Determination of |V_cb| and Related Results from BABAR

The CKM matrix element amplitude |V_cb| was determined using the data collected by the BABAR detector. The partial branching fraction, lepton-energy moments, and hadron-mass moments were measured in inclusive semileptonic decays B -> X_c l nu. A global fit to a Heavy-Quark-Expansion calculation allowed precise determination of |V_cb|, m_b, m_c, B(B -> X_c l nu) and four non-perturbative parameters.Comment: 5 pages, 2 postscript figures, contributed to the Proceedings of MESON 200

Probing Polarized Gluon Distributions through Charmed Hadron Production in Polarized pp Collisions at BNL--RHIC Energy

In order to extract information about behavior of polarized gluons in the nucleon, charmed hadron productions, i.e. D* meson and Lambda_c baryon productions, are studied in polarized pp reactions at BNL-RHIC energy. For these processes, the spin correlation asymmetry D_{LL} between the target proton and the produced charmed hadron, and its statistical sensitivity delta D_{LL} are calculated. From analyses on these processes, we found that the pseudo-rapidity distribution of D_{LL} in the limited transverse momentum region is quite effective for distinguishing the model of polarized gluons as well as the model of spin-dependent fragmentation functions.Comment: 1+14 pages, 14 figures, added references and comments, To appear in Int. Journal of Modern Phys.

Charmed Hadron Production in Polarized pp Collisions

To extract information about polarized gluons in the proton, production of charmed hadrons, in particular, \Lambda_c^+ baryon in pp collisions was studied. We calculated the transverse momentum distribution and the pseudo-rapidity distribution of the spin correlation asymmetry A_{LL} between the initial proton and the produced \Lambda_c^+. Those statistical sensitivities were also calculated under the condition of RHIC experiment. We found that the pseudo-rapidity distribution of A_{LL} is promising for testing the model of polarized gluons in the proton and also the spin-dependent fragmentation model of a charm quark decaying into \Lambda_c^+ baryon.Comment: 1+6 pages, Latex2e, 4 eps figures, Talk given at SPIN 2002, Brookhaven National Laboratory, September 9-13, 2002, To appear in the Proceeding

Spectroscopy and Decays of Heavy Mesons

Assuming Coulomb-like as well as confining scalar potential, we have solved Shr\"odinger equation perturbatively in $1/m_Q$ with a heavy quark mass $m_Q$. The lowest order equation is examined carefully. Mass levels are fitted with experimental data for $D/B$ mesons at each level of perturbation. Meson wave functions obtained thereby can be used to calculate ordinary form factors as well as Isgur-Wise functions for semileptonic weak decays and other physical quantities. All the above calculations are expanded in $1/m_Q$ order by order to determine parameters as well as to compare with results of Heavy Quark Effective Theory.Comment: 4 page

A Deep Infrared Search for AXP 1E 1841-045

Multi-colour (JHKs) imaging and photometry of the field of the Anomalous X-ray Pulsar AXP 1E 1841-045 is analysed in the light of new, accurate coordinates from Chandra (Wachter et al, 2004). From excellentquality images, we find multiple sources in and around the position error circle. Of these, none can be confidently identified as the infrared counterpart. The limiting magnitudes reached were J=22.1, H=20.7 and Ks=19.9$ (95% confidence).Comment: 8 pages LaTeX, 2 eps figures; ApJ accepte