A gas-filled Time Projection Chamber and a radioactive neutron source were used to study recoil tracks produced by scattering of the multi-MeV neutrons on gas nuclei. Since the event readout is triggered by the first electron arrival, the initial time and position in the electron drift direction are unknown, leading to a translational uncertainty in this direction. By using the track width due to electron diffusion, the coordinate along the drift direction was determined. With a suitable width calibration at a known drift distance, it is found that width measurements of the track can provide useful information for establishing a well-defined gas fiducial volume for the interactions. The coordinate determination is also sufficiently precise that it can be used as a third parameter in kinematic reconstruction of the neutron collision, providing improved knowledge of the neutron collision process. Despite a wide range of track ionization levels resulting from the broad spectrum of neutron energies and varying angles of scatter, the coordinate determination is not sensitive to the track ionization.

The three-dimensional (3-D) detection of millimeter-scale ionization trails is of interest for detecting nuclear recoils in directional fast neutron detectors and in direction-sensitive searches for weakly interacting massive particles (WIMPs), which may constitute the Dark Matter of the universe. We report on performance characterization of a miniature gas target Time Projection Chamber (TPC) where the drift charge is avalanche-multiplied with Gas Electron Multipliers (GEMs) and detected with the ATLAS FE-I3 Pixel Application Specific Integrated Circuit (ASIC). We report on measurements of gain, gain resolution, point resolution, diffusion, angular resolution, and energy resolution with low-energy X-rays, cosmic rays, and alpha particles, using the gases Ar:CO2 (70:30) and He:CO2 (70:30) at atmospheric pressure. We discuss the implications for future, larger directional neutron and Dark Matter detectors. With an eye to designing and selecting components for these, we generalize our results into analytical expressions for detector performance whenever possible. We conclude by demonstrating the 3-D directional detection of a fast neutron source.

Gases for potential use as targets for directional dark matter detection were tested in a prototype detector using two sequential Gas Electron Multipliers, or GEMs. The sensitive volume consists of a mini-TPC of 12cm length and 7.5cm diameter. An FEI3 pixel chip, developed for the ATLAS experiment, was used to produce spatial measurements with high resolution. An Fe55 source produced photoelectrons by X-ray conversions in the sensitive volume, and images of these were recorded by the chip. Spatial resolution plots are shown for the gases, which include the practical electron range of the photoelectrons and the effects of diffusion in the mini-TPC. Avalanche gain and gain resolution measurements were made for the four gases tested, at atmospheric and sub-atmospheric pressures: Ar(70)/CO2(30), CF4, He(80)/CF4(20) and He(80)/isobutane(20).

The BaBar detector operated successfully at the PEP-II asymmetric e+e− collider at the SLAC National Accelerator Laboratory from 1999 to 2008. This report covers upgrades, operation, and performance of the collider and the detector systems, as well as the trigger, online and offline computing, and aspects of event reconstruction since the beginning of data taking.

We present our most recent work on the use of integrated silicon pixel electronics to read out gas-filled Time Projection Chambers (TPCs). Such detectors have great promise to measure the direction and energy of neutral particles via nuclear recoils that ionize the gas. We report on ongoing studies and refinement of the first prototype constructed at the University of Hawaii. We present data on the detection of alpha particles and fast neutrons using Ar:CO2 (70:30) and He:CO2 (70:30) gas, respectively. We also present plans and sensitivity estimates for a future Dark Matter search based on the technology under study.

Gas-filled Time Projection Chambers (TPCs) with Gas Electron Multipliers (GEMs) and pixels appear suitable for direction-sensitive WIMP dark matter searches. We present the background and motivation for our work on this technology, past and ongoing prototype work, and a development path towards an affordable, 1-m3-scale directional dark matter detector, D3. Such a detector may be particularly suitable for low-mass WIMP searches, and perhaps sufficiently sensitive to clearly determine whether the signals seen by DAMA, CoGeNT, and CRESST-II are due to low-mass WIMPs or background.

The branching fractions for the major decay modes of the ~ lepton are measured from a sample of tagged ~ decays selected from ~+~ pairs produced in e+e annihilation. The decay products of one member of the ~+~ pair are used to identify the event. The opposite member of the pair is then included in the sample if it satisfies an invariant-mass cut and a charged-multiplicity cut. In this way, we attempt to select an unbiased sample of ~ decays. The sample is divided into categories based on charged- and neutral-particle multiplicities, and charged-particle identification. The branching fractions are measured simultaneously, with an unfold technique and a maximum-likelihood fit, with the sum of the branching fractions constrained to be unity. The branching fractions for the decay modes ~ ~v K and ~ ~v, K* are fixed at the world averages in the fit. The following branching fractions are measured: and B(w 9)%%uo. The total branching fraction to one charged pion plus at least one neutra1 hadron is measured to be (37. 8+1. 2+1. 0)%. Limits on allowed decay modes involving the g meson are discussed.

Author(s): Aubert, B; Bona, M; Boutigny, D; Karyotakis, Y; Lees, JP; Poireau, V; Prudent, X; Tisserand, V; Zghiche, A; Garra Tico, J; Grauges, E; Lopez, L; Palano, A; Pappagallo, M; Eigen, G; Stugu, B; Sun, L; Abrams, GS; Battaglia, M; Brown, DN; Button-Shafer, J; Cahn, RN; Groysman, Y; Jacobsen, RG; Kadyk, JA; Kerth, LT; Kolomensky, YG; Kukartsev, G; Lopes Pegna, D; Lynch, G; Mir, LM; Orimoto, TJ; Osipenkov, IL; Ronan, MT; Tackmann, K; Tanabe, T; Wenzel, WA; Del Amo Sanchez, P; Hawkes, CM; Watson, AT; Koch, H; Schroeder, T; Walker, D; Asgeirsson, DJ; Cuhadar-Donszelmann, T; Fulsom, BG; Hearty, C; Mattison, TS; McKenna, JA; Khan, A; Saleem, M; Teodorescu, L; Blinov, VE; Bukin, AD; Druzhinin, VP; Golubev, VB; Onuchin, AP; Serednyakov, SI; Skovpen, YI; Solodov, EP; Todyshev, KY; Bondioli, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, AJ; Lund, P; Mandelkern, M; Martin, EC; Stoker, DP; Abachi, S; Buchanan, C; Foulkes, SD; Gary, JW; Liu, F; Long, O; Shen, BC; Vitug, GM; Zhang, L; Paar, HP; Rahatlou, S; Sharma, V; Berryhill, JW; Campagnari, C; Cunha, A | Abstract: We present a preliminary study of B- → D 0 (CP)π- and B- → D 0 (CP)K- decays, with the D 0 (CP)reconstructed in the CP-odd eigenstates Ksπ0, Ks, in the CP-even eigenstates K+K-, π+π-, and in the (non-CP) flavor eigenstate K ± π ± . Using a sample of about 382 million γ(4S) decays into BB pairs, collected with the BABAR detector operating at the PEP-II asymmetric-energy B Factory at SLAC, we measure the ratios of the branching fractions B(B- → D 0 CP±K-) + B(B+ → D 0 CP±K+) [B(B- → D 0 K-) + B(B+ → D 0 K+)]/2 and the direct CP asymmetry ACP± Ξ B(B-→D 0 CP±K-) - B(B+→D 0 CP±K+) B(B-→D 0 CP±K-) + B(B+→D 0 CP±K+) . The results are: RCP- = 0.81 ± 0.10(stat) ± 0.05(syst) RCP+ = 1.07 ± 0.10(stat) ± 0.04(syst) ACP- = -0.19 ± 0.12(stat) ± 0.02(syst) ACP+ = 0.35 ± 0.09(stat) ± 0.05(syst).

We present the case for a dark matter detector with directional sensitivity. This document was developed at the 2009 CYGNUS workshop on directional dark matter detection, and contains contributions from theorists and experimental groups in the field. We describe the need for a dark matter detector with directional sensitivity; each directional dark matter experiment presents their project's status; and we close with a feasibility study for scaling up to a one ton directional detector, which would cost around $150M.

We use a sample of 384 million BBbar events collected with the Babar detector at the PEP-II e+e- collider to study angular distributions in the rare decays B -> K* l+l-, where l+l- is either e+e- or mu+mu-. For low dilepton invariant masses, m(l+l-)<2.5 GeV/c^2, we measure a lepton forward-backward asymmetry AFB=0.24 (+0.18,-0.23) +/- 0.05 and K* longitudinal polarization FL=0.35 +/- 0.16 +/- 0.04$. For m(l+l-)>3.2$ GeV/c^2, we measure AFB=0.76 (+0.52,-0.32) +/- 0.07 FL=0.71 (+0.20,-0.22) +/- 0.04.

B. Aubert, M. Bona, Y. Karyotakis, J. P. Lees, V. Poireau, X. Prudent, V. Tisserand, A. Zghiche, J. Garra Tico, E. Grauges, L. Lopez, A. Palano, M. Pappagallo, G. Eigen, B. Stugu, L. Sun, G. S. Abrams, M. Battaglia, D.N. Brown, J. Button-Shafer, R. N. Cahn, R. G. Jacobsen, J. A. Kadyk, L. T. Kerth, Yu. G. Kolomensky, G. Kukartsev, G. Lynch, I. L. Osipenkov, M. T. Ronan,* K. Tackmann, T. Tanabe, W.A. Wenzel, C.M. Hawkes, N. Soni, A. T. Watson, H. Koch, T. Schroeder, D. Walker, D. J. Asgeirsson, T. Cuhadar-Donszelmann, B.G. Fulsom, C. Hearty, T. S. Mattison, J. A. McKenna, M. Barrett, A. Khan, M. Saleem, L. Teodorescu, V. E. Blinov, A.D. Bukin, A. R. Buzykaev, V. P. Druzhinin, V. B. Golubev, A. P. Onuchin, S. I. Serednyakov, Yu. I. Skovpen, E. P. Solodov, K.Yu. Todyshev, M. Bondioli, S. Curry, I. Eschrich, D. Kirkby, A. J. Lankford, P. Lund, M. Mandelkern, E. C. Martin, D. P. Stoker, S. Abachi, C. Buchanan, J.W. Gary, F. Liu, O. Long, B. C. Shen,* G.M. Vitug, Z. Yasin, L. Zhang, H. P. Paar, S. Rahatlou, V. Sharma, C. Campagnari, T.M. Hong, D. Kovalskyi, M.A. Mazur, J. D. Richman, T.W. Beck, A.M. Eisner, C. J. Flacco, C. A. Heusch, J. Kroseberg, W. S. Lockman, T. Schalk, B.A. Schumm, A. Seiden, M.G. Wilson, L. O. Winstrom, E. Chen, C. H. Cheng, D.A. Doll, B. Echenard, F. Fang, D. G. Hitlin, I. Narsky, T. Piatenko, F. C. Porter, R. Andreassen, G. Mancinelli, B. T. Meadows, K. Mishra, M.D. Sokoloff, F. Blanc, P. C. Bloom, W. T. Ford, J. F. Hirschauer, A. Kreisel, M. Nagel, U. Nauenberg, A. Olivas, J. G. Smith, K.A. Ulmer, S. R. Wagner, R. Ayad, A.M. Gabareen, A. Soffer, W.H. Toki, R. J. Wilson, D.D. Altenburg, E. Feltresi, A. Hauke, H. Jasper, M. Karbach, J. Merkel, A. Petzold, B. Spaan, K. Wacker, V. Klose, M. J. Kobel, H.M. Lacker, W. F. Mader, R. Nogowski, J. Schubert, K. R. Schubert, R. Schwierz, J. E. Sundermann, A. Volk, D. Bernard, G. R. Bonneaud, E. Latour, Ch. Thiebaux, M. Verderi, P. J. Clark, W. Gradl, S. Playfer, A. I. Robertson, J. E. Watson, M. Andreotti, D. Bettoni, C. Bozzi, R. Calabrese, A. Cecchi, G. Cibinetto, P. Franchini, E. Luppi, M. Negrini, A. Petrella, L. Piemontese, E. Prencipe, V. Santoro, F. Anulli, R. Baldini-Ferroli, A. Calcaterra, R. de Sangro, G. Finocchiaro, S. Pacetti, P. Patteri, I.M. Peruzzi,27,x M. Piccolo, M. Rama, A. Zallo, A. Buzzo, R. Contri, M. Lo Vetere, M.M. Macri, M. R. Monge, S. Passaggio, C. Patrignani, E. Robutti, A. Santroni, S. Tosi, K. S. Chaisanguanthum, M. Morii, R. S. Dubitzky, J. Marks, S. Schenk, U. Uwer, D. J. Bard, P. D. Dauncey, J. A. Nash, W. Panduro Vazquez, M. Tibbetts, P. K. Behera, X. Chai, M. J. Charles, U. Mallik, J. Cochran, H. B. Crawley, L. Dong, V. Eyges, W. T. Meyer, S. Prell, E. I. Rosenberg, A. E. Rubin, Y.Y. Gao, A.V. Gritsan, Z. J. Guo, C. K. Lae, A.G. Denig, M. Fritsch, G. Schott, N. Arnaud, J. Béquilleux, A. D’Orazio, M. Davier, J. Firmino da Costa, G. Grosdidier, A. Höcker, V. Lepeltier, F. Le Diberder, A.M. Lutz, S. Pruvot, P. Roudeau, M.H. Schune, J. Serrano, V. Sordini, A. Stocchi, W. F. Wang, G. Wormser, D. J. Lange, D.M. Wright, I. Bingham, J. P. Burke, C. A. Chavez, J. R. Fry, E. Gabathuler, R. Gamet, D. E. Hutchcroft, D. J. Payne, C. Touramanis, A. J. Bevan, K. A. George, F. Di Lodovico, R. Sacco, M. Sigamani, G. Cowan, H.U. Flaecher, D.A. Hopkins, S. Paramesvaran, F. Salvatore, A. C. Wren, D.N. Brown, C. L. Davis, K. E. Alwyn, N. R. Barlow, R. J. Barlow, Y.M. Chia, C. L. Edgar, G.D. Lafferty, T. J. West, J. I. Yi, J. Anderson, C. Chen, A. Jawahery, D.A. Roberts, G. Simi, J.M. Tuggle, C. Dallapiccola, S. S. Hertzbach, X. Li, E. Salvati, S. Saremi, R. Cowan, D. Dujmic, P. H. Fisher, K. Koeneke, G. Sciolla, M. Spitznagel, F. Taylor, R. K. Yamamoto, M. Zhao, S. E. Mclachlin,* P.M. Patel, S. H. Robertson, A. Lazzaro, V. Lombardo, F. Palombo, J.M. Bauer, L. Cremaldi, V. Eschenburg, R. Godang, R. Kroeger, D.A. Sanders, D. J. Summers, H.W. Zhao, S. Brunet, D. Côté, M. Simard, P. Taras, F. B. Viaud, H. Nicholson, G. De Nardo, L. Lista, D. Monorchio, C. Sciacca, M.A. Baak, G. Raven, H. L. Snoek, C. P. Jessop, K. J. Knoepfel, J.M. LoSecco, G. Benelli, L. A. Corwin, K. Honscheid, H. Kagan, R. Kass, J. P. Morris, A.M. Rahimi, J. J. Regensburger, S. J. Sekula, Q. K. Wong, N. L. Blount, J. Brau, R. Frey, O. Igonkina, J. A. Kolb, M. Lu, R. Rahmat, N. B. Sinev, D. Strom, J. Strube, E. Torrence, G. Castelli, N. Gagliardi, A. Gaz, M. Margoni, M. Morandin, M. Posocco, M. Rotondo, F. Simonetto, R. Stroili, C. Voci, P. del Amo Sanchez, E. Ben-Haim, H. Briand, G. Calderini, J. Chauveau, P. David, L. Del Buono, O. Hamon, Ph. Leruste, J. Malclès, J. Ocariz, A. Perez, J. Prendki, L. Gladney, M. Biasini, R. Covarelli, E. Manoni, C. Angelini, G. Batignani, S. Bettarini, M. Carpinelli,60,k A. Cervelli, F. Forti, M.A. Giorgi, PHYSICAL REVIEW D 79, 072003 (2009)

We present constraints on the angle gamma of the unitarity triangle with a Dalitz analysis of neutral D decays to K-S pi(+)pi(-) from the processes B-0 ->(D)over bar(0)K(*0) ((B)over bar(0)-> D-0(K)over bar (*0)) and B-0 ->(DK*0)-K-0 ((B)over bar(0)->(D)over bar(0)(K)over bar(*0)) with K-*0 -> K+pi(-) ((K)over bar(*0)-> K-pi(+)). Using a sample of 371x10(6) B(B)over bar pairs collected with the BABAR detector at PEP-II, we constrain the angle gamma as a function of r(S), the magnitude of the average ratio between b -> u and b -> c amplitudes.

We perform a measurement of the CP asymmetry in b-->sgamma decays using a sample of 383 x 10(6) B[over] B events collected by the BABAR detector at the SLAC PEP-II asymmetric B factory. We reconstruct 16 flavor-specific B decay modes containing a high-energy photon and a hadronic system X_(s) containing an s quark. We measure the CP asymmetry to be -0.011+/-0.030(stat)+/-0.014(syst) for a hadronic system mass between 0.6 and 2.8 GeV/c(2).