Some Remarks Concerning the Strong Interaction

1
Some Remarks Concerning the Strong Interaction

• Hans Gerhard Fischer
• CERN

2
Layout of talk

• 1. Introduction
• 2. Thirty-five years of collaboration with
• the Soltan Institute The ISR period
• - conclusions in the mid-1980s
• 3. Thirty-five years of collaboration with
• the Soltan Institute NA49 times
• - conclusions in the mid-2000s
• 4. Some concluding remarks

3
MOTTO 1

• It is a capital mistake to theorize
• before one has data

4
MOTTO 1

• It is a capital mistake to theorize
• before one has data
• Sherlock Holmes in
• A scandal in Bohemia
• Sir Arthur Conan Doyle, 1892

5
Find title  search  12000 entries since 1970
6
Strong coupling constant as a function of
momentum transfer
as
Momentum transfer
7
Pentaquark rush number of papers per year

8
THoofts String Configurations
Wilczek Diquark 0.1fm
Stable configuration
9
A Diquark Scattering Model for High pT Proton
Production in pp Collisions at the ISR

• Z.Phys. C28(1985)335
• A.Breakstone, H.B.Crawley, G.M.Dallavalle,
  K.Doroba,
• D.Drijard, F.Fabbri, A.Firestone, H.G.Fischer,
  H.Frehse,
• W.Geist, G.Giacomelli, R.Gokieli, M.Gorbics,
  P.Hanke,
• M.Heiden, W.Herr, E.E.Kluge, J.W.Lamsa, T.Lohse,
• R.Mankel, W.T.Meyer, T.Nakada, M.Panter,
  A.Putzer,
• K.Rauschnabel, B.Rensch, F.Rimondi, M.Schmelling,
• G.Siroli, R.Sosnowski, M.Szczekowski, G.Ullaland,
• D.Wegener
• ABCDHW Collaboration

10
Pentaquark rush number of papers per year

11
Observation of Charmed D Meson Production in pp
Collisions

• Phys.Lett. B81(1979)250
• D.Drijard, H.G.Fischer, W.Geist, R.Gokieli,
  P.G.Innocenti,
• V.Korbel, A.Minten, A.Norton, R.Sosnowski,
  S.Stein,
• O.Ullaland, H.D.Wahl (CERN)
• P.Bourtaud, M.DellaNegra, G.Fontaine, P.Frenkiel,
• C.Ghesqiere, D.Linglin, G.Sajot (College de
  France)
• H.Frehse, E.E.Kluge, M.Heiden, A.Putzer, J.Stiewe
• (Heidelberg)
• P.Hanke, W.Hofmann, M.Panter, K.Rauschnabel,
• J.Spengler, D.Wegener (Karlsruhe)

12
(No Transcript)
13
Further Investigation of Beauty Baryon Production
at the ISR

• Phys.Lett. B108(1982)361
• D.Drijard, H.G.Fischer, H.Frehse, W.Geist,
  P.G.Innocenti,
• J.W.Lamsa, W.T.Meyer, A.Norton, O.Ullaland,
  H.D.Wahl
• (CERN)
• G.Fontaine, C.Ghesquiere, G.Sajot (College de
  France)
• W.Hofmann, M.Panter, K.Rauschnabel, J.Spengler,
• D.Wegener (Dortmund)
• P.Hanke, M.Heiden, E.E.Kluge, T.Nakada, A.Putzer
• (Heidelberg)
• M.DellaNegra, D.Linglin (LAPP Annecy)
• R.Gokieli, R.Sosnowski (Warsaw)

14
Angular Distributions of Charged Particles
between 30 and 90 Degrees at ISR Energies

• Phys.Lett. B39(1972)654
• M.Breidenbach, G.Charpak, G.Coignet,
  D.Drijard,
• H.G.Fischer, G.Fuegge, Ch.Gottfried, H.Grote,
• A.Minten, F.Sauli, M.Szeptycka, E.G.H.Williams

15
Angular distribution of charged particles
(pseudorapidity)

16
Pseudorapidity distributions at different energies
17
The rising rapidity plateau
18
Split Field Magnet Spectrometer
19
Acceptance coverage of experiments in xF and pT
SPS
ISR
RHIC
LHC
20
Inclusive Charged Particle Cross Sections from
ppInteractions at ISR Energies

• Z.Phys. C69(1995)55
• A.Breakstone, H.B.Crawley, A.Firestone,
  M.Gorbics,
• L.D.Isenhower, J.W.Lamsa, W.T.Meyer (Ames)
• R.Campanini, M.Cuffiani, G.M.Dallavalle,
  M.Deninno,
• F.Fabbri, G.Giacomelli,F.Rimondi, G.Siroli
  (Bologna)
• D.Drijard, H.G.Fischer, W.Geist, G.Mornacchi,
  M.Panter,
• O.Ullaland, R.Yeung (CERN)
• T.Lohse, R.Mankel, K.Rauschnabel, M.Schmelling,
• D.Wegener (Dortmund)
• H. Floege, H.Frehse, L.Gesswein, P.Hanke,
  M.Heiden,
• W.Herr, E.E.Kluge, T.Nakada, A.Putzer, B.Rensch
• (Heidelberg)
• K.Doroba,R.Gokieli, R.Sosnowski, M.Szczekowski
• (Warsaw)
• ABCDHW Collaboration

21
Piminus xF Distributions from ISR

22
Feynman x distributions of positive pions from
ISR (CHLM Collaboration)
23
Hard Parton Scattering

• f(pT) pT- 4 f(xT)
• xT 2pT / vs
• Experimentally found at ISR
• For pions f(pT) pT - 8 f(xT)
• For protons f(pT) pT - 12 f(xT)

24
Observation of Jet Structure in High p(T) Events
at the ISRand the Importance of Parton
Transverse Momentum

• Nucl.Phys. B127(1977)1
• M.DellaNegra, D.Drijard, H.G.Fischer, G.Fontaine,
• H.Frehse, P.Frenkiel, C.Ghesquiere, R.Gokieli,
  P.Hanke,
• W.Hofmann, P.G.Innocenti, W.Isenbeck, E.E.Kluge,
• V.Korbel, D.Linglin, A.Minten, A.Norton,
  A.Putzer, G.Sajot,
• R.Sosnowski, S.Stein, J.Stiewe, H.D.Wahl,
  D.Wegener
• CCHK COLLABORATION

25
Steepen up predicted pT distribution by
introducing parton transverse momentum
26
First order QCD with parton intrinsic transverse
momentum
27
One of the first complete  models of event
structure with hard parton scattering
28
Push limit of pT up to 12 GeV/c
29
Add initial and final state gluon radiation
30
Flavour Tagging of Parton Jets and Separationof
Parton Subprocesses in Hard pp Collisions at the
ISR

• 
  Z.Phys.C25(1984)21
• A.Breakstone, C.D.Buchanan, R.Campanini,
  H.B.Crawley, M.Dallavalle,
• K.Doroba, D.Drijard, F.Fabbri, A.Firestone,
  H.G.Fischer, H.Frehse, W.Geist,
• G.Giacomelli, R.Gokieli, M.Gorbics, P.Hanke,
  M.Heiden, W.Herr, E.E.Kluge,
• J.W.Lamsa, T.Lohse, W.T.Meyer, G.Mornacchi,
  T.Nakada, M.Panter, A.Putzer,
• K.Rauschnabel, F.Rimondi, R.Sosnowski,
  M.Szczekowski, O.Ullaland,
• D.Wegener
• ABCDHW Collaboration

31
A Diquark Scattering Model for High pT Proton
Production in pp Collisions at the ISR

• Z.Phys. C28(1985)335
• A.Breakstone, H.B.Crawley, G.M.Dallavalle,
  K.Doroba,
• D.Drijard, F.Fabbri, A.Firestone, H.G.Fischer,
  H.Frehse,
• W.Geist, G.Giacomelli, R.Gokieli, M.Gorbics,
  P.Hanke,
• M.Heiden, W.Herr, E.E.Kluge, J.W.Lamsa, T.Lohse,
• R.Mankel, W.T.Meyer, T.Nakada, M.Panter,
  A.Putzer,
• K.Rauschnabel, B.Rensch, F.Rimondi, M.Schmelling,
• G.Siroli, R.Sosnowski, M.Szczekowski, G.Ullaland,
• D.Wegener
• ABCDHW Collaboration

32
Introduce Hard Diquark Scattering and Form Factor

• f(pT) pT- 4 (1Q2/M2) 1 f(xT)
• diquark structure function
• diquark fragmentation function
• fit M2 ? M2 10 20 GeV2

33
Fits to the observed p/pion ratio as a function
of transverse momentum
p/pi ratio
pT
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Conclusions from ISR 1970-1990

• Parton dynamics manifest in all areas of hadronic
• interactions
• - rising central rapidity plateau (gluons,
  sea quarks)
• - forward particle production pictures
  valence partons
• (counting rules)
• - hard parton scattering leads to high pT
  production
• (perturbative QCD already applicable in
  the few
• GeV/c region)
• Underlying mechanism Intermediate partonic
  state
• present in all hadronic interactions,
  initiated by gluon
• exchange colour exchange ? strings
  

35
MOTTO 2

• It is the nature of an hypothesis, when once a
• man has conceived it, that it assimilates
  everything to itself as proper nourishment,
• and, from the first moment of your begetting
  it,
• it generally grows the stronger by everything
• you see, hear, read or understand.
• Tristram Shandy
• Laurence Sterne, 1750

36
On the Hadronic Production of Lepton Pairs from
Heavy Flavour Decay

• Z.Phys. C19(1983)159
• H.G.Fischer and W.M.Geist (CERN)

37
Lepton pair mass spectra fitted with combination
of DDbar and BBar semileptonic decays
Watch upper limits Of cross sections DDbar
6 microbarn at SPS 25 microbarn at ISR BBbar
50 nbarn at sqrt(s)27 GeV
38
Layout of NA49 experiment
Zestaw duzych Komór Projekcji Czasowej (TPC)
detektory sladowe polaczonez identyfikacja
czastek przezpomiar
39
Inclusive production of charged pions in pp
collisions at 158 GeV/c beam momentum

• Eur.Phys.J. C45 (2006) 343
• C.Alt, T.Anticic, B.Baatar, D.Barna, J.Bartke,
  L.Betev, H.Bialkowska, C.Blume,
• B.Boimska, M.Botje, J.Bracinik, P.Buncic,
  V.Cerny, P.Christakoglou, O.Chvala,
• P.Dinkelaker, J.Dolejsi, V.Eckardt, H.G.Fischer,
  D.Flierl,Z.Fodor, P.Foka, V.Friese,
• M.Gazdzicki, K.Grebieszkov, C.Hoehne, K.Kadija,
  A.Karev, M.Kliemant, S.Kniege,
• V.I.Kolesnikov, E.Kornas, R.Korus, M.Kowalski,
  I.Kraus, M.Kreps, M.vanLeeuwen,
• B.Lungwitz, M.Makariev, A.I.Malakhov, M.Mateev,
  G.L.Melkumov, M.Mitrovski,
• S.Mrowczynski, G.Palla, D.Panayotov, A.Petridis,
  R.Renfordt, M.Rybczinsky,
• A.Rybicki, A.Sandoval, N.Schmitz, T.Schuster,
  P.Seyboth, F.Sikler, E.Skrzypczak,
• G.Stefanek, R.Stock, H.Stroebele, T.Susa,
  J.Sziklai, P.Szymanski, V.Trubnikov,
• D.Varga, M.Vassiliou, G.I.Veres, G.Vesztergombi,
  D.Vranik, S.Wenig,, A.Wetzler,
• Z.Wlodarczyk, I.K.Yoo

40
Inclusive pion cross sections as a function of pT
for different xF
41
Inclusive pion cross sections as a function of xF
for different pT
42
Inclusive pion cross sections for pCarbon
minimum bias collisions
43
Status of final data analysis


44
Pions in pPb (1)
n 4.2

45
Pions in pPb (2)
n 5.2

46
Pions in PbPb
150ltnchlt300

47
Pions in PbPb

48
Linear plot of pion cross section in pp
interactions
49
Contribution from known Delta and Delta cross
section
50
3 dimensional plot of pi cross section
Data
M1.232 GeV no Breit-Wigner
Relativistic Breit-Wigner
51
Projection of 3 dimensional plot on xF and pT
52
Resonance treatment in  microscopic  models

53

54
Feynman x distribution of pion density dN/dx
55
pT distributions at different xF compared
toresonance decay
56
Prediction from resonance decay up to pT3
GeV/ccompared to existing measurements as a
function of vs

57
Back to central rapidity plateaupT dependence
at different s

xF 0
R ratio to NA49
58
Back to central rapidity plateaupT dependence
at different s
59
Back to central rapidity plateaupT dependence
at different s
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s dependence of pion production at fixed pT

61
Conclusions from NA49 2008

• What about the intermediate partonic phase?
• What about the partonic central production
• mechanism?
• What about the trace of valence partons in
  forward
• production?
• What about the Drell-Yan mechanism?
• What about partonic hard scattering?
• Where is the shadow line between perturbative
• and non-perturbative QCD?

62
Could it be that

• - there is no intermediate partonic phase
• - there is no direct manifestation of partonic
  structure
• and dynamics, examples
• - absence of tightly bound diquarks,
  pentaquarks
• (exotics in general?)
• - alternative explanation for  rising
  rapidity plateau  and
• forward hadron production
• - the  shadow line  between soft and hard
  processes
• is much higher in momentum transfer than
  generally
• assumed

63
Could it finally be that

• soft hadronic production is governed by high
• mass resonance excitation and cascading
• decay,
• - not as assumed by thermodynamics
• - not as used in  microscopic  models
• - not as precribed by string fragmentation
• experimentation should play a new role in a
• situation where theory evidently breaks
• down the tools for this are available!

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Motto1 completed

• It is a capital mistake to theorize
• before one has data.
• Insensibly one begins to twist facts
• to suit theories
• instead of theories
• to suit facts
• Sherlock Holmes