Download or read book A Search for the Rare Decay B0 arrow Tau Tau at the Babar Experiment written by Christopher Thomas Potter and published by . This book was released on 2005 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Search for the Rare Decay B tau tau at the BaBar Experiment written by Christopher Thomas Potter and published by . This book was released on 2006 with total page 223 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Standard Model of particle physics predicts that the branching ratio for the rare decay B{sup 0} {yields} {tau}{sup +}{tau}{sup -} is 3.1 x 10{sup -8}, though untested models which could supersede it predict large enhancements. This dissertation describes the search for this rare decay in 210.4 fb{sup -1} of B{sup 0}{bar B}{sup 0} data collected at the {Upsilon}(4S) resonance in the Babar detector at the Stanford Linear Accelerator Center. In the analysis, one neutral B meson is fully reconstructed in a hadronic mode and recoil events which are consistent with each tau decaying in a mode {tau} {yields} {pi}{nu}, {rho}{nu}, or l{nu}{bar {nu}} are selected. There is no evidence for signal. The result is consistent with a downward fluctuation by 1.1 statistical standard deviations of the expected Standard Model background. Taking the expected background, the number of observed events and the expected statistical and systematic errors into account yields 2.7 x 10{sup -3} as the upper limit for B{sup 0} {yields} {tau}{sup +}{tau}{sup -} at the 90% confidence level.
Download or read book Search for the Rare Decay B to Pi L l in the BaBar Experiment written by and published by . This book was released on 2007 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for the Rare Decay B0 J in the BABAR Experiment written by Sheila McLachlin and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for the Rare Decay B0 J psi gamma in the BABAR Experiment written by Sheila McLachlin and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Search for the Rare Decay B0 to Tau tau AtBaBar written by J. C. Chen and published by . This book was released on 2005 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the results of a search for the decay B{sup 0} {yields} {tau}{sup +}{tau}{sup -} in a data sample of (232 {+-} 3) x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} decays using the BABAR detector. Certain extensions of the Standard Model predict measurable levels of this otherwise rare decay. We reconstruct fully one neutral B meson and seek evidence for the signal decay in the rest of the event. We find no evidence for signal events and obtain {Beta}(B{sup 0} {yields} {tau}{sup +}{tau}{sup -})
Download or read book A Search for the Decay of a B Meson Into a Kaon and a Tau Lepton Pair at the BaBar Experiment written by Racha Cheaib and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "The flavour changing neutral current (FCNC) process , B+ → K+ [tau]+[tau]−, is highly sup-pressed in the Standard Model (SM). This decay is forbidden at tree level and only occursat lowest order via one-loop diagrams. B+ → K+ [tau]+[tau]− thus has the potential to providea stringent test of the SM and a fertile ground for new physics searches. Contributions dueto virtual particles in the loop allow one to probe, at relatively low energies, new physicsat large mass scales. We search for the rare FCNC process B+ → K+ [tau]+[tau]− using datacollected by the BABAR detector at the SLAC National Accelerator Laboratory. The BABARdata sample corresponds to a total integrated luminosity, at the energy of the [UPSILON](4S) reso-nance, of 424.4 fb−1 and 471 million BB pairs. For this search, hadronic Btag reconstructionis employed, where one B is exclusively reconstructed via one of many possible hadronicmodes. The remaining decay products in an event are then attributed to the signal B, onwhich the search for B+ → K+ [tau]+[tau]− is performed. Each [tau] is required to decay leptonically,into either an electron or a muon and the lepton neutrinos. Furthermore, a multi-variateanalysis technique (neural network) is used to select for signal events and suppress dominantbackground modes. No significant signal is observed. The resulting branching fraction ismeasured to be B(B+ → K+[tau]+[tau]−) = 1.310.66 (stat.)+0.35(sys.) × 10−3, which is consistent −0.61 −0.25with zero at the 1.9[sigma] level, with an upper limit of 2.25 ×10−3 at the 90% confidence level." --
Download or read book A Search for the Decays B Arrow L nu and B degree arrow L Tau l written by Miika A. Klemetti and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "We present searches for the leptonic decays B + [arrow] l+nu and the lepton flavor violating decays B[degree][arrow] l[symbol][tau][symbol], where l = e, [mu], with data collected by the BABAR experiment at SLAC. These searches utilize a technique in which we fully reconstruct the accompanying B̄ in [Upsilon](4S)[arrow] BB̄ events, and look for a monoenergetic lepton in the signal B frame. The signal yield in the data is extracted from a fit to the signal lepton candidate momentum distribution in the signal B rest frame. Using a data sample of approximately 378 million BB̄ pairs (342 fb-1), we find no evidence of signal in any of the decay modes. Branching fraction upper limits of B (B+[arrow] e +[nu])
Download or read book A Search for the Decay of a B Meson Into a Kaon and a Tau Lepton Pair at the BaBar Experiment written by and published by . This book was released on 2016 with total page 235 pages. Available in PDF, EPUB and Kindle. Book excerpt: The flavour changing neutral current (FCNC) process, $B^+$ → $K^+ [tau]^+ [tau]^-$ highly suppressed in the Standard Model (SM). This decay is forbidden at tree level and only occurs at lowest order via one-loop diagrams.$B^+$ → $K^+ [tau]^+ [tau]^-$ thus has the potential to provide a stringent test of the SM and a fertile ground for new physics searches. Contributions due to virtual particles in the loop allow one to probe, at relatively low energies, new physics at large mass scales. We search for the rare FCNC process $B^+$ → $K^+ [tau]^+ [tau]^-$ using data collected by the BaBaR detector at the SLAC National Accelerator Laboratory. The BaBaR data sample corresponds to a total integrated luminosity, at the energy of the [Tau](4S) resonance, of 424.4 $fb^-1$ and 471 million $B\bar{B}$ pairs. For this search, hadronic $B_{tag}$ reconstruction is employed, where one B is exclusively reconstructed via one of many possible hadronic modes. The remaining decay products in an event are then attributed to the signal B, on which the search for $B^+$ → $K^+ [tau]^+ [tau]^-$ is performed. Each [tau] is required to decay leptonically, into either an electron or a muon and the lepton neutrinos. Furthermore, a multi-variate analysis technique (neural network) is used to select for signal events and suppress dominant background modes. No significant signal is observed. The resulting branching fraction is measured to be $\beta(B^+$ → $K^+ [tau]^+)$ = $1.31^{0:66}_{-0:61}$(stat.) $^{+0:35}_{-0:25}$(sys.) x 10$^{-3}$, which is consistent with zero at the 1.9[sigma] level, with an upper limit of 2.25 x 10$^{-3}$, at the 90% confidence level.
Download or read book Search for the decay B at the BABAR experiment written by Stephan Otto and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rare Decays And Exotic States With BaBar written by S. H. Robertson and published by . This book was released on 2006 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results from the BABAR experiment are presented for searches for several rare FCNC B and D meson decays, including the modes B{sup 0} {yields} {ell}{sup +}{ell}{sup -} and D{sup 0} {yields} {ell}{sup +}{ell}{sup -}, B {yields} ({rho}, {omega}){gamma} and B{sup +} {yields} (K, {pi}){sup +}{nu}{bar {nu}}. Limits on lepton flavor violation in neutrino-less {tau} decays are also discussed. Finally, results of BABAR searches for the strange pentaquark states {Theta}{sup +}(1540), {Xi}{sup --}(1860) and {Xi}{sup 0}(1860) are summarized.
Download or read book Studies of the Decay B arrow Eta cK at the BABAR Experiment written by Nicholas Robert Barlow and published by . This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rare Decays in BaBar written by Emmanuele Salvati and published by . This book was released on 2010 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for the Rare Decay B0 J psi in the BABAR Experiment written by Sheila McLachlin and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for the Rare Leptonic Decay B Tau Nubar written by and published by . This book was released on 2004 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a search for the decay B− →?− {bar {nu}}{sub?} in a sample of 88.9 x 106 B{bar B}pairs recorded with the BABAR detector at the SLAC B-Factory. One of the two B mesons from the?(4S) is reconstructed in a hadronic or a semileptonic final state and the decay products of the other B in the event are analyzed for consistency with a B− →?− {bar {nu}}{sub {tau}} decay. We find no evidence of a signal and set an upper limit on the branching fraction of?(B− → {tau}− {bar {nu}}{sub {tau}})
Download or read book A Study of the Rare Charmless Hadronic B Decay B rightwards Arrow A rtlch ltrch 486 Using the BaBar Detector written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for the Rare Decay K L arrow pi 0 pi 0 mu mu written by David Graham Phillips and published by . This book was released on 2009 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt:
