HEP Phenomenology·hep-ph

Fri·Apr 26, 2024Friday·April 26, 2024

27 papers—18 primary·9 cross-listed·reconstructed*

01*
Foundations of automatic feature extraction at LHC--point clouds and graphs
Akanksha Bhardwaj🇺🇸 · Partha Konar🇮🇳 · Vishal S. Ngairangbam🇬🇧
Deep learning algorithms will play a key role in the upcoming runs of the Large Hadron Collider (LHC), helping bolster various fronts ranging from fast and accurate detector simulations to physics analysis probing possible deviations from the Standard Model. The game-changing feature of these new algorithms is the ability to extract relevant information from high-dimensional input spaces, often regarded as "replacing the expert" in designing physics-intuitive variables. While this may seem true at first glance, it is far from reality. Existing research shows that physics-inspired feature extractors have many advantages beyond improving the qualitative understanding of the extracted features. In this review, we systematically explore automatic feature extraction from a phenomenological viewpoint and the motivation for physics-inspired architectures. We also discuss how prior knowledge from physics results in the naturalness of the point cloud representation and discuss graph-based applications to LHC phenomenology.
hep-phEur.Phys.J.ST(2024)·1 citation
02*
Heavy Dark Matter in White Dwarfs: Multiple-Scattering Capture and Thermalization
Nicole F. Bell🇦🇺 · Giorgio Busoni🇦🇺 · Sandra Robles🇬🇧 · Michael Virgato🇦🇺
We present an improved treatment for the scattering of heavy dark matter from the ion constituents of a white dwarf. In the heavy dark matter regime, multiple collisions are required for the dark matter to become gravitationally captured. Our treatment incorporates all relevant physical effects including the dark matter trajectories, nuclear form factors, and radial profiles for the white dwarf escape velocity and target number densities. Our capture rates differ by orders of magnitude from previous estimates, which have typically used approximations developed for dark matter scattering in the Earth. We also compute the time for the dark matter to thermalize in the center of the white dwarf, including in-medium effects such as phonon emission and absorption from the ionic lattice in the case where the star has a crystallized core. We find much shorter thermalization timescales than previously estimated, especially if the white dwarf core has crystallized. We illustrate the importance of our improved approach by determining the cross section required for accumulated asymmetric dark matter to self-gravitate.
hep-phastro-ph.COastro-ph.HEastro-ph.SRJCAP(2024)·10 citations
03*
Stability of the electroweak vacuum with respect to vacuum tunneling to the Komatsu vacuum in the cMSSM
Hyukjung Kim🇰🇷 · Ewan D. Stewart🇹🇷 · Heeseung Zoe🇹🇷
We investigate the stability of the electroweak vacuum with respect to vacuum tunneling to the Komatsu vacuum, which exists when $m_{L}^{2} + m_{H_{u}}^{2} < 0$ , in the cMSSM. Employing the numerical tools SARAH, SPheno and CosmoTransitions, we scan and constrain the parameter space of the cMSSM up to 10 TeV. Regions excluded due to having a vacuum tunneling half-life less than the age of the observable universe are concentrated near the regions where the electroweak vacuum is tachyonic and are more stringent at smaller $m_{0}$ , larger and negative $A_{0}$ , and larger $tan β$ . New excluded regions, which satisfy $m_{h} ≃ 125 GeV$ , are found.
hep-ph0 citations
04*
Low-mass dark sector searches with deuteron photodisintegration
Cornelis J.G. Mommers🇩🇪 · Marc Vanderhaeghen🇩🇪
Recent years have seen much activity in searches for dark-sector messenger particles in the 10-100 MeV mass range, especially in view of a potential new light boson conjectured by the ATOMKI collaboration, X17. Under the assumption that the messenger particle has definite parity and either zero or unit spin, quite stringent bounds already exist on its coupling to electrons and protons. Equally stringent bounds on the neutron coupling do not exist yet, but are nonetheless desirable. We explore how measurements of deuteron photodisintegration with a quasi-free neutron can yield bounds on the neutron coupling, and compute projections for a potential measurement at the lowenergy high-intensity electron scattering experiment MAGIX@MESA. The projected bounds are found to be competitive for an axial-vector or pseudoscalar scenario, but not for a vector or scalar scenario.
hep-phnucl-exnucl-thPRD(2024)·2 citations
05*
Gauged Q-ball dark matter through a cosmological first-order phase transition
Siyu Jiang🇨🇳 · Fa Peng Huang🇨🇳 · Pyungwon Ko🇰🇷
As a new type of dynamical dark matter mechanism, we discuss the stability of the gauged Q-ball dark matter and its production mechanism through a cosmological first-order phase transition. This work delves into the study of gauged Q-ball dark matter generated during the cosmic phase transition. We demonstrate detailed discussions on the stability of gauged Q-balls to rigorously constrain their charge and mass ranges. Additionally, employing analytic approximations and the mapping method, we provide qualitative insights into gauged Q-balls. We establish an upper limit on the gauge coupling constant and give the relic density of stable gauged Q-ball dark matter formed during a first-order phase transition. Furthermore, we discuss potential observational signatures or constraints of gauged Q-ball dark matter, including astronomical observations and gravitational wave signals.
hep-phJHEP(2024)·22 citations
06*
Lessons from ATLAS and CMS measurements of Higgs boson decays to second generation fermions
Yosef Nir🇮🇱 · Purvaash Panduranghan Udhayashankar🇮🇱
There is now experimental evidence for Higgs boson decay into a pair of muons, and significant constraints on the Higgs boson decay into a charm quark-antiquark pair. The data on Higgs boson decays into second generation fermions probes various extensions of the Standard Model. We analyze the implications for the Standard Model effective field theory (SMEFT), without and with minimal flavor violation (MFV), for two Higgs doublet models (2HDM) with natural flavor conservation (NFC), for models with vector-like fermions, and for specific models that predict significant modifications of the Yukawa couplings to the light generations.
hep-phhep-exJHEP(2024)·5 citations
07*
Uncovering the mystery of $X (3872)$ with the coupled-channel dynamics
Jun-Zhang Wang🇨🇳 · Zi-Yang Lin🇨🇳 · Yan-Ke Chen🇨🇳 · Lu Meng🇩🇪 · Shi-Lin Zhu🇨🇳
The $X (3872)$ , as the first and the most crucial member in the exotic charmoniumlike $X Y Z$ family, has been studied for a long time. However, its dynamical origin, whether stemming from a $D D ˉ^{*}$ hadronic molecule or the first excited $P$ -wave charmonium $χ_{c 1} (2 P)$ , remains controversial. In this Letter, we demonstrate that the $X (3872)$ definitely does not result from the mass shift of the higher bare $χ_{c 1} (2 P)$ resonance pole in the coupled-channel dynamics involving a short-distance $c c ˉ$ core and the long-distance $D D ˉ^{*}$ channels. Instead, it originates from either the $D D ˉ^{*}$ molecular pole or the shadow pole associated with the anti-resonance of the $P$ -wave charmonium, depending on the weak or strong coupling mode, respectively. To differentiate these origins and fully exploit the nature of $X (3872)$ , we conduct a comprehensive analysis in a couple-channel dynamics framework, including the isospin violation, the three-body $D D ˉ π$ effect, the dynamical width of $D^{*}$ , and non-open-charm decays of the bare $χ_{c 1} (2 P)$ . Our findings highlight the pivotal role of the coupled-channel dynamics in explaining the disparity between the pole widths of $X (3872)$ and $T_{cc}^{+}$ , while also predicting a new resonance with $J^{P C} = 1^{++}$ around 4.0 GeV. By matching the newly observed $χ_{c 1} (4010)$ by the LHCb Collaboration to our predicted resonance, we conclude that the $X (3872)$ most likely originates from the $D D ˉ^{*}$ pole with a confidence level exceeding $99.7%$ .
hep-phhep-exhep-latPRD(2025)·10 citations
08*
A holographic bottom-up approach to $Σ$ baryons
Xi Guo🇨🇳 · Miguel Angel Martin Contreras🇨🇳 · Xun Chen🇨🇳 · Dong Xiang🇨🇳
In this work, we discuss the description of neutral $Σ$ baryons with $I (J^{P}) = 1 (1/ 2^{+})$ and $I (J^{P}) = 1 (3/ 2^{+})$ using two bottom-up approaches: the deformed background and the static dilaton. In both models, we consider a non-linear Regge trajectory extension motivated by the \emph{strange} nature that $Σ$ baryons have. We found that both models describe these systems with an RMS error smaller than 10 $%$ . We also perform a configurational entropy calculation in both models to discuss hadronic stability.
hep-phCPC(2025)·10 citations
09*
Understanding small neutrino mass and its implication
Hsiang-nan Li🇹🇼
We have derived previously the relations between the neutrino masses and mixing angles in a dispersive analysis on the mixing of neutral leptonic states. The only involved assumption is that the electroweak symmetry of the Standard Model (SM) is restored at a high energy scale in some new physics scenario, which diminishes the box diagrams responsible for the mixing. Here we include corrections to the analysis up to three loops, arising from exchanges of additional neutral and charged scalars in the electroweak symmetric phase. The solution to the dispersion relation for the $μ^{-} e^{+}$ - $μ^{+} e^{-}$ mixing generates a typical neutrino mass $m_{ν} \sim O (1)$ eV in the SM unambiguously. The solution also favors the normal ordering of the neutrino masses over the inverted one, and links the large electroweak symmetry restoration, i.e., new physics scale to the small neutrino mass.
hep-phChin.J.Phys.(2024)·9 citations
10*
Illuminating Black Hole Shadow with Dark Matter Annihilation
Yifan Chen🇩🇰 · Ran Ding🇨🇳 · Yuxin Liu🇨🇳 · Yosuke Mizuno🇨🇳 · Jing Shu🇨🇳 · Haiyue Yu🇨🇳 · Yanjie Zeng🇨🇳
The Event Horizon Telescope (EHT) has significantly advanced our ability to study black holes, achieving unprecedented spatial resolution and revealing horizon-scale structures. Notably, these observations feature a distinctive dark shadow--primarily arising from faint jet emissions--surrounded by a bright photon ring. Anticipated upgrades of the EHT promise substantial improvements in dynamic range, enabling deeper exploration of low-background regions, particularly the inner shadow defined by the lensed equatorial horizon. Our analysis shows that observations of these regions transform supermassive black holes into powerful probes for annihilating dark matter, which is expected to accumulate densely in their vicinity. By analyzing the black hole image morphology and performing electron-positron propagation calculations in realistic plasma backgrounds derived from general relativistic magnetohydrodynamic simulations, we set stringent constraints on dark matter annihilation, requiring contributions below the astrophysical emission. These constraints, derived from both current EHT observations and projections for future upgraded arrays, exclude a substantial region of previously unexplored parameter space and remain robust against astrophysical uncertainties, including black hole spin and plasma temperature variations.
hep-phastro-ph.COastro-ph.HEgr-qcPRL(2025)·17 citations
11*
Neutrino many-body flavor evolution: the full Hamiltonian
Vincenzo Cirigliano🇺🇸 · Srimoyee Sen🇺🇸 · Yukari Yamauchi🇺🇸
We study neutrino flavor evolution in the quantum many-body approach using the full neutrino-neutrino Hamiltonian, including the usually neglected terms that mediate non-forward scattering processes. Working in the occupation number representation with plane waves as single-particle states, we explore the time evolution of simple initial states with up to $N = 10$ neutrinos. We discuss the time evolution of the Loschmidt echo, one body flavor and kinetic observables, and the one-body entanglement entropy. For the small systems considered, we observe `thermalization' of both flavor and momentum degrees of freedom on comparable time scales, with results converging towards expectation values computed within a microcanonical ensemble. We also observe that the inclusion of non-forward processes generates a faster flavor evolution compared to the one induced by the truncated (forward) Hamiltonian.
hep-phnucl-thquant-phPRD(2024)·30 citations
12*
Calculable neutrino Dirac mass matrix and one-loop $θ ˉ$ in the minimal left-right symmetric model
Gang Li🇨🇳 · Ding-Yi Luo🇨🇳 · Xiang Zhao🇨🇳
We revisit the contribution to the strong CP parameter $θ ˉ$ from leptonic CP violation at one-loop level in the minimal left-right symmetric model in the case of generalized parity as the left-right symmetry. The Hermitian neutrino Dirac mass matrix $M_{D}$ can be calculated using the light and heavy neutrino masses and mixings. We propose a parametrization of the right-handed neutrino mixing matrix $V_{R}$ and construct the heavy neutrino mass that maintains the Hermiticity of $M_{D}$ . We further apply it to evaluate the one-loop $θ ˉ$ , denoted as $θ ˉ_{l oo p}$ , as a function of the sterile neutrino masses for explicit examples of $V_{R}$ . By requiring the magnitude of $θ ˉ_{l oo p} ≲ 1 0^{- 10}$ , we derive the upper limits on the sterile neutrino masses, which are within reach of direct searches at the Large Hadron Collider and neutrinoless double beta decay experiments. Furthermore, our parametrization is pertinent for other phenomenological investigations.
hep-phPRD(2024)·8 citations
13*
$R_{D^{(*)}}$ and survival of the fittest scalar leptoquark
Damir Bečirević🇫🇷 · Svjetlana Fajfer🇸🇮 · Nejc Košnik🇸🇮 · Lovre Pavičić🇸🇮
Motivated by the long-standing discrepancy in lepton flavor universality ratios $R_{D}$ and $R_{D^{*}}$ we assess the status of scalar leptoquark states $R_{2}$ , $R_{2}$ and $S_{1}$ which can in principle provide a desired enhancement of $B (B \to D^{(*)} τ ν)$ in a minimal setup with two Yukawa couplings only. We consider unavoidable low-energy constraints, $Z$ -pole measurements as well as high- $p_{T}$ constraints. After setting mass of each leptoquark to $1.5$ TeV we find that of all considered states only $S_{1}$ leptoquark, coupled to both chiralities of leptons and quarks, is still a completely viable solution while the scenario with $R_{2}$ is in growing tension with $Γ (Z \to τ τ)$ and with the LHC constraints on the di-tau tails at high- $p_{T}$ . We comment on the future experimental tests of $S_{1}$ scenario.
hep-phPRD(2024)·21 citations
14*
Quantum effects on the evaporation of PBHs: contributions to dark matter
Md Riajul Haque🇮🇳 · Suvashis Maity🇮🇳 · Debaprasad Maity🇮🇳 · Yann Mambrini🇫🇷
We compute the relic abundance of dark matter in the presence of Primordial Black Holes (PBHs) beyond the semiclassical approximation. We take into account the quantum corrections due to the memory burden effect, which is assumed to suppress the black hole evaporation rate by the inverse power of its own entropy. Such quantum effect significantly enhances the lifetime, rendering the possibility of PBH mass $≲ 1 0^{9}$ g being the sole dark matter (DM) candidate. However, Nature can not rule out the existence of fundamental particles such as DM. We, therefore, include the possibility of populating the dark sector by the decay of PBHs to those fundamental particles, adding the contribution to stable PBH whose lifetime is extended due to the quantum corrections. Depending on the strength of the burden effect, we show that a wide range of parameter space opens up in the initial PBH mass and fundamental dark matter mass plane that respects the correct relic abundance.
hep-phastro-ph.COhep-thJCAP(2024)·54 citations
15*
Type-I two-Higgs-doublet model and gravitational waves from domain walls bounded by strings
Bowen Fu🇨🇳 · Anish Ghoshal🇵🇱 · Stephen F. King🇬🇧 · Moinul Hossain Rahat🇪🇸
The spontaneous breaking of a $U (1)$ symmetry via an intermediate discrete symmetry may yield a hybrid topological defect of \emph{domain walls bounded by cosmic strings}. The decay of this defect network leads to a unique gravitational wave signal spanning many orders in observable frequencies, that can be distinguished from signals generated by other sources. We investigate the production of gravitational waves from this mechanism in the context of the type-I two-Higgs-doublet model extended by a $U (1)_{R}$ symmetry, that simultaneously accommodates the seesaw mechanism, anomaly cancellation, and eliminates flavour-changing neutral currents. The gravitational wave spectrum produced by the string-bounded-wall network can be detected for $U (1)_{R}$ breaking scale from $1 0^{12}$ to $1 0^{15}$ GeV in forthcoming interferometers including LISA and Einstein Telescope, with a distinctive $f^{3}$ slope and inflexion in the frequency range between microhertz and hertz.
hep-phastro-ph.COJHEP(2024)·19 citations
16*
Gravitational wave signatures of post-fragmentation reheating
Marcos A. G. Garcia🇲🇽 · Mathias Pierre🇩🇪
After cosmic inflation, coherent oscillations of the inflaton field about a monomial potential $V (ϕ) \sim ϕ^{k}$ result in an expansion phase characterized by a stiff equation-of-state $w ≃ (k - 2) / (k + 2)$ . Sourced by the oscillating inflaton condensate, parametric (self)resonant effects can induce the exponential growth of inhomogeneities eventually backreacting and leading to the fragmentation of the condensate. In this work, we investigate realizations of inflation giving rise to such dynamics, assuming an inflaton weakly coupled to its decay products. As a result, the transition to a radiation-dominated universe, i.e. reheating, occurs after fragmentation. We estimate the consequences on the production of gravitational waves by computing the contribution induced by the stiff equation-of-state era in addition to the signal generated by the fragmentation process for $k = 4, 6, 8, 10$ . We find that the signal generated during the fragmentation process gives a larger contribution than the one induced by the stiff equation-of-state era in given frequency ranges for all values of $k$ . Our results are independent of the reheating temperature provided that reheating is achieved posterior to fragmentation. Our work shows that the dynamics of such weakly-coupled inflaton scenario can actually result in characteristic gravitational wave spectra with frequencies from Hz to GHz, in the reach of future gravitational wave observatories, in addition to the complementarity between upcoming detectors in discriminating (post)inflation scenarios. We advocate the need of developing high-frequency gravitational wave detectors to gain insight into the dynamics of inflation and reheating.
hep-phastro-ph.COhep-thJCAP(2024)·10 citations
17*
Dirac leptogenesis from asymmetry wash-in via scatterings
Tomáš Blažek🇸🇰 · Julian Heeck🇺🇸 · Jan Heisig🇩🇪 · Peter Maták🇸🇰 · Viktor Zaujec🇸🇰
Leptogenesis typically requires the introduction of heavy particles whose out-of-equilibrium decays are essential for generating a matter-antimatter asymmetry, according to one of Sakharov's conditions. We demonstrate that in Dirac leptogenesis, scatterings between the light degrees of freedom -- Standard Model particles plus Dirac neutrinos - are sufficient to generate the asymmetry. The generation requires at least two effective charges conserved by the fast Standard Model interactions. Due to its vanishing source term in the Boltzmann equations, the asymmetry of right-handed neutrinos solely arises through wash-in processes. Sakharov's conditions are satisfied because the right-handed neutrino partners are out of equilibrium. Consequently, heavy degrees of freedom never needed to be produced in the early universe, allowing for a reheating temperature well below their mass scale. Considering a minimal leptoquark model, we discuss the viable parameter space along with the potential observational signature of an increased number of effective neutrinos in the early universe.
hep-phastro-ph.COPRD(2024)·6 citations
18*
Seesaw Limit of the Nelson-Barr Mechanism
A. L. Cherchiglia🇧🇷 · A. G. Dias🇧🇷 · J. Leite🇪🇸 · C. C. Nishi🇧🇷
We investigate how the solution to the strong CP problem and the explanation for the observed fermion mass hierarchies can be intrinsically related. Specifically, we explore the Nelson-Barr mechanism and identify its "seesaw limit", where light quark masses are suppressed by large CP-violating terms. Upon adding three (two) vector-like quarks that mix with the down-type (up-type) quark sector of the Standard Model, we demonstrate how the lack of CP violation in the strong sector and the observed quark mass hierarchy can be simultaneously achieved.
hep-phPLB(2025)·4 citations
19*
Position-space renormalization schemes for four-quark operators in HQET
Joshua Lin🇺🇸 · William Detmold🇺🇸 · Stefan Meinel🇺🇸
X-space schemes are gauge-invariant, regulator-independent renormalization schemes that are defined by requiring position-space correlation functions of gauge invariant operators to be equal to their noninteracting values at particular kinematic points. These schemes can be used to nonperturbatively renormalize composite operators in Lattice Quantum Chromodynamics (LQCD), and by computing matching coefficients between the X-space scheme and MSbar in the dimensionally-regulated continuum, matrix elements calculated with LQCD can be converted to MSbar-renormalized matrix elements. Using X-space schemes for Heavy Quark Effective Theory (HQET) operators has the additional benefit that appropriate ratios of position-space correlation functions cancel the power divergent static-quark self-energy of Lattice HQET nonperturbatively. This work presents the O( $α_{S}$ ) matching coefficients between X-space renormalized four-quark flavor-nonsinglet HQET operators relevant for the lifetimes of charm- and bottom-hadrons, and four-quark HQET operators relevant for mixing between neutral mesons containing a heavy quark, such as B-Bbar mixing.
↳ hep-lathep-phJHEP(2024)·6 citations
20*
Confronting the Diversity Problem: The Limits of Galaxy Rotation Curves as a tool to Understand Dark Matter Profiles
Isabel S. Sands · Philip F. Hopkins🇺🇸 · Xuejian Shen🇺🇸 · Michael Boylan-Kolchin🇺🇸 · James Bullock🇺🇸 · Claude-Andre Faucher-Giguere · Francisco J. Mercado · Jorge Moreno🇺🇸 · Lina Necib🇺🇸 · Xiaowei Ou🇺🇸 · Sarah Wellons · Andrew Wetzel🇺🇸
While galaxy rotation curves provide one of the most powerful methods for measuring dark matter profiles in the inner regions of rotation-supported galaxies, at the dwarf scale there are factors that can complicate this analysis. Given the expectation of a universal profile in dark matter-only simulations, the diversity of observed rotation curves has become an often-discussed issue in Lambda Cold Dark Matter cosmology on galactic scales. We analyze a suite of Feedback in Realistic Environments (FIRE) simulations of $1 0^{10} - 1 0^{12}$ $M_{⊙}$ halos with standard cold dark matter, and compare the true circular velocity to rotation curve reconstructions. We find that, for galaxies with well-ordered gaseous disks, the measured rotation curve may deviate from true circular velocity by at most 10% within the radius of the disk. However, non-equilibrium behavior, non-circular motions, and non-thermal and non-kinetic stresses may cause much larger discrepancies of 50% or more. Most rotation curve reconstructions underestimate the true circular velocity, while some reconstructions transiently over-estimate it in the central few kiloparsecs due to dynamical phenomena. We further demonstrate that the features that contribute to these failures are not always visibly obvious in HI observations. If such dwarf galaxies are included in galaxy catalogs, they may give rise to the appearance of "artificial" rotation curve diversity that does not reflect the true variation in underlying dark matter profiles.
↳ astro-ph.GAastro-ph.COhep-phApJ(2026)·13 citations
21*
Standing wave in perturbed anti-de Sitter spacetimes with a naked singularity
Kai Lin🇨🇳 · Wei-Liang Qian🇨🇳
In the framework of black hole perturbation theory, this work investigates the standing wave solutions in Reissner-Nordtsröm (RN) anti-de Sitter (AdS) spacetimes with a naked singularity. These solutions can be viewed as a specific class of quasinormal modes exhibiting distinct characteristics. The imaginary parts of their frequencies are numerically vanishing, allowing them to persist over an extended period. Besides, these modes are predominantly stationary in terms of the evolution of spacetime waveforms. The numerical calculations are carried out employing the finite difference method, and the quasinormal frequencies extracted by the Prony method are shown to be consistent with those obtained using the matrix method. The obtained waveforms and quasinormal frequencies are shown to be drastically different from those of an extreme RN-AdS black hole. As the quasinormal modes are primarily dissipative, the non-dissipative standing waves are attributed to the nature that the singularity can neither be a sink nor a source of the gravitational system.
↳ gr-qchep-phPRD(2024)·1 citation
22*
Deci-Hz gravitational waves from the self-interacting axion cloud around the rotating stellar mass black hole
Hidetoshi Omiya🇯🇵 · Takuya Takahashi🇯🇵 · Takahiro Tanaka🇯🇵 · Hirotaka Yoshino🇯🇵
Gravitational waves from condensates of ultra-light particles, such as axion, around rotating black holes are a promising probe to search for unknown physics. For this purpose, we need to characterize the signal to detect the gravitational waves, which requires tracking the evolution of the condensates, including various effects. The axion self-interaction causes the non-linear coupling between the superradiant modes, resulting in complicated branching of evolution. Most studies so far have considered evolution under the non-relativistic approximation or the two-mode approximation. In this paper, we numerically investigate the evolution of the axion condensate without these approximations, taking higher multipole modes into account. We also investigate the possible signature in gravitational waves from the condensate. We show that the higher multipole modes are excited, leading to the gravitational wave signal by the transition of the axion between different levels. The most prominent signal of gravitational waves arises from the transition between modes with their angular quantum numbers different by two. The gravitational wave signal is emitted in the deci-Hz band for stellar mass black holes, which might be observable with the future gravitational wave detectors.
↳ gr-qcastro-ph.COhep-phPRD(2024)·25 citations
23*
Generalized boost transformations in finite volumes and application to Hamiltonian methods
Yan Li🇨🇾 · Jia-Jun Wu🇨🇳 · T.-S. H. Lee🇺🇸 · R. D. Young🇦🇺
The investigation of hadron interactions within lattice QCD has been facilitated by the well-known quantisation condition, linking scattering phase shifts to finite-volume energies. Additionally, the ability to utilise systems at finite total boosts has been pivotal in smoothly charting the energy-dependent behaviour of these phase shifts. The existing implementations of the quantization condition at finite boosts rely on momentum transformations between rest and moving frames, defined directly in terms of the energy eigenvalues. This energy dependence is unsuitable in the formulation of a Hamiltonian.In this work, we introduce a novel approach to generalise the three-momentum boost prescription, enabling the incorporation of energy-independent finite-volume Hamiltonians within moving frames. We demonstrate the application of our method through numerical comparisons, employing a phenomenological $π π$ scattering example.
↳ hep-lathep-phJHEP(2024)·6 citations
24*
Cosmological probes of Dark Radiation from Neutrino Mixing
Itamar J. Allali🇺🇸 · Daniel Aloni🇺🇸 · Nils Schöneberg🇪🇸
Models of stepped dark radiation have recently been found to have an important impact on the anisotropies of the cosmic microwave background, aiding in easing the Hubble tension. In this work, we study models with a sector of dark radiation with a step in its abundance, which thermalizes after big bang nucleosynthesis by mixing with the standard model neutrinos. For this, we extend an earlier work which has focused on the background evolution only until the dark sector thermalizes by deriving the full background and perturbation equations of the model and implementing them in an Einstein-Boltzmann solving code. We expound on the behavior of this model, discussing the wide range of parameters that result in interesting and viable cosmologies that dynamically generate dark radiation during a range of epochs. We find that for the strongly self-coupled regime, there is no large cosmological impact for a tight prior on the mass, whereas larger mass ranges allow a smooth interpolation between a behavior close to the $Λ$ CDM cosmological standard model and close to an additional component of strongly self-interacting dark radiation. In the weakly self-coupled regime we find that we can accommodate a parameter space relevant for the neutrino anomalies as well as one relevant to easing the Hubble tension.
↳ astro-ph.COhep-phJCAP(2024)·27 citations
25*
Charged pion vortices in rotating systems
D. N. Voskresensky🇷🇺
Possibilities for formation of the charged pion field vortices in a rotating empty vessel (in vacuum) and in the rotating pion gas with a dynamically fixed particle number at zero temperature are studied within the $λ ∣ ϕ ∣^{4}$ model. It is shown that in the former case at a rapid rotation a supervortex of a charged pion field can be formed. Important role played by the electric field is demonstrated. Field configurations in presence and absence of the pion self-interaction are found. Conditions for formation of the vortex lattice at the rotation of the charged pion gas at zero temperature are studied. Observational effects are discussed.
↳ nucl-thcond-mat.quant-gashep-phPhys.Part.Nucl.Lett.(2024)·6 citations
26*
Searches for Supersymmetry (SUSY) at the Large Hadron Collider
Sophie Kadan🇺🇸
This paper provides an overview of supersymmetry (SUSY) and the ongoing efforts to detect SUSY particles at the Large Hadron Collider (LHC). SUSY proposes corresponding "sparticles" for each Standard Model particle, with the potential to resolve the hierarchy problem, identify dark matter, and unify forces at high energy scales. We explore the key observables central to SUSY searches at the LHC, such as effective mass ( $M_{eff}$ ), scalar sum of transverse momenta ( $H_{T}$ ), and stransverse mass ( $M_{T 2}$ )--each of which is instrumental in distinguishing SUSY particles by their mass scales and decay characteristics. The paper also discusses the challenges of differentiating SUSY signals from Standard Model backgrounds, particularly in scenarios without significant missing transverse momentum ( $E_{T}^{miss}$ ). A critical aspect of these searches is achieving high signal purity while effectively managing background detection. The LHC employs sophisticated detection techniques to enhance the signal-to-noise ratio--crucial for isolating genuine SUSY events from prevalent Standard Model processes such as multijet productions, gauge bosons with jets, and top quark pairs. Through this examination, the paper aims to illuminate the challenges and potential breakthroughs in SUSY searches, assessing their broader implications for fundamental physics.
↳ hep-exhep-ph5 citations
27*
Flavor's Delight
Hans Peter Nilles🇩🇪 · Saul Ramos-Sanchez🇲🇽
Discrete flavor symmetries provide a promising approach to understand the flavor sector of the standard model of particle physics. Top-down (TD) explanations from string theory reveal two different types of such flavor symmetries: traditional and modular flavor symmetries that combine to the eclectic flavor group. There have been many bottom-up (BU) constructions to fit experimental data within this scheme. We compare TD and BU constructions to identify the most promising groups and try to give a unified description. Although there is some progress in joining BU and TD approaches, we point out some gaps that have to be closed with future model building.
↳ hep-thhep-phEntropy(2024)·7 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.