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The K- pi+ S-wave from the D+ --> k- pi+ pi+ Decay

Description: Using data from FOCUS (E831) experiment at Fermilab, we present a model independent partial-wave analysis of the K{sup -}{pi}{sup +} S-wave amplitude from the decay D{sup +} {yields} K{sup -}{pi}{sup +}{pi}{sup +}. The S-wave is a generic complex function to be determined directly from the data fit. The P- and D-waves are parameterized by a sum of Breit-Wigner amplitudes. The measurement of the S-wave amplitude covers the whole elastic range of the K{sup -}{pi}{sup +} system.
Date: May 1, 2009
Creator: Link, J. M.; Yager, P. M.; /UC, Davis; Anjos, J. C.; Bediaga, I.; Castromonte, C. et al.
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The K- pi+ S-wave from the D+ --> K- pi+ pi+ Decay

Description: Using data from FOCUS (E831) experiment at Fermilab, we present a model independent partial-wave analysis of the K{sup -}{pi}{sup +} S-wave amplitude from the decay D{sup +} {yields} K{sup -}{pi}{sup +}{pi}{sup +}. The S-wave is a generic complex function to be determined directly from the data fit. The P- and D-waves are parameterized by a sum of Breit-Wigner amplitudes. The measurement of the S-wave amplitude covers the whole elastic range of the K{sup -}{sup +} system.
Date: May 1, 2009
Creator: Link, J. M.; Yager, P. M.; /UC, Davis; Anjos, J. C.; Bediaga, I.; Castromonte, C. et al.
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Dalitz plot analysis of the D+ ---> K- pi+ pi+ decay in the FOCUS experiment

Description: Using data collected by the high energy photoproduction experiment FOCUS at Fermilab we performed a Dalitz plot analysis of the Cabibbo favored decay D{sup +} {yields} K{sup -}{pi}{sup +}{pi}{sup +}. This study uses 53653 Dalitz-plot events with a signal fraction of {approx} 97%, and represents the highest statistics, most complete Dalitz plot analysis for this channel. Results are presented and discussed using two different formalisms. The first is a simple sum of Breit-Wigner functions with f… more
Date: May 1, 2007
Creator: Link, J. M.; Yager, P. M.; /UC, Davis; Anjos, J. C.; Bediaga, I.; Castromonte, C. et al.
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Study of the D0 ---> pi- pi+ pi- pi+ decay

Description: Using data from the FOCUS (E831) experiment at Fermilab, they present new measurements for the Cabbibo-suppressed decay mode D{sup 0} {yields} {pi}{sup -}{pi}{sup +}{pi}{sup -}{pi}{sup +}. They measure the branching ratio {Lambda}(D{sup 0} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -})/{Lambda}(D{sup 0} {yields} K{sup -} {pi}{sup +}{pi}{sup -}{pi}{sup +}) = 0.0914 {+-} 0.0018 {+-} 0.0022. An amplitude analysis has been performed, a first for this channel, in order to determine the reson… more
Date: January 1, 2007
Creator: Link, J. M.; Yager, P. M.; /UC, Davis; Anjos, J. C.; Bediaga, I.; Castromonte, C. et al.
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A Non-parametric approach to measuring the K- pi+ amplitudes in D+ ---> K- K+ pi+ decay

Description: Using a large sample of D{sup +} {yields} K{sup -}K{sup +}{pi}{sup +} decays collected by the FOCUS photoproduction experiment at Fermilab, we present the first non-parametric analysis of the K{sup -}{pi}{sup +} amplitudes in D{sup +} {yields} K{sup -}K{sup +}{pi}{sup +} decay. The technique is similar to the technique used for our non-parametric measurements of the D{sup +} {yields} {bar K}*{sup 0} e{sup +}{nu} form factors. Although these results are in rough agreement with those of E687, we … more
Date: December 1, 2006
Creator: Link, J. M.; Yager, P. M.; /UC, Davis; Anjos, J. C.; Bediaga, I.; Castromonte, C. et al.
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Anisotropy studies around the Galactic Centre at EeV energies with the Auger Observatory

Description: Data from the Pierre Auger Observatory are analyzed to search for anisotropies near the direction of the Galactic Centre at EeV energies. The exposure of the surface array in this part of the sky is already significantly larger than that of the fore-runner experiments. Our results do not support previous findings of localized excesses in the AGASA and SUGAR data. We set an upper bound on a point-like flux of cosmic rays arriving from the Galactic Centre which excludes several scenarios predicti… more
Date: July 1, 2006
Creator: Aglietta, M.; Aguirre, C.; Allard, D.; Allekotte, I.; Allison, P.; Alvarez, C. et al.
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An upper limit to the photon fraction in cosmic rays above 10**19-eV from the Pierre Auger Observatory

Description: An upper limit of 16% (at 95% c.l.) is derived for the photon fraction in cosmic rays with energies above 10{sup 19} eV, based on observations of the depth of shower maximum performed with the hybrid detector of the Pierre Auger Observatory. This is the first such limit on photons obtained by observing the fluorescence light profile of air showers. This upper limit confirms and improves on previous results from the Haverah Park and AGASA surface arrays. Additional data recorded with the Auger s… more
Date: June 1, 2006
Creator: Abraham, J.; Aglietta, M.; Aguirre, C.; Allard, D.; Allekotte, I.; Allison, P. et al.
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New measurement of BR(D+ ---> rho0 mu+ nu) / BR(D+ ---> anti-K*0 mu+ nu) branching ratio

Description: Using data collected by the FOCUS experiment at Fermilab, the authors present a new measurement of the charm semileptonic branching ratio BR(D{sup +} {yields} {rho}{sup 0}{mu}{sup +}{nu})/BR(D{sup +}{yields}{bar K}*{sup 0} {mu}{sup +}{nu}). From a sample of 320 {+-} 44 and 11,372 {+-} 161 D{sup +} {yields} {rho}{sup 0}{mu}{sup +}{nu} and D{sup +} {yields} K{sup -}{pi}{sup +}{mu}{sup +}{nu} events respectively, they find BR(D{sup +} {yields} {rho}{sup 0}{mu}{sup +}{nu})/BR(D{sup +}{yields}{bar K… more
Date: November 1, 2005
Creator: Link, J. M.; Yager, P. M.; Anjos, J. C.; Bediaga, I.; Castromonte, C.; Machado, A. A. et al.
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A Non-parametric approach to the D+ ---> anti-K*0 mu+ nu form-factors

Description: Using a large sample of D{sup +} {yields} K{sup -} {pi}{sup +} {mu}{sup +}{nu} decays collected by the FOCUS photo-production experiment at Fermilab, we present the first measurements of the helicity basis form factors free from the assumption of spectroscopic pole dominance. We also present the first information on the form factor that controls the s-wave interference discussed in a previous paper by the FOCUS collaboration. We find reasonable agreement with the usual assumption of spectroscop… more
Date: September 1, 2005
Creator: Link, J. M.; Yager, P. M.; /UC, Davis; Anjos, J. C.; Bediaga, I.; Castromonte, C. et al.
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Study of the decay asymmetry parameter and CP violation parameter in the Lambda(c)+ ---> Lambda pi+ decay

Description: Using data from the FOCUS (E831) experiment at Fermilab, we present a new measurement of the weak decay-asymmetry parameter a{sub {Lambda}{sub c}} in {Lambda}{sub c}{sup +} {yields} {Lambda}{pi}{sup +} decay. Comparing particle with antiparticle decays, we obtain the first measurement of the CP violation parameter {Alpha} {triple_bond} a{sub {Lambda}{sub c}} + a{sub {ovr {Lambda}{sub c}}}/a{sub {Lambda}{sub c}} - a{sub {ovr {Lambda}{sub c}}}. We obtain a{sub {Lambda}{sub c}} = -0.78 {+-} 0.16 {… more
Date: September 1, 2005
Creator: Link, J. M.; Yager, P. M.; /UC, Davis; Anjos, J. C.; Bediaga, I.; Castromonte, C. et al.
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Model independent measurement of S-wave K- pi+ systems using D+ ---> K pi pi decays from Fermilab E791

Description: A model-independent partial-wave analysis of the S-wave component of the K{pi} system from decays of D{sup +} mesons to the three-body K{sup -}{pi}{sup +}{pi}{sup +} final state is described. Data come from the Fermilab E791 experiment. Amplitude measurements are made independently for ranges of K{sup -}{pi}{sup +} invariant mass, and results are obtained below 825 MeV/c{sup 2}, where previous measurements exist only in two mass bins. This method of parametrizing a three-body decay amplitude re… more
Date: July 1, 2005
Creator: Aitala, E. M.; Amato, S.; Anjos, J. C.; Appel, J. A.; Ashery, D.; Banerjee, S. et al.
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Search for Lambda+(c) ---> p K+ pi- and D+(s) ---> K+ K+ pi- using genetic programming event selection

Description: The authors apply a genetic programming technique to search for the doubly Cabibbo suppressed decays {Lambda}{sub c}{sup +} {yields} pK{sup +} {pi}{sup -} and D{sub s}{sup +} {yields} K{sup +}K{sup +}{pi}{sup -}. They normalize these decays to their Cabibbo favored partners and find BR({Lambda}{sub c}{sup +} {yields} pK{sup +}{pi}{sup -})/BR({Lambda}{sub c}{sup +} {yields} pK{sup -}{pi}{sup +}) = (0.05 {+-} 0.26 {+-} 0.02)% and BR(D{sub s}{sup +} {yields} K{sup +}K{sup +}{pi}{sup -})/BR(D{sub s… more
Date: July 1, 2005
Creator: Link, J. M.; Yager, P. M.; Anjos, J. C.; Bediaga, I.; Castromonte, C.; Machado, A. A. et al.
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Search for a strongly decaying neutral charmed pentaquark

Description: We present a search for a charmed pentaquark decaying strongly to D{sup (*)}-p. Finding no evidence for such a state, we set limits on the cross section times branching ratio relative to D*{sup -} and D{sup -} under particular assumptions about the production mechanism.
Date: June 1, 2005
Creator: Link, J. M.; Yager, P. M.; /UC, Davis; Anjos, J. C.; Bediaga, I.; Castromonte, C. et al.
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Search for T violation in charm meson decays

Description: Using data from the FOCUS (E831) experiment, they have searched for T violation in charm meson decays using the four-body decay channels D{sup 0} {yields} K{sup -}K{sup +} {pi}{sup -}{pi}{sup +}, D{sup +} {yields} K{sub S}{sup 0}K{sup +}{pi}{sup -}{pi}{sup +}, and D{sub s}{sup +} {yields} K{sub S}{sup 0}K{sup +}{pi}{sup -}{pi}{sup +}. The T violation asymmetry is obtained using triple-product correlations and assuming the validity of the CPT theorem. They find the asymmetry values to be A{sub T… more
Date: June 1, 2005
Creator: Link, J. M.; Yager, P. M.; /UC, Davis; Anjos, J. C.; Bediaga, I.; Castromonte, C. et al.
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Study of Lambda+(c) Cabibbo favored decays containing a Lambda baryon in the final state

Description: Using data from the FOCUS experiment (FNAL-E831), they study the decay of {Lambda}{sub c}{sup +} baryons into final states contain a {Lambda} hyperon. The branching fractions of {Lambda}{sub c}{sup +} into {Lambda}{pi}{sup +}, {Lambda}{pi}{sup +}{pi}{sup +}{pi}{sup -} and {Lambda}{bar K}{sup 0}K{sup +} relative to that into pK{sup -} {pi}{sup +} are measured to be 0.217 {+-} 0.013 {+-} 0.020, 0.508 {+-} 0.024 {+-} 0.024 and 0.142 {+-} 0.018 {+-} 0.022, respectively. New measurements are also re… more
Date: May 1, 2005
Creator: Link, J. M.; Yager, P. M.; /UC, Davis; Anjos, J. C.; Bediaga, I.; Castromonte, C. et al.
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A Measurement of the D+(s) lifetime

Description: A high statistics measurement of the D{sub s}{sup +} lifetime from the Fermilab fixed-target FOCUS photoproduction experiment is presented. They describe the analysis of the two decay modes, D{sub s}{sup +} {yields} {phi}(1020){pi}{sup +} and D{sub s}{sup +} {yields} {bar K}*(892){sup 0}K{sup +}, used for the measurement. The measured lifetime is 507.4 {+-} 5.5(stat.) {+-} 5.1(syst.) is using 8961 {+-} 105 D{sub s}{sup +} {yields} {phi}(1020){pi}{sup +} and 4680 {+-} 90 D{sub s}{sup +} {yields}… more
Date: April 1, 2005
Creator: Link, J. M.; Yager, P. M.; /UC, Davis; Anjos, J. C.; Bediaga, I.; Castromonte, C. et al.
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Hadronic mass spectrum analysis of D+ ---> K- pi+ mu+ nu decay and measurement of the K*(892)0 mass and width

Description: We present a K{pi} mass spectrum analysis of the four-body semileptonic charm decay D{sup +} {yields} K{sup -}{pi}{sup +}{mu}{sup +}{nu} in the range of 0.65 GeV/c{sup 2} < m{sub K{pi}} < 1.5 GeV/c{sup 2}. We observe a non-resonant contribution of 5.30 {+-} 0.74{sub -0.51}{sup +0.99}% with respect to the total D{sup +} {yields} K{sup -} {pi}{sup +}{mu}{sup +}{nu} decay. For the K*(892){sup 0} resonance, we obtain a mass of 895.41 {+-} 0.32{sub -0.36}{sup +0.35} NeV/c{sup 2}, a width of 47… more
Date: March 1, 2005
Creator: Link, J. M.; Yager, P. M.; /UC, Davis; Anjos, J. C.; Bediaga, I.; Gobel, C. et al.
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Measurement of the doubly Cabibbo suppressed decay D0 ---> K+ pi- and a search for charm mixing

Description: The authors present an analysis of the decay D{sup 0} {yields} K{sup +}{pi}{sup -} based on FOCUS data. From a sample of 234 signal events, they find a branching ratio of {Lambda}(D{sup 0} {yields} K{sup +}{pi}{sup -})/{Lambda}(D{sup 0} {yields} K{sup -}{pi}{sup +}) = (0.429{sub -0.061}{sup +0-.063} {+-} 0.027)% under the assumptions of no mixing and no CP violation. Allowing for CP violation, the find a branching ratio of (0.435{sub -0.061}{sup +0.063} {+-} 0.028)% and a CP asymmetry of 0.178{… more
Date: December 1, 2004
Creator: Link, J. M.; Yager, P. M.; /UC, Davis; Anjos, J. C.; Bediaga, I.; Gobel, C. et al.
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Study of the D0 ---> K+ K- pi+ pi-

Description: Using data from the FOCUS (E831) experiment at Fermilab, the authors present a new measurement for the Cabibbo-suppressed decay mode D{sup 0} {yields} K{sup +}K{sup -}{pi}{sup +}{pi}{sup -}. They measure: {Lambda}(D{sup 0} {yields} K{sup +}K{sup -}{pi}{sup +}{pi}{sup -})/{Lambda}(D{sup 0} {yields} K{sup -}{pi}{sup -}{pi}{sup +}{pi}{sup +}) = 0.0295 {+-} 0.0011 {+-} 0.0008. An amplitude analysis has been performed in order to determine the resonant substructure of this decay mode. The dominant c… more
Date: November 1, 2004
Creator: Link, J. M.; Yager, P. M.; /UC, Davis; Anjos, J. C.; Bediaga, I.; Gobel, C. et al.
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White paper report on using nuclear reactors to search for a value of theta13

Description: There has been superb progress in understanding the neutrino sector of elementary particle physics in the past few years. It is now widely recognized that the possibility exists for a rich program of measuring CP violation and matter effects in future accelerator {nu} experiments, which has led to intense efforts to consider new programs at neutrino superbeams, off-axis detectors, neutrino factories and beta beams. However, the possibility of measuring CP violation can be fulfilled only if the … more
Date: February 26, 2004
Creator: Anderson, K.; Anjos, J. C.; Ayres, D.; Beacom, J.; Bediaga, I.; de Bellefon, A. et al.
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Results on charm production from E791, a high statistics charm hadroproduction experiment at Fermilab

Description: Fermilab experiment E791 collected a large sample of charm events to study several aspects of charm physics. Many topics on production and decay of charm particles can be covered with this data set. This talk will concentrate on the production asymmetry of charm mesons.
Date: May 1994
Creator: Banerjee, S.; Appel, J. A.; Aitala, E. M.; Amato, S.; Anjos, J. C.; Bediaga, I. et al.
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Fermilab E791

Description: Fermilab E791, a very high statistics charm particle experiment, recently completed its data taking at Fermilab`s Tagged Photon Laboratory. Over 20 billionevents were recorded through a loose transverse energy trigger and written to 8mm tape in the 1991--92 fixed target run at Fermilab. This unprecedented data sample containing charm is being analysis on many-thousand MIP RISC computing farms set up at sites in the collaboration. A glimpse of the data taking and analysis effort is presented. We… more
Date: October 1, 1992
Creator: Amato, S.; Anjos, J. C.; Bediaga, I.; Costa, I.; de Mello Neto, J. R. T.; de Miranda, J. M. et al.
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