DSpace Arşivi :: by Yazar "Achasov M.N." değerine göre listeleniyor

Yazar "Achasov M.N." seçeneğine göre listele

Listeleniyor 1 - 14 / 14

Evidence of the hc → KS0 K+π-+ c. c. decay
(American Physical Society, 2024) Ablikim M.; Achasov M.N.; Adlarson P.; Çetin, Serkant Ali
Based on (2.712±0.014)×109 ψ(3686) events collected by the BESIII Collaboration, evidence of the hadronic decay hc→KS0K+π-+c.c. is found with a significance of 4.3σ in the ψ(3686)→π0hc process. The branching fraction of hc→KS0K+π-+c.c. is measured to be (7.3±1.8±0.8)×10-4, where the first and second uncertainties are statistical and systematic, respectively. Combining with the exclusive decay width of ηc→KK̄π, our result indicates inconsistencies with both pQCD and NRQCD predictions. © 2024 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.
Evidence of the singly Cabibbo suppressed decay Λc+ →pπ0
(American Physical Society, 2024) Ablikim M. a; Achasov M.N.; Adlarson P.; Çetin, Serkant Ali
Evidence for the singly Cabibbo suppressed decay Λc+→pπ0 is reported for the first time with a statistical significance of 3.7σ based on 6.0 fb-1 of e+e- collision data collected at center-of-mass energies between 4.600 and 4.843 GeV with the BESIII detector at the BEPCII collider. The absolute branching fraction of Λc+→pπ0 is measured to be (1.56-0.58+0.72±0.20)×10-4. Combining with the branching fraction of Λc+→nπ+, (6.6±1.3)×10-4, the ratio of the branching fractions of Λc+→nπ+ and Λc+→pπ0 is calculated to be 3.2-1.2+2.2. As an important input for the theoretical models describing the decay mechanisms of charmed baryons, our result indicates that the nonfactorizable contributions play an essential role and their interference with the factorizable contributions should not be significant. In addition, the absolute branching fraction of Λc+→pη is measured to be (1.63±0.31stat±0.11syst)×10-3. © 2024 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.
Measurement of e+e− → ωη′ cross sections at s = 2.000 to 3.080 GeV
(Springer Science and Business Media Deutschland GmbH, 2024) Ablikim, Medina N.; Achasov M.N.; Adlarson, Patrik; Çetin, Serkant Ali; Kolcu, Onur Buğra
We measured the Born cross sections for the process e+e− → ωη′ at 22 center-of-mass energies from 2.000 to 3.080 GeV with the BESIII detector at the BEPCII collider. We observed a resonant structure with a statistical significance of 9.6σ. A Breit-Wigner fit determines its mass to be MR = (2153 ± 30 ± 31) MeV/c2 and its width to be ΓR = (167 ± 77 ± 7) MeV, where the first uncertainties are statistical and the second are systematic. © The Author(s) 2024.
Measurement of the branching fraction for ? (3686) ?? KS0 KS0
(American Physical Society, 2021) Ablikim M.; Achasov M.N.; Adlarson P.; Ahmed S.; Albrecht M.; Aliberti R.; Çetin, Serkant Ali; Kolcu, Onur Buğra
Analyzing (448.1±2.9)×106 ?(3686) events collected with the BESIII detector at the BEPCII collider, the ?(3686)??KS0KS0 decay is observed for the first time. The branching fraction for this decay is determined to be B?(3686)??KS0KS0=(7.04±0.39±0.36)×10-5, where the first uncertainty is statistical and the second is systematic.
Measurement of the branching fraction of the singly cabibbo-suppressed decay ?c+ ? ?k+
(APS, 2022) Ablikim M.; Achasov M.N.; Baldini Ferroli R.; Balossino I.; Bertani M.; Kolcu, Onur Buğra; Çetin, Serkant Ali
We report a branching fraction measurement of the singly Cabibbo-suppressed decay ?c+??K+ using a data sample collected with the BESIII detector at the BEPCII storage ring. The data span center-of-mass energies from 4.599 to 4.950 GeV and correspond to an integrated luminosity of 6.44 fb-1. The branching fraction of ?c+??K+ relative to that of the Cabibbo-favored decay ?c+???+ is measured to be R=B(?c+??K+)B(?c+???+)=(4.78±0.34±0.20)%. Combining with the world-average value of B(?c+???+), we obtain B(?c+??K+)=(6.21±0.44±0.26±0.34)×10-4. Here the first uncertainties are statistical, the second systematic, and the third comes from the uncertainty of the ?c+???+ branching fraction. This result, which is more precise than previous measurements, does not agree with theoretical predictions, and suggests that nonfactorizable contributions have been underestimated in current models. © 2022 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.
Observation of the decay ?(3686) ? ? ?? ¯ + and measurement of its angular distribution
(Springer link, 2022) Ablikim M.; Achasov M.N.; Adlarson P.; Albrecht M.; Aliberti R.; Amoroso A.; An M.R.; An Q.; Bai X.H.; Bai Y.; Bakina O.; Baldini Ferroli R.; Çetin, Serkant Ali; Kolcu, Onur Buğra
Using (448.1 ± 2.9) × 106?(3686) events collected with the BESIII detector at the BEPCII collider, the decay ?(3686) ?? ?? ¯ + is observed for the first time with a branching fraction of (2.82 ± 0.04stat.± 0.08syst.) × 10?4, and the angular parameter ??? is measured to be 0.96 ± 0.09stat.± 0.03syst.. [Figure not available: see fulltext.] © 2022, The Author(s).
Observation of the hindered electromagnetic dalitz decay ? (3686) ?e+e-?c
(APS, 2022) Ablikim M.; Achasov M.N.; Adlarson P.; Albrecht M.; Bai X.H.; Amoroso A.
Using a data sample of (448.1±2.9)×106 ?(3686) decays collected at an e+e- center-of-mass energy of 3.686 GeV by the BESIII detector at Beijing Electron Positron Collider II, we report an observation of the hindered electromagnetic Dalitz decay ?(3686)?e+e-?c with a significance of 7.9?. The branching fraction is determined to be B(?(3686)?e+e-?c)=(3.77±0.40stat±0.18syst)×10-5, agreeing well with the prediction of the vector meson dominance model. This is the first measurement of the electromagnetic Dalitz transition between the ?(3686) and the ?c, which provides new insight into the electromagnetic properties of this decay, and offers new opportunities to measure the absolute branching fractions of ?c decays. © 2022 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.
Search for the weak decay ?(3686) ? ?+c ?¯? + c.c.
(2023) Achasov M.N.; Adlarson P.; Albrecht M.; Amoroso A.; An M.R.; Çetin, Serkant Ali; Kolcu, Onur Buğra
Using (448.1±2.9)×106 ?(3686) events collected with the BESIII detector, we perform the first search for the weak baryonic decay ?(3686) ? ?+c ?¯? + c.c.. The analysis procedure is optimized using a blinded method. No significant signal is observed, and the upper limit on the branching fraction (B) of ?(3686) ? ?+c ?¯? + c.c. is set as 1.4 × 10?5 at the 90% confidence level. © 2023 Institute of Physics Publishing. All rights reserved.
Search for ηc (2S) →π+π-ηc and ηc (2S) →π+π- KS0 K±π∓ decays
(American physical society, 2024) Ablikim, M.; Achasov M.N.; Adlarson P.; Çetin, Serkant Ali; Kolcu, Onur Buğra
Based on (27.12 +/- 0.14) x 10(8) psi(2S) events collected by the BESIII detector, we search for the decay eta(c)(2S) -> pi(+)pi(-)eta(c) via psi(2S) -> gamma eta(c)(2S). No significant signal is observed, and the upper limit on the product branching fraction B(psi(2S) -> gamma eta(c) (2S)) x B(eta(c) (2S) -> pi(+)pi(-)eta(c)) is determined to be 2.21 x 10(-5) at the 90% confidence level. In addition, the eta(c)(2S) -> pi(+)pi(-KSK +/-)-K-0 pi(-/+) decay is studied via psi(2S) -> gamma eta(c)(2S) and is observed with a statistical significance of 10 sigma for the first time. The branching fraction of eta(c)(2S) -> pi(+)pi(-KSK +/-)-K-0 pi(-/+) is determined to be (1.33 +/- 0.11 +/- 0.40 +/- 0.95)x10(-2), where the first uncertainty is statistical, the second is systematic, and the third uncertainty is due to the quoted B(psi(2S) -> gamma eta(c)(2S)).
Study of e+e- →π+π-π0 at s from 2.00 to 3.08 GeV at BESIII
(American physical society, 2024) Ablikim, M.; Achasov M.N.; Adlarson P.; Çetin, Serkant Ali; Kolcu, Onur Buğra
With the data samples taken at center-of-mass energies from 2.00 to 3.08 GeV with the BESIII detector at the BEPCII collider, a partial wave analysis on the e+e-→π+π-π0 process is performed. The Born cross sections for e+e-→π+π-π0 and its intermediate processes e+e-→ρπ and ρ(1450)π are measured as functions of s. The results for e+e-→π+π-π0 are consistent with previous results measured with the initial state radiation method within one standard deviation, and improve the uncertainty by a factor of ten. By fitting the line shapes of the Born cross sections for the e+e-→ρπ and e+e-→ρ(1450)π, a structure with mass M=2119±11±15 MeV/c2 and width Γ=69±30±5 MeV is observed with a significance of 5.9σ, where the first uncertainties are statistical and the second ones are systematic. This structure can be interpreted as an excited ω state. © 2024 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.
Study of e+e- →ωX (3872) and γx (3872) from 4.66 to 4.95 GeV
(American physical society, 2024) Ablikim, M.; Achasov M.N.; Adlarson P.; Çetin, Serkant Ali; Kolcu, Onur Buğra
Using data samples with an integrated luminosity of 4.5 fb-1 collected by the BESIII detector at center-of-mass energies ranging from 4.66 GeV to 4.95 GeV, we study the processes of e+e-→ωX(3872) and e+e-→γX(3872). With the e+e-→ωX(3872) process, the branching fraction ratio RB(X(3872)→γJ/ψ)B(X(3872)→π+π-J/ψ) is measured to be 0.38±0.20stat±0.01syst (R<0.83 at 90% confidence level). In addition, we measure the ratio of the average cross section of e+e-→ωX(3872) to e+e-→ωχc1(ωχc2) to be σωX(3872)/σωχc1(σωX(3872)/σωχc2)=5.2±1.0stat±1.9syst(5.5±1.1stat±2.4syst). Finally, we search for the process of e+e-→γX(3872), and no obvious signal is observed. The upper limit on the ratio of the average cross section of e+e-→γX(3872) to e+e-→ωX(3872) is set as σγX(3872)/σωX(3872)<0.23 at 90% confidence level.
Study of the decays χcJ → Λ Λ ¯ φ
(American physical society, 2024) Ablikim, M.; Achasov M.N.; Adlarson P.; Çetin, Serkant Ali; Kolcu, Onur Buğra
Based on (2712.4±14.3)×106 e+e-→ψ(3686) events collected with the BESIII detector operating at the BEPCII Collider, we report the first evidence of χc0→ΛΛ¯φ decays and the first observation of χc1,2→ΛΛ¯φ decays, with significances of 4.1σ, 11.3σ and 13.0σ, respectively. The decay branching fractions of χc0,1,2→ΛΛ¯φ are measured to be (2.99±1.24±0.19)×10-5, (6.01±0.90±0.40)×10-5, and (7.13±0.81±0.36)×10-5, where the first uncertainties are statistical and the second systematic. No obvious enhancement near the ΛΛ¯ production threshold or excited Λ state is found in the Λφ (or Λ¯φ) system.
Study of the semileptonic decay ?c+ ? ?e+?e
(American Physical Society, 2022) Ablikim M.; Achasov M.N.; Adlarson P.; Albrecht M.; Amoroso A.; Çetin, Serkant Ali; Kolcu, Onur Buğra
The study of the Cabibbo-favored semileptonic decay ?c+??e+?e is reported using a 4.5 fb-1 data sample of e+e- annihilations collected at center-of-mass energies ranging from 4.600 GeV to 4.699 GeV with the BESIII detector at the BEPCII collider. The branching fraction of the decay is measured to be B(?c+??e+?e)=(3.56±0.11stat±0.07syst)%, which is the most precise measurement to date. Furthermore, we perform an investigation of the internal dynamics in ?c+??e+?e. We provide the first direct comparisons of the differential decay rate and form factors with those predicted from lattice quantum chromodynamics (LQCD) calculations. Combining the measured branching fraction with a q2-integrated rate predicted by LQCD, we determine |Vcs|=0.936±0.017B±0.024LQCD±0.007??c. © 2022 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.
Study of η′ → π+π−l+l− decays at BESIII
(Springer science and bsiness media deutschland GmbH, 2024) Ablikim, M.; Achasov M.N.; Adlarson P.; Çetin, Serkant Ali
With a sample of (10087 +/- 44) x 10(6)J/psi events accumulated with the BESIII detector, we analyze the decays eta ' -> pi(+)pi(-)l(+)l(-)(l = e, mu) via the process J/psi -> gamma eta '. The branching fractions are measured to be B(eta ' -> pi(+)pi(-)e(+)e(-)) = (2.45 +/- 0.02(stat.) +/- 0.08(syst.)) x 10(-3) and B(eta ' -> pi(+)pi(-)mu(+)mu(-)) = (2.16 +/- 0.12(stat.) +/- 0.06(syst.)) x 10(-5), and the ratio is B(eta '->pi(+)pi(-)e(+)e(-))/B(eta '->pi(+)pi(-)mu(+)mu(-)) =113.4 +/- 0.9(stat.) +/- 3.7(syst.). In addition, by combining the eta ' -> pi(+)pi(-)e(+)e(-) and eta ' -> pi(+)pi(-)mu(+)mu(-) decays, the slope parameter of the electromagnetic transition form factor is measured to be b(eta ')=1.30 +/- 0.19 (GeV/c(2))(-2), which is consistent with previous measurements from BESIII and theoretical predictions from the VMD model. The asymmetry in the angle between the pi(+)pi(-) and l(+)l(-) decay planes, which has the potential to reveal the CP-violation originating from an unconventional electric dipole transition, is also investigated. The asymmetry parameters are determined to be A(CP)(eta '->pi(+)pi(-)e(+)e(-)) = (-0.21 +/- 0.73(stat.) +/- 0.01(syst.))% and A(CP)(eta '->pi(+)pi(-)mu(+)mu(-)) = (0.62 +/- 4.71(stat.) +/- 0.08(syst.))%, implying that no evidence of CP-violation is observed at the present statistics. Finally, an axion-like particle is searched for via the decay eta ' -> pi(+)pi(-)a, a -> e(+)e(-), and upper limits of the branching fractions are presented for the mass assumptions of the axion-like particle in the range of 0 - 500 MeV/c(2).

Yazar "Achasov M.N." seçeneğine göre listele

Sayfa Başına Sonuç

Sıralama seçenekleri