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Start Over Author "K. O'Shaughnessy" Journal physical review letters
21 results on '"K. O'Shaughnessy"'

1. Search for Rare and Forbidden Charm Meson DecaysD0→Vℓ+ℓ−andhhℓℓ

Author

K. O'Shaughnessy, dos Reis Ac, K. C. Peng, A. K. Tripathi, S. M. Yang, N. R. Stanton, Alberto Santoro, A. J. Slaughter, A. Nguyen, P.A. Kasper, S. Yoshida, A. Napier, K. Denisenko, S. B. Bracker, A. Álvarez Fernández, M. Sheaff, S. Amato, D. Yi, D. C. Langs, R. Weiss-Babai, R. A. Burnstein, L. M. Cremaldi, E. Wolin, G. F. Fox, B. Quinn, A.B. d'Oliveira, A. Rafatian, E.M. Aitala, C. James, N. W. Reay, J. Leslie, N. Witchey, S. Takach, G. Hurvits, C. Zhang, S. Watanabe, de Mello Neto, M. V. Purohit, B. Lundberg, R. H. Milburn, H.S. Carvalho, A.K.S. Santha, A.M. Halling, S. Banerjee, Kevin Stenson, J. C. Anjos, J. A. Appel, R. A. Sidwell, J. Magnin, Sokoloff, R. Zaliznyak, D. J. Summers, K. Gounder, Daniel Ashery, T. Carter, A. J. Schwartz, D. A. Sanders, L. Perera, G. Blaylock, G. Herrera, K. Thorne, Simon Kwan, D. Mihalcea, S. Devmal, H. A. Rubin, S. Radeztsky, P. Gagnon, C. L. Darling, R. J. Stefanski, N. K. Copty, J. Solano, J. Wiener, J.J. Reidy, C. Göbel, S. MayTal-Beck, de Miranda Jm, B. T. Meadows, P. R. Burchat, and I. Bediaga

Subjects
Physics, Particle physics, Antiparticle, Muon, Meson, Neutral current, High Energy Physics::Phenomenology, General Physics and Astronomy, Nuclear physics, Pseudoscalar, High Energy Physics::Experiment, Vector meson, Charm (quantum number), Lepton
Abstract

We report results of a search for flavor-changing neutral current (FCNC), lepton flavor, and lepton-number violating decays of the ${D}^{0}$ (and its antiparticle) into three and four bodies. Using data from Fermilab charm hadroproduction experiment E791, we examine modes with two leptons (muons or electrons) and a ${\ensuremath{\rho}}^{0}$, ${\overline{K}}^{*0}$, or $\ensuremath{\varphi}$ vector meson or a nonresonant $\ensuremath{\pi}\ensuremath{\pi}$, $K\ensuremath{\pi}$, or $\mathrm{KK}$ pair of pseudoscalar mesons. No evidence for any of these decays is found. Therefore, we present branching-fraction upper limits at 90% confidence level for the 27 decay modes examined (18 new).

Published
2001
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2. Study of theDs+→π−π+π+Decay and Measurement off0Masses and Widths

Author

G. F. Fox, D. J. Summers, K. Gounder, J. M. De Miranda, B. T. Meadows, M. D. Sokoloff, J. R. T. de Mello Neto, P.A. Kasper, S. B. Bracker, S. Radeztsky, S. Watanabe, J.J. Reidy, M. Sheaff, R. J. Stefanski, S. Devmal, R. A. Sidwell, S. Takach, B. Lundberg, I. Bediaga, C. Zhang, A. J. Slaughter, J. A. Appel, A. Napier, Daniel Ashery, K. Denisenko, P. Gagnon, A.M. Halling, D. Yi, K. C. Peng, H.S. Carvalho, S. M. Yang, A. Nguyen, A. Massafferri, H. A. Rubin, N. K. Copty, S. MayTal-Beck, R. Zaliznyak, Simon Kwan, S. Yoshida, A. K. Tripathi, D. C. Langs, M. V. Purohit, C. L. Darling, K. O'Shaughnessy, G. Blaylock, A.K.S. Santha, J. Solano, C. James, S. Amato, A.B. d'Oliveira, E.M. Aitala, Alberto Santoro, J. C. Anjos, N. W. Reay, J. Leslie, J. Magnin, D. A. Sanders, J. Wiener, L. Perera, D. Mihalcea, A. C. dos Reis, R. Weiss-Babai, A. Álvarez Fernández, L. M. Cremaldi, K. Thorne, Patricia R. Burchat, E. Wolin, S. Banerjee, N. Witchey, C. Göbel, A. J. Schwartz, R. H. Milburn, R. A. Burnstein, N. R. Stanton, A. Rafatian, G. Hurvits, Kevin Stenson, G. Herrera, T. Carter, and B. Quinn

Subjects
Physics, Crystallography, Particle physics, Pi, General Physics and Astronomy, Dalitz plot
Abstract

From a sample of $848\ifmmode\pm\else\textpm\fi{}44$ ${D}_{s}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{+}$ decays, we find $\ensuremath{\Gamma}({D}_{s}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{+})/\ensuremath{\Gamma}({D}_{s}^{+}\ensuremath{\rightarrow}\ensuremath{\varphi}{\ensuremath{\pi}}^{+})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.245\ifmmode\pm\else\textpm\fi{}{0.028}_{\ensuremath{-}0.012}^{+0.019}$. Using a Dalitz plot analysis of this three body decay, we find significant contributions from the channels ${\ensuremath{\rho}}^{0}(770){\ensuremath{\pi}}^{+}$, ${\ensuremath{\rho}}^{0}(1450){\ensuremath{\pi}}^{+}$, ${f}_{0}(980){\ensuremath{\pi}}^{+}$, ${f}_{2}(1270){\ensuremath{\pi}}^{+}$, and ${f}_{0}(1370){\ensuremath{\pi}}^{+}$. We also present the values obtained for masses and widths of the resonances ${f}_{0}(980)$ and ${f}_{0}(1370)$.

Published
2001
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3. Experimental Evidence for a Light and Broad Scalar Resonance inD+→π−π+π+Decay

Author

N. R. Stanton, N. Witchey, D.C. Langs, S. Radeztsky, S. MayTal-Beck, A. Nguyen, Alberto Santoro, Kevin Stenson, J. Magnin, A.K. Tripathi, A.M. Halling, D. J. Summers, K. Gounder, R. H. Milburn, I. Bediaga, C. Zhang, R. A. Burnstein, J. A. Appel, G. F. Fox, S. M. Yang, S. Yoshida, P.A. Kasper, J.J. Reidy, A. Massafferri, A. Rafatian, J. Wiener, R. J. Stefanski, G. Blaylock, A. Napier, H.S. Carvalho, B. Lundberg, de Miranda Jm, K. Denisenko, D. Yi, Sokoloff, N. W. Reay, J. Leslie, G. Hurvits, C. Göbel, S. Takach, S. Watanabe, R. Weiss-Babai, B. T. Meadows, Daniel Ashery, M. Sheaff, C. L. Darling, S. B. Bracker, D. A. Sanders, A. J. Schwartz, Simon Kwan, Sudeshna Banerjee, J. C. Anjos, T. Carter, G. Herrera, P. Gagnon, C. James, R. Zaliznyak, N. K. Copty, S. Amato, B. Quinn, H. A. Rubin, de Mello Neto, J. Solano, D. Mihalcea, A. J. Slaughter, M. V. Purohit, A.K.S. Santha, K. O'Shaughnessy, dos Reis Ac, S. Devmal, L.P. Perera, R. A. Sidwell, Patricia R. Burchat, A.B. d'Oliveira, E.M. Aitala, A. Álvarez Fernández, L. M. Cremaldi, E. Wolin, K. C. Peng, and K. Thorne

Subjects
Physics, Nuclear magnetic resonance, Amplitude, Scalar (mathematics), Analytical chemistry, Pi, General Physics and Astronomy, Dalitz plot, Resonance
Abstract

From a sample of 1172 +/- 61 D(+)-->pi(-)pi(+)pi(+) decays, we find gamma(D(+)-->pi(-)pi(+)pi(+))/gamma(D(+)-->K-pi(+)pi(+)) = 0.0311 +/- 0.0018(+0.0016)(-0.0026). Using a coherent amplitude analysis to fit the Dalitz plot of these decays, we find strong evidence that a scalar resonance of mass 478(+24)(-23) +/- 17 MeV/c(2) and width 324(+42)(-40) +/- 21 MeV/c(2) accounts for approximately half of all decays.

Published
2001
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4. Search for the Pentaquark via thePcs¯0→φπpDecay

Author

S. Yoshida, S. Banerjee, A. K. Tripathi, A. J. Slaughter, S. MayTal-Beck, A. Napier, J. C. Anjos, D. Yi, R. Weiss-Babai, S. Gerzon, N. R. Stanton, J. R. T. de Mello Neto, A. Nguyen, Daniel Ashery, C. James, B. Lundberg, J. Leslie, E.M. Aitala, B. T. Meadows, D. C. Langs, M. Sheaff, M. D. Sokoloff, P. R. Burchat, N. W. Reay, S. B. Bracker, J. A. Appel, P. Gagnon, S. Amato, H. A. Rubin, K. O'Shaughnessy, J. Lichtenstadt, I. Bediaga, H.S. Carvalho, G. Blaylock, R. H. Milburn, C. Zhang, Simon Kwan, R. Zaliznyak, T. Carter, A. B. d'Oliveira, J. Wiener, P.A. Kasper, N. K. Copty, J. J. Reidy, A. J. Schwartz, K. Denisenko, S. Takach, C. Göbel, A. K. S. Santha, M. V. Purohit, R. A. Sidwell, S. Watanabe, G. Herrera, S. Radeztsky, A. C. dos Reis, C. L. Darling, D. J. Summers, K. Gounder, J. M. De Miranda, A.M. Halling, L. Perera, K. Thorne, B. Quinn, Alberto Santoro, R. A. Burnstein, A. Rafatian, G. Hurvits, Kevin Stenson, N. Witchey, K. C. Peng, A. Álvarez Fernández, L. M. Cremaldi, and E. Wolin

Subjects
Physics, Particle decay, Particle physics, Pion, Meson, Branching fraction, High Energy Physics::Phenomenology, Hadron, General Physics and Astronomy, High Energy Physics::Experiment, Energy (signal processing), Pentaquark, Bar (unit)
Abstract

We report results of the first search for the pentaquark P_{{c bar}s} which is predicted to be a doublet of states: P^0_{{c bar}s}=({c bar} s u u d) and P^-_{{c bar}s}=({c bar} s d d u). A search was made for the decay P^0_{{c bar}s} --> phi,pi,p in data from Fermilab experiment E791, in which 500 GeV/c pi^- beam interacted with nuclear targets. We present upper limits at 90% confidence level for the ratio of cross section times branching fraction of this decay to that for the decay D_s --> phi,pi. The upper limits are 0.031 and 0.063 for M(P^0_{{c bar}s}) = 2.75 and 2.86 GeV/c^2, respectively, assuming a P^0_{{c bar}s} lifetime of 0.4 ps.

Published
1998
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5. Measurement of the Form-Factor Ratios forD+→K¯*0e+νe

Author

N. R. Stanton, N. K. Copty, C. Zhang, P.A. Kasper, D. Mihalcea, Kevin Stenson, A. K. Tripathi, A. C. dos Reis, S. MayTal-Beck, J. Solano, A. J. Slaughter, R. H. Milburn, B. T. Meadows, M. D. Sokoloff, G. P. Gagnon, J. R. T. de Mello Neto, P. R. Burchat, Daniel Ashery, J. Wiener, A. Napier, K. Denisenko, N. W. Reay, J. Leslie, S. Yoshida, K. C. Peng, B. Quinn, D. Yi, D. C. Langs, I. Bediaga, H. A. Rubin, R. Weiss-Babai, D. J. Summers, C. James, K. Gounder, N. Witchey, Simon Kwan, M. V. Purohit, J. M. De Miranda, J.J. Reidy, K. O'Shaughnessy, A.K.S. Santha, S. Banerjee, H.S. Carvalho, Alberto Santoro, J. C. Anjos, A. Álvarez Fernández, B. Lundberg, R. A. Burnstein, L. M. Cremaldi, M. Sheaff, J. A. Appel, E. Wolin, D. A. Sanders, G. Blaylock, A. Rafatian, G. Hurvits, T. Carter, C. L. Darling, R. A. Sidwell, L. Perera, A. J. Schwartz, S. B. Bracker, A.B. d'Oliveira, E.M. Aitala, K. Thorne, S. Takach, S. Radeztsky, A. Nguyen, G. Herrera, S. Amato, A.M. Halling, G. F. Fox, S. Watanabe, and R. Zaliznyak

Subjects
Physics, Particle physics, General Physics and Astronomy, Electron neutrino
Abstract

We present a measurement of the form-factor ratios r_V=V(0)/A_1(0) and r_2=A_2(0)/A_1(0) for the decay D^+ -> \overline K^{*0} e^+ \nu_e. The measurement is based on a signal of approximately 3000 $D^+ -> \overline K^{*0} e^+ \nu_e, \overline K^{*0} -> K^-\pi^+$ decays reconstructed in data from charm hadroproduction experiment E791 at Fermilab. The results are r_V = 1.84 +- 0.11 +- 0.08 and r_2 = 0.71 +- 0.08 +- 0.09.

Published
1998
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6. Search forD0D¯0Mixing in Semileptonic Decay Modes

Author

E. M. Aitala, S. Amato, J. C. Anjos, J. A. Appel, D. Ashery, S. Banerjee, I. Bediaga, G. Blaylock, S. B. Bracker, P. R. Burchat, R. A. Burnstein, T. Carter, H. S. Carvalho, N. K. Copty, I. Costa, L. M. Cremaldi, C. Darling, K. Denisenko, A. Fernandez, P. Gagnon, S. Gerzon, C. Gobel, K. Gounder, A. M. Halling, G. Herrera, G. Hurvits, C. James, P. A. Kasper, S. Kwan, D. C. Langs, J. Leslie, B. Lundberg, S. MayTal-Beck, B. Meadows, J. R. T. de Mello Neto, R. H. Milburn, J. M. de Miranda, A. Napier, A. Nguyen, A. B. d'Oliveira, K. O'Shaughnessy, K. C. Peng, L. P. Perera, M. V. Purohit, B. Quinn, S. Radeztsky, A. Rafatian, N. W. Reay, J. J. Reidy, A. C. dos Reis, H. A. Rubin, A. K. S. Santha, A. F. S. Santoro, A. J. Schwartz, M. Sheaff, R. A. Sidwell, A. J. Slaughter, M. D. Sokoloff, N. R. Stanton, K. Stenson, K. Sugano, D. J. Summers, S. Takach, K. Thorne, A. K. Tripathi, S. Watanabe, R. Weiss-Babai, J. Wiener, N. Witchey, E. Wolin, D. Yi, S. Yoshida, R. Zaliznyak, and C. Zhang

Subjects
Physics, Nuclear physics, Semileptonic decay, chemistry, Bar (music), High Energy Physics::Phenomenology, General Physics and Astronomy, chemistry.chemical_element, High Energy Physics::Experiment, Fermilab, Carbon, Mixing (physics)
Abstract

We report the result of a search for D0 - D0_bar mixing in the data from hadroproduction experiment E791 at Fermilab. We use the D* tag and semileptonic decay vertices of D0 to look for wrong-sign decays with mixing time dependence.

Published
1996
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7. Search for the Flavor-Changing Neutral-Current DecaysD+→π+μ+μ−andD+→π+e+e−

Author

E. M. Aitala, S. Amato, J. C. Anjos, J. A. Appel, D. Ashery, S. Banerjee, I. Bediaga, G. Blaylock, S. B. Bracker, P. R. Burchat, R. A. Burnstein, T. Carter, H. S. Carvalho, I. Costa, L. M. Cremaldi, C. Darling, K. Denisenko, A. Fernandez, P. Gagnon, S. Gerzon, C. Gobel, K. Gounder, D. Granite, A. M. Halling, G. Herrera, G. Hurvits, C. James, P. A. Kasper, N. Kondakis, S. Kwan, D. C. Langs, J. Leslie, J. Lichtenstadt, B. Lundberg, A. Manacero, S. MayTal-Beck, B. Meadows, J. R. T. de Mello Neto, R. H. Milburn, J. M. de Miranda, A. Napier, A. Nguyen, A. B. d'Oliveira, K. O'Shaughnessy, K. C. Peng, L. P. Perera, M. V. Purohit, B. Quinn, S. Radeztsky, A. Rafatian, N. W. Reay, J. J. Reidy, A. C. dos Reis, H. A. Rubin, A. K. S. Santha, A. F. S. Santoro, A. J. Schwartz, M. Sheaff, R. A. Sidwell, A. J. Slaughter, J. G. Smith, M. D. Sokoloff, N. R. Stanton, K. Sugano, D. J. Summers, S. Takach, K. Thorne, A. K. Tripathi, S. Watanabe, R. Weiss, J. Wiener, N. Witchey, E. Wolin, D. Yi, R. Zaliznyak, and C. Zhang

Subjects
Physics, Particle physics, Flavor-changing neutral current, Pi, Mass spectrum, General Physics and Astronomy, Micro/Micro
Published
1996
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8. Dalitz Plot Analysis of the DecayD+→K−π+π+and Indication of a Low-Mass ScalarKπResonance

Author

dos Reis Ac, S. M. Yang, J. Magnin, S. Yoshida, K. C. Peng, A. K. Tripathi, S. MayTal-Beck, P.A. Kasper, A.M. Halling, D. A. Sanders, J. C. Anjos, Simon Kwan, K. O'Shaughnessy, L. Perera, S. Takach, H.S. Carvalho, C. James, Alberto Santoro, K. Thorne, A. Álvarez Fernández, N. Witchey, J. Wiener, B. Lundberg, A. J. Slaughter, S. Banerjee, C. Göbel, D. C. Langs, L. M. Cremaldi, E. Wolin, C. Zhang, J.J. Reidy, A. J. Schwartz, D. Mihalcea, S. Radeztsky, R. A. Sidwell, B. Quinn, A. Nguyen, N. W. Reay, J. Leslie, I. Bediaga, A. Napier, G. Herrera, R. Zaliznyak, K. Denisenko, R. H. Milburn, G. Blaylock, M. V. Purohit, de Mello Neto, M. Sheaff, P. Gagnon, J. A. Appel, S. Amato, D. J. Summers, K. Gounder, A.K.S. Santha, N. R. Stanton, D. Yi, T. Carter, R. Weiss-Babai, Solano Salinas Cj, G. F. Fox, C. L. Darling, A. Massafferri, de Miranda Jm, B. T. Meadows, Kevin Stenson, P. R. Burchat, S. Watanabe, R. A. Burnstein, A. Rafatian, A.B. d'Oliveira, E.M. Aitala, G. Hurvits, S. B. Bracker, R. J. Stefanski, N. K. Copty, Sokoloff, Daniel Ashery, H. A. Rubin, and S. Devmal

Subjects
Physics, Particle decay, Particle physics, Pion, Meson, Hadron, General Physics and Astronomy, Resonance, Dalitz plot, Elementary particle, Boson
Abstract

We study the Dalitz plot of the decay ${D}^{+}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{+}$ with a sample of 15090 events from Fermilab experiment E791. Modeling the decay amplitude as the coherent sum of known $K\ensuremath{\pi}$ resonances and a uniform nonresonant term, we do not obtain an acceptable fit. If we allow the mass and width of the ${K}_{0}^{*}(1430)$ to float, we obtain values consistent with those from PDG but the ${\ensuremath{\chi}}^{2}$ per degree of freedom of the fit is still unsatisfactory. A good fit is found when we allow for the presence of an additional scalar resonance, with mass $797\ifmmode\pm\else\textpm\fi{}19\ifmmode\pm\else\textpm\fi{}43\text{ }\mathrm{M}\mathrm{e}\mathrm{V}/{\mathrm{c}}^{\mathrm{2}}$ and width $410\ifmmode\pm\else\textpm\fi{}43\ifmmode\pm\else\textpm\fi{}87\text{ }\mathrm{M}\mathrm{e}\mathrm{V}/{\mathrm{c}}^{2}$. The mass and width of the ${K}_{0}^{*}(1430)$ become $1459\ifmmode\pm\else\textpm\fi{}7\ifmmode\pm\else\textpm\fi{}5\text{ }\mathrm{M}\mathrm{e}\mathrm{V}/{\mathrm{c}}^{\mathrm{2}}$ and $175\ifmmode\pm\else\textpm\fi{}12\ifmmode\pm\else\textpm\fi{}12\text{ }\mathrm{M}\mathrm{e}\mathrm{V}/{\mathrm{c}}^{\mathrm{2}}$, respectively. Our results provide new information on the scalar sector in hadron spectroscopy.

Published
2002
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9. Dalitz plot analysis of the decay D(+)--K(-)pi(+)pi(+) and indication of a low-mass scalar Kpi resonance

Author

E M, Aitala, S, Amato, J C, Anjos, J A, Appel, D, Ashery, S, Banerjee, I, Bediaga, G, Blaylock, S B, Bracker, P R, Burchat, R A, Burnstein, T, Carter, H S, Carvalho, N K, Copty, L M, Cremaldi, C, Darling, K, Denisenko, S, Devmal, A, Fernandez, G F, Fox, P, Gagnon, C, Göbel, K, Gounder, A M, Halling, G, Herrera, G, Hurvits, C, James, P A, Kasper, S, Kwan, D C, Langs, J, Leslie, B, Lundberg, J, Magnin, A, Massafferri, S, MayTal-Beck, B, Meadows, J R T, de Mello Neto, D, Mihalcea, R H, Milburn, J M, de Miranda, A, Napier, A, Nguyen, A B, d'Oliveira, K, O'Shaughnessy, K C, Peng, L P, Perera, M V, Purohit, B, Quinn, S, Radeztsky, A, Rafatian, N W, Reay, J J, Reidy, A C, dos Reis, H A, Rubin, D A, Sanders, A K S, Santha, A F S, Santoro, A J, Schwartz, M, Sheaff, R A, Sidwell, A J, Slaughter, M D, Sokoloff, C J, Solano Salinas, N R, Stanton, R J, Stefanski, K, Stenson, D J, Summers, S, Takach, K, Thorne, A K, Tripathi, S, Watanabe, R, Weiss-Babai, J, Wiener, N, Witchey, E, Wolin, S M, Yang, D, Yi, S, Yoshida, R, Zaliznyak, and C, Zhang

Abstract

We study the Dalitz plot of the decay D(+)--K(-)pi(+)pi(+) with a sample of 15090 events from Fermilab experiment E791. Modeling the decay amplitude as the coherent sum of known Kpi resonances and a uniform nonresonant term, we do not obtain an acceptable fit. If we allow the mass and width of the K(*)(0)(1430) to float, we obtain values consistent with those from PDG but the chi(2) per degree of freedom of the fit is still unsatisfactory. A good fit is found when we allow for the presence of an additional scalar resonance, with mass 797+/-19+/-43 MeV/c(2) and width 410+/-43+/-87 MeV/c(2). The mass and width of the K(*)(0)(1430) become 1459+/-7+/-5 MeV/c(2) and 175+/-12+/-12 MeV/c(2), respectively. Our results provide new information on the scalar sector in hadron spectroscopy.

Published
2002

10. Search for rare and forbidden Charm Meson decays D0 --Vl+l- and hhll

Author

E M, Aitala, S, Amato, J C, Anjos, J A, Appel, D, Ashery, S, Banerjee, I, Bediaga, G, Blaylock, S B, Bracker, P R, Burchat, R A, Burnstein, T, Carter, H S, Carvalho, N K, Copty, L M, Cremaldi, C, Darling, K, Denisenko, S, Devmal, A, Fernandez, G F, Fox, P, Gagnon, C, Gobel, K, Gounder, A M, Halling, G, Herrera, G, Hurvits, C, James, P A, Kasper, S, Kwan, D C, Langs, J, Leslie, B, Lundberg, J, Magnin, S, MayTal-Beck, B, Meadows, J R, de Mello Neto, D, Mihalcea, R H, Milburn, J M, de Miranda, A, Napier, A, Nguyen, A B, d'Oliveira, K, O'Shaughnessy, K C, Peng, L P, Perera, M V, Purohit, B, Quinn, S, Radeztsky, A, Rafatian, N W, Reay, J J, Reidy, A C, dos Reis, H A, Rubin, D A, Sanders, A K, Santha, A F, Santoro, A J, Schwartz, M, Sheaff, R A, Sidwell, A J, Slaughter, M D, Sokoloff, J, Solano, N R, Stanton, R J, Stefanski, K, Stenson, D J, Summers, S, Takach, K, Thorne, A K, Tripathi, S, Watanabe, R, Weiss-Babai, J, Wiener, N, Witchey, E, Wolin, S M, Yang, D, Yi, S, Yoshida, R, Zaliznyak, and C, Zhang

Abstract

We report results of a search for flavor-changing neutral current (FCNC), lepton flavor, and lepton-number violating decays of the D0 (and its antiparticle) into three and four bodies. Using data from Fermilab charm hadroproduction experiment E791, we examine modes with two leptons (muons or electrons) and a rho(0), K( *0), or straight phi vector meson or a nonresonant pi(pi), Kpi, or KK pair of pseudoscalar mesons. No evidence for any of these decays is found. Therefore, we present branching-fraction upper limits at 90% confidence level for the 27 decay modes examined (18 new).

Published
2000

11. Direct measurement of the pion valence-quark momentum distribution, the pion light-cone wave function squared

Author

A. Napier, K. Denisenko, D. Yi, R. Weiss-Babai, R. A. Burnstein, J. Wiener, A. Rafatian, L.P. Perera, A. J. Schwartz, B. Lundberg, A.M. Halling, C. Göbel, N. R. Stanton, G. Hurvits, N. W. Reay, A. J. Slaughter, J. Leslie, S. Radeztsky, A. Nguyen, G. Herrera, Alberto Santoro, S. Gerzon, J. A. Appel, R. A. Sidwell, B. T. Meadows, A. Álvarez Fernández, Kevin Stenson, L. M. Cremaldi, E. Wolin, D. J. Summers, K. Gounder, J. M. De Miranda, Daniel Ashery, H. A. Rubin, Simon Kwan, N. Witchey, D.C. Langs, M. V. Purohit, P. Gagnon, D. A. Sanders, R. H. Milburn, Sudeshna Banerjee, P.A. Kasper, A.K.S. Santha, N. K. Copty, K. Thorne, K. C. Peng, S. Takach, S. Amato, J. C. Anjos, I. Bediaga, M. Sheaff, G. F. Fox, G. Blaylock, R. Zaliznyak, A.B. d'Oliveira, E.M. Aitala, C. L. Darling, S. Watanabe, J. R. T. de Mello Neto, D. Mihalcea, H.S. Carvalho, A. C. dos Reis, S. Deval, Michael Sokoloff, J. Lichtenstadt, K. O'Shaughnessy, S. M. Yang, S. Yoshida, B. Quinn, S. MayTal-Beck, A.K. Tripathi, S. B. Bracker, J. Solano, J.J. Reidy, Patricia R. Burchat, T. Carter, R. J. Stefanski, C. Zhang, and C. James

Subjects
Quark, Physics, Particle physics, Valence (chemistry), General Physics and Astronomy, FOS: Physical sciences, Square (algebra), High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), Pion, Light cone, Transverse momentum, High Energy Physics::Experiment, Fermilab, Wave function, Nuclear Experiment
Abstract

We present the first direct measurements of the pion valence quark momentum distribution which is related to the square of the pion light-cone wave function. The measurements were carried out using data on diffractive dissociation of 500 GeV/c $��^-$ into di-jets from a platinum target at Fermilab experiment E791. The results show that the $|q\bar {q}>$ light-cone asymptotic wave function, which was developed using perturbative QCD methods, describes the data well for $Q^2 \sim 10 ~{\rm (GeV/c)^2}$ or more. We also measured the transverse momentum distribution of the diffractive di-jets., 13 pages, 4 figures

Published
2000

12. Experimental evidence for a light and broad scalar resonance in D(+) --pi(-)pi(+)pi(+) decay

Author

E M, Aitala, S, Amato, J C, Anjos, J A, Appel, D, Ashery, S, Banerjee, I, Bediaga, G, Blaylock, S B, Bracker, P R, Burchat, R A, Burnstein, T, Carter, H S, Carvalho, N K, Copty, L M, Cremaldi, C, Darling, K, Denisenko, S, Devmal, A, Fernandez, G F, Fox, P, Gagnon, C, Gobel, K, Gounder, A M, Halling, G, Herrera, G, Hurvits, C, James, P A, Kasper, S, Kwan, D C, Langs, J, Leslie, B, Lundberg, J, Magnin, A, Massafferri, S, MayTal-Beck, B, Meadows, J R, de Mello Neto, D, Mihalcea, R H, Milburn, J M, de Miranda, A, Napier, A, Nguyen, A B, d'Oliveira, K, O'Shaughnessy, K C, Peng, L P, Perera, M V, Purohit, B, Quinn, S, Radeztsky, A, Rafatian, N W, Reay, J J, Reidy, A C, dos Reis, H A, Rubin, D A, Sanders, A K, Santha, A F, Santoro, A J, Schwartz, M, Sheaff, R A, Sidwell, A J, Slaughter, M D, Sokoloff, J, Solano, N R, Stanton, R J, Stefanski, K, Stenson, D J, Summers, S, Takach, K, Thorne, A K, Tripathi, S, Watanabe, R, Weiss-Babai, J, Wiener, N, Witchey, E, Wolin, S M, Yang, D, Yi, S, Yoshida, R, Zaliznyak, and C, Zhang

Abstract

From a sample of 1172 +/- 61 D(+)--pi(-)pi(+)pi(+) decays, we find gamma(D(+)--pi(-)pi(+)pi(+))/gamma(D(+)--K-pi(+)pi(+)) = 0.0311 +/- 0.0018(+0.0016)(-0.0026). Using a coherent amplitude analysis to fit the Dalitz plot of these decays, we find strong evidence that a scalar resonance of mass 478(+24)(-23) +/- 17 MeV/c(2) and width 324(+42)(-40) +/- 21 MeV/c(2) accounts for approximately half of all decays.

Published
2000

13. Study of the D(+)(s)--pi(-)pi(+)pi(+) decay and measurement of f(0) masses and widths

Author

E M, Aitala, S, Amato, J C, Anjos, J A, Appel, D, Ashery, S, Banerjee, I, Bediaga, G, Blaylock, S B, Bracker, P R, Burchat, R A, Burnstein, T, Carter, H S, Carvalho, N K, Copty, L M, Cremaldi, C, Darling, K, Denisenko, S, Devmal, A, Fernandez, G F, Fox, P, Gagnon, C, Gobel, K, Gounder, A M, Halling, G, Herrera, G, Hurvits, C, James, P A, Kasper, S, Kwan, D C, Langs, J, Leslie, B, Lundberg, J, Magnin, A, Massafferri, S, MayTal-Beck, B, Meadows, J R, de Mello Neto, D, Mihalcea, R H, Milburn, J M, de Miranda, A, Napier, A, Nguyen, A B, d'Oliveira, K, O'Shaughnessy, K C, Peng, L P, Perera, M V, Purohit, B, Quinn, S, Radeztsky, A, Rafatian, N W, Reay, J J, Reidy, A C, dos Reis, H A, Rubin, D A, Sanders, A K, Santha, A F, Santoro, A J, Schwartz, M, Sheaff, R A, Sidwell, A J, Slaughter, M D, Sokoloff, J, Solano, N R, Stanton, R J, Stefanski, K, Stenson, D J, Summers, S, Takach, K, Thorne, A K, Tripathi, S, Watanabe, R, Weiss-Babai, J, Wiener, N, Witchey, E, Wolin, S M, Yang, D, Yi, S, Yoshida, R, Zaliznyak, and C, Zhang

Abstract

From a sample of 848+/-44 D(+)(s)--pi(-)pi(+)pi(+) decays, we find gamma(D(+)(s)--pi(-)pi(+)pi(+))/gamma(D(+)(s)--straight phipi(+)) = 0.245+/-0.028(+0.019)(-0.012). Using a Dalitz plot analysis of this three body decay, we find significant contributions from the channels rho(0)(770)pi(+), rho(0)(1450)pi(+), f(0)(980)pi(+), f(2)(1270)pi(+), and f(0)(1370)pi(+). We also present the values obtained for masses and widths of the resonances f(0)(980) and f(0)(1370).

Published
2000

14. Dalitz plot analysis of the decay D(+)-->K(-)pi(+)pi(+) and indication of a low-mass scalar Kpi resonance.

Author

Aitala EM, Amato S, Anjos JC, Appel JA, Ashery D, Banerjee S, Bediaga I, Blaylock G, Bracker SB, Burchat PR, Burnstein RA, Carter T, Carvalho HS, Copty NK, Cremaldi LM, Darling C, Denisenko K, Devmal S, Fernandez A, Fox GF, Gagnon P, Göbel C, Gounder K, Halling AM, Herrera G, Hurvits G, James C, Kasper PA, Kwan S, Langs DC, Leslie J, Lundberg B, Magnin J, Massafferri A, MayTal-Beck S, Meadows B, de Mello Neto JR, Mihalcea D, Milburn RH, de Miranda JM, Napier A, Nguyen A, d'Oliveira AB, O'Shaughnessy K, Peng KC, Perera LP, Purohit MV, Quinn B, Radeztsky S, Rafatian A, Reay NW, Reidy JJ, dos Reis AC, Rubin HA, Sanders DA, Santha AK, Santoro AF, Schwartz AJ, Sheaff M, Sidwell RA, Slaughter AJ, Sokoloff MD, Solano Salinas CJ, Stanton NR, Stefanski RJ, Stenson K, Summers DJ, Takach S, Thorne K, Tripathi AK, Watanabe S, Weiss-Babai R, Wiener J, Witchey N, Wolin E, Yang SM, Yi D, Yoshida S, Zaliznyak R, and Zhang C

Abstract

We study the Dalitz plot of the decay D(+)-->K(-)pi(+)pi(+) with a sample of 15090 events from Fermilab experiment E791. Modeling the decay amplitude as the coherent sum of known Kpi resonances and a uniform nonresonant term, we do not obtain an acceptable fit. If we allow the mass and width of the K(*)(0)(1430) to float, we obtain values consistent with those from PDG but the chi(2) per degree of freedom of the fit is still unsatisfactory. A good fit is found when we allow for the presence of an additional scalar resonance, with mass 797+/-19+/-43 MeV/c(2) and width 410+/-43+/-87 MeV/c(2). The mass and width of the K(*)(0)(1430) become 1459+/-7+/-5 MeV/c(2) and 175+/-12+/-12 MeV/c(2), respectively. Our results provide new information on the scalar sector in hadron spectroscopy.

Published
2002
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15. Direct measurement of the pion valence-quark momentum distribution, the pion light-cone wave function squared.

Author

Aitala EM, Amato S, Anjos JC, Appel JA, Ashery D, Banerjee S, Bediaga I, Blaylock G, Bracker SB, Burchat PR, Burnstein RA, Carter T, Carvalho HS, Copty NK, Cremaldi LM, Darling C, Denisenko K, Deval S, Fernandez A, Fox GF, Gagnon P, Gerzon S, Gobel C, Gounder K, Halling AM, Herrera G, Hurvits G, James C, Kasper PA, Kwan S, Langs DC, Leslie J, Lichtenstadt J, Lundberg B, MayTal-Beck S, Meadows B, de Mello Neto JR, Mihalcea D, Milburn RH, de Miranda JM, Napier A, Nguyen A, d'Oliveira AB, O'Shaughnessy K, Peng KC, Perera LP, Purohit MV, Quinn B, Radeztsky S, Rafatian A, Reay NW, Reidy JJ, dos Reis AC, Rubin HA, Sanders DA, Santha AK, Santoro AF, Schwartz AJ, Sheaff M, Sidwell RA, Slaughter AJ, Sokoloff MD, Solano J, Stanton NR, Stefanski RJ, Stenson K, Summers DJ, Takach S, Thorne K, Tripathi AK, Watanabe S, Weiss-Babai R, Wiener J, Witchey N, Wolin E, Yang SM, Yi D, Yoshida S, Zaliznyak R, and Zhang C

Abstract

We present the first direct measurements of the pion valence-quark momentum distribution which is related to the square of the pion light-cone wave function. The measurements were carried out using data on diffractive dissociation of 500 GeV/c pi(-) into dijets from a platinum target at Fermilab experiment E791. The results show that the /q&q> light-cone asymptotic wave function describes the data well for Q2 approximately 10 (GeV/c)(2) or more. We also measured the transverse momentum distribution of the diffractive dijets.

Published
2001
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16. Observation of color-transparency in diffractive dissociation of pions.

Author

Aitala EM, Amato S, Anjos JC, Appel JA, Ashery D, Banerjee S, Bediaga I, Blaylock G, Bracker SB, Burchat PR, Burnstein RA, Carter T, Carvalho HS, Copty NK, Cremaldi LM, Darling C, Denisenko K, Devmal S, Fernandez A, Fox GF, Gagnon P, Gerzon S, Gobel C, Gounder K, Halling AM, Herrera G, Hurvits G, James C, Kasper PA, Kwan S, Langs DC, Leslie J, Lichtenstadt J, Lundberg B, MayTal-Beck S, Meadows B, de Mello Neto JR, Mihalcea D, Milburn RH, de Miranda JM, Napier A, Nguyen A, d'Oliveira AB, O'Shaughnessy K, Peng KC, Perera LP, Purohit MV, Quinn B, Radeztsky S, Rafatian A, Reay NW, Reidy JJ, dos Reis AC, Rubin HA, Sanders DA, Santha AK, Santoro AF, Schwartz AJ, Sheaff M, Sidwell RA, Slaughter AJ, Sokoloff MD, Solano J, Stanton NR, Stefanski RJ, Stenson K, Summers DJ, Takach S, Thorne K, Tripathi AK, Watanabe S, Weiss-Babai R, Wiener J, Witchey N, Wolin E, Yang SM, Yi D, Yoshida S, Zaliznyak R, and Zhang C

Abstract

We have studied the diffractive dissociation into dijets of 500 GeV/c pions scattering coherently from carbon and platinum targets. Extrapolating to asymptotically high energies (where t(min)-->0), we find that when the per-nucleus cross section for this process is parametrized as sigma = sigma0Aalpha, alpha has values near 1.6, the exact result depending on jet transverse momentum. These values are in agreement with those predicted by theoretical calculations of color-transparency.

Published
2001
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17. Search for rare and forbidden Charm Meson decays D0 --> Vl+l- and hhll.

Author

Aitala EM, Amato S, Anjos JC, Appel JA, Ashery D, Banerjee S, Bediaga I, Blaylock G, Bracker SB, Burchat PR, Burnstein RA, Carter T, Carvalho HS, Copty NK, Cremaldi LM, Darling C, Denisenko K, Devmal S, Fernandez A, Fox GF, Gagnon P, Gobel C, Gounder K, Halling AM, Herrera G, Hurvits G, James C, Kasper PA, Kwan S, Langs DC, Leslie J, Lundberg B, Magnin J, MayTal-Beck S, Meadows B, de Mello Neto JR, Mihalcea D, Milburn RH, de Miranda JM, Napier A, Nguyen A, d'Oliveira AB, O'Shaughnessy K, Peng KC, Perera LP, Purohit MV, Quinn B, Radeztsky S, Rafatian A, Reay NW, Reidy JJ, dos Reis AC, Rubin HA, Sanders DA, Santha AK, Santoro AF, Schwartz AJ, Sheaff M, Sidwell RA, Slaughter AJ, Sokoloff MD, Solano J, Stanton NR, Stefanski RJ, Stenson K, Summers DJ, Takach S, Thorne K, Tripathi AK, Watanabe S, Weiss-Babai R, Wiener J, Witchey N, Wolin E, Yang SM, Yi D, Yoshida S, Zaliznyak R, and Zhang C

Abstract

We report results of a search for flavor-changing neutral current (FCNC), lepton flavor, and lepton-number violating decays of the D0 (and its antiparticle) into three and four bodies. Using data from Fermilab charm hadroproduction experiment E791, we examine modes with two leptons (muons or electrons) and a rho(0), K( *0), or straight phi vector meson or a nonresonant pi(pi), Kpi, or KK pair of pseudoscalar mesons. No evidence for any of these decays is found. Therefore, we present branching-fraction upper limits at 90% confidence level for the 27 decay modes examined (18 new).

Published
2001
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18. Experimental evidence for a light and broad scalar resonance in D(+) --> pi(-)pi(+)pi(+) decay.

Author

Aitala EM, Amato S, Anjos JC, Appel JA, Ashery D, Banerjee S, Bediaga I, Blaylock G, Bracker SB, Burchat PR, Burnstein RA, Carter T, Carvalho HS, Copty NK, Cremaldi LM, Darling C, Denisenko K, Devmal S, Fernandez A, Fox GF, Gagnon P, Gobel C, Gounder K, Halling AM, Herrera G, Hurvits G, James C, Kasper PA, Kwan S, Langs DC, Leslie J, Lundberg B, Magnin J, Massafferri A, MayTal-Beck S, Meadows B, de Mello Neto JR, Mihalcea D, Milburn RH, de Miranda JM, Napier A, Nguyen A, d'Oliveira AB, O'Shaughnessy K, Peng KC, Perera LP, Purohit MV, Quinn B, Radeztsky S, Rafatian A, Reay NW, Reidy JJ, dos Reis AC, Rubin HA, Sanders DA, Santha AK, Santoro AF, Schwartz AJ, Sheaff M, Sidwell RA, Slaughter AJ, Sokoloff MD, Solano J, Stanton NR, Stefanski RJ, Stenson K, Summers DJ, Takach S, Thorne K, Tripathi AK, Watanabe S, Weiss-Babai R, Wiener J, Witchey N, Wolin E, Yang SM, Yi D, Yoshida S, Zaliznyak R, and Zhang C

Abstract

From a sample of 1172 +/- 61 D(+)-->pi(-)pi(+)pi(+) decays, we find gamma(D(+)-->pi(-)pi(+)pi(+))/gamma(D(+)-->K-pi(+)pi(+)) = 0.0311 +/- 0.0018(+0.0016)(-0.0026). Using a coherent amplitude analysis to fit the Dalitz plot of these decays, we find strong evidence that a scalar resonance of mass 478(+24)(-23) +/- 17 MeV/c(2) and width 324(+42)(-40) +/- 21 MeV/c(2) accounts for approximately half of all decays.

Published
2001
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19. Study of the D(+)(s)-->pi(-)pi(+)pi(+) decay and measurement of f(0) masses and widths.

Author

Aitala EM, Amato S, Anjos JC, Appel JA, Ashery D, Banerjee S, Bediaga I, Blaylock G, Bracker SB, Burchat PR, Burnstein RA, Carter T, Carvalho HS, Copty NK, Cremaldi LM, Darling C, Denisenko K, Devmal S, Fernandez A, Fox GF, Gagnon P, Gobel C, Gounder K, Halling AM, Herrera G, Hurvits G, James C, Kasper PA, Kwan S, Langs DC, Leslie J, Lundberg B, Magnin J, Massafferri A, MayTal-Beck S, Meadows B, de Mello Neto JR, Mihalcea D, Milburn RH, de Miranda JM, Napier A, Nguyen A, d'Oliveira AB, O'Shaughnessy K, Peng KC, Perera LP, Purohit MV, Quinn B, Radeztsky S, Rafatian A, Reay NW, Reidy JJ, dos Reis AC, Rubin HA, Sanders DA, Santha AK, Santoro AF, Schwartz AJ, Sheaff M, Sidwell RA, Slaughter AJ, Sokoloff MD, Solano J, Stanton NR, Stefanski RJ, Stenson K, Summers DJ, Takach S, Thorne K, Tripathi AK, Watanabe S, Weiss-Babai R, Wiener J, Witchey N, Wolin E, Yang SM, Yi D, Yoshida S, Zaliznyak R, and Zhang C

Abstract

From a sample of 848+/-44 D(+)(s)-->pi(-)pi(+)pi(+) decays, we find gamma(D(+)(s)-->pi(-)pi(+)pi(+))/gamma(D(+)(s)-->straight phipi(+)) = 0.245+/-0.028(+0.019)(-0.012). Using a Dalitz plot analysis of this three body decay, we find significant contributions from the channels rho(0)(770)pi(+), rho(0)(1450)pi(+), f(0)(980)pi(+), f(2)(1270)pi(+), and f(0)(1370)pi(+). We also present the values obtained for masses and widths of the resonances f(0)(980) and f(0)(1370).

Published
2001
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20. Search for D0D-bar0 Mixing in Semileptonic Decay Modes.

Author

Aitala EM, Amato S, Anjos JC, Appel JA, Ashery D, Banerjee S, Bediaga I I, Blaylock G, Bracker SB, Burchat PR, Burnstein RA, Carter T, Carvalho HS, Copty NK, Costa I I, Cremaldi LM, Darling C, Denisenko K, Fernandez A, Gagnon P, Gerzon S, Gobel C, Gounder K, Halling AM, Herrera G, Hurvits G, James C, Kasper PA, Kwan S, Langs DC, Leslie J, Lundberg B, MayTal-Beck S, Meadows B, de Mello Neto JR, Milburn RH, de Miranda JM, Napier A, Nguyen A, d'Oliveira AB, O'Shaughnessy K, Peng KC, Perera LP, Purohit MV, Quinn B, Radeztsky S, Rafatian A, Reay NW, Reidy JJ, dos Reis AC, Rubin HA, Santha AK, Santoro AF, Schwartz AJ, Sheaff M, Sidwell RA, Slaughter AJ, Sokoloff MD, Stanton NR, Stenson K, Sugano K, Summers DJ, Takach S, and Thorne K

Published
1996
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21. Search for the flavor-changing neutral-current decays D+--> pi + micro+ micro- and D+--> pi +e+e-

Author

Aitala EM, Amato S, Anjos JC, Appel JA, Ashery D, Banerjee S, Bediaga I I, Blaylock G, Bracker SB, Burchat PR, Burnstein RA, Carter T, Carvalho HS, Costa I I, Cremaldi LM, Darling C, Denisenko K, Fernandez A, Gagnon P, Gerzon S, Gobel C, Gounder K, Granite D, Halling AM, Herrera G, Hurvits G, James C, Kasper PA, Kondakis N, Kwan S, Langs DC, Leslie J, Lichtenstadt J, Lundberg B, Manacero A, MayTal-Beck S, Meadows B, de Mello Neto JR, Milburn RH, de Miranda JM, Napier A, Nguyen A, d'Oliveira AB, O'Shaughnessy K, Peng KC, Perera LP, Purohit MV, Quinn B, Radeztsky S, Rafatian A, Reay NW, Reidy JJ, dos Reis AC, Rubin HA, Santha AK, Santoro AF, Schwartz AJ, Sheaff M, Sidwell RA, Slaughter AJ, Smith JG, Sokoloff MD, Stanton NR, and Sugano K

Published
1996
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