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論文

Study of $$e^+e^-to Upsilon(rm1S,2S)eta$$ and $$e^+e^-to Upsilon(rm 1S)eta^{prime}$$ at $$sqrt{s}=10.866$$ GeV with the Belle detector

Kovalenko, E.*; 谷田 聖; Belle Collaboration*; 他181名*

Physical Review D, 104(11), p.112006_1 - 112006_12, 2021/12

 被引用回数:0 パーセンタイル:0.01(Astronomy & Astrophysics)

We report the first observation of the processes $$e^+e^-toUpsilon(rm 1S,2S)eta$$ at $$sqrt{s}$$=10.866 GeV with a $$10.2sigma$$ and $$16.5sigma$$ significance respectively. The measured Born cross sections are $$sigma(e^+e^- to Upsilon(2S)eta)=2.07 pm 0.21 pm 0.19$$ pb, and $$sigma(e^+e^- to Upsilon(rm 1S)eta)=0.42 pm 0.08 pm 0.04$$ pb. We also set the upper limit on the cross section of the process $$e^+e^- to Upsilon(rm 1S)eta^{prime}$$ to be $$sigma(e^+e^- to Upsilon(rm 1S)eta^{prime}) < 0.035$$~pb at $$90%$$ CL. The results are obtained with the data sample collected with the Belle detector at the KEKB asymmetric-energy $$e^+e^-$$ collider in the energy range from 10.63 GeV to 11.02 GeV.

論文

Measurements of $$q^2$$ moments of inclusive $$B rightarrow X_c ell^+ nu_{ell}$$ decays with hadronic tagging

van Tonder, R.*; 谷田 聖; Belle Collaboration*; 他202名*

Physical Review D, 104(11), p.112011_1 - 112011_32, 2021/12

 被引用回数:11 パーセンタイル:69.20(Astronomy & Astrophysics)

We present the measurement of the first to fourth order moments of the four-momentum transfer squared, $$q^2$$, of inclusive $$B rightarrow X_c ell^+ nu_{ell}$$ decays using the full Belle data set of 711 $$mathrm{fb}^{-1}$$ of integrated luminosity at the $$Upsilon(4S)$$ resonance where $$ell = e, mu$$. The determination of these moments and their systematic uncertainties open new pathways to determine the absolute value of the CKM matrix element $$V_{cb}$$ using a reduced set of matrix elements of the heavy quark expansion. In order to identify and reconstruct the $$X_c$$ system, we reconstruct one of the two $$B$$-mesons using machine learning techniques in fully hadronic decay modes. The moments are measured with progressively increasing threshold selections on $$q^2$$ starting with a lower value of 3.0 $$mathrm{GeV}^2$$ in steps of 0.5 $$mathrm{GeV}^2$$ up to a value of 10.0 $$mathrm{GeV}^2$$. The measured moments are further unfolded, correcting for reconstruction and selection effects as well as QED final state radiation. We report the moments separately for electron and muon final states and observe no lepton flavor universality violating effects.

論文

Measurement of differential branching fractions of inclusive $${B to X_u , ell^+, nu_{ell}}$$ decays

Cao, L.*; 谷田 聖; Belle Collaboration*; 他199名*

Physical Review Letters, 127(26), p.261801_1 - 261801_8, 2021/12

 被引用回数:5 パーセンタイル:53.82(Physics, Multidisciplinary)

The first measurements of differential branching fractions of inclusive semileptonic $${B to X_u , ell^+, nu_{ell}}$$ decays are performed using the full Belle data set of 711 fb$$^{-1}$$ of integrated luminosity at the $$Upsilon(4S)$$ resonance and for $$ell = e, mu$$. Differential branching fractions are reported as a function of the lepton momentum, the four-momentum-transfer squared, light-cone momenta, the hadronic mass, and the hadronic mass squared. They are obtained by subtracting the backgrounds from semileptonic $${B to X_c , ell^+, nu_{ell}}$$ decays and other processes, and corrected for resolution and acceptance effects. The measured distributions are compared to predictions from inclusive and hybrid $${B to X_u , ell^+, nu_{ell}}$$ calculations.

論文

Search for $$B^{0} to tau^pm ell^mp$$ ($$ell=e,mu$$) with a hadronic tagging method at Belle

Atmacan, H.*; 谷田 聖; Belle Collaboration*; 他219名*

Physical Review D, 104(9), p.L091105_1 - L091105_9, 2021/11

 被引用回数:4 パーセンタイル:35.35(Astronomy & Astrophysics)

We present a search for the lepton-flavor-violating decays $$B^{0} to tau^pm ell^mp$$, where $$ell=(e,,mu)$$, using the full data sample of $$772 times 10^6$$ $$B overline{B}$$ pairs recorded by the Belle detector at the KEKB asymmetric-energy $$e^+e^-$$ collider. We use events in which one $$B$$ meson is fully reconstructed in a hadronic decay mode. The $$tau^pm$$ lepton is reconstructed indirectly using the momentum of the reconstructed $$B$$ and that of the $$ell^mp$$ from the signal decay. We find no evidence for $$B^{0} to tau^pm ell^mp$$ decays and set upper limits on their branching fractions at 90% confidence level of $$cal B$$($$B^{0} to tau^pm mu^{mp}$$)$$ < 1.5 times 10^{-5}$$ and $$cal B$$($$B^{0} to tau^pm e^{mp}$$)$$ < 1.6 times 10^{-5}$$.

論文

Precise measurement of the $$D^0$$ and $$D^+$$ lifetimes at Belle II

Abudin$'e$n, F.*; 谷田 聖; Belle II Collaboration*; 他385名*

Physical Review Letters, 127(21), p.211801_1 - 211801_9, 2021/11

 被引用回数:6 パーセンタイル:59.12(Physics, Multidisciplinary)

We report a measurement of the $$D^0$$ and $$D^+$$ lifetimes using $$D^0to K^-pi^+$$ and $$D^+to K^-pi^+pi^+$$ decays reconstructed in $$e^+e^-to cbar{c}$$ data recorded by the Belle II experiment at the SuperKEKB asymmetric-energy $$e^+e^-$$ collider. The data, collected at center-of-mass energies at or near the $$Upsilon(4S)$$ resonance, correspond to an integrated luminosity of $$72,{rm fb}^{-1}$$. The results, $$tau(D^0) = 410.5pm1.1,{rm(stat)}pm0.8,{rm(syst.)},{rm fs}$$ and $$tau(D^+) = 1030.4pm4.7,{rm(stat)}pm3.1,{rm(syst.)},{rm fs}$$, are the most precise to date and are consistent with previous determinations.

論文

Search for lepton-flavor-violating tau-lepton decays to $$ellgamma$$ at Belle

宇野 健太*; 谷田 聖; Belle Collaboration*; 他181名*

Journal of High Energy Physics (Internet), 2021(10), p.19_1 - 19_12, 2021/10

 被引用回数:11 パーセンタイル:69.20(Physics, Particles & Fields)

Charged lepton flavor violation is forbidden in the Standard Model but possible in several new physics scenarios. In many of these models, the radiative decays $$tau^{pm}rightarrowell^{pm}gamma$$ ($$ell=e,mu$$) are predicted to have a sizeable probability, making them particularly interesting channels to search at various experiments. An updated search via $$tau^{pm}rightarrowell^{pm}gamma$$ using full data of the Belle experiment, corresponding to an integrated luminosity of 988 fb$$^{-1}$$, is reported for charged lepton flavor violation. No significant excess over background predictions from the Standard Model is observed, and the upper limits on the branching fractions, $$mathcal{B}(tau^{pm}rightarrow mu^{pm}gamma)$$ $$leq$$ $$4.2times10^{-8}$$ and $$mathcal{B}(tau^{pm}rightarrow e^{pm}gamma)$$ $$leq$$ $$5.6times10^{-8}$$, are set at 90% confidence level.

論文

Measurement of the branching fraction of $$Lambda_c^+ to p omega$$ decay at Belle

Li, S. X.*; 谷田 聖; Belle Collaboration*; 他193名*

Physical Review D, 104(7), p.072008_1 - 072008_8, 2021/10

 被引用回数:3 パーセンタイル:27.57(Astronomy & Astrophysics)

Using 980.6 $$rm fb^{-1}$$ of data collected with the Belle detector operating at the KEKB asymmetric-energy $$e^+e^-$$ collider, we present a measurement of the branching fraction of the singly Cabibbo-suppressed decay $$Lambda_c^+ to p omega$$. A clear $$Lambda_c^+$$ signal is observed for $$Lambda_c^+ to p omega$$ with a statistical significance of 9.1 standard deviations, and we measure the ratio of branching fractions $${cal B}(Lambda_c^+ to p omega)/{cal B}(Lambda_c^+ to p K^- pi^+) = (1.32 pm 0.12 (rm stat) pm 0.10 (rm syst))times 10^{-2}$$, from which we infer the branching fraction $${cal B}(Lambda_c^+ to p omega) = (8.27 pm 0.75 (rm stat) pm 0.62 (rm syst) pm 0.42 (rm ref))times 10^{-4}$$. The first quoted uncertainty is statistical, the second systematic, and the third from the reference mode $$Lambda_c^+ to p K^- pi^+$$.

論文

Measurement of branching fractions and search for $$CP$$ violation in $$D^{0}topi^{+}pi^{-}eta$$, $$D^{0}to K^{+}K^{-}eta$$, and $$D^{0}tophieta$$ at Belle

Li, L. K.*; 谷田 聖; Belle Collaboration*; 他187名*

Journal of High Energy Physics (Internet), 2021(9), p.75_1 - 75_21, 2021/09

 被引用回数:1 パーセンタイル:9.61(Physics, Particles & Fields)

We measure the branching fractions and $$CP$$ asymmetries for the singly Cabibbo-suppressed decays $$D^{0}topi^{+}pi^{-}eta$$, $$D^{0}to K^{+}K^{-}eta$$, and $$D^{0}tophieta$$, using 980 fb$$^{-1}$$ of data from the Belle experiment at the KEKB $$e^+e^-$$ collider. We obtain $$mathcal{B}(D^{0}topi^{+}pi^{-}eta) = [1.22pm 0.02,({rm stat})pm 0.02,({rm syst})pm 0.03,(mathcal{B}_{rm ref})]times 10^{-3},, mathcal{B}(D^{0}to K^{+}K^{-}eta) = [1.80,^{+0.07}_{-0.06},({rm stat})pm 0.04,({rm syst})pm 0.05,(mathcal{B}_{rm ref})]times 10^{-4},, mathcal{B}(D^{0}tophieta) = [1.84pm 0.09,({rm stat})pm 0.06,({rm syst})pm 0.05,(mathcal{B}_{rm ref})]times 10^{-4},, $$ where the third uncertainty ($$mathcal{B}_{rm ref}$$) is from the uncertainty in the branching fraction of the reference mode $$D^{0} to K^{-}pi^{+}eta$$. The color-suppressed decay $$D^{0}tophieta$$ is observed for the first time, with very high significance. The results for the $$CP$$ asymmetries are $$A_{CP}(D^{0}topi^{+}pi^{-}eta) = [0.9pm 1.2,({rm stat})pm 0.5,({rm syst})]%,, A_{CP}(D^{0}to K^{+}K^{-}eta) = [-1.4pm 3.3,({rm stat})pm 1.1,({rm syst})]%,, A_{CP}(D^{0}tophieta) = [-1.9pm 4.4,({rm stat})pm 0.6,({rm syst})]%,. $$ The results for $$D^{0}topi^{+}pi^{-}eta$$ are a significant improvement over previous results. The branching fraction and $$A_{CP}$$ results for $$D^{0}to K^{+}K^{-}eta$$, and the $$A_{CP}$$ result for $$D^{0}tophieta$$, are the first such measurements. No evidence for $$CP$$ violation is found in any of these decays.

論文

Measurement of the masses and widths of the $$Sigma_c(2455)^+$$ and $$Sigma_c(2520)^+$$ baryons

Yelton, J.*; 谷田 聖; Belle Collaboration*; 他205名*

Physical Review D, 104(5), p.052003_1 - 052003_8, 2021/09

 被引用回数:4 パーセンタイル:35.35(Astronomy & Astrophysics)

Using 980 $${rm fb}^{-1}$$ of data ${collected}$ with the Belle detector operating at the KEKB asymmetric-energy $$e^+e^-$$ collider, we report the measurements of the masses, and the first measurements of the instrinsic widths, of the $$Sigma_c(2455)^+$$ and $$Sigma_c(2520)^+$$ charmed baryons. We find $$M(Sigma_c(2455)^+)-M(Lambda_c^+) = 166.17pm 0.05^{+0.16}_{-0.07} {rm MeV}/c^2$$, $$Gamma(Sigma_c(2455)^+) = 2.3 pm 0.3 pm 0.3 {rm MeV/c^2}$$, $$M(Sigma_c(2520)^+)-M(Lambda_c^+) = 230.9 pm 0.5 ^{+0.5}_{-0.1} {rm MeV}/c^2$$, and $$Gamma(Sigma_c(2520)^+) = 17.2^{+2.3 +3.1}_{-2.1 -0.7} {rm MeV}/c^2$$, where the uncertainties are statistical and systematic, respectively. These measurements can be used to test models of the underlying quark structure of the $$Sigma_c$$ states.

論文

Evidence for the decay $$Omega_{c}^{0} to pi^+Omega(2012)^- to pi^+ (bar{K}Xi)^{-}$$

Li, Y.*; 谷田 聖; Belle Collaboration*; 他190名*

Physical Review D, 104(5), p.052005_1 - 052005_9, 2021/09

 被引用回数:9 パーセンタイル:62.46(Astronomy & Astrophysics)

Using a data sample of 980~fb$$^{-1}$$ collected with the Belle detector operating at the KEKB asymmetric-energy $$e^+e^-$$ collider, we present evidence for the $$Omega(2012)^-$$ in the resonant substructure of $$Omega_{c}^{0} to pi^+ (bar{K}Xi)^{-}$$ ($$(bar{K}Xi)^{-}$$ = $$K^-Xi^0$$ + $$bar{K}^0 Xi^-$$) decays. The significance of the $$Omega(2012)^-$$ signal is 4.2$$sigma$$ after considering the systematic uncertainties. The ratio of the branching fraction of $$Omega_{c}^{0} to pi^{+} Omega(2012)^- to pi^+ (bar{K}Xi)^{-}$$ relative to that of $$Omega_{c}^{0} to pi^{+} Omega^-$$ is calculated to be 0.220 $$pm$$ 0.059(stat.) $$pm$$ 0.035(syst.). The individual ratios of the branching fractions of the two isospin modes are also determined, and found to be $${cal B}(Omega_{c}^0 to pi^+ Omega(2012)^-) times {cal B}(Omega(2012)^- to K^-Xi^0)/{cal B}(Omega_{c}^0 to pi^+ K^- Xi^0)$$ =(9.6 $$pm$$ 3.2(stat.) $$pm$$ 1.8(syst.))% and $${cal B}(Omega_{c}^0 to pi^+ Omega(2012)^-) times {cal B}(Omega(2012)^- to bar{K}^0 Xi^-)/{cal B}(Omega_{c}^0 to pi^+ bar{K}^0 Xi^-)$$ = (5.5 $$pm$$ 2.8(stat.) $$pm$$ 0.7(syst.))%.

論文

Measurements of the branching fractions of the semileptonic decays $$Xi_{c}^{0} to Xi^{-} ell^{+} nu_{ell}$$ and the asymmetry parameter of $$Xi_{c}^{0} to Xi^{-} pi^{+}$$

Li, Y. B.*; 谷田 聖; Belle Collaboration*; 他182名*

Physical Review Letters, 127(12), p.121803_1 - 121803_8, 2021/09

 被引用回数:27 パーセンタイル:92.17(Physics, Multidisciplinary)

Using data samples of 89.5 and 711 fb$$^{-1}$$ recorded at energies of $$sqrt{s}=10.52$$ and $$10.58$$ GeV, respectively, with the Belle detector at the KEKB $$e^+e^-$$ collider, we report measurements of branching fractions of semileptonic decays $$Xi_{c}^{0} to Xi^{-} ell^{+} nu_{ell}$$ ($$ell=e$$ or $$mu$$) and the $$CP$$-asymmetry parameter of $$Xi_{c}^{0} to Xi^{-} pi^{+}$$ decay. The branching fractions are measured to be $${cal B}(Xi_{c}^{0} to Xi^{-} e^{+} nu_{e}$$)=($$1.31 pm 0.04 pm 0.07 pm 0.38$$)% and $${cal B}(Xi_{c}^{0} to Xi^{-} mu^{+} nu_{mu}$$)=($$1.27 pm 0.06 pm 0.10 pm 0.37$$)%, and the decay parameter $$alpha_{Xipi}$$ is measured to be $$0.63 pm 0.03 pm 0.01$$ with much improved precision compared to the current world average. The corresponding ratio $${cal B}(Xi_{c}^{0} to Xi^{-} e^{+} nu_{e})$$/$${cal B}(Xi_{c}^{0} to Xi^{-} mu^{+} nu_{mu})$$ is 1.03 $$pm$$ 0.05 $$pm$$ 0.07, which is consistent with the expectation of lepton flavor universality. The first measured asymmetry parameter $${cal A}_{CP} = (alpha_{Xi^{-}pi^{+}} + alpha_{bar{Xi}^{+}pi^{-}})/(alpha_{Xi^{-}pi^{+}} - alpha_{bar{Xi}^{+}pi^{-}}) = 0.024 pm 0.052 pm 0.014$$ is found to be consistent with zero. The first and the second uncertainties above are statistical and systematic, respectively, while the third ones arise due to the uncertainty of the $$Xi_{c}^{0} to Xi^{-} pi^+$$ branching fraction.

論文

Search for the decay $$B_s^0 rightarrow eta^prime eta$$

Nisar, N. K.*; 谷田 聖; Belle Collaboration*; 他197名*

Physical Review D, 104(3), p.L031101_1 - L031101_8, 2021/08

 被引用回数:1 パーセンタイル:9.61(Astronomy & Astrophysics)

We report the results of the first search for the decay $$B_s^0 rightarrow eta^prime eta$$ using $$121.4~textrm{fb}^{-1}$$ of data collected at the $$Upsilon(5S)$$ resonance with the Belle detector at the KEKB asymmetric-energy $$e^+e^-$$ collider. We observe no significant signal and set a 90% confidence-level upper limit of $$6.5 times 10^{-5}$$ on the branching fraction of this decay.

論文

Measurements of partial branching fractions of inclusive $$B to X_u , ell^+, nu_{ell}$$ decays with hadronic tagging

Cao, L.*; 谷田 聖; Belle Collaboration*; 他236名*

Physical Review D, 104(1), p.012008_1 - 012008_32, 2021/07

 被引用回数:10 パーセンタイル:65.88(Astronomy & Astrophysics)

We present measurements of partial branching fractions of inclusive semileptonic $$B to X_u , ell^+, nu_{ell}$$ decays using the full Belle data set of 711 fb$$^{-1}$$ of integrated luminosity at the $$Upsilon(4S)$$ resonance and for $$ell = e, mu$$. Inclusive semileptonic $$B to X_u , ell^+, nu_{ell}$$ decays are CKM suppressed and measurements are complicated by the large background from CKM-favored $$B to X_c , ell^+, nu_{ell}$$ transitions, which have a similar signature. Using machine learning techniques, we reduce this and other backgrounds effectively, whilst retaining access to a large fraction of the $$B to X_u , ell^+, nu_{ell}$$ phase space and high signal efficiency. We measure partial branching fractions in three phase-space regions covering about $$31%$$ to $$86%$$ of the accessible $$B to X_u , ell^+, nu_{ell}$$ phase space. The most inclusive measurement corresponds to the phase space with lepton energies of $$E_ell^B > 1 $$ GeV, and we obtain $$Delta mathcal{B}(B to X_u ell^+ , nu_ell) = left( 1.59 pm 0.07 pm 0.16 right) times 10^{-3}$$ from a two-dimensional fit of the hadronic mass spectrum and the four-momentum-transfer squared distribution, with the uncertainties denoting the statistical and systematic error. We find $$left|V_{ub} right| = left( 4.10 pm 0.09 pm 0.22 pm 0.15 right) times 10^{-3}$$ from an average of four calculations for the partial decay rate with the third uncertainty denoting the average theory error. This value is higher but compatible with the determination from exclusive semileptonic decays within 1.3 standard deviations.

論文

Search for the $$eta_{c2}(1D)$$ in $$e^+e^-togammaeta_{c2}(1D)$$ at $$sqrt{s}$$ near 10.6 GeV at Belle

Jia, S.*; 谷田 聖; Belle Collaboration*; 他200名*

Physical Review D, 104(1), p.012012_1 - 012012_9, 2021/07

 被引用回数:0 パーセンタイル:0.01(Astronomy & Astrophysics)

For the first time we search for the $$eta_{c2}(1D)$$ in $$e^+e^-togammaeta_{c2}(1D)$$ at $$sqrt{s}$$ = 10.52, 10.58, and 10.867 GeV with data samples of 89.5 fb$$^{-1}$$, 711 fb$$^{-1}$$, and 121.4 fb$$^{-1}$$, respectively, accumulated with the Belle detector at the KEKB asymmetric energy electron-positron collider. No significant $$eta_{c2}(1D)$$ signal is observed in the mass range between 3.8 and 3.88 GeV/$$c^2$$. The upper limit at 90% confidence level on the product of the Born cross section for $$e^+e^- to gammaeta_{c2}(1D)$$ and branching fraction for $$eta_{c2}(1D)to gamma h_c(1P)$$ is determined to be $$sigma(e^+e^- to gammaeta_{c2}(1D)){cal B}(eta_{c2}(1D)to gamma h_c(1P))$$ $$<$$ 4.9 fb at $$sqrt{s}$$ near 10.6 GeV.

論文

Search for $$B_{s}^{0} rightarrow eta^{prime} X_{sbar{s}}$$ at Belle using a semi-inclusive method

Dubey, S.*; 谷田 聖; Belle Collaboration*; 他171名*

Physical Review D, 104(1), p.012007_1 - 012007_11, 2021/07

 被引用回数:1 パーセンタイル:9.61(Astronomy & Astrophysics)

We report the first search for the penguin-dominated process $$B_{s}^{0} rightarrow eta^{prime} X_{sbar{s}}$$ using a semi-inclusive method. A 121.4 $$mathrm{fb}^{-1}$$ integrated luminosity $$Upsilon(5S)$$ data set collected by the Belle experiment, at the KEKB asymmetric-energy $$e^+e^-$$ collider, is used. We observe no statistically significant signal and including all uncertainties, we set a 90% confidence level upper limit on the partial branching fraction at 1.4 $$times$$ 10$$^{-3}$$ for $$M(X_{sbar{s}})$$ $$leq$$ 2.4 GeV/$$c^{2}$$.

論文

Measurement of the energy dependence of the $$e^+e^-to Bbar{B}$$, $$Bbar{B}^*$$ and $$B^*bar{B}^*$$ exclusive cross sections

Mizuk, R.*; 谷田 聖; Belle Collaboration*; 他188名*

Journal of High Energy Physics (Internet), 2021(6), p.137_1 - 137_35, 2021/06

 被引用回数:7 パーセンタイル:53.99(Physics, Particles & Fields)

We report the first measurement of the exclusive cross sections $$e^+e^-to Bbar{B}$$, $$e^+e^-to Bbar{B}^*$$, and $$e^+e^-to B^*bar{B}^*$$ in the energy range from 10.63 GeV to 11.02 GeV. The $$B$$ mesons are fully reconstructed in a large number of hadronic final states and the three channels are identified using a beam-constrained-mass variable. The shapes of the exclusive cross sections show oscillatory behavior with several maxima and minima. The results are obtained using data collected by the Belle experiment at the KEKB asymmetric-energy $$e^+e^-$$ collider.

論文

Measurements of branching fractions and asymmetry parameters of $$Xi^0_cto Lambdabar K^{*0}$$, $$Xi^0_cto Sigma^0bar K^{*0}$$, and $$Xi^0_cto Sigma^+K^{*-}$$ decays at Belle

Jia, S.*; 谷田 聖; Belle Collaboration*; 他186名*

Journal of High Energy Physics (Internet), 2021(6), p.160_1 - 160_13, 2021/06

 被引用回数:5 パーセンタイル:42.69(Physics, Particles & Fields)

Using a data sample of 980 fb$$^{-1}$$ collected with the Belle detector at the KEKB asymmetric-energy $$e^+e^-$$ collider, we study the processes of $$Xi^0_cto Lambdabar K^{*0}$$, $$Xi^0_cto Sigma^0bar K^{*0}$$, and $$Xi^0_cto Sigma^+K^{*-}$$ for the first time. The relative branching ratios to the normalization mode of $$Xi^0_c to Xi^- pi^+$$ are measured to be $${cal B}(Xi^0_cto Lambdabar K^{*0})/{cal B}(Xi_c^0 to Xi^-pi^+)=0.18 pm 0.02({rm stat.})pm0.01({rm syst.}),$$ $${cal B}(Xi^0_cto Sigma^0bar K^{*0})/{cal B}(Xi_c^0to Xi^-pi^+)=0.69pm0.03({rm stat.})pm0.03({rm syst.}),$$ $${cal B}(Xi^0_cto Sigma^+K^{*-})/{cal B}(Xi_c^0to Xi^-pi^+)=0.34pm0.06({rm stat.})pm0.02({rm syst.}),$$ where the uncertainties are statistical and systematic, respectively. We obtain the branching fractions of $$Xi^0_cto Lambdabar K^{*0}$$, $$Xi^0_cto Sigma^0bar K^{*0}$$, and $$Xi^0_cto Sigma^+K^{*-}$$ to be $${cal B}(Xi^0_cto Lambdabar K^{*0})=(3.3pm0.3({rm stat.})pm0.2({rm syst.})pm1.0({rm ref.}))times10^{-3},$$ $${cal B}(Xi^0_cto Sigma^0bar K^{*0})=(12.4pm0.5({rm stat.})pm0.5({rm syst.})pm3.6({rm ref.}))times10^{-3},$$ $${cal B}(Xi^0_cto Sigma^+K^{*-})=(6.1pm1.0({rm stat.})pm0.4({rm syst.})pm1.8({rm ref.}))times10^{-3},$$ where the uncertainties are statistical, systematic, and from $${cal B}(Xi_c^0 to Xi^-pi^+)$$, respectively. The asymmetry parameters $$alpha(Xi^0_cto Lambdabar K^{*0})$$ and $$alpha(Xi^0_cto Sigma^+K^{*-})$$ are $$0.15pm0.22({rm stat.})pm0.04({rm syst.})$$ and $$-0.52pm0.30({rm stat.})pm0.02({rm syst.})$$, respectively, where the uncertainties are statistical followed by systematic.

論文

First determination of the spin and parity of the charmed-strange baryon $$Xi_{c}(2970)^+$$

Moon, T. J.*; 谷田 聖; Belle Collaboration*; 他203名*

Physical Review D, 103(11), p.L111101_1 - L111101_9, 2021/06

 被引用回数:18 パーセンタイル:83.68(Astronomy & Astrophysics)

We report results from a study of the spin and parity of $$Xi_{c}(2970)^+$$ using a $$980~mathrm{fb^{-1}}$$ data sample collected by the Belle detector at the KEKB asymmetric-energy $$e^{+}e^{-}$$ collider. The decay angle distributions in the chain $$Xi_{c}(2970)^+ to Xi_c(2645)^{0}pi^{+} to Xi_c^{+}pi^{-}pi^{+}$$ are analyzed to determine the spin of this charmed-strange baryon. The angular distributions strongly favor the $$Xi_{c}(2970)^+$$ spin $$J =1/2$$ over $$3/2$$ or $$5/2$$, under an assumption that the lowest partial wave dominates in the decay. We also measure the ratio of $$Xi_{c}(2970)^+$$ decay branching fractions $$R={mathcal{B}[ Xi_{c}(2970)^+ to Xi_c(2645)^{0}pi^{+} ]} $$ / $${ mathcal{B}[ Xi_{c}(2970)^+ to Xi_c^{prime0}pi^{+} ]} $$ =1.67 $$pm 0.29mathrm{(stat.)}^{ +0.15}_{-0.09}mathrm{(syst.)} $$ $$pm 0.25mathrm{(IS)}$$, where the last uncertainty is due to possible isospin-symmetry-breaking effects. This $$R$$ value favors the spin-parity $$J^P=1/2^+$$ with the spin of the light-quark degrees of freedom $$s_{l}=0$$. This is the first determination of the spin and parity of a charmed-strange baryon.

論文

Measurement of the resonant and nonresonant branching ratios in $$Xi_{c}^{0} rightarrow Xi^{0} K^+ K^-$$

McNeil, J. T.*; 谷田 聖; Belle Collaboration*; 他193名*

Physical Review D, 103(11), p.112002_1 - 112002_11, 2021/06

 被引用回数:3 パーセンタイル:27.57(Astronomy & Astrophysics)

Using the entire data sample of $$980$$ $$rm fb^{-1}$$ integrated luminosity collected with the Belle detector at the KEKB asymmetric-energy $$e^{+}e^{-}$$ collider, we present an amplitude analysis measuring the branching fractions of the Cabibbo-allowed, $$W$$-exchange resonant decay $$Xi_{c}^{0} rightarrow Xi^{0} phi (to K^+ K^-)$$ with a polarized $$phi$$ and the non-resonant decay via a direct process $$Xi_{c}^{0} rightarrow Xi^{0} K^+ K^-$$. We present these measurements, relative to the normalization mode $$Xi^{-}pi^{+}$$, and find branching ratios $$frac{mathcal{B}(Xi_{c}^{0} rightarrow Xi^{0} phi (rightarrow K^{+}K^{-}))}{mathcal{B}(Xi_{c}^{0} rightarrow Xi^{-} pi^{+})}$$ = $${rm 0.036 pm 0.004 (stat.) pm 0.002 (syst.)}$$ and $$frac{mathcal{B}(Xi_{c}^{0} rightarrow Xi^{0} K^{+} K^{-})}{mathcal{B}(Xi_{c}^{0} rightarrow Xi^{-} pi^{+})}$$ = $$ 0.039 pm 0.004 ({rm stat.}) pm 0.002 {rm (syst.)}$$ which suggest that only minor cusping peaks occur in the combinatorial background of $$Omega^{*-} to Xi^{0}K^{-}$$ due to these $$Xi_{c}^{0}$$ decays.

論文

Measurement of branching fractions and $$CP$$ asymmetries for $$D_s^{+} rightarrow K^+ (eta, pi^0) $$ and $$D_s^{+} rightarrow pi^+ (eta, pi^0)$$ decays at Belle

Guan, Y.*; 谷田 聖; Belle Collaboration*; 他202名*

Physical Review D, 103(11), p.112005_1 - 112005_11, 2021/06

 被引用回数:5 パーセンタイル:42.69(Astronomy & Astrophysics)

We report measurements of the branching fractions and $$CP$$ asymmetries for $$D_s^{+} rightarrow K^{+} eta $$, $$D_s^{+} rightarrow K^{+} pi^0 $$, and $$D_s^{+} rightarrow pi^{+} eta $$ decays, and the branching fraction for $$D_s^{+} rightarrow pi^{+} pi^0$$. Our results are based on a data sample corresponding to an integrated luminosity of 921 fb$$^{-1}$$ collected by the Belle detector at the KEKB $$e^+e^-$$ asymmetric-energy collider. Our measurements of $$CP$$ asymmetries in these decays are the most precise to-date; no evidence for $$CP$$ violation is found.

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