Beyond the God Particle Read Online Free

physicists make a particle beam strike an atom that is sitting at rest in a fixed target, like a block of lead or beryllium, just like the light beam striking the target on the glass slide under the microscope. However, physicists realized that in the subsequent particle collisions with the atoms in the block of material, much of the precious energy of acceleration of the incoming beam is wasted. The outgoing particles emerging from the collision acquire “recoil momentum,” which takes away the useful energy. However, if two particle beams could be fired at each other and made to collide head-on, then there need be no recoil momentum and all the energy is available to probe deep inside of matter. The full particle beam energy becomes available to make adetailed image, or to actually produce new and previously unseen and very short-lived elementary particles. This is the concept of the modern “ particle collider .” The Fermilab Tevatron and the CERN LHC (previously CERN's LEP collider) were and are all-powerful and useful particle colliders. But what a challenge this is—to make infinitesimally small particles that are smaller than a millionth of a billionth of a golf ball in size, traveling almost at the speed of light, hit each other head-on!
    The world's first proton–proton collider, called the Intersecting Storage Rings (ISR), was built and came into operation at CERN in 1971. The ISR was a very small machine by today's standards, but there were daunting challenges to overcome just to make it work. The ISR produced the world's first head-on proton–proton collisions. It was actually constructed on French soil on land adjoining the original CERN site in Switzerland. At the same time, the first electron–positron collider was ramping up at Stanford Linear Collider laboratory.
    THE GRAND SYNTHESIS
    By the early 1970s theoretical physicists had sewn all the available data from a century of research together, much of it coming from the data produced at high-energy particle accelerators, and had developed a remarkable descriptive and predictive theory that has come to be known as the “Standard Model.” One of the great achievements of the Standard Model is that it united two of the known forces in nature into one unified entity. These two forces are electromagnetism , the force associated with ordinary electricity, light, and magnetism, together with a very feeble force, so feeble that it wasn't even noticed until the 1890s, called the weak interactions . Though this latter force is “weak,” without it the sun could not shine and we would not exist.
    The electromagnetic force is associated with particles, called photons , that are the particles of light. Likewise, the Standard Model predicted that the weak force must be associated with three previously unseen particles, called the W + , W – , and Z 0 (these are called the “weak bosons”; “bosons” are defined in the Appendix). These three particles were predicted to be very heavy by particle physics standards (the W + and W – are 80 times heavier than the proton,and the Z 0 is 90 times heavier than the proton), and they have extremely short lifetimes, less than one trillionth of a trillionth of a second. But physicists realized that these particles could in principle be produced and detected in a sufficiently energetic collider experiment. Alas, no machines existed at the time the Standard Model was put together that were capable of producing the weak bosons, but indirect hints of their existence continued to emerge in various experiments. These “indirect” hints compelled the ultimate construction of a machine capable of directly producing and observing the W + , W – , Z 0 .
    In the early 1970s the first big accelerator at Fermilab (called the Main Ring) came into existence, while CERN had built, upon their existing PS, the Super Proton Synchrotron (SPS). Both the Fermilab Main Ring and the CERN SPS were a whopping four miles in circumference