0000000000524924
AUTHOR
J. Biernat
showing 12 related works from this author
Cross section measurement of e+e−→pp¯η and e+e−→pp¯ω at center-of-mass energies between 3.773 GeV and 4.6 GeV
2021
Feasibility study for the measurement of πN transition distribution amplitudes at P¯ANDA in p¯p→J/ψπ0
2017
The exclusive charmonium production process in (P) over barp annihilation with an associated pi 0 meson (p) over barp -> J/psi pi(0) is studied in the framework of QCD collinear factorization. The feasibility of measuring this reaction through the J/psi -> e(+) e(-) decay channel with the AntiProton ANnihilation at DArmstadt ((P) over bar ANDA) experiment is investigated. Simulations on signal reconstruction efficiency as well as the background rejection from various sources including the (P) over barp -> pi(+)pi(-)pi(0) and (p) over barp -> J/psi pi(0)pi(0) reactions are performed with PANDAROOT, the simulation and analysis software framework of the (P) over bar ANDA experiment. It is show…
First measurement of the |t|-dependence of coherent J/ψ photonuclear production
2021
The first measurement of the dependence on $|t|$, the square of the momentum transferred between the incoming and outgoing target nucleus, of coherent J/ψ photoproduction is presented. The data were measured with the ALICE detector in ultra-peripheral Pb-Pb collisions at a centre-of-mass energy per nucleon pair $\sqrt{s_{\rm NN}} = 5.02$ TeV with the J/$\psi$ produced in the central rapidity region $|y| < 0.8$, which corresponds to the small Bjorken-$x$ range $(0.3 − 1.4) \times 10 ^{−3}$. The measured $|t|$-dependence is not described by computations based only on the Pb nuclear form factor, while the photonuclear cross section is better reproduced by models including shadowing according t…
Observation of the Leptonic Decay $D^+ → τ^+ ν_τ$
2019
Physical review letters 123(21), 211802 (2019). doi:10.1103/PhysRevLett.123.211802
Measurement of the inclusive branching fraction for ψ(3686)→KS0+anything
2021
Abstract Using 5.9 pb−1 of e + e − annihilation data collected at center-of-mass energies from 3.640 to 3.701 GeV with the BESIII detector at the BEPCII Collider, we measure the observed cross sections of e + e − → K S 0 X (where X = anything ). From a fit to these observed cross sections with the sum of continuum and ψ ( 3686 ) and J / ψ Breit-Wigner functions and considering initial state radiation and the BEPCII beam energy spread, we obtain for the first time the product of ψ ( 3686 ) leptonic width and inclusive decay branching fraction Γ ψ ( 3686 ) e e B ( ψ ( 3686 ) → K S 0 X ) = ( 373.8 ± 6.7 ± 20.0 ) eV, and assuming Γ ψ ( 3686 ) e e is ( 2.33 ± 0.04 ) keV from PDG value, we measur…
Measurement of Proton Electromagnetic Form Factors in e+e−→pp¯ in the Energy Region 2.00–3.08 GeV
2020
The process of e+e−→pp¯ is studied at 22 center-of-mass energy points (s) from 2.00 to 3.08 GeV, exploiting 688.5 pb−1 of data collected with the BESIII detector operating at the BEPCII collider. The Born cross section (σpp¯) of e+e−→pp¯ is measured with the energy-scan technique and it is found to be consistent with previously published data, but with much improved accuracy. In addition, the electromagnetic form-factor ratio (|GE/GM|) and the value of the effective (|Geff|), electric (|GE|), and magnetic (|GM|) form factors are measured by studying the helicity angle of the proton at 16 center-of-mass energy points. |GE/GM| and |GM| are determined with high accuracy, providing uncertaintie…
Study of Open-Charm Decays and Radiative Transitions of the X(3872)
2020
The processes X(3872)→D*0D¯0+c.c.,γJ/ψ,γψ(2S), and γD+D− are searched for in a 9.0 fb−1 data sample collected at center-of-mass energies between 4.178 and 4.278 GeV with the BESIII detector. We observe X(3872)→D*0D0¯+c.c. and find evidence for X(3872)→γJ/ψ with statistical significances of 7.4σ and 3.5σ, respectively. No evident signals for X(3872)→γψ(2S) and γD+D− are found, and the upper limit on the relative branching ratio Rγψ≡{B[X(3872)→γψ(2S)]}/{B[X(3872)→γJ/ψ]}<0.59 is set at 90% confidence level. Measurements of branching ratios relative to decay X(3872)→π+π−J/ψ are also reported for decays X(3872)→D*0D0¯+c.c.,γψ(2S),γJ/ψ, and γD+D−, as well as the non-D*0D0¯ three-body decays π0…
Study of doubly strange systems using stored antiprotons
2016
Bound nuclear systems with two units of strangeness are still poorly known despite their importance for many strong interaction phenomena. Stored antiprotons beams in the GeV range represent an unparalleled factory for various hyperon-antihyperon pairs. Their outstanding large production probability in antiproton collisions will open the floodgates for a series of new studies of systems which contain two or even more units of strangeness at the PANDA experiment at FAIR. For the first time, high resolution gamma-spectroscopy of doubly strange Lambda Lambda-hypernuclei will be performed, thus complementing measurements of ground state decays of Lambda Lambda-hypernuclei at J-PARC or possible …
Study of e+e−→π0X(3872)γ and search for Zc(4020)0→X(3872)γ
2021
Observation of a Near-Threshold Structure in the K + Recoil-Mass Spectra in e + e − → K + ( D s − D * 0 + D s * − D 0 )
Measurements of mixed harmonic cumulants in Pb–Pb collisions at sNN=5.02 TeV
2021
Correlations between moments of different flow coefficients are measured in Pb–Pb collisions at sNN=5.02 TeV recorded with the ALICE detector. These new measurements are based on multiparticle mixed harmonic cumulants calculated using charged particles in the pseudorapidity region |η|<0.8 with the transverse momentum range 0.2<pT<5.0 GeV/c. The centrality dependence of correlations between two flow coefficients as well as the correlations between three flow coefficients, both in terms of their second moments, are shown. In addition, a collection of mixed harmonic cumulants involving higher moments of v2 and v3 is measured for the first time, where the characteristic signature of ne…
Measurement of the Cross Section for e+e−→Ξ−Ξ¯+ and Observation of an Excited Ξ Baryon
2020
Using a total of 11.0 fb−1 of e+e− collision data with center-of-mass energies between 4.009 and 4.6 GeV and collected with the BESIII detector at BEPCII, we measure fifteen exclusive cross sections and effective form factors for the process e+e−→Ξ−Ξ¯+ by means of a single baryon-tag method. After performing a fit to the dressed cross section of e+e−→Ξ−Ξ¯+, no significant ψ(4230) or ψ(4260) resonance is observed in the Ξ−Ξ¯+ final states, and upper limits at the 90% confidence level on ΓeeB for the processes ψ(4230)/ψ(4260)→Ξ−Ξ¯+ are determined. In addition, an excited Ξ baryon at 1820 MeV/c2 is observed with a statistical significance of 6.2–6.5σ by including the systematic uncertainty, an…