Author : Nicholas L. Blount
Publisher :
Page : 236 pages
File Size : 18,39 MB
Release : 2008
Category : B mesons
ISBN :
Author : Dana Lindemann
Publisher :
Page : pages
File Size : 47,10 MB
Release : 2012
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ISBN :
"This thesis presents the searches for two rare B meson decays: the radiative leptonic decay B+ -> l+ nu gamma (l = e, mu) and the flavor-changing neutral current B -> K(*) nu nubar. These searches use the full dataset collected by the BaBar experiment, which corresponds to almost 500 million BB pairs. After fully reconstructing the hadronic decay of one of the B mesons in Upsilon(4S) -> BB decays, evidence of B+ -> l+ nu gamma or B -> K(*) nu nubar is looked for in the rest of the event. No significant evidence of either signal decay is observed. Model-independent branching-fraction upper limits are set at BR(B ->e nu gamma)17 x10 {-6}, BR(B -mu nu gamma)24 x10 {-6}, and BR(B -l nu gamma)15.6 x10 {-6}, all at the 90% confidence level. These are currently the most stringent published upper limits for B+ - l+ nu gamma. In addition, branching-fraction upper limits are set at BR(B -> K+ nu nubar)3.7 x10 {-5}, BR(B - K0 nu nubar)8.0 x10 {-5}, BR(B - K*+ nu nubar)11.5 x10 {-5}, and BR(B - K*0 nu nubar)9.2 x10 {-5}, all at the 90% confidence level. For additional sensitivity to New Physics contributions, partial B - K(*) nu nubar branching-fraction upper limits are also determined over the full kinematic range." --
Author :
Publisher :
Page : 115 pages
File Size : 21,26 MB
Release : 1941
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ISBN :
Author :
Publisher :
Page : 5 pages
File Size : 19,1 MB
Release : 2002
Category :
ISBN :
We present preliminary results on hadronic decays of B mesons, based on data recorded at the?(4S) resonance with the BABAR detector at the PEP-II B-factory at SLAC. We measure branching fractions of many B decay modes, including decays to J/??K, J/???− and?{sub c}K final states. We report the observation of the decay B → D{sub s}+?− and the first measurement of the flavor-tagged D meson production in B° decays. Since their preliminary nature, the results presented in this paper are based on different data samples.
Author : Stephanie A. Majewski
Publisher :
Page : 218 pages
File Size : 12,93 MB
Release : 2007
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Author :
Publisher :
Page : 5 pages
File Size : 11,52 MB
Release : 2001
Category :
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Using 22.7M B{bar B} events collected with the BABAR detector at SLAC, we present preliminary measurements of the branching fractions for charmless hadronic decays of B mesons into two-body, quasi two-body and three-body final states with pions, kaons, and? and a0 resonances. In the search for exclusive B° →??−?°, we measure?(B° →?{sup ±}(770)?{sup {-+}}) = (28.9 ± 5.4 ± 4.3) x 10−6, together with the relative asymmetry?{sub phys} = -0.04 ± 0.18 {+-} 0.02. We also set the upper limits on B° →?°(770)?°, non-resonant B° →?+?−?°, B° → a0{sup {+-}}(→??{sup {+-}})?{sup {-+}} and B° → K°{bar K}°.
Author :
Publisher :
Page : pages
File Size : 18,58 MB
Release : 2004
Category :
ISBN :
The authors present a search for B decays to charmless final states involving charged or neutral a[sub 0] mesons. The data sample corresponds to 89 million B[bar B] pairs collected with the BABAR detector operating at the PEP-II asymmetric-energy B Factory at SLAC. They find no significant signals and determine the following 90% C.L. upper limits: [Beta](B[sup 0] [yields] a[sub 0][sup -] [pi][sup +])
Author : A. Lazzaro
Publisher :
Page : 3 pages
File Size : 43,32 MB
Release : 2005
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ISBN :
The authors present results for measurement of the decays to charmless final states of B{sup 0} meson to {eta}K{sup 0}, {eta}{omega}, a{sub 1}{sup +}(1260){pi}{sup -} with a{sub 1}{sup +}(1260) {yields} {pi}{sup +}{pi}{sup +}{pi}{sup -}, and of B{sup +} to {eta}{rho}{sup +}, {eta}{prime}{pi}{sup +}. Analyses are based on data taken with the BABAR detector at the PEP-II asymmetric e{sup +}e{sup -} collider at SLAC.
Author :
Publisher :
Page : pages
File Size : 41,72 MB
Release : 2004
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Based on a data sample of an integrated luminosity of 57.4 fb[sup -1] at the [Upsilon](4S) resonance taken with the BABAR detector using the SLAC PEP-II asymmetric-energy B-Factory, hadronic decays of B meson with the final states D(*) and three pions are studied. The study is performed by fully reconstructing the exclusive decays of B [yields] D(*) a[sub 1](1260) and the non-resonant modes B [yields] D(*) [rho][sup 0][pi] and B [yields] D(*) [pi][pi][pi]. The current status of the study is presented and a dominant B [yields] D(*) a[sub 1](1260) decay is shown.
Author :
Publisher :
Page : pages
File Size : 39,1 MB
Release : 2003
Category :
ISBN :
The radiative decays of the B meson to the final states K*(892)[gamma] and[rho](770)[gamma] proceed through virtual effective flavor-changing neutral current processes which are sensitive to contributions from high mass scales from within the Standard Model of particle interactions and from possible new physics. In the context of the Standard Model, these transitions are of interest in probing the weak interaction behavior of the top quark. In particular, the ratio of branching fractions for the two processes can be used to extract the ratio of Cabibbo-Kobayashi-Maskawa matrix elementsV[sub td]/V[sub ts]. Potential new physics contributions in these virtual transitions may induce new sources of direct CP violation and enhancement or suppression of the rate of these processes. The B[yields] K*[gamma] is a manifestation of the b[yields] s[gamma] radiative transition. This process has been previously observed by the CLEO collaboration and its branching fraction measured. While the theoretical prediction for the inclusive rate of b[yields] s[gamma] transitions is more robust than that of the exclusive B[yields] K*[gamma], the prospects for precise measurements of[Beta][B[yields] K*[gamma]] and direct CP violation in this channel has attracted considerable attention. The analysis described here represents an improved measurement of the B[yields] K*[gamma] branching factions and a more sensitive search for direct CP violation. In 22.7 x 10[sup 6] B[bar B] events collected by the BABAR detector in 1999-2000, we measure:[Beta][B[sup 0][yields] K*[sup 0][gamma]]= 4.23[+-] 0.40(stat.)[+-] 0.22(syst.) x 10[sup -5] and[Beta][B[sup+][yields] K*[sup+][gamma]]= 3.83[+-] 0.62(stat.)[+-] 0.22(syst.) x 10[sup -5]. We find no evidence for direct CP violation in the decays and constrain -0.170
