A proposed laser measurement system for determining surface contour

Electro-optical system can scan a large /100 ft./ antenna in 30 seconds. Comparison of the reflected signal with a reference signal from a Pockel-cell modulator driver yields a signal that can be correlated with the distance covered by the laser. A scanning arrangement then enables contour measurement

Comment on "On the TST_S-Anomaly in Betaine Calcium Chloride Dihydrate"

Recently, Hlinka and Ishibashi [J. Phys. Soc. Jpn. 67, 495 (1998)] discussed the $T_S$-anomaly in betaine calcium chloride dihydrate (BCCD) in a Landau-type approach. We comment on the shortcomings of this approach and discuss the $T_S$-anomaly in the framework of a microscopical pseudo spin model based on a realistic description of BCCD in terms of symmetry-adapted local modes.Comment: 2 pages, RevTex, submitted to J. Phys. Soc. Jp

Note on Tests of the Factorization Hypothesis and the Determination of Meson Decay Constants

We discuss various tests of the factorization hypothesis making use of the close relationship between semi-leptonic and factorized nonleptonic decay amplitudes. It is pointed out that factorization leads to truely model-independent predictions for the ratio of nonleptonic to semi-leptonic decay rates, if in the nonleptonic decay a spin one meson of arbitrary mass or a pion take the place of the lepton pair. Where the decay constants of those mesons are known, these predictions represent ideal tests of the factorization hypothesis. In other cases they may be used to extract the decay constants. Currently available data on the decays $\bar B^0 \to D^+\pi^-,\, D^{*+}\pi^-,\, D^+\varrho^-,\, D^{*+}\varrho^-$ are shown to be in excellent agreement with the factorization results. A weighted average of the four independent values for the QCD coefficient $a_1$ extracted from the data gives $a_1=1.15\pm 0.06$ suggesting that it may be equal to the Wilson coefficient $c_1(\mu)$ evaluated at the scale $\mu = m_b$.Comment: (9 pages, ReVTeX, no figures), HD-THEP-92-3

Subleading Shape Functions in Inclusive B Decays

The contributions of subleading shape functions to inclusive decay distributions of B mesons are derived from a systematic two-step matching of QCD current correlators onto soft-collinear and heavy-quark effective theory. At tree-level, the results can be expressed in terms of forward matrix elements of bi-local light-cone operators. Four-quark operators, which arise at O(g^2), are included. Their effects can be absorbed entirely into a redefinition of other shape functions. Our results are in disagreement with some previous studies of subleading shape-function effects in the literature. A numerical analysis of B->X_u+l+nu decay distributions suggests that power corrections are small, with the possible exception of the endpoint region of the charged-lepton energy spectrum.Comment: 22 pages, 2 figures; several typos corrected; version published in JHE

Peculiarities of isotopic temperatures obtained from p+A collisions at 1 GeV

Nuclear temperatures obtained from inclusive measurements of double isotopic yield ratios of fragments produced in 1 GeV p + A collisions amount to about 4 MeV nearly independent from the target mass.Comment: 4 pages, 4 figures, to be submitted to Eur. Phys. J.

B Mixing

The neutral $B$ mesons, $B^0$ and $B_s$, can oscillate between their particle and antiparticle states owing to flavor-changing weak interactions. In recent years, techniques to detect these oscillations as a function of the meson's decay time have been developed. In this article the physics of flavor oscillations is reviewed and theoretical predictions are summarized. The many observations that demonstrate the time-dependence of B^0-\B0bar oscillations are presented along with a combined measurement of its frequency, $\delta m_d$. The attempts to measure the $B_s$ oscillation frequency, both directly and indirectly, are then summarized. Finally, values for the CKM elements $|V_{td}|$ and $|V_{ts}/V_{td}|$ are extracted

Quark-binding effects in inclusive decays of heavy mesons

We present a new approach to the analysis of quark-binding effects in inclusive decays of heavy mesons within the relativistic dispersion quark model. Various differential distributions, such as electron energy spectrum, $q^2$- and $M_X$-distributions, are calculated in terms of the $B$ meson soft wave function which also determines long-distance effects in exclusive transition form factors. Using the quark-model parameters and the $B$ meson wave function previously determined from the description of the exclusive $b \to u$ transitions within the same dispersion approach, we provide numerical results on various distributions in the inclusive $B \to X_c l\nu$ decays.Comment: revtex, 18 pages, preprint HD-THEP-99-50 (Heidelberg) and RM3-TH/99-13 (Roma

Infrared Singularities and Soft Gluon Resummation with Massive Partons

Infrared divergences of QCD scattering amplitudes can be derived from an anomalous dimension matrix, which is also an essential ingredient for the resummation of large logarithms due to soft gluon emissions. We report a recent analytical calculation of the anomalous dimension matrix with both massless and massive partons at two-loop level, which describes the two-loop infrared singularities of any scattering amplitudes with an arbitrary number of massless and massive partons, and also enables soft gluon resummation at next-to-next-to-leading-logarithmic order. As an application, we calculate the infrared poles in the q qbar -> t tbar and gg -> t tbar scattering amplitudes at two-loop order.Comment: Talk presented at Loops and Legs in Quantum Field Theory 2010, Woerlitz, Germany, April 25-30, 201

Bc Meson Formfactors and Bc-->PV Decays Involving Flavor Dependence of Transverse Quark Momentum

We present a detailed analysis of the Bc form factors in the BSW framework, by investigating the effects of the flavor dependence on the average transverse quark momentum inside a meson. Branching ratios of two body decays of Bc meson to pseudoscalar and vector mesons are predicted.Comment: 18 pages, 5 figure

Semileptonic B Decays into Excited Charmed Mesons (D1D_1, D2∗D^*_2) in HQEFT

Exclusive semileptonic B decays into excited charmed mesons ($D_1$, $D^*_2$) are studied up to the order of $1/m_Q$ in the framework of the heavy quark effective field theory (HQEFT), which contains the contributions of both particles and antiparticles. Two wave functions $\eta^b_0$ and $\eta^c_0$, which characterize the contributions from the kinematic operator at the order of $1/m_Q$, are calculated by using QCD sum rule approach in HQEFT. Zero recoil values of other two wave functions $\kappa'_1$ and $\kappa'_2$ are extracted from the excited charmed-meson masses. Possible effects from the spin-dependent transition wave functions which arise from the magnetic operators at the order of $1/m_Q$ are analyzed. It is shown that the experimental measurements for the branching ratios of $B \to D_1 l\nu$ and $B \to D^*_2 l\nu$ can be understood in the framework of HQEFT.Comment: 27 pages, RevTex, 4 figures, 3 tables, to be published in IJMP