Ferrara @ Fermilab · tional to the product of branching ratios: BR(~p -+ Ec) X BR(Ec final state)....

October82018 GiannieDalpiaz^2Fest- Ferrara 1

Ferrara Fermilab@


Where,Ibelieve,itstarted

Nel 1979 ha proposto lo studio della spettroscopia del Charmonio, utilizzando un getto di Idrogeno gassoso e gli antiprotoni raffreddati della sorgente del CERN accumulati nel ISR del CERN, in tale modo si sfruttavala grande risoluzion e energetica dei fasci raffreddatied il fatto che nell'annichilazione antiprotone protonesi ha accesso in formazione a tutti gli stati di spin e parità, mentre nell'annichilazione e+e- si ha accesso solo agli stati vettoriali.Il peggiore rapporto segnale-rumore è stato superatocon uno spettrometro semplice che guardava idecadimenti elettromagneti degli stati di charmonio.


P.Dalpiaz,ProceedingsofthefirstLEARworkshop,Karlsruhe,Germany,editedbyH.Poth,1979

areallyneatideaandtheplayingfieldtowhichitappliedfullofrichesforthetaking.


asof1999

AfullQCDspectrumtoinvestigateandstudy


Unconventional indeed...Preciousantiprotons,&runningamachineafactor10belowitstypicalenergy..

Volume 171, number 1 PHYSICS LETTERS B 17 April 1986

S E A R C H F O R T H E t Pt C H A R M O N I U M S T A T E IN ~p A N N I H I L A T I O N S AT T H E C E R N I N T E R S E C T I N G S T O R A G E R I N G S

R704 Collaborat ion

Annecy ( L A P P ) - C E R N - G e n o a - L y o n ( I P N ) - O s l o - R o m e - S t r a s b o u r g - T u r i n

C. B A G L I N a, S. B A I R D b, G. B A S S O M P I E R R E a, G. B O R R E A N I c, J.-C. B R I E N T a C. B R O L L a.1, J.-M. B R O M d, L. B U G G E e, T. BUR, AN e, J.-P. B U R Q f, A. BUSSII~RE a, A. B U Z Z O g, R. C E S T E R c M. C H E M A R I N f, M. C H E V A L L I E R f, B. E S C O U B E S d, j. F A Y f, S. F E R R O N I g, V. G R A C C O g, J.-P. G U I L L A U D ~, E. K H A N - A R O N S E N b, K. K I R S E B O M e, A. K Y L L I N G e, B. I L L E f, M. L A M B E R T f, L. L E I S T A M b A. L U N D B Y b, M. M A C R I s, F. M A R C H E T T O c, E. M E N I C H E T T I c, Ch. M ( ) R C H ~, B. M O U E L L I C b D. OLSEN e, N. P A S T R O N E c, L. P E T R I L L O h M.G. PIA g, J. P O O L E b M. P O U L E T ~, G. R I N A U D O ~, A. S A N T R O N I ~, M. SEVERI h, G. S K J E V L I N G ~, S. S T A P N E S ~ and B. S T U G U * a LAPP, F-74019 Annecy-le-Vieux Cedex, France b CERN, CH-1211 Geneva 23, Switzerland ¢ University of Turin, 1-10124 Turin, Italy a CRN, F-67037 Strasbourg Cedex, France e University of Oslo, N-IO00 Oslo 3, Norway f 1PN Lyon, F-69622 Villeurbanne, France g University and INFN, 1-16126 Genoa, Italy h University of Rome, 1-00100 Rome, Italy

Received 7 February 1986

This experiment has been performed at the CERN Intersecting Storage Rings to study the direct formation of charmonium states in antiproton-proton annihilations. The experimental program has partly been devoted to an inclusive scan for ~p ~ JA/, + X in the range 3520-3530 MeV/c 2. A cluster of five events has been observed in a narrow energy band, centred on the centre of gravity of the 3P s states where the 1 P1 is expected to be. When interpreted as a new resonance, these data yield a mass m = 3525.4+0.8 MeV/c 2.

1. I n t r o d u c t i o n . The study of charmonium (Ec) is considered as a powerful tool for understanding the forces between quarks. The knowledge of the mass shift of the 1P 1 state relative to the centre of gravity (COG) of the spin-averaged 3pj states is very impor- tant for establishing the nature of the spin-dependent forces in quantum chromodynamics (QCD). Recent theoretical work based on the short-range hypothesis for spin-spin and tensor forces predicts this mass shift to be very small * 1 i Deceased, 21 July 1984.

, t For recent discussions, see ref. [ 1 ] and references therein.

0370-2693/86/$ 03.50 © Elsevier Science Publishers B.V. (North-Holland Physics Pubhshing Division)

At e+e - storage rings, the (~c) states not carrying the quantum numbers of the photon can only be reached through decays from 1 - higher-mass states. In contrast, all the (-6c) states can be formed, through gluon exchange, directly from an ant iproton-proton initial state, the formation cross section being propor- tional to the product of the branching ratios: BR(~p -+ Ec) X BR(Ec -+ final state).

Charmonium formation in ~p annihilations has been studied by the R704 Collaboration at the CERN Intersecting Storage Rings (ISR). Because o f the expected high hadronic background, we chose to tag the

135

NoLogo


Withasmallamountofluminosity,demonstratedthefeasibilityandthepotentialofthetechnique,andachievedremarkablemeasurementsofmassesandwidthsofchistatesetc ..ThentheIntersectingStorageRingswereclosedandbecamejusttheLSR(LEPStorageRings)PlanswereafoottomovethistoFermilabwhereanantiprotonsourcewasbeingdevelopedfortheTevatron

8 x 103”/cmz/sec. The beam-lifetime with the gas-jet on is presently 40 hours and the experiment runs in a mode where antiprotons are accumulated for about 24 hours, the experiment takes data for 48 hours (accumulating some 400 to 600 inverse nanobarns) and the cycle is then repeated. The initial work of the experiment is to understand in detail the systematics of the detector (efficiencies, backgrounds ) and the beam (momentum spread, and energy calibration). Figure 4 shows the mass distribution of candidate J/zl, events as reconstructed in the central calorimeter using a preliminary set of calibration constants.The scanning capabilities of the antiproton source have been exercised by making measurements on the ~1 and x1 states. Figure 5 shows some initial scans of these states; these early data are impressively clean and suggest that this run should be quite rewarding. If time permits before the fall shutdown, the experiment will search for the *PI state. The program will then continue in the next part of the fixed target run scheduled to start in 1991,

References

,] Fermilab P-760: A Proposal to investigate the formation of Charmonium States using the PBAR Accumulator Ring: Spokesperson R. Cester Fermilab’, University of Ferrara’, University of Genovas, University of California at Irvine’, Northwestern Universitys, Pennsylvania State University’ and University of TorinoT. Armstrong, T.‘, Bettoni, D.‘, Bharadwaj, V.‘, Biino, C.7, Borreani, G.a, Broemmelsiek, D.4, Buzzo, A.3, Calabrese, R.s, Ceccucci, A.‘, Cester, R.‘, Church, M.l, Dalpiaz, P.2, Fast, J.‘, Ferretti-DaIpiaz, P.s, Ferroni, M.s, Ginsburg, C.M.s, Gollwitzer,K.‘, Hahn, A.l, Hasan, A.“, Hsueh, S.Y.‘, Lewis, R.” Luppi, E.z, Macri, M.3, Majewska, A.6, Mandelkern, M.‘, Marchetto, F.‘, Marinelli, M.s, Marques, J.‘, Marsh, W.‘, Martini, M.s, Masuzawa, M.s, Menichetti, E.7, Migliori, A.7, Mussa, R.7, Pales-

4

1986



anti-protondebuncherandaccumulatorrings

E760/E835

Home

PROPOSAL TO CONTINUE THE STUDY OF CHARMONIUM SPECTROSCOPY IN

PROTON-ANTIPROTON ANNIHILATIONS (Revised proposal P-835)

T.A.Armstrong6 , D. Bettonf', V. Bharadwajl, C. Biino1, G. Borreani1, D. Broemmelsiek ..··, A.

Buzzo3, R. Calabrese2 , A. Ceccucci1, R. Cester1, M. Church!, P. Dalpiaz2 , P.F. Dalpiaz2 , D.

Dimitroyannis li , M. Fabbri2, J. Fast...·, A. Gianoli2, C.M. Ginsburgli•• , K. Gollwitzer..··, A. Hahn!,

M. Hasan6, S. Hsueh1 , R. Lewis6, M. Lovetere3, E. Luppi2, M. Macrf3, A.M. Majewska6••, M.

Mandelkern4, F. Marchetto1, M. Marinelli3, J. Marques..··, W. Marsh1 , M. Martini2, M. Masuzawali,.,

E. Menichetti1, A. Migliori1, R. Mussa1, M. Pallavicini3, S. Palestini1, S. Passaggio3, N. Pastrone1,

C. Patrignani3, J. Peoples Jr.l, F. Petrucci:i, M.G. Pia3, S. Pordes!, P. Rapidis!, R. Rayl, J. Reid6•• ,

G. Rinaudo1, B. Roccuzzo1, J. Rosenli , A. Santroni3, M. Sarmientoli, M. Savrie'2, J. Schultz", K.K.

Sethli , A. Smith"'·, G.A. SmithS, M. Sozzi1, S. Trokenheimli,., S. Werkema1, Y. Zhang6 , J. Zhaoli,.,

G. Zioulas".

1 Fermi National Accelerator Laboratory, Batat1ia, Hlinois 60510, U.S.A.

2I.N.F.N. and Unit1er,ity of Ferrara, .14100 Ferrara, Italy

3I.N.F.N. and Unit1er,ity of Genoa, 161.16 Genoa, Italy

.. Unit1ersity of California at Irmne, California 92717, U.S.A.

Ii Northwe,tern Unit1er,ity, Et1anston, Rlinois 60208, U.S.A.

6 Pennsylt1ania State Unit1er,ity, Unit1er,ity Parle, Pennsylt1ania 16802, U.S.A.

1I.N.F.N. and Unit1er,ity of Turin, 10125 Turin, Italy.

• Student ezpected to graduate on current data.

The E760 Collaboration September 1 1992

FERMILAB-PROPOSAL-0835



Ferrarabuilttheinnertrackingchamber– aradialprojectionchambertomeasureq

E760ApparatusSchematic


FerrarabuiltadoublesetofScintillatingfibertrackers- tomeasureq

E835ApparatusSchematic

h_c->gg

MeV


c0

pb

Chi-1andChi-2Massmeasurements

c0Chi-0 Chi-1 Chi-2

Chi-0,1,and2widthandmassmeasurements

1986- 2005


Precisionmeasurementsoncharmonium states

Ø 25papersonphysicsresults

Ø 35Ph.D’s minted…

startingfromNel 1979 ha proposto..

1986- 2005


Nel 1979 ha proposto..

L’esperimento è stato realizzato prima all’ISR e completato con le collaborazioni E760 ed E835 all’Accumulatore di Antiprotoni del Fermi-Lab, ottenendo importanti risultati tra i qualirisaltano la misura diretta della larghezza deglistati χc dell’ ηc e la scoperta dello stato 1P1 del charmonio.

Bravo, bravo, bravo

Thecharmonium atFermilabstorystartsofficiallyin1986,Itwentonindataruns from1990to2001– andpaperscameouttillatleast2005toexploitfullythedataweaccumulated– anditcontinuestoliveinsomeveryhappymemories..


AletterfromJohnPeoplesabouttheoccasionhewasawardedthisdoctorate.


DearStephen,IknowthisislatebutthereisonereminiscenceofPiero thatIwanttosharebecausePiero organizedawonderfulandmeaningfulday.

ItwasthedayIreceivedanhonorarydoctoratefromtheUniversityofFerraraontheoccasionofthe650thanniversaryofthefoundingoftheUniversityofFerrara.Ibelieveitwasin1992or1993.InordertoqualifyforthishonorIwasastudentattheUniversityforadayandIwasexpectedtogiveashortspeechtothedignitariesofthetownwhoassembledfortheevent.Itinvolvedmanydignitariesfromthecityandfrom theUniversity;butnottoomany,justtherightnumbertomakeitwarm,personalandfestive.Eachpersonhadacolorfuluniform to representtheirstationinFerrara.Theyassembledforaparadetotheauditorium,Piero andIwerepartoftheparade,wemarchedintotheauditorium,therewereremarks,Igavemyshortspeechoninternationalcollaborationinscience;ofwhichtheCharmonium experimentwasafineexample,andthenIreceivedanhonorarydegreefromtheUniversity.ManyofourItaliancolleaguesfromE760were inattendanceandlaterthateveningweallwenttodinner.Itwasawonderfulday;infactthemostmemorabledayofmylife.Theparadeofthedignitariesisstillvividinmymind.The degreeparchmentwassobeautifulthatNancy,mywife,frameditinabeautifulornateframeafterIreturnedhome.IstillseeiteverydayinmystudyinthecontinuingcarecommunityinwhichIlive.Thethemeofmyspeechwasinternationalcollaborationinscienceanditisstillanobleandthoughtfulwayofworkingtogether.Ihopeitdoesnot disappearinthesedaysofTrumpandSalvini.Piero arrangedthewholedayandevening.WorkingonE760wassuchajoywhenIwasabletoworkonit.PleasethankPiero formydayashisstudentandhelpingtoguideE760.Therearepicturesoftheevent,butIcannotfindthem.ThemarchofthedignitarieswasonethatIparticularlycherish..IapologizethatIdelayedmyresponseforsolong.

BestRegards,John

LetterfromJohnPeoples,ex-directorFermilab..

Ferrara @ Fermilab · tional to the product of branching ratios: BR(~p -+ Ec) X BR(Ec final state)....

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