Monitoring techniques and alarm procedures for CMS Services and Sites in WLCG

The CMS offline computing system is composed of roughly 80 sites (including most experienced T3s) and a number of central services to distribute, process and analyze data worldwide. A high level of stability and reliability is required from the underlying infrastructure and services, partially covered by local or automated monitoring and alarming systems such as Lemon and SLS; the former collects metrics from sensors installed on computing nodes and triggers alarms when values are out of range, the latter measures the quality of service and warns managers when service is affected. CMS has established computing shift procedures with personnel operating worldwide from remote Computing Centers, under the supervision of the Computing Run Coordinator at CERN. This dedicated 24/7 computing shift personnel is contributing to detect and react timely on any unexpected error and hence ensure that CMS workflows are carried out efficiently and in a sustained manner. Synergy among all the involved actors is exploited to ensure the 24/7 monitoring, alarming and troubleshooting of the CMS computing sites and services. We review the deployment of the monitoring and alarming procedures, and report on the experience gained throughout the first two years of LHC operation. We describe the efficiency of the communication tools employed, the coherent monitoring framework, the proactive alarming systems and the proficient troubleshooting procedures that helped the CMS Computing facilities and infrastructure to operate at high reliability levels

CMS Distributed Computing Integration in the LHC sustained operations era

After many years of preparation the CMS computing system has reached a situation where stability in operations limits the possibility to introduce innovative features. Nevertheless it is the same need of stability and smooth operations that requires the introduction of features that were considered not strategic in the previous phases. Examples are: adequate authorization to control and prioritize the access to storage and computing resources; improved monitoring to investigate problems and identify bottlenecks on the infrastructure; increased automation to reduce the manpower needed for operations; effective process to deploy in production new releases of the software tools. We present the work of the CMS Distributed Computing Integration Activity that is responsible for providing a liaison between the CMS distributed computing infrastructure and the software providers, both internal and external to CMS. In particular we describe the introduction of new middleware features during the last 18 months as well as the requirements to Grid and Cloud software developers for the future

HEP Applications Experience with the European DataGrid Middleware and Testbed

Workpackage 8 of the European Datagrid project was formed in January 2001 with representatives from the four LHC experiments, and with experiment independent people from five of the six main EDG partners. In September 2002 WP8 was strengthened by the addition of effort from BaBar and D0. The original mandate of WP8 was, following the definition of short- and long-term requirements, to port experiment software to the EDG middleware and testbed environment. A major additional activity has been testing the basic functionality and performance of this environment. This paper reviews experiences and evaluations in the areas of job submission, data management, mass storage handling, information systems and monitoring. It also comments on the problems of remote debugging, the portability of code, and scaling problems with increasing numbers of jobs, sites and nodes. Reference is made to the pioneeering work of Atlas and CMS in integrating the use of the EDG Testbed into their data challenges. A forward look is made to essential software developments within EDG and to the necessary cooperation between EDG and LCG for the LCG prototype due in mid 2003

Formant frequency values for vowel stimuli.

<p>Formant frequency values for vowel stimuli.</p

Electroweak measurements in electron–positron collisions at w-boson-pair energies at lep

Contains fulltext : 121524.pdf (preprint version ) (Open Access

Determination of sin2 \u3b8 w eff using jet charge measurements in hadronic Z decays

The electroweak mixing angle is determined with high precision from measurements of the mean difference between forward and backward hemisphere charges in hadronic decays of the Z. A data sample of 2.5 million hadronic Z decays recorded over the period 1990 to 1994 in the ALEPH detector at LEP is used. The mean charge separation between event hemispheres containing the original quark and antiquark is measured forbbar b andcbar c events in subsamples selected by their long lifetimes or using fast D*\u2019s. The corresponding average charge separation for light quarks is measured in an inclusive sample from the anticorrelation between charges of opposite hemispheres and agrees with predictions of hadronisation models with a precision of 2%. It is shown that differences between light quark charge separations and the measured average can be determined using hadronisation models, with systematic uncertainties constrained by measurements of inclusive production of kaons, protons and \u39b\u2019s. The separations are used to measure the electroweak mixing angle precisely as sin2 \u3d1 {w/eff}=0.2322\ub10.0008(exp.stat.) \ub10.0007(exp.syst.)\ub10.0008(sep.). The first two errors are due to purely experimental sources whereas the third stems from uncertainties in the quark charge separations

Three-prong \u3c4 decays with charged kaons

Final states with charged kaons in three-prong \u3c4 decays are studied by exploiting the particle identification from the dE/dx measurement. The results are based on a sample of about 1.6 7 105 detected \u3c4 pairs collected with the ALEPH detector between 1991 and 1995 around the Z peak. The following branching ratios have been measured: B(\u3c4- \u2192 K 12K+\u3c0 12\u3bd\u3c4) = (1.63 \ub1 0.21 \ub1 0.17) 7 10 123, B(\u3c4 12 \u2192 K 12\u3c0+\u3c0 12\u3bd\u3c4) = (2.14 \ub1 0.37 \ub1 0.29) 7 10 123, B(\u3c4 12 \u2192 K 12K+\u3c0 12\u3c00\u3bd\u3c4) = (0.75 \ub1 0.29 \ub1 0.15) 7 10 123, and B(\u3c4 12 \u2192 K 12\u3c0+\u3c0 12\u3c00\u3bd\u3c4) = (0.61 \ub1 0.39 \ub1 0.18) 7 10 123. The first two measurements are more precise than the current world averages, while the last two channels are investigated for the first time. The 95% C.L. upper limit on the branching ratio for the decay \u3c4 12 \u2192 K 12K+K 12\u3bd\u3c4 is 0.19 7 10 123. A study of intermediate states occurring in the K 12K+\u3c0 12\u3bd\u3c4 and K 12\u3c0+\u3c0 12\u3bd\u3c4 decays is also presented

Charm counting in b decays

The inclusive production of charmed particles in decays has been measured from the yield of D0, D+, Ds+ and Λc+ decays in a sample of events with high b purity collected with the ALEPH detector from 1992 to 1995. From these measurements, adding the charmonia production rate and an estimate of the charmed strange baryon contribution, the average number of charm quarks per b decay is determined to be nc = 1.230 ± 0.036 ± 0.038 ± 0.053, where the uncertainties are due to statistics, systematic effects and branching ratios, respectively

Measurement of Λ polarization from Z decays

The polarization of Λ baryons from Z decays is studied with the Aleph apparatus. Evidence of longitudinal polarization of s quarks from Z decay is observed for the first time. The measured longitudinal Λ polarization is PLΛ = −0.32 ± 0.07 for . This agrees with the prediction of −0.39 ± 0.08 from the standard model and the constituent quark model, where the error is due to uncertainties in the mechanism for Λ production. The observed Λ polarization is diluted with respect to the primary s quark polarization by Λ baryons without a primary s quark. Measurements of the Λ forward-backward asymmetry and of the correlation between back-to-back Λ pairs are used to check this dilution. In addition the transverse Λ polarization is measured. An indication of transverse polarization, more than two standard deviations away from zero, is found along the normal to the plane defined by the thrust axis and the Λ direction