From noise to signal - a new approach to LHCb muon optimization

One has to exploit the LHCb muon detector at the lowest possible gas gain and operational voltage in order to minimize the charge accumulated during 10 years of the LHCb experiment keeping the aging effects as low as possible. The detector lifetime prolongation 1.5-2 times can be achieved following the optimization of the LHCb muon system proposed in this note. An optimization of the LHCb muon system assumes: minimization of the electronics thresholds and detector gas gain, a choice of the working point near the knee of the efficiency plateau at high enough efficiency at stabilization the signal-to-noise ratio during long-term data taking runs by gas gain stabilization. An efficiency of each chamber tuned once by a time alignment remains constant at the constant gas gain. Cluster size, cross-talks, multi-hits become constant and minimal at constant and minimal gas gain. It is shown in the note how to reconstruct the noise distribution in each chamber already installed in the pit and to measure precisely offset and the Equivalent Noise Charge ($ENC$) both of which specify the minimal electronics threshold. $ENC$ enlargement problem related to threshold increasing at high particle rates is discussed. $ENC$ monitoring for each physical channel of the system during the LHCb experiment is proposed in order to detect aging of the LHCb muon system at the earliest stage and make correction

Measurement of the absolute gas gain and gain variations study in straw-tube detectors

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A straw tube detector for the PANDA experiment

The PANDA experiment will be built at the FAIR facility in Darmstadt (Germany) to perform accurate tests of the strong interaction through pp and pA annihilations. This paper will address the design issue of the Straw Tube Tracker (STT), one of the two options proposed for the PANDA Central Tracker

Performance of the LHCb muon system with cosmic rays

The LHCb Muon system performance is presented using cosmic ray events collected in 2009. These events allowed to test and optimize the detector configuration before the LHC start. The space and time alignment and the measurement of chamber efficiency, time resolution and cluster size are described in detail. The results are in agreement with the expected detector performance.Comment: Submitted to JINST and accepte

Measurement of the front-end dead-time of the LHCb muon detector and evaluation of its contribution to the muon detection inefficiency

A method is described which allows to deduce the dead-time of the front-end electronics of the LHCb muon detector from a series of measurements performed at different luminosities at a bunch-crossing rate of 20 MHz. The measured values of the dead-time range from 70 ns to 100 ns. These results allow to estimate the performance of the muon detector at the future bunch-crossing rate of 40 MHz and at higher luminosity

Performance of the LHCb muon system

The performance of the LHCb Muon system and its stability across the full 2010 data taking with LHC running at ps = 7 TeV energy is studied. The optimization of the detector setting and the time calibration performed with the first collisions delivered by LHC is described. Particle rates, measured for the wide range of luminosities and beam operation conditions experienced during the run, are compared with the values expected from simulation. The space and time alignment of the detectors, chamber efficiency, time resolution and cluster size are evaluated. The detector performance is found to be as expected from specifications or better. Notably the overall efficiency is well above the design requirementsComment: JINST_015P_1112 201

ИНТЕЛЛЕКТУАЛЬНАЯ АВТОМАТИЗИРОВАННАЯ СИСТЕМА УПРАВЛЕНИЯ ПРОЦЕССОМ ПЛАВКИ ПВ-3 МЕДНОГО ЗАВОДА ЗФ ОАО «ГМК “НОРИЛЬСКИЙ НИКЕЛЬ”»

Peculiarity of Synthesized Smart Management Control System (SSMCS) PV-3 with regard to Vanyukov Process at copper production Zapolyarny branch of OJSC «Mining and Metallurgical Complex “Norilsk Nickel”» is use of universal description of complex multifactor model in the form of semantic network on specific restricted vocabulary. That is substantially decreased dimension of subject area without losses of semantic with retention of operability of all their elements. Application of tailor-made method of acquisition and formalization knowledge in analytical expression allows perform convolution of multivendor on its physical nature information into polynominal model exactly for given process, phenomenon or object. There was showed efficiency of application of SSMCS PV-3while execution concept of management on the base of «principle of settlement of conflicts» in industrial conditions.Особенностью синтезированной интеллектуальной автоматизированной системы управления (ИАСУ) ПВ-3 применительно к процессу Ванюкова на медном заводе Заполярного филиала ОАО «ГМК “Норильский никель”» является использование универсального описания сложной многофакторной модели в виде семантической сети на специфичном ограниченном словаре. Это существенно снижает размерность предметной области без потери семантики с сохранением функциональности всех ее элементов. Применение уникальной методики извлечения и формализации экспертных знаний в аналитическое выражение позволяет производить свертку разнородной по своей физической природе информации в полиномиальные модели именно для данного процесса, явления или объекта. Показана эффективность применения ИАСУ ПВ-3 при реализации концепции управления на основе «принципа разрешения конфликтов» в промышленных условиях

First observation of Bs -> D_{s2}^{*+} X mu nu decays

Using data collected with the LHCb detector in proton-proton collisions at a centre-of-mass energy of 7 TeV, the semileptonic decays Bs -> Ds+ X mu nu and Bs -> D0 K+ X mu nu are detected. Two structures are observed in the D0 K+ mass spectrum at masses consistent with the known D^+_{s1}(2536) and $D^{*+}_{s2}(2573) mesons. The measured branching fractions relative to the total Bs semileptonic rate are B(Bs -> D_{s2}^{*+} X mu nu)/B(Bs -> X mu nu)= (3.3\pm 1.0\pm 0.4)%, and B(Bs -> D_{s1}^+ X munu)/B(Bs -> X mu nu)= (5.4\pm 1.2\pm 0.5)%, where the first uncertainty is statistical and the second is systematic. This is the first observation of the D_{s2}^{*+} state in Bs decays; we also measure its mass and width.Comment: 8 pages 2 figures. Published in Physics Letters