Meslek YüksekokuluVocational Schoolhttp://hdl.handle.net/20.500.12294/3582019-03-26T12:24:59Z2019-03-26T12:24:59ZDetermination of the number of psi(3686) events at BESIIIKolcu, Onur Buğrahttp://hdl.handle.net/20.500.12294/13632019-03-24T00:02:08Z2018-01-01T00:00:00ZDetermination of the number of psi(3686) events at BESIII
Kolcu, Onur Buğra
The numbers of psi(3686) events accumulated by the BESIII detector for the data taken during 2009 and 2012 are determined to be (107.0 +/- 0.8)x10(6) and (341.1 +/- 2.1)x10(6), respectively, by counting inclusive hadronic events, where the uncertainties are systematic and the statistical uncertainties are negligible. The number of events for the sample taken in 2009 is consistent with that of the previous measurement. The total number of psi(3686) events for the two data taking periods is (448.1 +/- 2.9) x 10(6).
Kolcu, Onur Buğra
2018-01-01T00:00:00ZMeasurement of e(+)e(-) -> pi(0)pi(0)psi(3686) at root s from 4.009 to 4.600 GeV and observation of a neutral charmoniumlike structureKolcu, Onur Buğrahttp://hdl.handle.net/20.500.12294/13512019-03-24T00:01:46Z2018-01-01T00:00:00ZMeasurement of e(+)e(-) -> pi(0)pi(0)psi(3686) at root s from 4.009 to 4.600 GeV and observation of a neutral charmoniumlike structure
Kolcu, Onur Buğra
Using ethorne-collision data collected with the BESIII detector at the BEPCII collider corresponding to an integrated luminosity of 5.2 fb(-1) at center-of-mass energies (root s) from 4.009 to 4.600 GeV, the process e(+)e(-) -> pi(0)pi(0)psi(3686) is studied for the first time. The corresponding Born cross sections are measured and found to be half of those of the reaction e(+)e(-) -> pi(0)pi(0)psi(3686). This is consistent with the expectation from isospin symmetry. Furthermore, the Dalitz plots for pi(0)pi(0)psi(3686) are accordant with those of pi(0)pi(0)psi(3686) at all energy points, and a neutral analog to the structure in pi(+/-)psi(3686) around 4040 MeV/c(2) first observed at root s = 4.416 GeV is observed in the isospin neutral mode at the same energy.
2018-01-01T00:00:00ZObservation of a cross-section enhancement near mass threshold in e(+)e(-) -> Lambda(Lambda)over-barKolcu, Onur Buğrahttp://hdl.handle.net/20.500.12294/13502019-03-24T00:02:00Z2019-01-01T00:00:00ZObservation of a cross-section enhancement near mass threshold in e(+)e(-) -> Lambda(Lambda)over-bar
Kolcu, Onur Buğra
The process e(+)e(-) -> Lambda(Lambda) over bar is studied using data samples at root s = 2.2324, 2.400, 2.800 and 3.080 GeV collected with the BESIII detector operating at the BEPCII collider. The Born cross section is measured at root s = 2.2324 GeV, which is 1.0 MeVabove the Lambda(Lambda) over bar mass threshold, to be 305 +/- 45(-36)(+66) pb, where the first uncertainty is statistical and the second systematic. The cross section near threshold is larger than that expected from theory, which predicts the cross section to vanish at threshold. The Born cross sections at root s = 2.400, 2.800 and 3.080 GeV are measured and found to be consistent with previous experimental results, but with improved precision. Finally, the corresponding effective electromagnetic form factors of Lambda are deduced.
2019-01-01T00:00:00ZObservation of e(+)e(-) -> phi chi(c1) and phi chi(c2) at root s=4.600 GeVKolcu, Onur Buğrahttp://hdl.handle.net/20.500.12294/13492019-03-24T00:02:12Z2018-01-01T00:00:00ZObservation of e(+)e(-) -> phi chi(c1) and phi chi(c2) at root s=4.600 GeV
Kolcu, Onur Buğra
Using a data sample collected with the BESIII detector operating at the BEPCII storage ring at a center-of-mass energy of root s = 4.600 GeV, we search for the production of e(+)e(-) -> phi chi(c0,1,2). A search is also performed for the charmonium-like state X(4140) in the radiative transition e(+)e(-) -> gamma X(4140) with X(4140) subsequently decaying into phi J/psi The processes e(+)e(-) -> phi chi(c1) and phi chi(c2) are observed for the first time, each with a statistical significance of more than 10 sigma, and the Born cross sections are measured to be (4.2(-1.0)(+1.7) +/- 0.3) and (6.7(-1.7)(+3.4) +/- 0.5) pb, respectively, where the first uncertainties are statistical and the second systematic. No significant signals are observed for e(+)e(-) -> phi chi(c0) and e(+)e(-) -> gamma X(4140) and upper limits on the Born cross sections at 90% C. L. are provided at root s = 4.600 GeV.
2018-01-01T00:00:00Z