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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.

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At least 1,333 records · Page 74
All sourcesNASA NTRSDOE OSTI
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↗
DOE OSTI2017

Observation of the helicity-selection-rule suppressed decay of the χ c 2 charmonium state

The decays of χ c 2 → K + K - π 0 , K S K ± π ∓ , and π + π - π 0 are studied with the ψ ( 3686 ) data samples collected with the Beijing Spectrometer (BESIII). For the first time, the branching fractions of χ c 2 → K*$\bar{K}$ , χ c 2 → $a_2^±$(1320)π ∓ /$a_2^0$(1320)π 0 , and χ c 2 → ρ( 770 ) ± π ∓ are measured. Here, K*$\bar{K}$ denotes both K* ± K ∓ and its isospin-conjugated process K* 0 $\bar{K}$ 0 +c.c., and K* denotes the resonances K*(892), $K_2^*$(1430), and $K_3^*$(1780). The observations indicate a strong violation of the helicity selection rule in χ c 2 decays into vector and pseudoscalar meson pairs. The measured branching fractions of χ c 2 → K*(892)$\bar{K}$ are more than ten times larger than the upper limit of χ c 2 → ρ ( 770 ) ± π ∓ , which is so far the first direct observation of a significant U -spin symmetry breaking effect in charmonium decays.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2018

Measurement of the decays Λ c → Σ π π at Belle

We report measurements of the branching fractions of the decays Λ c + → Σ + π - π + , Λ c + → Σ 0 π + π 0 and Λ c + → Σ + π 0 π 0 relative to the reference channel Λ c + → p K - π + . The analysis is based on the full data sample collected at and near the Υ ( 4 S ) resonance by the Belle detector at the KEKB asymmetric-energy e + e - collider, corresponding to an integrated luminosity of 711 fb - 1 . We measure B ( Λ c + → Σ + π - π + ) / B ( Λ c + → p K - π + ) = 0.7 19 ± 0.003 ± 0.02 4 , B ( Λ c + → Σ 0 π + π 0 ) / B ( Λ c + → p K - π + ) = 0. 575 ± 0.005 ± 0.0 36 and B ( Λ c + → Σ + π 0 π 0 ) / B ( Λ c + → p K - π + ) = 0. 247 ± 0.006 ± 0.01 9 . The listed uncertainties are statistical and systematic, respectively.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗