Particles
• During the years 1975-80, when the models founding the study of
elementary particles upon the
quarks was in wide development, but that evidence for a direct
observation of such constituents was long to come, I wondered if it was
not possible that the quarks would not exist as such particles. Indeed,
It may be conceived that these “quarks entities”
would describe some symmetries of interactions, but without necessary
consequence that some corresponding corpuscles would exist.
I was guided in this approach by the analogy with electromagnetism, for
which the magnetic effects are some complementary components of the
electric field, with this particularity that there exist electric
charges but not magnetic charges
(in the “standard” models). In the same time moreover
was developped an active research for magnetic monopoles
(predicted by some theories) all efforts of which seemed to be vain.
It did not seem to be a priori inconceivable to search for
models with quarks fields devoid of particles, corresponding to some
complementary components of leptons fields, with of course the
difficulty to found in which space such a
complementarity could happen.
This approach seemed to me as much interesting as I was more or less
suspicious of the expressions propounded for the interaction potential
between quarks, leading to infinite linearly
[1]. The “required” decrease of interactions at a large
distance was to my mind an unavoidable argument.
• Since then, I have found no trace of any theory of this kind, but my
opinion has partly changed in other respects.
• Within the philosophy of newtonian mechanics, a material point is
“isolated” (or quasi-isolated) in space if it is far enough from every
other object, because it is presupposed that interactions decrease at a
large distance. Newton more or less infers from this the
logic of the inertia notion : without interaction, the space (which he
suppose to exist even without interaction) being everywhere alike,
there is no reason for any change in the motion.
From this afterwards follows the necessity to distinguish some
“galilean” frameworks, within which mechanics is expressed “more
simply”. Thus when an observer, with respect to his galilean framework,
turns a pail of water about its vertical axis, he sees the surface of
water that incurvates itself as result of the rotation. On the
contrary, if the observer lets the pail fixed and revolves round it, he
sees a surface which remains horizontal.
• Within Mach's philosophy on the contrary [2, 3], an “isolated”
material
point is subject to interactions
that are not necessarily individually negligible with the distant
objects, but such as globally their effect seems independent of the
position, precisely because they are distant (which makes the relative
motion to be small) and that these remote objects are numerous and
uniformly and isotropically distributed (which causes that, for many
aspects, their actions compensate among themselves).
He deduced from that quite a different approach of the inertia
phenomenon. If the observer which revolves round the pail has no
influence, because he constitutes only a negligible part of the whole
set of objects in interaction with the water, on the contrary the whole
Universe revolving round the pail would cause an action equivalent to
what is called “inertia” within a revolving (not galilean) framework of
the newtonian theory.
• In other words, the newtonian theory has this
superiority to put in “short-circuit” all the
difficulties connected to these possible and inobservable interactions
: it is “spontaneously renormalized”.
But when is reached the theoretical level where it is attempted to
connect the elementary microscopic processes and the macroscopic
observations, the newtonian theory has the defect of its qualities : it
fails to recognize what happens before the renormalization
(and it describes that probably very badly).
• Thus, now it seems to me more and more likely that not only the mass
of elementary constituents is
necessarily zero before renormalization, but also, in some manner, the
decrease of their interactions with respect to the “distance”
[4].
More precisely, when an elementary constituent interacts, it does that
in exactly the same way whatever the distance is, in so far as this
distance is only a statistical consequence of the whose set of
interactions ; le decrease of interactions with the distance than can
happen only in their statistical description. Since then, not only it
becomes plausible that the interaction potential of quarks increases
linearly with the distance (before renormalization), but it seems that
it should be the same for every “elementary” corpuscle. Thus it would
be asked, on the
contrary, if the leptons are or not really elementary and, if
affirmative, asked if the
“bare” propagator which is assigned to them does correspond to their
elementary properties.
__________________
References :
1. see as
example :
“Le plasma de quarks et de gluons en
laboratoire”, J.Y.
Grossiord, CNRS - Images de la physique n° 2002, p. 98,
december 2002 ;
“Prix Nobel - physique”, La Recherche n° 382, p. 60, january 2005.
2. see as example (without consequently accept all the argumentations
defended by Mach,
whose philosophy also led him to refuse the atomistic interpretation of
matter) :
“La Mécanique”, E. Mach, ed. J.
Gabay (french translation) ;
“Le vrai et le réel”, Pour
la Science - les génies de la science, n° 27 (“Planck, la
révolution quantique”), may 2006.
3. some effects connected to revolving systems have been tested within
the framework of general relativity ; they dont exactly correspond to
Mach's point of vue, which is to imagine the Universe revolving round a
pail (that is “impossible” for an infinite Universe in a relativistic
theory) ; see as example : “La relativité générale
vérifiée à 99%”, L. Blanchet, La Recherche n°
381, december 2004.
4. I might be as such as tempted by the analogy used by
socio-physicists, according to which the changes are caused by nearness
interactions, but inertia is cause by the whole set of large distance
interactions ; see as
example the comment : “Globalisation, mais pas
uniformisation”, Pour la
Science n° 313, p. 20, november 2003.
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