1. Next big thing in high energy physics – II
Gagan Mohanty
TIFR, Mumbai
Ooty
December 27, 2016

2. Where do we stand?
Quarks and leptons are basic building blocks and interact among themselves via exchange of gluons, photon, W and Z bosons

3. 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

4. There are lots that the SM is silent about...
In addition to these grandiose questions, there are many hidden ones within SM

5. The SM is an enigma... Why there are only three family?
Why such a great disparity of mass?
...

6. Both are equally important
Let’s take a step back...
Energy frontier
Luminosity frontier
1964: CPV in K
1974: J/y (c quark)
1975: t lepton
Both are equally important
1977:  (b quark)
1983: W and Z
1987: B0-mixing
1995: t quark
2001: CPV in B
2004: Direct CPV
2007: D0-mixing
2012: Higgs
Next target is discovery of new physics (NP)

7. Two approaches to NP Future flavor physics facilities Baryogenesis
Neutrino mass
SM is incomplete
Dark matter
Grand unification
Mass hierarchy
There must be New TeV scale !!
Super-
symmetry ?
Extra-dimension ?
Composite
Higgs ?
But , or what?
Flavor physics: key to identify the theory B D K n t m …
Future flavor physics facilities
Direct Search
LHC, ILC

8. Energy vs. luminosity frontier
Direct production by NP particles
Virtual effects in quantum loop q ~ s p p b c ~ g g ~ q ~ c ~ ~ n q _ q l-
Tunnel effect
Energy frontier
Luminosity frontier
Diagonal terms
Off-diagonal terms
Higher energy scale
can be probed (even
if LHC finds no NP)

9. Flavor provides a NP treasure chest Competitive & complementary
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 !
m  e conv (14-18) m facility
m (g-2) ppm m facility
Unique at
SuperKEKB, t/c
G. Isidori et al.,
Ann.Rev.Nucl.Part.Sci. 60, 355 (2010)
+ report by B.Golob

10. 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

11. 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

12. e+e- colliding machines
40 times higher luminosity
8x1035
KEKB
SuperKEKB
STCF
BEPC II _
Coherent MM
Clean environment
Missing n’s
Inclusive

13. 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

14. Strategy for high luminosity
Lorentz factor
Geometrical reduction factors
due to crossing angle and
hour-glass effect
Classical electron radius
Beam size ratio
Increase beam current, I
Larger beam-beam par, xy
Smaller b*y
(+low emmittance)
Nano-beam scheme
Invented by P. Raimondi at Frascati
Adopted by the SuperKEKB Factory

15. Nano-beam scheme L KEKB (w/o crab) Hourglass condition:
Half crossing
angle: f
22mrad
Hourglass condition:
βy*>~ L=sx/f
1mm
SuperKEKB
100mm
5mm
~50nm
1mm
100mm
5mm
83mrad

16. SuperKEKB x 40 gain in luminosity L=8·1035 s-1cm-2 e- 2.3 A
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
Positron source
Damping ring
Redesign the lattices of HER & LER to squeeze the emittance
New positron target / capture section
Low emittance gun
TiN-coated beam pipe with antechambers
Low emittance electrons to inject
L=8·1035 s-1cm-2
x 40 gain in luminosity

17. Machine parameters sz sx* sy* parameters KEKB(@record) SuperKEKB LER
units
LER
HER
Beam energy Eb
3.5 8 4 7
GeV
Half crossing angle φ 11
41.5
mrad
# 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*
1200/5.9
32/0.27
25/0.30 mm
Beam currents Ib
1.64
1.19
3.6
2.6 A
beam-beam param. ξy
0.129
0.090
0.0881
0.0807
Bunch Length sz
6.0
5.0
Horizontal Beam Size
sx*
150 10 um
Vertical Beam Size
sy*
0.94
0.048
0.059
Luminosity L
2.1 x 1034
8 x 1035
cm-2s-1

18. Luminosity projection
Goal of Belle II/SuperKEKB
Assumes full operation
funding profile.
Integrated luminosity
(ab-1)
9 months/year
20 days/month
Commissioning starts
early Full Physics 2018
Peak luminosity
(cm-2s-1)
Assumes KEKB Luminosity learning curve x 80
Shut-
down
Calendar Year

19. Belle II detector
BKLM
EKLM
TOP
Construction
in progress
CDC

20. 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:
Pixel detector (PXD)
Silicon micro-vertex detector (SVD)
Double-sided Si microstrip sensors
VXD requirements
SVD
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
PXD

21. 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 7
262 mm
38 mm 0o
6.7% 4 1 10
390 mm
80 mm
11.9o
2.7% 5 12
515 mm
104 mm
17.2o
1.3% 6 16
645 mm
135 mm
21.1o
0.9%
For the 1st time, we are involved in such an advanced detector project

22. A fully assembled module
Sensor Δx
(µm) Δy Δz BW
-49
-35
-34 CE -6
-15
-22 FW -7
-47 94
Over a length of about 60 cms
Design specs: ±150µm (Δx, Δy ) ±200µm (Δz)
Before reaching here, needed to pass through several stages of a stringent international review procedure

23. India in Belle (II) 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)
The Home Team.

24. 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