FCAL and Super Belle Leszek Zawiejski Motivations Requirement

FCAL and Super Belle Leszek Zawiejski ■ ■ Motivations Requirement to improve super-Belle detector hermeticity FCAL detectors and super-Belle proposal Problems, questions – starting point for discussion on the proposal FCAL Collaboration Meeting , May 07, 2008, Kraków Slides on Belle results are based on M. Różańska, M. Yamauchi, M. Hazumi prezentations

Motivations I High precision physics which can be studied with super-Belle detector II Test in running experiment, FCAL detectors before realisation of the ILC project

Mt. Tsukuba KEKB Belle B meson yield Super B Factory

Belle Experiment Beam crossing angle : 22 mrad 1. 3 million B B pairs / day _ Total ~770 106 B B pairs _ peak luminosity: 1. 71 x 1034 cm-2 s-1 world record

Major achievements at Belle collaboration 13 countries ~400 collaborators As of June 2007 # of papers : 219 # of citations: 9883 Evidence for D 0 mixing Observation of direct CP violation in B g + - Evidence for B g 1. P Violation in B Decays 2. Fundamental SM Parameters (Complex Quark Couplings) 3. Beyond the SM (BSM) 4. Unanticipated New Particles Observation of b g dg Evidence for direct CP violation in B g K+ - Decisive confirmation of Kobayashi-Maskawa model Measurements of CP violation in B g f. Ks, h’Ks etc. Observation of CP violation in B meson system Discovery of X(3872) Observation of B g K(*)ll

Examples: B decays with missing energy requirement to improve hermeticity of the Belle detector Examples: B h , B+ + , Bo D*- + expected decay rates B 0 D*- + B+ + B h examples of SM amplitudes b O(10 -5) W O(10 -2) O(10 -4) c b u b W W t Z s, d Small hadronic effects; theoretically clean. Sensistive to New Pysics poorly known: multiple ’s in final states experimentaly difficult !

Experimental Techniques B decay with missing energy e. g. B+ K+ Btag Bsig signature: K+ invisible K (4 S) reconstruct Btag at B-factories: e+e- (4 S) BB Btag reconstruction: Two ways of Btag reconstruction: Ø BB event ■ Select Bsig candidate and check whether remaining particles are consistent with B decay („inclusive” Btag reconstruction) Ø which particles belong to Bsig Ø kinematical constraints on Bsig Psig = - Ptag ■ Reconstruct Btag (in exclusive mode) and check whether remaining particles are consistent with Bsig („exclusive” Btag reconstruction)

B h(*) Expected BF’s in the SM: Flavor Changing Neutral Current process: Z-mediated electroweak penguin. W + box diagrams b t Z b s, d t W t s, d W J. H. Jeon et al. , PL B 636, 270 (2006) Sensistive to New other weakly Physics in loops, e. g. : coupled particles: b s, d b s, d h S S possible window to light dark matter, not accessible in direct searches e. g. C. Bird et al. , PRL 93, 201803 (2004) DAMA CDMS

B h(*) - method h(*) = K*+, K*0, K+, K 0, +, 0, Reconstruct Btag in hadronic mode: Btag E = Ei - Ebeam Mbc = E 2 beam-( pi)2 (4 S) h(*) + nothing 788 K B 535 M BB signal signature: MC EECL: residual energy in calorimeter for signal: EECL 0 B candidates Mbc[Ge. V/c 2] background suppression: 1. 6 < ph(*) < 2. 5 Ge. V/c suppress b c reject 2 -body (eg. B K* )

B h(*) - results signal SM BF 20 535 M BB hepex/0707. 0138 submitted to PRL Theoretical predictions: C. Bird et al. , PRL 93, 201803 (2004) K+ momentum 1. 6 < p* < 2. 5 Ge. V/c Nb = 20. 0 4. 0 Nobs = 10 BF(B+ K+ ) < 1. 4 x 10 -5 @90% CL B K* Light dark matter? Can be searched ( or ) in super-Belle

B purely leptonic B theoretically very clean, SM BF: decay: W-mediated b u annihilation W Sensistive to Charged Higgs b u B decay constant f. B=0. 216 0. 022 Ge. V from HPQCD Collab. , PRL 95, 212001 LQCD (2005) providing f. B is known H effects to branching fraction: H mbtan +mccot m tan 2 Decay amplitude m m tan b Karlsruhe SUSY 07 Maria Rozanska for the Belle Collaboration W. S. Hou, PR D 48, 2342 14 (1993)

B - results 449 M BB taking |Vub| = (4. 39 HFAG 0. 33)× 10 -3 from Constraint on Charged Higgs (2 HDM II) excluded r. H PRL 97, 251802 (2006)

B D(*) mbtan +mccot b c W Theoretical tool: Heavy Quark Effective Theory (HQET) Expected SM BF’s~O (10 -2) b c H m tan ü Sensitive to extended Higgs sector ü New Physics at tree level ü Sensitive observables e. g. polarization; possible O(1 ) effects inclusive BF(b c ) = (2. 48 0. 26)% from LEP PDG 2007 Y. Okada: CP violation & CKM; plenary talk at ICHEP 06 H-b-u vertex measured in B H-b-c vertex measured in B D H-b-t vertex measured in direct production by LHC.

Forward Detector K. F Chen, C. Peng

Forward Region

K. F Chen, C. Peng

FCAL detectors – candidates for use in Belle upgrade project? Pair Monitor

Lumi. Cal calorimeter The current design: EM Si/W calorimeter with 30 layers with the following thicknesses: Tungsten - 3. 5 mm Silicon sensor - 0. 32 mm Support - 0. 6 mm Electronic space - 0. 1 mm Inner radius of the active area : 80 mm Outer radius : 195 mm Sensor segmentation – 64 cylinders with 48 sectors in azimuth Calorimeter can be placed 2270 mm from IP Several ( 3 ) sensor layers can be used as tracker detector? Can an increase in granularity will be acceptable for FE electronics design as was prepared recently for ILC? Angular coverage from ~ 30 mrad to 80 mrad (ILD installation place)

Lumi. Cal extension : add silicon tracker (pad/pixel layers?

(p. CVD, Ga. As, s. CVD, radiation hard Si)

Possible places for FCAL detectors at super-Belle The central region Yoshuke talk FW 5. 3 – 11. 1 degree, BW 165. 1 – 172. 7 degree or somewhere outside the central region ?

PROBLEMS - QUESTIONS Proposal to install FCAL detectors in super-Belle detector creates several problems and questions. Sensors&mechanics What sensors(silicon/diamond/Ga. As) granularity seems to be sufficient? How many layers? What will be optimal type of the detector: calorimeter (tungsten/sensors) and tracker (with a few layers) or only tracker (pads, pixels layers) How big energy deposit can be expected in sensors (shower, MIP’s)? What power will be distributed by FE electronics – a way of cooling Radiation dose( during for example in year operation) ? Place – how far from IP? Depends on type of the selected detector, accepted range for polar angle and background -outside the both sides of Belle detector, clamped on beam pipe? Monte Carlo (physics and detector ) studies can help to give answers for most of them FE electronics& readout What will be occupancy? Manpower and short time is a big problem: if the FE and readout electronics (ASIC, fanout) as designed for ILD detector can be used (with small modifications) for super-Belle project.

Discussion on possible participation in super-Belle ? q How useful in realization of ours ILD tasks can be experience obtained by work of FCAL detectors in super-Belle experiment ? q Which FCAL groups (worked on the corresponding detector) can really be interested? q From realisation of the particular scientific tasks in Institutions working in FCAL, such group should became an official member of super- Belle collaboration q Timetable : what is exactly a death time for installation of FCAL detector (s) inside super-Belle - 2012? It will be necessary to estimate more precisely available menpower and cost. q Financial support – requested money, with help from super-Belle collaboration? Such money should cover the build the prototypes, temporary work of specialists, travel expences, staying in KEKB. The possibility to get a big money from national financial institutions (polish) are very limited.

Strategy of super-Belle collaboration

Roadmaps : KEKB Experiment + upgrade

and ILC 2005 2006 2007 2008 2009 2010 2011 2012 GDE process RDR Tech, Design Phase 1 TDP 2 construction LHC physics commissioning physics site selection CLIC R&D EUROTe. V EUDET

Summary Super Belle Physics program will be very excited An increase of the detector hermeticity help in selection rare processes FCAL detectors (with possible modifications), can play important role in suplaying information on the missing energy (for selection the very clean sample of events) One can expect big problems with manpower, money, short timetable for realisation, formalities how to become the official member of super Belle collaboration Futher discussion on possibility to join the project is necessary