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Vernon Barger

Publications and source records attributed to Vernon Barger.

At least 19 recordsLinked to original sources
arXiv2026

Level-Four Modular Symmetry Selected by the Harmonic Pattern of Quark and Lepton Masses

The mass ratios of the quarks and charged leptons follow a simple pattern. The logarithmic generation steps come in a two to one ratio, a note to its octave, and the ordering is mirrored between the up-down and down-lepton comparisons. The pattern, read as charge counting on a $Z_N$ clock, is realized at level four and at no level that is not a multiple of four, which motivates modular level four and the finite group $S_4$, with the generations in the triplet at $T$ charges $(3,1,0)$ and the mirror in the sign singlet. The charged-lepton mass ratios lie on a theta-dressed lattice at $0.02\%$, which sets the base $\varepsilon=0.18664$, taken as $14/75$, and the harmonic modulus $\tau=1.0685i$. Five postulates in the weight one-half theta constants, identified on the same data, reproduce the six quark masses from three lepton masses and the electroweak scale. Two more and one empirical relation for $|V_{td}|$ close the CKM matrix, giving $|V_{us}|=\sqrt{m_d/m_s}=0.2255$, $|V_{cb}|=0.04197$, $|V_{ub}|=0.003721$, and $\delta=1.138$ against the measured $1.139\pm0.023$, with no continuous parameter. The unitarity triangle follows, with apex $(0.161,0.348)$ against the measured $(0.161\pm0.010,0.347\pm0.010)$, and $J=3.11\times10^{-5}$ against $(3.09\pm0.07)\times10^{-5}$. The same structure carries the neutrinos. A single theta insertion gives $\sin\theta_{13}=\theta_2(\tau)m_2/m_3$, which holds at $0.7\sigma$ on the 207-day JUNO data, and the harmonic condition completes a normal-ordered spectrum with $m_1=0.25$~meV, $\Sigma m_\nu=0.0589$~eV, a CP-conserving phase $\delta_{CP}=\pi$, and effective Majorana masses quantized at $1.3$ to $3.9$~meV. The ultraviolet completion belongs to the magnetized torus class, with Pati--Salam the natural gauge embedding.

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arXiv2026

Exothermic dark matter and the 248 keV nuclear recoil in LUX-ZEPLIN

The single 248-keV nuclear-recoil candidate reported by LZ is reproduced by dark matter that downscatters, with the relic in the excited state of a pseudo-Dirac pair and a splitting \delta\simeq-350\keV. Every interpretation so far advanced is endothermic and places the splitting within a few percent of the xenon kinematic ceiling, so that the predicted count changes from zero to 143 times its central value as the halo escape speed runs from 500 to 600 km/s. The downscattering branch has no threshold speed; the same variation changes its count by 0.3 %. The ratio of counts below 70 keV to those above is 0.011, so the null standard search follows from the kinematics. A weak-strength coupling overproduces the event by 8.9\times10^{5}, so the mediator is a dark-sector one, and longevity of the relic excited state requires |\delta|<2m_e. Solving the coupled Boltzmann system removes the one free normalization. Rotating to the eigenchannels of the off-diagonal potential gives \sigma_0=(\pi/k^2)\sin^2(\delta_+-\delta_-), whose phase difference is 0.03 to 1.3 rad, so the Born rate exceeds the s-wave unitarity bound where it is used. One event then requires \sigma_p\simeq2\times10^{-42} cm^2 and a kinetic mixing \epsilon\simeq1\times10^{-6} at m_{A'}=1\GeV, with beam-dump coverage below 0.6\GeV pushing the mediator above that value. The ground state upscatters endothermically through the same operator, which excludes |\delta|\lesssim300 keV and makes the published endothermic reading the small-splitting limit of one model. The decisive test is argon, whose first form-factor zero lies at 695 keV against 94.6 keV for xenon; argon yields 4 to 6 events per tonne-year near 250 keV, where the endothermic reading is forbidden at any exposure.

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arXiv2026

Cosmological moduli problem ameliorated by decaying WIMPs

We investigate the cosmological moduli problem (CMP) in the context of supersymmetric models where discrete R-symmetries are used to suppress the mu term, and where mu is regenerated via Kim--Nilles superpotential operators. In such theories, a global U(1)_{PQ} emerges as an accidental, approximate symmetry which solves the strong CP problem. R-parity is also generated as accidental but approximate, where RPV operators gain a (f_a/m_P)^n suppression. When n=1, the thermally-produced LSPs may decay before BBN in the early universe, leaving axion-only dark matter of the SUSY DFSZ type. Meanwhile, the dominant cosmological constraint on light stringy moduli previously came from the modulus-induced WIMP overproduction problem. WIMP overproduction is now ameliorated by the RPV WIMP decays, but the moduli-induced BBN bound may be exacerbated by convolving long-lived modulus decay with long-lived RPV WIMP decay: long-lived particle (LLP) cascade decays. In this context, moduli as light as m_\phi ~ 130 TeV may be allowed which can reconcile naturalness with the presence of stringy moduli in the early universe.

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arXiv2026

Commensurate Structure of Quark and Lepton Mixing: Eighteenth Powers of One Parameter and a Digital-Clock Quantization of the Unitarity Triangles

We identify two commensurate structures in the measured quark and lepton mixing data, one multiplicative and one angular, and their exact relation. With the hierarchy parameter $\varepsilon\equiv|V_{ub}|^{3/10}=0.1869\pm0.0018$, the measured Fritzsch--Xing (FX) angles satisfy $\sin\theta_u=\varepsilon^{26/18}$, $\sin\theta_d=\varepsilon^{17/18}$, and $\sin\theta=\varepsilon^{34/18}$ with coefficients within $2.5\%$ of unity, and the phase is maximal, $\phi_{\rm FX}=92.3^\circ\pm2.7^\circ$ against $\pi/2$. Unit coefficients reproduce the remaining moduli at the percent level and fix the derived Jarlskog invariant, $J=\varepsilon^{111/18}\sin\phi_{\rm FX}$, matching the measured $3.08(14)\times10^{-5}$. The rephasing-invariant image of this structure is a unitarity triangle quantized on the $\pi/24$ lattice, a digital clock, $(\alpha,\beta,\gamma)=(12,3,9)\times7.5^\circ$, consistent with data at $1\sigma$ through $\alpha\simeq\phi_{\rm FX}$ and the theorem $\tan\beta\simeq\sqrt{\varepsilon}$; degree-level $\gamma$ confronts $67.5^\circ$--$68^\circ$. For the leptons, where only the angular structure can act, its PMNS analog, formed from columns $1$ and $3$, free of Majorana phases, on the same lattice requires $\delta_{\rm CP}\simeq296^\circ$ in the upper octant or $244^\circ$ in the lower, testable at DUNE and Hyper-Kamiokande. The quark and lepton triangles share $\beta=22.5^\circ$, measured for quarks, predicted for leptons, and differ by a transfer of two lattice units, with corollary $\delta_{\rm CP}\simeq-\delta\simeq295^\circ$. The same $\varepsilon$ sets the neutrino mass ratio, $r\equiv m_2/m_3=\varepsilon^{19/18}$, and the PMNS first row follows in powers of $r$, $(r^{1/9},\,r^{1/3},\,\tfrac{\sqrt{3}}{2}r)$, both relations at $0.2\sigma$ and testable at JUNO. The analysis is confined to the parameterization level; no dynamics is assumed.

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arXiv2026

The $\pi/12$ model: trimaximal first-column lepton mixing with charged-lepton $\mu$--$\tau$ breaking

The first column of the lepton mixing matrix carries two independent magnitude conditions: the trimaximal norm $|U_{e1}|^2=2/3$ and the $\mu$--$\tau$ balance $|U_{\mu1}|=|U_{\tau1}|$. We parameterize their violation by $\varepsilon_1\equiv(3/2)|U_{e1}|^2-1$ and $\varepsilon_2\equiv3(|U_{\tau1}|^2-|U_{\mu1}|^2)$ and show that current data treat the two differently in central value: including the first JUNO measurement, $\varepsilon_1=+0.014\pm0.010$ is consistent with zero, while $\varepsilon_2=+0.29^{+0.07}_{-0.13}$ is large but disfavors zero at only $1.5\sigma$ on the global-fit profile likelihood, the driving phase being still poorly measured. This asymmetry selects the $\pi/12$ model. Its neutrino sector is TM$_1$ with the electron-row condition $|U_{e2}|/|U_{e3}|=2+\sqrt3$ that fixes $\sin^2\theta_{13}=(2-\sqrt3)/12=0.02233$ and $\sin^2\theta_{12}=0.31811$. A charged-lepton 2--3 rotation $R_{23}(\theta_e,\alpha)$ leaves the electron row exactly invariant and generates $\varepsilon_2=\sin2\theta_e\cos\alpha$. In an $S_4\times C_4\times C_3\times C_2$ realization, the rotation arises from a single additional flavon whose alignment forces $\alpha=0$; a natural angle $\theta_e\simeq2^\circ$ then reproduces the departure of $\theta_{23}$ from maximal while pinning the CP phase to $\delta=272^\circ\pm2^\circ$, near-maximal CP violation with $\varepsilon_2=-0.066$. The current $\theta_{23}$--$\delta$ measurements thereby become a sharp test: the predicted $\delta$ sits $1.7\sigma$ from the present central value on the same profile likelihood, the predicted $\varepsilon_2$ has the opposite sign to the measured one, and the Hyper-Kamiokande design precision of $20^\circ$ on $\delta$ resolves the question at $3\sigma$. The mass predictions are inherited unchanged, $\Sigma m_\nu=65.6$ meV and $m_{\beta\beta}=5.4$ meV, at the current DESI bound in $\Lambda$CDM.

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arXiv2026

The KM3NeT 220 PeV event: a neutrino messenger from the grand unification scale?

The 220~PeV neutrino KM3-230213A, in tension with IceCube and Auger unless narrow, admits a two-body reading: relic decay $X \to \nu\bar\nu$ with $m_X \approx 4.4\times10^{8}$~GeV. Consistency with neutrino and $\gamma$-ray bounds sets $\tau/f \approx 10^{29}$--$10^{30}$~s, lifetime over relic fraction. For a flavored $^1S_0$ onium, the operator scale lands in the Majorana-mass range of unified models: one Higgs insertion gives a singlet mediator, $M/|C_7|^{1/3} \approx 10^{14}$--$10^{16}$~GeV across the allowed relic fraction; two give the seesaw window; Dirac or Majorana neutrinos select the branch. We give the construction and its decisive tests.

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arXiv2026

Serendipitous supersymmetric solution to the strong CP problem

The Minimal Supersymmetric Standard Model (MSSM) has several problems: 1. its $\mu$ term must be forbidden, then regenerated at the weak scale, 2. it allows for $R$-parity violating superpotential terms which lead to rapid proton decay, 3. it allows for dimension-5 proton decay operators. The usual imposition of $R$- or matter parity $P_M$ solves only the second of these, whereas anomaly-free discrete $\mathbb{Z}_n^R$ symmetries (consistent with grand unification) address all of them. Once the $\mu$-term is forbidden by the imposition of a discrete $\mathbb{Z}_n^R$ symmetry (which can emerge as a discrete remnant of string compactifications to 4-dimensions), the MSSM develops an accidental global $U(1)_{PQ}$ symmetry (thus providing a plausible origin for the global $U(1)_{PQ}$ needed for solving the strong CP problem). By coupling the Higgs fields to PQ-charged gauge singlet fields $X,\ Y$ (in the Kim-Nilles mechanism), and imposing SUSY breaking, one regenerates $\mu$ at the weak scale whilst breaking the discrete $\mathbb{Z}_n^R$ and the $U(1)_{PQ}$. The broken global $U(1)_{PQ}$ develops a pseudo-Goldstone boson, the DFSZ axion, thus (perhaps inadvertently) solving the strong CP problem. In this setting, SUSY develops a dark matter candidate, the SUSY DFSZ axion, and possibly, though not necessarily, a WIMP dark matter candidate as well, depending on the order of the induced $R$-parity violating operators.

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arXiv2026

Can blind spots save neutralino dark matter in natural supersymmetry models?

Natural supersymmetry (SUSY) models remain viable even in the face of LHC Run 2 sparticle search limits. However, the LZ experiment has placed strong limits on light higgsino dark matter even when the higgsinos carry only their thermally-produced abundance, with the bulk of the dark matter composed of axions. One way out is the possibility of WIMP direct detection blind spots where cancellations in direct detection (DD) couplings lead to tiny DD rates. We examine natural SUSY models with mu <0 and \mu >0 but find that the surviving blind spots all lie in the unnatural region where the superpotential |mu | parameter is much greater than the weak scale gaugino masses; the few natural candidates are excluded by LHC soft-dilepton searches and by the measured Higgs mass. Within NUHM2/NUHM3-type gravity-mediated models with positive gaugino masses and assuming a thermally produced neutralino fractional abundance, direct-detection blind spots do not rescue stable light higgsino dark matter in the electroweak-natural region. Thus, within this framework, stable light higgsino dark matter is disfavored, although special circumstances like large entropy dilution of all relics is still possible. This points to SUSY models with {\it unstable} light higgsinos as perhaps the preferred alternative.

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arXiv2026

Generation as Compositeness: A Subconstituent Interpretation of the $B$-Lattice Flavor Hierarchy

We interpret the $B$-lattice flavor framework as a compositeness hierarchy: all three fermion generations are elementary chiral fields, but third-generation Yukawa couplings are undressed ($Q=0$), while lighter generations acquire their Yukawa couplings through chains of spin-$0$ subconstituents (``hops'') whose depth is counted by the $\mathbb{Z}_9$ discrete gauge symmetry. The $\mathbb{Z}_9$ charge admits a two-index decomposition $q_9\mapsto(a,b)$ that identifies two hop species ($\alpha$, $\beta$) and organizes all fundamental scales from $v_{\rm EW}$ to $M_{\rm Pl}$ on a ``ninths ladder'' $\Lambda\times\epsilon^{n/9}$. The lattice structure yields the CKM and PMNS mixing parameterizations (with all mixing exponents expressible as charge differences $\Delta Q$ dressed by a universal Fritzsch--Xing phase shift of $\pm 1/9$), a seesaw benchmark $m_3\simeq 51$~meV, the axion mass window $m_a\sim 7$--$12\;\mu$eV, and the prediction $\tan\beta\simeq 10$--$16$ (from the chain internal factor combined with the DFSZ-II two-Higgs-doublet structure), all from two parameters ($\Lambda$ and $\epsilon = 14/75$). Generation-dependent Peccei--Quinn charges restore the axion--photon coupling ($C_{a\gamma}\simeq 0.6$--$1.0$) from ``back to invisible'' suppression. An illustrative UV realization in terms of hypercolor-confined scalars communicated to the SM by a gauge-invariant messenger chain is presented as an existence proof.

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arXiv2026

Natural SUSY with mixed axion/axino dark matter

While supersymmetric models provide a solution to the big hierarchy problem, natural SUSY is also allowed by the little hierarchy problem. In supersymmetric models which include the Peccei-Quinn (PQ) solution to the strong CP problem, one expects the presence of an axion-axino-saxion supermultiplet with a micro-eV-scale axion and a saxion with mass of order the soft breaking scale. The axino mass is much more model-dependent, and may occur in the range of keV-TeV: over 9 orders of magnitude. This leads to the possibility of the axino as lightest SUSY particle (LSP) and the presence of mixed axion plus axino dark matter. The case of natural SUSY with higgsino-like WIMPs as LSP seems (nearly) excluded by multi-ton noble liquid WIMP detector limits, even in the case where the LSP has a depleted abundance compared to axions. We examine the case where the axino is LSP leading to mixed axion-axino dark matter in a natural SUSY context. We map out regions of PQ scale f_a vs. axino mass m_{\ta} parameter space where such a scenario remains viable in both the SUSY DFSZ and KSVZ axion models. For axino mass ~100 keV, we find solutions in accord with the measured dark matter abundance with mainly warm axino dark matter for f_a~ 10^{11} GeV and also solutions with mainly axion cold DM and a tiny axino contribution for higher f_a~ 3\times 10^{12} GeV.

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arXiv2026

Unified Flavor: Lattice Quantization, Chain Locality, and a Dynamical Origin of Hierarchical Yukawas

We present Unified Flavor (UF), a framework that synthesizes the $B$-lattice flavor hierarchy with a dynamical realization based on TeV-scale vectorlike fermion (VLF) chains. Hierarchical Yukawa couplings arise from discrete ninths-quantized lattice exponents enforced by a single flavon $\Phi$ with $\epsilon\equiv\langle\Phi\rangle/\Lambda=1/B$, $B=75/14$. Effective Yukawa entries are generated as algebraic path sums along nearest-neighbor chains of vectorlike quarks (VLQs), factorizing into entry, chain-propagation, and exit amplitudes controlled by the discrete gauge charges. A multi-messenger structure -- in which each Yukawa entry receives coherent contributions from several chain configurations -- generates O(1) complex coefficients whose phases are the physical origin of CP violation. We derive a general chain-inversion theorem, perform systematic perturbative diagonalization of both up- and down-type Yukawa textures, and show that the Cabibbo--Kobayashi--Maskawa (CKM) mixing hierarchy and CP-phase structure emerge naturally from the lattice exponent algebra and multi-messenger interference. All six quark masses are reproduced with O(1) coefficients that are essentially unity. The chain locality simultaneously suppresses dangerous flavor-changing neutral currents (FCNCs) and satisfies electroweak precision constraints, while requiring VLQs with masses in the multi-TeV range accessible at the High-Luminosity Large Hadron Collider (HL-LHC). The same discrete gauge symmetry that enforces the lattice structure also protects the Peccei--Quinn axion quality, unifying flavor, CP violation, and the strong CP problem. The framework extends to the lepton sector, reproducing charged-lepton mass hierarchies, the normal-ordered neutrino spectrum, and PMNS mixing with a predictive two-branch octant--$\delta$ correlation testable at DUNE and Hyper-Kamiokande.

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arXiv2026

Lepton Mixing from a Lattice Flavon Model: A Two-Branch Octant-delta Prediction

We extend the single-flavon $B$-lattice Froggatt--Nielsen (FN) framework, previously successful for quark masses and Cabibbo-Kobayashi-Maskawa (CKM) mixing, to the lepton sector. The same $B$-lattice power structure ($\epsilon\equiv 1/B\simeq 0.19$) generates charged-lepton mass hierarchies and a normal-ordered neutrino spectrum; large neutrino mixing angles require an additional approximate $Z_2$ mu--tau reflection symmetry, broken at $\mathcal{O}(\epsilon)$ to generate a nonzero reactor angle and CP-violating phase. The PMNS matrix factorizes as $U_{\rm PMNS}=U_e^\dagger U_\nu$, with near-tribimaximal $U_\nu$ corrected by small charged-lepton rotations whose phases are aligned by the single-flavon origin of the Yukawa textures. A single interference relation expresses the observed Dirac phase $\delta$ as the neutrino-sector phase $\delta_\nu$ shifted by a calculable charged-lepton correction, and correlates the sign of that shift with the atmospheric octant; this produces a two-branch prediction in the $(\theta_{23},\delta)$ plane: a lower-octant solution with $\theta_{23}\approx 43^\circ$, $\delta\approx 286^\circ$, and an upper-octant solution with $\theta_{23}\approx 46^\circ$, $\delta\approx 299^\circ$. This structure has a geometric form as a $\nu_3$-column normalization triangle whose base angle is $2\theta_{23}$, with maximal mixing the $90^\circ$ limit and the octant fixed by the side of $90^\circ$ on which the base angle falls. The lower octant is mildly favored, by a margin that depends on the coefficient prior. Both branches place the Dirac phase above $270^\circ$, i.e. near-maximal leptonic CP violation, favored by T2K. The Jarlskog invariant $J_{\rm CP}\simeq -0.03$ is nearly branch-independent; only precision measurements of the atmospheric octant and Dirac phase at DUNE, Hyper-Kamiokande, IceCube, and JUNO can distinguish the two solutions.

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arXiv2026

Flavor in Ninths and a Discrete Gauge Origin of the QCD Axion

Quark and lepton hierarchies are organized by rational powers of a single parameter (the quark masses and mixings in ninths, the charged-lepton mass ratios in sixths). We argue that this structure points to a discrete $\mathbb{Z}_{18}$ origin of Froggatt--Nielsen symmetry, fixed as the least common denominator $\mathrm{lcm}(9,6)=18$, with its $\mathbb{Z}_9$ subgroup governing the quark lattice and the full $\mathbb{Z}_{18}\cong\mathbb{Z}_9\times\mathbb{Z}_2$ required to accommodate the half-integer lepton charges. The flavon is the unique $\mathbb{Z}_{18}$-charged scalar with a large VEV, so its phase is the Peccei--Quinn axion; the \emph{same} symmetry then solves the strong $CP$ problem and forbids every Planck-suppressed PQ-violating operator below dimension eighteen. Our central result is that, because the order of $\mathbb{Z}_{18}$ is fixed by the flavor data rather than chosen to protect the axion, the resulting high axion quality (the residual shift of the axion vacuum from $\bar\theta=0$ being only $|\Delta\bar\theta|\lesssim 3\times10^{-27}$) is a prediction of the flavor structure rather than an imposed ingredient. The axion is a generation-dependent Type-II DFSZ axion with domain-wall number $N_{\rm DW}=6$. The decisive phenomenological consequence is that the same non-universal charges that reproduce the fermion masses enhance the axion--photon coupling to an observable level, $C_{a\gamma}\simeq0.6$--$1.0$ (well above the higgsino-suppressed MSSM value), placing the dark-matter axion at $m_a\simeq 7$--$12~\mu$eV within reach of upcoming haloscope searches.

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arXiv2026

Quark Mixing from a Lattice Flavon Model: A Four-Magnitude Parameterization

We show that quark weak mixing follows from the same one-flavon, three-messenger Froggatt-Nielsen construction, with a single hierarchy parameter $B$ ($\epsilon \equiv 1/B$) and a rational-exponent "$B$-lattice", that organizes the fermion mass spectrum in companion work. The lattice exponents, together with a four-phase messenger coefficient model, account for the four measured CKM magnitudes and, through the Fritzsch-Xing reconstruction, the full $3\times 3$ CKM matrix and the Jarlskog invariant $J$, providing a consistency test of the single-$B$ hypothesis. A benchmark Yukawa pair on the lattice reproduces, under direct diagonalization, the light-quark masses to better than 5%, all nine CKM magnitudes to better than 1.2%, and $J$ within $0.3\sigma$ of the PDG global fit, with order-unity coefficients; a $10^7$-configuration phase scan shows the CKM hierarchy to be generic once the quark masses are fit, while percent-level agreement across all four magnitudes is not. The near-maximal CP phase admits a geometric interpretation: equal-weight messenger interference fixes the phase at exactly $\pi/2$ for any individual phase values, and the fitted $\phi_{\rm FX} \simeq 93^\circ$ measures the departure from this limit. The same lattice parameter fixes the charged-lepton mass ratio $m_\mu/m_\tau = c_\mu \epsilon^{5/3}$, whose exponent is the second-generation lepton charge sum; this yields $|V_{ub}| \simeq (m_\mu/m_\tau)^2$, agreeing with the measured value at about the 6% level, and the equivalent form $|V_{ub}| \simeq \sin^3\theta_{13}$ ties the smallest CKM magnitude to the smallest PMNS magnitude, the two routes furnishing complementary determinations of the same ninths-lattice quantity from the quark and lepton sectors.

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arXiv2026

Two-over-Two Lattice Flavor from a Single Flavon with Three Messenger Chains

Flavor hierarchies are organized by a single parameter $B\simeq 5.357$ in a single-flavon Froggatt--Nielsen (FN) framework, in which each effective Yukawa entry arises from the sum of \emph{three} unit-magnitude messenger chains. We present benchmark complex $O(1)$ Yukawa matrices that reproduce quark and charged-lepton masses at $M_Z$ as powers of $\epsilon\equiv 1/B$. The organizing principle is a two-over-two (2/2) lattice of quadrilateral mass ratios, which maps directly to a rational lattice of FN exponents. Sequential dominance preserves the leading-power exponent matrices, while subleading messenger chains generate entry-dependent complex $O(1)$ coefficients and provide a UV-friendly origin for CP violation. Neutrino masses are discussed at the level of eigenvalues within the same $B^n$ counting.

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arXiv2026

pMSSM versus complete models and the excellent prospects for top-squark discovery at HL-LHC

LHC sparticle search limits are usually performed within the context of simplified models and subsequently interpreted within the 19 parameter phenomenological MSSM (pMSSM) as to how many models avoid search limits for a particular sparticle mass, often including WIMP dark matter constraints. We provide a critical discussion of this procedure and how it can go wrong due to the introduction of new prejudices. By ameliorating these conditions, one is pushed into the more plausible four extra parameter non-universal Higgs model (NUHM4). Implementing a decoupling/quasi-degeneracy solution to the SUSY flavor and CP problems leads to first/second generation sfermions in the tens-of-TeV range. In this case, the natural solutions typically contain top-squarks in the 1-2 TeV range which are accessible to high-lumi LHC (HL-LHC) searches. This search channel, along with higgsino and wino pair production, may allow a nearly complete scan of natural/plausible parameter space by HL-LHC.

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arXiv2025

One-flavon flavor: A single hierarchical parameter $B$ organizes quarks and leptons at $M_Z$

Flavor hierarchies emerge from a single hierarchical parameter $B$ in a one-flavon Froggatt--Nielsen scheme. Fixing $B=5.357$ from charged-lepton ratios ($m_e:m_\mu:m_\tau\!\propto\!\epsilon^5:\epsilon^2:1$, $\epsilon=1/B$), we reproduce quark masses and CKM targets at $M_Z$ with $\ordone$ coefficients. The same $\epsilon$ gives viable lepton textures and benchmarks for $U_{\rm PMNS}$, $\sum m_\nu$, and $m_{\beta\beta}$. Compact correlations ($|V_{us}|,|V_{cb}|,|V_{ub}|,\theta_{13}^{\rm PMNS}$) follow from powers of $\epsilon$.

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arXiv2025

Natural supersymmetry at a muon collider

There is great interest within the particle physics community for building a $\mu^+\mu^-$ collider with center-of-mass (CoM) energies ranging from $\sqrt{s}\sim$ 1-14 TeV. For Beyond-the-Standard-Model (BSM) physics, natural supersymmetry seems perhaps the most motivated, plausible extension of the Standard Model. Here, we examine what can be accomplished by a muon collider with regards to natural SUSY at various muon collider CoM energies. In natural SUSY -- especially in the guise that would emerge from the string landscape -- one expects sparticles to be spread over two orders of magnitude in mass values. A muon collider with highly variable beam energies would be most useful for targeting 2-body reaction thresholds and Higgs boson resonances.

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