumption and vehicle safety. This paper investigates the modeling and simulation of EMB systems for HEVs. The HEV powertrain was modeled to include the internal combustion engine, electric motor, battery and transmission. The performance simulation for the regenerative braking system of the HEV was performed using MATLAB/Simulink. The control performance of the EMB system was evaluated via the simulation of the regenerative braking of the HEV during various driving conditions.
TL;DR: In this article, the effect of ternary alloying elements (X, V, Cr, Fe, Zr, Hf, Mo, Sn, Al) on the shape memory behavior of Ti-30Ta-X alloys was investigated.
TL;DR: In this article, the effect of cyclic deformation on superelasticity was investigated in a Ti-26 at.% Nb alloy with a constant maximum applied strain of 2.5% until the 500th cycle.
TL;DR: In this paper, the authors present a search for high-mass neutral resonances using dimuon data corresponding to an integrated luminosity of 2.3 fb$^{-1}$ collected in {$p\bar p$} collisions at {$\sqrt{s}$ = 1.96 TeV} by the Fermilab Tevatron.
Abstract: We present a search for high-mass neutral resonances using dimuon data corresponding to an integrated luminosity of 2.3 fb$^{-1}$ collected in {$p\bar p$} collisions at {$\sqrt{s}$ = 1.96 TeV} by the CDF II detector at the Fermilab Tevatron. No significant excess above the standard model expectation is observed in the dimuon invariant-mass spectrum. We set 95% confidence level upper limits on $\sigma \cdot BR (p \bar{p} \to X \to \mu \bar{\mu})$, where $X$ is a boson with spin 0, 1, or 2. Using these cross section limits, we determine lower mass limits on sneutrinos in R-parity-violating supersymmetric models, $Z'$ bosons, and Kaluza-Klein gravitons in the Randall-Sundrum model.
TL;DR: In this paper, the authors presented updated measurements of time-dependent CP asymmetries in fully reconstructed neutral B decays containing a charmonium meson using the BABAR detector at the PEP-II asymmetric energy e(+)e(-) storage rings operating at the SLAC National Accelerator Laboratory.
Abstract: We present updated measurements of time-dependent CP asymmetries in fully reconstructed neutral B decays containing a charmonium meson. The measurements reported here use a data sample of (465 +/- 5)x10(6) Upsilon(4S)-> B B decays collected with the BABAR detector at the PEP-II asymmetric energy e(+)e(-) storage rings operating at the SLAC National Accelerator Laboratory. The time-dependent CP asymmetry parameters measured from J psi K-S(0), J psi K-L(0), psi(2S)K-S(0), eta K-c(S)0, chi K-c1(S)0, and J/psi K-*(892)(0) decays are: C-f=0.024 +/- 0.020(stat)+/- 0.016(syst) and -eta S-f(f)=0.687 +/- 0.028(stat)+/- 0.012(syst).
TL;DR: In this article, a sample of 384 million BBbar events collected with the Babar detector at the PEP-II e+e- collider was used to study angular distributions in the rare decays B* l+l-, where l+ l- is either e+ e- or mu+mu-.
Abstract: We use a sample of 384 million BBbar events collected with the Babar detector at the PEP-II e+e- collider to study angular distributions in the rare decays B -> K* l+l-, where l+l- is either e+e- or mu+mu-. For low dilepton invariant masses, m(l+l-) 3.2$ GeV/c^2, we measure AFB=0.76 (+0.52,-0.32) +/- 0.07 FL=0.71 (+0.20,-0.22) +/- 0.04.
TL;DR: In this article, the authors measured branching fractions and integrated rate asymmetries for the rare decays B + K((*))l(+)l(-), where l(+) l(-) is either e(+)e(-) or mu(+)mu(-), using a sample of 384x10(6) BB events collected with the BABAR detector at the PEP-II e+e(+) collider.
Abstract: We measure branching fractions and integrated rate asymmetries for the rare decays B -> K((*))l(+)l(-), where l(+)l(-) is either e(+)e(-) or mu(+)mu(-), using a sample of 384x10(6) BB events collected with the BABAR detector at the PEP-II e(+)e(-) collider. We find no evidence for direct CP or lepton-flavor asymmetries. However, for dilepton masses below the J/psi resonance, we find evidence for unexpectedly large isospin asymmetries in both B -> Kl(+)l(-) and B -> K(*)l(+)l(-) which differ, respectively, by 3.2 sigma and 2.7 sigma, including systematic uncertainties, from the standard model expectations.
TL;DR: It is suggested that the inhibitory effects of ursolic acid, isolated from the roots of A. arguta, on obesity, might be attributable to the inhibition of lipid absorption through the inhibited of pancreatic lipase and by enhancing lipolysis in fat cells.
Abstract: The aim of this study was to investigate the anti-obestic effects of ursolic acid isolated from the roots of Actinidia arguta, as well as the mechanism of action of this compound. This was conducted by testing whether ursolic acid inhibited the elevation of the rat plasma triacylglycerol levels after oral administration of a lipid emulsion containing corn oil in rats. Ursolic acid prevented the elevation of plasma triacylglycerol levels 2 h after oral administration of the lipid emulsion at a dose of 100 mg/kg. Furthermore, ursolic acid inhibited phosphodiesterase activity in vitro with an IC50 of 51.21 μM and enhanced lipolysis in rat fat cells. We suggest that the inhibitory effects of ursolic acid, isolated from the roots of A. arguta, on obesity, might be attributable to the inhibition of lipid absorption through the inhibition of pancreatic lipase and by enhancing lipolysis in fat cells.
TL;DR: In this paper, a measurement of the t{bar t} differential cross section with respect to the tbar t invariant mass in p{bar p} collisions at {radical}s = 1.96 TeV using an integrated luminosity of 2.7 fb{sup -1}.
Abstract: We present a measurement of the t{bar t} differential cross section with respect to the t{bar t} invariant mass, d{sigma}/dM{sub t{bar t}}, in p{bar p} collisions at {radical}s = 1.96 TeV using an integrated luminosity of 2.7 fb{sup -1} collected by the CDF II experiment. The t{bar t} invariant mass spectrum is sensitive to a variety of exotic particles decaying into t{bar t} pairs. The result is consistent with the standard model expectation, as modeled by PYTHIA with CTEQ5L parton distribution functions.
TL;DR: A measurement of the top-quark mass M_{t} in the dilepton decay channel tt[over] --> bl;{'+} nu_{l};{'}b[over ]l;{-}nu[ over ]_{l}.
Abstract: We report a measurement of the top-quark mass M-t in the dilepton decay channel tt -> bl('+)nu(')(l)b1 nu(l). Events are selected with a neural network which has been directly optimized for statistical precision in top-quark mass using neuroevolution, a technique modeled on biological evolution. The top-quark mass is extracted from per-event probability densities that are formed by the convolution of leading order matrix elements and detector resolution functions. The joint probability is the product of the probability densities from 344 candidate events in 2.0 fb(-1) of pp collisions collected with the CDF II detector, yielding a measurement of M-t=171.2 +/- 2.7(stat)+/- 2.9(syst) GeV/c(2).
TL;DR: In this paper, the authors reported e;{+}e;{-}-->bb[over ] cross section measurements by the BABAR experiment performed during an energy scan in the range of 10.54 to 11.20 GeV at the SLAC PEP-II e,{+]e,{ -} collider.
Abstract: We report e;{+}e;{-}-->bb[over ] cross section measurements by the BABAR experiment performed during an energy scan in the range of 10.54 to 11.20 GeV at the SLAC PEP-II e;{+}e;{-} collider. A total relative error of about 5% is reached in more than 300 center-of-mass energy steps, separated by about 5 MeV. These measurements can be used to derive precise information on the parameters of the Upsilon(10860) and Upsilon(11020) resonances. In particular we show that their widths may be smaller than previously measured.
TL;DR: In this paper, a set of measurements of particle production in inelastic pbar{p} collisions collected with a minimum-bias trigger at the Tevatron Collider with the CDF II experiment is reported.
Abstract: We report a set of measurements of particle production in inelastic pbar{p} collisions collected with a minimum-bias trigger at the Tevatron Collider with the CDF II experiment. The inclusive charged particle transverse momentum differential cross section is measured, with improved precision, over a range about ten times wider than in previous measurements. The former modeling of the spectrum appears to be incompatible with the high particle momenta observed. The dependence of the charged particle transverse momentum on the event particle multiplicity is analyzed to study the various components of hadron interactions. This is one of the observable variables most poorly reproduced by the available Monte Carlo generators. A first measurement of the event transverse energy sum differential cross section is also reported. A comparison with a Pythia prediction at the hadron level is performed. The inclusive charged particle differential production cross section is fairly well reproduced only in the transverse momentum range available from previous measurements. At higher momentum the agreement is poor. The transverse energy sum is poorly reproduced over the whole spectrum. The dependence of the charged particle transverse momentum on the particle multiplicity needs the introduction of more sophisticated particle production mechanisms, such as multiple parton interactions, in order to be better explained.
TL;DR: A search for the eta_{b}(1S) meson in the radiative decay of the Upsilon(2S) resonance using a sample of 91.6x10(6) Upsilon-2S events recorded with the BABAR detector at the PEP-II B factory at the SLAC National Accelerator Laboratory is performed.
Abstract: We have performed a search for the eta_b(1S) meson in the radiative decay of the Upsilon(2S) resonance using a sample of 91.6 million Upsilon(2S) events recorded with the BABAR detector at the PEP-II B factory at the SLAC National Accelerator Laboratory. We observe a peak in the photon energy spectrum at E_gamma = 610.5 {+4.5} {-4.3} (stat) +/- 1.8 (syst) MeV, corresponding to an eta_b(1S) mass of 9392.9 {+4.6} {-4.8} (stat) +/- 1.9 (syst) MeV/c^2. The branching fraction for the decay Upsilon(2S) --> gamma eta_b(1S) is determined to be (4.2 {+1.1} {-1.0} (stat) +/- 0.9 (syst)) x 10^(-4). The ratio B(Upsilon(2S) --> gamma eta_b(1S))/B(Upsilon(3S) --> gamma eta_b(1S)) = 0.89 {+0.25} {-0.23} (stat) {+0.12}{-0.16} (syst) is consistent with the ratio expected for magnetic dipole transitions to the eta_b(1S) meson.
TL;DR: A search for the non-standard-model process u(c) + g --> t using pp[over ] collision data collected by the Collider Detector at Fermilab II detector yields no evidence for flavor-changing neutral current top-quark production.
Abstract: We report on the first search for top-quark production via flavor-changing neutral-current (FCNC) interactions in the non-standard-model process u(c)+g -> t using ppbar collision data collected by the CDF II detector. The data set corresponds to an integrated luminosity of 2.2/fb. The candidate events feature the signature of semileptonic top-quark decays and are classified as signal-like or background-like by an artificial neural network trained on simulated events. The observed discriminant distribution is in good agreement with the one predicted by the standard model and provides no evidence for FCNC top-quark production, resulting in a Bayesian upper limit on the production cross section sigma (u(c)+g -> t) u+g) c+g) < 5.7 x 10^{-3}.
TL;DR: In this article, the exclusive production of in initial-state-radiation events, from e(+)e(-) annihilations at a center-of-mass energy near 10.58 GeV, was performed to search for charmonium and possible new resonances.
Abstract: We perform a study of the exclusive production of in initial-state-radiation events, from e(+)e(-) annihilations at a center-of-mass energy near 10.58 GeV, to search for charmonium and possible new resonances. The data sample corresponds to an integrated luminosity of 384 fb(-1) and was recorded by the BABAR experiment at the PEP-II storage rings. The D (D) over bar, D*(D) over bar, D*(D) over bar* mass spectra show clear evidence of several psi resonances. However, there is no evidence for Y(4260) -> D*(D) over bar or Y(4260) -> D*(D) over bar*.
TL;DR: In this article, a search for exclusive Z boson production in proton-antiproton collisions at {radical}s = 1.96 TeV, using the CDF II detector at Fermilab was presented.
Abstract: We present a search for exclusive Z boson production in proton-antiproton collisions at {radical}s = 1.96 TeV, using the CDF II detector at Fermilab. We observe no exclusive Z {yields} {ell}{sup +}{ell}{sup -} candidates and place the first upper limit on the exclusive Z cross section in hadron collisions, {sigma}{sub excl}(Z) 40 GeV=c{sup 2} and |{eta}{sub {ell}}| < 4 to be {sigma} = 0.24{sub -0.10}{sup +0.13} pb, which is the first measurement for this mass range and is consistent with the standard model prediction.
TL;DR: In this paper, the authors reported the observation of the bottom, doublystrange baryon through the decay chain {Omega}{sub b}{sup -}, where J/{psi} {yields} {mu}{sup +} {m{m}k{m{k}k} + 0.13{sub -0.40}+ 0.27}(stat.) {+-} 0.02(syst.) ps.
Abstract: The authors report the observation of the bottom, doubly-strange baryon {Omega}{sub b}{sup -} through the decay chain {Omega}{sub b}{sup -} {yields} J/{psi}{Omega}{sup -}, where J/{psi} {yields} {mu}{sup +} {mu}{sup -}, {Omega}{sup -} {yields} {Lambda}K{sup -}, and {Lambda} {yields} p {pi}{sup -}, using 4.2 fb{sup -1} of data from p{bar p} collisions at {radical}s = 1.96 TeV, and recorded with the Collider Detector at Fermilab. A signal is observed whose probability of arising from a background fluctuation is 4.0 x 10{sup -8}, or 5.5 Gaussian standard deviations. The {Omega}{sub b}{sup -} mass is measured to be 6054.4 {+-} 6.8(stat.) {+-} 0.9(syst.) MeV/c{sup 2}. The lifetime of the {Omega}{sub b}{sup -} baryon is measured to be 1.13{sub -0.40}{sup +0.53}(stat.) {+-} 0.02(syst.) ps. In addition, for the {Xi}{sub b}{sup -} baryon they measure a mass of 5790.9 {+-} 2.6(stat.) {+-} 0.8(syst.) MeV/c{sup 2} and a lifetime of 1.56{sub -0.25}{sup +0.27}(stat.) {+-} 0.02(syst.) ps.
19 Apr 2009
TL;DR: This paper considers the use of Traffic Dispersion Graphs (TDGs) to classify network traffic and develops an application classification framework dubbed Graption (Graph-based classification), which provides a systematic way to harness the power of network-wide behavior, flow-level characteristics, and data mining techniques.
Abstract: Monitoring network traffic and classifying applications are essential functions for network administrators. In this paper, we consider the use of Traffic Dispersion Graphs (TDGs) to classify network traffic. Given a set of flows, a TDG is a graph with an edge between any two IP addresses that communicate; thus TDGs capture network-wide interactions. Using TDGs, we develop an application classification framework dubbed Graption (Graph-based classification). Our framework provides a systematic way to harness the power of network-wide behavior, flow-level characteristics, and data mining techniques. As a proof of concept, we instantiate our framework to detect P2P applications, and show that it can identify P2P traffic with recall and precision greater than 90% in backbone traces, which are particularly challenging for other methods.