323,859 research outputs found
Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′
No full textFirst evidence of the B 0 → J / ψ ω decay is found and the B s 0 → J / ψ η and B s 0 → J / ψ η ′ decays are studied using a dataset corresponding to an integrated luminosity of 1.0 fb -1 collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV. The branching fractions of these decays are measured relative to that of the B 0 → J / ψ ρ 0 decay:frac(B (B 0 → J / ψ ω), B (B 0 → J / ψ ρ 0)) = 0.89 ± 0.19 (stat) - 0.13 + 0.07 (syst),frac(B (B s 0 → J / ψ η), B (B 0 → J / ψ ρ 0)) = 14.0 ± 1.2 (stat) - 1.5 + 1.1 (syst) - 1.0 + 1.1 (frac(f d, f s)),frac(B (B s 0 → J / ψ η ′), B (B 0 → J / ψ ρ 0)) = 12.7 ± 1.1 (stat) - 1.3 + 0.5 (syst) - 0.9 + 1.0 (frac(f d, f s)), where the last uncertainty is due to the knowledge of f d / f s, the ratio of b-quark hadronization factors that accounts for the different production rate of B 0 and B s 0 mesons. The ratio of the branching fractions of B s 0 → J / ψ η ′ and B s 0 → J / ψ η decays is measured to befrac(B (B s 0 → J / ψ η ′), B (B s 0 → J / ψ η)) = 0.90 ± 0.09 (stat) - 0.02 + 0.06 (syst)
Search for the rare decays J/y -> D-s(-) rho(+) and J/psi -> <(D)over bar(0)<(K)over bar*(0)
No full textA search for the rare decays of J/psi -> D-S(-) rho(+) + c.c. and J/psi -> D-S(-)rho(+) + c.c.) <1.3 x 10(-5) and beta(J/psi -
Search for the rare decays J/ψ → Dsρ+ + c.c. and J/ψ → D0K∗0 + c.c
No full textA search for the rare decays of J/psi -> D-S(-) rho(+) + c.c. and J/psi -> <(D)over bar(0)<(K)over bar*(0) + c.c. is performed with a data sample of 225.3-million J/psi events collected with the Beijing Spectrometer III detector. No evident signal is observed. Upper limits on the branching fractions are determined to be beta(J/psi -> D-S(-)rho(+) + c.c.) < 1.3 x 10(-5) and beta(J/psi -> <(D)over bar(0)<(K)over bar*(0) + c.c.) < 2.5 x 10(-6) at the 90% confidence level.AuthorOverflow(378
Search for the rare decays J/y -> D-s(-) rho(+) and J/psi -> <(D)over bar(0)<(K)over bar*(0)
No full textA search for the rare decays of J/psi -> D-S(-) rho(+) + c.c. and J/psi -> D-S(-)rho(+) + c.c.) <(D)over bar(0)<(K)over bar*(0) + c.c.) < 2.5 x 10(-6) at the 90% confidence level
Search for B -> J/psi D decays
No full textWe report a search for B -> J/psi D decays, based on a sample of 124 x 10(6) B (B) over bar events collected with the BABAR detector at the PEP-II storage ring of the Stanford Linear Accelerator Center. No significant signal is found. We obtain upper limits on the branching fractions of 1.3 x 10(-5) for B-0 -> J/psi(D) over bar (0) and 1.2 x 10(-4) for B+ -> J/psi D+ at 90% confidence level
Famennian (Upper Devonian) conodont zonation: revised global standard.
No full textThe revision of the Famennian part of the “Late Devonian Standard Conodont Zonation” is based on the in-equivalence
between biozones and time, and the rejection of the presumed single phyletic concept on which the previous zonation
was based. It is also intended to simplify the zonation, eliminating the zonal groups named after only one taxon, and
biozones that are defined by a Last Appearance Datum (LAD). The proposed revision is largely based on the zonation
proposed by Ziegler and Sandberg (1990) and is for the most part correlatable using the same zonal markers. Modifications
have only been made when strictly necessary, as the aim of the proposal is to maintain the stability of over 50 years
of studies. The 22 zones constituting the revised zonation are defined by the First Appearance Datum (FAD) of species
or subspecies that have a well-established stratigraphic range and wide geographic distribution. Each zone is named after
the taxon for which the FAD defines the lower boundary. For each zone an association of other species useful for its
identification is listed
Spin-orbit force, recoil corrections, and possible B(B)over-bar* and D(D)over-bar* molecular states
No full textIn the framework of the one-boson exchange model, we have calculated the effective potentials between two heavy mesons B (B) over bar* and D (D) over bar* from the t- and u-channel pi-, eta, rho-, omega-, and sigma-meson exchanges with four kinds of quantum number: I = 0, J(PC) = 1(++); 1 = 0, J(PC) = 1(+-); I = 1, J(PC) = 1(++); I = 1, J(PC) = 1(+-). We keep the recoil corrections to the B (B) over bar* and D (D) over bar* systems up to O(1/m(2)) The spin-orbit force appears at O(1/M), which turns out to be important for the very loosely bound molecular states. Our numerical results show that the momentum-related corrections are unfavorable to the formation of the molecular states in the I = 0, J(PC) = 1(++) and I = 1, J(PC) = 1(+-) channels in the D (D) over bar* system.Astronomy & AstrophysicsPhysics, Particles & FieldsSCI(E)[email protected]; [email protected]; [email protected]
Search for B-0 -> J/psi D-0 and B+ -> J/psi D-0 pi(+) decays
No full textWe report the results of a search for the decay modes B-0 -> J/psi(D) over bar (0) and B+ -> J/psi(D) over bar (0)pi(+). The analysis is based on 140 fb(-1) of data accumulated by the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. No significant signals are observed and we determine the branching fraction upper limits B(B-0 -> J/psi(D) over bar (0)) < 2.0 x 10(-5) and b(B+-> J/psi(D) over bar (0)pi(+)) < 2.5 x 10(-5) at 90% confidence level. These results rule out the explanation of the excess in the low momentum region of the inclusive J/psi spectrum as intrinsic charm content in the B meson. The branching fractions of the corresponding nonresonant decay channels are also reported.Astronomy & AstrophysicsPhysics, Particles & FieldsSCI(E)0ARTICLE9null7
Measurement of the B-d(0)-(B)over-bar(d)(0) flavor oscillation frequency and study of same side flavor tagging of B mesons in p(p)over-bar collisions
No full textB-d(0)-(B) over bar(d)(0) oscillations are observed in ''self-tagged'' samples of partially reconstructed B mesons decaying into a lepton and a charmed meson collected in p (p) over bar collisions at root s = 1.8 TeV. A flavor tagging technique is employed which relies upon the correlation between the flavor of B mesons and the charge of a nearby particle. We measure the flavor oscillation frequency to be Delta m(d) = 0.471 (+0.078)(-0.068) +/- 0.034 ps(-1). The tagging method is also demonstrated in exclusive samples of B-u(+) --> J/psi K+ and B-d(0)-->J/psi K-*0(892), where similar flavor-charge correlations are observed. The tagging characteristics of the various samples are compared with each other, and with Monte Carlo simulations. [S0556-2821(99)05901-9]
Search for J/ψ weak decays containing a D meson
No full textUsing a sample of about 10 billion J/ψ events with the BESIII detector, we search for the weak decays of J/ψ → D<over bar>0π0 + c.c., J/ψ → D<over bar>0η + c.c., J/ψ → D<over bar>0ρ0 + c.c., J/ψ → D-π+ + c.c., and J/ψ → D-ρ+ + c.c., Since no significant signal is observed, we set the upper limits of the branching fractions of these decays to be B(J/ψ → D<over bar>0π0 + c.c.) < 4.7 x 10-7, B(J/ψ → D<over bar>0η + c.c.) < 6.8 x 10-7, B(J/ψ → D<over bar>0ρ0 + c.c.) < 5.2x10-7, B(J/ψ → D-π+ c.c.) < 7.0 x 10-8, and B(J/ψ → D-ρ+ + c.c.) < 6.0 x 10-7 at the 90% confidence level.For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.110.032020</p
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