Search for the rare decays K(L)→π0π0µ+µ- and K(L)→π0π0X0→π0π0µ+µ-.

The KTeV E799 experiment has conducted a search for the rare decays, K(L)→π(0)π(0)µ(+)µ(-) and K(L)→π(0)π(0)X(0)→π(0)π(0)µ(+)µ(-), where the X(0) is a possible new neutral boson that was reported by the HyperCP experiment with a mass of (214.3 ± 0.5) MeV/c(2). We find no evidence for either decay. We obtain upper limits of Br(K(L)→π(0)π(0)X(0)→π(0)π(0)µ(+)µ(-)) < 1.0 × 10(-10) and Br(K(L)→π(0)π(0)µ(+)µ(-)) < 9.2 × 10(-11) at the 90% confidence level. This result rules out the pseudoscalar X(0) as an explanation of the HyperCP result under the scenario that the dsX(0) coupling is completely real.

Measurements of the decay KL-->e+ e- gamma.

The E799-II (KTeV) experiment at Fermilab has collected 83 262 K(L)-->e+ e- gamma(gamma) events above a background of 79 events. We measure a decay width, normalized to the K(L)-->pi0pi0pi(D)0 (pi0-->gammagamma, pi0-->gammagamma, pi(D0-->e+ e- gamma(gamma)) decay width, of Gamma(K(L)-->e+e-gamma(gamma))/Gamma(K(L)-->pi0pi0pi(D)0)=(1.3302+/-0.0046(stat)+/-0.0102(syst)) x 10(-3). We also measure parameters of two K(L)gamma*gamma form factor models. In the Bergström-Massó-Singer parametrization, we find Calpha(K*)= -0.517 +/- 0.030(stat) +/- 0.022(syst). We separately fit for the first parameter of the D'Ambrosio-Isidori-Portolés model and find alpha(DIP)= -1.729 +/- 0.043(stat) +/- 0.028(syst).

Impact of the heavy-quark matching scales in PDF fits.

We investigate the impact of displaced heavy-quark matching scales in a global fit. The heavy-quark matching scale µ m determines at which energy scale µ the QCD theory transitions from N F to N F + 1 in the variable flavor number scheme (VFNS) for the evolution of the parton distribution functions (PDFs) and strong coupling α S ( µ ) . We study the variation of the matching scales, and their impact on a global PDF fit of the combined HERA data. As the choice of the matching scale µ m effectively is a choice of scheme, this represents a theoretical uncertainty; ideally, we would like to see minimal dependence on this parameter. For the transition across the charm quark (from N F = 3 to 4), we find a large µ m = µ c dependence of the global fit χ 2 at NLO, but this is significantly reduced at NNLO. For the transition across the bottom quark (from N F = 4 to 5), we have a reduced µ m = µ b dependence of the χ 2 at both NLO and NNLO as compared to the charm. This feature is now implemented in xFitter 2.0.0, an open source QCD fit framework.

Search for the decay K(L) --> pi(0)&mgr;(+)&mgr;(-)

We report on a search for the decay K(L)-->pi(0)&mgr;(+)&mgr;(-) carried out as a part of the KTeV experiment at Fermilab. This decay is expected to have a significant CP violating contribution and a direct measurement will either support the Cabibbo-Kobayashi-Maskawa mechanism for CP violation or point to new physics. Two events were observed in the 1997 data with an expected background of 0.87+/-0.15 events, and we set an upper limit B(K(L)-->pi(0)&mgr;(+)&mgr;(-))<3. 8x10(-10) at the 90% confidence level.

Search for the weak decay of a lightly bound H0 dibaryon

We present results of a search for a new form of hadronic matter, a six-quark, dibaryon state called the H0, a state predicted to exist in several theoretical models. Analyzing data collected by experiment E799-II at Fermilab, we searched for the decay H0-->Lambdappi(-) and found no candidate events. We place an upper limit on [B(H0-->Lambdappi(-))dsigma(H)/dOmega]/(dsigma(Xi)/dOmega) and, in the context of published models, exclude the region of lightly bound mass states just below the LambdaLambda mass threshold, 2.194

Observation of CP violation in K(L)-->pi(+)pi(-)e(+)e(-) decays

We report the first observation of a manifestly CP violating effect in the K(L)-->pi(+)pi(-)e(+)e(-) decay mode. A large asymmetry was observed in the distribution of these decays in the CP-odd and T-odd angle straight phi between the decay planes of the e(+)e(-) and pi(+)pi(-) pairs in the K(L) center of mass system. After acceptance corrections, the overall asymmetry is found to be [13.6+/-2. 5(stat)+/-1.2(syst)]%. This is the largest CP-violating effect yet observed when integrating over the entire phase space of a mode and the first such effect observed in an angular variable.

[A comparative evaluation of the results of using a method for the endoscopic denervation of the corpus gastricum and for local laser therapy in the combined treatment of patients with duodenal ulcers]. / Sravnitel'naia otsenka rezul'tatov ispol'zovaniia metoda éndoskopicheskoi denervatsii tela zheludka i mestnoi lazeroterapii v kompleksnom lechenii bol'nykh s duodenal'nymi iazvami.

The authors provide the results of the treatment of patients with duodenal ulcers using common conservative therapy, local laser therapy and endoscopic denervation of the body of the stomach. Inclusion of endoscopic treatment methods into multimodality treatment brought about the enhancement of the treatment efficacy, more pronounced with endoscopic denervation.

[Use of silver nitrate and low-energy laser radiation in local therapy of gastroduodenal ulcers]. / Primenenie rastvorov azotnokislogo serebra i nizkoénergeticheskogo lazernogo izlucheniia v mestnom lechenii gastroduodenal'nykh iazv.

The authors presented comparative assessment of local therapy of gastroduodenal ulcers using laser radiation, sprinkling with silver nitrate solutions and their combined use against a background of routine antiulcerative therapy. The sprinkling of ulcers with silver nitrate solutions resulted in a 10-fold decrease in the titer of microbial bodies and fungus colonies. The shortest periods of ulcer healing were noted in the combination of laser radiation with sprinkling with silver nitrate solutions. The authors found it appropriate to use for local therapy combinations of drugs of diverse pathogenetic effect.

[Polymer biodegradable peptide films. Preliminary results of use of thyroliberin films in substance abuse treatment and psychiatry]. / Polimernye biorastvorimye plënki s peptidami. Predvaritelnye rezultaty primeneniia plënok s tiroliberinom v narkologii i psikhiatrii.

The paper contains data on the new highly effective agent thyropol which is a film from biocompatible copolymers with the immobilized peptide agent thyroid-releasing hormone, which has pronounced antialcoholic and psychotropic activities.

[Metrological software of laser medical equipment]. / Metrologicheskoe obespechenie lazernoi meditsinskoi tekhniki.

The paper considers the laser medical equipment situation that has established in Russia and that is characterized by the wide medical application of laser technologies and appropriate software and by inadequate development and imperfection of required metrological software and maintenance of laser equipment.

[Diagnosis and endoscopic treatment of reflux esophagitis]. / Diagnostika i éndoskopicheskoe lechenie refliuks-ézofagita.

The article analyses the use of endoscopic selective drug denervation of the stomach (ESDDS) in 58 patients with reflux esophagitis. Complex appraisal of the efficacy of the treatment showed the result to be good and satisfactory in one month in 96.4% of cases and 6 month after ESDDS in 89.1% of cases; the respective values in the same terms after nonoperative treatment were 66.7% and 54.5%. The pathogenetic substantiation of the use of ESDDS is the arrest of the flow of pathological vegetative impulses due to its action, which promotes restoration of regulation of the main functions of the gastroesophageal system which become almost natural, and normalizes processes of autocleansing of the esophagus. The method may be recommended for treating active manifestations of reflux esophagitis and preventing recurrences, including cases of its combination with duodenal ulcer.

[Selective endoscopic pharmacologic denervation of the stomach in the treatment of reflux esophagitis associated with duodenal ulcer]. / Endoskopicheskaia selektivnaia medikamentoznaia denervatsiia zheludka v lechenii refliuks-ézofagita, sochetannogos iazvennoi bolezn'iu dvenadtsatiperstnoi kishki.

A method of the endoscopic selective medicamentous denervation of the stomach with the help of an alcohol-novocain solution is described. The method was used in 44 patients with reflux-esophagitis which was successfully cupped off in 93.1% of the patients. In the control group the result was 66.6%.

The development of enabling technologies for producing active interrogation beams.

A U.S./Russian collaboration of accelerator scientists was directed to the development of high averaged-current (∼1 mA) and high-quality (emittance ∼15 πmm mrad; energy spread ∼0.1%) 1.75 MeV proton beams to produce active interrogation beams that could be applied to counterterrorism. Several accelerator technologies were investigated. These included an electrostatic tandem accelerator of novel design, a compact cyclotron, and a storage ring with energy compensation and electron cooling. Production targets capable of withstanding the beam power levels were designed, fabricated, and tested. The cyclotron/storage-ring system was theoretically studied and computationally designed, and the electrostatic vacuum tandem accelerator at BINP was demonstrated for its potential in active interrogation of explosives and special nuclear materials.

Search for lepton-flavor-violating decays of the neutral kaon.

The Fermilab KTeV experiment has searched for lepton-flavor-violating decays of the K(L) meson in three decay modes. We observe no events in the signal region for any of the modes studied, and we set the following upper limits for their branching ratios at the 90% C.L.: BR(K(L) --> pi(0) micro(+/-) e(-/+)) <7.6 x 10(-11); BR(K(L) --> pi(0)pi(0) micro(+/-) e(-/+)) <1.7 x 10(-10); BR(pi(0) --> micro(+/-) e(-/+)) <3.6 x 10(-10). This result represents a factor of 82 improvement in the branching ratio limit for K(L) --> pi(0) micro(+/-) e(-/+) and is the first reported limit for K(L) --> pi(0)pi(0) micro(+/-) e(-/+).

Determination of the parity of the neutral pion via its four-electron decay.

We present a new determination of the parity of the neutral pion via the double Dalitz decay pi0-->e+e-e+e-. Our sample, which consists of 30,511 candidate decays, was collected from KL-->pi0pi0pi0 decays in flight at the KTeV-E799 experiment at Fermi National Accelerator Laboratory. We confirm the negative pi0 parity and place a limit on scalar contributions to the pi0-->e+e-e+e- decay amplitude of less than 3.3% assuming CPT conservation. The pi0gamma*gamma* form factor is well described by a momentum-dependent model with a slope parameter fit to the final state phase-space distribution. Additionally, we have measured the branching ratio of this mode to be B(pi0-->e+e-e+e-)=(3.26+/-0.18)x10(-5).

First observation of K{L}-->pi{+/-}e{-/+}nue{+}e{-}.

This Letter is the first report of the K{L}-->pi{+/-}e{-/+}nue{+}e{-} decay. Based on 19 208+/-144 events, we determine the branching fraction, B(K{L}-->pi{+/-}e{-/+}nue{+}e{-}M_{e{+}e{-}}>5 MeV/c{2},E{e{+}e{-}}{*}>30 MeV)=(1.285+/-0.041)x10{-5}, and Gamma(K{e3ee}M{e{+}e{-}}>5 MeV/c{2})/Gamma(K{e3})=[4.57+/-0.04(stat)+/-0.14(syst)]x10{-5}. This ratio agrees with a theoretical prediction based on chiral perturbation theory (ChPT) calculated to O(p{4}). The measured kinematical distributions agree with those predicted by just ChPT O(p{4}), but show significant disagreement with ones predicted by leading-order ChPT.