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Double-sided silicon microstrip sensors are known to be sensitive to the radiation dose received during operation. The lifetime fluence for the Silicon Tracking System of the CBM experiment is estimated as 1014 1 MeV neq cm−2. In order to maintain the signal-to-noise ratio sufficiently high during all the time of operation we study the newest sensor prototypes irradiated to the single and double lifetime doses. The results of the tests are addressed in this paper.

Double-sided silicon microstrip sensors will be used in the Silicon Tracking System of the CBM experiment. During experimental run they will be exposed to a radiation field of up to 1x1014 1 MeV neq cm-2. Radiation tolerance studies were made on prototypes from two different vendors. Results from these prototype detectors before and after irradiation to twice that neutron fluence are discussed.

During 2011 the LHCb experiment at CERN collected 1.0 fb −1 of pp collisions. Due to the large heavy quark production cross-sections, these data provide unprecedented samples of heavy flavoured hadrons. The first results from LHCb have made a significant impact on the flavour physics landscape and have definitively proved the concept of a dedicated experiment in the forward region at a hadron collider. This document discusses the implications of these first measurements on classes of extensions to the Standard Model, bearing in mind the interplay with the results of searches for on-shell production of new particles at ATLAS and CMS. The physics potential of an upgrade to the LHCb detector, which would allow an order of magnitude more data to be collected, is emphasised.

A search is presented for long-lived particles with a mass between 25 and 50  GeV / c 2 and a lifetime between 1 and 200 ps in a sample of proton–proton collisions at a centre-of-mass energy of s = 7  TeV, corresponding to an integrated luminosity of 0.62  fb - 1 , collected by the LHCb detector. The particles are assumed to be pair-produced by the decay of a standard model-like Higgs boson. The experimental signature of the long-lived particle is a displaced vertex with two associated jets. No excess above the background is observed and limits are set on the production cross-section as a function of the long-lived particle mass and lifetime.

The double differential cross sections of the Drell-Yan lepton pair ( , dielectron or dimuon) production are measured as functions of the invariant mass , transverse momentum , and . The observable, derived from angular measurements of the leptons and highly correlated with , is used to probe the low- region in a complementary way. Dilepton masses up to 1 are investigated. Additionally, a measurement is performed requiring at least one jet in the final state. To benefit from partial cancellation of the systematic uncertainty, the ratios of the differential cross sections for various ranges to those in the Z mass peak interval are presented. The collected data correspond to an integrated luminosity of 36.3 of proton-proton collisions recorded with the CMS detector at the LHC at a centre-of-mass energy of 13 . Measurements are compared with predictions based on perturbative quantum chromodynamics, including soft-gluon resummation.

A search is reported for pairs of light Higgs bosons ( ) produced in supersymmetric cascade decays in final states with small missing transverse momentum. A data set of LHC collisions collected with the CMS detector at and corresponding to an integrated luminosity of 138 is used. The search targets events where both bosons decay into pairs that are reconstructed as large-radius jets using substructure techniques. No evidence is found for an excess of events beyond the background expectations of the standard model (SM). Results from the search are interpreted in the next-to-minimal supersymmetric extension of the SM, where a \"singlino\" of small mass leads to squark and gluino cascade decays that can predominantly end in a highly Lorentz-boosted singlet-like and a singlino-like neutralino of small transverse momentum. Upper limits are set on the product of the squark or gluino pair production cross section and the square of the branching fraction of the in a benchmark model containing almost mass-degenerate gluinos and light-flavour squarks. Under the assumption of an SM-like branching fraction, bosons with masses in the range 40-120 arising from the decays of squarks or gluinos with a mass of 1200-2500 are excluded at 95% confidence level.

The production of Z bosons associated with jets is measured in collisions at with data recorded with the CMS experiment at the LHC corresponding to an integrated luminosity of 36.3 . The multiplicity of jets with transverse momentum is measured for different regions of the Z boson's , from lower than 10 to higher than 100 . The azimuthal correlation between the Z boson and the leading jet, as well as the correlations between the two leading jets are measured in three regions of . The measurements are compared with several predictions at leading and next-to-leading orders, interfaced with parton showers. Predictions based on transverse-momentum dependent parton distributions and corresponding parton showers give a good description of the measurement in the regions where multiple parton interactions and higher jet multiplicities are not important. The effects of multiple parton interactions are shown to be important to correctly describe the measured spectra in the low regions.

A search is performed for the as yet unobserved baryonic Λb→Λη′ and Λb→Λη decays with 3fb−1 of proton-proton collision data recorded by the LHCb experiment. The B0→K0Sη′ decay is used as a normalisation channel. No significant signal is observed for the Λb→Λη′ decay. An upper limit is found on the branching fraction of B(Λb→Λη′)<3.1×10−6 at 90% confidence level. Evidence is seen for the presence of the Λb→Λη decay at the level of 3σ significance, with a branching fraction B(Λb→Λη)=(9.3+7.3−5.3)×10−6.

The angular distribution of the dimuon system of the decays.

Abstract The double differential cross sections of the Drell–Yan lepton pair ($$\\ell ^+\\ell ^-$$ℓ + ℓ - , dielectron or dimuon) production are measured as functions of the invariant mass$$m_{\\ell \\ell }$$m ℓ ℓ , transverse momentum$$p_{\\textrm{T}} (\\ell \\ell )$$p T ( ℓ ℓ ) , and$$\\varphi ^{*}_{\\eta }$$φ η ∗ . The$$\\varphi ^{*}_{\\eta }$$φ η ∗ observable, derived from angular measurements of the leptons and highly correlated with$$p_{\\textrm{T}} (\\ell \\ell )$$p T ( ℓ ℓ ) , is used to probe the low-$$p_{\\textrm{T}} (\\ell \\ell )$$p T ( ℓ ℓ ) region in a complementary way. Dilepton masses up to 1$$\\,\\text {Te\\hspace{-.08em}V}$$Te V are investigated. Additionally, a measurement is performed requiring at least one jet in the final state. To benefit from partial cancellation of the systematic uncertainty, the ratios of the differential cross sections for various$$m_{\\ell \\ell }$$m ℓ ℓ ranges to those in the Z mass peak interval are presented. The collected data correspond to an integrated luminosity of 36.3$$\\,\\text {fb}^{-1}$$fb - 1 of proton–proton collisions recorded with the CMS detector at the LHC at a centre-of-mass energy of 13$$\\,\\text {Te\\hspace{-.08em}V}$$Te V . Measurements are compared with predictions based on perturbative quantum chromodynamics, including soft-gluon resummation.