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UCLEAR PH?SIC: Nuclear F'hysics B (Proc. Suppl.) 25P+ (1992) 1 8 Nort i~- Hoiia~+d
PROCEEDINGS
) , J r l ~ l N 1 l ~ o , J t l . I . J ' J t J k ' ~ O ,.~'
O*t u l ~
INTERNATIONAL CONFERENCE ON ELASTIC AND DIFFRACTIVE SCATTERING
(4111 Blois Workshop) May 22-25, 1991, Isola d'EIba, Italy
Basarab NICOLESCU
Division de Physique Th(~.orique *, Institut de Physique Nucl~aire, 91406 Orsay Cedex and LPTPE, Universit(~ Pierre et Marie Curie, 4 Place Jassieu, 75252 Paris Cedex 0~, France
Ladies and gentlemen, colleagues and friends,
The local organizing committee of this Conference asked
us, Tran Thanh Van and myself, to give the opening
address. Unfortunately, Tran Thanh Van could not come to
this Conference, so I have to assume this difficult task.
Why do I say that this task is difficult? Well simply because
the organizers asked us to proviae not only a brief history
of the BIois Workshops but also a simple descri~ :,on, in a
non-specialized language, of the physics arguments
underlying these workshops. All the difficulty lies in these
two words: "simple description".
l,e~ me begin with the beginning.
1. BRIEF HISTORY OF THE BLOIS WORKSHOPS
Already in 1983-84, Tran Thanh Van and myself, we
began to discuss about organizing an international
workshop on "Elastic and Diffractive Scattering". Our main
motivation can be formulated in the form of an axiom:
"what is fundamental remains fundamental whatever
happens". I mean that our domain in question is a
fundamental domain of strong interactions. You can say
tha; the above axiom is so trivial and obvious, that one can
wonder why we spent almost two years discussing about
the opportunity to organize such a workshop. The
explanation is very simple: the quoted axiom is in fact
extremely obscure.
First of all, our modem times are characterized by the
well known fact that everything that was considered in the
past as fundamental is considered now as senseless or
accidental: God, truth, life, man, universe. That is the
reason why philosophers speak so much about death: death
of GOd, death of ideologies, end of history. To that,
physicists add the possible death of the universe (for
example, by the desintegration of the proton). In some
sense, our world appears as being a groundless world.
You can of course point out that we are doing physics
not philosophy and therefore one can forget about these too
general considerations which have nothing to do with our
field of interest. You are right, in a sense which has to be
made precise. After all we hnve in physics fundamental
laws and principles, fundamental building blocks of matter,
fundamental theories and fundamental experimental results.
However, in our days, something is considered as really
"fundamental" if it is connected to a fashionable, dynamical
theory. This is the link with the previous general
considerations, in the 1980's the relation between our field
and the universally recognized theory of strong interactions
- Quantum Chromodynamics (QCD) - was not at all clear,
for physical reasons I will u'y to explain latter.
So, in few words, before the 1st Blois Workshop ot, r
field of interest, considered by some of us as
"fundamental", was pon-fashionable. That was the reason
why our domain was in a sort of lethargy. Therefore we
had to confront two dangers. The first, a relatively minor
one, was to find sufficient money to organize the
workshop. The second, a major one, v¢as the possibility of
*Unit(~ de Recherche des Universit(5 Paris 11 et Paris 6, Associ~e au CNRS
2 B. Nicolescu / Opening address
~.n -no.,cc-~Sf-] Cr'-fere"ee ,-hiah co,=!ld n ' e n w l d e ~ ~trnnc,
al~U.rl;eli,~ i.~%'L w ,..u _=. ., _= _, ~, ,_u_,,_,_~ ~=, ,=~=,a =rlgiG O! g~oDg
~n[emc-ons. V--/e bad ~_u ~-_u~e a te~b~e re~p~n~biiity
However, Tran Tnanh Van and myscii, we kept being e n n f i t ~ e n t i n t h e i n t i h _ r . . . . . . . . ~ - - - t ~ , . . . . . . . . : . . . . . . , - : - - i l l | l i l t a l l l l l l l _ i Y l l l t - ~ 4 t l l l ~ l . I l l l ~ I I ~ X U I I R
experimental results were already obtained at the CERN
S~pS collider and we knew that exciting new experiments
were planned both at the CERN S~pS and at the Tcvatron
colliders. We bet on the future.
However, the most important fact was the moral help
we got from several physicists we contacted all over the
world. These physicists who provided us the courage of
organizing our meeting are now, most of them, in the
Permanent Committee of our Blois Workshops.
To our nice surprise several important French scientific
organisms gave us a decent sum of money to organize the
workshop. A very important condition of the success of the
meeting was, of course, the practical organization of the
workshop by Rencontres de Moriond, whose efficiency is
well known.
Our feelings after the organization of the 1st Biois
workshop arc perhaps best expressed in our foreword to
the Proceedings of the meeting: "Organizing in 1985 an
international workshop on elastic and diffractive scattering
was not an obvious idea. If this field is generally
recognized as being of fundamental importance for our
understanding of hadron interactions, it is only marginally
discussed in the major international conferences... We were
happy to see that the response of our community was
beyond our expectations, in fact, all individuals or groups
active in this field were present at our Blois mccting...The
future was much in prominence at the workshop,
stimulating a lot of excitement." We underlined here one
major condition of the success of our meeting: the response
of our community, which was beyond our expectations.
Last, but not the least, was the magical place of Chateau
de Blois.
We did not choose Blois in a random way. It was a
deliberate choice, based upon elaborate considerations.
First of all, we chose Chateau de Blois as a symbol of
the encounter between science an~ .:-,lture. C.P. Snow
introduced the famou~ expression "two cultures" of our
modern times: the humanistic culture and the scientific
culture~ which never communicate between them_ A t. our
modeat aca!e, we wanted to show that this separation is
At a pctiiaps mote subconscious level, the Chateau de . . . . . . . . . e~ '_ l J . . . . . . . .- *t'~_ . . . .
D lU!~nl - : . . . . . . . . . . . . . w ~ b ~ t ) ! = ! ~ w _ l ! ~ l L ' - " !!~gl:l-- L~I--I! L I W I I ! ! ~ ! 1 1 1 ; z l ! l I i 4 _ g ! l l l ! l : ~ l ] l
testimony of the past but empty, without life, good just for
guided tours. We made it full of life, having our sessions
inside the castle. A symbol of the life we expected in future
for our own field.
As you know very well, CMteau de Blois is a high
place not only of culture but also of the history of France.
We had our sessions in a nice room located on the 2nd
floor of Chateau de Blois. On the third floor occured a
tragic and important moment in the history of France: the
powerful rival of the king Henri III, le duc de Guise, was
assassinated by 20 people paid by the king. This happened
in 1588, almost at the same time as in Italy, a young man,
25 years old, called Galileo Galilei, got the chair of
mathematics at the University of Pisa. it was of course
pleasant to think that four centuries later and one floor
down, we could solve rivalry problems not by murder or
killing but by more scientific objective methods.
The most important output of our Blois Workshop was
the collective proposal made by numerous participants to
transform the Blois meeting into a regular biennial event. In
fact, the Blois Workshop was really prolific: it generated
not one, but two series of Blois meetings. The first one is
our series of Blois Workshops which keep the name of
Blois, are organized all over the world and treat always the
same subject - Elastic and Diffractive Scattering. The
second one is known under the name "Rencontres de
Biois", parallel to the well-known "Rencontres de
Moriond". They are organized always in Blois and treat
various subjects in physics, astrophysics and biology. The
last meeting, in 1991, was a pluridisciplinary meeting on
origins of life.
Soon after the decision of transforming the Blois
meeting in a regular biennial event we formed the
Permanent Committee of o,,r Blois Workshops. The
members of this comminee~r¢ the following: Bernard
Aubcrt (LAPP), Giorgio BeL'fctini (Pisa), t Rodney L. Cool
(Rockefeller), Daniel l)cnegri (Saclay), Giorgio Giacomclli
(Bologna), Alan Krisch (Ann Arbor), Nicola N. Khuri
B. Nicolesc~ / Opening address 3
(Roma), Bas~-ab Nicolescu ,..__o.,-_-_;,~,:~ . . . . . " ~,~;~. .... Ores- ..~._,_,.~.,~,;. . . . . . . . . . .
John Peo~ie~ (Fe~:ilab). En~t-o F--:edazzi foo --~), ~ Tmn
Tnanh Van (Orasay), C.N. Yang (Stony ~rooK).
• . can say :ha: m c ~ p2qys!c!S!S are !he rc~_! !aj..qcrs o!
our Blois Workshops. The role of the Permanent
Committee is crucial in organizing the Blois Workshops
and I will describe it at the end of this section.
In pronouncing these names I feel a deep emotion
invading me when thinking of Rodney Cool, who is no
longer with us. Of course, 1 knew Rodney Cool as a
physicist Iongtime before he participated at the 1st Blois
Workshop. With big enthusiasm he accepted to be a
member of the Permanent Committee and to be the
chairman of the Program Committee ef the 2rid Blois
Workshop held in New York. I had the opportunity to
highly appreciate his human values. I think that Rodney
Cool will remain for all of us an exemplary case of man and
physicist.
For the further aspects of the history of the Blois
Workshops, I will insist more on experimental data
(number of participants, experimentalists, theorists etc.)
and on the evolution of our subject.
After the 1st Blois Workshop in 1985, three other
workshops wen: organized:
- 1987: 2nd Blois Workshop, New York, USA. Local
organizing committee: Konstantin Goulianos and Nicola
Khuri;
- 1989: 3rd Blois Workshop, Evans,on, USA. Local
organizing committee: Martin Block, Roy Rubinstein,
Uday Sukhatme and Alan White;
- 1991: 4th Blois Workshop, Isola d'Elba, Italy. Local
organizing comittee: Stefano Belforte, Franco Cervelli,
Riccardo Paoletti, Crisdna Vannini and Stcfano Zuchelli.
The success of the previous meetings allow us to
predict the success of the present meeting.
Let us analyze first some experimental data.
One stoking fact is the noticeable increase in the number
of participants as compared to the 1st Blois Workshop.
Another striking fact is the appearance of new names of
physicists who have become attracted by our Workshops
because of the evolution of the subject. This last fact is very
encouraging for the future of our Workshops,
t
Oi" • .................. ~ ..................... - v I ~ 19~ 1919 1991Mw
FIGURE 1 Number of participants in terms of geographical regions.
In Fig.l I show the number of participants in terms of
geographical regions. It is worthwhile to make two
remarks:
!) We can easily see the predominance of the "local"
physicists. This s a natural, but somewhat unpleasant
phenomenon and it has to be ce."rected, in other words we
need more money to pay travel or staying expenses for
physicists coming from countries located far from the
organizing country;
2) There is a quantum jump in the number of physicists
from Soviet Union: from 0 in 1985 to 13 in 1991. This
quantum jump corresponds to the only one increasing function in Fig. 1. This is a good sign of changes in our
world and we hope that everything wil l continue on this
line. It would be also desirable to have a bngger number nf
participants, not only from URSS, but also from the
countries of Eastern Europe.
80 ~
60
40
, W of I~MlOOantS
f
z 0
0 , , ,
Ig65 1911"/ 19119 1991
FIGURE 2
The number of experimentalists vs the number of theorists
at the different Blois Workshops.
4 B. Nicolescu / Opening address
In Fig. 2, I show the number of experimentalists vs the
ca~ also make two rem:!~ks:
of experimentalists participating at our Workshops. This is
a very positive feature;
2) The rrg an value of the ratio experimentalists/theorists
over the last three Workshops is ~ 1.6, i.e. two times
bigger than that ar the 1st Blois Workshop. This is a
healthy value of the ratio.
Now, we have to understand the meaning of these
quantitative aspects through the qualitative changes which
already occured or will Occur in our field.
Soon after the 1st Blois Workshop, Elliot Leader wrote
in the CERN Courtier: "...although asymptopia may be far
indeed, the 7.:th to it is not through a desert but through a
flourishirg region of exciting physics....". Such an
assertion could seem at that moment too optimistic, in fact
it was just realistic. ! have in mind not only the many
interesting things which happened both in experiment and
theory in our field from 1985 till now but also the unique
possibility in the world to study at CERN both ~p and ~p
scattering at ultra-high energies. The name of this
wonderful machine is well-known: the Large Hadron
Collider (LHC).
In order to be alive, our Workshops have to adapt
themselves ,o the unavoidable changes occuring with time
in our field. In fact, they are nourished by these changes.
So, the highlight of the 2nd Blois Workshop held in the
New York was an exciting and extraordinary experimental
result obtained by the UA4 Collaboration at the CERN
S~pS collider. It concerns the behaviour of the real part of
the pp amplitude at high energy. This result was a true
surprise for the majority of the physicists working in the
field of strong interactions. If this experimental result is
really true, it would have extremely important
consequences both on theoretical and experimental level.
The emphasis of the 3rd Blois Workshop held in
Evanston was on a different aspect: theoretical progress in
our field. While confronting new and very important
experimental results obtained at the Tevatron, the meeting
centered more on theoretical problems. This fact was
reflected even by the slight but significant change of the title
of the Workshop: "Elastic aqd diffractive scattering - The
Rlcfi~. and lhig ig eerlainlv a healthy develnnmenL" Thi~ i~
a capital remark. If we want to keep our field and our
Workshops alive we need to connect our venerable and
fundamental field of research with the modem theory of
strong interactions - QCD, i.e. with the dynamics
expressed in terms of quarks and gluons.
In this connection, it is interesting to note that in their
Foreword to the Proceedings of the 3rd BIois Workshop,
Martin Block and Alan White used a very happy expression
- "Berlin Wall" - to characterize the separation between
perturbative and non-perturbative aspects of QCD. This
expression was in fact premonitory: the Workshop occured
in May 1989, and only few months after the real Wall of
Shame disappeared, vanished. Let us hope that the physical
"Berlin Wall" will disappear also in a not too far future.
I can not obviously predict what will be the highlight of
the present Workshop. We have to wait few days and see.
But I think that 1 can safely predict that there would be
several interesting surprises.
Let me close this section by indicating how we are
functioning.
First of all we have, as I already said, the Permanent
Committee of our Workshops. It has the very difficult task
to define the scientific orientation of the meetings in terms
of the general changes in high-energy strong interaction
physics. It also has the very difficult task of choosing
between different organisation proposals for every next
meeting. ! must tell you that we always had more than two
countries wanting to organize the next meeting. This very
healthy fact shows the interest of our community for our
Workshops.
1995 is a special date: the I(~h anniversary of the Blois
Workshop. Several col '¢agues and friends already
suggested us that it would be natural to celebrate this
anniversary by organizing the 6th Blois Workshop back in
France, perhaps even in Blois. Of course Tran Thanh Van
and myself we are open to this possibility. However, the
Permanent Committee has to take the final decision.
A very important role is played by the International
B, Nicolescll / Openitlg adclre,s.~ 5
Advisory Committee, whose composition changes from
one mee6ng ~o .:he o':her, it ha5 to define the ~peci::°ic
sciemiSc o~emafic~,, co~esoondi~e ~o ii'.--e eivea moment of
--me, -- gas -o define -he ~iea~.ifi~: ~.~u~ztarr. uf ;hr. rattling,
and it _has to solve the main.problems of the practical
organisation of the meeting.
Of course, the hard work is done by the members of the
Local Organizing Committee. I think that we have to
congratulate all of them. They devoted so much of their
time and energy to the success of our meetings. They have
to solve hundrezls and hundreds of problems of
organization both on scientific and practical level and
clearly they solved them always in a nice and efficient way.
In any case, we can say, using the words of Konstantin
Goulianos in his foreword to the Proceedings of the 2nd
Blots Workshop, that our Workshops provide".., a home
for scientific exchange and progress in this specialized field
of physics."l very much like this word "home" because it
crystallises precisely what we had in mind when we
organized the I st Blots Workshop.
2. WHAT WE ARE TRYING TO UNDERSTAND ?
In fact I already made previously several suggestions
about physical challenges underlying ot.'r Workshops. Now
! will try to make the point more precise ta t still in a
nonspecialized language.
Very often people ask to particle physicists: "What are
you really doing?" In order to answer we have to forget
equations, theories, data and to use everyday language. My
own children put to me, of course, the same question. I use
to answer: "We try to reconstruct the universe". They think
that it is a joke. It is in fact only half-a-joke.
A famous quantum law gives us the connection between the
energy spread of a quantum event and the spread in time or
distance. If we want to penetrate in a smaller and smaller
region of space or of time, we have to increase the energy.
Higher and higher energy accelerators bring us, in some
sense, backwards in time, towards the early universe.
Looking in a smaller and smaller region of space and time
we are in fact n~arer of the physics of the early universe.
Why do we thim¢ ,)hat this kind of physics is extremely
interesting? The gates of the quantum world open at a
staggering small distance : -10 -13 cm. The unification of
strong, elec~omagnetic and weak ;~¢ract ons takes oiace at
a f~b~iou~ e.,'!ergy: = !@5 times grca~er thlm the ene--.gy
corrcspoad--'ng -':.o ¢h¢ mass of ---q~e pro~o'~. "FFis e~ergy
C i . i ~ i ~ N ~ i ; ~ g i 0 t i l l i i i i l ~ i l [ ~ s l m l l l ~ i ~ [ a l i C O i - - i [ J -~7 Ci'~. i i l i l l~
would be that of a speck of dust. The unification of all
physical interactions takes place at an energy still more
fabulous: 1019 times the mass of the proton, which
corresponds to an even tinier distance. These simple
considerations can give you a flavour of what the word
"asymptopia" can mean. Of course, this kind of energies
will be never obtained in our human-made accelerators:
there are technical barriers of impossibility. The best
accelerator was probably the cosmic accelerator of the early
universe, were all secrets of physics were clearly exposed.
Unfortunately at that time physicists were not yet present.
My previous answer is of course too general. One has
to say what is really specific to our field of physics - Elastic
and Diffractive Scattering. For that, I will use again an
analogy with d,e early universe.
We know that if we approach the "origin" in time of the
universe, t = 0, everything blows up. Universe blows up,
but also equations of physicists blow up. We can speak
about extremely tiny times, like say t -10 -35 see. However
we ~-¢ not allowed to speak about the "origin" t = 0: time
it.~:lf I'x)ses meaning in this limit.
In strong interactions we have also a key-parameter,
called "momentum transfer", which characterizes the
transfer of momenta between colliding panicles. By an
amusing coincidence the letter used for this key-paramete;
is also "t". There is also something special about the regime
defined by t = 0 and high energy, which concerns our field
of interest in some sense, the equation.,; blow up towards
t=0. In fact. there is a kind of duality between small-t and
high-t regimes. At high-t the quarks, very close one to the
other, behave paradoxically like they were free, and allow
us to make clean computations, the corresponding
experimental events being rare cven,s. On the contrary, at
small t, the strong interactions appear in ;heir full splendor.
The experimental events are very abundant. There are also
crucial experimental and theoretical quantities appearing
precisely at t = 0. There is only one annoying thing: mere is
a huge complexity of interactions in this regime, which
6 B. Nicolescu / Opening address
5ireNe +~ uaders-and -_he oNgin of ~gi: h ~ e comp]cxiw: b;'
another para~ioxicai property, when two quarks are very far ~+ +r.__l. ~.s.__ = . . . . . J _ e . . . . . . . --.__ ~s- . . . . . . e__~ ~-_~
f i ne o r e~ l=n o l ne r i n~ re~n I l l ~ n x r A l l n ~ Ha i l n ~ l l m l n ~ : l r ~_ . . . . . . . . . . . . . . . . . • . . . . . . . . . . . . r . . . . . . ~ . . . . . . . . . . . . . . m . . . .
(like everything in such a situation will do in ordinary life),
they are so attracted one by the other that they like to stay
together for ever, permanently confined in the hadron. In
order to realize their permanent community, the quarks will
do everything they can do in th~s aim and in such a way
they generate a huge complexity.
However, there is a difference with the impassable
barrier towards the origin of time of our universe. There is
an experimental proof that strong interactions do not blow
up at t = 0, when the scattering becomes "elastic": all the
experimental data concerning the strong interactions at t = 0
are finite quantities. The barrier between high-t and small-t
regimes is surely not in,passable in Nature. Therefore, the
theory has to follow Nature and find out a way from the
present situation. In this important search, new theoretical
ideas are of course crucial, but also crucial are the expected
new experimental results to be obtained at the present
accelerators and the ones we hope to get at the planned new
accelerators, in order to guide our steps.
I hope that I have succeeded, even in an approximate
way, to give you a feeling about the beauty, the interest and
the importance of our field of physics, it is an exemplary
case of the encounter of tradition and modernity. However,
in order to make this encounter successful there is one
crucial interacting factor: new experimental data. Only then
our initial axiom will keep alive: "what is fundamental
remains fundamental whatever it happens".
3. FUTURE
We all know, from our ordinary life, that almost all our
predictions are wrong• Laymen, like the theoretical
physicists, are much safer in making rrtrodictions than
predictions. And even theorists, whose job is precisely to
make predictions, are relatively happy when they are
wrong, because this means that something really interesting
happens. So, I keep my predictions about what future
could bring to us for m l physics talk. I prefer to discuss
here just one point: the future experiments, in connection
with our Workshops. The reason is simple: without new
e×pefimental data, pa~.~Me p:hysics wi'i become a branch ef
metaphysic5 or a branch of ma~hema~c~.
We have the chance to expect in [he near future new l n l p r P ~ n n ~ P ' l ~ n ~ r l , ~ r u a . n l r ~ l l r P ~ l l l r ~ r r n l r n l n l ~ e , ~ l ~ n r l ~ m ~ l r n ~ n P ~ o . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . O 1 ~ D
the CERN S~pS and the Tevatron colliders. In fact, some
of them will be probably presented even at this meeting.
We also eagerly expect the realization of experimental
projects at the future machines: UNK, RHIC, LHC and
SSC.
Let me underline just one fascinating possibility: that of
having both pp and ~p options at LHC. at a cost
comparable or very ~lightly higher than that of having just
one option. Without any kind of chauvinism we have to
clearly state that the europeans will have here a unique
opportunity for a crucial experiment. This opportunity is
unique both in space and in time. In space, because
nowhere else in the world one can do such an experiment in
the multi-TeV region of energy and in time, because, at
least for the future century, one can not foresee such a
possibility from the technical and financial point of view.
Why do I say that this possibility is fascinating? It is, of
course, difficult to explain that in simple words. First of
all, let us note that we know, from various fields of physics
and even other sciences, that Nature seems to work by
keeping a very subtle balance between the respect of a
fundamental symmetry and a very small violation of this
symmetry. In its turn, the very small violation of the
fundamental symmetry generates fundamental laws and
fundamental phenomena. Perhaps the most famous
example is given by the history of our own universe. The
very early universe was probably characterized by the
symmetry between matter and antimatter. An extremely
small violation of this symmetry, also compatible with the
known physical laws, was sufficient to lead rapidly to the
predominance of the matter over the antimatter. Finally,our
universe like it is now and also life could appear.
In a relatively similar way we can put the following
question: is the asymptotic symmetry of pp and ~p
interactions accompanied by a violation of this symmetry ?
The asymmetry between pp and ~p interactions would lead
to tremendous experimental and theoretical consequences.
At LHC we have a unique chance to study this problem. In
fact, we should win in both cases: either symmetry or
B. Nicolescu / Opening address 7
~ . : . . . . . . . . . c~:..:_= this eroNem of symmetry or
v.,Jbi~,, impossible t~ be solvea ~y i.heory ia iis pze~ni
.,.;u .^ " . . . . . . . ersta~ i~g s ~ g . . , , i . .a . . . . . . . . .
of strong interaction physics.
Of course many of us present here dreamt or dream
about this fascinating possibility of having both pp and ~p
options in the multi-TeV region of energies. I begun myself
to dream about this possibility in 1972-1973. In 1976-1977
when I spent a long stay in Berkeley, we had the chance to
have as neighbours Bruno Autin and his family. Naturally
we begun to speak about this possibility. Several years
passed and from my discussions with the specialists of
accelerators I became more and more convinced that this
possibility is in fact realistic. Let me quote the conclusions
of Bruno Autin's talk at the 1st Blois Workshop in 1985:
"One of the highlights of this workshop devoted to elastic
and diffractive scattering is the interest of pursuing the
comparison between pp and ~p collisions...Another point
which is worth emphasizing is the great activity in the field
of stochastic cooling. Its t~se for either proton or antiproton
beams may open new realms to basic parameters like
luminosity or beam lifetime of any future machine."
Retroactively, these words sound prophetic. In our days,
the dream is very near to become reality. The specialized
talks at the recent Aachen Workshop on LHC are very
encouraging in this direction. Our community emphasizes
more and more the need for having both pp and ~p at LHC.
Let us hope that the physicists who will take the final
decision will recognize the fundamental charac:er for the
future of strong interactions of having both ~p and pp at
LHC.
I do not know if the organizers chose Isola d'Elba for
symbolic reasons or just for practical reasons. In any case,
it is difficult to resist to think about one emperor who had
once a huge empire and who saw himself suddenly ruling
over just one island. One year later he went back to Pads in
triumph. I leave open to you all the many possible symbolic
interpretations of these facts.
i very much hope ~hat this L onterenee will be an
extremely s-~c':-rs"fv! one~ a mi!cs~one i:: the ::'s:- of g'oei~
Workshops. . . . . . . . . . . . | a m m a l r o P a ~ " ~ | r h | c t l l l ~ I I ~ l I I l ~ : U ! t H r - - r ' t ~ . . r g n . - ' l n C n ~ . . . . . . . .
Workshops, I would like to tb~nk first those who, by their
sponsorship, made this Workshop possible: The lstituto
Nazionale di Fisica Nucleate (INFN), the Italian Physical
Society (SIF), the European Physical Society (EPS), the
University of Visa and the University of Bologna. We are
really bonoured that oar Conference is sponsored by such
prestigious ins:itutions.
I would like to thank also very warmely the
International Advisory Committee and the Local Organizing
Committee, ,vho did a hard and efficient work both on
scientific and practical level.
I thank also the members of the secretariat - Susanna
Antichi, Monica Fagioli, Adriana Guerrieri and Paola
Zalone - who spent, I am sure, much energy for the
organization of this Conference. In fact, their work will
continue in the next clays and even after the Conference
when, together with the members of the Local Organizing
Committee, they will take care of the important task of
editing our Proceedings.
Let me finally thank all of you who participate at this
Conference. You are in fact those who, by your active
presence, bring life to our Blois Workshops.
REFERENCES
1. Proceedings of the 1 st Blois Workshop on Elastic and
Diffractive Scattering, Chateau de Blois, France, 3-6
June 1985, edited by B. Nicolescu and J. Tran Thanh
Van, Editions Fronti~res, 1986.
2. Proceedings of the 2nd Blois Workshop on Elastic and
Diffractive Scattering, New York, USA, 15-18
October 1987, edited by K. Goulianos, Editions
Fronti~:res, 1988.
3. Proceedings of the 3rd Blois Workshop on Elastic and
Diffractive Scattering - The Interface of Soft and Hard
Processes in QCD, Evanston, USA, 2-6 May 1989,
edited by M.M. Block and A.R. White, Nuclear
Physics B (proc. Suppl.) 12 0990).
8 B. Nicolescu / Opening address
4. Proceedings of the ECFA Large Hadro~ Co;iider
Workshop, Aachen, Federa! Republic of Ge~.-~ any, 4-
D. Rein, CERN 90-10/ECFA 90-133, 3 December
1990. See, in particular the talks given by D. Denegri,
E. Leader and G. Matthia¢.