An Extensible Business Process Approach for Managing Institutional Roles & Responsibilities ? A New Horizon for LLNL (open access)

An Extensible Business Process Approach for Managing Institutional Roles & Responsibilities ? A New Horizon for LLNL

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Date: September 20, 2006
Creator: Aaron, C
System: The UNT Digital Library
Measurement of B(d) mixing using opposite-side flavor tagging (open access)

Measurement of B(d) mixing using opposite-side flavor tagging

We report on a measurement of the B{sub d}{sup 0} mixing frequency and the calibration of an opposite-side flavor tagger in the D0 experiment. Various properties associated with the b quark on the opposite side of the reconstructed B meson are combined using a likelihood-ratio method into a single variable with enhanced tagging power. Its performance is tested with data, using a large sample of reconstructed semileptonic B {yields} {mu}D{sup 0} X and B {yields} {mu}D* X decays, corresponding to an integrated luminosity of approximately 1 fb{sup -1}. The events are divided into groups depending on the value of the combined tagging variable, and an independent analysis is performed in each group. Combining the results of these analyses, the overall effective tagging power is found to be {var_epsilon}{prime}D{sup 2} = (2.48 {+-} 0.21{sub -0.06}{sup +0.08})%. The measured B{sub d}{sup 0} mixing frequency {Delta}m{sub d} = 0.506 {+-} 0.020 (stat) {+-} 0.016 (syst) ps{sup -1} is in good agreement with the world average value.
Date: September 1, 2006
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
System: The UNT Digital Library
Measurement of the CP-violation parameter of B0 mixing and decay with p anti-p ---> mu mu X data (open access)

Measurement of the CP-violation parameter of B0 mixing and decay with p anti-p ---> mu mu X data

The authors measure the dimuon charge asymmetry A in p{bar p} collisions at a center of mass energy {radical}s 1960 GeV. The data was recorded with the D0 detector and corresponds to an integrated luminosity of approximately 1.0 fb{sup -1}. Assuming that the asymmetry A is due to asymmetric B{sup 0} {leftrightarrow} {bar B}{sup 0} mixing and decay, they extract the CP-violation parameter of B{sup 0} mixing and decay: R({epsilon}{sub B{sup 0}}/1) + |{epsilon}{sub B{sup 0}}|{sup 2} = A{sub B{sup 0}}/4 = -0.0023 {+-} 0.0011(stat) {+-} 0.0008(syst). A{sub B{sup 0}} is the dimuon charge asymmetry from decays of B{sup 0}{bar B}{sup 0} pairs. The general case, with CP violation in both B{sup 0} and B{sub s}{sup 0} systems, is also considered. Finally they obtain the forward-backward asymmetry that quantifies the tendency of {mu}{sup +} to go in the proton direction and {mu}{sup -} to go in the anti-proton direction. The results are consistent with the standard model and constrain new physics.
Date: September 1, 2006
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
System: The UNT Digital Library
Measurement of the top quark mass in the dilepton channel (open access)

Measurement of the top quark mass in the dilepton channel

We present a measurement of the top quark mass in the dilepton channel based on approximately 370 pb{sup -1} of data collected by the D0 experiment during Run II of the Fermilab Tevatron collider. We employ two different methods to extract the top quark mass. We show that both methods yield consistent results using ensemble tests of events generated with the D0 Monte Carlo simulation. We combine the results from the two methods to obtain a top quark mass m{sub t} = 178.1 {+-} 8.2 GeV. The statistical uncertainty is 6.7 GeV and the systematic uncertainty is 4.8 GeV.
Date: September 1, 2006
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
System: The UNT Digital Library
Measurement of the top quark mass in the lepton+jets final state with the matrix element method (open access)

Measurement of the top quark mass in the lepton+jets final state with the matrix element method

We present a measurement of the top quark mass with the Matrix Element method in the lepton+jets final state. As the energy scale for calorimeter jets represents the dominant source of systematic uncertainty, the Matrix Element likelihood is extended by an additional parameter, which is defined as a global multiplicative factor applied to the standard energy scale. The top quark mass is obtained from a fit that yields the combined statistical and systematic jet energy scale uncertainty.
Date: September 1, 2006
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
System: The UNT Digital Library
Measurement of the W boson helicity in top quark decay at D0 (open access)

Measurement of the W boson helicity in top quark decay at D0

The authors present a measurement of the fraction f{sub +} of right-handed W bosons produced in top quark decays, based on a candidate sample of t{bar t} events in the {ell}+jets and dilepton decay channels corresponding to an integrated luminosity of 370 pb{sup -1} collected by the D0 detector at the Fermilab Tevatron p{bar p} Collider at {radical}s = 1.96 TeV. They reconstruct the decay angle {theta}* for each lepton. By comparing the cos{theta}* distribution from the data with those for the expected background and signal for various values of f{sub +}, they find f{sub +} = 0.056 {+-} 0.080(stat) {+-} 0.057(syst). (f{sub +} < 0.23 at 95% C.L.), consistent with the standard model prediction of f{sub +} = 3.6 x 10{sup -4}.
Date: September 1, 2006
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
System: The UNT Digital Library
Measurement of the Lambda0(b) Lifetime in Lambda0(b) ---> J/psi Lambda0 in p anti-p Collisions at s**(1/2) = 1.96-TeV (open access)

Measurement of the Lambda0(b) Lifetime in Lambda0(b) ---> J/psi Lambda0 in p anti-p Collisions at s**(1/2) = 1.96-TeV

The authors report a measurement of the {Lambda}{sub b}{sup 0} lifetime in the exclusive decay {Lambda}{sub b}{sup 0} {yields} J/{psi}{Lambda}{sup 0} in p{bar p} collisions at {radical}s = 1.96 TeV using an integrated luminosity of 1.0 fb{sup -1} of data collected by the CDF II detector at the Fermilab Tevatron. Using fully reconstructed decays, they measure {tau}({Lambda}{sub b}{sup 0}) = 1.593{sub -0.078}{sup +0.083}(stat.) {+-} 0.033(syst.) ps. This is the single most precise measurement of {tau}({Lambda}{sub b}{sup 0}) and is 3.2 {sigma} higher than the current world average.
Date: September 1, 2006
Creator: Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D. et al.
System: The UNT Digital Library
Search for V + A current in top quark decay in p anti-p collisions at s**(1/2) = 1.96 TeV (open access)

Search for V + A current in top quark decay in p anti-p collisions at s**(1/2) = 1.96 TeV

The authors report an upper limit on the fraction of V + A current, f{sub V+A}, in top quark decays, using approximately 700 pb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV acquired by the upgraded Collider Detector at Fermilab. For the decay t {yields} Wb {yields} {ell}{nu}b (where {ell} = e or {mu}), the invariant mass of the charged lepton and the bottom quark jet is sensitive to the polarization of the W boson. They determine f{sub V+A} = -0.06 {+-} 0.25 given a top quark mass of 175 GeV/c{sup 2}. They set an upper limit on f{sub V+A} of 0.29 at the 95% confidence level, which represents an improvement by a factor of two on the previous best direct limit.
Date: September 1, 2006
Creator: Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D. et al.
System: The UNT Digital Library
Observation of B0(s) - anti-B0(s) Oscillations (open access)

Observation of B0(s) - anti-B0(s) Oscillations

The authors report the observation of B{sub s}{sup 0}-{bar B}{sub s}{sup 0} oscillations from a time-dependent measurement of the B{sub s}{sup 0}-{bar B}{sub s}{sup 0} oscillation frequency {Delta}m{sub s}. Using a data sample of 1 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron, they find signals of 5600 fully reconstructed hadronic B{sub s} decays, 3100 partially reconstructed hadronic B{sub s} decays, and 61,500 partially reconstructed semileptonic B{sub s} decays. They measure the probability as a function of proper decay time that the B{sub s} decays with the same, or opposite, flavor as the flavor at production, and they find a signal for B{sub s}{sup 0}-{bar B}{sub s}{sup 0} oscillations. The probability that random fluctuations could produce a comparable signal is 8 x 10{sup -8}, which exceeds 5{sigma} significance. They measure {Delta}m{sub s} = 17.77 {+-} 0.10(stat) {+-} 0.07(syst) ps{sup -1} and extract |V{sub td}/V{sub ts}| = 0.2050 {+-} 0.0007(exp{sub -0.0060}{sup +0.0081})(theor).
Date: September 1, 2006
Creator: Abulencia, A.; Adelman, Jahred A.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D. et al.
System: The UNT Digital Library
The CDF II eXtremely fast tracker upgrade (open access)

The CDF II eXtremely fast tracker upgrade

The CDF II Extremely Fast Tracker is the trigger track processor which reconstructs charged particle tracks in the transverse plane of the CDF II central outer tracking chamber. The system is now being upgraded to perform a three dimensional track reconstruction. A review of the upgrade is presented here.
Date: September 1, 2006
Creator: Abulencia, A.; Azzurri, P.; Cochran, E.; Dittmann, J.; Donati, S.; Efron, J. et al.
System: The UNT Digital Library
Progress on the Europium Neutron-Capture Study using DANCE (open access)

Progress on the Europium Neutron-Capture Study using DANCE

The accurate measurement of neutron-capture cross sections of the Eu isotopes is important for many reasons including nuclear astrophysics and nuclear diagnostics. Neutron capture excitation functions of {sup 151,153}Eu targets were measured recently using a 4{pi} {gamma}-ray calorimeter array DANCE located at the Los Alamos Neutron Science Center for E{sub n} = 0.1-100 keV. The progress on the data analysis efforts is given in the present paper. The {gamma}-ray multiplicity distributions for the Eu targets and Be backing are significantly different. The {gamma}-ray multiplicity distribution is found to be the same for different neutron energies for both {sup 151}Eu and {sup 153}Eu. The statistical simulation to model the {gamma}-ray decay cascade is summarized.
Date: September 5, 2006
Creator: Agvaanluvsan, U.; Becker, J. A.; Macri, R. A.; Parker, W.; Wilk, P.; Wu, C. Y. et al.
System: The UNT Digital Library
Medical Sequencing at the extremes of Human Body Mass (open access)

Medical Sequencing at the extremes of Human Body Mass

Body weight is a quantitative trait with significantheritability in humans. To identify potential genetic contributors tothis phenotype, we resequenced the coding exons and splice junctions of58 genes in 379 obese and 378 lean individuals. Our 96Mb survey included21 genes associated with monogenic forms of obesity in humans or mice, aswell as 37 genes that function in body weight-related pathways. We foundthat the monogenic obesity-associated gene group was enriched for rarenonsynonymous variants unique to the obese (n=46) versus lean (n=26)populations. Computational analysis further predicted a significantlygreater fraction of deleterious variants within the obese cohort.Consistent with the complex inheritance of body weight, we did notobserve obvious familial segregation in the majority of the 28 availablekindreds. Taken together, these data suggest that multiple rare alleleswith variable penetrance contribute to obesity in the population andprovide a deep medical sequencing based approach to detectthem.
Date: September 1, 2006
Creator: Ahituv, Nadav; Kavaslar, Nihan; Schackwitz, Wendy; Ustaszewski,Anna; Martin, Joes; Hebert, Sybil et al.
System: The UNT Digital Library
CDMS, Supersymmetry and Extra Dimensions (open access)

CDMS, Supersymmetry and Extra Dimensions

This report talks about CDMS, Supersymmetry and Extra Dimensions
Date: September 1, 2006
Creator: Akerib, D. S.; Attisha, M. J.; Bailey, C. N.; Baudis, Laura; Bauer, Daniel Adams; Brink, P. L. et al.
System: The UNT Digital Library
The Evolution of Two-Component Systems in Bacteria RevealsDifferent Strategies for Niche Adaptation (open access)

The Evolution of Two-Component Systems in Bacteria RevealsDifferent Strategies for Niche Adaptation

Two-component systems including histidine protein kinasesrepresent the primary signal transduction paradigm in prokaryoticorganisms. To understand how these systems adapt to allow organisms todetect niche-specific signals, we analyzed the phylogenetic distributionof nearly 5000 histidine protein kinases from 207 sequenced prokaryoticgenomes. We found that many genomes carry a large repertoire of recentlyevolved signaling genes, which may reflect selective pressure to adapt tonew environmental conditions. Both lineage-specific gene family expansionand horizontal gene transfer play major roles in the introduction of newhistidine kinases into genomes; however, there are differences in howthese two evolutionary forces act. Genes imported via horizontal transferare more likely to retain their original functionality as inferred from asimilar complement of signaling domains, while gene family expansionaccompanied by domain shuffling appears to be a major source of novelgenetic diversity. Family expansion is the dominantsource of newhistidine kinase genes in the genomes most enriched in signalingproteins, and detailed analysis reveals that divergence in domainstructure and changes in expression patterns are hallmarks of recentexpansions. Finally, while these two modes of gene acquisition arewidespread across bacterial taxa, there are clear species-specificpreferences for which mode is used.
Date: September 13, 2006
Creator: Alm, Eric; Huang, Katherine & Arkin, Adam
System: The UNT Digital Library
A Standard format for Les Houches event files (open access)

A Standard format for Les Houches event files

A standard file format is proposed to store process and event information, primarily output from parton-level event generators for further use by general-purpose ones. The information content is identical with what was already defined by the Les Houches Accord five years ago, but then in terms of Fortran commonblocks. This information is embedded in a minimal XML-style structure, for clarity and to simplify parsing.
Date: September 1, 2006
Creator: Alwall, J.; Ballestrero, A.; Bartalini, P.; Belov, S.; Boos, E.; Buckley, A. et al.
System: The UNT Digital Library
Microprocessor-controlled, wide-range streak camera (open access)

Microprocessor-controlled, wide-range streak camera

Bechtel Nevada/NSTec recently announced deployment of their fifth generation streak camera. This camera incorporates many advanced features beyond those currently available for streak cameras. The arc-resistant driver includes a trigger lockout mechanism, actively monitors input trigger levels, and incorporates a high-voltage fault interrupter for user safety and tube protection. The camera is completely modular and may deflect over a variable full-sweep time of 15 nanoseconds to 500 microseconds. The camera design is compatible with both large- and small-format commercial tubes from several vendors. The embedded microprocessor offers Ethernet connectivity, and XML [extensible markup language]-based configuration management with non-volatile parameter storage using flash-based storage media. The camera’s user interface is platform-independent (Microsoft Windows, Unix, Linux, Macintosh OSX) and is accessible using an AJAX [asynchronous Javascript and XML]-equipped modem browser, such as Internet Explorer 6, Firefox, or Safari. User interface operation requires no installation of client software or browser plug-in technology. Automation software can also access the camera configuration and control using HTTP [hypertext transfer protocol]. The software architecture supports multiple-simultaneous clients, multiple cameras, and multiple module access with a standard browser. The entire user interface can be customized.
Date: September 1, 2006
Creator: Amy E. Lewis, Craig Hollabaugh
System: The UNT Digital Library
Metal Plasmas for the Fabrication of Nanostructures (open access)

Metal Plasmas for the Fabrication of Nanostructures

A review is provided covering metal plasma production, theenergetic condensation of metal plasmas, and the formation ofnanostructures using such plasmas. Plasma production techniques includepulsed laser ablation, filtered cathodic arcs, and various forms ofionized physical vapor deposition, namely magnetron sputtering withionization of sputtered atoms in radio frequency discharges,self-sputtering, and high power impulse magnetron sputtering. Thediscussion of energetic condensation focuses on the control of kineticenergy by biasing and also includes considerations of the potentialenergy and the processes occurring at subplantation and implantation. Inthe final section on nanostructures, two different approaches arediscussed. In the top-down approach, the primary nanostructures arelithographically produced and metal plasma is used to coat or filltrenches and vias. Additionally, multilayers with nanosize periods(nanolaminates) can be produced. In the bottom-up approach, thermodynamicforces are used to fabricate nanocomposites and nanoporous materials bydecomposition and dealloying.
Date: September 21, 2006
Creator: Anders, Andre
System: The UNT Digital Library
Determination of the Form Factors for the Decay B0 -> D*-l+nu_l and of the CKM Matrix Element |Vcb| (open access)

Determination of the Form Factors for the Decay B0 -> D*-l+nu_l and of the CKM Matrix Element |Vcb|

The authors present a combined measurement of the Cabibbo-Kobayashi-Maskawa matrix element |V{sub cb}| and of the parameters {rho}{sup 2}, R{sub 1}, and R{sub 2}, which fully characterize the form factors of the B{sup 0} {yields} D*{sup -}{ell}{sup +}{nu}{sub {ell}} decay in the framework of HQET, based on a sample of about 52,800 B{sup 0} {yields} D*{sup -}{ell}{sup +}{nu}{sub {ell}} decays recorded by the BABAR detector. The kinematical information of the fully reconstructed decay is used to extract the following values for the parameters (where the first errors are statistical and the second systematic): {rho}{sup 2} = 1.156 {+-} 0.094 {+-} 0.028, R{sub 1} = 1.329 {+-} 0.131 {+-} 0.044, R{sub 2} = 0.859 {+-} 0.077 {+-} 0.022, F(1)|V{sub cb}| = (35.03 {+-} 0.39 {+-} 1.15) x 10{sup -3}. By combining these measurements with the previous BABAR measurements of the form factors which employs a different technique on a partial sample of the data, they improve the statistical accuracy of the measurement, obtaining: {rho}{sup 2} = 1.179 {+-} 0.048 {+-} 0.028, R{sub 1} = 1.417 {+-} 0.061 {+-} 0.044, R{sub 2}, = 0.836 {+-} 0.037 {+-} 0.022, and F(1)|V{sub cb}| = (34.68 {+-} 0.32 {+-} 1.15) x 10{sup -3}. Using the …
Date: September 26, 2006
Creator: Aubert, B.
System: The UNT Digital Library
Improved Measurements of the Branching Fractions for B0 into pi+pi- and B0 into K+pi-, and a Search for B0 into K+K- (open access)

Improved Measurements of the Branching Fractions for B0 into pi+pi- and B0 into K+pi-, and a Search for B0 into K+K-

The authors present measurements of the branching fractions for the charmless two-body decays B{sup 0} {yields} {pi}{sup +}{pi}{sup -} and B{sup 0} {yields} K{sup +}{pi}{sup -}, and a search for the decay B{sup 0} {yields} K{sup +}K{sup -}. They include the effects of final-state radiation from the daughter mesons for the first time, and quote branching fractions for the inclusive processes B{sup 0} {yields} h{sup +}h'{sup -}n{gamma}, where h and h' are pion or kaons. The maximum value of the sum of the energies of the n undetected photons, E{sub {gamma}}{sup max}, is mode-dependent. Using a data sample of approximately 227 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at SLAC.
Date: September 26, 2006
Creator: Aubert, B.
System: The UNT Digital Library
Inclusive Lambda_c Production in e+e- Annihilations at sqrt{s}=10.54 GeV and in Upsilon(4S) Decays (open access)

Inclusive Lambda_c Production in e+e- Annihilations at sqrt{s}=10.54 GeV and in Upsilon(4S) Decays

We present measurements of the total production rates and momentum distributions of the charmed baryon {Lambda}{sub c}{sup +} in e{sup +}e{sup -} {yields} hadrons at a center-of-mass energy of 10.54 GeV and in {Upsilon}(4S) decays. In hadronic events at 10.54 GeV, charmed hadrons are almost exclusively leading particles in e{sup +}e{sup -} {yields} c{bar c} events, allowing direct studies of c-quark fragmentation. We measure a momentum distribution for {Lambda}{sub c}{sup +} baryons that differs significantly from those measured previously for charmed mesons. Comparing with a number of models, we find none that can describe the distribution completely. We measure an average scaled momentum of (x{sub p}) = 0.574 {+-} 0.009 and a total rate of N{sub {Lambda}{sub c}}{sup q{bar q}} = 0.057 {+-} 0.002(exp.) {+-} 0.015(BF) {Lambda}{sub c}{sup +} per hadronic event, where the experimental error is much smaller than that due to the branching fraction into the reconstructed decay mode, pK{sup -} {pi}{sup +}. In {Upsilon}(4S) decays we measure a total rate of N{sub {Lambda}{sub c}}{sup {Upsilon}} = 0.091 {+-} 0.006(exp.) {+-} 0.024(BF) per {Upsilon}(4S) decay, and find a much softer momentum distribution than expected from B decays into a {Lambda}{sub c}{sup +} plus an antinucleon and one to …
Date: September 7, 2006
Creator: Aubert, B.
System: The UNT Digital Library
Measurement of Branching Fractions and Charge Asymmetries in B Decays to an eta Meson and a K* Meson (open access)

Measurement of Branching Fractions and Charge Asymmetries in B Decays to an eta Meson and a K* Meson

The authors present measurements of branching fractions and charge asymmetries for the decays B {yields} {eta}K*, where K8 indicates a spin 0, 1, or 2 K {pi} system. The data sample corresponds to 344 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 SLAC. They measure the branching fractions (in units of 10{sup -6}): {Beta}(B{sup 0} {yields} {eta}K*{sup 0}(892)) = 16.5 {+-} 1.1 {+-} 0.8, {Beta}(B{sup +} {yields} {eta}K*{sup +}(892)) = 18.9 {+-} 1.8 {+-} 1.3, {Beta}(B{sup 0} {yields} {eta}(K{pi})*{sub 0}{sup 0}) = 11.0 {+-} 1.6 {+-} 1.5, {Beta}(B{sup +} {yields} {eta}(K{pi}){sub 0}*{sup +}) = 18.2 {+-} 2.6 {+-} 2.6, {Beta}(B{sup 0} {yields} {eta}K*{sub 2}{sup 0}(1430)) = 9.6 {+-} 1.8 {+-} 1.1, and {Beta}(B{sup +} {yields} {eta}K*{sub 2}{sup +}(1430)) = 9.1 {+-} 2.7 {+-} 1.4. They also determine the charge asymmetries for all decay modes.
Date: September 26, 2006
Creator: Aubert, B.
System: The UNT Digital Library
Measurement of CP Asymmetries and Branching Fractions in B to pi pi and B to K pi Decays. (open access)

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

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.
System: The UNT Digital Library
Measurement of CP-Violating Asymmetries in B0 to (rho pi)0 Using a Time-Dependent Dalitz Plot Analysis (open access)

Measurement of CP-Violating Asymmetries in B0 to (rho pi)0 Using a Time-Dependent Dalitz Plot Analysis

We report a measurement of CP-violating asymmetries in B{sup 0} {yields} ({rho}{pi}){sup 0} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup 0} decays using a time-dependent Dalitz plot analysis. The results are obtained from a data sample of 347 million {Upsilon}(4S) {yields} B{bar B} decays, collected by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We measure 26 coefficients of the bilinear form factor terms occurring in the time-dependent decay rate of the B{sup 0} meson and derive the physically relevant quantities from these coefficients. In particular we find a three standard deviation evidence of direct CP-violation in the B{sup 0} {yields} {rho}{sup {+-}}{pi}{sup {-+}} decays, with systematic uncertainties included. We also achieve a constraint of the angle {alpha} of the Unitarity Triangle. All results presented are preliminary.
Date: September 26, 2006
Creator: Aubert, B.
System: The UNT Digital Library
Measurement of the Branching Fraction and Photon Energy Moments of B to Xs gamma and A_cp (B to X_{s+d} gamma) (open access)

Measurement of the Branching Fraction and Photon Energy Moments of B to Xs gamma and A_cp (B to X_{s+d} gamma)

The photon spectrum in B {yields} X{sub s}{gamma} decay, where X{sub s} is any strange hadronic state, is studied using a data sample of 88.5 x 10{sup 6} e{sup +}e{sup -} {yields} {Upsilon}(4S) {yields} B{bar B} decays collected by the BABAR experiment at SLAC. The partial branching fraction, {Delta}{Beta}(B {yields} X{sub s}{gamma}) = (3.67 {+-} 0.29(stat.) {+-} 0.34(sys.) {+-} 0.29(model)) x 10{sup -4}, the first moment <E{sub {gamma}}> = 2.288 {+-} 0.025 {+-} 0.017 {+-} 0.015 GeV and the second moment <E{sub {gamma}}{sup 2}> = 0.0328 {+-} 0.0040 {+-} 0.0023 {+-} 0.0036 GeV{sup 2} are measured for the photon energy range 1.9 GeV < E{sub {gamma}} < 2.7 GeV. They are also measured for narrower E{sub {gamma}} ranges. The moments are then fit to recent theoretical calculations to extract the Heavy Quark Expansion parameters, m{sub b} and {mu}{sub {pi}}{sup 2}, and to extrapolate the partial branching fraction to E{sub {gamma}} > 1.6 GeV. In addition, the direct CP asymmetry A{sub CP}(B {yields} X{sub s+d{gamma}}) is measured to be -0.110 {+-} 0.115(stat.) {+-} 0.017(sys.).
Date: September 26, 2006
Creator: Aubert, B.
System: The UNT Digital Library