Detailed tests and analysis of ageing effects of high irradiation dose on Multi-Strip Multi-Gap Resistive Plate Counters (MSMGRPC) based on low resistivity glass electrodes, foreseen to be used for the most forward polar angles covered by the Time-of Flight (ToF) sub-detector of the Compressed Baryonic Matter (CBM) experiment at Facility for Antiprotons and Ion Research (FAIR) - Darmstadt are reported. The tests were performed at a multi-purpose irradiation facility of IFIN-HH based on Co-60 source. MSMGRPC efficiency, cluster size, surface and volume resistivity of the glass electrodes after irradiation are measured and compared with their values before irradiation. The results of a comprehensive analysis of the composition and properties of the deposited layers on the glass electrodes, based on different methods, i.e. Scanning Electron Microscope (SEM), X-ray Photoelectron Spectroscopy (XPS), foil Elastic Recoil Detection Analysis (ERDA), Rutherford Backscattering Spectrometry (RBS), Atomic Force Microscopy (AFM) and Terahertz Time Domain Spectroscopy (THz-TDS), are presented.

This erratum corrects measurements of the prompt and secondary (from-b).

Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (mu_B > 500 MeV), effects of chiral symmetry, and the equation-of-state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2022, in the context of the worldwide efforts to explore high-density QCD matter.

The new JINR project [1] is aimed at studies of highly excited nuclear matter created in nuclei by a high-energy deuteron beam. The matter is studied through observation of its particular decay products - pairs of energetic particles with a wide opening angle, close to 180°. The new precision hybrid magnetic spectrometer SCAN-3 is to be built for detecting charged (π±, K±, p) and neutral (n) particles produced at the JINR Nuclotron internal target in dA collisions. One of the main and complex tasks is a study of low-energy ηA interaction and a search for η-bound states (η-mesic nuclei). Basic elements of the spectrometer and its characteristics are discussed in the article.

Two dimensional position sensitive timing MGMSRPC prototypes were developed for the low polar angles of the CBM - TOF wall. Four MGMSRPC counters were arranged in a staggered geometrical configuration along the z direction, with overlap along and across the strips, in order to define a basic architecture for the inner zone of the CBM-TOF wall. This configuration was tested with mixed electron-pion beam at CERN-PS and with reaction products resulted from the heavy ion induced reactions at SIS18 - GSI Darmstadt and SPS - CERN. The performance of the basic architecture in conditions close to the ones expected for their operation in the inner zone o the CBM - TOF wall at SIS100/FAIR will be presented.

Charged hadron identification in the Compressed Baryonic Matter experiment (CBM) is realized via the Time-of-Flight method [1]. For this purpose the CBM-ToF collaboration designed a Time-of-Flight wall composed of Multi-gap Resistive Plate Chambers (MRPCs). Due to the high interaction rate in CBM of 10 MHz the key challenge is the development of high rate MRPCs above 25 kHz/cm2 which become possible after the development of low resistive glass with extremely good quality. In this article we present the actual conceptual design of the ToF-wall which is subdivided in three parts namely the outer wall, the inner wall and the forward zone that are discussed in detail.

We review status and perspectives of the search of the η-mesic nuclei at the synchrotron NUCLOTRON. This article present the results obtained at the spectrometer “SCAN” and the plans to study the interaction of eta-meson with nucleon and modification of the particle properties in the nuclear matter.

A new transition radiation detector (TRD) prototype foreseen to fulfill the requirements of the TRD subdetector of the CBM experiment at FAIR has been designed, constructed and tested with electrons and pions of a few GeV/c. The detector prototype was build with the original TRD architecture which preserves the high conversion efficiency of transition radiation in a single TRD layer. This TRD architecture is based on two multiwire proportional chambers readout by a common double-sided pad read-out electrode. The triangular shape of the readout pads gives access to the position information in both coordinates which defines the readout electrode plane. Pion efficiency as a function of number of TRD layers and position resolution were studied using electron and pion beams delivered by PS at CERN. Dedicated front-end electronics, designed for high counting rate environment was used. An extrapolated pion efficiency of 0.5% for a six layer TRD configuration at 90% electron efficiency using a regular foil radiator was obtained. The position resolution across the pads is of the order of 320μm and along the pads of 5.5 mm.

A transition radiation detector (TRD) prototype based on a single multiwire proportional chamber coupled with a small drift region was developed for the innermost part of the CBM-TRD subsystem. It preserves the same gas thickness for transition radiation absorption as the double-sided TRD prototype for which a pion misidentification probability of better than 1% for a six layer configuration was obtained. In the same time it fulfills the requirement of a high geometrical efficiency of CBM-TRD stations. The readout electrode geometry with triangular shaped pads gives access to a two-dimensional position information with a single TRD layer. The detector was tested with a mixed electron/pion beam of 1–5GeV/c momentum at the CERN PS accelerator. A pion misidentification probability of 1.18% for a six layer configuration based on this architecture was obtained. The two-dimensional position resolutions (along and across the pads) were measured. The pad signals were processed using a new front-end electronics called Fast Analog Signal Processor (FASP), designed for high-counting-rate environments. CADENCE simulations were used for further optimization of the FASP amplifier for operating this new architecture.

Absolute luminosity measurements are of general interest for colliding-beam experiments at storage rings. These measurements are necessary to determine the absolute cross-sections of reaction processes and are valuable to quantify the performance of the accelerator. Using data taken in 2010, LHCb has applied two methods to determine the absolute scale of its luminosity measurements for proton-proton collisions at the LHC with a centre-of-mass energy of 7 TeV. In addition to the classic "van der Meer scan" method a novel technique has been developed which makes use of direct imaging of the individual beams using beam-gas and beam-beam interactions. This beam imaging method is made possible by the high resolution of the LHCb vertex detector and the close proximity of the detector to the beams, and allows beam parameters such as positions, angles and widths to be determined. The results of the two methods have comparable precision and are in good agreement. Combining the two methods, an overal precision of 3.5% in the absolute luminosity determination is reached. The techniques used to transport the absolute luminosity calibration to the full 2010 data-taking period are presented.

The B-s(0)-(B) over bar (0)(s) oscillation frequency Delta m(s) is measured with 36 pb(-1) of data collected in pp collisions at = 7 TeV by the LHCb experiment at the Large Hadron Collider. A total of 1381 B-s(0) -> D-s(-) pi(+) and B-s(0) -> D-s(-) pi(+)pi(-)pi(+) signal decays are reconstructed, with average decay time resolutions of 44 fs and 36 fs, respectively. An oscillation signal with a statistical significance of 4.6 sigma is observed. The measured oscillation frequency is Delta m(s) = 17.63 +/- 0.11 (stat) +/-0.02 (syst)ps(-1) (C) 2012 CERN. Published by Elsevier B.V. All rights reserved.

The production of J/psi pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has been observed using an integrated luminosity of 37.5 pb(-1) collected with the LHCb detector. The production cross-section for pairs with both J/psi in the rapidity range 2 < y(J/psi) < 4.5 and transverse momentum p(T)(J/psi) < 10 GeV/c issigma(J/psi J/psi) = 5.1 +/- 1.0 +/- 1.1 nb,where the first uncertainty is statistical and the second systematic. (C) 2011 CERN. Published by Elsevier B.V. All rights reserved.

Measurement of mixing-induced CP violation in (B) over bar (0)(s) decays is of prime importance in probing new physics. So far only the channel (B) over bar (0)(s) -> J/psi phi has been used. Here we report on a measurement using an LHCb data sample of 0.41 fb(-1), in the CP odd eigenstate J/psi f(0)(980), where f(0)(980) -> pi(+)pi(-). A time-dependent fit of the data with the (B) over bar (0)(s) lifetime and the difference in widths of the heavy and light eigenstates constrained to the values obtained from (B) over bar (0)(s) -> J/psi phi yields a value of the CP violating phase of -0.44 +/- 0.44 +/- 0.02 rad, consistent with the Standard Model expectation. (C) 2012 CERN. Published by Elsevier B.V. All rights reserved.