Riazuddin, also spelled as Riaz-Uddin (Urdu:
رياض الدين;‎ 10 November 1930 – 9
September 2013), was a Pakistani theoretical
physicist, specialising in high-energy physics
and nuclear physics. Starting his scientific
research in physics in 1958, Riazuddin was
considered one of the early pioneers of Pakistan's
nuclear weapons development and atomic deterrence
development. He was the director of the Theoretical
Physics Group (TPG) of the Pakistan Atomic
Energy Commission (PAEC) from 1974 until 1984.
Riazuddin was the only pupil of Nobel laureate
in Physics Abdus Salam..
Riazuddin carried out his research at the
International Centre for Theoretical Physics
(ICTP), the Pakistan Atomic Energy Commission
(PAEC), the European Organization for Nuclear
Research (CERN) and Daresbury Laboratory where
he published papers in mathematics and physics.
Riazuddin also played an important role in
education in Pakistan, contributing to the
rise of science in Pakistan. Riazuddin authored
several scientific books on particle physics
and quantum mechanics. Later in his life,
he joined the National University of Sciences
and Technology (NUST) as a visiting professor
of the theoretical physics. From 2004 until
his death, he also served on the Board of
Governors of Pakistan Institute of Engineering
and Applied Sciences (PIEAS).
== Biography ==
=== Early years ===
Riazuddin was born in Ludhiana in British
Punjab of the British Indian Empire in 1930.
After the Partition of India, his family migrated
to Pakistan in 1947 and settled in Lahore,
West-Pakistan. At age 17, Riazuddin attended
Punjab University, and took his B.Sc.(Hons)
in Mathematics under the supervision of Abdus
Salam in 1951. Riazuddin was the only student
to study Physics and Mathematics under the
supervision of Abdus Salam at the Undergraduate
level at Punjab University and at the Postgraduate
level at Cambridge University. As a student
of mathematics, he learned the advanced course
on quantum mechanics under Abdus Salam, as
he had made the course of quantum mechanics
outside the regular curriculum. In 1951, Salam
funded his scholarship, and helped him gain
admission to the graduate school of Punjab
University. In 1953, Salam supervised his
M.Sc. in Applied Mathematics where his master's
dissertation dealt with fundamental concepts
of mathematical physics. By the time he published
his thesis in 1953, he received a Gold medal
from the Punjab University for post-graduate
contributions to physics and mathematics.With
the help of Salam, Riazuddin went to the United
Kingdom on a scholarship and attended Cambridge
University. At Cambridge, he was awarded his
PhD in Theoretical physics in 1959. Riazuddin's
dissertation was written on "Charge Radius
of Pion" which also covered many issues relevant
to the field of quantum theory. Riazuddin
returned to Pakistan where he joined Punjab
University as an Associate professor. In 1968,
Riazuddin was awarded the Gold Medal in Physical
Sciences for scientists under 40 years of
age by the Pakistan Academy of Sciences.
=== Academic career ===
Riazuddin had joined Punjab University ini
1959 as an associate professor of Mathematics.
Four years later, he travelled to the United
States for a fellowship awarded by Norman
March and Michael Duff. He became a research
associate professor at the University of Rochester
where he stayed until 1965. The same year,
he joined the University of Pennsylvania where
he taught physics until 1966. Later, he went
to Chicago, Illinois where he joined his brother
Fayyazuddin, and theoretical physicists Faheem
Hussain and Peter Rottoli. Riazuddin joined
University of Chicago's Enrico Fermi Institute
where they created the "Relativity Group".
In 1968, Riazuddin returned to Pakistan on
the request of Salam, and joined Quaid-i-Azam
University's Institute of Physics. He was
the founding director of the Institute of
Physics (IP) where he engaged in research
on string theory, the theory of relativity,
particle physics and nuclear physics. Later,
the scientists of the Relativity Group at
the Enrico Fermi Institute returned to Pakistan
on the request of Salam. In 1970, he returned
to the United States where he became Professor
of Mathematics at the University of Maryland.
Riazuddin left the United States for Italy
as he was asked by Salam to join the International
Centre for Theoretical Physics in 1970. He
was joined by other students of Salam where
they created a Theoretical Physics Group at
the ICTP. In 1971, Riazuddin traveled to the
United Kingdom to join the Daresbury Nuclear
Physics Laboratory where he was joined by
Michael Duff. At Daresbury, he became senior
research associate. There, Riazuddin gained
expertise and specialised in nuclear physics.
At Daresbury, he trained British scientists
in the field of nuclear physics.In 1981, he
became visiting professor of physics and mathematics
at the University of Iowa and Virginia Polytechnic
Institute and State University, now Virginia
Tech. In 1982, Riazuddin came back to Pakistan
where he joined Quaid-e-Azam University as
a professor of theoretical physics. In 1982,
Riazuddin also went to Saudi Arabia where
he joined King Fahd University of Petroleum
and Minerals and became Chairman of the Department
of Mathematics and Statistics and also taught
physics at the Department of Physics. In 1983,
Riazuddin, along with Asghar Qadir, went to
Trieste, Italy, to join the International
Centre for Theoretical Physics. Both scientists
joined Salam where they continued research
in their fields. In 1998, Riazuddin left King
Fahd University of Petroleum and Minerals
and returned to Pakistan to rejoin PAEC.
=== Scientific research ===
During his post-graduate research, Riazuddin
made contributions to mathematical physics,
as he was highly interested in complex mathematical
series, and its relation to modern physics.
In 1959, Riazuddin was the first physicist
to use the dispersion relation for Compton
scattering of virtual photons on pions to
analyse their charge radius. For this contribution,
he was awarded the doctorate in physics (theoretical)
by Cambridge University. He seldom published
papers, preferring long correspondences with
his brother Fayyazuddin, mentor Abdus Salam,
and colleagues including Asghar Qadir, Michael
Duff, and Masud Ahmad. During the 1960s, he
associated himself with complex mathematical
applications of nuclear physics. In 1960,
Riazuddin used Nucleon-nucleon dispersion
relation to discriminate proton-proton scattering
in pseudoscalar mesons. In 1965, Riazuddin
carried out the pioneering work on vector
currents, in which he showed the discrepancy
between μ-decay and the constant gravity,
and the strong interaction renormalisation
of the Beta (β)-decay.The same year, the
U.S. Atomic Energy Commission, partnering
with the Pakistan Atomic Energy Commission,
sponsored Riazuddin to undertake further research.
Along with Munir Ahmad Rashid and Fayyazuddin,
Riazuddin realised that the physical baryons
are considered broken in special unitary groups,
symmetric groups and the tensor product. The
relevant papers were submitted at the United
States Atomic Energy Commission. In 1967,
at the Fermi Institute, Riazuddin, with his
brother Fayyazuddin, carried out research
in the field of current algebra, where they
applied the mathematical framework of current
algebra in the applications of radiative decays
of mesons.In 1982, Riazuddin and Fayyazuddin
published a pioneering work on K mesons. Riazuddin
postulated that radioactive decay in K mesons
have almost vanished when chiral symmetry
is introduced. After the introduction, the
symmetries break the Standard Model of particle
physics, even when the contribution from penguin
diagrams is included.From 1972, Riazuddin
made pioneering research on neutrinos— an
elusive particle postulated by Wolfgang Pauli
in 1930. In 1972, Riazuddin and Fayyazuddin
were the first to post mathematical frameworks
of Current-algebra in neutrino scattering
to determine the Scale invariance of Chiral
symmetry breaking the Hamiltonian Quantum
Mechanics.
n 1987, Riazuddin and Fayyazuddin theorised
that it is possible get light-neutrino masses
in the range of a few electron volts by equalising
the masses of superheavy neutrinos in background
independence (universality).In 2000, Riazuddin
began his research in the series unsolved
problems in physics. In 2005, at the National
Center for Physics (NCP), Riazuddin presented
his papers on neutrinos where he provided
the mathematical framework of the neutrinos.
Neutrinos have heavier masses but the neutrino
oscillations do not completely identify the
overall scale of their exact masses because
they are exceedingly tiny. To determine the
exact masses, Riazuddin introduced the laws
of limits, as he realised there was a limit,
to the electron energy spectra in tritium
β-decay. In 2007, Riazuddin introduced SU(3)
symmetry in the theory of double beta decay.
He postulated the light neutrinos formed a
triplet state in a SU(3) symmetry during the
process. In 2008, Riazuddin pointed out that
the neutrino mass has μ and τ symmetry and
the Lepton number remains constant, a new
type of Seesaw mechanism is formed, the so-called
Riazuddin's Seesaw Model, the Dirac mass matrix
provided the Yukawa coupling to follow the
Majorana fermion to satisfy the Leptogenesis
asymmetry. Riazuddin proposed that this interaction
can be avoided when two of the heavy right-hand
neutrinos are (nearly) degenerate.In 2009,
Riazuddin published a mathematical theory
of the non-standard model, and its brief extensions
to τ (tau) particles — particles that are
similar to electrons with negative electric
charge. In an experiment performed at the
Synchrotron light source installed at the
National Center for Physics (NCP), now the
Abdus Salam Centre for Physics, Riazuddin
observed the decay of the Tau particle, in
which he theorised that hadronisation vector
currents and axial vectors can be used to
study the implicit properties and functions
of hadronic resonances, together with Chiral
symmetry. These natural elements can be assigned
to the parts' weak current that the strong
nuclear interaction conserves. With the introduction
of such elementary particles, it became critical
to study the particle elements that hold the
weak interaction.
== 1971 war and atomic bomb project ==
During his stay at PAEC, Riazuddin and Fayyazuddin
were central figures of Pakistan's atomic
program during the early and critical years.
In December 1972, Riazuddin returned to Pakistan
on the request of Salam. Salam asked Riazuddin
to report to Munir Ahmad Khan — chairman
of the Pakistan Atomic Energy Commission at
that time. At PAEC, Salam assigned Riazuddin
to his Theoretical Physics Group (TPG). The
Theoretical Physics Group took research in
fast neutron calculations — how neutrons
moved in a nuclear chain reaction – the
theory simultaneity — how would fission
weapon would detonated from several points
at the same point during the detonation process
– and hydrodynamics – how the explosion
produced by a chain reaction might behave
– and what kind of and how much fissile
material and reflectors would be used. Salam
had attracted theoretical physicists who worked
under Riazuddin despite his younger age. Riazuddin
was among the scientists who attended the
Multan meeting that was managed by Salam and
convened by Pakistan President Zulfikar Ali
Bhutto. After the meeting, Salam took Riazuddin,
with Munir Ahmad Khan, to Bhutto's residence
in Islamabad where the scientists briefed
Bhutto about the development of the nuclear
weapons programme.Although Salam had traveled
to the United States to evade the Indo-Pakistani
war of 1971, he returned to Pakistan with
stacks of historical books on the Manhattan
Project in December 1971. In December 1973,
the University of Maryland offered him a fellowship,
and on the advice of Salam, Riazuddin went
to United States. There, he became a senior
research scientist at the University of Maryland,
and obtained the open-source information on
the "Manhattan Project" from the Library of
Congress. Riazuddin carefully studied American
theoretical physicist J. Robert Oppenheimer's
approach to develop the first implosion device,
and made further advances on Tolman-Oppenheimer-Volkoff
limit, Oppenheimer-Phillips process, Born–Oppenheimer
approximation.
After his return from the United States, Riazuddin
was inducted into the Pakistan Atomic Energy
Commission (PAEC) as member (technical). In
1974, he began to take research with the TPG,
and began one of the pioneering member of
the TPG. In 1973, Raziddin Siddiqui formed
the Mathematical Physics Group (MPG) which
closely collaborated with Theoretical Physics
Group. Riazuddin called his mathematician
friend Asghar Qadir, who specialised in special
relativity under Riazuddin and Salam, to join
the Mathematical Physics Group. Later in his
career, Qadir published a college text book
on theory of special relativity. Shortly after
the India surprise nuclear test — Pokhran-I,
Munir Ahmad Khan called for a meeting to initiate
the work on atomic bomb. Riazuddin and Salam
represented the Theoretical Physics Group
(TPG), and it was decided to develop the implosion
method for the first device. During the meeting,
the word "bomb" was never used; instead academic
scientists preferred to use the scientific
research rationale. The Theoretical Physics
Group began its research and directly reported
to Abdus Salam.In 1977 both MPG and TPG scientists
completed the design and calculation of an
atomic bomb. Along with Qadir, Riazuddin continued
to develop the theoretical designs of the
atomic weapon during 1978. In 1982 the PAEC
finally developed the device under the leadership
of Munir Ahmad Khan. The PAEC carried out
the first cold-test of the TPG's theoretical
design by May 1983 at Kirana Hills. The test
teams were headed by Ishfaq Ahmad, a nuclear
physicist, and Munir Ahmad Khan supervised
the testings.Riazuddin later disclosed that
he worked as part of the team, under Abdus
Salam, that worked on designs for Pakistan's
nuclear explosive device. As he explained:
Riazuddin also worked in a neutron particle
accelerator at PAEC. In 2000, Riazuddin retired
from PAEC as a chief scientist. In the same
year, he was elected as Fellow of the Third
World Academy of Sciences and Fellow of the
Islamic World Academy of Sciences (IAS). Riazuddin
was also a visiting scientist at CERN.
== Legacy and fame ==
Riazuddin was an internationally known theoretical
physicist. He had made contributions with
CERN's Large Hadron Collider (LHC). At CERN,
he was a widely respected theoretician. Riazuddin
is the recipient of Pakistan's highest civil
awards: Tamgha-i-Imtiaz, Sitara-i-Imtiaz,
Hilal-i-Imtiaz. He is one of the Pakistani
scientists who were very close to Pakistani
Prime Minister Zulfiqar Ali Bhutto and Abdus
Salam. At PAEC, Riazuddin had closely worked
with another noted Pakistani theoretical physicist
Raziuddin Siddiqui (late). Later in life,
he worked as a professor of theoretical physics
and neutrino physics at the National University
of Sciences and Technology, in Islamabad.
He had also been the director of the Riazuddin
National Center for Physics, also at Quaid-e-Azam
University. He was most famous for his TPG
Group work Riazuddin and his team of theoretical
physicists are widely credited to have developed
and designed Pakistan's nuclear weapon devices.
On 26 April 2009, a day-long conference was
held in Islamabad to pay tribute to an eminent
research scientist and theoretical physicist,
Riazuddin. The conference was organised by
National University of Sciences and Technology
(NUST) and Riazuddin National Centre for Physics
(RNCP). In the conference, Masud Ahmad, who
is also the student of his, said:
"Prof. Riaz always put in his best efforts
to obtain original results while working on
various issues related to science and technology".
NUST Rector and a famous Pakistani aerospace
engineer, Air Commodore Muhammad Asghar also
paid tributes to him and said:
"Prof. Riazuddin has a very strong and professional
background in the field of Physics. He achieved
many distinctions and awards from national
as well as international institutes, which
includes Tamgha-e-Imtiaz, Sitara-i-Imtiaz
and Hilal-e-Imtiaz and awards from UNESCO,
Economic Cooperation Organization and COMSTECH
Prize in Physics".
== Institutes named after Riazuddin ==
Riazuddin National Center for Physics, Quaid-e-Azam
University, in Islamabad.
== Publications and scientific articles ==
=== 
Bibliography ===
Theory of Weak Interaction in Particle Physics,
John Wiley, New York, 1969. (Written jointly
with R. E. Marshak and C. P. Ryan).
Quantum Mechanics, World Scientific, Singapore,
1990. (Written jointly with Fayyazuddin).
A Modern Introduction to Particle Physics,
World Scientific, Singapore, 1994. (Written
jointly with Fayyazuddin).
Contemporary Physics: Proceedings of the International
Symposium (written jointly with Faheem Hussain,
Jamil Aslam, Riazuddin
Physics and contemporary needs. Vol.5 by Riazuddin,
Asghar Qadir
Physics and Contemporary Needs. Written and
edited by Riazuddin
Selected Papers of Abdus Salam, with Commentary
by A. Ali, Abdus Salam, Fayyazuddin, Riazuddin.
Modern Introduction to Particle Physics (vol.
2), by Fayyazuddin and Riazuddin
Radiative D* decay using vector meson dominance
by Riazuddin and Fayyazuddin
On the gluon dipole penguin contribution to
nonleptonic hyperon decays. By Riazuddin and
N. Paver
* Mathematical Physics, jointly written with
Faheem Hussain, Riazuddin, Asghar Qadir, Mohammad
Jamil Aslam, Hamid Saleem.
=== Scientific articles ===
The Role of Great Equations in Life by Riazuddin,
Riazuddin National Center of Physics.
Tribimaximal mixing and leptogenesis in a
seesaw model, Riazuddin, Islamabad.
Dirac equation in (1+2) dimensions for quasi-particles
in graphene and quantum field theory of their
Coulomb interaction. Riazuddin, Riazuddin
National Center for Physics.
(SU) × U(1) model for electroweak unification
and sterile neutrinos. Jointly written with
Riazuddin and Fayyazuddin.
An SU(3) symmetry for light neutrinos, Riazuddin
Branching Ratio and CP-asymmetry for B→
gamma decays, jointly written with M. Jamil
Aslam and Riazuddin
Neutrino flavour mixing in an SU(3) symmetry
for light neutrinos. Published by Riazuddin
Neutrinos: recent developments and origin
of neutrino mass matrix, Riazuddin (May 2004)
Role of Mathematics in Physical Sciences,
Riazuddin (February 2004)
Some comments on narrow resonances. By Fayyazuddin
and Riazuddin (September 2003)
Neutrino Mass Matrix with Approximate Flavor
Symmetry, Riazuddin (July 2003)
Particle Aspects of Cosmology and Baryogenesis,
Riazuddin (February 2003)
Role of lepton flavor violating (LFV) muon
decay in Seesaw model and LSND by M. Jamil
Aslam and Riazuddin(September 2002)
Role of gauge invariance in B→v gamma radiative
weak decays, Riazuddin (October 2001)
The ∑ and τ in D and B decays, jointly
written, N. Paver and Riazuddin (July 2001)
Potential Models for Radiative Rare B Decays,
Saeed Ahmad and Riazuddin (January 2001)
Off-diagonal structure of neutrino mass matrix
in see-saw mechanism and electron-muon-tau
lepton universality, Riazuddin (July 2000)
Two body non-leptonic $Lambda_b$ decays in
quark model with factorization ansatz, published,
Fayyazuddin and Riazuddin (February 1998)
Double Counting Ambiguities in the Linear
Sigma Model by A. Bramon, Riazuddin and M.
D. Scadron (September 1997)
Vector Meson Exchanges and CP Asymmetry in,
Riazuddin, N. Paver and F. Simeoni
