Download or read book Rare decays B Xd gamma gamma in the standard model written by Ahmed Ali and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rare decays B Xd gamma in the standard model written by A. Ali and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rare Decays B X D Gamma in the Standard Model written by A. Ali and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rare Decays B becomes Xd gamma in the Standard Model written by Ahmed Ali and published by . This book was released on 1992 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rare decay B K gamma BK in the standard model written by Cesáreo A. Dominguez and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rare Decay B becomes K gamma in the Standard Model written by C. A. Domínguez and published by . This book was released on 1988 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for the Decay D0 gamma gamma and Measurement of the Decay D0 pi 0 pi 0 written by James Paul Morris and published by . This book was released on 2009 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The Standard Model is the best current description of fundamental interactions and particles; however, the Standard Model has certain shortcomings which have driven particle physicists for the last 30 years to search for phenomena which provide evidence for the next theory beyond the Standard Model. To this end, using the BaBar detector, we search for evidence of the rare decay D* -> D0[pi];D0->[gamma][gamma]. The branching fraction of this decay is enhanced up to 200 times the standard model prediction in certain beyond-the-Standard-Model theories. A measurement of a significant branching fraction would provide evidence for a new theory of particle physics. We describe our search for this rare decay and an improved measurement of the associated decay, B(D0-> [pi]0 [pi]0) using an integrated luminosity corresponding to 470.5 fb−1 of e e− data collected by the BaBar detector at the PEP-II asymmetric ee− collider at SLAC from 1999-2007. We place an upper limit of B(D0->[gamma][gamma]) 2.51 X 10−6 at 90% confidence level and find B(D0-[pi]0[pi]0) = (8.4 " 0.1 " 0.4 " 0.3) X 10−4.
Download or read book A Search for the Rare Decay B0 2 gamma gamma written by and published by . This book was released on 2010 with total page 197 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes a search for the rare radiative decay B0 → [gamma][gamma], where the charged congugate mode is implied throughout. These decays are highly suppressed in the Standard Model where the branching fraction is expected to be of order 10-8. In some new physics scenarios this could be enhanced by up to an order of magnitude to 10-7. Therefore an observation of a significant signal above the Standard Model prediction could be a sign of new physics.
Download or read book Search for the Rare Decay B0bar D 0 Gamma written by and published by . This book was released on 2005 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report on a search for the rare decay {bar B}° → D*°[gamma], which in the standard model is dominated by W-exchange. The analysis is based on a data sample comprising 87.8 x 106 B{bar B} pairs collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. No significant signal is observed, and an upper limit on the branching fraction of 2.5 x 10−5 at the 90% confidence level is obtained.
Download or read book Radiative B Decays written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We summarize the constraints placed on physics beyond the Standard Model from the recent CLEO observations of the exclusive decay B [yields] K*[gamma] and bound on the inclusive model b [yields] s[gamma].
Download or read book A Search for the Rare Decay B rightarrow gamma gamma written by and published by . This book was released on 2011 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report the result of a search for the rare decay B° 2![gamma][gamma] in 426 fb−1 of data, corresponding to 226 million B°{bar B}° pairs, collected on the [Upsilon](4S) resonance at the PEP-II asymmetric-energy ee− collider using the BABAR detector. We use a maximum likelihood fit to extract the signal yield and observe 2112{sup +13} signal events with a statistical signficance of 1.9 [sigma]. This corresponds to a branching fraction [Beta](B° 2![gamma][gamma]) = (1.7 ± 1.1(stat.) ± 0.2(syst.)) x 10−7. Based on this result, we set a 90% confidence level upper limit of [Beta](B° 2![gamma][gamma])
Download or read book The Radiative Rare Decays B K K Gamma in the Light Cone QCD Sum Rule Approach written by Abdelkader S. Safir and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics Reach of Rare B Decays written by and published by . This book was released on 2002 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The author discusses the theoretical and empirical status of b 2!s[gamma], b 2!sl l− decays, as well as their future prospects. I emphasize those observables in rare b-decays which can potentially establish new physics and distinguish between extensions of the Standard Model. He briefly reviews current models of electroweak symmetry breaking, all of which can carry interesting flavor characteristics accessible with b-physics experiments.
Download or read book The Radiative Rare Decays B K g K Gamma in the Light Cone QCD Sum Rule Approach written by Abdelkader-Salim Safir and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurements of B V Gamma Decays written by and published by . This book was released on 2010 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: The standard model has been highly successful at describing current experimental data. However, extensions of the standard model predict particles that have masses at energy scales that are above the electroweak scale. The flavor-changing neutral current processes of the B meson are sensitive to the influences of these new physics contributions. These processes proceed through loop diagrams, thus allowing new physics to enter at the same order as the standard model. New physics may contribute to the enhancement or suppression of rate asymmetries or the decay rates of these processes. The transition B → V[gamma] (V = K*(892), [rho](770), [omega](782), [phi](1020)) represents radiative decays of the B meson that proceed through penguin processes. Hadronic uncertainties limit the theoretical accuracy of the prediction of the branching fractions. However, uncertainties, both theoretical and experimental, are much reduced when considering quantities involving ratios of branching fractions, such as CP or isospin asymmetries. The most dominant exclusive radiative b → s transition is B → K*[gamma]. We present the best measurements of the branching fractions, direct CP, and isospin asymmetries of B → K*[gamma]. The analogous b → d transitions are B → [rho][gamma] and B → [omega][gamma], which are suppressed by a factor of.
Download or read book A Search for the Rare Decay Mu E Gamma Gamma written by and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental search for the lepton-family number nonconserving decay, .mu. .-->. e.gamma gamma., has been conducted at the Clinton P. Anderson Meson Physics Facility (LAMPF) using the Crystal Box detector. The detector consists of a modular NaI(Tl) calorimeter, scintillator hodoscope, and a high-resolution, cylindrical drift chamber. It provides a large solid-angle for detecting three-body decays and has good resolutions in the time, position, and energy measurements to eliminate unwanted backgrounds. No evidence for .mu.+ .-->. e+.gamma gamma. is found, giving an upper limit for the branching ratio of GAMMA(.mu. .-->. e.gamma gamma.)/GAMMA(.mu. .-->. e nu anti nu) less than or equal to 7.2 x 10−11 (90% C.L.). This result is an improvement of more than two orders of magnitude in the existing limit. 109 refs., 39 figs.
Download or read book Studying B S Gamma at BABAR Using a Fully Inclusive Method written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The b [yields] s[gamma] decay represents a possible electromagnetic ''loop'' penguin decay of the B meson. This FCNC process is of high theoretical interest because various scenarios of new physics are expected to have contributions at the same (one loop) level as the Standard Model. The large sample of B[bar B] meson decays collected by the BaBar experiment makes a precision measurement of this rare decay possible. In conjunction with Standard Model predictions at the 10% level, it brings new physics effects into the realm of detection--or seriously constrains models that could predict them. A fully inclusive technique is presented to study the b [yields] s[gamma] transition as a function of photon energy, using 88.5 [+-] 1.0 x 10[sup 6] B[bar B] meson decays collected by the BaBar experiment in the years 2000 to 2002. The expected statistical and systematic uncertainties have been fully determined which enables first comparisons with theoretical predictions and other experimental results. It also lays the basis for the determination of the inclusive branching fraction [Beta](B [yields] X[sub s][gamma]) and the measurement of the photon energy spectrum.
