F. Palla

The performance of the ALEPH detector at the LEP e+e− collider is reviewed. The accuracy of the tracking detectors to measure the impact parameter and momentum of charged tracks is specified. Calorimeters are used to measure photons and neutral hadrons, and the accuracy obtained in energy and angle is given. An essential property of the detector is its ability to identify particles; the performance in identification of electrons, muons, neutrinos (from missing energy), charged hadrons, π0's and V0's is described.

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 z =ppbeam> 0.3. 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 ΛΛ 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.

Inclusive π±, K± and $$(p,\bar p)$$ differential cross-sections in hadronic decays of the Z have been measured as a function ofz=P hadron/P beam, the scaled momentum. The results are based on approximately 520 000 events measured by the ALEPH detector at LEP during 1992. Charged particles are identified by their rate of ionization energy loss in the ALEPH Time Projection Chamber. The position, ξ*, of the peak in the ln(1/z) distribution is determined, and the evolution of the peak position with centre-of-mass energy is compared with the prediction of QCD.

This research aimed to explore the feasibility of fortifying bread with cooked Vitelotte potato powder and Citrus albedo, comparing the use of baker's yeast or sourdough as leavening agents. Breads obtained were thus subjected to physico-chemical and sensory characterizations. The replacement of part of the wheat flour with purple potato and albedo determined a significant enhancement of the phenolic profile and antioxidant status of fortified breads, as well as a longer shelf life. Thanks to its acidity and antimicrobial activity, sourdough improved the levels of health-promoting compounds and stability. Both the fortification and the leavening agent deeply affected the organoleptic, expression, and the aroma profile, of the fortified bread. Interestingly, albedo addition, despite its effectiveness in boosting the phenolic profile, determined a higher perception of aftertaste and bitterness, irrespective of the leavening agent. Based on these results, the use of purple potatoes and Citrus albedo, if properly formulated, could represent a valuable strategy for the development of high-quality products, with longer shelf-life.

From a sample of 152,000 τ decays collected by the ALEPH detector at LEP an upper limit of 24 MeV at 95% CL on the τ neutrino mass has been determined. The limit is obtained using a two dimensional likelihood fit of the visible energy and the invariant mass distribution of 25 τ → 5π(π0)ντ events.

This chapter of the "Flavor in the era of LHC" workshop report discusses flavor-related issues in the production and decays of heavy states at the LHC at high momentum transfer Q, both from the experimental and the theoretical perspective. We review top quark physics, and discuss the flavor aspects of several extensions of the standard model, such as supersymmetry, little Higgs models or models with extra dimensions. This includes discovery aspects, as well as the measurement of several properties of these heavy states. We also present publicly available computational tools related to this topic.

Pediatric jaw osteosarcoma is uncommon, and data are scarce regarding clinical presentation, prognostic factors, and outcome.A single-institution medical record review from 1983 to 2008 for 12 patients age ≤ 21 years was undertaken for this study.Median diagnosis age was 16.3 years (range, 6.3-21.9). Nine patients had mandible tumors. Osteoblastic subtype was most common (4 patients). Most tumors were large (ie, T2; n = 8) and high-grade (n = 8). Treatment characteristics were varied. Median follow-up was 27.1 months (range, 8-252 months). Five patients had tumor necrosis <80% after chemotherapy. No deaths were observed.Jaw osteosarcoma outcome is better compared to extremity osteosarcoma, but further study is required regarding clinical prognostic factors.

Using 1.45 million hadronic Z decays collected by the ALEPH experiment at LEP, the b → τ−ν-τX branching ratio is measured to be 2.75 ± 0.30 ± 0.37%. In addition an upper limit of 1.8 × 10−3 at 90% confidence level is placed upon the exclusive branching ratio of B−→ τ−ν-τ. These measurements are consistent with SM expectations, and put the constraint tan βMh±< 0.52 GeV−1 at 90% confidence level on all Type II two Higgs doublet models (such as the MSSM).

A study of scaling violations in fragmentation functions performed by the ALEPH collaboration at LEP is presented. Data samples enriched in uds, c, b and gluon jets, respectively, together with measurements of the longitudinal and transverse inclusive cross sections are used to extract the fragmentation function for the gluon and for each flavour. The measurements are compared to data from experiments at energies between 22 GeV and 91 GeV and scaling violations consistent with QCD predictions are observed. From this, a measurement of the strong coupling constant αs(Mz) = 0.126 ±0.009 is obtained.

Searches for supersymmetric particles produced in e+e− collisions at centre-of-mass energies of 130 and 136 GeV have been performed in a data sample of 5.7 pb−1 collected in the autumn of 1995 by the ALEPH detector at LEP. No candidate events were found, allowing limits to be set on the masses and production cross-sections of scalar leptons, scalar tops, charginos and neutralinos. The domains previously excluded at LEP1 are substantially extended. For instance, masses of gaugino-like charginos smaller than 67.8 GeV/c2 are excluded at the 95% C.L. for scalar neutrino masses larger than 200 GeV/c2.

Winemaking variables and techniques are known to affect the composition of wines. To obtain a rapid and safe fermentation course, with a reduced risk of proliferation of unwanted microbial species, frequent recourse is made to the use of selected microorganisms, which can greatly simplify the complex management of the fermentation process. In particular, selected strains of lactic acid bacteria are used, which are much more sensitive than yeasts to the operating conditions of the medium. In this regard, the overall aim of this research was to verify whether the early inoculation of homolactic acid bacteria for hexoses (Lactobacillus plantarum) carried out after 24 h, compared with that of saccharomycetes operating alcoholic fermentation, could be advantageous compared with a traditional innoculation with a different heterolactic bacterial strain for hexoses (Oenococcus oeni) operated at the end of alcoholic fermentation. The grape variety chosen was Sangiovese, the protagonist of Tuscan oenology. The evaluation focused on different aspects such as the management of winery operations, and the quality and longevity of the product; was carried out in all phases of winemaking; and analysed both from a chemical and sensory point of view.

The detection band of the interferometric gravitational wave detector VIRGO can be extended down to a few Hz by suspending each optical component of the interferometer from a chain of mechanical filters designed to suppress the transmission of seismic vibrations. Each mechanical filter supports the weight of the stages below it through a set of cantilevered blade springs. A system of permanent magnets, providing an “antispring” force, helps to reduce the highest vertical resonance of the chain from 7 Hz to about 2 Hz. This improvement allows VIRGO to reduce the frequency detection threshold from 10 Hz to about 4 Hz. A characterization of the mechanical filters is provided in this paper.

Measurements of the inclusive cross-sections forK 0 and Λ production in hadronic decays of the Z are presented together with measurements of two-particle correlations within pairs of Λ andK 0. The results are compared with predictions from the hadronization models Jetset, based on string fragmentation, and Herwig, based on cluster decays. TheK 0 spectrum is found to be harder than predicted by both models, while the Λ spectrum is softer than predicted. The correlation measurements are all reproduced well by Jetset, while Herwig misses some of the qualitative features and overestimates the size of the $$\Lambda \bar \Lambda $$ correlation. Finally, the possibility of Bose-Einstein correlation in theK 0 K 0 system is discussed.

Quark and gluon jets with the same energy, 24 GeV, are compared in symmetric three-jet configurations from hadronic Z decays observed by the ALEPH detector. Jets are defined using the Durham algorithm. Gluon jets are identified using an anti-tag on b jets, based on a track impact parameter method. The comparison of gluon and mixed flavour quark jets shows that gluon jets have a softer fragmentation function, a larger angular width and a higher particle multiplicity, Evidence is presented which shows that the corresponding differences between gluon and b jets are significantly smaller. In a statistically limited comparison the multiplicity in c jets was found to be comparable with that observed for the jets of mixed quark flavour.

Pixel detectors at HL-LHC experiments or other future experiments are facing new challenges, especially in terms of unprecedented levels of radiation and particle flux. This paper describes the progress made by the CHIPIX65 project of INFN for the development of a new generation readout ASIC using CMOS 65 nm technology.

This paper is a review of recent progress of RD53 Collaboration. Results obtained on the study of the radiation effects on 65 nm CMOS have matured enough to define first strategies to adopt in the design of analog and digital circuits. Critical building blocks and analog very front end chains have been designed, tested before and after 5–800 Mrad. Small prototypes of 64×64 pixels with complex digital architectures have been produced, and point to address the main issues of dealing with extremely high pixel rates, while operating at very small in-time thresholds in the analog front end. The collaboration is now proceeding at full speed towards the design of a large scale prototype, called RD53A, in 65 nm CMOS technology.

Abstract The characterization of compact non-traveling-wave Mach-Zehnder modulators for optical readout in high-energy physics experiments is reported to provide power-efficient alternatives to conventional traveling-wave devices and a more resilient operation compared to ring modulators. Electro-optical small-signal and large-signal measurements showcase the performances of custom NTW-MZMs designed and fabricated in iSiPP50G IMEC's technology in the framework of INFN's FALAPHEL project. Bit-error-rate results demonstrate their potential suitability for optical links up to 25 Gb/s when equipped with either conventional deep-etched or radiation-hardened shallow-etched free-carrier-based phase shifters.

The Virgo gravitational wave detector is an interferometer with 3 km long arms in construction near Pisa to be commissioned in the year 2000. Virgo has been designed to achieve a strain sensitivity of a few times at 200 Hz. A large effort has gone into the conception of the mirror suspension system, which is expected to reduce noise to the level of at 10 Hz. The expected signals and main sources of noise are briefly discussed; the choices made are illustrated together with the present status of the experiment.

From approximately 3 million hadronic decays of Z bosons recorded with the aleph detector at lep, a sample of 410 ± 32 B0→ D∗+ℓ−νℓ candidates is selected, where ℓ is either an electron or a muon. The differential decay rate dΓ (B0→ D∗+ℓ−νℓ)dω from this sample is fitted, yielding a value for the product of the CKM matrix element |Vcb| and the normalisation of the decay form factor at the point of zero recoil of the D∗+ meson F(ω = 1)|Vcb| = (31.4 ± 2.3stat ± 2.5syst) × 10−3. A value for |Vcb| is extracted using theoretical calculations of the form factor normalisation, with the result |Vcb| = (34.5 ± 2.5stat ± 2.7syst ± 1.5theory) × 10−3. From the integrated s the measured branching fraction is Br(B0→ D∗+ℓ−νℓ) = (5.18 ± 0.30stat± 0.62syst)%.

Using a sample of about 1.46 million hadronic Z decays collected between 1991 and 1993 with the ALEPH detector at LEP, the energy distribution of the B0 and B± mesons produced at the Z resonance is measured by reconstructing semileptonic decays B → ℓνℓD(X) or B→ ℓνℓD∗+(X). The charmed mesons are reconstructed through the decay modes D0 → K−π+, D0 → K−π+π−π+, D+ → K−π+π+ and D∗+→ D0π+. The neutrino energy is estimated from the missing energy in the lepton hemisphere. Accounting for B∗ and B∗∗ production, the shape of the scaled energy distribution xE(b) for mesons containing a b quark is compared to the predictions of different fragmentation models. The mean value of xE(b) is found to be 〈xE(b)〉 = 0.715 ± 0.007(stat) ± 0.013(syst).

Each optical component of the interferometric gravitational wave detector VIRGO is suspended from a cascade of mechanical filters designed to suppress the transmission of seismic vibrations. Each mechanical filter supports the weight of the filters below it by means of a set of steel cantilever blade springs. The stress from the load acting on the blades was found to induce a drooping of the blade tips of several microns per day due to a series of microscopic yielding events (micro-creep). This process induces a mechanical displacement shot-noise on the optical component which can dominate the small displacements produced by gravitational waves. The use of a special precipitation hardened steel (Maraging C250), instead of common spring steel, allows the construction of blades that show an acceptable stability under stress.

The Λb polarization in hadronic Z decays is measured in semileptonic decays from the average energies of the charged lepton and the neutrino. In a data sample of approximately 3 million hadronic Z decays collected by the ALEPH detector at LEP between 1991 and 1994, 462 ± 31 Λb candidates are selected using (Λπ+)-lepton correlations. From this event sample, the Λb polarization is measured to be PΛb = −0.23−0.20+0.24(stat.)−0.07+0.08(syst.).

VIRGO is a detector of gravitational waves based on a laser interferometer with 3 km long arms, now under construction. In order to detect gravitational waves down to 10 Hz, the seismic noise has to be reduced by several orders of magnitude. New mechanical filters using cantilever springs as elastic elements have been developed for the VIRGO seismic isolation system. The spring total stiffness is reduced by more than one order of magnitude using magnetic antispring. A control system allows one to keep the spring length constant. The new filters provide an attenuation ≥40 dB each for frequencies above 10 Hz and, compared to the previously adopted solution (gas springs), are much less sensitive to temperature changes.

Silicon photonics is standing out as a potential technology for the development of radiation-tolerant optical transceivers. In this work, we report the preliminary electro-optical characterization of two radiation-hardened-by-design shallow-etched Mach–Zehnder modulators with different doping configurations.

In order to stimulate new engagement and trigger some concrete studies in areas where further work would be beneficial towards fully understanding the physics potential of an $e^+e^-$ Higgs / Top / Electroweak factory, we propose to define a set of focus topics. The general reasoning and the proposed topics are described in this document.

Abstract The Serenity-S1 is a production-optimised Advanced Telecommunications Computing Architecture (ATCA) processing blade based on the AMD Xilinx Virtex Ultrascale+ device. It incorporates many developments from the Serenity-A and Serenity-Z prototype cards and, where possible, adopts solutions being used across CERN. Due to the shortage of components during the recent semiconductor crisis, commonly used components in the prototypes had to be replaced by new ones after qualification. In this work, we discuss various improvements to simplify manufacturing, the performance of new components, some of the more difficult aspects of procurement, the performance of production-grade Samtec 25 Gb/s optical firefly parts, and concerns regarding the rack cooling infrastructure.

We review the prospects for B-decay physics at the LHC as discussed in the 1999 workshop on Standard Model physics at the LHC. Contents

Measurements of the subjet structure of quark and gluon jets in hadronic Z decays are presented. The analysis is based on one million hadronic events recorded by the Aleph detector. Roughly symmetric three-jet events are selected with a coarse jet-resolution cut-off, y1. Gluon jets are identified with a purity of 94.6% in those events where evidence of long-lived heavy-flavour hadrons in the other two jets is found. The jets are then analyzed using a smaller cut-off y0 (< y1) so that subjets are resolved. The properties of the jets (subjet multiplicities (Nq), (Ng) and rates Rng(q) for n = 1, 2, 3, 4) are determined and are found to be in good agreement with the expectations of perturbative QCD as long as the subjet resolution parameter y0 is sufficiently large to keep non-perturbative effects small. In particular, the ratio (Ng − 1)(Nq − 1), which to leading order in QCD is given by the ratio of colour factors CACF = 94, is measured to be 1.96 ± 0.15 for y0 = 2 · 10−3, but falls to 1.29 ± 0.03 for y0 = 1.6 · 10−5.

Motivated by the success of the flavour physics programme carried out over the last decade at the Large Hadron Collider (LHC), we characterize in detail the physics potential of its High-Luminosity and High-Energy upgrades in this domain of physics. We document the extraordinary breadth of the HL/HE-LHC programme enabled by a putative Upgrade II of the dedicated flavour physics experiment LHCb and the evolution of the established flavour physics role of the ATLAS and CMS general purpose experiments. We connect the dedicated flavour physics programme to studies of the top quark, Higgs boson, and direct high-$p_T$ searches for new particles and force carriers. We discuss the complementarity of their discovery potential for physics beyond the Standard Model, affirming the necessity to fully exploit the LHC's flavour physics potential throughout its upgrade eras.

This paper presents the design and experimental verification of two drivers designed to be compliant with the high radiation dose levels present in the inner layers of the CERN's Large Hadron Collider (LHC) experimental chambers. The drivers, designed to face up to 800 Mrad (SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) Total Ionizing Dose, are able to sustain up to 5 Gbps bit-rate links when integrated in a 65 nm CMOS technology. They are designed to drive two Silicon Photonics optical modulators, Mach Zehnder Modulator and Ring Resonator, which have shown high rad-tolerant levels. The high dose level hardness of the drivers has been achieved by adopting the following Radiation Hardening By Design (RHBD) techniques: enhancement of the MOSFETs model to take into account the effects of high radiation dose levels and of single event effects on the devices, avoidance of using P-MOSFETs, increase of the minimum MOSFET lengths for the switching devices, and the use of Enclosed Layout Transistors shape plus some layout precautions. Moreover, to increase the drivers speed, techniques like buffer chain and inductive peaking are used in the drivers' design. The experimental results have verified the matching of the high-speed high-voltage constraint required by the application. The Total Ionization Dose tests have shown, at 800 Mrad (SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ), a 30% and 25% amplitude reduction of the output signals eye diagrams of the Mach Zehnder Modulator driver and of the Ring Resonator driver, respectively. In the worst case, in which the drivers will be placed within 5 cm from the beamline of the CMS experiment of the upgraded LHC, the heavy ions tests have shown a BER of 5.19e-8.

This paper presents the design and the experimental characterization of a 10 Gb/s electronic driver for silicon Mach-Zehnder modulators (MZMs). This driver is able to operate in harsh environments characterized by radiation levels up to 1 Grad(SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) total ionizing dose (TID). To compensate for the detrimental effects that radiation produces on the target 65 nm bulk silicon technology both device- and circuit-level radiation hardened by design (RHBD) techniques are developed and implemented. Extreme TID levels are faced using long-channel transistors with enclosed layout, avoiding the use of p-MOSFETs, and implementing a differential self-biased cascode architecture with common-mode feedback. Band-widening techniques, e.g., inductive peaking, cross-coupled capacitors, and buffer chaining, have been used to improve the driver’s frequency response and reach the targeted data rate. Electrical measurements show 10 Gb/s waveforms with an eye diagram amplitude suitable for MZM driving. Electro-optical measurements performed connecting the electronic driver to a silicon photonic MZM confirm the achievement of a 10 Gb/s system-level operability. The radiation hardness of the driver is verified by exposing the integrated circuit to X-rays. The measurements confirm the ability of the driver to work up to 1 Grad with an eye amplitude reduction of only 10% and a 7% increment in the rise and fall times, validating the effectiveness of the implemented RHBD techniques.

The lifetime of the Bs0 meson is measured in approximately 3 million hadronic Z decays accumulated using the ALEPH detector at LEP from 1991 to 1994. Seven different Ds− decay modes were reconstructed and combined with an opposite sign lepton as evidence of semileptonic Bs0 decays. Two hundred and eight Ds−ℓ+ candidates satisfy selection criteria designed to ensure precise proper time reconstruction and yield a measured Bs0 lifetime of τ(Bs0) = 1.59−0.15+0.17 (stat) ±0.03 (syst) ps. Using a larger, less constrained sample of events, the product branching ratio is measured to be Br(b→Bs0) ·Br(Bs0→Ds−ℓ+νX) = 0.82 ± 0.09 (stat) −0.14+0.13 (syst) %.

A lower limit is set on the Bs0 meson oscillation parameter Δms using data collected from 1991 to 1994 by the ALEPH detector. Events with a high transverse momentum lepton and a reconstructed secondary vertex are used. The high transverse momentum leptons are produced mainly by b hadron decays, and the sign of the lepton indicates the particle/antiparticle final state in decays of neutral B mesons. The initial state is determined by a jet charge technique using both sides of the event. A maximum likelihood method is used to set a lower limit of Δms. The 95% confidence level lower limit on Δms ranges between 5.2 and ̷6.5(h̷c2) ps−1 when the fraction of b quarks from Z0 decays that form Bs0 messons is varied from 8% to 16%. Assuming that the B0s fraction is 12%, the lower limit would be ̷Δms> 6.1(h̷c2) ps−1 at 95% confidence level. For xs = ΔmsτBs, this limit also gives xs > 8.8 using the B0s lifetime of τBs = 1.55 ± 0.11 ps and shifting the central value of τBs down by 1σ.

Interstrip and backplane capacitances on silicon microstrip detectors with p+ strip on n substrate of 320μm thickness were measured for pitches between 60 and 240μm and width over pitch ratios between 0.13 and 0.5. Parametrisations of capacitance w.r.t. pitch and width were compared with data. The detectors were measured before and after being irradiated to a fluence of 4×1014protons/cm2 of 24GeV/c momentum. The effect of the crystal orientation of the silicon has been found to have a relevant influence on the surface radiation damage, favouring the choice of a 〈100〉 substrate. Working at high bias (up to 500 V in CMS) might be critical for the stability of detector, for a small width over pitch ratio. The influence of having a metal strip larger than the p+ implant has been studied and found to enhance the stability.

The inclusive production of D∗± mesons in photon-photon collisions has been measured by the Aleph experiment at LEP with a beam energy of 45 GeV. The D∗+ are detected in their decay to D0π+ with the D0 observed in three separate decay modes: (1) K−π+, (2) K−π+π0 and (3) K−π+π−π+, and analagously for the D∗− modes. A total of 33 events was observed from an integrated luminosity of 73 pb−1 which corresponds to a cross section for Σ(e+e−→ e+e−D∗±X) of 155 ± 33 ± 21 pb. This result is compatible with both the direct production γγ → cc in the Born approximation and with a more complete calculation which includes both radiative QCD corrections and contributions in which one of the photons is first resolved into its quark and gluon constituents. The shapes of distributions for events containing a D∗+ are found to be better described by the latter.

The paper shows the radiation effects on 65 nm standard CMOS technology and RHBD (Radiation Hardening By Design) techniques developed to reduce the mosfets performance degradation. The paper is focused on the techniques to address extremely high Total Ionization Dose (TID) up to 1 Grad, which is the level required for the planned upgrade of the CERN’s LHC (HL-LHC). Today, only few data of single mosfets measurement at 1 Grad are presented in literature. These data are collected and transistors models are developed to presents, in this paper, the first system simulation results at 1 Grad conditions. As case of study, the performance reduction of two full-custom D flip-flops are presented, highlighting the robustness against radiation of CML technology for high-speed applications (10 Gbps).

High-energy physics experiments require links able to sustain high-speed data transfer while exposed to radiation phenomena. This paper outlines the design of a radiation-hard line driver for communication up to 10 Gb/s allowing designers to satisfy this need. The driver design relies on radiation hard by design techniques adopted to increase its radiation hardness. In addition, broad banding solutions are employed to sustain high-speed communications. Simulations show the driver’s ability to operate up to 10 Gb/s when exposed to 1 Grad total ionization dose. Furthermore, it is demonstrated that the proposed driver is robust to single-event effects.

In this paper we analyse the noise level induced by changes in the mass density distribution around the Virgo interferometric antenna. These stochastic mass density fluctuations generate a gravitational field which couples directly to the mirrors of the optical apparatus, and it could be relevant if the planned final sensitivity of the Virgo interferometer is to be reached.

In a sample of 1.5 million hadronic decays of the Z collected by the ALEPH detector, a search is carried out for the decays B→ D10(2420)l−νX and B→ D2∗0(2460)l−νX. The product branching ratio for D10 production is measured to be Br(b →B) × Br(B→ D10l−νX) × Br(D10→ D∗+π−) = (2.04 ± 0.58stat± 0.34syst) × 10−3, and a 95% confidence level limit of Br(b →B) × Br(B→ D2∗0l−νX) × Br(D2∗0→ D∗+π−) ≤ 0.81 × 10−3 is obtained for D2∗0 production. A topological search sensitive to the processes above, but also to wide resonances that decay to D∗+π− and to non-resonant D∗+π− production is also carried out, yielding Br(b→B) ×Br(B→D∗+π−l−νX)= (3.7 ± 1.0stat± 0.7syst) × 10−3. Direct evidence of D∗π production inconsistent with D10 and D2∗0 in semileptonic B decay is presented.

Using about 1.5 million hadronic Z decays recorded with the aleph detector, the lifetime of the b baryons has been measured using two independent data samples. From a maximum likelihood fit to the impact parameter distribution of leptons in 519 Λℓ− combinations containing a b baryon sample of 290 decays, the measured b baryon lifetime is τb—baryon = 1.05−0.11+0.12(stat)±0.09(syst) ps. The lifetime of the Λb0 baryon from a maximum likelihood fit to the proper time distribution of 58 Λc+ℓ− candidates containing a Λb0 sample of 44 decays, is τΛb0 = 1.02−0.18+0.23(stat) ± 0.06(syst) ps.

Data collected by ALEPH in the years 1990, 1991 and 1992 have been used to update a previous search for CP violation in the decay of the Z into τ+τ−. The measurement of the weak dipole form factor of the τ lepton has been performed by studying correlations between the τ leptons. No signal of CP violation was found. The weak dipole form factor is found to be d̃τ= (+0.15 ± 0.58stat± 0.38sys)10−17e · cm, obtained with 19628 identified τ+τ− events. This gives an upper limit on the weak dipole form factor of d̃τ< 1.5 · 10−17e · cm at the 95% confidence level.

A wideband (dc to 500 Hz) low noise accelerometer has been developed. It makes use of a suspended mass whose displacement relative to the supporting structure is sensed by a linear variable differential transformer. It works both in horizontal and in vertical direction. The electronics is connected to the mechanical structure through 12 m long cables. The spectral sensitivity is 7×10−10 (m/s2)/√Hz below 6 Hz. The accelerometer will be used to perform an inertial damping of the resonances of the suspension of the mirrors in VIRGO, an interferometric antenna for gravitational waves detection.

The process e+e−→, where l is a charged or a neutral lepton and f any charged fermion, is analyzed. The study uses the ALEPH data collected at LEP from 1989 to 1993 at centre-of-mass energies between 88 and 95 GeV, corresponding to almost two million hadronic Z decays and to a total integrated luminosity of 79 pb−1. For all channels, the data agree well with the standard model expectation both in shape and normalization. The indication of an excess in the $$e^ + e^ - \to \tau ^ + \tau ^ - f\bar f$$ channel, reported by ALEPH in 1991, is not confirmed.

The CDF Associative-Memory device (AM), proven technology developed for the Silicon-Vertex-Trigger at the CDF experiment, is one of the proposed solutions at the LHC for track reconstruction at level-1 in the HL-LHC upgrade, for very high-luminosity conditions (hundreds proton-proton collisions every 25 ns, at 5×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">34</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">- 2</sup> sec <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">- 1</sup> ). This luminosity requires a drastic revision of the existing trigger strategies. In the CMS experiment, one of the identified challenges for future upgrades is the capability of using already at L1 the tracker information to trigger events. Simulation studies show that this can be achieved by correlating hits on two closely spaced silicon strip sensors. This strategy requires massive computing power, to minimize the online execution time of complex tracking algorithms and the “combinatorial challenge.” The AM allows to compare the tracker information of each event to pre-calculated “expectations” (pattern matching) in a so short time that tracks can contribute to the trigger decision. One of the main challenges for the CMS tracker is the latency due to the tracker data distribution to the AM processors. A very parallelized readout architecture and a possible layout are discussed.

We designed, realized, and tested a 2.5-Gb/s optical wireless communication (OWC) system prototype, that should be employed in high energy physics (HEP) experiments, such as the compact muon solenoid (CMS). The system consists of off-the-shelf components, mainly a vertical cavity surface emitting laser (VCSEL) and a PIN photodiode with a proper ball lens. Since it should be used to transmit data among particle sensors in neighboring rings of the CMS, its target distance is 10 cm. Its most attractive feature is that it does not require a (complex) active tracking system because its measured tolerance to misalignment is around <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\pm$</tex-math> </inline-formula> 1 mm (at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$10^{-12}$</tex-math></inline-formula> bit error rate). We also report the X-rays irradiation tests of all components (Quartz lens, VCSEL, and PIN photodiode): None of them showed any degradation up till 238-Mrad (Si) dose. These results indicate that the designed OWC can be a viable solution for future HEP experiments.

Searches for supersymmetric particles produced in e+e− interactions at the Z peak have been performed under the assumptions that R-parity is not conserved, that the dominant R-parity violating coupling involves only leptonic fields, and that the lifetime of the lightest supersymmetric particle can be neglected. In a data sample collected by the ALEPH detector at LEP up to 1993, and corresponding to almost two million hadronic Z decays, no signal was observed. As a result, supersymmetric particle masses and couplings are at least as well constrained as under the usual assumption of R-parity conservation.

The Michel parameters and the average τ-neutrino helicity are measured using correlations between the decays of the τ+ and τ− produced on the Z resonance and observed in the ALEPH detector at LEP. The Michel parameters, ϱl, ηl, ξl, (δξ)l, are determined from τ → lνlντ with l = (e, μ), and the average τ neutrino helicity, 〈h(ντ)〉, from τ → hν with h = (π, ϱ, a1). The results obtained with e−μ universality are: ϱl = 0.751±0.039±0.022, ηl = −0.04±0.15±0.11, ξl = 1.18±0.15±0.06, (δξ)l = 0.88±0.11±0.07, and the average τ neutrino helicity 〈h(ντ)〉 = −1.006±0.032±0.019. No significant deviation from the Standard Model V-A prediction is observed.

The VIRGO experiment was approved in September 1993. The goal of the French-Italian collaboration is to detect gravitational waves using a 3 km arm-length Michelson interferometer. The construction of this detector, which will be installed in Pisa, is under way. The experiment is planned to take data, in a large bandwidth (10 Hz-10 kHz), at the beginning of the year 2000 with nominal sensitivity close to h = 3 X 10-‘3/&. The motivations, detection principle, main sources of noise and status of the experiment are presented.

A proposal for a pixel based Level-1 trigger for the Super-LHC is presented. The trigger is based on fast track reconstruction using the full pixel granularity exploiting a readout which connects different layers in specific trigger towers, located in the radial region between 25 and 50 cm from the beam line. The trigger will implement the current CMS High Level Trigger functionality in a novel detector concept. A possible layout is discussed and implications on the data links are evaluated. Finally the performances are shown.

This paper presents the characterization of the new Associative Memory chip (version 7) designed and fabricated in 28 nm CMOS. The design aims at: enhancing links from/to FPGAs; increasing bandwidth thanks to full custom LVDS transceivers; and reducing power consumption and silicon area by means of new memory cells designed with full-custom approach. The design was submitted in December 2016; the prototypes were fabricated and packaged in a 17 × 17 Ball Grid Array (BGA) standalone package. Prototype characterization confirms the chip functionality. The final chip will be assembled in a System In Package (SiP) together with a bare FPGA die.

Using about 950000 hadronic events collected during 1991 and 1992 with the ALEPH detector, the ratios rb=αsbαsudsc and ruds=αsudsαscb have been measured in order to test the flavour independence of the strong coupling constant αs. The analysis is based on event-shape variables using the full hadronic sample, two b-quark samples enriched by lepton tagging and lifetime tagging, and a light-quark sample enriched by lifetime antitagging. The combined results are rb = 1.002±0.023 and ruds = 0.971 ± 0.023.

An ultralow resonant frequency vertical seismic activity attenuation filter prototype has been designed and built as the vertical component of a Pre-Isolation Stage (PIS) for low-frequency Seismic Attenuation (SA) chains. The task of the PIS is to reduce the excitation of the chain payload's resonant residual motions. A characterization and the performance of the prototype are reported along with some design considerations. An attenuation of 45 dB has been achieved in the region of interest (the SA chain resonant frequency band) and an upgrade to more than 50 dB attenuation is easily achievable. Tests of active feedback loop attenuation driven by electro magnetic actuators and controlled by a Digital Signal Processor reading a precision vertical accelerometer have been successfully performed. The filter also effectively acts as a precision positioner for the suspended payload.

The Silicon Vertex Trigger (SVT) provides the CDF experiment with a powerful tool for fast and precise track finding and fitting at trigger level. The system enhances the experiment's reach on B-physics and large PT-physics coupled to b quarks. We review the main design features and the performance of the SVT with particular attention to the recent upgrade that improved its capabilities. Finally, we will focus on additional improvements of the functionality of such a system in a more general experimental context.

In this paper we present a new Associative Memory (AM) chip designed in the 28 nm TSMC HPL technology. Two of the main characteristics of the new chip are reduced power consumption and an increased memory cell area density by the use of two newly designed memory cell technologies. The aim of the new chip is to test the new technologies with realistic front-end functions. The integration of the AM and FPGA is also enhanced. In addition, LVDS drivers and receivers are implemented to strengthen the signal integrity of the I/Os. The new AM chip design is submitted for the fabrication. The die will be packaged in a 17 × 17 Ball Grid Array (BGA) standalone package with a Silicon In Package (SiP) structure mounting AM dies and a bare die FPGA.

A data sample of about 3.0 million hadronicZ decays collected by the ALEPH experiment at LEP in the years 1991 through 1994 is used to make an inclusive selection of B hadron events. In this event sample 4227±140±252B* mesons in the decayB*→Bγ and 1944±108±161B** u,d mesons decaying into a B meson and a charged pion are reconstructed. Here and in the followingB** u,d denotes the eightL=1(bū) and (bd) states and their charge conjugate. For the well establishedB* meson the following quantities are obtained:ΔM=M B*−MB=(45.30±0.35±0.87) MeV/c2 andN B*/(N B+N B*)=(77.1±2.6±7.0)%. The angular distribution of the photons in theB* rest frame is used to measure the relative contribution of longitudinalB* polarization states to beσ L/(σ L+σ T)=(33±6±5)%. In theM(Bπ)−M(B) mass difference resonance structure is observed at (424±4±10) MeV/c2, for which the shape and position is consistent with the expectation forB** u,d states decaying intoB(*)π ±. The relative production rate is determined to be $$\begin{gathered} \frac{{BR(Z \to b \to B_{u,d}^{ * * } )}}{{BR(Z \to b \to B_{u,d} )}} \hfill \\ = [27.9 \pm 1.6(stat) \pm 5.9(syst) {}_{ - 5.6}^{ + 3.9} (model)]\% \hfill \\ \end{gathered} $$ where the third error reflects the uncertainty due to different production and decay models for the broadB** u,d states.

The lifetimes of theB 0 andB + mesons have been measured with theAleph detector at LEP, using approximately 3 million hadronic Z decays collected in the period 1991–1994. In the first of three methods, semileptonic decays ofB 0 andB + mesons were partially reconstructed by identifying events containing a lepton with an associatedD*− or % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGabmirayaara% WaaWbaaSqabeaacaaIWaaaaaaa!37B5! $$\bar D^0 $$ meson. The second method used fully reconstructedB 0 andB + mesons. The third method, used to measure theB 0 lifetime, employed a partial reconstruction technique to identifyB 0→D*− π + X decays. The combined results are % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGceaqabeaacqaHep% aDdaWgaaWcbaacbaGaa8hmaaqabaGccqGH9aqpcaaIXaGaaiOlaiaa% iwdacaaI1aGaeyySaeRaaGimaiaac6cacaaIWaGaaGOnaiabgglaXk% aaicdacaGGUaGaaGimaiaaiodaruqqYLwySbacfaGaa4hiaiaa-bha% caWFZbGaaiilaaqaaiabes8a0naaBaaaleaacaWFRaaabeaakiabg2% da9iaaigdacaGGUaGaaGynaiaaiIdacqGHXcqScaaIWaGaaiOlaiaa% icdacaaI5aGaeyySaeRaaGimaiaac6cacaaIWaGaaG4maiaa+bcaca% WFWbGaa83CaiaacYcaaeaadaWcbaWcbaGaeqiXdq3aaSbaaWqaaiaa% -TcaaeqaaaWcbaGaeqiXdq3aaSbaaWqaaiaa-bdaaeqaaaaakiabg2% da9iaaigdacaGGUaGaaGimaiaaiodacqGHXcqScaaIWaGaaiOlaiaa% icdacaaI4aGaeyySaeRaaGimaiaac6cacaaIWaGaaGOmaiaac6caaa% aa!72AD! $$\begin{gathered} \tau _0 = 1.55 \pm 0.06 \pm 0.03 ps, \hfill \\ \tau _ + = 1.58 \pm 0.09 \pm 0.03 ps, \hfill \\ \tfrac{{\tau _ + }}{{\tau _0 }} = 1.03 \pm 0.08 \pm 0.02. \hfill \\ \end{gathered} $$ .

One of the proposed solutions for a transverse momentum (pT) based trigger at SLHC for the CMS experiment is based on the concept known as the "cluster width" approach, in which clusters produced by low pT tracks are rejected based on the width of the cluster shape, made either on a single strip sensor or a doublet of strip sensors by a suitable electronics logic at the level of the front-end. This information can then be used in many ways to provide first level trigger primitives. These kinds of modules are inexpensive, and coupled high-speed opto-electronic components this concept provides the simplest solution to the first level trigger for SLHC trackers. We will present the simulation studies aimed to optimize the concept, as well as the basic building blocks of the module and their connectivity. Finally we will provide the experimental validation of it by using data collected by the CMS Tracker during the Cosmic runs in 2008 and 2009 as well as the first collision data from the LHC.

This work presents a design of a driver in 65 nm TSMC technology for a custom MZM designed to withstand non-ionizing energy losses (NIEL) of up few 1016 n/cm 2 and up to 500 Mrad total ionization doses (TID). The design of the driver is optimized for a TID exceeding 500 Mrad, for a target bit rate of 10 Gbps. The driver uses a CML (Current Mode Logic) architecture. A cascode architecture is adopted in the last stage to increase the driving voltage. Two driver designs have been implemented, the largest sizing 347 × 180 μm2 layout area and about 170 mW predicted power consumption at 500 Mrad. The ASIC has been submitted to foundry in May 2018.

In Italy, Chianti Classico identifies a territory located in the heart of Tuscany that was once known as Chianti. From the pedological point of view, the entire DOCG (Denomination of controlled and guaranteed origin) has some common features but also shows many specific features related to certain small areas that give rise to the presence of many "terroirs". Due to the intertwining created by the alternation of valleys and hills and the different characteristics of the territory, factors such as altitude and exposure play a very important role in the vegetative and productive expression of grapes. Some production areas were identified within the appellation where it is argued that the terroir and the grapes are quite distinct from those of other surrounding areas, albeit within the Chianti Classico appellation. On the basis of this information and considering that no data are available in the literature, the present study proposed an innovative multidisciplinary approach (analytical and statistical) that was capable of carrying out an objective evaluation of the various sub-areas investigated, using Sangiovese grapes as the variety in question. This research took into account the climatic results and the different pedological characteristics, evaluating the evolutionary phenomena that were linked to the ripening of the grapes in each phase of its formation.

In a data sample of four million hadronic Z decays collected with the ALEPH detector at LEP, four Λb baryon candidates are exclusively reconstructed in the Λb → Λc+π− channel, with the Λc+ decaying into pK−π+, pK0, or Λπ+π+π−. The probability of the observed signal to be due to a background fluctuation is estimated to be 4.2 × 10−4. The mass of the Λb is measured to be 5614±21 (stat.) ± 4 (syst.) MeV/c2.

Earlier measurements at LEP of isolated hard photons in hadronic Z decays, attributed to radiation from primary quark pairs, have been extended in the ALEPH experiment to include hard photon productioninside hadron jets. Events are selected where all particles combine democratically to form hadron jets, one of which contains a photon with a fractional energyz≥0.7. After statistical subtraction of non-prompt photons, the quark-to-photon fragmentation function,D(z), is extracted directly from the measured 2-jet rate. By taking into account the perturbative contributions toD(z) obtained from anO(ααs) QCD calculation, the unknown non-perturbative component ofD(z) is then determined at highz. Provided due account is taken of hadronization effects nearz=1, a good description of the other event topologies is then found.

An improved measurement of the average b hadron lifetime is performed using a sample of 1.5 million hadronic Z decays, collected during the 1991–1993 runs of ALEPH, with the silicon vertex detector fully operational. This uses the three-dimensional impact parameter distribution of lepton tracks coming from semileptonic b decays and yields an average b hadron lifetime of 1.533 ± 0.013 ± 0.022 ps.

The RD53 collaboration is developing a large scale pixel front-end chip, which will be a tool to evaluate the performance of 65 nm CMOS technology in view of its application to the readout of the innermost detector layers of ATLAS and CMS at the HL-LHC. Experimental results of the characterization of small prototypes will be discussed in the frame of the design work that is currently leading to the development of the large scale demonstrator chip RD53A to be submitted in early 2017. The paper is focused on the analog processors developed in the framework of the RD53 collaboration, including three time over threshold front-ends, designed by INFN Torino and Pavia, University of Bergamo and LBNL and a zero dead time front-end based on flash ADC designed by a joint collaboration between the Fermilab and INFN. The paper will also discuss the radiation tolerance features of the front-end channels, which were exposed to up to 800 Mrad of total ionizing dose to reproduce the system operation in the actual experiment.

RD53A is a large scale 65 nm CMOS pixel demonstrator chip that has been developed by the RD53 collaboration for very high rate (3 GHz/cm 2 ) and very high radiation levels (500 Mrad, possibly 1 Grad) for ATLAS and CMS phase 2 upgrades.It features serial powering operation and design variations in the analog and digital pixel matrix for different testing purposes.The design and verification of RD53A are described together with an outline of the plans to develop final pixel chips for the two experiments.

The High Luminosity LHC (HL-LHC) will deliver luminosities of up to 5 × 1034 Hz/cm2, with an average of about 140 overlapping proton-proton collisions per bunch crossing. These extreme pileup conditions place stringent requirements on the trigger system to be able to cope with the resulting event rates. A key component of the CMS upgrade for HL-LHC is a track trigger system which would identify tracks with transverse momentum above 2 GeV/c already at the first-level trigger. This paper presents the status of proposals for implementing the L1 tracking in conjunction with the planned upgrade for the silicon tracker of the CMS experiment.

In this paper we describe a Content Addressable Memory architecture designed in 28 nm CMOS technology and based on the 65 nm XORAM cell previously developed. The cell is composed by two main blocks: a 6T SRAM, and a 4T XOR logic gate. Each XORAM cell makes a bitwise comparison between input data and stored data. The memory is organized in 18-bit words, and all the 18 XOR outputs bits must have a low logic value to trigger a high logic value of the single bit match line. A 18-input NOR gate performs this operation. The memory operation is triggered by the change of the least significant bit of the 18-bit input word, which is delayed w.r.t. the other bits. In this way, the logic does not require any clock. The proposed architecture is based on CMOS combinational logic, and it does not require any precharge operation, nor control and timing logic. The Associative Memory block is useful for several pattern recognition tasks, such as track recognition in high energy physics experiments, and image recognition for medical applications.

This work presents the experimental characterization of a compact non-traveling-wave Mach-Zehnder modulator fabricated in a standard foundry process. Non-return-to-zero modulation was validated till 30 Gb/s by BER measurements and 13.2 GHz-6-dBe electro-optic bandwidth was measured under single-arm driving.

From 1.4 million hadronic Z decays collected by the ALEPH detector at LEP, an enriched sample of Z → cc̄ events is extracted by requiring the presence of a high momentum D∗±. The charm quark forward-backward charge asymmetry at the Z pole is measured to be AFB0.c = (8.0 ± 2.4) % corresponding to an effective electroweak mixing angle of sin2θWeff = 0.2302 ± 0.0054.

The B0 - B̄0 average mixing parameter χ and b forward-backward asymmetry AFB0(b) are measured from a sample of about 4 200 000 Z → qq̄ events recorded with the ALEPH detector at LEP in the years 1990–1995. High transverse momentum electrons and muons produced in b semileptonic decays provide the tag of the quark flavour and of its charge. The average mixing parameter and the pole b asymmetry are measured to be χ = 0.1246 ± 0.0051stat ± 0.0052syst, AFB0(b) = 0.1008 ± 0.0043stat ± 0.0028syst. The value of sin2θweff = 0.23198 ± 0.00092 is extracted from the asymmetry measurement.

We present results obtained with full-size wedge silicon microstrip detectors bonded to APV6 (Raymond et al., Proceedings of the 3rd Workshop on Electronics for LHC Experiments, CERN/LHCC/97-60) readout chips. We used two identical modules, each consisting of two crystals bonded together. One module was irradiated with 1.7×1014neutrons/cm2. The detectors have been characterized both in the laboratory and by exposing them to a beam of minimum ionizing particles. The results obtained are a good starting point for the evaluation of the performance of the “ensemble” detector plus readout chip in a version very similar to the final production one. We detected the signal from minimum ionizing particles with a signal-to-noise ratio ranging from 9.3 for the irradiated detector up to 20.5 for the non-irradiated detector, provided the parameters of the readout chips are carefully tuned.

A Real-Time demonstrator based on the ATCA Pulsar-IIB custom board and on the Pattern Recognition Mezzanine (PRM) board has been developed as a flexible platform to test and characterize low-latency algorithms for track reconstruction and L1 Trigger generation in future High Energy Physics experiments.The demonstrator has been extensively used to test and characterize the Track-Trigger algorithms and architecture based on the use of the Associative Memory ASICs and of the PRM cards.The flexibility of the demonstrator makes it suitable to explore other solutions fully based on a high-performance FPGA device.

Optical links are rapidly becoming pervasive in the readout chains of particle physics detector systems. Silicon photonics (SiPh) stands as an attractive candidate to sustain the radiation levels foreseen in the next-generation experiments, while guaranteeing, at the same time, multi-Gb/s and energy-efficient data transmission. Integrated electronic drivers are needed to enable SiPh modulators’ deployment in compact on-detector front-end modules. A current-mode logic-based driver harnessing a pseudo-differential output stage is proposed in this work to drive different types of SiPh devices by means of the same circuit topology. The proposed driver, realized in a 65 nm bulk technology and already tested to behave properly up to an 8 MGy total ionizing dose, is hybridly integrated in this work with a lumped-element Mach–Zehnder modulator (MZM) and a ring modulator (RM), both fabricated in a 130 nm silicon-on-insulator (SOI) process. Bit-error-rate (BER) performances confirm the applicability of the selected architecture to either differential and single-ended loads. A 5 Gb/s data rate, in line with the current high energy physics requirements, is achieved in the RM case, while a packaging-related performance degradation is captured in the MZM-based system, confirming the importance of interconnection modeling.

This work discusses the design and the main results relevant to the characterization of analog front-end processors in view of their operation in the pixel detector readout chips of ATLAS and CMS at the High-Luminosity LHC.The front-end channels presented in this paper are part of RD53A, a large scale demonstrator designed in a 65 nm CMOS technology by the RD53 collaboration.The collaboration is now developing the full-sized readout chips for the actual experiments.Some details on the improvements implemented in the analog front-ends are provided in the paper.

We present the exploratory approach of Project FOCS (Free Space Optical communications for Space), which aims at proposing and demonstrating new applications of Visible Light Communications (VLC) for satellites. The first selected application scenario that will be investigated deals with transmission of Gbit/s signals on very small satellites, e.g. CubeSats. The second selected research line will be about low-bit-rate communication between satellites over > 100 m distances.

Abstract Optical Wireless Communication (OWC) system for particles detector can be a viable solution for reducing the complexity of the optical fibre network used to extract the data from the detector. In this work we present the initial study of the tolerance to misalignment for the OWC system under investigation. We observed that using collimators of beam waist from 0.35 mm to 3.5 mm we can obtain tolerance in range from ± 0.25 mm to ± 0.8 mm . We also observed using ray trace simulation that both transmitting power and tolerance can be improved by using optimized lens at the receiver having VCSEL as transmitting source.

A simulation framework has been developed to test and characterize algorithms, architectures and hardware implementations of the vastly complex CMS Track Trigger for the high luminosity upgrade of the CMS experiment at the Large Hadron Collider in Geneva. High-level SystemC models of all system components have been developed to simulate a portion of the track trigger. The simulation of the system components together with input data from physics simulations allows evaluating figures of merit, like delays or bandwidths, under realistic conditions. The use of SystemC for high-level modelling allows co-simulation with models developed in Hardware Description Languages, e.g. VHDL or Verilog. Therefore, the simulation framework can also be used as a test bench for digital modules developed for the final system.

High speed optical fiber or copper wire communication systems are frequently deployed for readout data links used in particle physics detectors. Future detector upgrades will need more bandwidth for data transfer, but routing requirements for new cables or optical fiber will be challenging due to space limitations. Optical wireless communication (OWC) can provide high bandwidth connectivity with an advantage of reduced material budget and complexity of cable installation and management. In a collaborative effort, Scuola Superiore Sant'Anna and INFN Pisa are pursuing the development of a free-space optical link that could be installed in a future particle physics detector or upgrade. We describe initial studies of an OWC link using the inner tracker of the Compact Muon Solenoid (CMS) detector as a reference architecture. The results of two experiments are described: the first to verify that the laser source transmission wavelength of 1550 nm will not introduce fake signals in silicon strip sensors while the second was to study the source beam diameter and its tolerance to misalignment. For data rates of 2.5 Gb/s and 10 Gb/s over a 10 cm working distance it was observed that a tolerance limit of ±0.25 mm to ±0.8 mm can be obtained for misaligned systems with source beam diameters of 0.38 mm to 3.5 mm, respectively.

The increment of luminosity at HL-LHC will require the introduction of tracker information at Level-1 trigger system for the experiments in order to maintain an acceptable trigger rate for selecting interesting events despite the one order of increased magnitude in the minimum bias interactions. In order to extract the track information in the required latency (∼ 5–10 μ s depending on the experiment), a dedicated hardware processor needs to be used. We here propose a prototype system (Pattern Recognition Mezzanine) as core of pattern recognition and track fitting for HL-LHC experiments, combining the power of both Associative Memory custom ASIC and modern Field Programmable Gate Array (FPGA) devices.

A proposal for a pixel-based Level 1 trigger for the Super-LHC is presented. The trigger is based on fast track reconstruction using the full pixel granularity exploiting a readout which connects different layers in specific trigger towers. The trigger will implement the current CMS high level trigger functionality in a novel concept of intelligent detector. A possible layout is discussed and implications on data links are evaluated.

Abstract The Future Circular Collider FCC-ee aims at unprecedented luminosities to be obtained with the crab-waist collision scheme. In this paper we describe the mechanical model of the interaction region layout including its assembly procedure. After a discussion on the requirements and constraints, we present the engineered design of the vacuum chamber with the cooling system, the bellows, the vertex and outer tracker detectors and their integration in a carbon-fibre lightweight support structure that will support also the luminosity calorimeter.

Links able to sustain high-speed data transfer while exposed to radiation phenomena are required by several applications, including aerospace and high-energy physics experiments. To satisfy this need, this paper outlines the design of a radiation-hard line driver for communication up to 10 Gb/s. The driver design is focused on the techniques adopted to increase its radiation hardness, namely the use of long-channel transistors, the avoidance of p-type MOSFETs and thick oxide devices. Circuital strategies to boost driver speed, such as inductive peaking, buffer chaining, and optimal layout placement and routing, are discussed and implemented to compensate for the downsides caused by adopted radiation-hard techniques. The driver, fabricated in 65 nm technology, has been experimentally tested demonstrating its ability to operate up to 10 Gb/s in a radiation-pervaded environment. In particular, after exposure to 1 Grad(SiO2) X-ray, the line driver exhibits an output signal amplitude reduction of 18.3% and a jitter increase of 5.53%. Performed temperature tests highlight that the line driver is capable to operate at 125 °C with 15.9% and 6.7% output signal swing reduction and jitter increase, respectively. The temperature tests also demonstrate the driver’s ability to work up to 160 °C with an output signal swing reduction below 25% and a jitter increase below 12%.

We realized a high-speed Optical Wireless Communication (OWC) system for short distances, and then tested its transmitter and receiver boards against the most challenging issues that the devices can face in the space environment. As the system is made of commercially available optoelectronic components, operating at 850 nm, there was no specific preliminary indication that they can survive in the space environment. Thus, we thoroughly tested our OWC boards against strong acceleration and typical mechanical vibrations (up to 7.5g, 850 Hz), then over a wide temperature range (−40°C<T<80 °C) and finally against X-ray irradiation (1 Mrad). In all tests, the OWC system suffered no relevant issue. This is clear evidence that OWC technology, realized by Commerical Off-the-Shelf components, can be suitable for space applications.

The Serenity-S1 is a Xilinx Virtex Ultrascale+ based Advanced Telecommunications Computing Architecture (ATCA) processing blade that has been optimised for production. It incorporates many developments from the Serenity-A and Serenity-Z prototype cards and, where possible, adopts solutions being used across CERN. It also uses many new parts because commonly used parts have disappeared from the market during the semiconductor crisis, with only some returning. Improvements to simplify manufacture, the performance of new components, some of the more difficult aspects of procurement, the performance of production-grade Samtec 25\,Gb/s optical firefly parts, and issues with the rack cooling infrastructure are discussed.

This paper describes the SER28_V1 circuit: including thea prototype of an 8 Gbps 20-bit Serializer developed in a commercial CMOS 28nm technology. The circuit is designed to be radiation-tolerant up to a Total Ionizing Dose (TID) of 10 MGy Grad in view of applications in the readout of future High Energy Physics experiments. It will be used as building block of a Double-Data-Rate 16 Gbps Serializer that will be integrated in the demonstrator of a 64 Gbps optical data link based on Ring-Resonators and radiation-tolerant electronics. The circuit includes a radiation-tolerant Built-In-Self-Test module and LVDS and CML differential drivers and receivers. Results of test and characterization of SER28_V1 prototypes are presented.

Searches for charginos and neutralinos produced in e+e− collisions at centre-of-mass energies of 130 and 136 GeV have been performed under the assumptions that R-parity is not conserved, that the dominant R-parity violating coupling involves only leptonic fields, and that the lifetime of the lightest supersymmetric particle can be neglected. In the 5.7 pb−1 data sample collected by ALEPH, no candidate events were found. As a result, chargino and neutralino masses and couplings are constrained and the domains previously excluded at LEP1 are extended.

This paper describes the main achievements in the development of radiation resistant silicon detectors to be used in the CMS tracker. After a general description of the basic requirements for the operation of large semiconductor systems in the LHC environment, the issue of radiation resistance is discussed in detail. Advantages and disadvantages of the different technological options are presented for comparison. Laboratory measurements and test beam data are used to check the performance of several series of prototypes fabricated by different companies. The expected performance of the final detector modules are presented together with preliminary test beam results on system prototypes.

The VIRGO SuperAttenuator is a complex six-degrees of freedom remote-controlled mechanism that isolates a 80 kg payload from environmental perturbations, such as the seismic noise. It consists of a Pre-Isolator stage, a chain of mechanical filters and a last stage, holding the payload. The Pre-Isolator and the filters are essentially harmonic oscillators with a low resonant frequency. The filters are designed to work below 500 mHz in all degrees of freedom. During the last year, a Pre-Isolator with resonant frequencies of 30 mHz in three degrees of freedom has been engineered and built. Intensive studies on the long-term spring behaviour have been performed to find a metal suitable to be stressed up to 1 kN/mm2 with no evidence of creep.

Mechanical filters using cantilever springs as elastic elements have been developed for the seismic isolation system of the VIRGO gravitational wave detector. A two-stage suspension has been built in order to study how the attenuation performances of individual filters combine when the filters are cascaded. An attenuation ⩾80 dBin the vertical direction and ⩾110 dBin the horizontal direction has been attained for frequencies above 10 Hz.

The Phase 2 upgrades of silicon pixel detectors at HL-LHC experiments feature extreme require- ments, such as: 50x50 μm pixels, high rate (3 GHz/cm2), unprecedented radiation levels (1 Grad), high readout speed and serial powering. As a consequence a new readout chip is required. In this framework the RD53 collaboration submitted RD53A, a large scale chip demonstrator de- signed in 65 nm CMOS technology, integrating a matrix of 400×192 pixels. It features design variations in the analog and digital pixel matrix for testing purposes. An overview of the building blocks will be given together with test results on single chips.

The RD53A large scale pixel demonstrator chip has been developed in 65 nm CMOS technology by the RD53 collaboration, in order to face the unprecedented design requirements of the pixel 2 phase upgrades of the CMS and ATLAS experiments at CERN. This prototype chip is designed to demonstrate that a set of challenging specifications can be met, such as: high granularity (small pixels of 50×50 or 25× 100 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) and large pixel chip size (~2×2 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ), high hit rate (3 GHz/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ), high readout speed, very high radiation levels (500 Mrad - 1 Grad) and operation with serial powering. Furthermore, coping with the long latency of the trigger signal (~12.5 μs), used to select only events of interest in order to achieve sustainable output data rates, requires increased buffering resources in the limited pixel area. The RD53A chip has been fabricated in an engineer run. It integrates a matrix of 400×192 pixels and features various design variations in the analog and digital pixel matrix for testing purposes. This paper presents an overview of the chip architecture and of the methodologies used for efficient design of large complex mixed signal chips for harsh radiation environments. Experimental results obtained from the characterization of the RD53A chip are reported to demonstrate that design objectives have been achieved. Moreover, design improvements and new features being developed in the RD53B framework for final ATLAS and CMS production chips are discussed.

Precise tracking information in the online selection of interesting physics events is extremely beneficial at hadron colliders.The CDF experiment at the Tevatron, has shown for the first time the impact of the tracking in triggers, allowing to achieve unprecedented precision in B-physics measurements.The CMS experiment at LHC will largely make use of tracking information at high level trigger, after the Level-1 acceptance.The increased luminosity of the Super-LHC collider will impose to CMS a drastic revision of the Level-1 trigger strategy, incorporating the tracker information at the first stage of the selection.After a review of the CDF and CMS approaches we will discuss several possible Level-1 tracker based concepts for the upgraded CMS detector at Super-LHC.One approach is based on associative memories, which has already been demonstrated in CDF.It makes use of binary readout in the front end electronics, followed by transfer of the full granularity data off detector using optical links to dedicated processors which reconstruct tracks.

The increase of luminosity at HL-LHC will require the introduction of tracker information at Level-1 trigger system for the experiments to maintain an acceptable trigger rate to select interesting events despite the one order of magnitude increase in the minimum bias interactions. To extract in the required latency the track information a dedicated hardware has to be used. We present the tests of a prototype system (Pattern Recognition Mezzanine) as core of pattern recognition and track fitting for HL-LHC ATLAS and CMS experiments, combining the power of both Associative Memory custom ASIC and modern Field Programmable Gate Array (FPGA) devices.

Next generation of pixel detectors for the first layers of the ATLAS and CMS experiments at the High-Luminosity Large Hadron Collider (HL-LHC) are expected to sustain the particle flow rates up to ~2 GHz/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The very high radiation levels and small available space makes it impossible to envisage optical conversion on chip, which should be done using electrical links, implying that a significant material contribution will be associated with data transport out of the detector volume. In this paper the results of the implementation of a lossless arithmetic data compression are presented. The proposed implementation achieves an average bandwidth reduction factor between 1.7 and 2.2, depending on the readout configuration. In addition, it is shown that the similar compression ratio can be achieved by using Huffman coding.

The increase of the luminosity in the High Luminosity upgrade of the CERN Large Hadron Collider (HL-LHC) will require the use of Tracker information in the evaluation of the Level-1 trigger in order to keep the trigger rate acceptable (i.e.: <; 1MHz). A custom real-time system will be needed to extract the track information within the latency constraints (<;10usec). We developed the prototype of the building block of this system, the Pattern Recognition Mezzanine (PRM) that combines the power of both Associative Memory custom ASICs and modern FPGA devices. The architecture and the functionalities of the PRM are described here.