Author: "Swallow, E." / Topic: particle physics - experiment - Searchworks@Jio Institute Digital Library Search Results

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33 results on '"Swallow, E."'

1. Recent results on Kaon decays from NA48/2

Author: Bizzeti, A., Anzivino, G., Arcidiacono, R., Baldini, W., Balev, S., Batley, J. R., Behler, M., Bi-Fani, S., Biino, C., Bloch-Devaux, B., Bocquet, G., Cabibbo, N., Calvetti, M., Cartiglia, N., Ceccucci, A., Cenci, P., Cerri, C., Cheshkov, C., Chèze, J. B., Clemencic, M., Collazuol, G., Costantini, F., Cotta Ramusino, A., Coward, D., Cundy, D., Dabrowski, A., Dalpiaz, P., Damiani, C., Beer, M., Derré, J., Dibon, H., Dilella, L., Doble, N., Eppard, K., Falaleev, V., Fantechi, R., Fidecaro, M., Fiorini, L., Fiorini, M., Fonseca Martin, T., Frabetti, P. L., Gatignon, L., Gersabeck, E., Gianoli, A., Giudici, S., Gonidec, A., Goudzovski, E., Goy Lopez, S., Hita-Hochgesand, M., Holder, M., Hristov, P., Iacopini, E., Imbergamo, E., Jeitler, M., Kalmus, G., Kekelidze, V., Kleinknecht, K., Kozhuharov, V., Kubischta, W., Lamanna, G., Lazzeroni, C., Lenti, M., Litov, L., Madigozhin, D., Maier, A., Mannelli, I., Marchetto, F., Marchevski, R., Marel, G., Markytan, M., Marouelli, P., Martini, M., Masetti, L., Mazzucato, E., Michetti, A., Mikulec, I., Misheva, M., Molokanova, N., Monnier, E., Moosbrugger, U., Morales Morales, C., Munday, D. J., Nappi, A., Neuhofer, G., Norton, A., Patel, M., Pepe, M., Peters, A., Petrucci, F., Petrucci, M. C., Peyaud, B., Mauro Piccini, Pierazzini, G., Polenkevich, I., Potrebenikov, Yu, Raggi, M., Renk, B., Rubin, P., Ruggiero, G., Savrié, M., Scarpa, M., Shieh, M., Slater, M. W., Sozzi, M., Stoynev, S., Swallow, E., Szleper, M., Valdata-Nappi, M., Vallage, B., Velasco, M., Veltri, M., Venditti, S., Wache, M., Wahl, H., Walker, A., Wanke, R., Widhalm, L., Winhart, A., Winston, R., Wood, M. D., Wotton, S. A., Zinchenko, A., and Ziolkowski, M.
Subjects: Physics, Particle physics, Chiral perturbation theory, Large Hadron Collider, Branching fraction, media_common.quotation_subject, Form factor (quantum field theory), Space (mathematics), Asymmetry, Particle Physics - Experiment, media_common
Abstract: The first observation of the $K^\pm → π^\pm π^0 e^+ e^-$ rare decay by the NA48/2 experiment at CERN SPS is reported, based on $∼2\times 10^{11} K^\pm$ decays recorded in 2003-2004. From a sample of 4919 candidates with 4.9% background the branching ratio in the full kinematic region is measured to be BR($K^± → π^± π^0 e^+ e^-) = (4.24\pm 0.14)\times 10^-6$.The study of the kinematic space shows evidence for a structure dependent contribution in agreement with predictions based on Chiral Perturbation Theory. The CP-violating asymmetry between $K^\pm → π^+ π^0 e^+ e^-$ and $K^- → π^- π^0 e^+ e^-$ decay rates has been measured, providing an upper limit $|A_{CP}| < 4.82 \times 10^{-2}$ at 90% CL.The NA48/2 combined measurement of the charged kaon semileptonic form factors, based on 4.4 million $K^\pm → π^0 e^± ν_e$ and 2.3 million $K^\pm → π^0 μ^\pm ν_μ$ events collected in 2004, is presented. This result represents the most precise form factor measurement from a combined $K_{l3}^{\pm}$ analysis.
Published: 2019

2. Searches for lepton number violation and resonances in $K^{\pm}\to\pi\mu\mu$ decays

Author: Batley, J.R., Kalmus, G., Lazzeroni, C., Munday, D.J., Slater, M.W., Wotton, S.A., Arcidiacono, R., Bocquet, G., Cabibbo, N., Ceccucci, A., Cundy, D., Falaleev, V., Fidecaro, M., Gatignon, L., Gonidec, A., Kubischta, W., Maier, A., Massri, K., Norton, A., Patel, M., Peters, A., Balev, S., Frabetti, P.L., Gersabeck, E., Goudzovski, E., Hristov, P., Kekelidze, V., Kozhuharov, V., Litov, L., Madigozhin, D., Molokanova, N., Polenkevich, I., Potrebenikov, Yu., Stoynev, S., Zinchenko, A., Monnier, E., Swallow, E., Winston, R., Rubin, P., Walker, A., Baldini, W., Cotta Ramusino, A., Dalpiaz, P., Damiani, C., Fiorini, M., Gianoli, A., Martini, M., Petrucci, F., Savrié, M., Scarpa, M., Wahl, H., Bizzeti, A., Lenti, M., Veltri, M., Calvetti, M., Celeghini, E., Iacopini, E., Ruggiero, G., Behler, M., Eppard, K., Kleinknecht, K., Marouelli, P., Masetti, L., Moosbrugger, U., Morales Morales, C., Renk, B., Wache, M., Wanke, R., Winhart, A., Coward, D., Dabrowski, A., Fonseca Martin, T., Shieh, M., Szleper, M., Velasco, M., Wood, M.D., Cenci, P., Pepe, M., Petrucci, M.C., Anzivino, G., Imbergamo, E., Nappi, A., Piccini, M., Raggi, M., Valdata-Nappi, M., Cerri, C., Fantechi, R., Collazuol, G., Dilella, L., Lamanna, G., Mannelli, I., Michetti, A., Costantini, F., Doble, N., Fiorini, L., Giudici, S., Pierazzini, G., Sozzi, M., Venditti, S., Bloch-Devaux, B., Cheshkov, C., Chèze, J.B., de Beer, M., Derré, J., Marel, G., Mazzucato, E., Peyaud, B., Vallage, B., Holder, M., Ziolkowski, M., Biino, C., Cartiglia, N., Marchetto, F., Bifani, S., Clemencic, M., Goy Lopez, S., Dibon, H., Jeitler, M., Markytan, M., Mikulec, I., Neuhofer, G., Widhalm, L., Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), NA48/2, Centre de Physique des Particules de Marseille ( CPPM ), Centre National de la Recherche Scientifique ( CNRS ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Aix Marseille Université ( AMU ), Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, Institut de Physique Nucléaire de Lyon ( IPNL ), Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Aix Marseille Université (AMU)
Subjects: CERN Lab, S010.46, branching ratio: upper limit, K: secondary beam, S010:Desig=46, resonance: lifetime, High Energy Physics - Experiment, [ PHYS.HEXP ] Physics [physics]/High Energy Physics - Experiment [hep-ex], [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], K: branching ratio, lepton number: violation, resonance: mass, hep-ex, CERN SPS, +pi-+muon%2B+muon%2B%22">K- --> pi- muon+ muon+, charged particle, inflaton, mass dependence, muon: pair production, intermediate state, K+: semileptonic decay, NA48, +pi%2B+muon-+muon%22">K+ --> pi+ muon- muon, S029AD2, Particle Physics - Experiment, experimental results, K-: semileptonic decay
Abstract: The NA48/2 experiment at CERN collected a large sample of charged kaon decays to final states with multiple charged particles in 2003--2004. A new upper limit on the rate of the lepton number violating decay $K^{\pm}\to\pi^{\mp}\mu^{\pm}\mu^{\pm}$ is reported: $\mathcal{B}(K^{\pm}\to\pi^{\mp}\mu^{\pm}\mu^{\pm}), Comment: 15 pages, accepted for publication in Physics Letters B
Published: 2017

3. ChPT tests at the NA48 and NA62 experiments at CERN

Author: NA48/2, Collaborations, NA62, Ambrosino, F., Antonelli, A., Anzivino, G., Arcidiacono, R., Baldini, W., Balev, S., Batley, J. R., Behler, M., Bifani, S., Biino, C., Bizzeti, A., Bloch-Devaux, B., Bocquet, G., Bolotov, V., Bucci, F., Cabibbo, N., Calvetti, M., Cartiglia, N., Ceccucci, A., Cenci, P., Cerri, C., Cheshkov, C., Chèze, J. B., Clemencic, M., Collazuol, G., Costantini, F., Ramusino, A. Cotta, Coward, D., Cundy, D., Dabrowski, A., D'Agostini, G., Dalpiaz, P., Damiani, C., Danielsson, H., De Beer, M., Dellacasa, G., Derré, J., Dibon, H., Di Filippo, D., DiLella, L., Doble, N., Duk, V., Engelfried, J., Eppard, K., Falaleev, V., Fantechi, R., Fidecaro, M., Fiorini, L., Fiorini, M., Martin, T. Fonseca, Frabetti, P. L., Fucci, A., Gallorini, S., Gatignon, L., Gersabeck, E., Gianoli, A., Giudici, S., Gonidec, A., Goudzovski, E., Lopez, S. Goy, Gushchin, E., Hallgren, B., Hita-Hochgesand, M., Holder, M., Hristov, P., Iacopini, E., Imbergamo, E., Jeitler, M., Kalmus, G., Kekelidze, V., Kleinknecht, K., Kozhuharov, V., Kubischta, W., Kurshetsov, V., Lamanna, G., Lazzeroni, C., Lenti, M., Leonardi, E., Litov, L., Madigozhin, D., Maier, A., Mannelli, I., Marchetto, F., Marel, G., Markytan, M., Marouelli, P., Martini, M., Masetti, L., Massarotti, P., Mazzucato, E., Michetti, A., Mikulec, I., Misheva, M., Molokanova, N., Monnier, E., Moosbrugger, U., Morales, C. Morales, Moulson, M., Movchan, S., Munday, D. J., Napolitano, M., Nappi, A., Neuhofer, G., Norton, A., Numao, T., Obraztsov, V., Palladino, V., Patel, M., Pepe, M., Peters, A., Petrucci, F., Petrucci, M. C., Peyaud, B., Piandani, R., Piccini, M., Pierazzini, G., Polenkevich, I., Popov, I., Potrebenikov, Yu., Raggi, M., Renk, B., Retière, F., Riedler, P., Romano, A., Rubin, P., Ruggiero, G., Salamon, A., Saracino, G., Savrié, M., Scarpa, M., Semenov, V., Sergi, A., Serra, M., Shieh, M., Shkarovskiy, S., Slater, M. W., Sozzi, M., Spadaro, T., Stoynev, S., Swallow, E., Szleper, M., Valdata-Nappi, M., Valente, P., Vallage, B., Velasco, M., Veltri, M., Venditti, S., Wache, M., Wahl, H., Walker, A., Wanke, R., Widhalm, L., Winhart, A., Winston, R., Wood, M. D., Wotton, S. A., Yushchenko, O., Zinchenko, A., and Ziolkowski, M.
Subjects: Nuclear physics, Physics, High Energy Physics - Experiment (hep-ex), Large Hadron Collider, FOS: Physical sciences, High Energy Physics::Experiment, Particle Physics - Experiment, High Energy Physics - Experiment
Abstract: The NA48/2 Collaboration at CERN has accumulated unprecedented statistics of rare kaon decays in the Ke4 modes: Ke4(+-) ($K^\pm \to \pi^+ \pi^- e^\pm \nu$) and Ke4(00) ($K^\pm \to \pi^0 \pi^0 e^\pm \nu$) with nearly one percent background contamination. The detailed study of form factors and branching rates, based on these data, has been completed recently. The results brings new inputs to low energy strong interactions description and tests of Chiral Perturbation Theory (ChPT) and lattice QCD calculations. In particular, new data support the ChPT prediction for a cusp in the $\pi^0\pi^0$ invariant mass spectrum at the two charged pions threshold for Ke4(00) decay. New final results from an analysis of about 400 $K^\pm \to \pi^\pm \gamma \gamma$ rare decay candidates collected by the NA48/2 and NA62 experiments at CERN during low intensity runs with minimum bias trigger configurations are presented. The results include a model-independent decay rate measurement and fits to ChPT description., Comment: XIIth International Conference on Heavy Quarks and Leptons 2014, Mainz, Germany
Published: 2016

4. Precision tests of the Standard Model with kaon decays at CERN

Author: Aglieri Rinella, G, Aliberti, R, Ambrosino, F, Angelucci, B, Antonelli, A, Anzivino, G, Arcidiacono, R, Azhinenko, I, Baldini, W, Balev, S, Batley, Jr, Behler, M, Bendotti, J, Biagioni, A, Bifani, S, Biino, C, Bizzeti, A, Blazek, T, Blik, A, Bloch Devaux, B, Bocquet, G, Bolotov, V, Bonaiuto, V, Bragadireanu, M, Britton, D, Britvich, G, Brook, N, Bucci, F, Buescher, V, Butin, F, Cabibbo, N, Calvetti, M, Capitolo, E, Capoccia, C, Capussela, T, Carassiti, V, Cartiglia, N, Cassese, A, Catinaccio, A, Cecchetti, A, Ceccucci, A, Cenci, P, Cerny, V, Cerri, C, Cheshkov, C, Chèze, Jb, Chikilev, O, Ciaranfi, R, Clemencic, M, Collazuol, G, Cooke, P, Cooper, P, Corradi, G, Cortina Gil, E, Costantini, F, Cotta Ramusino, A, Coward, D, Cundy, D, Dabrowski, A, D'Agostini, G, Dainton, J, Dalpiaz, P, Damiani, C, Danielsson, H, De Beer, M, De Simone, N, Degrange, J, Derré, J, Di Filippo, D, Di Lella, L, Dibon, H, Dilella, L, Dixon, N, Doble, N, Duk, V, Elsha, V, Engelfried, J, Enik, T, Eppard, K, Falaleev, V, Fantechi, R, Federici, L, Fidecaro, M, Fiorini, L, Fiorini, M, Fonseca Martin, T, Frabetti, Pl, Fry, J, Fucci, A, Fulton, L, Gallorini, S, Gatignon, L, Gersabeck, E, Gianoli, A, Giudici, S, Glonti, L, Goncalves Martins, A, Gonidec, A, Gonnella, F, Goudzovski, E, Goy Lopez, S, Guida, R, Gushchin, E, Hahn, F, Hallgren, B, Heath, H, Herman, F, Holder, M, Hristov, P, Hutchcroft, D, Iacopini, E, Imbergamo, E, Jamet, O, Jarron, P, Jeitler, M, Kalmus, G, Kampf, K, Kaplon, J, Karjavin, V, Kekelidze, V, Kholodenko, S, Khoriauli, G, Khudyakov, A, Kiryushin, Y, Kleinknecht, K, Kluge, A, Koval, M, Kozhuharov, V, Krivda, M, Kubischta, W, Kudenko, Y, Kunze, J, Lamanna, G, Lazzeroni, C, Leitner, R, Lenci, R, Lenti, M, Leonardi, E, Lichard, P, Lietava, R, Litov, L, Lomidze, D, Lonardo, A, Lurkin, N, Madigozhin, D, Maier, A, Maire, G, Makarov, A, Mannelli, I, Mannocchi, G, Mapelli, A, Marchetto, F, Marel, G, Markytan, M, Marouelli, P, Martini, M, Masetti, L, Massarotti, P, Massri, K, Matak, P, Mazza, G, Mazzucato, E, Menichetti, E, Michetti, A, Mikulec, I, Mirra, M, Misheva, M, Molokanova, N, Monnier, E, Moosbrugger, U, Morales Morales, C, Morant, J, Morel, M, Moulson, M, Movchan, S, Munday, Dj, Munday, D, Napolitano, M, Nappi, A, Neuhofer, G, Newson, F, Norton, A, Noy, M, Nuessle, G, Obraztsov, V, Padolski, S, Page, R, Palladino, V, Pardons, A, Patel, M, Pedreschi, E, Pepe, M, Perez Gomez, F, Perrin Terrin, M, Peters, A, Petrov, P, Petrucci, F, Petrucci, Mc, Peyaud, B, Piandani, R, Piccini, M, Pierazzini, G, Pietreanu, D, Pinzino, J, Pivanti, M, Polenkevich, I, Popov, I, Potrebenikov, Y, Protopopescu, D, Raffaelli, F, Raggi, M, Renk, B, Riedler, P, Romano, A, Rubin, P, Ruggiero, G, Russo, V, Ryjov, V, Salamon, A, Salina, G, Samsonov, V, Santovetti, E, Saracino, G, Sargeni, F, Savrié, M, Scarpa, M, Schifano, S, Semenov, V, Sergi, A, Serra, M, Shieh, M, Shkarovskiy, S, Slater, Mw, Sotnikov, A, Sougonyaev, V, Sozzi, M, Spadaro, T, Spinella, F, Staley, R, Statera, M, Stoynev, S, Sutcliffe, P, Swallow, E, Szilasi, N, Szleper, M, Tagnani, D, Valdata Nappi, M, Valente, P, Vallage, B, Vasile, M, Vassilieva, V, Velasco, M, Velghe, B, Veltri, M, Venditti, S, Vormstein, M, Wache, M, Wahl, H, Walker, A, Wanke, R, Wertelaers, P, Widhalm, L, Winhart, A, Winston, R, Wood, Md, Wotton, Sa, Wrona, B, Yushchenko, O, Zamkovsky, M, Zinchenko, A, and Ziolkowski, M
Subjects: Physics, History, Sterile neutrino, Particle physics, Physics beyond the Standard Model, High Energy Physics::Phenomenology, NA62 experiment, Lepton number, dark matter, Computer Science Applications, Education, Standard Model, Settore FIS/04 - Fisica Nucleare e Subnucleare, Higgs sector, Nuclear physics, Pion, High Energy Physics::Experiment, Kaon decays, Neutrino, Nuclear Experiment, Neutrino oscillation, Kaon decays, dark matter, confidence intervals, Particle Physics - Experiment, confidence intervals, Lepton
Abstract: Recent results and prospects for precision tests of the Standard Model in kaon decay-in-flight experiments at CERN are presented. A measurement of the ratio of leptonic decay rates of the charged kaon at the level of 0.4% precision constrains the parameter space of new physics models with extended Higgs sector, a fourth generation of quarks and leptons or sterile neutrinos. Searches for heavy neutrino mass states and the dark photon in the ∼ 100 MeV/c(2) mass range based on samples collected in 2003-2007 are in progress and prospects will be discussed. The NA62 experiment, starting in 2014, will search for a range of lepton number and lepton flavour violating decays of the charged kaon and the neutral pion at improved sensitivities down to ∼ 10(-12), which will probe new physics scenarios involving heavy Majorana neutrinos or R-parity violating SUSY.
Published: 2015

5. Search for the dark photon in π0 decays by the NA48/2 experiment at CERN

Author: Goudzovski, Evgueni, Anzivino, G., Arcidiacono, R., Baldini, W., Balev, S., Batley, J. R., Behler, M., Bifani, S., Biino, C., Bizzeti, A., Bloch Devaux, B., Bocquet, G., Cabibbo, Nicola, Calvetti, M., Cartiglia, N., Ceccucci, A., Cenci, P., Cerri, C., Cheshkov, C., Chèze, J. B., Clemencic, M., Collazuol, G., Costantini, F., Ramusino, A. Cotta, Coward, D., Cundy, D., Dabrowski, A., Dalpiaz, P., Damiani, C., De Beer, M., Derré, J., Dibon, H., Dilella, L., Doble, N., Eppard, K., Falaleev, V., Fantechi, R., Fidecaro, M., Fiorini, L., Fiorini, M., Martin, T. Fonseca, Frabetti, P. L., Gatignon, L., Gersabeck, E., Gianoli, A., Giudici, S., Gonidec, A., Goudzovski, E., Lopez, S. Goy, Holder, M., Hristov, P., Iacopini, E., Imbergamo, E., Jeitler, M., Kalmus, G., Kekelidze, V., Kleinknecht, K., Kozhuharov, V., Kubischta, W., Lamanna, G., Lazzeroni, C., Lenti, M., Litov, L., Madigozhin, D., Maier, A., Mannelli, I., Marchetto, F., Marel, G., Markytan, M., Marouelli, P., Martini, M., Masetti, L., Mazzucato, E., Michetti, A., Mikulec, I., Molokanova, N., Monnier, E., Moosbrugger, U., Morales, C. Morales, Munday, D. J., Nappi, A., Neuhofer, G., Norton, A., Patel, M., Pepe, M., Peters, A., Petrucci, F., Petrucci, M. C., Peyaud, B., Piccini, M., Pierazzini, G., Polenkevich, I., Potrebenikov, Y. u., Raggi, Mauro, Renk, B., Rubin, P., Ruggiero, G., Savrié, M., Scarpa, M., Shieh, M., Slater, M. W., Sozzi, M., Stoynev, S., Swallow, E., Szleper, M., Valdata Nappi, M., Vallage, B., Velasco, M., Veltri, M., Venditti, S., Wache, M., Wahl, H., Walker, A., Wanke, R., Widhalm, L., Winhart, A., Winston, R., Wood, M. D., Wotton, S. A., Zinchenko, A., and Ziolkowski, M.
Subjects: Physics, Particle physics, Large Hadron Collider, kaon decays, hep-ex, QC1-999, Space (mathematics), Dark photon, High Energy Physics - Experiment, Physics and Astronomy (all), dark photon, dark photon, exclusion limit, kaon decays, Pi, exclusion limit, Decay chain, Particle Physics - Experiment
Abstract: A sample of $4.687\times 10^6$ fully reconstructed $K^\pm\to\pi^\pm\pi^0_D$, $\pi^0_D\to\gamma e^+e^-$ decay candidates in the kinematic range $m_{ee}>10~{\rm MeV}/c^2$ with a negligible background contamination collected by the NA48/2 experiment at CERN in 2003-04 is analysed to search for the dark photon ($A'$) via the decay chain $K^\pm\to\pi^\pm\pi^0$, $\pi^0\to\gamma A'$, $A'\to e^+e^-$. No signal is observed, and preliminary exclusion limits on space of dark photon mass $m_A'$ and mixing parameter $\varepsilon^2$ are reported., Comment: Talk given at the DHF 2014 conference, Messina, Italy, 24-26 September 2014
Published: 2015

6. Detailed study of the $K^\pm \rightarrow \pi^0 \pi^0 e^\pm \nu $ ($K_{e4}^{00}$) decay properties

Author: Batley, J.R., Kalmus, G., Lazzeroni, C., Munday, D.J., Slater, M.W., Wotton, S.A., Arcidiacono, R., Bocquet, G., Cabibbo, N., Ceccucci, A., Cundy, D., Falaleev, V., Fidecaro, M., Gatignon, L., Gonidec, A., Kubischta, W., Norton, A., Maier, A., Patel, M., Peters, A., Balev, S., Frabetti, P.L., Gersabeck, E., Goudzovski, E., Hristov, P., Kekelidze, V., Kozhuharov, V., Litov, L., Madigozhin, D., Molokanova, N., Polenkevich, I., Potrebenikov, Yu., Stoynev, S., Zinchenko, A., Monnier, E., Swallow, E., Winston, R., Rubin, P., Walker, A., Baldini, W., Cotta Ramusino, A., Dalpiaz, P., Damiani, C., Fiorini, M., Gianoli, A., Martini, M., Petrucci, F., Savrie, M., Scarpa, M., Wahl, H., Bizzeti, A., Lenti, M., Veltri, M., Calvetti, M., Celeghini, E., Iacopini, E., Ruggiero, G., Behler, M., Eppard, K., Gersabeck, M., Kleinknecht, K., Marouelli, P., Masetti, L., Moosbrugger, U., Morales Morales, C., Renk, B., Wache, M., Wanke, R., Winhart, A., Coward, D., Dabrowski, A., Fonseca Martin, T., Shieh, M., Szleper, M., Velasco, M., Wood, M.D., Cenci, P., Pepe, M., Petrucci, M.C., Anzivino, G., Imbergamo, E., Nappi, A., Piccini, M., Raggi, M., Valdata-Nappi, M., Cerri, C., Fantechi, R., Collazuol, G., DiLella, L., Lamanna, G., Mannelli, I., Michetti, A., Costantini, F., Doble, N., Fiorini, L., Giudici, S., Pierazzini, G., Sozzi, M., Venditti, S., Bloch-Devaux, B., Cheshkov, C., Cheze, J.B., De Beer, M., Derre, J., Marel, G., Mazzucato, E., Peyaud, B., Vallage, B., Holder, M., Ziolkowski, M., Biino, C., Cartiglia, N., Marchetto, F., Bifani, S., Clemencic, M., Goy Lopez, S., Dibon, H., Jeitler, M., Markytan, M., Mikulec, I., Neuhofer, G., and Widhalm, L.
Subjects: Particle Physics - Experiment
Abstract: A sample of 65210 $K^\pm \rightarrow \pi^0 \pi^0 e^\pm \nu $ ($K_{e4}^{00}$) decay candidates with $1\%$ background contamination has been collected in 2003--2004 by the NA48/2 collaboration at the CERN SPS. A study of the differential rate provides the first measurement of the hadronic form factor variation in the plane $(M_{\pi\pi}^2 ,M_{e\nu}^2)$ and brings evidence for a cusp-like structure in the distribution of the squared $\pi^0\pi^0$ invariant mass around $4m_{\pi^+}^2$. Exploiting a model independent description of this form factor, the branching ratio, inclusive of radiative decays, is obtained using the $K^\pm \rightarrow \pi^0 \pi^0 \pi^\pm $ decay mode as normalization. It is measured to be BR$(K_{e4}) = (2.552 ± 0.010_{stat} \pm 0.010_{syst} \pm 0.032_{ext}) \times 10^{−5}$ which improves the current world average precision by an order of magnitude while the $1.4\%$ relative precision is dominated by the external uncertainty from the normalization mode. A comparison with the properties of the corresponding mode involving a $\pi^+ \pi ^-$ pair ($K_{e4}^{+-}$) is also presented. A sample of 65210 $\mathrm{K^{\pm}} \rightarrow \pi^{0} \pi^{0} \mathrm{e^{\pm}} \nu$ ($\mathrm{K}_{\mathrm{e}4}^{00}$) decay candidates with $1\%$ background contamination has been collected in 2003$-$2004 by the NA48/2 collaboration at the CERN SPS. A study of the differential rate provides the first measurement of the hadronic form factor variation in the plane $(M_{\pi\pi}^2,M_{e\nu}^2)$ and brings evidence for a cusp-like structure in the distribution of the squared $\pi^{0} \pi^{0}$ invariant mass around $4m_{\pi^+}^2$. Exploiting a model independent description of this form factor, the branching ratio, inclusive of radiative decays, is obtained using the $\mathrm{K^{\pm}} \rightarrow \pi^{0} \pi^{0} \pi^{\pm}$ decay mode as normalization. It is measured to be BR($\mathrm{K}_{\mathrm{e}4}^{00}$) = $(2.552 \pm 0.010_{stat} \pm 0.010_{syst} \pm 0.032_{ext} ) \times 10^{-5}$, which improves the current world average precision by an order of magnitude while the $1.4\%$ relative precision is dominated by the external uncertainty from the normalization mode. A comparison with the properties of the corresponding mode involving a $\pi^{+} \pi^{-}$ pair ($\mathrm{K}_{\mathrm{e}4}^{+-}$) is also presented.
Published: 2014

7. Recent NA48/2 and NA62 results

Author: Madigozhin, D., Ambrosino, F., Antonelli, A., Anzivino, G., Arcidiacono, R., Baldini, W., Balev, S., Batley, J. R., Behler, M., Bifani, S., Biino, C., Bizzeti, A., Bloch-Devaux, B., Bocquet, G., Bolotov, V., Bucci, F., Cabibbo, N., Calvetti, M., Cartiglia, N., Ceccucci, A., Cenci, P., Cerri, C., Cheshkov, C., Cheze, J. B., Clemencic, M., Collazuol, G., Costantini, F., Cotta Ramusino, A., Coward, D., Cundy, D., Dabrowski, A., D Agostini, G., Dalpiaz, P., Damiani, C., Danielsson, H., Beer, M., Dellacasa, G., Derre, J., Dibon, H., Di Filippo, D., Dilella, L., Doble, N., Duk, V., Engelfried, J., Eppard, K., Falaleev, V., Fantechi, R., Fidecaro, M., Fiorini, L., Fiorini, M., Fonseca Martin, T., Frabetti, P. L., Fucci, A., Gallorini, S., Gatignon, L., Gersabeck, E., Gianoli, A., Giudici, S., Gonidec, A., Goudzovski, E., Goy Lopez, S., Gushchin, E., Hallgren, B., Hita-Hochgesand, M., Holder, M., Hristov, P., Iacopini, E., Imbergamo, E., Jeitler, M., Kalmus, G., Kekelidze, V., Kleinknecht, K., Kozhuharov, V., Kubischta, W., Kurshetsov, V., Lamanna, G., Lazzeroni, C., Lenti, M., Leonardi, E., Leandar Litov, Maier, A., Mannelli, I., Marchetto, F., Marel, G., Markytan, M., Marouelli, P., Martini, M., Masetti, L., Massarotti, P., Mazzucato, E., Michetti, A., Mikulec, I., Misheva, M., Molokanova, N., Monnier, E., Moosbrugger, U., Morales Morales, C., Moulson, M., Movchan, S., Munday, D. J., Napolitano, M., Nappi, A., Neuhofer, G., Norton, A., Numao, T., Obraztsov, V., Palladino, V., Patel, M., Pepe, M., Peters, A., Petrucci, F., Petrucci, M. C., Peyaud, B., Piandani, R., Piccini, M., Pierazzini, G., Polenkevich, I., Popov, I., Potrebenikov, Yu, Raggi, M., Renk, B., Retiere, F., Riedler, P., Romano, A., Rubin, P., Ruggiero, G., Salamon, A., Saracino, G., Savrie, M., Scarpa, M., Semenov, V., Sergi, A., Serra, M., Shieh, M., Shkarovskiy, S., Slater, M. W., Sozzi, M., Spadaro, T., Stoynev, S., Swallow, E., Szleper, M., Valdata-Nappi, M., Valente, P., Vallage, B., Velasco, M., Veltri, M., Venditti, S., Wache, M., Wahl, H., Walker, A., Wanke, R., Widhalm, L., Winhart, A., Winston, R., Wood, M. D., Wotton, S. A., Yushchenko, O., Zinchenko, A., and Ziolkowski, M.
Subjects: High Energy Physics - Experiment (hep-ex), hep-ex, FOS: Physical sciences, Particle Physics - Experiment, High Energy Physics - Experiment
Abstract: The NA48/2 Collaboration at CERN has accumulated and analysed unprecedented statistics of rare kaon decays in the $K_{e4}$ modes: $K_{e4}(+-)$ ($K^\pm \to \pi^+ \pi^- e^\pm \nu$) and $K_{e4}(00)$ ($K^\pm \to \pi^0 \pi^0 e^\pm \nu$) with nearly one percent background contamination. It leads to the improved measurement of branching fractions and detailed form factor studies. New final results from the analysis of 381 $K^\pm \to \pi^\pm \gamma \gamma$ rare decay candidates collected by the NA48/2 and NA62 experiments at CERN are presented. The results include a decay rate measurement and fits to Chiral Perturbation Theory (ChPT) description., Comment: Prepared for the Proceedings of "Moriond QCD and High Energy Interactions. March 22-29 2014." conference
Published: 2014

8. A new measurement of the $K^{\pm} \rightarrow \pi^{\pm} \gamma \gamma$ decay at the NA48/2 experiment

Author: Batley, J.R., Kalmus, G., Lazzeroni, C., Munday, D.J., Slater, M.W., Wotton, S.A., Arcidiacono, R., Bocquet, G., Cabibbo, N., Ceccucci, A., Cundy, D., Falaleev, V., Fidecaro, M., Gatignon, L., Gonidec, A., Kubischta, W., Norton, A., Maier, A., Patel, M., Peters, A., Balev, S., Frabetti, P.L., Gersabeck, E., Goudzovski, E., Hristov, P., Kekelidze, V., Kozhuharov, V., Litov, L., Madigozhin, D., Molokanova, N., Polenkevich, I., Potrebenikov, Yu., Stoynev, S., Zinchenko, A., Monnier, E., Swallow, E., Winston, R., Rubin, P., Walker, A., Baldini, W., Cotta Ramusino, A., Dalpiaz, P., Damiani, C., Fiorini, M., Gianoli, A., Martini, M., Petrucci, F., Savrie, M., Scarpa, M., Wahl, H., Bizzeti, A., Lenti, M., Veltri, M., Calvetti, M., Celeghini, E., Iacopini, E., Ruggiero, G., Behler, M., Eppard, K., Kleinknecht, K., Marouelli, P., Masetti, L., Moosbrugger, U., Morales Morales, C., Renk, B., Wache, M., Wanke, R., Winhart, A., Coward, D., Dabrowski, A., Fonseca Martin, T., Shieh, M., Szleper, M., Velasco, M., Wood, M.D., Cenci, P., Pepe, M., Petrucci, M.C., Anzivino, G., Imbergamo, E., Nappi, A., Piccini, M., Raggi, M., Valdata-Nappi, M., Cerri, C., Fantechi, R., Collazuol, G., DiLella, L., Lamanna, G., Mannelli, I., Michetti, A., Costantini, F., Doble, N., Fiorini, L., Giudici, S., Pierazzini, G., Sozzi, M., Venditti, S., Bloch-Devaux, B., Cheshkov, C., Cheze, J.B., De Beer, M., Derre, J., Marel, G., Mazzucato, E., Peyaud, B., Vallage, B., Holder, M., Ziolkowski, M., Biino, C., Cartiglia, N., Marchetto, F., Bifani, S., Clemencic, M., Goy Lopez, S., Dibon, H., Jeitler, M., Markytan, M., Mikulec, I., Neuhofer, G., and Widhalm, L.
Subjects: Particle Physics - Experiment
Abstract: The NA48/2 experiment at CERN collected two data samples with minimum bias trigger conditions in 2003 and 2004. A measurement of the rate and dynamic properties of the rare decay $K^\pm\to\pi^\pm\gamma\gamma$ from these data sets based on 149 decay candidates with an estimated background of $15.5\pm0.7$ events is reported. The model-independent branching ratio in the kinematic range $z=(m_{\gamma\gamma}/m_K)^2>0.2$ is measured to be ${\cal B}_{\rm MI}(z>0.2) = (0.877 \pm 0.089) \times 10^{-6}$, and the branching ratio in the full kinematic range assuming a particular Chiral Perturbation Theory description to be ${\cal B}(K_{\pi\gamma\gamma}) = (0.910 \pm 0.075) \times 10^{-6}$. The NA48/2 experiment at CERN collected two data samples with minimum bias trigger conditions in 2003 and 2004. A measurement of the rate and dynamic properties of the rare decay K±→π±γγ from these data sets based on 149 decay candidates with an estimated background of 15.5±0.7 events is reported. The model-independent branching ratio in the kinematic range z=(mγγ/mK)2>0.2 is measured to be BMI(z>0.2)=(0.877±0.089)×10−6 , and the branching ratio in the full kinematic range assuming a particular Chiral Perturbation Theory description to be B(Kπγγ)=(0.910±0.075)×10−6 . The NA48/2 experiment at CERN collected two data samples with minimum bias trigger conditions in 2003 and 2004. A measurement of the rate and dynamic properties of the rare decay $K^\pm\to\pi^\pm\gamma\gamma$ from these data sets based on 149 decay candidates with an estimated background of $15.5\pm0.7$ events is reported. The model-independent branching ratio in the kinematic range $z=(m_{\gamma\gamma}/m_K)^2>0.2$ is measured to be ${\cal B}_{\rm MI}(z>0.2) = (0.877 \pm 0.089) \times 10^{-6}$, and the branching ratio in the full kinematic range assuming a particular Chiral Perturbation Theory description to be ${\cal B}(K_{\pi\gamma\gamma}) = (0.910 \pm 0.075) \times 10^{-6}$.
Published: 2014

9. New measurement of the $K^{\pm} \to \pi^+\pi^-e^{\pm}\nu(K_{e4} )$ decay branching ratio and hadronic form factors

Author: Batley, J.R., Kalmus, G., Lazzeroni, C., Munday, D.J., Slater, M.W., Wotton, S.A., Arcidiacono, R., Bocquet, G., Cabibbo, N., Ceccucci, A., Cundy, D., Falaleev, V., Fidecaro, M., Gatignon, L., Gonidec, A., Kubischta, W., Norton, A., Maier, A., Patel, M., Peters, A., Balev, S., Frabetti, P.L., Gersabeck, E., Goudzovski, E., Hristov, P., Kekelidze, V., Kozhuharov, V., Litov, L., Madigozhin, D., Molokanova, N., Polenkevich, I., Potrebenikov, Yu., Stoynev, S., Zinchenko, A., Monnier, E., Swallow, E., Winston, R., Rubin, P., Walker, A., Baldini, W., Cotta Ramusino, A., Dalpiaz, P., Damiani, C., Fiorini, M., Gianoli, A., Martini, M., Petrucci, F., Savrie, M., Scarpa, M., Wahl, H., Bizzeti, A., Lenti, M., Veltri, M., Calvetti, M., Iacopini, E., Ruggiero, G., Behler, M., Eppard, K., Kleinknecht, K., Marouelli, P., Masetti, L., Moosbrugger, U., Morales Morales, C., Renk, B., Wache, M., Wanke, R., Winhart, A., Coward, D., Dabrowski, A., Fonseca Martin, T., Shieh, M., Szleper, M., Velasco, M., Wood, M.D., Cenci, P., Pepe, M., Petrucci, M.C., Anzivino, G., Imbergamo, E., Nappi, A., Piccini, M., Raggi, M., Valdata-Nappi, M., Cerri, C., Fantechi, R., Collazuol, G., DiLella, L., Lamanna, G., Mannelli, I., Michetti, A., Costantini, F., Doble, N., Fiorini, L., Giudici, S., Pierazzini, G., Sozzi, M., Venditti, S., Bloch-Devaux, B., Cheshkov, C., Cheze, J.B., De Beer, M., Derre, J., Marel, G., Mazzucato, E., Peyaud, B., Vallage, B., Holder, M., Ziolkowski, M., Biino, C., Cartiglia, N., Marchetto, F., Bifani, S., Clemencic, M., Goy Lopez, S., Dibon, H., Jeitler, M., Markytan, M., Mikulec, I., Neuhofer, G., and Widhalm, L.
Subjects: Particle Physics - Experiment
Abstract: A sample of more than one million $K^{\pm} \rightarrow \pi^{+} \pi^{-} e^{\pm} \nu$ ($K_{e4}$) decay candidates with less than one percent background contamination has been collected by the NA48/2 experiment at the CERN SPS in 2003--2004, allowing a detailed study of the decay properties. The branching ratio, inclusive of $K_{e4\gamma}$ decays, is measured to be BR$(K_{e4}) = (4.257 \pm 0.016_{exp} \pm0.031_{ext}) \times 10^{-5}$ with a total relative error of 0.8%. This measurement complements the study of S- and P-wave hadronic form factors by assigning absolute values to the relative hadronic form factors obtained earlier in a simultaneous analysis of the $\pi\pi$ scattering lengths conducted on the same data sample. The overall form factor normalization $f_s = 5.705 \pm 0.017_{exp} \pm 0.031_{ext}$ is obtained with a total relative precision of 0.6%. A sample of more than one million K±→π+π−e±ν ( Ke4 ) decay candidates with less than one percent background contamination has been collected by the NA48/2 experiment at the CERN SPS in 2003–2004, allowing a detailed study of the decay properties. The branching ratio, inclusive of Ke4γ decays, is measured to be BR(Ke4)=(4.257±0.016exp±0.031ext)×10−5 with a total relative error of 0.8% . This measurement complements the study of S- and P-wave hadronic form factors by assigning absolute values to the relative hadronic form factors obtained earlier in a simultaneous analysis of the ππ scattering lengths conducted on the same data sample. The overall form factor normalization fs=5.705±0.017exp±0.031ext is obtained with a total relative precision of 0.6% . A sample of more than one million Ke4 decay candidates with less than one percent background contamination has been collected by the NA48/2 experiment at the CERN SPS in 2003-2004, allowing a detailed study of the decay properties. The branching ratio, inclusive of radiative Ke4gamma decays, is measured to be BR(Ke4) = (4.257 +/- 0.016_exp +/- 0.031_ext) x 10-5 with a total relative error of 0.8%. This measurement complements the study of S- and P-wave hadronic form factors by assigning absolute values to the relative hadronic form factors obtained earlier in a simultaneous analysis of the pion-pion scattering lengths conducted on the same data sample. The overall form factor normalization f_s = 5.705 +/- 0.017_exp +/- 0.031_ext is obtained with a total relative precision of 0.6%.
Published: 2012

10. New measurement of the $K^{\pm} \to \pi^{\pm}\mu^{+}\mu^{-}$ decay

Author: Batley, J.R., Kalmus, G., Lazzeroni, C., Munday, D.J., Slater, M.W., Wotton, S.A., Arcidiacono, R., Bocquet, G., Cabibbo, N., Ceccucci, A., Cundy, D., Falaleev, V., Fidecaro, M., Gatignon, L., Gonidec, A., Kubischta, W., Norton, A., Maier, A., Patel, M., Peters, A., Balev, S., Frabetti, P.L., Goudzovski, E., Hristov, P., Kekelidze, V., Kozhuharov, V., Litov, L., Madigozhin, D., Marinova, E., Molokanova, N., Polenkevich, I., Potrebenikov, Yu., Stoynev, S., Zinchenko, A., Monnier, E., Swallow, E., Winston, R., Rubin, P., Walker, A., Baldini, W., Cotta Ramusino, A., Dalpiaz, P., Damiani, C., Fiorini, M., Gianoli, A., Martini, M., Petrucci, F., Savrie, M., Scarpa, M., Wahl, H., Bizzeti, A., Lenti, M., Veltri, M., Calvetti, M., Celeghini, E., Iacopini, E., Ruggiero, G., Behler, M., Eppard, K., Kleinknecht, K., Marouelli, P., Masetti, L., Moosbrugger, U., Morales Morales, C., Renk, B., Wache, M., Wanke, R., Winhart, A., Coward, D., Dabrowski, A., Fonseca Martin, T., Shieh, M., Szleper, M., Velasco, M., Wood, M.D., Cenci, P., Pepe, M., Petrucci, M.C., Anzivino, G., Imbergamo, E., Nappi, A., Piccini, M., Raggi, M., Valdata-Nappi, M., Cerri, C., Fantechi, R., Collazuol, G., Di Lella, L., Lamanna, G., Mannelli, I., Michetti, A., Costantini, F., Doble, N., Fiorini, L., Giudici, S., Pierazzini, G., Sozzi, M., Venditti, S., Bloch-Devaux, B., Cheshkov, C., Cheze, J.B., De Beer, M., Derre, J., Marel, G., Mazzucato, E., Peyaud, B., Vallage, B., Holder, M., Ziolkowski, M., Biino, C., Cartiglia, N., Marchetto, F., Bifani, S., Clemencic, M., Goy Lopez, S., Dibon, H., Jeitler, M., Markytan, M., Mikulec, I., Neuhofer, G., and Widhalm, L.
Subjects: Particle Physics - Experiment
Abstract: A sample of 3120 $K^\pm\to\pi^\pm\mu^+\mu^-$ decay candidates with $(3.3\pm0.7)$% background contamination has been collected by the NA48/2 experiment at the CERN SPS, allowing a detailed study of the decay properties. The branching ratio was measured to be ${\rm BR}=(9.62\pm0.25)\times 10^{-8}$. The form factor $W(z)$, where $z=(M_{\mu\mu}/M_K)^2$, was parameterized according to several models. In particular, the slope of the linear form factor $W(z)=W_0(1+\delta z)$ was measured to be $\delta=3.11\pm0.57$. Upper limits of $2.9\times 10^{-2}$ and $2.3\times 10^{-2}$ on possible charge asymmetry and forward-backward asymmetry were established at 90% CL. An upper limit ${\rm BR}(K^\pm\to\pi^\mp\mu^\pm\mu^\pm)
Published: 2010

11. Precise tests of low energy QCD from $K_{e4}$ decay properties

Author: Batley, Jr, Kalmus, G, Lazzeroni, C, Munday, Dj, Slater, Mw, Wotton, Sa, Arcidiacono, Roberta, Bocquet, G, Cabibbo, Nicola, Ceccucci, A, Cundy, D, Falaleev, V, Fidecaro, M, Gatignon, L, Gonidec, A, Kubischta, W, Norton Alan Robert, Maier, A, Patel, M, Peters, A, Balev, S, Frabetti, Pl, Goudzovski, E, Hristov, P, Kekelidze, V, Kozhuharov, V, Litov, L, Madigozhin, D, Marinova Evelina Mihova, Molokanova, N, Polenkevich, I, Potrebenikov, Y, Stoynev, S, Zinchenko, A, Monnier, E, Swallow, E, Winston, R, Rubin, P, Walker, A, Baldini, Wander, Cotta Ramusino Angelo, Dalpiaz, Pietro, Damiani, Chiara, Fiorini, Massimiliano, Gianoli, Alberto, Martini, Marco, Petrucci, Fabrizio, Savrie', Mauro, Scarpa, Marcella, Wahl, Heinrich, Bizzeti, Andrea, Lenti, Massimo, Veltri, Michele, Calvetti, Mario, Celeghini, Enrico, Iacopini, Enrico, Ruggiero, Giuseppe, Behler, M, Eppard, K, Kleinknecht, K, Marouelli, P, Masetti, L, Moosbrugger, U, Morales, Cm, Renk, B, Wache, M, Wanke, R, Winhart, A, Coward, D, Dabrowski, A, Martin, Tf, Shieh, M, Szleper, M, Velasco, M, Wood, Md, Cenci, Patrizia, Pepe, Monica, Petrucci Maria Carmela, Anzivino, Giuseppina, Imbergamo, Ermanno, Nappi, Aniello, Piccini, Mauro, Raggi, Mauro, Valdata, Marisa, Cerri, Claudio, Fantechi, Riccardo, Collazuol, Gianmaria, Dilella, L, Lamanna, Gianluca, Mannelli, Italo, Michetti, Andrea, Costantini, Flavio, Doble, N, Fiorini, Luca, Giudici, Sergio, Pierazzini, Giuseppe, Sozzi, Marco, Venditti, Stefano, Bloch Devaux, B, Cheshkov, C, Cheze, Jb, De Beer, M, Derre, J, Marel, G, Mazzucato, E, Peyaud, B, Vallage, B, Holder, M, Ziolkowski, M, Biino, Cristina, Cartiglia, Nicolo', Marchetto Flavio Pietro, Bifani, Simone, Clemencic, Marco, Goy Lopez Silvia, Dibon, H, Jeitler, M, Markytan, M, Mikulec, I, Neuhofer, G, and Widhalm, L.
Subjects: LENGTHS, MONTE-CARLO, KE4 DECAYS, PI-PI SCATTERING, FORM-FACTORS, ONE-LOOP, CONSTANTS, EQUATION, ISOSPIN BREAKING, PHASE-SHIFTS, Particle Physics - Experiment
Abstract: We report results from the analysis of the $K^{\pm} \rightarrow \pi^{+} \pi^{-} e^{\pm} \nu$ (Ke4) decay by the NA48/2 collaboration at the CERN SPS, based on the total statistics of 1.13 million decays collected in 2003-2004. The hadronic form factors in the S- and P-wave and their variation with energy are obtained. The phase difference between the S- and P-wave states of the $\pi \pi$ system is accurately measured and allows a precise determination of $a_{0}^{0}$ and $a_{0}^{2}$, the I=0 and I=2 S-wave $\pi \pi$ scattering lengths: $a_{0}^{0} = 0.2220 \pm 0.0128_{stat} \pm 0.0050_{syst} \pm 0.0037_{th}, a_{0}^{2}$ = $-0.0432 \pm 0.0086_{stat} \pm 0.0034_{syst} \pm 0.0028_{th}.$ Combination of this result with the other NA48/2 measurement obtained in the study of $K^{\pm} \rightarrow \pi^{0} \pi^{0} \pi^{\pm}$ decays brings an improved determination of $a_{0}^{0}$ and the first precise experimental measurement of $a_{0}^{2}$, providing a stringent test of Chiral Perturbation Theory predictions and lattice QCD calculations. Using constraints based on analyticity and chiral symmetry, even more precise values are obtained: $a_{0}^{0} = 0.2196 \pm 0.0028_{stat} \pm 0.0020_{syst}$ and $a_{0}^{2} = -0.0444 \pm 0.0007_{stat} \pm 0.0005_{syst} \pm 0.0008_{ChPT}$.
Published: 2010

12. New precise measurements of the $\Xi^{0} \to \Lambda \gamma$ and $\Xi^{0} \to \Sigma^{0}\gamma$ decay asymmetries

Author: Batley, J.R., Kalmus, G.E., Lazzeroni, C., Munday, D.J., Patel, M., Slater, M.W., Wotton, S.A., Arcidiacono, R., Bocquet, G., Ceccucci, A., Cundy, D., Doble, N., Falaleev, V., Gatignon, L., Gonidec, A., Grafstrom, P., Kubischta, W., Mikulec, I., Norton, A., Panzer-Steindel, B., Rubin, P., Wahl, H., Goudzovski, E., Hristov, P., Kekelidze, V., Litov, L., Madigozhin, D., Molokanova, N., Potrebenikov, Yu., Stoynev, S., Zinchenko, A., Monnier, E., Swallow, E., Winston, R., Sacco, R., Walker, A., Baldini, W., Gianoli, A., Dalpiaz, P., Frabetti, P.L., Martini, M., Petrucci, F., Savrie, M., Scarpa, M., Calvetti, M., Collazuol, G., Iacopini, E., Ruggiero, G., Bizzeti, A., Lenti, M., Veltri, M., Behler, M., Eppard, K., Eppard, M., Hirstius, A., Kleinknecht, K., Koch, U., Marouelli, P., Masetti, L., Moosbrugger, U., Morales-Morales, C., Peters, A., Wanke, R., Winhart, A., Dabrowski, A., Fonseca Martin, T., Velasco, M., Cenci, P., Lubrano, P., Pepe, M., Anzivino, G., Imbergamo, E., Lamanna, G., Michetti, A., Nappi, A., Petrucci, M.C., Piccini, M., Valdata, M., Cerri, C., Fantechi, R., Costantini, F., Fiorini, L., Giudici, S., Pierazzini, G., Sozzi, M., Mannelli, I., Cheshkov, C., Cheze, J.B., De Beer, M., Debu, P., Gouge, G., Marel, G., Mazzucato, E., Peyaud, B., Vallage, B., Holder, M., Maier, A., Ziolkowski, M., Biino, C., Cartiglia, N., Marchetto, F., Pastrone, N., Clemencic, M., Goy Lopez, S., Menichetti, E., Wislicki, W., Dibon, H., Jeitler, M., Markytan, M., Neuhofer, G., and Widhalm, L.
Subjects: High Energy Physics::Experiment, Nuclear Experiment, Particle Physics - Experiment
Abstract: The decay asymmetries of the weak radiative Hyperon decays $\Xi^{0}\to \Lambda \gamma$ and $\Xi^{0} \to \Sigma^{0}\gamma$ have been measured with high precision using data of the NA48/1 experiment at CERN. From about 52000 $\Xi^{0}\to \Lambda \gamma$ and 15000 $\Xi^{0} \to \Sigma^{0}\gamma$ decays, we obtain for the decay asymmetries $\alpha_{\Xi^{0}\to \Lambda\gamma}$ = -0.704 +- 0.019$_{stat}$ +- 0.064$_{syst}$ and $\alpha_{\Xi^{0}\to \Sigma^{0}\gamma}$ = -0.729 +- 0.030$_{stat}$ +- 0.076$_{syst}$, respectively. These results are in good agreement with previous experiments, but more precise. The decay asymmetries of the weak radiative Hyperon decays Xi0 \to Lambda gamma and Xi0 \to Sigma0 gamma have been measured with high precision using data of the NA48/1 experiment at CERN. From about 52000 Xi0 \to Lambda gamma and 15000 Xi0 \to Sigma0 gamma decays, we obtain for the decay asymmetries alpha(Xi0 \to Lambda gamma) = -0.704 +/- 0.019(stat) +/- 0.064(syst) and alpha(Xi0 \to Sigma0 gamma) = -0.729 +/- 0.030(stat) +/- 0.076(syst), respectively. These results are in good agreement with previous experiments, but more precise. The decay asymmetries of the weak radiative hyperon decays Ξ 0 → Λ γ and Ξ 0 → Σ 0 γ have been measured with high precision using data of the NA48/1 experiment at CERN. From about 52 000 Ξ 0 → Λ γ and 15 000 Ξ 0 → Σ 0 γ decays, we obtain for the decay asymmetries α Ξ 0 → Λ γ = − 0.704 ± 0.019 stat ± 0.064 syst and α Ξ 0 → Σ 0 γ = − 0.729 ± 0.030 stat ± 0.076 syst , respectively. These results are in good agreement with previous experiments, but more precise.
Published: 2010

13. Precision measurement of the ratio BR($K_{S} \to \pi^{+}\pi^{-}e^{+}e^{-}$)/BR($K_{L} \to \pi^{+}\pi^{-}\pi^{0}_{D}$)

Author: Batley, J R, Kalmus, G E, Lazzeroni, C, Munday, D J, Patel, M, Slater, M W, Wotton, S A, Arcidiacono, R, Bocquet, G, Ceccucci, A, Cundy, D, Doble, N, Falaleev, V, Gatignon, L, Gonidec, A, Grafström, P, Kubischta, W, Marchetto, F, Mikulec, I, Norton, A, Panzer-Steindel, B, Rubin, P, Wahl, H, Goudzovski, E, Hristov, P, Kekelidze, V, Kozhuharov, V, Litov, L, Madigozhin, D, Molokanova, N, Potrebenikov, Yu., Stoynev, S, Zinchenko, A, Monnier, E, Swallow, E C, Winston, R, Sacco, R, Walker, A, Baldini, W, Dalpiaz, P, Frabetti, P L, Gianoli, A, Martini, M, Petrucci, F, Scarpa, M, Savrié, M, Bizzeti, A, Calvetti, M, Collazuol, E, Iacopini, E, Lenti, M, Ruggiero, G, Veltri, M, Behler, M, Eppard, K, Eppard, M, Hirstius, A, Kleinknecht, K, Koch, U, Marouelli, P, Masetti, L, Moosbrugger, U, Morales Morales, C, Peters, A, Wanke, R, Winhart, A, Dabrowski, A, Fonseca Martin, T, Szleper, M, Velasco, M, Anzivino, G, Cenci, P, Imbergamo, E, Lamanna, G, Lubrano, P, Michetti, A, Nappi, A, Pepe, M, Petrucci, M C, Piccini, M, Valdata, M, Cerri, C, Costantini, F, Fantechi, R, Fiorini, L, Giudici, S, Mannelli, I, Pierazzini, G, Sozzi, M, Cheshkov, C, Chèze, J B, De Beer, M, Debu, P, Gouge, G, Marel, G, Mazzucato, E, Peyaud, B, Vallage, B, Holder, M, Maier, A, Ziolkowski, M, Biino, C, Cartiglia, N, Clemencic, M, Goy Lopez, S, Menichetti, E, Pastrone, N, Wislicki, W, Dibon, H, Jeitler, M, Markytan, M, Neuhofer, G, and Widhalm, L
Subjects: High Energy Physics::Phenomenology, High Energy Physics::Experiment, Particle Physics - Experiment
Abstract: The $K_{S} \rightarrow \pi^{+}\pi^{-}e^{+}e^{-}$ decay mode was investigated using the data collected in 2002 by the NA48/1 collaboration. With about 23,k $K_{S} \rightarrow \pi^{+}\pi^{-}e^{+}e^{-}$ events and 59,k $K_{L} \rightarrow \pi^{+}\pi^{-}\pi^{0}_{D}$ normalization decays, the $K_{S} \rightarrow \pi^{+}\pi^{-}e^{+}e^{-}$ branching ratio relative to the $K_{L}\rightarrow \pi^{+}\pi^{-}\pi^{0}_{D}$ one was determined to be BR($K_{S} \rightarrow \pi^{+}\pi^{-}e^{+}e^{-}$)/BR($K_{L} \rightarrow \pi^{+}\pi^{-}\pi^{0}_{D}$) = $ (3.28 \pm 0.06_{stat}\pm 0.04_{syst})\times 10^{-2}$. This result was used to set the upper limit $|g_{E1}/g_{BR}| \lt 3.0$ at $90%$ CL on the presence, in the decay amplitude, of an E1 direct emission ($g_{E1}$) term relative to the dominant inner bremsstrahlung ($g_{BR}$) term. The CP-violating asymmetry ${cal A}_{\phi}$ in the sin$\phi$,cos$\phi$ distribution of $K_{S} \rightarrow \pi^{+}\pi^{-}e^{+}e^{-}$ events, where $\phi$ is the angle between the $\pi^{+} \pi^{-}$ and the $e^{+}e^{-}$ decay planes in the kaon centre of mass, was found to be ${cal A}_{\phi} = (-0.4 pm 0.8)%$, consistent with zero. These results are in good agreement with a description of the $K_{S} \rightarrow \pi^{+}\pi^{-}e^{+}e^{-}$ decay amplitude dominated by the CP-even inner bremsstrahlung process.
Published: 2010

14. Measurement of the direct emission and interference terms and search for CP violation in the decay $K^{\pm} \rightarrow \pi^{\pm}\pi^{0} \gamma$

Author: Batley, J.R., Kalmus, G., Lazzeroni, C., Munday, D.J., Slater, M.W., Wotton, S.A., Arcidiacono, R., Bocquet, G., Cabibbo, N., Ceccucci, A., Cundy, D., Falaleev, V., Fidecaro, M., Gatignon, L., Gonidec, A., Kubischta, W., Norton, A., Maier, A., Patel, M., Peters, A., Balev, S., Frabetti, P.L., Goudzovski, E., Hristov, P., Kekelidze, V., Kozhuharov, V., Litov, L., Madigozhin, D., Marinova, E., Molokanova, N., Polenkevich, I., Potrebenikov, Yu., Stoynev, S., Zinchenko, A., Monnier, E., Swallow, E., Winston, R., Rubin, P., Walker, A., Baldini, W., Cotta Ramusino, A., Dalpiaz, P., Damiani, C., Fiorini, M., Gianoli, A., Martini, M., Petrucci, F., Savrie, M., Scarpa, M., Wahl, H., Bizzeti, A., Lenti, M., Veltri, M., Calvetti, M., Celeghini, E., Iacopini, E., Ruggiero, G., Behler, M., Eppard, K., Kleinknecht, K., Marouelli, P., Masetti, L., Moosbrugger, U., Morales, C., Renk, B., Wache, M., Wanke, R., Winhart, A., Coward, D., Dabrowski, A., Martin, T.Fonseca, Shieh, M., Szleper, M., Velasco, M., Wood, M.D., Cenci, P., Petrucci, M.C., Pepe, M., Anzivino, G., Imbergamo, E., Nappi, A., Piccini, M., Raggi, M., Valdata-Nappi, M., Cerri, C., Fantechi, R., Collazuol, G., DiLella, L., Lamanna, G., Mannelli, I., Michetti, A., Costantini, F., Doble, N., Fiorini, L., Giudici, S., Pierazzini, G., Sozzi, M., Venditti, S., Bloch-Devaux, B., Cheshkov, C., Cheze, J.B., De Beer, M., Derre, J., Marel, G., Mazzucato, E., Peyaud, B., Vallage, B., Holder, M., Ziolkowski, M., Bifani, S., Biino, C., Cartiglia, N., Clemencic, M., Lopez, S.Goy, Marchetto, F., Dibon, H., Jeitler, M., Markytan, M., Mikulec, I., Neuhofer, G., and Widhalm, L.
Subjects: Particle Physics - Experiment
Abstract: We report on the measurement of the direct emission (DE) and interference (INT) terms of the $K^{\pm} \rightarrow \pi^{\pm}\pi^{0}\gamma$ decay by the NA48/2 experiment at the CERN SPS. From the data collected during 2003 and 2004 about 600k such decay candidates have been selected. The relative amounts of DE and INT with respect to the internal bremsstrahlung (IB) contribution have been measured in the range $0 \pi\pm\pi^0 g decay by the NA48/2 experiment at the CERN SPS. From the data collected during 2003 and 2004 about 600k such decay candidates have been selected. The relative amounts of DE and INT with respect to the internal bremsstrahlung (IB) contribution have been measured in the range 0
Published: 2010

15. Empirical parameterization of the $K^{\pm} \to \pi^{\pm}\pi^{0}\pi^{0}$ decay Dalitz plot

Author: Batley, J R, Culling, A J, Kalmus, G, Lazzeroni, C, Munday, D J, Slater, M W, Wotton, S A, Arcidiacono, R, Bocquet, G, Cabibbo, N, Ceccucci, A, Cundy, D, Falaleev, V, Fidecaro, M, Gatignon, L, Gonidec, A, Kubischta, W, Norton, A, Maier, A, Patel, M, Peters, A, Balev, S, Frabetti, P L, Goudzovski, E, Hristov, P, Kekelidze, V, Kozhuharov, V, Litov, L, Madigozhin, D, Marinova, E, Molokanova, N, Polenkevich, I, Potrebenikov, Yu, Stoynev, S, Zinchenko, A, Monnier, E, Swallow, E, Winston, R, Rubin, P, Walker, A, Baldini, W, Cotta Ramusino, A, Dalpiaz, P, Damiani, C, Fiorini, M, Gianoli, A, Martini, M, Petrucci, F, Savrié, M, Scarpa, M, Wahl, H, Calvetti, M, Iacopini, E, Ruggiero, G, Bizzeti, A, Lenti, M, Veltri, M, Behler, M, Eppard, K, Kleinknecht, K, Marouelli, P, Masetti, L, Moosbrugger, U, Morales Morales, C, Renk, B, Wache, M, Wanke, R, Winhart, A, Coward, D, Dabrowski, A, Fonseca Martin, T, Shieh, M, Szleper, M, Velasco, M, Wood, M D, Anzivino, G, Imbergamo, E, Nappi, A, Piccini, M, Raggi, M, Valdata-Nappi, M, Cenci, P, Pepe, M, Petrucci, M C, Cerri, C, Fantechi, R, Collazuol, G, DiLella, L, Lamanna, G, Mannelli, I, Michetti, A, Costantini, F, Doble, N, Fiorini, L, Giudici, S, Pierazzini, G, Sozzi, M, Venditti, S, Bloch-Devaux, B, Cheshkov, C, Chèze, J B, De Beer, M, Derré, J, Marel, G, Mazzucato, E, Peyaud, B, Vallage, B, Holder, M, Ziolkowski, M, Biino, C, Cartiglia, N, Marchetto, F, Bifani, S, Clemencic, M, Goy Lopez, S, Dibon, H, Jeitler, M, Markytan, M, Mikulec, I, Neuhofer, G, and Widhalm, L
Subjects: Particle Physics - Experiment
Abstract: As first observed by the NA48/2 experiment at the CERN SPS, the $\pi^{0}\pi^{0}$ invariant mass ($M_{00}$) distribution from $K^{\pm} \rightarrow \pi^{\pm}\pi^{0}\pi^{0}$ decay shows a cusp-like anomaly at $M_{00}=2m_{+}$, where $m_{+}$ is the charged pion mass. An analysis to extract the $\pi\pi$ scattering lengths in the isospin $I=0$ and $I=2$ states, $a_{0}$ and $a_{2}$, respectively, has been recently reported. In the present work the Dalitz plot of this decay is fitted to a new empirical parameterization suitable for practical purposes, such as Monte Carlo simulations of $K^{\pm} \rightarrow \pi^{\pm}\pi^{0}\pi^{0}$ decays.
Published: 2009

16. Precise measurement of the $K^{\pm} \to \pi^{\pm}e^{+}e^{−}$ decay

Author: Batley, J.R., Culling, A.J., Kalmus, G., Lazzeroni, C., Munday, D.J., Slater, M.W., Wotton, S.A., Arcidiacono, R., Bocquet, G., Cabibbo, N., Ceccucci, A., Cundy, D., Falaleev, V., Fidecaro, M., Gatignon, L., Gonidec, A., Kubischta, W., Norton, A., Maier, A., Patel, M., Peters, A., Balev, S., Frabetti, P.L., Goudzovski, E., Hristov, P., Kekelidze, V., Kozhuharov, V., Litov, L., Madigozhin, D., Marinova, E., Molokanova, N., Polenkevich, I., Potrebenikov, Yu., Stoynev, S., Zinchenko, A., Monnier, E., Swallow, E., Winston, R., Rubin, P., Walker, A., Baldini, W., Cotta Ramusino, A., Dalpiaz, P., Damiani, C., Fiorini, M., Gianoli, A., Martini, M., Petrucci, F., Savrie, M., Scarpa, M., Wahl, H., Bizzeti, A., Calvetti, M., Celeghini, E., Iacopini, E., Lenti, M., Martelli, F., Ruggiero, G., Veltri, M., Behler, M., Eppard, K., Kleinknecht, K., Marouelli, P., Masetti, L., Moosbrugger, U., Morales Morales, C., Renk, B., Wache, M., Wanke, R., Winhart, A., Coward, D., Dabrowski, A., Fonseca Martin, T., Shieh, M., Szleper, M., Velasco, M., Wood, M.D., Anzivino, G., Cenci, P., Imbergamo, E., Nappi, A., Pepe, M., Petrucci, M.C., Piccini, M., Raggi, M., Valdata-Nappi, M., Cerri, C., Fantechi, R., Collazuol, G., DiLella, L., Lamanna, G., Mannelli, I., Michetti, A., Costantini, F., Doble, N., Fiorini, L., Giudici, S., Pierazzini, G., Sozzi, M., Venditti, S., Bloch-Devaux, B., Cheshkov, C., Cheze, J.B., De Beer, M., Derre, J., Marel, G., Mazzucato, E., Peyaud, B., Vallage, B., Holder, M., Ziolkowski, M., Bifani, S., Biino, C., Cartiglia, N., Clemencic, M., Goy Lopez, S., Marchetto, F., Dibon, H., Jeitler, M., Markytan, M., Mikulec, I., Neuhofer, G., and Widhalm, L.
Subjects: Particle Physics - Experiment
Abstract: A sample of 7253 $K^\pm\to\pi^\pm e^+e^-(\gamma)$ decay candidates with 1.0% background contamination has been collected by the NA48/2 experiment at the CERN SPS, allowing a precise measurement of the decay properties. The branching ratio in the full kinematic range was measured to be ${\rm BR}=(3.11\pm0.12)\times 10^{-7}$, where the uncertainty includes also the model dependence. The shape of the form factor $W(z)$, where $z=(M_{ee}/M_K)^2$, was parameterized according to several models, and, in particular, the slope $\delta$ of the linear form factor $W(z)=W_0(1+\delta z)$ was determined to be $\delta=2.32\pm0.18$. A possible CP violating asymmetry of $K^+$ and $K^-$ decay widths was investigated, and a conservative upper limit of $2.1\times 10^{-2}$ at 90% CL was established. A sample of 7253 $K^\pm\to\pi^\pm e^+e^-(\gamma)$ decay candidates with 1.0% background contamination has been collected by the NA48/2 experiment at the CERN SPS, allowing a precise measurement of the decay properties. The branching ratio in the full kinematic range was measured to be ${\rm BR}=(3.11\pm0.12)\times 10^{-7}$, where the uncertainty includes also the model dependence. The shape of the form factor $W(z)$, where $z=(M_{ee}/M_K)^2$, was parameterized according to several models, and, in particular, the slope $\delta$ of the linear form factor $W(z)=W_0(1+\delta z)$ was determined to be $\delta=2.32\pm0.18$. A possible CP violating asymmetry of $K^+$ and $K^-$ decay widths was investigated, and a conservative upper limit of $2.1\times 10^{-2}$ at 90% CL was established. A sample of 7253 K±→π±e+e−(γ) decay candidates with 1.0% background contamination has been collected by the NA48/2 experiment at the CERN SPS, which allowed a precise measurement of the decay properties. The branching ratio in the full kinematic range was measured to be BR=(3.11±0.12)×10−7 , where the uncertainty includes also the model dependence. The shape of the form factor W(z) , where z=(Mee/MK)2 , was parameterized according to several models, and, in particular, the slope δ of the linear form factor W(z)=W0(1+δz) was determined to be δ=2.32±0.18 . A possible CP violating asymmetry of K+ and K− decay widths was investigated, and a conservative upper limit of 2.1×10−2 at 90% CL was established.
Published: 2009

17. Determination of the S-wave pi pi scattering lengths from a study of K-+/- -> pi(+/-)pi(0)pi(0) decays

Author: Batley, J R, Culling, A J, Kalmus, G, Lazzeroni, C, Munday, D J, Slater, M W, Wotton, S A, Arcidiacono, R, Bocquet, G, Cabibbo, N, Ceccucci, A, Cundy, D, Falaleev, V, Fidecaro, Maria, Gatignon, L, Gonidec, A, Kubischta, W, Norton, A, Maier, A, Patel, M, Peters, A, Balev, S, Frabetti, P L, Goudzovski, E, Khristov, P Z, Kekelidze, V, Kozhuharov, V, Litov, L, Madigozhin, D T, Marinova, E, Molokanova, N, Polenkevich, I, Potrebenikov, Yu, Stoynev, S, Zinchenko, A, Monnier, E, Swallow, E, Winston, R, Rubin, P, Walker, A, Baldini, W, Cotta-Ramusino, A, Dalpiaz, P, Damiani, C, Fiorini, M, Gianoli, A, Martini, M, Petrucci, F, Savrié, M, Scarpa, M, Wahl, H, Calvetti, M, Iacopini, E, Ruggiero, G, Bizzeti, A, Lenti, M, Veltri, M, Behler, M, Eppard, K, Kleinknecht, K, Marouelli, P, Masetti, L, Moosbrugger, U, Morales-Morales, C, Renk, B, Wache, M, Wanke, R, Winhart, A, Coward, D, Dabrowski, A, Fonseca-Martin, T, Shieh, M, Szleper, M, Velasco, M, Wood, M D, Anzivino, G, Imbergamo, E, Nappi, A, Piccini, M, Raggi, M, Valdata-Nappi, M, Cenci, P, Pepé, M, Pettrucci, M C, Cerri, C, Fantechi, R, Collazuol, G, Di Lella, L, Lamanna, G, Mannelli, I, Michetti, A, Costantini, F, Doble, N, Fiorini, L, Giudici, S, Pierazzini, G, Sozzi, M, Venditti, S, Bloch-Devaux, B, Cheshkov, C, Chèze, J B, De Beer, M, Derré, J, Marel, G, Mazzucato, E, Peyaud, B, Vallage, B, Holder, M, Ziolkowski, M, Bifani, S, Biino, C, Cartiglia, N, Marchetto, F, Clemencic, M, Goy-Lopez, S, Dibon, H, Jeitler, M, Markytan, M, Mikulec, I, Neuhofer, G, and Widhalm, L
Subjects: DIRECT CP-VIOLATION, Particle physics, Physics and Astronomy (miscellaneous), Meson, Hadron, Elementary particle, High Energy Physics - Experiment, ATOMS, Particle decay, Pion, kaoni, SEARCH, ELECTROMAGNETIC CORRECTIONS, Engineering (miscellaneous), Physics, kaon decays, Scattering, decadimenti, scattering lengths, Effective mass (spring–mass system), pion scattering, Crystallography, Isospin, Particle Physics - Experiment
Abstract: We report the results from a study of the full sample of ~ 6.031 10^7 K+- -> pi+- pi0 pi0 decays recorded by the NA48/2 experiment at the CERN SPS. As first observed in this experiment, the pi0 pi0 invariant mass M00 distribution shows a cusp-like anomaly in the region around M00 = 2m+, where m+ is the charged pion mass. This anomaly has been interpreted as an effect due mainly to the final state charge exchange scattering process pi+ pi- -> p0 p0 in K+- -> pi+- pi+ pi- decay. Fits to the M00 distribution using two different theoretical formulations provide the presently most precise determination of (a0 - a2), the difference between the pi pi S-wave scattering lengths in the isospin I=0 and I=2 states. Higher-order pi pi rescattering terms, included in the two formulations, allow also an independent, though less precise, determination of a2., Comment: 19 pages, 12 figures
Published: 2009

18. First observation and measurement of the decay $K^{\pm} \to\pi^{\pm}e^{+}e^{-}\gamma$

Author: Batley, J.R., Culling, A.J., Kalmus, George E., Lazzeroni, Cristina, Munday, D.J., Slater, M.W., Wotton, S.A., Arcidiacono, Roberta, Bocquet, G., Cabibbo, N., Ceccucci, Augusto, Cundy, D., Falaleev, V., Fidecaro, M., Gatignon, L., Gonidec, A., Kubischta, W., Norton, A., Maier, A., Patel, M., Peters, A., Balev, S., Frabetti, P.L., Goudzovski, E., Hristov, Peter, Kekelidze, V., Kozhuharov, V., Litov, Leandar, Madigozhin, D., Marinova, E., Molokanova, N., Polenkevich, I., Stoynev, S., Zinchenko, A., Monnier, E., Swallow, E., Winston, R., Rubin, Philip D., Walker, A., Baldini, W., Cotta Ramusino, A., Dalpiaz, P., Damiani, C., Fiorini, M., Gianoli, Alberto, Martini, M., Petrucci, F., Savrie, M., Scarpa, M., Wahl, H., Bizzeti, A., Calvetti, M., Celeghini, Enrico, Iacopini, E., Lenti, M., Martelli, F., Ruggiero, G., Veltri, M., Behler, M., Eppard, K., Handel, C., Kleinknecht, Konrad, Marouelli, P., Masetti, L., Moosbrugger, U., Morales Morales, C., Renk, B., Wache, M., Wanke, R., Winhart, A., Coward, D.H., Dabrowski, A., Fonseca Martin, T., Shieh, M., Szleper, M., Velasco, M., Wood, M.D., Anzivino, Giuseppina, Cenci, P., Imbergamo, E., Nappi, Nello, Pepe, M., Petrucci, M.C., Piccini, M., Raggi, M., Valdata-Nappi, Marisa, Cerri, C., Collazuol, G., Costantini, Flavio, Di, L., Doble, Niels, Fantechi, R., Fiorini, L., Giudici, S., Lamanna, G., Mannelli, Italo, Michetti, A., Pierazzini, G., Sozzi, Marco S., Bloch-Devaux, Brigitte, Cheshkov, C., Cheze, J.B., De Beer, M., Derre, J., Marel, G., Mazzucato, E., Peyaud, B., Vallage, B., Holder, M., Ziolkowski, M., Bifani, S., Biino, C., Cartiglia, N., Clemencic, M., Goy Lopez, S., Marchetto, Flavio Pietro, Dibon, Heinz, Jeitler, Manfred, Markytan, M., Mikulec, I., Neuhofer, G., and Widhalm, L.
Subjects: Particle Physics - Experiment
Abstract: Using the full data set of the NA48/2 experiment, the decay $K^{\pm} \rightarrow \pi^{\pm} e^{+} e^{-}\gamma$ is observed for the first time, selecting 120 candidates with $7.3 \pm 1.7$ estimated background events. With $K^{\pm} \rightarrow \pi^{\pm} \pi^{0}_{D}$ as normalisation channel, the branching ratio is determined in a model-independent way to be Br$(K^{\pm} \rightarrow \pi^{\pm} e^{+} e^{-}\gamma, m_{ee\gamma} > 260$ MeV/c$^{2}) = (1.19 \pm 0.12_{stat} \pm 0.04_{syst}) \times 10^{-8}$. This measured value and the spectrum of the $e^{+}e^{-}\gamma$ invariant mass allow a comparison with predictions of Chiral Perturbation Theory. Using the full data set of the NA48/2 experiment, the decay K±→π±e+e−γ is observed for the first time, selecting 120 candidates with 7.3±1.7 estimated background events. With K±→π±πD0 as normalisation channel, the branching ratio is determined in a model-independent way to be Br(K±→π±e+e−γ,meeγ>260 MeV/c2)=(1.19±0.12stat±0.04syst)×10−8 . This measured value and the spectrum of the e+e−γ invariant mass allow a comparison with predictions of chiral perturbation theory. Using the full data set of the NA48/2 experiment, the decay K+- -> pi+- e+ e- gamma is observed for the first time, selecting 120 candidates with 7.3 +- 1.7 estimated background events. With K+- -> pi+- pi0D as normalisation channel, the branching ratio is determined in a model-independent way to be Br(K+- -> pi+- e+ e- gamma, m_eegamma > 260 MeV/c^2) = (1.19 +- 0.12_stat +- 0.04_syst) x 10^-8. This measured value and the spectrum of the e+ e- gamma invariant mass allow a comparison with predictions of Chiral Perturbation Theory.
Published: 2007

19. Search for direct CP violating charge asymmetries in $K^\pm\to\pi^\pm\pi^+\pi^-$ and $K^\pm\to\pi^\pm\pi^0\pi^0$ decays

Author: Batley, J Richard, Culling, A J, Kalmus, George Ernest, Lazzeroni, C, Munday, D J, Slater, M W, Wotton, S A, Arcidiacono, R, Bocquet, G, Cabibbo, Nicola, Ceccucci, A, Cundy, Donald C, Falaleev, V, Fidecaro, Maria, Gatignon, L, Gonidec, A, Kubischta, Werner, Norton, A, Maier, A, Patel, M, Peters, A, Balev, S, Frabetti, P L, Goudzovski, E, Khristov, P Z, Kekelidze, V D, Kozhuharov, V, Litov, L, Madigozhin, D T, Marinova, E, Molokanova, N A, Polenkevich, I, Potrebenikov, Yu K, Stoynev, S, Zinchenko, A I, Monnier, E, Swallow, E, Winston, R, Rubin, P, Walker, A, Baldini, W, Cotta-Ramusino, A, Dalpiaz, P, Damiani, C, Fiorini, M, Gianoli, A, Martini, M, Petrucci, F, Savrié, M, Scarpa, M, Wahle, H, Bizzeti, A, Calvetti, M, Celeghini, E, Iacopini, E, Lenti, M, Martelli, F, Ruggiero, G, Veltri, M, Behler, M, Eppard, K, Kleinknecht, K, Marouelli, P, Masetti, L, Moosbrugger, U, Morales-Morales, C, Renk, B, Wache, M, Wanke, R, Winhart, A, Coward, D, Dabrowski, A, Fonseca-Martin, T, Shieh, M, Szleper, M, Velasco, M, Wood, M D, Anzivino, Giuseppina, Cenci, P, Imbergamo, E, Nappi, A, Pepé, M, Petrucci, M C, Piccini, M, Raggi, M, Valdata-Nappi, M, Cerri, C, Collazuol, G, Costantini, F, Di Lella, L, Doble, N, Fantechi, R, Fiorini, L, Giudici, S, Lamanna, G, Mannelli, I, Michetti, A, Pierazzini, G M, Sozzi, M, Bloch-Devaux, B, Cheshkov, C, Chèze, J B, De Beer, M, Derré, J, Marel, Gérard, Mazzucato, E, Peyaud, B, Vallage, B, Holder, M, Ziolkowski, M, Bifani, S, Biino, C, Cartiglia, N, Clemencic, M, Goy-Lopez, S, Marchetto, F, Dibon, Heinz, Jeitler, Manfred, Markytan, Manfred, Mikulec, I, Neuhofer, G, and Widhalm, L
Subjects: Particle Physics - Experiment, High Energy Physics - Experiment
Abstract: A measurement of the direct CP violating charge asymmetries of the Dalitz plot linear slopes $A_g=(g^+-g^-)/(g^++g^-)$ in $K^\pm\to\pi^\pm\pi^+\pi^-$ and $K^\pm\to\pi^\pm\pi^0\pi^0$ decays by the NA48/2 experiment at CERN SPS is presented. A new technique of asymmetry measurement involving simultaneous $K^+$ and $K^-$ beams and a large data sample collected allowed a result of an unprecedented precision. The charge asymmetries were measured to be $A^c_g=(-1.5\pm2.2)\times10^{-4}$ with $3.11\times 10^9$ $K^{\pm}\to\pi^\pm\pi^+\pi^-$ decays, and $A^n_g=(1.8\pm1.8)\times10^{-4}$ with $9.13\times 10^7$ $K^{\pm}\to\pi^\pm\pi^0\pi^0$ decays. The precision of the results is limited mainly by the size of the data sample., Comment: 29 pages, 9 figures. An updated version accepted by the EPJC
Published: 2007

20. Measurements of the $\Xi^0$ lifetime and the $\overline{\Xi^0}/\Xi^0$ flux ratio in a neutral beam

Author: Batley, J Richard, Kalmus, George Ernest, Lazzeroni, C, Munday, D J, Patel, M, Slater, M W, Wotton, S A, Arcidiacono, R, Bocquet, G, Ceccucci, A, Cundy, Donald C, Doble, N, Falaleev, V, Gatignon, L, Gonidec, A, Grafström, P, Kubischta, Werner, Mikulec, I, Norton, A, Panzer-Steindel, B, Rubin, P, Wahl, H, Goudzovski, E, Khristov, P Z, Kekelidze, V D, Litov, L, Madigozhin, D T, Molokanova, N A, Potrebenikov, Yu K, Stoynev, S, Zinchenko, A I, Monnier, E, Swallow, E, Winston, R, Sacco, R, Walker, A, Baldini, W, Dalpiaz, P, Frabetti, P L, Gianoli, A, Martini, M, Petrucci, F, Savrié, M, Scarpa, M, Bizzeti, A, Calvetti, M, Collazuol, G, Iacopini, E, Lenti, M, Ruggiero, G, Veltri, M, Behler, M, Eppard, K, Eppard, M, Hirstius, A, Kleinknecht, K, Koch, U, Marouelli, P, Masetti, L, Moosbrugger, U, Morales-Morales, C, Peters, A, Wanke, R, Winhart, A, Dabrowski, A, Fonseca-Martin, T, Velasco, M, Anzivino, Giuseppina, Cenci, P, Imbergamo, E, Lamanna, G, Lubrano, P, Michetti, A, Nappi, A, Pepé, M, Petrucci, M C, Piccini, M, Valdata, M, Cerri, C, Costantini, F, Fantechi, R, Fiorini, L, Giudici, S, Mannelli, I, Pierazzini, G M, Sozzi, M, Cheshkov, C, Chèze, J B, De Beer, M, Debu, P, Gouge, G, Marel, Gérard, Mazzucato, E, Peyaud, B, Vallage, B, Holder, M, Maier, A, Ziolkowski, M, Biino, C, Cartiglia, N, Clemencic, M, Goy-Lopez, S, Marchetto, F, Menichetti, E, Pastrone, N, Wislicki, W, Dibon, Heinz, Jeitler, Manfred, Markytan, Manfred, Neuhofer, G, and Widhalm, L
Subjects: Particle Physics - Experiment
Abstract: A total of 235 698 Xi0 -> Lambda pi0 and 21 527 anti-Xi0 -> anti-Lambda pi0 decays were selected from data obtained by the NA48/1 experiment at CERN. From this sample, the lifetime of the Xi0 hyperon was measured to be (3.065 +- 0.012(stat) +- 0.014(syst)) x 10^-10 s. This result is about two standard deviations above the world average and an order of magnitude more precise than the previous best measurement. With the same data sample, we have measured the ratio of anti-Xi0 and Xi0 fluxes in proton collisions at 400 GeV/c on a beryllium target.
Published: 2007

21. Determination of the relative decay rate $K_{S} \to \pi e \nu$ / $K_{L} \to \pi e \nu$

Author: Batley, J R, Kalmus, George Ernest, Lazzeroni, C, Munday, D J, Patel, M, Slater, M W, Wotton, S A, Arcidiacono, R, Bocquet, G, Ceccucci, A, Cundy, Donald C, Doble, N, Falaleev, V, Gatignon, L, Gonidec, A, Grafström, P, Kubischta, Werner, Marchetto, F, Mikulec, I, Norton, A, Panzer-Steindel, B, Rubin, P, Wahl, H, Goudzovski, E, Khristov, P Z, Kekelidze, V, Litov, L, Madigozhin, D T, Molokanova, N, Potrebenikov, Yu, Stoynev, S, Zinchenko, A, Monnier, E, Swallow, E, Winston, R, Sacco, R, Walker, A, Baldini, W, Dalpiaz, P, Frabetti, P L, Gianoli, A, Martini, M, Petrucci, F, Scarpa, M, Savrié, M, Bizzeti, A, Calvetti, M, Collazuol, G, Graziani, G, Iacopini, E, Lenti, M, Martelli, F, Ruggiero, G, Veltri, M, Behler, M, Eppard, K, Eppard, M, Hirstius, A, Kleinknecht, K, Koch, U, Masetti, L, Marouelli, P, Moosbrugger, U, Morales-Morales, C, Peters, A, Wanke, R, Winhart, A, Dabrowski, A, Fonseca-Martin, T, Goy-Lopez, S, Velasco, M, Anzivino, Giuseppina, Cenci, P, Imbergamo, E, Lamanna, G, Lubrano, P, Michetti, A, Nappi, A, Pepé, M, Petrucci, M C, Piccini, M, Valdata, M, Cerri, C, Costantini, F, Fantechi, R, Fiorini, L, Giudici, S, Mannelli, I, Pierazzini, G, Sozzi, M, Cheshkov, C, Chèze, J B, De Beer, M, Debu, P, Gouge, G, Marel, Gérard, Mazzucato, E, Peyaud, B, Vallage, B, Holder, M, Maier, A, Ziolkowski, M, Biino, C, Cartiglia, N, Clemencic, M, Menichetti, E, Pastrone, N, Wislicki, W, Dibon, Heinz, Jeitler, Manfred, Markytan, Markytan, Neuhofer, G, and Widhalm, L
Subjects: Particle Physics - Experiment
Abstract: The decay rate of $K_{S} \to \pi e \nu$ relative to the rate of $K_{L} \to \pi e \nu$ has been measured by the NA48 collaboration in a neutral Kaon beam originating from 400 GeV proton-Be interactions at the CERN SPS. The result is $0.993 \pm 0.026_{stat} \pm 0.022_{syst}$, compatible with 1 in agreement with the Standard Model prediction at tree level. It implies $BR(K_{S} \to\pi e \nu) = (7.05 \pm 0.18_{stat.} \pm 0.16_{syst.}) \times 10^{-4}$.
Published: 2007

22. Measurement of the Dalitz plot slopes of the $K^{\pm} \to \pi^{\pm}\pi^{+}\pi^{-}$ decay

Author: Batley, J.R., Culling, A.J., Kalmus, G., Lazzeroni, C., Munday, D.J., Slater, M.W., Arcidiacono, R., Bocquet, G., Cabibbo, N., Ceccucci, A., Cundy, D., Falaleev, V., Fidecaro, M., Gatignon, L., Gonidec, A., Kubischta, W., Norton, A., Maier, A., Patel, M., Peters, A., Balev, S., Frabetti, P.L., Goudzovski, E., Hristov, P., Kekelidze, V., Kozhuharov, V., Litov, L., Madigozhin, D., Marinova, E., Molokanova, N., Polenkevich, I., Potrebenikov, Yu., Stoynev, S., Zinchenko, A., Monnier, E., Swallow, E., Winston, R., Rubin, P., Walker, A., Baldini, W., Ramusino, A.Cotta, Dalpiaz, P., Damiani, C., Fiorini, M., Gianoli, A., Martini, M., Petrucci, F., Savrie, M., Scarpa, M., Bizzeti, A., Calvetti, M., Celeghini, E., Iacopini, E., Lenti, M., Martelli, F., Ruggiero, G., Veltri, M., Behler, M., Eppard, K., Kleinknecht, K., Marouelli, P., Masetti, L., Moosbrugger, U., Morales, C.Morales, Renk, B., Wache, M., Wanke, R., Winhart, A., Coward, D.H., Dabrowski, A., Fonseca Martin, T., Shieh, M., Szleper, M., Velasco, M., Wood, M.D., Anzivino, A.G., Cenci, P., Imbergamo, E., Nappi, A., Pepe, M., Petrucci, M.C., Piccini, M., Raggi, M., Anzivino, G., Cerri, C., Collazuol, G., Costantini, F., DiLella, L., Doble, N., Fantechi, R., Fiorini, L., Giudici, S., Lamanna, G., Mannelli, I., Michetti, A., Pierazzini, G., Sozzi, M., Bloch-Devaux, Brigitte, Cheshkov, C., Cheze, J.B., De Beer, M., Derre, J., Marel, G., Mazzucato, E., Peyaud, B., Vallage, B., Holder, M., Ziolkowski, M., Bifani, S., Biino, C., Cartiglia, N., Clemencic, M., Lopez, S.Goy, Marchetto, F., Dibon, H., Jeitler, M., Markytan, M., Mikulec, I., Neuhofer, G., and Widhalm, L.
Subjects: Particle Physics - Experiment
Abstract: The distribution of the $K^{\pm} \to \pi^{\pm}\pi^{+}\pi^{-}$ decays in the Dalitz plot has been measured by the NA48/2 experiment at the CERN SPS with a sample of $4.71 \times 10^{8}$ fully reconstructed events. With the standard Particle Data Group parameterization the following values of the slope parameters were obtained: $g=(-21.134 \pm 0.014)$%, $h=(1.848 \pm 0.039)$%, $k=(-0.463 \pm 0.012)$%. The quality and statistical accuracy of the data have allowed an improvement in precision by more than an order of magnitude, and are such as to warrant a more elaborate theoretical treatment, including pion-pion rescattering, which is in preparation. The distribution of the K±→π±π+π− decays in the Dalitz plot has been measured by the NA48/2 experiment at the CERN SPS with a sample of 4.71×108 fully reconstructed events. With the standard Particle Data Group parameterization the following values of the slope parameters were obtained: g=(−21.134±0.017)% , h=(1.848±0.040)% , k=(−0.463±0.014)% . The quality and statistical accuracy of the data have allowed an improvement in precision by more than an order of magnitude, and are such as to warrant a more elaborate theoretical treatment, including pion–pion rescattering, which is in preparation. The distribution of the $K^\pm\to\pi^\pm\pi^+\pi^-$ decays in the Dalitz plot has been measured by the NA48/2 experiment at the CERN SPS with a sample of $4.71\times 10^8$ fully reconstructed events. With the standard Particle Data Group parameterization the following values of the slope parameters were obtained: $g=(-21.134\pm0.017)\%$, $h=(1.848\pm0.040)\%$, $k=(-0.463\pm0.014)\%$. The quality and statistical accuracy of the data have allowed an improvement in precision by more than an order of magnitude, and are such as to warrant a more elaborate theoretical treatment, including pion-pion rescattering, which is in preparation.
Published: 2007

23. Measurements of charged kaon semileptonic decay branching fractions $K^{\pm} \to \pi^{0} \mu^{\pm} \nu$ and $K^{\pm} \to \pi^{0} e^{\pm} \nu$ and their ratio

Author: Batley, J.R., Lazzeroni, C., Munday, D.J., Slater, M.W., Wotton, S.A., Arcidiacono, R., Bocquet, G., Cabibbo, N., Ceccucci, A., Cundy, D., Falaleev, V., Fidecaro, M., Gatignon, L., Gonidec, A., Kubischta, W., Norton, A., Patel, M., Peters, A., Balev, S., Frabetti, P.L., Goudzovski, E., Hristov, P., Kekelidze, V., Kozhuharov, V., Litov, L., Madigozhin, D., Marinova, E., Molokanova, N., Polenkevich, I., Potrebenikov, Yu., Stoynev, S., Zinchenko, A., Monnier, E., Swallow, E., Winston, R., Rubin, P., Walker, A., Baldini, W., Cotta Ramusino, A., Dalpiaz, P., Damiani, C., Fiorini, M., Gianoli, A., Martini, M., Petrucci, F., Savrie, M., Scarpa, M., Wahl, H., Bizzeti, A., Calvetti, M., Celeghini, E., Iacopini, E., Lenti, M., Martelli, F., Ruggiero, G., Veltri, M., Behler, M., Eppard, K., Kleinknecht, K., Marouelli, P., Masetti, L., Moosbrugger, U., Morales Morales, C., Renk, B., Wache, M., Wanke, R., Winhart, A., Coward, D.H., Dabrowski, A., Fonseca Martin, T., Shieh, M., Szleper, M., Velasco, M., Wood, M.D., Anzivino, G., Cenci, P., Imbergamo, E., Pepe, M., Petrucci, M.C., Piccini, M., Raggi, M., Valdata-Nappi, M., Cerri, C., Collazuol, G., Costantini, F., DiLella, L., Doble, N., Fantechi, R., Fiorini, L., Giudici, S., Lamanna, G., Mannelli, I., Michetti, A., Pierazzini, G., Sozzi, M., Bloch-Devaux, Brigitte, Cheshkov, C., Cheze, J.B., De Beer, M., Derre, J., Marel, G., Mazzucato, E., Peyaud, B., Vallage, G., Holder, M., Maier, A., Ziolkowski, M., Bifani, S., Biino, C., Cartiglia, N., Clemencic, M., Goy Lopez, S., Marchetto, F., Dibon, H., Jeitler, M., Markytan, M., Mikulec, I., Neuhofer, G., and Widhalm, L.
Subjects: Particle Physics - Experiment
Abstract: Measured ratios of decay rates for $\Re_{K_{e3}/K_{2\pi}}, \Re_{K_{\mu3}/K_{2\pi}}$ and $\Re_{K_{\mu3}/K_{e3}}$ are presented. These measurements are based on $K^{\pm}$ decays collected in a dedicated run in 2003 by the NA48/2 experiment at CERN. The results obtained are $\Re_{K_{e3}/K_{2\pi}} = 0.2496 \pm 0.0009_{(stat)} \pm 0.0004_{(syst)}$ and $\Re_{K_{mu3}K_{2\pi}} = 0.1637 \pm 0.0006_{(stat)} \pm 0.0003_{(syst)}$. Using the PDG average for the $K^{\pm} \rightarrow \pi^{\pm}\pi^{0}$ normalisation mode, both values are found to be larger than the current values given by the Particle Data Book and lead to a larger magnitude of the $|V_{us}|$ CKM parameter than previously accepted. In addition, a new measured value of $\Re_{K_{\mu3}/K_{e3}} = 0.656 \pm 0.003_{(stat)} \pm 0.001_{(syst)}$ is compared to the semi-empirical predictions based on the latest form factor measurements. Measured ratios of decay rates for Ke3/K2\pi, K\mu3/K2\pi and K\mu3/Ke3 are presented. These measurements are based on K^+- decays collected in a dedicated run in 2003 by the NA48/2 experiment at CERN. The results obtained are Ke3/K2\pi = 0.2470 +/- 0.0009 (stat) +/- 0.0004 (syst) and K\mu3/K2\pi = 0.1637 +/- 0.0006 (stat) +/- 0.0003 (syst). Using the PDG average for the K^+- -> \pi^+-\pi^0 normalisation mode, both values are found to be larger than the current values given by the Particle Data Book and lead to a larger magnitude of the |V_{us}| CKM element than previously accepted. When combined with the latest Particle Data Book value of |V_{ud}|, the result is in agreement with unitarity of the CKM matrix. In addition, a new measured value of K\mu3/Ke3 = 0.663 +/- 0.003(stat) +/- 0.001(syst) is compared to the semi-empirical predictions based on the latest form factor measurements.
Published: 2006

24. Measurement of the branching ratios of the decays $\Xi^{0}\rightarrow \sigma^{+} e^{-} \overline{\nu}_{e}$ and $\overline{\Xi^{0}}\rightarrow \overline{\sigma^{+}} e^{+} \nu_{e}$

Author: Batley, J Richard, Anzivino, Giuseppina, Arcidiacono, R, Baldini, W, Behler, M, Biino, C, Bizzeti, A, Bocquet, G, Calvetti, M, Cartiglia, N, Ceccucci, A, Cenci, P, Cerri, C, Cheshkov, C, Chèze, J B, Clemencic, M, Collazuol, G, Costantini, F, Cundy, Donald C, Dabrowski, A, Dalpiaz, P, De Beer, M, Debu, P, Dibon, Heinz, Doble, N, Eppard, K, Eppard, M, Falaleev, V, Fantechi, R, Fiorini, L, Fonseca-Martin, T, Frabetti, P L, Gatignon, L, Gianoli, A, Giudici, S, Gonidec, A, Goudzovski, E, Gouge, G, Goy-Lopez, S, Grafström, P, Hirstius, A, Holder, M, Iacopini, E, Imbergamo, E, Jeitler, Manfred, Kalmus, George Ernest, Kekelidze, V D, Khristov, P Z, Kleinknecht, K, Koch, U, Kubischta, Werner, Lamanna, G, Lazzeroni, C, Lenti, M, Litov, L, Lubrano, P, Madigozhin, D T, Maier, A, Mannelli, I, Marchetto, F, Marel, Gérard, Markytan, Manfred, Marouelli, P, Martini, M, Masetti, L, Mazzucato, E, Menichetti, E, Michetti, A, Mikulec, I, Molokanova, N A, Monnier, E, Moosbrugger, U, Morales-Morales, C, Munday, D J, Nappi, A, Neuhofer, G, Norton, A, Panzer-Steindel, B, Pastrone, N, Patel, M, Pepé, M, Peters, A, Petrucci, F, Petrucci, M C, Peyaud, B, Piccini, M, Pierazzini, G M, Potrebenikov, Yu K, Rubin, P, Ruggiero, G, Sacco, R, Savrié, M, Scarpa, M, Slater, M W, Sozzi, M, Stoynev, S, Swallow, E C, Valdata, M, Vallage, B, Velasco, M, Veltri, M, Wahl, H, Walker, A, Wanke, R, Widhalm, L, Winhart, A, Winston, R, Wislicki, W, Wotton, S A, Zinchenko, A I, and Ziolkowski, M
Subjects: High Energy Physics::Phenomenology, High Energy Physics::Experiment, Particle Physics - Experiment
Abstract: From 56 days of data taking in 2002, the NA48/1 experiment observed 6316 $\Xi^{0}\rightarrow \Sigma^{+} e^{-} \overline{\nu}_{e}$ candidates (with the subsequent $\Sigma^{+} \rightarrow p \pi^{0}$ decay) and 555 $\overline{\Xi^{0}}\rightarrow \overline{\Sigma^{+}} e^{+} \nu_{e}$ candidates with background contamination of $215 \pm 44$ and $136 \pm 8$ events, respectively. From these samples, the branching ratios BR($\Xi^{0}\rightarrow \Sigma^{+} e^{-} \overline{\nu}_{e})=(2.51 \pm0.03_{\mathrm{stat}}\pm 0.09_{\mathrm{syst}})\times10^{-4}$ and BR($\overline{\Xi^{0}}\rightarrow \overline{\Sigma^{+}} e^{+} \nu_{e})= (2.55 \pm 0.12_{\mathrm{stat}}\pm{0.10}_{\mathrm{syst}}) \times 10^{-4}$ were measured allowing the determination of the CKM matrix element $|V_{\mathrm{us}}| = 0.209^{+0.023}_{-0.028}$. Using the Particle Data Group average for $|V_{\mathrm{us}}|$ obtained in semileptonic kaon decays, we measured the ratio $g_1/f_1 = 1.20 \pm 0.05$ of the axial-vector to vector form factors.
Published: 2006

25. Search for direct CP-violation in $K^{\pm}\to \pi^{\pm}\pi^{0}\pi^{0}$ decays

Author: Batley, J.R., Culling, A.J., Kalmus, G., Lazzeroni, C., Munday, D.J., Slater, M.W., Arcidiacono, R., Bocquet, G., Cabibbo, N., Ceccucci, A., Cundy, D., Falaleev, V., Fidecaro, M., Gatignon, L., Gonidec, A., Kubischta, W., Norton, A., Maier, A., Patel, M., Peters, A., Balev, S., Frabetti, P.L., Goudzovski, E., Hristov, P., Kekelidze, V., Kozhuharov, V., Litov, L., Madigozhin, D., Marinova, E., Molokanova, N., Polenkevich, I., Potrebenikov, Yu., Stoynev, S., Zinchenko, A., Monnier, E., Swallow, E., Winston, R., Rubin, P., Walker, A., Baldini, W., Cotta Ramusino, A., Dalpiaz, P., Damiani, C., Fiorini, M., Gianoli, A., Martini, M., Petrucci, F., Savrie, M., Scarpa, M., Wahl, H., Bizzeti, A., Calvetti, M., Celeghini, E., Iacopini, E., Lenti, M., Martelli, F., Ruggiero, G., Veltri, M., Behler, M., Eppard, K., Kleinknecht, K., Marouelli, P., Masetti, L., Moosbrugger, U., Morales Morales, C., Renk, B., Wache, M., Wanke, R., Winhart, A., Coward, D.H., Dabrowski, A., Fonseca Martin, T., Shieh, M., Szleper, M., Velasco, M., Wood, M.D., Anzivino, G., Cenci, P., Imbergamo, E., Nappi, A., Pepe, M., Petrucci, M.C., Piccini, M., Raggi, M., Valdata-Nappi, M., Cerri, C., Collazuol, G., Costantini, F., DiLella, L., Doble, N., Fantechi, R., Fiorini, L., Giudici, S., Lamanna, G., Mannelli, I., Michetti, A., Pierazzini, G., Sozzi, M., Bloch-Devaux, Brigitte, Cheshkov, C., Cheze, J.B., De Beer, M., Derre, J., Marel, G., Mazzucato, E., Peyaud, B., Vallage, B., Holder, M., Ziolkowski, M., Bifani, S., Biino, C., Cartiglia, N., Clemencic, M., Goy Lopez, S., Dibon, H., Jeitler, M., Markytan, M., Mikulec, I., Neuhofer, G., and Widhalm, L.
Subjects: Particle Physics - Experiment
Abstract: A search for direct CP-violation in $K^{\pm}\to \pi^{\pm}\pi^{0}\pi^{0}$ decays based on 47.14 million events has been performed by the NA48/2 experiment at the CERN SPS. The asymmetry in the Dalitz plot linear slopes $A_{g}=(g^{+} - g^{-})/(g^{+} + g^{-})$ is measured to be $A_{g}=(1.8 \pm 2.6) \times 10^{-4}$. The design of the experiment and the method of analysis provide good control of instrumental charge asymmetries in this measurement. The precision of the result is limited by statistics and is almost one order of magnitude better than that of previous measurements by other experiments. A search for direct CP-violation in K+- --> pi+-pi0pi0 decays based on 47.14 million events has been performed by the NA48/2 experiment at the CERN SPS. The asymmetry in the Dalitz plot linear slopes A_g=(g^+ - g^-)/(g^+ + g^-) is measured to be A_g=(1.8 +- 2.6).10^{-4}. The design of the experiment and the method of analysis provide good control of instrumental charge asymmetries in this measurement. The precision of the result is limited by statistics and is almost one order of magnitude better than that of previous measurements by other experiments. A search for direct CP-violation in K±→π±π0π0 decay based on 47.14 million events has been performed by the NA48/2 experiment at the CERN SPS. The asymmetry in the Dalitz plot linear slopes Ag=(g+−g−)/(g++g−) is measured to be Ag=(1.8±2.6)×10−4 . The design of the experiment and the method of analysis provide good control of instrumental charge asymmetries in this measurement. The precision of the result is limited by statistics and is almost one order of magnitude better than that of previous measurements by other experiments.
Published: 2006

26. Search for direct CP-violation in $K^{\pm} \to \pi^{\pm} \pi^{0} \pi^{0}$ decays

Author: Batley, J Richard, Culling, A J, Kalmus, George Ernest, Lazzeroni, C, Munday, D J, Slater, M W, Wotton, S A, Arcidiacono, R, Bocquet, G, Cabibbo, Nicola, Ceccucci, A, Cundy, Donald C, Falaleev, V, Fidecaro, Maria, Gatignon, L, Gonidec, A, Kubischta, Werner, Norton, A, Maier, A, Patel, M, Peters, A, Balev, S, Frabetti, P L, Goudzovski, E, Khristov, P Z, Kekelidze, V D, Kozhuharov, V, Litov, L, Madigozhin, D T, Marinova, E, Molokanova, N A, Polenkevich, I, Potrebenikov, Yu K, Stoynev, S, Zinchenko, A I, Monnier, E, Swallow, E, Winston, R, Rubin, P, Walker, A, Baldini, W, Cotta-Ramusino, A, Dalpiaz, P, Damiani, C, Fiorini, M, Gianoli, A, Martini, M, Petrucci, F, Savrié, M, Scarpa, M, Wahle, H, Bizzeti, A, Calvetti, M, Celeghini, E, Iacopini, E, Lenti, M, Martelli, F, Ruggiero, G, Veltri, M, Behler, M, Eppard, K, Kleinknecht, K, Marouelli, P, Masetti, L, Moosbrugger, U, Morales-Morales, C, Renk, B, Wache, M, Wanke, R, Winhart, A, Coward, D, Dabrowski, A, Fonseca-Martin, T, Shieh, M, Szleper, M, Velasco, M, Wood, M D, Anzivino, Giuseppina, Cenci, P, Imbergamo, E, Nappi, A, Pepé, M, Petrucci, M C, Piccini, M, Raggi, M, Valdata-Nappi, M, Cerri, C, Collazuol, G, Costantini, F, Di Lella, Luigi, Doble, Niels T, Fantechi, R, Fiorini, L, Giudici, Sergio, Lamanna, G, Mannelli, I, Michetti, A, Pierazzini, G M, Sozzi1, M, Bloch-Devaux, B, Cheshkov, C, Chèze, J B, De Beer, M, Derr, J, Marel, Gérard, Mazzucato, E, Peyaud, B, Vallage, B, Holder, M, Ziolkowski, M, Bifani, S, Biino, C, Cartiglia, N, Clemencic, M, Goy-Lopez, S, Marchetto, F, Dibon, Heinz, Jeitler, Manfred, Markytan, Manfred, Mikulec, I, Neuhofer, G, and Widhalm, L
Subjects: Particle Physics - Experiment
Abstract: A search for direct CP-violation in $K^{\pm}\rightarrow \pi^\pm \pi^0 \pi^0$ decay based on 47.14 million events has been performed by the NA48/2 experiment at the CERN SPS. The asymmetry in the Dalitz plot linear slopes $A_g = ( g^+ -g^- ) / ( g^+ + g^- )$ is measured to be $A_g = (1.8 \pm 2.6) \cdot10^{-4}$. The design of the experiment and the method of analysis provide good control of instrumental charge asymmetries in this measurement. The precision of the result is limited by statistics and is almost one order of magnitude better than that of previous measurements by other experiments.
Published: 2006

27. A measurement of the CP-conserving component of the decay $K^{0}_{S} \to \pi^{+}\pi^{-}\pi^{0}$

Author: Batley, J Richard, Lazzeroni, C, Munday, D J, Patel, M, Slater, M W, Wotton, S A, Arcidiacono, R, Bocquet, G, Ceccucci, A, Cundy, Donald C, Doble, Niels T, Falaleev, V, Gatignon, L, Gonidec, A, Grafström, P, Kubischta, Werner, Marchetto, F, Mikulec, I, Norton, A, Panzer-Steindel, B, Rubin, P, Wahl, H, Goudzovski, E, Gurev, D, Khristov, P Z, Kekelidze, V D, Litov, L, Madigozhin, D T, Molokanova, N A, Potrebenikov, Yu K, Stoynev, S, Zinchenko, A I, Monnier, E, Swallow, E, Winston, R, Sacco, R, Walker, A, Baldini, W, Dalpiaz, P, Frabetti, P L, Gianoli, A, Martini, M, Petrucci, F, Scarpa, M, Savrié, M, Bizzeti, A, Calvetti, M, Collazuol, G, Graziani, G, Iacopini, E, Lenti, M, Martelli, F, Ruggiero, G, Veltri, M, Behler, M, Eppard, K, Eppard, M, Hirstius, A, Kleinknecht, K, Koch, U, Masetti, L, Marouelli, P, Moosbrugger, U, Morales-Morales, C, Peters, A, Wache, M, Wanke, R, Winhart, A, Dabrowski, A, Fonseca-Martin, T, Velasco, M, Anzivino, Giuseppina, Cenci, P, Imbergamo, E, Lamanna, G, Lubrano, P, Michetti, A, Nappi, A, Pepé, M, Petrucci, M C, Piccini, M, Valdata, M, Cerri, C, Costantini, F, Fantechi, R, Fiorini, L, Giudici, Sergio, Mannelli, I, Pierazzini, G M, Sozzi, M, Cheshkov, C, Chèze, J B, De Beer, M, Debu, P, Gouge, G, Marel, Gérard, Mazzucato, E, Peyaud, B, Vallage, B, Holder, M, Maier, A, Ziolkowski, M, Biino, C, Cartiglia, N, Clemencic, M, Goy-Lopez, S, Menichetti, E, Pastrone, N, Wislicki, W, Dibon, Heinz, Jeitler, Manfred, Markytan, Manfred, and Neuhofer, G
Subjects: Particle Physics - Experiment
Abstract: The NA48 collaboration has measured the amplitude of the CP-conserving component of the decay $K^{0}_{S} \to \pi^{+}\pi^{-}\pi^{0}$ relative to $K^{0}_{L} \to \pi^{+}\pi^{-}\pi^{0}$. For the characteristic parameter $\lambda$, the values Re $\lambda = 0.038 \pm 0.010$ and Im $\lambda = - 0.013 \pm 0.007$ have been extracted. These values agree with earlier measurements and with theoretical predictions from chiral perturbation theory.
Published: 2005

28. Observation of a cusp-like structure in the $\pi^{0}\pi^{0}$ invariant mass distribution from $K^{+-} \to \pi^{+-}\pi^{0}\pi^{0}$ decay and determination of the $\pi\pi$ scattering lengths

Author: Batley, J Richard, Anzivino, Giuseppina, Arcidiacono, R, Baldini, W, Balev, S, Behler, M, Biino, C, Bizzeti, A, Bloch-Devaux, B, Bocquet, G, Cabibbo, Nicola, Calvetti, M, Cartiglia, N, Ceccucci, A, Celeghini, E, Cenci, P, Cerri, C, Cheshkov, C, Chèze, J B, Clemencic, M, Collazuol, G, Costantini, F, Cotta-Ramusino, A, Coward, D, Cundy, Donald C, Dabrowski, A, Dalpiaz, P, Damiani, C, De Beer, M, Derré, J, Di Lella, Luigi, Dibon, Heinz, Doble, Niels T, Eppard, K, Falaleev, V, Fantechi, R, Fidecaro, Maria, Fiorini, L, Fiorini, M, Fonseca-Martin, T, Frabetti, P L, Gatignon, L, Gianoli, A, Giudici, Sergio, Gonidec, A, Goudzovski, E, Goy-Lopez, S, Holder, M, Iacopini, E, Imbergamo, E, Jeitler, Manfred, Kekelidze, V D, Khristov, P Z, Kleinknecht, K, Kozhuharov, V, Kubischta, Werner, Lamanna, G, Lazzeroni, Cristina, Lenti, M, Litov, L, Madigozhin, D T, Maier, A, Mannelli, I, Marchetto, F, Marel, Gérard, Marinova, E, Markytan, Manfred, Marouelli, P, Martelli, F, Martini, M, Masetti, L, Mazzucato, E, Michetti, A, Mikulec, I, Molokanova, N A, Monnier, E, Moosbrugger, U, Morales-Morales, C, Munday, D J, Neuhofer, G, Norton, A, Patel, M, Pepé, M, Peters, A, Petrucci, F, Petrucci, M C, Peyaud, B, Piccini, M, Pierazzini, G M, Polenkevich, I, Potrebenikov, Yu K, Raggi, M, Renk, B, Rubin, P, Ruggiero, G, Savrié, M, Scarpa, M, Shieh, M, Slater, M W, Sozzi, M, Stoynev, S, Swallow, E, Szleper, M, Valdata-Nappi, M, Vallage, B, Velasco, M, Veltri, M, Wache, M, Wahl, H, Walker, A, Wanke, R, Widhalm, L, Winhart, A, Winston, R, Wood, M D, Wotton, S A, Zinchenko, A I, and Ziolkowski, M
Subjects: Particle Physics - Experiment
Abstract: We report the results from a study of $\sim 2.3 \times 10^{7} K^{\pm} \to \pi^{\pm}\pi^{0}\pi^{0}$ decays recorded by the NA48/2 experiment at the CERN SPS, showing an anomaly in the $\pi^{0}\pi^{0}$ invariant mass ($M_{00}$) distribution in the region around $M_{00} = 2m_{+}$, where $m_{+}$ is the charged pion mass. This anomaly, never observed in previous experiments, can be interpreted as an effect due mainly to the final state charge exchange scattering process $\pi^{+}\pi^{-} \to \pi^{0}\pi^{0}$ in $K^{\pm} \to \pi^{\pm}\pi^{+}\pi^{-}$ decay. It provides a precise determination of $a_{0} - a_{2}$, the difference between the $\pi\pi$ scattering lengths in the isospin $I=0$ and $I=2$ states. A best fit to a rescattering model corrected for isospin symmetry breaking gives $(a_{0} − a_{2})m_{+} = 0.268 \pm 0.010$( stat. ) $\pm 0.004 $(syst.), with additional external uncertainties of $\pm 0.013$ from branching ratio and theoretical uncertainties. If the correlation between $a_{0}$ and $a_{2}$ predicted by chiral symmetry is taken into account, this result becomes $(a_{0} − a_{2})m_{+} = 0.264 \pm 0.006$( stat.) $\pm 0.004$( syst.) $\pm 0. 013$(ext).
Published: 2005

29. Observation of the rare decays $K_{S} \to \pi^{0} \mu^{+} \mu^{-}$

Author: Batley, J.R., Kalmus, G.E., Lazzeroni, C., Munday, D.J., Patel, M., Slater, M.W., Wotton, S.A., Arcidiacono, R., Bocquet, G., Ceccucci, A., Cundy, D., Doble, N., Falaleev, V., Gatignon, L., Gonidec, A., Grafstrom, P., Kubischta, W., Marchetto, F., Mikulec, I., Norton, A., Panzer-Steindel, B., Rubin, P., Wahl, H., Monnier, E., Swallow, E., Winston, R., Goudzovski, E., Gurev, D., Hristov, P., Kekelidze, V., Kozhuharov, V., Litov, L., Madigozhin, D., Molokanova, N., Potrebenikov, Yu., Stoynev, S., Zinchenko, A., Sacco, R., Walker, A., Baldini, W., Dalpiaz, P., Duclos, J., Frabetti, P.L., Gianoli, A., Martini, M., Petrucci, F., Scarpa, M., Savrie, M., Bizzeti, A., Calvetti, M., Graziani, G., Iacopini, E., Lenti, M., Martelli, F., Ruggiero, G., Veltri, M., Behler, M., Eppard, K., Eppard, M., Hirstius, A., Kleinknecht, K., Koch, U., Masetti, L., Marouelli, P., Moosbrugger, U., Morales Morales, C., Peters, A., Wanke, R., Winhart, A., Dabrowski, A., Fonseca Martin, T., Szleper, M., Velasco, M., Anzivino, G., Cenci, P., Imbergamo, E., Lamanna, G., Lubrano, P., Michetti, A., Nappi, A., Pepe, M., Petrucci, M.C., Piccini, M., Valdata, M., Cerri, C., Collazuol, G., Costantini, F., Fantechi, R., Fiorini, L., Giudici, S., Mannelli, I., Pierazzini, G., Sozzi, M., Cheshkov, C., Cheze, J.B., De Beer, M., Debu, P., Gouge, G., Marel, G., Mazzucato, E., Peyaud, B., Vallage, B., Holder, M., Maier, A., Ziolkowski, M., Biino, C., Cartiglia, N., Clemencic, M., Goy-Lopez, S., Menichetti, Ezio A., Pastrone, N., Wislicki, W., Dibon, H., Jeitler, M., Markytan, M., Neuhofer, G., and Widhalm, L.
Subjects: Particle Physics - Experiment
Abstract: A search for the decay $K_{S} \to \pi^{0} \mu^{+} \mu^{-}$ has been made by the NA48/1 Collaboration at the CERN SPS accelerator. The data were collected during 2002 with a high intensity $K_{S}$ beam. Six events were found with a background expectation of $0.22^{+0.18}_{0.11}$ events. Using a vector matrix element and unit form factor, the measured branching ratio is $B(K_{S} \to \pi^{0}\mu^{+}\mu^{-}) = [2.9^{+1.5}_{-1.2}(stat) \pm 0.2(syst)] \times 10^{9}$. A search for the decay KS→π0μ+μ− has been made by the NA48/1 Collaboration at the CERN SPS accelerator. The data were collected during 2002 with a high-intensity KS beam. Six events were found with a background expectation of 0.22−0.11+0.18 events. Using a vector matrix element and unit form factor, the measured branching ratio is B(KS→π0μ+μ−)=[2.9−1.2+1.5(stat)±0.2(syst)]×10−9. A search for the decay K_S -> pi^0mu^+mu^- has been made by the NA48/1 Collaboration at the CERN SPS accelerator. The data were collected during 2002 with a high-intensity K_S beam. Six events were found with a background expectation of 0.22^+0.18_-0.11 event. Using a vector matrix element and unit form factor, the measured branching ratio is B(K_S -> pi^0mu^+mu^-)=[2.9^+1.5_-1.2(stat)+/-0.2(syst)]x10^{-9}.
Published: 2004

30. Observation of the rare decay $K_{S} \rightarrow \pi^0 e^{+}e^{-}$

Author: Batley, J Richard, Kalmus, George Ernest, Lazzeroni, C, Munday, D J, Patel, M, Slater, M W, Wotton, S A, Arcidiacono, R, Bocquet, G, Ceccucci, Augusto, Cundy, Donald C, Doble, Niels T, Falaleev, V P, Gatignon, L, Gonidec, A, Grafström, P, Kubischta, Werner, Marchetto, F, Mikulec, I, Norton, A, Panzer-Steindel, B, Rubin, P, Wahl, H, Goudzovski, E, Gurev, D, Khristov, P Z, Kekelidze, V D, Litov, L, Madigozhin, D T, Molokanova, N A, Potrebenikov, Yu K, Stoynev, S, Zinchenko, A I, Monnier, E, Swallow, E C, Winston, R, Sacco, R, Walker, A, Baldini, W, Dalpiaz, Pietro, Frabetti, P L, Gianoli, A, Martini, M, Petrucci, F, Scarpa, M, Savrié, M, Bizzeti, A, Calvetti, M, Collazuol, G, Graziani, G, Iacopini, E, Lenti, M, Martelli, F, Ruggiero, G, Veltri, M, Behler, M, Eppard, K, Eppard, M, Hirstius, A, Kleinknecht, K, Koch, U, Masetti, L, Marouelli, P, Moosbrugger, U, Morales-Morales, C, Peters, A, Wanke, R, Winhart, A, Dabrowski, A, Fonseca-Martin, T, Goy-Lopez, S, Velasco, M, Anzivino, Giuseppina, Cenci, P, Imbergamo, E, Lamanna, G, Lubrano, P, Michetti, A, Nappi, A, Pepé, M, Petrucci, M C, Piccini, M, Valdata, M, Cerri, C, Costantini, F, Fantechi, R, Fiorini, Luca, Giudici, Sergio, Mannelli, I, Pierazzini, G M, Sozzi, M, Cheshkov, C, Chèze, J B, De Beer, M, Debu, P, Gouge, G, Marel, Gérard, Mazzucato, E, Peyaud, B, Vallage, B, Holder, M, Maier, A, Ziolkowski, M, Biino, C, Cartiglia, N, Clemencic, M, Menichetti, E, Pastrone, N, Wislicki, W, Dibon, Heinz, Jeitler, Manfred, Markytan, Manfred, Neuhofer, Günther, and Widhalm, L
Subjects: Particle Physics - Experiment
Abstract: A search for the decay $K_{S} \rightarrow \pi^0 e^{+}e^{-}$ has been made by the NA48/1 experiment at the CERN SPS accelerator. Using data collected during 89 days in 2002 with a high-intensity $K_{S}$ beam, 7 events were found with a background of 0.15 events. The branching fraction $BR(K_{S} \rightarrow \pi^0 e^{+}e^{-}, m_{ee} > 0.165$ GeV/c$^{2}) = (3.0^{+1.5}_{-1.2(stat)} \pm 0.2(syst)) \times 10^{-9}$ has been measured. Using a vector matrix element and a form factor equal to one, the measurement gives $BR(K_{S} \rightarrow \pi^0 e^{+}e^{-}) = (5.8^{+2.9}_{-2.4}) \times 10^{-9}$.
Published: 2003

31. First observation and study of $K^\pm \to \pi^\pm \pi^0 e^+ e^-$ decay at the NA48/2 experiment

Author: Misheva, M. H., Anzivino, G., Arcidiacono, R., Balev, S., Batley, J. R., Behler, M., Bifani, S., Biino, C., Bizzeti, A., Bloch-Devaux, B., Bocquet, G., Cabibbo, N., Calvetti, M., Cartiglia, N., Ceccucci, A., Cenci, P., Cerri, C., Cheshkov, C., Cheze, J. B., Ciemencic, M., Collazuol, G., Costantini, F., Cotta Ramusino, A., Coward, D., Cundy, D., Dabrowski, A., Dalpiaz, P., Damiani, C., Beer, M., Derre, J., Dibon, H., Dilella, L., Doble, N., Eppard, K., Falaleev, V., Fantechi, R., Fidecaro, M., Fiorini, L., Fiorini, M., Fonseca, T., Martin, M., Frabetti, P. L., Gatignon, L., Gersabeck, E., Gianoli, A., Giudici, S., Gonidec, A., Goudzovski, E., Goy Lopez, S., Holder, M., Hris, P., Iacopini, E., Imbergamo, E., Jeitler, M., Kalmus, G., Kekelidze, V., Kleinknecht, K., Kozhuharov, V., Kubis, W., Lamanna, G., Lazzeroni, C., Lenti, M., Leandar Litov, Madigozhin, D., Maier, A., Mannelli, I., Marchetto, F., Mare, G., Markytan, M., Marouelli, P., Martini, M., Masetti, L., Mazzucato, E., Michetti, A., Mikulec, I., Molokanova, N., Monnier, E., Moosbrugger, U., Morales Morales, C., Munday, D. J., Nappi, A., Neuhofer, G., Norton, A., Pa, M., Pepe, M., Peters, A., Petrucci, F., Petrucci, M. C., Peyaud, B., Piccini, M., Pierazzini, G., Polenkevich, I., Potrebenikov, Yu, Raggi, M., Renk, B., Rubin, P., Ruggiero, G., Savrie, M., Scarpa, M., Shieh, M., Slater, M. W., Sozzi, M., Stoynev, S., Swallow, E., Szleper, M., Valdata-Nappi, M., Vallage, B., Velasco, M., Veltri, M., Venditti, S., Wache, M., Wahl, H., Walker, A., Wanke, R., Widhalm, L., Winhart, A., Winston, R., Wood, M. D., Wotton, S. A., Yushchenko, A., Zinchenko, M., and Ziolkowski, M.
Subjects: Particle Physics - Experiment
Abstract: A sample of almost 2000 $K^\pm \to \pi^\pm \pi^0 e^+ e^-$ rare decays with a background contamination below 3% is observed for the first time by the NA48/2 experiment at CERN/SPS. The preliminary branching ratio in the full kinematic region is obtained to be $BR(K^\pm \to \pi^\pm \pi^0 e^+ e^-)$ = (4.06 ± 0.17) x $10^{-6}$ by analyzing the data set recorded in 3-month NA48/2 run during 2003. The measured value is in agreement with the theoretical prediction within one standard deviation.

32. First Observation and Study of the $K^\pm \to \pi^\pm \pi^0 e^+ e^-$ Decay

Author: Batley, J. R., Kalmus, G., Lazzeroni, C., Munday, D. J., Slater, M. W., Wotton, S. A., Arcidiacono, R., Bocquet, G., Cabibbo, N., Ceccucci, A., Cundy, D., Falaleev, V., Fidecaro, M., Gatignon, L., Gonidec, A., Kubischta, W., Maier, A., Norton, A., Patel, M., Peters, A., Balev, S., Frabetti, P. L., Gersabeck, E., Goudzovski, E., Hristov, P., Kekelidze, V., Kozhuharov, V., Litov, L., Madigozhin, D., Misheva, M., Molokanova, N., Polenkevich, I., Potrebenikov, Yu, Stoynev, S., Zinchenko, A., Monnier, E., Swallow, E., Winston, R., Rubin, P., Walker, A., Dalpiaz, P., Damiani, C., Fiorini, M., Martini, M., Petrucci, F., Savrié, M., Scarpa, M., Wahl, H., Baldini, W., Cotta Ramusino, A., Gianoli, A., Calvetti, M., Celeghini, E., Iacopini, E., Lenti, M., Ruggiero, G., Bizzeti, A., Veltri, M., Behler, M., Eppard, K., Hita-Hochgesand, M., Kleinknecht, K., Marouelli, P., Masetti, L., Moosbrugger, U., Morales Morales, C., Renk, B., Wache, M., Rainer Wanke, Winhart, A., Coward, D., Dabrowski, A., Fonseca Martin, T., Shieh, M., Szleper, M., Velasco, M., Wood, M. D., Anzivino, G., Imbergamo, E., Nappi, A., Piccini, M., Raggi, M., Valdata-Nappi, M., Cenci, P., Pepe, M., Petrucci, M. C., Costantini, F., Doble, N., Fiorini, L., Giudici, S., Pierazzini, G., Sozzi, M., Venditti, S., Collazuol, G., Dilella, L., Lamanna, G., Mannelli, I., Michetti, A., Cerri, C., Fantechi, R., Bloch-Devaux, B., Cheshkov, C., Chèze, J. B., Beer, M., Derré, J., Marel, G., Mazzucato, E., Peyaud, B., Vallage, B., Holder, M., Ziolkowski, M., Bifani, S., Clemencic, M., Goy Lopez, S., Biino, C., Cartiglia, N., Marchetto, F., Dibon, H., Jeitler, M., Markytan, M., Mikulec, I., Neuhofer, G., Widhalm, L., Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, and NA48/2
Subjects: K+: branching ratio: measured, CERN Lab, background, hep-ex, +pi%2B+pi0+electron+positron%22">K+ --> pi+ pi0 electron positron, perturbation theory: chiral, K: secondary beam, CERN SPS, K-: branching ratio: measured, asymmetry: CP, High Energy Physics - Experiment, S010.120, parity: violation, K+: semileptonic decay, kinematics, NA48, CP: violation, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], structure, S010:Desig=120, Particle Physics - Experiment, +pi-+pi0+electron+positron%22">K- --> pi- pi0 electron positron, experimental results, K-: semileptonic decay
Abstract: The NA48/2 experiment at CERN reports the first observation of the $K^\pm \to \pi^\pm \pi^0 e^+ e^-$ decay from an exposure of $1.7 \times 10^{11}$ charged kaon decays recorded in $2003-2004$. A sample of 4919 candidates with 4.9% background contamination allows the determination of the branching ratio in the full kinematic region, BR($K^\pm \to \pi^\pm \pi^0 e^+ e^-)=(4.24 \pm 0.14)\times10^{-6}$. The study of the kinematic space shows evidence for a structure dependent contribution in agreement with predictions based on chiral perturbation theory. Several P- and CP-violating asymmetries are also evaluated., Comment: 15 pages, 4 figures, 1 table

33. Precision tests of the Standard Model with Kaon decays at CERN

Author: G. Lamanna, F. Ambrosino, A. Antonelli, G. Anzivino, R. Arcidiacono, W. Baldini, S. Balev, J.R. Batley, M. Behler, S. Bifani, C. Biino, A. Bizzeti, B. Bloch-Devaux, G. Bocquet, V. Bolotov, F. Bucci, N. Cabibbo, M. Calvetti, N. Cartiglia, A. Ceccucci, P. Cenci, C. Cerri, C. Cheshkov, J.B. Chèze, M. Clemencic, G. Collazuol, F. Costantini, A. Cotta Ramusino, D. Coward, D. Cundy, A. Dabrowski, G. D'Agostini, P. Dalpiaz, C. Damiani, H. Danielsson, M. De Beer, G. Dellacasa, J. Derré, H. Dibon, D. Di Filippo, L. DiLella, N. Doble, V. Duk, J. Engelfried, K. Eppard, V. Falaleev, R. Fantechi, M. Fidecaro, L. Fiorini, M. Fiorini, T. Fonseca Martin, P.L. Frabetti, A. Fucci, S. Gallorini, L. Gatignon, E. Gersabeck, A. Gianoli, S. Giudici, A. Gonidec, E. Goudzovski, S. Goy Lopez, E. Gushchin, B. Hallgren, M. Hita-Hochgesand, M. Holder, P. Hristov, E. Iacopini, E. Imbergamo, M. Jeitler, G. Kalmus, V. Kekelidze, K. Kleinknecht, V. Kozhuharov, W. Kubischta, V. Kurshetsov, C. Lazzeroni, M. Lenti, E. Leonardi, L. Litov, D. Madigozhin, A. Maier, I. Mannelli, F. Marchetto, G. Marel, M. Markytan, P. Marouelli, M. Martini, L. Masetti, P. Massarotti, E. Mazzucato, A. Michetti, I. Mikulec, M. Misheva, N. Molokanova, E. Monnier, U. Moosbrugger, C. Morales Morales, M. Moulson, S. Movchan, D.J. Munday, M. Napolitano, A. Nappi, G. Neuhofer, A. Norton, T. Numao, V. Obraztsov, V. Palladino, M. Patel, M. Pepe, A. Peters, F. Petrucci, M.C. Petrucci, B. Peyaud, R. Piandani, M. Piccini, G. Pierazzini, I. Polenkevich, I. Popov, Yu. Potrebenikov, M. Raggi, B. Renk, F. Retière, P. Riedler, A. Romano, P. Rubin, G. Ruggiero, A. Salamon, G. Saracino, M. Savrié, M. Scarpa, V. Semenov, A. Sergi, M. Serra, M. Shieh, S. Shkarovskiy, M.W. Slater, M. Sozzi, T. Spadaro, S. Stoynev, E. Swallow, M. Szleper, M. Valdata-Nappi, P. Valente, B. Vallage, M. Velasco, M. Veltri, S. Venditti, M. Wache, H. Wahl, A. Walker, R. Wanke, L. Widhalm, A. Winhart, R. Winston, M.D. Wood, S.A. Wotton, O. Yushchenko, A. Zinchenko, M. Ziolkowski, Lamanna, G., Ambrosino, Fabio, Antonelli, A., Anzivino, G., Arcidiacono, R., Baldini, W., Balev, S., Batley, J. R., Behler, M., Bifani, S., Biino, C., Bizzeti, A., Bloch Devaux, B., Bocquet, G., Bolotov, V., Bucci, F., Cabibbo, N., Calvetti, M., Cartiglia, N., Ceccucci, A., Cenci, P., Cerri, C., Cheshkov, C., Chèze, J. B., Clemencic, M., Collazuol, G., Costantini, F., Cotta Ramusino, A., Coward, D., Cundy, D., Dabrowski, A., D'Agostini, G., Dalpiaz, P., Damiani, C., Danielsson, H., De Beer, M., Dellacasa, G., Derré, J., Dibon, H., DI FILIPPO, Domenico, Dilella, L., Doble, N., Duk, V., Engelfried, J., Eppard, K., Falaleev, V., Fantechi, R., Fidecaro, M., Fiorini, L., Fiorini, M., Fonseca Martin, T., Frabetti, P. L., Fucci, A., Gallorini, S., Gatignon, L., Gersabeck, E., Gianoli, A., Giudici, S., Gonidec, A., Goudzovski, E., Goy Lopez, S., Gushchin, E., Hallgren, B., Hita Hochgesand, M., Holder, M., Hristov, P., Iacopini, E., Imbergamo, E., Jeitler, M., Kalmus, G., Kekelidze, V., Kleinknecht, K., Kozhuharov, V., Kubischta, W., Kurshetsov, V., Lazzeroni, C., Lenti, M., Leonardi, E., Litov, L., Madigozhin, D., Maier, A., Mannelli, I., Marchetto, F., Marel, G., Markytan, M., Marouelli, P., Martini, M., Masetti, L., Massarotti, Paolo, Mazzucato, E., Michetti, A., Mikulec, I., Misheva, M., Molokanova, N., Monnier, E., Moosbrugger, U., Morales Morales, C., Moulson, M., Movchan, S., Munday, D. J., Napolitano, Marco, Nappi, A., Neuhofer, G., Norton, A., Numao, T., Obraztsov, V., Palladino, Vito, Patel, M., Pepe, M., Peters, A., Petrucci, F., Petrucci, M. C., Peyaud, B., Piandani, R., Piccini, M., Pierazzini, G., Polenkevich, I., Popov, I., Potrebenikov, Y. u., Raggi, M., Renk, B., Retière, F., Riedler, P., Romano, A., Rubin, P., Ruggiero, G., Salamon, A., Saracino, Giulio, Savrié, M., Scarpa, M., Semenov, V., Sergi, A., Serra, M., Shieh, M., Shkarovskiy, S., Slater, M. W., Sozzi, M., Spadaro, T., Stoynev, S., Swallow, E., Szleper, M., Valdata Nappi, M., Valente, P., Vallage, B., Velasco, M., Veltri, M., Venditti, S., Wache, M., Wahl, H., Walker, A., Wanke, R., Widhalm, L., Winhart, A., Winston, R., Wood, M. D., Wotton, S. A., Yushchenko, O., Zinchenko, A., and Ziolkowski, M.
Subjects: Physics, Particle physics, Nuclear and High Energy Physics, Large Hadron Collider, kaon decays, 010308 nuclear & particles physics, Physics beyond the Standard Model, Flavor-changing neutral current, kaon decays, lepton number violation, High Energy Physics::Phenomenology, Clean environment, NA62 experiment, 01 natural sciences, Standard Model, Nuclear physics, lepton number violation, Kaon Physics, Lepton Flavour Violation, NA62, 0103 physical sciences, High Energy Physics::Experiment, 010306 general physics, Particle Physics - Experiment, Particle Physics - Phenomenology, Lepton
Abstract: Effects of new physics in flavor could be found both in Flavor Changing Neutral Current (FCNC) processes and in Lepton Flavor Violation (LFV) modes. The former offer the possibility to deeply test the standard model in a clean environment, while the latter are sensitive to contribution from several models beyond the standard model. In the Kaon sector both FCNC and LFV will be investigated in the NA62 experiment. In addition the kaons sector is an ideal place where to look for new particles and tiny effects, in the region of hundreds of MeV/ c 2 . In this paper prospects for exotic searches in NA62 will be presented, together with recent results from NA48/2 and NA62-RK on LFV kaon decays modes.
Published: 2016

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33 results on '"Swallow, E."'

1. Recent results on Kaon decays from NA48/2

2. Searches for lepton number violation and resonances in $K^{\pm}\to\pi\mu\mu$ decays

3. ChPT tests at the NA48 and NA62 experiments at CERN

4. Precision tests of the Standard Model with kaon decays at CERN

5. Search for the dark photon in π0 decays by the NA48/2 experiment at CERN

6. Detailed study of the $K^\pm \rightarrow \pi^0 \pi^0 e^\pm \nu $ ($K_{e4}^{00}$) decay properties

7. Recent NA48/2 and NA62 results

8. A new measurement of the $K^{\pm} \rightarrow \pi^{\pm} \gamma \gamma$ decay at the NA48/2 experiment

9. New measurement of the $K^{\pm} \to \pi^+\pi^-e^{\pm}\nu(K_{e4} )$ decay branching ratio and hadronic form factors

10. New measurement of the $K^{\pm} \to \pi^{\pm}\mu^{+}\mu^{-}$ decay

11. Precise tests of low energy QCD from $K_{e4}$ decay properties

12. New precise measurements of the $\Xi^{0} \to \Lambda \gamma$ and $\Xi^{0} \to \Sigma^{0}\gamma$ decay asymmetries

13. Precision measurement of the ratio BR($K_{S} \to \pi^{+}\pi^{-}e^{+}e^{-}$)/BR($K_{L} \to \pi^{+}\pi^{-}\pi^{0}_{D}$)

14. Measurement of the direct emission and interference terms and search for CP violation in the decay $K^{\pm} \rightarrow \pi^{\pm}\pi^{0} \gamma$

15. Empirical parameterization of the $K^{\pm} \to \pi^{\pm}\pi^{0}\pi^{0}$ decay Dalitz plot

16. Precise measurement of the $K^{\pm} \to \pi^{\pm}e^{+}e^{−}$ decay

17. Determination of the S-wave pi pi scattering lengths from a study of K-+/- -> pi(+/-)pi(0)pi(0) decays

18. First observation and measurement of the decay $K^{\pm} \to\pi^{\pm}e^{+}e^{-}\gamma$

19. Search for direct CP violating charge asymmetries in $K^\pm\to\pi^\pm\pi^+\pi^-$ and $K^\pm\to\pi^\pm\pi^0\pi^0$ decays

20. Measurements of the $\Xi^0$ lifetime and the $\overline{\Xi^0}/\Xi^0$ flux ratio in a neutral beam

21. Determination of the relative decay rate $K_{S} \to \pi e \nu$ / $K_{L} \to \pi e \nu$

22. Measurement of the Dalitz plot slopes of the $K^{\pm} \to \pi^{\pm}\pi^{+}\pi^{-}$ decay

23. Measurements of charged kaon semileptonic decay branching fractions $K^{\pm} \to \pi^{0} \mu^{\pm} \nu$ and $K^{\pm} \to \pi^{0} e^{\pm} \nu$ and their ratio

24. Measurement of the branching ratios of the decays $\Xi^{0}\rightarrow \sigma^{+} e^{-} \overline{\nu}_{e}$ and $\overline{\Xi^{0}}\rightarrow \overline{\sigma^{+}} e^{+} \nu_{e}$

25. Search for direct CP-violation in $K^{\pm}\to \pi^{\pm}\pi^{0}\pi^{0}$ decays

26. Search for direct CP-violation in $K^{\pm} \to \pi^{\pm} \pi^{0} \pi^{0}$ decays

27. A measurement of the CP-conserving component of the decay $K^{0}_{S} \to \pi^{+}\pi^{-}\pi^{0}$

28. Observation of a cusp-like structure in the $\pi^{0}\pi^{0}$ invariant mass distribution from $K^{+-} \to \pi^{+-}\pi^{0}\pi^{0}$ decay and determination of the $\pi\pi$ scattering lengths

29. Observation of the rare decays $K_{S} \to \pi^{0} \mu^{+} \mu^{-}$

30. Observation of the rare decay $K_{S} \rightarrow \pi^0 e^{+}e^{-}$

31. First observation and study of $K^\pm \to \pi^\pm \pi^0 e^+ e^-$ decay at the NA48/2 experiment

32. First Observation and Study of the $K^\pm \to \pi^\pm \pi^0 e^+ e^-$ Decay

33. Precision tests of the Standard Model with Kaon decays at CERN

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33 results on '"Swallow, E."'

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