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B meson decays to charmless meson pairs containing eta or eta'

Description: The authors present updated measurements of the branching fractions for B{sup 0} meson decays to {eta}K{sup 0}, {eta}{eta}, {eta}{phi}, {eta}{omega}, {eta}{prime}K{sup 0}, {eta}{prime}{eta}{prime}, {eta}{prime}, {phi}, and {eta}{prime}{omega} and branching fractions and CP-violating charge asymmetries for B{sup +} decays to {eta}{pi}{sup +}, {eta}K{sup +}, {eta}{prime}{pi}{sup +}, and {eta}{prime} K{sup +}. The data represent the full dataset of 467 x 10{sup 6} B{bar B} pairs collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at the SLAC National Accelerator Laboratory. Besides large signals for the four charged B decays modes and for B{sup 0} {yields} {eta}{prime}K{sup 0}, they find evidence for three B{sup 0} decays modes at greater than 3.0{sigma} significance. They find {Beta}(B{sup 0} {yields} {eta}K{sup 0}) = (1.15{sub -0.38}{sup +0.43} {+-} 0.09) x 10{sup -6}, {Beta}(B{sup 0} {yields} {eta}{omega}) = (0.94{sub -0.30}{sup +0.35} {+-} 0.09) x 10{sup -6}, and {Beta}(B{sup 0} {yields} {eta}{prime}{omega}) = (1.01{sub -0.38}{sup +0.46} {+-} 0.09) x 10{sup -6}, where the first (second) uncertainty is statistical (systematic). For the B{sup +} {yields} {eta}K{sup +} decay mode, they measure the charge asymmetry {Alpha}{sub ch} (B{sup +} {yields} {eta}K{sup +}) = -0.36 {+-} 0.11 {+-} 0.03.
Date: December 14, 2009
Creator: Aubert, : B.
Partner: UNT Libraries Government Documents Department

Dalitz Plot Analysis of B- -> D+ pi- pi-

Description: The author reports on a Dalitz plot analysis of B{sup -} {yields} D{sup +}{pi}{sup -}{pi}{sup -} decays, based on a sample of about 383 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. They find the total branching fraction of the three-body decay: {Beta}(B{sup -} {yields} D{sup +} {pi}{sup -}{pi}{sup -}) = (1.08 {+-} 0.01 {+-} 0.05) x 10{sup -3}. the masses and widths of D*{sub 2}{sup 0} and D*{sub 0}{sup 0}, the 2{sup +} and 0{sup +} c{bar u} P-wave states decaying to D{sup +}{pi}{sup -}, are measured: m{sub D*{sub 2}{sup 0}} = (2460.4 {+-} 1.2 {+-} 1.2 {+-} 1.9) MeV/c{sup 2}, {Lambda}{sub D*{sub 2}{sup 0}} = (41.8 {+-} 2.5 {+-} 2.1 {+-} 2.0) MeV, m{sub D*{sub 0}{sup 0}} = (2297 {+-} 8 {+-} 5 {+-} 19) MeV/c{sup 2} and {Lambda}{sub D*{sub 0}{sup 0}} = (273 {+-} 12 {+-} 17 {+-} 45) MeV. The stated errors reflect the statistical and systematic uncertainties, and the uncertainty related to the assumed composition of signal events and the theoretical model.
Date: January 29, 2009
Creator: Aubert, : B.
Partner: UNT Libraries Government Documents Department

Improved Measurement of the CKM Angle gamma in B^-+ to D^(*) K^(*)-+Decays with a Dalitz Plot Analysis of D Decays to K_S^0 pi+ pi- and K_S^0 K+ K-

Description: We report on an improved measurement of the Cabibbo-Kobayashi-Maskawa CP-violating phase {gamma} through a Dalitz plot analysis of neutral D meson decays to K{sub s}{sup 0}{pi}{sup +}{pi}{sup -} and K{sub s}{sup 0}K{sup +}K{sup -} produced in the processes B{sup {-+}} {yields} DK{sup {-+}}, B{sup {-+}} {yields} D* K{sup {-+}} with D* {yields} D{pi}{sup 0}, D{gamma}, and B{sup {-+}} {yields} DK*{sup {-+}} with K8{sup {-+}} {yields} K{sub S}{sup 0}{pi}{sup {-+}}. Using a sample of 383 million B{bar B} pairs collected by the BABAR detector, we measure {gamma} = (76 {+-} 22 {+-} 5{+-} 5){sup o} (mod 180{sup o}), where the first error is statistical, the second is the experimental systematic uncertainty and the third reflects the uncertainty on the description of the Dalitz plot distributions. The corresponding two standard deviation region is 29{sup o} < {gamma} < 122{sup o}. This result has a significance of direct CP violation ({gamma} {ne} 0) of 3.0 standard deviations.
Date: April 22, 2008
Creator: Aubert, : B.
Partner: UNT Libraries Government Documents Department

Measurement of the Semileptonic Decays B->D tau nu and B->D* tau nu

Description: The authors present measurements of the semileptonic decays B{sup -} {yields} D{sup 0} {tau}{sup -} {bar {nu}}{sub {tau}}, B{sup -} {yields} D*{sup 0} {tau}{sup -}{bar {nu}}{sub {tau}}, {bar B}{sup 0} {yields} D{sup +} {tau}{sup -} {bar {nu}}{sub {tau}}, and {bar B}{sup 0} {yields} D*{sup +} {tau}{sup -}{bar {nu}}{sub {tau}}, which are sensitive to non-Standard Model amplitudes in certain scenarios. The data sample consists of 232 x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II e{sup +}e{sup -} collider. They select events with a D or D* meson and a light lepton ({ell} = e or {mu}) recoiling against a fully reconstructed B meson. They perform a fit to the joint distribution of lepton momentum and missing mass squared to distinguish signal B {yields} D{sup (*)}{tau}{sup -} {bar {nu}}{sub {tau}} ({tau}{sup -} {yields} {ell}{sup -} {bar {nu}}{sub {ell}}{nu}{sub {tau}}) events from the backgrounds, predominantly B {yields} D{sup (*)} {ell}{sup -}{bar {nu}}{sub {ell}}. They measure the branching-fraction ratios R(D) {triple_bond} {Beta}(B {yields} D{tau}{sup -} {bar {nu}}{sub {tau}})/{Beta}(B {yields} D{ell}{sup -} {bar {nu}}{sub {ell}}) and R(D*) {triple_bond} {Beta}(B {yields} D*{tau}{sup -} {bar {nu}}{sub {tau}})/{Beta}(B {yields} D* {ell}{sup -} {bar {nu}}{sub {ell}}) and, from a combined fit to B{sup -} and {bar B}{sup 0} channels, obtain the results R(D) = (41.6 {+-} 11.7 {+-} 5.2)% and R(D*) = (29.7 {+-} 5.6 {+-} 1.8)%, where the uncertainties are statistical and systematic. Normalizing to measured B{sup -} {yields} D{sup (*)0} {ell}{sup -} {bar {nu}}{sub {ell}} branching fractions, they obtain {Beta}(B {yields} D{tau}{sup -} {bar {nu}}{sub {tau}}) = (0.86 {+-} 0.24 {+-} 0.11 {+-} 0.06)% and {Beta}(B {yields} D*{tau}{sup -} {bar {nu}}{sub {tau}}) = (1.62 {+-} 0.31 {+-} 0.10 {+-} 0.05)%, where the additional third uncertainty is from the normalization mode. They also present, for the first time, distributions of ...
Date: February 23, 2009
Creator: Aubert, : B.
Partner: UNT Libraries Government Documents Department

Measurement of Time-Dependent CP Asymmetry in B0->ccbar K(*)0 Decays

Description: The authors present updated measurements of time-dependent Cp asymmetries in fully reconstructed neutral B decays containing a charmonium meson. The measurements reported here use a data sample of (465 {+-} 5) x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric energy e{sup +}e{sup -} storage rings operating at the SLAC National Accelerator Laboratory. The time-dependent CP asymmetry parameters measured from J/{psi} K{sub S}{sup 0}, J/{psi}K{sub L}{sup 0}, {psi}(2S)K{sub S}{sup 0}, {eta}{sub c}K{sub S}{sup 0}, {chi}{sub c1}K{sub S}{sup 0} and J/{psi} K*(892){sup 0} decays are: C{sub f} = 0.024 {+-} 0.020(stat) {+-} 0.016(syst) and -{eta}{sub f}S{sub f} = 0.687 {+-} 0.028(stat) {+-} 0.012(syst).
Date: February 12, 2009
Creator: Aubert, : B.
Partner: UNT Libraries Government Documents Department

Measurement of time dependent CP asymmetry parameters in B0 meson decays to omegaKs, etaprimeKz, and pi0Ks

Description: The authors present measurements of the time-dependent CP-violation parameters S and C in the decays B{sup 0} {yields} {omega}K{sub S}{sup 0}, B{sup 0} {yields} {eta}{prime}K{sup 0}, reconstructed as {eta}{prime}K{sub S}{sup 0} and {eta}{prime}K{sub L}{sup 0}, and B{sup 0} {yields} {pi}{sup 0}K{sub S}{sup 0}. The data sample corresponds to the full BABAR dataset of 467 x 10{sup 6} B{bar B} pairs produced at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at the Stanford Linear Accelerator Center. The results are S{sub {omega}K{sub S}{sup 0}} = 0.55{sub -0.29}{sup +0.26} {+-} 0.02, C{sub {omega}K{sub S}{sup 0}} = -0.52{sub -0.20}{sup +0.22} {+-} 0.03, S{sub {eta}{prime}K{sup 0}} = 0.57 {+-} 0.08 {+-} 0.02, C{sub {eta}{prime}K{sup 0}} = -0.08 {+-} 0.06 {+-} 0.02, S{sub {pi}{sup 0}K{sub S}{sup 0}} = 0.55 {+-} 0.20 {+-} 0.03, and C{sub {pi}{sup 0}K{sub S}{sup 0}} = 0.13 {+-} 0.13 {+-} 0.03, where the first errors are statistical and the second systematic. These results are consistent with the previous measurements and the world average of sin2{beta} measured in B{sup 0} {yields} J/{psi}K{sub S}{sup 0}.
Date: September 10, 2008
Creator: Aubert, : B.
Partner: UNT Libraries Government Documents Department

Observation and Polarization Measurement of B0 --> a1(1260) a1(1260)- Decay

Description: The authors present measurements of the branching fraction {Beta} and longitudinal polarization fraction f{sub L} for B{sup 0} {yields} a{sub 1}(1260){sup +} a{sub 1}(1260){sup -} decays, with a{sub 1}(1260){sup {+-}} {yields} {pi}{sup -}{pi}{sup +}{pi}{sup {+-}}. The data sample, collected with the BABAR detector at the SLAC National Accelerator Laboratory, represents 465 x 10{sup 6} produced B{bar B} pairs. They measure {Beta}(B{sup 0} {yields} a{sub 1}(1260){sup +} a{sub 1}(1260){sup -}) x [{Beta}(a{sub 1}(1260){sup +} {yields} {pi}{sup -}{pi}{sup +}{pi}{sup +})]{sup 2} = (11.8 {+-} 2.6 {+-} 1.6) x 10{sup -6} and f{sub L} = 0.31 {+-} 0.22 {+-} 0.10, where the first uncertainty is statistical and the second systematic. The decay mode is measured with a significance of 5.0 standard deviations including systematic uncertainties.
Date: August 3, 2009
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 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

Search for Decays of B0 Mesons into e+e-, \mu+\mu-, and e+-\mu+- Final States

Description: The authors present a search for the decays B{sup 0} {yields} e{sup +}e{sup -}, B{sup 0} {yields} {mu}{sup +}{mu}{sup -} and B{sup 0} {yields} e{sup {+-}}{mu}{sup {-+}} using data collected with the BABAR detector at the PEP-II e{sup +}e{sup -} collider at SLAC. Using a dataset corresponding to 384 x 10{sup 6} B{bar B} pairs, they do not find evidence of any of the three decay modes. They obtain upper limit on the branching fractions, at 90% confidence level, of {Beta}(B{sup 0} {yields} e{sup +}e{sup -}) < 11.3 x 10{sup -8}, {Beta}(B{sup 0} {yields} {mu}{sup +}{mu}{sup -}) < 5.2 x 10{sup -8}, and {Beta}(B{sup 0} {yields} e{sup {+-}}{mu}{sup {-+}}) < 9.2 x 10{sup -8}.
Date: December 19, 2007
Creator: Aubert, : B.
Partner: UNT Libraries Government Documents Department

Measurement of Branching Fractions of Radiative Charm Decays

Description: We present a measurement of the branching fractions for the Cabibbo-favored radiative decay, D{sup 0} {yields} {bar K}*{sup 0}{gamma}, and the Cabibbo-suppressed radiative decay, D{sup 0} {yields} {phi}{gamma}. These measurements are based on a data sample corresponding to an integrated luminosity of 387.1 fb{sup -1}, recorded with the BABAR detector at the PEP-II e{sup +}e{sup -} asymmetric-energy collider operating at center-of-mass energies 10.58 and 10.54 GeV. We measure the branching fractions relative to the well-studied decay D{sup 0} {yields} K{sup -}{pi}{sup +} and find {Beta}(D{sup 0} {yields} {bar K}*{sup 0}{gamma})/{Beta}(D{sup 0} {yields} K{sup -}{pi}{sup +}) = (8.43 {+-} 0.51 {+-} 0.70) x 10{sup -3} and {Beta}(D{sup 0} {yields} {phi}{gamma})/{Beta}(D{sup 0} {yields} K{sup -}{pi}{sup +}) = (7.15 {+-} 0.78 {+-} 0.69) x 10{sup -4}, where the first error is statistical and the second is systematic. This is the first measurement of {Beta}(D{sup 0} {yields} {bar K}*{sup 0} {gamma}).
Date: August 18, 2008
Creator: Aubert, B
Partner: UNT Libraries Government Documents Department

Measurement of CP Asymmetries and Branching Fractions in B to pi pi and B to K pi Decays.

Description: The authors present preliminary measurements of the Cp asymmetries and branching fractions for B {yields} {pi}{pi} and B {yields} K{pi} decays. A total of 347 million B{bar B} events collected by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at SLAC are used for these results.
Date: September 26, 2006
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

Measurement of the Branching Fraction, Polarization, and CP Asymmetries in B0->rho0rho0 Decay, and Implications for the CKM Angle alpha

Description: We study B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0} decays in a sample of 465 x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} events collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider located at the Stanford Linear Accelerator Center (SLAC). We measure the branching fraction {Beta} = (0.92 {+-} 0.32 {+-} 0.14) x 10{sup -6} and longitudinal polarization fraction f{sub L} = 0.75{sub -0.14}{sup +0.11} {+-} 0.04, where the first uncertainty is statistical and the second is systematic. The evidence for the B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0} signal has a significance of 3.1 standard deviations, including systematic uncertainties. We investigate the proper-time dependence of the longitudinal component in the decay and measure the CP-violating coefficients S{sub L}{sup 00} = (0.3 {+-} 0.7 {+-} 0.2) and C{sub L}{sup 00} = (0.2 {+-} 0.8 {+-} 0.3). They study the implication of these results for the unitarity triangle angle {alpha}.
Date: September 10, 2008
Creator: Aubert, B
Partner: UNT Libraries Government Documents Department

Measurement of the CP-violating Asymmetries in B0->K0Spi0 and of the Branching Fraction of B0->K0pi0

Description: The authors present a measurement of the time-dependent CP-violating asymmetries in B{sup 0} {yields} K{sub S}{sup 0}{pi}{sup 0} decays based on 348 million {Upsilon}(4S) {yields} B{bar B} events collected by the BABAR experiment at the PEP-II asymmetric-energy B Factory at SLAC. They measure the direct Cp-violating asymmetry C{sub K{sub S}{sup 0}{pi}{sup 0}} = 0.20 {+-} 0.16 {+-} 0.03 and the CP-violating asymmetry in the interference between mixing and decay S{sub K{sub S}{sup 0}{pi}{sup 0}} = 0.33 {+-} 0.26 {+-} 0.04 where the first error is statistical and the second systematic. On the same sample, they measure the decay branching fraction, obtaining {Beta}(B{sup 0} {yields} K{sub S}{sup 0}{pi}{sup 0}) = (10.5 {+-} 0.7 {+-} 0.5) x 10{sup -6}. All results presented here are preliminary.
Date: September 26, 2006
Creator: Aubert, B
Partner: UNT Libraries Government Documents Department

Measurement of the Relative Branching Fractions for B^- to D/D^{*}/D^{**}(D^{(*)}\pi) \ell^- \bar{\nu}_{\ell} with a Large Sample of Tagged B Mesons

Description: We present a study of B semileptonic decays into charm final states based on 211.7 fb{sup -1} of data collected at the {Upsilon}(4S) resonance with the BABAR detector at the PEP-II e{sup +}e{sup -} storage ring. Using a novel technique based on the simultaneous fit of a set of variables reconstructed on the recoil of a B tagged in an hadronic decay mode, we measure the relative branching fractions {Lambda}(B{sup -} {yields} D{sup 0}{ell}{sup -}{bar {nu}}{sub {ell}}) = 0.611 {+-} 0.022 (stat.) {+-} 0.027 (syst.) and {Lambda}(B{sup -} {yields} D**{sup 0})(D{sup (*)}{pi}){ell}{sup -}{bar {nu}}{sub {ell}}/{Lambda}(B{sup -} {yields} DX{ell}{sup -}{bar {nu}}{sub {ell}}) = 0.173 {+-} 0.017 (stat.) {+-} 0.021 (syst.).
Date: September 26, 2006
Creator: Aubert, B
Partner: UNT Libraries Government Documents Department

Measurement of |Vcb| and the Form-Factor Slope for BBar -> Dlnu Decays on the Recoil of Fully Reconstructed B Mesons

Description: We present a measurement of the CKM matrix element |V{sub cb}| and the form-factor slope {rho}{sup 2} for {bar B} {yields} D{ell}{sup -} {bar {nu}}{sub {ell}} decays based on 417 fb{sup -1} of data collected at the {Upsilon}(4S) resonance with the BABAR detector. The semileptonic decays are selected in B{bar B} events in which the hadronic decay of the second B meson is fully reconstructed. From the measured differential decay rate of the signal decay we determine G(1)|V{sub cb}| = (43.0 {+-} 1.9 {+-} 1.4) x 10{sup -3}, {rho}{sup 2} = 1.20 {+-} 0.09 {+-} 0.04, where G(1) is the hadronic form factor at the point of zero recoil. Using a lattice calculation for G(1) we extract |V{sub cb}| = (39.8 {+-} 1.8 {+-} 1.3 {+-} 0.9) x 10{sup -3}, where the stated errors refer to the statistical, systematic, and form factor uncertainties. We also present a measurement of the exclusive branching fractions, {Beta}(B{sup -} {yields} D{sup 0} {ell}{sup -} {bar {nu}}{sub {ell}}) = (2.31 {+-} 0.08 {+-} 0.07)% and {Beta}({bar B}{sup 0} {yields} D{sup +} {ell}{sup -} {bar {nu}}{sub {ell}}) = (2.23 {+-} 0.11 {+-} 0.08)%.
Date: August 21, 2008
Creator: Aubert, B
Partner: UNT Libraries Government Documents Department

Measurements of Branching Fractions for B+ -> rho+ gamma, B0 -> rho0 gamma, and B0 -> omega gamma

Description: The authors present branching fraction measurements for the radiative decays B{sup +} {yields} {rho}{sup +}{gamma}, B{sup 0} {yields} {rho}{sup 0}{gamma}, and B{sup 0} {yields} {omega}{gamma}. The analysis is based on a data sample of 465 million B{bar B} events collected with the BABAR detector at the PEP-II asymmetric-energy B Factory located at the Stanford Linear Accelerator Center (SLAC). They find {Beta}(B{sup +} {yields} {rho}{sup +}{gamma}) = (1.20{sub -0.37}{sup +0.42} {+-} 0.20) x 10{sup -6}, {Beta}(B{sup 0} {yields} {rho}{sup 0}{gamma}) = (0.97{sub -0.22}{sup +0.24} {+-} 0.06) x 10{sup -6}, and a 90% C.L. upper limit {Beta}(B{sup 0} {yields} {omega}{gamma}) < 0.9 x 10{sup -6}, where the first error is statistical and the second is systematic. They also measure the isospin-violating quantity {Lambda}(B{sup +} {yields} {rho}{sup +}{gamma})/2{Lambda}(B{sup 0} {yields} {rho}{sup 0}{gamma}) - 1 = -0.43{sub -0.22}{sup +0.25} {+-} 0.10.
Date: August 15, 2008
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 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

Production and Decay of Omega_c^0

Description: We present an analysis of inclusive {Omega}{sub c}{sup 0} baryon production and decays in 230.5 fb{sup -1} of data recorded with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at the Stanford Linear Accelerator Center. {Omega}{sub c}{sup 0} baryons are reconstructed in four final states ({Omega}{sup -}{pi}{sup +}, {Omega}{sup -}{pi}{sup +}{pi}{sup 0}, {Omega}{sup -}{pi}{sup +}{pi}{sup +}{pi}{sup -}, {Xi}{sup -}K{sup -}{pi}{sup +}{pi}{sup +}) and the ratios of branching fractions for these final states are measured. We also measure the momentum spectrum of the {Omega}{sub c}{sup 0} baryons in the e{sup +}e{sup -} center-of-mass frame. From the spectrum, they observe {Omega}{sub c}{sup 0} production from B decays and in c{bar c} events, and extract the two rates of production.
Date: March 21, 2007
Creator: Aubert, B
Partner: UNT Libraries Government Documents Department

Search for B0 to K*+ K*-

Description: The authors report the results of a search for the decay B{sup 0} {yields} K*{sup +}K*{sup -} with a sample of 454 {+-} 5 million B{bar B} pairs collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at the Stanford Linear Accelerator Center. They obtain an upper limit at the 90% confidence level on the branching fraction for {Beta}(B{sup 0} {yields} K*{sup +}K*{sup -}) < 2.0 x 10{sup -6}, assuming the decay is fully longitudinally polarized.
Date: August 7, 2008
Creator: Aubert, B
Partner: UNT Libraries Government Documents Department

Search for Dimuon Decays of a Light Scalar in Radiative Transitions Y(3S) -> gamma A0

Description: The fundamental nature of mass is one of the greatest mysteries in physics. The Higgs mechanism is a theoretically appealing way to account for the different masses of elementary particles and implies the existence of a new, yet unseen particle, the Higgs boson. We search for evidence of a light scalar (e.g. a Higgs boson) in the radiative decays of the narrow {Upsilon}(3S) resonance: {Upsilon}(3S) {yields} {gamma}A{sup 0}, A{sup 0} {yields} {mu}{sup +}{mu}{sup -}. Such an object appears in extensions of the Standard Model, where a light CP-odd Higgs boson naturally couples strongly to b-quarks. We find no evidence for such processes in a sample of 122 x 10{sup 6} {Upsilon}(3S) decays collected by the BABAR collaboration at the PEP-II B-factory, and set 90% C.L. upper limits on the branching fraction product {Beta}({Upsilon}(3S) {yields} {gamma}A{sup 0}) x {Beta}(A{sup 0} {yields} {mu}{sup +}{mu}{sup -}) at (0.25 - 5.2) x 10{sup -6} in the mass range 0.212 {<=} m{sub A{sup 0}} {<=} 9.3 GeV. We also set a limit on the dimuon branching fraction of the {eta}{sub b} meson {Beta}({eta}{sub b} {yields} {mu}{sup +}{mu}{sup -}) < 0.8% at 90% C.L. The results are preliminary.
Date: June 2, 2009
Creator: Aubert, B
Partner: UNT Libraries Government Documents Department

Search for Invisible Decays of a Light Scalar in Radiative Transitions Y(3S)->gamma A0

Description: We search for a light scalar particle produced in single-photon decays of the {Upsilon}(3S) resonance through the process {Upsilon}(3S) {yields} {gamma} + A{sup 0}, A{sup 0} {yields} invisible. Such an object appears in Next-to-Minimal Supersymmetric extensions of the Standard Model, where a light CP-odd Higgs boson naturally couples strongly to b-quarks. If, in addition, there exists a light, stable neutralino, decays of A{sup 0} could be preferentially to an invisible final state. We search for events with a single high-energy photon and a large missing mass, consistent with a 2-body decay of {Upsilon}(3S). We find no evidence for such processes in a sample of 122 x 10{sup 6} {Upsilon}(3S) decays collected by the BABAR collaboration at the PEP-II B-factory, and set 90% C.L. upper limits on the branching fraction {Beta}({Upsilon}(3S) {yields} {gamma}A{sup 0}) x {Beta}(A{sup 0} {yields} invisible) at (0.7-31) x 10{sup -6} in the mass range m{sub A{sup 0}} {le} 7.8 GeV. The results are preliminary.
Date: November 5, 2008
Creator: Aubert, B
Partner: UNT Libraries Government Documents Department