A
bstract
A search for the
K
+
→
π
+
X
decay, where
X
is a long-lived feebly interacting particle, is performed through an interpretation of the
K
+
→
π
+
ν
ν
¯
analysis of data collected in 2017 by ...the NA62 experiment at CERN. Two ranges of
X
masses, 0–110 MeV
/c
2
and 154–260 MeV
/c
2
, and lifetimes above 100 ps are considered. The limits set on the branching ratio, BR(
K
+
→
π
+
X
), are competitive with previously reported searches in the first mass range, and improve on current limits in the second mass range by more than an order of magnitude.
The Muon Ionization Cooling Experiment (MICE) collaboration seeks to demonstrate the feasibility of ionization cooling, the technique by which it is proposed to cool the muon beam at a future ...neutrino factory or muon collider. The emittance is measured from an ensemble of muons assembled from those that pass through the experiment. A pure muon ensemble is selected using a particle-identification system that can reject efficiently both pions and electrons. The position and momentum of each muon are measured using a high-precision scintillating-fibre tracker in a 4 T solenoidal magnetic field. This paper presents the techniques used to reconstruct the phase-space distributions in the upstream tracking detector and reports the first particle-by-particle measurement of the emittance of the MICE Muon Beam as a function of muon-beam momentum.
Performance of the NA62 trigger system Cortina Gil, E.; Kleimenova, A.; Minucci, E. ...
The journal of high energy physics,
03/2023, Volume:
2023, Issue:
3
Journal Article
Peer reviewed
Open access
A
bstract
The NA62 experiment at CERN targets the measurement of the ultra-rare
K
+
→
π
+
ν
ν
¯
decay, and carries out a broad physics programme that includes probes for symmetry violations and ...searches for exotic particles. Data were collected in 2016–2018 using a multi-level trigger system, which is described highlighting performance studies based on 2018 data.
Precise measurement of neutrino beam direction and intensity was achieved based on a new concept with modularized neutrino detectors. INGRID (Interactive Neutrino GRID) is an on-axis near detector ...for the T2K long baseline neutrino oscillation experiment. INGRID consists of 16 identical modules arranged in horizontal and vertical arrays around the beam center. The module has a sandwich structure of iron target plates and scintillator trackers. INGRID directly monitors the muon neutrino beam profile center and intensity using the number of observed neutrino events in each module. The neutrino beam direction is measured with accuracy better than 0.4mrad from the measured profile center. The normalized event rate is measured with 4% precision.
The continuing threat to biodiversity lends urgency to the need of identification of sustainable source of natural products. This is not so much trouble if there is a microbial source of the ...compound. Herein, violacein, a natural indolic pigment extracted from
Chromobacterium violaceum, was evaluated for its antitumoral potential against the Ehrlich ascites tumor (EAT)
in vivo and
in vitro. Evaluation of violacein cytotoxicity using different endpoints indicated that EAT cells were twofold (IC
50
=
5.0
μM) more sensitive to the compound than normal human peripheral blood lymphocytes.
In vitro studies indicated that violacein cytotoxicity to EAT cells is mediated by a rapid (8–12
h) production of reactive oxygen species (ROS) and a decrease in intracellular GSH levels, probably due to oxidative stress. Additionally, apoptosis was primarily induced, as demonstrated by an increase in Annexin-V positive cells, concurrently with increased levels of DNA fragmentation and increased caspase-2, caspase-9 and caspase-3 activities up to 4.5-, 6.0- and 5.5-fold, respectively, after 72
h of treatment. Moreover, doses of 0.1 and 1.0
μg
kg
−1 violacein, administered intraperitoneally (i.p.) to EAT-bearing mice throughout the lifespan of the animals significantly inhibited tumor growth and increased survival of mice. In view of these results, a 35-day toxicity study was conducted
in vivo. Complete hematology, biochemistry (ALT, AST and creatinine levels) and histopathological analysis of liver and kidney indicated that daily doses of violacein up to 1000
μg
kg
−1 for 35 days are well tolerated and did not cause hematotoxicity nor renal or hepatotoxicity when administered i.p. to mice. Altogether, these results indicate that violacein causes oxidative stress and an imbalance in the antioxidant defense machinery of cells culminating in apoptotic cell death. Furthermore, this is the first report of its antitumor activity
in vivo, which occurs in the absence of toxicity to major organs.
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