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Next big thing in high energy physics – II
Gagan Mohanty
TIFR, Mumbai
WAPP2016 @ Ooty
December 27, 2016
Where do we stand?
 Quarks and leptons are basic building blocks
and interact among themselves via exchange
of gluons, photon, W and Z bosons
A modern periodic table?
 Combining quantum mechanics (physics of small) and relativity (physics
of fast) along with plethora of particles discovered  Standard Model of
particle physics
There are lots that the SM is silent about...
 In addition to these grandiose questions, there are many hidden ones within SM
The SM is an enigma...
① Why there are only three family?
② Why such a great disparity of mass?
③ ...
Let’s take a step back...
Energy frontier
Luminosity frontier
1964: CPV in K
1974: J/y (c quark)
1975: t lepton
1977:  (b quark)
1983: W and Z
Both are equally
important
1987: B0-mixing
1995: t quark
2012: Higgs
2001: CPV in B
2004: Direct CPV
2007: D0-mixing
Next target is discovery of new physics (NP)
Two approaches to NP
Baryogenesis
SM is incomplete
Dark matter
Neutrino mass
Mass hierarchy
Grand
unification
There must be New Physics @ TeV scale !!
But
Supersymmetry ?
y y
Direct Search
LHC, ILC
Extradimension ?
D>4
Composite
Higgs ?
, or what?
h = yy
Flavor physics: key to identify the theory
B
D
t
K
m
n
Future flavor physics facilities
…
Energy vs. luminosity frontier
Direct production by NP particles
Virtual effects in quantum loop
~
q
p
p
s
b
~
c
~
g ~
~
q
c
_
q
q
g
n~
lTunnel effect
Energy frontier
Luminosity frontier
Diagonal terms
m

2
q ij

m112 m122
2
21
m
2
22
m
m132
2
23
m
2
2
2
m31
m32
m33
Off-diagonal terms
Higher energy scale
can be probed (even
if LHC finds no NP)
Flavor provides a
NP treasure chest
,t
Variety of measurements !
m facility
K experiments
LHCb
Super t/c factory
Super B factory
Competitive &
complementary
vs. energy frontier experiments
among flavor experiments
Unique feature !
G. Isidori et al.,
Ann.Rev.Nucl.Part.Sci. 60, 355 (2010)
+ report by B.Golob
m  e conv.
m (g-2)
10 -(14-18) m facility
0.14ppm m facility
Unique at
SuperKEKB, t/c
Two prominent discrepancies
B  D(*)tn
3.9s
 Tree-level process  sensitive to possible
charged Higgs contribution
 ~4σ discrepancy with respect to the SM
prediction
B  K(*)l+l-
3.7s
2.1s
 FCNC process
 NP in quantum loop
 Two experiments find tantalizing difference  need more data to clear the picture
t physics: LFV decays
t LFV decays
 Assuming massive neutrino, the typical LFV
decay rate are of order 10−54
 Therefore, any signal would provide clear
evidence for NP
e+e- colliding machines
SuperKEKB
8x1035
40 times higher
luminosity
KEKB
STCF
BEPC II
BEPC II
_
Coherent MM
Clean environment
 Missing n’s
 Inclusive
Most visible legacy from Belle
Proper time difference between two B mesons
 Established beyond any doubt that the Kobayashi-Maskawa phase is responsible
for CP violation (CPV) within the standard model
 The CPV content, however, falls short by several orders of magnitude to explain
the matter-antimatter asymmetry in our universe

Strategy for high luminosity
*I  


s
g
y   y RL
L
1 *  *  
2ere  s x   y  Ry 
Lorentz factor
Classical electron radius
Geometrical reduction factors
due to crossing angle and
hour-glass effect
Beam size ratio
• Increase beam current, I
• Larger beam-beam par, y
• Smaller *y (+low emmittance)
Nano-beam scheme
Invented by P. Raimondi at Frascati
Adopted by the SuperKEKB Factory
Nano-beam scheme
L
KEKB
Half crossing
angle: f
Hourglass condition:
βy*>~ L=sx/f
SuperKEKB
(w/o crab)
22mrad
1mm
100mm
5mm
s *y  I y  RL 
L


1 * 
2ere  s x   *y  Ry 
~50nm
g 
1mm
100mm
5mm

83mrad
N  N- f
L
R
* * L
4s xs y
SuperKEKB
Colliding bunches
Belle II
New IR
e- 2.3 A
New superconducting
/permanent final focusing
quads near the IP
New beam pipe
& bellows
e+ 4.0 A
Replace short dipoles
with longer ones (LER)
Add / modify RF systems
for higher beam current
Low emittance positrons
to inject
Redesign the lattices of HER &
LER to squeeze the emittance
TiN-coated beam pipe with
antechambers
Positron source
Damping ring
New positron target /
capture section
Low emittance gun
Low emittance electrons
to inject
L=8·1035 s-1cm-2
x 40 gain in luminosity
Machine parameters
KEKB(@record)
parameters
SuperKEKB
LER
HER
LER
HER
3.5
8
4
7
units
Beam energy
Eb
Half crossing angle
φ
11
41.5
# of Bunches
N
1584
2500
Emittance Horizontal
εx
18
24
3.2
4.6
nm
Emittance ratio
κ
0.88
0.66
0.27
0.28
%
Beta functions at IP
βx*/βy*
Beam currents
Ib
1.64
1.19
3.6
2.6
beam-beam param.
ξy
0.129
0.090
0.0881
0.0807
Bunch Length
6.0
6.0
6.0
5.0
mm
150
150
10
11
um
Vertical Beam Size
sz
sx*
sy*
0.048
0.059
um
Luminosity
L
Horizontal Beam Size
1200/5.9
0.94
2.1 x 1034
GeV
mrad
32/0.27 25/0.30
8 x 1035
mm
A
cm-2s-1
Integrated luminosity
(ab-1)
Luminosity projection
Goal of Belle II/SuperKEKB
Assumes full operation
funding profile.
Peak luminosity
(cm-2s-1)
9 months/year
20 days/month
Commissioning starts
early 2016. Full Physics 2018
Assumes KEKB Luminosity
learning curve x 80
Shutdown
Calendar Year
Belle II detector
BKLM
EKLM
TOP
Construction
in progress
CDC
At the heart of Belle II...
 Lies a sophisticated vertexing and inner tracking system (VXD)
to:
• Determine the vertex position of the
weakly decaying particles
• Precisely measure the track position
and momentum for low-pT tracks
 It is composed of:
a)
b)
Pixel detector (PXD)
Silicon micro-vertex detector (SVD)
– Double-sided Si microstrip sensors
SVD
PXD
VXD requirements
• Fast – to operate in high rate environment
• Excellent spatial resolution (~15 μm)
• Radiation hard (up to 100 kGray)
• Good tracking capability – to track charged
particles down to 50 MeV in pT
SVD and TIFR in it
Layer
Institute
3
Melbourne
4
TIFR Mumbai
5
HEPHY Vienna
6
Kavli IPMU
Layer#
Sensor/ladder
Origami
Ladder
Length
Radius
Slant angle
Occupancy
3
2
0
7
262 mm
38 mm
0o
6.7%
4
3
1
10
390 mm
80 mm
11.9o
2.7%
5
4
2
12
515 mm
104 mm
17.2o
1.3%
6
5
3
16
645 mm
135 mm
21.1o
0.9%
 For the 1st time, we are involved in such an advanced detector project
A fully assembled module
Sensor
Δx
(µm)
Δy
(µm)
Δz
(µm)
BW
-49
-6
-7
-35
-15
-47
-34
-22
94
CE
FW
Design specs: ±150µm (Δx, Δy ) ±200µm (Δz)
 Before reaching here, needed to pass through several stages of a
stringent international review procedure
India in Belle (II)
①
②
③
④
⑤
⑥
⑦
⑧
⑨
⑩
IISER Mohali (Prof. V. Bhardwaj)
IIT Bhubaneswar (Prof. S. Bahinipati, N. Dash)
IIT Guwahati (Prof. B. Bhuyan, D. Kalita, K. Nath)
IIT Hyderabad (Prof. A. Giri, Prof. S. Desai, S. Choudhury)
IIT Madras (Prof. P. Behera, Prof. J. Libby, A. Kaliyar, P.
Krishnan, P.K. Resmi)
IMSc Chennai (Prof. R. Sinha)
PU Chandigarh (Prof. J.B. Singh, R. Garg)
PAU Ludhiana (Prof. R. Kumar)
MNIT Jaipur (Prof. K. Lalwani, M. Chahal, Y. Saini)
TIFR Mumbai (Prof. T. Aziz, Prof. G. Mohanty, Dr. D. Dutta,
Dr. V. Gaur, V. Babu, S. Mohanty★, D. Sahoo, S. Divekar,
M.M. Kolwalkar, S.N. Mayekar, K.K. Rao)
Summary
 Flavor physics: important/complementary driving force
with energy frontier in HEP: past (SM)  future (NP)
 Super flavor facilities will take such role in searching
and establishing NP in various ways
 SuperKEKB is under construction (Belle II will be taking
data starting late 2018)
 LHCb plans upgrade: competition/complementary
 Super t/charm factory: BINP, China
 e+e-: clean environment, pure (tagged) mesons
Hope to discover NP in near future either/both in flavor
physics and energy frontier experiments