Observation of transverse polarization asymmetries of charged pion pairs in e+e- annihilation near √s = 10.58 GeV.

The interference fragmentation function translates the fragmentation of a quark with a transverse projection of the spin into an azimuthal asymmetry of two final-state hadrons. In e(+)e(-) annihilation the product of two interference fragmentation functions is measured. We report nonzero asymmetries for pairs of charge-ordered π(+)π(-) pairs, which indicate a significant interference fragmentation function in this channel. The results are obtained from a 672 fb(-1) data sample that contains 711 × 10(6) π(+)π(-) pairs and was collected at and near the Υ(4S) resonance, with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider.

Observation of X(3872)→J/ψγ and search for X(3872)→ψ'γ in B decays.

We report a study of B→(J/ψγ)K and B→(ψ'γ)K decay modes using 772×106 B ̅B events collected at the Υ(4S) resonance with the Belle detector at the KEKB energy-asymmetric e(+)e(-) collider. We observe X(3872)→J/ψγ and report the first evidence for χ(c2)→J/ψγ in B→(X_{c ̅cγ)K decays, while in a search for X(3872)→ψ'γ no significant signal is found. We measure the branching fractions, B(B(±)→X(3872)K(±))B(X(3872)→J/ψγ)=(1.78(-0.44)(+0.48)±0.12)×10(-6), B(B(±)→χ(c2)K(±))=(1.11(-0.34)(+0.36)±0.09)×10(-5), B(B(±)→X(3872)K(±))B(X(3872)→ψ'γ)<3.45×106 (upper limit at 90% C.L.), and also provide upper limits for other searches.

Evidence for the suppressed decay B(-)→DK(-), D→K(+)π(-).

The suppressed decay chain B(-)→DK(-), D→K(+)π(-), where D indicates a D(¯)(0) or D(0) state, provides important information on the CP-violating angle ϕ(3). We measure the ratio R(DK) of the decay rates to the favored mode B(-)→DK(-), D→K(-)π(+) to be R(DK)=[1.63(-0.41)(+0.44)(stat)(-0.13)(+0.07)(syst)]×10(-2), which indicates the first evidence of the signal with a significance of 4.1σ. We also measure the asymmetry A(DK) between the charge-conjugate decays to be A(DK)=-0.39(-0.28)(+0.26)(stat)(-0.03)(+0.04)(syst). The results are based on the full 772×10(6) BB(¯) pair data sample collected at the Υ(4S) resonance with the Belle detector.

Observation of B(s)(0) → D(s)(*-) π+ and B(s)(0) → D(s)(*-) ρ+ and measurement of the B(s)(0) → D(s)(*-) ρ+ longitudinal polarization fraction.

First observations of the B(s)(0) → D(s)(*-) π+, B(s)(0) → D(s)(-) ρ+ and B(s)(0) → D(s)(*-) ρ+ decays are reported together with measurements of their branching fractions: B(B(s)(0) → D(s)(*-) π+) = [2.4(-0.4)(+0.5)(stat) ± 0.3(syst) ± 0.4(f(s))]×10(-3), B(B(s)(0) → D(s)(-) ρ+) = [8.5(-1.2)(+1.3)(stat) ± 1.1(syst) ± 1.3(f(s))]×10(-3) and B(B(s)(0) → D(s)(*-) ρ+) = [11.9(-2.0)(+2.2)(stat) ± 1.7(syst) ± 1.8(f(s))]×10(-3) (f(s) = N(B(s)(*) B(s)(*))/N(bb)). From helicity-angle distributions, we measured the longitudinal polarization fraction in B(s)(0) → D(s)(*-) ρ+ decays to be f(L)(B(s)(0) → D(s)(*-) ρ+) = 1.05(-0.10)(+0.08)(stat)(-0.04)(+0.03)(syst). These results are based on a 23.6 fb(-1) data sample collected at the Υ(5S) resonance with the Belle detector at the KEKB e+ e- collider.

Search for a low mass particle decaying into µ+ µ- in B0 → K*0 X and B0 → ρ0 X at Belle.

We search for dimuon decays of a low mass particle in the decays B0→K*0 X and B0→ρ0 X using a data sample of 657×10(6)BB events collected with the Belle detector at the KEKB asymmetric-energy e+ e- collider. We find no evidence for such a particle in the mass range from 212 MeV/c2 to 300 MeV/c2 for lifetimes below 10(-12) s, and set upper limits on its branching fractions. In particular, we search for a particle with a mass of 214.3 MeV/c2 reported by the HyperCP experiment, and obtain upper limits on the products B(B0→K*0 X)×B(X→µ+ µ- )<2.26(2.27)×10(-8) and B(B0→ρ0 X)×B(X→µ+ µ-)<1.73(1.73)×10(-8) at 90% C.L. for a scalar (vector) X particle.

Search for CP violation in the decays D(s)+ --> KS0pi+ and D(s)+ --> KS0K+.

We have searched for CP violation in the charmed meson decays D((s))(+) --> K(S)(0)pi(+) and D((s))(+) --> K(S)(0)K(+) using 673 fb(-1) of data collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. No evidence for CP violation is observed. We report the most sensitive CP asymmetry measurements to date for these decays: A(CP)(D(+)-->K(S)(0)pi(+)) = (-0.71 +/- 0.19 +/- 0.20)%, A(CP)(D(s)(+) --> K(S)(0)pi(+)) = (+5.45 +/- 2.50 +/- 0.33)%, A(CP)(D(+) --> K(S)(0)K(+)) = (-0.16 +/- 0.58 +/- 0.25)%, and A(CP)(D(s)(+) --> K(S)(0)K(+)) = (+0.12 +/- 0.36 +/- 0.22)%, where the first uncertainties are statistical and the second are systematic.

Evidence for a new resonance and search for the Y(4140) in the gammagamma-->phiJ/psi process.

The process gammagamma-->phiJ/psi is measured using a data sample of 825 fb{-1} collected with the Belle detector. A narrow peak of 8.8{-3.2}{+4.2} events, with a significance of 3.2 standard deviations including systematic uncertainty, is observed. The mass and natural width of the structure [named X(4350)] are measured to be [4350.6{-5.1}{+4.6}(stat)+/-0.7(syst)] MeV/c{2} and [13{-9}{+18}(stat)+/-4(syst)] MeV, respectively. The product of its two-photon decay width and branching fraction to phiJ/psi is [6.7{-2.4}{+3.2}(stat)+/-1.1(syst)] eV for J{P}=0{+}, or [1.5{-0.6}{+0.7}(stat)+/-0.3(syst)] eV for J{P}=2{+}. No signal for the Y(4140)-->phiJ/psi structure reported by the CDF Collaboration in B-->K{+}phiJ/psi decays is observed, and limits of Gamma_{gammagamma}(Y(4140))B(Y(4140)-->phiJ/psi)<41 eV for J{P}=0;{+} or <6.0 eV for J{P}=2{+} are determined at the 90% C.L. This disfavors the scenario in which the Y(4140) is a D{s}{*+}D{s}{*-} molecule.

Observation of a charmoniumlike enhancement in the gammagamma-->omega(J)/psi process.

We report the results of a search for a charmoniumlike state produced in the process gammagamma-->omegaJ/psi in the 3.9-4.2 GeV/c{2} mass region. We observe a significant enhancement, which is well described by a resonant shape with mass M=(3915+/-3+/-2) MeV/c{2} and total width Gamma=(17+/-10+/-3) MeV. This enhancement may be related to one or more of the three charmoniumlike states so far reported in the 3.90-3.95 GeV/c{2} mass region.

First measurement of inclusive B→Xsη decays.

We report a first measurement of inclusive B→Xsη decays, where Xs is a charmless state with unit strangeness. The measurement is based on a pseudoinclusive reconstruction technique and uses a sample of 657×10(6)BB pairs accumulated with the Belle detector at the KEKB e+e- collider. For MXs < 2.6 GeV/c2, we measure a branching fraction of [26.1±3.0(stat)-2.1+1.9(syst)-7.1+4.0(model)]×10(-5) and a direct CP asymmetry of ACP=-0.13±0.04-0.03+0.02. Over half of the signal occurs in the range MXs > 1.8 GeV/c2.

Observation of B(s)(0) → D(s)(*)+ D(s)(*)- using e+ e- collisions and a determination of the B(s)-B(s) width difference ΔΓ(s).

We have made the first observation of B(s)(0)→D(s)(*)+ D(s)(*)- decays using 23.6 fb(-1) of data recorded by the Belle experiment running on the Υ(5S) resonance. The branching fractions are measured to be B(B(s)(0)→D(s)+ D(s)-)=(1.03(-0.32-0.25)(+0.39+0.26))%, B(B(s)(0)→D(s)(*±) D(s)(∓))=(2.75(-0.71)(+0.83)±0.69)%, and B(B(s)(0)→D(s)*+ D(s)*-)=(3.08(-1.04-0.86)(+1.22+0.85))%; the sum is B[B(s)(0)→D(s)(*)+ D(s)(*)-]=(6.85(-1.30-1.80)(+1.53+1.79))%. Assuming B(s)(0)→D(s)(*)+ D(s)(*)- saturates decays to CP-even final states, the branching fraction determines the ratio ΔΓ(s)/cosφ, where ΔΓ(s) is the difference in widths between the two B(s)-B(s) mass eigenstates, and φ is a CP-violating weak phase. Taking CP violation to be negligibly small, we obtain ΔΓ(s)/Γ(s)=0.147(-0.030)(+0.036)(stat)(-0.041)(+0.042)(syst), where Γ(s) is the mean decay width.

Measurement of the Decay B_(s);(0)-->D_(s);(-)pi;(+) and Evidence for B_(s);(0)-->D_(s);(-/+)K;(+/-) in e;(+)e;(-) Annihilation at sqrt[s] approximately 10.87 GeV.

We have studied B_(s);(0)-->D_(s);(-)pi;(+) and B_(s);(0)-->D_(s);(-/+)K;(+/-) decays using 23.6 fb;(-1) of data collected at the Upsilon(5S) resonance with the Belle detector at the KEKB e;(+)e;(-) collider. This highly pure B_(s);(0)-->D_(s);(-)pi;(+) sample is used to measure the branching fraction, B(B_(s);(0)-->D_(s);(-)pi;(+))=[3.67_(-0.33);(+0.35)(stat)-0.42+0.43(syst)+/-0.49(f_(s))]x10;(-3) (f_(s)=N_(B_(s);((*))B[over ]_(s);((*)))/N_(bb[over ])) and the fractions of B_(s);(0) event types at the Upsilon(5S) energy, in particular N_(B_(s);(*)B[over ]_(s);(*))/N_(B_(s);((*))B[over ]_(s);((*)))=(90.1_(-4.0);(+3.8)+/-0.2)%. We also determine the masses M(B_(s);(0))=(5364.4+/-1.3+/-0.7) MeV/c;(2) and M(B_(s);(*))=(5416.4+/-0.4+/-0.5) MeV/c;(2). In addition, we observe B_(s);(0)-->D_(s);(-/+)K;(+/-) decays with a significance of 3.5sigma and measure B(B_(s);(0)-->D_(s);(-/+)K;(+/-))=[2.4_(-1.0);(+1.2)(stat)+/-0.3(syst)+/-0.3(f_(s))]x10;(-4).

Measurement of the time-dependent CP asymmetries in B0-->K(S)(0)rho(0)gamma decays.

We report the first measurement of time-dependent CP asymmetry in B(0)-->K(S)(0)rho(0)gamma decays based on 657 x 10(6) BB pairs collected with the Belle detector at the KEKB asymmetric-energy collider. We measure the CP-violating parameter S_{K_{S};{0}rho;{0}gamma}=0.11+/-0.33(stat)-0.09+0.05(syst) from a signal of 212+/-17 events. We also obtain the effective direct CP-violating parameter A{eff}=0.05+/-0.18(stat)+/-0.06(syst) for mK(S)0pi+pi- <1.8 GeV/c(2) and 0.6 GeV/c(2)

Observation of B{0}-->ppK*0 with a large K*0 polarization.

Using a 492 fb{-1} data sample collected near the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e{+}e{-} collider, we observe the decay B{0}-->ppK*0 with a branching fraction of (1.18{-0.25}{+0.29}(stat)+/-0.11(syst))x10{-6}. We study the decay dynamics of B{0}-->ppK*0 and compare with B{+}-->ppK*+. The K*0 meson is found to be almost 100% polarized (with a fraction of (101+/-13+/-3)% in the helicity zero state), while the K*+ meson has a (32+/-17+/-9)% fraction in the helicity zero state. The direct CP asymmetries for B{0}-->ppK*0 and B{+}-->ppK*+ are measured to be -0.08+/-0.20+/-0.02 and -0.01+/-0.19+/-0.02, respectively. In addition, we report improved measurements of the branching fractions B(B{+}-->ppK*+)=(3.38{-0.60}{+0.73}+/-0.39)x10{-6} and B(B{0}-->ppK{0})=(2.51{-0.29}{+0.35}+/-0.21)x10{-6}, which supersede our previous measurements.

Observation of the psi(4415)-->DD2*(2460) decay using initial-state radiation.

We report measurements of the exclusive cross section for e(+)e(-)-->D(0)D(-)pi(+) over the center-of-mass energy range 4.0 GeV to 5.0 GeV with initial-state radiation and the first observation of the decay psi(4415)-->D(0)D(-)pi(+). From a study of the resonant substructure in psi(4415) decay we conclude that the psi(4415)-->D(0)D(-)pi(+) decay is dominated by psi(4415)-->DD(2)(*)(2460). We obtain B(psi(4415)-->D(0)D(-)pi(nonresonant)(+))/B(psi(4415)-->DD(2)(*)(2460)-->D(0)D(-)pi(+))<0.22 at 90% C.L. The analysis is based on a data sample collected with the Belle detector with an integrated luminosity of 673 fb(-1).

Evaluation of quality of spermatozoa prepared by SpermPrep method as compared to those prepared by MiniPercoll.

As it is quick and easy to prepare sperm with SpermPrep column, this method was assessed in the andrology laboratory for IUI preparations, as an alternative to Percoll, since Percoll is not available in market. This paper evaluates sperm prepared by SpermPrep method and compares them to those prepared by MiniPercoll for matched asthenozoospermic specimens. Spermatozoa prepared with MiniPercoll were of significantly higher quality, when compared with those prepared by SpermPrep, in terms of computer-assisted sperm motion parameters, recovery of motile fraction, morphology, hypoosmotic swelling and nuclear stability as assessed by sodium dodecyl sulphate exposure. SpermPrep did not appear to be equivalent to MiniPercoll and therefore could not be widely applied to asthenozoospermic specimens. It may be used on an individual basis, depending on the initial semen sample. Although other density gradient methods such as colloidal silica particles coated with silane appear to be equivalent to Percoll, they need to be critically evaluated with respect to their batches or different sources of vendors and be compared to Percoll as a standard method.

Attrition of the Zeigarnik effect: role of subjects' expectancy aroused by placebos.

The present paper describes the effect for 45 medical students and interns of "placebo" treatment on the Zeigarnik effect. Attrition of the Zeigarnik effect caused by placebo was resistant to caffeine and diazepam (ns = 58 and 28).

Inhibition of delta 5-3 beta hydroxysteroid dehydrogenase activity in pre-implantation mouse embryos and their implantation by sheep ovarian follicular fluid peptide.

The activity of delta 5-3 beta hydroxysteroid dehydrogenase (delta 5-3 beta HSD) in pre-implantation mouse embryos was inhibited following their prior incubation with partially purified sheep ovarian follicular fluid peptide (OFFP). OFFP, 5 microliter, injected into the uterine lumen of day 4 pregnant mice impaired the ensuing implantation of embryos. Our observations suggest that OFFP may inhibit steroid metabolizing activity in pre-implantation embryos and thereby interfere with the process of implantation.