Beyond the SM: Tevatron Results & Potential

Beyond the SM: Tevatron Results & Potential

Greg Landsberg

Prague LHC WorkshopJuly 10, 2003

Way

LHC Workshop, July 7-12, 2003

Greg Landsberg, Beyond the SM @ the Tevatron

2

Outline

Life Beyond the Standard Model

New Physics’ Many Faces

The Tevatron Lessons

Run II Stats

Beyond SUSY

More Fun in Extra Dimensions

Conclusions



3

Life Within the Standard Model

…is boringly precise: …but not at all boring:– SM accommodates, but does not explain:

EWSB CP-violation Fermion masses

– Higgs self-coupling is positive, which leads to a triviality problem that bounds mH from above

– The natural mH value is , where is the scale of new physics; if SM is valid up to GUT scale, an extreme ((v/mGUT)2) fine-tuning is required

v MGUT MPl

GravitationalForce

E [GeV]

EM/HyperchargeForce

Weak Force

Strong ForceInvers

e S

treng

th

RGE equations

1016102 1019

Direct

MH < 211 GeV @ 95% CL(Combined EW fit)

MH > 113.5 GeV @ 95% CL

(LEP2, up to 209 GeV)



4

New Physics’ Many Faces

Supersymmetry– mSUGRA like– Gauge MSB– Gaugino MSB– Anomaly MSB

Strong Dynamics– Technicolor– Top See-Saw– Compositeness

Exotics– Leptoquarks– Extra gauge bosons

Extra Dimensions– Large/Infinite Volume Extra Dimensions– Warped Extra Dimensions– Universal Extra Dimensions

Something COMPLETELY unexpected



5

Searches for New Physics

Electroweak/Heavy Flavor/QCD Physics:– Most properties are well known– Mainly precision measurements

Higgs physics:– Most signatures are known– A few free parameters– Well-defined search strategy

Searches for New Physics:– Do not even know what it is and where it is

Little doubt exists that it must be there, maybe just around the corner– Only vague ideas about signatures

Many channels, many possibilities of statistical fluctuations Might not be possible to use ‘cousin channels’ as a discovery proof

(e.g., RPV SUSY)– An ultimate challenge and an ultimate prize!



6

Searches at the Tevatron

The Tevatron energy might or might not be in the right range for new physics discovery

– Perhaps with the exception of minimal technicolor models, the LHC is really the machine for ultimate test

– Instead of giving you a review of full capabilities of the Tevatron in all possible channels we use for searches, I’ll give you my personal view on the most promising discovery channels at the Tevatron

Consider both targeted and signature-based searches to cover all the bases

– A few hints from Run I: eeMET, e + X “top” events, etc.– Importance of b’s and ’s– New physics in top production and decay– “Grand finale” model-independent searches a la Sleuth [DØ, PRD

62, 92004 (2000); PRL 86, 3712 (2001); PRD 64, 012004 (2001)]



7

The Tevatron Lessons

The upgraded Tevatron with 10% higher energy still has not crossed new energy threshold, so it’s unlikely that NP would appear as “spectacular events,” such as copious SUSY or black hole production

– Need to be patient It’s likely that NP will manifest itself first as a marginal event excess in

a number of related channels– Need for optimal combination of various channels to reach the discovery

significance (cf. Higgs) It’s likely that NP will be overwhelmed by the SM backgrounds in the

channels of interest– Need reliable background calculation tools and advanced methods of

background suppression, while retaining high sensitivity for the signal It’s given that with the complexity of modern detectors, particle ID is

based on a large number of variables– Need for advanced multivariate particle ID techniques

It’s possible that NP searches would require special triggers– Need for fast triggering methods in a complex environment



8

Run II Detectors

Significantly upgraded experiments with three major subdetectors:

• Hermetic Calorimeters• Central Tracker• Muon Detectors

CDF

DØ

Multiple detectors – multiple handles:• EM: calorimetry, preshowers, (tracking, ionization) • Muons: central and outer tracks, ionization, calorimetry• ’s: tracking, calorimetery• Jets: tracking, calorimetry



9

Tevatron Reach for New Physics

A rule of thumb: for pair production of heavy objects cross section drops by a factor of 2 for every 20 GeV in the object mass:

– 2 fb-1 effective x30 in accumulated statistics (higher energy, efficiency)– 10 fb-1 effective x150 in accumulated statistics – Constant S/√B (statistics-limited case):

Run IIa: 20 GeV x log230 or 100 GeV increase in the mass reach Run IIb: 20 GeV x log2150 or 145 GeV improvement in the mass reach

Nowadays mass limits are ~100 GeV thus Run IIa will double the phase space probed; Run IIb will add only additional 20%

– If I were to bet if the Tevatron is going to see NP, I’d bet on Run IIa; if we do not see any evidence with ~2 fb-1, it’s likely that the Tevatron is simply not in the right energy range to probe it

Note: if the error on the background is systematics-limited, the reach compared to Run I does not improve at all, as S/B = S/(aB) const:

– Some backgrounds can be measured from data; thus guaranteeing B ~ 1/√∫Ldt, but not all of them!

– Desperate need for NkLO (k ≥ 1) Monte Carlo for accurate SM background description!



10

Tevatron Lesson: the Monte Carlo

In a perfect world…– MC is as glamorous as your

detector (often not built yet!)– You can bet on it!– Who needs the data?!!

In the real world…– Only a schematic description– Lack of non-Gaussian effects– The GIGO effect

Do not rely on MC – it will look quite different from the actual data taken with the new detectors; we witnessed this in both Run I and Run II



11

Fast Monte Carlo – A Good Compromise?

Parametric fast MC:– Is flexible and tunable with real data– Easily interfaced with modern event generators– Able to generate large samples of events on a short time scale



12

Run II Stats

1/8 of the expected Run IIa statistics (2 fb-1) have been delivered already; most of it in the last few months

Data taking efficiency is ~90% for both the CDF and DØ collaborations

EPS’03 and LP’03 results will break the new level of statistics, exceeding those in Run I

While the future of the Tevatron upgrade became uncertain recently, we are proceeding with an aggressive upgrade schedule with the shutdown planned in about 2 years to replace the silicon detectors



13

Search for Exotics at the Tevatron

It’s a long shot, as signatures are often not clear and physics motivation is frequently questionable

– “To find Exotica, call 1-800-EXOTICA” - WNUA , Chicago Technicolor models have been restricted significantly by

LEP (both direct searches and precision measurements)– Run II should confirm or exclude simplest versions of technicolor

and topcolor models Additional gauge bosons and leptoquarks:

– Come in many SM extensions, particularly in GUTs; however, they do not solve SM problems per se

– Significantly constrained by the LEP precision electroweak data Massive Slow-Moving Particles

– Limited motivation (need high degeneracy or exotic particles)– Both collaborations utilize TOF and dE/dx to perform searches



14

Searches for Extra Gauge Bosons

Example: Z’ searches– Current limits ~700 GeV– Run II sensitivity ~1 TeV– Not a significant extension of

the parameter space

M > 620 GeV (DØ)M > 665 GeV (CDF)

SM-like Z’ couplings

E6 Z’ couplings

∫Ldt ~ 40 pb-1



15

Searches for Leptoquarks

A lot of excitement 6 years ago, due to reported HERA high-Q2 event excess Interest largely evaporated since the LQ interpretation of HERA result was

shown to be wrong by the Tevatron Nevertheless, searches are under way, and expected Run II sensitivity

extends to 300-350 GeV for scalar LQ’s

CDF Run II: MLQ1 > 230 GeV DØ Run II: MLQ2 > 157 GeV

∫Ldt = 30 pb-1



16

More Fun in Extra Dimensions

Caveat: the large hierarchy of scales picture is based solely on the log extrapolation of gauge couplings by some 14 decades in energy

– How valid is that?

1998: abstract mathematics meets phenomenology: extra spatial dimensions have been first used to:

– “Hide” the hierarchy problem by making gravity as strong as other gauge forces in (4+n)-dimensions (Arkani-Hamed, Dimopoulos, Dvali)

– Explore modification of the RGE in (4+n)-dimensions to achieve low-energy unification of the gauge forces (Dienes, Dudas, Gherghetta)

Burst of ideas to follow:– 1999: possible rigorous solution of the

hierarchy problem by utilizing metric of curved anti-deSitter space (Randall, Sundrum)

– 2000: “democratic” (universal) extra dimensions, equally accessible by all the SM fields (Appelquist, Chen, Dobrescu)

– 2001: “contracted” extra dimensions – use them and then lose them (Arkani-Hamed, Cohen, Georgi)

All these models result in rich low-energy phenomenology

MZ MGUTMS M’GUT

GravitationalForce

logE

EM/HyperchargeForce

Weak Force

Strong Force

Real GUT Scale

VirtualImage

Invers

e S

tren

gth

M’Pl

MPl=1/GN

~ 1 TeV



17

Math Meets Physics

Math physics: some dimensionalities are quite special Example: Laplace equation in two dimensions has

logarithmic solution; for any higher number of dimensions it obeys power law instead

Some of these peculiarities exhibit themselves in condensed matter physics, e.g. diffusion equation solutions allow for long-range correlations in 2D-systems (cf. flocking)

Modern view in topology: one dimension is trivial; two and three spatial dimensions are special (properties are defined by the topology); any higher number is not

Do we live in a special space, or only believe that we are special?

One of the most innovating and exciting recent ideas, yet barely tested experimentally!



18

Using the Extra Dimension Paradigm

EWSB from extra dimensions:– Hall, Kolda [PL B459, 213 (1999)]

(lifted Higgs mass constraints)– Antoniadis, Benakli, Quiros [NP B583,

35 (2000)] (EWSB from strings in ED)– Cheng, Dobrescu, Hill [NP B589, 249

(2000)] (strong dynamics from ED)– Mirabelli, Schmaltz [PR D61, 113011

(2000)] (Yukawa couplings from split left- and right-handed fermions in ED)

– Barbieri, Hall, Namura [hep-ph/0011311] (radiative EWSB via t-quark in the bulk)

Flavor/CP physics from ED:– Arkani-Hamed, Hall, Smith, Weiner

[PRD 61, 116003 (2000)] (flavor/CP breaking fields on distant branes in ED)

– Huang, Li, Wei, Yan [hep-ph/0101002] (CP-violating phases from moduli fields in ED)

Neutrino masses and oscillations from ED:

– Arkani-Hamed, Dimopoulos, Dvali, March-Russell [hep-ph/9811448] (light Dirac neutrinos from right-handed neutrinos in the bulk or light Majorana neutrinos from lepton number breaking on distant branes)

– Dienes, Dudas, Gherghetta [NP B557, 25 (1999)] (light neutrinos from right-handed neutrinos in ED or ED see-saw mechanism)

– Dienes, Sarcevic [PL B500, 133 (2001)] (neutrino oscillations w/o mixing via couplings to bulk fields)

Many other topics from Higgs to dark matter



19

The ADD Model

SM fields are localized on the (3+1)-brane; gravity is the only gauge force that “feels” the bulk space

What about Newton’s law?

Ruled out for flat extra dimensions, but not for sufficiently small compactified extra dimensions:

Flat Dimension

Com

pact

Dim

ensi

on

1

2123

212

11

nnn

PlPl r

mm

Mr

mm

MrV

Rr

rR

mm

MrV

nnnPl

for

1 2123

Gravity is fundamentally strong force, bit we do not feel that as it is diluted by the volume of the bulk

G’N = 1/MD2; MD 1

TeV

More precisely, from Gauss’s

law:

Amazing as it is, but no one has tested Newton’s law to distances less than 1mm (as of 1998)

Thus, the fundamental Planck scale could be as low as 1 TeV for n > 1

nPl

nD RMM 22

4 ,106

3 , 3

2 , 7.0

1 ,108

2

1

12

12

/2

nm

nnm

nmm

nm

M

M

MR

n

D

Pl

D

2]3[/1 nPlM



20

Collider Signatures for Large ED

Kaluza-Klein gravitons couple to the momentum tensor, and therefore contribute to most of the SM processes

For Feynman rules for GKK see:– Han, Lykken, Zhang, PR D59, 105006

(1999)– Giudice, Rattazzi, Wells, Nucl. Phys.

B544, 3 (1999) Since graviton can propagate in the bulk,

energy and momentum are not conserved in the GKK emission from the point of view of our 3+1 space-time

Depending on whether the GKK leaves our world or remains virtual, the collider signatures include single photons/Z/jets with missing ET or fermion/vector boson pair production

If the energy is above Planck scale, copious black hole production is inevitable

Real Graviton EmissionMonojets at hadron colliders

GKK

gq

q GKK

gg

g

Single VB at hadron or e+e- colliders

GKK

GKK

GKK

GKK

V

VV V

Virtual Graviton Emission Fermion or VB pairs at hadron or e+e- colliders

V

V

GKKGKK

f

ff

f



21

Virtual Graviton Effects

In the case of pair production via virtual graviton, gravity effects interfere with the SM (e.g., l+l- at hadron colliders):

Therefore, production cross section has three terms: SM, interference, and direct gravity effects

The sum in KK states is divergent in the effective theory, so in order to calculate the cross sections, an explicit cut-off, MS, is required

An expected value of the cut-off is MD, as this is the scale at which the effective theory breaks down, and the string theory needs to be used to calculate production

– Direct emission and virtual effects are complementary methods of probing ADD model

Unfortunately, a number of similar papers calculating the virtual graviton effects appeared simultaneously

Hence, there are three major conventions on how to write the effective Lagrangian:

– Hewett, Phys. Rev. Lett. 82, 4765 (1999)– Giudice, Rattazzi, Wells, Nucl. Phys.

B544, 3 (1999); revised version, hep-ph/9811291

– Han, Lykken, Zhang, Phys. Rev. D59, 105006 (1999); revised version, hep-ph/9811350

Fortunately (after a lot of discussions and revisions) all three conventions turned out to be equivalent and only the definitions of MS are different:

M,cosfM

nbM,cosf

M

nadMcosd

d

dMcosd

d

*

S

*

S

*SM

*

2814

22



22

Tevatron Searches

High-mass, low |cos| tail is a characteristic signature of LED [Cheung, GL, PRD 62 076003 (2000)]

2-dimensional method resolves this tail from the high-mass, high |cos| tail due to collinear divergencies in the SM diphoton production

Best limits on the effective Planck scale come from the DØ Run I data:

– MS(Hewett) > 1.1/1.0 TeV () T(GRW) > 1.2 TeV– MS(HLZ) > 1.0-1.4 TeV (n=2-7)

Similar limits already set with Run II data

New 120 pb-1 analysis out next week! Sensitivity in Run II and at the LHC

(HLZ, from [Cheung, GL, PRD 62 076003 (2000)])

50 pb-1



23

Hadron Colliders: Graviton Emission

qq/gg q/gGKK – jets + MET final state– Z()+jets is irreducible

background– Challenging signature due to

large instrumental backgrounds from jet mismeasurement, cosmics, etc.

– DØ pioneered this search in Run I and set limits [PRL 90, 251802 (2003)] MD > 0.7-1.0 TeV

– CDF just announced similar preliminary limits

qq GKK–

+MET final state– CDF search [PRL 89, 281801

(2002)] set limits between 500 and 600 GeV

Theory:[Giudice, Rattazzi, Wells, Nucl. Phys. B544, 3 (1999) and corrected version, hep-ph/9811291][Mirabelli, Perelstein, Peskin, PRL 82, 2236 (1999)]

n MD reach, Run I

MD reach, Run II

MD reach, LHC 100 fb-1

2 1100 GeV 1400 GeV 8.5 TeV

3 950 GeV 1150 GeV 6.8 TeV

4 850 GeV 1000 GeV 5.8 TeV

5 700 GeV 900 GeV 5.0 TeV



24

Intermediate-size extra dimensions with TeV-1 radius

Introduced by Antoniadis [PL B246, 377 (1990)] in the string theory context; used by Dienes/Dudas/ Gherghetta [PL B436, 55 (1998)] to allow for low-energy unification

– SM gauge bosons can propagate in these extra dimensions

– Expect ZKK, WKK, gKK resonances

– Effects of the virtual exchange of the Kaluza-Klein modes of vector bosons at lower energies

Gravity is not included in this model Antoniadis/Benaklis/Quiros [PL B460,

176 (1999)] – direct excitations; require LHC energies

[ABQ, PL B460, 176 (1999)]

IBQ ZKK

TeV-1 Extra Dimensions



25

Current Limits on TeV-1 ED

From Cheung/GL [PRD 65, 076003 (2002)]



26

Tevatron Tests in Run II

We expect the dijet and DY production to be the most sensitive probes of TeV-1 extra dimensions

The 2D-technique similar to the search for ADD effects in the virtual exchange yields the best sensitivity in the DY production [Cheung/GL, PRD 65, 076003 (2002)]

Similar (or slightly better) sensitivity is expected in the dijet channel; detailed cuts and NLO effects need to be studied

Run IIb could yield sensitivity similar to the current limits from indirect searches at LEP

These tests are complementary in nature to those via loop diagrams at LEP

From Cheung/GL [PRD 65, 076003 (2002)]



27

Randall-Sundrum Scenario

Randall-Sundrum (RS) scenario [PRL 83, 3370 (1999); PRL 83, 4690 (1999)]

– Gravity can be localized near a brane due to the non-factorizable geometry of a 5-dimensional space

– + brane (RS) – no low energy effects– +– branes (RS) – TeV Kaluza-Klein

modes of graviton– ++ branes (Lykken-Randall) – low

energy collider phenomenology, similar to ADD with n=6

– –+– branes (Gregory-Rubakov-Sibiryakov) – infinite volume extra dimensions, possible cosmological effects

– +–+ branes (Kogan et al.) – very light KK state, some low energy collider phenomenology

G

Planck branex5

SM brane

Davoudiasl, Hewett, Rizzo PRD 63, 075004 (2001)

Drell-Yan at the LHC



28

Current Constraints

Neither gravity experiments, nor cosmology provide interesting limits on most of the RS models

Existing limits come from collider experiments, dominated by precision electroweak measurements at LEP

As the main effect involves direct excitation of the GKK, energy is the key

Given the existing constraints and the theoretically preferred parameters, there is not much the Tevatron can do to test RS models

Extra degree of freedom due to the compact dimension results in a light scalar field – the radion

Again, Tevatron sensitivity is very limited

LHC is the place to probe RS models

; 1 2352 ckr

Pl ek

MM

ckrPleM



29

Run II Searches

CDF pioneered RS graviton searches in the dilepton and dijet modes

Limited increase in sensitivity with larger statistics



30

Universal Extra Dimensions

The most “democratic” ED model: all the SM fields are free to propagate in extra dimension(s) with the size Rc = 1/Mc ~ 1 TeV-1 [Appelquist, Cheng, Dobrescu, PRD 64, 035002 (2001)]

– Instead of chiral doublets and singlets, introduce vector-like quarks and leptons– Gravitational force is not included in this model

The number of universal extra dimensions is not fixed:– It’s feasible that there is just one (MUED)– The case of two extra dimensions is theoretically attractive, as it breaks down to a

chiral SM and has additional nice features, such as guaranteed proton stability, etc.

Every particle acquires KK modes with masses Mn2 = M0

2 + Mc2, n = 0, 1, 2, …

– Kaluza-Klein number (n) is conserved at the tree level, i.e. n1 n2 n3 … = 0; consequently, the lightest KK mode cold be stable (and is an excellent dark matter candidate [Cheng, Feng, Matchev, PRL 89, 211301 (2002)])

– Hence, KK-excitations are produced in pairs, similar to SUSY particles Consequently, current limits (dominated by precision electroweak constraints,

particularly on the T-parameter) are sufficiently low (Mc ~ 300 GeV for one ED and of the same order, albeit more model-dependent for >1 ED)



31

UED Phenomenology

Naively, one would expect large clusters of nearly degenerate states with the mass around 1/RC, 2/RC, …

Cheng, Feng, Matchev, Schmaltz: not true, as radiative corrections tend to be large (up to 30%); thus the KK excitation mass spectrum resembles that of SUSY!

Minimal UED model with a single extra dimension, compactified on an S1/Z2 orbifold

– Odd fields do not have 0 modes, so we identify them w/ “wrong” chiralities, so that they vanish in the SM

Q, L (q, l) are SU(2) doublets (singlets) and contain both chiralities[Cheng, Matchev, Schmaltz, PRD 66, 056006 (2002)]

MC = 1/RC = 500 GeV



32

UED Spectroscopy

First level KK-states spectroscopy

[CMS, PRD 66, 056006 (2002)]

Decay:B(g1→Q1Q) ~ 50%B(g1→q1q) ~ 50%B(q1→q) ~ 100%

B(t1→W1b, H1

+b) ~

B(Q1→QZ1:W1:1) ~ 33%:65%:2%B(W1→L1:1L) = 1/6:1/6 (per flavor)B(Z1→1:LL1) ~ 1/6:1/6 (per flavor)B(L1→1L) ~ 100%B(1→1) ~ 100%

B(H1

→1, H

±*1) ~ 100%Production: q1q1 + X → MET + jets (~had/4); but:

low MET

Q1Q1+ X→ V1V’1 + jets → 2-4 l + MET

(~had/4)



33

Production Cross Section

Q1Q1, q1q1

[Rizzo, PRD 64, 095010 (2001)]

Run II, s = 2 TeV

Reasonably high rate up to M ~ 500 GeV



34

Sensitivity in the Four-Lepton Mode

Only the gold-plated 4-leptons + MET mode has been considered in the original paper

Sensitivity in Run IIb can exceed current limits

Much more promising channels:

– dileptons + jets + MET + X (x9 cross section)

– trileptons + jets + MET + X (x5 cross section)

Detailed simulations is required: important to see this process implemented in a MC

One could use SUSY production with adjusted masses and branching fractions as a temporary fix

L is per experiment; (single experiment)

[Cheng, Matchev, Schmaltz, PRD 66, 056006 (2002)]



35

Almost No Extra Dimensions

Novel idea: build a multidimensional theory that is reduced to a four-dimensional theory at low energies [Arkani-Hamed, Cohen, Georgi, Phys. Lett. B513, 232 (1991)]

An alternative EWSB mechanism, the so-called Little Higgs (a pseudo-goldstone boson, responsible for the EWSB) [Arkani-Hamed, Cohen, Katz, Nelson, JHEP 0207, 034 (2002)]

Limited low-energy phenomenology: one or more additional vector bosons; a charge +2/3 vector-like quark (decaying into V/h+t), necessary to cancel quadratic divergencies), possible additional scalars (sometimes even stable!), all in a TeV range

Unfortunately, the Tevatron reach is very poor; LHC would be the machine to probe this model

However: keep an eye on it – this is currently the topic du jour in phenomenology of extra dimensions; new signatures are possible!



36

(Instead of) Conclusions

ED are one of the most exciting novel ideas, yet barely tested experimentally:– ADD: virtual graviton effects, direct graviton emission, string resonances– TeV-1 dimensions: VKK, virtual effects– RS: graviton excitations, SM particle excitation, radion, direct graviton emission– Universal extra dimensions: rich SUSY-like phenomenology

Like in SUSY searches, Run II would double the parameter space probed, which makes this subject one of the most exciting exotic channels to explore

Both CDF and DØ collaborations pursue this avenue very actively

Channel Extra Dimensions Probe Other New Physics

Dilepton ADD, TeV-1, RS Z’, compositeness

Diphotons ADD, some RS Compositeness, higgs, monopoles

Dijet ADD, TeV-1, Strings Compositeness, technicolor

Monojets ADD, some RS Light gravitino, other SUSY

Monophotons ADD, some RS GMSB, light gravitino, ZZ/Z couplings

Monoleptons TeV-1, some RS W’

Dijet + MET ADD, Universal SUGRA, Leptoquarks

Leptons + MET Universal SUGRA



37

Grand Finale: Have We Missed Anything?

SLEUTH (formerly known as SHERLOCK) [DØ, PRD 62, 92004 (2000); PRL 86, 3712 (2001); PRD 64, 012004 (2001)] is an attempt to use multivariate techniques to answer the above question

– Generalizes search for high-pT physics by identifying global variables, correlated with the pT of a process, and then looking for “reasonable” contiguous areas in the resulting multivariate space yielding maximum excess of data above the SM background

– Unusual, data-driven approach; an interesting method to answer the question of whether there was an evidence for new physics in the data posteriori

– Takes into account the fact that search for excesses was performed in many different variables and channels by adjusting the probability accordingly; consequently, trades decreased significance for increased generality

– Used by DØ to reanalyze Run 1 data in a semi-model-independent way and quantify the degree of the agreement between the data and the SM predictions in some 30 previously studied channels



38

DØ Run 1 Sleuth Results

Sleuth is a nice tool to use before closing the door and shutting off the lights: have we forgotten or missed anything

It crucially relies on background understanding and won’t help at this (most time-consuming) step

Not very competitive with direct search for a known signature (e.g. mass peak)

P() = -1.23 → P = 0.89,i.e. 89% of hypothetical experimentswould have seen more “interesting” results in these 32 channels than DØ

~ ~



39

ADD and Dijet Production

[Atwood, Bar-Shalom, Sony, PRD 62, 056008 (2000)], used HLZ formalism Look at the dijet production cross section as a function of = s/s Reach at the Tevatron ~1.5 TeV (2 fb-1), at the LHC ~10 TeV (30 fb-1) –

comparable to that in the dilepton/diphoton channels Also, tt invariant mass and pT at the Tevatron or LHC (Run IIa reach: ~1.2 TeV;

LHC: ~6 TeV) [Rizzo, hep-ph/9910255 (1999)]

^

LHC, SM

MS = 2 TeV

MS = 4 TeV

MS = 6 TeV

Tevatron, SMMS = 0.75 TeV

MS = 1.5 TeV

Beyond the SM: Tevatron Results & Potential

Documents

Transcript of Beyond the SM: Tevatron Results & Potential