Measurement of the ratioB(B+→Xeν)/B(B0→

Abstract

We report measurements of the inclusive electron momentum spectra in decays of charged and neutral B mesons, and of the ratio of semileptonic branching fractions BB ! Xe and BB 0 ! Xe. These were performed on a sample of 231 10 6 B B events recorded with the BABAR detector at the 4S resonance. Events are selected by fully reconstructing a hadronic decay of one B meson and identifying an electron among the decay products of the recoiling B meson. We obtain BB ! Xe=BB 0 ! Xe 1:074 0:041 stat 0:026 syst .

Nature of the vector resonance Y(2175)

“…The full width Γ full has the small overlapping region with Γ = (58 ± 16 ± 20) MeV extracted in Ref. [1], but agreement with data of the BESIII Collaboration is considerably better. In calculations of the Γ full , we have taken into account only three strong decays of the resonance Y .…”

“…Another family of the {Y } resonances occupies the light segment of meson spectroscopy and incorporates the famous "old" state Y (2175), and new ones X(2239) and X(2100) seen recently. The structure Y (2175) was discovered by the BaBar Collaboration in the initial-state radiation process e + e − → γ ISR φf 0 (980) as a resonance in the φf 0 (980) invariant mass spectrum [1]. The mass and width of this resonance measured by BaBar amount to m = (2175±10±15) MeV and Γ = (58±16±20) MeV, respectively.…”

Observation of a Resonant Structure in e+e−→K+KAblikim1, Ачасов2, Adlarson3 et al. 2020Phys. Rev. Lett.Self Cite37190View full textAdd to dashboardCite

“…The vector meson state Y (2175), denoted as the φ(2170) by the Particle Data Group (PDG) [1], is currently one of the most interesting particles in light hadron spectroscopy. The φ(2170) was first observed by BaBar [2] and subsequently confirmed by several other experiments [3][4][5][6][7]. The internal constituents of the φ(2170) are still unknown, which has stimulated extensive theoretical discussions.…”

“…No significant signal was observed. The BaBar collaboration performed an analysis of e + e − → K + K − π + π − and K + K − π 0 π 0 using 454 fb −1 data via the initial state radiation (ISR) process [2]. Beside clearly observing the process e + e − → φππ, abundant K * structures were observed in the Kπ(π) invariant mass spectrum, such as the K * (892) and K * 2 (1430), as well as the K 1 (1270) and K 1 (1400).…”

A new search for the doubly charmed baryon $$\Xi _{cc}^ + $$ at the LHC

“…In 2002 and 2005, the SELEX Collaboration at the Tevatron collider claimed the observation of Ξ + cc via the decay modes Ξ + cc → Λ + c K − π + [10] and Ξ + cc → pD + K − [11]. However, such large Ξ + cc production rates reported by the SELEX Collaboration have not been confirmed either by the FOCUS Collaboration [12] at the same collider or by the BABAR and BELLE Collaborations [13,14] at the e + e − colliders. In 2013, the LHCb Collaboration performed the first search of the Ξ + cc baryon at the LHC with their collected data sample at that time, corresponding to an integrated luminosity of 0.65 fb −1 recorded at a centre-of-mass energy of 7 TeV; No significant signal was found.…”