Charged kaon mass measurement using the Cherenkov effect Graf, N.; Lebedev, A.; Abrams, R.J. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
03/2010, Letnik:
615, Številka:
1
Journal Article
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Odprti dostop
The two most recent and precise measurements of the charged kaon mass use X-rays from kaonic atoms and report uncertainties of 14 and 22
ppm yet differ from each other by 122
ppm. We describe the ...possibility of an independent mass measurement using the measurement of Cherenkov light from a narrow-band beam of kaons, pions, and protons. This technique was demonstrated using data taken opportunistically by the Main Injector Particle Production experiment at Fermi National Accelerator Laboratory which recorded beams of protons, kaons, and pions ranging in momentum from
+
37
to
+
63
GeV
/
c
. The measured value is
491.3
±
1.7
MeV
/
c
2
, which is within
1.4
σ
of the world average. An improvement of two orders of magnitude in precision would make this technique useful for resolving the ambiguity in the X-ray data and may be achievable in a dedicated experiment.
A search for supersymmetry is presented based on events with large missing transverse energy, no isolated electron or muon, and at least three jets with one or more identified as a bottom-quark jet. ...A simultaneous examination is performed of the numbers of events in exclusive bins of the scalar sum of jet transverse momentum values, missing transverse energy, and bottom-quark jet multiplicity. The sample, corresponding to an integrated luminosity of 19.4 fb−1, consists of proton–proton collision data recorded at a center-of-mass energy of 8 TeV with the CMS detector at the LHC in 2012. The observed numbers of events are found to be consistent with the standard model expectation, which is evaluated with control samples in data. The results are interpreted in the context of two simplified supersymmetric scenarios in which gluino pair production is followed by the decay of each gluino to an undetected lightest supersymmetric particle and either a bottom or top quark–antiquark pair, characteristic of gluino mediated bottom- or top-squark production. Using the production cross section calculated to next-to-leading-order plus next-to-leading-logarithm accuracy, and in the limit of a massless lightest supersymmetric particle, we exclude gluinos with masses below 1170 GeV and 1020 GeV for the two scenarios, respectively.
Abstract The aim of this study was to compare histomorphometrically the new bone tissue obtained using two different distraction methods, and evaluate these two methods in terms of their advantages ...and disadvantages. In 36 New Zealand adult male rabbits, divided into two groups, a gradual distraction was performed using a device placed on the lateral surface of the mandibular corpus. In one group osteotomy was not performed and osteogenesis by periosteal distraction (OPD) only was used. In the other group, conventional distraction osteogenesis (DO) was performed. After a 7-day latent phase, the same distraction protocol was applied to both groups. Each group of rabbits was further divided into three sub-groups killed on the 15th, 30th and 60th days of the consolidation period, and histological analysis was performed. The mean extent of newly formed bone tissue was 14.4 mm2 in the OPD groups and 25.4 mm2 in the DO groups. When compared statistically, there were significant differences between all the DO and OPD sub-groups. The newly formed bone tissue obtained by OPD was rich in interstitial fatty tissue. These results indicate that bone tissue newly formed by OPD is not suitable for occlusal forces.
IceCube collaboration has published two papers on ultrahigh energy neutrinos observation, recently. They have used the data collected in two years in their first publication, which reveals ...observation of two PeV energy neutrino events. The second publication of the collaboration including more data has also confirmed main features of the former paper. In literature, various interpretations of the IceCube data have been proposed. In this study, it is shown that PeV energy neutrino events observed by the IceCube collaboration can be interpreted as resonance production of color octet neutrinos with masses in \(500-800\) GeV range.
Objective: The aim of the study was to evaluate the influence of dental and periodontal treatments to the course of oral ulcers in patients with Behcet’s disease (BD).
Methods: Fifty‐eight ...consecutive BD patients with oral ulcers were studied. Twenty‐nine patients were in the intervention group (F/M: 15/14, mean age: 39.6 ± 6.9 years) and 29 (F/M: 15/14, 39.4 ± 10.6 years) were followed with a conventional treatment approach. In addition to oral hygiene education, dental and periodontal treatments were carried out in the intervention group, whereas the control group was only given oral hygiene education. Patients were evaluated in the pre‐treatment observation period (1 month), treatment period (1 month) and 6 months after treatment.
Results: An increase in the number of new oral ulcers (4.1 ± 3.5) was observed within 2 days during the treatment compared with 3–30 days during treatment month (2.3 ± 1.2) (P = 0.002). However, 6 months after the treatment, the number of oral ulcers (1.9 ± 1.5) was significantly lower compared with the pre‐treatment observation (4.8 ± 3.2) (P = 0.000) and treatment periods (6.4 ± 2.3) in the intervention group (P = 0.05), whereas a similar oral ulcer presence was observed in the control group (2.8 ± 2.4, 3.7 ± 2.3 and 4.8 ± 4.3, respectively) (P > 0.05). Dental and periodontal indices were also better in the intervention group during the 6‐month follow‐up.
Conclusion: Our results suggest that, in BD patients, dental and periodontal therapies could be associated with a flare‐up of oral ulcers in the short term, but may decrease their number in longer follow‐up. They also lead to a better oral health.
Measurements are presented of the associated production of a W boson and a charm-quark jet (W + c) in pp collisions at a center-of-mass energy of 7 TeV. The analysis is conducted with a data sample ...corresponding to a total integrated luminosity of 5 inverse femtobarns, collected by the CMS detector at the LHC. W boson candidates are identified by their decay into a charged lepton (muon or electron) and a neutrino. The W + c measurements are performed for charm-quark jets in the kinematic region ptjet > 25 GeV, abs(eta) < 2.5, for two different thresholds for the transverse momentum of the lepton from the W-boson decay, and in the pseudorapidity range abs(etaell) < 2.1. Hadronic and inclusive semileptonic decays of charm hadrons are used to measure the following total cross sections: sigma(pp to W + c + X) times B(W to ell nu) = 107.7 +/- 3.3 (stat.) +/- 6.9 (syst.) pb (ptell > 25 GeV) and sigma(pp to W + c + X) times B(W to ell nu) = 84.1 +/- 2.0 (stat.) +/- 4.9 (syst.) pb (ptell > 35 GeV), and the cross section ratios sigma(pp to W+ + c + X)/sigma(pp to W- + c + X) = 0.954 +/- 0.025 (stat.) +/- 0.004 (syst.) (ptell > 25 GeV) and sigma(pp to W+ + c bar + X)/sigma(pp to W- + c + X) = 0.938 +/- 0.019 (stat.) +/- 0.006 (syst.) (ptell > 35 GeV). Cross sections and cross section ratios are also measured differentially with respect to the absolute value of the pseudorapidity of the lepton from the W-boson decay. These are the first measurements from the LHC directly sensitive to the strange quark and antiquark content of the proton. Results are compared with theoretical predictions and are consistent with the predictions based on global fits of parton distribution functions.
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