Wed·Dec 9, 2020Wednesday·December 9, 2020

1. 01*

   An asymptotically safe SU(5) GUT

   M. Fabbrichesi🇮🇹 · C. M. Nieto🇨🇴 · A. Tonero🇨🇦 · A. Ugolotti🇩🇪

   We minimally extend the Standard Model field content by adding new vector-like fermions at the TeV scale to allow gauge coupling unification at a realistic scale. We embed the model into a $SU(5)$ grand unified theory that is asymptotically safe and features an interacting fixed point for the gauge coupling. There are no Landau poles of the $U(1)$ gauge and Higgs couplings. Gauge, Yukawa and Higgs couplings are retraced from the fixed point and matched at the grand unification scale to those of the Standard Model rescaled up to the same energy. All couplings, their fixed point values and critical exponents always remain in the perturbative regime.

   hep-phPRD(2021)·11 citations
2. 02*

   Warm Inflation, Neutrinos and Dark matter: a minimal extension of the Standard Model

   Miguel Levy🇵🇹 · João G. Rosa🇵🇹 · Luis B. Ventura🇵🇹

   We show that warm inflation can be realized within a minimal extension of the Standard Model with three right-handed neutrinos, three complex scalars and a gauged lepton/B-L U(1) symmetry. This simple model can address all the shortcomings of the Standard Model that are not related to fine-tuning, within general relativity, with distinctive experimental signatures that can be probed in the near future. The inflaton field emerges from the collective breaking of the U(1) symmetry, and interacts with two of the right-handed neutrinos, sustaining a high-temperature radiation bath during inflation. The discrete interchange symmetry of the model protects the scalar potential against large thermal corrections and leads to a stable inflaton remnant at late times which can account for dark matter. Consistency of the model and agreement with Cosmic Microwave Background observations naturally yield light neutrino masses below 0.1 eV, while thermal leptogenesis occurs naturally after a smooth exit from inflation into the radiation era.

   hep-phastro-ph.COgr-qcJHEP(2021)·23 citations
3. 03*

   Probing Effective Field Theory Approach in the CP Violating Minimal Linear $\sigma$ Model

   J. Alonso-Gonzalez🇪🇸 · J.M. Lizana🇨🇭 · V. Martinez-Fernandez🇵🇱 · L. Merlo🇪🇸 · S. Pokorski🇵🇱

   The Minimal Linear $\sigma$ Model is a useful theoretical laboratory. One can investigate in a perturbative renormalisable model the properties of the Higgs boson as a pseudo-Goldstone boson, the phenomenological effects of the radial mode of the field $\mathtt{s}$ which spontaneously breaks the global $SO(5)$ symmetry and the validity of conclusions based on the Effective Field Theory approach with the field $\mathtt{s}$ in the spectrum, after the decoupling of heavy degrees of freedom. In this paper all those issues are discussed in the framework of the Minimal Linear $\sigma$ Model with CP violating phases leading to pseudoscalar components in the effective Standard Model Yukawa couplings. Also the character of the electroweak phase transition in the presence of the field $\mathtt{s}$ is investigated.

   hep-phEPJC(2021)·8 citations
4. 04*

   A relatively light, highly bino-like dark matter in the $Z_3$-symmetric NMSSM and recent LHC searches

   Waleed Abdallah🇮🇳 · AseshKrishna Datta🇮🇳 · Subhojit Roy🇮🇳

   A highly bino-like Dark Matter (DM), which is the Lightest Supersymmetric Particle (LSP), could be motivated by the stringent upper bounds on the DM direct detection rates. This is especially so when its mass is around or below 100 GeV for which such a bound tends to get most severe. Requiring not so large a higgsino mass parameter, that would render the scenario reasonably natural, prompts such a bino-like state to be relatively light. In the Minimal Supersymmetric Standard Model (MSSM), in the absence of comparably light scalars, such an excitation, if it has to be a thermal relic, is unable to meet the stringent experimental upper bound on its abundance unless its self-annihilation hits a funnel involving either the $Z$-boson or the Standard Model (SM)-like Higgs boson. We demonstrate that, in such a realistic situation, a highly bino-like DM of the popular $Z_3$-symmetric Next-to-Minimal Supersymmetric Standard Model (NMSSM) is viable over an extended range of its mass, from our targeted maximum in the vicinity of the mass of the top quark down to about 30 GeV. This is facilitated by the presence of comparably light singlet-like states that could serve as funnel (scalars) and/or coannihilating (singlino) states even as the bino-like LSP receives a minimal (but optimal) tempering triggered by suitably light higgsino states that, in the first place, evade stringent lower bounds on their masses that can be derived from the Large Hadron Collider (LHC) experiments only in the presence of a lighter singlino-like state. An involved set of blind spot conditions is derived for the DM direct detection rates by considering for the very first time the augmented system of neutralinos comprising of the bino, the higgsinos and the singlino which highlights the important roles played by the NMSSM parameters $\lambda$ and $\tan \beta$ in delivering a richer phenomenology.

   hep-phhep-exJHEP(2021)·18 citations
5. 05*

   Gravitational Waves from Dark Yang-Mills Sectors

   James Halverson🇺🇸 · Cody Long🇺🇸 · Anindita Maiti🇺🇸 · Brent Nelson🇺🇸 · Gustavo Salinas🇺🇸

   Dark Yang-Mills sectors, which are ubiquitous in the string landscape, may be reheated above their critical temperature and subsequently go through a confining first-order phase transition that produces stochastic gravitational waves in the early universe. Taking into account constraints from lattice and from Yang-Mills (center and Weyl) symmetries, we use a phenomenological model to construct an effective potential of the semi quark-gluon plasma phase, from which we compute the gravitational wave signal produced during confinement for numerous gauge groups. The signal is maximized when the dark sector dominates the energy density of the universe at the time of the phase transition. In that case, we find that it is within reach of the next-to-next generation of experiments (BBO, DECIGO) for a range of dark confinement scales near the weak scale.

   hep-phastro-ph.COhep-thJHEP(2021)·84 citations
6. 06*

   Leptonic Sum Rules from Flavour Models with Modular Symmetries

   Julia Gehrlein🇺🇸 · Martin Spinrath🇹🇼

   Sum rules in the lepton sector provide an extremely valuable tool to classify flavour models in terms of relations between neutrino masses and mixing parameters testable in a plethora of experiments. In this manuscript we identify new leptonic sum rules arising in models with modular symmetries with residual symmetries. These models simultaneously present neutrino mass sum rules, involving masses and Majorana phases, and mixing sum rules, connecting the mixing angles and the Dirac CP-violating phase. The simultaneous appearance of both types of sum rules leads to some non-trivial interplay, for instance, the allowed absolute neutrino mass scale exhibits a dependence on the Dirac CP-violating phase. We derive analytical expressions for these novel sum rules and present their allowed parameter ranges as well as their predictions at upcoming neutrino experiments.

   hep-phJHEP(2021)·22 citations
7. 07*

   Semileptonic weak decays of anti-triplet charmed baryons in the light-front formalism

   C.Q. Geng🇨🇳 · Chia-Wei Liu🇨🇳 · Tien-Hsueh Tsai🇹🇼

   We systematically study the semileptonic decays of ${\mathbf{B}}_{\mathbf{c}}\to {\mathbf{B}}_{\mathbf{n}}{\ell }^{+}{\nu }_{\ell }$ in the light-front constituent quark model, where ${\mathbf{B}}_{\mathbf{c}}$ represent the anti-triplet charmed baryons of $({\Xi }_c^0,{\Xi }_c^{+},{\Lambda }_c^{+})$ and ${\mathbf{B}}_{\mathbf{n}}$ correspond to the octet ones. We determine the spin-flavor structures of the constituents in the baryons with the Fermi statistics and calculate the decay branching ratios ($\mathcal{B}$s) and averaged asymmetry parameters ($\alpha$s) with the helicity formalism. In particular, we find that $\mathcal{B}({\Lambda }_c^{+}\to \Lambda e^{+}{\nu }_e,n{e}^{+}{\nu }_e)=(3.55\pm 1.04,0.36\pm 0.15)\%$, $\mathcal{B}({\Xi }_c^{+}\to {\Xi }^0{e}^{+}{\nu }_e,{\Sigma }^0{e}^{+}{\nu }_e,\Lambda e^{+}{\nu }_e)=(11.3\pm 3.35),0.33\pm 0.09,0.12\pm 0.04\%$ and $\mathcal{B}({\Xi }_c^0\to {\Xi }^{-}{e}^{+}{\nu }_e,{\Sigma }^{-}{e}^{+}{\nu }_e)=(3.49\pm 0.95,0.22\pm 0.06)\%$. Our results agree with the current experimental data. Our prediction for $\mathcal{B}({\Lambda }_c^{+}\to n{e}^{+}{\nu }_e)$ is consistent with those in the literature, which can be measured by the charm-facilities, such as BESIII and BELLE. Some of our results for the ${\Xi }_c^{+(0)}$ semileptonic channels can be tested by the experiments at BELLE as well as the ongoing ones at LHCb and BELLEII.

   hep-phhep-exPRD(2021)·26 citations
8. 08*

   Search for new light vector boson using $J/\Psi$ at BESIII and Belle II

   Kayoung Ban🇰🇷 · Yongsoo Jho🇰🇷 · Youngjoon Kwon🇰🇷 · Seong Chan Park🇰🇷 · Seokhee Park🇰🇷 · Po-Yan Tseng🇰🇷

   We investigate various search strategies for light vector boson $X$ in $\mathcal{O}(10)\mathrm{MeV}$ mass range using $J/\Psi$ associated channels at BESIII and Belle II: (i) $J/\Psi \to {\eta }_{c}X$ with $10^{10}J/\Psi$s at BESIII, (ii) $J/\Psi ({\eta }_c+X)+\ell \bar{\ell }$ production at Belle~II, and (iii) $J/\Psi +X$ with the displaced vertex in $X\to e^{+}{e}^{-}$ decay are analyzed and the future sensitivities at Belle II with 50 ${\mathrm{ab}}^{-1}$ luminosity are comprehensively studied. By requiring the displaced vertex to be within the beam pipe, the third method results in nearly background-free analysis, and the vector boson-electron coupling and the vector boson mass can be probed in the unprecedented range, $10^{-4}\le |{\epsilon }_e|\le 10^{-3}$ and $9\mathrm{MeV}\le m_X\le 100\mathrm{MeV}$ with 50 ${\mathrm{ab}}^{-1}$ at Belle II. This covers the favored signal region of ${}^8{\mathrm{Be}}^{\ast }$ anomaly recently reported by Atomki experiment with $m_X\simeq 17\mathrm{MeV}$.

   hep-phhep-exJHEP(2021)·16 citations
9. 09*

   Master integrals for bipartite cuts of three-loop photon self energy

   R.N. Lee🇷🇺 · A.I. Onishchenko🇷🇺

   We calculate master integrals for bipartite cuts of the three-loop propagator QED diagrams. These master integrals determine the spectral density of the photon self energy. Our results are expressed in terms of the iterated integrals, which, apart from the $4m$ cut, reduce to Goncharov's polylogarithms. The master integrals for $4m$ cut have been calculated in our previous paper in terms of the one-fold integrals of harmonic polylogarithms and complete elliptic integrals. We provide the threshold and high-energy asymptotics of the master integrals found, including those for $4m$ cut.

   hep-phJHEP(2021)·8 citations
10. 10*

    NLO QCD corrections to the processes pp $\to$ ZZ with 0, 1 and 2 jets at the LHC

    K.Djamaa🇩🇿 · A. Mohamed-Meziani🇩🇿

    We propose an implementation of ZZ, ZZj and ZZjj productions in MadGraph5_aMC@NLO framework at $\sqrt{s}$ = 14 TeV. We calculate these processes at leading order and next-to-leading order with QCD corrections and we present a theoretical prediction of their total cross sections with different cuts in transverse momentum of jets, including gluon fusion contributions. In the same time we estimate their theoretical uncertainty. We discuss the various kinematical distributions spectrums at partonic level and hadronic level applying the showering and hadronization using Pythia8. In order to reconstruct the events similar to that found at LHC, we use the ATLAS cards and the fast detector simulation Delphes.

    hep-phPhys.Part.Nucl.Lett.(2022)·0 citations
11. 11*

    Nonperturbative calculations of form factors for exclusive semileptonic $B_{(s)}$ decays

    Jonathan M. Flynn🇬🇧 · Ryan C. Hill🇬🇧 · Andreas Jüttner🇬🇧 · Amarjit Soni🇺🇸 · J. Tobias Tsang🇩🇰 · Oliver Witzel🇺🇸

    Precise theoretical predictions derived from the Standard Model are a key ingredient in searches for new physics in the flavor sector. The large mass and long lifetime of the $b$ quark make processes involving $b$ quarks of particular interest. We use lattice simulations to perform nonperturbative QCD calculations for semileptonic $B_{(s)}$ decays. We present results from our determinations of $B_s\to D_s\ell \nu$ and $B_s\to K\ell \nu$ semileptonic form factors and provide an outlook for our $B\to \pi \ell \nu$ calculation. In addition we discuss the determination of $R$-ratios testing lepton-flavor universality and suggest use of an improved ratio. Our calculations are based on the set of 2+1 flavor domain wall Iwasaki gauge field configurations generated by the RBC-UKQCD collaboration featuring three lattice spacings of $1/a=1.78$, $2.38$, and $2.79\text{GeV}$. Heavy $b$-quarks are simulated using the relativistic heavy quark action.

    hep-phhep-latPoS(2021)·6 citations
12. 12*

    Bounds on the scale of noncommutativity from mono photon production in ATLAS Runs -1 and -2 experiments at LHC energies

    M. R. Bekli🇩🇿 · I. Chadou.🇩🇿 · N. Mebarki🇩🇿

    Leading order study of direct photon production from proton-proton collisions, in the framework of Minimal (Seiberg-Witten) Non-Commutative Standard Model (NCSM), taking into account the Earth-rotation effects. We found that relative non-commutative contributions increase significantly at very high photon transverse momentum. Therefore, using Run-1 (\sqrt{s}= 8 TeV) and Run-2 (\sqrt{s}= 13 TeV) ATLAS experimental data of inclusive isolated prompt photon cross-section, TeV-Scale bounds of the non-commutativity (NC) parameter are obtained. For space-space non-commutativity, we obtain: {\Lambda}b=1.145 \pm 0.015 TeV , and for space-time non-commutativity, we obtain : {\Lambda}e=1.125 \pm 0.035 TeV.

    hep-phInt.J.Geom.Meth.Mod.Phys.(2021)·3 citations
13. 13*

    Quark, pion and axial condensates in three-flavor finite isospin chiral perturbation theory

    Prabal Adhikari🇺🇸 · Jens O. Andersen🇳🇴 · Martin A. Mojahed🇳🇴

    We calculate the light quark condensate, the strange quark condensate, the pion condensate, and the axial condensate in three-flavor chiral perturbation theory ($\chi$PT) in the presence of an isospin chemical potential at next-to-leading order at zero temperature. It is shown that the three-flavor $\chi$PT effective potential and condensates can be mapped onto two-flavor $\chi$PT ones by integrating out mesons with strange quark content (kaons and eta), with renormalized couplings. We compare the results for the light quark and pion condensates at finite pseudoscalar source with ($2+1$)-flavor lattice QCD, and we also compare the axial condensate at zero pseudoscalar and axial sources with lattice QCD data. We find that the light quark, pion, and axial condensates are in very good agreement with lattice data. There is an overall improvement by including NLO effects.

    hep-phEPJC(2021)·16 citations
14. 14*

    On nuclear coalescence in small interacting systems

    M. Kachelriess🇳🇴 · S. Ostapchenko🇷🇺 · J. Tjemsland🇳🇴

    The formation of light nuclei can be described as the coalescence of clusters of nucleons into nuclei. In the case of small interacting systems, such as dark matter and $e^{+}{e}^{-}$ annihilations or $pp$ collisions, the coalescence condition is often imposed only in momentum space and hence the size of the interaction region is neglected. On the other hand, in most coalescence models used for heavy ion collisions, the coalescence probability is controlled mainly by the size of the interaction region, while two-nucleon momentum correlations are either neglected or treated as collective flow. Recent experimental data from $pp$ collisions at LHC have been interpreted as evidence for such collective behaviour, even in small interacting systems. We argue that these data are naturally explained in the framework of conventional QCD inspired event generators when both two-nucleon momentum correlations and the size of the hadronic emission volume are taken into account. To include both effects, we employ a per-event coalescence model based on the Wigner function representation of the produced nuclei states. This model reproduces well the source size for baryon emission and the coalescence factor $B_2$ measured recently by the ALICE collaboration in $pp$ collisions.

    hep-phnucl-thEPJA(2021)·32 citations
15. 15*

    A comprehensive study on the semileptonic decay of heavy flavor mesons

    Lu Zhang🇨🇳 · Xian-Wei Kang🇨🇳 · Xin-Heng Guo🇨🇳 · Ling-Yun Dai🇨🇳 · Tao Luo🇨🇳 · Chao Wang🇨🇳

    The semileptonic decay of heavy flavor mesons offers a clean environment for extraction of the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements, which describes the CP-violating and flavor changing process in the Standard Model. The involved form factors where the dynamical information is encoded play an essential role in achieving any conclusive statement. That is, the knowledge of the form factors should be under good control, requiring one to examine more observables in addition to the branching fraction. In this paper, we provide the mean value and the $q^2$-dependent shape for further observables [differential decay distribution ($d\Gamma /d{q}^2$), forward-backward asymmetry (${\mathcal{A}}_{FB}^l$), longitudinal ($P_L^l$) and transverse ($P_T^l$) polarization of a charged lepton, longitudinal polarization of a vector meson in the final state ($F_L^l(V)$), leptonic convexity parameter ($C_F^l$), and trigonometric moments ($W_i^l$) in the decay of $D_{(s)}$ and $B_{(s)}$ to $P/V{l}^{+}{\nu }_l$ ($l=e$, $\mu$ or $\tau$)], based on the predictions of the relevant form factors from the covariant light-front quark model. $P$ and $V$ denote the pseudoscalar and vector meson, respectively. As a comparison, we find a good agreement with the results from the covariant confining quark model and the relativistic quark model in the literature. As it has been observed that the $P_L^l$ and $F_L^l(V)$ are crucial quantities to discriminate various New Physics models, the reexamination of these observables from a different method is also essential and necessary.

    hep-phhep-exJHEP(2021)·35 citations
16. 16*

    Scalar Fully-heavy Tetraquark States $Q{Q}^{\prime }\bar{Q}\overline{Q^{\prime }}$ in QCD Sum Rules

    Bo-Cheng Yang🇨🇳 · Liang Tang🇨🇳 · Cong-Feng Qiao🇨🇳

    Very recently, the LHCb Collaboration observed distinct structures with the $cc\bar{c}\bar{c}$ in the $J/\Psi$-pair mass spectrum. In this work, we construct four scalar ($J^{PC}=0^{++}$) $[8_c{]}_{Q\overline{Q^{\prime }}}\otimes [8_c{]}_{Q^{\prime }\bar{Q}}$ type currents to investigate the fully-heavy tetraquark state $Q{Q}^{\prime }\bar{Q}\overline{Q^{\prime }}$ in the framework of QCD sum rules, where $Q=c,b$ and $Q^{\prime }=c,b$. Our results suggest that the broad structure around 6.2-6.8 GeV can be interpreted as the $0^{++}$ octet-octet tetraquark states with masses $6.44\pm 0.11$ GeV and $6.52\pm 0.10$ GeV, and the narrow structure around $6.9$ GeV can be interpreted as the $0^{++}$ octet-octet tetraquark states with masses $6.87\pm 0.11$ GeV and $6.96\pm 0.11$ GeV, respectivley. Extending to the b-quark sector,the masses of their fully-bottom partners are found to be around 18.38-18.59 GeV. Additionally, we also analyze the spectra of the $[c\bar{c}][b\bar{b}]$ and $[c\bar{b}][b\bar{c}]$ tetraquark states, which lie in the range of 12.51-12.74 GeV and 12.49-12.81 GeV, respectively.

    hep-phEPJC(2021)·98 citations
17. 17*

    Minimal inverse-seesaw mechanism with Abelian flavour symmetries

    H. B. Camara🇵🇹 · R. G. Felipe🇵🇹 · F. R. Joaquim🇵🇹

    We study the phenomenology of the minimal $(2,2)$ inverse-seesaw model supplemented with Abelian flavour symmetries. To ensure maximal predictability, we establish the most restrictive flavour patterns which can be realised by those symmetries. This setup requires adding an extra scalar doublet and two complex scalar singlets to the Standard Model, paving the way to implement spontaneous CP violation. It is shown that such CP-violating effects can be successfully communicated to the lepton sector through couplings of the scalar singlets to the new sterile fermions. The Majorana and Dirac CP phases turn out to be related, and the active-sterile neutrino mixing is determined by the active neutrino masses, mixing angles and CP phases. We investigate the constraints imposed on the model by the current experimental limits on lepton flavour-violating decays, especially those on the branching ratio $BR(\mu \to e\gamma )$ and the capture rate $CR(\mu -e,\mathrm{Au})$. The prospects to further test the framework put forward in this work are also discussed in view of the projected sensitivities of future experimental searches sensitive to the presence of heavy sterile neutrinos. Namely, we investigate at which extent upcoming searches for $\mu \to e\gamma$, $\mu \to 3e$ and $\mu -e$ conversion in nuclei will be able to test our model, and how complementary will future high-energy collider and beam-dump experiments be in that task.

    hep-phJHEP(2021)·20 citations
18. 18*

    Where is the lightest charmed scalar meson?

    Meng-Lin Du🇩🇪 · Feng-Kun Guo🇨🇳 · Christoph Hanhart🇩🇪 · Bastian Kubis🇩🇪 · Ulf-G. Meißner🇩🇪

    The lightest charmed scalar meson is known as the $D_0^{\ast }(2300)$, which is one of the earliest new hadron resonances observed at modern $B$ factories. We show here that the parameters assigned to the lightest scalar $D$-meson are in conflict with the precise LHCb data of the decay $B^{-}\to D^{+}{\pi }^{-}{\pi }^{-}$. On the contrary, these data can be well described by an unitarized chiral amplitude containing a much lighter charmed scalar meson, the $D_0^{\ast }(2100)$. We also extract the low-energy $S$-wave $D\pi$ phase of the decay $B^{-}\to D^{+}{\pi }^{-}{\pi }^{-}$ from the data in a model-independent way, and show that its difference from the $D\pi$ scattering phase shift can be traced back to an intermediate ${\rho }^{-}$ exchange. Our work highlights that an analysis of data consistent with chiral symmetry, unitarity, and analyticity is mandatory in order to extract the properties of the ground-state scalar mesons in the singly heavy sector correctly, in analogy to the light scalar mesons $f_0(500)$ and $K_0^{\ast }(700)$.

    hep-phhep-exPRL(2021)·54 citations
19. 19*

    Kinematical Observables in Semi-Invisible Decays

    Kai Ma🇨🇳

    Invisible particles frequently appear in final state in studying physics at colliders. Experimental precision is also low in measuring missing energy. In this paper, we propose a general approach for studying process involving invisible particles. We provided two kinematical observables which are sensitive to production kinematics in different regions, and hence are complementary. Usage of our approach is illustrated by three examples. It is shown that our observables are still useful in case of that the significance S/B is relatively low.

    hep-phhep-ex0 citations
20. 20*

    Spontaneous Peccei-Quinn symmetry breaking renders sterile neutrino, axion and $\chi$boson to be candidates for dark matter particles

    She-Sheng Xue🇮🇹

    We study the Peccei-Quinn (PQ) symmetry of the sterile right-handed neutrino sector and the gauge symmetries of the Standard Model. Due to four-fermion interactions, spontaneous breaking of these symmetries at the electroweak scale generates top-quark Dirac mass and sterile-neutrino Majorana mass. The top quark channel yields massive Higgs, $W^{\pm }$ and $Z^0$ bosons. The sterile neutrino channel yields the heaviest sterile neutrino Majorana mass, sterile Nambu-Goldstone axion (or majoron) and massive scalar $\chi$boson. Four-fermion operators effectively induce their tiny couplings to SM particles. We show that a sterile QCD axion is the PQ solution to the strong CP problem. The lightest and heaviest sterile neutrinos ($m_N^e\sim 10^2$ keV and $m_N^{\tau }\sim 10^2$ GeV), a sterile QCD axion ($m_a<10^{-8}$ eV, $g_{a\gamma }<10^{-13}{\mathrm{GeV}}^{-1}$) and a Higgs-like $\chi$boson ($m_{\chi }\sim 10^2$ GeV) can be dark matter particle candidates, for the constraints of their tiny couplings and long lifetimes inferred from the $W$-boson decay width, Xenon1T and precision fine-structure-constant experiments. The axion and $\chi$boson couplings to SM particles are below the values reached by current laboratory experiments and astrophysical observations for directly or indirectly detecting dark matter particles.

    hep-phastro-ph.COgr-qchep-ex+1NPB(2022)·6 citations
21. 21*

    The Weak Scale as a Trigger

    Nima Arkani-Hamed🇺🇸 · Raffaele Tito D'Agnolo🇫🇷 · Hyung Do Kim🇰🇷

    Does the value of the Higgs mass parameter affect the expectation value of local operators in the Standard Model? For essentially all local operators the answer to this question is "no", and this is one of the avatars of the hierarchy problem: nothing is "triggered" when the Higgs mass parameter crosses zero. In this letter, we explore settings in which Higgs mass parameters $can$ act as a "trigger" for some local operators ${\mathcal{O}}_T$. In the Standard Model, this happens for ${\mathcal{O}}_T=\mathrm{Tr}(G\tilde{G})$. We also introduce a "type-0" two Higgs doublet model, with a $Z_4$ symmetry, for which ${\mathcal{O}}_T=H_1{H}_2$ is triggered by the Higgs masses, demanding the existence of new Higgs states necessarily comparable to or lighter than the weak scale, with no wiggle room to decouple them whatsoever. Surprisingly, this model is not yet entirely excluded by collider searches, and will be incisively probed by the high-luminosity run of the LHC, as well as future Higgs factories. We also discuss a possibility for using this trigger to explain the origin of the weak scale, invoking a landscape of extremely light, weakly interacting scalars ${\varphi }_i$, with a coupling to ${\mathcal{O}}_T$ needed to make it possible to find vacua with small enough cosmological constant. The weak scale trigger links the tuning of the Higgs mass to that of the cosmological constant, while coherent oscillations of the ${\varphi }_i$ can constitute dark matter.

    hep-phastro-ph.COhep-thPRD(2021)·63 citations
22. 22*

    Dispersive analysis of the Primakoff reaction $\gamma K\to K\pi$

    Maximilian Dax🇩🇪 · Dominik Stamen🇩🇪 · Bastian Kubis🇩🇪

    We provide a dispersion-theoretical representation of the reaction amplitudes $\gamma K\to K\pi$ in all charge channels, based on modern pion-kaon $P$-wave phase shift input. Crossed-channel singularities are fixed from phenomenology as far as possible. We demonstrate how the subtraction constants can be matched to a low-energy theorem and radiative couplings of the $K^{\ast }(892)$ resonances, thereby providing a model-independent framework for future analyses of high-precision kaon Primakoff data.

    hep-phhep-exnucl-thEPJC(2021)·20 citations
23. 23*

    Diophantine equations with sum of cubes and cube of sum

    Bogdan A. Dobrescu🇺🇸 · Patrick J. Fox🇺🇸

    We solve Diophantine equations of the type $a(x^3+y^3+z^3)=(x+y+z{)}^3$, where $x,y,z$ are integer variables, and the coefficient $a\ne 0$ is rational. We show that there are infinite families of such equations, including those where $a$ is any cube or certain rational fractions, that have nontrivial solutions. There are also infinite families of equations that do not have any nontrivial solution, including those where $1/a=1-24/m$ with restrictions on the integer $m$. The equations can be represented by elliptic curves unless $a=9$ or 1, and any elliptic curve of nonzero $j$-invariant and torsion group $\mathbb{Z}/3k\mathbb{Z}$ for $k=2,3,4$, or $\mathbb{Z}/2\mathbb{Z}\times \mathbb{Z}/6\mathbb{Z}$ corresponds to a particular $a$. We prove that for any $a$ the number of nontrivial solutions is at most 3 or is infinite, and for integer $a$ it is either 0 or $\infty$. For $a=9$, we find the general solution, which depends on two integer parameters. These cubic equations are important in particle physics, because they determine the fermion charges under the $U(1)$ gauge group.

    ↳ math.NThep-phhep-thCommun.Num.Theor.Phys.(2022)·7 citations
24. 24*

    The Shape of the Correlation Function

    Jakub Cimerman🇨🇿 · Chrisopher Plumberg🇺🇸 · Boris Tomášik🇸🇰

    The correlation function measured in ultrarelativistic nuclear collisions is strongly non-Gaussian. Using two different models we study which effects can influence its shape and how much. In particular, we focus on the parametrizations expressed with the help of Lévy-stable distributions. We show that the Lévy index may deviate substantially from 2 due to non-critical effects such as resonance decays, event-by-event fluctuations and functional dependence on $Q_{LI}$ or similar. We also study the corrections including the first-order Lévy expansion.

    ↳ nucl-thhep-phnucl-exPoS(2021)·2 citations
25. 25*

    Forward quark jet-nucleus scattering in a light-front Hamiltonian approach

    Meijian Li🇺🇸

    We investigate the scattering of a quark jet on a high-energy heavy nucleus using the time-dependent light-front Hamiltonian approach. We simulate a real-time evolution of the quark in a strong classical color field of the relativistic nucleus, described as the Color Glass Condensate. We study the sub-eikonal effect by letting the quark jet carry realistic finite longitudinal momenta, and we find sizeable changes on the transverse coordinate distribution of the quark. We also observe the energy loss of the quark through gluon emissions in the $|q⟩+|qg⟩$ Fock space. This approach provides us with an opportunity to study scattering processes from non-perturbative aspects.

    ↳ nucl-thhep-phPoS(2021)·1 citation
26. 26*

    Beyond 4D Tracking: Using Cluster Shapes for Track Seeding

    Patrick J. Fox🇺🇸 · Shangqing Huang🇺🇸 · Joshua Isaacson🇺🇸 · Xiangyang Ju🇺🇸 · Benjamin Nachman🇺🇸

    Tracking is one of the most time consuming aspects of event reconstruction at the Large Hadron Collider (LHC) and its high-luminosity upgrade (HL-LHC). Innovative detector technologies extend tracking to four-dimensions by including timing in the pattern recognition and parameter estimation. However, present and future hardware already have additional information that is largely unused by existing track seeding algorithms. The shape of clusters provides an additional dimension for track seeding that can significantly reduce the combinatorial challenge of track finding. We use neural networks to show that cluster shapes can reduce significantly the rate of fake combinatorical backgrounds while preserving a high efficiency. We demonstrate this using the information in cluster singlets, doublets and triplets. Numerical results are presented with simulations from the TrackML challenge.

    ↳ physics.ins-dethep-exhep-phphysics.data-an+1JINST(2021)·12 citations
27. 27*

    First Observations of Solar Disk Gamma Rays over a Full Solar Cycle

    Tim Linden🇸🇪 · John F. Beacom🇺🇸 · Annika H. G. Peter🇺🇸 · Benjamin J. Buckman🇺🇸 · Bei Zhou🇺🇸 · Guanying Zhu🇺🇸

    The solar disk is among the brightest gamma-ray sources in the sky. It is also among the most mysterious. No existing model fully explains the luminosity, spectrum, time variability, and morphology of its emission. We perform the first analysis of solar-disk gamma rays over a full 11-year solar cycle, utilizing a powerful new method to differentiate solar signals from astrophysical backgrounds. We produce: (i) a robustly measured spectrum from 100 MeV to 100 GeV, reaching a precision of several percent in the 1-10 GeV range, (ii) new results on the anti-correlation between solar activity and gamma-ray emission, (iii) strong constraints on short-timescale variability, ranging from hours to years, and (iv) new detections of the equatorial and polar morphologies of high-energy gamma rays. Intriguingly, we find no significant energy dependence in the time variability of solar-disk emission, indicating that strong magnetic-field effects close to the solar surface, rather than modulation throughout the heliosphere, must primarily control the flux and morphology of solar-disk emission.

    ↳ astro-ph.HEastro-ph.SRhep-phPRD(2022)·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.