G. ARNISON J, A. ASTBURY J, B. AUBERT b, C. BACCI i, G. BAUER x, A. BI~ZAGUET d R. BOCK d T.J.V. BOWCOCK f, M. CALVETTI d p. CATZ b, p. CENNINI d, S. CENTRO d F. CERADINI d,i S. CITTOLIN d, D. CLINE 1, C. COCHET k, j. COLAS b, M. CORDEN c D. DALLMAN d,1, D. DAU 2, M. DeBEER k, M. DELLA NEGRA b,d, M. DEMOULIN d, D. DENEGRI k, A. Di CIACCIO i, D. DiBITONTO d, L. DOBRZYNSKI g, J.D. DOWELL c K. EGGERT a, E. EISENHANDLER f, N. ELLIS d, p. ERHARD a, H. FAISSNER a, M. FINCKE 21 G. FONTAINE g, R. FREY h, R. FR()HWIRTH l, j . GARVEY c, S. GEER g, C. GHESQUII~RE g, P. GHEZ b, K. GIBONI a, W.R. GIBSON f, Y. GIRAUD-HI~RAUD g, A. GIVERNAUD k, A. GONIDEC b, G. GRAYER J, T. HANSL-KOZAIqECKA a, W.J. HAYNES J, L.O. HERTZBERGER 3, C. HODGES h D. HOFFMANN a, H. HOFFMANN d, D.J. HOLTHUIZEN 3, R.J. HOMER c, A. HONMA f, W. JANK d, G. JORAT d, P.I.P. KALMUS f, V. KARIMAKI e, R. KEELER f, I. KENYON c, A. KERNAN h R. KINNUNEN e, W. KOZANECKI h, D. KRYN d,g, F. LACAVA i, j._p. LAUGIER k, j..p. LEES b, H. LEHMANN a, R. LEUCHS a, A. LI~VI~QUE k,d, D. LINGLIN b, E. LOCCI k, j . . j . MALOSSE k, T. MARKIEWICZ d, G. MAURIN d, T. McMAHON c, j._p. MENDIBURU g, M.-N. MINARD b M. MOHAMMADI 1, M. MORICCA i, K. MORGAN h, H. MUIRHEAD 4, F. MULLER d, A.K. NANDI J, L. NAUMANN d, A. NORTON d, A. ORKIN-LECOURTOIS g, L. PAOLUZI i, F. PAUSS d, G. PIANO MORTARI i, E. PIETARINEN e, M. PIMI,g, e, A. PLACCI d, j.p. PORTE d E. RADERMACHER a, j. RANSDELL h, H. REITHLER a, j._p. REVOL d, j. RICH k, M. RIJSSENBEEK d, C. ROBERTS J, J. ROHLF d, p. ROSSI d, C. RUBBIA d, B. SADOULET d, G. SAJOT g, G. SALVI f, G. SALVINI i, j . SASS k, j . SAUDRAIX k, A. SAVOY-NAVARRO k, D. SCHINZEL d, W. SCOTT J, T.P. SHAH J, M. SPIRO k, j . STRAUSS 1, j. STREETS c, K. SUMOROK d, F. SZONCSO l, D. SMITH h, C. TAO 3, G. THOMPSON f, J. TIMMER d, E. TSCHESLOG a, j . TUOMINIEMI e, B. Van EIJK 3, j..p. VIALLE d, j . VRANAg, V. VUILLEMIN d, H.D. WAHL 1, p. WATKINS c, j. WILSON c, C. WULZ 1, G.Y. XIE d, M. YVERT b and E. ZURFLUH d

The forward proton spectrometer is part of the H1 detector at the HERA collider. Protons with energies above 500GeV and polar angles below 1mrad can be detected by this spectrometer. The main detector components are scintillating fiber detectors read out by position-sensitive photo-multipliers. These detectors are housed in the so-called Roman Pots which allow them to be moved close to the circulating proton beam. Four Roman Pot stations are located at distances between 60 and 90m from the interaction point.

The UA1 Collaboration has recently improved its measurement of the beauty production cross-section by including explicit measurements of bb correlations. Using these data we have determined the strong coupling constant αs. The comparison of the measured cross-section for 2-body final states with O(αs3) QCD predictions yields a measurement of αs(20 GeV) = 0.145−0.010 exp −0.016 th+0.012 +0.013, corresponding to αs(Mz) = 0.113−0.006 exp −0.009 th+0.007 +0.008. This is the first theoretically well-defined measurement of αs from a purely hadronic production process. Evaluating αs from cross-sections at different Q2-values we find that the running of αs is needed for internal consistency of the UA1 data.

We report on measurements of correlated\(b\bar b\) production in\(p\bar p\) collisions at\(\sqrt s = 630GeV\), using dimuon data to tag both theb and\(\bar b\) quarks. Starting from an inclusive dimuon sample we obtain improved cross-sections for single inclusive beauty production and confirm our earlier results on\(B^0 - \bar B^0\) mixing. From a study of\(b\bar b\) correlations we derive explicit cross-sections for semi-differential\(b\bar b\) production. We compare the measured cross-sections and correlations to\(\mathcal{O}\left( {\alpha _s^3 } \right)\) QCD predictions and find good quantitative agreement. From the measured angular distributions we establish a size-able contribution from higher order QCD processes with a significance of about seven standard deviations. A large nonperturbative contribution to these higher order corrections is excluded.

We report on measurements of correlated <img src="/fulltext-image.asp?format=htmlnonpaginated&src=Q2115JQQ165J57QH_html\10052_2005_Article_BF01641885_TeX2GIFIE3.gif" border="0" alt=" $$b\bar b$$ " /> production in <img src="/fulltext-image.asp?format=htmlnonpaginated&src=Q2115JQQ165J57QH_html\10052_2005_Article_BF01641885_TeX2GIFIE4.gif" border="0" alt=" $$p\bar p$$ " /> collisions at <img src="/fulltext-image.asp?format=htmlnonpaginated&src=Q2115JQQ165J57QH_html\10052_2005_Article_BF01641885_TeX2GIFIE5.gif" border="0" alt=" $$\sqrt s = 630GeV$$ " />, using dimuon data to tag both theb and <img src="/fulltext-image.asp?format=htmlnonpaginated&src=Q2115JQQ165J57QH_html\10052_2005_Article_BF01641885_TeX2GIFIE6.gif" border="0" alt=" $$\bar b$$ " /> quarks. Starting from an inclusive dimuon sample we obtain improved cross-sections for single inclusive beauty production and confirm our earlier results on <img src="/fulltext-image.asp?format=htmlnonpaginated&src=Q2115JQQ165J57QH_html\10052_2005_Article_BF01641885_TeX2GIFIE7.gif" border="0" alt=" $$B^0 - \bar B^0$$ " /> mixing. From a study of <img src="/fulltext-image.asp?format=htmlnonpaginated&src=Q2115JQQ165J57QH_html\10052_2005_Article_BF01641885_TeX2GIFIE8.gif" border="0" alt=" $$b\bar b$$ " /> correlations we derive explicit cross-sections for semi-differential <img src="/fulltext-image.asp?format=htmlnonpaginated&src=Q2115JQQ165J57QH_html\10052_2005_Article_BF01641885_TeX2GIFIE9.gif" border="0" alt=" $$b\bar b$$ " /> production. We compare the measured cross-sections and correlations to <img src="/fulltext-image.asp?format=htmlnonpaginated&src=Q2115JQQ165J57QH_html\10052_2005_Article_BF01641885_TeX2GIFIE10.gif" border="0" alt=" $$\mathcal{O}\left( {\alpha _s^3 } \right)$$ " /> QCD predictions and find good quantitative agreement. From the measured angular distributions we establish a size-able contribution from higher order QCD processes with a significance of about seven standard deviations. A large nonperturbative contribution to these higher order corrections is excluded.

A search for multifractal structures, in analogy with multifractal theories, is performed on UA1 minimum bias events. A downward concave multifractal spectral function,f(α) (where α is the Lipschitz-Hölder exponent), indicates that there are self-similar cascading processes, governing the evolution from the quark to the hadron level, in the final states of hadronic interactions.f(α) is an accurate measure of the bin to bin fluctuations of any observable. It is shown that the most sensitive comparison between data and the Monte Carlo models, GENCL and PYTHIA 4.8 can be made usingf(α). It is found that these models do not fully reproduce the behaviour of the data.

A search for multifractal structures, in analogy with multifractal theories, is performed on UA1 minimum bias events. A downward concave multifractal spectral function,f(α) (where α is the Lipschitz-Hölder exponent), indicates that there are self-similar cascading processes, governing the evolution from the quark to the hadron level, in the final states of hadronic interactions.f(α) is an accurate measure of the bin to bin fluctuations of any observable. It is shown that the most sensitive comparison between data and the Monte Carlo models, GENCL and PYTHIA 4.8 can be made usingf(α). It is found that these models do not fully reproduce the behaviour of the data.

We report on the first observation of the beauty baryon Λb in an exclusive decay channel at the CERN pp collider. Using 4.7 pb−1 of muon data collected in the 1988/89 collider runs we reconstruct 16±5 Λb's in the decay mode Λb→JψΛ above a background of 9±1 events, corresponding to a significance of about five standard deviations. We measure the Λb mass to be mΛb=5640±50±30 MeV/c2. Using the beauty cross-section measured by UA1 we deduce for the product of the production fraction and branching ratio fΛb Br (Λb→JψΛ)=(1.8±1.0)×10-10. Our sample contains three-muon event in which the beauty particle opposite to the Λb is tagged by the third muon. We also observe an indication of a signal in the decay channel B0→JψK0∗ with a significance of three standard deviations.

We report measurements of b-quark and B-hadron production in pp̄ collisions at √s=630 GeV. We use muon samples to extract beauty production cross-sections over a wide range of transverse momentum in the central rapidity range |y| < 1.5. We compare our results to an O(αs3) QCD prediction and find good agreement over the measured b-quark transverse momentum range 6 GeV/c to 54 GeV/c. Using the shape of the pT and y distribution predicted by QCD to extrapolate our data, we infer a total cross-section for b-quark production at √s=630 GeV of σ(pp̄→bb̄+X)=19.3±7(exp.)±9(th.μb.

An analysis of W and Z boson production at UA1, using 4.66 pb-1 of data from the 1988 and 1989 CERN ppBAR Collider runs at square root of s = 0.63 TeV, yields R = sigma(w)Br(W --> mu-v)/sigma(z)Br(z --> mu-mu) = 10.4(-1.5)(+1.8)(stat.) +/- 0.8(syst). We find R = 9.5(-1.0)(+1.1)(stat. + syst.) when combining all available UA1 data, in both the electron and muon channel, taken in the period 1983-1989. In the framework of the standard model, the value of R is used to infer the total width of the W boson, I(w) (tot) = 2.18(-0.24)(+0.26) (exp.) +/- 0.04 (theory) GeV/c2.

We have measured the production cross-section times branching ratio for J/ψ→μ+μ− in pp̄ interactions at √s = 630 GeV in the kinematic range |y|<2.0 and pT>5 GeV/c, BR(J/ψ→μ+μ−)σ(pp̄→J/ψ)=6.18±0.24±0.81 nb. The data sample collected in 1988 and 1989 for an integrated luminosity of 4.7 pb−1 represents a fivefold improvement over the statistics in our earlier study of the J/ψ production process, and the pT distribution which is measured extends to 28 GeV/c. Using event topology we show that the rate for the direct production of J/ψ, via radiative decays of χ states, is larger than that for production via B-hadrons. Production of ψ′ is also studied using the decay modes <ψ′→μ+μ− and ψ′→J/ψπ+ψ−.

We report on a search for the decays B0 --> mu+mu-, B --> mu+mu-X and B(d)0 --> mu+mu-K0*, which are expected to be rare if mediated by flavor changing neutral currents. Using data collected during the 1984-1989 CERN ppBAR Collider runs, the UA1 search was carried out using mu+mu- events with 3.9 < M(mu-mu) < 5.5 GeV/c2. We find 90% confidence level upper limits on the branching ratios for B0 --> mu+mu- of 8.3 x 10(-6), for B --> mu+mu-X of 5.0 x 10(-5), and for B(d)0 --> mu+mu-K0* of 2.3 x 10(-5). Implications for upper limits on the t-quark mass are discussed.