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SuperB Progress Report: Detector

Description: This report describes the present status of the detector design for SuperB. It is one of four separate progress reports that, taken collectively, describe progress made on the SuperB Project since the publication of the SuperB Conceptual Design Report in 2007 and the Proceedings of SuperB Workshop VI in Valencia in 2008.
Date: February 14, 2012
Creator: Grauges, E.; /Barcelona U., ECM; Donvito, G.; Spinoso, V.; /INFN, Bari /Bari U.; Manghisoni, M. et al.
Partner: UNT Libraries Government Documents Department

Observation and Study of the Baryonic B-meson Decays B to D(*) p pbar (pi) (pi)

Description: We present results for B-meson decay modes involving a charm meson, protons, and pions using 455 x 10{sup 6} B{bar B} pairs recorded by the BABAR detector at the SLAC PEP-II asymmetric-energy e{sup +}e{sup -} collider. The branching fractions are measured for the following ten decays: {bar B}{sup 0} {yields} D{sup 0}p{bar p}, {bar B}{sup 0} {yields} D*{sup 0}p{bar p}, {bar B}{sup 0} {yields} D{sup +}p{bar p}{pi}{sup -}, {bar B}{sup 0} {yields} D*{sup +}p{bar p}{pi}{sup -}, B{sup -} {yields} D{sup 0}p{bar p}{pi}{sup -}, B{sup -} {yields} D*{sup 0}pp{pi}{sup -}, {bar B}{sup 0} {yields} D{sup 0}p{bar p}{pi}{sup -}{pi}{sup +}, {bar B}{sup 0} {yields} D*{sup 0}p{bar p}{pi}{sup -}{pi}{sup +}, B{sup -} {yields} D{sup +}p{bar p}{pi}{sup -}{pi}{sup -}, and B{sup -} {yields} D*{sup +}p{bar p}{pi}{sup -}{pi}{sup -}. The four B{sup -} and the two five-body B{sup 0} modes are observed for the first time. The four-body modes are enhanced compared to the three- and the five-body modes. In the three-body modes, the M(p{bar p}) and M(D{sup (*)0}p) invariant mass distributions show enhancements near threshold values. In the four-body mode {bar B}{sup 0} {yields} D{sup +}p{bar p}{pi}{sup -}, the M(p{pi}{sup -}) distribution shows a narrow structure of unknown origin near 1.5GeV/c{sup 2}. The distributions for the five-body modes, in contrast to the others, are similar to the expectations from uniform phase-space predictions.
Date: February 15, 2012
Creator: del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP et al.
Partner: UNT Libraries Government Documents Department

Measurements of time-dependent CP asymmetries in B0 --> D(*)+D(*)- decays

Description: We present new measurements of time-dependent CP asymmetries for B{sup 0} {yields} D{sup (*)+}d{sup (*)-} decays using (467 {+-} 5) x 10{sup 6} B{bar B} pairs collected with the BABAR detector located at the PEP-II B Factory at the Stanford Linear Accelerator Center. We determine the CP-odd fraction of the B{sup 0} {yields} D*{sup +}D*{sup -} decays to be R{perpendicular} = 0.158 {+-} 0.028 {+-} 0.006 and find CP asymmetry parameters for the CP-even component of the decay S{sub +} = -0.76 {+-} 0.16 {+-} 0.04 and C{sub +} = 0.00 {+-} 0.12 {+-} 0.02. We measure S = -0.63{+-}0.36{+-}0.05 and C = -0.07{+-}0.23{+-}0.03 for B{sup 0} {yields} D{sup +}D{sup -}, S = -0.62{+-}0.21{+-}0.03 and C = 0.08 {+-} 0.17 {+-} 0.04 for B{sup 0} {yields} D*{sup +}D{sup -}, and S = -0.73 {+-} 0.23 {+-} 0.05 and C = 0.00 {+-} 0.17 {+-} 0.03 for B{sup 0} {yields} D{sup +}D*{sup -}. For the B{sup 0} {yields} D*{sup {+-}}D{sup {-+}} decays, we also determine the CP-violating asymmetry A = 0.008 {+-} 0.048 {+-} 0.013. In each case, the first uncertainty is statistical and the second is systematic. The measured values for the asymmetries are all consistent with the Standard Model.
Date: February 12, 2009
Creator: Aubert, B.; Bona, M.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E. et al.
Partner: UNT Libraries Government Documents Department

ATF2 Proposal Volume 2

Description: For achieving the high luminosity required at the International Linear Collider (ILC), it is critical to focus the beams to nanometer size with the ILC Beam Delivery System (BDS), and to maintain the beam collision with a nanometer-scale stability. To establish the technologies associated with this ultra-high precision beam handling, it has been proposed to implement an ILC-like final focus optics in an extension of the existing extraction beamline of ATF at KEK. The ATF is considered to be the best platform for this exercise, since it provides an adequate ultra-low emittance electron beam in a manner dedicated to the development of ILC. The two major goals for this facility, called ATF2, are: (A) Achievement of a 37 nm beam size, and (B) control of beam position down to 2 nm level. The scientific justification for the ATF2 project and its technical design have been described in Volume 1 of the ATF2 Proposal [1]. We present here Volume 2 of the ATF2 Proposal, in which we present specifics of the construction plans and the group organization to execute the research programs at ATF2. The sections in this report have been authored by relevant ATF2 subgroups within the International ATF Collaboration. The time line of the project is described in Section 2. Section 3 discuss the structure of the international collaboration. Sections 4 and 5 discuss budget considerations, which are presented as well as the design and construction tasks to be shared by the international collaboration at ATF2. Concluding remarks have been contributed by Dr. Ewan Paterson, Chair of the International Collaboration Board of the ATF collaboration.
Date: February 27, 2006
Creator: Grishanov, B.I.; Logachev, P.; Podgorny, F.; Telnov, V.; /Novosibirsk, IYF; Angal-Kalinin, D. et al.
Partner: UNT Libraries Government Documents Department

Search for CP Violation in the Decay tau- \to pi- K^0_S (>= 0 pi0) nu_tau

Description: We report a search for CP violation in the decay {tau}{sup -} {yields} {pi}{sup -}K{sub S}{sup 0}({>=} 0{pi}{sup 0}){nu}{sub {tau}} using a dataset of 437 million {tau} lepton pairs, corresponding to an integrated luminosity of 476 fb{sup -1}, collected with the BABAR detector at the PEP-II asymmetric energy e{sup +}e{sup -} storage rings. The CP-violating decay-rate asymmetry is determined to be (-0.45 {+-} 0.24 {+-} 0.11)%, approximately three standard deviations from the Standard Model prediction of (0.33 {+-} 0.01)%.
Date: February 16, 2012
Creator: Lees, J.P.; Poireau, V.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E. et al.
Partner: UNT Libraries Government Documents Department

Search for the decay B^+ \to K_S^0 K_S^0 \pi ^+

Description: The authors search for charmless decays of charged B mesons to the three-body final state K{sub S}{sup 0}K{sub S}{sup 0}{pi}{sup +}. Using a data sample of 423.7 fb{sup -1} collected at the {Upsilon}(4S) resonance with the BABAR detector, corresponding to (465.1 {+-} 5.1) x 10{sup 6} B{bar B} pairs, they find no significant signal and determine a 90% confidence level upper limit on the branching fraction of 5.1 x 10{sup -7}.
Date: February 23, 2009
Creator: Aubert, B.; Bona, M.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E. et al.
Partner: UNT Libraries Government Documents Department