DIRECTORATE FOR MATHEMATICAL AND PHYSICAL SCIENCES 



AND ENGINEERING 



MPE Mission 



The program of the Directorate for Mathe- 

 matical and Physical Sciences and Engineering 

 (MPE) is designed to support research that will 

 augment knowledge and understanding of: 



• Mathematics and computer science 



• The most fundamental laws of physics and 

 chemistry 



• How those laws are reflected in the properties 

 and behavior of materials 



• The basic principles of engineering, and limits 

 to exploitation of those principles. 



In pursuit of these goals, the Directorate con- 

 ducts more than 40 subprograms in which research 

 ranges from the quest for the ultimate fundamental 

 particles to investigating the role of gravity in the 

 evolution, structure, and fate of the universe. Ad- 

 ditionally, funding for instrumentation and for ex- 

 isting, new, or improved facilities serving the dis- 

 ciplines involved in its programs constitutes an 

 important part of the Directorate's support of ba- 

 sic research. In some cases — for example, in gravi- 

 tational physics — it is not easy to draw a sharp line 

 between progress in instrumentation and the re- 

 search itself. The Directorate's activities in provid- 

 ing instrumentation and facilities will be described 

 in some detail in the course of this discussion, in 

 close relation to significant projects in actual re- 

 search and in program initiation and development. 



Examples of Basic Research 



Below are some significant projects involving 

 basic research. 



Discovery of a charmed baryon. Physicists have 

 announced the discovery of a "charmed baryon," 

 a subatomic particle, which gives scientists a deep- 

 er insight into the basic structure of matter. The 

 findings add support to the view that matter such 

 as that found in atomic nuclei is composed of basic 

 constituents known as "quarks" (fractionally 

 charged particles). Up until recently the efi'ects of 

 only three types of quarks have manifested them- 

 selves, but a fourth type referred to as the 

 "charmed" quark is required to explain the latest 

 experiments. 



"Charm" is an attribute or behavioral character- 

 istic which, like electric charge, is additive. Al- 

 though difficult to destroy, charm is not completely 

 indestructible. Over very long periods, it is possi- 



ble for charm to disappear owing to the action of 

 the weak interactions — weak because they take so 

 long to act. As a result charmed particles are long 

 lived. Longevity is their distinctive characteristic 

 over other particles of this class. 



The discovery of the baryon by physicists from 

 Columbia University (supported by NSF), and 

 from Fermi National Accelerator Laboratory (Fer- 

 milab), the University of Illinois, and the Universi- 

 ty of Hawaii supported by the Energy Research 

 and Development Administration (ERDA) is be- 

 lieved to confirm the presence of charm in nature. 

 The "baryon" mass of 2.26 billion electron volts, 

 its long lifetime before disintegration, and its final 

 products of decay exactly fit expectations based on 

 the four-quark picture. 



The Columbia-Fermilab-Illinois-Hawaii team 

 intensified its search for charm following the dis- 

 covery in November 1974 of the J or Psi particle. 

 The J/Psi was presumed to be made of a quark 

 carrying a unit of positive charm and an antiquark 

 carrying a unit of negative charm. 



In the combination of the J/Psi particle the net 

 charm carried is zero since the charm of the quark 

 is annulled by the negative charm of the antiquark. 

 Although the J/Psi and similar states discovered 

 shortly thereafter supplied strong supporting evi- 

 dence to confirm the reality of charm, it was neces- 

 sary to find particles in which a charmed quark 

 combines with one or more of the three other 

 types of quarks that do not carry charm so there is 

 no neutralizing effect. 



It was not until the finding reported by the group 

 of scientists from Columbia University, University 

 of Hawaii, University of Illinois, and the Fermi 

 National Accelerator Laboratory that this latest 

 link between observation and prediction had been 

 made. The basic combination of quarks forming 

 charmed baryons has been found. Physicists are 

 confident that in addition to these lowest mass 

 charmed particles a rich spectrum of others awaits 

 to be discovered. 



The question of the existence of fractionally 

 charged particles (quarks). Evidence for a fraction- 

 al charge less than that of the electron has been 

 reported. The smallest known electric charges in 

 nature are those of the electron and proton, each 

 of which has a single negative or positive unit of 

 charge respectively. Such charges balance out 

 each other in atoms, the simplest being the hydro- 

 gen atom with one proton for a nucleus and one 

 electron in its shell. 



NATIONAL SCIENCE FOUNDATION 21 1 



