Search NASA⌕ Search

SEARCH · Search NASA

Results for “Sample Collection”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 811 records · Page 45
All sourcesNASA NTRSDOE OSTI
DOE OSTI2010

Evidence for direct CP violation in the decay B{sup {+-}{yields}D(*)}K{sup {+-}}, D{yields}K{sub S}{sup 0{pi}+{pi}-} and measurement of the CKM phase {phi}{sub 3}

We present a new measurement of the unitarity triangle angle {phi}{sub 3} using a Dalitz plot analysis of the K{sub S}{sup 0{pi}+{pi}-} decay of the neutral D meson produced in B{sup {+-}{yields}D(*)}K{sup {+-}} decays. The method exploits the interference between D{sup 0} and D{sup 0} to extract the angle {phi}{sub 3}, strong phase {delta}, and the ratio r of suppressed and allowed amplitudes. We apply this method to a 605 fb{sup -1} data sample collected by the Belle experiment. The analysis uses three decays: B{sup {+-}{yields}D}K{sup {+-}}, and B{sup {+-}{yields}D}*K{sup {+-}}with D*{yields}D{pi}{sup 0} and D*{yields}D{gamma}, as well as the corresponding charge-conjugate modes. From a combined maximum likelihood fit to the three modes, we obtain {phi}{sub 3}=78.4 deg. (+10.8 deg./-11.6 deg.){+-}3.6 deg. (syst){+-}8.9 deg. (model). CP conservation in this process is ruled out at the confidence level (1-CL)=5x10{sup -4}, or 3.5 standard deviations.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Measurement of {Upsilon}(5S) decays to B{sup 0} and B{sup +} mesons

Decays of the {Upsilon}(5S) resonance to channels with B{sup +} and B{sup 0} mesons are studied using a 23.6 fb{sup -1} data sample collected with the Belle detector at the KEKB asymmetric-energy e{sup +}e{sup -} collider. Fully reconstructed B{sup +{yields}}J/{psi}K{sup +}, B{sup 0{yields}}J/{psi}K*{sup 0}, B{sup +{yields}}D{sup 0{pi}+}, and B{sup 0{yields}}D{sup -{pi}+} decays are used to obtain the charged and neutral B production rates per bb event, f(B{sup +})=(72.1{sub -3.8}{sup +3.9{+-}}5.0)% and f(B{sup 0})=(77.0{sub -5.6}{sup +5.8{+-}}6.1)%. Assuming equal rates to B{sup +} and B{sup 0} mesons in all channels produced at the {Upsilon}(5S) energy, we measure the fractions for transitions to two-body and three-body channels with B meson pairs, f(BB)=(5.5{sub -0.9}{sup +1.0{+-}}0.4)%, f(BB*+B*B)=(13.7{+-}1.3{+-}1.1)%, f(B*B*)=(37.5{sub -1.9}{sup +2.1{+-}}3.0)%, f(BB{pi})=(0.0{+-}1.2{+-}0.3)%, f(BB*{pi}+B*B{pi})=(7.3{sub -2.1}{sup +2.3{+-}}0.8)%, and f(B*B*{pi})=(1.0{sub -1.3}{sup +1.4{+-}}0.4)%. The latter three fractions are obtained assuming isospin conservation.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Measurement of the branching fractions and the invariant mass distributions for {tau}{sup -{yields}}h{sup -}h{sup +}h{sup -{nu}}{sub {tau}}decays

We present a study of {tau}{sup -{yields}{pi}-{pi}+{pi}-{nu}}{sub {tau}}, {tau}{sup -{yields}}K{sup -{pi}+{pi}-{nu}}{sub {tau}}, {tau}{sup -{yields}}K{sup -}K{sup +{pi}-{nu}}{sub {tau}}, and {tau}{sup -{yields}}K{sup -}K{sup +}K{sup -{nu}}{sub {tau}} decays using a 666 fb{sup -1} data sample collected with the Belle detector at the KEKB asymmetric-energy e{sup +}e{sup -} collider at and near a center-of-mass energy of 10.58 GeV. The branching fractions are measured to be B({tau}{sup -{yields}{pi}-{pi}+{pi}-{nu}}{sub {tau}})=(8.42{+-}0.00{sub -0.25}{sup +0.26})x10{sup -2}, B({tau}{sup -{yields}}K{sup -{pi}+{pi}-{nu}}{sub {tau}})=(3.30{+-}0.01{sub -0.17}{sup +0.16})x10{sup -3}, B({tau}{sup -{yields}}K{sup -}K{sup +{pi}-{nu}}{sub {tau}})=(1.55{+-}0.01{sub -0.05}{sup +0.06})x10{sup -3}, and B({tau}{sup -{yields}}K{sup -}K{sup +}K{sup -{nu}}{sub {tau}})=(3.29{+-}0.17{sub -0.20}{sup +0.19})x10{sup -5}, where the first uncertainty is statistical and the second is systematic. These branching fractions do not include contributions from modes in which a {pi}{sup +{pi}-} pair originates from a K{sub S}{sup 0} decay. We also present the unfolded invariant mass distributions for these decays.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Search for B{sub s}{sup 0{yields}}hh decays at the {Upsilon}(5S) resonance

We have searched for B{sub s}{sup 0{yields}}hh decays, where h stands for a charged or neutral kaon, or a charged pion. These results are based on a 23.6 fb{sup -1} data sample collected with the Belle detector on the {Upsilon}(5S) resonance at the KEKB asymmetric-energy e{sup +}e{sup -} collider, containing 1.25x10{sup 6} B{sub s}{sup (*)}B{sub s}{sup (*)} events. We observe the decay B{sub s}{sup 0{yields}}K{sup +}K{sup -} and measure its branching fraction, B(B{sub s}{sup 0{yields}}K{sup +}K{sup -})=[3.8{sub -0.9}{sup +1.0}(stat){+-}0.5(syst){+-}0.5(f{sub s})]x10{sup -5}. The first error is statistical, the second is systematic, and the third error is due to the uncertainty in the B{sub s}{sup 0} production fraction in e{sup +}e{sup -{yields}}bb events. No significant signals are seen in other decay modes, and we set upper limits at the 90% confidence level: B(B{sub s}{sup 0{yields}}K{sup -{pi}+})<1.2x10{sup -5}, B(B{sub s}{sup 0{yields}{pi}+{pi}-})<2.6x10{sup -5}, and B(B{sub s}{sup 0{yields}}K{sup 0}K{sup 0})<6.6x10{sup -5}.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Measurement of the B 0 s . Production Cross Section withB 0 s →J/ψΦ Decays in pp Collisions at √s=7 TeV

The B 0 s differential production cross section is measured as functions of the transverse momentum and rapidity in pp collisions at √s=7 TeV, using the B 0 s →J/ψΦ decay, and compared with predictions based on perturbative QCD calculations at next-to-leading order. The data sample, collected by the CMS experiment at the LHC, corresponds to an integrated luminosity of 40 pb⁻¹. The B 0 s is reconstructed from the decays J/ψ→μ⁺μ⁻ and Φ→K⁺K⁻. The integrated B 0 s cross section times B 0 s →J/ψΦ branching fraction in the range 8 B T <50 GeV/c and |yB|<2.4 is measured to be 6.9±0.6±0.6 nb, where the first uncertainty is statistical and the second is systematic.

Chatrchyan, S.↗
DOE OSTI2012

Observation of e⁺e⁻→ηJ/ψ at center-of-mass energy √s=4.009 GeV

Using a 478 pb⁻¹ data sample collected with the BESIII detector operating at the Beijing Electron Positron Collider storage ring at a center-of-mass energy of s√=4.009 GeV, the production of e⁺e⁻→ηJ/ψ is observed for the first time with a statistical significance of greater than 10σ. The Born cross section is measured to be (32.1±2.8±1.3) pb, where the first error is statistical and the second systematic. Assuming the ηJ/ψ signal is from a hadronic transition of the ψ(4040), the fractional transition rate is determined to be B(ψ(4040)→ηJ/ψ)=(5.2±0.5±0.2±0.5)×10⁻³, where the first, second, and third errors are statistical, systematic, and the uncertainty from the ψ(4040) resonant parameters, respectively. The production of e⁺e⁻→π0J/ψ is searched for, but no significant signal is observed, and B(ψ(4040)→π⁰J/ψ)<2.8×10⁻⁴ is obtained at the 90% confidence level.

Ablikim, M.↗
DOE OSTI2013

Measurement of the inclusive semileptonic branching fraction B ( B s 0 → X - ℓ + ν ℓ ) at Belle

Here, we report a measurement of the inclusive semileptonic B s 0 branching fraction in a 121 fb - 1 data sample collected near the Υ ( 5 S ) resonance with the Belle detector at the KEKB asymmetric energy e + e - collider. Events with B s 0 ( * ) B ¯ s 0 ( * ) pairs are selected by reconstructing a tag side D s + and identifying a signal side lepton ℓ + ( ℓ = e , μ ) that is required to have the same-sign charge to ensure that both originate from different B s 0 mesons. The B s 0 → X - ℓ + ν ℓ branching fraction is extracted from the ratio of the measured yields of D s + mesons and D s + ℓ + pairs and the known production and branching fractions. The inclusive semileptonic branching fraction is measured to be [ 10.6 ± 0.5 ( stat ) ± 0.7 ( syst ) ] % .

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

First observation of the Z b 0 ( 10610 ) in a Dalitz analysis of Υ ( 10860 ) → Υ ( n S ) π 0 π 0

Here, we report the first observation of Υ ( 10860 ) → Υ ( 1 , 2 , 3 S ) π 0 π 0 decays. The neutral partner of the Z b ± ( 10610 ) , the Z b 0 ( 10610 ) decaying to Υ ( 2 , 3 S ) π 0 , is observed for the first time with a 6.5 σ significance using a Dalitz analysis of Υ ( 10860 ) → Υ ( 2 , 3 S ) π 0 π 0 decays. The findings are obtained with a 121.4 fb - 1 data sample collected with the Belle detector at the Υ ( 10860 ) resonance at the KEKB asymmetric-energy e + e - collider.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

Measurement of the decays B s 0 → J / ψ Φ ( 1020 ) , B s 0 → J / ψ f 2 ' ( 1525 ) and B s 0 → J / ψ K + K – at Belle

In this paper, we report a measurement of the branching fraction of the decay B s 0 → J / ψ Φ ( 1020 ) , evidence and a branching fraction measurement for B s 0 → J / ψ f 2 ' ( 1525 ) , and the determination of the total B s 0 → J / ψ K + K – branching fraction, including the resonant and non-resonant contributions to the K+K– channel. We also determine the S-wave contribution within the Φ(1020) mass region. The absolute branching fractions are B[ B s 0 → J / ψ Φ ( 1020 ) ] = (1.25 ± 0.07(stat) ± 0.08(syst) ± 0.22(fs)) × 10 –3 , B[ B s 0 → J / ψ f 2 ' ( 1525 ) ] = (0.26 ± 0.06(stat) ± 0.02(syst) ± 0.05(fs)) × 10 –3 and B[ B s 0 → J / ψ K + K – ] = (1.01 ± 0.09(stat) ± 0.10(syst) ± 0.18(fs)) × 10 –3 , where the last systematic error is due to the branching fraction of bb¯→ B$^{(*)}_{s}$B$^{(*)}_{s}$. The branching fraction ratio is found to be B[ B s 0 → J / ψ f 2 ' ( 1525 ) ]/B[ B s 0 → J / ψ Φ ( 1020 ) ] = (21.5 ± 4.9(stat) ± 2.6(syst)). All results are based on a 121.4 fb –1 data sample collected at the Υ(5S) resonance by the Belle experiment at the KEKB asymmetric-energy e + e – collider.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2014

Observation of a new charged charmoniumlike state in B ¯ 0 → J / ψ K – π + decays

We present the results of an amplitude analysis of B¯ 0 → J/ψK – π + decays. A new charged charmoniumlike state Z c (4200) + decaying to J/ψπ + is observed with a significance of 6.2σ. The mass and width of the Z c (4200) + are 4196$^{+31+17}_{–29–13}$ MeV/c 2 and 370$^{+70+70}_{–70–132}$ MeV, respectively; the preferred assignment of the quantum numbers is J P = 1 + . In addition, we find evidence for Z c (4430) + → J/ψπ + . In conclusion, the analysis is based on a 711 fb –1 data sample collected by the Belle detector at the asymmetric-energy e + e – collider KEKB.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2015

Amplitude analysis of e + e - →Υ(nS)π + π - at $\sqrt{s}$ = 10.886 GeV

Here, we report results on studies of the e + e - annihilation into three-body Υ ( n S ) π + π - ( n = 1 , 2 , 3 ) final states including measurements of cross sections and the full amplitude analysis. The cross sections measured at s = 10.866 GeV and corrected for the initial state radiation are σ ( e + e - → Υ ( 1 S ) π + π - ) = ( 2.27 ± 0.12 ± 0.14 ) pb , σ ( e + e - → Υ ( 2 S ) π + π - ) = ( 4.07 ± 0.16 ± 0.45 ) pb , and σ ( e + e - → Υ ( 3 S ) π + π - ) = ( 1.46 ± 0.09 ± 0.16 ) pb . Amplitude analysis of the three-body Υ ( n S ) π + π - final states strongly favors I G ( J P ) = 1 + ( 1 + ) quantum-number assignments for the two bottomonium-like Z b ± states, recently observed in the Υ ( n S ) π ± and h b ( m P ) π ± ( m = 1 , 2 ) decay channels. The results are obtained with a 121.4 fb - 1 data sample collected with the Belle detector at the KEKB asymmetric-energy e + e - collider.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2015

Study of B – → D K – π + π – and B – → D π – π + π – decays and determination of the CKM angle γ

We report a study of the suppressed B¯ → DK – π + π – and favored B¯ → D π – π + π – decays, where the neutral D meson is detected through its decays to the K ∓ π ± and CP -even K + K – and π + π – final states. The measurement is carried out using a proton-proton collision data sample collected by the LHCb experiment, corresponding to an integrated luminosity of 3.0 fb –1 . We observe the first significant signals in the CP -even final states of the D meson for both the suppressed B ¯ → DK – π + π – and favored B ¯ → D π – π + π – modes, as well as in the doubly Cabibbo suppressed D → K + π – final state of the B ¯ → D π – π + π – decay. Evidence for the suppressed decay B ¯ → DK – π + π – , with D → K + π – , is also presented. From the observed yields in the B ¯→ DK – π + π – , B ¯ → D π – π + π – and their charge conjugate decay modes, the most probable value of the weak phase γ corresponds to γ = (74 +20 –19 )°. This is one of the most precise single-measurement determinations of γ to date.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2016

Studies of charmed strange baryons in the Λ D final state at Belle

In this report, we discuss the discovery of Ξ c ( 3055 ) 0 , observed by its decay into the final-state Λ D 0 , and present the first observation and evidence of the decays of Ξ c ( 3055 ) + and Ξ c ( 3080 ) + into Λ D + . Furthermore, we perform a combined analysis of the Λ D + with the Σ c + + K - and Σ c * + + K - decay modes to measure the ratios of branching fractions, masses and widths with improved accuracy. We measure the ratios of branching fractions B ( Ξ c ( 3055 ) + → Λ D + ) / B ( Ξ c ( 3055 ) + → Σ c + + K - ) = 5.09 ± 1.01 ± 0.76 , B ( Ξ c ( 3080 ) + → Λ D + ) / B ( Ξ c ( 3080 ) + → Σ c + + K - ) = 1.29 ± 0.30 ± 0.15 , and B ( Ξ c ( 3080 ) + → Σ c * + + K - ) / B ( Ξ c ( 3080 ) + → Σ c + + K - ) = 1.07 ± 0.27 ± 0.04 , where the uncertainties are statistical and systematic. The analysis is performed using a 980 fb - 1 data sample collected with the Belle detector at the KEKB asymmetric-energy e + e - collider.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

Observation of an alternative χ c 0 ( 2 P ) candidate in e + e - → J / ψ D D ¯

IN this work, we perform a full amplitude analysis of the process e + e - → J / ψ D D ¯ , where D refers to either D 0 or D + . A new charmoniumlike state X * ( 3860 ) that decays to D D ¯ is determined with a significance of 6.5 σ . Its mass is ( 3862 - 32 + 26 - 13 + 40 ) MeV / c 2 , and its width is ( 201 - 67 + 154 - 82 + 88 ) MeV . The J P C = 0 + + hypothesis is favored over the 2 + + hypothesis at the level of 2.5 σ . The analysis is based on the 980 fb - 1 data sample collected by the Belle detector at the asymmetric-energy e + e - collider KEKB.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗