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Albayrak, O.

Publications and source records attributed to Albayrak, O..

At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

Observation of the helicity-selection-rule suppressed decay of the χ c 2 charmonium state

The decays of χ c 2 → K + K - π 0 , K S K ± π ∓ , and π + π - π 0 are studied with the ψ ( 3686 ) data samples collected with the Beijing Spectrometer (BESIII). For the first time, the branching fractions of χ c 2 → K*$\bar{K}$ , χ c 2 → $a_2^±$(1320)π ∓ /$a_2^0$(1320)π 0 , and χ c 2 → ρ( 770 ) ± π ∓ are measured. Here, K*$\bar{K}$ denotes both K* ± K ∓ and its isospin-conjugated process K* 0 $\bar{K}$ 0 +c.c., and K* denotes the resonances K*(892), $K_2^*$(1430), and $K_3^*$(1780). The observations indicate a strong violation of the helicity selection rule in χ c 2 decays into vector and pseudoscalar meson pairs. The measured branching fractions of χ c 2 → K*(892)$\bar{K}$ are more than ten times larger than the upper limit of χ c 2 → ρ ( 770 ) ± π ∓ , which is so far the first direct observation of a significant U -spin symmetry breaking effect in charmonium decays.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2017

Search for the rare decay D + → D 0 e + ν e

Using a data set with an integrated luminosity of $2.93\text{ }\text{ }{\mathrm{fb}}^{{-}1}$ collected at $\sqrt{s}=3.773\text{ }\mathrm{GeV}$ with the BESIII detector operating at the BEPCII storage rings, we search for the rare decay ${D}^{+}{\rightarrow}{D}^{0}{e}^{+}{{\nu}}_{e}$. No signal events are observed. We set the upper limit on the branching fraction for ${D}^{+}{\rightarrow}{D}^{0}{e}^{+}{{\nu}}_{e}$ to be $1.0\times{}1{0}^{{-}4}$ at the 90% confidence level.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

Determination of the Spin and Parity of the Z c ( 3900 )

In this paper, the spin and parity of the Z c (3900) ± state are determined to be J P = 1 + with a statistical significance larger than 7σ over other quantum numbers in a partial wave analysis of the process e + e - → π + π - J/Ψ. We use a data sample of 1.92 fb -1 accumulated at $ \sqrt{s}=4.23 $ and 4.26 GeV with the BESIII experiment. When parametrizing the Z c (3900) ± with a Flatté-like formula, we determine its pole mass M pole = (3881.2±4.2 stat ±52.7 syst ) MeV/c 2 and pole width Γ pole = (51.8± 4.6 stat ± 36.0 syst ) MeV. Finally, we also measure cross sections for the process e + e - → Z c (3900) + π - + c.c. → J/Ψπ + π - and determine an upper limit at the 90% confidence level for the process e + e - → Z c (4020) + π - + c.c. → J/Ψ π + π - .

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

Analysis of $D$ + → $K¯$ 0 $e$ + $ν$ $e$ and $D$ + → $π$ 0 $e$ + $ν$ $e$ semileptonic decays

Using 2.93 fb –1 of data taken at 3.773 GeV with the BESIII detector operated at the BEPCII collider, we study the semileptonic decays D + → K¯ 0 e + ν e and D + → π 0 e + ν e . Here, we measure the absolute decay branching fractions B(D + → K¯ 0 e + ν e ) = (8.60 ± 0.06 ± 0.15) × 10 –2 and B(D + → π 0 e + ν e ) = (3.63 ± 0.08 ± 0.05) × 10 –3 , where the first uncertainties are statistical and the second systematic. We also measure the differential decay rates and study the form factors of these two decays. With the values of |V cs | and |V cd | from Particle Data Group fits assuming CKM unitarity, we obtain the values of the form factors at q 2 = 0, $f$ $^{K}_{+}$(0) = 0.725 ± 0.004 ± 0.012 and $f$ $^{π}_{+}$(0) = 0.622 ± 0.012 ± 0.003. Taking input from recent lattice QCD calculations of these form factors, we determine values of the CKM matrix elements |V cs | = 0.944 ± 0.005 ± 0.015 ± 0.024 and |V cd | = 0.210 ± 0.004 ± 0.001 ± 0.009, where the third uncertainties are theoretical.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

Measurement of integrated luminosity and center-of-mass energy of data taken by BESIII at √s = 2.125 GeV*

To study the nature of the state Y (2175), a dedicated data set of e + e – collision data was collected at the center-of-mass energy of 2.125 GeV with the BESIII detector at the BEPCII collider. By analyzing large-angle Bhabha scattering events, the integrated luminosity of this data set is determined to be 108.49±0.02±0.85 pb –1 , where the first uncertainty is statistical and the second one is systematic. In addition, the center-of-mass energy of the data set is determined with radiative dimuon events to be 2126.55±0.03±0.85 MeV, where the first uncertainty is statistical and the second one is systematic.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗