1,645 research outputs found
Complete Next to Leading Order QCD Corrections to the Photon Structure Functions and
We present the complete NLO QCD analysis of the photon structure functions
and for a real photon target. In
particular we study the heavy flavor content of the structure functions which
is due to two different production mechanisms, namely collisions of a virtual
photon with a real photon, and with a parton. We observe that the charm
contributions are noticeable for as well as
in the x-region studied.Comment: Latex 34 pages, 24 figures, uuencoded, attached at end, ITP-SB-93-46,
FERMILAB-Pub-93/240-T, SMU HEP 93-1
Search for CP violation in tau -> K^0_S pi nu_tau decays at Belle
We report on a search for CP violation in tau -> K^0_S pi nu_tau decays using
a data sample of 699 fb^{-1} collected in the Belle experiment at the KEKB
electron-positron asymmetric-energy collider. The CP asymmetry is measured in
four bins of the invariant mass of the K^0_S pi system and found to be
compatible with zero with a precision of O(10^{-3}) in each mass bin. Limits
for the CP violation parameter Im(eta_S) are given at a 90 % confidence level.
These limits are |Im(eta_S)|<0.026 or better, depending on the parameterization
used to describe the hadronic form factors and improve upon previous limits by
one order of magnitude
Observation of B+ -> Dbar*0 tau+ nu_tau and Evidence for B+ -> Dbar^0 tau+ nu_tau at Belle
We present measurements of B+ -> Dbar*0 tau+ nu_tau and B+ -> Dbar^0 tau+
nu_tau decays in a data sample of 657 x 10^6 BBbar pairs collected with the
Belle detector at the KEKB asymmetric-energy e+e- collider. We find
446^{+58}_{-56} events of the decay B+ -> Dbar*0 tau+ nu_tau with a
significance of 8.1 standard deviations, and 146^{+42}_{-41} events of the
decay B+ -> Dbar0 tau+ nu_tau with a significance of 3.5 standard deviations.
The latter signal provides the first evidence for this decay mode. The measured
branching fractions are B(B+ -> Dbar*0 tau+ nu_tau)=(2.12^{+0.28}_{-0.27}
(stat) +- 0.29 (syst)) % and B(B+ -> Dbar0 tau+ nu_tau)=(0.77 +- 0.22 (stat) +-
0.12 (syst)) %.Comment: 6 pages, 4 figures, submitted to Phys. Rev. Let
Evidence for a new resonance and search for the Y(4140) in
The process \gamma \gamma \to \phi \jpsi is measured for \phi \jpsi
masses between threshold and 5 GeV/, using a data sample of 825
fb collected with the Belle detector. A narrow peak of
events, with a significance of 3.2 standard deviations
including systematic uncertainty, is observed. The mass and natural width of
the structure (named X(4350)) are measured to be
and
, respectively. The
product of its two-photon decay width and branching fraction to \phi\jpsi is
for , or
for . No
signal for the Y(4140)\to \phi \jpsi structure reported by the CDF
Collaboration in B\to K^+ \phi \jpsi decays is observed, and limits of
\Gamma_{\gamma \gamma}(Y(4140)) \BR(Y(4140)\to\phi \jpsi)<41 \hbox{eV} for
or for are determined at the 90% C.L. This
disfavors the scenario in which the Y(4140) is a molecule.Comment: 9 pages, 3 figures, publication in Phys. Rev. Lett. 104, 112004, 201
Evidence for direct CP violation in the decay B->D(*)K, D->KsPi+Pi- and measurement of the CKM phase phi3
We present a new measurement of the unitarity triangle angle phi3 using a
Dalitz plot analysis of the KsPi+Pi- decay of the neutral D meson produced in
B->D(*)K decays. The method exploits the interference between D0 and D0bar to
extract the angle phi3, strong phase delta and the ratio r of suppressed and
allowed amplitudes. We apply this method to a 605 fb-1 data sample collected by
the Belle experiment. The analysis uses three decays: B->DK, and B->D*K with
D*->DPi0 and D*->Dgamma, as well as the corresponding charge-conjugate modes.
From a combined maximum likelihood fit to the three modes, we obtain phi3 =
78.4^+10.8_-11.6 +- 3.6 (syst) +- 8.9 (model) degrees. CP conservation in this
process is ruled out at the confidence level (1-CL)=5x10^-4, or 3.5 standard
deviations.Comment: 10 pages, 5 figures, 4 tables. Replaced by version published in Phys.
Rev.
First Measurement of Inclusive B -> X_s eta Decays
We report a first measurement of inclusive B -> X_s eta decays, where X_s is
a charmless state with unit strangeness. The measurement is based on a
pseudo-inclusive reconstruction technique and uses a sample of 657 x 10^6
BB-bar pairs accumulated with the Belle detector at the KEKB e^+e^- collider.
For M_{X_s} < 2.6 GeV/c^2, we measure a branching fraction of (26.1 +/- 3.0
(stat) +1.9 -2.1 (syst) +4.0 -7.1 (model)) x 10^-5 and a direct CP asymmetry of
A_{CP} = -0.13 +/- 0.04 +0.02 -0.03. Over half of the signal occurs in the
range M_{X_s} > 1.8 GeV/c^2.Comment: 6 pages, 1 figure, 1 table, submitted to Physical Review Letter
The main concerns of European anaesthesiology postgraduate trainees: A European survey
This is the first study intended to identify the European anaesthesiology trainees' main concerns, to initiate a process of improvement of the training in anaesthesiology by the European Society of Anaesthesiology (ESA). The authors developed an electronic survey which addressed seven different concerns: autonomy transition, technical skills, exchange programs, residency costs, residency workload, employment prospects and educational contents/preparation for the European Diploma in Anaesthesiology and Intensive Care (EDAIC). The survey was disseminated by email to all anaesthesiology trainees registered in ESA and all European National Societies were asked to distribute the survey to their graduating trainees. 665 trainees initiated the survey with a completion rate of 54.6%. The trainees' main concerns were in descending order: educational contents, residency costs, employment prospects, residency workload, exchange programs, technical skills and autonomy transition. This report analyzes the three main concerns in more detail. 68% of respondents were unaware of the existence of the ESA e-learning platform. Other means to improve the preparation for the EDAIC such as a multiple-choice questions book should be developed. The main reason for not becoming an ESA Trainee member was the associated cost and 68% of respondents gave up activities or opportunities during their residency due to economic constraints; 56% of respondents considered emigrating for economic reasons and 28% elected Northern/Central Europe. The results of the present survey may provide additional background information for the development of specific improvements in strategies for training in anaesthesiology. (c) 2018 Elsevier Ltd. All rights reserved
Measurement of and branching ratios
We report an improved measurement of and branching ratios using 605 fb of data collected with the Belle
detector at the KEKB asymmetric-energy collider. The measured
branching ratios with respect to the Cabibbo-favored modes are = 0.18990.0022
and =
0.08030.0019 where the first uncertainties are statistical and
the second are systematic
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