Wed·Sep 28, 2022Wednesday·September 28, 2022

1. 01*

   Anomalous and axial Z' contributions to g-2

   Pascal Anastasopoulos🇦🇹 · Kunio Kaneta🇯🇵 · Elias Kiritsis🇫🇷 · Yann Mambrini🇫🇷

   We study the effects of an anomalous Z' boson on the anomalous magnetic moment of the muon (g-2), and especially the impact of its axial coupling. We mainly evaluate the negative contribution to (g-2) of such couplings at one-loop and look at the anomalous couplings generated at two loops. We find areas of the parameter space, where the anomalous contribution becomes comparable and even dominant compared to the one-loop contribution. We show that in such cases, the cutoff of the theory is sufficiently low, so that new charged fermions can be found in the next round of collider experiments. We comment on the realization of such a context in string theory orientifolds.

   hep-phhep-exJHEP(2023)·13 citations
2. 02*

   The Equation of State with the EPOS3 model

   Maria Stefaniak🇵🇱 · Klaus Werner🇫🇷 · Johannes Jahan🇫🇷 · Hanna Zbroszczyk🇵🇱

   Transitions between different states of matter and their thermodynamic properties are described by the Equation of State (EoS). A universal representation of the EoS of Quantum Chromodynamics (QCD) for the wide range of phase diagram has yet to be determined. The expectation of the systems to undergo various types of transitions depending on the temperature (T), the chemical potential ({\mu}B), and other thermodynamic features make solving that puzzle challenging. Furthermore, it needs to be apparent which experimentally measurable observables could provide helpful information for determining EoS. The application of different EoS for hydrodynamical evolution was introduced in the EPOS3 generator, which allows one to study its changing effect on the experimental observables. The family of EoS proposed by the BEST Collaboration was implemented. The Critical Point (CP) location and the strength of criticality variations were investigated with particle yield, transverse momentum spectra, flow, and moments of the net-proton distributions.

   hep-phhep-exnucl-thPRC(2023)·5 citations
3. 03*

   One generation of standard model Weyl representations as a single copy of $\mathbb{R}\otimes \mathbb{C}\otimes \mathbb{H}\otimes \mathbb{O}$

   N. Furey🇩🇪 · M.J. Hughes🇬🇧

   Peering in from the outside, $\mathbb{A}:=\mathbb{R}\otimes \mathbb{C}\otimes \mathbb{H}\otimes \mathbb{O}$ looks to be an ideal mathematical structure for particle physics. It is 32 $\mathbb{C}$-dimensional: exactly the size of one full generation of fermions. Furthermore, as alluded to earlier in arXiv:1806.00612, it supplies a richer algebraic structure, which can be used, for example, to replace SU(5) with the SU(3)$\times$SU(2)$\times$U(1) / ${\mathbb{Z}}_6$ symmetry of the standard model. However, this line of research has been weighted down by a difficulty known as the fermion doubling problem. That is, a satisfactory description of SL(2,$\mathbb{C}$) symmetries has so far only been achieved by taking two copies of the algebra, instead of one. Arguably, this doubling of states betrays much of $\mathbb{A}$'s original appeal. In this article, we solve the fermion doubling problem in the context of $\mathbb{A}$. Furthermore, we give an explicit description of the standard model symmetries, $g_{sm}$, its gauge bosons, Higgs, and a generation of fermions, each in the compact language of this 32 $\mathbb{C}$-dimensional algebra. Most importantly, we seek out the subalgebra of $g_{sm}$ that is invariant under the complex conjugate - and find that it is given by $su(3{)}_C\oplus u(1{)}_{EM}$. Could this new result provide a clue as to why the standard model symmetries break in the way that they do?

   hep-phhep-thPLB(2022)·20 citations
4. 04*

   Top partners and scalar dark matter -- a non-minimal reappraisal

   Alan S. Cornell🇿🇦 · Aldo Deandrea🇫🇷 · Thomas Flacke🇰🇷 · Benjamin Fuks🇫🇷 · Lara Mason🇿🇦

   A large set of models beyond the Standard Model of particle physics suggest that the top quark plays a special role in fundamental interactions. At the same time some of these models predict that a particle responsible for dark matter is present in the physical spectrum of the theory, and in particular cases dark matter may be specially linked to the top sector. Such a new physics configuration occurs, for instance, in composite frameworks that additionally feature vector-like quarks as mediators of the interactions of the dark matter with the Standard Model. We investigate the interplay of top-philic dark matter and the presence of several vector-like top partners. Such a non-minimal setup with several vector-like fermions is typical of composite scenarios, and we make use of an effective model to study to which extent such non-minimality modifies the collider and cosmological phenomenology of the minimal model, the latter only including one vector-like mediator of the dark matter interactions with the Standard Model.

   hep-phPRD(2023)·8 citations
5. 05*

   Four-quark scatterings in QCD I

   Wei-jie Fu🇨🇳 · Chuang Huang🇨🇳 · Jan M. Pawlowski🇩🇪 · Yang-yang Tan🇨🇳

   We investigate dynamical chiral symmetry breaking and the emergence of mesonic bound states from the infrared dynamics of four-quark scatterings. Both phenomena originate from the resonant scalar-pseudoscalar channel of the four-quark scatterings, and we compute the functional renormalisation group (fRG) flows of the Fierz-complete four-quark interaction of up and down quarks with its $t$ channel momentum dependence. This is done in the isospin symmetric case, also including the flow of the quark two-point function. This system can be understood as the fRG analogues of the complete Bethe-Salpeter equations and quark gap equation. The pole mass of the pion is determined from both direct calculations of the four-quark flows in the Minkowski regime of momenta and the analytic continuation based on results in the Euclidean regime, which are consistent with each other.

   hep-phnucl-thSciPost Phys.(2023)·31 citations
6. 06*

   Report of the Topical Group on Physics Beyond the Standard Model at Energy Frontier for Snowmass 2021

   Tulika Bose🇺🇸 · Antonio Boveia🇺🇸 · Caterina Doglioni🇬🇧 · Simone Pagan Griso🇺🇸 · James Hirschauer🇺🇸 · Elliot Lipeles🇺🇸 · Zhen Liu · Nausheen R. Shah🇺🇸 · Lian-Tao Wang · Kaustubh Agashe🇺🇸 · Juliette Alimena🇨🇭 · Sebastian Baum🇺🇸 and 310 other authors

   This is the Snowmass2021 Energy Frontier (EF) Beyond the Standard Model (BSM) report. It combines the EF topical group reports of EF08 (Model-specific explorations), EF09 (More general explorations), and EF10 (Dark Matter at Colliders). The report includes a general introduction to BSM motivations and the comparative prospects for proposed future experiments for a broad range of potential BSM models and signatures, including compositeness, SUSY, leptoquarks, more general new bosons and fermions, long-lived particles, dark matter, charged-lepton flavor violation, and anomaly detection.

   hep-phhep-ex64 citations
7. 07*

   One-loop on-shell and off-shell decay $H^{\ast }\to VV$ at future $e^{-}{e}^{-}$ collider

   Anh Thu Nguyen (HCMUS)🇻🇳 · Dzung Tri Tran (HCMUS)🇻🇳 · Khiem Hong Phan (DuyTan Univ.)🇳🇱

   One-loop on-shell and off-shell decays $H\to VV$ with $VV=\gamma \gamma ,Z\gamma ,ZZ$ are presented in this paper. The effects of one-loop on-shell and off-shell Higgs decays in Higgs productions at $e^{-}{e}^{-}$ collisions are also then examined. We find that the impacts of one-loop Higgs decays are significant and they are must be taken into account at $e^{-}{e}^{-}$ collision.

   hep-phJ.Phys.Conf.Ser.(2023)·3 citations
8. 08*

   $U_A(1)$ symmetry restoration at high baryon density

   Jianing Li🇨🇳 · Jin Gui🇨🇳 · Pengfei Zhuang🇨🇳

   We study the relation between chiral and $U_A(1)$ symmetries in the quark-meson model. Although quarks and mesons are described in mean field approximation, the topological susceptibility characterizing the $U_A(1)$ breaking comprises two components: one controlled by the condensate and the other by the meson fluctuation. The $U_A(1)$ restoration is governed by the competition of these components. In a hot medium, the condensates melt. However, the fluctuation is enhanced. Therefore, the $U_A(1)$ symmetry cannot be solely restored via the temperature effect. Nevertheless, the baryon density reduces the condensates and fluctuation, and thereby, the $U_A(1)$ symmetry can only be restored in a dense or dense and hot medium. The strange condensate plays a weak role in the susceptibility, and the chiral and $U_A(1)$ symmetry restorations occur almost at the same critical point.

   hep-phnucl-thCPC(2023)·3 citations
9. 09*

   Searching for $CP$ violation through two-dimensional angular distributions in four-body decays of bottom and charmed baryons

   Zhen-Hua Zhang🇨🇳

   It is proposed to search for $CP$ violation through the two-fold angular distributions in the four-body decays of bottom and charmed hadrons. The two polar angles in the two-fold angular distributions are correlated, to which the interferences of intermediate resonances are one important origin. These interferences will leave tracks in the two-fold angular distributions, with which the $CP$ violation can be studied. Special attention is paid to the case when all the intermediate resonances are different, which is unique to four-body decays. It is suggested to look for $CP$ violation in four-body decays such as ${\Lambda }_b^0\to p{\pi }^{-}{\pi }^{+}{\pi }^{-}$ through the analysis of the two-fold angular distributions. The method proposed in this paper is also widely applicable to other four-body decays processes.

   hep-phhep-exPRD(2023)·10 citations
10. 10*

    Information entropy and fragmentation functions

    Guillermo Benito-Calviño🇪🇸 · Javier García-Olivares🇪🇸 · Felipe J. Llanes-Estrada (Univ. Complutense Madrid)🇪🇸

    Several groups have recently investigated the flow of information in high-energy collisions, from the entanglement entropy of the proton yielding classical Shannon entropy of its parton distribution functions (pdfs), through jet splitting generating entropy, to the entropy distribution in hadron decays. Lacking in the literature is a discussion of the information entropy of fragmentation functions (FFs) in the instances where they can be considered as probability distributions, and we here provide it. We find that this entropy is a single, convenient number to characterize future progress in the extraction of fragmentation functions. We also deploy the related Kullback-Leibler divergence between two distributions to assess existing relations among FFs and parton distribution functions (pdfs) such as that of Barone, Drago and Ma. From a couple of current parametrizations of FFs, we do not find supporting empirical evidence for the relation, although it is possible that FFs and pdfs have similar power-laws near the $x=1$ endpoint.

    hep-phNPA(2023)·11 citations
11. 11*

    Global fits of simplified models for dark matter with GAMBIT I. Scalar and fermionic models with s-channel vector mediators

    Christopher Chang🇦🇺 · Pat Scott🇦🇺 · Tomás E. Gonzalo🇩🇪 · Felix Kahlhoefer🇩🇪 · Anders Kvellestad🇳🇴 · Martin White🇦🇺

    Simplified models provide a useful way to study the impacts of a small number of new particles on experimental observables and the interplay of those observables, without the need to construct an underlying theory. In this study, we perform global fits of simplified dark matter models with GAMBIT using an up-to-date set of likelihoods for indirect detection, direct detection and collider searches. We investigate models in which a scalar or fermionic dark matter candidate couples to quarks via an s-channel vector mediator. Large parts of parameter space survive for each model. In the case of Dirac or Majorana fermion dark matter, excesses in LHC monojet searches and relic density limits tend to prefer the resonance region, where the dark matter has approximately half the mass of the mediator. A combination of vector and axial-vector couplings to the Dirac candidate also leads to competing constraints from direct detection and unitarity violation.

    hep-phEPJC(2023)·26 citations
12. 12*

    Determination of pion distribution amplitudes from the electromagnetic form factor with the data-driven dispersion relation

    Jian Chai🇨🇳 · Shan Cheng🇨🇳 · Jun Hua🇨🇳

    We study the pion electromagnetic form factor in the modulus squared dispersion relation, and do the model independent extraction of the most important nonperturbative parameters in pion light-cone distribution amplitude. The motivation of this work is the recent measurement of timelike form factor in the resonant regions, which makes up the piece lacking solid QCD-based calculation. With the perturbative QCD calculation up to next-to-leading-order QCD corrections and twist four level of meson distribution amplitudes, we obtain the chiral mass of pion meson as $m_0^{\pi }(1\mathrm{GeV})=1.31_{-0.30}^{+0.27}\mathrm{GeV}$. More accuracy measurement of the timelike form factor are desirable to help us to determine the lowest gegenbauer moments in pion distribution amplitudes with the data-driven dispersion relation method developed in this work.

    hep-phEPJC(2023)·8 citations
13. 13*

    Precise perturbative predictions from fixed-order calculations

    Jiang Yan🇨🇳 · Zhi-Fei Wu🇨🇳 · Jian-Ming Shen🇨🇳 · Xing-Gang Wu🇨🇳

    The intrinsic conformality is a general property of the renormalizable gauge theory, which ensures the scale-invariance of a fixed-order series at each perturbative order. Following the idea of intrinsic conformality, we suggest a novel single-scale setting approach under the principle of maximum conformality (PMC) with the purpose of removing the conventional renormalization scheme-and-scale ambiguities. We call this newly suggested single-scale procedure as the PMC${}_{\infty }$-s approach, in which an overall effective ${\alpha }_s$, and hence an overall effective scale is achieved by identifying the $\{{\beta }_0\}$-terms at each order. Its resultant conformal series is scale-invariant and satisfies all renormalization group requirements. The PMC${}_{\infty }$-s approach is applicable to any perturbatively calculable observables, and its resultant perturbative series provides an accurate basis for estimating the contribution from the unknown higher-order (UHO) terms. Using the Higgs decays into two gluons up to five-loop QCD corrections as an example, we show how the PMC${}_{\infty }$-s works, and we obtain ${\Gamma }_{\mathrm{H}}{|}_{{\text{PMC}}_{\infty }\text{-s}}^{\mathrm{PAA}}=334.45_{-7.03}^{+7.07}\mathrm{KeV}$ and ${\Gamma }_{\mathrm{H}}{|}_{{\text{PMC}}_{\infty }\text{-s}}^{B.A.}=334.45_{-6.29}^{+6.34}\mathrm{KeV}$. Here the errors are squared averages of those mentioned in the body of the text. The Pad$\acute{e}$ approximation approach (PAA) and the Bayesian approach (B.A.) have been adopted to estimate the contributions from the UHO-terms. We also demonstrate that the PMC${}_{\infty }$-s approach is equivalent to our previously suggested single-scale setting approach (PMCs), which also follows from the PMC but treats the $\{{\beta }_i\}$-terms from different point of view. Thus a proper using of the renormalization group equation can provide a solid way to solve the scale-setting problem.

    hep-phJ.Phys.G(2023)·18 citations
14. 14*

    Imprints of vector field non-standard couplings on solar neutrino flux

    H. Yazdani Ahmadabadi🇮🇷 · H. Mohseni Sadjadi🇮🇷

    Regarding the proximity of dark energy scale and neutrino mass, one can get new insight into the probe signatures of vector field dark energy component on neutrino flavor conversion. A vector field is assumed to be conformally coupled to various matter components through a screening paradigm. We show how the oscillation probabilities evolve differently with a finite-size matter density like the Sun for different values of relevant model parameters. Considering existing neutrino flavor conversion data, we point out how this non-standard coupling affects neutrino fluxes and also we compute the discrepancy in the total flux of solar electron-neutrinos.

    hep-phgr-qchep-thPLB(2024)·5 citations
15. 15*

    Family Non-universal $Z^{\prime }$ Effects on $B_{d,s}\to K^{\ast 0}{\overline{K}}^{\ast 0}$ Decays in Perturbative QCD Approach

    Ying Li🇨🇳 · Guo-Hua Zhao🇨🇳 · Yan-Jun Sun🇨🇳 · Zhi-Tian Zou🇨🇳

    The nonleptonic decays $B_{d,s}\to K^{\ast 0}{\overline{K}}^{\ast 0}$ are reanalyzed in perturbative QCD approach, which is based on the $k_{\mathrm{T}}$ factorization. In the standard model, the calculated branching fraction and longitudinal polarization fraction of $B_d\to K^{\ast 0}{\overline{K}}^{\ast 0}$ are in agreement with experimental measurements, while the predictions of $B_s\to K^{\ast 0}{\overline{K}}^{\ast 0}$ cannot agree with data simultaneously. The parameter that combines of longitudinal polarization fractions and branching fractions evaluated to be $L_{K^{\ast }{\overline{K}}^{\ast 0}}^{\mathrm{PQCD}}=12.7_{-3.2}^{+5.6}$, which is also larger than that abstracted from experimental measurements. We then study all observables by introducing a family non-universal $Z^{\prime }$ boson in $b\to sq\bar{q}$ transitions. In order to reduce the number of new parameters, we simplify the model as possible. It is found that with the fixed value ${\omega }_{B_s}=0.55$, these exists parameter space where all measurements, including the branching fraction, longitudinal polarization fraction and $L_{K^{\ast }{\overline{K}}^{\ast 0}}$-parameter, could be accommodated simultaneously. All our results and the small parameter space could be further tested in the running LHC experiments, Belle-II and future high-energy colliders.

    hep-phhep-exPRD(2022)·10 citations
16. 16*

    Looking for the effects of New Physics in the ${\Lambda }_b⟶{\Lambda }_c(\to \Lambda \pi )\ell \nu$ decay mode

    Damir Bečirević🇫🇷 · Florentin Jaffredo🇫🇷

    One of the most pragmatic ways to look for the effects of New Physics at low energy scales is to study a detailed angular distribution of various decay modes, and in particular those based on $b\to c\ell {\bar{\nu }}_{\ell }$. In this paper we focus onto ${\Lambda }_b⟶{\Lambda }_c(\to \Lambda \pi )\ell \nu$ in a generic effective theory setup in which, besides the Standard Model, we allow for all the possible covariant dimension-six effective operators capturing the contributions arising at high energy scales, beyond the Standard Model. We list a number of observables that could be used as a diagnostic tool to check for the presence of New Physics and to discriminate among its various scenarios. We also briefly comment on ${\Lambda }_c\to \Lambda l\nu$.

    hep-phhep-exhep-lat18 citations
17. 17*

    Bottom hadro-chemistry in high-energy hadronic collisions

    Min He🇨🇳 · Ralf Rapp🇺🇸

    The hadro-chemistry of bottom quarks ($b$) produced in hadronic collisions encodes valuable information on the mechanism of color-neutralization in these reactions. Since the $b$-quark mass is much larger than the typical hadronic scale of $\sim$1\,GeV, $b\bar{b}$ pair production is expected to be well separated from subsequent hadronization processes. A significantly larger fraction of $b$ baryons has been observed in proton-proton ($pp$) and proton-antiproton ($p\bar{p}$) reactions relative to $e^{+}{e}^{-}$ collisions, challenging theoretical descriptions. We address this problem by employing a statistical hadronization approach with an augmented set of $b$-hadron states beyond currently measured ones, guided by the relativistic quark model and lattice-QCD computations. Assuming {\it relative} chemical equilibrium between different $b$-hadron yields, thermal densities are used as fragmentation weights of $b$-quarks into various hadron species. With quark model estimates of the decay patterns of excited states, the fragmentation fractions of weakly-decaying $b$ hadrons are computed and found to agree with measurements in $p\bar{p}$ collisions at the Tevatron. By combining transverse-momentum ($p_T$) distributions of $b$-quarks from perturbative QCD with thermal weights and independent fragmentation toward high $p_T$, a fair description of the $p_T$-dependent ${\bar{B}}_s^0/B^{-}$ and ${\Lambda }_b^0/B^{-}$ ratios measured in $pp$ collisions at the LHC is obtained. Finally, we implement the hadro-chemistry into a strongly-coupled transport approach for $b$-quarks in heavy-ion collisions, utilizing previously determined $b$-quark transport coefficients in the Quark-Gluon Plasma, to highlight the modifications of hadro-chemistry and collective behavior of $b$ hadrons in Pb-Pb collisions at the LHC.

    hep-phhep-exnucl-exnucl-thPRL(2023)·32 citations
18. 18*

    Testing entanglement and Bell inequalities in $H\to ZZ$

    J. A. Aguilar-Saavedra🇪🇸 · A. Bernal🇪🇸 · J. A. Casas🇪🇸 · J. M. Moreno🇪🇸

    We discuss quantum entanglement and violation of Bell inequalities in the $H\to ZZ$ decay, in particular when the two $Z-$bosons decay into light leptons. Although such process implies an important suppression of the statistics, this is traded by clean signals from a "quasi maximally-entangled" system, which makes it very promising to check these crucial phenomena at high energy. In this paper we devise a novel framework to extract from $H\to ZZ$ data all significant information related to this goal, in particular spin correlation observables. In this context we derive sufficient and necessary conditions for entanglement in terms of only two parameters. Likewise, we obtain a sufficient and improved condition for the violation of Bell-type inequalities. The numerical analysis shows that with a luminosity of $L=300{\text{fb}}^{-1}$ entanglement can be probed at $>3\sigma$ level. For $L=3{\text{ab}}^{-1}$ (HL-LHC) entanglement can be probed beyond the $5\sigma$ level, while the sensitivity to a violation of the Bell inequalities is at the $4.5\sigma$ level

    hep-phhep-thquant-phPRD(2023)·136 citations
19. 19*

    Signatures of excited monopolium

    Huner Fanchiotti🇦🇷 · Carlos A. Garcia-Canal🇦🇷 · Marco Traini🇮🇹 · Vicente Vento🇪🇸

    We study electromagnetic properties of particles with magnetic moment and no charge using their behavior when traversing coils and solenoids. These particles via the Faraday-Lenz law create a current whose energy we calculate. We analyze both the case of very long lived, almost stable, particles and those with a finite lifetime. We use this development to study the behavior of monopolium a monopole-antimonopole bound state in its excited states.

    hep-phEur.Phys.J.Plus(2022)·6 citations
20. 20*

    Probing right-handed neutrinos dipole operators

    Daniele Barducci🇮🇹 · Enrico Bertuzzo🇧🇷 · Marco Taoso🇮🇹 · Claudio Toni🇮🇹

    We consider the minimal see-saw extension of the Standard Model with two right-handed singlet fermions $N_{1,2}$ with mass at the GeV scale, augmented by an effective dipole operator between the sterile states. We firstly review current bounds on this effective interaction from fixed-target and collider experiments as well as from astrophysical and cosmological observations. We then highlight the prospects for testing the decay $N_2\to N_1\gamma$ induced by the dipole at future facilities targeting long lived particles such as ANUBIS, CODEX-b, FACET, FASER 2, MAPP and SHiP.

    hep-phhep-exJHEP(2023)·38 citations
21. 21*

    $B_c$ enhancement with non-thermalized bottom quarks in nuclear collisions at Large Hadron Collider

    Jiaxing Zhao🇨🇳 · Pengfei Zhuang🇨🇳

    We study $B_c$ production in high-energy nuclear collisions in a transport approach with dissociation and regeneration at finite temperatures. Due to the rare production in p+p collisions and the strong combination of uncorrelated $c$ and $\bar{b}$ quarks in the quark-gluon plasma, the $B_c$ yield is significantly enhanced in the nuclear collisions at the Large Hadron Collider. Moreover, the centrality and momentum-dependent yield of $B_c$ sensitively reflect the thermalization degree of bottom quarks. And the newly observed experimental data favors a far from the thermal bottom quark distribution in the quark-gluon plasma.

    hep-phnucl-thEPJA(2025)·5 citations
22. 22*

    Drell-Yan cross-sections with fiducial cuts: impact of linear power corrections and $q_T$-resummation in PDF determination

    Simone Amoroso🇩🇪 · Ludovica Aperio Bella🇩🇪 · Maarten Boonekamp🇫🇷 · Stefano Camarda🇨🇭 · Alexander Glazov🇩🇪 · Alessandro Guida · Renat Sadykov · Yulia Yermolchyk🇷🇺

    Measurement at Hadron colliders of neutral- and charged-current Drell-Yan production provide essential constraints in the determination of parton distribution functions. Experimentally, they have reached percent level precision, challenging the accuracy of the theoretical predictions. In this work we benchmark the novel implementation in $\text{DYTurbo}$ of linear fiducial power corrections in the $q_T$-subtraction formalism at NLO and NNLO in QCD. We illustrate how the inclusion of linear fiducial power corrections impacts predictions for precise $W$ and $Z$ measurements from the LHC and affects their description by modern global parton distribution functions. The further inclusion of $q_T$-resummation corrections in the theoretical predictions leads to a better modelling of the lepton $p_T$ distribution and we study how this improve the description of the data.

    hep-ph3 citations
23. 23*

    Non-standard neutrino interactions in light mediator models at reactor experiments

    Bhaskar Dutta🇺🇸 · Sumit Ghosh🇺🇸 · Tianjun Li🇨🇳 · Adrian Thompson🇺🇸 · Ankur Verma🇺🇸

    Compared to other neutrino sources, the huge anti-neutrino fluxes at nuclear reactor based experiments empower us to derive stronger bounds on non-standard interactions of neutrinos with electrons mediated by light scalar/vector mediators. At neutrino energy around $200$~keV reactor anti-neutrino flux is at least an order of magnitude larger compared to the solar flux. The atomic and crystal form factors of the detector materials related to the details of the atomic structure becomes relevant at this energy scale as the momentum transfers would be small. Non-standard neutrino-electron interaction mediated by light scalar/vector mediator arises naturally in many low-scale models. We also propose one such new model with a light scalar mediator. Here, we investigate the parameter space of such low-scale models in reactor based neutrino experiments with low threshold Ge and Si detectors, and find the prospect of probing/ruling out the relevant parameter space by finding the projected sensitivity at $90\%$ confidence level by performing a ${\chi }^2$-analysis. We find that a detector capable of discriminating between electron recoil and nuclear recoil signal down to a very low threshold such as $5$~eV placed in reactor based experiment would be able to probe a larger region in parameter space compared to the previously explored region. A Ge (Si) detector with $10$~kg-yr exposure and 1 MW reactor anti-neutrino flux would be able to probe the scalar and vector mediators with masses below 1 keV for coupling products $\sqrt{g_{\nu }{g}_e}$ $\sim$ $1\times 10^{-6}(9.5\times 10^{-7})$ and $1\times 10^{-7}(8\times 10^{-8})$, respectively.

    hep-phJHEP(2023)·23 citations
24. 24*

    Probing Axions via Light Circular Polarization and Event Horizon Telescope

    Soroush Shakeri🇮🇷 · Fazlollah Hajkarim🇮🇹

    The impact of axion-like particles on the light polarization around the horizon of suppermassive black hole (SMBH) is discussed in the light of the latest polarization measurement of the Event Horizon Telescope (EHT). We investigate different sources of the polarization due to axion interaction with photons and the magnetic field of SMBH. These can modify the linear and circular polarization parameters of the emitted light. We have shown that a significant circular polarization can be produced via the photon scattering from the background magnetic field with axions as off-shell particles. This can further constrain the parameter space of ultralight axion-like particles and their couplings with photons. The future precise measurements of circular polarization can probe the features of ultralight axions in the near vicinity of SMBH.

    hep-phastro-ph.COastro-ph.GAJCAP(2023)·18 citations
25. 25*

    Constraints on axion-like dark matter from a SERF comagnetometer

    Itay M. Bloch🇺🇸 · Roy Shaham🇮🇱 · Yonit Hochberg🇮🇱 · Eric Kuflik🇮🇱 · Tomer Volansky🇮🇱 · Or Katz (for the NASDUCK Collaboration)🇺🇸

    Ultralight axion-like particles are well-motivated relics that might compose the cosmological dark matter and source anomalous time-dependent magnetic fields. We report on terrestrial bounds from the Noble And Alkali Spin Detectors for Ultralight Coherent darK matter (NASDUCK) collaboration on the coupling of axion-like particles to neutrons and protons. The detector uses nuclei of noble-gas and alkali-metal atoms and operates in the Spin-Exchange Relaxation-Free~(SERF) regime, achieving high sensitivity to axion-like dark matter fields. Conducting a month-long search, we cover the mass range of $1.4\times 10^{-12}$~eV/$c^2$ to $2\times 10^{-10}$~eV/$c^2$ and provide limits which supersede robust astrophysical bounds, and improve upon previous terrestrial constraints by over two orders of magnitude for many masses within this range for protons, and up to two orders of magnitude for neutrons. These are the first reliable terrestrial bounds reported on the coupling of protons with axion-like dark matter, covering an unexplored terrain in its parameter space.

    hep-phhep-exphysics.atom-phquant-phNature Commun.(2023)·61 citations
26. 26*

    Medium-enhanced $c\bar{c}$ radiation

    Maximilian Attems · Jasmine Brewer · Gian Michele Innocenti · Aleksas Mazeliauskas · Sohyun Park · Wilke van der Schee · Urs Wiedemann

    We show that the same QCD formalism that accounts for the suppression of high-$p_T$ hadron and jet spectra in heavy-ion collisions predicts medium-enhanced production of $c\bar{c}$ pairs in jets.

    hep-phnucl-exnucl-thPRL(2024)·22 citations
27. 27*

    {\Lambda}(1520) resonance production with respect to transverse spherocity using EPOS3+UrQMD

    Nasir Mehdi Malik🇮🇳 · Sanjeev Singh Sambyal🇮🇳

    Resonances are sensitive to the properties of the medium created in heavy ion collision. They also provide insight into the properties of the hadronic phase. Studying the dependence of the yield of resonances on transverse spherocity and multiplicity allows us to understand the resonance production mechanism with event topology and system size, respectively. The results reported pertains to {\Lambda}(1520) . The data from EPOS3 is used for the present analysis.

    hep-phhep-exSciPost Phys.Proc.(2024)·0 citations
28. 28*

    Future of computing at the Large Hadron Collider

    Dhananjay Saikumar🇬🇧

    High energy physics (HEP) experiments at the LHC generate data at a rate of $\mathcal{O}(10)$ Terabits per second. This data rate is expected to exponentially increase as experiments will be upgraded in the future to achieve higher collision energies. The increasing size of particle physics datasets combined with the plateauing single-core CPU performance is expected to create a four-fold shortage in computing power by 2030. This makes it necessary to investigate alternate computing architectures to cope with the next generation of HEP experiments. This study provides an overview of different computing techniques used in the LHCb experiment (trigger, track reconstruction, vertex reconstruction, particle identification). Furthermore, this research led to the creation of three event reconstruction algorithms for the LHCb experiment. These algorithms are benchmarked on various computing architectures such as the CPU, GPU, and a new type of processor called the IPU, each roughly containing $\mathcal{O}(10)$, $\mathcal{O}(1000)$, and $\mathcal{O}(1000)$ cores respectively. This research indicates that multi-core architectures such as GPUs and IPUs are better suited for computationally intensive tasks within HEP experiments.

    hep-phhep-ex0 citations
29. 29*

    Magnetogenesis from early structure formation due to Yukawa forces

    Ruth Durrer🇨🇭 · Alexander Kusenko🇺🇸

    Yukawa interactions can mediate relatively long-range attractive forces between fermions in the early universe. Such a globally attractive interaction creates an instability that can result in the growth of structure in the affected species even during the radiation dominated era. The formation and collapse of fermionic microhalos can create hot fireballs at the sites of the collapsing halos which inject energy into the cosmic plasma. In this paper we study a new phenomena which can take place in such models. We show that the injected energy can be partially converted into primordial magnetic fields and we estimate the correlation scale and the power spectrum of these fields. We show that they may be the seeds of the observed astrophysical magnetic fields.

    ↳ astro-ph.COhep-phJCAP(2023)·6 citations
30. 30*

    Improved Mixed Dark Matter Halo Model for Ultralight Axions

    Sophie M. L. Vogt🇩🇪 · David J. E. Marsh🇬🇧 · Alex Laguë🇨🇦

    We present a complete halo model for mixed dark matter composed of cold dark matter (CDM) and ultralight axion-like particles (ULAs). Our model treats ULAs as a biased tracer of CDM, in analogy to treatments of massive neutrinos and neutral hydrogen. The model accounts for clustering of ULAs around CDM host halos, and fully models the cross correlations of both components. The model inputs include the ULA Jeans scale, and soliton density profile. Our model can be used to predict the matter power spectrum, $P(k)$, on non-linear scales for sub-populations of ULAs across the mass range $10^{-33}\text{ eV}\le m\le 10^{-21}\text{ eV}$, and can be calibrated against future mixed DM simulations to improve its accuracy. The mixed DM halo model also allows us to assess the importance of various approximations.

    ↳ astro-ph.COhep-phPRD(2023)·42 citations
31. 31*

    Testing Explanations of Short Baseline Neutrino Anomalies

    Nicolò Foppiani🇺🇸

    The experimental observation of neutrino oscillations profoundly impacted the physics of neutrinos, from being well understood theoretically to requiring new physics beyond the standard model of particle physics. Indeed, the mystery of neutrino masses implies the presence of new particles never observed before, often called sterile neutrinos, as they would not undergo standard weak interactions. And while neutrino oscillation measurements entered the precision era, reaching percent-level precision, many experimental results show significant discrepancies with the standard model, at baselines much shorter than typical oscillation baselines, like LSND, MiniBooNE, gallium experiments, and reactor antineutrino measurements. These short baseline anomalies could be explained by the addition of a light sterile neutrino, with mass in the $1-10\text{eV}$ range, however, in strong tension with many null experimental observations. Other explanations that rely on sterile neutrinos with masses in the $1-500\text{MeV}$ could resolve the tension. Here we test both classes of models. On the one hand, we look for datasets collected at a short baseline which can constrain heavy sterile neutrino models. We find that the minimal model is fully constrained, but several extensions of this model could weaken the current constraint and be tested with current and future datasets. On the other hand, we test the presence of neutrino oscillations at short baselines, induced by a light sterile state, with the data collected by the MicroBooNE experiment, a liquid argon time projection chamber specifically designed to resolve the details of each neutrino interaction. We report null results from both analyses, further constraining the space of possible explanations for the short baseline anomalies. If new physics lies behind the short baseline anomaly puzzle, it is definitely not described by a simple model.

    ↳ hep-exhep-ph4 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.