NRQCD Predictions of D-Wave Quarkonia 3DJ(J=1,2,3)^3D_{J}(J=1,2,3) Decay into Light Hadrons at Order αs3\alpha_{s}^{3}

In this paper, in the framework of NRQCD we study the light hadron (LH) decays of the spin-triplet (S=1) D-wave heavy quarkonia. The short distance coefficients of all Fock states in the $^3D_J(J=1,2,3)$ quarkonia including D-wave color-singlet, P-wave color-octet and S-wave color-singlet and color-octet are calculated perturbatively at $\alpha_{s}^3$ order. The operator evolution equations of the four-fermion operators are also derived and are used to estimate the numerical values of the long distance matrix elements. We find that for the $c\bar{c}$ system, the LH decay widths of $\psi(1^3D_J)$ predicted by NRQCD is about $2\sim3$ times larger than the phenomenological potential model results, while for the $b\bar{b}$ system the two theoretical estimations of $\Gamma(\Upsilon(1^3D_J)\to LH)$ are in coincidence with each other. Our predictions for $\psi(1^3D_J)$ LH decay widths are $\Gamma(\psi(1^3D_J)\to LH)=(0.43,0.05,0.17)$MeV for J=1,2,3; and for $\Upsilon(1^3D_J)$, $\Gamma(\Upsilon(1^3D_J)\to LH)=(6.91,0.75,2.75)$KeV for J=1,2,3.Comment: 12 figures, references added, published version in PR

Application of millimeter-wave differential probe for crack detection on riveted structures

This thesis proposes the use of a W-band wideband differential probe for crack detection on riveted structures, such as aircraft fuselage lap joints. Detection of crack at its early stage (surface-breaking) is particularly important to prevent the development of a fatigue crack. This probe utilizing millimeter-wave frequencies serves as a viable candidate on detecting surface-breaking cracks, as it can be employed in measurements in a non-contact fashion, while allowing for high spatial-resolution images and the abilities to penetrate through dielectric materials (paint), making it attractive for detecting small cracks. In previous works, a V-band differential probe has shown promise for detecting surface breaking crack near a fastener head. This work is extended in this thesis by investigating the surface crack detection capability of the W-band differential probe. The W-band probe is tested with various intentional misalignments of the probe, as well as a paint layer covering the crack, the variations in its crack detection capability are then observed. The measurement results indicate that this fabricated probe is capable of detecting a surface crack at a length of 1.27 mm (adjacent to a fastener head), and the detection is not significantly affected by a slight misalignment, although consequently some undesired signals may also be registered. In addition, a layer of thick paint over crack introduces uncertainties to the detection signals and complicates the evaluations. To reduce the significance of these undesired signals, SAR filter is applied to the results. The outcome demonstrates an enhanced crack detection and weakened undesired signals, but the influence of a thick paint layer cannot be completely removed. A more in-depth analysis regarding the influence of paint on crack detection may be desired to fully understand the crack detection capabilities of the W-band differential probe --Abstract, page iii

Synthesis and crystal structure of the first 6a-thiathiophthen metal complex [Mo(CO)_5PPh_(2]2)(µ-C_5H_2S_3)

The first 6a-thiathiophthen metal complex was prepared by treating M(CO_)5[PPh_2CS_2CH_2C≡CH] with a catalytic amount of secondary amine or tertiary amine; the structure of the 6a-thiathiophthen molybdenum complex is confirmed by an X-ray diffraction analysis

B-meson Semi-inclusive Decay to 2−+2^{-+} Charmonium in NRQCD and X(3872)

The semi-inclusive B-meson decay into spin-singlet D-wave $2^{-+}$ charmonium, $B\to \eta_{c2}+X$, is studied in nonrelativistic QCD (NRQCD). Both color-singlet and color-octet contributions are calculated at next-to-leading order (NLO) in the strong coupling constant $\alpha_s$. The non-perturbative long-distance matrix elements are evaluated using operator evolution equations. It is found that the color-singlet $^1D_2$ contribution is tiny, while the color-octet channels make dominant contributions. The estimated branching ratio $B(B\to \eta_{c2}+X)$ is about $0.41\,\times10^{-4}$ in the Naive Dimensional Regularization (NDR) scheme and $1.24\,\times10^{-4}$ in the t'Hooft-Veltman (HV) scheme, with renormalization scale $\mu=m_b=4.8$\,GeV. The scheme-sensitivity of these numerical results is due to cancelation between ${}^1S_0^{[8]}$ and ${}^1P_1^{[8]}$ contributions. The $\mu$-dependence curves of NLO branching ratios in both schemes are also shown, with $\mu$ varying from $\frac{m_b}{2}$ to $2m_b$ and the NRQCD factorization or renormalization scale $\mu_{\Lambda}$ taken to be $2m_c$. Comparison of the estimated branching ratio of $B\to \eta_{c2}+X$ with the observed branching ratio of $B \to X(3872)+K$ may lead to the conclusion that X(3872) is unlikely to be the $2^{-+}$ charmonium state $\eta_{c2}$.Comment: Version published in PRD, references added, 26 pages, 9 figure

Relativistic corrections to J/ψJ/\psi exclusive and inclusive double charm production at B factories

In order to clarify the puzzling problems in double charm production, relativistic corrections at order $v^{2}$ to the processes $e^{+}e^{-}\to J/\psi+\eta_{c}$ and $e^{+}e^{-}\to J/\psi+c\bar{c}$ at B factories are studied in non-relativistic quantum chromodynamics. The short-distance parts of production cross sections are calculated perturbatively, while the long-distance matrix elements are estimated from $J/\psi$ and $\eta_c$ decays up to errors of order $v^4$. Our results show that the relativistic correction to the exclusive process $e^{+}e^{-}\to J/\psi+\eta_{c}$ is significant, which, when combined together with the next-to-leading order $\alpha_{s}$ corrections, could resolve the large discrepancy between theory and experiment; whereas for the inclusive process $e^{+}e^{-}\to J/\psi+c\bar{c}$ the relativistic correction is tiny and negligible. The physical reason for the above difference between exclusive and inclusive processes largely lies in the fact that in the exclusive process the relative momentum between quarks in charmonium substantially reduces the virtuality of the gluon that converts into a charm quark pair, but this is not the case for the inclusive process, in which the charm quark fragmentation $c\to J/\psi+c$ is significant, and QCD radiative corrections can be more essential.Comment: Version to appear in PRD. In the summary an explicit statement added: "for the J/\psi eta_c cross section the relativistic correction alone gives an enhancement factor of 1.7 while the combination of relativistic correction with QCD radiative correction results in a much larger enhancement factor of 9". One reference added. A few typos correcte

Internationalisation Strategy of Iconic Malaysian High Fashion Brands

PurposeThe purpose of this paper is to explore the success factors behind four globally recognised Malaysian high fashion brands. The three main sub‐objectives are: to map the process of high fashion internationalisation onto the general retail internationalisation literature; to engage fashion within the more general marketing and branding literature; to open up a qualitative line of inquiry in internationalisation research, from an Asian business perspective.Design/methodology/approachThe research design is qualitative, using a case study approach. The paper reports part of a wider study that entailed 32 depth interviews with leading practitioners in four countries, in addition to secondary and informal data sources.FindingsThe chosen case studies achieved their international success through a high degree of cultural assimilation obtained within locations of intense industrial concentration. Knowledge of education, location, language, networks and management systems were important to sustain world class standards of creative design, branding, quality management and marketing communication. For many Asian fashion brands, recognition in key European and American markets enhances the domestic prestige of the brand.Research limitations/implicationsThe research generates contextualised insights that are not statistically generalisable.Practical implicationsThe study offers first hand insights into high fashion branding and retail internationalisation from four of the most celebrated Asian designers.Originality/valueThe study responds to a need, highlighted in the literature, for more research into the internationalisation strategies of high fashion retail brands.</jats:sec