4th Concept detector: mostly orthogonal to other three concepts The main contacts and principals: Aldo Penzo, Sorina Popescu, Corrado Gatto, Nural Akchurin, Richard Wigmans, John Hauptman. Pixel Vertex (PX) 5-micron pixels (like GLC CCD, or SiD thin pixel) TPC (like GLD or LDC) with “gaseous club sandwich” Triple-readout fiber calorimeter: scintillation/Cerenkov/neutron (new) Muon dual-solenoid geometry (new) basic design B Basic conceptual design: four basic, powerful systems, all as simple as possible:

Aldo Penzo – DREAM talk Sorina Popescu – DAQ and DCS TPC talk Corrado Gatto – Simulation and Reconstruction talk 4 th meeting: Saturday 15:00- 16:00 Other 4 th -right colleagues here: Giovanni Pauletta, Franco Grancagnolo New groups: Wuhan, China; INFN-Messina, Italy “Go Fourth and propagate” – God (but we are not purposefully recruiting)

AutoCADGEANT simulation of HZ event

(muon annulus) Outer Solenoid Inner Solenoid “Wall of coils”

(muon annulus) Bow-tie toroids i(A)

Pixel Vertex: CCD (GLD) or thin pixel (SiD) 5-micron pixel size [xyz-resolution, occupancy suppression] b,c,τ lifetime tagging Anchor one end of charged track for momentum resolution Hope it’s also cheap in the end: multiple layers, large radius (e.g., go out to r = 20 cm)

Simple geometry of SiD Pixel Vertex

Tracking TPC: like GLD or LDC, but smaller Comprehensive pattern recognition, resolution and redundancy Whole event tracking and vertex definitions dE/dx for oddly ionizing objects e-γ discrimination, K 0 s, multiple event vertices “Gaseous club sandwich” (Timmermans, Colas, Lepeltier, Gluckstern) B field of 3.5T Avoid any other auxilliary tracking system

Calorimetry: Triple fiber and dual crystal Spatial fluctuations are huge ~λ int with high density EM deposits: fine spatial sampling with scintillating fibers every 2mm EM fraction fluctuations are huge, 5→95% of total shower energy: insert clear fibers generating Cerenkov light by electrons above E th = 0.25 MeV measuring nearly exclusively the EM component of the shower (mostly from π 0 →γγ) Binding energy (BE) losses from nuclear break-up: measure MeV neutron component of shower. Triple fiber: measure every shower three different ways: “3-in-1 calorimeter”

DREAM module: simple, robust, not intended to be “best” and anything, just test dual-readout principle Unit cell Back end of 2-meter deep module Physical channel structure

Downstream end of DREAM module, showing HV and signal connectors

DREAM module, looking upstream in H4 beam Beam hodoscope Module 2-meters x 30-cm diameter Cu+fibers Table for x-y scanning

Dual-Readout: Measure every shower twice - in Scintillation light and in Cerenkov light. (e/h) C =  C  e/h) S =  S ~ 1.4 C = [ f EM + (1 – f EM ) /  C ] E S = [ f EM + ( 1 – f EM ) /  C ] E C / E = 1 /  C + f EM (1 – 1/  C ) 200 GeV “jets” Data NIM A537 (2005) 537.

DREAM data 200 GeV π - : Energy response Scintillating fibers Scint + Cerenkov f EM  (C/E shower - 1/  C ) (4% leakage fluctuations) Scint + Cerenkov f EM  (C/E beam - 1/  C ) (suppresses leakage) Data NIM A537 (2005) 537.

More important than good Gaussian response: DREAM module calibrated with 40 GeV e - into the centers of each tower responds linearly to π - and “jets” from 20 to 300 GeV. Hadronic linearity may be the most important achievement of dual- readout calorimetry. e-e- Data NIM A537 (2005) 537.

W decay to DREAM “jets”  M W 2 =2E 1 E 2 (1 – cos  MWMW

Invariant Mass of W  jj … jet data from DREAM beam test 1.Sample W Breit-Wigner 2.Calculate  3.Align W quarks with DREAM beam hodoscopes 4.Take two data events from DREAM “jet” runs; data events contain physical energy and position fluctuations. 5.Calculate and plot di-jet mass.

W  jj and Z  jj superposed: DREAM jet data Z 0 lab momenta: 100 GeV/c 150 GeV/c 200 GeV/c 250 GeV/c 300 GeV/c 400 GeV/c

DREAM module 3 scintillating fibers 4 Cerenkov fibers “Unit cell” → ILC-type module 2mm W or brass plates; fibers every 2 mm (Removes correlated fiber hits)

(1) Measure MeV neutrons (binding energy losses) by time. t(ns) → (protons) (neutrons) Pathlength (cm) Velocity of MeV neutrons is ~ 0.05 c (1)Scintillation light from np→np scatters comes late; and, (2) neutrons fill a larger volume

(2) Measure MeV neutrons (binding energy losses) by separate hydrogenous fiber A hydrogenous scintillating fiber measures proton ionization from np→np scatters; A second scintillating non-hydrogenous fiber measures all charged particles, but except protons from np scatters; This method has the weakness that the neutron component is the difference of two signals.

(3) Measure MeV neutrons (binding energy losses) with a neutron-sensitive fiber Lithium-loaded or Boron-loaded fiber (Pacific Northwest Laboratory has done a lot of work on these) Some of these materials are difficult liquids Nuclear processes may be slow compared to 300 ns. But, most direct method we know about.

(4) Measure MeV neutrons (binding energy losses) using different Birk’s constants Birk’s constant parameterizes the reduction in detectable ionization from heavily ionizing particles (essentially due to recombination) Use two scintillating fibers with widely different Birk’s constants. Two problems: (i) hard to get a big difference, and (ii) neutron content depends on the difference of two signals.

Dual-readout crystal EM section (in front of triple-readout module) Half of all hadrons interact in the “EM section” … so it has to be a “hadronic section” also to preserve excellent hadronic energy resolution. Dual-readout of light in same medium: idea tested at CERN (2004) “Separation of Scintillation and Cerenkov Light in an Optical Calorimeter”, NIM A550 (2005) 185. Use multiple MPCs (probably four, two on each end of crystal), with filters. Physics gain: excellent EM energy resolution (statistical term very small), excellent spatial resolution with small transverse crystal size. (This is what CMS needs …) Calorimeter: triple-readout fibers + dual-readout crystals in front

Dual-Solenoid magnetic field (ANSYS calculation, Bob Wands, Fermilab) R(m) Not actually optimized 2.TPC tracking field uniform to 1% 3.Stray field <1% 4.W=4 GJ <CMS 5.De-centering force small 6.Uses CMS coil design.0 z(m)

CMS internal coil structure: (everybody’s prototype; now cold) One turn /2.2cm Maximum current per turn = 20 kA

Dual-solenoid B field density: TPC tracking (3.5T) Muon tracking (1.1T)

Muon dual-solenoid: Advantages Good momentum resolution: σ/p 2 ~ (GeV/c) -1 (Muons bent in Fe are fundamentally limited to σ/p = 10%/√L, independent of momentum) Field is achievable, B is smooth in (θ,φ), and ∫Bdl is also smooth out to end of outer solenoid. ATLAS-like, but simpler. Excellent low momentum  acceptance and efficiency Access to detector, flexibility for future physics Can control field on and around beam line.

B z (z) field on axis & B r (z) at r=50cm B z gets small in z; could be optimized to shorten both solenoids; … BzBz BrBr z(m)

and ∫Bdl along muon trajectories ∫Bdl along muon trajectories Cos 

Muons through a dual-readout calorimeter: separation of ionization and radiative processes Scintillation: ionization + bremsstrahlung + pair production Cerenkov: bremsstrahlung + pair production Difference S-C is ionization and is constant, independent of muon energy. This is a unique muon tag.

Separation of pions from muons at 20 GeV   Muons Pions DREAM test beam data (unpublished)

Four 5-GeV muons through detector as test Muons are clean and obvious; Acceptance at 5 GeV is good; Momentum and energy measurements must add up for a real muon; GEANT simulation in very good shape in a very short time; Still, there is more fun work to do.

IVCRoot simulation and analysis of muons through tracking in muon annulus Full Kalman filter reconstruction and pattern recognition through TPC

Benchmark physics problem: use DREAM data to substitute for jets from Z in Higgs+Z production Generate a Pythia HZ event, radiation turned off Same trick as with W  jj, substitute two DREAM jets at whatever beam energies are available and at that angle to give the Briet-Wigner mass of the Z or W. Can choose any Higgs mass (five are shown in the Detector Outline Document: 130, 200, 400, 600 and 800 GeV/c 2 ) “Better than GEANT” Will put in radiation next, and scale the beam data with care.

m H = 130 GeV/c 2 reconstruction: use DREAM test beam “jet” events to substitute for jets from Z 0 e + e -  HZ  H + jj (Pythia) Use DREAM data for jets, with genuine energy and spatial fluctuations Randomly take two 50- GeV jets from data file Calculate missing mass and plot …  3.2 GeV/c 2 Repeat for GeV jets, …, , , , GeV

m H = 600 GeV/c 2 : use DREAM test beam “jet” events to substitute for jets from Z 0 Same method as in previous figure … resolution not so bad.

e + e -  H 0 Z 0  W + W -       jj e -     Illustrates all the detectors of 4 th Concept … particle ID “obvious”

Summary of 4 th Concept work We expect to measure all fermions and bosons of the standard model: uds, c, b, e, µ, τ, ν, γ, W, Z. Simulation and reconstruction in good shape, and improving Calorimeter and muon are new ideas, and will get more work Outline Document available: Dual-readout crystal beam test scheduled; detailed design of triple-readout fiber test module underway. This “detector concept” environment is an excellent venue for the floating and study of so many extraordinary ideas and instruments for the ILC, viz., billion channel detectors, TPCs and pixel vertex detectors, PFA with its intimate calorimeter- tracking connection, DAQ, and all with high precision.