Ernest Orlando Lawrence Berkeley National Laboratory
We demonstrate that novel limits on prompt axion-like particles (ALPs) in the hard-to-probe mass range near the neutral pion - the so-called pion chimney - may be obtained from recasting KL3π06γK_L \to 3\pi^0 \to 6\gamma KOTO data to search for KL2π0a6γK_L \to 2\pi^0 a \to 6\gamma. We also explore the power of KOTO 6γ6\gamma data to probe KL2π0aK_L \to 2\pi^0a for a broader range of ALP masses, incorporating displaced decays.
We study the Type IIA limit of the M theory fivebrane configuration corresponding to N=1 supersymmetric QCD with massless quarks. We identify the effective gauge coupling constant that fits with Novikov-Shifman-Veinshtein-Zakharov exact beta function. We find two different Type IIA limits that correspond to the electric and magnetic descriptions of SQCD, as observed in the massive case by Schmaltz and Sundrum. The analysis is extended to the case of symplectic and orthogonal gauge groups. In any of the cases considered in this paper, the electric and magnetic configurations are smoothly interpolated via MM theory. This is in sharp contrast with the proposed derivation of N=1 duality within the weakly coupled Type IIA string theory where a singularity is inevitable unless one turns on a parameter that takes the theory away from an interesting point.
We study the constraints of crossing symmetry and unitarity in general 3D Conformal Field Theories. In doing so we derive new results for conformal blocks appearing in four-point functions of scalars and present an efficient method for their computation in arbitrary space-time dimension. Comparing the resulting bounds on operator dimensions and OPE coefficients in 3D to known results, we find that the 3D Ising model lies at a corner point on the boundary of the allowed parameter space. We also derive general upper bounds on the dimensions of higher spin operators, relevant in the context of theories with weakly broken higher spin symmetries.
We advocate for the construction of a new detector element at the LHCb experiment, designed to search for displaced decays of beyond standard model long-lived particles, taking advantage of a large shielded space in the LHCb cavern that is expected to soon become available. We discuss the general features and putative capabilities of such an experiment, as well as its various advantages and complementarities with respect to the existing LHC experiments and proposals such as SHiP and MATHUSLA. For two well-motivated beyond Standard Model benchmark scenarios -- Higgs decay to dark photons and BB meson decays via a Higgs mixing portal -- the reach either complements or exceeds that predicted for other LHC experiments.
This research provides analytical calculations for non-perturbative condensates and hadron spectra in SU(Nc) gauge theories perturbed by anomaly-mediated supersymmetry breaking. It demonstrates a continuous crossover from near-supersymmetric to non-supersymmetric regimes, correcting the scaling of the pion decay constant and yielding results consistent with Quantum Chromodynamics expectations and experimental observations.
A recent measurement by the D0 collaboration finds a like-sign di-muon charge asymmetry in the B system that is roughly 3 sigma larger than the value predicated by the Standard Model. This suggests new physics contributing to B-Bbar mixing. For the current central value of the CP asymmetry, the required size of Gamma_{12}^s is larger than Standard Model estimates of this quantity. In this paper, we will explore the constraints on new physics contributions to Gamma_{12}^s. We show that there are two dimension six operators of Standard Model fields in the electroweak Hamiltonian whose coefficients are not constrained enough to rule out possible contributions from new physics. We argue that a more precise measurement of tau(B_s)/tau(B_d), which is possible with currently available data, could either support or strongly constrain the existence of new physics in Gamma_{12}^s.
The mixing of neutral mesons is sensitive to some of the highest scales probed in laboratory experiments. In light of the planned LHCb Upgrade II, a possible upgrade of Belle II, and the broad interest in flavor physics in the tera-ZZ phase of the proposed FCC-ee program, we study constraints on new physics contributions to BdB_d and BsB_s mixings which can be obtained in these benchmark scenarios. We explore the limitations of this program, and identify the measurement of Vcb|V_{cb}| as one of the key ingredients in which progress beyond current expectations is necessary to maximize future sensitivity. We speculate on possible solutions to this bottleneck. Given the current tension with the standard model (SM) in semileptonic BB decays, we explore how its resolution may impact the search for new physics in mixing. Even if new physics has the same CKM and loop suppressions of flavor changing processes as the SM, the sensitivity will reach 2 TeV, and it can be much higher if any SM suppressions are lifted. We illustrate the discovery potential of this program.
Run 5 of the HL-LHC era (and beyond) may provide new opportunities to search for physics beyond the standard model (BSM) at interaction point 2 (IP2). In particular, taking advantage of the existing ALICE detector and infrastructure provides an opportunity to search for displaced decays of beyond standard model long-lived particles (LLPs). While this proposal may well be preempted by ongoing ALICE physics goals, examination of its potential new physics reach provides a compelling comparison with respect to other LLP proposals. In particular, full event reconstruction and particle identification could be possible by making use of the existing L3 magnet and ALICE time projection chamber. For several well-motivated portals, the reach competes with or exceeds the sensitivity of MATHUSLA and SHiP, provided that a total integrated luminosity of approximately 100fb1100\, \text{fb}^{-1} could be delivered to IP2.
We use supersymmetric chiral dynamics perturbed by anomaly-mediated supersymmetry breaking to obtain a high-quality, composite axion that solves the strong CP problem. The strong dynamics arises from a supersymmetric SU(10) chiral gauge theory with massless matter chiral superfields. This leads to a stable, nonsupersymmetric vacuum, calculated exactly, where a spontaneously broken U(1)U(1) global symmetry, identified with the Peccei-Quinn symmetry, gives rise to a composite QCD axion. The chiral gauge theory also admits a discrete Z4\mathbb{Z}_{4} (or Z8,16\mathbb{Z}_{8,16}) gauge symmetry that forbids PQ-violating operators up to dimension eight. An extension to an SU(14)×Z12SU(14)\times \mathbb{Z}_{12} chiral gauge theory incorporates SO(10)SO(10) grand unification where the unification scale is identified with the PQ-breaking scale and PQ-violating operators are forbidden up to dimension 20. The supersymmetry breaking scale, near 100 TeV, ameliorates the Higgs hierarchy problem, while colored NGBs may be detected at future colliders via decays to gluons or form heavy isotopes.
Precise measurements of bcτνˉb\to c\tau\bar\nu decays require large resource-intensive Monte Carlo (MC) samples, which incorporate detailed simulations of detector responses and physics backgrounds. Extracted parameters may be highly sensitive to the underlying theoretical models used in the MC generation. Because new physics (NP) can alter decay distributions and acceptances, the standard practice of fitting NP Wilson coefficients to SM-based measurements of the R(D())R(D^{(*)}) ratios can be biased. The newly developed HAMMER software tool enables efficient reweighting of MC samples to arbitrary NP scenarios or to any hadronic matrix elements. We demonstrate how HAMMER allows avoidance of biases through self-consistent fits directly to the NP Wilson coefficients. We also present example analyses that demonstrate the sizeable biases that can otherwise occur from naive NP interpretations of SM-based measurements. The HAMMER library is presently interfaced with several existing experimental analysis frameworks and we provide an overview of its structure.
We clarify the notion of Wilsonian renormalization group (RG) invariance in supersymmetric gauge theories, which states that the low-energy physics can be kept fixed when one changes the ultraviolet cutoff, provided appropriate changes are made to the bare coupling constants in the Lagrangian. We first pose a puzzle on how a quantum modified constraint (such as Pf(Q^i Q^j) = \Lambda^{2(N+1)} in SP(N) theories with N+1 flavors) can be RG invariant, since the bare fields Q^i receive wave function renormalization when one changes the ultraviolet cutoff, while we naively regard the scale \Lambda as RG invariant. The resolution is that \Lambda is not RG invariant if one sticks to canonical normalization for the bare fields as is conventionally done in field theory. We derive a formula for how \Lambda must be changed when one changes the ultraviolet cutoff. We then compare our formula to known exact results and show that their consistency requires the change in \Lambda we have found. Finally, we apply our result to models of supersymmetry breaking due to quantum modified constraints. The RG invariance helps us to determine the effective potential along the classical flat directions found in these theories. In particular, the inverted hierarchy mechanism does not occur in the original version of these models.
We propose correspondences between 4d quantum field theories with N=2,1,0 (super)conformal invariance and Type IIB string theory on various orbifolds. We argue using the spacetime string theory, and check using the beta functions (exactly for N=2,1 and so far at 1-loop for the gauge couplings in the N=0 case), that these theories have conformal fixed lines. The latter case potentially gives well-defined non-supersymmetric vacua of string theory, with a mechanism for making the curvature and cosmological constant small at nontrivial string coupling. We suggest a correspondence between nonsupersymmetric conformal fixed lines and nonsupersymmetric string vacua with vanishing vacuum energy.
A multi-axion framework is developed to resolve the long-standing cosmological conflict between high-scale cosmic inflation and axion dark matter, demonstrating that models previously disfavored due to stable domain walls can be viable if the determinant of their anomaly matrix equals one. This approach allows for post-inflationary axion production compatible with primordial gravitational waves and potentially explains the NANOGrav signal.
We propose a novel direct detection concept to search for dark matter with 100~keV to 100~MeV masses. Such dark matter can scatter off molecules in a gas and transfer an O(1)\mathcal{O}(1) fraction of its kinetic energy to excite a vibrational and rotational state. The excited ro-vibrational mode relaxes rapidly and produces a spectacular multi-infrared-photon signal, which can be observed with ultrasensitive photodetectors. We discuss in detail a gas target consisting of carbon monoxide molecules, which enable efficient photon emission even at a relatively low temperature and high vapor pressure. The emitted photons have an energy in the range 180~meV to 265~meV. By mixing together carbon monoxide molecules of different isotopes, including those with an odd number of neutrons, we obtain sensitivity to both spin-independent interactions and spin-dependent interactions with the neutron. We also consider hydrogen fluoride, hydrogen bromide, and scandium hydride molecules, which each provide sensitivity to spin-dependent interactions with the proton. The proposed detection concept can be realized with near-term technology and allows for the exploration of orders of magnitude of new dark matter parameter space.
This paper presents a comprehensive analysis of the phase structure of SU(N_c) supersymmetric QCD (SQCD) under Anomaly Mediated Supersymmetry Breaking (AMSB). It systematically identifies stable chiral symmetry breaking minima and demonstrates that loop-level AMSB effects can stabilize baryonic runaway directions in specific N_f regimes, while delineating the limits of calculability in others.
We discuss anomalies associated with outer automorphisms in gauge theories based on classical groups, namely charge conjugations for SU(N)SU(N) and parities for SO(2r)SO(2r). We emphasize the inequivalence (yet related by a flavor transformation) between two versions of charge conjugation for SU(2k)SU(2k), SO(2r)SO(2r), and E6E_6 symmetries. The subgroups that commute with the outer automorphisms are identified. Some charge conjugations can lead to a paradox, which is resolved by the observation that they are anomalous and hence not symmetries. We then discuss anomaly matching conditions that involve the charge conjugations or parities. Interesting examples are given where the charge conjugation is spontaneously broken.
Hitoshi Murayama, from UC Berkeley and Kavli IPMU, developed a theoretically controlled method by applying Anomaly-Mediated Supersymmetry Breaking (AMSB) to Supersymmetric QCD (SQCD), enabling exact analytical study of non-supersymmetric QCD-like theories. This approach provides a rigorous demonstration of dynamical chiral symmetry breaking and reveals emergent supersymmetry within the infrared conformal window.
We present models of resonant self-interacting dark matter in a dark sector with QCD, based on analogies to the meson spectra in Standard Model QCD. For dark mesons made of two light quarks, we present a simple model that realizes resonant self-interaction (analogous to the ϕ\phi-K-K system) and thermal freeze-out. We also consider asymmetric dark matter composed of heavy and light dark quarks to realize a resonant self-interaction (analogous to the Υ(4S)\Upsilon(4S)-B-B system) and discuss the experimental probes of both setups. Finally, we comment on the possible resonant self-interactions already built into SIMP and ELDER mechanisms while making use of lattice results to determine feasibility.
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