D. van Eijk

Performance of the LHCb Outer Tracker

The LHCb Outer Tracker is a gaseous detector covering an area of 5 x 6 m(2) with 12 double layers of straw tubes. The detector with its services are described together with the commissioning and calibration procedures. Based on data of the first LHC running period from 2010 to 2012, the performance of the readout electronics and the single hit resolution and efficiency are presented. The efficiency to detect a hit in the central half of the straw is estimated to be 99.2%, and the position resolution is determined to be approximately 200 mu m. The Outer Tracker received a dose in the hottest region corresponding to 0.12 C/cm, and no signs of gain deterioration or other ageing effects are observed.

First observation of B-bar_s^0 -> D_s2^*+ X mu^- nu-bar decays

Using data collected with the LHCb detector in proton-proton collisions at a centre-of-mass energy of 7 TeV, the semileptonic decays B

First observation of the decay B-bar^0_s -> D^0 K^{*0} and a measurement of the ratio of branching fractions B( B^0_s -> D^0 K^{*0})/B( B-bar^0 -> D^0 \rho^0)

The first observation of the decay

First observation of

\bar{B}^0_s \to D^0 K^{*0}

B^0_s \to J/\psi f_0(980)

using

decays

pp

Measurements of the branching fractions for B{sub (s)}{yields}D{sub (s)}{pi}{pi}{pi} and {Lambda}{sub b}{sup 0}{yields}{Lambda}{sub c}{sup +}{pi}{pi}{pi}

data collected by the LHCb detector at a centre-of-mass energy of 7 TeV, corresponding to an integrated luminosity of 36 pb

Measurement of sigma (pp -> b(b)over-barX) at root s=7 TeV in the forward region

^{-1}

Radiation hardness of the LHCb Outer Tracker

, is reported. A signal of

Ageing in the LHCb outer tracker: Aromatic hydrocarbons and wire cleaning

34.4 \pm 6.8