| 51. |
- Ablikim, M., et al.
(författare)
-
Study of D+ -> K-pi(+)e(+)nu(e)
- 2016
-
Ingår i: PHYSICAL REVIEW D. - 2470-0010. ; 94:3
-
Tidskriftsartikel (refereegranskat)abstract
- We present an analysis of the decay D+ -> K-pi(+)e(+)nu(e) based on data collected by the BESIII experiment at the psi(3770) resonance. Using a nearly background-free sample of 18262 events, we measure the branching fraction B(D+ -> K-pi+e+nu e) = (3.77 +/- 0.03 +/- 0.08)%. For 0.8 < m(K pi) < 1.0 GeV/c(2), the partial branching fraction is B(D+ -> K-pi+e+nu e)([0.8,1.0]) = (3.39 +/- 0.03 +/- 0.08)%. A partial wave analysis shows that the dominant (K) over bar* (892)degrees component is accompanied by an S-wave contribution accounting for (6.05 +/- 0.22 +/- 0.18)% of the total rate and that other components are negligible. The parameters of the (K) over bar* (892)degrees resonance and of the form factors based on the spectroscopic pole dominance predictions are also measured. We also present a measurement of the (K) over bar* (892)degrees helicity basis form factors in a model-independent way.
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| 52. |
- Ablikim, M., et al.
(författare)
-
Study of decay dynamics and CP asymmetry in D+ -> K(L)(0)e(+)nu(e) decay
- 2015
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 92:11
-
Tidskriftsartikel (refereegranskat)abstract
- Using 2.92 fb(-1) of electron-positron annihilation data collected at root s = 3.773 GeV with the BESIII detector, we obtain the first measurements of the absolute branching fraction B(D+ -> K(L)(0)e(+)nu(e)) = (4.481 +/- 0.027(stat) +/- 0.103(sys))% and the CP asymmetry A(CP)(D+-> KL0e+nu e) = (-0.59 +/- 0.60(stat) +/- 1.48(sys))%. From the D+ -> K(L)(0)e(+)nu(e) differential decay rate distribution, the product of the hadronic form factor and the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element, f(+)(K)(0)vertical bar V-cs vertical bar, is determined to be 0.728 +/- 0.006(stat) +/- 0.011(sys). Using vertical bar V-cs vertical bar from the SM constrained fit with the measured f(+)(K)(0)vertical bar V-cs vertical bar, f(+)(K)(0) = 0.748 +/- 0.007(stat) +/- 0.012(sys) is obtained, and utilizing the unquenched Lattice QCD (LQCD) calculation for f(+)(K)(0), vertical bar V-cs vertical bar = 0.975 +/- 0.008(stat) +/- 0.015(sys) +/- 0.025(LQCD).
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| 53. |
- Ablikim, M., et al.
(författare)
-
Study of dynamics of D-0 -> K(-)e(+)nu(e) and D-0 -> pi(-)e(+)nu(e) decays
- 2015
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 92:7
-
Tidskriftsartikel (refereegranskat)abstract
- In an analysis of a 2.92 fb(-1) data sample taken at 3.773 GeV with the BESIII detector operated at the BEPCII collider, we measure the absolute decay branching fractions B(D-0 -> K(-)e(+)nu(e)) = (3.505 +/- 0.014 +/- 0.033)% and B(D-0 -> pi(-)e(+)nu(e)) = (0.295 +/- 0.004 +/- 0.003)%. From a study of the differential decay rates we obtain the products of hadronic form factor and the magnitude of the Cabibbo-Kobayashi-Maskawa (CKM) matrix element f(+)(K)(0)vertical bar V-cs vertical bar = 0.7172 +/- 0.0025 +/- 0.0035 and f(+)(pi)(0)vertical bar V-cd vertical bar = 0.1435 +/- 0.0018 +/- 0.0009. Combining these products with the values of vertical bar V-cs(d)vertical bar from the SM constraint fit, we extract the hadronic form factors f(+)(K)(0) = 0.7368 +/- 0.0026 +/- 0.0036 and f(+)(pi)(0) = 0.6372 +/- 0.0080 +/- 0.0044, and their ratio f(+)(pi)(0)/f(+)(K)(0) = 0.8649 +/- 0.0112 +/- 0.0073. These form factors and their ratio are used to test unquenched lattice QCD calculations of the form factors and a light cone sum rule (LCSR) calculation of their ratio. The measured value of f(+)(K(pi))(0)vertical bar V-cs(d)vertical bar and the lattice QCD value for f(+)(K(pi))(0) are used to extract values of the CKM matrix elements of vertical bar V-cs vertical bar = 0.9601 +/- 0.0033 +/- 0.0047 +/- 0.0239 and vertical bar V-cd vertical bar = 0.2155 +/- 0.0027 +/- 0.0014 +/- 0.0094, where the third errors are due to the uncertainties in lattice QCD calculations of the form factors. Using the LCSR value for f(+)(pi)(0)/f(+)(K)(0), we determine the ratio vertical bar V-cd vertical bar/vertical bar V-cs vertical bar = 0.238 +/- 0.004 +/- 0.002 +/- 0.011, where the third error is from the uncertainty in the LCSR normalization. In addition, we measure form factor parameters for three different theoretical models that describe the weak hadronic charged currents for these two semileptonic decays. All of these measurements are the most precise to date.
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| 54. |
- Ablikim, M., et al.
(författare)
-
Study of e(+)e(-) -> omega chi(cJ) at Center of Mass Energies from 4.21 to 4.42 GeV
- 2015
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 114:9
-
Tidskriftsartikel (refereegranskat)abstract
- Based on data samples collected with the BESIII detector at the BEPCII collider at nine center of mass energies from 4.21 to 4.42 GeV, we search for the production of e(+)e(-) -> omega chi(cJ) (J = 0, 1, 2). The process e(+)e(-) -> omega chi(c0) is observed for the first time, and the Born cross sections at root s = 4.23 and 4.26 GeV are measured to be (55.4 +/- 6.0 +/- 5.9) and (23.7 +/- 5.3 +/- 3.5) pb, respectively, where the first uncertainties are statistical and the second are systematic. The omega chi(c0) signals at the other seven energies and the e(+)e(-) -> omega chi(c1) and omega chi(c2) signals are not significant, and the upper limits on the cross sections are determined. By examining the omega chi(c0) cross section as a function of center of mass energy, we find that it is inconsistent with the line shape of the Y(4260) observed in e(+)e(-) -> pi(+)pi(-) J/psi Assuming the omega chi(c0) signals come from a single resonance, we extract the mass and width of the resonance to be (4230 +/- 8 +/- 6) MeV/c(2) and (38 +/- 12 +/- 2) MeV, respectively, and the statistical significance is more than 9 sigma.
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| 55. |
- Ablikim, M., et al.
(författare)
-
Study of J/psi -> eta phi pi(+)pi(-) at BESIII
- 2015
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 91:5
-
Tidskriftsartikel (refereegranskat)abstract
- invariant mass spectrum of phi f(0)(980) with a statistical significance of greater than 10 sigma. The corresponding mass and width are determined to be M = 2200 +/- 6(stat) +/- 5(syst) MeV/c(2) and Gamma = 104 +/- 15(stat) +/- 15(syst) MeV, respectively, and the product branching fraction is measured to be B(J/psi ->eta Y(2175), Y(2175)->phi f(0)(980), f(0)(980)->pi(+)pi(-)) = (1.20 +/- 0.14(stat)+/- 0.37(syst))x10(-4). The results are consistent within errors with those of previous experiments. We also measure the branching fraction of J/psi ->phi f(1)(1285) with f(1)(1285)->eta pi(+)pi(-) and set upper limits on the branching fractions for J/psi ->phi eta(1405)/phi X(1835)/phi X(1870) with eta(1405)/X(1835)/X(1870)->eta pi(+)pi(-) at the 90% confidence level.
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| 56. |
- Ablikim, M., et al.
(författare)
-
Study of J/Psi -> p(p)over-bar phi at BESIII
- 2016
-
Ingår i: PHYSICAL REVIEW D. - 2470-0010. ; 93:5
-
Tidskriftsartikel (refereegranskat)abstract
- Using a data sample of 1.31×109 J/ψ events accumulated with the BESIII detector, the decay J/ψ→pp¯ϕ is studied via two decay modes, ϕ→KS0KL0 and ϕ→K+K-. The branching fraction of J/ψ→pp¯ϕ is measured to be B(J/ψ→pp¯ϕ)=[5.23±0.06(stat)±0.33(syst)]×10-5, which agrees well with a previously published measurement, but with a significantly improved precision. No evident enhancement near the pp¯ mass threshold, denoted as X(pp¯), is observed, and the upper limit on the branching fraction of J/ψ→X(pp¯)ϕ→pp¯ϕ is determined to be B(J/ψ→X(pp¯)ϕ→pp¯ϕ)<2.1×10-7 at the 90% confidence level.
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| 57. |
- Ablikim, M., et al.
(författare)
-
Study of psi decays to the Xi(-)(Xi)over-bar(+) and Sigma(1385)(-/+)(Sigma)over-bar(1385)(+/-) final states
- 2016
-
Ingår i: PHYSICAL REVIEW D. - 2470-0010. ; 93:7
-
Tidskriftsartikel (refereegranskat)abstract
- We study the decays of the charmonium resonances J/psi and psi(3686) to the final states Xi(-)(Xi) over bar (+), S(1385)(-/+)(Sigma) over bar (1385)(+/-) based on a single baryon tag method using data samples of (223.7 +/- 1.4) x 10(6) J/psi and (106.4 +/- 0.9) x 10(6) psi(3686) events collected with the BESIII detector at the BEPCII collider. The decay psi(3686) -> Sigma(1385)(-/+)(Sigma) over bar (1385)(+/-) is observed for the first time, and the measurements of the other processes, including the branching fractions and angular distributions, are in good agreement with, and much more precise than, the previously published results. Additionally, the ratios B(psi(3686)->Xi(-)(Xi) over bar (+))/B(J/psi ->Xi(-)(Xi) over bar (+)), B(psi(3686)->Sigma(1385)(-)(Sigma) over bar (1385)(+))/B(J/psi ->Sigma(1385)(-)(Sigma) over bar (1385)(+)) and B(psi(3686)->Sigma(1385)(+)(Sigma) over bar (1385)(-))/B(J/psi ->Sigma(1385)(+)(Sigma) over bar (1385)(-)) are detetmind
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| 58. |
- Singh, B. P., et al.
(författare)
-
Experimental access to Transition Distribution Amplitudes with the PANDA experiment at FAIR
- 2015
-
Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 51:8
-
Tidskriftsartikel (refereegranskat)abstract
- Baryon-to-meson Transition Distribution Amplitudes (TDAs) encoding valuable new information on hadron structure appear as building blocks in the collinear factorized description for several types of hard exclusive reactions. In this paper, we address the possibility of accessing nucleon-to-pion (pi N) TDAs from (p) over barp -> e(+)e(-)pi(0) reaction with the future PANDA detector at the FAIR facility. At high center-of-mass energy and high invariant mass squared of the lepton pair q(2), the amplitude of the signal channel (p) over barp -> e(+)e(-)pi(0) admits a QCD factorized description in terms of pi N TDAs and nucleon Distribution Amplitudes (DAs) in the forward aid backward kinematic regimes. Assuming the validity of this factorized description, we perform feasibility studies for measuring (p) over barp -> e(+)e(-)pi(0) with the PANDA detector. Detailed simulations on signal reconstruction efficiency as well as on rejection of the most severe background channel, i.e. (p) over barp -> pi(+)pi(-)pi(0) were performed for the center-of-mass energy squared s = 5 GeV2 and s = 10 GeV2, in the kinematic regions 3.0 < q(2) < 4.3 GeV2 and 5 < q(2) < 9 GeV2, respectively, with a neutral pion scattered in the forward or backward cone vertical bar cos theta(pi 0)vertical bar > 0.5 in the proton-antiproton center-of-mass frame. Results of the simulation show that the particle identification capabilities of the PANDA detector will allow to achieve a background rejection factor of 5 . 10(7) (1 . 10(7)) at low (high) q(2) for s = 5 GeV2, and of 1 . 10(8) (6 . 10(6)) at low (high) q(2) for s = 10 GeV2, while keeping the signal reconstruction efficiency at around 40%. At both energies, a clean lepton signal can be reconstructed with the expected statistics corresponding to 2 of integrated luminosity. The cross sections obtained from the simulations are used to show that a test of QCD collinear factorization can be done at the lowest order by measuring scaling laws and angular distributions. The future measurement of the signal channel cross section with PANDA will provide a new test of the perturbative QCD description of a novel class of hard exclusive reactions and will open the possibility of experimentally accessing pi N TDAs.
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| 59. |
- Ablikim, M., et al.
(författare)
-
Amplitude analysis of the chi(c1) -> eta pi(+)pi(-) decays
- 2017
-
Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 95:3
-
Tidskriftsartikel (refereegranskat)abstract
- Using 448.0 x 10(6) psi(3686) events collected with the BESIII detector, an amplitude analysis is performed for psi(3686) -> gamma chi(c1), chi(c1) ->eta pi(+)pi(-) decays. The most dominant two- body structure observed is a(0)(980)(+/-) pi(-/+); a(0)(980)(+/-) -> eta pi(+/-.) line shape is modeled using a dispersion relation, and a significant nonzero a(0) (980) coupling to the eta'pi channel is measured. We observe chi(c1) -> a(2)(1700)pi production for the first time, with a significance larger than 17 sigma. The production of mesons with exotic quantum numbers, J(PC) = 1(-+), is investigated, and upper limits for the branching fractions chi(c1) -> pi(1)(1400)(+/-)pi(-/+) , chi(c1) -> pi(1)(1600)(+/-)pi(-/+) and chi(c1) -> pi 1(2015)(+/-)pi(-/+) with subsequent pi(1)(X)(+/-) -> eta pi(+/-) decay, are determined.
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| 60. |
- Ablikim, M., et al.
(författare)
-
Determination of the Spin and Parity of the Z(c)(3900)
- 2017
-
Ingår i: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 119:7
-
Tidskriftsartikel (refereegranskat)abstract
- The spin and parity of the Z(c)(3900)(+/-) state are determined to be J(P) = 1(+) with a statistical significance larger than 7 sigma over other quantum numbers in a partial wave analysis of the process e(+)e(-) -> pi(+)pi(-) J/psi We use a data sample of 1.92 fb(-1) accumulated at root s = 4.23 and 4.26 GeV with the BESIII experiment. When parametrizing the Z(c)(3900)(+/-) with a Flatte-like formula, we determine its pole mass M-pole = (3881.2 +/- 4.2(stat) +/- 52.7(syst)) MeV/c(2) and pole width Gamma(pole) = (51.8 +/- 4.6(stat) +/- 36.0(syst)) MeV. We also measure cross sections for the process e(+)e(-) -> Z(c)(3900)(+)pi(-) + c.c. -> J/psi pi(+)pi(-) and determine an upper limit at the 90% confidence level for the process e(+)e(-) -> Z(c)(4020)(+)pi(-) + c.c. -> J/psi pi(+)pi(-).
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