The present study determined the effect of untreated wastewater on the prevalence of carbapenem resistance in
Acinetobacter baumannii
(CRAB) in both the wastewater and the receiving river water ...surrounding Cuttack City. Physiochemical parameters, heavy metal contamination factors (CF), contamination degree (CD), pollution load index (PLI), and microbiological content (total coliform, fecal form, and CRAB) were analyzed in two untreated urban wastewater and three in receiving river water (upstream, catchment, and downstream). The high BOD, CF, CD, and PLI in urban wastewater, river catchment, and downstream revealed intense anthropogenic activity. After
bla
OXA-51
detection and clonal analysis by ERIC-PCR, a total of 73 CRAB were selected for further analysis. All the CRAB isolates were 100% resistant to penicillin, β-lactam/β-lactamase inhibitor, cephalosporin, and carbapenem groups of antibiotics. The antibiotic profile showed 73.97% CRAB isolates assigned as extremely drug resistant. Detection of carbapenemase (
bla
NDM
and
bla
OXA-48
) and co-harboring ESBL (
bla
TEM
) genes, the highest at the river, reflects direct disposal of biomedical wastes. MAR index (> 0.2) and virulence index (> 0.5) in 59 isolates were classified as a high threat posing a severe human risk. A similar ERIC pattern between the isolates from two different locations (catchment and downstream) indicates their dissemination downstream through river water flow. The extraordinary ability of resistant
A. baumannii
to thrive in the river makes it unfit for household activities and poses a public health threat. Therefore, frequent monitoring of resistance levels in water could help direct antibiotic use and resistance management.
A
bstract
The cross section for coherent photonuclear production of J/
ψ
is presented as a function of the electromagnetic dissociation (EMD) of Pb. The measurement is performed with the ALICE ...detector in ultra-peripheral Pb-Pb collisions at a centre-of-mass energy per nucleon pair of
s
NN
= 5.02 TeV. Cross sections are presented in five different J/
ψ
rapidity ranges within |
y
| < 4, with the J/
ψ
reconstructed via its dilepton decay channels. In some events the J/
ψ
is not accompanied by EMD, while other events do produce neutrons from EMD at beam rapidities either in one or the other beam direction, or in both. The cross sections in a given rapidity range and for different configurations of neutrons from EMD allow for the extraction of the energy dependence of this process in the range 17 <
W
γ
Pb
,
n
< 920 GeV, where
W
γ
Pb
,
n
is the centre-of-mass energy per nucleon of the
γ
Pb system. This range corresponds to a Bjorken-
x
interval spanning about three orders of magnitude: 1.1 × 10
−
5
<
x
< 3.3 × 10
−
2
. In addition to the ultra-peripheral and photonuclear cross sections, the nuclear suppression factor is obtained. These measurements point to a strong depletion of the gluon distribution in Pb nuclei over a broad, previously unexplored, energy range. These results, together with previous ALICE measurements, provide unprecedented information to probe quantum chromodynamics at high energies.
A
bstract
The jet angularities are a class of jet substructure observables which characterize the angular and momentum distribution of particles within jets. These observables are sensitive to ...momentum scales ranging from perturbative hard scatterings to nonperturbative fragmentation into final-state hadrons. We report measurements of several groomed and ungroomed jet angularities in pp collisions at
s
= 5
.
02 TeV with the ALICE detector. Jets are reconstructed using charged particle tracks at midrapidity (
|η| <
0
.
9). The anti-
k
T
algorithm is used with jet resolution parameters
R
= 0
.
2 and
R
= 0
.
4 for several transverse momentum
p
T
ch
jet
intervals in the 20–100 GeV/
c
range. Using the jet grooming algorithm Soft Drop, the sensitivity to softer, wide-angle processes, as well as the underlying event, can be reduced in a way which is well-controlled in theoretical calculations. We report the ungroomed jet angularities,
λ
α
, and groomed jet angularities,
λ
α
,g
, to investigate the interplay between perturbative and nonperturbative effects at low jet momenta. Various angular exponent parameters
α
= 1, 1.5, 2, and 3 are used to systematically vary the sensitivity of the observable to collinear and soft radiation. Results are compared to analytical predictions at next-to-leading-logarithmic accuracy, which provide a generally good description of the data in the perturbative regime but exhibit discrepancies in the nonperturbative regime. Moreover, these measurements serve as a baseline for future ones in heavy-ion collisions by providing new insight into the interplay between perturbative and nonperturbative effects in the angular and momentum substructure of jets. They supply crucial guidance on the selection of jet resolution parameter, jet transverse momentum, and angular scaling variable for jet quenching studies.
A
bstract
The production of J
/ψ
is measured at midrapidity (
|y| <
0
.
9) in proton-proton collisions at
s
= 5
.
02 and 13 TeV, through the dielectron decay channel, using the ALICE detector at the ...Large Hadron Collider. The data sets used for the analyses correspond to integrated luminosities of
L
int
= 19.4
±
0.4 nb
−
1
and
L
int
= 32.2
±
0.5 nb
−
1
at
s
= 5
.
02 and 13 TeV, respectively. The fraction of non-prompt J
/ψ
mesons, i.e. those originating from the decay of beauty hadrons, is measured down to a transverse momentum
p
T
= 2 GeV
/c
(1 GeV
/c
) at
s
= 5
.
02 TeV (13 TeV). The
p
T
and rapidity (
y
) differential cross sections, as well as the corresponding values integrated over
p
T
and
y
, are carried out separately for prompt and non-prompt J
/ψ
mesons. The results are compared with measurements from other experiments and theoretical calculations based on quantum chromodynamics (QCD). The shapes of the
p
T
and
y
distributions of beauty quarks predicted by state-of-the-art perturbative QCD models are used to extrapolate an estimate of the
b
b
¯
pair cross section at midrapidity and in the total phase space. The total
b
b
¯
cross sections are found to be
σ
b
b
¯
= 541
±
45 (stat
.
)
±
69
syst
.
−
12
+
10
(extr
.
)
μ
b and
σ
b
b
¯
= 218
±
37 (stat
.
)
±
31
syst
.
−
9.1
+
8.2
(extr
.
)
μ
b at
s
= 13 and 5.02 TeV, respectively. The value obtained from the combination of ALICE and LHCb measurements in pp collisions at
s
= 13 TeV is also provided.
This article reports on the inclusive production cross section of several quarkonium states,
J
/
ψ
,
ψ
(
2
S
)
,
Υ
(
1
S
)
,
Υ
(
2
S
)
, and
Υ
(
3
S
)
, measured with the ALICE detector at the LHC, ...in pp collisions at
s
=
5.02
TeV. The analysis is performed in the dimuon decay channel at forward rapidity (
2.5
<
y
<
4
). The integrated cross sections and transverse-momentum (
p
T
) and rapidity (
y
) differential cross sections for
J
/
ψ
,
ψ
(
2
S
)
,
Υ
(
1
S
)
, and the
ψ
(
2
S
)
-to-
J
/
ψ
cross section ratios are presented. The integrated cross sections, assuming unpolarized quarkonia, are:
σ
J
/
ψ
(
p
T
<
20
GeV/c) = 5.88 ± 0.03 ± 0.34
μ
b,
σ
ψ
(
2
S
)
(
p
T
<
12
GeV/c) = 0.87 ± 0.06 ± 0.10
μ
b,
σ
Υ
(
1
S
)
(
p
T
<
15
GeV/c) = 45.5 ± 3.9 ± 3.5 nb,
σ
Υ
(
2
S
)
(
p
T
<
15
GeV/c) = 22.4 ± 3.2 ± 2.7 nb, and
σ
Υ
(
3
S
)
(
p
T
<
15
GeV/c) = 4.9 ± 2.2 ± 1.0 nb, where the first (second) uncertainty is the statistical (systematic) one. For the first time, the cross sections of the three
Υ
states, as well as the
ψ
(
2
S
)
one as a function of
p
T
and
y
, are measured at
s
=
5.02
TeV at forward rapidity. These measurements also significantly extend the
J
/
ψ
p
T
reach and supersede previously published results. A comparison with ALICE measurements in pp collisions at
s
=
2.76
, 7, 8, and 13 TeV is presented and the energy dependence of quarkonium production cross sections is discussed. Finally, the results are compared with the predictions from several production models.
A
bstract
The production of inclusive, prompt and non-prompt J/
ψ
was studied for the first time at midrapidity (−1
.
37
< y
cms
<
0
.
43) in p-Pb collisions at
s
NN
= 8
.
16 TeV with the ALICE ...detector at the LHC. The inclusive J/
ψ
mesons were reconstructed in the dielectron decay channel in the transverse momentum (
p
T
) interval 0
< p
T
<
14 GeV/
c
and the prompt and non-prompt contributions were separated on a statistical basis for
p
T
>
2 GeV/
c
. The study of the J/
ψ
mesons in the dielectron channel used for the first time in ALICE online single-electron triggers from the Transition Radiation Detector, providing a data sample corresponding to an integrated luminosity of 689 ± 13
μ
b
−
1
. The proton-proton reference cross section for inclusive J/
ψ
was obtained based on interpolations of measured data at different centre-of-mass energies and a universal function describing the
p
T
-differential J/
ψ
production cross sections. The
p
T
-differential nuclear modification factors
R
pPb
of inclusive, prompt, and non-prompt J/
ψ
are consistent with unity and described by theoretical models implementing only nuclear shadowing.
A
bstract
The first measurement of the e
+
e
−
pair production at low lepton pair transverse momentum (
p
T
,
ee
) and low invariant mass (
m
ee
) in non-central Pb–Pb collisions at
s
NN
= 5
.
02 TeV ...at the LHC is presented. The dielectron production is studied with the ALICE detector at midrapidity (
|η
e
| <
0
.
8) as a function of invariant mass (0.4
≤ m
ee
<
2
.
7 GeV/
c
2
) in the 50–70% and 70–90% centrality classes for
p
T
,
ee
<
0.1 GeV/
c
, and as a function of
p
T
,
ee
in three
m
ee
intervals in the most peripheral Pb–Pb collisions. Below a
p
T
,
ee
of 0.1 GeV/
c
, a clear excess of e
+
e
−
pairs is found compared to the expectations from known hadronic sources and predictions of thermal radiation from the medium. The
m
ee
excess spectra are reproduced, within uncertainties, by different predictions of the photon–photon production of dielectrons, where the photons originate from the extremely strong electromagnetic fields generated by the highly Lorentz-contracted Pb nuclei. Lowest-order quantum electrodynamic (QED) calculations, as well as a model that takes into account the impact-parameter dependence of the average transverse momentum of the photons, also provide a good description of the
p
T
,
ee
spectra. The measured
p
T
,
ee
2
of the excess
p
T
,
ee
spectrum in peripheral Pb–Pb collisions is found to be comparable to the values observed previously at RHIC in a similar phase-space region.
A
bstract
The production of strange hadrons (
K
S
0
, Λ, Ξ
±
, and Ω
±
), baryon-to-meson ratios (Λ
/
K
S
0
, Ξ
/
K
S
0
, and Ω
/
K
S
0
), and baryon-to-baryon ratios (Ξ
/
Λ, Ω
/
Λ, and Ω
/
Ξ) ...associated with jets and the underlying event were measured as a function of transverse momentum (
p
T
) in pp collisions at
s
= 13 TeV and p Pb collisions at
s
NN
= 5
.
02 TeV with the ALICE detector at the LHC. The inclusive production of the same particle species and the corresponding ratios are also reported. The production of multi-strange hadrons, Ξ
±
and Ω
±
, and their associated particle ratios in jets and in the underlying event are measured for the first time. In both pp and p–Pb collisions, the baryon-to-meson and baryon-to-baryon yield ratios measured in jets differ from the inclusive particle production for low and intermediate hadron
p
T
(0.6–6 GeV/
c
). Ratios measured in the underlying event are in turn similar to those measured for inclusive particle production. In pp collisions, the particle production in jets is compared with P
ythia
8 predictions with three colour-reconnection implementation modes. None of them fully reproduces the data in the measured hadron
p
T
region. The maximum deviation is observed for Ξ
±
and Ω
±
which reaches a factor of about six. The event multiplicity dependence is further investigated in p−Pb collisions. In contrast to what is observed in the underlying event, there is no significant event-multiplicity dependence for particle production in jets. The presented measurements provide novel constraints on hadronisation and its Monte Carlo description. In particular, they demonstrate that the fragmentation of jets alone is insufficient to describe the strange and multi-strange particle production in hadronic collisions at LHC energies.
A
bstract
The production of
π
±
, K
±
, and
p
¯
p
is measured in pp collisions at
s
= 13 TeV in different topological regions of the events. Particle transverse momentum (
p
T
) spectra are measured ...in the “toward”, “transverse”, and “away” angular regions defined with respect to the direction of the leading particle in the event. While the toward and away regions contain the fragmentation products of the near-side and away-side jets, respectively, the transverse region is dominated by particles from the Underlying Event (UE). The relative transverse activity classifier,
R
T
=
N
T
/〈
N
T
〉, is used to group events according to their UE activity, where
N
T
is the measured charged-particle multiplicity per event in the transverse region and 〈
N
T
〉 is the mean value over all the analysed events. The first measurements of identified particle
p
T
spectra as a function of
R
T
in the three topological regions are reported. It is found that the yield of high transverse momentum particles relative to the
R
T
-integrated measurement decreases with increasing
R
T
in both the toward and the away regions, indicating that the softer UE dominates particle production as
R
T
increases and validating that
R
T
can be used to control the magnitude of the UE. Conversely, the spectral shapes in the transverse region harden significantly with increasing
R
T
. This hardening follows a mass ordering, being more significant for heavier particles. Finally, it is observed that the
p
T
-differential particle ratios
p
+
p
¯
/
π
+
+
π
−
and (K
+
+ K
−
)
/
(
π
+
+
π
−
) in the low UE limit (
R
T
→ 0) approach expectations from Monte Carlo generators such as PYTHIA 8 with Monash 2013 tune and EPOS LHC, where the jet-fragmentation models have been tuned to reproduce e
+
e
−
results.
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