lliE SPS EXPERIMENTAL PROGRAM

MARIA FIDECARO CERN, Geneva (Switzerland)

Abs tract : The experimental program at the SPS is reviewed as it takes shape from the proposals put forward up to this Spring .

Resume : Le programme d'experiences aupres du SPS est passe en revue , tel qu 'il se profile d'apres les propositions presentees jusqu'a maintenant .

191 1. INTRODUCTION

The Super (and Subterranean) Synchrotron (SPS) is expected to start operating in the middle of 1976 when will be extracted in the West Hall at 200 GeV.

experimental progrannne to be carried out in the first year of oper­ ation is at present being set-up . Thorough discussions took place at the Tirrenia Meeting in September, 1972 and in January, 1973 P. Falk-Vairant presentedAn the final report of the Executive Corrnnittee of the ECFA . In April Letters of Intent were called in; some of which were later transformed into proposals by the Spring of 1974 .

I will try to give an outline of this progrannne as seen by an inter­ ested layman i I apologize for the distorsions and the omissions .

Working within some boundary conditions , the physicists wanted to make use of: a) The West Hall (Fig . 1 and Appendix) b) A large bubble chamber BEBC , 3 m long , 3.70 m diameter to be filled with hydrogen or deuterium in a 5 Tesla magnetic field. Possibly a second heavy liquid bubble chamber 4.8 m long , 1.9 m diameter (Gargamelle) in a 2 Tesla magnetic field could be used. 3 c) A large magnet (2 x 3 x 1.5 m ) 1.8 Tesla, filled with a flexible system of detectors (Omega) .

Also they had to bear in mind that particles are expected in the North Area at the beginning of 1978 . Here the Hall EHNl will include two hadron beams up to 350 GeV/c, an electron/hadron beam up to 270 GeV/c, a medium energy hadron beam up to 200 GeV/c. The Hall EHN2 will be reserved for muon and protons experiments only.

A Working Group is looking at the feasibility and the opportunity of a general facility (Dynosaure) to perform experiments on hadron/electron phys ics in the Hall EHNl . A British, French , German Collaboration is preparing a wh ite book on possible ways of studying elastic and inelastic µ-p/d scattering (with polarized unpolarized targets) .

2. WANF (WEST NEUTRINO FAC ILI1Y)

The importanceand ot neutrino and muon phys ics has already been recognized. In both cases the interest was shown mostly to utilize these particles as THE AREA 2 probes of internal structure of hadrons in an inclusive study of q , Vplot .

The relative merits of using a narrow band (NB) beam (Ev at ± 7%, flux

192 at ±3%, 10 events on complex nuclei in 30 days) or a wide band beam 5 (108 events on complex nuclei, 103 in deuterium or hydrogen) were discussed. Eventually it was decided to build a beam capable of operating with protons to 400 GeV, and a NB beam in the West Area . (WB) About twenty Letters of Intent referred to neutrino experiments either WB with BEBC filled with or or Ne , or with Gargamelle filled with propane up or freon, with or without an external muon identifier EMI .

The installation of Gargamelle behind an electronic experimental facility Hz Dz is now decided . The latter (SPSC-Pl) will consist of a (scintillator Fe) + calorimeter plus an iron core magnet sandwitched with scintillators drift chambers to form a modular system to momentum analyse the muons , Fig . The calorimeter could be eventually replaced by a more sophisticated liquid Argon counter , SPSC-P3 . There is also room for a somewhat smaller apparatusand z to perform other classes of experiments on neutrinos . .

3. HADRONIC PHYSICS IN BEBC

About forty groups who wrote Letters of Intent showed interest in per­ forming more conventional hadronic phys ics.

Of these approximately thirteen wanted to use BEBC at a beam momenta 40-100 GeV/c (Mirabelle at Serpukhov works at 32 GeV/c) . Most of them called for an separated beam. Many concerned experiments with an external parti­ cle identifier (EPI) and for a track sensitive target (TST) .

This chamber promises to be a competitive instrument up to - 100 GeV RF especially for the more complicated type of events , and one should remember that NAL does no t at present plan the installation of an separated beam, but that an important experimental bubble chamber progrannne with - and p TI beam is being requested there . RF It has now been decided that an separated (up to 75 GeV/c) beam will be constructed while for the external particle identifiers (based on relativ­ istic rise of ionisation and/or on forward gannna detection) progress status of the projects were reported . RF

4 . THE a.IEGA SPECTRa.IETER

In four Letters of Intent and one proposal the groups wanted to use the Omega Spectrometer . Transformations of this spectrometer are planned to be carried out in steps in order to be able to start experiments as early as possible in the West Area . In addition to building a downstream lever arm consisting of drift chambers, three Cerenkov and a y-detector , it : .s planned

193 to gradually replace the optical system within the magnet by drift chamber modules or wire chamber planes . Special attention is being paid to the data acquisition problems in view of the expected high rate . The beams foreseen are an separated hadron beam (up to 40 GeV/c) and an electron- beam, including a photon tagging system.

Various schools of thought flourish around Omega . Is Omega a bubble RF chamber with an electronic read out (Letters of Intent for a K+ interaction trigger, SPSC-I 73/37 and for inclusive studies from different particles and targets , SPSC-I 73/55) or should it be used for exclusive two body or quasi two body reactions with a rather selective trigger , where the geometry would be used to cover a large solid angle? In both cases the separated Kaan beam, which is for the first time available above 3 GeV/c to counter physicists , makes a new class of experiments possible. 4TI

One of the groups at present working on Omega proposes to make use of high energy in order to produce heavier mesons , SPSC-I 73/38 . Another group proposes to explore a region where Regge poles might be important and which becomes accessible only at high energy , SPSC-I 73/54 . They want to be able to establish or to disprove the Reggeon- scattering model

, -, ' ,�/·') s' p /� where a trigger with incident and outgoing of small momentum transfer ; - TI selects, in principle, events of Reggeized p-nucleon scattering - the choice = 2 of beam energy is given by s' << s (f.i.: s' � 1/10 s, s' 10 GeV , 0 s 100 GeV2) . The Omega seems ideal for this TIexperiment where moderate = multiplicities , small transverse momentum and restricted mass of the excited target particle are expected .

Also new is the line of research of a British, French , German Collabor­ ation which want to make use of the tagged photon beam, SPSC-P 10, Fig . 3 and 4. The emphasis will be on multibody final states . They will expect 5 2 x 10 per pulse with energies above 20 GeV; the resolution on the proposed tagging system is ±150 MeV , while the uncertainty in transverse � momentum is 10 MeV/c. � The following experiments are of particular interest:

i) photoprod� uction of vector mesons : p, w, ii) search for new vector mesons iii) diffraction dissociation processes iv) high multiplicity reactions : to compare with�. hadron-induced processes and

194 to obtain the energy dependence of the Illllltiplicity v) total hadronic cross-section, measured by summing all exclusive channels vi) elastic Compton scattering on protons vii) reactions with l'Psmall cross-sections : e.g., pseudoscalar meson production, deep inelastic Compton scattering and lepton pair production . The in­ variant masses W (W = 6.2 GeV at k 20 GeV, up to W = 13.7 GeV at k lCXJ GeV) are comparable to those which could be obtained in virtual photoproduction with higher energy electrons or IllllOns in the North Area . = The use of polarized photon beam and/or a polarized proton ·target is also = envisaged but at a later time .

5. HYPERON BEAM

Strong interest has been expressed in the field of phys ics opened by the construction of a hyperon beam in the West Area. In Table 1 the particle 1HE fluxes expected when the attenuated primary beam is dump are shown . The inter­ est is roughly shared between weak and strong interaction experiments: a) elastic scattering and production of strange resonances by diffractive excitation in E-p and �-p interactions between 75 and 150 GeV/c . ± b) study of the decays �- + Ae-v, �- + E 0 e-v and E + Aev .

Table 1

Particle fluxes at the end of the hyperon beam

GeV/c GeV/c GeV/c Momentum Negative beam Negative beam Positive beam

Incident protons 150x 100 x 100 x

- - 11- ' 6 109 5 106 K 7 10 0 - - x E - - x ' x10 6 10 - - 3 4 - 7 10 10 - 7 104 4 103 p - - x + 100 100 - - 11+ 0.6 x (lK 0.6- - x + 0.8 10 6 E - - 5 ± ± 2.4 10 Note that for p, 11 and K the figures represent the numbers of 2.4 104 these particles in the channel. For the hyperons they represent the numbers actually identified by the DISC. 150

195 A possible layout is shown in Fig . 5. The hadronic experiment would throw light on the mechanism for diffractive production, shrinkage of forward elas­ tic peak and various SU(3) and quark model predictions for baryon-baryon inter­ actions and for partial widths of and resonances . In particular it would investigate the SU(3) properties of the Pomeron .

The weak interaction program which will be carried out first will measure - y* �* the branching ratios for Ae \i and to test on this part of the e baryonic octet the Cabibbo theory. The comparison between - + A + and - v E- _,. Ae \i should provide a sensitive test for the existence of second class - currents . � + +E'ev E + 6. OTIIER HADRON BEAMS IN TIIE WEST HALL

Eventually in the West Hall will be room for two unseparated hadron beams up to 50 and 80 GeV/c (H3 and H respectively) plus a neutral beam N3 . The latter is not requested at present , but seven Proposals have been submitted for the charged beams .

In these proposals we can see some common features from an experimental point of view: all of them involve a rather complex apparatus consisting of vertex detector and a long forward spectrometer (like the tail of a comet ..). a for physics , central lines appear . One originates from the behaviour two of the hadron-hadron elastic scattering at large momentum transfer in partic­ ular proton-proton. This had been interpreted at an early stage in terms of pointAs scattering inside the hadrons . an extension of these ideas an inverse power law for large P hadrons from inclusive reactions was predicted. It was T then observed at the ISR and the ISR results are influencing the proposals in more than one way . The other line concernsAs the peripheral interactions and takes advantage of better kinematical conditions and larger fluxes of beam particles than at the PS.

The proposers of SPSC-P4 concentrate on events associated with particles with large transverse momentum . Specifically they want to study : ± ± i) Dependence of high Pr events on the incident particle (rr ,� ,p ) }i) Composition of the events as a function of Pr and the nature of the high P particle on which they trigger. T iii) jet like correlations occur , suggestive of parton-parton scattering? iv) What is the jet cross-section, multiplicity, composition and mass distribution? v) Do new massive objects exist such as e.g., heavy "fire balls", resonances , charmed particles, etc .?

196 The apparatus as shown in Fig . 6, consists of fast (MWPC 's) magnetic a vertex detector plus a field free forward lever arm composed of Cerenkov hodoscopes, sandwiched between drift chambers . The trigger is on charged particles with P � GeV/c emitted at 80° 1CXJ0 in c.m.s. (the detection T � e � 7 of n° is planned at a later stage) . At 150 GeV/c and with 10 incident particles per pulse the rate is 12,0CXJ events/day (safety factor 0.5) . The direction, sign, charge3 and momentum of all charged particles produced in the projectile fragmentation region are measured by means of a forward spect­ rometer . This experiment is very similar to the ones done at the ISR and a comparison is made by the proposers in Table 2.

Table 2

Comparison of SPS vs ISR for high P studi es t

Quantity ISR SPS Comments

max P at equal rate 8 GeV/c(X =0. 3) GeV/c (X =0.6) t t 5 t

"probing the proton ": 15 -15 2.5 10 � .o 10 ISR has some . max**) x cm x cm resolution t.X•h /p advantages t

"jet focusing" in c.m. ratio 1.1 1 : P /M jet t jet y

identification difficult due tc easy due to SPS better particle= low momenta and Lorentz trans- large lab solid formation (use angle of standard gas counters) c

variation of incident not possible easy for 11p,pp proj ectile possible for Kp SPS experiments necessary threshold effects in not so easy P "'> 50 GeV/c + inc (e.g. p/n ratio) available p t

assuming equal high P cross sections th e different .incident particles . t for 7 10 per day ; we re�all that the ISR luminosity corresponds to "' 10 "' particles on 30 cm H target. a 2 * ) **)

197 Similar plans are made by the authors of 1SPSC-P6 (North Hall) . They would like to extend the line of research carried out at present at the ISR by com­ paring the hadronic production in the projectile fragmentation cone and in the pionization region as induced by different projectiles interacting with protons and nuclei . At the ISR the importance of diffractive exc itation of the primary particles and the existence of short range two -body correlations has been shown . Now it is necessary to study the semi-inclusive channels such as single or two-particle spectra inside events of a given topology. For instance, the signature for diffractive events is made clearer if one requires the quasi­ elastic particle in the forward (backward) direction to be separated by a large rapidity gap from the remaining particles .

The momentum and the charge of all particles produced in the projectile fragmentation region (including photons) are measured in the forward spectro- meter (Fig. 7) . A vertex detector �agnet and chambers) provide information on the emission angle and momentum of the charged particles produced in the target fragmentation region and in the remaining part of the pionization region. No particle identification is planned . When the scaling properties of the production in the projectile fragmentation region is taken into account , the general pattern of the events will appear the same if the currents of the magnets in the forward spectrometer are scaled down according to the reduc­ tion of the beam momentum . The goal is a rapidity resolution of better than 0.05 to be compared with the unity which is the rapidity interval character­ istic of two-particles correlations .

A classical experiment, but not an easy one , is the study of the behaviour around 90° in c.m.s. of two-body reactions , especially elastic scattering . At PS energies the features are very different for the different channels and seem to reflect the constituent content of the interacting hadrons , Figs . 8 , 9 and 10. For different reactions various models reproduce qualitatively and sometimes even quantitively the angular distributions , the ratio of the cross­ n section and the energy dependence (Fig . 11) . The latter (do/dt s- f(B � ciJ where n lies between 6 and 11) slows down at higher energy possibly towards a limiting asymptotic distribution. For instance, the interchange constituents model of Blankenbecler, Brodsky and Gunion gives a very different energy 10 dependence for nucleon-nucleon scattering at 90° (s- ) and for meson-nucleon -8 scattering (s ) and also a large difference between pp and pp cross- sections . This difference is not reproduced by the models involving gluon exchanges or ·the hadronic bremsstrhlung .

experimental program along these lines is presented in the proposal

An

198 SPSC-P9 . 1he authors plan to use the apparatus shown in Fig. 12. 1he geomet­ rical acceptance varies roughly linearly from 0.37 at 90° in c.m.s. to 0.07 at 37 -38 20 °, between 20 and 60 GeV/c with a cross-section sensitivity of l0- - lo cm2/GeV2 •

At smaller angles 10° c.m.s., -t 1.4 GeV2) but away from the forward � peak, the ISR data had shown a considerable structure in p-p elastic scatter­ ing , Fig. 13. 1he aim of the proposal SPSC-P8 is to get some insight into the spin dependence of the proces(< s, by measuring with a polarized target, between SO and 150 GeV/c, the asymmetry of the pp elastic scattering (-0.3 t 3GeV2). � � Constraints for various models could be established since the polarization results from the interference of the single flip amplitude with a linear combin­ ation of the other four ; these together describe the pp scattering . Already at PS energies the polarization data show considerable structure: the shape is reproduced by implementing the Chou-Yang model , which gives the dip structure observed at the ISR, with - f Regge exchanges . With increasing energy the w polarization should develop a prominent change from negative to positive value , Fig . 14.

1he layout proposed (Fig. 15) is adequate for other polarization experi­ ments such as nucleon-isobar production, backward elastic and Kp) and + inelastic (rr±p + �± K ) scattering (SPSC-P8, Addendum) . 1he extension of this program in the North Hall is being considered in order to measure at large P T (3 - 4 GeV) inclusive reactions . Since there the inclusive(rrp reactions could correspond to a small number of channels one could hope to have a large polar­ ization (SPSC-M20) . A very similar program is proposed with a somewhat differ­ ent apparatus in SPSC-Pl2.

Already in the pp polarization experiment one looks at the interference of the mo st internal part of the nucleon with the external one . Two proposals are devoted to investigating the peripheral interactions .

1he authors of SPSC-P7 propose to study with a modified version of the CERN-Munich spectrometer (Fig. 16) the quasi-two-body hadron reactions :

+ - + - rr p (rr rr )n, (K K )n, ( p)n; + p - - + - K p + (K rr )n, (K�rr )p, over a wide kinematical range and at energies up to 80 GeV. 1he main aims of this investigation are : i) To learn about the production mechanism (energy and t-dependence)

199 ii) To study and Kn interactions through phase shift analysis to high masses . iii) To search for high-mass boson resonances . TITI up The apparatus will consist of a beam spectrometer ; a liquid-hydrogen target surrounded by a 4n solid angle anticoincidence counter arrangement; a forward spectrometer equipped with two magnets , wire spark chambers, Cerenkov hodoscopes and a trigger system.

At SPS energies and with the modified spectrometer, the acceptance for for­ ward going particle systems will be much higher than in the present set-up , in particular at high invariant masses and high t (Figs . 17 and 18) . The proposers

want to clarify the existence of p ' (1600) , to extend phase-shift analys is up to m = 3 GeV, to determine the TI and A - trajectories (the latter becoming TITI 2 important at large t) and the relative contribution of the two as the energy increases.

A further advantage of SPS energies will be the accessibility of very low t for the production of high mass boson states. At 3 GeV mass, t drops from min 0.07 GeV2 at 20 GeV to 0.0035 GeV2 at 80 GeV. Moreover , a cleaner determination of the spin-parity of boson resonances should be possible because the overlap * with low mass N 's in the Dalitz plot becomes less and less serious .

The authors of SPSC-Pll propose to measure with high statistics and mass resolution (� 20 MeV) , production and decay properties of (S 0 or 1) bosons and (S = 0) baryons in the reactions : *+ + + + + + *+ K+- p -p ,p-p N -p AK+ + K + K�n- ; + x-p + K�K-p; + + A - * ( K )= N 1/2) states) in the range (the latter being a clean way to select (I = 0.05 $t$ 0.6 GeV2 for beam- momenta between 20 and 100 GeV/c, and with masses TI P to 5 GeV at 100 GeV/c. The apparatus (Fig . 19) consists of a recoil proton detector , and a forward detector without magnet, covering a large solid angle. The aim of the experiment is to perform in each channel: up - a complete spherical harmonics moments analysis in the mass range from threshold up to 5 GeV, to investigate the spin components produced in the reaction, dcr - the measurement of the cross-sections p functions of s mm'dt as and t with small normalization errors , - the study of the same channels with particles and ant iparticles with minimum relative errors .

200 The s-dependence in baryonic exchanges ( and backward elastic scattering between 25 and 110 GeV/c) will be investigated with the apparatus shown in Fig. 22. The core is a large magnet (Goliath) filled with wire chambers and followed by a system to momentum select the recoil protons . The authors of this proposal SPSC-PS hope to see a break in the s-dependence of dcr/du, the break occurring when the dominant mechanism for the reaction changes . Regge-like exchange (Figs . 20 and 21) might be primarily responsible for the reactions at lower s 80 GeV2 ); parton-parton interactions which presumably fall more slowly with s, will then take over . This would most likely occur at large Jul 1 GeV2) where conventional baryon exchange amplitudes are low (the measurements will(� cover au-range up to 1.3 GeV2 •

7. CONCLU(�SIONS

The experimental program at the SPS for the first period of operation is taking shape . We ak interactions will be studied extensively with the neutrino and the hyperon facilities . The Qnega Spectrometer will be up-graded with new detectors and fed by special beams (either RF-separated hadrons or tagged photons) .

In addition to the beams for Clnega and BEBC , two beams will be available for hadronic experiments . The experimental set-ups proposed so far are very similar: they include a vertex detector around the target (an anticoincidence for neutrals or a slow particle spectrometer) and a forward spectrometer (to sweep out the beam, to trigger on high P ' and to measure effective masses) . The phys ics T is an extension of the PS program and a complement of the ISR investigations .

When comparing with the NAL program one is struck by the few proposals yet submitted (14 for the SPS as against 300 at NAL) . There will be no as experiment of the beam survey type and the search for quarks , monopoles, etc. , is left to the ISR. There will be no internal target and no single arm spectrometer . Only one group showed interest in observing and e-pairs pro­ µ- duced by dumping the primary beam.

However the SPS program looks very exciting and now there is certainly more optimism which the Rencontres de Moriond helped to stimulate .

201 REFERENCES

The above information was derived from the following docl.Dilents :

1. Reports of the 300 GeV Working Groups , CERN/ECFA/72/4, Vo l. 1 - 3.

2. SPSC Minutes .

3. G. Petrucci, D. Plane , M. Reinharz; Proposed secondary beams for counter experiments in the SPS West Hall, SPSC-T 13 .

4. Letters of Intent for Omega :

4.1 British, French , German Collaboration: A program of photon and electron physics using the Omega facility, SPSC - I 73/8 (see also SPSC - P + 4.2 I.S. Hughes and R. Turnbull; Studies of n p processes at 35 and 65 GeV/ c us ing the Omega Spectrometer with the SPS, SPSC - I 73/37 . 4.3 Bari, Bonn, CERN , Daresbury , Glasgow, Liverpo9l, Milan Group ; Meson10) . physics with the Omega in an R.F. separated beam in the West Area at the SPS , SPSC - I 73/38. 4,4 W. Beusch et al . (CERN - ETH Collaboration) ; A study of Reggeon­ nucleon scattering , SPSC - I 73/54. 4.5 Pavia and Torino University Group ; Study of hadron fragmentation in the momentlDil region (30 - 70 GeV/c) where correlations are nearly absent, SPSC - I 73/55. 5. Proposals submitted up to April, 1974: SPSC-Pl: Proposal to study high-energy neutrino _ interactions at the SPS by M. Holder, J. Steinberger, H. Wah l, E.G.H. Williams, CERN ; C. Geweniger, K. Kleinknecht, Dortmund; F. Eisele, V. Hepp , E. Klunge, K. Tittel, Heidelberg ; M. Banner , R. Turlay, Saclay. SPSC-P2: Proposal to out experiments with high-energy charged hyperons at the SPS by R. Baldi , P. Extermann, Nef, Universite de Geneve ; J. Heintze , G. Heinzelmann, H. Rieseberg , H. Stelzer, A. Wagner , A. Walenta, Heidelberg ; P. Rosselet, R. Weill, Lausane ; J.C. Chollet, J.-M. Gaillard, B. Merkel, J.-P. Repellin,carry G. Sauvage , Orsay ; R.M. Brown, E.S. Groves, B.D. Jones , R.J. Ott, J.J. Thresher, RHEL;c. J.J. Blaising , Y. Chatelus , M. Croissiaux, R. �brand, A. Navarro-Savoy , G. Schultz , Strasbourg- SPSC-P3: Proposal to study inelastic neutrino interactions at the SPS using a counter set-up by G. Alexander , W. Schmidt-Parzefall, K. Winter , CERN ; F. Blisser, G. F1Ugge , F. Niebergall, P.E. Schl.Dilacher, Hamburg; W.D. Apel , J. Ausltlnder, J. Engler , D.E.C. Fries , F. M'inning , H. Mliller , H. Schneider , K.H. Schmidt , D. Wegener , Karlsruhe ; J. Lloyd , G. Myatt, D.H. Perkins , A.M. Segar, Oxford; I. Corbett, N.H. Lipman, R.S. Orr, T. Sanford, H.P. Sharp , W.T. Toner , T.G. Walker , RHEL; E.H. Belamy, P.V. March , J. Strong , D. Thomas , London .

202 SPSC P4: Proposal for a detailed study of high-P events at the SPS by - t P. Baillon, G. Bizard, C. Brianan, Y. Declais , R. Donald, J. Duchon, D. Edwards , M. Ferro-Luzzi, B. French, B, Ghidini, W. Kienzle , F. Lefevres, P. Litchfield, L, Mandelli, F. M.lller , J.-M. Perreau, V, Picciarelli, J.P. Patry, J. Seguinot, L. Tallone , T, Ypsilantis, Bari, Caen, CERN , Liverpool, Milan. SPSC-PS: Measurement of backward 2-body and quasi-2-body reactions induced on unpolarized and polarized protons by rr± , K± , p ranging from 25 to 120 GeV/ c by R. Barate , P. Bareyre , P. Bonamy, P. Borgeaud , J,C, Brisson, M. David, J. Ernwein, J. Feltesse, G. Laurens , P. Le Du, Y. Lemoigne , H. Roussarie , A. Roussarie, G. Villet, Saclay; B. Brabson, M. Corcoran, R. Crittenden, R. Heinz , H. Neal , D. Rus t, Indiana. SPSC-P6: Proposal for the comparative study of hadron fragmentation with the SPS by A. Baroncelli, C. Bosio, G. Matthiae , ISS; G. Bologna , B. D'Ettore Piazzoli , F.L. Fabbri, G. Matone , P. Picchi , A. Reale , L. Satta, M. Severi, P. Spillantini , R. Visentin, Frascati; G, Bellini, A. Cantore , R. Car , M. di Corato , P.L. Frabetti, P.F. Manfredi, F. Palombo, P.G. Rancoita, S. Sala, G. Vegni , Milan; S.R. Amendolia, E. Bertolucci, C. Bradaschia, A. DelGuer ra, L. Foa, A. Giazotto , M, Giorgi, A. Menzione , F. Orsitto, G. Pierazzini , P. Rehak, L. Ristori, A. Scribano , A. Stefanini, L. Vincelli, Pisa; SPSC-P7: Proposal to study some exclusive reactions in and Kp inter­ actions in the energy range to 80 GeV by C. Daum, L. Hertzberger , Hoogland, Amsterdam; B. C. Jones , K. Rybicki , P. Weilhannner, CERN ; H. Becker , H. Dietl, G. Grayer , E. Lorenz , W. Mlinner , U. Stierlin, Munich-MPI; R. Cashmore , Oxford ; C. Damerell, B. Ratcliffeirp , RHEL . SPSC-PS: Proposal to measureup polariza tion in pp and elastic scattering atW. large momentum transfer Hyamsby W. , Bartl , R. Birsa, F. Bradamante , H. Dibon, G. Fidecaro , M. Fidecaro , M. Giorgi, Ch. Gottfried, W. Kittenberger , G. Leder , Kaj erotto , G. Neuhofer , A. Penzo, M. Pernicka , L. Piemontese, L. Pregernig , P. Schiavon, M. Steuer, A. Vascotto , A.rrp Villa ri, CERN , Trieste, Vienna . SPSC-P9 : Proposal to study exclusive hadronic processes at large P by T T. Buran, A.W. Buzzo, A. Eide , S. Ferroni , V. Gracco , J. Haidorsen, T. Jacobsen, K.E. Johansson, A. Lundby, M. Macri, L. Rossi, A. Santroni , S.O. S¢rensen, CERN , Genova , Oslo Collaboration. SPSC-PlO: Proposal for a progrannne of photon and electron physics us ing the Omega Spectrometer and the SPS by T. Armstrong , P. Bussey, J. Rutherglen, I. Skillicorn, K. Smith , Glasgow University; J.K. Bienlein, DESY ; B. Bouquet, B. D'Almagne , A. Ferrer, P. Petrov , F. Richard , Orsay; G. Brookes, W. Galbraith, Sheffield; A.B. Clegg , Newton , Lancaster; I.P. Duerdoth, R.J. Ellison, M. Ibbotson, Manchester ; P.J. Duke , M.A.R. Kemp , J. Litt, R. Marshall, Daresbury ; P. Fleury, G. de Rosny, A. Rouge, H. Videau , I. Videau, Ecole Polytechnique ; K. Heinloth, K. Milller, E. Paul , B�:mn; D. Tr'eille, CERN . D. SPSC-Pll: Proposal to study energy dependence of the quasi two-body reactions ± ± ± ± ± K:!=p K* p + rr , rr p X p + K K± and p N* p +( :_)by R. Baldi , T. B6hringer�, P. Extermann, M.N�. Focacci-Kie� nzle, O. Gu�isan, V. Hungerbiihler , M. Martin, A. Mennoud, C. Nef, P. Siegrist, Geneva .

203 SPSC-Pl2: Proposal to investigate spin-dependent effects in high-energy hadron-proton interactions at SPS energies by J. Antilles, L. Dick, A. Gsponer , A. Gonidec, M. Werlen, D. Perret-Gallix, CERN ; A. �lichalowicz , Orsay; D. Aschman, D. Crabb , K. Green, C. Macdowell, G.L. Salmon, Oxford . SPSC-Pl3: Proposal to study pp reactions in BEBC at 25,50 and 100 (?) GeV/c by A. Apostolakis, A. Angelopoulos , A. Stergiou, Athens ; A. Filippas , G. Grammatikakis , E. Simopoulou, Democritus ; J.R. Fry, P. Mason, H. Muirhead, Liverpool; M. Markytan, H. Lambacber, P. Porth, Vienna . + SPSC-Pl4: Proposal for a SOOK pictures exposure of BEBC in a 70 GeV K separated beam by D.C. Colley, G. Cox, J. Kinson, M. Votruba, P. Watkins , Binningham ; N. Carney , M. Drevennann, Y. Goldschmidt-Clennont , E. Pagiola, E. Quereigh, J. Schotanus , B. Tallini , CERN; C. Caso, F. Conte , R. Contri, M. Dameri, D. Teodoro , G. Tomasini , V. Trevisan, Genova; R. Windmolders, V.P. Henri, Grard, P. Herquet, Mons.; J.J. Dumont , J. Lemonne, P. Peeters , Brussels .

F.

204 APPENDIX Proposed secondary beruns for counter experiments in the SPS West Hall

Flux at Detector* Beam Description Momentum (for 101 2 interacting protons) Code (GeV/c) Particle At Momentum Max.

Max. O' Sl RF separated 40 J K;r++ .107 beam to 7 p 108 Qnega ; uns eparated 1 11- 64.107 pI\ 2.107}

El/Hl Electron/ 80 (Onega e ' 10' hadron beam branch) 11+ 5.10' 100 (to area K+ 3.107 north of p 8.108 at 80 GeV Omega) 2.108 11- 4.106 I\ 10' }

H3 High-energy 150 4.107 + high-reso- j'i11 8.106 lution beam p 3.109 107 11- 4.104 K- iir 4.103

Pl Attenuated 200 p 108 - 1011 proton beam

N3 Neutral - n �1 .8 107 ; for 10 -a beam str 120 ::; p ::; 150 GeV/c** (long lived) K' �105 90 110 GeV/c*** ::;

p $

205 =

SPS WEST EXPERIMENTAL AREA Fig. 1 GENERAL LAYOUT

35 -40 m

6 6

rragiet ,;., units units "" 6 units iron iron iron core G .:..

Fig. 2 �--tJ�- ---� Hadron shower detectors

206 RADIATOR BEAM E .M. PAIR PHOTON DUMP DETECTOR DETECTOR

e- fWT� 1 e- I w, w,

MOMENTUM1�1 TA GGING SYSTEM OMEGA FA CILITY A�IALYSIS

w, w, W3

T

Fig. 3

5

Interaction Trigger Beam veto Electron veto Fig.

4

207 BEAM GAM'M GAMMAELECTRONS DETECTOR CONVERTERS PROTCNS \

IE:JI "--..BEAM / CHAMBERS DC 1,2 f-z E 2L SCALEIm

5

Fig.

I 30° ______90°

I I

I j7T0fI uture det8cto

S M M C TRIGGER • 2 C1 � 1 2 i ,,. s1 HIGH -PT _2£'ECTROMETER

SCALE 1- Im._, ( , K, P)

Fig. (plan view )

208 a. a. 1 a. a.

• '" '"

.".L•

209 CJ> E 0 .0 0 'b 0 0 O"> lt'l

-a!'

,.,; i;::

'?'o___ o •

{:>/11a�)/qw IP/DP Z ,.,,..J.'° _ I

•

�

't:: � ( J "

• /+-- ,,

L I _.___ ..

210 GeV/c A GeV/c

TT+ 10 =-= Parton model 0 K+ 10 0 K + 5GeV

-1 cos0 c.m. 0

Fig. 11

AEG Magnet

Fig. 12

211 piblished be p PP-PP

Majerolto to

\ 0.2 ...... - - · ' · · ·-· :::;.·:;:...<.":'" =:: I : ' · - - - ...,.,. .. :::.:.:·.:::: ·· :;:··················· ···� ...,, ,..,,,.:,,.,.,.,,....,,.....""_· -- �---- ::; · ···· · \300 _1 -----�-·-·- 0.1 I 17. 5 100 -..., I "\I_, �V�

0.2 o.4 o.6 o.r·-·-·----·-t· 1.4 1.6 1.8 2.0 2.2 2.4 2.6 I -I -0.1

-0.2 14

212 Fig. Hodoscope m4 BH+BV at 50,100 ,150 pp - pp GeV/c 3

MWPCBB

87 86 85 MWPC F1 F2 F3 F4 ,F5 F6 FH+FV 84 83 Beam 81+ 2 t:-0.3 : ------_ �------Hodoscopet:-3.0 polarized target Gt!Vk analyzing magnet �'.""'

'-----

0 10 20 30 40 50 m

Fig. 15

w w 5 Ill Ille b A c,

I

A 0 25m

Fig. 16

213 �c urve:: k·R+ 1 leading trajectory Jma x=

6

5 p (2290) � c g � (PARTICLE DATA 4 • GROUP) f,A2 f' Lo. (pp • (pp 3 v (7) This experrment p, w • • n-p -n-ppn•1c) 2 0 -n•n-) '!J E ¢ P' 0 0 Mass squ ared

s•

2 3 4 5Fig. 176 7 8 9 10

100

- � 80

60 Pt ab LLJ 60 GeV u z 40

p Fig. mnn

18 214 Lead scintillator Lead sandwich

6 �----;--MWPC �

I. v �Ill c MW�/ , 1 m RANGE__.�

, l .- m 20 10 ev 6 Scale for P 100 G inc Ge /c = 50 I o/ • m b � ,% V:Proportional scintillation counter

MWPC: Multi wire proportional chambers

N VI .... Fig. 19 ,,.+ p

50 Ge V/c

-- GORE " --- WIZKIO ... S AM -·-·- ... FULLCR ··------HIPPIE

I> 1cf"

- . 0.2 -0.1 0 4 -0.7 -1.0 -1.3

2 u(GeV/,i:l

�-··· ..� ..,� ""\ �" ··· �·· ···· ······· iO ''- '······· '"':----- ········· ....- " ------:::::::-. "U '..., ..

1 10- --- GORE ----- WIZKIO ; . - - - - 1." • • SCRAM ,,. -a:;. ••••-••• FULL HIPPIE Bt; -a ELASTIC

7rp BACKWARD 50(GtV/c)

02 --0.l -0.4 -1.0 -1.3

u

-0.7 (GIN/c}20 2

Fi g. 216 t.0 ---�--,�-�----.,..----,.---..., . GeV/c ! \ 50.0 .8 ! \ GORE ---WIZKID .6 'I\(' \\ -·-- SCRAM '. \ • • • ····FULL HIPPIE .4 :.i l!i'. \ \ 1. .. \ .2 I:! ; \ \ �.;:: a I \ IIi \ \ li , 2 -. , 2 I ' �-- ii -.4 "' ', \ \ I '. \ I -G •I \ \ \ 'I \ -.e I ' , I .· ,' - . __ I ___• t L._ ' .l.o.:.----'L-----1.-·_-....._·...;:-:::_-1 ;1 2 o.i -0.t -0.4u(GtV /c l-0.7 . ' O ..Jll ...: -t.O -1.3

1.0 .------.----.---,.....--.----r----...,

.8 . \ I\ \ .6 \ \ °¥ .... \ ...... ;...... ,. \\ .. · . , /. .. "- \ � I I \ .2 _....II / I ...... ti . ....-,". . .4 :�-;:;-·-- .. . _ Ii! ...... ex . . / � -.2 .D I----'-""'------�---- WIZKIO ...:...... ,.. __;::� ...... FULL HIPPIE ••• •• •

-.6 --GORE -.4 BACKWARD ELASTIC -.8 -•-•� SCRAM ... -

-1.0 '-----'L-----1.----'-----'-----'7rp 50lGeV/c) 0.2 -0.I -0.4 -0.7 -1.0 -L3 u

(Gell21/c) •

Fig. 217 I I I I I

I

N E N !O �(/) 0

,_ ,_

u u

�r

218