Higgs Factories based on: - LEP3 circular e + e - machine - SAPPHIRE gg collider

1. Higgs Factories based on: - LEP3 circular e+e- machine - SAPPHIRE gg collider Mayda M. Velasco Northwestern University BNL Seminar -- Jan. 17, 2013

2. Higgs Discovery in July 2012 …and what we know today H  ZZ H  WW H  bb

3. “Rich” mass region Access to Higgs partial widths of to Bosons and Fermions Already measuring its characteristics Mass from gg plus ZZ  4L* M = 125.8 ± 0.4 (stat) ± 0.4 (syst) Parity 0+ : Scalar hypothesis consistent at a 0.6s level* 0- : Pseudo scalar hypothesis excluded at 2.5s level* Coupling To both bosons and fermions Spin No sensitivity yet to separate between Spin 0 & Spin 2 However, some argue that the observed rate is an indication that is not a spin 2 object * CMS based… Similar at ATLAS

4. What we should know by 2022?

5. So, what is next?Low Energy Higgs Factory  Concepts Some examples of measurements  needed  after  the  LHC: Today… discussed two types of factories that could do the job! • Continue to characterize  the state • Coupling to  the  top  quark • Self  couplings • Total width • Need  to  evaluate  (new  physics)  loop induced  effects • Hgg, Hgg, HZg • Precision  electroweak  measurements • Precision  mass  measurements  (W,  Z,  top,  ...)   • Need  to  determine  the  (tree level)  structure  of  the  theory   • Invisible  Higgs  decays,  Exotic  Higgs  decays? • CP mixing and violations?

6. LEP3 and TLEP  Low Energy CIRCULAR e+e- machines

7. LEP3 and TLEP -- e+e- ring In the LHC tunnel (LEP3)or a new tunnel (TLEP) TLEP (80 km, e+e- ~350 GeV c.m.) PSB PS (0.6 km) SPS (6.9 km) LHC (26.7 km) LEP3 (e+e-, 240 GeV c.m.) VHE-LHC ( later… pp, 100 TeVc.m.) • Instantaneous luminosity larger than 1034/s/cm2at maximum energy • Larger at smaller energies • Delivered in 2 or 4 interaction points ATLAS and CMS in LEP3

8. The two options • Installation in the LHC tunnel “LEP3” • inexpensive (<0.1 x LC) • tunnel exists • reusing ATLAS and CMS detectors • reusing LHC cryoplants interference with LHC and HL-LHC • New larger tunnel “TLEP” • higher energy reach, (5-10)x higher luminosity • decoupled from LHC/HL-LHC operation & construction • tunnel can later serve for HE-LHC (factor 3 in energy from tunnel alone) with LHC remaining as injector  (4-5)x more expensive (new tunnel, cryoplants, detectors)

9. Putting LEP3 into the LHC tunnel? LHC tunnel cross section with space reserved for a future lepton machine like LEP3 [blue box above the LHC magnet] and with the presently proposed location of the LHeC ring [red]

10. TLEP tunnel in the Geneva area – “best” option «Pre-FeasibilityStudy for an 80-km tunnel at CERN» John Osborne and Caroline Waaijer, CERN, ARUP & GADZ, submitted to ESPG

11. LEP3 and TLEP Basic parameters: eett ee ZH eeWW ee Z

12. Beam Lifetime • LEP2: • beam lifetime ~ 6 h • dominated by radiativeBhabha scattering with cross section s ~ 0.215 barn • LEP3 with L~1034 cm−2s−1 at each of several IPs: tbeam,LEP3~18 minutes from rad. Bhabha scattering → solution: top-up injection Beam lifetime also limited due to beamstrahlung, but can be compensated for using: (1) large momentum acceptance (h ≥ 3%), and/or (2) flat(ter) beams and/or (3) fast replenishing

13. Example:Top-up injection at PEP-II/BaBar Before Top-Up Injection After Top-Up Injection

14. Other LEP3 parameters • arc optics • same as for LHeC:ex,LHeC<1/3 ex,LEP1.5 at equal beam energy, • optical structure compatible with present LHC machine (not optimum!) • small momentum compaction (short bunch length) • assume ey/ex ~5x10-3similar to LEP (ultimate limit ey ~ 1 fm from opening angle) • RF • RF frequency 1.3 GHz or 700 MHz • ILC/ESS-type RF cavities high gradient (20 MV/m assumed, 2.5 times LEP gradient) • total RF length for LEP3 at 120 GeV similar to LEP at 104.5 GeV • short bunch length (small b*y) • cryo power ≤LHC • synchrotron radiation • energy loss / turn: Eloss[GeV]=88.5×10−6 (Eb[GeV])4 /ρ[m]. • higher energy loss than necessary • arc dipole field =0.153 T • compact magnet • critical photon energy = 1.4 MeV • 50 MW/beam (total wall plug power ~200 MW ~ LHC complex)→4x1012 e±/beam

15. LEP3 as Higgs Factory • Higgs-strahlung is main production process: • HZZ coupling observed at the LHC  • Vector boson fusion give small contribution • Reasonable background level MH=125 GeV

16.  Higgs  measurements at LEP3(√s = 240 GeV)

17. Other Higgs measurements at LEP3(√s = 240 GeV)

18. TLEP Physics program Same as LEP3… • Less synchrotron radiation and … • five times more luminosity at √s = 240 GeV • 2 to 5 times more luminosity at √s = mZ or 2mW • Top physics at √s = 350 GeV • precision top mass measurement

19. Linear  versus  Circular e+e- 5 Years 

20. Comment: Beamstrahlung effect at LEP3 much smaller than for ILC Beamstrahlung much more benign than for linear collider; LEP3/TLEP are clean machines

21. Linear  versus  Circular e+e-

22. Other precision measurements

23. LEP3 could open a whole new era in EW precision measurements MH=215 GeV

24. Summary: Low energy e+e-  Higgs  Factories (ILC 250, 350, LEP3, TLEP)  TLEP Peskin

25. UNK Higgs Factory, 2012 FNAL site filler, 2012 LEP3 2011 West Coast design, 2012 LEP3 on LI, 2012 SuperTristan 2012 Chinese Higgs Factory, 2012 LEP3 in Texas, 2012 Only discussed: LEP3 and TLEP (& ILC), but many more options for circular e+e- Higgs factories are becoming popular around the world

26. cern.ch/accnet SAPPHiRE &LHeC SAPPHIRE Low Energy HIGGS Factory Based ON Photon-Photon Collisions

27. ggcollider based on e-e- Combining photon science & particle physics! Compton scattering: e− glaser→e−g can transfer 80% of e- energy to g glaser:Pulses of a several Joules with a l~350nm (3.53 eV) for Ee- ~ 80 GeV

28. e-e-, e-g and ggcolliders • Higgs produced in s-channel (low eeCoM) • Starts from e-e- therefore, both beam can be highly polarized • Laser or FEL needed to generate high g-beam (e− glaser→e−g)are now available • Opportunity to work with technology, that is of interest to other fields of basic science and industry • Compact machine: less that 10 Km in diameter • Fits in various national labs • “Low cost”

29. e-e-gg Spectrum tuned for Higgs

30. gg: H production in ggH Photon beam polarization

31. Cross sections convoluted with the expected beam profile l1l2=1 l1l2=0

32. Linearly polarized laser Circularly polarized laser

33. Only with ggC In s-channel production of Higgs: == 0 if CP is conserved == +1 (-1) for CP is conserved for A CP-Even (CP-Odd) Higgs If A1≠0, A2≠0 and/or |A3| < 1, the Higgs is a mixture of CP-Even and CP-Odd states Possible to search for CP violation in gg H  fermions without having to measure their polarization In bb, a ≤1% asymmetry can be measure with 100 fb-1 that is, in 1/2 years arXiv:0705.1089v2

34. This is why we should consider a low energy ggcollider,like SAPPHIRE, as a Higgs Factory Search for the unexpected properties of the Higgs in a model independent way… That is, Higgs CP Mixing and Violations CP asymmetries at the 1% level or better will be accessible with current designs by taking advantage of both linear and circular polarization

35. SAPPHiRE Scale ~ European XFEL, About 20k Higgs per year SAPPHiRE: Small Accelerator for Photon-Photon Higgs production using Recirculating Electrons

36. Energy loss of multiple passes D

37. Prototype arc magnets eRHIC dipole model (BNL) LHeC dipole models (BINP & CERN) 5 mm gap max. field 0.43 T (30 GeV) 25 mm gap max. field 0.264 T (60 GeV)

39. SAPPHiREgg luminosity Luminosity spectra for SAPPHiRE as functions of ECM(gg), for 3 possible normalized distancesr≡lCP-IP/(gsy*) (left) and different polarizations of in-coming e- & g(right)

40. Possible Configurations at FNAL 1) 2) IP 5 Linacs 2 Linacs IP

41. Edward Nissen Possible Configurations at JLAB Town Hall meeting Dec 19 2011 85 GeV Electron energy γ c.o.m. 141 GeV 103 GeV Electron energy γ c.o.m. 170 GeV

42. Ex. of physics program relevant to our understanding of Higgs that will be accessible with SAPPHIRE • e-e- ---> sin2qW (running) • e- g ---> MW • gg to H • GgggttH • GTotal • CP mixing and violation in a model independent way from both gHff and gHVV

43. e-e-: Moller Scattering to get running of sin2qW > mbarn Should we aim at higher eeEcm? Currently 160 GeV

44. e- g: MW from e-gW-n • Mass measurement from W hadron events • Or from energy scan

45. e- ge- g gggg gg- channel

46. Ggg/Ggg= 30% at ILC after 5 years

47. Assuming that we know DBr(h bb) ~2% Only with ggC %2 Measurement of Ggg • 4% constraint in ttH • Yukawa coupling %10 Measurement of GTotal

48. Low energy gg colliders • This machine will be crucial to study the CP mixing and violation in the Higgs sector • Using the e-e- component of the beam, we could not only make precise measurements of the running of sin2qW, but also: • Majorana neutrinos by searching for e-e- W-W- • Many more physics topics that go well beyond Higgs • Tau Tau factory … good to study g-2 of the t lepton • Quark structure of the photon, etc.

49. Conclusions • LEP3and SAPPHIREmay some of the cheapest possible option to study the Higgs (cost ~1B scale), feasible, ee component “off the shelf”, but perhaps not easy • TLEP is more expensive (~5 BEuro?), but clearly superior in terms of energy & luminosity, and extendable towards VHE-LHC, preparing ≥50 years of exciting e+e-, pp, ep/A physics at highest energies • SAPPHiRE matches infrastructure, expertise & sites of many HEP or former or future HEP laboratories (JLAB, SLAC, KEK, FNAL, BNL, DESY,…)

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