SUSY phenomenology circa 2020

Howie Baer (baer at ou dot edu), Pheno2020 University of Oklahoma May 4, 2020

m(higgs) finetuned in SM for cuto↵ m(weak) • 120 cosmological constant 10 expected • 10 ✓¯ 10 (strong CP/QCD) • ⇠

``The appearance of fine- tuning in a scientific theory is like a cry of distress from nature, complaining that something needs to be better explained’’

virtual Pitt PACC meeting 1 SUSY phenomenology of 20th century

mediation: gravity (mSUGRA/CMSSM), gauge, anomaly • : sparticles 100 GeV scale • ⇠ dark matter: WIMP/neutralino via stau-co, A-funnel or FP •

2 21 century experiments meet 20th century theory

m = 125.18 0.16 GeV • h ± m > 2.1 TeV • g˜ m˜ > 1.1 TeV • t1 no sign of WIMPs (via DD) •

These values/limits lead to impression that Weak Scale SUSY largely excluded except for few remote regions of p-space

3 21 century

1. discrete R-symmetries: mu-problem,p-decay, R-parity, gravity-safe global PQ symmetry

2. naturalness: BG, HS, EW

3. DM: need axion for strong CP, SUSY mu-problem: mainly DFSZ axion plus -like WIMP

4. string landscape: solves CC problem, role in ? Yes

4 SUSY mu problem:

The SUSY preserving mu-parameter is usually tuned within spectrum calculator computer codes and otherwise ignored. But more basically, it should be ~m(Planck), or else in string theory=0 (no arbitrary mass scales)

But: phenomenologically, need mu~m(weak)~100-300 GeV (practical naturalness: independent contributions to observables should be of order of or less than the measured value).

Recent review: summarize 20 solutions

5 6 Recent mu solution:

Discrete R symmetries: can arise from string compactification • Anomaly-free, GUT consistent (Lee et al.) ZR arXiv:1102.3595 • 4,6,8,12,24 R-parity, forbid µ,suppressp-decay, allow m(⌫) • ) R strongest: Z24: gravity-safe PQ symmetry arises as accidental, approx- • imate global symmetry! which solves strong CP via DFSZ axion!

BBS, arXiv:1810.03713

R-parity and global PQ arise from same7 source: Z24^R 8 Developments in naturalness

2 @ log mZ EENZ/BG: BG maxi • ⌘ | @ log pi | highly parameter dependent: for same spectra, • changes radically depending on model parameters may be correlated: top-down string models • parameters may be selected for: landscape •

2 mHu HS = m2 • h

implies three 3rd gen squarks m˜ ˜ < 500 GeV • t1,2,b1 back-of-envelope cal’n sets • numerous terms 0inRGE ! this then ignores dependent contributions m2 , m2 : • Hu Hu HB, Barger, Huang, violates practical naturalness Mustafayev, Tata: arXiv:1207.3343

2 2 d 2 u 2 m mH +⌃d (mH +⌃u)tan Z = d u µ2 m2 ⌃u(t˜ ) µ2 2 tan2 1 Hu u 1,2 • ⇠ max contribution on RHS /(m2 /2) • EW ⌘ | | Z model independent • for correlated soft terms • BG ! EW for combined dependent contibutions 9 • HS ! EW Whereas (artificial) CMSSM/mSUGRA is now excluded as natural, there is plenty of natural p-space in non-artificial models such as NUHM2,3

Typical spectrum for low ∆EW models mSUGRA with A0 =0

first/second generation 4 10 matter scalars

˜b1 t˜2 stops, sbottoms, gluinos t˜1 g˜

3 10 (GeV) W˜ ± 2 Z˜4 wino m

˜ Z3 bino

Z˜2 h W˜ ± Higgs, ˜ 1 2 Z1 10 Z0 gauge bosons W ±

0 5 10 10 15 Dark matter from SUSY with radiatively-driven naturalness

Short answer: both axion and (thermally-underproduced) higgsino-like WIMP

Typically 80-90% axions; 10-20% WIMPs

Should ultimately see WIMPs

Axion coupling suppressed by presence of higgsinos- axion detection much tougher :(

11 DM production in SUSY DFSZ: solve eight coupled Boltzmann equations

wimp

Bae, HB, Chun; Bae, HB, Lessa, Serce

radiation

gravitino saxion axino a(CO) re-heat 12 Direct higgsino detection rescaled for minimal local abundance ⇠ ⌦TPh2/0.12 ⌘

Bae, HB, Barger,Savoy,Serce

Xe-1-ton now operating!

natural SUSY

Can test completely with ton scale detector or equivalent (subject to minor caveats) 13 It is sometimes invoked that maybe we should abandon naturalness: after all, isn’t the cosmological constant (CC) fine-tuned?

In a multiverse with 10^500 vacua with different CCs, then the value of the CC may not be surprising since larger values would lead to runaway pocket universes where galaxies wouldn’t condense- anthropics: no observers in such universes (Weinberg)

The CC is as natural as possible subject to the condition that it allows for galaxy condensation (structure principle)

14 To handle string landscape and concomitant multiverse, Douglas introduced concept of stringy naturalness

(anthropics hides here)

This embodies Weinberg’s prediction of CC

Can we apply similar reasoning to magnitude of weak scale? m(weak)~=m(W,Z,h)~100 GeV

see talk by S. Salam in Theory session

15 dP/d f f O ⇠ prior · selection

What is f(prior) for SUSY breaking scale?

In string theory, usually multiple (~10) hidden sectors containing a variety of F- and D- breaking fields

For comparable and values, then expect

2n +n 1 f m F D prior ⇠ soft Douglas ansatz arXiv:0405279

Under single F-term SUSY breaking, expect linear increasing statistical selection of soft terms

16 What about f(selection)?

Originally, people adopted

to penalize soft terms straying too far from weak scale

This doesn’t work for variety of cases

• Too big soft terms can lead to CCB minima: must veto such vacua • Bigger m(Hu)^2 leads to more natural value at weak scale • Bigger A(t) trilinear suppresses t1, t2 contribution to weak scale

Adopt mu solution which leads to natural, weak scale value of mu~100-350 GeV

Then for statistically selected soft terms, m(weak) is output, not input

Must veto too large m(weak) values: nuclear physics screwed up (Agrawal, Barr, Donoghue, Seckel, 1998)

Factor four deviation of weak scale17 from measured value => EW < 30 Agrawal, Barr, Donoghue, Seckel result (1998): weak scale cannot deviate by more than factor 2-5 from its measured value lest disasters occur in nuclear physics

Our Domain ++ p, Δ stable 20 10 0 )

0 -10 ++ Δ stable τB < tchem -20 Log (v/v

-30 no stable nuclei no light nuclei ? -40 stellar evolution ? -18 -15 -12 -9 -6 -3 0 3 6 9 12 15 18

2 2 2 1/2 sgn(µ ) Log(1+|µ |/fπ )

18 mHu =1.3m0

statistical draw to large soft terms balanced by anthropic draw toward red (m(weak)~100 GeV): then m(Higgs)~125 GeV and natural SUSY spectrum! Denef, Douglas, JHEP0405 (2004) 072 Giudice, Rattazzi, NPB757 (2006) 19; Dutta, Mimura, PLB648 (2007) 357 HB, Barger, Savoy, Serce,19 PLB758 (2016) 113 Under stringy naturalness, a 3 TeV gluino is more natural than a 300 GeV gluino!

higher density of dots => more stringy natural!

n=4 draw

n=1 draw

HB, Barger, Salam: arXiv:1906.07741, HB, Barger, Sengupta:arXiv:1912.01672 20 Making the picture more quantitative: dN [m2 ,m , ⇤]=f (m2 ) f f dm2 vac hidden weak SUSY hidden · EWFT · cc hidden

m(h)~125 most favored for n=1,2 HB,Barger, Serce, Sinha: arXiv:1712.01399 21 What is corresponding distribution for gluino mass?

typically beyond LHC 14 reach (may need HE-LHC)

22 and m(t1)?

23 first/second generation sfermions pulled to common bound 20-40 TeV thus solving SUSY flavor/CP problems: Sengupta talk

24 Conclusions:

• SUSY very much alive: natural for mu~100-300 GeV

• EW naturalness: higgsino-like WIMP

• QCD naturalness: axion

• SUSY mu problem/Little Hierarchy: SUSY DFSZ axion-PQ gravity-safe

• DM=higgsino-like WIMP+DFSZ axion admixture?

• multi-ton SI noble liquid detectors should probe all p-space

• string landscape: pull mh->125 and sparticles beyond LHC/Run2 reach

• (HL)-LHC: direct higgsino pair prod => SDLJMET signature!

• HE-LHC27 TeV may be required for gluinos/stops

• ILC500 is ideal for light higgsinos

25 SUSY DFSZ axion: large range in m(a) but coupling reduced may need to probe broader and deeper! 26 Mainly higgsino-like WIMPs thermally underproduce DM

green: excluded; red/blue:allowed

HB, Barger, Mickelson

IsaReD

Factor of 10-15 too low

27 But so far we have addressed only Part 1 of fine-tuning problem:

In QCD sector, the term must occur

But neutron EDM says it is not there: strong CP problem

(frequently ignored by SUSY types) Best solution after 35 years: PQWW/KSVZ/DFSZ invisible axion

In SUSY, axion accompanied by axino and saxion

Changes DM calculus: expect mixed WIMP/axion DM (2 particles) 28 mixed axion-neutralino production in early universe

neutralinos: thermally produced (TP) or NTP viaa ˜, s or G˜ decays • s,a˜ – re-annihilation at TD axions: TP, NTP via s aa, bose coherent motion (BCM) • saxions: TP or via BCM • – s gg: entropy dilution – s SUSY : augment neutralinos – s aa: dark radiation (N < 1.6) eff axinos: TP • – a˜ SUSY augments neutralinos gravitinos: TP, decay to SUSY • 29 =>

30 higgsino abundance

axion abundance

mainly axion CDM for fa<~10^12 GeV; for higher fa, then get increasing wimp abundance

Bae,31 HB,Lessa,Serce Prospects for SD WIMP searches:

32 Prospects for IDD WIMP searches:

suppressed by square of diminished WIMP abundance 33 Prospects for discovering SUSY with radiatively-driven naturalness at LHC and ILC

34 Sparticle prod’n along RNS model-line at LHC14:

higgsinos

gauginos

gluinos

higgsino pair production dominant-but only soft visible energy release from higgsino decays largest visible cross section: wino pairs

gluino pairs sharply dropping35 gluino pair cascade decay signatures

will need HE-LHC (27 TeV) to36 probe unified SUSY models Top squark searches: HE-LHC can see entire natural p-space: discover or falsify natural SUSY!

37 Distinctive new same-sign diboson (SSdB) signature from SUSY models with light higgsinos!

(soft)

(soft)

wino pair production

This channel offers added reach of LHC14 fornSUSY; it is also indicative of wino-pair prod’n followed by decay to higgsinos

38 See direct higgsino pair production recoiling from ISR (monojet signal)?

typically 1% S/BG after cuts: very tough to do!

39 + What about pp Z˜ Z˜ j with Z˜ Z˜ ` ` ? ! 1 2 2 ! 1

Han, Kribs, Martin, Menon, PRD89 (2014) 075007; HB, Mustafayev, Tata, PRD90 (2014) 115007;

40 use MET to construct m^2(tau-tau)

41 HL-LHC14 can see most of nSUSY p-space via soft OS dilepton+MET channel

42 Smoking gun signature: light higgsinos at ILC: ILC is Higgs/higgsino factory!

(higgsino) (Zh)

+ ˜1 ˜1 0 0 ˜1˜2

3-15 GeV higgsino mass gaps no problem in clean ILC environment

HB, Barger, Mickelson, Mustafayev, Tata arXiv:1404:7510

43 + + 0 0 e e ˜ ˜ (`⌫ ˜ )+(qq¯0˜ ) ! 1 1 ! ` 1 1 0 measure m(jj)

44 + 0 0 0 + 0 e e ˜ ˜ ˜ +(` `˜ ) ! 1 2 ! 1 1 + + measure m(` `)

45 46 47 #2: Higgs mass or large-log fine-tuning HS

It is tempting to pick out one-by-one quantum fluctuations but must combine log divergences before taking any limit

2 2 2 2 Xt = mQ3 + mU3 + mHu + At

neglect gauge pieces, S, mHu and running; then we can integrate from m(SUSY) to Lambda

3f 2 m2 t m2 + m2 + A2 ln(⇤/m ) Hu ⇠8⇡2 Q3 U3 t SUSY 2 2 m˜ ˜ < 500 GeV m /(m /2) < 10 t1,2,b1 HS ⇠ h h mg˜ < 1.5 TeV

then At can’t be too big old natural SUSY 48 What’s wrong with this argument? In zeal for simplicity, have made several simplifications: most egregious is that one sets m(Hu)^2=0 at beginning to simplify m2 (⇤) and m2 are not independent! Hu Hu violates prime directive!

The larger m2 (⇤) becomes, then the Hu larger becomes the cancelling correction!

HB, Barger, Savoy

49 HS ' EW

To fix: combine dependent terms:

m2 µ2 + m2 (⇤)+m2 where now both h ' Hu Hu µ2 and m2 (⇤)+m2 are m2 Hu Hu ⇠ Z After re-grouping: HS ' EW

Instead of: the radiative correction m2 m2 Hu Z we now have: the radiatively-corrected m2⇠ m2 Hu ⇠ Z

50 HS ' EW Recommendation: put this horse out to pasture

2 2 3ft 2 2 2 m 2 m + m + A ln(⇤/mSUSY ) Hu ⇠8⇡ Q3 U3 t R.I.P.

sub-TeV 3rd generation squarks not required for naturalness 51 EW is highly selective: most constrained models are ruled out except NUHM2 and its generalizations:

scan over p-space with m(h)=125.5+-2.5 GeV:

0.1%

1%

10%

HB, Barger, Mickelson,Padeffke-Kirkland, PRD89 (2014) 115019 52 Applied properly, all three measures agree: naturalness is unambiguous and highly predictive!

Radiatively-driven natural SUSY, or RNS:

(typically need mHu~25-50% higher than m0)

53 54