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... Why there are only three family? Why such a great disparity of mass? ...

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)

Two approaches to NP Future flavor physics facilities Baryogenesis Neutrino mass SM is incomplete Dark matter Grand unification Mass hierarchy There must be New Physics @ 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

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)

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. 10 -(14-18) m facility m (g-2) 0.14ppm m facility Unique at SuperKEKB, t/c G. Isidori et al., Ann.Rev.Nucl.Part.Sci. 60, 355 (2010) + report by B.Golob

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 40 times higher luminosity 8x1035 KEKB SuperKEKB STCF 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 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

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

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

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

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 2016. Full Physics 2018 Peak luminosity (cm-2s-1) Assumes KEKB Luminosity learning curve x 80 Shut- down 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: 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

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

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

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.

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