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Theoretical Overview of B Physics
→ personal perspectives ←
Xin-Qiang Li
Central China Normal University
Talk given at HFCPV-2018, Zhengzhou, 2018/10/26
Outline
Introduction
Theoretical tools for B physics
B − B mixings: ∆Ms,d, ∆Γs,d, as,dfs
Bs,d → µ+µ−: powerful model killing
Semi-leptonic decays: |Vub|, |Vcb| and R(D(∗))
Exclusive b→ s`+`− decays: several anomalies
Non-leptonic decays: higher-order pert. corrs
Conclusion
2 / 35
Why B physics:
I What is B physics: properties, productions and decays of vari-ous hadrons containing at least one bottom quark;
Bu,d,s,c mesons, Λb baryon
I Why study B physics: three main motivations;
3 / 35
Dedicated B-physics experiments:
I Past: first observation of B → Xsγ by CLEO in 1994; continued by Tevatron @
Fermilab and the two B-factories: BaBar @ SLAC and Belle @ KEK with many key
measurements; [A. J. Bevan et al., “The Physics of the B Factories,” 1406.6311]
I Current: dedicated LHCb (also ATLAS and CMS) @ LHC with many exciting
results; [I. Bediaga et al., “Physics case for an LHCb Upgrade II - Opportunities
in flavour physics, and beyond, in the HL-LHC era,” arXiv:1808.08865]
I Future: besides LHCb @ LHC, also Belle II @ SuperKEKB expected to start
data taking in 2018, designed to find NP beyond the SM of particle physics;
[https://confluence.desy.de/display/BI/B2TiP+WebHome; 1808.10567]
assl
±3.0 × 10 4
±10.0 × 10 4
±33.0 × 10 4
[ ]±0.35
±1.5
±1.5
±5.4
s [mrad]
±22
±4
±14
±49
A
±1.0 × 10 5
±35.0 × 10 5
±4.3 × 10 5
±28.0 × 10 5
Current
HL-LHC
2025
LHCb
LHCb
ATLAS/CMS
Belle II
RK [%]±0.70
±3.6
±2.2
±10.0
R(D * ) [%]±0.20
±0.50
±0.72
±2.6
(B0 + )(B0
s+ ) [%]
±21
±10
±34
±90
Current
HL-LHC
2025
LHCb
LHCb
ATLAS/CMS
Belle II
4 / 35
Theoretical tasks for B physics:
I Main task: try to improve the theory predictions to match the more
and more precise exp. data;
I Many dynamical frameworks developed: HQET, SCET, NRQCD,
QCDF, pQCD, · · · ↪→ based on QCD, and separate pert. from non-
pert. strong interaction effects ↔ factorization theorem;
I For the non-pert. objects: mostly from Lattice QCD and LCSR,· · · ; [for reviews see: http://flag.unibe.ch/, and https://hflav.web.cern.ch/]
160 175 190 205 220 235 250
=+
+=
+=
MeV
ETM 09DETM 11AALPHA 11ETM 12BALPHA 12AETM 13B, 13CALPHA 13ALPHA 14
FLAG average for =
HPQCD 09FNAL/MILC 11HPQCD 12 / 11AHPQCD 12RBC/UKQCD 13A (stat. err. only)RBC/UKQCD 14ARBC/UKQCD 142RBC/UKQCD 141
FLAG average for = +
HPQCD 13ETM 13E
FLAG average for = + +
5 / 35
Current status of B physics:
I The CKM mechanism of flavor & CP violation well established! ↪→2008 Nobel Prize for Kobayashi and Maskawa;
I Information on UT from tree- and loop-level processes well consistent!
6 / 35
Current status of B physics:
I Remember: O(20%) NP contributions to most FCNC processes still
allowed by the current data;
I Several intriguing tensions/anomalies do observed in flavour physics,
might be any BSM signals?
Br(B->pi^0 pi^0)A_CP(B->pi K)
Z.Ligeti,1606.02756
† all of them not yet conclu-sive: theo. uncertaintiesor exp. fluctuations?
† except for theo. cleanestmodes, more cross-checksneeded;
† exp. measurements of re-lated observables needed;
† indep. theory and latticecalculations needed;
7 / 35
How to describe B-hadron weak decays:
I At the quark level: B-hadron weak decays mediated by weakcharged-current Jµcc coupled to W±;
Lcc = −g2√
2Jµcc W
†µ + h.c., Jµcc = (uL, cL, tL) γµ VCKM
dLsLbL
↪→ VCKM: describes flavor violation, and very predictive, especially for CPV!
I In the real world: no free quarks due to confinement; quarksalways confined inside hadrons through soft-gluon exchanges;
↪→ In B physics, simple weak decays overshadowed by complex strong interactions!
8 / 35
Typical features for B-hadron weak decays:
I A typical multi-scale problem and scales are highly hierarchical;
EW interaction scale � ext. mom’a in B rest frame � QCD-bound state effectsmW ∼ 80.4 GeV � mb ∼ 4.8 GeV � ΛQCD ∼ 1 GeV
I Starting point Leff : integrate out heavy d.o.f. (mW,Z,t � mb), physics
above (below) µ ∼ mb contained in Ci (〈Oi〉); [A. J. Buras, 1102.5650]
I Ci: RG-improved pert. calculable;
matching at µ0 and running to µb;
NNLL accuracy available!9 / 35
Hadronic matrix elements for B-hadron weak decays:
I How to evaluate 〈f |Oi|B〉: 〈0|Oi|B〉, 〈π|Oi|B〉, 〈ππ|Oi|B〉, 〈B|Oi|B〉,· · · ;
I 〈M1M2|Oi|B〉: not yet possible in lattice QCD; expressed in terms of (few)
universal non-pert. hadronic quantities with pert. calculable coefficients;
- dynamical approaches based on factorization theorems: PQCD, QCDF,
SCET, · · · ; [Keum, Li, Sanda, Lu, Yang ’00;
Beneke, Buchalla, Neubert, Sachrajda, ’00;
Bauer, Flemming, Pirjol, Stewart, ’01]
- (approximate) symmetries of QCD: Isospin, U-Spin, V-Spin, and flavor
SU(3) symmetries, · · · ; [Zeppenfeld, ’81;
London, Gronau, Rosner, Chiang, Cheng et al.]10 / 35
B − B mixings:
I Motivation: strongly suppressed in SM; highly sensitive to BSM effects;
↪→ Λ ≥ 103 TeV
I ∆Ms,d.= 2|M s,d
12 |: calculated from box diagrams with internal virtual par-
ticles; main uncertainty from Bag parameters 〈Bq |Oi|Bq〉 ∝ f2BqB
(i)Bq
;
∆MSMd = (0.53+0.03
−0.04) ps−1
∆MHFAGd = (0.5065± 0.0019) ps−1
∆MSMs = (18.1+1.1
−1.2) ps−1
∆MHFAGs = (17.757± 0.021) ps−1
[Kirk, Lenz and Rauh, 1711.02100;
T. Rauh, talk given at CKM2018]11 / 35
B − B mixings:
I ∆Γs,d.= 2|Γs,d12 | cosφs,d12 : arise from absorptive part of box diagrams, dom-
inated by tree-level b→ ccs(d) transitions; [Artuso/Borissov/Lenz, 1511.09466]
Γs12 =Λ3
m3b
[Γs,(0)3 +
αs
4πΓs,(1)3 +
(αs4π
)2Γs,(2)3 + ...
]+
Λ4
m4b
(Γs,(0)4 + ...
)+ ... [H. M. Asatrian et al, 1709.02160]
b s
s b
c
cSecond OPE = Heavy Quark Expansion (HQE)
I as,dfs.=
∣∣∣ Γs,d12
Ms,d12
∣∣∣ sinφs,d12 : motivated by 2013 D0 dimuon charge asymmetry!
-0.4 -0.2 -0.0 0.2 0.4φ ccss [rad]
0.06
0.08
0.10
0.12
0.14
∆Γs[p
s−1]
ATLAS 19.2 fb−1
D0 8 fb−1
CMS 19.7 fb−1
CDF 9.6 fb−1Combined
LHCb 3 fb−1
SM
68% CL contours(∆ log L = 1.15)
HFLAVPDG 2018
)0(BSLA-0.02 -0.01 0 0.01 0.02
) s0(B
SL
A
-0.02
-0.01
0
0.01
HFLAVPDG 2018
B factoryaverage
LHCbXµ(*)
(s) D→ 0(s)B
0DXµ(*)
(s) D→ 0(s)B
0Dmuons
0Daverage
10×Theory
World average
= 12χ∆
12 / 35
B − B mixing:
I ∆Ms,d vs ∆Γs,d: state-of-the-art comparison; [Kirk, Lenz and
Rauh, 1711.02100; T. Rauh, talk given at CKM2018]
I SM predictions and exp. averages consistent with each other!
↪→ Large NP effect in Bs,d mixings now closed!
13 / 35
Bs,d → µ+µ−:
I Facts about Bs,d → µ+µ−: highly suppressed within the SM;
- helicity suppressed, by a factor of (mµ/mB)2;
- FCNC process, forbidden at tree-level, proceed
only via loop diagrams;
- CKM suppressed by |VtbV ∗ts|2;
↪→ very sensitive to NP, especially from OS(P );
I Theory status: CA now to NNLO QCD + NLO EW; enhanced EM correction
included; [Bobeth et al., 1311.0903; Beneke, Bobeth and Szafron, 1708.09152]
Heff = −GF α√2πs2W
[VtbV
∗tq
A,S,P∑i
(CiOi + C′iO′i
)+ h.c.
]OA = (qγµPLb) (¯γµγ5`) , OS(P ) = mb(qPRb) [¯(γ5)`]
B(Bs → µ+µ−) = (3.57± 0.17)× 10−9, B(Bd → µ+µ−) = (1.06± 0.09)× 10−10
14 / 35
Bs,d → µ+µ−:
I CMS + LHCb and LHCb updated results: [1411.4413, 1703.05747]
B(Bs → µ+µ−) = (3.0 ±0.6+0.3−0.2) · 10−9 (7.8σ);
B(Bd → µ+µ−) = (3.9+1.6−1.4) ·
10−10 (3.0σ);
)−µ+µ → 0s
BF(B0 2 4 6 8
9−10×
)− µ+ µ
→ 0B
F(B
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.99−10×
68.27%
95.45%
99.73%
99.99%
SM
LHCb
I Powerful in model killing: good consistency between SM and exp. data;
[D. Straub, 1205.6094]
15 / 35
Bs,d → µ+µ−:
I Time-dependent observables: due to sizeable ∆Γs; [De Bruyn et
al., 1204.1737; Fleischer et al., 1703.10160; 1709.04735]
I With the updated LHC: these observables provide new d.o.f. for NP
searches; [Fleischer, Jaarsma, Tetlalmatzi-Xolocotzi, 1703.10160; 1709.04735]
16 / 35
|Vub| and |Vcb| problem:
I Importance of |Vxb|: play a key role in determining the apex of UT;
- |Vub| or |Vub/Vcb| constraints
drectly the UT;
- b→ s induced FCNC processes∝|VtbV ∗ts|2 ' |Vcb|2
[1 +O(λ2)
];
- εK ' x|Vcb|2 + · · · ;
↪→ More precise determination of
|Vxb| is of utmost importance!
I Incl. vs excl. methods: [Nandi, Gambino, Tackmann, talks at CKM 2016]
- Inclusive |Vcb|: OPE/HQE, dominated by theory uncertainties, especially by
correlations of theoretical parameters;
- Inclusive |Vub|: OPE/HQE, limited knowledge of leading and subleading SFs;
- Exclusive |Vxb|: how precise can the form factors be calculated by LQCD or LCSR;
17 / 35
|Vub| and |Vcb| problem:
I Status of global fit for |Vxb|: [Gambino, Silva, Bona, talks at CKM2018]
I Results for CKM2018: [Silva, Bona, talks at CKM2018]
|Vcb|incl. = (42.2± 0.4± 0.6) · 10−3, |Vub|incl. = (4.44± 0.17± 0.31) · 10−3
|Vcb|excl. = (41.2± 0.6± 0.9± 0.2) · 10−3, |Vub|excl. = (3.72± 0.09± 0.22) · 10−3
↪→ |Vxb| tension significantly reduced, especially for |Vcb|!
↪→ global fit favours |Vub|excl. & |Vcb|incl.!18 / 35
R(D) and R(D∗) anomalies:
I B → D(∗)τ ν decays: tree-level processes;massive τ makes them sensitive
to tree-level NP like RH currents, charged Higgs, leptoquarks, · · · ;
I Current status: R(D(∗)) =Br(B→D(∗)τντ )
Br(B→D(∗)`ν`); [BaBar, 1205.5442, 1303.0571;
Belle, 1507.03233, 1607.07923, 1612.00529; LHCb, 1506.08614, 1708.08856]
0.2 0.3 0.4 0.5 0.6R(D)
0.2
0.25
0.3
0.35
0.4
0.45
0.5
R(D
*) BaBar, PRL109,101802(2012)Belle, PRD92,072014(2015)LHCb, PRL115,111803(2015)Belle, PRD94,072007(2016)Belle, PRL118,211801(2017)LHCb, PRL120,171802(2018)Average
Average of SM predictions
= 1.0 contours2χ∆
0.003±R(D) = 0.299 0.005±R(D*) = 0.258
HFLAV
Summer 2018
) = 74%2χP(
σ4
σ2
HFLAVSummer 2018
. R(D)SM = 0.299± 0.003 2.3σ
[0.407± 0.039± 0.024]
. R(D∗)SM = 0.258± 0.005 3.0σ
[0.306± 0.013± 0.007]
↪→ combined ∼ 3.78σ deviation!
I Theo.: more precise lattice calculations for B → D(∗) FFs at non-zero recoil!
I Exp.: AD(∗)
λ , RD∗
L , Λb → Λcτ ν, Bs → D(∗)s τ ν, Bc → J/Ψ(ηc)τ ν, B → Xcτ ν;
19 / 35
R(D) and R(D∗) anomalies:I Importance of other observables: [Celis, Jung, Li, Pich, 1612.07757]
I Bc-lifetime constraint: [Li/Yang/Zhang, 1605.09308; Hu/Li/Yang, 1810.04939]
LSMEFT = L(4)SM +
1
Λ2
∑i
Ci(Λ)Qi,
Q(3)lq = (lγµτ
I l)(qγµτIq), Q(1)lequ = (lje)εjk(qku)
Qledq = (lje)(dqj), Q(3)lequ = (ljσµνe)εjk(qkσµνu)
↪→ V −A and/or tensor Lorentz structure needed!
20 / 35
R(D) and R(D∗) anomalies:
I The observed tension is model independent: exclusive alreadyover-saturates inclusive; [M. Freytsis, Z. Ligeti, J. Ruderman, 1506.08896]
B The data on R(D) and R(D∗) imply:
Br(B → D∗τ ν) + Br(B → Dτν) = (2.78± 0.25)%
B Including the four lightest orbitally excited D meson states:
Br(B → D(∗)τ ν) + Br(B → D∗∗τ ν) ∼ 3%
B From inclusive=∑
exclusive: Br(b→ Xcτ ν) = (2.35± 0.23)% (LEP)
I R(Xc) constraint: [Kamali/Rashed/Datta,1801.08259; Lai/Li/Li/Yang, w.i.p.]
-2.0 -1.5 -1.0 -0.5 0.0
0.15
0.20
0.25
0.30
0.35
gL
R(Xc)
-0.2 -0.1 0.0 0.1 0.2 0.3 0.4 0.50.15
0.20
0.25
0.30
gT
R(Xc)
21 / 35
R(D) and R(D∗) anomalies:
I Another hint of LFUV: around 1.7σ above SM; [LHCb, 1711.05623;
Cohen/Lamm/Lebed, 1807.02730; Wang/Zhu, 1808.10830]
R(J/ψ) =Br(Bc → J/ψτντ )
Br(Bc → J/ψ`ν`)= 0.71± 0.17± 0.18 vs 0.20 ∼ 0.39 (theo.)
I Future prospects with Belle-II and LHCb very promising![Albrecht
et al., 1709.10308; I. Bediaga et al., 1808.08865]
3 23 50 300Integrated Luminosity [fb−1]
0.001
0.01
0.1
Ab
solu
teσR
(X)
LHCb
X = D∗, τ− → µ−νµντX = D∗, τ− → π−π+π−ντ
X = J/ψ, τ− → µ−νµντ
R(D)
R(D
*)
0.3 0.35 0.4 0.450.24
0.26
0.28
0.3
0.32
0.34
LHCb Belle II
Future WA SM predictionSM
σ1
σ3
σ5
σ7
σ9
-18fb
-122fb
-150fb
-15ab-150ab
I Maybe the first tantalizing hint for BSM? Let’s stay tuned!22 / 35
Exclusive b→ s`+`− decays:
I Heff for b→ s`+`−: [Bobeth, Gambino, Gorbahn, Haisch, hep-ph/0312090]
Hb→seff = −4GF√
2VtbV
∗ts
∑i
(CiOi + C′iO′i
), O(′)
7 =e
16π2mb(sσµνPR(L)b
)Fµν
O(′)9 =
e2
16π2
(sγµPL(R)b
) (¯γµ`
)O(′)
10 =e2
16π2
(sγµPL(R)b
) (¯γµγ5`
)I Amplitudes for exclusive decays: [Descotes-Genon, talk at FPCP 2016;
Bobeth, Chrzaszcz, Dyk, and Virto, arXiv:1707.07305]
B M
ℓ+
ℓ−
O7,7′
B M
ℓ+
ℓ−
O9,10,9′,10′...
2
B M
ℓ+
ℓ−
O7,7′
B M
ℓ+
ℓ−
O9,10,9′,10′...
2
B M
ℓ+
ℓ−
Oi
cc
3
A(`)L,Rλ = N (`)
λ
{(C
(`)9 ∓C
(`)10 )Fλ(q2)+
2mbMB
q2
[C
(`)7 F
Tλ (q2)−16π2MB
mbHλ(q2)
]}23 / 35
Exclusive b→ s`+`− decays:I Hadronic matrix elements of Oi: [Beneke/Feldmann/Seidel, 0106067,
0412400; Grinstein/Pirjol, hep-ph/0404250; Beylich/Buchalla/Feldmann, 1101.5118]
† Large recoil (low-q2)
- very low-q2 (≤ 1 GeV2)
dominated by O7;
- low-q2 ([1, 6] GeV2)
dominated by O9,10;
- QCDF or SCET, LCSR;
† Small recoil (high-q2) - dominated by O9,10; - local OPE + HQET;
I Key issues: how large of power corrs from b→ scc→ s`+`− for q2 ≤ 6 GeV2
and from fact. FF terms? [Descotes-Genon et al., 1510.04239]
24 / 35
Exclusive b→ s`+`− decays:I Parametrisation of Hλ(q2): [Khodjamirian et al., 1006.4945; Bobeth et
al., 1707.07305;]
AL,Rλ = Nλ{
(C9 ∓ C10)Fλ(q2) +2mbMB
q2
[C7FTλ (q2)− 16π2MB
mbHλ(q2)
]}
Hλ(z) =1− z z∗
J/ψ
z − zJ/ψ
1− z z∗ψ(2S)
z − zψ(2S)
Hλ(z), Hλ(z) =[ K∑k=0
α(λ)k zk
]Fλ(z)
z(q2) ≡√t+ − q2 −
√t+ − t0√
t+ − q2 +√t+ − t0
I Based on analyticity + data and valid for −7 ≤ q2 ≤ m2ψ(2S)
: [Bobeth et al.,
1707.07305; Chrzaszcz et al., 1805.06378; Mauri et al., 1805.06401]
NP9C Re
3− 2− 1− 0 1
NP
10C
Re
1.5−
1−
0.5−
0
0.5
1
1.5
2
2.5
99% CLLHCb Run2
]-1LHCb Upgrade [50 fb
]-1LHCb Phase 2 [300 fb
]-1BelleII [50 ab
25 / 35
Exclusive b→ s`+`− decays:I Observed anomalies: [Dettori, Langenbruch, talks at Moriond 2018]
]4c/2 [GeV2q0 5 10 15
5'P
1−
0.5−
0
0.5
1
(1S)
ψ/J
(2S)
ψ
LHCb data
Belle data
ATLAS data
CMS dataSM from DHMVSM from ASZB
]4c/2 [GeV2q
0 5 10 15 20
KR
0
0.5
1
1.5
2
SM
LHCbLHCb
LHCb BaBar Belle
PRL 113, 151601 (2014)
0 1 2 3 4 5 6
q2 [GeV2/c4]
0.0
0.2
0.4
0.6
0.8
1.0
RK
∗0
LHCb
LHCb
BIP
CDHMV
EOS
flav.io
JC
]4c/2 [GeV2q5 10 15
]4
c2
GeV
8 [
10
2q
)/d
µµ
φ→
s0B
dB
( 0
1
2
3
4
5
6
7
8
9LHCb
SM pred.
Data
I Comments: 1, P ′5 stat. fluctuation unlikely; 2, precise evaluation of QED effect in
R(∗)K very necessary; 3, cross-checks about hadronic nuisance parameters needed;
26 / 35
Exclusive b→ s`+`− decays:
I Global fits to b→ s`+`− data: [Danny van Dyk, talk at CKM2018]
I Conclusion: while different in the treatment of local and non-local hadronic contri-
butions, all groups agree on a negative shift to C9 by −1.1...−1.76 ' −25...40%
of the SM value, although other contributions are also possible.
27 / 35
Exclusive b→ s`+`− decays:I New global fits: [Capdevila et al., 1704.05340; D. Straub, talk at CKM2018]
I New directions for model builders: [G. Isodro, talk at CKM2018]
28 / 35
Non-leptonic B decays:I To leading power in the heavy-quark expansion, 〈M1M2|Oi|B〉 obeys the follow-
ing factorization formula: [Beneke, Buchalla, Neubert, Sachrajda, ’99-’04]
〈M1M2|Oi|B〉 ' m2B F
BM1+ (0) fM2
∫du T Ii (u) φM2
(u) + (M1 ↔M2)
+ fB fM1 fM2
∫dωdvdu T IIi (ω, v, u) φB(ω) φM1 (v) φM2 (u)
+O(1/mb)
Oi (μ)
+ O(1/M )W
i (μ)C
μ ∼ m> b
π +
π-
0Bi=1...10
π +0B
π-
C i (μ)i,j=1...10
π-
0B
Ojfact(μ)
T (μ)ijI
jfact(μ)Q
T (μ)ijII+
μ m b<
+ O(1/m )b
π+
I Systematic framework to all orders in αs, but limited accuracy by 1/mb corrs.29 / 35
Non-leptonic B decays:
I Status of the hard kernels T I,II : [Bell/Beneke/Huber/Li, from ’09]
I Missing NNLO pieces: 2-loop tree with insertion of penguin operators Q3−6;
2-loop penguin with insertion of penguin operators Q3−6; work in progress!30 / 35
Non-leptonic B decays:
I How to deal with power corrections of order O(1/mb);
I New insights from collider-physics applications like collinear anomaly/rapidity di-
vergence? [Becher/Neubert ’10; Becher/Bell ’11; Chiu/Jain/Neill/Rothstein ’12]
↪→ our next task: how to evaluate the power corrections?31 / 35
Non-leptonic B decays:I Tree-dominated decays: Brs [×10−6] [Beneke, Huber, Li ’09]
I Theory II: small λB and form-factor hypothesis are more favoured;
I Colour-allowed modes well described, but colour-suppressed modes less;32 / 35
Non-leptonic B decays:I Penguin-dominated decays: ACP [×10−2] [Bell, Beneke, Huber, Li ’15]
I “NLO” and “NNLO”: including only pert. calculable SD contribution;
I “NNLO+LD”: power-suppressed spectator and annihilation terms included back;
I For πK, NNLO change minor, since the total penguin αc4 = ac4 + rπχac6 + βc3;
I NNLO correction does not help resolving the observed πK CP asymmetry puzzle;
33 / 35
Non-leptonic B decays:I Brs and ratios: 10−3 (b→ cud), 10−4 (b→ cus) [Huber, Krankl, Li ’16]
I For Bd decays, NNLO Brs higher than the data; for Λb decays, NNLO Brs smaller
than the data; ↪→ non-negligible power corrections with natural size ∼ 10−15%?34 / 35
Conclusion and outlook
I High-luminosity frontier is very complementary to high-energy fron-
tier, especially for NP searches;
I Great progress achieved in both theo. and exp. sides for B physics,
and also a very promising future (LHCb and Belle II, · · · );
I CKM mechanism of flavor and CP violation well established. How-
ever, 20% NP effects in most FCNC processes often possible;
I Several deviations observed at 2 ∼ 4σ in b → cτ ν and b → sµµ
decays, implications of LFUV? Lets stay tuned!
I QCDF at leading power and at NNLO in QCD established and almost
complete. Any further breakthroughs welcome;
Thank You for Your Attention!35 / 35