On b- and tau-multiplicities per event in SUSY (mSUGRA) and instrumental implications

We investigate the probability to find a b or tau in SUSY production with the mSUGRA model. We find that in the entire parameter space the probability per event to find a b-jet of E_T^b > 50 GeV within CMS acceptance (eta < 2.4) is significant for all tan(beta), varying from a 10 % level to 90 % depending on the m_0, m_1/2 region. The probabilities per event to find a tau with the same kinematical cuts is also significant and it increases sharply with tan(beta). These findings point to the central role a microvertex device would play in case that SUSY (mSUGRA) is indeed realized in nature and found at the LHC. First investigations done in the context of the more general MSSM scenario confirm the findings based on mSUGRA.Comment: 19 pages, 13 figures, 3 table

The CMS detector and physics at the LHC

We discuss the physics issues at the LHC, the CMS detector, one of the two general purpose detectors planned at the LHC, and the expected physics performance of LHC detectors in the search for SM and SUSY Higgs bosons, some SUSY particle searches and some possibilities in B and heavy ion physics

Proučavanje H → ZZ → 4ℓ ± pomoću cjelovite geant simulacije detektora CMS

We study the detection of H → ZZ → 4ℓ ± in the CMS detector at the nominal LHC energy √ s = 14 TeV and the possibility for an early detection at a reduced energy √ s = 10 TeV. A systematic study of the multi–lepton mass resolution is performed, including effects of internal and external radiation through detailed GEANT simulations. At √ s = 14 TeV, an integrated luminosity of 104 pb−1 allows exploration at a ≥ 5σ significance level a mass range from mH ≈ 2mZ up to mH ≈ 400 GeV. For 105 pb−1 , the mass reach is about 650 GeV. At √ s = 10 TeV, an integrated luminosity of 104 pb−1 does not provide a 5σ significance level for any value of Higgs mass, and 2 × 104 pb−1 alows one to explore a mass range from mH ≈ 2mZ to ≈ 350 GeV at ≥ 5σ level.Proučava se detekcija H → ZZ → 4ℓ ± procesa u detektoru CMS na nominalnoj energiji LHC √ s = 14 TeV i mogućnost ranijeg opažanja na manjoj energiji od 10 TeV. Studija uključuje instrumentalne efekte za elektrone i muone i njihov utjecaj na razlučivanje višeleptonskih masa

Eksperiment CMS na LHC-u

We discuss the current status of the Large Hadron Collider (LHC) machine, the progress on the construction of the CMS detector and some expectations for physics studies and searches at the LHC.Opisujemo sadašnje stanje gradnje ubrzivača LHC, napredak u gradnji detektora CMS i neka očekivanja fizičkih istraživanja i traganja na LHC-

Report of experience in the use of palate prosthesis

La disfunción velofaríngea (DVF) es el resultado de un inadecuado funcionamiento de estructuras dinámicas que trabajan para controlar el mecanismo velofaringeo, (paladar blando, las paredes laterales y pared posterior de faringe) que separa las cavidades nasal y oral durante el habla. La DVF, causada por falta de tejidos se denomina insuficiencia velofaríngea (IVF), y es un factor generador de problemas en el habla por defecto estruc-tural, que requiere tratamiento de manejo físico pudiendo ser este abordado desde la reparación quirúrgica o con prótesis de paladar1, 2.La corrección de la IVF debe ser realizada por un equipo interdisciplinario3. Método: se confeccionaron las correspondientes prótesis de paladar en cuatro pacientes adolescente/adultos seleccionados, sin posibilidades de reparación quirúrgica del esfínter velofaríngeo. Se realizó seguimiento, control y terapia. Se analizaron los resultados obtenidos. Conclusiones: Los resultados positivos solo fueron observados claramente en los pacientes que realizaron su tratamiento fonoaudiológico específico luego de la colocación de su prótesis de paladar obturadora con bulbo.Velopharyngeal dysfunction (DVF) is the result of an inadequate functioning of dynamic structures who work to control the velopharyngeal mechanism (soft palate, lateral walls and posterior pharyngeal wall) that separates the nasal and oral cavities during speech. FVD, caused by lack of tissues, is called velopharyngeal insufficiency (IVF), and it is a factor that generates problems in speech due to a structural defect, which requires physical manage ment treatment, which can be approached from surgical repair or with palatal prosthesis1,2. The correction of the IVF must be carried out by an interdisciplinary team3. Method: the corresponding palate prostheses were made in four selected adolescent / adult patients, without the possibility of surgical repair of the velopharyngeal sphincter. Follow-up, control and therapy were carried out. The results obtained were analyzed. Conclusions: The positive results were only clearly observed in the patients who underwent their specific speech therapy treatment after the placement of their bulbous obturator palate prosthesis.Fil: Fernández Salto, María Laura . Universidad Nacional de Cuyo. Facultad de OdontologíaFil: Denegri, María Alicia. Universidad Nacional de Cuyo. Facultad de OdontologíaFil: Monllor, María Laura. Mendoza. Ministerio de SaludFil: González Marotta, Alejandra. Mendoza. Ministerio de SaludFil: Díaz, Daniel. Universidad Nacional de Cuyo. Facultad de OdontologíaFil: Aferri, Homero Carneiro. Universidade de São Paulo (Brasil)Fil: Dutka, Jeniffer de Cássia Rillo. Universidade de São Paulo (Brasil

Performance of the CMS Cathode Strip Chambers with Cosmic Rays

The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

Search for supersymmetry in events with b-quark jets and missing transverse energy in pp collisions at 7 TeV

Results are presented from a search for physics beyond the standard model based on events with large missing transverse energy, at least three jets, and at least one, two, or three b-quark jets. The study is performed using a sample of proton-proton collision data collected at sqrt(s) = 7 TeV with the CMS detector at the LHC in 2011. The integrated luminosity of the sample is 4.98 inverse femtobarns. The observed number of events is found to be consistent with the standard model expectation, which is evaluated using control samples in the data. The results are used to constrain cross sections for the production of supersymmetric particles decaying to b-quark-enriched final states in the context of simplified model spectra.Comment: Submitted to Physical Review

Performance and Operation of the CMS Electromagnetic Calorimeter

The operation and general performance of the CMS electromagnetic calorimeter using cosmic-ray muons are described. These muons were recorded after the closure of the CMS detector in late 2008. The calorimeter is made of lead tungstate crystals and the overall status of the 75848 channels corresponding to the barrel and endcap detectors is reported. The stability of crucial operational parameters, such as high voltage, temperature and electronic noise, is summarised and the performance of the light monitoring system is presented