A
bstract
The cross-sections of exclusive (coherent) photoproduction
J/ψ
and
ψ
(2S) mesons in ultra-peripheral PbPb collisions at a nucleon-nucleon centre-of-mass energy of 5
.
02 TeV are measured ...using a data sample corresponding to an integrated luminosity of 228 ± 10 μb
−
1
, collected by the LHCb experiment in 2018. The differential cross-sections are measured separately as a function of transverse momentum and rapidity in the nucleus-nucleus centre-of-mass frame for
J/ψ
and
ψ
(2S) mesons. The integrated cross-sections are measured to be
σ
J
/
ψ
coh
= 5
.
965
±
0
.
059
±
0
.
232
±
0
.
262 mb and
σ
ψ
2
S
coh
= 0
.
923
±
0
.
086
±
0
.
028
±
0
.
040 mb, where the first listed uncertainty is statistical, the second systematic and the third due to the luminosity determination. The cross-section ratio is measured to be
σ
ψ
2
S
coh
/
σ
J
/
ψ
coh
= 0
.
155
±
0
.
014
±
0
.
003, where the first uncertainty is statistical and the second is systematic. These results are compatible with theoretical predictions.
A
bstract
The CKM angle
γ
is determined from
CP
-violating observables measured in
B
±
→
D
K
∓
π
±
π
±
π
∓
h
±
, (
h
=
K, π
) decays, where the measurements are performed in bins of the decay ...phase-space of the
D
meson. Using proton-proton collision data collected by the LHCb experiment at centre-of-mass energies of 7
,
8 and 13 TeV, corresponding to a total integrated luminosity of 9 fb
−
1
,
γ
is determined to be
γ
=
54.8
+
6.0
−
5.8
+
0.6
−
0.6
+
6.7
−
4.3
∘
,
where the first uncertainty is statistical, the second systematic and the third from the external inputs on the coherence factors and strong phases of the
D
-meson decays.
A
bstract
An amplitude analysis of the
D
+
→ π
−
π
+
π
+
decay is performed with a sample corresponding to 1.5 fb
−
1
of integrated luminosity of
pp
collisions at a centre-of-mass energy
s
= 8 TeV ...collected by the LHCb detector in 2012. The sample contains approximately six hundred thousand candidates with a signal purity of 95%. The resonant structure is studied through a fit to the Dalitz plot where the
π
−
π
+
S-wave amplitude is extracted as a function of
π
−
π
+
mass, and spin-1 and spin-2 resonances are included coherently through an isobar model. The S-wave component is found to be dominant, followed by the
ρ
(770)
0
π
+
and
f
2
(1270)
π
+
components. A small contribution from the
ω
(782)
→ π
−
π
+
decay is seen for the first time in the
D
+
→ π
−
π
+
π
+
decay.
Observation of the B+→ Jψη′K+ decay Alessio, F.; Aliouche, Z.; Artamonov, A. ...
The journal of high energy physics,
08/2023, Letnik:
2023, Številka:
8
Journal Article
Recenzirano
Odprti dostop
A
bstract
The
B
+
→
Jψη
′
K
+
decay is observed for the first time using proton-proton collision data collected by the LHCb experiment at centre-of-mass energies of 7, 8, and 13 TeV, corresponding to ...a total integrated luminosity of 9 fb
−
1
. The branching fraction of this decay is measured relative to the known branching fraction of the
B
+
→ ψ
(2
S
)
K
+
decay and found to be
B
B
+
→
Jψη
′
K
+
B
B
+
→
ψ
2
S
K
+
=
4.91
±
0.47
±
0.29
±
0.07
×
10
−
2
,
where the first uncertainty is statistical, the second is systematic and the third is related to external branching fractions. A first look at the
J/ψη
′ mass distribution is performed and no signal of intermediate resonances is observed.
A
bstract
A search for
CP
violation in D
0
→
π
−
π
+
π
0
decays is reported, using
pp
collision data collected by the LHCb experiment from 2015 to 2018 corresponding to an integrated luminosity of 6 ...fb
−
1
. An unbinned model-independent approach provides sensitivity to local
CP
violation within the two-dimensional phase space of the decay. The method is validated using the Cabibbo-favoured channel D
0
→ K
−
π
+
π
0
and background regions of the signal mode. The results are consistent with
CP
symmetry in this decay.
Search for D∗(2007)0→μ+μ- in B-→π-μ+μ- decays Adeva, B.; Adlarson, P.; Aidala, C. A. ...
The European physical journal. C, Particles and fields,
07/2023, Letnik:
83, Številka:
7
Journal Article
Recenzirano
Odprti dostop
The very rare
D
∗
(
2007
)
0
→
μ
+
μ
-
decay is searched for by analysing
B
-
→
π
-
μ
+
μ
-
decays. The analysis uses a sample of beauty mesons produced in proton–proton collisions collected with the ...LHCb detector between 2011 and 2018, corresponding to an integrated luminosity of 9
\,fb
-
1
. The signal signature corresponds to simultaneous peaks in the
μ
+
μ
-
and
π
-
μ
+
μ
-
invariant masses. No evidence for an excess of events over background is observed and an upper limit is set on the branching fraction of the decay at
B
(
D
∗
(
2007
)
0
→
μ
+
μ
-
)
<
2.6
×
10
-
8
at
90
%
confidence level. This is the first limit on the branching fraction of
D
∗
(
2007
)
0
→
μ
+
μ
-
decays and the most stringent limit on
D
∗
(
2007
)
0
decays to leptonic final states. The analysis is the first search for a rare charm-meson decay exploiting production via beauty decays.
Introduction
The Rey–Osterrieth Complex Figure Test (RCFT) is one of the most commonly used neuropsychological tests in Sweden and Norway. However, no publications provide normative data for this ...population. The objective of this study was to present demographically adjusted norms for a Swedish and Norwegian population and to evaluate these in an independent comparison group.
Methods
The RCFT was administrated to 344 healthy controls recruited from the Swedish Gothenburg MCI study, the Norwegian Dementia Disease Initiation study, and the Swedish Cardiopulmonary Bioimage Study. Age ranged from 49 to 77 years (mean = 62.4 years, SD = 5.0 years), and education ranged from 6 to 24 years (mean = 13.3 years, SD = 3.0 years). Using a regression‐based procedure, we investigated the effects of age, sex, and years of education on test performance. We compared and evaluated our Swedish and Norwegian norms with North American norms in an independent comparison group of 145 individuals.
Results
In healthy controls, age and education were associated with performance on the RCFT. When comparing normative RCFT performance in an independent comparison group, North American norms generally overestimated immediate and delayed recall performance. In contrast, our Swedish and Norwegian norms appear to better take into account factors of age and education.
Conclusions
We presented demographically adjusted norms for the RCFT in a Swedish and Norwegian sample. This is the first normative study of the RCFT that presents normative data for this population. In addition, we showed that North American norms might produce inaccurate normative estimations in an independent comparison group.
Objective: To assess the role of brief neuropsychological assessments in prediction and identification of Alzheimer's disease (AD) pathology and progression to AD dementia. Method: Adults (N = 255; ...range = 40-81 years) with self-reported cognitive decline underwent baseline and 2-year follow-up clinical assessment, including a brief neuropsychological screening and lumbar puncture. Five different mild cognitive impairment (MCI) algorithms were applied on baseline cognitive test results: one conventional, three amnestic (lenient, stringent, multidomain), and one comprehensive criterion. We compared predictive and diagnostic accuracy of these MCI criteria by performing logistic regression analyses and calculating diagnostic accuracy measures for 2-year outcomes of (1) clinical diagnosis of AD dementia and (2) cerebrospinal fluid biomarkers in the Alzheimer's continuum. Results: The lenient amnestic MCI criterion showed the largest effect size for predicting progression to AD dementia (OR = 13.762, 99% CI = 1.969-96.194, p = .001) and AD biomarkers (OR = 4.855, 99% CI = 1.974-11.924, p < .001) after 2 years. This criterion was sensitive for progression to dementia (sensitivity = 92.0%, specificity = 54.8%, positive likelihood ratio LR+ = 2.03, LR− = 0.15) and showed the highest overall diagnostic accuracy for AD biomarkers (sensitivity = 72.7%, specificity = 59.1%, LR+ = 1.78, negative likelihood ratio LR− = 0.46). The multidomain amnestic MCI criterion produced the highest specificity for dementia (sensitivity = 76.0%, specificity = 73.0%, LR+ = 2.82, LR− = 0.33) and AD biomarkers (sensitivity = 46.8% specificity = 70.9% LR+ = 1.61, LR− = 0.75). Conclusions: Defining MCI using a brief neuropsychological battery provided limited accuracy for progression to AD dementia and cerebrospinal fluid Aβ. The lenient amnestic MCI criterion identified the highest number of individuals who progressed to clinical AD or showed biomarker pathology, but this approach included a substantial number of false positives.
Key Points
Question: How can results from brief cognitive testing best be used to identify individuals with higher risk of developing Alzheimer's disease and dementia within 2 years? Findings: Test results from brief cognitive testing show variable ability to discriminate between healthy individuals and those with signs of disease. Importance: Brief and low-cost cognitive assessment methods for early Alzheimer's disease can be widely employed and provide useful clinical information but may not be sufficiently accurate to be used in isolation. Next Steps: Future research on this topic could involve direct comparison of brief cognitive testing with larger test batteries.
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