The decay K → π0eν has been studied using in-flight decays detected with the ”ISTRA+” spectrometer operating in the 25-GeV negative secondary beam of the U-70 PS. About 550K events were collected for the analysis. The λ+ parameter of the vector form-factor has been measured: λ+ = 0.0286 ± 0.0008(stat) ± 0.0006(syst). The limits on the possible tensor and scalar couplings have been obtained: fT/f+(0) = 0.021 −0.075(stat)± 0.026(syst); fS/f+(0) = 0.002 +0.020 −0.022(stat)± 0.003(syst)

Results of study of the radiative kaon decay K-->pi0 e nu gamma at ISTRA+ setup are presented. 4476 events of this decay have been observed. The branching ratio is measured.

Results of the study of the K− → π0e−νγ decay at ISTRA+ setup are presented. 4476 events of this decay have been observed. The ratio of branching rati os (R), R = Br(K −→π0e−νeγ) Br(K−→π0e−νe) = (1.81± 0.03(stat.)± 0.07(syst.))× 10−2, has been obtained for E∗ γ > 10 MeV andθ ∗ eγ > 10◦. For comparison with previous experiments, the branching ra tio with cutsE∗ γ > 10 MeV, 0.6 < cosθ ∗ eγ < 0.9 is calculated,R = Br(K−→π0e−νeγ) Br(K−→π0e−νe) = (0.47± 0.02(stat.) ± 0.03(syst.)) × 10 −2. For the cutsE∗(γ) > 30 MeV andθ ∗ eγ > 20◦, used in most theoretical papers, we have obtained Br(K− → π0e−νeγ) = (3.13± 0.09± 0.14) × 10−4. For the asymmetryAξ we get Aξ = −0.015±0.021. At present it is the best estimate of this asymmetry.

Using data collected with the ISTRA+ spectrometer during the 2001 run of the U-70 proton synchrotron in Protvino, the first observation of the radiative kaon decay K − → µ−π0γν is reported. The ratio Br(K µ3γ, 5 < E*γ < 30 MeV)/Br(K µ3) is found to be [0.270 ± 0.029(stat.) ± 0.026(syst.)]% and the ratio Br(K µ3γ, 30 < E*γ < 60 MeV)/Br(K µ3) = [0.0448 ± 0.0068(stat.) ± 0.0099(syst.)]%. These ratios are consistent with the theoretical predictions 0.21 and 0.047%, respectively. The measured angular distribution asymmetry for the region 5 < E*γ < 30 MeV, A(cos ϑ*µγ) = 0.093 ± 0.141, is two standard deviations away from the theoretical prediction of 0.354. The measured asymmetry in the T-odd variable ξ = pγ · (pµ × pπ)/m K 3 is −0.03 ± 0.13.

The transverse single-spin asymmetry for charged hadrons (π ±, K ±, p, \(\bar p\)) produced in proton-nucleus collisions was measured for c.m. production angles in the range 40°–79°. The measurements were performed with the FODS-2 setup by using a 40-GeV polarized proton beam originating from the accelerator of the Institute for High Energy Physics (Protvino) and hitting carbon and copper nuclear targets. The data in question were obtained in the polarized-proton-fragmentation region (0.0 < x F < 0.7, 0.6 < p T < 2.5 GeV/c). In agreement with data obtained at other energies, the single-spin asymmetry for π ± mesons is significant at high x F. For the first time, a sizable analyzing power, which changes sign at x F = 0.43, is observed for protons. The dependence of the analyzing power on the target-nucleus mass is insignificant.

Results of study of the K^ - →π ^0 e^ - νγ decay at the ISTRA+ setup are presented. We observed 4476 events of this decay. The branching ratio is found to be R = Br(K^ - →π ^0 e^ - ν_e γ )/Br(K^ - →π ^0 e^ - ν_e ) = (1.81±0.03(stat.)±0.07(syst.)) × 10 −2 for E * γ > 10 MeV and θ * eγ > 10°. For comparison with the previous experiment the branching ratio with cuts E * γ > 10 MeV, 0.6 < cos θ * eγ < 0.9 is calculated: R = Br(K^ - →π ^0 e^ - ν_e γ )/Br(K^ - →π ^0 e^ - ν_e ) = (0.47±0.02(stat.) ± 0.03(syst.)) × 10 −2 . For the cuts E * γ > 30 MeV and θ * eγ > 20°, used in most theoretical papers, Br = (3.06 ± 0.09(stat.) ± 0.14(syst.)) × 10 −4 . For the asymmetry we get A ξ = −0.015 ± 0.021. At present it is the best estimate of this asymmetry.

Using data collected with the ISTRA+ spectrometer during the 2001 run of the U-70 proton synchrotron in Protvino, the first observation of the radiative kaon decay K- --> mu(-) pi(0) gamma nu is reported. The ratio Br(K-mu 3 gamma, 5 < E-gamma* < 30 MeV)/ Br(K-mu 3) is found to be [0.270 +/- 0.029(stat.) +/- 0.026( syst.)]% and the ratio Br(K-mu 3 gamma, 30 < E-gamma* < 60 MeV)/ Br(K-mu 3) = [0.0448 +/- 0.0068( stat.) +/- 0.0099( syst.)]%. These ratios are consistent with the theoretical predictions 0.21 and 0.047%, respectively. The measured angular distribution asymmetry for the region 5 < E-gamma* < 30 MeV, A(cos theta*(mu gamma)) = 0.093 +/- 0.141, is two standard deviations away from the theoretical prediction of 0.354. The measured asymmetry in the T - odd variable xi = p(gamma) . (p(mu) x p(pi))/m(K)(3) is - 0.03 +/- 0.13.

Results of study of the \(K^ - \to \pi ^0 e^ - \overline \nu \gamma \) decay at the ISTRA+ setup are presented. We observed 4476 events of this decay. The branching ratio is found to be \(R = \frac{{Br(K^ - \to \pi ^0 e^ - \overline \nu _e \gamma )}}{{Br(K^ - \to \pi ^0 e^ - \overline \nu _e )}}\) = (1.81±0.03(stat.)±0.07(syst.)) × 10−2 for E*γ > 10 MeV and θ*eγ > 10°. For comparison with the previous experiment the branching ratio with cuts E*γ > 10 MeV, 0.6 < cos θ*eγ < 0.9 is calculated: R = \(\frac{{Br(K^ - \to \pi ^0 e^ - \overline \nu _e \gamma )}}{{Br(K^ - \to \pi ^0 e^ - \overline \nu _e )}}\) = (0.47±0.02(stat.) ± 0.03(syst.)) × 10−2. For the cuts E*γ > 30 MeV and θ*eγ > 20°, used in most theoretical papers, Br = (3.06 ± 0.09(stat.) ± 0.14(syst.)) × 10−4. For the asymmetry we get A ξ = −0.015 ± 0.021. At present it is the best estimate of this asymmetry.

The design, manufacture and testing of lightweight glass-coated beryllium spherical converging mirrors for the RICH1 detector of the LHCb experiment are described. The mirrors need to be lightweight to minimize the material budget and fluorocarbon-compatible to avoid degradation in the RICH1 C4F10 gas radiator. Results of the optical measurements for small-sized prototypes and for a full-sized prototype mirror are reported.

Results of study of the K- -> pi(0)e(-)(v) over bar gamma decay at the ISTRA+ setup are presented. We observed 4476 events of this decay. The branching ratio is found to be R = Br(K- -> pi(0)e(-)(v) over bar (e)gamma)/Br(K- -> pi(0)e(-)(v) over bar (e)) = (1.81 +/- 0.03(stat.) +/- 0.07(syst.)) x 10(-2) for E-gamma* > 10 MeV, 0.6 < cos theta(e gamma)* < 0.9 is calculated: R = Br(K- -> pi(0)e(-)(v) over bar (e)gamma)/Br(K- -> pi(0)e(-)(v) over bar (e)) = (0.47 +/- 0.02(stat.) +/- 0.03 (syst.)) x 10(-2). For the cuts E-gamma* > 30 MeV and theta(e gamma)* > 20 degrees, used in most theoretical papers, Br = (3.06 +/- 0.09(stat.) +/- 0.14(syst.)) x 10(-4). For the asymmetry we get A(xi) = -0.015 +/- 0.021. At present it is the best estimate of this asymmetry.

The transverse single-spin asymmetry was measured for charged hadrons (π ±, K ±, p, \(\bar p\)) produced in proton-nucleus collisions. The measurements were performed at the FODS-2 spectrometer by using a polarized proton beam that was accelerated to an energy of 40 GeV at the accelerator of the Institute for High Energy Physics (IHEP, Protvino) and which was made to hit carbon and copper nuclear targets. The data in question were obtained in the range of c.m. angles between 73° and 94° near the central region (−0.01 < x F < 0.27, 0.7 < p T < 3.6 GeV/c). The single-spin asymmetry for π + and K + mesons is significant at high values of p T and moderately small positive values of x F. The analyzing power for other hadrons (π −, K −, p, \(\bar p\)) is compatible with zero in the p T range studied here. The dependence of the analyzing power on the mass number of the target nucleus is insignificant.

The transverse single-spin asymmetry was measured for charged hadrons (π ±, K ±, p, \(\bar p\)) produced in proton-nucleus collisions. The measurements were performed with the aid of the FODS-2 spectrometer by using a 40-GeV polarized proton beam from the accelerator of the Institute for High Energy Physics (IHEP, Protvino) and carbon and copper nuclear targets. The data subjected to the analysis in the present study were obtained for c.m. angles in the range 95°–112° in the vicinity of the central region (−0.08 < x F < −0.06, 0.7 < p T < 3.4 GeV/c). The analyzing power is found to be only slightly dependent on the mass number of the target nucleus. The basic results obtained by measuring the single-spin asymmetry at three values of the particle-detection angle are discussed.

The branching fraction for the decay $K^{-} \to \pi^{0} e \bar \nu$ is measured using in-flight decays detected with {\bf ISTRA+} setup working at the 25 GeV negative secondary beam of the U-70 PS:\linebreak $Br_{K_{e3}}= (5.124 \pm 0.009 (stat) \pm 0.029(norm) \pm 0.030(syst))%$. From this value the $|V_{us}|$ element of the CKM matrix is extracted, using previously measured $f_{+}(t)$ form factor: $|V_{us}|=0.227 \pm 0.002$. The results are in agreement with recent measurements by BNL E865, FNAL KTeV, KLOE.

The branching ratio in the charged-pion-kinetic-energy region of 55 to 90 MeV for the direct photon emission in the K − → π − π 0 γ decay has been measured using in-flight decays detected with the ISTRA+ setup operating in the 25-GeV/ c negative secondary beam of the U-70 PS. The value Br(DE)=[0.37±0.39(stat.)±0.10(syst.)]×10 −5 obtained from the analysis of 930 completely reconstructed events is consistent with the average value of two stopped-kaon experiments, but it differs by 2.5 standard deviations from the average value of three in-flight-kaon experiments. The result is also compared with recent theoretical predictions.

At the future Facility for Antiproton and Ion Research in Darmstadt (FAIR) a dedicated heavy-ion experiment investigating the properties of highly Compressed Baryonic Matter is proposed (CBM). A key observable of the physics program will be a precise measurement of low-mass vector mesons in their leptonic decay channel. The essential experimental tool for identifying the decay electrons will be a gaseous RICH detector. The concept of this RICH detector will be introduced and discussed.

The single spin asymmetry for charge hadron production off nuclei (C, Cu) has been measured using 40 GeV/c polarized proton beam. The measurements were carried out using FODS-2 experimental setup at IHEP. The data are presented in the central region and the forward region with respect to the incident protons.

Ardashev E., Bogolyubsky M., Bulgakov N. et al. PROPOSAL. An Experiment For Studying Mechanisms of Charmed Particle Production and Decays in pA-Interactions at 70 GeV/c: IHEP Preprint 96–98. – Protvino, 1996. – p. 47, figs. 24, tables 7, refs.: 52. In the proposal of an experiment the aimes of a continuation of charm particle production studies started in the framework of experiment E–161 with the SVD set-up are formulated. From an analysis of the existing data on charm hadroproduction obtained in fixed target experiments and of modern theoretical ideas on mechanisms of heavy quark production in hadronic collisions it is shown that conducting an experiment at the energy near the threshold of charm production offers an unique opportunity to verify the intrinsic charm hypothesis and to estimate a possible contribution of such a mechanism to the charm particle yield. A capability of an experiment in this energy range for a study of exclusive nonleptonic decays of Λc -baryons is also envisaged. The upgrade for the SVD set-up needed to realize the proposed program of physical investigations, including problems of fabrication of the new precision vertex detector, of the trigger system electronics and of development of the data acquisition system is considered. The results of the detailed Monte Carlo simulation of the charmed events triggering efficiency and of the probability to detect charmed hadron decays with the upgraded SVD set-up are presented. Finally the organization of the data handling system using the interactive program of the graphical analysis of events is discussed and the rate of statistics accumulation is estimated.

The single transverse spin asymmetry data for the charged hadron production in pC and pCu interactions are presented. The measurements have been performed at FODS-2 experimental setup using 40 GeV/c IHEP polarized proton beam. The hadron transverse momentum range is from 0.5 GeV/c up to 4 GeV/c. The data obtained off the nuclear targets are compared with the proton target data measured earlier with the same experimental setup and with the data of other experiments. Key-words: spin, asymmetry, hadron production,polarization, quarks, QCD. Submitted to the XVII International Seminar on High Energy Physics ”Relativistic Nuclear Physics and Quantum Chromodynamics”, September 27 October 2, 2004, Dubna, Russia