Cool Muon Colliders Caltech October 9 2001 Cool

Cool Muon Colliders: Caltech October 9, 2001 Cool Muon Colliders Studies at Columbia University & Nevis Labs Raphael Galea Allen Caldwell Stefan Schlenstedt (DESY/Zeuten) Halina Abramowitz(Tel Aviv University) Summer Students: http: //www. nevis. columbia. edu/~galea/mucos Christos Georgiou Daniel Greenwald Yujin Ning Inna Shpiro Will Serber

Cool Muon Colliders: Caltech October 9, 2001 2 Outline • Muon Colliders Motivation – History • Physics – Higgs, neutrino physics, new & old physics • Cooling obstacle – Ionization cooling – Frictional cooling http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 3 History • Concept first proposed to Budker & Skrinsky in 60’s and early 70’s • Ionization cooling developed by Skrinsky & Parkhomchuk in 1981 • Furthered by Neuffer & Palmer resulting in formation of Muon Collider collaboration in 1995 http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 4 The Future • Lepton Collider clean but limited in energy by synchrotron radiation a 1/m^4 • Hardron Collider higher energy Mp~2000 x. Me – 1/3 -1/10 energy taking part in collision – Difficult to separate the underlying event • Muon Collider – Not limited by synchrotron radiation Mm~200 x. Me – Easily scaleable – Compact machines http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 5 http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 Livingston Curve http: //www. nevis. columbia. edu/~galea/mucos 6

Cool Muon Colliders: Caltech October 9, 2001 7 Muon Collider in Perspective http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 8 Physics Motivation • m+m- couple directly to Higgs – S channel HIGGS FACTORY • Muons can be polarized (20% polarization will be achievable) – High beam resolution • If proven technology machine scalable – High mass resonances, technicolour, SUSY… • Cool muons can be used as a source of n’s http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 9 Higgs Factory http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 10 Higgs Properties • Scan 0. 0015 fb-1/point • 1 year of running at L=1. 5 x 1031 cm-2 s-1 • (0. 15 fb-1)/year to measure Higgs mass to 1 -2 Me. V http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 11 Light Higgs • Gh=2 -3 Me. V for tanb<2 • Gh=2 -500 Me. V for tanb~50 http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 12 Resolving Mass Degeneracies http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 13 No Higgs @ LHC? ? With 10 fb-1 of lumi devoted to threshold scan: m+m- W+WDm(W)=20 Me. V m+m- t+t. Dm(t)=200 Me. V m+m- Zh Dm(h)=140 Me. V http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 14 Supersymmetry • Heavy • 50 fb-1 can lead to DM(c+)=35, 45 Me. V for • M(c+)=100 Me. V & M(v)=500, 300 Ge. V SUSY scalar pair production is p-wave suppresse M=1 Te. V requires collider of 3 -4 Te. V CMS http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 15 Cooling Motivation 1. 2. 3. 4. http: //www. nevis. columbia. edu/~galea/mucos p produced by intense p beam on target p captured by strong focusing field p to m Resulting muons occupy large & diffuse phase space

Cool Muon Colliders: Caltech October 9, 2001 16 Ionization Cooling • Transverse Cooling • Muons lose energy by d. E/dx & replaced longitudinally by RF • High field solenoids • low Z absorbers http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 17 Longitudinal Cooling • Ionization cooling using a wedge absorber + dispersion • Exchange emittance between transverse & longitudinal direction http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 18 Frictional Cooling • Bring muons to a kinetic energy (T) range where d. E/dx increases with T • Constant E-field applied to muons resulting in equilibrium energy http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 19 Problems/Comments: • large d. E/dx @ low kinetic energy • low average density • Apply to get below the d. E/dx peak • m+ has the problem of Muonium formation • s(Mm) dominates over e-stripping s in all gases except He • m- has the problem of Atomic capture • s calculated up to 80 e. V not measured below ~1 Ke. V • Cool m’s extracted from gas cell T=1 ms so a scheme for reacceleration must be developed http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 20 Basic Design http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 21 Muon Motion in Cooling Cell http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 22 Target Optimization • Want low energy muons hence need to optimize pion production accordingly for: – – Proton Driver Energy Target Material Target Dimensions Target Orientation Peripheral Central http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 23 Magnet Capture Peripheral Central p p+ pm+ m- • +ve & -ve in same channel p+, m+ p p-, m- • Separate charges at source http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 24 Phase Rotation • Apply simple E-field form : Emax • Optimize muon yield as a function of t 1, t 2 & Length of the phase rotation region http: //www. nevis. columbia. edu/~galea/mucos t 1 t 2

Cool Muon Colliders: Caltech October 9, 2001 25 http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 26 Multiple Scattering • To date simulations only considered continuous d. E/dx • May turn out that component of E-field parallel to B-field needed • Technically difficult because of large angle scatters at low energies http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 27 PSI Experiment • Experiment study Lamb Shift in Muonic Atoms • Muon Spectrum 10 -40 Ke. V • 5 T Magnet with D=20 cm bore http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 28 Nevis Setup http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 29 Simulation @ Nevis • Vary E-field, density & length of gas cell • Simulation with no Multiple Scattering • E-field parallel to Bfield so muons do not stop http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 30 http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 31 http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 32 Goals of Experiment • Measure X-ray released from capture in Gas Atom • Check understanding of energy loss, multiple scattering • Measure m- capture cross section at low energies in He & H 2 http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 33 Nevis lab: • Multipurpose Vacuum Chamber • Fast Logic Readout • MCP Detector • X-ray MWPC development underway http: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 34 MWPC X-ray Detector • 4 channel prototype • Possible extension to tracker – track decay e - from captured mhttp: //www. nevis. columbia. edu/~galea/mucos

Cool Muon Colliders: Caltech October 9, 2001 35 Summary • Muon Colliders promise a bright future for HEP – Physics Factory, Higgs, n’s, s-channel resonances • Major hurdle is cooling but efforts are going forward with a plan to demonstrate emittance exchange • Exciting alternative concept for muon cooling – Frictional Cooling – Possibility to cool both signs at once – Experiment to measure m- capture cross section planned…. . STAY TUNED http: //www. nevis. columbia. edu/~galea/mucos