uu.seUppsala University Publications
Change search
Link to record
Permanent link

Direct link
BETA
Andersson, Walter Ikegami
Alternative names
Publications (10 of 92) Show all publications
Ablikim, M., Andersson, W. I., Johansson, T., Kupsc, A., Li, C., Papenbrock, M., . . . Zou, J. H. (2019). Determination of the Pseudoscalar Decay Constant f(Ds)(+) via D-s(+) -> mu(+)nu(mu). Physical Review Letters, 122(7), Article ID 071802.
Open this publication in new window or tab >>Determination of the Pseudoscalar Decay Constant f(Ds)(+) via D-s(+) -> mu(+)nu(mu)
Show others...
2019 (English)In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 122, no 7, article id 071802Article in journal (Refereed) Published
Abstract [en]

Using a 3.19 fb(-1) data sample collected at an e(+)e(-) center-of-mass energy of E-cm = 4.178 GeV with the BESIII detector, we measure the branching fraction of the leptonic decay D-s(+) -> mu(+)nu(mu) to be BDs+ -> mu+nu mu = (5.49 +/- 0.16(stat) +/- 0.15(syst)) x 10(-3). Combining our branching fraction with the masses of the D-s(+) and mu(+) and the lifetime of the D-s(+), we determine f(Ds+)vertical bar V-cs vertical bar = 246.2 +/- 3.6(stat) +/- 3.5(syst) MeV. Using the c -> s quark mixing matrix element vertical bar V-cs vertical bar determined from a global standard model fit, we evaluate the D-s(+) decay constant f(Ds+) = 252.9 +/- 3.7(stat) +/- 3.6(syst) MeV. Alternatively, using the value of f(Ds+) calculated by lattice quantum chromodynamics, we find vertical bar V-cs vertical bar = 0.985 +/- 0.014(stat) +/- 0.014(syst). These values of BDs+ -> mu+nu mu, f(Ds+)vertical bar V-cs vertical bar, f(Ds+) and vertical bar V-cs vertical bar are each the most precise results to date.

Place, publisher, year, edition, pages
AMER PHYSICAL SOC, 2019
National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-379259 (URN)10.1103/PhysRevLett.122.071802 (DOI)000459583400004 ()30848637 (PubMedID)
Funder
Swedish Research Council
Note

For complete list of authors see http://dx.doi.org/10.1103/PhysRevLett.122.071802

Available from: 2019-03-18 Created: 2019-03-18 Last updated: 2019-03-18Bibliographically approved
Ablikim, M., Andersson, W. I., Johansson, T., Kupsc, A., Li, C., Pettersson, J., . . . Zou, J. H. (2019). First Measurement of the Form Factors in D-s(+) -> K(0)e(+)nu(e) and D-s(+) -> K*(0)e(+)nu(e) Decays. Physical Review Letters, 122(6), Article ID 061801.
Open this publication in new window or tab >>First Measurement of the Form Factors in D-s(+) -> K(0)e(+)nu(e) and D-s(+) -> K*(0)e(+)nu(e) Decays
Show others...
2019 (English)In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 122, no 6, article id 061801Article in journal (Refereed) Published
Abstract [en]

We report on new measurements of Cabibbo-suppressed semileptonic D-s(broken vertical bar) decays using 3.19 fb(-1) of e(broken vertical bar)e(-) annihilation data sample collected at a center-of-mass energy of 4.178 GeV with the BESIII detector at the BEPCII collider. Our results include branching fractions B(D-s(+) -> K(0)e(+)nu(e)) = [3.25 +/- 0.38(stat) +/- 0.16(syst)] x 10(-3) and B(D-s(+) -> K*(0)e(+)nu(e)) = [2.37 +/- 0.26(stat) +/- 0.20(syst)] x 10(-3), which are much improved relative to previous measurements, and the first measurements of the hadronic form-factor parameters for these decays. For D-s(+) -> K(0)e(+)nu(e), we obtain f(+)(0) = 0.720 +/- 0.084(stat) +/- 0.013(syst), and for D-s(+) -> K*(0)e(+)nu(e), we find form-factor ratios r(V) = V(0)/A(1)(0) = 1.67 +/- 0.34(stat) +/- 0.16(syst) and r(2) = A(2)(0)/A(1)(0) = 0.77 +/- 0.28(stat) +/- 0.07(syst).

Place, publisher, year, edition, pages
AMER PHYSICAL SOC, 2019
National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-378373 (URN)10.1103/PhysRevLett.122.061801 (DOI)000458825100002 ()30822077 (PubMedID)
Funder
Swedish Research Council
Note

For complete list of authors see http://dx.doi.org/10.1103/PhysRevLett.122.061801

Available from: 2019-03-07 Created: 2019-03-07 Last updated: 2019-03-07Bibliographically approved
Ablikim, M., Andersson, W. I., Johansson, T., Kupsc, A., Li, C., Papenbrock, M., . . . Zou, J. H. (2019). Measurement of e(+) e(-) -> K+ K- cross section at root s=2.00-3.08 GeV. Physical Review D: covering particles, fields, gravitation, and cosmology, 99(3), Article ID 032001.
Open this publication in new window or tab >>Measurement of e(+) e(-) -> K+ K- cross section at root s=2.00-3.08 GeV
Show others...
2019 (English)In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 99, no 3, article id 032001Article in journal (Refereed) Published
Abstract [en]

The cross section of the process e(+) e(-) -> K+ K- is measured at a number of center-of-mass energies root s from 2.00 to 3.08 GeV with the BESIII detector at the Beijing Electron Positron Collider (BEPCII). The results provide the best precision achieved so far. A resonant structure around 2.2 GeV is observed in the cross section line shape. A Breit-Wigner fit yields a mass of M = 2239.2 +/- 7.1 +/- 11.3 MeV/c(2) and a width of Gamma = 139.8 +/- 12.3 +/- 20.6 MeV, where the first uncertainties are statistical and the second ones are systematic. In addition, the timelike electromagnetic form factor of the kaon is determined at the individual center-of-mass energy points.

Place, publisher, year, edition, pages
AMER PHYSICAL SOC, 2019
National Category
Subatomic Physics Astronomy, Astrophysics and Cosmology
Identifiers
urn:nbn:se:uu:diva-377602 (URN)10.1103/PhysRevD.99.032001 (DOI)000457699400001 ()
Funder
Swedish Research Council
Note

For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.99.032001

Available from: 2019-02-26 Created: 2019-02-26 Last updated: 2019-03-07Bibliographically approved
Ablikim, M., Andersson, W. I., Johansson, T., Kupsc, A., Li, C., Papenbrock, M., . . . Zou, J. H. (2019). Measurement of the absolute branching fractions of Lambda(+)(c) -> Lambda eta pi(+) and Sigma(1385) (+) eta. Physical Review D: covering particles, fields, gravitation, and cosmology, 99(3), Article ID 032010.
Open this publication in new window or tab >>Measurement of the absolute branching fractions of Lambda(+)(c) -> Lambda eta pi(+) and Sigma(1385) (+) eta
Show others...
2019 (English)In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 99, no 3, article id 032010Article in journal (Refereed) Published
Abstract [en]

We study the decays Lambda(+)(c) -> Lambda eta pi(+) and Sigma(1385)(+)eta based on Lambda(+)(c)(Lambda) over bar (c) pairs produced in e(+)e(-) collisions at a center-of-mass energy of root s = 4.6 GeV, corresponding to an integrated luminosity of 567 pb(-1). The data sample was accumulated with the BESIII detector at the BEPCII collider. The branching fractions are measured to be beta(Lambda(+)(c) -> Lambda eta pi(+)) = (1.84 +/- 0.21 (stat) +/- 0.15(syst))% and B(Lambda(+)(c) -> Sigma(1385)(+) eta) = (0.91 +/- 0.18 (stat) +/- 0.09 (syst))%, constituting the most precise measurements to date.

National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-378989 (URN)10.1103/PhysRevD.99.032010 (DOI)000459207600002 ()
Funder
Swedish Research CouncilGerman Research Foundation (DFG)
Note

For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.99.032010

Available from: 2019-03-19 Created: 2019-03-19 Last updated: 2019-03-19Bibliographically approved
Ablikim, M., Andersson, W. I., Johansson, T., Kupsc, A., Li, C., Papenbrock, M., . . . Zou, J. H. (2019). Measurement of the Dynamics of the Decays D-s(+ )-> eta(('))e(+)nu(e). Physical Review Letters, 122(12), Article ID 121801.
Open this publication in new window or tab >>Measurement of the Dynamics of the Decays D-s(+ )-> eta(('))e(+)nu(e)
Show others...
2019 (English)In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 122, no 12, article id 121801Article in journal (Refereed) Published
Abstract [en]

Using e(+)e(-) annihilation data corresponding to an integrated luminosity of 3.19 fb(-1) collected at a center-of-mass energy of 4.178 GeV with the BESIII detector, we measure the absolute branching fractions BDs+->eta e+nu e = (2.323 +/- 0.063(stat) +/- 0.063(syst))% and BDs+->eta'e+nu e = (0.824 +/- 0.073(stat) +/- 0.027(syst))% via a tagged analysis technique, where one D-s is fully reconstructed in a hadronic mode. Combining these measurements with previous BESIII measurements of B-D+->eta(')e+(nu e),the eta - eta' mixing angle in the quark flavor basis is determined to be phi(P) = (40.1 +/- 2.1(stat) +/- 0.7(syst))degrees. From the first measurements of the dynamics of Ds+ -> eta(')e(+)nu(e) decays, the products of the hadronic form factors f(+)(eta('))(0) and the Cabibbo-Kobayashi-Maskawa matrix element vertical bar V-cs vertical bar are determined with different form factor parametrizations. For the two-parameter series expansion, the results are f(+)(eta) (0) vertical bar V-cs vertical bar = 0.4455 +/- 0.0053(stat) +/- 0.0044(syst) and f(+)(eta)' (0) vertical bar V-cs vertical bar and = 0.477 +/- 0.049(stat) +/- 0.011(syst).

Place, publisher, year, edition, pages
AMER PHYSICAL SOC, 2019
National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-381581 (URN)10.1103/PhysRevLett.122.121801 (DOI)000462933300001 ()30978074 (PubMedID)
Funder
Swedish Research Council
Note

For complete list of authors see http://dx.doi.org/10.1103/PhysRevLett.122.121801

Available from: 2019-04-16 Created: 2019-04-16 Last updated: 2019-04-16Bibliographically approved
Ablikim, M., Andersson, W. I., Johansson, T., Kupsc, A., Li, C., Papenbrock, M., . . . Zou, J. H. (2019). Measurement of B(J/ψ→η'e+e−) and search for a dark photon. Physical Review D: covering particles, fields, gravitation, and cosmology, 99(1), Article ID 012013.
Open this publication in new window or tab >>Measurement of B(J/ψ→η'e+e−) and search for a dark photon
Show others...
2019 (English)In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 99, no 1, article id 012013Article in journal (Refereed) Published
Abstract [en]

Using a data sample of (1310.6 +/- 7.0) x 10(6) J/psi decay events collected with the BESIII detector at BEPCII, we study the electromagnetic Dalitz decay J/psi -> eta ' e(+)e(-) with two dominant eta' decay modes, eta' -> gamma pi(+)pi(-) and eta' -> pi(+)pi(-)eta . The branching fraction is determined to be B(J/psi -> eta ' e(+)e(-)) = (6.59 +/- 0.07 +/- 0.17) x 10(-5), which improves in precision by a factor of 2 over the previous BESIII measurement. A search for the dark photon (gamma') is performed via J/psi -> eta'gamma',gamma' -> e(+)e(-). Excluding the w and phi mass regions, no significant signal is observed in the mass range from 0.1 to 2.1 GeV/e2. We set upper limits at the 90% confidence level on B(J/psi -> eta 'gamma') x B(gamma' -> e(+)e(-)), B(J/psi -> eta 'gamma') and the mixing strength as a function of dark photon mass. This is among the first searches for dark photons in charmonium decays.

National Category
Subatomic Physics Astronomy, Astrophysics and Cosmology
Identifiers
urn:nbn:se:uu:diva-377349 (URN)10.1103/PhysRevD.99.012013 (DOI)000456798900002 ()
Funder
Swedish Research Council
Note

Title in WoS: Measurement of B(J/psi -> eta ' e(+)e(-)) and search for a dark photon

For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.99.012013

Available from: 2019-02-20 Created: 2019-02-20 Last updated: 2019-02-20Bibliographically approved
Ablikim, M., Andersson, W. I., Johansson, T., Kupsc, A., Li, C., Papenbrock, M., . . . Zou, J. (2019). Measurements of e(+)e(-)-> (KSK +/-)-K-0 pi(-/+)pi(0) and (KSK +/-)-K-0 pi(-/+)eta at center-of-mass energies from 3.90 to 4.60 GeV. Physical Review D: covering particles, fields, gravitation, and cosmology, 99(1), Article ID 012003.
Open this publication in new window or tab >>Measurements of e(+)e(-)-> (KSK +/-)-K-0 pi(-/+)pi(0) and (KSK +/-)-K-0 pi(-/+)eta at center-of-mass energies from 3.90 to 4.60 GeV
Show others...
2019 (English)In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 99, no 1, article id 012003Article in journal (Refereed) Published
Abstract [en]

Using 5.2 fb(-1) e(+)e(-) annihilation data samples collected with the BESIII detector, we measure the cross sections of e(+)e(-)->(KSK +/-)-K-0 pi(-/+)pi(0) and (KSK +/-)-K-0 pi(-/+)eta at center-of-mass energies from 3.90 to 4.60 GeV. In addition, we search for the charmoniumlike resonance Y(4260) decays into (KSK +/-)-K-0 pi(-/+)pi(0) and (KSK +/-)-K-0 pi(-/+)eta and Z(c)(0,+/-) (3900) decays into (KSK +/-)-K-0 pi(-/+)(,0) and (KSK +/-)-K-0 eta. Corresponding upper limits are provided since no clear signal is observed.

Place, publisher, year, edition, pages
AMER PHYSICAL SOC, 2019
National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-375886 (URN)10.1103/PhysRevD.99.012003 (DOI)000455365100001 ()
Funder
Swedish Research CouncilGerman Research Foundation (DFG), CRC 1044German Research Foundation (DFG), FOR 2359
Note

For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.99.012003

Available from: 2019-02-04 Created: 2019-02-04 Last updated: 2019-02-04Bibliographically approved
Ablikim, M., Andersson, W. I., Johansson, T., Kupsc, A., Li, C., Papenbrock, M., . . . Zou, J. H. (2019). Measurements of the absolute branching fractions and CP asymmetries for D+ -> (KS,LK+)-K-0 (pi(0)). Physical Review D: covering particles, fields, gravitation, and cosmology, 99(3), Article ID 032002.
Open this publication in new window or tab >>Measurements of the absolute branching fractions and CP asymmetries for D+ -> (KS,LK+)-K-0 (pi(0))
Show others...
2019 (English)In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 99, no 3, article id 032002Article in journal (Refereed) Published
Abstract [en]

Using e(+)e(-) collision data corresponding to an integrated luminosity of 2.93 fb(-1) taken at a center-of-mass energy of 3.773 GeV with the BESIII detector, we determine the absolute branching fractions B(D+ -> (KSK+)-K-0) = (3.02 +/- 0.09 +/- 0.08) x 10(-3), B(D+ -> (KSK+)-K-0 pi(0)) = (5.07 +/- 0.19 +/- 0.23) x 10(-3), B(D+ -> (KLK+)-K-0) = (3.21 +/- 0.11 +/- 0.11) x 10(-3), and B(D+ -> (KLK+)-K-0 pi(0)) = (5.24 +/- 0.22 +/- 0.22) x 10(-3), where the first and second uncertainties are statistical and systematic, respectively. The branching fraction B(D+ -> (KSK+)-K-0) is consistent with the world average value and the other three branching fractions are measured for the first time. We also measure the CP asymmetries for the four decays and do not find a significant deviation from zero.

Place, publisher, year, edition, pages
AMER PHYSICAL SOC, 2019
National Category
Subatomic Physics Astronomy, Astrophysics and Cosmology
Identifiers
urn:nbn:se:uu:diva-378534 (URN)10.1103/PhysRevD.99.032002 (DOI)000458137100001 ()
Funder
Swedish Research Council
Note

For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.99.032002

Available from: 2019-03-22 Created: 2019-03-22 Last updated: 2019-03-22Bibliographically approved
Ablikim, M., Andersson, W. I., Johansson, T., Kupsc, A., Li, C., Papenbrock, M., . . . Zou, J. H. (2019). Observation of D+→f0(500)e+νe and Improved Measurements of D→ρe+νe. Physical Review Letters, 122(6), Article ID 062001.
Open this publication in new window or tab >>Observation of D+→f0(500)e+νe and Improved Measurements of D→ρe+νe
Show others...
2019 (English)In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 122, no 6, article id 062001Article in journal (Refereed) Published
Abstract [en]

Using a data sample corresponding to an integrated luminosity of 2.93 fb(-1) recorded by the BESIII detector at a center-of-mass energy of 3.773 GeV, we present an analysis of the decays D-0 -> pi(-) pi(0) e(vertical bar) nu(e) and D-vertical bar -> pi(-) pi(vertical bar) e(vertical bar) nu(e). By performing a partial wave analysis, the pi(vertical bar) pi(-) S-wave contribution to D-vertical bar -> pi(-) pi(vertical bar) e(vertical bar) nu(e) is observed to be (25.7 +/- 1.6 +/- 1.1)% with a statistical significance greater than 10 sigma, besides the dominant P-wave contribution. This is the first observation of the S-wave contribution. We measure the branching fractions B(D0 -> rho(-) e(+) nu(e)) = (1.445 +/- 0.058 +/- 0.039) x 10(-3), B(D+ -> rho(0) e(+) nu(e)) = (1.860 +/- 0.070 +/- 0.061) x 10(-3), and B(D+ -> f(0)(500)e(+) nu(e),f(0)(500) -> pi(+) pi(-)) = (6.30 +/- 0.43 +/- 0.32) x 10(-4). An upper limit of B(D+ -> f(0)(980)e(+) nu(e),f(0)(980)-> pi(+) pi(-)) < 2.8 x 10(-5) is set at the 90% confidence level. We also obtain the hadronic form factor ratios of D -> rho e(+) nu(e) at q(2) = 0 assuming the single-pole dominance parametrization: r(V) ={[V(0)]/[A(1)(0)]}=1.695 +/- 0.083 +/- 0.051, r(2) = {[A(2)(0)]/[A(1)(0)]} = 0.845 +/- 0.056 +/- 0.039.

National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-379001 (URN)10.1103/PhysRevLett.122.062001 (DOI)000458824200004 ()30822062 (PubMedID)
Funder
Swedish Research Council
Note

For complete list of authors see http://dx.doi.org/10.1103/PhysRevLett.122.062001

Available from: 2019-03-25 Created: 2019-03-25 Last updated: 2019-03-25Bibliographically approved
Ablikim, M., Andersson, W. I., Johansson, T., Kupsc, A., Li, C., Papenbrock, M., . . . Zou, J. H. (2019). Observation of D-s(+) -> p(n)over-bar and confirmation of its large branching fraction. Physical Review D: covering particles, fields, gravitation, and cosmology, 99(3), Article ID 031101.
Open this publication in new window or tab >>Observation of D-s(+) -> p(n)over-bar and confirmation of its large branching fraction
Show others...
2019 (English)In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 99, no 3, article id 031101Article in journal (Refereed) Published
Abstract [en]

The baryonic decay D-s(+) -> p (n) over bar is observed, and the corresponding branching fraction is measured to be (1.21 +/- 0.10 +/- 0.05) x 10(-3), where the first uncertainty is statistical and second systematic. The data sample used in this analysis was collected with the BESIII detector operating at the BEPCII e(+)e(-) double-ring collider with a center-of-mass energy of 4.178 GeV and an integrated luminosity of 3.19 fb(-1). The result confirms the previous measurement by the CLEO Collaboration and is of greatly improved precision. This result will improve our understanding of the dynamical enhancement of the W-annihilation topology in the charmed meson decays.

Place, publisher, year, edition, pages
AMER PHYSICAL SOC, 2019
National Category
Subatomic Physics Astronomy, Astrophysics and Cosmology
Identifiers
urn:nbn:se:uu:diva-378372 (URN)10.1103/PhysRevD.99.031101 (DOI)000458818300001 ()
Funder
Swedish Research Council
Note

For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.99.031101

Available from: 2019-03-07 Created: 2019-03-07 Last updated: 2019-03-07Bibliographically approved
Organisations

Search in DiVA

Show all publications