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The paper presents the theoretical prerequisites for centralization of automotive vehicles maintenance and repair as a regional logistics system. The concept of centralization is analyzed, the basic principles are considered. As a conceptual scheme of centralization, the scheme of the hub airport was adopted, to which all requests for maintenance and repairs flock and, after completion, are put into operation. To optimize this system, the mathematical apparatus of the queuing theory and criteria for the effectiveness of its application are used. The closed form of the queuing system is substantiated. The trend of efficiency indicators with an increase in the scale of the enterprise (the number of serviced machines) is analyzed. Efficiency indicators such as technical readiness ratios, fleet utilization, and productivity are increasing. Indicators such as specific investment in the production and technical base, the labor intensity of maintenance and repair, the consumption of spare parts are reduced. However, these dependences are nonlinear damping, which is explained by the action of the law of damped efficiency. At a certain scale of the enterprise (level of centralization), saturation and a sharp change (the so-called "breakthrough") of performance indicators occur either due to the structure of the production and technical base, or due to new organizational forms.

The UA9 setup, installed in the Super Proton Synchrotron (SPS) at CERN, was exploited for a proof of principle of the double-crystal scenario, proposed to measure the electric and the magnetic moments of short-lived baryons in a high-energy hadron collider, such as the Large Hadron Collider (LHC). Linear and angular actuators were used to position the crystals and establish the required beam configuration. Timepix detectors and high-sensitivity Beam Loss Monitors were exploited to observe the deflected beams. Linear and angular scans allowed exploring the particle interactions with the two crystals and recording their efficiency. The measured values of the beam trajectories, profiles and of the channeling efficiency agree with the results of a Monte-Carlo simulation., 25 pages, 13 figures

International audience; Experiments to measure the electric and the magnetic moments of short-lived baryons using an internal target and two bent crystals in the vicinity of one of the existing LHC detectors were recently proposed, in the frame of the Physics Beyond Colliders Working Group at CERN. Investigating fixed-target physics in the LHC with in-vacuum solid targets is an unprecedented challenge. As a preparatory step, the layout of the UA9 experiment, installed in the CERN SPS to explore beam manipulations assisted by bent crystals, has been modified to study the feasibility of the double-crystal scenario in a circular accelerator. Ideally, the first crystal should capture halo protons in channeling states directing them onto the internal target to produce rare baryons, whilst the second crystal, located just downstream of the target, should channel the baryons, rotate their polarization vector and deflect them towards the detector area. The upgraded UA9 layout is presented. Preliminary measurements providing an insight of the beam behavior are reported.

Strong reduction of multiple scattering for channeled particles has been observed in an experiment on the deflection of a 180 GeV/c π+-meson beam by bent silicon crystals. The RMS deflections due to multiple scattering for the channeled particles were about six times smaller than for non-channeled ones. It was shown that the approach suggested recently for the description of multiple scattering for channeled particles using the experimental data for random crystal orientations gives fair agreement with the experiment. Keywords: Crystal, Channeling, Multiple scattering, Dechanneling, Beam deflection

International audience; At large accelerators, bent crystals are employed to deflect weakly divergent proton beams at the stages of extraction and collimation. We demonstrate that a divergent particle beam may be efficiently deflected using a crystal with a focusing entry face. A 180 GeV/c pion beam with divergence near 0.060 mrad, which exceeds the Lindhard angle by a factor of 4, has been experimentally deflected by 0.25 mrad with efficiency near 22%. The proposed focusing crystal may serve as an element of a novel particle optics for secondary-particle beams in the TeV energy region.

Experimental results on deflection of a 180 GeV/c π+-meson beam by a 23 mm long bent silicon crystal are analyzed to study the dechanneling process of particles due to multiple scattering. A new approach for the determination of contributions from atomic nuclei and electrons to the multiple scattering using the experimental data for random crystal orientations is suggested. The results of simulations performed using this approach, in which the contribution from atomic electrons is considered according to the prescription of Bethe, are in a good agreement with the experiment.

International audience; Recent discussions about accelerators in high energy physics identified several challenges for the future, where it is necessary to focus particle beams over a distance of a few cm. In this paper, we investigate the focusing of particles by a new crystal device having such a capability. The trajectories of 180 GeV/ c pions passing through a 500 µm thick focusing crystal were reconstructed using silicon microstrip detectors. It is shown that a parallel beam of particles can be focused in one plane at a distance of 15.5 cm from the crystal, in a narrow line with an rms width of 8 µm.

International audience; This paper is devoted to an experimental study of focusing and defocusing positively charged particle beams with the help of specially bent single crystals. Four crystals have been fabricated for this purpose. The studies have been performed at the CERN SPS in 400 GeV/c proton and 180 GeV/c pion beams. The results of measurements of beam envelopes are presented. The rms size of the horizontal profile at the focus was 5–8 times smaller than at the exit of the crystals. The measured focal lengths were 4–21 m. The results of measurements are in good agreement with calculations. Possible applications of focusing crystals in present and future high energy accelerators are discussed.

We studied the dechanneling length of 150 GeV / c π − interacting with a short bent silicon crystal. Dechanneling length measures the rate and the strength of incoherent interactions of channeled particles in a crystal. The mechanism of dechanneling of negatively charged particles has been elucidated through simulation and experiment. It was found that the dechanneling length for negative particles is comparable to the nuclear dechanneling length for positive charges. Indeed, dechanneling of negative particles occurs as a result of incoherent interactions with the nuclei because the trajectories of such particles always intersect atomic planes, explaining the lower channeling efficiency for such particles. Obtained results can be useful for the design of crystals for manipulating high-energy negative particle beams through channeling.

A deflection efficiency of about 61 % was observed for 400 GeV/c protons due to channeling, most strongly along the 〈110〉 axis of a bent silicon crystal. It is comparable with the deflection efficiency in planar channeling and considerably larger than in the case of the 〈111〉 axis. The measured probability of inelastic nuclear interactions of protons in channeling along the 〈110〉 axis is only about 10 % of its amorphous level whereas in channeling along the (110) planes it is about 25 % . High efficiency deflection and small beam losses make this axial orientation of a silicon crystal a useful tool for the beam steering of high energy charged particles.

Two high-accuracy goniometers equipped with two bent silicon crystals were installed in the betatron cleaning insertion of the CERN Large Hadron Collider (LHC) during its long shutdown. First beam tests were recently performed at the LHC with 450 GeV/c and 6500 GeV/c stored proton beams to investigate the feasibility of beam halo collimation assisted by bent crystals. For the first time channeling of 6500 GeV/c protons was observed in a particle accelerator. A strong reduction of beam losses due to nuclear inelastic interactions in the aligned crystal in comparison with its amorphous orientation was detected. The loss reduction value was about 24. Thus, the results show that deflection of particles by a bent crystal due to channeling is effective for this record particle energy., peer-reviewed

Experiments were performed at the CERN SPS with 120 GeV/c stored proton beams to assess the possibility of beam halo collimation assisted by bent crystals. A bent crystal was used to deflect horizontally by an angle of about 170 mu rad the beam halo protons in channeling states directing them into a 60 cm long tungsten absorber. The halo loss rate due to nuclear inelastic interactions of protons in the aligned crystal was up to five times smaller than for its amorphous orientation. Channeled fractions, (75 +/- 4)% and (85 +/- 5)% for the two tested silicon crystals, were measured by intercepting the deflected beam with another collimator located between the crystals and the absorber. The pixel detector (MEDIPIX) installed in a Roman pot inside the beam pipe was used to obtain visual images of the deflected beam. (C) 2010 Elsevier B.V. All rights reserved.

Channeling in a short bent silicon crystal was investigated at the CERN SPS using 400-GeV/c protons with an angular spread much narrower than the critical channeling angle. Particle dechanneling due to multiple scattering on the atomic nuclei of the crystal was observed and its dechanneling length was measured to be about 1.5 mm. For a crystal with length comparable to such dechanneling length, an efficiency of 83.4% was recorded, which is close to the maximum value expected for a parallel beam and exceeds the previously known limitation of deflection efficiency for long crystals.

The aim of the investigation was to assess a new approach to the analysis of variations in 100 successive R‒R intervals duration in determining heart rate dynamics variants during an orthostatic test. Materials and Methods. Electrocardiogram was recorded and duration of 100 R‒R intervals following each other was measured during an orthostatic test in 74 healthy children aged 12.8±0.16 years, 34 of which were training to play football during 1.5‒2 years. While processing numeric series of 100 R‒R intervals we were the first to apply color coding of each value, including those corresponding to the “true” heart rate (THR) parameter. For this purpose, having divided the region of R‒R interval values from 0.35 to 1.25 into i spaces by 0.15 s, each interval value depending on its belonging to i, as well as R‒R intervals corresponding to THR, were marked by a certain color. A THR parameter was determined by a known empirical equation (118.1‒0.57a) beats per minute, where a is age in years. Evaluating the whole set of parameters: mode (Mo, s) — the most frequently occurring R‒R interval duration; mode amplitude (AMo) — a number of Mo value repetitions — some of which were used in cardiointervalography for the first time (a total quantity of i spaces, in which R‒R interval variations occurred — it; the quantity of transitions from one space i to another — Nabs; R‒R duration corresponding to THR). Results. The approach developed made it possible to present clearly the change of the heart rate in time, to assess quantitatively the heart rate dynamics in time and determine the variants of its alteration in the orthostatic test. Their set in healthy children with a high level of physical activity has been found to be similar, though the ratio of diverse variants is different: in changing over to orthostasis cases of a weak influence of the vegetative nervous system on the heart rate occur more often in the young football players than in children with a lower physical load. Conclusion. Application of color coding of the R‒R intervals succession and assessment of the suggested set of parameters for heart rate variability investigation make it possible to present clearly heart rate dynamics and evaluate activity intensity of various parts of the vegetative nervous system without conversion of the numeric series of R‒R interval succession to the analog form. The software for automated processing of the investigated data, created on the basis of the algorithm suggested by us, provides the opportunity to assess a vegetative control of the heart rate in various groups under investigation.

The volume reflection of 1-GeV protons by a bent crystal has been observed. The crystal is made of single crystal silicon. The (111) atomic planes are bent owing to the elastic quasimosaicity effect, which makes it possible to reduce the crystal length for a beam to 30 µm. It is found that the probability of the reflection effect is higher than the probability of the channeling effect (0.71 vs. 0.63), and the deflection angle of the protons reflected inside the crystal is equal to 1.39 ± 0.04 in terms of the critical angle for channeling under the conditions of the experiment (170 µrad). The width of the reflected peak is equal to 1.76 ± 0.04 in the same units. The protons that are not involved in channeling at the angular position of maximum channeling undergo volume reflection and are deflected in the direction opposite to the channeled beam by the angle 1.01 ± 0.05 in terms of the critical angle for channeling. The width of the reflected peak is equal to 1.94 ± 0.08 in the same units.

A radical increase in the efficiency of beam extraction from an accelerator is achieved with a short (7 mm long) crystal bent by a small angle (1.7 mrad) by increasing the number of times particles pass through the crystal. A particle extraction efficiency of ~20%, in agreement with the prediction of the theory, was achieved experimentally. A record high intensity of the extracted beam 1.9×1011 protons per cycle, which is four orders of magnitude higher than previous results, is obtained.

Multiple volume reflection by different planes passing through the 〈111〉 axis in a bent silicon crystal was observed for the first time for 150 GeV/c negative particles, π- mesons, at one of the secondary beams of the CERN SPS. The beam of π- mesons was deflected opposite to the crystal bend by an angle of about 48 μrad, which is 4.6 times larger than in a single volume reflection by the (110) bent planes. The one-side deflection efficiency was about 65%. Multiple volume reflection transforms to a single volume reflection when the orientation angle of the 〈111〉 axis relative to the beam direction is increased. Copyright © 2011 Europhysics Letters Association.

Probability of inelastic nuclear interactions in a short bent silicon crystal for its orientations optimal for channeling and volume reflection was investigated using 400 GeV/c protons of the CERN SPS. The contribution of nuclear interactions from channeled protons was observed to be about 3–4% of the probability for the amorphous orientation. For the crystal orientation optimal for volume reflection the nuclear interaction probability of protons was a few percents larger than in the amorphous case. It was shown that in the limiting case of a quasi parallel beam realizing for the collider beam halo the inelastic nuclear losses should decrease by more than five times, which is an additional advantage of a crystal as a primary collimator for the LHC collimation system.

Different kinds of deflection in a silicon crystal bent along the 〈111〉 axis was observed for 150 GeV/ c negative particles, mainly π − mesons, at one of the secondary beams of the CERN SPS. The whole beam was deflected to one side in quasi-bound states of doughnut scattering (DSB) by atomic strings with the efficiency (95.4 ± 0.2)% and with the peak position close to the bend crystal angle, α = 185 μrad . It was observed volume capture of π − mesons into the DSB states with a probability higher than 7%. A beam deflection opposite to the crystal bend was observed for some orientations of the crystal axis due to doughnut scattering and subsequent multiple volume reflections of π − mesons by different bent planes crossing the axis.

Multiple volume reflections of the 400 GeV / c proton beam by the sequence of fourteen bent silicon strips has been studied at the CERN SPS. The sequence is close to be parallel that is the spread of the strip orientation angles is much smaller than their bend angle and eleven strips working coherently in the regime of volume reflections deflected the beam by 110 μrad with the efficiency 88%, which is significantly larger than the estimation based on independent reflections. The mechanism giving the efficiency increase has been studied by simulation. It appears that many particles volume captured in one of the strips take part in volume reflections in the subsequent ones. Such a crystal multi reflector can be successfully used as a primary collimator for the beam halo collimation of high-energy accelerators.

The radiation emitted by $180\ensuremath{-}\mathrm{GeV}∕c$ volume-reflected electrons and positrons impinging on a bent crystal has been measured by the H8RD22 Collaboration on the H8 beamline at the CERN SPS. A dedicated spectrometer has been developed to measure high-energy photon spectra (up to $\ensuremath{\sim}100\phantom{\rule{0.3em}{0ex}}\mathrm{GeV}$) under volume reflection: photon and charged particle beams have been separated by a bending magnet and leptons were detected and tagged by microstrip silicon detectors and a Pb-scintillator sampling calorimeter. A comparison between the experimental and analytical data for the amorphous and volume-reflection cases is presented and the differences are discussed.

Multiple volume reflection by different planes in a bent silicon crystal with its 〈111〉 axis orientation close to the beam direction was observed for the first time for 400 GeV/c protons at the CERN SPS. The proton beam was deflected to the side opposite to the crystal bend by an angle of about 67 μrad, which is five times larger than in a single volume reflection by the (110) bent planes. The registered efficiency of one side deflection was about 84%. It was shown that multiple volume reflection transforms to a single volume reflection when the orientation angle of the 〈111〉 axis relative to the beam direction is increased.

Deflection due to planar channeling and volume reflection in short bent silicon crystals was observed for the first time for 150 GeV / c negative particles, π − mesons, at one of the secondary beams of the CERN SPS. The deflection efficiency was about 30% for channeling and higher than 80% for volume reflection. Volume reflection occurs, in spite of the attractive character of the forces acting between the particles and the crystal planes, in a wide angular range of the crystal orientations determined by the crystal bend angle.

Deflection due to axial channeling in a silicon crystal bent along the 〈111〉 axis was observed for 150 GeV/c negative particles, mainly π − mesons, at one of the secondary beams of the CERN SPS. The whole beam was deflected to one side with the efficiency of about 90% and with the peak position at the bend crystal angle α = 43 μrad . The deflection occurs mainly due to doughnut scattering of above-barrier particles by the atomic strings of the crystal. However, due to a high probability of particle recapture into bound states with the atomic strings their contribution to the deflection should be about 15% for our case according to simulation results.

The interactions of 400 GeV protons with different sequences of bent silicon crystals have been investigated at the H8 beam line of the CERN Super Proton Synchrotron. The multiple volume reflection of the proton beam has been studied in detail on a five-crystal reflector measuring an angular beam deflection theta = 52.96 +/- 0.14 microrad. The efficiency was found larger than 80% for an angular acceptance at the reflector entrance of 70 microrad, with a maximal efficiency value of epsilon = 0.90 +/- 0.01 +/- 0.03.

The trend of volume reflection parameters (deflection angle and efficiency) in a bent (110) silicon crystal has been investigated as a function of the crystal curvature with 400 GeV/c protons on the H8 beam line at the CERN Super Proton Synchrotron. This Letter describes the analysis performed at six different curvatures showing that the optimal radius for volume reflection is approximately 10 times greater than the critical radius for channeling. A strong scattering of the beam by the planar potential is also observed for a bend radius close to the critical one.

This paper presents a detailed study of the deflection phenomena of a $400\text{ }\text{ }\mathrm{GeV}/c$ proton beam impinging on a new generation of bent silicon crystals; the tests have been performed at the CERN Super Proton Synchrotron H8 beam line. Channeling and volume reflection angles are measured with an extremely precise goniometer and with high resolution silicon microstrip detectors. Volume reflection has been observed and measured for the first time at this energy, with a single-pass efficiency as large as 98%, in good agreement with the simulation results. This efficiency makes volume reflection a possible candidate for collimation with bent crystals at the CERN Large Hadron Collider.

The doubling of the angle of beam deflection due to volume reflection of protons by a sequence of two bent silicon crystals was experimentally observed at the 400 GeV proton beam of the CERN SPS. A similar sequence of short bent crystals can be used as an efficient primary collimator for the Large Hadron Collider.

A high performance apparatus has been designed and built by the H8-RD22 collaboration for the study of channeling and volume reflection phenomena in the interaction of 400 GeV/c protons with bent silicon crystals, during the 2006 data taking in the external beamline H8 of the CERN SPS. High-quality silicon short crystals were bent by either anticlastic or quasimosaic effects. Alignment with the highly parallel (8 murad divergence) proton beam was guaranteed through a submicroradian goniometric system equipped with both rotational and translational stages. Particle tracking was possible by a series of silicon microstrip detectors with high-resolution and a parallel plate gas chamber, triggered by various scintillating detectors located along the beamline. Experimental observation of volume reflection with 400 GeV/c protons proved true with a deflection angle of (10.4+/-0.5) murad with respect to the unperturbed beam, with a silicon crystal whose (111) planes were parallel to the beam.

Beam deflection due to axial channeling in a silicon crystal bent along the < 111 > axis was observed with 400 GeV/c protons at the CERN Super Proton Synchrotron. The condition for doughnut scattering of protons by the atomic strings of the crystal was attained. Such a condition allowed one to observe a beam deflection of 50 mu rad with about 30% efficiency. The contribution of hyperchanneled states of protons to the observed beam deflection was less than 2% according to simulation results.

For the new generation of high intensity hadronic machines as, for instance, LHC, halo collimation is a necessary issue for the accelerator to operate at the highest possible luminosity and to prevent the damage of superconductor magnets. We propose an experiment aimed to systematic study of the channeling phenomenology and of the newly observed "volume reflection" effect. This experiment will be performed for an external SPS beamline and will make use of a primary proton beam with 400 GeV/c momentum and very small (∼ 3 μ rad) divergence. The advantage of a proposed experiment is precise tracking of particles that interacted with a crystal, so that to determine the single-pass effciency for all the processes involved. For this purpose, a telescope equipped with high-resolution silicon microstrip detectors will be used. New generation silicon crystals and an extra-precise goniometer are mandatory issues. Main goal of the experiment is to get the precise information on channeling of relativistic particles and, ultimately, on the feasibility of such technique for halo collimation at LHC. In this contribution we review the status of the setting-up of experimental apparatus and its future development in sight of the planned run in September 2006.© (2007) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The volume reflection phenomenon was detected while investigating 400 GeV proton interactions with bent silicon crystals in the external beam H8 of the CERN Super Proton Synchrotron. Such a process was observed for a wide interval of crystal orientations relative to the beam axis, and its efficiency exceeds 95%, thereby surpassing any previously observed value. These observations suggest new perspectives for the manipulation of high-energy beams, e.g., for collimation and extraction in new-generation hadron colliders, such as the CERN Large Hadron Collider.

The article presents a survey of authors' studies over the recent five years on some topical problems of the proximal femur biomechanics: the evolution of a necrotic area in the hip head and the possibility of its replacement by the composite implant; the mechanical interaction between the composite implant and the femur bone; the numerical analysis of muscular forces acting on the hip joint during walking; the construction of phenomenological kinetic equation for bone tissue internal remodeling; the influence of the scheme of therapeutic loading on the recovering of the bone tissue elastic modulus in human proximal femur after its long enforced immobilization; the computer simulation of bone tissue remodeling in proximai femur under the variations of hip joint daily loading history. The analysis of the main findings is presented, and the prospects of further investigations are outlined., В статье представлен обзор результатов исследований, выполненных авторами за последние пять лет по ряду актуальных проблем биомеханики проксимального отдела бедра: развитие некротической области в головке бедра и возможность её замещения имплантатом из композиционного материала; механическое взаимодействие имплантата из композиционного материала и бедренной кости; построение кинетического и определяющего соотношений упругой приспосабливающейся к изменяющимся нагрузкам среды, реабилитационное восстановление механических свойств губчатой костной ткани головки и шейки бедра после вынужденной иммобилизации конечности; компьютерное моделирование процесса перестройки костной ткани проксимального отдела бедра при изменении характера нагрузок на тазобедренный сустав. Приведен анализ результатов и намечены перспективы дальнейших исследований. Библ. 16.

The technique of beam focusing by a bent crystal is described and results from its application presented in this note. A 70 GeV 2 mm wide proton beam was deflected and focused into a narrow 200 μm wide strip.

Erratum to : "Double volume reflection of a proton beam by a sequence of two bent crystals" [Phys. Lett. B 658 (2008) 109] (DOI:10.1016/j.physletb.2007.10.070)

Differential cross sections for elastic scattering of pions and protons on helium have been measured at incident momenta ranging from 50 to 300 GeV/c in the t-range 0.008 < | < | < 0.05 (GeV/c)2. Both recoil α-particles and forward particles were detected in this experiment. The experimental method provided an absolute normalization of the cross sections with an estimated precision of 1%. From the analysis of the data, the diffraction slope parameters and total cross sections have been obtained. The results are compared with Glauber model calculations.

We have measured the ionization loss of highly relativistic protons and pions passing through an ionization chamber filled with hydrogen at 10 atm pressure. The Lorentz factor of the particles ranged from γ = 100 to γ = 1800. The ionization loss was found our results disagree with the theoretical predictions of Tsytovich, according to which radiative corrections lead to a decrease in the ionization loss at higher energies.

Differential cross-sections for pp elastic scattering in the transfer momentum range 2 x 10−3 ⩽ |t| ⩽ x8 10−3 (GeV/c)2 were studied with a hydrogen filled ionization chamber which was used as a target and as a detector of the recoiled protons. The measurements have been done at Plab. = 1.11 GeV/c, 1.28 GeV/c, 1.34 GeV/c, 1.40 GeV/c and 1.70 GeV/c. The real part of the spin independent forward scattering amplitude has been determined, the results being in agreement with the dispersion relation calculations.

The differential cross section ofπ−p scattering has been measured in the energy region 100–345 GeV and in thet-range 0.002

The differential cross section of pp scattering has been measured in the energy region 100–300 GeV and in the t -range 0.002 t | c ) 2 . The results on the real part of the scattering amplitude agrees with dispersion relation calculations. We also report on our determination of the slope parameter b together with an analysis of the world data of b for different hadrons and different t -values. It is shown that the data are consistent with the hypothesis of a universal shrinkage of the hadronic diffraction cone at high energies.

In a small-angle elastic scattering experiment (NA8) in the H8 beam of the CERN Super Proton Synchrotron, the absolute momentum of the incident beam particles has been determined from data on hadron— 4 He elastic scattering. Measurements were performed at beam momenta ranging from 100 GeV/ c to 300 GeV/ c , and the average absolute momentum was determined with a precision of 0.15%. This method can be applied also at higher energies.

Heavy flavor experiments currently in progress at e{sup +}e{sup -} colliders or in the fixed target programs at CERN and Fermilab are aimed at collecting large samples (> 10,000 reconstructed events) of charmed events. These experiments will provide a great deal of information about charmed meson systems, but the expected yield of charmed baryons is not large--10% or less of the sample size. The most detailed study of the charm strange baryon {Xi}{sub c}{sup +} comes not from a large-statistics central production experiment at high energy but rather from a 20-day run at modest beam flux in the CERN hyperon beam. This proposal exploits the advantages in triggering and particle identification of large-x production to make a systematic study of charm baryon production and decay systematics. For the dominant ({approx} 10% branching ratio) modes of these baryons, they expect to collect 10{sup 6} triggered events in each mode per running period. This will give adequate statistics to study even highly suppressed modes. The study of meson systematics by the Mark III spectrometer at SPEAR led to a revolution in the understanding of charmed meson decay mechanisms. No present experiment will supply a similar data set for the charmed baryons. A fixed target experiment cannot supply the absolute branching ratios that e{sup +}e{sup -} annihilation on the {Upsilon}(3770) resonance provides for the Mark III data. They can supply relative branching ratios for the non-leptonic and semileptonic decay modes of charmed baryons and establish the importance of two-body resonance modes in the decay mechanism. This information, along with lifetime measurements for {Lambda}{sub c}{sup +}, {Sigma}{sub c}{sup ++}, {Sigma}{sub c}{sup +}, {Sigma}{sub c}{sup 0}, {Xi}{sub c}{sup +} and {Omega}{sub c}{sup 0} baryons, will permit evaluation in the baryon sector of the role of color suppression, Pauli suppression, sextet enhancement and other varied mechanisms which influence decay rates of charmed hadrons. This information will be very difficult to obtain from existing spectrometers because of the wide range of particle identification methods needed to handle different decay modes. SELEX is designed specifically to do this job, as they said in the Letter of Intent.

The differential cross section has been measured at 30, 50, 80, 100, 120 and 140 GeV/ c for 0.002 t | GeV / c ) 2 . The results show that the π − p real part goes from negative to positive values below 80 GeV/ c . The slope parameter in the t -region measured is significantly higher than what has been found − t = 0.2 (GeV/ c ) 2 .

Differential cross sections for π − p and pp elastic scattering have been measured at incident momenta ranging from 30 to 345 GeV and in the t range 0.002 (GeV/ c ) 2 ⩽ | t | ⩽ 0.04 (GeV/ c ) 2 . From the analysis of the data, the ratio ϱ ( t = 0) of the real to the imaginary parts of the forward scattering amplitude was determined together with the logarithmic slope b of the diffraction cone. The results on the real parts confirm the validity of the forward dispersion relations at high energies. Using the dispersion relations, it was shown that the experimental data on ϱ π −p( t = 0) require a continuous rise of the total πp cross sections, at least up to the energy of 2000 GeV, thus revealing a close similarity in high-energy behaviour of πp and pp interactions. The results on the slope parameters from this experiment together with the analysis of the available world data demonstrate that the existing experimental data are consistent with the hypothesis of a universal shrinkage of the hadronic diffraction cone at high energies. The value of the asymptotic shrinkage parameter α p ′ was found to be independent of the kind of the incident hadron and of the momentum transfer in the t range | t | ⩽ 0.2 (GeV/ c ) 2 : 2 α p ′ = ± 3 (GeV/ c ) −2 .