Yazar "Albrecht, M." seçeneğine göre listele

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    Amplitude analysis and branching fraction measurement of the decay D-s(+) -> pi(+)pi(0)pi(0)
    (SPRINGER, 2022) Ablikim, M.; Achasov, M. N.; Adlarson, P.; Ahmed, S.; Albrecht, M.; Kolcu, Onur Buğra
    Using a data set corresponding to an integrated luminosity of 6.32fb(-1) recorded by the BESIII detector at center-of-mass energies between 4.178 and 4.226 GeV, an amplitude analysis of the decay D-s(+) -> pi(+)pi(0)pi(0 ) is performed, and the relative fractions and phases of different intermediate processes are determined. The absolute branching fraction of the decay D-s(+) -> pi(+)pi(0)pi(0)is measured to be (0.50 +/- 0.04(stat) 0.02(syst) )%. The absolute branching fraction of the intermediate process D-s(+) -> f(0)(980)pi(+), f(0)(980) ->pi(0)pi(0 ), is determined to be (0.28 +/- 0.04(stat) +/- 0.04(syst))%.
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    Amplitude analysis and branching fraction measurement of the decay D-s(->)+ K+pi(+)pi(-)pi(0)
    (SPRINGER, 2022) Ablikim, M.; Achasov, M. N.; Adlarson, P.; Albrecht, M.; Aliberti, R.
    he singly Cabibbo-suppressed decay Ds -> K+pi(+)pi(-)pi(0) is observed by using a data set corresponding to an integrated luminosity of 6.32 fb(-1) recorded by the BESIII detector at the centre-of-mass energies between 4.178 and 4.226 GeV. The first amplitude analysis of Ds+-> K+pi(+)pi(-)pi(0) reveals the sub-structures in this decay and determines the fractions and relative phases of different intermediate processes. The dominant intermediate process is Ds+ -> K-*0 rho(+), with a fit fraction of (40.5 +/- 2.8(stat.) +/- 1.5(syst.))%. With the detection efficiency based on our amplitude analysis, the absolute branching fraction for Ds+-> K+pi(+)pi(-)pi(0) is measured to be (9.75 +/- 0.54(stat.)+/- 0.17(syst.)) x 10(-3).
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    Amplitude analysis of Ds+ ? ?+ ?- ?+
    (Amer Physical Soc, 2022) Ablikim, M.; Achasov, M. N.; Adlarson, P.; Ahmed, S.; Albrecht, M.; Aliberti, R.; Çetin, Serkant Ali
    Utilizing the data set corresponding to an integrated luminosity of 3.19 fb(-1) collected by the BESIII detector at a center-of-mass energy of 4.178 GeV, we perform an amplitude analysis of the D-s(+) -> pi(+) pi(-) pi(+) decay. The sample contains 13,797 candidates with a signal purity of similar to 80%. The amplitude and phase of the contributing pi pi S wave are measured based on a quasi-model-independent approach, along with the amplitudes and phases of the P and D waves parametrized by Breit-Wigner models. The fit fractions of different intermediate decay channels are also reported.
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    Cross section measurements of the e(+)e(-) -> D*D+*(-) and e(+)e(-) -> D*D-+(-) processes at center-of-mass energies from 4.085 to 4.600 GeV
    (SPRINGER, 2022) Ablikim, M.; Achasov, M. N.; Adlarson, P.; Albrecht, M.; Çetin, Serkant Ali; Kolcu, Onur Buğra
    The Born cross sections of the e(+)e(-) -> D*D+*(-) and e(+)e(-) -> D*D-+(-) processes are measured using e(+)e(-) collision data collected with the BESIII experiment at center-of-mass energies from 4.085 to 4.600 GeV, corresponding to an integrated luminosity of 15.7 fb(-1). The results are consistent with and more precise than the previous measurements by the Belle, Babar and CLEO collaborations. The measurements are essential for understanding the nature of vector charmonium and charmonium-like states.
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    Evidence for the ?c(2S) ? ?+?-? decay
    (Amer Physical Soc, 2023) Ablikim, M.; Achasov, M. N.; Adlarson, P.; Albrecht, M.; Aliberti, R.; Amoroso, A.; Çetin, Serkant Ali
    The decay eta(c)(2S) -> pi(+)pi(-)eta is searched for through the radiative transition psi(3686) -> gamma eta(c)(2S) using 448 million psi(3686) events accumulated at the BESIII detector. The first evidence of eta(c)(2S) -> pi(+)pi(-)eta is found with a statistical significance of 3.5 sigma. The product of the branching fractions of psi(3686) -> gamma eta(c)(2S) and eta(c)(2S) -> pi(+)pi(-)eta is measured to be Br(psi(3686) -> gamma eta(c)(2S)) x Br(eta(c)(2S) -> pi(+)pi(-)eta) = (2.97 +/- 0.81 +/- 0.26) x 10(-6), where the first uncertainty is statistical and the second one is systematic. The branching fraction of the decay eta(c)(2S) -> pi(+)pi(-)eta is determined to be Br(eta(c)(2S) -> pi(+)pi(-)eta) = (42.4 +/- 11.6 +/- 3.8 +/- 30.3) x 10(-4), where the third uncertainty is transferred from the uncertainty of the branching fraction of psi(3686) -> gamma eta(c)(2S).
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    Evidence for the Cusp Effect in ?0 Decays into ??0?0
    (Amer Physical Soc, 2023) Ablikim, M.; Achasov, M. N.; Adlarson, P.; Albrecht, M.; Aliberti, R.; Amoroso, A.; Çetin, Serkant Ali
    Using a sample of 4.3 x 105 eta' -> eta pi 0 pi 0 events selected from the ten billion J=psi event dataset collected with the BESIII detector, we study the decay eta' -> eta pi 0 pi 0 within the framework of nonrelativistic effective field theory. Evidence for a structure at pi+pi- mass threshold is observed in the invariant mass spectrum of pi 0 pi 0 with a statistical significance of around 3.5 sigma, which is consistent with the cusp effect as predicted by the nonrelativistic effective field theory. After introducing the amplitude for describing the cusp effect, the pi pi scattering length combination a0 - a2 is determined to be 0.226 10.060stat 10.013syst, which is in good agreement with theoretical calculation of 0.2644 10.0051.
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    First observation of the semileptonic decay ?c+ ? pK- e+ ?e
    (Amer Physical Soc, 2022) Ablikim, M.; Achasov, M. N.; Adlarson, P.; Albrecht, M.; Aliberti, R.; Amoroso, A.; Çetin, Serkant Ali
    Using 4.5 fb(-1) of e(+)e(-) annihilation data samples collected at the center-of-mass energies ranging from 4.600 GeV to 4.699 GeV with the BESIII detector at the BEPCII collider, a first study of the semileptonic decays Lambda(+)(c) -> pK(-)e(+)v(e), Lambda(+)(c) ->Lambda (1520)e(+)v(e) and Lambda(+)(c) -> Lambda (1405)e(+)v(e) is performed. The Lambda(+)(c) -> pK(-)e(+)v(e) decay is observed with a significance of 8.2 sigma and the branching fraction is measured to be B (Lambda(+)(c) -> pK(-)e(+)v(e)) = (0.88 +/- 0.17(stat) +/- 0.07(syst)) x 10(-3). We also report evidence of Lambda(+)(c) ->Lambda (1520)e(+)v(e) and Lambda(+)(c) -> Lambda (1405)e(+)v(e) with significances of 3.3 sigma and 3.2 sigma , respectively, and measure B (Lambda(+)(c) ->Lambda (1520)e(+)v(e) ) = (1.02 +/- 0.52(stat) +/- 0.11(syst) ) x 10(-3) andB (Lambda(+)(c) ->Lambda (1405) [-> pK(-)]e(+)v(e)) = (0.42 +/- 0.19(stat) +/- 0.04(syst)) x 10(-3). Combining these with the inclusive semileptonic Lambda(+)(c) branching fraction measured by BESIII, the relative fraction is determined to be [B (Lambda(+)(c) -> pK(-)e(+)v(e))/[B (Lambda(+)(c) -> Xe(+)v(e))] = (2.1 +/- 0.4(stat) +/- 0.2(syst))%, which provides a clear confirmation that semileptonic Lambda(+)(c) decays are not saturated by the Lambda l(+)v(e) final state.
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    Helicity amplitude analysis of ?cJ ? ??
    (Springer, 2023) Ablikim, M.; Achasov, M. N.; Adlarson, P.; Albrecht, M.; Aliberti, R.; Amoroso, A.; Çetin, Serkant Ali
    Using (447.9 +/- 2.3) million (3686) events collected with the BESIII detector, the decays of chi(cJ) -> phi phi (J = 0, 1, 2) have been studied via the decay psi(3686) ->gamma chi(cJ). The branching fractions of the decays chi(cJ) -> phi phi (J = 0, 1, 2) are determined to be (8.59 +/- 0.27 +/- 0.20) x 10(-4), (4.26 +/- 0.13 +/- 0.15) x 10(-4), and (12.67 +/- 0.28 +/- 0. 33) x 10(-4), respectively, which are the most precise measurements to date. From a helicity amplitude analysis of the process psi(3686) -> gamma chi(cJ), chi(cJ) -> phi phi, phi -> K+K-, the polarization parameters of the chi(cJ) -> phi phi decays are determined for the first time.
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    Improved measurement of the absolute branching fraction of inclusive semileptonic ?c plus decay
    (Amer Physical Soc, 2023) Ablikim, M.; Achasov, M. N.; Adlarson, P.; Albrecht, M.; Aliberti, R.; Amoroso, A.; Çetin, Serkant Ali
    Using 4.5 fb-1 of e+e- annihilation data samples collected at center-of-mass energies ranging from 4.600 to 4.698 GeV with the BESIII detector at the BEPCII collider, we measured the absolute branching fraction for the inclusive semileptonic decay A+c -Xe+ve, where X refers to any possible particle system. The branching fraction of the decay is determined to be B(A+c -Xe+ve) = (4.06 +/- 0.10stat +/- 0.09syst)%. Our result improves the precision of previous measurements of B(A+c -Xe+ve) by more than threefold. Using the known A+c lifetime and the charge-averaged semileptonic decay width of nonstrange charmed mesons, we measure the ratio of inclusive semileptonic decay widths Gamma(A+c -Xe+ve)/Gamma over bar (D -Xe+ve) = 1.28 +/- 0.05, where statistical and systematic uncertainties are combined.
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    Improved measurement of the branching fractions of the inclusive decays D+?K0SX and D0?K0SX
    (Amer Physical Soc, 2023) Ablikim, M.; Achasov, M. N.; Adlarson, P.; Albrecht, M.; Aliberti, R.; Amoroso, A.; Çetin, Serkant Ali
    By analyzing 2.93 fb-1 of e+e- collision data taken at the center-of-mass energy of 3.773 GeV with the BESIII detector, the branching fractions of the inclusive decays D+ & RARR; K0SX and D0 & RARR; K0SX are measured to be (33.11 & PLUSMN; 0.13 & PLUSMN; 0.36)% and (20.75 & PLUSMN; 0.12 & PLUSMN; 0.20)%, respectively, where the first uncertainties are statistical and the second are systematic. These results are consistent with the world averages of previous measurements, but with much improved precision.
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    Measurement of A baryon polarization in e(+) e(-) -> Lambda(Lambda)over-bar at root s=3.773 GeV
    (AMER PHYSICAL SOC, 2022) Ablikim, M.; Achasov, M. N.; Adlarson, P.; Ahmed, S.; Albrecht, M.; Çetin, Serkant Ali; Kolcu, Onur Buğra
    Using a data sample of psi(3770) events collected with the BESIII detector at BEPCII corresponding to an integrated luminosity of 2.9 fb-1, we report a measurement of A spin polarization in e+ e- -> Lambda(Lambda) over bar at = root s = 3.773 GeV. The significance of polarization is found to be 2 sigma including the systematic uncertainty, which implies a zero phase between the transition amplitudes of the Lambda(Lambda) over bar helicity states. This phase can be interpreted in terms of psionic form factors, and is determined to be Delta Phi(Psi) = Phi(Psi)(E) - Phi(Psi)(M) = (71(-46)(+66) +/- 5)degrees. Similarly, the ratio between the form factors is found to be R-psi = vertical bar G(E)(Psi)/G(M)(Psi)vertical bar = 0.48(-0.35)(+0.21) +/- 0.03. The first uncertainties are statistical and the second systematic.
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    Measurement of branching fraction of Ds*+ ? Ds+?0 relative to Ds*+ ? Ds+?
    (Amer Physical Soc, 2023) Ablikim, M.; Achasov, M. N.; Adlarson, P.; Albrecht, M.; Aliberti, R.; Amoroso, A.; Çetin, Serkant Ali
    Based on 7.33 fb(-1) of e(+)e(-) collision data taken at center-of-mass energies between 4.128 and 4.226 GeV with the BESIII detector, we measure the branching fraction of D-s*(+)-> D-s(+)pi(0) relative to that of D-s*(+) -> D-s(+)gamma to be (6.16 +/- 10.43 +/- 10.18)%. The first uncertainty is statistical and the second one is systematic. By using the world average value of the branching fraction of D-s*(+) -> D-s(+) e(+)e(-), we determine the branching fractions of D-s(*+) -> D-s(+)gamma and D-s(*+) -> D-s(+)pi(0) to be (93.57 +/- 10.38 +/- 10.22)% and (5.76 +/- 10.38 +/- 10.16)%, respectively.
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    Measurement of branching fractions of J/psi and psi(3686) decays to Sigma(+) and (Sigma)over-bar(-)
    (SPRINGER, 2021) Ablikim, M.; Achasov, M. N.; Adlarson, P.; Ahmed, S.; Albrecht, M.; Aliberti, R.; Çetin, Serkant Ali; Kolcu, Onur Buğra
    Using 1310.6 x 10(6) J/psi and 448.1 x 10(6) psi(3686) events collected with the BESIII detector, the branching fractions of J/psi decays to Sigma(+)(Sigma) over bar (-) is measured to be (10.61 +/- 0.04 +/- 0.36) x 10(-4), which is significantly more precise than the current world average. The branching fractions of psi(3686) decays to Sigma(+)(Sigma) over bar (-) is measured to be (2.52 +/- 0.04 +/- 0.09) x 10(-4), which is consistent with the previous measurements. In addition, the ratio of beta(psi(3686) -> Sigma(+)(Sigma) over bar (-)) / beta(J/psi -> Sigma(+)(Sigma) over bar (-)) is determined to be (23.8 +/- 1.1)% which violates the "12% rule".
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    Measurement of e (+) e (-) -> gamma chi(c0,c1,c2) cross sections at center-of-mass energies between 3.77 and 4.60 GeV
    (AMER PHYSICAL SOC, 2021) Ablikim, M.; Achasov, M. N.; Adlarson, P.; Ahmed, S.; Albrecht, M.; Aliberti, R.; Amoroso, A.; Kolcu, Onur Buğra
    BESIII detector at BEPCII. We observe for the first time e(+)e(-)->gamma chi(c1; c2) signals at root s = 4.180 GeV with statistical significances of 7.6s and 6.0s, respectively. The production cross section of e(+)e(-)->gamma chi(c1; c2) at each center-of-mass energy is also measured. We find that the line shape of the e(+)e(-) ->gamma chi(c1) cross section can be described with conventional charmonium states psi(3686), psi(3770), psi(4040), psi(4160). Compared with this, for the e(+)e(-) ->gamma chi(c2) channel, one more additional resonance is added to describe the cross section line shape. Its mass and width are measured to be M = 4371.7 +/- 7.5 +/- 1.8 MeV=c(2) and G(tot) 1/4 =51.1 +/- 17.6 +/- 1.9 MeV, where the first uncertainties are statistical and the second systematic. The significance of this resonance is estimated to be 5.8s, and its parameters agree with the Yo4360THORN resonance previously reported in e(+)e(-)-> pi+pi(-)psi(3686), and the Y(4390) in e(+)e(-). pi(+)pi(-) h(c) within uncertainties. No significant signal for the e(+)e(-->)gamma chi(c0) process is observed, and the upper limits of Born cross sections sigma(B)(e(+)e(-)->gamma chi(c0)) at 90% confidence level are reported.
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    Measurement of e plus e-? ??0 cross sections at center-of-mass energies between 3.508 and 4.600 GeV
    (Amer Physical Soc, 2023) Ablikim, M.; Achasov, M. N.; Adlarson, P.; Albrecht, M.; Aliberti, R.; Amoroso, A.; Çetin, Serkant Ali
    We present a measurement of the dressed cross sections for e+e- -> phi eta at different center-of-mass energies between 3.508 and 4.600 GeV based on 15.1 fb-1 of e+e- annihilation data collected with the BESIII detector operating at the BEPCII collider. In addition, a search for the decay Y(4230) -> phi eta is performed. No clear signal is observed and the corresponding upper limit is provided.
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    Measurement of e plus e-? AA? from 3.5106 to 4.6988 GeV and study of AA mass threshold enhancement
    (Amer Physical Soc, 2023) Xu, Wei; Ablikim, M.; Achasov, M. N.; Adlarson, P.; Albrecht, M.; Aliberti, R.; Çetin, Serkant Ali
    Using data samples with a total integrated luminosity of approximately 18 fb-1 collected by the BESIII detector operating at the Beijing Electron-Positron Collider II, the process e+e- & RARR; A over bar A & eta; is studied at center-of-mass energies between 3.5106 and 4.6988 GeV. The Born cross section for the process e+e-& RARR; A over bar A & eta; is measured. No significant structure is observed in the Born cross section line shape. An enhancement near the AA over bar mass threshold is observed for the first time in the process. The structure can be described by an S-wave Breit-Wigner function. Neglecting contribution of excited A states and potential interferences, the mass and width are determined to be (2356 & PLUSMN; 7 & PLUSMN; 15) MeV=c2 and (304 & PLUSMN; 28 & PLUSMN; 54) MeV, respectively, where the first uncertainties are statistical and the second are systematic.
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    Measurement of e+e- ? ??+?- cross section at s=2.000 to 3.080 GeV
    (Springer, 2023) Ablikim, M.; Achasov, M. N.; Adlarson, P.; Ahmed, S.; Albrecht, M.; Aliberti, R.; Çetin, Serkant Ali
    A partial wave analysis on the process e(+)e(-) -> omega(+)pi(-) is performed using 647 pb(-1) of data sample collected by using the BESIII detector operating at the BEPCII storage ring at center-of-mass (c.m.) energies from 2.000 GeV to 3.080 GeV. The Born cross section of the e(+)e(-) -> omega pi(+)pi(-) process is measured, with precision improved by a factor of 3 compared to that of previous studies. A structure near 2.25 GeV is observed in the energy-dependent cross sections of e(+)e(-) -> omega pi(+)pi(-) and omega pi(0)pi(0) with a statistical significance of 7.6 sigma, and its determined mass and width are 2232 +/- 19 +/- 27 MeV/c(2) and 93 +/- 53 +/- 20 MeV, respectively, where the first and second uncertainties are statistical and systematic, respectively. By analyzing the cross sections of subprocesses e(+)e(-) -> omega f(0)(500), omega f(0)(980), omega f(0)(1370), omega f(2)(1270), and b(1)(1235)pi, a structure, with mass M = 2200 +/- 11 +/- 17 MeV/c(2) and width Gamma = 74 +/- 20 +/- 24 MeV, is observed with a combined statistical significance of 7.9 sigma. The measured resonance parameters will help to reveal the nature of vector states around 2.25 GeV.
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    Measurement of e+e- ? ?p+p- cross section at ?s = 2.000 to 3.080 GeV (vol 01, 111, 2023)
    (Springer, 2023) Ablikim, M.; Achasov, M. N.; Adlarson, P.; Ahmed, S.; Albrecht, M.; Aliberti, R.; Çetin, Serkant Ali
    [Abstract Not Available]
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    Measurement of integrated luminosities at BESIII for data samples at center-of-mass energies between 4.0 and 4.6 GeV*
    (IOP Publishing Ltd, 2022) Ablikim, M.; Achasov, M. N.; Adlarson, P.; Ahmed, S.; Albrecht, M.
    The integrated luminosities of data samples collected in the BESIII experiment in 2016-2017 at center-of-mass energies between 4.19 and 4.28 GeV are measured with a precision better than 1% by analyzing large-angle Bhabha scattering events. The integrated luminosities of old datasets collected in 2010-2014 are updated by considering corrections related to detector performance, offsetting the effect of newly discovered readout errors in the electromagnetic calorimeter, which can haphazardly occur.
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    Measurement of psi(3686) -> lambda(lambda)over-bar eta and psi(3686) -> lambda(lambda)over-bar pi(0) decays
    (AMER PHYSICAL SOC, 2022) Ablikim, M.; Achasov, M. N.; Adlarson, P.; Albrecht, M.; Aliberti, R.; Çetin, Serkant Ali; Kolcu, Onur Buğra
    Based on a sample of 448.1 x 10(6) psi(3686) events collected with the BESIII detector, a study of psi(3686) -> Lambda(Lambda) over bar pi(0) and psi(3686) -> Lambda(Lambda) over bar eta is performed. Evidence of the isospin-violating decay psi(3686) -> Lambda(Lambda) over bar pi(0) is found for the first time with a statistical significance of 3.7 sigma, the branching fraction B(psi(3686) -> Lambda(Lambda) over bar pi(0)) is measured to be (1.42 +/- 0.39 +/- 0.59) x 10(-6), and its corresponding upper limit is determined to be 2.47 x 10(-6) at 90% confidence level. A partial wave analysis of psi(3686) -> Lambda(Lambda) over bar eta shows that the peak around Lambda eta invariant mass threshold favors a Lambda* resonance with mass and width in agreement with the Lambda(1670). The branching fraction of the psi(3686) -> Lambda(Lambda) over bar eta is measured to be (2.34 +/- 0.18 +/- 0.52) x 10(-5). The first uncertainties are statistical and the second are systematic.