Predictions From A U(2) Flavour Symmetry In Supersymmetric Theories

George Dvali; Lawrence Hall; Riccardo Barbieri

REVIEW

Predictions From A U(2) Flavour Symmetry In Supersymmetric Theories

Riccardo Barbieri, George Dvali, Lawrence Hall

High Energy Physics - Phenomenology · Submitted 21 Dec 1995 · 17 references

Pith's verdict: The core result — a specific heavy-doublet U(2) model that suppresses the first-second generation sfermion splitting to O(ε²ε'²) — is solid and worth citing, but the abstract's 'generic' and 'completely' oversell what Section 3 actually delivers.

T0 · AI review

How this review was made: An AI referee (selfhosted/deepseek-v4.1-flash) read the paper on October 29, 2026 and answered a fixed list of questions about it. T0 is the starting level every paper gets. The levels describe how deeply Pith has checked the paper, never the authors.

T0 AI review An AI read the paper and answered a fixed list of questions.
T1 Audit Automatic checks that the references and files the paper relies on exist and match.
T2 Compute The paper's code or calculations re-run with the same results.
T3 Formal statement The claims written out in a formal math language a computer can read.
T4 Proof Those claims proved, and the proof checked by computer.

How Pith checks papers →

· 3 major objections · 8 minor · Ask about this paper · The compiled record · Read the full review →

Challenge this review Comment (0) Read on arXiv ↗

Cite ▾

arXiv IDhep-ph/9512388 (version 1)

Pith IDLHWOX3D5, Pith's permanent record of this paper and its review

CitationGeorge Dvali, Lawrence Hall, Riccardo Barbieri. "Predictions From A U(2) Flavour Symmetry In Supersymmetric Theories." arXiv:hep-ph/9512388 (1995). https://pith.science/paper/LHWOX3D5

Cite this reviewBibTeX for Pith's review of this paper

Claim paper

Why Pith says this

Highlight any text to comment on it.

Editor's note

read the letter

Worth your time, but read the body, not the abstract. The abstract's 'generic' and 'completely' do not survive contact with Section 3, and that is the main thing to know going in. The technical core underneath is fine. What is actually new: the U(2) idea is Pomarol–Tommasini's and the texture is Dimopoulos–Hall–Raby's, but the renormalizable model in eq. (5) — one heavy U(2) doublet χ+χ̄, with the ψ_a φ_a χ̄ coupling absent — is theirs, and so is the observation that this specific heavy content pushes the first-second generation sfermion splitting down to O(ε²ε'²) rather than the O(ε²) a general operator analysis gives. That is the load-bearing result and it is a good one. The ε'→0 decoupling argument is clean: with only the antisymmetric φ_ab coupling, the light doublets drop out of the heavy-state composition as the first-generation Yukawa vanishes, so the soft masses stay degenerate. The CKM relations follow directly and are genuine predictions, not fits. Where it is soft. Their own eq. (12) says a general U(2) theory gives ε² splitting, 'leading to a problematic contribution to the ε parameter.' Only model (5) reaches eq. (13). So the solution is model-specific and the abstract should say so. Second, eqs. (19) and (21) are order-of-magnitude estimates that can exceed the measured ε: at m ~ 1 TeV and Δ_q/m² ~ 1, eq. (21) gives ~10⁻² against 2.3×10⁻³ observed, so consistency needs Δ_q/m² ≲ 0.5. They never state that bound. They do acknowledge that the third-generation splitting is not fixed by symmetry, so this is a scope problem, not an error. The 'explicit calculation' behind eq. (13) is not displayed; the decoupling argument covers it well enough that I would call that minor. One thing to keep in mind reading it now: |Vub/Vcb| = √(mu/mc) was the sharp prediction, and it has not aged well — 0.061 against roughly 0.09 today. |Vtd/Vts| = √(md/ms) did fine. Who should read it: anyone building U(2) or Froggatt–Nielsen flavour models, or working on SUSY flavour and CP. It is a standard reference and deserves to be. Send it out; referees should push on the abstract's scope claims and ask for the eq. (13) calculation, but the core holds.

Referee report

Significance

The paper makes a genuine and falsifiable prediction: the relations |Vub/Vcb| = sqrt(mu/mc) and |Vtd/Vts| = sqrt(md/ms) follow from the symmetry plus measured mass ratios, not from fitting the mixing angles, and the requirement sin(phi) >= 0.9 is a sharp corollary. The authors are also careful to show that the CKM form (8,9) survives for the most general W_Y, not only the renormalizable model, which is a meaningful robustness statement. The observation that the light-generation sfermion degeneracy is protected by the same small parameters that generate the fermion hierarchies, and that the leading dangerous operators require both epsilon and epsilon', is a useful structural insight that has been widely taken up. The EDM no-go, while conditional on the reality of A-terms, gaugino masses and mu, is clearly stated as such. These are real strengths and should be weighed in favour of the work.

Major objections (3)

[Abstract vs. §3, Eq. (12)] The abstract (abstract:s0) states that in a 'generic supersymmetric extension' a U(2) symmetry 'completely solves the flavour changing problem.' The body does not support the 'generic' and 'completely' qualifiers. Section 3's own Eq. (12) reports that a general operator analysis gives a first-second-generation sfermion splitting of order epsilon^2 = O(m_F2/m_F3), which the text itself describes as 'leading to a problematic contribution to the epsilon parameter of kaon physics.' Only the specific renormalizable model of Eq. (5), with a single heavy doublet chi + chi-bar and with the psi_a phi_a chi-bar coupling absent, achieves the O(epsilon^2 epsilon'^2) splitting of Eq. (13). The abstract should be rewritten to say that the solution holds for the class of models in which the U(2) breaking is transmitted to the light doublets only through the antisymmetric vev, and that the general U(2)-invariant effective theory does not by itself solve the problem.
[§4, Eq. (21)] Eq. (21) gives epsilon = O(10^-2) (1 TeV/m)^2 (Delta_q/m^2)^2 sin(phi) for m_gluino = m_squark = m. For the natural value Delta_q/m^2 ~ 1 and m ~ 1 TeV this estimate exceeds the measured epsilon = 2.3 x 10^-3 by a factor of a few, so consistency with the kaon data requires Delta_q/m^2 <~ 0.5. The paper does not state this implied bound, and the reader is left with the impression that the estimate is comfortably below the experimental value. The authors should state explicitly the range of Delta_q/m^2 for which Eq. (21) is consistent with the observed epsilon, and note that the same estimate, read the other way, constitutes a constraint on the third-generation splitting in this class of models.
[§3, Eq. (13)] The central degeneracy result, that the first-second-generation sfermion splitting is of order epsilon^2 epsilon'^2, is asserted rather than derived: the text says only that 'An explicit calculation, including the epsilon'-terms, shows that the corrections to exact degeneracy are of order epsilon^2 epsilon'^2.' The epsilon' -> 0 decoupling argument that precedes it, based on the potential of Eq. (14) and the observation that the light doublets do not feel U(2) breaking in that limit, is persuasive and largely fills the gap, but the reader cannot verify the claimed order without the explicit result. The authors should either display the leading operator or the one-loop/tree-level diagram that produces the epsilon^2 epsilon'^2 term, or enumerate the potentially dangerous U(2)-breaking soft operators and show that each carries the required epsilon'^2 suppression.

Minor objections (8)

[§2, Eq. (10a) vs. Eq. (10b)] The prediction |Vub/Vcb| = 0.061 ± 0.009 sits about one sigma below the quoted experimental average 0.08 ± 0.02. This is acceptable, but the text should say so explicitly rather than leaving the comparison to the reader, since the agreement is a headline result.
[§3, Eq. (12)] The right-hand side O(m_F2/m_F3) is a ratio of fermion masses of the second and third generations and is numerically equal to epsilon^2; the notation invites confusion with the dimensionless left-hand side. A parenthetical identifying O(m_F2/m_F3) with O(epsilon^2) would help.
[§4, Eq. (16)] The (1,3) entry of the mixing matrices is written only as 'O'. Given that the (1,2) and (2,3) entries are specified as s12 and s23, the (1,3) entry should be given explicitly as O(s12 s23) so that the reader can check the claimed phase structure.
[§2, Eq. (8)] The displayed CKM matrix is not manifestly unitary at the order shown. The text should state that the parametrization is unitary only to leading order in the small parameters s12 and s23, and that the neglected entries are of the same order as those retained.
[§4, Eq. (19)] The fourth power of (Delta_l/m^2) in the mu -> e gamma branching ratio should be justified or referenced, since the scaling with the splitting is not obvious from the preceding discussion of the mixing-matrix contribution.
[§2, Eq. (2a)] The phrase 'a singlet, or, more precisely, a 2-index antisymmetric tensor phi_ab' is slightly confusing, since for U(2) the antisymmetric tensor is itself a singlet. A sentence clarifying that phi_ab is the only U(2)-invariant carrying the second breaking scale would remove the ambiguity.
[§1 and §2] It is not stated whether the U(2) flavour group is gauged or global. Since the phenomenological conclusions depend on the absence of U(2) D-term contributions to the scalar masses, the status of the symmetry should be stated explicitly.
[§5, Conclusions] The conclusion that 'we do not expect sizeable EDMs for the quarks or the electron' should carry the caveat stated in §4, namely that it holds only under the assumption that the A parameters, gaugino masses and mu-term are all real and that the Yukawa couplings are the sole source of CP violation.

How Pith checks papers → · Full audit of this paper →

The paper

The paper claims

A $U(2)$ flavour symmetry acting on the lightest two generations can simultaneously suppress supersymmetric flavour-changing processes and predict two quark-mixing ratios.

The reading

The paper asks whether one flavour symmetry can do two jobs at once in a supersymmetric extension of the Standard Model: keep the first two sfermion generations nearly degenerate, so loop processes such as $K^0$–$��bar K^0$ mixing and $��mu��to e��gamma$ stay small, and constrain the otherwise arbitrary Yukawa couplings enough to predict quark mixing. It proposes a $U(2)$ symmetry acting on the lightest two generations, broken by two vacuum expectation values with $V��gg v$, and argues that the dangerous first-second generation mass splitting is suppressed to order $��epsilon^2��epsilon'^2$. The same breaking pattern produces a specific Yukawa texture whose approximate diagonalization gives $|V_{ub}/V_{cb}|=��sqrt{m_u/m_c}$ and $|V_{td}/V_{ts}|=��sqrt{m_d/m_s}$, plus a large CKM phase. If correct, this would turn the supersymmetric flavour problem and the fermion mass hierarchy into two faces of one symmetry-breaking story, with sharp predictions for kaon CP violation and lepton-flavour violation.

What carries the argument

The load-bearing mechanism is the $2+1$ representation of $U(2)$: the three matter generations split into a doublet $��psi_a$ ($a=1,2$) and a singlet $��psi$, while the symmetry is broken by $��langle��phi_a��rangle=(0,V)$ and $��langle��phi_{ab}��rangle=v��epsilon_{ab}$ with $V��gg v$. In the renormalizable version, the non-renormalizable Yukawa operators are generated by integrating out a heavy vector-like doublet $��chi_a+��bar��chi_a$; this heavy-sector choice is what makes the light doublets decouple from $U(2)$ breaking as $��epsilon'��to0$, leaving the first two sfermion generations degenerate to order $��epsilon^2��epsilon'^2$. The same spurion expansion fixes the Yukawa texture, and approximate diagonalization of that texture gives the CKM relations $|V_{ub}/V_{cb}|=��sqrt{m_u/m_c}$ and $|V_{td}/V_{ts}|=��sqrt{m_d/m_s}$.

Extended reading notes

Core claim

The central claim is that a $U(2)$ flavour symmetry acting on the lightest two generations, broken at a high scale by a doublet and an antisymmetric singlet vacuum expectation value, is enough to solve the supersymmetric flavour-changing problem and to force a predictive Yukawa texture. The paper argues that the first and second sfermion generations remain degenerate to order $��epsilon^2��epsilon'^2$, where $��epsilon=V/M$ and $��epsilon'=v/M$, so their contributions to $K^0$–$��bar K^0$ mixing, $��mu��to e��gamma$, and related CP observables are strongly suppressed. The resulting Yukawa texture has entries of order $1$, $��epsilon$, and $��epsilon'$ in fixed positions, and its approximate diagonalization yields $|V_{ub}/V_{cb}|=��sqrt{m_u/m_c}$ and $|V_{td}/V_{ts}|=��sqrt{m_d/m_s}$. The paper presents these relations as generic consequences of the $U(2)$ breaking pattern, not as accidents of a particular unified model.

Load-bearing premise

The load-bearing premise is that the first two sfermion generations stay degenerate to order $��epsilon^2��epsilon'^2$; the paper states that an explicit calculation including the $��epsilon'$ terms shows this, but it does not display that calculation, and the result depends on the heavy sector being a single $U(2)$ doublet.

Editorial extensions

If this is right

The first two sfermion generations are predicted to be highly degenerate, so flavour-changing and CP-violating contributions from their splitting are negligible.
The CKM ratios are predicted as $|V_{ub}/V_{cb}|=��sqrt{m_u/m_c}��approx0.061��pm0.009$ and $|V_{td}/V_{ts}|=��sqrt{m_d/m_s}��approx0.226��pm0.009$.
Fitting the observed $|V_{us}|$ requires a large CP-violating CKM phase, $��sin��phi��ge0.9$.
Under the stated assumptions that CP violation comes only from Yukawa couplings and that A-terms and gaugino masses are real, one-loop electric dipole moments for the electron and quarks are absent.
If the third-generation sfermion splitting is sizeable, $��mu��to e��gamma$ and the kaon $��epsilon$ parameter can receive significant supersymmetric one-loop contributions.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

The model gives a correlated test: if third-generation sfermion splitting is large, a future $��mu��to e��gamma$ signal and a large kaon CP asymmetry should appear together under a common superpartner mass scale, rather than as independent accidents.
A null electron EDM alongside a large CKM phase would be a distinctive consistency check of the paper's phase bookkeeping, separating it from generic supersymmetric models with new CP phases.
Because the CKM predictions scale as square roots of light quark mass ratios, future lattice shifts in $m_u/m_c$ or $m_d/m_s$ would move the predicted $|V_{ub}/V_{cb}|$ and $|V_{td}/V_{ts}|$ in a fixed way, giving a clean falsification pattern.
The degeneracy argument suggests a model-building rule: heavy mediators that communicate $U(2)$ breaking should transform as doublets, since singlet mediators would generate tree-level first-second generation splitting.

Original abstract

In a generic supersymmetric extension of the Standard Model, whether unified or not, a simple and well motivated U(2) symmetry, acting on the lightest two generations, completely solves the flavour changing problem and necessarily leads to a predictive texture for the Yukawa couplings.

The compiled record

The paper's own sentences, arranged, kept beside the review and separate from it. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.

Compiled by classifier-1.13-20260917 via OpenRouter, question bank abstract-p1-20260923, 2026-09-23: 1 request, 1,697 input tokens, $0.0001 reported.

What the abstract itself states, as probabilities: claims first 0.03 · states limitation 0.07 · human participants 0.01 · controlled comparison 0.02 · randomized assignment 0.01 · states quantitative result 0.04 · compares with prior results 0.11 · mentions code or data availability 0.01.

The abstract, sentence by sentence

arXiv listing abstract v1. Results and the main claim are underlined; show every role.

In a generic supersymmetric extension of the Standard Model, whether unified or not, a simple and well motivated U(2) symmetry, acting on the lightest two generations, completely solves the flavour changing problem and necessarily leads to a predictive texture for the Yukawa couplings.

background contribution method result interpretation main claim

What the classifier reports for each sentence. The number is the probability it gave the label.
#	sentence	role	the authors' own work	states the main conclusion	strength
s0	In a generic supersymmetric extension of the Standard Model, whether unified or not, a simple and well motivated U(2) symmetry, acting on the lightest two generations, completely solves the flavour changing problem and necessarily leads to a predictive texture for the Yukawa couplings.	result 0.68	0.47	0.86	asserted 1.00

What kind of paper the classifier reports this is: theoretical result 1.00 · evidence from proof or derivation 0.52.

What was examined, and what was not

sources read

arXiv listing abstract v1

not examined

full text
figures and tables
references and citing sentences
relations to other papers

levels run

P abstract

not run

S sections
T body sentences
C citations
R cross-paper relations

Every quoted sentence on this record is the authors'. Every label is from Pith's closed vocabulary, with the probability shown beside it. Every number in the measurements table is the authors', checked by code. Record as JSON

References

Works cited (17)

[1]

P. Renton, Rapporteur talk at the Int. Symposium on Lepton an d Pho- ton Interaction at High Energies, Beijing (August 1995), Oxford p reprint OUNP-95-20 (1995)

View on Pith 1995
[2]

S. Dimopoulos and H. Georgi, Nucl. Phys. B193 (1981) 150

View on Pith 1981
[3]

J. Ellis and D. Nanopoulos, Phys. Lett. B110 (1982) 44; R. Barbieri and R. Gatto, Phys. Lett. B110 (1982) 211

View on Pith 1982
[4]

S. Glashow, J. Iliopoulos and L. Maiani, Phys. Rev. D2 (1970)1285

View on Pith 1970
[5]

M. Dine, R. Leigh and A. Kagan, Phys. Rev. D48 (1993) 4269; Y. Nir and N. Seiberg, Phys. Lett. B309 (1993) 337

View on Pith 1993
[6]

For attempts at using ﬂavour symmetries, continuous or discre te, gauged or ungauged, Abelian or non-Abelian, to constrain both the fermion an d the sfermion spectrum, see: Reference [5] and M. Leurer, Y. Nir and N . Seiberg, Nucl. Phys. B398 (1993) 319. P. Pouliot and N. Seiberg, Phys Lett. B318 (1993) 169; D. Kaplan and M. Schmaltz, Phys. Rev. D49 (1994...

View on Pith 1993
[7]

R. Barbieri and L. Hall, Phys. Lett. B338 (1994) 212; R. Barbieri, L. Hall and A. Strumia, Nucl. Phys. B445 (1995) 219; R. Barbieri, L. Hall and A. Strumia, Nucl. Phys. B449 (1995) 437. 11

View on Pith 1994
[8]

See A. Pomarol and D. Tommasini, reference [6]

View on Pith
[9]

S. Dimopoulos and L. J. Hall, Phys. Lett. B344 (1995) 185

View on Pith 1995
[10]

S. Dimopoulos, L. J. Hall and S. Raby, Phys. Rev. Lett. 68 (1992) 1984; Phys. Rev. D45 (1992) 4192; L. Hall and A. Rasin, Phys. Lett. B315 (1993) 164

View on Pith 1992
[11]

J. Gasser and H. Leutwyler, Phys. Rep. 87 (1982)77

View on Pith 1982
[12]

H. Leutwyler, Nucl. Phys. B337 (1990) 108

View on Pith 1990
[13]

Review of Particle Properties, Phys. Rev. D50 (1994) 1316

View on Pith 1994
[14]

R. Barbieri, S. Ferrara and C. Savoy, Phys. Lett. B110 (1982) 343; A. Chamseddine, R. Arnowitt and P. Nath, Phys. Rev. Lett. 49 (1982) 970; L. Hall, J. Lykken and S. Weinberg, Phys. Rev. D27 (1983) 2359; H. Nilles, M. Srednicki and D. Wyler, Phys. Lett. B120 (1983) 346

View on Pith 1982
[15]

L. J. Hall, V. A. Kostelecky and S. Raby, Nucl. Phys. B267 (1986) 415; H. Georgi, Phys. Lett. B169 (1986) 231

View on Pith 1986
[16]

C. D. Froggatt and H. B. Nielsen, Nucl. Phys. B147 (1979) 277

View on Pith 1979
[17]

S. Dimopoulos and A. Pomarol, Phys. Lett. B353 (1995) 222. 12

View on Pith 1995

Forward citations

Cited by 39 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

Hierarchies from Higher Flavor Spin
hep-ph 2026-05 unverdicted novelty 7.0 of 10

Yukawa hierarchies are generated from powers of fully anarchic spurions in higher SU(2) and SU(3) flavor representations via progressive rank lifting through composite outer products, with explicit models and predicti...
Phenomenology of Non-Abelian Gauge and Goldstone Bosons in a U(2) Flavor Model
hep-ph 2025-11 unverdicted novelty 7.0 of 10

SU(2)_F bosons in a U(2)_F flavor model induce unsuppressed flavor-violating couplings, with K to pi X and mu to e X constraining the breaking scale v_phi to 10^11-10^12 GeV for light bosons and other processes constr...
Light new physics and the $\tau$ lepton dipole moments: prospects at Belle II
hep-ph 2025-10 unverdicted novelty 7.0 of 10

Light new particles generate asymmetries in e+e- to tau+tau- that allow model-dependent constraints on tau dipole moments, including non-zero effects without electron polarization via imaginary parts.
Flavor hierarchies with nonminimal irreducible representations
hep-ph 2025-10 unverdicted novelty 7.0 of 10

Introduces a new class of flavor models using non-minimal irreducible representations for the flavor-breaking spurion to generate fermion mass hierarchies accidentally from O(1) UV parameters via multiple insertions, ...
Looking forward to Lepton-flavor-violating ALPs
hep-ph 2020-06 accept novelty 6.5 of 10

A forward-detector configuration at MEG II, combined with recast bounds from past muon and tau experiments, would probe lepton-flavor-violating axion-like particles at decay constants up to about 3x10^10 GeV, beyond s...

Show 34 more citing papers

How natural are Froggatt-Nielsen Models?
hep-ph 2026-10 conditional novelty 6.0 of 10

Standard fine-tuning metrics overstate the naturalness of Froggatt-Nielsen quark models because they ignore how unlikely small parameter values are; a new prior-aware metric tracks Bayesian evidence.
Probing Lepton Flavor Violation at FCC-ee
hep-ph 2026-10 accept novelty 6.0 of 10

At FCC-ee, tau lepton decays into three leptons or a lepton and a photon can detect lepton flavor violation with greater sensitivity than Z boson decays, and can complement Higgs boson decays depending on the new phys...
Dark Matter Stability from residual flavour symmetries
hep-ph 2026-10 accept novelty 6.0 of 10

Continuous flavour symmetries can leave residual Z_2 symmetries that stabilize dark matter, exemplified by an SU(2)_F x U(1)_F model that fits lepton data and produces a sterile neutrino dark matter candidate via freeze-in.
New Physics in $ b \to s \tau^+\tau^-$ Processes and Correlations with $R(D^{(*)})$ and $B\to K^{(*)}\nu\bar\nu$: An (SM)EFT Analysis
hep-ph 2026-09 conditional novelty 6.0 of 10

Explaining the R(D(*)) and B->K nu nu excesses with third-generation SMEFT New Physics predicts b->s tau+tau- branching ratios of order 10^-5, with measurable differences that separate competing New Physics scenarios.
Maximal Abelian Flavor Symmetries
hep-ph 2026-06 unverdicted novelty 6.0 of 10

MAFS describes 15 flavor observables in SU(5) and SO(10) GUTs using 5 or 3 fitted small parameters at factor-of-two accuracy, implying large neutrino mixings and approximate leptogenesis without extra parameters in SU(5).
Deconstructed Weak Isospin from a Symplectic Symmetry
hep-ph 2026-03 conditional novelty 6.0 of 10

An Sp(6) completion of deconstructed weak isospin predicts six new flavour-changing gauge bosons and pushes the intermediate SU(2)^3 breaking scale above ~550 TeV (or ~150 TeV at large scale separation) via K/D mixing...
Light new physics and the $\tau$ lepton dipole moments
hep-ph 2025-11 unverdicted novelty 6.0 of 10

This work provides a comprehensive analysis of light new physics contributions to tau lepton dipole moments, detailing interpretations of asymmetry measurements for spin-0 and spin-1 bosons, their decoupling to the EF...
Inequalities for Standard Model Yukawa Couplings
hep-ph 2025-06 conditional novelty 6.0 of 10

The paper proves rigorous, basis-independent inequalities on combinations of Standard Model Yukawa matrix entries that follow from the observed hierarchical fermion masses and CKM angles.
Correlating $\epsilon^\prime/\epsilon$ to hadronic $B$ decays via $U(2)^3$ flavour symmetry
hep-ph 2019-09 conditional novelty 6.0 of 10

A U(2)^3 flavour-symmetric effective field theory can consistently explain the epsilon'/epsilon anomaly and hadronic B decay CP asymmetries, with a global fit about 3 sigma better than the Standard Model.
Lepton Flavor Non-Universality in B-meson Decays from a U(2) Flavor Model
hep-ph 2015-09 conditional novelty 6.0 of 10

A gauged U(2) flavor model with a multi-TeV Z' explains the b to s lepton-lepton anomalies with a single parameter, predicting enhanced electron and suppressed muon rates in B decays.
Hide and Seek With Natural Supersymmetry at the LHC
hep-ph 2012-02 conditional novelty 6.0 of 10

Natural supersymmetry with R-parity violation generically yields same-sign dileptons without large missing energy, and existing 2011 LHC searches already exclude gluinos below roughly 550 GeV.
U(2) and Minimal Flavour Violation in Supersymmetry
hep-ph 2011-05 conditional novelty 6.0 of 10

A U(2)^3 flavour symmetry in supersymmetry resolves the tension between kaon and B_d mixing and predicts S_psi_phi = 0.12 plus or minus 0.05, above the Standard Model value.
New Physics and CP Violation in Singly Cabibbo Suppressed D Decays
hep-ph 2006-09 conditional novelty 6.0 of 10

Percent-level CP asymmetries in singly Cabibbo suppressed D decays would signal new physics, and supersymmetric left-right squark mixing can generate them without violating mixing bounds.
A complete analysis of FCNC and CP constraints in general SUSY extensions of the standard model
hep-ph 1996-04 accept novelty 6.0 of 10

The paper derives model-independent upper bounds on off-diagonal sfermion mass insertions from kaon, B and D mixing, epsilon-prime over epsilon, b to s gamma, lepton-flavor decays, and electric dipole moments.
Neutrino Observables from a U(2) Flavor Symmetry
hep-ph 2020-09 conditional novelty 5.0 of 10

Neutrino masses and phases from U(2) texture zeros imply a total neutrino mass of 60-75 meV (2σ) and an effective Majorana mass below 4 meV (2σ) in all studied scenarios.
Explaining $b\to s\ell^+\ell^-$ and the Cabibbo Angle Anomaly with a Vector Triplet
hep-ph 2020-05 conditional novelty 5.0 of 10

A single SU(2)_L vector triplet with order-one couplings at 10 TeV can fit both the b to s lepton-pair anomalies and the Cabibbo Angle Anomaly, improving the global fit over the Standard Model.
A Realistic U(2) Model of Flavor
hep-ph 2018-05 conditional novelty 5.0 of 10

A non-supersymmetric U(2) flavor symmetry, plus a discrete D6 variant that permits Majorana neutrinos, reproduces all Standard Model fermion masses and mixings with order-one coefficients and predicts an axion that ca...
Search for direct production of supersymmetric partners of the top quark in the all-jets final state in proton-proton collisions at sqrt(s) = 13 TeV
hep-ex 2017-07 conditional novelty 5.0 of 10

No significant excess over standard model expectations is observed in all-hadronic top squark searches, and top squark masses are excluded up to 1040 GeV for large mass splitting and up to 660 GeV in compressed scenarios.
The Axiflavon
hep-ph 2016-12 conditional novelty 5.0 of 10

Identifying the Standard Model flavor symmetry with the Peccei-Quinn symmetry yields an axion whose photon coupling is fixed by measured fermion masses to a narrow range around the DFSZ value.
Searches for third-generation squark production in fully hadronic final states in proton-proton collisions at sqrt(s) = 8 TeV
hep-ex 2015-03 accept novelty 5.0 of 10

No excess appears in three complementary CMS hadronic searches, and top squarks below about 560 GeV and bottom squarks below about 650 GeV are excluded at 95% confidence when the lightest neutralino is nearly massless.
Search for top-squark pairs decaying into Higgs or Z bosons in pp collisions at sqrt(s) = 8 TeV
hep-ex 2014-05 accept novelty 5.0 of 10

No excess over standard model backgrounds is seen in LHC 8 TeV data for heavy top-squark pairs decaying via Higgs or Z bosons, excluding m_stop2 below 575 GeV for m_stop1 below 400 GeV at 95% confidence.
Search for new physics in events with same-sign dileptons and b jets in pp collisions at sqrt(s) = 8 TeV
hep-ex 2012-12 accept novelty 5.0 of 10

No excess of same-sign dilepton plus b-jet events appears in 10.5 fb^-1 of 8 TeV CMS data, which excludes gluinos below roughly 1 TeV and bottom squarks below 450 GeV in the modelled decay chains.
Anatomy and Phenomenology of FCNC and CPV Effects in SUSY Theories
hep-ph 2009-09 accept novelty 5.0 of 10

Correlation patterns among B, K, D and lepton observables separate supersymmetric flavour models with right-handed currents from those with left-handed currents, and both from Little-Higgs and Randall-Sundrum alternatives.
Fermion Masses and Mixings in a S4 Based Model
hep-ph 2009-01 conditional novelty 5.0 of 10

An S4-based supersymmetric flavor model reproduces tri-bimaximal neutrino mixing and quark masses, with a neutrino mass matrix predicting |mee| above 14.4 meV.
Systematic Study Of Leptonic Mixing In A Class Of SU_H(2) Models
hep-ph 2006-03 conditional novelty 5.0 of 10

In a class of SU_H(2) models with triplet-scalar neutrino masses, only the leading-order Le−Lμ−Lτ neutrino mass matrix survives the systematic scan, predicting an inverted hierarchy and a neutrinoless double beta deca...
New Physics Searches at Kaon and Hyperon Factories
hep-ph 2022-01 accept novelty 4.0 of 10

A broad review shows that rare kaon and hyperon decays can probe a wide range of light dark-sector models, and identifies concrete channels where next-generation experiments could close unexplored parameter space.
Search for top-squark pair production in the single-lepton final state in pp collisions at sqrt(s) = 8 TeV
hep-ex 2013-08 accept novelty 4.0 of 10

No excess over standard-model expectations appears in the single-lepton channel, and top squarks below roughly 650 GeV are excluded for light neutralinos.
Search for new physics in events with same-sign dileptons and b-tagged jets in pp collisions at sqrt(s) = 7 TeV
hep-ex 2012-05 accept novelty 4.0 of 10

No excess of same-sign dilepton events with b-tagged jets is observed in 4.98 fb^-1 of 7 TeV CMS data, and the resulting 95% CL limits constrain same-sign top production and several gluino and sbottom scenarios.
S-particles at their naturalness limits
hep-ph 2009-06 conditional novelty 4.0 of 10

A supersymmetric spectrum with light higgsinos and light stops and sbottoms yields multi-top final states at the LHC whose rates are governed by one inclusive branching ratio, roughly 25 to 50 percent.
Charged Lepton Flavour Violation: An Experimental and Theoretical Introduction
hep-ph 2017-08 accept novelty 3.0 of 10

No charged lepton flavour violation has been observed, but current muon limits already constrain new physics and planned experiments will improve sensitivity by orders of magnitude.
Flavour physics of leptons and dipole moments
hep-ph 2008-01 accept novelty 3.0 of 10

The report synthesizes current bounds and future prospects for charged-lepton flavor violation and electric dipole moments as probes of TeV-scale physics.
Flavor phenomenology of light dark particles
hep-ph 2026-06 unverdicted novelty 2.0 of 10

Review surveying limits and prospects for flavor-violating decays of light axion-like particles, highlighting complementarity of lab, astro, and cosmo probes up to 10^12 GeV scales.
Minimal Flavour Violation and Beyond
hep-ph 2012-02 accept novelty 2.0 of 10

The review argues that Minimal Flavour Violation, with Yukawa couplings as the only flavour spurions, keeps new physics consistent with quark-flavour data up to the TeV scale and yields testable correlations in B and ...
Discrete Flavor Symmetries and Models of Neutrino Mixing
hep-ph 2010-02 accept novelty 1.0 of 10

A review of how A4, S4, and related discrete flavor groups can produce tri-bimaximal neutrino mixing at leading order, with small calculable corrections and testable predictions for theta13 and lepton flavor violation.

How the literature uses it

85 arXiv papers cite this in 107 sentences

Each citing sentence is taken from the citing paper's LaTeX source and typed by Pith's classifier. A label appears at probability 0.8 or more (0.95 for support), a contest at 0.7 or more; the quoted words are the citing authors'. How each label was checked · JSON

Papers citing it · 72 sentences without a confident label

Contests it 1 paper

The original $U(2)$ models proposed in the context of supersymmetry [ref] have been disfavored by precision measurements in the $B$-factories [ref] , as they predicted the relation $V_ub/V_cb = √(m_u/m_c)$ which was not borne out experimentally.

Lepton Flavor Non-Universality in B-meson Decays from a U(2) Flavor Model · Introduction · contest 0.90

Builds on it 1 paper

In this work we build upon the previous studies in Refs. [ref] and propose a simple, non-supersymmetric $U(2)$ model of flavor that is compatible with an $SU(5)$ GUT structure.

A Realistic U(2) Model of Flavor · Introduction · 1.00

Compares with it 2 papers

The presence of these textures leads to accurate relations between CKM elements and masses, cf. Eq [ref], which in contrast to the original $U(2)$ flavor models in Refs. [ref] can be consistent with experimental data because of large rotations in the right-handed down quark sector.

A Realistic U(2) Model of Flavor · Summary and Conclusions · 0.90
Let us contrast this with existing implementations of $U(2)$ breaking [ref] , which generate the flavor structure of the light families.

Hierarchies from Higher Flavor Spin · Introduction · 0.91

Cites it as support 1 paper

This search is motivated by the consideration that relatively light top squarks, with masses below around 1, are necessary if SUSY is to be the natural solution to the hierarchy problem [ref] .

Search for top-squark pair production in the single-lepton final state in pp collisions at sqrt(s) = 8 TeV · Introduction · 0.99

Cites it as background 27 papers

A different way to address the SUSY flavour problem, that has received renewed interest recently [ref] , is to assume a strong generational hierarchy in the squark mass spectrum [ref] .

CP Violation in Supersymmetry with Effective Minimal Flavour Violation · Introduction · 0.89
Here, we assume a global $U(2)^3$ flavor symmetry in the quark sector [ref] .[The $U(2)^3$ flavour symmetry is analogous to Minimal Flavour Violation [ref] (MFV) which uses a global $U(3)^3$ flavour symmetry instead [ref] .

Correlating $\epsilon^\prime/\epsilon$ to hadronic $B$ decays via $U(2)^3$ flavour symmetry · Introduction · 0.84
In these models, the flavour structure of the Yukawa matrices is only generated after the breaking of a flavour symmetry [ref] and the flavour structure of the SUSY soft-breaking terms would also originate through the same mechanism [ref] .

Electric dipole moments from flavoured CP violation in SUSY · Introduction · 0.81

Discussion

Disagree with the review, or know something it missed? Leave a comment, highlight any passage above to comment on it, or challenge this review formally.

[1] [1]

P. Renton, Rapporteur talk at the Int. Symposium on Lepton an d Pho- ton Interaction at High Energies, Beijing (August 1995), Oxford p reprint OUNP-95-20 (1995)

View on Pith 1995

[2] [2]

S. Dimopoulos and H. Georgi, Nucl. Phys. B193 (1981) 150

View on Pith 1981

[3] [3]

J. Ellis and D. Nanopoulos, Phys. Lett. B110 (1982) 44; R. Barbieri and R. Gatto, Phys. Lett. B110 (1982) 211

View on Pith 1982

[4] [4]

S. Glashow, J. Iliopoulos and L. Maiani, Phys. Rev. D2 (1970)1285

View on Pith 1970

[5] [5]

M. Dine, R. Leigh and A. Kagan, Phys. Rev. D48 (1993) 4269; Y. Nir and N. Seiberg, Phys. Lett. B309 (1993) 337

View on Pith 1993

[6] [6]

For attempts at using ﬂavour symmetries, continuous or discre te, gauged or ungauged, Abelian or non-Abelian, to constrain both the fermion an d the sfermion spectrum, see: Reference [5] and M. Leurer, Y. Nir and N . Seiberg, Nucl. Phys. B398 (1993) 319. P. Pouliot and N. Seiberg, Phys Lett. B318 (1993) 169; D. Kaplan and M. Schmaltz, Phys. Rev. D49 (1994...

View on Pith 1993

[7] [7]

R. Barbieri and L. Hall, Phys. Lett. B338 (1994) 212; R. Barbieri, L. Hall and A. Strumia, Nucl. Phys. B445 (1995) 219; R. Barbieri, L. Hall and A. Strumia, Nucl. Phys. B449 (1995) 437. 11

View on Pith 1994

[8] [8]

See A. Pomarol and D. Tommasini, reference [6]

View on Pith

[9] [9]

S. Dimopoulos and L. J. Hall, Phys. Lett. B344 (1995) 185

View on Pith 1995

[10] [10]

S. Dimopoulos, L. J. Hall and S. Raby, Phys. Rev. Lett. 68 (1992) 1984; Phys. Rev. D45 (1992) 4192; L. Hall and A. Rasin, Phys. Lett. B315 (1993) 164

View on Pith 1992

[11] [11]

J. Gasser and H. Leutwyler, Phys. Rep. 87 (1982)77

View on Pith 1982

[12] [12]

H. Leutwyler, Nucl. Phys. B337 (1990) 108

View on Pith 1990

[13] [13]

Review of Particle Properties, Phys. Rev. D50 (1994) 1316

View on Pith 1994

[14] [14]

R. Barbieri, S. Ferrara and C. Savoy, Phys. Lett. B110 (1982) 343; A. Chamseddine, R. Arnowitt and P. Nath, Phys. Rev. Lett. 49 (1982) 970; L. Hall, J. Lykken and S. Weinberg, Phys. Rev. D27 (1983) 2359; H. Nilles, M. Srednicki and D. Wyler, Phys. Lett. B120 (1983) 346

View on Pith 1982

[15] [15]

L. J. Hall, V. A. Kostelecky and S. Raby, Nucl. Phys. B267 (1986) 415; H. Georgi, Phys. Lett. B169 (1986) 231

View on Pith 1986

[16] [16]

C. D. Froggatt and H. B. Nielsen, Nucl. Phys. B147 (1979) 277

View on Pith 1979

[17] [17]

S. Dimopoulos and A. Pomarol, Phys. Lett. B353 (1995) 222. 12

View on Pith 1995