126 research outputs found

    Analysis of the DDΛ‰βˆ—KD\bar{D}^*K system with QCD sum rules

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    In this article, we construct the color singlet-singlet-singlet interpolating current with I(JP)=32(1βˆ’)I\left(J^P\right)=\frac{3}{2}\left(1^-\right) to study the DDΛ‰βˆ—KD\bar{D}^*K system through QCD sum rules approach. In calculations, we consider the contributions of the vacuum condensates up to dimension-16 and employ the formula ΞΌ=MX/Y/Z2βˆ’(2Mc)2\mu=\sqrt{M_{X/Y/Z}^{2}-\left(2{\mathbb{M}}_{c}\right)^{2}} to choose the optimal energy scale of the QCD spectral density. The numerical result MZ=4.71βˆ’0.11+0.19 GeVM_Z=4.71_{-0.11}^{+0.19}\,\rm{GeV} indicates that there exists a resonance state ZZ lying above the DDΛ‰βˆ—KD\bar{D}^*K threshold to saturate the QCD sum rules. This resonance state ZZ may be found by focusing on the channel J/ΟˆΟ€KJ/\psi \pi K of the decay B⟢J/ΟˆΟ€Ο€KB\longrightarrow J/\psi \pi \pi K in the future.Comment: 9 pages, 4 figure

    Masses and decay constants of the heavy tensor mesons with QCD sum rules

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    In this article, we calculate the contributions of the vacuum condensates up to dimension-6 in the operator product expansion, study the masses and decay constants of the heavy tensor mesons D2βˆ—(2460)D_2^*(2460), Ds2βˆ—(2573)D_{s2}^*(2573), B2βˆ—(5747)B_2^*(5747), Bs2βˆ—(5840)B_{s2}^*(5840) using the QCD sum rules. The predicted masses are in excellent agreement with the experimental data, while the ratios of the decay constants fDs2βˆ—fD2βˆ—β‰ˆfBs2βˆ—fB2βˆ—β‰ˆfDsfD∣exp\frac{f_{D_{s2}^*}}{f_{D_{2}^*}}\approx\frac{f_{B_{s2}^*}}{f_{B_{2}^*}}\approx\frac{f_{D_{s}}}{f_{D}}\mid_{\rm exp}, where the exp denotes the experimental value.Comment: 13 pages, 13 figure

    Analysis of the mass and width of the X(4140)X(4140) as axialvector tetraquark state

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    In this article, we construct both the [sc]T[sΛ‰cΛ‰]A+[sc]A[sΛ‰cΛ‰]T[sc]_T[\bar{s}\bar{c}]_A+[sc]_A[\bar{s}\bar{c}]_T type and [sc]T[sΛ‰cΛ‰]Vβˆ’[sc]V[sΛ‰cΛ‰]T[sc]_T[\bar{s}\bar{c}]_V-[sc]_V[\bar{s}\bar{c}]_T type axialvector currents with JPC=1++J^{PC}=1^{++} to study the mass of the X(4140)X(4140) with the QCD sum rules. The predicted masses support assigning the X(4140)X(4140) to be the [sc]T[sΛ‰cΛ‰]Vβˆ’[sc]V[sΛ‰cΛ‰]T[sc]_T[\bar{s}\bar{c}]_V-[sc]_V[\bar{s}\bar{c}]_T type axialvector tetraquark state. Then we study the hadronic coupling constant gXJ/ΟˆΟ•g_{XJ/\psi\phi} with the QCD sum rules based on solid quark-hadron duality, and obtain the decay width Ξ“(X(4140)β†’J/ΟˆΟ•)=86.9Β±22.6 MeV\Gamma(X(4140)\to J/\psi \phi)=86.9\pm22.6\,{\rm{MeV}}, which is in excellent agreement with the experimental data 83\pm 21^{+21}_{-14} {\mbox{ MeV}} from the LHCb collaboration.Comment: 17 pages, 5 figure

    Culture-independent analysis of microflora in Gayals (Bos frontalis) feces

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    Comparative DNA sequence analysis of 16S/18S rRNA genes (rDNA) were undertaken to further our understanding of the make-up of micro-organisms communities in the feces of Gayals. Total DNA wereextracted from the feces of 5 Gayals. Two rDNA libraries (16S/18S rDNA) were constructed. In the 16S rDNA library, phylogenetic and sequence similarity analyses of the resultant 71 clone sequences revealed the presence of 67 operational taxonomic units (OTUs) or phylotypes and defined as having more than 97% of sequence similarity. The sequences were affiliated with the following phyla: Firmicutes (34.3%), Bacteroidetes (6.0%), Proteobacteria (4.5%), and uncultured bacteria (55.2%). A setof 58 sequences were analyzed in the 18S rDNA library, which were classified into 27 OTUs. They were mainly affiliated with the following phyla: Protozoa (25.9%), Basidiomycota (3.7%), Ascomycota (11.1%),and uncultured eukaryotes (59.3%). The sequence analysis indicated that more than half of the species, harbored in Gayals fecal belonged to the not-yet-cultured groups at 90% 16S/18S similarity levels with cultured species. In addition, micro-organisms of Chytridiomycetes was one of the most significant cellulose producing species obtained from the Gayal feces as well
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