NA48 experiment aims at measuring the direct CP Violation parameter Re(epsilon'/epsilon) in the decays of neutral kaons with an accuracy of 2x10^-4. A result based on 1997 data sample has recently been published, confirming the occurrence of direct CP Violation, with an error on Re(epsilon'/epsilon) of 7x10^-4. A new preliminary result based on a much larger data sample is presented.
Authors:NA48
Proposed speaker: B.Gorini
Contact person:Benedetto Gorini
(CERN),
benedetto.gorini@cern.ch
Sessions: PA-06 Light Flavor Physics ( Kaon, Muon ) / PL-02 CP Violation and Rare Decays ( Kaon, Muon )
Supporting papers:
Notes:
We discuss the theoretical and experimental status of the CP-violating ratio eps'/eps. The key element in our estimate is the fit of the Delta I=1/2 rule, which allows us to determine the model-dependent parameters in the hadronic matrix elements. Our semi-phenomenological approach enjoys numerical stability against variations of the renormalization scale and scheme dependence of the short- and long-distance components. The same dynamical mechanism at work in the selection rule also explains the larger value obtained for eps'/eps with respect to other estimates.
Authors:S. Bertolini, J.O. Eeg and M. Fabbrichesi
Proposed speaker: Marco Fabbrichesi
Contact person:Marco Fabbrichesi
(SISSA),
marco@he.sissa.it
Sessions: PA-06 Light Flavor Physics ( Kaon, Muon ) / PL-02 CP Violation and Rare Decays ( Kaon, Muon )
Supporting papers: Rev. Mod. Phys. 72 (2000) 65 hep-ph/0002234
Notes:
We calculate epsilon prime / epsilon within the Standard Model at lowest order in Chiral Perturbation Theory and to next to leading order in 1/N_c. We use CHPT at very low energies and perturbative QCD at high energies. For the intermediate energies we use an extended NJL model. The result is independent to the required order in alpha_S of the scheme used to calculate the Wilson coefficients.
Authors:Johan Bijnens and Joaquim Prades
Proposed speaker: Joaquim Prades
Contact person:Joaquim Prades
(Universidad de Granada),
Prades@ugr.es
Sessions: PA-06 Light Flavor Physics ( Kaon, Muon ) / PL-02 CP Violation and Rare Decays ( Kaon, Muon )
Supporting papers:
Notes:
We present new results for rare decays of the neutral Xi^0 hyperon. Using the data collected with the NA48 detector in a special high intensity run end of 1999, we measured the branching fraction and the decay asymmetry of the radiative decay Xi^0 -> Lambda gamma. The sign of the asymmetry has been unambiguously determined. In addition, we report on a new measurement of the Xi^0 semileptonic branching fraction and we present a new upper limit for the Delta S = 2 decay Xi^0 -> p pi-.
Authors:NA48 Collaboration
Proposed speaker: Rainer Wanke
Contact person:Rainer Wanke
(Universität Mainz),
Rainer.Wanke@uni-mainz.de
Sessions: PA-06 Light Flavor Physics ( Kaon, Muon ) / PL-02 CP Violation and Rare Decays ( Kaon, Muon )
Supporting papers:
Notes:
The KLOE experiment has collected 2.4 1/pb of integrated luminosity during the commissioning of the DAFNE phi-factory in 1999. The performance of the detector has been studied with about 2 million phi -> KL KS decays collected during this period, yielding also first measurements of relevant K parameters such as masses,lifetimes and main branching ratios. A clean Kshort -> pi+ pi- sample is used to select Klong -> 2pi CP-violating decays and Klong -> Kshort regeneration events in the detector material. Results on the regeneration probability in AlBeMet and carbon-fiber plus aluminum composite are presented. Klong identification is used to tag Kshort-mesons and to search for their semileptonic decays.
Authors:The KLOE collaboration
Proposed speaker: Antonio Passeri (ICHEP ID 1474)
Contact person:Juliet Lee-Franzini (ICHEP ID 1790)
(Laboratori Nazionali di Frascati),
Juliet.leefranzini@lnf.infn.it
Sessions: PA-06 Light Flavor Physics ( Kaon, Muon ) / PL-02 CP Violation and Rare Decays ( Kaon, Muon )
Supporting papers:
Notes:
The KLOE experiment has collected 2.4 1/pb of integrated luminosity during the commissioning of the DAFNE phi-factory in 1999. The performance of the detector has been studied with about 2 million phi -> KL KS decays collected during this period, yielding also first measurements of relevant K parameters such as masses,lifetimes and main branching ratios. A clean Kshort -> pi+ pi- sample is used to select Klong -> 2pi CP-violating decays and Klong -> Kshort regeneration events in the detector material. Results on the regeneration probability in AlBeMet and carbon-fiber plus aluminum composite are presented. Klong identification is used to tag Kshort-mesons and to search for their semileptonic decays.
Authors:The KLOE collaboration
Proposed speaker: Antonio Passeri (ICHEP ID 1474)
Contact person:Juliet Lee-Franzini (ICHEP ID 1790)
(Laboratori Nazionali di Frascati),
Juliet.leefranzini@lnf.infn.it
Sessions: PA-06 Light Flavor Physics ( Kaon, Muon ) / PL-02 CP Violation and Rare Decays ( Kaon, Muon )
Supporting papers:
Notes:5/12/00 TY-Moved from PL7a to PL2.
First evidence for the decay of $K_s \rightarrow \pi^+ \pi^- \e^+ \e^-$ as well as the study of both decays $K_s$ and $K_l$ into $\pi^+ \pi^- \e^+ \e^-$ are presented. New upper limit on the $K_s\rightarrow \pi^0 \e^+ \e^-$ decay branching ratio is obtained and the decay rates of $K_l\rightarrow \pi^0 \gamma \gamma$, $K_l\rightarrow \pi^0 \e^+ \e^-$, $K_l\rightarrow \e^+ \e^-$ \gamma \gamma$ and $K_s\rightarrow \gamma \gamma$ are measured. The experiment has been performed in the high intensity $K_s$ and $K_l$ beams with the NA48 detector at the CERN SPS.
Authors:The NA48 Collaboration
Proposed speaker: Vladimir Kekelidze
Contact person:Vladimir Kekelidze
(Joint Institute for Nuclear Research),
kekel@sunse.jinr.ru
Sessions: PA-06 Light Flavor Physics ( Kaon, Muon ) / PL-02 CP Violation and Rare Decays ( Kaon, Muon )
Supporting papers:
Notes:
We show that, on the contrary to the usual claims, fully supersymmetric CP violations in the kaon system are possible through the gluino mediated flavor changing interactions. Both $\epsilon_K$ and ${\rm Re} (\epsilon' / \epsilon_K)$ can be accommodated for relatively large $\tan\beta$ without any fine tunings or contradictions to the FCNC and EDM constraints.
Authors:Seungwon Baek, Ji-Ho Jang, Pyungwon Ko and Jae Hyun Park
Proposed speaker: Pyungwon Ko
Contact person:Pyungwon Ko
(KAIST),
pko@muon.kaist.ac.kr
Sessions: PA-06 Light Flavor Physics ( Kaon, Muon ) / PL-02 CP Violation and Rare Decays ( Kaon, Muon )
Supporting papers: (1) Preprint by S. Baek, J.H. Jang, P. Ko, J.H. Park. KAIST-99-04, Aug 1999. e-Print Archive: hep-ph/9907572 . Submitted to Phys. Rev. Lett.
Notes:
We expose a potential flaw in standard treatments of weak decay amplitudes, including that of epsilon'/epsilon. We show that (contrary to conventional wisdom) dimension-eight operators do contribute to weak amplitudes, at order G_F alpha_s and without 1/M_W^2 suppression. We demonstrate the existence of these operators with a simple weak hamiltonian and proceed to discuss their contribution in a general context. We estimate the effect of dimension-eight operators to be at the 100% level in a sum rule determination of the operator O_7 for mu = 1.5 GeV, suggesting presently available values of mu are too low to justify neglect of these effects.
Authors:Vincenzo Cirigliano, John F. Donoghue and Eugene Golowich
Proposed speaker: Eugene Golowich
Contact person:Eugene Golowich
(University of Massachusetts),
golowich@physics.umass.edu
Sessions: PA-06 Light Flavor Physics ( Kaon, Muon ) / PL-02 CP Violation and Rare Decays ( Kaon, Muon )
Supporting papers:
Notes:
The KEK-E246 experiment is searching for T-violating muon polarization in the K^+ -> pi^0 mu^+ nu decay using stopped K^+ at the 12 GeV proton synchrotron. This quantity would be a signal of new physics such as multi Higgs doublet, leptoquark, or a class of SUSY. Data acquisition of the experiment started in 1996. The first result, utilizing a double ratio method to suppress systematic errors, from the 1996 and 97 data has already been obtained and published as Im \xi = -0.013 +- 0.016 +- 0.003 currently the world's best limit. We are going to show the result from further analysis including the 1998 data.
Authors:KEK-E246 Collaboration
Proposed speaker: Masaharu Aoki
Contact person:Masaharu Aoki
(High Energy Accelerator Research Organization (KEK)),
masaharu.aoki@kek.jp
Sessions: PA-06 Light Flavor Physics ( Kaon, Muon ) / PL-02 CP Violation and Rare Decays ( Kaon, Muon )
Supporting papers: M. Abe, et al., Phys. Rev. Lett. 83, 4253 (1999)
Notes:
The E787 experiment at the BNL AGS, a search for the K^+\to\pi^+\nu\bar{\nu} and related decays, took data from 1995 to 1998 with the upgraded detector and beam line. Recent results on the \pi^+\nu\bar{\nu} decay as well as radiative kaon decays (\pi^+\pi^0\gamma, \mu^+\nu\gamma, \pi^+\gamma) are reported. Prospects for the sensitivity of \pi^+\nu\bar{\nu} with the E787 full dataset and for the new experiment E949 to continue the study at the BNL AGS are presented.
Authors:E787 Collaboration
Proposed speaker: Takeshi K. Komatsubara
Contact person:Takeshi K Komatsubara
(High Energy Accelerator Res Org (KEK)),
takeshi.komatsubara@kek.jp
Sessions: PA-06 Light Flavor Physics ( Kaon, Muon ) / PL-02 CP Violation and Rare Decays ( Kaon, Muon )
Supporting papers: hep-ex/0003019 : Measurement of Structure Dependent K^+ -> mu^+ nu gamma hep-ex/0002015 : Further Search for the Decay K^+ --> pi^+ nu nubar
Notes:
The most recent measurement of the direct CP violation parameter epsilon'/epsilon from the KTeV experiment at Fermilab will be described. Measurements of other parameters of the neutral kaon system, such as the K_S lifetime, the K_S -- K_L mass difference, and the relative phases of the CP violating and CP conserving amplitudes, also will be discussed.
Authors:KTeV Collaboration
Proposed speaker: E. Blucher
Contact person:Edward C. Blucher
(The University of Chicago),
blucher@hep.uchicago.edu
Sessions: PA-06 Light Flavor Physics ( Kaon, Muon ) / PL-02 CP Violation and Rare Decays ( Kaon, Muon )
Supporting papers:
Notes:
We give an updated analysis on the new sources of soft CP violating sources in minimal supersymmetric theories and some of its interesting extensions. We discuss the potential soft CP violating solution to the strong CP problem, the new constraints from two loop contributions to electric dipole moments of electron and neutron, possible new sources of contributions to $\epsilon$ and $\epsilon'$ and the possible supersymmetric mechanism for electroweak baryogensis.
Authors:Darwin Chang
Proposed speaker: Darwin Chang
Contact person:Darwin Chang
(National Tsing-Hua University),
chang@phys.nthu.edu.tw
Sessions: PA-06 Light Flavor Physics ( Kaon, Muon ) / PL-02 CP Violation and Rare Decays ( Kaon, Muon )
Supporting papers:
Notes:
The branching ratio and form factor of the rare kaon decay K -> mu+ mu- gamma will be presented. These results are from a sample of more than 9000 events collected in the Fermilab experiment KTeV-E799 during 1996-1997. We will also report on the status of some rare decay analysis of the 96-97 data. A run from July 1999 till Jan 2000 (99-00 data) triples the sensitivities with respect to the 96-97 data and a brief report will be presented.
Authors:KTeV - Arizona, Elmhurst, Fermilab, Osaka, Rice, Rutgers, UCLA, UCSD, Chicago, Colorado, Virginia, Wisconsin
Proposed speaker: Y. W. Wah
Contact person:Yau W Wah
(The University of Chicago),
wah@hep.uchicago.edu
Sessions: PA-06 Light Flavor Physics ( Kaon, Muon ) / PL-02 CP Violation and Rare Decays ( Kaon, Muon )
Supporting papers:
Notes:
A new experiment to search for lepton-flavor-violating muon decays, mu+ -> e+ gamma, with a sensitivity of 10^{-14} is in preparation with the aim of starting data-taking in the year 2003 at Paul Scherrer Institut (PSI). The experiment will utilize a new type of liquid xenon scintillation detector, capable of minimizing the pile-up problem, to measure photons with high energy- and timing-resolutions, and an innovative COnstant-Bending-RAdius (COBRA) spectrometer to measure positrons in the high rate environment. After describing the status of the preparations, the future prospects are presented.
Authors:S.Orito, T.Mori, T.Mashimo, S.Mihara, J.Yashima, W.Ootani, T.Doke, S.Suzuki, A.Maki, T.Haruyama, A.Yamamoto, Y.Kuno, B.I.Khazin, L.M.Barkov, A.A.Grebenuk, V.P.Smakhtin, J.Egger, W.-D.Herold, P.-R.Kettle, Univ Tokyo - Waseda Univ - KEK - Budker Inst - PSI
Proposed speaker: Toshinori Mori, University of Tokyo
Contact person:Toshinori Mori
(University of Tokyo),
mori@icepp.s.u-tokyo.ac.jp
Sessions: PA-06 Light Flavor Physics ( Kaon, Muon ) / PL-02 CP Violation and Rare Decays ( Kaon, Muon )
Supporting papers:
Notes:"Search for mu+ -> e+ gamma down to 10^{-14} branching ratio," Research Proposal to Paul Scherrer Institut, R-99-05.1, PSI, 1999.
General purpose detector CMD-2 has collected about 15 pb-1 at Phi resonance (about 20*10^6 Phi decays). The K+K- final state is 50% of all Phi decays and one of the collinear kaons can be a good tag to study decays of the other. All 6 major modes of charged kaon decays are separated by detector subsystem. From the analysis of about 25% of avalable data the ratio B(K->pipi0)/B(K->munu) = 0.339 +- 0.007 +- 0.007 has been obtaied, comparable with the best previous measurements. As a result of analysis of 25% of data (about 2000 events) the ratio: B(K->e pi nu)/(B(K->pipi0)+B(K->munu)) = 0.0578 +- 0.0020 +- 0.0020 has been obtained. The preliminary result based on full data set (about 8000-10000 Ke3 events) is expected to Conference time.
Authors:CMD-2 collaboration
Proposed speaker: Evgeny P. Solodov
Contact person:Evgeny P Solodov
(Budker Institute of Nuclear Physics),
solodov@inp.nsk.su
Sessions: PA-06 Light Flavor Physics ( Kaon, Muon ) /
Supporting papers:
Notes:(032)
We analyze the rare kaon decays $K_L \to \pi^0 \nu \bar \nu$, $K^+ \to \pi^+ \nu \bar \nu$, $K_L \to \pi^0 e^+ e^-$ and $K_L \to \mu^+ \mu^-$ in conjunction with the CP violating ratio $\epsilon'/\epsilon$ in a general class of supersymmetric models. We show that sizable deviations from the SM expectations are possible in both cases and we stress the importance of a measurement of the rare modes, in order to shed light on the realization of various supersymmetric scenarios.
Authors:G. Isidori
Proposed speaker: G. Isidori
Contact person:Gino Isidori
(INFN - Laboratori Nazionali di Frascati),
isidori@lnf.infn.it
Sessions: PA-06 Light Flavor Physics ( Kaon, Muon ) /
Supporting papers: A.J. Buras, G. Colangelo, G. Isidori, A. Romanino, L. Silvestrini, Nucl.Phys. B566 (2000) 3. G. Colangelo, G. Isidori, JHEP 9809 (1998) 009
Notes:
In the analysis of \epsilon^\prime/\epsilon it has been traditional to consider the isospin-breaking effects arising from electroweak-penguin contributions and from \pi^0-\eta and \pi^0-\eta^\prime mixing, yet additional isospin-violating effects exist. In particular, we study the isospin violation which arises from the u-d quark mass difference in the hadronization of the gluonic penguin operator, engendering contributions of an effective \Delta I=3/2 character. Using chiral perturbation theory and the factorization approximation for the hadronic matrix elements, we find within a specific model for the low-energy constants that we can readily accommodate an increase in \epsilon^\prime/\epsilon by a factor of two.
Authors:S. Gardner and G. Valencia
Proposed speaker: G. Valencia
Contact person:German E Valencia
(Fermilab (on leave from Iowa State University)),
valencia@iastate.edu
Sessions: PA-06 Light Flavor Physics ( Kaon, Muon ) / PL-02 CP Violation and Rare Decays ( Kaon, Muon )
Supporting papers: Phys.Lett.B466:355-362,1999
Notes:I'm sending this abstract at the request of one of the convenors, Professor Stefano Bertolini
Theoretical overview on rare muon decay and its potential to search for new physics is given. In particular, we stress importance of muon lepton flavor violation processes to explore interactions at a high energy scale in SUSY GUT and the SUSY model with right-handed neutrino.
Authors:Yasuhiro Okada
Proposed speaker: Yasuhiro Okada
Contact person:Yasuhiro Okada
(KEK),
yasuhiro.okada@kek.jp
Sessions: PA-06 Light Flavor Physics ( Kaon, Muon ) / PL-02 CP Violation and Rare Decays ( Kaon, Muon )
Supporting papers: MUON DECAY AND PHYSICS BEYOND THE STANDARD MODEL. By Yoshitaka Kuno, Yasuhiro Okada (KEK, Tsukuba). KEK-PREPRINT-99-69, Aug 1999. 109pp. Submitted to Rev.Mod.Phys. e-Print Archive: hep-ph/9909265
Notes:
We analyze the supersymmetric contributions to direct-CP-violating observables in $K \to \pi\pi\gamma$ decays induced by gluino-mediated magnetic-penguin operators. We find that $\epsp_{+-\gamma}$ and the differential width asymmetry of $K^\pm \to \pi^\pm \pi^0 \gamma$ decays could be substantially enhanced with respect to their Standard Model values, especially in the scenario where $\epsp/\eps$ is dominated by supersymmetric contributions. These observables could therefore provide a useful tool to search for New Physics effects in $|\Delta S|=1$ transitions, complementary to $\epsp/\eps$ and rare decays.
Authors:G. Colangelo, G. Isidori and J. Portoles
Proposed speaker: G. Colangelo
Contact person:G. Congaleno
(),
Sessions: PA-06 Light Flavor Physics ( Kaon, Muon ) /
Supporting papers: hep-ph/9908415
Notes:
A new Standard Model analysis of the direct CP violation parameter $\epsilon^\prime/\epsilon$ is presented. One of the main ingredients is the evaluation of a strong enhancement due to final state interactions (FSI). It is shown how, with our present understanding of the various inputs, it is possible to pin down the prediction of this important parameter with a theoretical accuracy of about 30$\%$. The new prediction Re $\epsilon^\prime/\epsilon = (1.44\pm (0.43)_{1/N_c} \pm (0.31)_{m_s}\pm (0.12)_{\rho})\, 10^{-3}$ is in good agreement with the present experimental world average.
Authors:E. Pallante, A. Pich, I. Scimemi
Proposed speaker: Elisabetta Pallante
Contact person:Elisabetta Pallante
(Barcelona Univ.),
pallante@ecm.ub.es
Sessions: PA-06 Light Flavor Physics ( Kaon, Muon ) / PL-02 CP Violation and Rare Decays ( Kaon, Muon )
Supporting papers: E. Pallante, A. Pich, Phys. Rev. Lett. 84(2000), hep-ph/9911233 E. Pallante, A. Pich, to appear E. Pallante, A. Pich, I. Scimemi, to appear
Notes:
We obtained large statistics data on K^{\pm} -> \pi^{\pm} \pi^0 \pi^0 decays using the tagging station of the Tagged Neutrino Facility at IHEP, Protvino. We present preliminary results on Dalitz-plot slopes for these decays. These are the first results obtained for both K+ and K- using the same experimental setup.
Authors:TNF collaboration
Proposed speaker: Alexander Kozelov
Contact person:Alexander V Kozelov
(IHEP),
kozelov@mx.ihep.su
Sessions: PA-06 Light Flavor Physics ( Kaon, Muon ) / PL-02 CP Violation and Rare Decays ( Kaon, Muon )
Supporting papers:
Notes:
Authors:Amarjit Soni
Proposed speaker: Amarjit Soni
Contact person:Amarjit Soni
(),
soni@bnl.gov
Sessions: PA-06 Light Flavor Physics ( Kaon, Muon ) /
Supporting papers:
Notes:6/7/00 TY-No abstract, but was in the program.
Authors:Hai-Yang Cheng
Proposed speaker: Hai-Yang Cheng
Contact person:Hai-Yang Cheng
(Academia Sinica),
phcheng@ccvax.sinica.edu.tw
Sessions: PA-06 Light Flavor Physics ( Kaon, Muon ) / PL-02 CP Violation and Rare Decays ( Kaon, Muon )
Supporting papers:
Notes:6/7/00 TY-No abstract, but was in the program.
End of abstracts for PA-06 Light Flavor Physics ( Kaon, Muon )