In data taken with the NA48 experiment at the CERN SPS in 1999, 730 candidates of the weak radiative hyperon decay Ξ → Λγ have been found with an estimated background of 58 ± 8 events. From these events the Ξ → Λγ decay asymmetry has been determined to α(Ξ → Λγ) = −0.78 ± 0.18stat ± 0.06syst, which is the first evidence of a decay asymmetry in Ξ → Λγ. The branching fraction of the decay has been measured to be Br(Ξ → Λγ) = (1.16 ± 0.05stat ± 0.06syst)× 10.

We present evidence for the existence of the strange b-flavoured meson B~ in a data sample of 470 628 hadronic Z decays recorded with the OPAL detector at LEP. A signal of 18.3±5.2(stat.)±0.9(syst.) D;;-£+ pairs (or charge conju,gate, R=e or R=Jl) is found after background subtraction, where the D, meson is detected in the )'lr and K*°K final states. Interpreting this signal as coming from the semileptonic deeay B~ --+ D; e+ v X and combining the two decay modes of the D., we find J(b--+ B~) · B(B~--+ D;;-R+vX) · B(D;;---+ >7r-)= (3.9±l.l(stat.)±0.8(syst.))x10-\ where J(b--+ B~) is the fraction of b quarks that result in a B~ meson in Z decays. This signal for the B~ is supported by our observation of an excess of 147±48 inclusive D, mesons in the >1r and K*°K modes above the number expected from B0 and B+ decays and from the fragmentation of primary c quarks. In addition, a search is made for the exclusive decay B~--+ JflP>. Based on one candidate event the 90% confidence level upper limit is determined to be f(b-+ B~) · B(B~ -+Jj./J>) < 0.22%. (Submitted to Physics Letters B) The 0 PAL Collaboration P.D. Acton, G. Alexander, J. Allison's, P.P. Allports, K.J. Anderson9 , S. Arcell?, A. Astbury2s, D. Axen29 , G. Azuelos1s,a, G.A. Bahan's, J.T.M. Baines's, A.H. Ball17, J. Banks's, R.J. Barlow's, S. Barnett's, J.R. Batley\ G. Bea.udoin18, A. Beck23, J. Becker10, T. Behnke27, K.W. BelP0, G. Bella, P. Berlich, S. Bethke , 0. Biebel', U. Binder10, l.J.Bloodworth , P.Bock11 , B.Boden3 , H.M.Bosch11 , S.Bougerolle29, H.Breukers, R.M. Brown20, A. Buijss, H.J. Burckharts, C. Burgard, I'. Capilupp?, R.K. Carnegies, A.A. Carter, J.R. CarterS, C.Y. Chang , D.G. Charlton8 , P.E.L. Clarke2S, I. Cohen23 , J.C. Clayton', W.J. Collins , J.E. Conboy , M. Cooper , M. Coupland , M. Cuffiani , S. Dado , G.M. Dallavalle, S. De Jong , L.A. del Pozos, H. Deng17, A. Dieckmann11 , M. Dittmar\ M.S. Dixit7 , E. do Couto e Silva12 , J.E. Duboscq , E. Duchovnis, G. Duckeck11 , l.P. Duerdoth1s, D.J.P. Dumass, P.A. ElcombeS, P.G. Estabrooks6 , E. Etzion23 , H. G. Evans9 , F. Fabbri2, M. Fincke-Keeler28, H.M. Fischer3, D.G. Fong17 , M. Foucher17, A. Gaidot 21 , 0. GaneFs, J.W. Gary\ J. Gascon , R.F. McGowan's, N.I. Geddes20, C. Geich-Gimbel3, S.W. Gensler , F.X. Gentit 21 , G. Giacomelli 2, V. Gibsons, W.R. Gibson13, J.D. Gillies20, J.Goldberg22 , M.J.Goodrick5 , W.Gorn\ C.Grandi , F.C.Grant5 , J.Hagemann27, G.G. Hanson , M. Hansroul8 , C.K. Hargrove7, P.F. Harrison1\ J. Hart8 , P.M. Hattersley', M. Hauschild , C.M. Haw kess, E. Heflin\ R.J. Hemingways, R.D. Heuer , J.C. Hill, S.J. Hillier', T. Hilse, D.A. Hinshaw, J.D. Hobbs , P.R. Hobson2s, D. Hochman26, R.J. Homer', A.K. Honma28·•, C.P. Howarth15 , R.E. Hughes-Jones16 , R. Humbert10, P. lgo-Kemenes11 , H. Ihssen11 , D.C. Imrie, A. C. Janissens, A. Jawahery, P.W. Jeffreys20 , H. Jeremie, M. Jimack2 , M. Jobes', R.W.L. Jones13, P. Jovanovic', C. Jui4 , D. Karlen6 , K. Kawagoe24, T. Kawamoto4, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, S. Kluth', T. Kobayashi; T.P. Kokott3 , S. Komamiya24, L. Kopke8 , J.F. Krals, R. Kowalewski6, J. von Krogh11 , J. Kroll , M. Kuwano4, P. Kyberd, G.D. Lafferty's, F. Lamarche, J.G. Layter\ P. Le Du2', P. Leblanc1s, A.M. Lee17, M.H. Lehto15, D. Lellouch2s, P. Lennert11 , C. Leroy18, J. Letts\ S. Levegriin3 , L. Levinsons, S.L. Lloyd'', F.K. Loebinger16, J.M. Lorah17 , B. Lorazo , M.J. Losty7, X. C. Lou12 , J. Ludwig10 , M. Mannellis, S. Marcellini 2, G. Maringer3 , C. Markus3 , A.J. Martin, J.P. Martin, T. Mashimo<, P. Mattig , U. Maur', J. McKenna2s, T.J. McMahon', J.R. McNutt2s, F. Meijerss, D. Menszner11 , F.S. Merritt9 , H. Mes , A. Michelinis, R.P. Middleton, G. Mikenberg, J. Mildenberger, D.J. Miller, R. Mir, W. Mohr, C. Moisan18 , A. Montanari2 , T. Mori24, M. Mo:rii24, T. Mouthuy12 •b, B. Nellen3, H.H. Nguyen9 , M. Nozaki24, S.W. O'Neale•', F.G. Oakham, F. Odorici, H.O. Ogren12 , C.J. Oram•", M.J. Oreglia9 , S. Orito24, J.P. Pansart2', B. Panzer-Steindel8 , P. Paschievici2s, G.N. Patrick, N. Paz-Jaoshvili" , P. Pfister10 , J.E. Pilcher9 , D. Pitman28, D.E. Plane8 , P. Poffenberger28 , B. Poli2 , A. Pouladdejs, E. Prebys8 , T.W. Pritchard13, H. Przysiezniak1s, G. Quast, M.W. Redmond , D.L. Rees', G.E. RichardE

From the 2002 data taking with a neutral kaon beam extracted from the CERN-SPS, the NA48/1 experiment observed 97 Xi(0) -> Sigma(+)mu(-)(nu) over bar (mu) candidates with a background contamination of 30.8 +/- 4.2 events. From this sample, the BR( Xi(0) -> Sigma(+)mu(-)(nu) over bar (mu) ) is measured to be (2.17 +/- 0.32(stat) +/- 0.17(syst)) x 10(-6). (C) 2013 Elsevier B.V. All rights reserved.

From the 2002 data taking with a neutral kaon beam extracted from the CERN-SPS, the NA48/1 experiment observed 97 $\Xi^{0}\rightarrow \Sigma^{+} \mu^{-} \bar{\nu}_{\mu}$ candidates with a background contamination of $30.8 \pm 4.2$ events. From this sample, the BR($\Xi^{0}\rightarrow \Sigma^{+} \mu^{-} \bar{\nu}_{\mu}$) is measured to be $(2.17 \pm 0.32_{\mathrm{stat}}\pm 0.17_{\mathrm{syst}})\times10^{-6}$.

The CERN Data Centre is reviewing strategies for optimizing the use of the existing infrastructure and expanding to a new data centre by studying how other large sites are being operated. Over the past six months, CERN has been investigating modern and widely-used tools and procedures used for virtualisation, clouds and fabric management in order to reduce operational effort, increase agility and support unattended remote data centres. This paper gives the details on the project's motivations, current status and areas for future investigation.

The KS→π+π−e+e− decay mode was investigated using the data collected in 2002 by the NA48/1 Collaboration. With about 23 k KS→π+π−e+e− events and 59 k KL→π+π−πD0 normalization decays, the KS→π+π−e+e− branching ratio relative to the KL→π+π−πD0 one was determined to be BR(KS→π+π−e+e−)/BR(KL→π+π−πD0)=(3.28±0.06stat±0.04syst)×10−2. This result was used to set the upper limit |gE1/gBR|<3.0 at 90% CL on the presence, in the decay amplitude, of an E1 direct emission (gE1) term relative to the dominant inner bremsstrahlung (gBR) term. The CP-violating asymmetry Aϕ in the sinϕcosϕ distribution of KS→π+π−e+e− events, where ϕ is the angle between the π+π− and the e+e− decay planes in the kaon centre of mass, was found to be Aϕ=(−0.4±0.8)%, consistent with zero. These results are in good agreement with a description of the KS→π+π−e+e− decay amplitude dominated by the CP-even inner bremsstrahlung process.

The CMS CERN Analysis Facility (CAF) was primarily designed to host a large variety of latency-critical workflows. These break down into alignment and calibration, detector commissioning and diagnosis, and high-interest physics analysis requiring fast-turnaround. In addition to the low latency requirement on the batch farm, another mandatory condition is the efficient access to the RAW detector data stored at the CERN Tier-0 facility. The CMS CAF also foresees resources for interactive login by a large number of CMS collaborators located at CERN, as an entry point for their day-by-day analysis. These resources will run on a separate partition in order to protect the high-priority use-cases described above. While the CMS CAF represents only a modest fraction of the overall CMS resources on the WLCG GRID, an appropriately sized user-support service needs to be provided. We will describe the building, commissioning and operation of the CMS CAF during the year 2008. The facility was heavily and routinely used by almost 250 users during multiple commissioning and data challenge periods. It reached a CPU capacity of 1.4MSI2K and a disk capacity at the Peta byte scale. In particular, we will focus on the performances in terms of networking, disk access and job efficiency and extrapolate prospects for the upcoming LHC first year data taking. We will also present the experience gained and the limitations observed in operating such a large facility, in which well controlled workflows are combined with more chaotic type analysis by a large number of physicists.

A total of 368415 Xi(0) --> Lambda Xi(0) and 31 171 (Xi(0)) over bar --> (Lambda) over bar pi(0) were selected from data recorded in the NA48/1 experiment during 2002 data taking. From this sample, the polarization of Xi(0) and (Xi(0)) over bar hyperons was measured to be P-Xi 0 = -0.102 +/- 0.012(stat) +/- 0.008(syst) and P-(Xi 0) over bar = -0.01 +/- 0.04(stat) 0.008(syst). The dependence of P-Xi 0 on the Xi(0) transverse momentum with respect to the primary proton beam is also presented. With the same data sample. the ratio of (Xi(0)) over bar and Xi(0) fluxes in proton collisions at 400 GeV/c oil a beryllium target was measured. (C) 2009 Elsevier B.V. All rights reserved.

We present a measurement of the ratio of the decay rates Gamma(KL -> pi+ pi-)/Gamma(KL -> pi e nu), denoted as Gamma(K2pi)/Gamma(Ke3). The analysis is based on data taken during a dedicated run in 1999 by the NA48 experiment at the CERN SPS. Using a sample of 47000 K2pi and five million Ke3 decays, we find Gamma(K2pi)/Gamma(Ke3) = (4.835 +- 0.022(stat) +- 0.016(syst)) x 10^-3. From this we derive the branching ratio of the CP violating decay KL -> pi+ pi- and the CP violation parameter |eta+-|. Excluding the CP conserving direct photon emission component KL -> pi+ pi- gamma, we obtain the results BR(KL -> pi+ pi-) = (1.941 +- 0.019) x 10^-3 and |eta+-| = (2.223 +- 0.012) x 10^-3.