HEP Phenomenology·hep-ph

Tue·Sep 20, 2022Tuesday·September 20, 2022

47 papers—32 primary·15 cross-listed·reconstructed*

01*
Parton Distributions and New Physics Searches: the Drell-Yan Forward-Backward Asymmetry as a Case Study
Richard D. Ball🇬🇧 · Alessandro Candido🇮🇹 · Stefano Forte🇮🇹 · Felix Hekhorn🇮🇹 · Emanuele R. Nocera🇮🇹 · Juan Rojo🇳🇱 · Christopher Schwan🇩🇪
We discuss the sensitivity of theoretical predictions of observables used in searches for new physics to parton distributions (PDFs) at large momentum fraction $x$ . Specifically, we consider the neutral-current Drell-Yan production of gauge bosons with invariant masses in the TeV range, for which the forward-backward asymmetry of charged leptons from the decay of the gauge boson in its rest frame is a traditional probe of new physics. We show that the qualitative behaviour of the asymmetry depends strongly on the assumptions made in determining the underlying PDFs. We discuss and compare the large- $x$ behaviour of various different PDF sets, and find that they differ significantly. Consequently, the shape of the asymmetry observed at lower dilepton invariant masses, where all PDF sets are in reasonable agreement because of the presence of experimental constraints, is not necessarily reproduced at large masses where the PDFs are mostly unconstrained by data. It follows that the shape of the asymmetry at high masses may depend on assumptions made in the PDF parametrization, and thus deviations from the traditionally expected behaviour cannot be taken as a reliable indication of new physics. We demonstrate that forward-backward asymmetry measurements could help in constraining PDFs at large $x$ and discuss the accuracy that would be required to disentangle the effects of new physics from uncertainties in the PDFs in this region.
hep-phhep-exEPJC(2022)·53 citations
02*
Report of the Topical Group on Wave Dark Matter for Snowmass 2021
Joerg Jaeckel🇩🇪 · Gray Rybka🇺🇸 · Lindley Winslow🇺🇸
There is a strong possibility that the particles making up the dark matter in the Universe have a mass below 1 eV and in many important situations exhibit a wave-like behavior. Amongst the candidates the axion stands out as particularly well motivated but other possibilities such as axion-like particles, light scalars and light vectors, should be seriously investigated with both experiments and theory. Discovery of any of these dark matter particles would be revolutionary. The wave-like nature opens special opportunities to gain precise information on the particle properties a well as astrophysical information on dark matter shortly after a first detection. To achieve these goals requires continued strong support for the next generations of axion experiments to probe significant axion parameter space this decade and to realize the vision of a definitive axion search program in the next 20 years. This needs to be complemented by strong and flexible support for a broad range of smaller experiments, sensitive to the full variety of wave-like dark matter candidates. These have their own discovery potential but can also be the test bed for future larger scale searches. Strong technological support not only allows for the optimal realization of the current and near future experiments but new technologies such as quantum measurement and control can also provide the next evolutionary jump enabling a broader and deeper sensitivity. Finally, a theory effort ranging from fundamental model building over investigating phenomenological constraints to the conception of new experimental techniques is a cornerstone of the current rapid developments in the search for wave-like dark matter and should be strengthened to have a solid foundation for the future.
hep-phhep-ex19 citations
03*
Tachyons as a Consequence of Light-Cone Reflection Symmetry
Alan Chodos🇺🇸
We introduce a new symmetry, Light-Cone Reflection (LCR), which interchanges timelike and spacelike intervals. Our motivation is to provide a reason, based on symmetry, why tachyons might exist, with emphasis on application to neutrinos. We show that LCR, combined with translations, leads to a much larger symmetry. We construct an LCR-invariant Lagrangian, and discuss some of its properties. In a simple example, we find complete symmetry in the spectrum between tachyons and ordinary particles. We also show that the theory allows for the introduction of a further gauge invariance related to chiral symmetry.
hep-phhep-thSymmetry(2022)·2 citations
04*
Report of the Topical Group on Cosmic Probes of Dark Matter for Snowmass 2021
Alex Drlica-Wagner🇺🇸 · Chanda Prescod-Weinstein🇺🇸 · Hai-Bo Yu🇺🇸 · Andrea Albert🇺🇸 · Mustafa Amin🇺🇸 · Arka Banerjee🇮🇳 · Masha Baryakhtar🇺🇸 · Keith Bechtol🇺🇸 · Simeon Bird🇺🇸 · Simon Birrer🇺🇸 · Torsten Bringmann🇳🇴 · Regina Caputo🇺🇸 and 28 other authors
Cosmological and astrophysical observations currently provide the only robust, positive evidence for dark matter. Cosmic probes of dark matter, which seek to determine the fundamental properties of dark matter through observations of the cosmos, have emerged as a promising means to reveal the nature of dark matter. This report summarizes the current status and future potential of cosmic probes to inform our understanding of the fundamental nature of dark matter in the coming decade.
hep-phastro-ph.COhep-ex40 citations
05*
Asymmetric Mediator in Scotogenic Model
Kento Asai🇯🇵 · Yuhei Sakai🇯🇵 · Joe Sato🇯🇵 · Yasutaka Takanishi🇯🇵 · Masato Yamanaka🇯🇵
The scotogenic model is the Standard Model (SM) with Z_2 symmetry and the addition of Z_2 odd right-handed Majorana neutrinos and SU(2)_L doublet scalar fields. We have extended the original scotogenic model by an additional Z_2 odd singlet scalar field that plays a role in dark matter. In our model, the asymmetries of the lepton and Z_2 odd doublet scalar are simultaneously produced through CP-violating right-handed neutrino decays. While the former is converted into baryon asymmetry through the sphaleron process, the latter is relaid to the DM density through the decay of SU(2)_L doublet scalar that is named "asymmetric mediator". In this way, we provide an extended scotogenic model that predicts the energy densities of baryon and dark matter being in the same order of magnitude, and also explains the low-energy neutrino masses and mixing angles.
hep-phastro-ph.HEPLB(2023)·3 citations
06*
Interpreting the $W$ -mass anomaly in the vectorlike quark models
Junjie Cao · Lei Meng · Liangliang Shang · Shiyu Wang · Bingfang Yang
The new measurement of $W$ -boson mass by the CDF collaboration revealed a remarkable $7 σ$ disagreement with the Standard Model (SM) prediction. If confirmed by other experiments, then the disagreement strongly indicates the existence of new physics beyond the SM. In this work, seven vectorlike quark (VLQ) extensions of the SM are investigated to interpret the anomaly, and it is found that three can explain the anomaly in broad parameter space. The explanations are consistent with the constraints from oblique parameters, the LHC search for VLQs, the measurements of the properties for the top quark, bottom quark, and Higgs boson, and the perturbativity criterion. The typical size of the involved Yukawa coupling is around 1, which is comparable to the top quark Yukawa coupling in the SM. The other extensions, however, either predict a negative correction to the mass in reasonable parameter space or explain the anomaly by unnatural theoretical input parameters.
hep-ph
07*
Formulating E- & T-Model Inflation in Supergravity
C. Pallis🇬🇷
We present novel realizations of E- and T-model inflation within Supergravity which are largely associated with the existence of a pole of order one and two respectively in the kinetic term of the inflaton superfield. This pole arises due to the selected logarithmic Kahler potentials K, which parameterize hyperbolic manifolds with scalar curvature related to the coefficient (-N)<0 of a logarithmic term. The associated superpotential W exhibits the same R charge with the inflaton-accompanying superfield and includes all the allowed terms. The role of the inflaton can be played by a gauge singlet or non-singlet superfield. Models with one logarithmic term in K for the inflaton, require N=2, some tuning -- of the order of 10^-5 -- between the terms of W and predict a tensor-to-scalar ratio r at the level of 0.001. The tuning can be totally eluded for more structured K's, with N values increasing with r and spectral index close or even equal to its present central observational value.
hep-phastro-ph.COhep-thJ.Phys.Conf.Ser.(2022)·2 citations
08*
Exclusive $J / ψ$ production in ultraperipheral Pb+Pb collisions to NLO pQCD
K. J. Eskola🇫🇮 · C. A. Flett🇫🇮 · V. Guzey🇫🇮 · T. Löytäinen🇫🇮 · H. Paukkunen🇫🇮
We present the first NLO pQCD study of coherent exclusive $J / ψ$ photoproduction in ultraperipheral heavy-ion collisions (UPCs) at the LHC. Taking the generalized parton distributions (GPDs) in their forward limit, as parton distribution functions (PDFs), we quantify the NLO contributions in the rapidity-differential cross section, show that the real part of the amplitude must not be neglected, study the gluon and quark contributions, chart the scale-choice and PDF uncertainties, and compare the NLO results with LHC and HERA data. We show that the scale dependence is significant but a scale choice can be found with which we reproduce the 2.76 and 5.02 TeV UPC data. In particular, we show that the process is clearly more sensitive to the nuclear quark PDFs than thought before.
hep-phnucl-thActa Phys.Polon.Supp.(2023)·1 citation
09*
$R^{2}$ Gravity Effects on the Kinetic Axion Phase Space
V.K. Oikonomou🇬🇷
In this work we consider the effect of an $R^{2}$ term on the kinetic misalignment axion theory. By using the slow-roll assumptions during inflation and the field equations, we construct an autonomous dynamical system for the kinetic axion, including the effects of the $R^{2}$ term and we solve numerically the dynamical system. As we demonstrate, the pure kinetic axion attractor is transposed to the right in the field phase space, and it is no longer $(ϕ, ϕ ˙) = (⟨ ϕ ⟩, 0)$ , but it is $(ϕ, ϕ ˙) = (⟨ ϕ^{'} ⟩, 0)$ , with $⟨ ϕ^{'} ⟩ \neq = 0$ some non-zero value of the scalar field with $⟨ ϕ^{'} ⟩ > ⟨ ϕ ⟩$ . This feature indicates that the kinetic axion mechanism is enhanced, and the axion oscillations are further delayed, compared with the pure kinetic axion case. The phenomenological implications on the duration of the inflationary era, on the commencing of the reheating era and the reheating temperature, are also discussed.
hep-phastro-ph.COgr-qchep-thEPL(2022)·9 citations
10*
Leptogenesis from composite singlets
Nobuki Yoshimatsu🇯🇵
We argue that dual singlets accommodate the thermal leptogenesis in the context of metastable supersymmetry breaking. This framework suggests that the reheating temperature is as low as O(10^4) GeV, and besides the neutrino masses, solely induced from the dual fermions, are present at O(0.1) eV. We also expect that the unstable gravitino, though long-lived, may cause a clear signal of the neutrino flux at O(10) MeV.
hep-phPRD(2024)·0 citations
11*
Unavoidable Higgs coupling deviations in the $Z_{2}$ -symmetric Georgi-Machacek model
Carlos Henrique de Lima🇨🇦 · Heather E. Logan🇨🇦
The $Z_{2}$ -symmetric version of the Georgi-Machacek model does not possess a decoupling limit in which all the new particles can be made arbitrarily heavy, opening the possibility that the model can be entirely excluded if experiments reveal no deviations from the Standard Model. We explore this model, focusing on the part of parameter space in which the vacuum expectation value of the triplets, $ν_{χ}$ , is small. In the small- $ν_{χ}$ limit, the second custodial-singlet scalar field $S$ necessarily becomes very light and can contribute to the total width of the 125 GeV Higgs boson $h$ via $h \to S S$ . We show that this process, together with LHC measurements of the $h \to γ γ$ rate, entirely excludes masses $m_{S} < m_{h} /2$ and thereby severely constrains the parameter space, setting an experimental lower bound $ν_{χ} ≳ 12.5$ GeV on the vacuum expectation value of the triplets. This lower bound makes it impossible to avoid deviations from the Standard Model in the couplings of $h$ to fermion and vector boson pairs. We study the remaining parameter space after imposing constraints from direct searches for the additional Higgs bosons, and show that it is on the edge of being fully excluded at $95%$ confidence level by LHC measurements of the 125 GeV Higgs boson's couplings. Measurements of these couplings at the future high-luminosity run of the LHC will have sufficient precision to entirely exclude the model at $5 σ$ if no deviations from the Standard Model are observed.
hep-phPRD(2022)·20 citations
12*
Weinberg's Compositeness
U. van Kolck🇫🇷
Nearly 60 years ago Weinberg suggested a criterion for particle "compositeness", which has acquired new life with the discovery of new, exotic hadrons. His idea resonates with model-based intuition. I discuss the role it plays in the context of another of Weinberg's creations, the model-independent framework of effective field theories.
hep-phnucl-thSymmetry(2022)·31 citations
13*
Chiral Separation Effect vs. Chiral Anomaly
Z.V.Khaidukov🇷🇺 · R.A.Abramchuk🇷🇺
We study relation between Chiral Separation Effect (CSE) and Chiral Anomaly, and argue that CSE does not inherit the immutability of Chiral Anomaly. For QED in the leading order in electric charge, with point-splitting regularization in real-time formalism, we demontrate, in regularization-dependent way though, that CSE is an infrared (IR) effect, while the Anomaly is an ultra-violet (UV) phenomena. Thus, CSE in general is sensitive to non-perturbative interactions that alter the theory IR properties, while the Anomaly is fixed by Lorentz symmetry. The simplest example of such an interaction is the Yukawa-like fermion mass.
hep-phhep-th0 citations
14*
Exotic bottomonium hadronic transitions
Jaume Tarrús Castellà🇺🇸
We report on a recent computation of the transitions of exotic bottomonium to standard bottomonium and light quark hadrons. We work under the assumption that the $Υ (10753)$ and $Υ (11020)$ can be described as the lowest laying and first excitation $1^{--}$ hybrid bottomonium states, respectively. The computation has two distinct parts: the heavy quark transition matrix elements, which are obtained in a nonrelativistic EFT incorporating the heavy quark, multipole and adiabatic expansions; and the hadronization of the gluonic operators into the light-meson final states. The single mesons production is obtained through the axial anomaly and a standard $π^{0} - η - η^{'}$ mixing scheme. Two pion and kaon production is obtained by solving the coupled Omnès problem. We also present result for semi-inclusive transitions.
hep-phEPJ Web Conf.(2022)·0 citations
15*
Analysis of localized CP asymmetry in $B ˉ_{s}^{0} \to π^{+} π^{-} π^{0} (K^{0})$
Yan-Lin Zhao · Gang Lü · Na-Wang · Xin-Heng Guo
An investigation about localized CP asymmetries for the processes of $B ˉ_{s}^{0} \to π^{+} π^{-} π^{0} (K^{0})$ is presented in this paper. The innovation of this paper is that there is a consideration of three-particle $ρ^{0} (770)$ , $ω (782)$ and $ϕ (1020)$ interferences effect. Generally, $ω (782)$ and $ϕ (1020)$ both can decay into $π^{+} π^{-}$ pair where can cause extremely small contribution from isospin symmetry breaking. Nevertheless, our analysis shows that $B ˉ_{s}^{0} \to π^{+} π^{-} π^{0} (K^{0})$ decay process can bring differential CP asymmetry about $65%$ ( $36%$ ) because of isospin symmetry breaking. To better compared with the data from experimental in the future, we integrate CP asymmetry over the invariant mass and obtain localized CP asymmetry value for the decay $B ˉ_{s}^{0} \to π^{+} π^{-} π^{0} (K^{0})$ . We find that there is an evident signal about CP asymmetry at invariant mass value $m (π^{+} π^{-})$ below the mass of $ρ (770)^{0}$ with the decay $B ˉ_{s}^{0} \to π^{+} π^{-} π^{0}$ .
hep-phEPJC(2023)·10 citations
16*
Nucleon spin decomposition with one dynamical gluon
Siqi Xu🇨🇳 · Chandan Mondal🇨🇳 · Xingbo Zhao🇨🇳 · Yang Li🇨🇳 · James P. Vary🇺🇸
We solve for the light-front wave functions of the nucleon from a light-front quantum chromodynamics (QCD) effective Hamiltonian with three-dimensional confinement. We obtain solutions using constituent three quarks combined with three quarks and one gluon Fock components. The resulting light-front wave functions provide a good quality description of the nucleon's quark distribution functions following QCD scale evolution. We present the effects from incorporating a dynamical gluon on the nucleon's gluon densities, helicity distribution and orbital angular momentum that constitutes the nucleon spin sum rule.
hep-phnucl-thPRD(2023)·57 citations
17*
Common origin of $θ_{13}$ and dark matter within the flavor symmetric scoto-seesaw framework
Joy Ganguly🇮🇳 · Janusz Gluza🇵🇱 · Biswajit Karmakar🇵🇱
To understand the observed pattern of neutrino masses and mixing as well as to account for the dark matter we propose a hybrid scoto-seesaw model based on the $A_{4}$ discrete flavor symmetry. In this setup, including at least two heavy right-handed neutrinos is essential to employ the discrete flavor symmetry that mimics once popular tribimaximal neutrino mixing at the leading order via type-I seesaw. The scotogenic contribution then acts as a critical deviation to reproduce the observed value of the reactor mixing angle $θ_{13}$ (within the trimaximal mixing scheme) and to accommodate potential dark matter candidates, pointing towards a common origin of $θ_{13}$ and dark matter. The model predicts the atmospheric angle to be in the upper octant, excludes some regions on the Dirac CP phase, and restricts the Majorana phases too. Further, normal and inverted mass hierarchies can be distinguished for specific values of the relative phases associated with the complex light neutrino mass matrix. Owing to the considered flavor symmetry, contributions coming from the scotogenic mechanism towards the lepton flavor violating decays such as $μ \to e γ$ , $τ \to e γ$ vanish, and a lower limit on the second right-handed neutrino mass can be obtained. Prediction for the effective mass parameter appearing in the neutrinoless double beta decay falls within the sensitivity of future experiments such as LEGEND-1k and nEXO.
hep-phJHEP(2022)·22 citations
18*
Flavor Structures of Quarks and Leptons from Flipped SU(5) GUT with $A_{4}$ Modular Flavor Symmetry
Xiao Kang Du🇨🇳 · Fei Wang🇨🇳
We propose to generate the flavor structures of the Standard Model plus neutrinos from flipped SU(5) GUT with $A_{4}$ modular flavor symmetry. Possible way to assign different moduli values for quarks and leptons in modular GUT scheme is discussed. We propose to reduce the multiple modular symmetries to a single modular symmetry in the low energy effective theory with proper boundary conditions. We classify all possible scenarios in this scheme according to the assignments of the modular $A_{4}$ representations for matter superfields and give the expressions of the quark and lepton mass matrices predicted by our scheme at the GUT scale. After properly selecting the modular weights for various superfields that can lead to better fitting, we can obtain the best-fit points with the corresponding $χ^{2}$ values for the sample subscenarios. We find that the flavor structures of the Standard Model plus neutrinos can be fitted perfectly in such a $A_{4}$ modular flavor GUT scheme with single or two modulus fields. Especially, the $χ_{t o t a l}^{2}$ of our fitting can be as low as $1.558$ for sample $I X^{'}$ of scenario $III$ even if only a single common modulus field for both quark and lepton sectors is adopted. The most predictive scenario $III$ , in which all superfields transform as triplets of $A_{4}$ , can be fitted much better with two independent moduli fields $τ_{q}, τ_{l}$ for quark sector and lepton sector ( $χ_{t o t a l}^{2} \approx 95$ ) than that with the single modulus case ( $χ_{t o t a l}^{2} \approx 282.4$ ).
hep-phJHEP(2023)·24 citations
19*
Next-to-leading-order QCD correction to the exclusive double charmonium production via $Z$ decays
Xuan Luo🇨🇳 · Hai-Bing Fu🇨🇳 · Hai-Jiang Tian🇨🇳 · Cong Li🇨🇳
In this paper, we preformed a further research on the exclusive productions of double charmonium via $Z$ -boson decay by using nonrelativistic QCD factorizations approach, where the single-photon fragmentation topologies of the QED diagrams, the interference terms between the QCD and full QED diagrams, the next-to-leading-order calculations of the interference terms are preformed. For the production of $J / ψ + J / ψ$ in $Z$ -boson decay, the interference terms show a significantly phenomenological effect due to the addition of the newly calculated NLO QCD corrections. After adding together all contributions, the branching fraction $B_{Z \to J / ψ J / ψ}$ still undershoots the CMS collaboration data obviously. In addition, we simultaneously complete the next-to-leading-order calculations for $Z \to J / ψ + η_{c} (χ_{c J})$ with $J = (0, 1, 2)$ . The calculated results show that the newly-calculated complete QED and cross terms will have obvious effective on the total decay widths.
hep-ph6 citations
20*
Features of hadronic and deconfined matter from AGS to LHC energies
M.Petrovici🇷🇴 · A. Pop🇷🇴
Previous extensive studies on the dependence of the average transverse momentum, its slope as a function of the hadron mass and the average transverse expansion on the particle multiplicity per unit rapidity and unit transverse overlap area of the colliding partners are extended to the ratio of the energy density to the entropy density. The behaviour of the ratio between the average transverse momentum and the square root of the particle multiplicity per unit rapidity and unit transverse overlap area $⟨ p_{T} ⟩ / ⟨ d N / d y ⟩ / S_{⊥}$ as a function of collision energy for a given centrality or as a function of centrality for a given collision energy supports the predictions of CGC and percolation based approaches. The dependence of the ratio of the energy density $⟨ d E_{T} / d y ⟩ / S_{⊥}$ to the entropy density $⟨ d N / d y ⟩ / S_{⊥}$ at different collision centralities for A-A collisions from AGS, SPS, RHIC and LHC energies is presented. The trend of this ratio towards a plateau at the highest RHIC energies followed by a steep rise at LHC energies is in agreement with theoretical predictions made 40 years ago that indicate this behaviour as a signature of a phase transition. This pattern strongly depends on the collision geometry, converging towards the dependence that characterizes the pp minimum bias (MB) collisions for the most peripheral A-A collisions. Expected similarities between pp and Pb-Pb collisions at LHC energies are confirmed.
hep-phPRC(2023)·4 citations
21*
Inclusive $b \to {u, c} ℓ^{-} ν ˉ_{ℓ}$ modes: polarized/unpolarized $Λ_{b}$
Francesco Loparco🇮🇹
The increasing number of flavour anomalies motivates the investigation of new processes where tensions similar to the observed ones may emerge. It is necessary to identify observables sensitive to physics beyond the Standard Model. The analysis which follows concerns the inclusive semileptonic decays of polarized beauty baryons, computed through the Heavy Quark Expansion at $O (1/ m_{b}^{3})$ and at the leading order in $α_{s}$ . New Physics interactions have been taken into account, extending the Standard Model $b \to U ℓ ν ˉ_{ℓ}$ low-energy Hamiltonian, where $U = {c, u}$ and $ℓ = {e, μ, τ}$ , including the full set of $D = 6$ operators with left-handed neutrinos. Among the possible observables one can consider, the ones depending on the spin of the decaying baryon are very appealing and can be considered for physics programmes of future facilities, such as FCC-ee.
hep-phhep-exhep-lat0 citations
22*
Quasi-degenerate dark photon and dark matter
Hang Zhou🇨🇳
We introduce an $S U (2)_{X}$ dark sector without any fermions and then realize a non-abelian kinetic mixing between the dark $S U (2)_{X}$ gauge fields and the standard model $S U (2)_{L} \times U (1)_{Y}$ gauge fields. While one of the dark gauge bosons becomes a dark photon, the others can keep stable to form a dark matter particle. The nearly degenerate masses of dark photon and dark matter could be tested if the dark photon and the dark matter are both observed in the future.
hep-phNPB(2024)·7 citations
23*
New Sum Rules for the $B_{c} \to J / ψ$ Form Factors
Marzia Bordone🇨🇭 · Alexander Khodjamirian🇩🇪 · Thomas Mannel🇩🇪
We derive new sum rules for the form factors of the $B_{c} \to J / ψ ℓ ν ˉ_{ℓ}$ semileptonic transitions, employing the vacuum-to- $B_{c}$ correlation function of the $J / ψ$ -interpolating and $b \to c$ weak currents. In the heavy quark limit and at a space-like momentum transfer to the weak current, a local operator-product expansion is valid for this correlation function. As a result, in the leading power, the non-perturbative input is reduced to the decay constant of $B_{c}$ meson. Furthermore, applying hadronic dispersion relation in the $J / ψ$ channel, we find that a non-vanishing OPE spectral density in the duality interval of $J / ψ$ emerges only at $O (α_{s})$ . We calculate this density in the relevant kinematic regime. The $B_{c} \to J / ψ$ form factors at space-like momentum transfer are then calculated from the new sum rules.
hep-phJHEP(2023)·9 citations
24*
Transverse momentum broadening from NLL BFKL to all orders in pQCD
Paul Caucal🇫🇷 · Yacine Mehtar-Tani🇺🇸
We study, to all orders in perturbative QCD, the universal behavior of the saturation momentum $Q_{s} (L)$ controlling the transverse momentum distribution of a fast parton propagating through a dense QCD medium with large size $L$ . Due to the double logarithmic nature of the quantum evolution of the saturation momentum, its large $L$ asymptotics is obtained by slightly departing from the double logarithmic limit of either next-to-leading log (NLL) BFKL or leading order DGLAP evolution equations. At fixed coupling, or in conformal $N = 4$ SYM theory, we derive the large $L$ expansion of $Q_{s} (L)$ up to order $α_{s}^{3/2}$ . In QCD with massless quarks, where conformal symmetry is broken by the running of the strong coupling constant, the one-loop QCD $β$ -function fully accounts for the universal terms in the $Q_{s} (L)$ expansion. Therefore, the universal coefficients of this series are known exactly to all orders in $α_{s}$ .
hep-phhep-thnucl-thPRD(2023)·9 citations
25*
Quantum jet clustering with LHC simulated data
Jorge J. Martínez de Lejarza🇪🇸 · Leandro Cieri🇪🇸 · Germán Rodrigo🇪🇸
We study the case where quantum computing could improve jet clustering by considering two new quantum algorithms that might speed up classical jet clustering algorithms. The first one is a quantum subroutine to compute a Minkowski-based distance between two data points, while the second one consists of a quantum circuit to track the rough maximum into a list of unsorted data. When one or both algorithms are implemented in classical versions of well-known clustering algorithms (K-means, Affinity Propagation and $k_{T}$ -jet) we obtain efficiencies comparable to those of their classical counterparts. Furthermore, in the first two algorithms, an exponential speed up in dimensionality and data length can be achieved when applying the distance or the maximum search algorithm. In the $k_{T}$ algorithm, a quantum version of the same order as FastJet is achieved.
hep-phquant-phPoS(2022)·10 citations
26*
Resummation of threshold logarithms in deeply-virtual Compton scattering
Jakob Schoenleber🇩🇪
I derive an all-order resummation formula for the logarithmically enhanced contributions proportional to $\frac{α _{s}^{n}}{x \pm ξ} lo g (\frac{ξ \pm x}{2 ξ})^{k}$ in the quark coefficient function of deeply-virtual-Compton scattering and the pion-photon transition form factor in momentum space. The resummation is performed at the next-to-next-to-leading logarithmic accuracy. The key observation is that the quark coefficient function itself factorizes in the $x \to \pm ξ$ limit, which allows for a resummation using renormalization group equations. A preliminary numerical analysis suggests that the corrections due to resummation for the quark contribution might be small.
hep-phJHEP(2023)·13 citations
27*
On quarkonium masses in 3D non-commutative space
Benedek Bukor🇸🇰 · Juraj Tekel🇸🇰
We modify the calculation of quarkonium masses using the radial WKB and Pekeris-type approximations for the case of three-dimensional, rotationally invariant non-commutative space. We obtain corrections to the charmonium ( $c c ˉ$ ), bottomonium ( $b b ˉ$ ) and bottom-charmed meson ( $c b ˉ$ ) masses due to the discrete short distance structure of the space introduced by the space non-commutativity. For the fundamental length at the Planck scale we obtain relative correction at the order of $1 0^{- 39}$ , and taking into account the current experimental data, we obtain the upper bound at the order of $1 0^{- 18} m$ for the fundamental length scale of space.
hep-phhep-thEur.Phys.J.Plus(2023)·8 citations
28*
Motivations for the Soft Wall holographic approach to strong interactions
Sergey Afonin🇷🇺 · Timofey Solomko🇷🇺
The hypothesis of gauge/gravity correspondence (or holographic duality) from string theory has led to unexpected and challenging ways for description of strongly coupled systems. Such descriptions are given in terms of weakly-coupled higher-dimensional gravitational theories. The holographic ideas have penetrated many branches of theoretical physics. We discuss motivations for the so-called Soft Wall holographic approach to non-perturbative strong interactions and its advantages.
hep-phhep-thPhys.Part.Nucl.(2023)·2 citations
29*
Local analytic sector subtraction for initial- and final-state radiation at NLO in massless QCD
Gloria Bertolotti🇮🇹 · Paolo Torrielli🇮🇹 · Sandro Uccirati🇮🇹 · Marco Zaro🇮🇹
Within the framework of local analytic sector subtraction, we present the subtraction of next-to-leading-order QCD singularities for processes featuring massless coloured particles in the initial as well as in the final state. The features of the method are explained in detail, including the introduction of an optimisation procedure aiming at improving numerical stability at the cost of no extra analytic complexity. A numerical validation is provided for a variety of processes relevant to lepton as well as hadron colliders. This work constitutes a relevant step in view of the application of our subtraction method to processes involving initial-state radiation at next-to-next-to-leading order in QCD.
hep-phJHEP(2022)·14 citations
30*
Light $Z^{'}$ Signatures at the LHC
Yaşar Hiçyılmaz🇹🇷 · Shaaban Khalil🇪🇬 · Stefano Moretti🇬🇧
In this work, we discuss a distinctive $pp \to Higgs \to Z^{'} Z^{'} \to 4 l$ ( $l = e, μ$ ) signal at the Large Hadron Collider (LHC), where the `Higgs' label refers to the SM-like Higgs state discovered in 2012 or a lighter one in the framework of a theoretical model embedding a spontaneously broken $U (1)^{'}$ symmetry in addition to the Standard Model (SM) gauge group. The additional $U (1)^{'}$ symmetry generates a very light $Z^{'}$ state, with both vector and axial (non-universal) couplings to fermions, which are able to explain the so-called Atomki anomaly, compliant with current measurements of the Anomalous Magnetic Moments (AMMs) of electron and muon as well as beam dump experiments. We show that the cross section for this process should be sufficiently large to afford one with significant sensitivity during Run 3 of the LHC.
hep-phPRD(2023)·5 citations
31*
Dark Dimension Gravitons as Dark Matter
Eduardo Gonzalo🇺🇸 · Miguel Montero🇺🇸 · Georges Obied🇺🇸 · Cumrun Vafa🇺🇸
We consider cosmological aspects of the Dark Dimension (a mesoscopic dimension of micron scale), which has recently been proposed as the unique corner of the quantum gravity landscape consistent with both the Swampland criteria and observations. In particular we show how this leads, by the universal coupling of the Standard Model sector to bulk gravitons, to massive spin 2 KK excitations of the graviton in the dark dimension (the "dark gravitons") as an unavoidable dark matter candidate. Assuming a lifetime for the current de Sitter phase of our universe of order Hubble, which follows from both the dS Swampland Conjecture and TCC, we show that generic features of the dark dimenson cosmology can naturally lead to the correct dark matter density and a resolution of the cosmological coincidence problem, where the matter/radiation equality temperature ( $T \sim$ 1 eV) coincides with the temperature where the dark energy begins to dominate. Thus one does not need to appeal to Weinberg's anthropic argument to explain this coincidence. The dark gravitons are produced at $T \sim$ 4 GeV, and their composition changes as they mainly decay to lighter gravitons, without losing much total mass density. The mass of dark gravitons is $m_{DM} \sim 1 - 100$ keV today.
hep-phhep-thJHEP(2023)·98 citations
32*
Resonant search for the X17 boson at PADME
Luc Darmé🇫🇷 · Marco Mancini🇮🇹 · Enrico Nardi🇮🇹 · Mauro Raggi🇮🇹
We discuss the experimental reach of the Frascati PADME experiment in searching for new light bosons via their resonant production in positron annihilation on fixed target atomic electrons. A scan in the mass range around 17 MeV will thoroughly probe the particle physics interpretation of the anomaly observed by the ATOMKI nuclear physics experiment. In particular, for the case of a spin-1 boson, the viable parameter space can be fully covered in a few months of data taking.
hep-phhep-exPRD(2022)·45 citations
33*
Instability in axion inflation with strong backreaction from gauge modes
Marco Peloso🇮🇹 · Lorenzo Sorbo🇺🇸
We perform an analytical study of the stability of the background solution of the model in which an inflaton, through an axionic coupling to a $U (1)$ gauge field, causes an amplification of the gauge field modes that strongly backreact on its dynamics. To this goal, we study the evolution of the gauge field modes coupled to the inflaton zero mode, treating perturbatively the deviation of the inflaton velocity from its mean-field value. As long as the system is in the strong backreaction regime we find that the inflaton velocity performs oscillations of increasing amplitude about the value it would have in the approximation of constant velocity, confirming an instability that has been observed in numerical studies.
↳ astro-ph.COhep-phhep-thJCAP(2023)·61 citations
34*
Fluctuations of conserved charges in hydrodynamics and molecular dynamics
Volodymyr Vovchenko🇺🇸
I present an overview of recent theoretical results on fluctuations of conserved charges in heavy-ion collisions obtained in relativistic hydrodynamics and molecular dynamics frameworks. In particular, I discuss the constraints on the location of the QCD critical point based on comparisons of experimental data on proton number cumulants with precision calculations of non-critical contributions. Recent developments on critical fluctuations in molecular dynamics simulations are covered as well.
↳ nucl-thhep-phnucl-exEPJ Web Conf.(2023)·0 citations
35*
Discretely Charged Dark Matter in Inflation Models Based on Holographic Space-time
T.Banks🇺🇸 · W.Fischler🇺🇸
The Holographic Space-time (HST) model of inflation has a potential explanation for dark matter as tiny primordial black holes. Motivated by a recent paper of Barrau\cite{barrau} we propose a version of this model where some of the Inflationary Black Holes (IBHs), whose decay gives rise to the Hot Big Bang, carry the smallest value of a discrete symmetry charge. The fraction $f$ of IBHs carrying this charge is difficult to estimate from first principles, but we fix it by requiring that the crossover between radiation and matter domination occurs at the correct temperature $T_{e q} \sim 1 e V = 1 0^{- 28} M_{P}$ . The fraction is small, $f \sim 2 \times 1 0^{- 9}$ so we believe this gives an extremely plausible model of dark matter.
↳ hep-thastro-ph.COgr-qchep-phUniverse(2022)·7 citations
36*
Partial wave analysis of the charmed baryon hadronic decay $Λ_{c}^{+} \to Λ π^{+} π^{0}$
BESIII Collaboration: M. Ablikim · M. N. Achasov · P. Adlarson · M. Albrecht · R. Aliberti · A. Amoroso · M. R. An · Q. An · X. H. Bai · Y. Bai · O. Bakina · R. Baldini Ferroli and 567 other authors
Based on $e^{+} e^{-}$ collision samples corresponding to an integrated luminosity of 4.4 $\mbox{fb$ ^{-1} $}$ collected with the BESIII detector at center-of-mass energies between $4.6 GeV$ and $4.7 GeV$ , a partial wave analysis of the charmed baryon hadronic decay $Λ_{c}^{+} \to Λ π^{+} π^{0}$ is performed, and the decays $Λ_{c}^{+} \to Λ ρ (770)^{+}$ and $Λ_{c}^{+} \to Σ (1385) π$ are studied for the first time. Making use of the world-average branching fraction $B (Λ_{c}^{+} \to Λ π^{+} π^{0})$ , their branching fractions are determined to be \begin{eqnarray*} \begin{aligned} \mathcal{B}(\Lambda_c^+\to\Lambda\rho(770)^+)=&(4.06\pm0.30\pm0.35\pm0.23)\times10^{-2},\\ \mathcal{B}(\Lambda_c^+\to\Sigma(1385)^+\pi^0)=&(5.86\pm0.49\pm0.52\pm0.35)\times10^{-3},\\ \mathcal{B}(\Lambda_c^+\to\Sigma(1385)^0\pi^+)=&(6.47\pm0.59\pm0.66\pm0.38)\times10^{-3},\\ \end{aligned} \end{eqnarray*} where the first uncertainties are statistical, the second are systematic, and the third are from the uncertainties of the branching fractions $B (Λ_{c}^{+} \to Λ π^{+} π^{0})$ and $B (Σ (1385) \to Λ π)$ . In addition, %according to amplitudes determined from the partial wave analysis, the decay asymmetry parameters are measured to be $α_{Λ ρ (770)^{+}} = - 0.763 \pm 0.053 \pm 0.045$ , $α_{Σ (1385)^{+} π^{0}} = - 0.917 \pm 0.069 \pm 0.056$ , and $α_{Σ (1385)^{0} π^{+}} = - 0.789 \pm 0.098 \pm 0.056$ .
↳ hep-exhep-lathep-phJHEP(2022)·42 citations
37*
Null test for cosmic curvature using Gaussian process
Peng-Ju Wu🇨🇳 · Jing-Zhao Qi🇨🇳 · Xin Zhang🇨🇳
The cosmic curvature $Ω_{K, 0}$ , which determines the spatial geometry of the universe, is an important parameter in modern cosmology. Any deviation from $Ω_{K, 0} = 0$ would have a profound impact on primordial inflation paradigm and fundamental physics. In this work, we adopt a cosmological model-independent method to test whether $Ω_{K, 0}$ deviates from zero. We use the Gaussian process to reconstruct the reduced Hubble parameter $E (z)$ and the derivative of distance $D^{'} (z)$ from observational data, and then determine $Ω_{K, 0}$ with a null test relation. The cosmic chronometer (CC) Hubble data, baryon acoustic oscillation (BAO) Hubble data, and supernovae Pantheon sample are considered. Our result is consistent with a spatially flat universe within the domain of reconstruction $0 < z < 2.3$ , at the $1 σ$ confidence level. In the redshift interval $0 < z < 1$ , the result favors a flat universe, while at $z > 1$ , it tends to favor a closed universe. In this sense, there is still a possibility for a closed universe. We also carry out the null test of the cosmic curvature at $0 < z < 4.5$ using the simulated gravitational wave standard sirens, CC+BAO and redshift drift Hubble data. The result shows that in the future, with the synergy of multiple high-quality observations, we can tightly constrain the spatial geometry or exclude the flat universe.
↳ astro-ph.COgr-qchep-phCPC(2023)·29 citations
38*
The causality and stability of relativistic spin-hydrodynamics
Golam Sarwar🇮🇳 · Md Hasanujjaman🇮🇳 · Jitesh R. Bhatt🇮🇳 · Hiranmaya Mishra🇮🇳 · Jan-e Alam🇮🇳
We study the causality and stability of relativistic hydrodynamics with the inclusion of the spin degree of freedom as a hydrodynamic field. We consider two specific models of spin-hydrodynamics for this purpose. A linear mode analysis for static background shows that a first-order dissipative spin-hydrodynamics remains acausal and admits instabilities. Besides, it is found that the inclusion of the spin field in hydrodynamics leads to new kinds of linear modes in the system. These new modes also exhibit instability and acausal behavior. The second model of the spin-hydrodynamics that we have considered here is equivalent to a particular second-order conventional hydrodynamics with no dissipative effects. For a static background, it is found that the linear modes of this model support the sound waves only. However, when the background has constant vorticity, then the model admits instability and acausality in certain situations. It is found that the spin-dynamics have an effect on the hydrodynamic response of the fluid. These findings point toward the need for a causal and stable theory with spin as a hydrodynamic field to describe the spin-polarized fluid.
↳ nucl-thcond-mat.stat-mechhep-phhep-thPRD(2023)·42 citations
39*
Classical and quantum cosmological solutions in teleparallel dark energy with anisotropic background geometry
Andronikos Paliathanasis🇿🇦
We investigate exact and analytic solutions for the field equations in teleparallel dark energy model where the physical space is described by the locally rotational symmetric Bianchi I, Bianchi III and Kantowski-Sachs geometries. We make use of the property that a point-like Lagrangian exist for the description of the field equations and variational symmetries are applied for the construction of invariant functions and conservation laws. The later are used for the derivation of new analytic solutions for the classical field equations and exact function forms for the wavefunction in the quantum limit.
↳ gr-qchep-phmath-phmath.MPSymmetry(2022)·8 citations
40*
Understanding the gravitational and magnetic environment of a very long baseline atom interferometer
Ali Lezeik · Dorothee Tell🇩🇪 · Klaus Zipfel · Vishu Gupta🇩🇪 · Étienne Wodey · Ernst Rasel🇩🇪 · Christian Schubert🇲🇽 · Dennis Schlippert🇩🇪
By utilizing the quadratic dependency of the interferometry phase on time, the Hannover Very Long Baseline Atom Interferometer facility (VLBAI) aims for sub nm/s $^{2}$ gravity measurement sensitivity. With its 10 m vertical baseline, VLBAI offers promising prospects in testing fundamental physics at the interface between quantum mechanics and general relativity. Here we discuss the challenges imposed on controlling VLBAI's magnetic and gravitational environment and report on their effect on the device's accuracy. Within the inner 8 m of the magnetic shield, residual magnetic field gradients expect to cause a bias acceleration of only 6 $\times$ 10 $^{- 14}$ m/s $^{2}$ while we evaluate the bias shift due to the facility's non-linear gravity gradient to 2.6 nm/s $^{2}$ . The model allows the VLBAI facility to be a reference to other mobile devices for calibration purposes with an uncertainty below the 10 nm/s $^{2}$ level.
↳ physics.atom-phhep-ph6 citations
41*
Probing the valence quark region of nucleons with Z bosons at LHCb
Hengne Li · LHCb collaboration
In this high- $x$ region, both the flavour content and structure of the nucleon parton distribution functions remains relatively poorly known. New LHCb measurements of Z and charm jet associated production could indicate a valence-like intrinsic-charm component in the proton wave function, and measurements of Z production in pPb collisions provide new constraints on the partonic structure of nucleons bound inside nuclei. Here we will discuss these new LHCb measurements and comparisons with state-of-the-art parton distribution function calculations.
↳ hep-exhep-ph1 citation
42*
Comments on the Entanglement Spectrum of de Sitter Space
Tom Banks🇺🇸 · Patrick Draper🇺🇸
We argue that the Schwarzschild-de Sitter black hole entropy formula does not imply that the entanglement spectrum of the vacuum density matrix of de Sitter space is flat. Specifically, we show that the expectation value of a random projection operator of dimension $d ≫ 1$ , on a Hilbert space of dimension $D ≫ d$ and in a density matrix $ρ = e^{- K}$ with strictly positive spectrum, is $\frac{d}{D} (1 + o (\frac{1}{d}))$ , independent of the spectrum of the density matrix. In addition, for a suitable class of spectra the asymptotic estimates $Tr (ρ K) \sim ln D - o (1)$ and $Tr [ρ (K - ⟨ K ⟩)^{2}] = a ⟨ K ⟩$ are compatible for any order one constant $a$ . We discuss a simple family of matrix models and projections that can replicate such modular Hamiltonians and the SdS entropy formula.
↳ hep-thgr-qchep-phJHEP(2023)·11 citations
43*
A closer look at dark photon explanations of the excess radio background
Sandeep Kumar Acharya🇬🇧 · Jens Chluba🇬🇧
The observed excess radio background has remained a puzzle for over a decade. A recent new physics solution involves dark matter that decays into dark photons in the presence of a thermal dark photon background. The produced non-thermal dark photon spectrum then converts into standard photons around the reionization era, yielding an approximate power-law radio excess with brightness temperature $T (ν) ≃ ν^{- 2.5}$ over a wide range of frequencies, $ν$ . This simple power-law model comes intriguingly close to the current data, even if several ingredients are required to make it work. In this paper, we investigate some of the details of this model, showcasing the importance of individual effects. In particular, significant deviation from a power law are present at $ν ≲ 100 MHz$ and $ν ≳ 1 GHz$ . These effects result in improving the fit to data compared to a power-law spectrum, and may become testable in future observations. We also highlight independent signatures that can be tested with future CMB spectral distortion experiments such as {\it PIXIE}.
↳ astro-ph.COastro-ph.HEhep-phMNRAS(2023)·11 citations
44*
Extracting nuclear matter properties from the neutron star matter equation of state using deep neural networks
Márcio Ferreira🇵🇹 · Valéria Carvalho🇵🇹 · Constança Providência🇵🇹
The extraction of the nuclear matter properties from neutron star (NS) observations is nowadays an important issue, in particular, the properties that characterize the symmetry energy which are essential to describe correctly asymmetric nuclear matter. We use deep neural networks (DNNs) to map the relation between cold $β$ -equilibrium NS matter and the nuclear matter properties. Assuming a quadratic dependence on the isospin asymmetry for the energy per particle of homogeneous nuclear matter and using a Taylor expansion up to fourth order in the iso-scalar and iso-vector contributions, we generate a dataset of different realizations of $β$ -equilibrium NS matter and the corresponding nuclear matter properties. The DNN model was successfully trained, attaining great accuracy in the test set. Finally, a real case scenario was used to test the DNN model, where a set of 33 nuclear models, obtained within a relativistic mean field approach or a Skyrme force description, were fed into the DNN model and the corresponding nuclear matter parameters recovered with considerable accuracy, in particular, the standard deviations $σ (L_{sym}) = 12.85$ MeV and $σ (K_{sat}) = 41.02$ MeV were obtained, respectively, for the slope of the symmetry energy and the nuclear matter incompressibility at saturation.
↳ nucl-thastro-ph.HEhep-phPRD(2022)·29 citations
45*
dmscatter: A Fast Program for WIMP-Nucleus Scattering
Oliver Gorton🇺🇸 · Calvin Johnson🇺🇸 · Changfeng Jiao🇺🇸 · Jonathan Nikoleyczik🇺🇸
Recent work, using an effective field theory framework, has shown the number of possible couplings between nucleons and the dark-matter-candidate Weakly Interacting Massive Particles (WIMPs) is larger than previously thought. Inspired by an existing Mathematica script that computes the target response, we have developed a fast, modern Fortran code, including optional OpenMP parallelization, along with a user-friendly Python wrapper, to swiftly and efficiently explore many scenarios, with output aligned with practices of current dark matter searches. A library of most of the important target nuclides is included; users may also import their own nuclear structure data, in the form of reduced one-body density matrices. The main output is the differential event rate as a function of recoil energy, needed for modeling detector response rates, but intermediate results such as nuclear form factors can be readily accessed.
↳ nucl-thastro-ph.COhep-phnucl-exComput.Phys.Commun.(2023)·11 citations
46*
Challenges for dark matter direct search with SiPMs
Alessandro Razeto🇮🇹 · Nicola Rossi🇮🇹
Liquid xenon and liquid argon detectors are leading the direct dark matter search and are expected to be the candidate technology for the forthcoming generation of ultra-sensitive large-mass detectors. At present, the scintillation light detection in those experiments is based on ultra-pure low-noise photo-multipliers. To overcome the issues in terms of the extreme radio-purity, costs, and technological feasibility of the future dark matter experiments, the novel SiPM-based photo-detector modules look promising candidates, capable of replacing the present light detection technology. However, the intrinsic features of SiPMs may limit the present expectations. In particular, interfering phenomena, especially related to the optical correlated noise, can degrade the energy and pulse shape resolutions. As a consequence, the projected sensitivity of the future detectors has to be reconsidered accordingly.
↳ hep-exastro-ph.IMhep-phFront.in Phys.(2023)·5 citations
47*
The Solenoidal Large Intensity Device (SoLID) for JLab 12 GeV
John Arrington🇺🇸 · Jay Benesch🇺🇸 · Alexandre Camsonne🇺🇸 · Jimmy Caylor🇺🇸 · Jian-Ping Chen🇺🇸 · Silviu Covrig Dusa🇺🇸 · Alexander Emmert🇺🇸 · George Evans🇺🇸 · Haiyan Gao🇺🇸 · J. Ole Hansen🇺🇸 · Garth M. Huber🇨🇦 · Sylvester Joosten🇺🇸 and 19 other authors
The Solenoidal Large Intensity Device (SoLID) is a new experimental apparatus planned for Hall A at the Thomas Jefferson National Accelerator Facility (JLab). SoLID will combine large angular and momentum acceptance with the capability to handle very high data rates at high luminosity. With a slate of approved high-impact physics experiments, SoLID will push JLab to a new limit at the QCD intensity frontier that will exploit the full potential of its 12 GeV electron beam. In this paper, we present an overview of the rich physics program that can be realized with SoLID, which encompasses the tomography of the nucleon in 3-D momentum space from Semi-Inclusive Deep Inelastic Scattering (SIDIS), expanding the phase space in the search for new physics and novel hadronic effects in parity-violating DIS (PVDIS), a precision measurement of $J / ψ$ production at threshold that probes the gluon field and its contribution to the proton mass, tomography of the nucleon in combined coordinate and momentum space with deep exclusive reactions, and more. To meet the challenging requirements, the design of SoLID described here takes full advantage of recent progress in detector, data acquisition and computing technologies. In addition, we outline potential experiments beyond the currently approved program and discuss the physics that could be explored should upgrades of CEBAF become a reality in the future.
↳ nucl-exhep-phphysics.ins-detJ.Phys.G(2023)·72 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.