Experimental summary of IAS Conference. Roman Pöschl

Transcription

1 Experimental summary of IAS Conference HKUST Jockey Club Hong Kong January 2018

2 Content of the talk Content Overview of detector talks given at the main conference and a summary of the Central Calorimeters for High Energy e+e- Colliders Comments: I will show no physics studies and physics results but will rather concentrate on detector R&D and system overview This is not an overview of worldwide detector R&D but of topics discussed at IAS HEP 2018 with focus on detectors relevant for e+e- colliders I try to project out at least one major trend for upcoming R&D for e+e- detectors Still the chosen curriculum represents hopefully a satisfactory snapshot of ongoing R&D efforts/programs Apologises for not covering all the topics (partially due to lack of slides) 2

3 Collider detectors Basic facts Hadron-hadron collisions e.g. LHC - Busy events - Requires clean filtering Hardware and software e+e- collisions - Clean events - Full event reconstruction 3

4 Detector systems hadron colliders 4

5 Detector systems ep colliders Asymmetric detector that shares features with pp-detectors 5

6 Detector systems e+e- colliders e+e- detector concepts for linear colliders Preferred solution Particle Flow Detectors CLIC Detector B= 4T SiD ILD B= 5T Highly granular calorimeters Central tracking with silicon Inner tracking with silicon B= 3.5T Central tracking with TPC 6

7 Detector systems e+e- colliders e+e- detector concepts for circular colliders Detector concept inspired by ILD but 3 T due to MDI constraints Detector concept with dual readout calorimeter and low magnetic field of 2T 7

8 Belle II Belle II Upgrade Belle 8

9 Vertex detectors - Challenges for vertex detectors - Primary vertex measurement - flavor tagging by reconstruction of secondary and tertiary vertices Impact parameter: σd0 < [5 10/(p[GeV]sin3/2θ)] μm (1/3 x SLD) Example: B-Meson production in ILD Simulation Cartoon by Sviatoslav Bilokin 9

10 Vertex detectors for e+e- Detectors I CMOS Counters MIMOSA Family (new 180) nm Technology - Pixel 16x16 and 16x64 μm2-0.6%/x0/layer (->0.35%X0...) - Integration time down to1 μs in future CLICPix within RD53 - R&D on 65nm technology - Ultra-thin (50 μm active) - Spatial resolution 3 μm - Time stamping 10ns CMOS in STAR 10

11 Vertex detectors for e+e- Detectors II FPCCD DEPFET Counters - Targeted Pixel size 5X5 and 10x10 μm2 => very low occupancy - Operated at 40oC => Cryostat required Thin Si sensor (Si-Oxide-Si sandwich) - Pixel 20x20 μm2-0.15%/x0/layer DEPFET in Belle II 11

12 ATLAS ITK 12

13 Central tracking Royal task of central tracking system Precise measurement of charged particles in e.g. Option 1: All silicon tracking μ μ Option 2: Gaseous tracking -> See next slides 13

14 Central tracking - TPC TPC is also option for CEPC Collaboration with LCTPC 14

15 TPC Towards a (new) prototype One R&D topic: Understand/master Ion Back Flow IBF*Gain V(V) 15

16 Short Excursion Dune LAr TPC JUNO DUNE HyperK 16

17 Particle Flow Detector Jet energy measurement by measurement of individual particles Maximal exploitation of precise tracking measurement large radius and length to separate the particles large magnetic field to sweep out charged tracks no material in front of calorimeters stay inside coil small Molière radius of calorimeters to minimize shower overlap high granularity of calorimeters to separate overlapping showers Particle flow as privileged solution for experimental challenges => Highly granular calorimeters!!! Emphasis on tracking capabilities of calorimeters 17

18 Particle Flow Algorithms I In ILD Concept Global design goal! PFA ARBOR is algorithm of choice for CEPC Detector with similar performance 18

19 Particle Flow Algorithms in LHC Experiments PFA works in hadronic environment and even under harsh pile-up conditions 19

20 Photon reconstruction 20

21 Calorimeter technologies for PFA Detectors Mainly organised within the collaboration All aspects were presented and discussed at this conference 21

22 CALICE - Technological Prototypes Technological and industrial solutions for the final detector R&D start start: 2010, Beam tests since 2011 Elm. calorimeters Semi-digital hadron calorimeter Analog hadron calorimeter Realistic dimensions Integrated front end electronic No drawback for precision measurements (NIM A (2011) 97) Small power consumption (Power pulsed electronics) 22

23 Semi-digital hadron calorimeter Glass RPCs as sensitive medium - Cost effective - Acceptable resolution at high efficiency - Allow for fine subdivision 1m3 technological prototype of SDHCAL - 52 x cells - Commissioned in 2011 Hadron shower Chamber efficiency 23

24 Analog hadron calorimeter 24

25 Intermezzo SiPM/MPPC Silcion photomultipliers have many applications Inside and outside of particle physics ~ Calorimeters for future e+e- colliders Tile Hcal, Dual readout, Scintillator Ecal ~2017 Huge step in quality of SiPM in last decade - ~Since 2003 MePHI/Pulsar (RU) - ~Since 2006 Hamamatsu - Recently Chinese producers - HL-LHC Calorimeters - Medical applications e.g. Endoscopie 25

26 SiW Ecal for a future LC Optimized for Particle Flow Algorithm Jet energy resolution 3-4%, Excellent photon-hadron separation Remark: New kid on the block Timing Basic Requirements: - Extreme high granularity - Compact and hermetic (inside magnetic coil) Basic Choices: - Tungsten as absorber material X0=3.5mm, RM=9mm, li=96mm Narrow showers Assures compact design The SiW ECAL in the ILD Detector - Silicon as active material Support compact design Allows for pixelisation Robust technology Excellent signal/noise ratio: ~10 - O(10^8) cells - No space => Large integration effort 26

27 SiW Ecal Elements of R&D Si Wafer Test beams Prototypes Real size layers Long layer ~1.5m Important lessons for detector construction 27

28 Intermezzo Forward calorimeters Semi-conductor counters 28

29 Exploiting the high granularity Hadronic cascades Hard interactions - Modern bubble chambers - revealing details of Hadronic cascades Primary particle - Motivation to add Granular calorimeters to GEANT4 validation chain Secondary particles/tracks 29

30 Exploiting the high granularity Hadronic cascades Tracks in SDHCAL Tracks in SiW Ecal active material: Si absorber: tungsten Geant active material: gas absorber: steel Geant

31 Exploiting the high granularity Software compensation Pion showers in combined CALICE beamtests Improvement by software compensation i.e. Adequate weighting of energy depositions Jet analysis in CLIC Software weighting improves jet energy resolution 31

32 High granularity and HL-LHC η=1.5 η=3-500 m2 Si, 6M cells - Detector design chosen to cope with and survive radiation doses of up to MeV n/cm2 at HL-LHC - Operation at -30oC => active cooling 32

33 HGCAL Baseline design 33

34 Pile up LHC 34

35 Pile up LHC - Timing Timing error: The pulse slew-rate (slope) dv/dt is the critcal parameter for tming consideraton For signals of many MIPs, only jiter σj = Noise/(slope) is relevant if the tme measuring circuit is under control. Note that for N concurrent MIPs, the jiter is σj (N) = 1/N* σj (MIP) The is the root cause for the good tming resoluton in calorimeters. 35

36 Pile up LHC - Timing Better dv/dt by active Si diodes? => Low Gain Avalanche Detectors 36

37 LGAD and ATLAS HGTD Add to n-on-p sensor an extra thin p-layer => gain of 50 w/o breakdown Time resolution In beam test 37

38 Timing Aspects on r/o electronics First ASICs that integrate timing for LHC: HGCROC and ALTOROC Don't forget precise clock distribution!!!!! 38

39 Merging all together Particle ID Elements of Particle ID 1) Precise vertex measurement 2) de/dx in tracking systems 3) Shower shapes in calorimeters 4) Timing measurements Example LC-TPC Proto 39

40 Particle ID in Belle II Time of Propagation system 40

41 ee->bb in ILD Vertex charge Kaon ID via de/dx Overall efficiency for correct b-charge determination 13% 41

42 PID in CEPC Detector 42

43 Can timing help? K/pi Time of arrival Few ps K/pi Cluster hits ~250 ps/hit p[gev] Tming resolution needs to be well below 1ns level, rather ps! 43

44 Timing Comment by expert C. de la Taille Comment R.P.: Still a long way to go but if we want to be successful in 10 years we have to start now 44

45 Timing Comment by expert C. de la Taille Comment R.P.: Still a long way to go but if we want to be successful in 10 years we have to start now 45

46 Micro Pattern Gas Detectors 46

47 MATHUSLA Baby Mathusla Hands on experience for young students and postdocs 47

48 Very personal conclusions Very rich R&D program presented at this conference Current status benefited from R&D for ILC oriented detectors One keyword Timing Particle ID and timing for e+e- colliders may need efforts beyond LHC reach Will be exciting to see the development towards HL-LHC... and may feedback experience into future detector R&D Particle Flow Detectors (even Dual r/o considers long. segmentation!) Credibility through large scale prototypes LHC upgrades will bring these efforts to system level With some focus on detectors for e+e- colliders R&D program is important by itself but also vital to train next generation on hardware ~50ps timing resolution to < 10ps A collider experiment ramps up Belle II (happens rarely these days) 48

49 Backup 49

50 Linear Electron-Positron Colliders Projects Energy: TeV Electron (and positron) polarisation TDR in DBD for detectors Footprint 31 km Energy: TeV CDR in 2012 Footprint 48km 50

51 Circular Electron-Positron Colliders Proposals CEPC e+ IP1 e- High Energy Booster(7.2Km) Medium Energy Booster(4.5Km) Low Energy BTC I P 4 Booster(0.4Km) LTB e+ elinac Proton Linac(240m) (100m) BTC I P 3 CEPC Coll ider I Ring(50Km ) P SppC Coll ider Ring (50Km) 2 ~100 km storage rings Coupled to hadron collider proposal GeV cms energy No long. beam polarisation CDR Phase IAS Conference ~50 km storage rings Coupled to hadron collider proposal GeV cms energy No long. beam polarisation (Pre-)CDR Phase Jan

52 Jet energy resolution Final state contains high energetic jets from e.g. Z,W decays Need to reconstruct the jet energy to the utmost precision! Goal is around dejet/ejet- 3-4% ( e.g. 2x better than ALEPH) Jet energy carried by Tracker Momentum Resolution GeV/c - Charged particles (e±, h±,μ±65% :(( Most precise measurement by Tracker Up to 100 GeV - Photons: 25% Measurement by Electromagnetic Calorimeter (ECAL) - Neutral Hadrons: 10% Measurement by Hadronic Calorimeter (HCAL) and ECAL 2 Jet = 2Track 2Had. 2elm. Confusion 52

53 Vertex detectors for LC Detectors I DEPFET Counters: Thin Si sensor (Si-Oxide-Si sandwich) - Pixel 20x20 mum2-0.15%/x0/layer Proposed for ILC Applied in Belle II Ladder test in DESY Beamtest CMOS Counters: 350 (new 180) nm Technology - Pixel 16x16 and 16x64mum2-0.6%/X0/layer (->0.35%X0...) - Time resolution down to 1 mus in future 3-4 mum resolution In SPS Beam test Proposed for ILC applied in STAR 53

54 Confusion term - Base measurement as much as possible on measurement of charged particles in tracking devices - Separate of signals by charged and neutral particles in calorimeter - Complicated topology by (hadronic) showers - Overlap between showers compromises correct assignment of calo hits Confusion Term Need to minimize the confusion term as much as possible!!! 54

55 CALICE Mission Final goal: A highly granular calorimeter optimised for the Particle Flow measurement of multi-jets fnal state at the International Linear Collider TCMT ECAL HCAL Imaging calorimeter Intermediate task: Build prototype calorimeters to Establish the technology Collect hadronic showers data with unprecedented granularity to - tune clustering algorithms - validate existing MC models E. Garutti 55

56 Detector requirements in high energy e+e- collisions Examples: W Fusion with final state neutrinos requires reconstruction of H decays into jets Jet energy resolution of ~3% for a clean W/Z separation F. Richard at International Linear Collider A worldwide event 56

57 ALEPH Pioneering Particle Flow Calorimetry... well actually energy flow... - LEP Experiment - Running First detector designed for PFA - TPC - Highly Granular Calorimeters e.g. Ecal 3 Layers Cells R&D since beginning of 80s - ALEPH benefited from progress in electronic chip improvement (dixit J. LeFrancois) References for the following - J. Le Francois Role of Pisa in ALEPH talk - H. Videau, hal-in2p H. Videau, NIM 225 (1984)

58 ALEPH Event display Hcal (Iron absorber, streamer tubes) Energy by analogue sum of Towers Shower pattern by digital r/o of pads Pads Ecal - Gaseous detector - 3 layers - High transverse segment. 3x3 cm2 Magnetic Coil between calorimeters :-( 58

59 The CALICE Collaboration Calorimeter R&D for the and beyond ~360 physicists/engineers from 60 institutes and 19 countries from 4 continents - Integrated R&D efort - Beneft/Accelerate detector development due to common approach 59

60 Jet energy resolution and diboson scattering ALEPH: jet energy resolution based on pure calorimetric information 120%/ E Z-> jets 60%/ E ee->ww, ZZ 'ALEPH resolution 30%/ E 60

61 Assets of particle flow calorimeters from the calorimetric point of view Detailed view into hadronic showers Lots of information to cope with shortcomings in energy resolution that may occur due to high sampling frequency => Opportunities for software compensation Resolution of shower substructure allows for in-situ calibration of detectors with track segments => In situ calibration and no or few calibration runs needed during detector operation Leakage correction Particle ID 61

62 PFA in LHC Experiments - CMS 62

63 PFA in LHC Experiments - CMS Particle flow works even in harsh hadron environment More on PFA in CMS at this workshop 63

64 PFA in LHC Experiments - ATLAS 64

65 PFA in LHC Experiments - ATLAS EPJC (2017) 77: even pile-up can be mitigated with PFA Approach 65

66 ... and in e+e- detectors? - Timing may be useful to clean up hadronic showers Identification of slow/fast component of hadron shower Time resolution needed O(1ns) - Timing for Particle ID Use the calorimeter as hodoscope or by inferring timing Information from signal formation by large energy deposits Time resolution needed O(10 ps) - (Major) hardware and software challenges ahead Do we have time for timing? (dixit Henri Videau) 66