3,388 research outputs found
Open charm meson spectroscopy: Where to place the latest piece of the puzzle
We discuss how to classify the meson recently
discovered by the BaBar Collaboration. We consider four possible assignments,
together with signatures useful to distinguish among them.Comment: RevTeX, 5 pages, 1 eps figur
Understanding ,
I briefly review the experimental observations concerning the charmed mesons
, and survey on some of the interpretations
proposed in order to understand their nature. I present an analysis of their
decay modes in the hypothesis that they can be identified with the scalar and
axial vector states of spectrum
(, ). The method is based on heavy quark symmetries
and Vector Meson Dominance ansatz. Comparison with present data supports the
interpretation.Comment: LaTex, 10 pages. Invited talk at Continuous Advances in QCD 2004,
Minneapolis, Minnesota, May 13-16 200
B -> X_u l nu decay distributions to order alpha_s
An analytic result for the O(alpha_s corrections to the triple differential B
-> X_u l nu decay rate is presented, to leading order in the heavy-quark
expansion. This is relevant for computing partially integrated decay
distributions with arbitrary cuts on kinematic variables. Several double and
single differential distributions are derived, most of which generalize known
results. In particular, an analytic result for the O(alpha_s) corrections to
the hadronic invariant mass spectrum is presented. The effects of Fermi motion,
which are important for the description of decay spectra close to infrared
sensitive regions, are included. The behaviour of perturbation theory in the
region of time-like momenta is also investigatedComment: 24 pages, 11 figures, 1 typo in eq.(5.4) corrected; version published
in JHEP06(1999)01
QCD Interactions of Heavy Mesons with Pions by Light-Cone Sum Rules
Light-cone QCD sum rules are employed to compute the strong coupling
constants: g_{B^* B^* pi}, g_{B_1 B_0 pi} and g_{B_1 B^* pi}, where (B,B^*) and
(B_0,B_1) are negative and positive parity (0^-,1^-) and (0^+,1^+) \bar qQ
doublets. The couplings are calculated both for finite values of the heavy
quark mass and in the infinite heavy quark mass limit, deriving sum rules for
m_Q \to \infty.Comment: Latex, 23 pages, 6 figures. Revised version to appear in Z. Phys.
On three-body decays and couplings of heavy mesons to light pseudoscalar mesons
We analyze the decay modes and and, using the available experimental data, we find bounds for the
constants g and h describing the strong coupling of heavy mesons to light
pseudoscalar mesons. Both the decay channels are dominated by broad L=1 charm
resonances; the dominance is effective also in and .Comment: LaTex, 16 pages, 5 figure
Radiative meson decays and - mixing: a QCD sum rule analysis
The radiative transitions and are analysed using QCD sum-rules. The results we obtain for and are in very good agreement with
existing experimental data. The related issue of mixing is
discussed and we give predictions for the and decay
constants in the framework of a mixing scheme in the quark-flavour basis.Comment: Latex, 15 pages, 3figures. Some typos correcte
Light-cone sum rules: A SCET-based formulation
We describe the construction of light-cone sum rules (LCSRs) for exclusive
-meson decays into light energetic hadrons from correlation functions within
soft-collinear effective theory (SCET). As an example, we consider the SCET sum
rule for the transition form factor at large recoil, including
radiative corrections from hard-collinear loop diagrams at first order in the
strong coupling constant.Comment: LaTex, 4 pages, 2 eps figures. Talk given at QCD05, 12th
International QCD Conference, 4-9th July 2005, Montpellier, Franc
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