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Observation of a Charmed Baryon Decaying to D0 p at a Mass Near 2.94 GeV/c2

Description: A search for charmed baryons decaying to D{sup 0}p reveals two states: the {Lambda}{sub c}(2880){sup +} baryon and a previously unobserved state at a mass of [2939.8 {+-} 1.3 (stat.) {+-} 1.0 (syst.)] MeV/c{sup 2} and with an intrinsic width of [17.5 {+-} 5.2 (stat.) {+-} 5.9 (syst.)] MeV. Consistent and significant signals are observed for the K{sup -}{pi}{sup +} and K{sup -}{pi}{sup +}{pi}{sup -}{pi}{sup +} decay modes of the D{sup 0} in 287 fb{sup -1} annihilation data recorded by the BABAR detector at a center-of-mass energy of 10.58 GeV. There is no evidence in the D{sup +}p spectrum of doubly-charged partners. The mass and intrinsic width of the {Lambda}{sub c}(2880){sup +} baryon and relative yield of the two baryons are also measured.
Date: March 29, 2006
Creator: Aubert, B.
Partner: UNT Libraries Government Documents Department

Observation of a New D_s Meson Decaying to D K at a Mass of 2.86 GeV/c^2

Description: The authors observe a new D{sub s} meson with mass (2856.6 {+-} 1.5{sub stat.} {+-} 5.0{sub syst.}) MeV/c{sup 2} and width (48 {+-} 7{sub stat.} {+-} 10{sub syst.}) MeV/c{sup 2} decaying into D{sup 0}K{sup +} and D{sup +}K{sub S}{sup 0}. In the same mass distributions they also observe a broad structure with mass (2688 {+-} 4{sub stat.} {+-} 3{sub syst.}) MeV/c{sup 2} and width (112 {+-} 7{sub stat.} {+-} 36{sub syst.}) MeV/c{sup 2}. To obtain this result they use 240 fb{sup -1} of data recorded by the BABAR detector at the PEP-II asymmetric e{sup +}e{sup -} storage rings at the Stanford Linear Accelerator Center running at center-of-mass energies near 10.6 GeV.
Date: October 4, 2006
Creator: Aubert, B.
Partner: UNT Libraries Government Documents Department

Observation of an Excited Charm Baryon Omega^*_C Decaying to Omega^0_C Gamma

Description: The authors report the first observation of an excited singly-charmed baryon {Omega}*{sub c} (css) in the radiative decay {Omega}{sub c}{sup 0}{gamma}, where the {Omega}{sub c}{sup 0} baryon is reconstructed in the decays to the final states {Omega}{sup -}{pi}{sup +}, {Omega}{sup -} {pi}{sup +}{pi}{sup 0}, {Omega}{sup -}{pi}{sup +}{pi}{sup -}{pi}{sup +}, and {Xi}{sup -} K{sup -} {pi}{sup +}{pi}{sup +}. This analysis is performed using a dataset of 230.7 fb{sup -1} collected by the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The mass difference between the {Omega}*{sub c} and the {Omega}{sub c}{sup 0} baryons is measured to be 70.8 {+-} 1.0(stat) {+-} 1.1(syst) MeV/c{sup 2}. They also measure the ratio of inclusive production cross sections of {Omega}*{sub c} and {Omega}{sub c}{sup 0} in e{sup +}e{sup -} annihilation.
Date: November 15, 2006
Creator: Aubert, B
Partner: UNT Libraries Government Documents Department

Observation of B+ -> K0bar K+ and B0 -> K0 K0bar

Description: The authors report observations of the b {yields} d penguin-dominated decays B{sup +} {yields} {bar K}{sup 0}K{sup +} and B{sup 0} {yields} K{sup 0}{bar K}{sup 0} in approximately 350 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector. They measure the branching fractions {Beta}(B{sup +} {yields} {bar K}{sup 0}K{sup +}) = (1.61 {+-} 0.44 {+-} 0.09) x 10{sup -6} and {Beta}(B{sup 0} {yields} K{sup 0}{bar K}{sup 0}) = (1.08 {+-} 0.28 {+-} 0.11) x 10{sup -6}, and the CP-violating charge asymmetry {Alpha}{sub CP} ({bar K}{sup 0} K{sup +}) = 0.10 {+-} 0.26 {+-} 0.03. Using a vertexing technique previously employed in several analyses of all-neutral final states containing kaons, they report the first measurement of time-dependent CP-violating asymmetries in B{sup 0} {yields} K{sub S}{sup 0}K{sub S}{sup 0}, obtaining S = -1.28{sub -0.73 -0.16}{sup +0.80 +0.11} and C = -0.40 {+-} 0.41 {+-} 0.06. They also report improved measurements of the branching fraction {Beta}(B{sup +} {yields} K{sup 0} {pi}{sup +}) = (23.9 {+-} 1.1 {+-} 1.0) x 10{sup -6} and CP-violating charge asymmetry {Alpha}{sub CP} (K{sup 0} {pi}{sup +}) = -0.029 {+-} 0.039 {+-} 0.010.
Date: August 16, 2006
Creator: Aubert, B.
Partner: UNT Libraries Government Documents Department

Observation of B Meson Decays to omegaK* and Improved Measurements for omegarho and omegaf0

Description: We present measurements of B meson decays to the final states {omega}K*, {omega}{rho}, and {omega}f{sub 0}, where K* indicates a spin 0, 1, or 2 strange meson. The data sample corresponds to 465 x 10{sup 6} B{bar B} pairs collected with the BABAR detector at the PEP-II e{sup +}e{sup -} collider at SLAC. B meson decays involving vector-scalar, vector-vector, and vector-tensor final states are analyzed; the latter two shed new light on the polarization of these final states. We measure the branching fractions for nine of these decays; five are observed for the first time. For most decays we also measure the charge asymmetry and, where relevant, the longitudinal polarization f{sub L}.
Date: January 29, 2009
Creator: Aubert, : B.
Partner: UNT Libraries Government Documents Department

Observation of B+ to b_1+K0 and Search for B-meson Decays to b_10K0 and b_1pi0

Description: We present the results of searches for decays of B mesons to final states with a b{sub 1} meson and a neutral pion or kaon. The data, collected with the BABAR detector at the Stanford Linear Accelerator Center, represent 465 million B{bar B} pairs produced in e{sup +}e{sup -} annihilation. The results for the branching fractions are, in units of 10{sup -6}, {Beta}(B{sup +} {yields} b{sub 1}{sup +}K{sup 0}) = 9.6 {+-} 1.7 {+-} 0.9, {Beta}(B{sup 0} {yields} b{sub 1}{sup 0}K{sup 0}) = 5.1 {+-} 1.8 {+-} 0.5 (< 7.8), {Beta}(B{sup +} {yields} b{sub 1}{sup +} {pi}{sup 0}) = 1.8 {+-} 0.9 {+-} 0.2 (<3.3), and {Beta}(B{sup 0} {yields} b{sub 1}{sup 0}{pi}{sup 0}) = 0.4 {+-} 0.8 {+-} 0.2 (<1.9), with the assumption that {Beta}(b{sub 1} {yields} {omega}{pi}) = 1. They also measure the charge asymmetry {Alpha}{sub ch} (B{sup +} {yields} b{sub 1}{sup +}K{sup 0}) = -0.03 {+-} 0.15 {+-} 0.02. The first error quoted is statistical, the second systematic, and the upper limits in parentheses indicate the 90% confidence level.
Date: May 14, 2008
Creator: Aubert, B.
Partner: UNT Libraries Government Documents Department

Observation of B to eta' K* and Evidence for B+ to eta' rho+

Description: The authors presented an observation of B {yields} {eta}{prime}K*. The data sample corresponds to 232 million B{bar B} pairs collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. They measure the branching fractions (in units of 10{sup -6}) {Beta}(B{sup 0} {yields} {eta}{prime}K*{sup 0}) = 3.8 {+-} 1.1 {+-} 0.5 and {Beta}(B{sup +} {yields} {eta}{prime}K*{sup +}) = 4.9{sub -1.7}{sup +1.9} {+-} 0.8, where the first error is statistical and the second systematic. A simultaneous fit results in the observation of B {yields} {eta}{prime}K* with {Beta}(B {yields} {eta}{prime}K*) = 4.1{sub -0.9}{sup +1.0} {+-} 0.5. They also search for B {yields} {eta}{prime}{rho} and {eta}{prime} f{sub 0}(980)(f{sub 0} {yields} {pi}{sup +}{pi}{sup -}) with results and 90% confidence level upper limits {Beta}(B{sup +} {yields} {eta}{prime}{rho}{sup +}) = 8.7{sub -2.8-1.3}{sup +3.1+2.3} (< 14), {Beta}(B{sup 0} {yields} {eta}{prime}{rho}{sup 0}) < 3.7, and {Beta}(B{sup 0} {yields} {eta}{prime} f{sub 0}(980)(f{sub 0} {yields} {pi}{sup +}{pi}{sup -})) < 1.5. Charge asymmetries in the channels with significant yields are consistent with zero.
Date: September 26, 2006
Creator: Aubert, B
Partner: UNT Libraries Government Documents Department

Observation of B0 -> chi_c0 K*0 and Evidence of B+ -> chi_c0 K*+

Description: The authors present the observation of the decay B{sup 0} {yields} {chi}{sub c0}K*{sup 0} as well as evidence of B{sup +} {yields} {chi}{sub c0}K*{sup +}, with an 8.9 and a 3.6 standard deviation significance, respectively, using a data sample of 454 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II B meson factory located at the Standard Linear Accelerator Center (SLAC). The measured branching fractions are: {Beta}(B{sup 0} {yields} {chi}{sub c0}K*{sup 0}) = (1.7 {+-} 0.3 {+-} 0.2) x 10{sup -4} and {Beta}(B{sup +} {yields} {chi}{sub c0}K*{sup +}) = (1.4 {+-} 0.5 {+-} 0.2) x 10{sup -4}, where the first quoted errors are statistical and the second are systematic. They obtain a branching fraction upper limit of {Beta}(B{sup +} {yields} {chi}{sub c0}K*{sup +}) < 2.1 x 10{sup -4} at the 90% confidence level.
Date: August 13, 2008
Creator: Aubert, : B.
Partner: UNT Libraries Government Documents Department

Observation of B0 Meson Decays to a1(1260)+- pi-+

Description: The authors present a measurement of the branching fraction of the decay B{sup 0} {yields} a{sub 1}{sup {+-}}(1260){pi}{sup {-+}} with a{sub 1}{sup {+-}}(1260) {yields} {pi}{sup {-+}}{pi}{sup {+-}}{pi}{sup {+-}}. The data sample corresponds to 218 x 10{sup 6} B{bar B} pairs produced in e{sup +}e{sup -} annihilation through the {Upsilon}(4S) resonance. The authors measure the branching fraction {Beta}(B{sup 0} {yields} a{sub 1}{sup {+-}}(1260){pi}{sup {-+}}){Beta}(a{sub 1}{sup {+-}}(1260){yields} {pi}{sup {-+}}{pi}{sup {+-}}{pi}{sup {+-}})=(16.6 {+-} 1.9 {+-} 1.5) x 10{sup -6}, where the first error quoted is statistical and the second is systematic.
Date: March 27, 2006
Creator: Aubert, B.
Partner: UNT Libraries Government Documents Department

Observation of CP violation in B^0 to eta' K^0

Description: The authors present measurements of the time-dependent CP-violation parameters S and C in B{sup 0} {yields} K{sup 0} decays. The data sample corresponds to 384 million B{bar B} pairs produced by e{sup +}e{sup -} annihilation at the {Upsilon}(4S). The results are S = 0.58 {+-} 0.10 {+-} 0.03, and C = -0.16 {+-} 0.07 {+-} 0.03. They observe mixing-induced CP violation with a significance of 5.5 standard deviations in this b {yields} s penguin dominated mode.
Date: October 6, 2006
Creator: Aubert, B.
Partner: UNT Libraries Government Documents Department

Observation of CP Violation in B0 to K+pi- and B0 to pi+pi-

Description: The authors report observations of CP violation in the decays B{sup 0} {yields} K{sup +}{pi}{sup -} and B{sup 0} {yields} {pi}{sup +}{pi}{sup -} in a sample of 383 million {Upsilon}(4S) {yields} B{bar B} events. They find 4372 {+-} 82 B{sup 0} {yields} K{sup +}{pi}{sup -} decays and measure the direct Cp-violating charge asymmetry {Alpha}{sub K{pi}} = -0.107 {+-} 0.018(stat){sub -0.004}{sup +0.007}(syst), which excludes the CP-conserving hypothesis with a significance of 5.5 standard deviations. In the same sample they find 1139 {+-} 49 B{sup 0} {yields} {pi}{sup +}{pi}{sup -} decays and measure the CP-violating asymmetries S{sub {pi}{pi}} = -0.60 {+-} 0.11(stat) {+-} 0.03(syst) and C{sub {pi}{pi}} = -0.21 {+-} 0.09(stat) {+-} 0.02(syst). CP conservation in B{sup 0} {yields} {pi}{sup +}{pi}{sup -} (S{sub {pi}{pi}} = C{sub {pi}{pi}} = 0) is excluded at a confidence level 1-C.L. = 8 x 10{sup -8}, corresponding to 5.4 standard deviations.
Date: March 14, 2007
Creator: Aubert, B.
Partner: UNT Libraries Government Documents Department

Observation of Decays $B^0\to D_s^{(*)+}\pi^-$ and$B^0\to D_s^{(*)-}K^+$

Description: The authors report the observation of decays B{sup 0} {yields} D{sub s}{sup (*)+} {pi}{sup -} and B{sup 0} {yields} D{sub s}{sup (*)-} K{sup +} in a sample of 230 x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} events recorded with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} storage ring. They measure the branching fractions {Beta}(B{sup 0} {yields} D{sub s}{sup +}{pi}{sup -}) = (1.3 {+-} 0.3(stat) {+-} 0.2(syst)) x 10{sup -5}, {Beta}(B{sup 0} {yields} D{sub s}{sup -}K{sup +}) = (2.5 {+-} 0.4(stat) {+-} 0.4(syst)) x 10{sup -5}, {Beta}(B{sup 0} {yields} D*{sub s}{sup +} {pi}{sup -}) = (2.8 {+-} 0.6(stat) {+-} 0.5 (syst)) x 10{sup -5}, and {Beta}(B{sup 0} {yields} D*{sub s}{sup -} K{sup +}) = (2.0 {+-} 0.5(stat) {+-} 0.4(syst)) x 10{sup -5}. The significance of the measurements to differ from zero are 5, 9, 6, and 5 standard deviations, respectively.
Date: April 19, 2006
Creator: Aubert, B.
Partner: UNT Libraries Government Documents Department

Observation of e+e- Annihilations into the C=+1 Hadronic Final States \rho^0\rho^0 and \phi\rho^0

Description: The authors report the first observation of e{sup +}e{sup -} annihilations into states of positive C-parity, namely {rho}{sup 0}{rho}{sup 0} and {phi}{rho}{sup 0}. The two states are observed in the {pi}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -} and K{sup +}K{sup -} {pi}{sup +}{pi}{sup -} final states, respectively, in a data sample of 225 fb{sup -1} collected by the BABAR experiment at the PEP-II e{sup +}e{sup -} storage rings at energies near {radical}s = 10.58 GeV. The distributions of cos {theta}*, where {theta}* is the center-of-mass polar angle of the {phi} meson or the forward {rho}{sup 0} meson, suggest production by two-virtual-photon annihilation. They measure cross sections within the range |cos {theta}*| < 0.8 of {sigma}(e{sup +}e{sup -} {yields} {rho}{sup 0} {rho}{sup 0}) = 20.7 {+-} 0.7(stat) {+-} 2.7(syst) fb and {sigma}(e{sup +}e{sup -} {yields} {phi}{rho}{sup 0}) = 5.7 {+-} 0.5(stat) {+-} 0.8(syst) fb.
Date: June 27, 2006
Creator: Aubert, B.
Partner: UNT Libraries Government Documents Department

Observation of the Bottomonium Ground State in the Decay Y(3S) to ynb

Description: The authors report the results of a search for the bottomonium ground state {eta}{sub b}(1S) in the photon energy spectrum with a sample of (109 {+-} 1) million of {Upsilon}(3S) recorded at the {Upsilon}(3S) recorded at the {Upsilon}(3S) energy with the BABAR detector at the PEP-II B factory at SLAC. They observe a peak in the photon energy spectrum at E{sub {gamma}} = 921.2{sub -2.8}{sup +2.1}(stat) {+-} 2.4(syst) MeV with a significance of 10 standard deviations. They interpret the observed peak as being due to monochromatic photons from the radiative transition {Upsilon}(3S) {yields} {gamma} {eta}{sub b}(1S). This photon energy corresponds to an {eta}{sub b}(1S) mass of 9388.9{sub -2.3}{sup +3.1}(stat) {+-} 2.7(syst) MeV/c{sup 2}. The hyperfine {Upsilon}(1S)-{eta}{sub b}(1S) mass splitting is 71.4{sub -3.1}{sup +2.3}(stat) {+-} 2.7(syst) MeV/c{sup 2}. The branching fraction for this radiative {Upsilon}(3S) decay is estimated to be (4.8 {+-} 0.5(stat) {+-} 1.2(syst)) x 10{sup -4}.
Date: July 11, 2008
Creator: Aubert, B.
Partner: UNT Libraries Government Documents Department

Observation of the decays B- to Ds(*)+ K- pi-

Description: The authors report first observations of the decays B{sup -} {yields} D{sub s}{sup (*)+} K{sup -}{pi}{sup -}, using 292 fb{sup -1} of data collected at the {Upsilon}(4S) resonance energy by the BABAR detector at the PEP-II e{sup +}e{sup -} collider. The branching fractions are measured to be {Beta}(B{sup -} {yields} D{sub s}{sup +}K{sup -}{pi}{sup -}) = (1.88 {+-} 0.13 {+-} 0.41) {center_dot} 10{sup -4} and {Beta}(B{sup -} {yields} D{sub s}{sup *+}K{sup -}{pi}{sup -}) = (1.84 {+-} 0.19 {+-} 0.40) {center_dot} 10{sup -4}.
Date: August 18, 2006
Creator: Aubert, B.
Partner: UNT Libraries Government Documents Department

Observation of the Exclusive Reaction e^+e^-\ to \phi\eta at \sqrt{s}=10.58 GeV

Description: The authors report the observation of e{sup +}e{sup -} {yields} {phi}{eta} near {radical}s = 10.58 GeV with 6.5 {sigma} significance in the K{sup +}K{sup -}{gamma}{gamma} final state in a data sample of 224 fb{sup -1} collected by the BABAR experiment at the PEP-II e{sup +}e{sup -} storage rings. They measure the restricted radiation-corrected cross section to be {sigma}(e{sup +}e{sup -} {yields} {phi}{eta}) = 2.1 {+-} 0.4(stat) {+-} 0.1(syst) fb within the range |cos{theta}*| < 0.8, where {theta}* is the center-of-mass polar angle of the {phi} meson. The {phi} meson is required to be in the invariant mass range of 1.008 < m{sub {phi}} < 1.035 GeV/c{sup 2}. The radiation corrected cross section in the full cos {theta}* range is extrapolated to be 2.9 {+-} 0.5(stat) {+-} 0.1(syst) fb.
Date: November 17, 2006
Creator: Aubert, B.
Partner: UNT Libraries Government Documents Department

Evidence for D(0)-Dbar(0) Mixing

Description: We present evidence for D{sup 0}-{bar D}{sup 0} mixing in D{sup 0} {yields} K{sup +}{pi}{sup -} decays from 384 fb{sup -1} of e{sup +}e{sup -} colliding-beam data recorded near {radical}s = 10.6GeV with the BABAR detector at the PEP-II storage rings at SLAC. We find the mixing parameters x{prime}{sup 2} = [-0.22 {+-} 0.30 (stat.) {+-} 0.21 (syst.)] x 10{sup -3} and y{prime} = [9.7 {+-} 4.4(stat.) {+-} 3.1(syst.)] x 10{sup -3}, and a correlation between them of -0.94. This result is inconsistent with the no-mixing hypothesis with a significance of 3.9 standard deviations. We measure R{sub D}, the ratio of doubly Cabibbo-suppressed to Cabibbo-favored decay rates, to be [0.303 {+-} 0.016 (stat.) {+-} 0.010 (syst.)]%. We find no evidence for CP violation.
Date: March 13, 2007
Creator: Aubert, B.
Partner: UNT Libraries Government Documents Department

Evidence for B- to rho0rho0 Decay and Implications for the CKM Angle alpha

Description: The authors search for the decays B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0}, B{sup 0} {yields} {rho}{sup 0} f{sub 0}(980), and B{sup 0} {yields} f{sub 0}(980) f{sub 0}(980) in a sample of about 384 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at SLAC. They find evidence for B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0} with 3.5{sigma} significance and measure the branching fraction {Beta} = (1.07 {+-} 0.33 {+-} 0.19) x 10{sup -6} and longitudinal polarization fraction f{sub L} = 0.87 {+-} 0.13 {+-} 0.04, where the first uncertainty is statistical, and the second is systematic. The uncertainty on the CKM unitarity angle {alpha} due to penguin contributions in B {yields} {rho}{rho} decays is 18{sup o} at the 1{sigma} level. They also set upper limits on the B{sup 0} {yields} {rho}{sup 0} f{sub 0}(980) and B{sup 0} {yields} f{sub 0}(980)f{sub 0}(980) decay rates.
Date: January 3, 2007
Creator: Aubert, B.
Partner: UNT Libraries Government Documents Department

Xic' Production at BABAR

Description: Using 232 fb{sup -1} of data collected by the BABAR detector, the {Xi}'{sub c}{sup +} and {Xi}'{sub c}{sup 0} baryons are reconstructed through the decays: {Xi}'{sub c}{sup +} {yields} {Xi}{sub c}{sup +}{gamma} and {Xi}'{sub c}{sup 0} {yields} {Xi}{sub c}{sup 0}{gamma}, where {Xi}{sub c}{sup +} {yields} {Xi}{sup -}{pi}{sup +}{pi}{sup +} and {Xi}{sub c}{sup 0} {yields} {Xi}{sup -} {pi}{sup +}. By measuring the efficiency-corrected yields in different intervals of the center-of-mass momentum, the production rates from B decays and from the continuum are extracted. For production from B decays, the branching fractions are found to be {Beta}(B {yields} {Xi}'{sub c}{sup +}X) x {Beta}({Xi}{sub c}{sup +} {yields} {Xi}{sup -}{pi}{sup +}{pi}{sup +}) = [1.69 {+-} 0.17 (exp.) {+-} 0.10 (model)] x 10{sup -4} and {Beta}(B {yields} {Xi}'{sub c}{sup 0}X) x {Beta} {Xi}{sub c}{sup 0} {yields} {Xi}{sup -} {pi}{sup +} = [0.67 {+-} 0.07 (exp.) {+-} 0.03 (model)] x 10{sup -4}. For production from the continuum the cross-sections are found to be {sigma}(e{sup +}e{sup -} {yields} {Xi}'{sub c}{sup +}X) x {Beta}({Xi}{sub c}{sup +} {yields} {Xi}{sup -} {pi}{sup +}{pi}{sup +}) = 141 {+-} 24 (exp.) {+-} 19 (model) fb and {sigma}(e{sup +}e{sup -} {yields} {Xi}'{sub c}{sup 0}X) x {Beta}({Xi}{sub c}{sup 0} {yields} {Xi}{sup -} {pi}{sup +}) = 70 {+-} 11 (exp.) {+-} 6 (model) fb. The helicity angle distributions of {Xi}'{sub c} decays are studied and found to be consistent with J = 1/2.
Date: September 26, 2006
Creator: Aubert, B
Partner: UNT Libraries Government Documents Department

Observation of Y(3940) to J/psi omega in B to J/psi omega K at BABAR

Description: The authors report the results of a study of the decays B{sup +} {yields} J/{psi}{omega}K{sup +} and B{sup 0} {yields} J/{psi}{omega}K{sub S}{sup 0} using 383 million B{bar B} events from {Upsilon}(4S) decays with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} storage rings. They observe evidence for Y(3940) {yields} J/{psi}{omega} with product branching fractions {Beta}(B{sup +} {yields} Y K{sup +}, Y {yields} J/{psi}{omega}) = (4.9 {+-} 1.0(stat) {+-} 0.5(syst)) x 10{sup -5} and {Beta}(B{sup 0} {yields} Y K{sup 0}, Y {yields} J/{psi}{omega}) = (1.5{sub -1.2}{sup +1.4}(stat){sub -0.2}{sup +0.2}(syst)) x 10{sup -5}. The measured mass and width are M(Y) = (3914.6{sub -3.4}{sup +3.8}(stat){sub -1.9}{sup +1.9}(syst)) MeV/c{sup 2} and {Lambda}(Y) = (33{sub -8}{sup +12}(stat){sub -5}{sup +5}(syst)) MeV, respectively.
Date: December 4, 2007
Creator: Aubert, B.
Partner: UNT Libraries Government Documents Department

Observation of $\Upsilon(4S) decays to$\pi^+pi^-\Upsilon(1S)$ and $\pi^+pi^-\Upsilon(1S)$

Description: The authors present the first measurement of {Upsilon}(4S) decays to {pi}{sup +}{pi}{sup -} {Upsilon}(1S) and {pi}{sup +}{pi}{sup -} {Upsilon}(2S) based on a sample of 230 x 10{sup 6} {Upsilon}(4S) mesons collected with the BABAR detector. They measure the product branching fractions {Beta}({Upsilon}(4S) {yields} {pi}{sup +}{pi}{sup -} {Upsilon}(1S)) x {Beta}({Upsilon}(1S) {yields} {mu}{sup +}{mu}{sup -}) = (2.23 {+-} 0.25{sub stat} {+-} 0.27{sub sys}) x 10{sup -6} and {Beta}({Upsilon}(4S) {yields} {pi}{sup +}{pi}{sup -}{Upsilon}(2S)) x {Beta}({Upsilon}(2S) {yields} {mu}{sup +}{mu}{sup -}) = (1.69 {+-} 0.26{sub stat} {+-} 0.20{sub sys}) x 10{sup -6}, from which they derive the partial widths {Lambda}({Upsilon}(4S) {yields} {pi}{sup +}{pi}{sup -} {Upsilon}(1S)) = (1.8 {+-} 0.4) keV and {Lambda}({Upsilon}(4S) {yields} {pi}{sup +}{pi}{sup -}{Upsilon}(2S)) = (2.7 {+-} 0.8) keV.
Date: April 19, 2006
Creator: Aubert, B.
Partner: UNT Libraries Government Documents Department

Measurement of CP Asymmetries in B0 to K0S K0S K0S Decays

Description: The authors present measurements of the time-dependent CP-violating asymmetries in B{sup 0} {yields} K{sub S}{sup 0}K{sub S}{sup 0}K{sub S}{sup 0} decays based on 384 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. They obtain the CP asymmetry parameters C = 0.02 {+-} 0.21 {+-} 0.05 and S = -0.71 {+-} 0.24 {+-} 0.04, where the first uncertainties are statistical and the second systematic. These results are consistent with standard model expectations.
Date: March 6, 2007
Creator: Aubert, B.
Partner: UNT Libraries Government Documents Department

Measurement of CP Asymmetry in B0 to Ks pi0 pi0 Decays

Description: We present a measurement of the time-dependent CP asymmetry for the neutral B-meson decay into the CP = +1 final state K{sub S}{sup 0}{pi}{sup 0}{pi}{sup 0}, with K{sub S}{sup 0} {yields} {pi}{sup +}{pi}{sup -}. We use a sample of approximately 227 million B-meson pairs recorded at the {Upsilon}(4S) resonance with the BABAR detector at the PEP-II B-Factory at SLAC. From an unbinned maximum likelihood fit we extract the mixing-induced CP-violation parameter S = 0.72 {+-} 0.71 {+-} 0.08 and the direct CP-violation parameter C = 0.23 {+-} 0.52 {+-} 0.13, where the first uncertainty is statistical and the second systematic.
Date: February 6, 2007
Creator: Aubert, B.
Partner: UNT Libraries Government Documents Department

Measurement of D^0-\overline{D^0} Mixing using the Ratio of Lifetimes for the Decays D^0 \to K^-\pi^+, K^-K^+, and \pi^-\pi^+

Description: The authors present a measurement of D{sup 0}-{bar D}{sup 0} mixing parameters using the ratios of lifetimes extracted from a sample of D{sup 0} mesons produced through the process D*{sup +} {yields} D{sup 0}{pi}{sup +}, that decay to K{sup -}{pi}{sup +}, I{sup -}K{sup +}, or {pi}{sup -}{pi}{sup +}. the Cabibbo-suppressed modes K{sup -}K{sup +} and {pi}{sup -}{pi}{sup +} are compared to the Cabibbo-favored mode K{sup -}{pi}{sup +} to obtain a measurement of ycp, which in the limit of CP conservation corresponds to the mixing parameter y. The analysis is based on a data sample of 384 fb{sup -1} collected by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider. They obtain ycp = [1.24 {+-} 0.39(stat) {+-} 0.13(syst)]%, which is evidence of D{sup 0}-{bar D}{sup 0} mixing at the 3{sigma} level, and {Delta}Y = [-0.26 {+-} 0.36(stat) {+-} 0.08(syst)]%, where {Delta}Y constrains possible CP violation. Combining this result with a previous BABAR measurement of ycp obtained from a separate sample of D{sup 0} {yields} K{sup -}K{sup +} events, they obtain ycp = [1.03 {+-} 0.33(stat) {+-} 0.19(syst)]%.
Date: January 8, 2008
Creator: Aubert, B
Partner: UNT Libraries Government Documents Department