Thu·Sep 16, 2021Thursday·September 16, 2021

1. 01*

   Measuring tau neutrino appearance probability via unitarity

   Ivan Martinez-Soler🇺🇸 · Hisakazu Minakata🇺🇸

   We propose a {\em unitarity method} for determining $\tau$ neutrino appearance probability $P({\nu }_{\mu }\to {\nu }_{\tau })$ in long-baseline (LBL) accelerator experiments and atmospheric neutrino observations. When simultaneous in situ measurements of $P({\nu }_{\mu }\to {\nu }_{\mu })$ and $P({\nu }_{\mu }\to {\nu }_e)$ proceed, as is typical in the LBL experiments, one can use unitarity to "measure" $P({\nu }_{\mu }\to {\nu }_{\tau })$. A theorists' toy analysis for the model-independent determination of $P({\nu }_{\mu }\to {\nu }_{\mu })$ and $P({\nu }_{\mu }\to {\nu }_e)$ is presented by using the NOvA data. It is shown in our analysis that $\text{lsim}$5\% (8\%) measurement of $\tau$ neutrino appearance probability in neutrino (antineutrino) mode is possible in the peak region $1.5\lesssim E_{\nu }\lesssim 2.5$ GeV. The $\nu$SM-independent nature of determination of the probabilities is emphasized.

   hep-phhep-exPRD(2021)·12 citations
2. 02*

   Understanding two same-sign and three leptons with $b$-jets in four top quark events at the LHC

   Thuso Mathaha🇿🇦 · Abhaya Kumar Swain🇿🇦 · Mukesh Kumar🇿🇦 · Xifeng Ruan🇿🇦 · Bruce Mellado🇿🇦

   The top quark is the heaviest known elementary particle of the Standard Model (SM) of particle physics and, therefore, it is expected to have large couplings to hypothetical new physics in many models beyond the SM (BSM). Various studies have predicted the presence of multi-lepton anomalies at the LHC. One of those anomalies is the excess production of two same-sign leptons and three isolated leptons in association with $b$-jets. These are reasonably well described by a 2HDM+$S$ model, where $S$ is a singlet scalar. Both the ATLAS and CMS experiments have reported sustained excesses in these final states. This includes corners of the phase-space where production of top quark pairs in association with a $W$ boson contributes to. Here, we investigate the production of two same-sign and three leptons from the production of four top quark final states. Our focus is on understanding the differences between the SM and BSM production mechanisms of four top quarks from $t\overline{t}A$ ($A\to t\overline{t}$) using Machine Leaning techniques with twelve discriminating kinematic variables.

   hep-phhep-ex1 citation
3. 03*

   Masses and magnetic moments of hadrons with one and two open heavy quarks: heavy baryons and tetraquarks

   Wen-Xuan Zhang🇨🇳 · Hao Xu🇨🇳 · Duojie Jia🇨🇳

   In this work, we compute masses and magnetic moments of the heavy baryons and tetraquarks with one and two open heavy flavors in a unified framework of MIT bag model. Using the parameters of MIT bag model, we confirm that an extra binding energy, which is supposed to exist between heavy quarks ($c$ and $b$) and between heavy and strange quarks in literatures, is required to reconcile light hadrons with heavy hadrons. Numerical calculations are made for all light mesons, heavy hadrons with one and two open heavy flavors, predicting the masses of doubly charmed baryons to be $M({\Xi }_{cc})=3.604$ GeV, $M({\Xi }_{cc}^{\ast })=3.714$ GeV, and that of the strange isosinglet tetraquark $ud\bar{s}\bar{c}$ with $J^P=0^{+}$ to be $M\left(ud\bar{s}\bar{c},0^{+}\right)=2.934$ GeV. The state mixing due to chromomagnetic interaction is shown to be sizable for the strange scalar tetraquark $nn\bar{s}\bar{c}$.

   hep-phPRD(2021)·65 citations
4. 04*

   Frugal $U(1{)}_X$ models with non-minimal flavor violation for $b\to s\ell \ell$ anomalies and neutrino mixing

   Disha Bhatia🇮🇳 · Nishita Desai🇮🇳 · Amol Dighe🇮🇳

   We analyze the class of models with an extra $U(1{)}_X$ gauge symmetry that can account for the $b\to s\ell \ell$ anomalies by modifying the Wilson coefficients $C_{9e}$ and $C_{9\mu }$ from their standard model values. At the same time, these models generate appropriate quark mixing, and give rise to neutrino mixing via the Type-I seesaw mechanism. Apart from the gauge boson $Z^{\prime }$, these frugal models only have three right-handed neutrinos for the seesaw mechanism, an additional $SU(2{)}_L$ scalar doublet for quark mixing, and a SM-singlet scalar that breaks the $U(1{)}_X$ symmetry. This set-up identifies a class of leptonic symmetries, and necessitates non-zero but equal charges for the first two quark generations. If the quark mixing beyond the standard model were CKM-like, all these symmetries would be ruled out by the latest flavor constraints on Wilson coefficients and collider constraints on $Z^{\prime }$ parameters. However, we identify a single-parameter source of non-minimal flavor violation that allows a wider class of $U(1{)}_X$ symmetries to be compatible with all data. We show that the viable leptonic symmetries have to be of the form $L_e\pm 3L_{\mu }-L_{\tau }$ or $L_e-3L_{\mu }+L_{\tau }$, and determine the $(M_{Z^{\prime }},g_{Z^{\prime }})$ parameter space that may be probed by the high-luminosity data at the LHC.

   hep-phJHEP(2022)·11 citations
5. 05*

   Light Speed Variation with Brane/String-Inspired Space-Time Foam

   Chengyi Li🇨🇳 · Bo-Qiang Ma🇨🇳

   Recently a series of studies on high energy gamma-ray burst~(GRB) photons suggest a light speed variation with linear energy dependence at the Lorentz violation scale of $3.6\times 10^{17}\mathrm{GeV}$, with subluminal propagation of high energy photons in cosmological space. We propose stringy space-time foam as a possible interpretation for this light speed variation. In such a string-inspired scenario, bosonic photon open-string travels \textit{in vacuo} at an infraluminal speed with an energy dependence suppressed by a single power of the string mass scale, due to the foamy structure of space-time at small scales, as described by D-brane objects in string theory. We present a derivation of this deformed propagation speed of the photon field in the infrared (IR) regime. We show that the light speed variation, revealed in the previous studies on GRBs time-delay data, can be well described within such a string approach towards space-time foam. We also derive the value of the effective quantum-gravity mass in this framework, and give a qualitative study on the theory-dependent coefficients. We comment that stringent constraints on Lorentz violation in the photon sector from complementary astrophysical observations can also be explained and understood in the space-time foam context.

   hep-phastro-ph.HEgr-qcResults Phys.(2021)·18 citations
6. 06*

   Light baryonium spectrum

   Bing-Dong Wan🇨🇳 · Sheng-Qi Zhang🇨🇳 · Cong-Feng Qiao🇨🇳

   We evaluate the light baryonium spectrum, viz. the baryon-antibaryon states, in the framework of QCD sum rules. The nonperturbative contributions up to dimension 12 are taken into account. Numerical results indicate that there might exist eight possible light baryonium states, i.e. $p$-$\bar{p}$, $\Lambda$-$\bar{\Lambda }$, $\Sigma$-$\bar{\Sigma }$, and $\Xi$-$\bar{\Xi }$ with quantum numbers of $0^{-+}$ and $1^{--}$. For the $\Lambda$-$\bar{\Lambda }$, $\Sigma$-$\bar{\Sigma }$, and $\Xi$-$\bar{\Xi }$ states, their masses are found above the corresponding dibaryon thresholds, while the masses of $p$-$\bar{p}$ states are not. The possible baryonium decay modes are analyzed, which are hopefully measurable in BESIII, BELLEII, and LHCb experiments.

   hep-phPRD(2022)·42 citations
7. 07*

   Null test searches for BSM physics with rare charm decays

   Marcel Golz🇩🇪

   Semileptonic Flavor Changing Neutral Current decays of charmed hadrons uniquely probe the up-sector of the Standard Model. Clean null test observables, such as CP-asymmetries, lepton-universality ratios, missing energy modes, lepton flavor violating modes and angular observables can be studied in a variety of charmed meson and baryon modes. An overview of null test opportunities with rare charm decays is presented and similarities and complementarities of different modes are worked out.

   hep-phhep-exPoS(2021)·1 citation
8. 08*

   Theory Closing Talk

   Gian F. Giudice🇨🇭

   In this talk I make some remarks about the search for the origin of the electroweak scale.

   hep-phhep-thPoS(2021)·3 citations
9. 09*

   Particles Multiplicity Based on Rapidity in Landau and Artificial Neural Network(ANN) Models

   D. M. Habashy🇪🇬 · Mahmoud Y. El-Bakry🇪🇬 · Abdel Nasser Tawfik🇪🇬 · R. M. Abdel Rahman🇪🇬 · Mahmoud Hanafy🇪🇬

   ANN model is used to estimate the multiplicity per rapidity for charged pions and kaons observed in various high-energy experiments from central Au+Au collisions with energies ranging from 2-200 GeV, and then compared to available experimental data, including RHIC-BRAHMS, and the future facilities at NICA and FAIR. We also used Landau hydrodynamical approach, which has a better describtion for the evolution of hot and dense matter produced in ultra-relativistic heavy-ion collisions. The approach is fitted to both results estimated from experiment and ANN simulation. We noticed that the Landau model accurately reproduces the entire range of multiplicity per rapidity for all created particles at all energies. Also ANN model can reproduce the multiplicity per rapidity very well for all considered particles.

   hep-phInt.J.Mod.Phys.A(2022)·5 citations
10. 10*

    Rapidity Distribution within Landau hydrodynamical model and EPOS event-generator at RHIC Energies

    R. M. Abdel Rahman🇪🇬 · Abdel Nasser Tawfik🇪🇬 · Mahmoud Y. El-Bakry🇪🇬 · D. M. Habashy🇪🇬 · Mahmoud Hanafy🇪🇬

    The rapidity distribution of well-defined particles pions, Kaons, protons and their antiparticles measured in the BRAHMS experiment (Au+Au collisions), at $\sqrt{s_{NN}}$ = $62.4$ and $200$ GeV, are compared with huge statistical ensembles of 100, 000 events deduced from the Cosmic Ray MonteCarlo (CRMC) EPOS event-generator. All these data are then compared to the Landau hydrodynamical model. We conclude that the Landau hydrodynamical model is capable of describing both experimental data and EPOS $1.99$ event-generator results, and that they are in good agreement.

    hep-phPhys.Scripta(2022)·4 citations
11. 11*

    Implementing Transverse Momentum Dependent splitting functions in Parton Branching evolution equations

    Lissa Keersmaekers🇧🇪

    The Parton Branching (PB) approach describes the evolution of transverse momentum dependent (TMD) parton densities. We propose to extend the PB method by including TMD splitting functions, instead of the DGLAP splitting functions which assume strong ordering in transverse momentum. We present the evolution equations and their numerical solution, which is the first Monte Carlo implementation including TMD splitting functions.

    hep-phSciPost Phys.Proc.(2022)·6 citations
12. 12*

    Cosmology of an Axion-Like Majoron

    Antonio J. Cuesta🇦🇷 · Mario E. Gómez🇪🇸 · José I. Illana🇪🇸 · Manuel Masip🇪🇸

    We propose a singlet majoron model that defines an inverse seesaw mechanism in the $\nu$ sector. The majoron $\varphi$ has a mass $m_{\varphi }\approx 0.5$ eV and a coupling to the $\tau$ lepton similar to the one to neutrinos. In the early universe it is initially in thermal equilibrium, then it decouples at $T\approx 500$ GeV and contributes with just $\Delta N_{\mathrm{eff}}=0.026$ during BBN. At $T=26$ keV (final stages of BBN) a primordial magnetic field induces resonant $\gamma \leftrightarrow \varphi$ oscillations that transfer 6% of the photon energy into majorons, implying $\Delta N_{\mathrm{eff}}=0.55$ and a 4.7% increase in the baryon to photon ratio. At $T\approx m_{\varphi }$ the majoron enters in thermal contact with the heaviest neutrino and it finally decays into $\nu \bar{\nu }$ pairs near recombination, setting $\Delta N_{\mathrm{eff}}=0.85$. The boost in the expansion rate at later times may relax the Hubble tension (we obtain $H_0=(71.4\pm 0.5)$ km/s/Mpc), while the processes $\nu \bar{\nu }\leftrightarrow \varphi$ suppress the free streaming of these particles and make the model consistent with large scale structure observations. Its lifetime and the fact that it decays into neutrinos instead of photons lets this axion-like majoron avoid the strong bounds that affect other axion-like particles of similar mass and coupling to photons.

    hep-phastro-ph.COhep-thJCAP(2022)·18 citations
13. 13*

    Forbidden Scalar Dark Matter and Dark Higgses

    George N. Wojcik🇺🇸 · Thomas G. Rizzo🇺🇸

    As experimental searches for WIMP dark matter continue to yield null results, models beyond the WIMP paradigm have proliferated in order to elude ever improving observational constraints, among them that of sub-GeV dark matter mediated by a massive vector portal (a dark photon) associated with a new dark $U(1)$ gauge symmetry. It has been previously noted that for a significant range of the parameter space of this class of models, the annihilation of dark matter particles into a pair of dark photons can dominate the freeze-out process even when this process is kinematically forbidden for dark matter at rest -- this is known as the "forbidden dark matter" (FDM) regime. Prior studies of this regime, however, assume that any "dark Higgs" associated with breaking the dark $U(1)$ and imparting mass to the dark photon is decoupled from the dark matter and as such plays no role in the freeze-out process. In this paper, we explore the effects of a dark Higgs on sub-GeV dark matter phenomenology in this FDM regime by considering the simplest possible construction in which there exist non-trivial dark matter-dark Higgs couplings: a model with a single complex scalar DM candidate coupled directly to the dark Higgs field. We find that for a wide range of parameter space, the dark Higgs can alter the resulting relic abundance by many orders of magnitude, and that this effect can remain significant even for a small dark matter-dark Higgs coupling constant. Considering measurements from direct detection and measurements of the CMB, we further find that points in this model's parameter space which recreate the appropriate dark matter relic abundance suffer only mild constraints from other sources at present, but may become accessible in near-future direct detection experiments.

    hep-phJHEP(2022)·20 citations
14. 14*

    An introduction to axions and their detection

    Igor G. Irastorza🇪🇸

    In these notes I try to introduce the reader to the topic of axions: their theoretical motivation and expected phenomenology, their role in astrophysics and as dark matter candidate, and the experimental techniques to detect them. Special emphasis is made in this last point, for which a relatively updated review of worldwide efforts and future prospects is made. The material is intended as an introduction to the topic, and it was prepared as lecture notes for Les Houches summer school 2021. Abundant references are included to direct the reader to deeper insight on the different aspects of axion physics.

    hep-phastro-ph.SRhep-exSciPost Phys.Lect.Notes(2022)·70 citations
15. 15*

    Collider search of light dark matter model with dark sector decay

    Yu Cheng🇨🇳 · Wei Liao🇨🇳 · Qi-Shu Yan🇨🇳

    We explore the possibility that the dark matter relic density is not produced by thermal mechanism directly, but by the decay of other heavier dark sector particles which on the other hand can be produced by the thermal freeze-out mechanism. Using a concrete model with a light dark matter from dark sector decay, we study the collider signature of the dark sector particles in association with Higgs production processes. We find that the future lepton colliders can be a better place to probe the signature of this kind of light dark matter model than the hadron collider such as LHC. Meanwhile, it is found that a Higgs factory with center of mass energy 250 GeV has a better potential to resolve the signature of this kind of light dark matter model than the Higgs factory with center of mass energy 350 GeV.

    hep-phCPC(2022)·4 citations
16. 16*

    Using Machine Learning techniques in phenomenological studies in flavour physics

    Jorge Alda🇪🇸 · Jaume Guasch🇪🇸 · Siannah Penaranda🇪🇸

    An updated analysis of New Physics violating Lepton Flavour Universality, by using the Standard Model Effective Field Lagrangian with semileptonic dimension six operators at $\Lambda =1\mathrm{TeV}$ is presented. We perform a global fit, by discussing the relevance of the mixing in the first generation. We use for the first time in this context a Montecarlo analysis to extract the confidence intervals and correlations between observables. Our results show that machine learning, made jointly with the SHAP values, constitute a suitable strategy to use in this kind of analysis.

    hep-phJHEP(2022)·8 citations
17. 17*

    Bosonic dark matter in a coherent state driven by thermal fermions

    Eung Jin Chun🇰🇷

    If there is a scalar boson field interacting dominantly with a quark or a lepton in the thermal background, its coherent oscillation can be generated through the thermal effect and becomes a good dark matter candidate in a wide range of the coupling and masses. We describe the general features of this mechanism and analyze how it works in various situations considering asymptotic limits where analytic solutions can be obtained.

    hep-phastro-ph.COPLB(2022)·9 citations
18. 18*

    Dark matter transient annihilations in the early Universe

    Katsuya Hashino🇨🇳 · Jia Liu🇨🇳 · Xiao-Ping Wang🇨🇳 · Ke-Pan Xie🇺🇸

    The cosmological evolution can modify the dark matter (DM) properties in the early Universe to be vastly different from the properties today. Therefore, the relation between the relic abundance and the DM constraints today needs to be revisited. We propose novel \textit{transient} annihilations of DM which helps to alleviate the pressure from DM null detection results. As a concrete example, we consider the vector portal DM and focus on the mass evolution of the dark photon. When the Universe cools down, the gauge boson mass can increase monotonically and go across several important thresholds; opening new transient annihilation channels in the early Universe. Those channels are either forbidden or weakened at the late Universe which helps to evade the indirect searches. In particular, the transient resonant channel can survive direct detection (DD) without tuning the DM to be half of the dark photon mass and can be soon tested by future DD or collider experiments. A feature of the scenario is the existence of a light dark scalar.

    hep-phastro-ph.COPRD(2022)·10 citations
19. 19*

    Updated detection prospects for relic neutrinos using coherent scattering

    Jack D. Shergold🇬🇧

    We review the existing proposals to detect relic neutrinos using the coherent scattering of a neutrino wind on a test mass. By considering the transformation of the neutrino momentum between reference frames, we demonstrate that the induced acceleration scales with the square of the neutrino mass for unclustered neutrinos, contrary to the existing literature. In addition, we show that there is a large contribution to this effect from coherent neutrino-electron scattering, which can exceed the neutrino-nucleus component by nearly an order of magnitude. Unfortunately, we find that even with this enhancement there are no existing experiments or proposals capable of detecting relic neutrinos using this method.

    hep-phhep-exJCAP(2021)·30 citations
20. 20*

    Searching for BSM Physics in Yukawa Couplings and Flavour Symmetries

    J. Alonso-Gonzalez🇪🇸 · A. de Giorgi🇪🇸 · L. Merlo🇪🇸 · S. Pokorski🇵🇱

    In the framework of the Standard Model Effective Field Theory, we compare the lower bounds on the scale of new physics possibly contributing to the $f\bar{f}h$ effective couplings, obtained from the measurements of different observables, under the assumption that the Wilson coefficients of the relevant dim 6 operators respect certain flavour structure: either the Minimal Flavour Violation (MFV) ansatz or a flavour symmetry, often invoked to explain the observed pattern of fermion masses and mixings. We perform a global analysis of the bounds following from the limits on the diagonal couplings measured in the Higgs boson production and decays at the LHC experiments. Another set of bounds is obtained from the limits on non-diagonal couplings constrained by the variety of flavour changing neutral current (FCNC) and radiative decay processes. With the present precision of the LHC data, the FCNC data give stronger bounds on the scale of new physics than the collider data (obviously, for the MFV ansatz only collider data are relevant): once the Wilson coefficients respect some flavour structure, the obtained bounds are in the TeV range. In the quark case, these limits are compatible with a few percent deviations from the SM Yukawa couplings and only mildly more stringent than those obtained from the available collider data. For leptons, instead, the FCNC bounds are stronger and then a signal in the near future collider data would mean the violation of the flavour symmetry or indicate the presence of additional beyond the Standard Model contributions, affecting the flavour observables, that leads to cancellations.

    hep-phJHEP(2022)·10 citations
21. 21*

    Dissecting the collinear structure of quark splitting at NNLL

    Mrinal Dasgupta🇬🇧 · Basem Kamal El-Menoufi🇬🇧

    We explore the collinear limit of final-state quark splittings at order ${\alpha }_s^2$. While at general NLL level, this limit is described simply by a product of leading-order $1\to 2$ DGLAP splitting functions, at the NNLL level we need to consider $1\to 3$ splitting functions. Here, by performing suitable integrals of the triple-collinear splitting functions, we demonstrate how one may extract ${\mathcal{B}}_2^q(z)$, a differential version of the coefficient $B_2^q$ that enters the quark form factor at NNLL and governs the intensity of collinear radiation from a quark. The variable $z$ corresponds to the quark energy fraction after an initial $1\to 2$ splitting, and our results yield effective higher-order splitting functions, which may be considered as a step towards the construction of NNLL parton showers. Further, while in the limit $z\to 1$ we recover the standard soft limit results involving the CMW coupling with scale $k_t$, the $z$ dependence we obtain also motivates the extension of the notion of a physical coupling beyond the soft limit.

    hep-phJHEP(2021)·21 citations
22. 22*

    Baryon diffusion near the QCD critical point

    Lipei Du (Ohio State U.)🇺🇸 · Xin An (North Carolina U.)🇺🇸 · Ulrich Heinz (Ohio State U.)🇺🇸

    Fireballs created in relativistic heavy-ion collisions at different beam energies have been argued to follow different trajectories in the QCD phase diagram in which the QCD critical point serves as a landmark. Using a (1+1)-dimensional model setting with transverse homogeneity, we study the complexities introduced by the fact that the evolution history of each fireball cannot be characterized by a single trajectory but rather covers an entire swath of the phase diagram, with the finally emitted hadron spectra integrating over contributions from many different trajectories. Studying the phase diagram trajectories of fluid cells at different space-time rapidities, we explore how baryon diffusion shuffles them around, and how they are affected by critical dynamics near the QCD critical point. We find a striking insensitivity of baryon diffusion to critical effects. Its origins are analyzed and possible implications discussed.

    ↳ nucl-thhep-phnucl-exPoS(2022)·4 citations
23. 23*

    Optical Observations and Modeling of the Superluminous Supernova 2018lfe

    Yao Yin🇺🇸 · Sebastian Gomez🇺🇸 · Edo Berger🇺🇸 · Griffin Hosseinzadeh🇺🇸 · Matt Nicholl🇬🇧 · Peter K. Blanchard🇺🇸

    We present optical imaging and spectroscopy of SN\,2018lfe, which we classify as a Type I superluminous supernova (SLSN-I) at a redshift of $z=0.3501$ with a peak absolute magnitude of $M_r\approx -22.1$ mag, one of the brightest SLSNe discovered. SN\,2018lfe was identified for follow-up using our FLEET machine learning pipeline. Both the light curve and the spectra of SN\,2018lfe are consistent with the broad population of SLSNe. We fit the light curve with a magnetar central engine model and find an ejecta mass of $M_{\mathrm{ej}}\approx 3.8$ M${}_{\odot }$, a magnetar spin period of $P\approx 2.9$ ms and a magnetic field strength of $B_{\perp }\approx 2.8\times 10^{14}$ G. The magnetic field strength is near the top of the distribution for SLSNe, while the spin period and ejecta mass are near the median values of the distribution for SLSNe. From late-time imaging and spectroscopy we find that the host galaxy of SN\,2018lfe has an absolute magnitude of $M_r\approx -17.85$, ($L_B\approx 0.029$ $L^{\ast }$), and an inferred metallicity of $Z\approx 0.3$ Z${}_{\odot }$, and star formation rate of $\approx 0.8$ M${}_{\odot }$ yr${}^{-1}$.

    ↳ astro-ph.HEastro-ph.SRhep-phApJ(2022)·5 citations
24. 24*

    An investigation of over-training within semi-supervised machine learning models in the search for heavy resonances at the LHC

    Benjamin Lieberman🇿🇦 · Joshua Choma🇿🇦 · Salah-Eddine Dahbi🇿🇦 · Bruce Mellado🇿🇦 · Xifeng Ruan🇿🇦

    In particle physics, semi-supervised machine learning is an attractive option to reduce model dependencies searches beyond the Standard Model. When utilizing semi-supervised techniques in training machine learning models in the search for bosons at the Large Hadron Collider, the over-training of the model must be investigated. Internal fluctuations of the phase space and bias in training can cause semi-supervised models to label false signals within the phase space due to over-fitting. The issue of false signal generation in semi-supervised models has not been fully analyzed and therefore utilizing a toy Monte Carlo model, the probability of such situations occurring must be quantified. This investigation of $Z\gamma$ resonances is performed using a pure background Monte Carlo sample. Through unique pure background samples extracted to mimic ATLAS data in a background-plus-signal region, multiple runs enable the probability of these fake signals occurring due to over-training to be thoroughly investigated.

    ↳ hep-exhep-ph0 citations
25. 25*

    Confining and chiral properties of QCD in extremely strong magnetic fields

    Massimo D'Elia🇮🇹 · Lorenzo Maio🇮🇹 · Francesco Sanfilippo🇮🇹 · Alfredo Stanzione🇮🇹

    We investigate, by numerical lattice simulations, the static quark-antiquark potential, the flux tube properties and the chiral condensate for $N_f=2+1$ QCD with physical quark masses in the presence of strong magnetic fields, going up to $eB=9$ GeV${}^2$, with continuum extrapolated results. The string tension for quark-antiquark separations longitudinal to the magnetic field is suppressed by one order of magnitude at the largest explored magnetic field with respect to its value at zero magnetic background, but is still non-vanishing; in the transverse direction, instead, the string tension is enhanced but seems to reach a saturation at around 50 % of its value at $B=0$. The flux tube shows a consistent suppression/enhancement of the overall amplitude, with mild modifications of its profile. Finally, we observe magnetic catalysis in the whole range of explored fields with a behavior compatible with a lowest Landau level approximation, in particular with a linear dependence of the chiral condensate on $B$ which is in agreement, within errors, with that already observed for $eB\sim 1$ GeV${}^2$.

    ↳ hep-lathep-phhep-thPRD(2021)·44 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.