Motion deblurring for optical character recognition

Master'sMASTER OF SCIENC

Z0Z_0 Boson Decays to Bc(∗)B^{(*)}_c Meson and Its Uncertainties

The programming new $e^{+}e^-$ collider with high luminosity shall provide another useful platform to study the properties of the doubly heavy $B_c$ meson in addition to the hadronic colliders as LHC and TEVATRON. Under the `New Trace Amplitude Approach', we calculate the production of the spin-singlet $B_c$ and the spin-triplet $B^*_c$ mesons through the $Z^0$ boson decays, where uncertainties for the production are also discussed. Our results show $\Gamma_{(^1S_0)}= 81.4^{+102.1}_{-40.5}$ KeV and $\Gamma_{(^3S_1)}=116.4^{+163.9}_{-62.8}$ KeV, where the errors are caused by varying $m_b$ and $m_c$ within their reasonable regions.Comment: 11 pages, 5 figures, 2 tables. To be published in Eur.Phys.J.

Production of the PP-Wave Excited BcB_c-States through the Z0Z^0 Boson Decays

In Ref.[7],we have dealt with the production of the two color-singlet $S$-wave $(c\bar{b})$-quarkonium states $B_c(|(c\bar{b})_{\bf 1}[^1S_0]>)$ and $B^*_c(|(c\bar{b})_{\bf 1}[^3S_1]>)$ through the $Z^0$ boson decays. As an important sequential work, we make a further discussion on the production of the more complicated $P$-wave excited $(c\bar{b})$-quarkonium states, i.e. $|(c\bar{b})_{\bf 1}[^1P_1]>$ and $|(c\bar{b})_{\bf 1}[^3P_J]>$ (with $J=(1,2,3)$). More over, we also calculate the channel with the two color-octet quarkonium states $|(c\bar{b})_{\bf 8}[^1S_0]g>$ and $|(c\bar{b})_{\bf 8}[^3S_1]g>$, whose contributions to the decay width maybe at the same order of magnitude as that of the color-singlet $P$-wave states according to the naive nonrelativistic quantum chromodynamics scaling rules. The $P$-wave states shall provide sizable contributions to the $B_c$ production, whose decay width is about 20% of the total decay width $\Gamma_{Z^0\to B_c}$. After summing up all the mentioned $(c\bar{b})$-quarkonium states' contributions, we obtain $\Gamma_{Z^0\to B_c} =235.9^{+352.8}_{-122.0}$ KeV, where the errors are caused by the main uncertainty sources.Comment: 8 pages, 5 figures and 2 tables. basic formulae in the appendix are cut off to match the published version, which can be found in v1. to be published in Eur.Phys.J.

Revisiting the Bs(∗)B^{(*)}_s-Meson Production at the Hadronic Colliders

The production of heavy-flavored hadron at the hadronic colliders provides a challenging opportunity to test the validity of pQCD predictions. There are two mechanisms for the $B^{(*)}_s$ hadroproduction, i.e. the gluon-gluon fusion mechanism via the subprocess $g+g\rightarrow B^{(*)}_s+b+\bar{s}$ and the extrinsic heavy quark mechanism via the subprocesses $g+\bar{b}\to B^{(*)}_s +\bar{s}$ and $g+s\to B^{(*)}_s +b$, both of which shall have sizable contributions in proper kinematic region. Different from the fixed-flavor-number scheme (FFNS) previously adopted in the literature, we study the $B^{(*)}_s$ hadroproduction under the general-mass variable-flavor-number scheme (GM-VFNS), in which we can consistently deal with the double counting problem from the above two mechanisms. Properties for the $B^{(*)}_s$ hadroproduction are discussed. To be useful reference, a comparative study of FFNS and GM-VFNS is presented. Both of which can provide reasonable estimations for the $B^{(*)}_s$ hadroproduction. At the Tevatron, the difference between these two schemes is small, however such difference is obvious at the LHC. The forthcoming more precise data on LHC shall provide a good chance to check which scheme is more appropriate to deal with the $B^{(*)}_s$-meson production and to further study the heavy quark components in hadrons.Comment: 18 pages, 8 figures, 4 tables. To match the published version. To be published in Eur.Phys.J.

Dynamic analysis and field investigation of a fluidized landslide in Guanling, Guizhou, China

On June 28, 2010, a large catastrophic landslide was triggered by a heavy rainfall in Guanling, Guizhou, China. This catastrophic event destroyed two villages and caused 99 casualties. The landslide involved the failure of about 985, 000 m[3] of sandstone from the source area. The displaced materials traveled about 1300 m with a descent of about 400 m, covering an area of 129, 000 m2 with the final volume being accumulated to be 1, 840, 000 m[3], approximately. To provide information for hazard zonation of similar type of landslides in the same area, we used a dynamic model (DAN3D) to simulate the runout behavior of the displaced landslide materials, and found that a combined frictional–Vollemy model could provide the best performance in simulating this landslide and the runout is precisely duplicated with a dynamic friction angle (ϕ) of 30° and a pore pressure ratio (ru) of 0.55 for the materials at the source area and with Vollemy parameters of friction coefficient f = 0.1 (dimensionless) and turbulent coefficient ξ = 400 m/s[2]. The simulated results indicated that the duration of the movement is estimated at about 60 s for a mean velocity 23 m/s. To examine the effectiveness of simulation by means of DAN3D and also to evaluate the reactivation potential of these displaced landslide materials depositing on the valley, we used electrical resistivity tomography (ERT) method to survey the depth and internal structure of landslide deposits. The ERT results showed that DAN3D gave a good prediction on the shape and runout distance of the landslide deposits, although the predicted maximum depths of landslide deposit on some areas were differing from those obtained by ERT method

Cognitive, social, emotional, and subjective health benefits of computer use in adults: a 9-year longitudinal study from the Midlife in the United States (MIDUS)

Computer use has been proposed to carry a host of benefits for cognitive function and socioemotional well-being in older adults. However, the literature on computer use remains equivocal as extant research suffers from mixed findings as well as methodological limitations, such as overreliance on cross-sectional designs, small sample sizes, and use of narrow criterions. The current studies (NStudy 1 = 3,294, NStudy 2 = 2,683) sought to address these limitations through the use of a large-scale, nationally representative, and longitudinal dataset. We found that frequency of computer use—over a period of approximately 9 years—longitudinally predicted positive changes in executive functioning, hedonic well-being, eudaimonic well-being, sense of control, optimism, self-esteem, and social relationships with family and friends. We also found that these cognitive and socioemotional benefits are associated with greater computer use over time. In contrast to studies showing that computer use promoted sedentary lifestyles or adverse physical health outcomes, we instead found that computer use longitudinally predicted better self-reported physical and mental health and reduced functional disabilities. The current findings attest to the promising benefits of computer use in promoting healthy cognitive and socioemotional functioning across midlife and old age