The orbitally-excited states D_1 and D_2 form degenerate doublet in the heavy-quark symmetry limit with hyperfine mass splitting proportional to 1/m_c. Measurement of the value of the mass splitting between these states is an important test of HQET predictions for intermediate mass c-quark and it provides valuable input to theoretical treatment of the corrections to the infinite mass quark limit.
The D_1 and D_2* states have been observed in CDF using Run II data, in the decay channels D_1, D_2* -> D*+ pi-. This is the first observation of these states in hadron colliders, and their observation has been possible thanks to the excellent performances of the CDF detector, in particular the silicon displaced vertex trigger.
The mass difference between the two states can be resolved
and a measurement of the D_1 and D_2* masses is
presented.
[D10.002] Production of Heavy-Strange Baryons in p\barp Collisions at \sqrts\sim 2 TeV at CDF Detector
Elena Gerchtein (Carnegie Mellon University)
A novel hadronic trigger at CDF provides a unique opportunity to study the properties of bottom and charmed baryons produced in p\barp collisions at \sqrts\sim 2 TeV.
We have searched for heavy-strange baryons in decay chains containing long lived hyperons -- \Xi and Ømega as decay products.
Long lived charged hyperons, \Xi^- and Ømega, are capable of traveling significant distances in the volume of the SVX/ISL detectors and producing hits in silicon, before decaying into pairs of \Lambda^0\pi^- and \Lambda^0\rmK^- respectively. This gives a unique opportunity of finding hyperon tracks in the SVX/ISL detectors. The tracking of hyperons in the silicon detector results in a dramatic reduction of the combinatorial background and an improvement of the momentum resolution compared with standard reconstruction using final decay products. For the first time at CDF we observed signal from Ømega hyperons.
We report an observation of charmed-strange baryon
isodoublet \left \ \Xi_c^0, \Xi_c^+\right \ for the
first time in p\bar\rmp collisions.
[D10.003] Observation of e^+e^- \rightarrow c\barc\,c\barc Production around \sqrts=10.56 GeV with the BaBar Detector.
Shuwei Ye (Univ. of Texas at Dallas), BaBar Collaboration
We report on a study of double c\barc production in
e^+e^- annihilations around \sqrts=10.56 GeV with the
BaBar detector, based on a total of 92 fb^-1. Signals
for \eta_c, \chi_c0, and \eta_c(2S) are observed in
the spectra of recoil mass against fully reconstructed
J/\psi and \psi(2S) decays. These double charmonium
events are interpreted as exclusive e^+e^-\rightarrow
c\barc\,c\barc interactions. Masses and widths of these
charmonia are obtained from fits to the signal peaks in the
recoil mass spectra. Exclusive e^+e^-\rightarrow
J/\psi\eta_c signal is observed in the data for the first
time, where J/\psi is detected via
J/\psi\rightarrow\ell^+ \ell^-, and the \eta_c is
recontructed with charged tracks and photons recoiling
against the J/\psi. Searches for e^+e^-\rightarrow
J/\psi\,D\,X have been carried out. A full Monte Carlo
study has been done.
[D10.004] Observation of the production of charmed baryons \Sigma_c^\circ and\$\Sigma_c^++ in p\barp collisions at \sqrts=1.96~ TeV
Dmitri Naumov (University of New Mexico)
We report on the observation of charmed baryon states
\Sigma_c^\circ and \Sigma_c^++ decaying strongly into
\Lambda_c^+ \pi^- and \Lambda_c^+ \pi^+, respectively,
where the \Lambda_c^+ state is reconstructed in the p K^-
\pi^+ mode. The analysis is based on data collected so far
with the CDF-II detector.
[D10.005] Measurement of the D \bar D production cross section at the \psi(3770)
Batbold Sanghi (Purdue University), CLEO Collaboration
Initial running of the CLEO-c detector has recorded the
world's largest sample of \psi(3770) decays. Using this
data we have measured the cross section for the process
\psi(3770) \rightarrow D \bar D in events in which a
single D meson is fully reconstructed and in events where
both D mesons are fully reconstructed.
[D10.006] Studies of charged and neutral D meson semileptonic decays
Laria Redjimi (Syracuse University), CLEO Collaboration
We present preliminary measurements of the branching
fractions and electron momentum spectra for the decays
D^+\rightarrow X \ell \nu and D^o\rightarrow X \ell \nu,
using the CLEO-c detector at the CESR e^+e^- collider.
Tagged D samples collected at the \psi(3770)
center-of-mass energy are used in these measurement.
[D10.007] Exclusive semileptonic decays of D mesons produced in the reaction \psi(3770) \rightarrow D \bar D
Victor Pavlunin (Purdue University), CLEO Collaboration
Initial running of the CLEO-c detector has provided the
world's largest sample of \psi(3770) decays. Using this
data we have reconstructed D mesons decaying to hadronic
final states and have used them to tag events with a
charm-anti-charm meson pair. Signals for a variety of decay
modes of the D^0 and D^+ will be presented and the
expected sensitivity for measuring semileptonic decay form
factors and the CKM matrix elements V_cs and V_cd
will be reviewed.
[D10.008] Studies of the leptonic decay D^+\rightarrow \mu^+ \nu_\mu
Nabil Menaa (Syracuse University), CLEO Collaboration
The purely leptonic decay of the D^+ meson is of great
interest because it provides direct access to the
pseudoscalar decay constant f_D^+. We present
preliminary studies of the decay D^+\rightarrow \mu^+
\nu_\mu that have been made with the CLEO-c detector at the
CESR e^+e^- collider operating at the \psi(3770)
center-of-mass energy. Our sample of tagged D^+ mesons has
been obtained by full reconstruction of D-meson decays
into several hadronic final states.
[D10.009] Search for non-D \bar D decays of the \psi(3770)
Guangshun Huang (Purdue University), CLEO Collaboration
Initial running of the CLEO-c detector has recorded the
world's largest sample of \psi(3770) decays. Using this
data we have searched for two-body, three-body and higher
multiplicity non-D \bar D decays of the \psi(3770).
[D10.010] A Dalitz Analysis of D^0\rightarrow K^+K^-\pi^0 Using CLEO III Data
Paras Naik (University of Illinois at Urbana-Champaign), CLEO Collaboration
We present preliminary results from a Dalitz analysis of the
Cabibbo suppressed charmed meson decay mode D^0\rightarrow
K^+K^-\pi0. The data used were accumulated by the CLEO III
experiment at the Cornell Electron Storage Ring.
[D10.011] Partial reconstruction of D_s^+ \to \phi \pi^+
Jeremy Williams (University of Illinois at Urbana-Champaign), CLEO Collaboration
Normalization to the branching fraction \cal B(D_s^+ \to
\phi \pi^+) is the largest uncertainty in the measurement
of many processes involving a D_s meson. We present a
measurement of \cal B(D_s^+ \to \phi \pi^+) / \cal
B(øverlineD^0 \to K^+ \pi^-) via partial reconstruction
of the decay B^0 \to D_s^*+ D^*- using the CLEO
detector at CESR.
[D10.012] Measurement of D^\circ and D^\pm Lifetime Ratio in CDF
Kim Giolo (Purdue)
CDF is collecting huge fully reconstructed charm samples,
thanks to its inclusive trigger on displaced vertices (SVT),
and is becoming a high precision experiment in the field of
mixing in the D^\circ sector. However lifetime
measurements are made difficult by the bias introduced by
the trigger selections. We present a method to account for
this bias along with a measurement of the lifetime ratio of
D^\circ \to K\pi and D^\pm \to K\pi\pi using 180 pb-1 of
runII data. Projections and estimates for a measurement of
lifetime difference in the D^\circ system are also shown.
[D10.013] Observation and Branching ratios for Charged and Neutral \Xi_c.
Matthew Charles (Univ. of Iowa), BaBar Collaboration
We report on the observations of charged and neutral \Xi_c
decays in the BABAR experiment with \sim 100 fb^-1
data. Multiple decay modes of each \Xi_c are observed.
Preliminary measurements of the ratio of branching fractions
are presented.
[D10.014] Measurement of the Charge and Neutral \Xi_c Masses.
Xuedong Chai (Univ. of Iowa), BaBar Collaboration
We present preliminary measurements of the masses of both
charged and neutral \Xi_c's along with their mass
difference from \sim 100 fb^-1 data collected by the
BABAR experiment. We use multiple decay modes for each
\Xi_c.
[D10.015] Inference of Schrödinger Equation from Newtonian Mechanics
P-I Johansson (Uppsala University, SW), J.X. Zheng-Johansson (IOFPR)
\def\nudlow\nu_d \def\nulow\nu \def\lf\left \def\rt\right \def\Adm \Ad \def\Ad\mit \Psi \def\pd\partial \def\rbr \def\runi\hat rWhat physical process does Schrödinger's wave describe ? what causes it waving? These questions, presenting since the founding of quantum mechanics, remain to date unanswered, and are provided with an answer in this work. We recently achieved a general scheme for forming a (basic) material particle through the Newtonian-Maxwellian solution for an oscillatory vaculeon (an elementary charge) and the mechanical disturbances, =electromagnetic (EM) waves, generated by it in the vacuum comprising electrically neutral but polarizable vacuons. Within the general scheme, combining now with Newtonian plane wave solution, for infinitesimal wave path if nonuniform potential V(\rb), we obtain the classical wave equation (a) for the particle's total wave, which reduces to (b) for its de Broglie (dB)- wave: \beginarraycc \frac\hbar^2 \nulow M [1-\frac12 \lf(\fracvc\rt)^2] \frac\pd ^2 \Adm(\rb,t) \pd x ^2 + \fracV(\rb)(\nulow+\nudlow) \Adm(\rb,t)= i \hbar (\nulow+\nudlow) \frac\pd \Adm(\rb,t) \pd t; &\qquad (a) \cr \ - \frac\hbar^2 2M \nabla^2 + V(\rb) \\Adm_d(\rb,t) = i \hbar \frac\pd \Adm_d(\rb,t) \pd t. &\qquad (b) \endarray Where \Adm(\rb,t) is the dimensionless total displacement of coupled vacuons, \nulow and \nudlow = \nulow (v/c)^2 EM- and dB- wave frequencies, M and m\simeq 1/\frac1M[1-\frac12 (\fracvc)^2] particle's rest- and relativistic- masses, v and c particle and light velocities, and \hbar Planck constant. (b) is identical to Schrödinger's wave equation. (Full work accepted for publication.)