Higgs Factories based on: - LEP3 circular e+e- machine

- SAPPHIRE gg collider

Mayda M. VelascoNorthwestern University

BNL Seminar -- Jan. 17, 2013

Higgs Discovery in July 2012

H WW

H bb

H ZZ

…and what we know today

“Rich” mass regionAlready 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

Access to Higgs partial widths of to Bosons and Fermions

* CMS based… Similar at ATLAS

What we should know by 2022?

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?

LEP3 AND TLEP LOW ENERGY CIRCULAR e+e- MACHINES

LEP3 and TLEP -- e+e- ring

PSB PS (0.6 km)SPS (6.9 km) LHC (26.7 km)

LEP3(e+e-, 240 GeV c.m.)

In the LHC tunnel (LEP3) or a new tunnel (TLEP)

• Instantaneous luminosity larger than 1034/s/cm2 at maximum energyLarger at smaller energiesDelivered in 2 or 4 interaction points ATLAS and CMS in LEP3

TLEP (80 km, e+e-

~350 GeV c.m.)

VHE-LHC ( later… pp, 100 TeV c.m.)

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)

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]

Putting LEP3 into the LHC tunnel?

«Pre-Feasibility Study for an 80-km tunnel at CERN»John Osborne and Caroline Waaijer, CERN, ARUP & GADZ, submitted to ESPG

TLEP tunnel in the Geneva area – “best” option

LEP3 and TLEP

LEP3 TLEPcircumference 26.7 km 80 kmmax beam energy 120 GeV 175 GeVmax no. of IPs 4 4 Lum. 350 GeV c.m. - 0.7x1034 cm-2s-1 Lum. 240 GeV c.m. 1034 cm-2s-1 5x1034 cm-2s-1 Lum. 160 GeV c.m. 5x1034 cm-2s-1 2.5x1035 cm-2s-1 Lum. 90 GeV c.m. 2x1035 cm-2s-1 1036 cm-2s-1

ee tt

ee ZH

ee WW

ee Z

Basic parameters:

Beam Lifetime

• LEP2: • beam lifetime ~ 6 h • dominated by radiative Bhabha 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

Example:Top-up injection at PEP-II/BaBar

Before Top-Up Injection

After Top-Up Injection

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 ~5x10-3 similar 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

Other LEP3 parameters

LEP3 as Higgs FactoryHiggs-strahlung is main production process: HZZ coupling observed at the LHC Vector boson fusion give small contribution Reasonable background level

MH=125 GeV

Higgs measurements at LEP3(√s = 240 GeV)

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

TLEP Physics programSame 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

Linear versus Circular e+e-

5 Years

Beamstrahlung much more benign

than for linear collider;

LEP3/TLEP are clean machines

Comment: Beamstrahlung effect at LEP3 much smaller than for ILC

Linear versus Circular e+e-

Other precision measurements

LEP3 could open a whole new era in EW precision measurements

MH=215 GeV

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

TLEP

Peskin

Only discussed: LEP3 and TLEP (& ILC), but many more options for circular e+e-

Higgs factories are becomingpopular around the world

LEP3 2011

SuperTristan 2012LEP3 on LI, 2012

LEP3 in Texas, 2012

FNAL site filler, 2012West Coast design, 2012

Chinese Higgs Factory, 2012

UNK Higgs Factory, 2012

SAPPHIRE LOW ENERGY HIGGS FACTORY BASED ON PHOTON-PHOTON COLLISIONS

SAPPHiRE & LHeC

cern.ch/accnet

Combining photon science & particle physics!

gg collider based on e-e-

glaser: Pulses of a several Joules with a l~350nm (3.53 eV) for Ee- ~ 80 GeV

Compton scattering: e− glaser → e−g

can transfer 80% of e- energy to g

e-e-, e-g and gg colliders

– Higgs produced in s-channel (low ee CoM)

– 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”

e-e- gg Spectrum tuned for Higgs

Photon beam polarization

gg: H production in gg H

Cross sections convoluted with the expected beam profile

l1l2=1

l1l2=0

Circularly polarized laser

Linearly polarized laser

Only with ggC

== 0 if CP is conserved

In s-channel production of Higgs:

== +1 (-1) for CP is conserved forA 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

This is why we should consider a low energy gg collider, 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

SAPPHiRE

SAPPHiRE: Small Accelerator for Photon-Photon Higgs production using Recirculating Electrons

Scale ~ European XFEL,About 20k Higgs per year

Energy loss of multiple passes

beam energy [ GeV]

DEarc [GeV] DsE [MeV]

10 0.0006 0.03820 0.009 0.4330 0.05 1.740 0.15 5.050 0.36 1060 0.75 2070 1.39 3580 1.19 27

total 3.89 57 (0.071%)

D

Prototype arc magnetsLHeC dipole models(BINP & CERN)

eRHIC dipole model (BNL)

5 mm gapmax. field 0.43 T (30 GeV)

25 mm gapmax. field 0.264 T (60 GeV)

SAPPHiRE symbol valuetotal electric power P 100 MWbeam energy E 80 GeVbeam polarization Pe 0.80bunch population Nb 1010

repetition rate frep 200 kHzbunch length sz 30 mmcrossing angle qc ≥20 mradnormalized horizontal/vert. emittance gex,y 5,0.5 mmhorizontal IP beta function bx* 5 mmvertical IP beta function by* 0.1 mmhorizontal rms IP spot size sx* 400 nmvertical rms IP spot size sy* 18 nmhorizontal rms CP spot size sx

CP 400 nmvertical rms CP spot size sy

CP 440 nme-e- geometric luminosity Lee 2x1034 cm-2s-1

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

SAPPHiRE gg luminosity

5 Linacs

IPIP

2 Linacs

Top Energy 80 GeV 80 GeV

Turns 3 4

Magnet ρ 644.75 m 706.65 m

Linacs (5) 5.59GeV 4.23GeV

δp/p 6.99x10-4 7.2x10-4

ϵnx Growth 1.7μm 1.8μm

Top Energy 80 GeV 80 GeV

Turns 4 5

Avg. Mag. ρ 661.9 m 701.1 m

Linacs (2) 10.68GeV 8.64GeV

δp/p 8.84x10-4 8.95x10-4

ϵnx Growth 2.8μm 2.85μm

1) 2)

Possible Configurations at FNAL

Possible Configurations at JLAB

85 GeV Electron energyγ c.o.m. 141 GeV

103 GeV Electron energyγ c.o.m. 170 GeV

Edward Nissen

Town Hall meeting Dec 19 2011

Ex. of physics program relevant to our understanding of Higgs that will be

accessible with SAPPHIRE

• e-e- ---> sin2 qW (running)• e- g ---> MW

• gg to H– Ggg gttH

– GTotal

– CP mixing and violation in a model independent way from both gHff and gHVV

e-e-: Moller Scattering to get running of sin2 qW

> mbarn

Should we aim at higher ee Ecm?Currently 160 GeV

e- g: MW from e-g W-n

• Mass measurement from W hadron events

• Or from energy scan

gg - channel

e- g e- g

gg g g

DGgg/Ggg = 30% at ILC after 5 years

%2 Measurement of Ggg

%10 Measurement of GTotal

Assuming that we know DBr(h bb) ~2%

Only with ggC

4% constraint in ttHYukawa coupling

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.

Conclusions• LEP3 and SAPPHIRE may 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,…)

BACKUP

SAPPHiRE DAY 19 February 20131. Physics case: Theory, John Ellis / King’s College2. Physics case: Experiment, Mayda Velasco / Northwestern U. 3. Machine concept & options – Frank Zimmermann / CERN4. Luminosity calculations (?) – Marco Zanetti / MIT Or Daniel Schulte / CERN5. Commercial lasers & future extrapolation - Laura Corner / JAI 6. R&D status for gamma-ray and X-ray generation based on Compton scattering at KEK, Junji

Urakawa / KEK7. Feedback R&D for Optical Cavity, Hiroshima U.8. Compton collision scheme of the EGAMMAS Proposal for ELI-NP, Luca Serafini /INFN-Milano 9. Optical cavity & IR design for gamma-gamma collider , Klaus Moenig/DESY 10. High finesse multi-mirror optical cavity w feedback, Fabian Zomer/LAL 11. LAL Compton collisions and Thom-X project, Alessandro Variola/LAL 12. Duke FEL-Compton scheme and outlook, Vladimir Litvinenko/BNL 13. High average power femtosecond laser technology, Marc Hanna/Institut d'Optique Palaiseau14. Current status and future of high-power ultrafast industrial lasers, Yoann Zaouter/Amplitude

Systemes15. Extrapolating Current Laser Technology for a SAPPHiRE Laser System, Jeff Gronberg/LLNL16. Gamma-gamma & Compton studies at FACET-2, Vitaly Yakimenko/SLAC

Self-generated FEL g beams (instead of laser)?

opticalcavity mirrors

wigglerconverting somee- energy into photons (l≈350 nm)

e- (80 GeV)

e- (80 GeV)

Comptonconversionpoint

gg IP

e- bende- bend

example: lu=200 cm, B=0.625 T, Lu=100 m, U0,SR=0.16 GeV, 0.1%Pbeam≈25 kW

“intracavity powers at MW levels are perfectly reasonable” – D. Douglas, 23 August 2012

scheme developed with Z. Huang

Source: Fiber lasers and amplifiers: an ultrafast performance evolution, Jens Limpert, Thomas Schreiber, and Andreas Tünnermann, Applied Optics, Vol. 49, No. 25 (2010)

power evolution of cw double-cladfiber lasers with diffraction limited beam quality over the past decade:factor 100 increase!

laser progress: example fiber lasers

LAL MightyLaser experiment at KEK-ATFnon-planar high finesse four mirror Fabry-Perot cavity;first Compton collisions observed in October 2010

I. Chaikovska, N. Delerue, A. Variola, F. Zomer et al

Comparison of measured and simulated gamma-ray energy spectra from Compton scattering

Gamma ray spectrum for different FPC stored laser power

Vacuum vessel for Fabry-Perot cavity installed at ATFOptical system used for laser power amplification and to inject laser into FPC Plan:

improve laserand FPC mirrors& gain several orders

I. Chaikovska, PhD thesis to be published