319 research outputs found
Evaluation of anti-ulcer activity of Ardisia crispa Thunb. D.C
Ardisia crispa Thunb D.C (Myrsinaceae), has long been used in treating various ailments among the local villagers. The objective of this study was to investigate experimentally the possible anti-ulcer activity of Ardisia crispa. The effect of hexane fraction of root of Ardisia crispa (ACRH) was evaluated in experimental ulcer models with necrotizing agents ie ethanol, NaCl, HCl, NaOH and also COX-1 inhibitor namely indomethacin as inducers. Four doses ie 10, 30, 100 and 300 mg/kg were selected for further study. Ulcer effects were determined by counting the total surface area of lesion in mm 2 . Results showed that ACRH provided significant protection in various experimental models used. Pretreatment with ACRH at all doses (10,30,100 and 300 mg/kg) has produced significant inhibition of gastric mucosal damage induced by 80% EtOH and 25% NaCl, whilst at 30, 100 and 300 mg/ kg, ACRH significantly reduced the lesion formation in ulcer induced by 0.6 M HCl, 0.2 M NaOH and 30 mg/kg indomethacin. The present study indicates that the hexane fraction of Ardisia crispa (ACRH) exhibits significant anti-ulcer effect
Search for Decays at Belle
We present a search for the B-> pi e^+ e^- and B-> pi \mu^+ \mu^- decays,
with a data sample of 657 million BBbar pairs collected with the Belle detector
at the KEKB collider. Signal events are reconstructed from a charged
or a neutral pion candidate and a pair of oppositely charged electrons or
muons. No significant signal is observed and we set the upper limit on the
isospin-averaged branching fraction BF(B -> \pi \ell^+\ell^-) < 6.2x10^-8 at
the 90% confidence level.Comment: 8 pages, 3 figures, accepted by PRD(RC
Dalitz analysis of B --> K pi psi' decays and the Z(4430)+
From a Dalitz plot analysis of B --> K pi psi' decays, we find a signal for
Z(4430)+ --> pi+ psi' with a mass M= (4443(+15-12)(+19-13))MeV/c^2, width
Gamma= (107(+86-43)(+74-56))MeV, product branching fraction BR(B0 --> K-
Z(4430)+) x BR(Z(4430)+ --> pi+ psi')= (3.2(+1.8-0.9)(+5.3-1.6)) x 10^{-5}, and
significance of 6.4sigma that agrees with previous Belle measurements based on
the same data sample. In addition, we determine the branching fraction BR(B^0
--> K*(892)^0 psi')= (5.52(+0.35-0.32)(+0.53-0.58)) x 10^{-4} and the fraction
of K*(892)^0 mesons that are longitudinally polarized f_L=
44.8(+4.0-2.7)(+4.0-5.3)%. These results are obtained from a 605fb^{-1} data
sample that contains 657 million B-anti-B pairs collected near the Upsilon(4S)
resonance with the Belle detector at the KEKB asymmetric energy e+e- collider.Comment: Final version published in PRD(RC
Evidence of time-dependent CP violation in the decay B0 to D*+D*-
We report a measurement of the CP-odd fraction and the time-dependent CP
violation in B0 to D*+D*- decays, using 657.10^6 BBbar events collected at the
Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy
e+e- collider. We measure a CP-odd fraction of
Rperp=0.125+/-0.043(stat)+/-0.023(syst). From the distributions of the
proper-time intervals between a B0to D*+D*- decay and the other B meson in the
event, we obtain evidence of CP violation with measured parameters
AD*+D*-=0.15+/-0.13(stat)+/-0.04(syst) and
SD*+D*-=-0.96+/-0.25(stat)-0.16+0.13(syst).Comment: Published in PR
Measurement Of |V_ub| From Inclusive Charmless Semileptonic B Decays
We present the partial branching fraction for inclusive charmless
semileptonic B decays and the corresponding value of the CKM matrix element
|Vub|, using a multivariate analysis method to access ~90% of the B -> Xu l nu
phase space. This approach dramatically reduces the theoretical uncertainties
from the b-quark mass and non-perturbative QCD compared to all previous
inclusive measurements. The results are based on a sample of 657 million B
-Bbar pairs collected with the Belle detector. We find that Delta BR(B -> Xu l
nu; p^*B_l>1.0 GeV/c=1.963 x (1 +/- 0.088(stat.) +/- 0.081(sys.)) x 10^-3.
Corresponding values of |Vub| are extracted using several theoretical
calculations.Comment: 9 pages, 1 figure, 2 tables. Published in PR
Search for Lepton Flavor and Lepton Number Violating tau Decays into a Lepton and Two Charged Mesons
We search for lepton flavor and lepton number violating tau decays into a
lepton (ell = electron or muon) and two charged mesons (h,h' = pi^\pm or
K^\pm), tau- -> ell-h+h'- and tau- -> ell+h-h'-, using 671 fb^{-1} of data
collected with the Belle detector at the KEKB asymmetric-energy e+e- collider.
We obtain 90% C.L. upper limits on the branching fractions in the range
(4.4-8.8)x10^{-8} for tau -> ehh', and (3.3-16)x10^{-8} for tau -> muhh'
processes. These results improve upon previously published upper limits by
factors between 1.6 to 8.8.Comment: 15 page, 7 figures, submitted to Phys. Lett.
Study of the decay
We present a study of with X(3872) decaying to using a sample of 657 million pairs recorded at the
resonance with the Belle detector at the KEKB asymmetric-energy
collider. Both and decay
modes are used. We find a peak of events with a mass of
, a width of and a product branching fraction , where the first errors are statistical
and the second ones are systematic. The significance of the signal is
. The difference between the fitted mass and the
threshold is calculated to be . We
also obtain an upper limit on the product of branching fractions of at
90% CL.Comment: 7 pages, 3 figures, BELLE-CONF-0832 contributed to ICHEP 2008,
revised and submitted to Phys. Rev. D R
Measurements of Charmless Hadronic b->s Penguin Decays in the pi+pi-K+pi- Final State and First Observation of B0 -> rho0K+pi-
We report measurements of charmless hadronic B^0 decays into the pi+pi-K+pi+
final state. The analysis uses a sample of 657x10^6 BBbar pairs collected with
the Belle detector at the KEKB asymmetric-energy e+e- collider at the Y(4S)
resonance. The decay B^0 -> rho0 Kpi is observed for the first time; the
significance is 5.0sigma and the corresponding partial branching fraction for
M_Kpi in (0.75,1.20) GeV/c^2 is [2.8 +- 0.5(stat) +-0.5(syst)] x 10^{-6}. We
also obtain the first evidence for B^0 -> f0Kpi with 3.5sigma significance and
for B^0 -> pi+pi-K*0 with 4.5sigma significance. For the two-body decays B^0 ->
rho0K*0 and B^0 -> f0K*0, the significances are 2.7sigma and 2.5sigma,
respectively, and the upper limits on the branching fractions are 3.4x10^{-6}
and 2.2x10^{-6} at 90% confidence level.Comment: 6 pages, 3 figures. accepted by PRD(RC
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