The BRAHMS experiment at RHIC Adamczyk, M; Antvorskov, L; Ashktorab, K ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
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Journal Article
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The BRAHMS experiment at RHIC was conceived to pursue the understanding of nuclear matter under extreme conditions by detailed measurements of charged hadrons over the widest possible range of ...rapidity and transverse momentum. The experiment consists of two spectrometers with complementary charged hadron detection capabilities as well as a series of global detectors for event characterization. A series of tracking detectors, time-of-flight arms and Cherenkov detectors enables momentum determination and particle identification over a wide range of rapidity and transverse momentum. Technical details and performance results are presented for the various detector subsystems. The performance of the entire system working together is shown to meet the goals of the experiment.
Background. There are a few indications known in the world to administer immunotherapy (IT) via immune checkpoint inhibitors (ICIs). Prescribing IT by means of ICIs in gastric cancer (GC) results ...from PDL1 ligand expression on tumor cells; high tumor mutation burden; GC with microsatellite instability MSI-h or DNA mismatch repair (MMR) failure; T-killer immunoscore (IS).
Purpose. To study the composition of the immunocellular phenotype of gastric malignancies.
Materials and methods. The paper presents the outcomes of a clinical study conducted at the premises of Thoracic Tumors Research Department of National Cancer Institute and Abdominal Oncosurgery Department of Municipal Non-Profit Enterprise “Odessa Regional Oncology Dispensary” of Odessa Regional Council enrolling 221 patients operated on for gastric cancer within the period from 2007 to 2013. The average age was 60.88 ± 10.5, men – 180, women – 41. A total of 143 gastrectomies and 78 distal subtotal resections were performed. The study group of patients to investigate IS consisted of 22 patients with gastric cancer. At the first stage, the density of immunocompetent TILs or TIMs were determined, where TILs quantified tumor-infiltrating lymphocytes and TIMs counted the number of tumor-infiltrating macrophages. The second step was assessing the severity of infiltration by immune cells of two compartments: the central areas of the tumor (CT) and around the edge of the tumor invasion (IM), i. e. in the peritumoral stroma.
Results and discussion. All patients included in the study were radically operated on. The tumors removed during surgery were examined by means of immunoscore. A particularly high correlation was observed between PD-L1 expression in cells and CD8 T-lymphocytes in tumor nest – 0.81. Immunoscore effect on the prognosis was 0.64. A negative high correlation was assessed between the concentration of M2 CD163 macrophages in the tumor and the metastases to regional lymph nodes – 0.65. A particularly high correlation between the concentration of CD3 and CD8 in the central areas of the tumor reaching 0.95. A particularly high correlation between PD-L1 expression in cells and CD3 cells in tumor nest – 0.84. The correlation between CD3 and CD8 in the tumor stroma was particularly high, 0.87. Conclusions. The study of immunoscore is essential both in terms of the impact on patient survival, as a prognostic factor, and with a view to more active administering and using immune-targeted drugs in the future.
We summarize the state of the art of a program of UV observations from space of meteor phenomena, a secondary objective of the JEM-EUSO international collaboration. Our preliminary analysis indicates ...that JEM-EUSO, taking advantage of its large FOV and good sensitivity, should be able to detect meteors down to absolute magnitude close to 7. This means that JEM-EUSO should be able to record a statistically significant flux of meteors, including both sporadic ones, and events produced by different meteor streams. Being unaffected by adverse weather conditions, JEM-EUSO can also be a very important facility for the detection of bright meteors and fireballs, as these events can be detected even in conditions of very high sky background. In the case of bright events, moreover, exhibiting some persistence of the meteor train, preliminary simulations show that it should be possible to exploit the motion of the ISS itself and derive at least a rough 3D reconstruction of the meteor trajectory. Moreover, the observing strategy developed to detect meteors may also be applied to the detection of nuclearites, exotic particles whose existence has been suggested by some theoretical investigations. Nuclearites are expected to move at higher velocities than meteoroids, and to exhibit a wider range of possible trajectories, including particles moving upward after crossing the Earth. Some pilot studies, including the approved Mini-EUSO mission, a precursor of JEM-EUSO, are currently operational or in preparation. We are doing simulations to assess the performance of Mini-EUSO for meteor studies, while a few meteor events have been already detected using the ground-based facility EUSO-TA.
•Use of the International Space Station for the purpose of meteor observations.•Observations of meteors at UV wavelengths.•Possibility to detect nuclearites, possible components of dark matter.•Possibility to exploit the persistence of meteor trains to derive 3D trajectories.
A prototype of a luminometer, designed for a future
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collider detector, and consisting at present of a four-plane module, was tested in the CERN PS accelerator T9 beam. The objective of this ...beam test was to demonstrate a multi-plane tungsten/silicon operation, to study the development of the electromagnetic shower and to compare it with MC simulations. The Molière radius has been determined to be 24.0 ± 0.6 (stat.) ± 1.5 (syst.) mm using a parametrization of the shower shape. Very good agreement was found between data and a detailed Geant4 simulation.
MoEDAL is designed to identify new physics in the form of stable or pseudostable highly ionizing particles produced in high-energy Large Hadron Collider (LHC) collisions. Here we update our previous ...search for magnetic monopoles in Run 2 using the full trapping detector with almost four times more material and almost twice more integrated luminosity. For the first time at the LHC, the data were interpreted in terms of photon-fusion monopole direct production in addition to the Drell-Yan-like mechanism. The MoEDAL trapping detector, consisting of 794 kg of aluminum samples installed in the forward and lateral regions, was exposed to 4.0 fb −1 of 13 TeV proton-proton collisions at the LHCb interaction point and analyzed by searching for induced persistent currents after passage through a superconducting magnetometer. Magnetic charges equal to or above the Dirac charge are excluded in all samples. Monopole spins 0, ½ , and 1 are considered and both velocity-independent and-dependent couplings are assumed. This search provides the best current laboratory constraints for monopoles with magnetic charges ranging from two to five times the Dirac charge.
We present spectra of charged pions and protons in 0–10% central Au+Au collisions at sNN=200 GeV at mid-rapidity (y=0) and forward pseudorapidity (η=2.2) measured with the BRAHMS experiment at RHIC. ...The spectra are compared to spectra from p+p collisions at the same energy scaled by the number of binary collisions. The resulting nuclear modification factors for central Au+Au collisions at both y=0 and η=2.2 exhibit suppression for charged pions but not for (anti-) protons at intermediate pT. The p¯/π− ratios have been measured up to pT∼3 GeV/c at the two rapidities and the results indicate that a significant fraction of the charged hadrons produced at intermediate pT range are (anti-) protons at both mid-rapidity and η=2.2.
We present a measurement of π−/π+, K−/K+ and p¯/p from p+p collisions at s=200 GeV over the rapidity range 0<y<3.4. For pT<2.0 GeV/c we see no significant transverse momentum dependence of the ...ratios. All three ratios are independent of rapidity for y≲1.5 and then steadily decline from y∼1.5 to y∼3. The π−/π+ ratio is below unity for y>2.0. The p¯/p ratio is very similar for p+p and 20% central Au+Au collisions at all rapidities. In the fragmentation region the three ratios seem to be independent of beam energy when viewed from the rest frame of one of the protons. Theoretical models based on quark–diquark breaking mechanisms overestimate the p¯/p ratio up to y≲3. Including additional mechanisms for baryon number transport such as baryon junctions leads to a better description of the data.
Transverse momentum spectra of protons and anti-protons measured in the rapidity range 0<y<3.1 from 0–10% central Au+Au collisions at sNN=62.4 GeV are presented. The rapidity densities, dN/dy, of ...protons, anti-protons and net-protons (Np–Np¯) have been deduced from the spectra over a rapidity range wide enough to observe the expected maximum net-baryon density. From mid-rapidity to y=1 the net-proton yield is roughly constant (dN/dy∼10), but rises to dN/dy∼25 at 2.3<y<3.1. The mean rapidity loss is 2.01±0.14±0.12 units from beam rapidity. The measured rapidity distributions are compared to model predictions. Systematics of net-baryon distributions and rapidity loss vs. collision energy are discussed.
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