Observation ofBcmesons inpp¯collisions at

F. Abe¹,

H. Akimoto²,

A. Akopian³

et al.

Abstract

We report the observation of bottom-charmed mesons B(c) in 1.8 TeV collisions using the CDF detector at the Fermilab Tevatron. The B(c) mesons were found through their semileptonic decays, B(c)(+/-) --> J/psi l(+/-)X. A fit to the J/psi l mass distribution yielded 20.4(-5.5)(+6.2) events from B(c) mesons. A test of the null hypothesis, i.e., an attempt to fit the data with background alone, was rejected at the level of 4.8 standard deviations. By studying the quality of the fit as a function of the assumed B(c) mass, we determined M(B(c)) = 6.40 +/- 0.39 (stat.)+/-0.13 (syst) GeV/c(2). From the distribution of trilepton intersection points in the plane transverse to the beam direction we measured the B(c) lifetime to be tau(B(c)) = 0.46(-0.16)(+0.18) (stat)+/-0.03 (syst) ps. We also measured the ratio of production cross section times branching fraction for Bc+ --> J/psi l(+) nu relative to that for B(+) --> J/psi K(+) to be sigma(B(c)) X B(B(c) --> J/psi l nu)/sigma(B) X B(B-->J/psi K) = 0.132(-0.037)(+0.041) (stat)+/-0.031 (syst)(-0.020)(+0.032)(lifetime)

Flavor asymmetry of polarized antiquark distributions and semi-inclusive DIS

“…(14), as can be seen from Fig.6. 6 Note that the HERMES data are in good agreement with the SLAC E143 data for the inclusive spin asymmetry [31]. Spin asymmetries in charged pion production.…”

Implications of new physics in the decays Bc→(J/ψ, ηc)τTran1, Ivanov2, Körner3 et al. 2018Phys. Rev. D824701View full textAdd to dashboardCite

“…Besides, the delta function in Eq. (2) implies that NP effects are supposed to appear in the tau mode only. The proposed Hamiltonian can be considered as a natural way to go beyond the SM since it is generalized from the well established SM Hamiltonian with the V − A structure by adding more currents.…”

“…In fact, the first observation of the B c meson by the CDF Collaboration was made in an analysis of this decay [2].…”

Open-flavor strong decays of open-charm and open-bottom mesons in the P03 model

“…Since the discovery of the J=Ψ and ϒ resonances in the 1970s, heavy meson physics (including the physics of charmonia [1,2], bottomonia [3,4], open-charm [5,6], and open-bottom [7][8][9] mesons) has been extensively studied and still is the subject of intensive theoretical and experimental research [10,11]. Recently, both the charmonium and bottomonium spectra have been enriched by the discovery of new particles [10,11] [10,16], Dð2740Þ 0 [10,17], and B J ð5970Þ 0 [10,18].…”