26 research outputs found
Study of decays to the final state and evidence for the decay
A study of decays is performed for the first time
using data corresponding to an integrated luminosity of 3.0
collected by the LHCb experiment in collisions at centre-of-mass energies
of and TeV. Evidence for the decay
is reported with a significance of 4.0 standard deviations, resulting in the
measurement of
to
be .
Here denotes a branching fraction while and
are the production cross-sections for and mesons.
An indication of weak annihilation is found for the region
, with a significance of
2.4 standard deviations.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-022.html,
link to supplemental material inserted in the reference
Constraints on Energy Intake in Fish: The Link between Diet Composition, Energy Metabolism, and Energy Intake in Rainbow Trout
The hypothesis was tested that fish fed to satiation with iso-energetic diets differing in macronutrient composition will have different digestible energy intakes (DEI) but similar total heat production. Four iso-energetic diets (2×2 factorial design) were formulated having a contrast in i) the ratio of protein to energy (P/E): high (HP/E) vs. low (LP/E) and ii) the type of non-protein energy (NPE) source: fat vs. carbohydrate which were iso-energetically exchanged. Triplicate groups (35 fish/tank) of rainbow trout were hand-fed each diet twice daily to satiation for 6 weeks under non-limiting water oxygen conditions. Feed intake (FI), DEI (kJ kg−0.8 d−1) and growth (g kg−0.8 d−1) of trout were affected by the interaction between P/E ratio and NPE source of the diet (P<0.05). Regardless of dietary P/E ratio, the inclusion of carbohydrate compared to fat as main NPE source reduced DEI and growth of trout by ∼20%. The diet-induced differences in FI and DEI show that trout did not compensate for the dietary differences in digestible energy or digestible protein contents. Further, changes in body fat store and plasma glucose did not seem to exert a homeostatic feedback control on DEI. Independent of the diet composition, heat production of trout did not differ (P>0.05). Our data suggest that the control of DEI in trout might be a function of heat production, which in turn might reflect a physiological limit related with oxidative metabolism
Measurement of the B0s →J/ψη lifetime
Using a data set corresponding to an integrated luminosity of 3 fb−1, collected by the LHCb experiment in pp collisions at centre-of-mass energies of 7 and 8 TeV, the effective lifetime in the Bs0→J/ψη decay mode, τeff, is measured to be
τeff=1.479±0.034 (stat)±0.011 (syst) ps. Assuming CP conservation, τeff corresponds to the lifetime of the light Bs0 mass eigenstate. This is the first measurement of the effective lifetime in this decay mode
Model-independent measurement of mixing parameters in D0 → K S 0 π+π− decays
The first model-independent measurement of the charm mixing parameters in the decay D 0 → K S 0 π + π − is reported, using a sample of pp collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 1.0 fb−1 at a centre-of-mass energy of 7 TeV. The measured values are
x=(−0.86±0.53±0.17)×10−2,y=(+0.03±0.46±0.13)×10−2,
x=(−0.86±0.53±0.17)×10−2,y=(+0.03±0.46±0.13)×10−2,
where the first uncertainties are statistical and include small contributions due to the external input for the strong phase measured by the CLEO collaboration, and the second uncertainties are systematic
Precipitation-induced surface brightenings seen on Titan by Cassini VIMS and ISS
Abstract Observations from Cassini VIMS and ISS show localized but extensive surface brightenings in the wake of the 2010 September cloudburst. Four separate areas, all at similar latitude, show similar changes: Yalaing Terra, Hetpet Regio, Concordia Regio, and Adiri. Our analysis shows a general pattern to the time-sequence of surface changes: after the cloudburst the areas darken for months, then brighten for a year before reverting to their original spectrum. From the rapid reversion timescale we infer that the process driving the brightening owes to a fine-grained solidified surface layer. The specific chemical composition of such solid layer remains unknown. Evaporative cooling of wetted terrain may play a role in the generation of the layer, or it may result from a physical grain-sorting process.National Aeronautics and Space Administration. ESA Cassini Projec
Applicability of case-based reasoning for selection of cyanide-free gold leaching methods
Observation of J /ψφ Structures Consistent with Exotic States from Amplitude Analysis of B+ →j /ψφK+ Decays
The first full amplitude analysis of B+→J/ψφK+ with J/ψ→μ+μ-, φ→K+K- decays is performed with a data sample of 3 fb-1 of pp collision data collected at s=7 and 8 TeV with the LHCb detector. The data cannot be described by a model that contains only excited kaon states decaying into φK+, and four J/ψφ structures are observed, each with significance over 5 standard deviations. The quantum numbers of these structures are determined with significance of at least 4 standard deviations. The lightest has mass consistent with, but width much larger than, previous measurements of the claimed X(4140) state
Study of Bc+ decays to the K+K−π+ final state and evidence for the decay Bc+→χc0π+
A study of
B
+
c
→
K
+
K
−
π
+
decays is performed for the first time using data corresponding to an integrated luminosity of
3.0
fb
−
1
collected by the LHCb experiment in
p
p
collisions at center-of-mass energies of 7 and 8 TeV. Evidence for the decay
B
+
c
→
χ
c
0
(
→
K
+
K
−
)
π
+
is reported with a significance of 4.0 standard deviations, giving
σ
(
B
+
c
)
σ
(
B
+
)
×
B
(
B
+
c
→
χ
c
0
π
+
)
=
(
9.
8
+
3.4
−
3.0
(
stat
)
±
0.8
(
syst
)
)
×
10
−
6
. Here
B
denotes a branching fraction while
σ
(
B
+
c
)
and
σ
(
B
+
)
are the production cross sections for
B
+
c
and
B
+
mesons. An indication of
¯
b
c
weak annihilation is found for the region
m
(
K
−
π
+
)
<
1.834
GeV
/
c
2
, with a significance of 2.4 standard deviations