Cosmogenic exposure data can be used to calculate time‐varying fault slip rates on normal faults with exposed bedrock scarps. The method relies on assumptions related to how the scarp is preserved, ...which should be consistent at multiple locations along the same fault. Previous work commonly relied on cosmogenic data from a single sample locality to determine the slip rate of a fault. Here we show that by applying strict sampling criteria and using geologically informed modeling parameters in a Bayesian‐inference Markov chain Monte Carlo method, similar patterns of slip rate changes can be modeled at multiple sites on the same fault. Consequently, cosmogenic data can be used to resolve along‐strike fault activity. We present cosmogenic 36Cl concentrations from seven sites on two faults in the Italian Apennines. The average slip rate varies between sites on the Campo Felice Fault (0.84 ± 0.23 to 1.61 ± 0.27 mm yr−1), and all sites experienced a period of higher than average slip rate between 0.5 and 2 ka and a period of lower than average slip rate before 3 ka. On the Roccapreturo fault, slip rate in the center of the fault is 0.55 ± 0.11 and 0.35 ± 0.05 mm yr−1 at the fault tip near a relay zone. The estimated time since the last earthquake is the same at each site along the same fault (631 ± 620 years at Campo Felice and 2,603 ± 1,355 years at Roccapreturo). These results highlight the potential for cosmogenic exposure data to reveal the detailed millennial history of earthquake slip on active normal faults.
Key Points
Fault slip rates constrained with cosmogenic isotopes from multiple sites on the same fault agree
Fault slip rate varies during the Holocene, and pulses of rapid slip rate are temporally correlated along strike
Cosmogenic isotopes on bedrock fault scarps provide a detailed record of activity, provided the sample locations are carefully selected
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
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.
A measurement of ∆Γs Agapopoulou, C.; Alessio, F.; Aliouche, Z. ...
The journal of high energy physics,
22/5, Letnik:
2024, Številka:
5
Journal Article
Recenzirano
Odprti dostop
A
bstract
Using a dataset corresponding to 9 fb
−
1
of integrated luminosity collected with the LHCb detector between 2011 and 2018 in proton-proton collisions, the decay-time distributions of the ...decay modes
B
s
0
→
J
/
ψη
′
and
B
s
0
→
J
/
ψ
π
+
π
−
are studied. The decay-width difference between the light and heavy mass eigenstates of the
B
s
0
meson is measured to be ∆Γ
s
= 0
.
087 ± 0
.
012 ± 0
.
009 ps
−
1
, where the first uncertainty is statistical and the second systematic.
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 search for rare B → Dμ+μ− decays Alessio, F.; Aliouche, Z.; Artamonov, A. ...
The journal of high energy physics,
02/2024, Letnik:
2024, Številka:
2
Journal Article
Recenzirano
Odprti dostop
A
bstract
A search for rare
B → Dμ
+
μ
−
decays is performed using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb
−
1
. No ...significant signals are observed in the non-resonant
μ
+
μ
−
modes, and upper limits of
B
B
0
→
D
¯
0
μ
+
μ
−
<
5.1
×
10
−
8
,
B
B
+
→
D
s
+
μ
+
μ
−
<
3.2
×
10
−
8
,
B
B
s
0
→
D
¯
0
μ
+
μ
−
<
1.6
×
10
−
7
and
f
c
/
f
u
·
B
B
c
+
→
D
s
+
μ
+
μ
−
<
9.6
×
10
−
8
are set at the 95 % confidence level, where
f
c
and
f
u
are the fragmentation fractions of a
B
meson with a
c
and
u
quark respectively in proton-proton collisions. Each result is either the first such measurement or an improvement by three orders of magnitude on an existing limit. Separate upper limits are calculated when the muon pair originates from a
J/ψ → μ
+
μ
−
decay. The branching fraction of
B
c
+
→
D
s
+
J
/
ψ
multiplied by the fragmentation-fraction ratio is measured to be
f
c
f
u
·
B
B
c
+
→
D
s
+
J
/
ψ
=
1.63
±
0.15
±
0.13
×
10
−
5
,
where the first uncertainty is statistical and the second systematic.
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.
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