Cynthia Mayumi | Pontificia Universidad Catolica del Peru (original) (raw)

Papers by Cynthia Mayumi

Research paper thumbnail of Search for electroweak single-top-quark production in p(p)over-bar collisions at root s=1.96 TeV

We report on a search for standard model t-channel and s-channel single-top quark production in p

Research paper thumbnail of Measurement of W gamma and Z gamma production in p(p)over-bar collisions at root s=1.96 TeV

The standard model predictions for W and Z production are tested using an integrated luminosity o... more The standard model predictions for W and Z production are tested using an integrated luminosity of 200 pb ÿ1 of p p collision data collected at the Collider Detector at Fermilab. The cross sections are measured by selecting leptonic decays of the W and Z bosons, and photons with transverse energy E T > 7 GeV that are well separated from leptons. The production cross sections and kinematic distributions for the W and Z data are compared to SM predictions.

Research paper thumbnail of Further search for the decay K+-->pi+nunu¯ in the momentum region P<195 MeV/c

Physical Review D, 2004

We report the results of a search for the decay K+→π+νν¯ in the kinematic region with π+ momentum... more We report the results of a search for the decay K+→π+νν¯ in the kinematic region with π+ momentum 140<P<195 MeV/c using the data collected by the E787 experiment at BNL. No events were observed. When combined with our previous search in this region, one candidate event with an expected background of 1.22±0.24 events results in a 90% C.L. upper limit of 2.2×10-9 on the branching ratio of K+→π+νν¯. We also report improved limits on the rates of K+→π+X0 and K+→π+X1X2 where X0,X1,X2 are hypothetical, massless, long-lived neutral particles.

Research paper thumbnail of Measurement of the W+W- production cross section in p(p)over-bar collisions at root s=1.96 TeV using dilepton events

Research paper thumbnail of Measurement of the J/psi meson and b-hadron production cross sections in p(p)over-bar collisions at root s=1960 GeV

We present a new measurement of the inclusive and differential production cross sections of J= me... more We present a new measurement of the inclusive and differential production cross sections of J= mesons and b hadrons in proton-antiproton collisions at s p 1960 GeV. The data correspond to an integrated luminosity of 39:7 pb ÿ1 collected by the CDF run II detector. We find the integrated cross section for inclusive J= production for all transverse momenta from 0 to 20 GeV=c in the rapidity range jyj < 0:6 to be 4:08 0:02stat 0:36 ÿ0:33 syst b. We separate the fraction of J= events from the decay of the long-lived b hadrons using the lifetime distribution in all events with p T J= > 1:25 GeV=c. We find the total cross section for b hadrons, including both hadrons and antihadrons, decaying to J= with transverse momenta greater than 1:25 GeV=c in the rapidity range jyJ= j < 0:6 is 0:330 0:005stat 0:036 ÿ0:033 syst b. Using a Monte Carlo simulation of the decay kinematics of b hadrons to all final states containing a J= , we extract the first measurement of the total single b-hadron cross section down to zero transverse momentum at s p 1960 GeV. We find the total single b-hadron cross section integrated over all transverse momenta for b hadrons in the rapidity range jyj < 0:6 to be 17:6 0:4stat 2:5 ÿ2:3 syst b.

Research paper thumbnail of Search for Bs(0)->mu(+)mu(-) and Bd(0)->mu(+)mu(-) decays in p(p)over-bar collisions at root s=1.96 TeV

Research paper thumbnail of Measurement of the forward-backward charge asymmetry of electron-positron pairs in (p)over-barp collisions at root s=1.96 TeV

We present the first measurement of the integrated forward-backward charge asymmetry in topantito... more We present the first measurement of the integrated forward-backward charge asymmetry in topantitop quark pair (tt) production in proton-antiproton (pp) collisions in the lepton+jets final state.

Research paper thumbnail of Measurement of the cross section for prompt diphoton production in p(p)over-bar collisions at root s=1.96 TeV

Research paper thumbnail of Further search for the decay K+→π+νν¯ in the momentum region P195 MeV/c

Research paper thumbnail of Search for the decay ? in the momentum region Pπ<195 MeV/c

Physics Letters B, 2002

We have searched for the decay K+→π+νν̄ in the kinematic region with pion momentum below the K+→π... more We have searched for the decay K+→π+νν̄ in the kinematic region with pion momentum below the K+→π+π0 peak. One event was observed, consistent with the background estimate of 0.73±0.18. This implies an upper limit on B(K+→π+νν̄)&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;4.2×10−9 (90% C.L.), consistent with the recently measured branching ratio of 1.57+1.75−0.82×10−10, obtained using the standard model spectrum and the kinematic region above the K+→π+π0

Research paper thumbnail of Numerical analysis of a cylindrical thin-pillar transistor (CYNTHIA

IEEE Transactions on Electron Devices, 1992

The authors have analyzed the characteristics of a cylindrical thin-pillar transistor (CYNTHIA), ... more The authors have analyzed the characteristics of a cylindrical thin-pillar transistor (CYNTHIA), which is a vertical MOS transistor with a cylindrical gate electrode surrounding a submicrometer-diameter silicon pillar. The device characteristics are calculated by solving Poisson's equation in cylindrical coordinates. Results showed that CYNTHIA has three superior features: excellent subthreshold characteristics, enhanced electron mobility, and increased sheet electron concentration. These superior characteristics result in a feature size twice that of vertical SO1 transistors. Our calculation is that CYNTHIA is quite an attractive device design for future ultra-high-density LSI's.

Research paper thumbnail of Measurement of the t(t)over-bar production cross section in p(p)over-barcollisions at root s=1.96 TeV using kinematic fitting of b-tagged lepton plus jet events

We present a measurement of the t t production cross section using 194 pb ÿ1 of CDF II data using... more We present a measurement of the t t production cross section using 194 pb ÿ1 of CDF II data using events with a high transverse momentum electron or muon, three or more jets, and missing transverse energy. The measurement assumes 100% t ! Wb branching fraction. Events consistent with t t decay are found by identifying jets containing heavy-flavor semileptonic decays to muons. The dominant backgrounds are evaluated directly from the data. Based on 20 candidate events and an expected background of 9:5 1:1 events, we measure a production cross section of 5:3 3:3 1:3 ÿ1:0 pb, in agreement with the standard model.

Research paper thumbnail of Search for anomalous kinematics in t(t)over-bar Dilepton events at CDF II

Research paper thumbnail of Measurement of the t(t)over-bar production cross section in p(p)over-bar collisions at root s=1.96 TeV using dilepton events

We present a measurement of the t t production cross section using 194 pb ÿ1 of CDF II data using... more We present a measurement of the t t production cross section using 194 pb ÿ1 of CDF II data using events with a high transverse momentum electron or muon, three or more jets, and missing transverse energy. The measurement assumes 100% t ! Wb branching fraction. Events consistent with t t decay are found by identifying jets containing heavy-flavor semileptonic decays to muons. The dominant backgrounds are evaluated directly from the data. Based on 20 candidate events and an expected background of 9:5 1:1 events, we measure a production cross section of 5:3 3:3 1:3 ÿ1:0 pb, in agreement with the standard model.

Research paper thumbnail of Observation of the narrow state X(3872)-> J/psi pi(+)pi(-) in (p)over-barp collisions at root s=1.96 TeV

Research paper thumbnail of Measurement of prompt charm meson production cross sections in p(p)over-bar collisions at root s=1.96 TeV

Research paper thumbnail of Measurement of the forward-backward charge asymmetry from W -> ev production in p(p)over-bar collisions at root s=1.96 TeV

We present the first measurement of the integrated forward-backward charge asymmetry in topantito... more We present the first measurement of the integrated forward-backward charge asymmetry in topantitop quark pair (tt) production in proton-antiproton (pp) collisions in the lepton+jets final state.

Research paper thumbnail of Measurement of the mass difference m(Ds(+))-m(D+) at CDF II

We present a measurement of the mass difference m(D s ϩ )Ϫm(D ϩ ), where both the D s ϩ and D ϩ a... more We present a measurement of the mass difference m(D s ϩ )Ϫm(D ϩ ), where both the D s ϩ and D ϩ are reconstructed in the ϩ decay channel. This measurement uses 11.6 pb Ϫ1 of data collected by CDF II using the new displaced-track trigger. The mass difference is found to be m(D s ϩ )Ϫm(D ϩ )ϭ99.41Ϯ0.38(stat) Ϯ0.21(syst) MeV/c 2 .

Research paper thumbnail of Search for ZZ and ZW production in pp(-) collisions at root s=1.96 TeV

Research paper thumbnail of 19127-106814-1-PB

Research paper thumbnail of Search for electroweak single-top-quark production in p(p)over-bar collisions at root s=1.96 TeV

We report on a search for standard model t-channel and s-channel single-top quark production in p

Research paper thumbnail of Measurement of W gamma and Z gamma production in p(p)over-bar collisions at root s=1.96 TeV

The standard model predictions for W and Z production are tested using an integrated luminosity o... more The standard model predictions for W and Z production are tested using an integrated luminosity of 200 pb ÿ1 of p p collision data collected at the Collider Detector at Fermilab. The cross sections are measured by selecting leptonic decays of the W and Z bosons, and photons with transverse energy E T > 7 GeV that are well separated from leptons. The production cross sections and kinematic distributions for the W and Z data are compared to SM predictions.

Research paper thumbnail of Further search for the decay K+-->pi+nunu¯ in the momentum region P<195 MeV/c

Physical Review D, 2004

We report the results of a search for the decay K+→π+νν¯ in the kinematic region with π+ momentum... more We report the results of a search for the decay K+→π+νν¯ in the kinematic region with π+ momentum 140<P<195 MeV/c using the data collected by the E787 experiment at BNL. No events were observed. When combined with our previous search in this region, one candidate event with an expected background of 1.22±0.24 events results in a 90% C.L. upper limit of 2.2×10-9 on the branching ratio of K+→π+νν¯. We also report improved limits on the rates of K+→π+X0 and K+→π+X1X2 where X0,X1,X2 are hypothetical, massless, long-lived neutral particles.

Research paper thumbnail of Measurement of the W+W- production cross section in p(p)over-bar collisions at root s=1.96 TeV using dilepton events

Research paper thumbnail of Measurement of the J/psi meson and b-hadron production cross sections in p(p)over-bar collisions at root s=1960 GeV

We present a new measurement of the inclusive and differential production cross sections of J= me... more We present a new measurement of the inclusive and differential production cross sections of J= mesons and b hadrons in proton-antiproton collisions at s p 1960 GeV. The data correspond to an integrated luminosity of 39:7 pb ÿ1 collected by the CDF run II detector. We find the integrated cross section for inclusive J= production for all transverse momenta from 0 to 20 GeV=c in the rapidity range jyj < 0:6 to be 4:08 0:02stat 0:36 ÿ0:33 syst b. We separate the fraction of J= events from the decay of the long-lived b hadrons using the lifetime distribution in all events with p T J= > 1:25 GeV=c. We find the total cross section for b hadrons, including both hadrons and antihadrons, decaying to J= with transverse momenta greater than 1:25 GeV=c in the rapidity range jyJ= j < 0:6 is 0:330 0:005stat 0:036 ÿ0:033 syst b. Using a Monte Carlo simulation of the decay kinematics of b hadrons to all final states containing a J= , we extract the first measurement of the total single b-hadron cross section down to zero transverse momentum at s p 1960 GeV. We find the total single b-hadron cross section integrated over all transverse momenta for b hadrons in the rapidity range jyj < 0:6 to be 17:6 0:4stat 2:5 ÿ2:3 syst b.

Research paper thumbnail of Search for Bs(0)->mu(+)mu(-) and Bd(0)->mu(+)mu(-) decays in p(p)over-bar collisions at root s=1.96 TeV

Research paper thumbnail of Measurement of the forward-backward charge asymmetry of electron-positron pairs in (p)over-barp collisions at root s=1.96 TeV

We present the first measurement of the integrated forward-backward charge asymmetry in topantito... more We present the first measurement of the integrated forward-backward charge asymmetry in topantitop quark pair (tt) production in proton-antiproton (pp) collisions in the lepton+jets final state.

Research paper thumbnail of Measurement of the cross section for prompt diphoton production in p(p)over-bar collisions at root s=1.96 TeV

Research paper thumbnail of Further search for the decay K+→π+νν¯ in the momentum region P195 MeV/c

Research paper thumbnail of Search for the decay ? in the momentum region Pπ<195 MeV/c

Physics Letters B, 2002

We have searched for the decay K+→π+νν̄ in the kinematic region with pion momentum below the K+→π... more We have searched for the decay K+→π+νν̄ in the kinematic region with pion momentum below the K+→π+π0 peak. One event was observed, consistent with the background estimate of 0.73±0.18. This implies an upper limit on B(K+→π+νν̄)&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;4.2×10−9 (90% C.L.), consistent with the recently measured branching ratio of 1.57+1.75−0.82×10−10, obtained using the standard model spectrum and the kinematic region above the K+→π+π0

Research paper thumbnail of Numerical analysis of a cylindrical thin-pillar transistor (CYNTHIA

IEEE Transactions on Electron Devices, 1992

The authors have analyzed the characteristics of a cylindrical thin-pillar transistor (CYNTHIA), ... more The authors have analyzed the characteristics of a cylindrical thin-pillar transistor (CYNTHIA), which is a vertical MOS transistor with a cylindrical gate electrode surrounding a submicrometer-diameter silicon pillar. The device characteristics are calculated by solving Poisson's equation in cylindrical coordinates. Results showed that CYNTHIA has three superior features: excellent subthreshold characteristics, enhanced electron mobility, and increased sheet electron concentration. These superior characteristics result in a feature size twice that of vertical SO1 transistors. Our calculation is that CYNTHIA is quite an attractive device design for future ultra-high-density LSI's.

Research paper thumbnail of Measurement of the t(t)over-bar production cross section in p(p)over-barcollisions at root s=1.96 TeV using kinematic fitting of b-tagged lepton plus jet events

We present a measurement of the t t production cross section using 194 pb ÿ1 of CDF II data using... more We present a measurement of the t t production cross section using 194 pb ÿ1 of CDF II data using events with a high transverse momentum electron or muon, three or more jets, and missing transverse energy. The measurement assumes 100% t ! Wb branching fraction. Events consistent with t t decay are found by identifying jets containing heavy-flavor semileptonic decays to muons. The dominant backgrounds are evaluated directly from the data. Based on 20 candidate events and an expected background of 9:5 1:1 events, we measure a production cross section of 5:3 3:3 1:3 ÿ1:0 pb, in agreement with the standard model.

Research paper thumbnail of Search for anomalous kinematics in t(t)over-bar Dilepton events at CDF II

Research paper thumbnail of Measurement of the t(t)over-bar production cross section in p(p)over-bar collisions at root s=1.96 TeV using dilepton events

We present a measurement of the t t production cross section using 194 pb ÿ1 of CDF II data using... more We present a measurement of the t t production cross section using 194 pb ÿ1 of CDF II data using events with a high transverse momentum electron or muon, three or more jets, and missing transverse energy. The measurement assumes 100% t ! Wb branching fraction. Events consistent with t t decay are found by identifying jets containing heavy-flavor semileptonic decays to muons. The dominant backgrounds are evaluated directly from the data. Based on 20 candidate events and an expected background of 9:5 1:1 events, we measure a production cross section of 5:3 3:3 1:3 ÿ1:0 pb, in agreement with the standard model.

Research paper thumbnail of Observation of the narrow state X(3872)-> J/psi pi(+)pi(-) in (p)over-barp collisions at root s=1.96 TeV

Research paper thumbnail of Measurement of prompt charm meson production cross sections in p(p)over-bar collisions at root s=1.96 TeV

Research paper thumbnail of Measurement of the forward-backward charge asymmetry from W -> ev production in p(p)over-bar collisions at root s=1.96 TeV

We present the first measurement of the integrated forward-backward charge asymmetry in topantito... more We present the first measurement of the integrated forward-backward charge asymmetry in topantitop quark pair (tt) production in proton-antiproton (pp) collisions in the lepton+jets final state.

Research paper thumbnail of Measurement of the mass difference m(Ds(+))-m(D+) at CDF II

We present a measurement of the mass difference m(D s ϩ )Ϫm(D ϩ ), where both the D s ϩ and D ϩ a... more We present a measurement of the mass difference m(D s ϩ )Ϫm(D ϩ ), where both the D s ϩ and D ϩ are reconstructed in the ϩ decay channel. This measurement uses 11.6 pb Ϫ1 of data collected by CDF II using the new displaced-track trigger. The mass difference is found to be m(D s ϩ )Ϫm(D ϩ )ϭ99.41Ϯ0.38(stat) Ϯ0.21(syst) MeV/c 2 .

Research paper thumbnail of Search for ZZ and ZW production in pp(-) collisions at root s=1.96 TeV

Research paper thumbnail of 19127-106814-1-PB