U. Gasparini

We report on a study of inclusive particle production in pp-interactions at 400 GeV/c. The data are based on 472 K reconstructed events recorded in the NA 27 experiment using the LEBC-EHS facility at CERN. The production cross sections are determined of pseudo scalar (π±,0, η andK ±), scalar (f 0(975)), vector (ρ±,0(770), ω(783), ϕ(1020),K *0(892), and $$\bar K^{ * 0} $$ (892)), and tensorf 0 mesons, of protons and antiprotons, and theΔ ++,+,0(1232), and Λ(1520) baryon resonances in the forward hemisphere of the center of mass system, as well as longitudinal and transverse momentum distributions. The results are compared with predictions of the FRITIOF model and with other experimental data.

The inclusive cross sections for forward D meson production at s=26 GeV in π−p interactions have been measured to be: σ(π−p→D0/D0+X)xF>0 = (10.1±2.2)μb, σ(π−p→D±+X)xF>0 = (5.7±1.6)μb. The distribution in xF for all D and for xF>0 has the form dσ/dxF=107−37+39(1−xF)7.5−1.7+2.5+5.4−3.8+6.0(1−xF)0.7−0.71.0μ b, with evidence for leading D production. The pT2 distribution is exponential with slope parameter [−1.18−0.16+0.18](GeV/ c)−2. The data are compared with predictions from first-order quark/gluon fusion calculations.

A study of the properties of charm particles produced in 400 GeV/cpp interactions is reported. The experiment was performed using the high resolution hydrogen bubble chamber LEBC in association with the European Hybrid Spectrometer at the CERN SPS. Details of the experimental set-up and operational procedures are given and the methods to extract samples of charm decays are discussed. Results are presented on the intrinsic properties of charm particles (masses, lifetimes, decay modes and branching ratios), adding, whenever appropriate, the relevant information obtained in a similar study made with 360 GeV/cπ − p interactions. The hadroproduction properties of charm states (total and differential cross sections, correlations) are presented and discussed in the context of current QCD inspired phenomenology.

We have measured the inclusive production properties of D and D messons produced from pp interactions at s=27.4 GeV. The differential production cross section is well represented by the empirical form d2σdxFdP2T=12[σ (D/D)(n+1)b](1−|xF|)n exp(−bp2T) with n=4.9 ± 0.5, b=(1.0±0.1)(GeV/c)−2, and the inclusive D/D cross section σ(D/D) is (30.2±3.3) ωb. The QCD fusion model predicts D/D production which is in good agreement with our data except for the magnitude of the cross section which depends sensitively on the assumed mass of the charm quark.

A study of the properties of charm particles produced in 360 GeV/c π- p interactions is reported. The experiment was performed using the high resolution hydrogen bubble chamber LEBC in association with the European Hybrid Spectrometer at the CERN SPS. Details of the exposure and operation of the spectrometer are given and the methods used to extract the charm data are presented. The essential physics results on the decay properties (lifetime, branching ratios) as well as on the hadroproduction properties (cross sections forD, $$\bar D$$ ,F, Λ c ,D, correlations between charm particles) are given.

A determination of branching ratios for D meson decays into all charged particle final states is reported. The values obtained: (D± → K∓π±π±/all D±) = (14 ± 6)% and (D0/D0 → K±π∓π+π−/all D0/D0) = (10 ± 4)%, are higher than those currently accepted. This result, if confirmed, implies a corresponding reduction in the accepted values for some total cross section measurements. Revised inclusive cross sections for D meson production in the forward hemisphere in π−p and pp interactions at 360 GeV/c, are presented.

Results are presented on charm meson lifetimes. The sample of charm particle decays was obtained by exposing the high resolution rapid cycling hydrogen bubble chamber (LEBC) coupled with the European Hybrid Spectrometer to π− and p beams at 360 GeV/c ffrom the CERN SPS. The analysis of ∼850 k pictures has yielded 77 events containing a total of 60 charm decays. From these, an unbiased sample of 31 D decays (15± and 16 D0) is issued in the lifetime analysis. The measured mean lifetimes for D± and D0 are (where the symbol D0 means D0 and D0):τ(D±)=8.4+3.5−2.2 × 10−13sτ(D0)=4.1+1.3−0.9 ×10−13s. Three unambiguous examples of F± decay have also been observed and the corresponding lifetime, based on 2 decays, is τ(F±)=2.1 +3.6−0.8 × 10 −13s

Charm D-meson production in 360 GeV π−p interactions has been studied using the high-resolution hydrogen bubble chamber LEBC and the European Hybrid Spectrometer. The data show evidence for leading quark effects both in the number of D-meson types and in the Feynman x distributions. The production cross section is of the form d2δdxdpT2∞(1-x)nexp(-apT2) with n = 2.8±0.8 and a = 1.1±0.3 (GeV/c)−2. The x distribution is, however, compatible with the presence of both central (n = 6) and leading (n = 1) D/Dproduction. The fraction of D-messons in the leading component is estimated to be ≈30%. The rapidity gap between members of reconstructed charm pairs is small compared to the available rapidity range. The inclusive cross section for single D-messons in the forward direction is: δ(D/D)=(408+15)μb (forx>0).

The Compact Muon Solenoid (CMS) experiment prepares its Phase-2 upgrade for the high-luminosity era of the LHC operation (HL-LHC). Due to the increase of occupancy, trigger latency and rates, the full electronics of the CMS Drift Tube (DT) chambers will need to be replaced. In the new design, the time bin for the digitization of the chamber signals will be of around 1 ns, and the totality of the signals will be forwarded asynchronously to the service cavern at full resolution. The new backend system will be in charge of building the trigger primitives of each chamber. These trigger primitives contain the information at chamber level about the muon candidates position, direction, and collision time, and are used as input in the L1 CMS trigger. The added functionalities will improve the robustness of the system against ageing. An algorithm based on analytical solutions for reconstructing the DT trigger primitives, called Analytical Method, has been implemented both as a software C++ emulator and in firmware. Its performance has been estimated using the software emulator with simulated and real data samples, and through hardware implementation tests. Measured efficiencies are 96 to 98% for all qualities and time and spatial resolutions are close to the ultimate performance of the DT chambers. A prototype chain of the HL-LHC electronics using the Analytical Method for trigger primitive generation has been installed during Long Shutdown 2 of the LHC and operated in CMS cosmic data taking campaigns in 2020 and 2021. Results from this validation step, the so-called Slice Test, are presented.

The final version of the European hybrid spectrometer (EHS) is described. EHS was used in the NA27 experiment to study charm particles produced in 360 GeV c π-p and 400 GeV c pp interactions. A rapid cycling, high resolution bubble chamber (LEBC) produced bubbles of 17 μm diameter which were measured with a precision of 2.5 μm. Short-lived charm particles are observed with an efficiency up to 90% (D±). The spectrometer accepts 70% of all particles produced, including approximately 100% of those in the forward hemisphere and the momenta of charged particles are measured to better than 1% over the whole momentum range. The charged particle identification detectors give information on 84% of the spectrometer tracks, half of which obtain unique identification. Two lead glass detectors measure the energy of electromagnetic showers such that the π0 mass distribution has a fwhm of 20 MeV c2. Hadronic showers are measured with two iron/scintillator calorimeters. The mass resolutions are 3.0, 0.9 and 11 MeV c2 for K0, Λ0 and D- charged particles respectively. The D0 mass is measured to be (1865.1 ± 1.8 ± 0.8) MeV c2. © 1987.

Charm-charm correlation properties are studied in detail for the first time using a sample of DD pairs produced in 360 GeV/c π−p interactions. The data are compared with various models of charm production.

Based on a sample of 22 four-prong D0/D0 decays produced in hydrogen by 360 GeV/c π−, we present the following new results: mean lifetime τ = (3.5−0.9+1.4) x 10−13s; production cross section for xF > 0.0, σ = (10.3 ± 3.5) ωb; the D → K±π±π+π− branching ratio = (7.1 ± 2.5)%.

The 40 MHz bunched muon beam set up at CERN was used in May 2003 to make a full test of the drift tubes local muon trigger. The main goal of the test was to prove that the integration of the various devices located on a muon chamber was adequately done both on the hardware and software side of the system. Furthermore the test provided complete information about the general performance of the trigger algorithms in terms of efficiency and noise. Data were collected with the default configuration of the trigger devices and with several alternative configurations at various angles of incidence of the beam. Tests on noise suppression and di-muon trigger capability were performed.

Charm data from 360 GeV/c π− p interactions are used to give results on D-meson branching ratios. The analysis is based on 114 charm events containing 183 observed charm particle decays. We present topological branching ratios and decay multiplicities, as well as the following inclusive branching ratios of D-mesons: B(D± → K∓ + anything) = 0.16−0.07 +0.08, if B(D0 → K ± + anything) = 0.44−0.10+0.11, ifB(D± → e± + 2,4 (rmcharged hadrons) = 0.07−0.05++0.08, B(D0 → e ± + anything) = 0.17−0.06+0.08.

Results of fitting the differential distributions in xF and pT2 of D mesons produced in 400 GeV/c p-p interactions to the form d2σdxFdpT2∝(1−xF)nexp[−(pT2/〈pT2〉)] are discussed. The D+ distribution is found to be relatively hard [n=3.1±0.8〈Pt2〉=1.32±0.27 (GeV/c)2] and the D̄0 distribution relatively soft [n=8.1±1.9,〈pT2〉=0.62±0.14 (GeV/c)2] compared to the average for all D's [n=4.9±0.5,〈pT2〉=0.99±0.10 (GeV/c)2]. It is suggested that these distributions could reflect contribution of leading di-quarks in pp collisions. Comparison is made with evidence for leading quarks in charm production in 360 GeV/cπ−p interactions.

The inclusive production of vector mesons (charged ρ(770), ω(783), ϕ(1020) and neutralK *(892)) in π− p interactions at 360 GeV/c is studied. The data are based on 160 000 reconstructed events recorded in the NA 27 Experiment using the LEBC-EHS facility at CERN. The production cross sections in the forward hemisphere in c.m.s. and the longitudinal momentum distributions are determined. The results are compared with data obtained at lower energies.

A prototype of the CMS Barrel Muon Detector incorporating all the features of the final chambers was built using the mass production assembly procedures and tools. The performance of this prototype was studied in a muon test beam at CERN and the results obtained are presented in this paper.

We present the measurements of the Λc production cross section in proton-proton interactions at s=27.4 GeV and give new limits on the exclusive branching ratio Λc→pK+π−.

We present the performance of the DELPHI lead glass calorimeter with vacuum phototriode readout. The behaviour of the counters in magnetic fields up to 1.1 T is discussed. Experimental results, obtained with an electron beam from 7 to 50 GeV/c, on noise, linearity, energy and position resolution are presented.

We report on the Λc properties observed with the LEBC-EHS set-up at CERN SPS with 360 GeVc π− and 400 GeVc p beams. The lifetime is (1.2−0.3+0.5)×10−13 s and the mass (2284.7 ± 2.3 ± 0.5)MeVc2.

In October 2001 the first produced CMS Barrel Drift Tube (DT) Muon Chamber was tested at the CERN Gamma Irradiation Facility (GIF) using a muon beam. A Resistive Plate Chamber (RPC) was attached to the top of the DT chamber, and, for the first time, both detectors were operated coupled together. The performance of the DT chamber was studied for several operating conditions, and for gamma rates similar to the ones expected at LHC. In this paper we present the data analysis; the results are considered fully satisfactory.

Bose-Einstein correlations among identically charged pions produced inpp collisions at 400 GeV/c are studied using the EHS spectrometer. Empoying the Kopylov-Podgoretskii parametrization, the average size of the emitting regionr k and its lifetime τ for pion production were determined to ber k=1.71±0.04 fm andcτ=0.89±0.05fm. The average sizer g in terms of the Lorentz invariant Goldhaber parametrization was determined to ber g=1.20±0.03fm. A decrease of the size with increasing momentum of the pions was observed. The size and the incoherence parameter of the pion emitting region were determined as a function of the charged particle multiplicity and the momentum of the pions. Identified charged kaons were used to study Bose-Einstein correlations among identically charged kaonsK ±K±. The average size of the emitting region for kaon production was determined to ber k=1.87±0.33fm in terms of the Kopylov-Podgoretskii parametrization. A study of the influence of a reference sample is presented.

The drift tube chambers developed for the muon barrel system of the CMS experiment at CERN are large area detectors with 8 measurement points in one direction and 4 in the other; each point has a resolution of about 200 mum. We are using two of such chambers for muon radiography, i.e. the detection and imaging of material with high atomic number Z through the measurement of the multiple scattering of cosmic- ray muons crossing the material itself. The chambers are self- triggered, using the trigger electronics developed for the CMS experiment. Such technique might be applied for example in cargo container inspection searching for high-Z materials. Our apparatus is composed by two chambers with a 7 m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> active area. In the gap between the chambers a container and the target material can be placed. Other two drift tube chambers, each with 4 measurement points, interleaved by a thick plane of Fe, give a rough determination of the cosmic muon momentum. We present results on the detection capability and performance of the system.

We present the final results on the D-meson liftime measurements obtained by the NA27 experiment. From a sample of 145 D0D0and149D± decays, we have measured τ(D0)=(4.6+0.6−0.5)×10−13 s, τ(D±)=(11.2+1.4−1.1)×10−13 s, with a ratio R=τ(D±)τ(D0)=2.4±0.4.

The first data on the production of D∗(2010) are presented as observed in π− -proton interactions at √s = 27 GeV. It is found that D∗(2010) dominates the total charm D-meson production, without a significant non-central component.

Two drift tubes (DTs) chambers of the CMS muon barrel system were exposed to a 40 MHz bunched muon beam at the CERN SPS, and for the first time the whole CMS Level-1 DTs-based trigger system chain was tested. Data at different energies and inclination angles of the incident muon beam were collected, as well as data with and without an iron absorber placed between the two chambers, to simulate the electromagnetic shower development in CMS. Special data-taking runs were dedicated to test for the first time the Track Finder system, which reconstructs track trigger candidates by performing a proper matching of the muon segments delivered by the two chambers. The present paper describes the results of these measurements.

The measurement of 12D 0 and 10D ± exclusive branching ratios are presented. The analysis is based on 608 spatially resolved charm particle decays produced in 360 GeV/c π− p and 400 GeV/cpp interactions.

Abstract A prototype calorimeter of lead glass bars read by one-stage vacuum photomultipliers (triodes) has been tested at CERN with electrons in the energy range 2–30 GeV. Different glass-triode combinations have been compared. An electronic amplification noise corresponding to about 30 MeV has been obtained. The space resolution has been measured to be 4.4 mm on average.

A comparative analysis of the global properties of 400 GeV/c proton-proton interactions with and without charm production is presented. Multiplicities, momentum distributions, sphericity and thrust of these interactions are compared.

The drift tubes based CMS barrel muon trigger, which uses self-triggering arrays of drift tubes, is able to perform the identification of the muon parent bunch crossing using a rather sophisticated algorithm. The identification is unique only if the trigger chain is correctly synchronized. Some beam test time was devoted to take data useful to investigate the synchronization of the trigger electronics with the machine clock. Possible alternatives were verified and the dependence on muon track properties was studied.

We present the results of a search for charm F mesons in 360 GeV/c π− p interactions. Several methods have been used; all yield no evidence for the F and are interpreted as 90% confidence level cross section upper limits.

The CMS drift tubes (DT) muon detector, built for withstanding the LHC expected integrated and instantaneous luminosities, will be used also in the High Luminosity LHC (HL-LHC) at a 5 times larger instantaneous luminosity and, consequently, much higher levels of radiation, reaching about 10 times the LHC integrated luminosity. Initial irradiation tests of a spare DT chamber at the CERN gamma irradiation facility (GIF++), at large (∼ O(100)) acceleration factor, showed ageing effects resulting in a degradation of the DT cell performance. However, full CMS simulations have shown almost no impact in the muon reconstruction efficiency over the full barrel acceptance and for the full integrated luminosity. A second spare DT chamber was moved inside the GIF++ bunker in October 2017. The chamber was being irradiated at lower acceleration factors, and only 2 out of the 12 layers of the chamber were switched at working voltage when the radioactive source was active, being the other layers in standby. In this way the other non-aged layers are used as reference and as a precise and unbiased telescope of muon tracks for the efficiency computation of the aged layers of the chamber, when set at working voltage for measurements. An integrated dose equivalent to two times the expected integrated luminosity of the HL-LHC run has been absorbed by this second spare DT chamber and the final impact on the muon reconstruction efficiency is under study. Direct inspection of some extracted aged anode wires presented a melted resistive deposition of materials. Investigation on the outgassing of cell materials and of the gas components used at the GIF++ are underway. Strategies to mitigate the ageing effects are also being developed. From the long irradiation measurements of the second spare DT chamber, the effects of radiation in the performance of the DTs expected during the HL-LHC run will be presented.

The drift chambers in the barrel region of the CMS detector are exposed to magnetic stray fields. To study the performance of the muon reconstruction and the drift time-based muon trigger, prototypes were tested under the expected magnetic field conditions at the H2 test facility at CERN. The results indicate that the overall chamber performance will not be affected. Only the bunch crossing identification capability in the small region near η=1.1, corresponding to the border of the solid angle region covered by the barrel, will be weakened.

As a part of a large experimental program aiming to produce high quality calibration data for the Forward ElectroMagnetic Calorimeter (FEMC) of the DELPHI detector at LEP, special runs were devoted to the study of the transverse profile of electromagnetic showers in lead glass. Results of this study are presented.

Theπ 0 andη 0 production is studied inπ − p interactions at 360 GeV/c. The cross section forπ 0 production in the forward hemisphere (X>0) isσ(π 0)=(49.7 ± 1.0 ± 1.1) mb and for η withX>0.1,N ch>2,σ(η 0)=(3.1 ± 0.5) mb. The ratio of theπ 0 toη 0 cross section forX>0.1,N ch>2 isσ(π 0)/σ(η 0). Results on FeynmanX andp T distributions are presented. The data were obtained using the European Hybrid Spectrometer EHS and the bubble chamber LEBC at CERN.

We report on a study ofρ 0 andf 2 inclusive production in π−−p interactions at 360 GeV/c, using the LEBC-EHS set-up at CERN and reconstructing about 165000 events. Theρ 0,f 2 andρ 3 0 cross sections are determined forx F >0,x F >0.4 andx F >0.6 respectively and theρ 0 andf 2 Feynman-x distributions and transverse momentum distributions are presented.

Abstract A study of the length distribution of charged secondary interactions gives no evidence for the existence of charged anomalons in the products of the interactions of 360 GeV/ c π − and protons in hydrogen. Fits to the data yield 95% confidence level upper limits for anomalon production as a function of anomalon mean free path.

Production of the muon barrel drift chambers called MB3 for the CMS experiment at the LHC has started at Legnaro INFN Labs in 2001. The detectors are fully equipped with the final front-end electronics and high-voltage boards, and test pulse and low-voltage systems. Before being moved to CERN, all chambers are tested and validated. After good noise level and proper high voltage behavior have been ensured, we collect cosmic-ray events triggered by an external scintillator system. We use those data to infer the main parameters of the chambers, namely, detection efficienc y, uniformity in behavior, timing properties (resolution, uniformity, dependence on track angle), and possible shifts of the wires and layers inside the superlayers. The method is particularly efficient in finding pathologies caused by trivial mistakes like, for example, an unconnected electrode, which can be quickly recovered.

Abstract A sample of ASIC prototypes of the first-level trigger front-end device for the muon barrel drift chambers of CMS was tested on a full size chamber prototype. Tests were performed at several incident angles on cosmic rays and at normal incidence using a muon beam. The chamber was irradiated using a 137 C s gamma source to simulate the LHC radiation environment. The performance of the tested prototypes with respect to efficiency, resolution and noise issues is reported.

D-meson lifetimes have been determined from decays observed in an exposure of the high resolution hydrogen bubble chamber LEBC in association with the European Hybrid Spectrometer (EHS) to an incident 360 GeV π− beam. Various techniques for lifetime determination are presented and the results compared. A new model-independent analysis based on the distribution in transverse decay length is introduced and preferred over other techniques. Best values are found to be: $$\begin{gathered} \tau (D^0 ) = \left( {4.1_{ - 0.3}^{ + 0.7} } \right) \times 10^{ - 13} s (60 decays) \hfill \\ \tau (D^ \pm ) = \left( {10.7_{ - 1.8}^{ + 2.8} } \right) \times 10^{ - 13} s (40 decays) \hfill \\ \end{gathered} $$ . The lifetime ratio is: $$T = \frac{{\tau (D^ \pm )}}{{\tau (D^0 )}} = 2.6_{ - 0.6}^{ + 0.8} $$ .

Results on the longitudinal-momentum distributions of π±, K±, protons and antiprotons produced in 360 GeV/c π− interactions are presented. They are compared with other available data and discussed in terms of π− fragmentation.

Charm data from 360 GeV/c π− p and 400 GeV/cpp interactions are used to give results onD-meson branching ratios. The analysis is based on 438 charm events containing 608 spatially resolved charm particle decays. We present topological branching ratios, as well as the following inclusive branching ratios ofD-mesons into kaons: $$\begin{gathered} B(D^ \pm \to K^ \mp + anything) = 0.17 \pm 0.07, \hfill \\ B(D^ \pm \to K^ \pm + anything) = 0.08_{ - 0.05}^{ + 0.06} , \hfill \\ B(D^0 \to K^ \pm + anything) = 0.42 \pm 0.08, \hfill \\ B(D^0 \to K^ + + anything) = 0.03_{ - 0.02}^{ + 0.05} , \hfill \\ \end{gathered} $$ and the following semi-electronic branching ratios ofD-mesons: $$\begin{gathered} B(D^ \pm \to e^ \pm + anything) = 0.20_{ - 0.07}^{ + 0.09} , \hfill \\ B(D^0 \to e^ \pm + anything) = 0.15 \pm 0.05. \hfill \\ \end{gathered} $$

During the High Luminosity LHC, the Drift Tube chambers installed in the CMS detector need to operate with an integrated dose ten times higher than expected at the LHC due to the increase in integrated luminosity from 300 fb-1 to 3000 fb-1. Irradiations have been performed to assess the performance of the detector under such conditions and to characterize the radiation aging of the detector. The presented analysis focuses on the behaviour of the high voltage currents and the dose measurements needed to extrapolate the results to High Luminosity conditions, using data from the photon irradiation campaign at GIF++ in 2016 as well as the efficiency analysis from the irradiation campaign started in 2017. Although the single-wire loss of high voltage gain observed of 70% is very high, the muon reconstruction efficiency is expected to decrease less than 20% during the full duration of High Luminosity LHC in the areas under highest irradiation.

To sustain and extend its discovery potential, the Large Hadron Collider (LHC) will undergo a major upgrade in the coming years, referred to as High Luminosity LHC (HLLHC), aimed to increase its instantaneous luminosity, 5 times larger than the designed limit, and, consequently leading to high levels of radiation, with the goal to collect 10 times larger the original designed integrated luminosity. The drift tube chambers (DT) of CMS muon detector system is built to proficiently measure and trigger on muons in the harsh radiation environment expected during the HL-LHC era. Ageing studies are performed at the CERNs gamma ray irradiation facility (GIF++) by measuring the muon hit efficiency of these detectors at various LHC operation conditions. One such irradiation campaign was started in October 2017, when a spare MB2 chamber moved inside the bunker and irradiated at lower acceleration factors. Two out of twelve layers of the DT chamber were operated while being irradiated with the radioactive source and then their muon hit efficiency was calculated in coincidence with other ten layers which were kept on the standby. The chamber absorbed an integrated dose equivalent to two times the expected integrated luminosity of the HL-LHC. Investigation on the outgassing of cell materials and of the gas components used at the GIF++ are underway and strategies to mitigate the aging effects are also being developed. The effect of radiation on the performance of DT chamber and its impact on the overall muon reconstruction efficiency expected during the HL-LHC are presented.

The integration of IMPALA/BOSS tools for CMS MC production with GRID is presented. A package called DOLLY has been designed and developed, which clones the scripts on the user interface and submits them by BOSS through the GRID to the computer element. These scripts initialize the locally installed IMPALA, which generates a production task and starts it on the same working node.

Recent DELPHI results concerning the production rates and lifetimes of b-baryons are reviewed. The average lifetime of the b-baryon is measured to be (1.19−0.13+0.15) ps. The first observation of the Ξb baryon together with a measurement of its lifetime is reported.

Examining lousely coupled parallel solutions as computing resource we found Local Area VAXcluster suitable for building a production Farm. We transformed, tuning LAVc parameters, a general purpose computing environment in a specialized one, optimized for the production needs. To face the higher complexity introduced by the subdivision of the production between several computers, we developed a central software structure that surveys the functioning of the farm, informs and interfaces the users, automatically closes productions, saves bookeeping information and reports errors. For this we needed an efficient process‐to‐process communication mechanism, that we found to be an innovative use of some Lock Management system features.