HEP Phenomenology·hep-ph

Wed·Feb 15, 2023Wednesday·February 15, 2023

22 papers—19 primary·3 cross-listed·reconstructed*

01*
Thermalization in the presence of a time-dependent dissipation and its impact on dark matter production
Debtosh Chowdhury🇮🇳 · Arpan Hait🇮🇳
In standard cosmological scenarios, a heavy meta-stable field dominates the energy density of the universe after inflation. The dissipation of this field continuously sources high-energy particles. In general, the dissipation rate of this meta-stable field can have a non-trivial time dependence. We study the impact of this time-dependent dissipation rate on the thermalization of the high-energy decay products of the meta-stable field. These energetic particles can contribute substantially to dark matter production in addition to the usual production from the thermal bath particles during reheating. We investigate the impact of this generalized dissipation on dark matter production in a model-independent way. We illustrate the parameter space that explains the observed dark matter relic abundance in various cosmological scenarios. We observed that dark matter having a mass larger than the maximum temperature attained by the thermal bath can be produced from the collision of the high-energy particles which are not yet thermalized.
hep-phastro-ph.COJHEP(2023)·39 citations
02*
SMEFiT: a flexible toolbox for global interpretations of particle physics data with effective field theories
Tommaso Giani🇳🇱 · Giacomo Magni🇳🇱 · Juan Rojo🇳🇱
The Standard Model Effective Field Theory (SMEFT) provides a robust framework to interpret experimental measurements in the context of new physics scenarios while minimising assumptions on the nature of the underlying UV-complete theory. We present the Python open source SMEFiT framework, designed to carry out parameter inference in the SMEFT within a global analysis of particle physics data. SMEFiT is suitable for inference problems involving a large number of EFT degrees of freedom, without restrictions on their functional dependence in the fitted observables, can include UV-inspired restrictions in the parameter space, and implements arbitrary rotations between operator bases. Posterior distributions are determined from two complementary approaches, Nested Sampling and Monte Carlo optimisation. SMEFiT is released together with documentation, tutorials, and post-analysis reporting tools, and can be used to carry out state-of-the-art EFT fits of Higgs, top quark, and electroweak production data. To illustrate its functionalities, we reproduce the results of the recent ATLAS EFT interpretation of Higgs and electroweak data from Run II and demonstrate how equivalent results are obtained in two different operator bases.
hep-phhep-exEPJC(2023)·73 citations
03*
Constructing the $J^{P (C)} = 1^{- (+)}$ light flavor hybrid nonet with the newly observed $η_{1} (1855)$
Bing Chen🇨🇳 · Si-Qiang Luo🇨🇳 · Xiang Liu🇨🇳
The recently discovered $η_{1} (1855)$ and the previously observed $π_{1} (1600)$ state present a valuable opportunity for the investigation of the $J^{P (C)} = 1^{- (+)}$ light hybrid nonet. In this study, we employ a semirelativistic quark potential model to examine the masses of the $J^{P (C)} = 1^{- (+)}$ light hybrid states. The static potential, which portrays the confinement force between the quark-antiquark pair in a hybrid system, is borrowed from the SU $(3)$ lattice gauge theory. Additionally, we utilize a constituent gluon model to analyze the strong decay characteristics of these light $1^{-+}$ hybrids. Our findings suggest that the $π_{1} (1600)$ and $η_{1} (1855)$ states could be potential candidates for $1^{-+}$ $(u u ˉ - d d ˉ) g / 2$ and $s s ˉ g$ hybrids, respectively. To ensure comprehensiveness, we also investigate the isospin partners of the $π_{1} (1600)$ and $η_{1} (1855)$ states within the $1^{- (+)}$ nonet $-$ specifically, the $(u u ˉ + d d ˉ) g / 2$ and $s q ˉ g$ ( $q = u$ and $d$ quarks) states. We propose some potential decay channels which could be explored in experimental settings to detect these undiscovered states.
hep-phPRD(2023)·21 citations
04*
Regge trajectory relations for the universal description of the heavy-light systems: diquarks, mesons, baryons and tetraquarks
Jiao-Kai Chen🇨🇳
Two newly proposed Regge trajectory relations are employed to analyze the heavy-light systems. One of the relations is $M = m_{1} + m_{2} + C^{'} + β_{x} x + c_{0 x}$ , $(x = l, n_{r})$ . Another reads $M = m_{1} + C^{'} + β_{x}^{2} (x + c_{0 x}) + \frac{4}{3} π β_{x} m_{2}^{3/2} (x + c_{0 x})^{1/4}$ . $M$ is the bound state mass. $m_{1}$ and $m_{2}$ are the masses of the heavy constituent and the light constituent, respectively. $l$ is the orbital angular momentum and $n_{r}$ is the radial quantum number. $β_{x}$ and $c_{0 x}$ are fitted. $m_{1}$ , $m_{2}$ and $C^{'}$ are input parameters. These two formulas consider both of the masses of heavy constituent and light constituent. We find that the heavy-light diquarks, the heavy-light mesons, the heavy-light baryons and the heavy-light tetraquarks satisfy these two formulas. When applying the first formula, the heavy-light systems satisfy the universal description irrespective of both of the masses of the light constituents and the heavy constituent. When using the second relation, the heavy-light systems satisfy the universal description irrespective of the mass of the heavy constituent. The fitted slopes differ distinctively for the heavy-light mesons, baryons and tetraquarks, respectively. When employing the first relation, the average values of $c_{f n_{r}}$ ( $c_{f l}$ ) are $1.026$ , $0.794$ and $0.553$ ( $1.026$ , $0.749$ and $0.579$ ) for the heavy-light mesons, the heavy-light baryons and the heavy-light tetraquarks, respectively. Upon application of the second relation, the mean values of $c_{f n_{r}}$ ( $c_{f l}$ ) are $1.108$ , $0.896$ and $0.647$ ( $1.114$ , $0.855$ and $0.676$ ) for the heavy-light mesons, the heavy-light baryons and the heavy-light tetraquarks, respectively. Moreover, the fitted results show that the Regge trajectories for the heavy-light systems are concave downwards in the $(M^{2}, n_{r})$ and $(M^{2}, l)$ planes.
hep-phEPJC(2024)·17 citations
05*
Heavy baryons in the Chiral Quark-Soliton Model
Michal Praszalowicz🇵🇱
We review applications of the Chiral Quark Soliton Model to heavy baryons and to doubly heavy tetraquarks.
hep-phActa Phys.Polon.Supp.(2023)·0 citations
06*
Chiral soliton lattice at next-to-leading order
Tomáš Brauner🇳🇴 · Helena Kolešová🇳🇴
We compute the free energy of the chiral soliton lattice state in quantum chromodynamics (QCD) at nonzero baryon chemical potential, temperature and external magnetic field at the next-to-leading order of chiral perturbation theory. This extends previous work where only a special limit of the chiral soliton lattice, the domain wall, was considered. Our results therefore serve as a consistency check of the previously established phase diagram of QCD at moderate magnetic fields and temperature and sub-nuclear baryon chemical potentials. Moreover, we use the result for the free energy to determine the magnetization carried by the domain wall and the chiral soliton lattice, both at the next-to-leading order.
hep-phhep-thJHEP(2023)·23 citations
07*
Jet substructure in neutral current deep inelastic e+p scattering at upcoming Electron-Ion Collider
Siddharth Jain🇮🇳 · R. Aggarwal🇮🇳 · M. Kaur🇮🇳
Predictions are made for the jet substructure of one-jet events produced in electron-proton neutral current deep inelastic scattering at the future Electron-Ion Collider for exchanged four-momentum squared, $Q^{2} > 125$ GeV $^{2}$ . Data are simulated using Monte Carlo event generators PYTHIA 8.304 and RAPGAP 3.308 at the center of mass energies $s$ = 63.2, 104.9 and 141 GeV. Jets and subjets are produced by longitudinally invariant $k_{T}$ cluster algorithm. The subjet multiplicity distributions and differential jet shapes are measured for different jet sizes and varying jet-resolution parameter. A comparison is presented between the $k_{T}$ and anti- $k_{T}$ cluster algorithms for the study of jets and subjets using the simulated data and the HERA data.
hep-phPRD(2023)·2 citations
08*
Fermionic dark matter-photon quantum interaction: A mechanism for darkness
G. B. de Gracia🇧🇷 · A. A. Nogueira🇧🇷 · R. da Rocha🇧🇷
Mass dimension one fermionic fields are prime candidates to describe dark matter, due to their intrinsic neutral nature, as they are constructed as eigenstates of the charge conjugation operator with dual helicity. To formulate the meaning of the darkness, the fermion-photon coupling is scrutinized with a Pauli-like interaction, and the path integral is then formulated from the phase space constraint structure. Ward-Takahashi-like identities and Schwinger-Dyson equations, together with renormalizability, are employed to investigate a phenomenological mechanism to avoid external light signals. Accordingly, the non-polarized pair annihilation and Compton-like processes are shown to vanish at the limit of small scattering angles even if considering 1-loop radiative corrections, reinforcing the dark matter interpretation. However, dark matter interactions with nucleons are still possible. Motivated by recent nucleon-recoil experiments to detect dark matter, we furnish a consistent theoretical setup to describe interaction with the photon compatible with the prevalence of darkness.
hep-phhep-thNPB(2023)·15 citations
09*
Gravitational capture of magnetic monopoles by primordial black holes in the early universe
Chen Zhang🇺🇸 · Xin Zhang🇺🇸
It is intriguing to ask whether the existence of primordial black holes (PBHs) in the early universe could significantly reduce the abundance of certain stable massive particles (SMP) via gravitational capture, after which the PBHs evaporate before BBN to avoid conflict with stringent bounds. For example, this mechanism is relevant to an alternative solution of the monopole problem proposed by Stojkovic and Freese, in which magnetic monopoles produced in the early universe are captured by PBHs, thus freeing inflation from having to occur during or after the corresponding phase transitions that produced the monopoles. In this work, we reanalyze the solution by modelling the capture process in the same way as the coexisting monopole annihilation. A subtle issue which is not handled properly in the previous literature is the choice of an effective capture cross section for diffusive capture. We model this aspect properly and justify our treatment. A monochromatic PBH mass function and a radiation-dominated era before PBH evaporation are assumed. We find that for Pati-Salam monopoles corresponding to a symmetry breaking scale between $1 0^{10} GeV$ and $1 0^{15} GeV$ , the capture rate is many orders of magnitude below what is needed to cause a significant reduction of the monopole density. Within our assumptions, we also find that the magnetic charge that is large enough to make an extremal magnetic black hole cosmologically stable cannot be obtained from magnetic charge fluctuation via monopole capture. The large magnetic charged required by cosmological stability can nevertheless be obtained from magnetic charge fluctuation at PBH formation, and if later the monopole abundance can be reduced significantly by some non-inflationary mechanism, long-lived near-extremal magnetic black holes of observational relevance might result.
hep-phastro-ph.COastro-ph.HEgr-qc+1JHEP(2023)·16 citations
10*
A hidden gauged $U (1)$ addressing radiative neutrino mass, dark matter, $(g - 2)_{μ}$ , and $H_{0}$ tension
Ujjal Kumar Dey🇮🇳 · Hiroshi Okada🇰🇷
We propose a radiative seesaw model with a hidden $U (1)$ gauge symmetry. In order to have anomaly cancellations, we need to introduce several new fermions that contribute to muon anomalous magnetic dipole moment $(g - 2)_{μ}$ as well as explain the neutrino oscillation data. We also consider a fermionic dark matter candidate that correlates with $(g - 2)_{μ}$ and neutrino mass matrix at the same time. We show allowed regions in our input parameters satisfying several constraints. Finally, we also briefly discuss the possibility of the resolution of the Hubble tension via neutrino self-interactions mediated by a lighter hidden gauge boson without spoiling our model.
hep-ph0 citations
11*
Bottomonium vector resonances and threshold effects
E. van Beveren🇵🇹 · G. Rupp🇵🇹
The bottomonium spectrum is the perfect testing ground for the confining potential and unitarisation effects. The bottom quark is about three times heavier than the charm quark, so that $b b ˉ$ systems probe primarily the short-range part of that potential. Also, the much smaller colour-hyperfine interaction in the $B$ mesons make the $B B ˉ$ threshold lie significantly higher than the $D D ˉ$ threshold in charmonium, on a relative scale of course. A further complicating circumstance is that none of the experimentally observed vector $b b ˉ$ mesons has been positively identified as a $^{3} D_{1}$ state, contrary to the situation in charmonium. This makes definite conclusions about level splittings very problematic. Finally, there are compelling indications that the $Υ (10580)$ is not the $Υ (4 S)$ state, as is generally assumed. Here we review an analysis of experimental bottomonium data which show indications of the two lowest and so far unlisted $^{3} D_{1}$ states below the $B B ˉ$ threshold. Next an empirical modelling of vector $b b ˉ$ resonances above the open-bottom threshold is revisited, based on the Resonance-Spectrum-Expansion production formalism applied to other experimental data. A recent effective-Lagrangian study supporting our non-resonant assignment of the $Υ (10580)$ is briefly discussed as well.
hep-phhep-exActa Phys.Polon.Supp.(2023)·0 citations
12*
The oblique parameters in the 2HDM with Vector-Like Quarks: Confronting $M_{W}$ CDF-II Anomaly
Hamza Abouabid (1)🇲🇦 · Abdesslam Arhrib (1)🇲🇦 · Rachid Benbrik (2)🇲🇦 · Mohammed Boukidi (2)🇲🇦 · Jaouad El Falaki (3)((1) Université Abdelmalek Essaadi, FSTT, Tangier, Morocco, (2) Polydisciplinary Faculty, Laboratory of Fundamental and Applied Physics, Cadi Ayyad University, Sidi Bouzid, Safi, Morocco, (3) LPTHE, Physics Department, Faculty of Sciences, Ibn Zohr University, Agadir, Morocco)🇲🇦
The CDF collaboration has released a new measurement of the $W$ boson mass using their complete data set with 8.8 fb $^{- 1}$ in $p p ˉ$ collisions. This result deviates from the Standard Model prediction by around 7 $σ$ . We explain how the two Higgs doublet model (2HDM) with vector-like quarks is affected by the recently discovered W boson mass. In our study, we include both theoretical constraints such as perturbative unitarity and vacuum stability as well as a number of experimental constraints. We also look into how the effective mixing angle, measured by the SLD collaboration in addition to the CDF W-boson mass, is used to determine the $S$ and $T$ parameters. In the alignment limit, we investigate the case where the lighter CP-even neutral Higgs boson of the 2HDM is the one found at the LHC and demonstrate how the parameter space of the 2HDM type II in the presence of vector-like quarks is constrained. It is found that in most cases, there is a cancellation between the 2HDM and vector-like quarks contributions, which enlarges the parameter space of both models.
hep-phJ.Phys.G(2024)·26 citations
13*
Improved sensitivities of ESS $ν$ SB from a two-detector fit
F. Capozzi🇮🇹 · C. Giunti🇮🇹 · C.A. Ternes🇮🇹
We discuss the improvement of the sensitivity of ESS $ν$ SB to the discovery of CP violation and to new neutrino physics which can be obtained with a two-detector fit of the data of the near and far detectors. In particular, we consider neutrino non-standard interactions generated by very heavy vector mediators, nonunitary neutrino mixing, and neutrino oscillations due to the mixing of the ordinary active neutrinos with a light sterile neutrino.
hep-phhep-exJHEP(2023)·13 citations
14*
Sub-leading twist transverse momentum dependent parton distributions in the light-front quark-diquark model
Shubham Sharma🇮🇳 · Narinder Kumar🇮🇳 · Harleen Dahiya🇮🇳
In this study, the T-even sub-leading twist transverse momentum dependent distributions (TMDs) of proton in the light-front quark-diquark model (LFQDM) have been investigated. We have derived the overlap form of the light-front wave functions (LFWFs) for the sub-leading twist proton TMDs by detangling the un-integrated quark-quark correlator for the semi-inclusive deep inelastic scattering (SIDIS). We have obtained the explicit expressions of TMDs for both the cases of the diquark being a scalar or a vector and analysed their relationships with leading twist TMDs within the same model. Average transverse momenta and average square transverse momenta for the TMDs have been tabulated and compared with the results from the light-front bag model and the light-front constituent quark model (LFCQM). In addition to this, we have also compared our results for the PDF $e (x)$ with the recent CLAS collaboration results.
hep-phNPB(2023)·20 citations
15*
Central exclusive diffractive production of a single photon in high-energy proton-proton collisions within the tensor-Pomeron approach
Piotr Lebiedowicz🇵🇱 · Otto Nachtmann🇩🇪 · Antoni Szczurek🇵🇱
We discuss central-exclusive production (CEP) of photons via different fusion processes in the reaction $pp \to pp γ$ at high energies, available at RHIC and LHC, within the tensor-pomeron model. We consider two types of processes, the photoproduction contribution via the photon-pomeron and photon-reggeon fusion reactions, and the purely diffractive contribution via the reggeon-pomeron and odderon-pomeron fusion reactions. We present predictions for the measurements of photons at midrapidity, $∣ y ∣ < 2.5$ , and at relatively low transverse momentum, $0.1 GeV < k_{⊥} < 1 GeV$ . To check the main results of our study the measurement of the outgoing protons is not necessary. This is of relevance, e.g., for the present version of the ALICE detector at the LHC. Several differential distributions, for instance, in $y$ , $k_{⊥}$ and $ω$ , the rapidity, the absolute value of the transverse momentum, and the energy of the photon, respectively, are presented. We show that the photoproduction is an important process in the kinematic region specified above. There it gives a much larger cross section than diffractive bremsstrahlung. This is remarkable as the CEP cross section is of order $α_{em}^{3}$ whereas the bremsstrahlung one is only of order $α_{em}$ . On the other hand, the soft-photon bremsstrahlung where the basic $pp \to pp$ reaction is due to strong interaction diffraction is more important than CEP in the forward rapidity range, $∣ y ∣ > 4$ , and/or at very low $k_{⊥}$ . We leave it as a challenge for the planned ALICE 3 experiment at the LHC to study these two contributions to soft photon production in $pp$ collisions. This could shed new light on the so called ``soft photon puzzle'' in hadron-hadron collisions.
hep-phhep-exPRD(2023)·10 citations
16*
Dark top partner
Haiying Cai🇰🇷 · Giacomo Cacciapaglia🇫🇷
Composite Higgs models with extended symmetries can feature mesonic dark matter candidates. In fundamental CHMs, the origin of dark parity can be explained in the UV theory. Combined with top partial compositeness, this leads to non-chiral Yukawa interaction connecting mesonic DM with one dark top partner and one SM top. We examine the DM phenomenology in SU(6)/SO(6) and SU(6)/Sp(6) CHMs with the presence of dark top partners. Phenomenological constraints require the mass of top partner in even parity to be of the multi-TeV order.
hep-phJHEP(2023)·1 citation
17*
Complex $S_{3}$ -symmetric 3HDM
A. Kunčinas🇵🇹 · O. M. Ogreid🇳🇴 · P. Osland🇳🇴 · M. N. Rebelo🇵🇹
CP violation plays a very important role in nature with implications both for Particle Physics and for Cosmology. Accounting for the observed matter anti-matter asymmetry of the Universe requires the existence of new sources of CP violation beyond the Standard Model. In models with an extended scalar sector CP violation can emerge either explicitly, i.e., at the Lagrangian level, or spontaneously. In the context of multi-Higgs extensions of the Standard Model imposing the existence of a scalar basis where all couplings are real is a sufficient condition for CP to be explicitly conserved. We discuss a three-Higgs-doublet model with an underlying $S_{3}$ symmetry, allowing in principle for complex couplings. In this framework it is possible to have either spontaneous or explicit CP violation in the scalar sector, depending on the regions of parameter space corresponding to the different possible vacua of the $S_{3}$ symmetric potential. We list all possible vacuum structures allowing for CP violation in the scalar sector specifying whether it can be explicit or spontaneous. It is by now established that CP is violated in the flavour sector and that the Cabibbo-Kobayashi-Maskawa matrix is complex. In order to understand what are the possible sources of CP violation in the Yukawa sector we analyse the implications of the different available choices of representations for the quarks under the $S_{3}$ group. This classification is based strictly on the exact $S_{3}$ -symmetric scalar potential with no soft symmetry breaking terms. The scalar sector of one such model was explored numerically. After applying the theoretical and the most important experimental constraints the available parameter space is shown to be able to give rise to light neutral scalars at the $O (MeV)$ scale.
hep-phJHEP(2023)·20 citations
18*
Searching for Low-Mass Resonances Decaying into $W$ Bosons
Guglielmo Coloretti🇨🇭 · Andreas Crivellin🇨🇭 · Srimoy Bhattacharya🇿🇦 · Bruce Mellado🇿🇦
In this article, we recast and combine the CMS and ATLAS analyses of the Standard Model Higgs boson decaying to a pair of $W$ bosons in order to search for low-mass resonances in this channel. We provide limits on the corresponding cross section assuming direct production via gluon fusion. For the whole range of masses we consider (90GeV to 200GeV), the observed limit on the cross section turns out to be weaker than the expected one. Furthermore, at $\approx 95$ GeV the limit is weakest and a new scalar decaying into a pair of $W$ bosons (which subsequently decay leptonically) with a cross section $\approx 0.5$ pb is preferred over the Standard Model hypothesis by $≳ 2.5 σ$ . In light of the excesses in the $γ γ$ , $τ^{+} τ^{-}$ and $b b ˉ$ channels at similar masses, this strengthens the case for such a new Higgs boson. Furthermore, this analysis also gives room for the scalar candidate at 151GeV decaying into $W$ bosons.
hep-phhep-exPRD(2023)·60 citations
19*
Generalized parton distributions through universal moment parameterization: non-zero skewness case
Yuxun Guo🇺🇸 · Xiangdong Ji🇺🇸 · M. Gabriel Santiago🇺🇸 · Kyle Shiells🇨🇦 · Jinghong Yang🇺🇸
We present the first global analysis of generalized parton distributions (GPDs) combing lattice quantum chromodynamics (QCD) calculations and experiment measurements including global parton distribution functions (PDFs), form factors (FFs) and deeply virtual Compton scattering (DVCS) measurements. Following the previous work where we parameterize GPDs in terms of their moments, we extend the framework to allow for the global analysis at non-zero skewness. Together with the constraints at zero skewness, we fit GPDs to global DVCS measurements from both the recent JLab and the earlier Hadron-Electron Ring Accelerator (HERA) experiments with two active quark flavors and leading order QCD evolution. With certain choices of empirical constraints, both sea and valence quark distributions are extracted with the combined inputs, and we present the quark distributions in the proton correspondingly. We also discuss how to extend the framework to accommodate more off-forward constraints beyond the small $ξ$ expansion, especially the lattice calculated GPDs.
hep-phnucl-thJHEP(2023)·61 citations
20*
Gravitational waves from defect-driven phase transitions: domain walls
Simone Blasi🇧🇪 · Ryusuke Jinno🇪🇸 · Thomas Konstandin🇩🇪 · Henrique Rubira🇩🇪 · Isak Stomberg🇩🇪
We discuss the gravitational wave spectrum produced by first-order phase transitions seeded by domain wall networks. This setup is important for many two-step phase transitions as seen for example in the singlet extension of the standard model. Whenever the correlation length of the domain wall network is larger than the typical bubble size, this setup leads to a gravitational wave signal that is shifted to lower frequencies and with an enhanced amplitude compared to homogeneous phase transitions without domain walls. We discuss our results in light of the recent PTA hints for gravitational waves.
↳ astro-ph.COhep-phJCAP(2023)·54 citations
21*
Perturbative analysis of the Wess-Zumino flow
Daisuke Kadoh🇯🇵 · Kengo Kikuchi🇯🇵 · Naoya Ukita🇯🇵
We investigate an interacting supersymmetric gradient flow in the Wess-Zumino model. Thanks to the nonrenormalization theorem and an appropriate initial condition, we find that any correlator of flowed fields is ultraviolet finite. This is shown at all orders of the perturbation theory using the power counting theorem for one-particle irreducible supergraphs. Since the model does not have the gauge symmetry, the mechanism of realizing the ultraviolet finiteness is quite different from that of the Yang-Mills flow, and this could provide further understanding of the gradient flow approach.
↳ hep-thhep-lathep-phPRD(2023)·2 citations
22*
$^{113}$ Cd $β$ -decay spectrum and $g_{A}$ quenching using spectral moments
Joel Kostensalo🇫🇮 · Eligio Lisi🇮🇹 · Antonio Marrone🇮🇹 · Jouni Suhonen🇫🇮
We present an alternative analysis of the $^{113}$ Cd $β$ -decay electron energy spectrum in terms of spectral moments $μ_{n}$ , corresponding to the averaged values of $n^{th}$ powers of the $β$ particle energy. The zeroth moment $μ_{0}$ is related to the decay rate, while higher moments $μ_{n}$ are related to the spectrum shape. The here advocated spectral-moment method (SMM) allows for a complementary understanding of previous results, obtained using the so-called spectrum-shape method (SSM) and its revised version, in terms of two free parameters: $r = g_{A} / g_{V}$ (the ratio of axial-vector to vector couplings) and $s$ (the small vector-like relativistic nuclear matrix element, $s$ -NME). We present numerical results for three different nuclear models with the conserved vector current hypothesis (CVC) assumption of $g_{V} = 1$ . We show that most of the spectral information can be captured by the first few moments which are simple quadratic forms (conic sections) in the $(r, s)$ plane: an ellipse for $n = 0$ and hyperbolae for $n \geq 1$ , all being nearly degenerate as a result of cancellations among nuclear matrix elements. The intersections of these curves, as obtained by equating theoretical and experimental values of $μ_{n}$ , identify the favored values of $(r, s)$ at a glance, without performing detailed fits. In particular, we find that values around $r \sim 1$ and $s \sim 1.6$ are consistently favored in each nuclear model, confirming the evidence for $g_{A}$ quenching in $^{113}$ Cd, and shedding light on the role of the $s$ -NME. We briefly discuss future applications of the SMM to other forbidden $β$ -decay spectra sensitive to $g_{A}$ .
↳ nucl-thhep-exhep-phnucl-exPRC(2023)·18 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.