Background
The presence of a mediastinal hyperfunctioning parathyroid gland is a rare condition that occurs in about 1% to 2% of cases. We present our experience with video-endoscopic ...parathyroidectomy and a review of the literature.
Methods
In seven patients (four male, three female; age 28–67 years) mediastinal hyperfunctioning parathyroid glands were removed by the thoracoscopic route (VATS). Six patients suffered from primary hyperpathyroidism and one woman from recurrent secondary hyperparathyroidism. Additionally, articles concerning endoscopic treatment of mediastinal parathyroid glands were collected from the medical databases. A total of 58 patients were found in the English and French literature.
Results
Neither intraoperative nor postoperative complications occurred in our patients. Operating time was 90 minutes (range 40–180 minutes). After a mean follow-up of 29 ± 12 months (range 3–64), all patients are biochemically cured. The cases in the literature showed healing in 57 of 58 cases. Their mean operating time was 112 minutes (range 40–240 minutes). One perioperative death due to myocardial infarction and a major complications rate of 7% are described.
Conclusion
The thoracoscopic approach to mediastinal parathyroidectomy is a safe, feasible technique with a low complication rate and good cosmetic outcome. It should become the standard surgical access for mediastinal hyperfunctioning parathyroid glands.
We report constraints on light dark matter (DM) models using ionization signals in the XENON1T experiment. We mitigate backgrounds with strong event selections, rather than requiring a scintillation ...signal, leaving an effective exposure of (22±3) tonne day. Above ∼0.4 keV_{ee}, we observe <1 event/(tonne day keV_{ee}), which is more than 1000 times lower than in similar searches with other detectors. Despite observing a higher rate at lower energies, no DM or CEvNS detection may be claimed because we cannot model all of our backgrounds. We thus exclude new regions in the parameter spaces for DM-nucleus scattering for DM masses m_{χ} within 3-6 GeV/c^{2}, DM-electron scattering for m_{χ}>30 MeV/c^{2}, and absorption of dark photons and axionlike particles for m_{χ} within 0.186-1 keV/c^{2}.
We report the first experimental results on spin-dependent elastic weakly interacting massive particle (WIMP) nucleon scattering from the XENON1T dark matter search experiment. The analysis uses the ...full ton year exposure of XENON1T to constrain the spin-dependent proton-only and neutron-only cases. No significant signal excess is observed, and a profile likelihood ratio analysis is used to set exclusion limits on the WIMP-nucleon interactions. This includes the most stringent constraint to date on the WIMP-neutron cross section, with a minimum of 6.3×10^{-42} cm^{2} at 30 GeV/c^{2} and 90% confidence level. The results are compared with those from collider searches and used to exclude new parameter space in an isoscalar theory with an axial-vector mediator.
The ATLAS Hadronic Tau Trigger Mahlstedt, Joern
Journal of physics. Conference series,
01/2014, Volume:
513, Issue:
1
Journal Article
Peer reviewed
Open access
During the 2012 run, the Large Hadron Collider (LHC) reached instantaneous luminosities of nearly 1034 cm−2s−1 with bunch crossings occuring every 50 ns. In this difficult environment of several ...overlapping interactions per bunch crossing (pile-up), the trigger system of the ATLAS detector has the task of reducing the event rate from 20 MHz to a few hundred Hz while keeping the most interesting physics events. Being the heaviest of all leptons, the tau lepton plays an important role in many physics processes. The ability to trigger on events containing hadronically decaying taus is therefore of special interest. This paper summarizes the concept of the ATLAS tau trigger and the improvements made in 2012. Furthermore the performance of the triggers including efficiency and rate measurements are presented and an outlook towards future developments of the tau trigger algorithms is given.
Geant4 simulation of the ABALONE photosensor Pieramico, G.; Biondi, R.; D'andrea, V. ...
Il nuovo cimento della Società italiana di fisica. Sezione C, Geophysics and space physics,
2022, Volume:
45, Issue:
1
Journal Article
Peer reviewed
The ABALONE is a new type of photosensor produced by PhotonLab, Inc. with cost effective mass production, robustness and high performance. This modern technology provides sensitivity to visible and ...UV light, exceptional radio-purity and excellent detection performance in terms of intrinsic gain, afterpulsing rate, timing resolution and single-photon sensitivity. The ABALONE is based on the acceleration of photoelectrons in vacuum. These are generated in a traditional photocathode and guided towards a window of scintillating material. The resulting scintillation light can be read from the outside via a silicon photomultiplier (SiPM). The device has been proposed as a possible candidate for the DARWIN experiment. We performed the complete simulation of the detector, mapped the electrostatic field within the vacuum of the sensor and studied its possible optimization.
We developed a detector signal characterization model based on a Bayesian network trained on the waveform attributes generated by a dual-phase xenon time projection chamber. By performing inference ...on the model, we produced a quantitative metric of signal characterization and demonstrate that this metric can be used to determine whether a detector signal is sourced from a scintillation or an ionization process. We describe the method and its performance on electronic-recoil (ER) data taken during the first science run of the XENONnT dark matter experiment. We demonstrate the first use of a Bayesian network in a waveform -based analysis of detector signals. This method resulted in a 3% increase in ER event-selection efficiency with a simultaneously effective rejection of events outside of the region of interest. The findings of this analysis are consistent with the previous analysis from XENONnT, namely a background-only fit of the ER data.
We perform a blind search for particle signals in the XENON1T dark matter detector that occur close in time to gravitational-wave signals in the LIGO and Virgo observatories. No particle signal is ...observed in the nuclear recoil and electronic recoil channels within ±500 seconds of observations of the gravitational-wave signals GW170104, GW170729, GW170817, GW170818, and GW170823. We use this null result to constrain monoenergetic neutrinos and axion-like particles emitted in the closest coalescence GW170817, a binary neutron star merger. We set new upper limits on the fluence (time-integrated flux) of coincident neutrinos down to 17 keV at the 90% confidence level. Furthermore, we constrain the product of the coincident fluence and cross section of axion-like particles to be less than 10 −29 cm 2 /cm 2 in the 5.5–210 keV energy range at the 90% confidence level.
A low-energy electronic recoil calibration of XENON1T, a dual-phase xenon time projection chamber, with an internal
37
Ar source was performed. This calibration source features a 35-day half-life and ...provides two mono-energetic lines at 2.82 keV and 0.27 keV. The photon yield and electron yield at 2.82 keV are measured to be (
32.3
±
0.3
) photons/keV and (
40.6
±
0.5
) electrons/keV, respectively, in agreement with other measurements and with NEST predictions. The electron yield at 0.27 keV is also measured and it is (
68
.
0
-
3.7
+
6.3
) electrons/keV. The
37
Ar calibration confirms that the detector is well-understood in the energy region close to the detection threshold, with the 2.82 keV line reconstructed at (
2.83
±
0.02
) keV, which further validates the model used to interpret the low-energy electronic recoil excess previously reported by XENON1T. The ability to efficiently remove argon with cryogenic distillation after the calibration proves that
37
Ar can be considered as a regular calibration source for multi-tonne xenon detectors.
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