QUARK MODEL OF HADRONS 1 based on the quark model

It is based on the clerk model of advance which will tell you that how to study and how to get good marks in your class and in your school

1. Welcome to my Presentation Myself Simran Kaur Class :- B.sc Final Year University roll no.:- 2210560442 Class roll no.:- SM1-21-71

2. QUARK MODEL OF HADRONS Submitted to:- Prof. Surrender Kumar

3. INTRODUCTION Gell-Mann and G. Zweig proposed a quark model for understanding SU (3) classification of Hadrons. Particles, like mesons and baryons collectively form a category called Hadrons. It is known that all the nuclei differs from each other on the basis of their mass, spin or charge. All these nuclei consists of only two type of particles i.e. neutrons and protons, in different numbers. It is believed that Hadrons can not be elementary particles, but they must consists of various combinations of a few smaller particles. In 1963 Gell-Mann proposed that all the hadrons(mesons and baryons) are composed of, three still more fundamental particles, called quarks.

4. Quarks are thought to be elementary point particles like leptons with no internal structure but unlike other particles have fractional charges. Each quark has got either positive or negative charge, equal to fraction of an electronic charge (e) and is assigned a specific quantum number. The original three quarks were labelled as; up(u) , down(d), and strange(s) along with their antiparticles, later on three more quarks along with their antiparticle namely charm (c),bottom or beauty (b) and top (t) were introduces.

5. The Quarks and Antiquarks are assigned following values for their charges: u= +2/3e d=-1/3e s=-1/3e c=+2/3e b=-1/3e t=+2/3e ū:-2/3e :+1/3e   :-2/3e   :+1/3e   :-2/3e   :+1/3e  

6. The Quantum Numbers of Quarks are given as: Quarks S B C Charge(e) u 1/3 +2/3 d 1/3 -1/3 s -1 1/3 -1/3 c 1/3 +1 2/3 b 1/3 -1/3 t 1/3 +2/3

7. Quark combinations of Neutron and Proton(baryons) There are three types ( flavour ) of quarks constituting hadrons are up (u) ,down (d) and strange (s) . Each baryon is made up of three quarks (q q q). For example; the neutron is a baryon with quark content ‘ ddu ’ and the proton is also a baryon with quark content ‘ uud ’. u d d d (a)Neutron u u d (b)Proton

8. Quark Combination of Each meson is composed of a quark and antiquark pair (q . The flavour of these antiquarks may be different. For example meson has a quark combination of u, and has a quark combination of ū s.       )       u đ ū s    

9. Electric charge on Quarks Quarks have fractional electric charge. The mass and spin of an antiquark is same as of the corresponding quark. +2/3e +2/3e -1/3e u u d Proton +2/3e -1/3e -1/3e u d d Neutron +2/3e +1/3e u đ   Proton ( uud combination) Charge , q=+e Neutron ( udd combination) Charge, q=0 charge, q=+ ve

10. Formation of Hadron Hadron Quark content Baryon number B Charge (e) Spin Strangeness S uđ 1/3-1/3=0 +2/3+1/3=+1 ↑↓=0 0+0=0 u 1/3-1/3=0 +2/3+1/3=+1 ↑↓=0 0+1=+1 p uud 1/3+1/3+1/3=+1 +2/3+2/3-1/3=+1 ↑↑↓=1/2 0+0+0=0 n ddu 1/3+1/3+1/3=+1 -1/3-1/3+2/3=0 ↓↓↑=1/2 0+0+0=0 sss 1/3+1/3+1/3=+1 -1/3-1/3-1/3=-1 ↑↑↑=3/2 -1-1-1=-3 Hadron Quark content Baryon number B Charge (e) Spin Strangeness S uđ 1/3-1/3=0 +2/3+1/3=+1 ↑↓=0 0+0=0 1/3-1/3=0 +2/3+1/3=+1 ↑↓=0 0+1=+1 p uud 1/3+1/3+1/3=+1 +2/3+2/3-1/3=+1 ↑↑↓=1/2 0+0+0=0 n ddu 1/3+1/3+1/3=+1 -1/3-1/3+2/3=0 ↓↓↑=1/2 0+0+0=0 sss 1/3+1/3+1/3=+1 -1/3-1/3-1/3=-1 ↑↑↑=3/2 -1-1-1=-3

11. Thank You