HERA Physicists put flesh on putative particle
When particles crash in atom smashers, bizarre events occur.
"Soft collisions", two speeding particles (e.g. protons) strike each other w/ glancing blow.
One breaks up while other travels on unscathed.
The surviving particle emitted a force-carrying particle called a pomeron, which struck the other
one and shattered it.
     QCD couldn't explain it.
     The pomeron is made up of pointlike particles with measureable distribution.  


                                               _____^  electron out     
                                         _____/     
                                    ____/     
                                   /     
        electron in ->----->----->+                        -> 
                                    ____   photon      ___/
                                        \_____       _/      particle shower
                                              \_____.---->
                                                    |
                                                    |
                                                    | pomeron
                                                    |
       proton out <-------------------------<------------------------------<--  proton in

soft collisions w/ portons are 15% of all collisions.  Involves strongly interacting
particles, to be controlled by the strong force.  
    Found collisions of protons and antiprotons gave jets of
particles, leaving either p/anti-p unscathed.  Trademark of diffractive scattering.
In these collisions, one or two jets of particles emitted at large angles, signaling
a hard collisions between pointlike objects.
   At HERA collide e- w/ p+.  Can see how pomerons emit and how pointlike particles
distributed in them.  
   At HERA, e- & p+ interact electromagnetically because electrons don't feel 
the strong force.  This interaction takes place when an electron emits a photons,
which then strikes a charged component of the proton headon - a type of hard 
collision known as deep inelastic scattering.  The higher the energy of the 
collision , the shorter the wavelength of the photon, so the collision in effect 
probes the proton with a pulse of light that has a wavelength short enough to 
reveal the internal structure of the proton.

 
+
 Boron Nitride Nanotubes 
The successful synthesis of pure boron nitride nanotubes is reported.  
Multiwalled tubes with inner diameters of the order of 1-3 nanometers and with 
lengths up to 200 nanometers were produced in a carbon-free plasma discharge
between a BN-packed tungsten rod and a cooled copper electrode.  Electron 
energy-loss psectroscopy on individual tubes yielded B:N ratios of approximately
1, which is consistent with theoretical predictions of stable BN tube structures.


--fin