
The
INT
program
on
Quantitative
Large
Amplitude
Shape
Dynamics:
fission
and
heavy
ion
fusion
was
held
in
Seattle,
WA
from
23
September
to
15
November,
2013.
The
organizers
were:
A.N.
Andreyev
(University
of
York),
G.F.
Bertsch
(Institute
for
Nuclear
Theory),
W.
Loveland
(Oregon
State
University),
and
W.
Nazarewicz
(University
of
Tennessee/ORNL).
The
intent
of
this
program
was
to:
(i)
bring
together
theorists
working
on
predictive
theories
of
the
underlying
shape
dynamics
to
compare
various
approaches
and
computational
methodologies;
(ii)
actively
foster
collaborations
between
the
major
actors
in
the
field,
including
collaborations
between
experiment
and
theory;
(iii)
identify
critical
experimental
data
that
will
inform
theoretical
developments;
and
(iv)
identify
strategies
and
resources
to
break
computational
barriers
in
this
area.
We
believe
that
excellent
progress
has
been
made
in
all
four
areas.
The
program
was
well
attended,
with
65
total
participants.
Week
4
of
the
program
was
organized
as
predominantly
experimental
workshop,
which
dealt
largely
with
new
data
on
fission
and
fusion
to
challenge
nuclear
theory.
Week
7
of
the
program
contained
a
workshop
on
Reactor
Antineutrinos.
The
program
needs
to
be
put
into
the
perspective
of
the
intellectual
development
that
occurred
since
the
last
INT
program
on
largeamplitude
dynamics,
INT953
(organized
by
Bertsch
and
Nazarewicz).
As
presented
in
the
talks,
we
now
have
accurate
descriptions
(<
1
MeV)
of
fission
barriers
based
on
selfconsistent
meanfield
theory,
with
the
beginnings
of
systematic
error
assessments
of
the
theory.
Quantitative
results
are
now
available
the
calculation
of
heavyion
fusion
cross
sections
by
TDHF.
The
calculations
of
spontaneous
fission
lifetimes
have
become
much
more
sophisticated
in
the
context
of
the
WKB
barrier
penetration
model:
more
collective
degrees
of
freedom
are
taken
into
account
in
setting
the
fission
path;
the
path
may
now
be
determined
by
minimizing
the
action;
the
inertia
term
in
the
action
integral
may
be
treated
in
a
way
consistent
with
the
instanton
formulation
of
barrier
penetration.
We
also
saw
a
major
advance
in
the
theory
of
fission
mass
distributions:
many
of
the
details
can
be
reproduced
by
a
statistical
treatment
with
diffusive
dynamics.
We
expect
that
new
experimental
efforts
discussed
during
the
program
will
not
only
greatly
increase
the
database
for
which
current
theory
can
be
applied
but
will
also
provide
its
crucial
tests.
We
expect
that
there
will
be
a
number
of
new
collaborations
or
at
least
new
theoretical
studies
that
will
have
genesis
in
INT133.

An
initial
goal
of
the
program,
to
reevaluate
the
basic
assumption
in
the
theory
of
nuclear
fission,
is
being
realized
by
a
position
paper
being
drafted
to
investigate
a
new
approach
to
making
a
theory
that
is
both
broad
enough
to
treat
the
adiabatic
and
the
dissipative
limits
of
fission
dynamics,
as
well
as
being
computationally
tractable.

A
reporting
guide
is
being
prepared
for
theorists
to
make
it
easier
to
compare
different
methods
and
to
assess
the
reliability
of
theory
for
applications.
The
guide
includes
the
list
of
measured/evaluated
quantities
(spontaneous
fission
halflives,
fission
barrier
heights,
fission
fragment
mass
distributions,
and
excitation
energies
of
fission
isomers)
that
can
be
used
to
benchmark
various
methodologies
and
optimize
models.
The
guide
also
gives
recommendations
on
error
analysis
of
the
theory
and
how
to
present
the
uncertainties.
Finally,
a
prioritized
set
of
measurements
related
to
reactor
antineutrinos
will
be
published.
We
think
that
the
embedded
experimental
workshops
greatly
enriched
the
program
as
they
brought
contact
between
theory
and
experiment
to
the
forefront.
The
discussions
between
the
two
groups
enhanced
the
understanding
of
both
groups
and
led
to
productive
collaborations.
We
strongly
recommend
having
these
opportunities
to
be
part
of
future
INT
programs.
