ゼツアツ コウトウ ウンドウ ケイソク システム ニ ヨル パーキンソンビョウ カンジャ ノ エンゲ ドウタイ ヒョウカ

The different forms of flowers in a species have attracted the attention of many evolutionary biologists, including Charles Darwin. In Fagopyrum esculentum (common buckwheat), the occurrence of dimorphic flowers, namely short-styled and long-styled flowers, is associated with a type of self-incompatibility (SI) called heteromorphic SI. The floral morphology and intra-morph incompatibility are both determined by a single genetic locus named the S-locus. Plants with short-styled flowers are heterozygous (S/s) and plants with long-styled flowers are homozygous recessive (s/s) at the S-locus. Despite recent progress in our understanding of the molecular basis of flower development and plant SI systems, the molecular mechanisms underlying heteromorphic SI remain unresolved. By examining differentially expressed genes from the styles of the two floral morphs, we identified a gene that is expressed only in short-styled plants. The novel gene identified was completely linked to the S-locus in a linkage analysis of 1,373 plants and had homology to EARLY FLOWERING 3. We named this gene S-LOCUS EARLY FLOWERING 3 (S-ELF3). In an ion-beam-induced mutant that harbored a deletion in the genomic region spanning S-ELF3, a phenotype shift from short-styled flowers to long-styled flowers was observed. Furthermore, S-ELF3 was present in the genome of short-styled plants and absent from that of long-styled plants both in world-wide landraces of buckwheat and in two distantly related Fagopyrum species that exhibit heteromorphic SI. Moreover, independent disruptions of S-ELF3 were detected in a recently emerged self-compatible Fagopyrum species and a self-compatible line of buckwheat. The nonessential role of S-ELF3 in the survival of individuals and the prolonged evolutionary presence only in the genomes of short-styled plants exhibiting heteromorphic SI suggests that S-ELF3 is a suitable candidate gene for the control of the short-styled phenotype of buckwheat plants

An Upper Bound on the Decay tau -> mu gamma from Belle

We have performed a search for the lepton-flavor-violating decay tau -> mu gamma using a data sample of 86.3fb^{-1} accumulated by the Belle detector at KEK. No evidence for a signal is seen, and we set an upper limit for the branching fraction of B(tau -> mu gamma) < 3.1 x 10^{-7} at the 90% confidence level.Comment: 6 pages, 4 figuresm, submitted to Phys. Rev. Let

Observation of a narrow charmonium-like state in exclusive B+ -> K+ pi+pi- J/psi decays

We report the observation of a narrow charmonium-like state produced in the exclusive decay process B+ -> K+ pi+pi- J/psi. This state, which decays into pi+pi- J/psi, has a mass of 3872.0+-0.6(stat)+-0.5(syst) MeV, a value that is very near the M_D + M_D* mass threshold. The results are based on an analysis of 152M B-Bbar events collected at the Upsilon(4S) resonance in the Belle detector at the KEKB collider. The statistical significance of the signal is in excess of 10 sigma.Comment: 10 pages 4 figures, submitted to Physical Review Letter

Evidence for B0->pi0pi0

We report evidence for the decay B0->pi0pi0. The analysis is based on a data sample of 152million BBbar pairs collected at the Upsilon(4s) resonance with the Belle detector at the KEKB e+e- storage ring. We find 25.6+9.3/-8.4(stat)+1.6/-1.4(syst) B0->pi0pi0 signal events with a significance of 3.4 standard deviations. We measure the branching fraction to be (1.7+-0.6(stat)+-0.2(syst))*10^{-6}.Comment: Submitted to PR

Observation of B→K∗ℓ+ℓ−B \to K^* \ell^+ \ell^-

We report the first observation of the flavor-changing neutral current decay $B \to K^* \ell^+ \ell^-$ and an improved measurement of the decay $B \to K \ell^+ \ell^-$, where $\ell$ represents an electron or a muon, with a data sample of 140 fb${}^{-1}$ accumulated at the $\Upsilon(4S)$ resonance with the Belle detector at KEKB. The results for the branching fractions are ${\cal B}(B \to K^* \ell^+ \ell^-)=(11.5^{+2.6}_{-2.4} \pm 0.8 \pm 0.2) \times 10^{-7}$ and ${\cal B}(B \to K \ell^+ \ell^-)=(4.8^{+1.0}_{-0.9} \pm 0.3 \pm 0.1) \times 10^{-7}$, where the first error is statistical, the second is systematic and the third is from model dependence.Comment: 11 pages, 2 figures, submitted to PR

Measurement of Time-Dependent CP-Violating Asymmetries in B0 --> phi Ks0, K+ K- Ks0, and eta' Ks0 Decays

We present an improved measurement of CP-violation parameters in B0 --> phi Ks0, K+ K- Ks0, and eta' Ks0 decays based on a 140 fb-1 data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB energy-asymmetric e+e- collider. One neutral B meson is fully reconstructed in one of the specified decay channels, and the flavor of the accompanying B meson is identified from its decay products. CP-violation parameters for each of the three modes are obtained from the asymmetries in the distributions of the proper-time intervals between the two B decays. We find that the observed CP asymmetry in the B0 --> phi Ks0 decay differs from the standard model (SM) expectation by 3.5 standard deviations, while the other cases are consistent with the SM.Comment: 10 pages, 4 postscript figures, submitted to Physical Review Letters, also contributed to the XXI International Symposium on Lepton and Photon Interactions at High Energies, Aug 11-16, 2003, Fermilab, Illinois US

Evidence for CP-Violating Asymmetries in B0->pi+pi- Decays and Constraints on the CKM Angle phi2

We present an improved measurement of CP-violating asymmetries in B0 -> pi+ pi- decays based on a 78 fb^-1 data sample collected at the Y(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We reconstruct one neutral B meson as a B0 -> pi+ pi- CP eigenstate and identify the flavor of the accompanying B meson from inclusive properties of its decay products. We apply an unbinned maximum likelihood fit to the distribution of the time intervals between the two B meson decay points. The fit yields the CP-violating asymmetry amplitudes Apipi = +0.77+/-0.27(stat)+/-0.08(syst) and Spipi = -1.23+/-0.41(stat)+0.08/-0.07(syst), where the statistical uncertainties are determined from Monte Carlo pseudo-experiments. We obtain confidence intervals for CP-violating asymmetry parameters Apipi and Spipi based on a frequentist approach. We rule out the CP-conserving case, Apipi=Spipi=0, at the 99.93% confidence level. We discuss how these results constrain the value of the CKM angle phi2.Comment: 26 pages, 13 figures, submitted to Phys. Rev.