Transcript Dr.Sinha - Indico

Collider to CosmologyMini Bang to the Big Bang
Bikash Sinha
INSA Emeritus Scientist
Variable Energy Cyclotron Centre
Festschrift, Professor Pijushpani Bhattacharya
13th October, 2015
Four basic forces United
Infinitely small universe
?
BIG BANG
DAWN OF TIME
Physics as we know it does not exist
2
HUBBLE’S DISCOVERY
Universe is expanding.
The expansion follows specific mathematical relation.
This implies universe was much smaller
in the past and hence it was much
denser and hotter.
In the early universe matter existed in
the form of fundamental particles.
3
UNIVERSE STARTED WITH A BIG BANG !!
Big Bang
• Universe was born 14 billion years ago
through a massive explosion called Big
Bang.
• At that moment, all matter was
compressed into a space billions of times
smaller than a proton.
• Beginning of space and time.
• Since that moment the cosmic bodies are
moving away from each other, and the
universe is expanding.
4
Cosmic Time Line
BIG
BANG
Arrow of Time
Emission of cosmic
background radiation
Dark ages
First stars
First supernovae
and black holes
Modern galaxies
5
Cosmic Time Line
BIG
Arrow of Time
BANG
Emission of cosmic
background radiation
Dark ages
First stars
First supernovae
and black holes
Modern galaxies
6
7
8
The cosmological big bang is played out at LHC albeit in a
miniature scale, with the little bangs between two nuclei.
As is well known the big bang is a display of gravity, space
and time where as the little bang is essentially to do with
confinement and subsequently to deconfinement in
extreme conditions.
On the other extreme end of the phase diagramme
lies a domain of very high baryonic density but at rather
low temperature, a scenario for neutron star matter, of
compressed baryonic matter and a temperature, very near
zero.
9
It is widely conjectured that the quark gluon sector of such
matter may indeed consist of “colour super conductors” and
high density hadronic (neutron) matter or hybrid matter in the
hadronic sector.
We study the spin down behaviour of a rotating neutron
star with the realisation that changes in the internal structure as
the star spins down, will be reflected in the moment of inertia
and hence the deceleration. In this letter we are not considering
the “recycling” scenario of binary system.
During the spin down of a (say) millisecond neutron star,
the central density increases with decreasing centrifugal force;
leading to a phase transition from the somewhat incompressible
nuclear matter to the highly compressible, perfect fluid, quark
matter in the stellar core.
10
Indeed as the bulge of quark matter in the stellar
core increases in dimension, a perfect fluid of QCD
colour will set in, and, the perfect colour fluid will
splash into hadronic matter transforming more of
hadronic matter to colour superconducting quark
matter. After the quark gluon matter dominates in
the core, the star would contract significantly and its
moment of inertia decreases sharply, a common
signature of phase transition from confined to
deconfined matter.
11
The nature of the phase transition from hadrons to
quarks in a neutron star, thus is unique and very
different; from the experiments carried out on our
earth. The continuous process of phase transition
closely resembles cross over but not exactly identical. It
is
felt
that
by
means
of
designing
ingenious
experiments conducted by ”CBM” type of detector this
novel matter can be discovered; one possibility of
course is to study ”CBM” but at cooler environment,
analogous to the core of neutron star.
12
Possible existence of quark- matter in dense neutron- stars is discussed
using Quantum Chromo-dynamical equation of state for cold degenerate
quark- matter.
Radiation at CERN-SPS
16
WA98 Experiment at CERN-SPS
•Observation of collective flow
Phys. Lett. B403 (1997) 390.
•Scaling of particle production:
Phys. Lett. B458 (1999) 422.
•DCC Search:
Phys. Lett. B420 (1998) 169
Phys.Rev.C64:011901,2001,
Phys. Rev. C 2003
•Fluctuations:
Phys. Rev. C, May 2002
– DIRECT PHOTONS
17
PMD in WA98 Experiment
18
Brookhaven National Laboratory, New York
PHOBOS
1 km
RHIC
PHENIX

BRAHMS
h
STAR
PHENIX
BARC & BHU
STAR
STAR
IOP
Bhubaneswar
Panjab U., Chandigarh
Rajasthan U., Jaipur
Jammu U., Jammu
VECC,
Kolkata
19
STAR experiment at RHIC, BNL
20
CERN, Geneva
ALICE @ LHC:
• Photon
Multiplicity Detector
• IOP
Bhubaneswar
•Panjab U.
Chandigarh
• Rajasthan U. Jaipur
• Jammu U.
Jammu
• VECC
Kolkata
LHC
• Muon Arm Project
• SINP
• AMU
Kolkata
Aligarh
9km
SPS
WA93 & WA98 @ SPS:
IOP
Bhubaneswar
Panjab U., Chandigarh
Rajasthan U., Jaipur
Jammu U., Jammu
VECC,
Kolkata
21
ALICE Experiment at LHC
PMD
photons
PMD
Modules
MUON arm
m-pairs
Muon
chambers
22
23
24
(nucl-th/0508043, J. Alam, J. Nayak, P.Roy,
A. Dutt-Mazumder, B.S.)
Radiation at RHIC
25
J.K. Nayak, B. Sinha / Physics Letters B 719 (2013) 110–115
26
FROM THE TERRESTRIAL LIGHT
to
THE COSMIC LIGHT,
NO ORDINARY LIGHT
Light from large Megellanic clouds –
150,000 light years away
27
28
Survivability of Cosmological Quark Nuggets:
(Chromoelectric flux-tube fission model):
First order phase transition (q-h)
E. Witten Phys. Rev. D 30 (1984)
P. Bhattacharya, J. Alam, B.Sinha,
Sibaji Raha: Phys Rev.D 48 (1993)
Chromo electric Flux-tube fission
P. Bhattacharya
J. Alam
S. Raha
B.S. (PRD ’93)
[dNB/dt]abs = -2π2 [ nN υN / mN T2] exp [mN - μNq / T ] [ dNB / dt ] ev
The net charge of baryon number of the QN is
dNB /dt = [dNB/dt ]ev + [dNB/dt]abs
Strange quark nuggets (SQN)
H
H
L
L
L
L
L
H
L
Isolated expanding bubbles of low temp
In high temp phase
L
Expanding bubbles meet
H
L
L
L
H
Isolated shrinking bubbles of High temp phase
CEFT MODEL
Glendenning & matsui -1983
•
o
•
meson evaporation
oo
••
•
Sumiyoshi et al 1990
Baryon evaporation
QN with a baryon number NB at the time t
will stop evaporating further (thus survive)
if the “time scale” of evaporation
>> Hubble expansion (Cooling time scale)
[Source: P.
Bhattacharjee, J.
Alam, B. Sinha and
S. Raha, 1993, Phys.
Rev. D 48, 10, 46304638
[Source: P.
Bhattacharjee, J. Alam,
B. Sinha and S. Raha,
1993, Phys. Rev. D 48,
10, 4630-4638
[Source: P.
Bhattacharjee, J.
Alam, B. Sinha and
S. Raha, 1993, Phys.
Rev. D 48, 10, 46304638
So, Quark Nuggets with
NB , in ≥ 1043. 5 are
stable and survive forever!!
MACHO , Relics of
Q-H phase transition
Sibaji Banerjee
A. Bhattacharya
S. Ghose
S. Raha, B.Sinha
Mon. Not. R. Astronomical Society (2002)
Gravitational Lensing :
(13-17) Milky Way halo MACHOs, detected
in the direction of Large Magellanic cloud
Mass range (0.15-0.95) M‫סּ‬
Most probable ~ 0.5 M‫סּ‬
Suttherland (1999)
Alocock (2000)
Above the threshold for Nuclear fusion
=> evolution of metastable (TFVD)
(Strange Quark Nuggets, SQN)
Entire Cold Dark Matter (CDM)
(ΩCDM~0.3-0.35) can be comfortably
explained by stable SQN’s
Alam, Raha & B.S. Astrophysical journal (1999)
S. Banerjee et. al. PLB 611 (2005)
Nucl. Phys A774(2006)
Cold Dark Matter
and the Cosmic Phase
Transition
It is entirely plausible that during the primordial
quark hadron phase transition in the universe,
microseconds after the Big Bang, supercooling takes
place, accompanied by mini inflation. With μ/T ∼ 1
(μ is chemical potential), leading to a first order
phase transition, there will be relics in the form of
quark nuggets, and, that they consist of Strange
Quark Matter. The possibility that these SQM
nuggets may well be the candidates of cold dark
matter is critically examined. A cursory comparison
with the neutron star is presented at the end.
…to be published in Journal of Physics: Conference Series
Ref: Boeckel T and Schaner- Bielich J 2010 Phys. Rev. Lett. 105 041301
- η b/ ηγ ~ 10 -10
- expansion time scale ~ 10 –5 sec
____
Mini Bang ?= Big Bang
Turbulance
Inflation
Gravitation
Horizon
45
LITTLE BANG
VS.
BIG BANG(B.B)
1. B.B expanding against the pull of Gravity (G)
L.B expanding against the pull of the Bag (B)
Both Very Violent
46
2.
Entropy is mysteriously produced
at some early stage
t
Approximately conserved later
B.B.
v
( )  H (t )
H(t) : time dependent
“Hubble’’ Const
L.B.
v
( )  HT
HT : Tensor ; anisotropic as time t
Anisotropy
isotropy
~
Freeze out ~ Hubble like
47
3.
B.B :
Eq. Of state, Gravity
DARK MATTERS
Even “shocking”
DARK Energy ~ 73%
(-ve) pressure
Accl Universe (Non Zero Cosmological Const)
QGP
“B”
Hadrons ( Zero density & Pressure )
deccelerate
48
.
4
L.B. : ( Observed Hadrons )
Analogous to the microwave cosmic radiation of B.B :
Are seen at the moment of their
last interaction (decouple)
freeze out
Ω- hyperons decouple earlier and/or
Leptons & photons
5.
Fluctuation :
(L.B) QGP
∆
T
~ 10 5 ( B.B )
T
(Microwave heat both)
Hadrons ( Fluctuation )
B. B is much better studied
49