Tue·Oct 2, 2018Tuesday·October 2, 2018

1. 01*

   Dynamical Dark Matter, MATHUSLA, and the Lifetime Frontier

   David Curtin🇨🇦 · Keith R. Dienes🇺🇸 · Brooks Thomas🇺🇸

   MATHUSLA is a proposed surface detector at CERN that would be able to observe the decays of non-hadronic electrically neutral long-lived particles (LLPs) with almost no background or trigger limitations. This would allow MATHUSLA to probe sub-GeV to TeV masses and lifetimes up to $c\tau \sim 10^7\mathrm{m}$. MATHUSLA can play an important role in probing dark-matter scenarios involving extended hidden sectors, where additional dark states often manifest as LLPs. A prime example of such a scenario is furnished by the Dynamical Dark Matter (DDM) framework, which intrinsically gives rise to large ensembles of dark states exhibiting a broad range of masses and lifetimes. In this paper, we examine the extent to which MATHUSLA can probe the DDM parameter space, and we demonstrate that MATHUSLA may be capable of providing direct confirmation of certain unique aspects of the DDM framework which might be difficult to probe in other ways.

   hep-phPRD(2018)·31 citations
2. 02*

   Pole position of the $a_1(1260)$ from $\tau$-decay

   JPAC Collaboration: M.Mikhasenko🇩🇪 · A.Pilloni🇺🇸 · M.Albaladejo🇺🇸 · C.Fernandez-Ramirez🇲🇽 · A.Jackura🇺🇸 · V.Mathieu🇺🇸 · J.Nys🇧🇪 · A.Rodas🇪🇸 · B.Ketzer🇩🇪 · A.P.Szczepaniak🇺🇸

   We perform an analysis of the three-pion system with quantum numbers $J^{PC}=1^{++}$ produced in the weak decay of $\tau$ leptons. The interaction is known to be dominated by the axial meson $a_1(1260)$. We build a model based on approximate three-body unitarity and fix the free parameters by fitting it to the ALEPH data on ${\tau }^{-}\to {\pi }^{-}{\pi }^{+}{\pi }^{-}{\nu }_{\tau }$ decay. We then perform the analytic continuation of the amplitude to the complex energy plane. The singularity structures related to the $\pi \pi$ subchannel resonances are carefully addressed. Finally, we extract the $a_1(1260)$ pole position $m_p^{(a_1(1260))}-i{\Gamma }_p^{(a_1(1260))}/2$ with $m_p^{(a_1(1260))}=(1209\pm 4_{-9}^{+12})\text{MeV}$, ${\Gamma }_p^{(a_1(1260))}=(576\pm 11_{-20}^{+89})\text{MeV}$}.

   hep-phPRD(2018)·45 citations
3. 03*

   Faint Light from Dark Matter: Classifying and Constraining Dark Matter-Photon Effective Operators

   Bradley J. Kavanagh🇳🇱 · Paolo Panci🇨🇭 · Robert Ziegler🇨🇭

   Even if Dark Matter (DM) is neutral under electromagnetism, it can still interact with the Standard Model (SM) via photon exchange from higher-dimensional operators. Here we classify the general effective operators coupling DM to photons, distinguishing between Dirac/Majorana fermion and complex/real scalar DM. We provide model-independent constraints on these operators from direct and indirect detection. We also constrain various DM-lepton operators, which induce DM-photon interactions via RG running or which typically arise in sensible UV-completions. This provides a simple way to quickly assess constraints on any DM model that interacts mainly via photon exchange or couples to SM leptons.

   hep-phastro-ph.COJHEP(2019)·71 citations
4. 04*

   Power corrections and renormalons in parton quasi-distributions

   V.Braun🇩🇪 · A.Vladimirov🇩🇪 · J.-H.Zhang🇩🇪

   Perturbative expansions for short-distance quantities in QCD are factorially divergent and this deficiency can be turned into a useful tool to investigate nonperturbative corrections. In this work, we use this approach to study the structure of power corrections to parton quasi-distributions and pseudo-distributions which appear in lattice calculations of parton distribution functions. As the main result, we predict the functional dependence of the leading power corrections to quasi(pseudo)-distributions on the Bjorken $x$ variable. We also show that these corrections can be strongly affected by the normalization procedure.

   hep-phhep-latPRD(2019)·125 citations
5. 05*

   Recent progress in Nuclear Parton Distributions

   Pia Zurita🇺🇸

   The determination of the parton distribution functions (PDFs) is crucial for a complete understanding of the protons and neutrons that make most of the visible matter in the universe. Years of dedicated studies have yielded a quite precise knowledge of the behavior of partons moving collinearly within a proton. However Deep Inelastic Scattering (DIS) experiments off nuclei have shown a non-trivial difference with respect to DIS in protons, hinting that the partons in a nuclear medium do not behave the same way as in a free proton. In this work we will discuss the latest results in nuclear parton distribution functions (nPDFs) and how data from planned future experiments can help broaden our understanding of the nPDFs.

   hep-ph7 citations
6. 06*

   Scouring meson decays for true muonium

   Yao Ji🇩🇪 · Henry Lamm🇺🇸

   Rare meson decay experiments promise to measure branching ratios as small as $10^{-13}$. This presents an opportunity to discover the ${\mu }^{+}{\mu }^{-}$ bound state true muonium. We consider a set of possible channels, all with branching ratios above $\sim 10^{-11}$. For the electromagnetic decays $\eta /{\eta }^{\prime }\to ({\mu }^{+}{\mu }^{-})\gamma$, theoretical and phenomenological form factors $F_{\eta /{\eta }^{\prime }\gamma {\gamma }^{\ast }}(Q^2)$ allow predictions of $\mathcal{B}\mathcal{R}({\eta }^{\prime }\to ({\mu }^{+}{\mu }^{-})\gamma )\sim 4.8\times 10^{-10}$ and $\mathcal{B}\mathcal{R}({\eta }^{\prime }\to ({\mu }^{+}{\mu }^{-})\gamma )\sim 3.7\times 10^{-11}$ at the 5% level. Discussion of experimental prospects and potential backgrounds are made.

   hep-phhep-exPRD(2019)·12 citations
7. 07*

   NNLO final-state quark-pair corrections in four dimensions

   Ben Page🇩🇪 · Roberto Pittau🇪🇸

   We describe how NNLO final state quark-pair corrections are computed in FDR by directly enforcing gauge invariance and unitarity in the definition of the regularized divergent integrals. The whole procedure is strictly four-dimensional and renormalization is performed by simply fixing bare parameters in terms of physical measurements. We give details of our approach and demonstrate how virtual and real contributions can be merged together without relying on dimensional regularization. As an example, we recompute the $H\to b\bar{b}+jets$ and ${\gamma }^{\ast }\to jets$ inclusive rates at the NNLO accuracy in the large $N_F$ limit of QCD.

   hep-phhep-thEPJC(2019)·14 citations
8. 08*

   CTEQ-TEA parton distribution functions with intrinsic charm

   Marco Guzzi🇺🇸 · Tie-Jiun Hou🇹🇼 · Sayipjamal Dulat🇨🇳 · Jun Gao🇨🇳 · Joey Huston🇺🇸 · Pavel Nadolsky🇺🇸 · Carl Schmidt🇺🇸 · Jan Winter🇺🇸 · Keping Xie🇺🇸 · C.-P. Yuan🇺🇸

   The possibility of a (sizable) nonperturbative contribution to the charm parton distribution function (PDF) in a nucleon is investigated together with theoretical issues arising in its interpretation. Results from the global PDF analysis are presented. The separation of the universal component of the nonperturbative charm from the rest of the radiative contributions is discussed and the potential impact of a nonperturbative charm PDF on LHC scattering processes is illustrated. An estimate of nonperturbative charm magnitude in the CT14 and CT14HERA2 global QCD analyses at the next-to-next-to leading order (NNLO) in the QCD coupling strength is given by including the latest experimental data from HERA and the Large Hadron Collider (LHC). A comparison between different models of intrinsic charm is shown and prospects for standard candle observables at the LHC are illustrated.

   hep-phEPJ Web Conf.(2018)·3 citations
9. 09*

   Axino abundances in high-scale supersymmetry

   Ki-Young Choi🇰🇷 · Hyun Min Lee🇰🇷

   We consider the thermal production of axino dark matter in high-scale supersymmetry where all the superpartners except the axino are heavier than the maximum and reheating temperatures. In this case, the axinos are produced dominantly in pairs from the scattering of SM particles in thermal plasma in the early Universe after inflation. We find that the thermal averaged scattering cross section for the axino pair production is given by $⟨\sigma v⟩\propto T^4$ in Kim-Shifman-Vainstein-Zakharov (KSVZ) axion model, while it does not depend on the temperature in Dine-Fischler-Srednicki-Zhitnitski (DFSZ) axion model. As a result, the axinos produced during the early matter domination is diluted by the entropy production, so the axino abundance is determined mainly by the reheating temperature, unlike the case with gravitino dark matter. We show that the axino pair production in DFSZ model opens up new parameter space for axino dark matter, due to non-decoupled Higgsino interactions at tree level.

   hep-phastro-ph.COPhys.Dark Univ.(2018)·8 citations
10. 10*

    Self-consistency and covariance of light-front quark models: testing via $P$, $V$ and $A$ meson decay constants, and $P\to P$ weak transition form factors

    Qin Chang🇨🇳 · Xiao-Nan Li🇨🇳 · Xin-Qiang Li🇨🇳 · Fang Su🇨🇳 · Ya-Dong Yang🇨🇳

    In this paper, we test the self-consistencies of the standard and the covariant light-front quark model and study the zero-mode issue via the decay constants of pseudoscalar ($P$), vector ($V$) and axial-vector ($A$) mesons, as well as the $P\to P$ weak transition form factors. With the traditional type-I correspondence between the manifestly covariant and the light-front approach, the resulting $f_V$ as well as $f_{{}^{1}A}$ and $f_{{}^{3}A}$ obtained with the $\text{lbd}=0$ and $\text{lbd}=\pm$ polarization states are different from each other, which presents a challenge to the self-consistency of the covariant light-front quark model. However, such a self-consistency problem can be "resolved" within the type-II scheme, which requires an additional replacement $M\to M_0$ relative to the type-I case. Moreover, the replacement $M\to M_0$ is also essential for the self-consistency of the standard light-front quark model. In the type-II scheme, the valence contributions to the physical quantities~($\mathcal{Q}$) considered in this paper are alway the same as that obtained in the standard light-front quark model, $[\mathcal{Q}{]}_{val.}=[\mathcal{Q}{]}_{\mathrm{SLF}}$, and the zero-mode contributions to $f_{V{,}^{1}A{,}^{3}A}$ and $f_{-}(q^2)$ exist only formally but vanish numerically, which implies further that $[\mathcal{Q}{]}_{val.}\dot{=}[\mathcal{Q}{]}_{\mathrm{full}}$. In addition, the manifest covariance of the covariant light-front quark model is violated in the traditional type-I scheme, but can be recovered by taking the type-II scheme.

    hep-phPRD(2018)·51 citations
11. 11*

    On the scattering of a high-energy cosmic ray electrons off the dark matter

    V. Beylin🇷🇺 · M. Bezuglov🇷🇺 · V. Kuksa🇷🇺 · E. Tretyakov🇷🇺 · A. Yagozinskaya🇷🇺

    High-energy cosmic ray electrons interaction with Dark Matter particles are considered. In particular, a weakening of energy spectrum of cosmic electrons is predicted resulting from inelastic electron scattering on hyper-pions in the hypercolor extension of the Standard Model. Corresponding cross section and angular distributions of secondary neutrino are calculated and studied. We also briefly discuss some effects of scattering processes of such type.

    hep-phInt.J.Mod.Phys.A(2019)·8 citations
12. 12*

    $R_D$ and $R_{D^{\ast }}$: Theoretical Development

    Ryoutaro Watanabe🇨🇦

    Recent theoretical developments on $R_D$ and $R_{D^{\ast }}$ -- discrepancies between experimental data and the Standard Model predictions have been reported (B anomaly) -- are reviewed. New Physics explanations for the B anomaly and other relevant observables to obtain additional bounds on New Physics are also summarized. This is the proceedings for the talk at CIPANP2018 which was held on May 29 2018.

    hep-ph1 citation
13. 13*

    Assigning the newly reported ${\Sigma }_b(6097)$ as a $P$-wave excited state and predicting its partners

    Bing Chen🇨🇳 · Xiang Liu🇨🇳

    The newly observed ${\Sigma }_b(6097)$ provides us a good chance to further construct the high excited states of the bottom baryon family. In this work, we explain the ${\Sigma }_b(6097)$ to be a $1P$ state with $J^P=5/2^{-}$ or $3/2^{-}$ by giving the mass spectrum analysis and the strong decay calculation, and predict the existence of $1P$ and $2S$ partners of the ${\Sigma }_b(6097)$, where their masses and the corresponding decay behaviors are presented. Because of the success of describing the ${\Sigma }_b(6097)$ and the former observed ${\Xi }_b(6227)$ under the quasi-two-body treatment to the bottom baryons, we continue to predict the ${\Omega }_b$ partners of ${\Sigma }_b(6097)$ by the same method, which are the $1P$ and $2S$ states of the $bss$ baryon system. Identifying these predicted bottom baryons will be a research topic full of challenge and opportunity for future experiments especially the LHCb.

    hep-phhep-exPRD(2018)·52 citations
14. 14*

    Model-independent Astrophysical Constraints on Leptophilic Dark Matter in the Framework of Tsallis Statistics

    Atanu Guha🇮🇳 · P. S. Bhupal Dev🇺🇸 · Prasanta Kumar Das🇮🇳

    We derive model-independent astrophysical constraints on leptophilic dark matter (DM), considering its thermal production in a supernova core and taking into account core temperature fluctuations within the framework of $q$-deformed Tsallis statistics. In an effective field theory approach, where the DM fermions interact with the Standard Model via dimension-six operators of either scalar-pseudoscalar, vector-axial vector, or tensor-axial tensor type, we obtain bounds on the effective cut-off scale $\Lambda$ from supernova cooling and free-streaming of DM from supernova core, and from thermal relic density considerations, depending on the DM mass and the $q$-deformation parameter. Using Raffelt's criterion on the energy loss rate from SN1987A, we obtain a lower bound on $\text{Lda}\gtrsim 3$ (12) TeV corresponding to $q=1.0(1.1)$ and an average supernova core temperature of $T_{\mathrm{SN}}=30$ MeV. From the optical depth criterion on the free-streaming of DM fermions from the outer 10\% of the SN1987A core, the cooling bound is restricted to $\text{Lda}\gtrsim 1$ TeV. Both cooling and free-streaming bounds are insensitive to the DM mass $m_{\chi }$ for $m_{\chi }\lesssim T_{\mathrm{SN}}$, whereas for $m_{\chi }\gg T_{\mathrm{SN}}$, the bounds weaken significantly due to the Boltzmann-suppression of the DM number density. We also calculate the thermal relic density of the DM particles in this setup and find that it imposes an upper bound on ${\Lambda }^4/m_{\chi }^2$, which together with the cooling/free-streaming bound significantly constrains light leptophilic DM.

    hep-phastro-ph.HEJCAP(2019)·40 citations
15. 15*

    Pion condensation and QCD phase diagram at finite isospin density

    Jens O. Andersen🇳🇴 · Prabal Adhikari🇺🇸 · Patrick Kneschke🇳🇴

    We use the Polyakov-loop extended two-flavor quark-meson model as a low-energy effective model for QCD to study 1) the possibility of inhomogeneous chiral condensates and its competition with a homogeneous pion condensate in the $\mu$--${\mu }_I$ plane at $T=0$ and 2) the phase diagram in the ${\mu }_I$--$T$ plane. In the $\mu$--${\mu }_I$ plane, we find that an inhomogeneous chiral condensate only exists for pion masses lower that 37.1 MeV and does not coexist with a homogeneous pion condensate. In the ${\mu }_I$--$T$ plane, we find that the phase transition to a Bose-condensed phase is of second order for all values of ${\mu }_I$ and we find that there is no pion condensation for temperatures larger than approximately 187 MeV. The chiral critical line joins the critical line for pion condensation at a point, whose position depends on the Polyakov-loop potential and the sigma mass. For larger values of ${\mu }_I$ these curves are on top of each other. The deconfinement line enters smoothly the phase with the broken $O(2)$ symmetry. We compare our results with recent lattice simulations and find overall good agreement

    hep-phPoS(2019)·10 citations
16. 16*

    Diagnosing New Physics with LUV and LFV B Decays

    Alakabha Datta🇺🇸

    An important prediction of the standard model is the universality of the gauge interactions of the three generation of charged leptons. Violation of this universality would be a clean evidence of new physics (NP) beyond the standard model. In recent times anomalies in measurements of certain $B$ decays indicate violation of lepton universality (LUV). I will discuss how one may probe this LUV new physics via related decays and distributions. I will point out that LUV new physics can often lead to lepton flavor violation (LFV) and I will discuss some promising decays to look for LFV new physics.

    hep-ph0 citations
17. 17*

    Masses of doubly heavy baryons in the Bethe-Salpeter equation approach

    Qi-Xin Yu🇨🇳 · Xin-Heng Guo🇨🇳

    A doubly heavy baryon can be regarded as composed of a heavy diquark and a light quark. In this picture, we study the masses of the doubly heavy diquarkes in the Bethe-Salpeter (BS) formalism first, which are then used as one of the inputs in studying the masses of the doubly heavy baryons in the quark-diquark model. We establish the BS equations for both the heavy diquarks and the heavy baryons with and without taking the heavy quark limit, respectively. These equations are solved numerically with the kernel containing the scalar confinement and one-gluon-exchange terms. The mass of the doubly charmed baryon ${\Xi }_{cc}^{(\ast )}$ is obtained in both approaches, $3.60\sim 3.65\mathrm{GeV}$ (${\Xi }_{cc}^{(\ast )}$) under the heavy quark limit, $3.53\sim 3.56\mathrm{GeV}$ for ${\Xi }_{cc}$ and $3.61\sim 3.63\mathrm{GeV}$ for ${\Xi }_{cc}^{\ast }$ without taking the heavy quark limit. The masses of ${\Xi }_{bc}^{\prime }$, ${\Xi }_{bc}^{(\ast )}$, ${\Xi }_{bb}^{(\ast )}$, ${\Omega }_{cc}^{(\ast )}$, ${\Omega }_{bc}^{\prime }$, ${\Omega }_{bc}^{(\ast )}$ and ${\Omega }_{bb}^{(\ast )}$ are also predicted in the same way. We find that the corrections to the results in the heavy quark limit are about $-0.02\mathrm{GeV}\sim -0.11\mathrm{GeV}$ for the masses of the doubly heavy baryons.

    hep-phNPB(2019)·46 citations
18. 18*

    Quarkonium: a theory overview

    Elena G. Ferreiro🇪🇸

    Quarkonium has long been proposed as one of the golden probes to identify the phase transition from confined hadronic matter to the deconfined quark-gluon plasma in heavy-ion collisions. Since then, we have achieved a better understanding, not only about the propagation of quarkonium in-medium, but also about its production. Recent theoretical developments in our comprehension of the quarkonium production mechanism in proton-proton collisions and on the propagation of quarkonia in proton-nucleus and nucleus-nucleus collisions are reviewed and discussed.

    hep-phnucl-thNPA(2019)·4 citations
19. 19*

    Hard-core Radius of Nucleons within the Induced Surface Tension Approach

    K. A. Bugaev🇺🇦 · A. I. Ivanytskyi🇺🇦 · V. V. Sagun🇺🇦 · B. E. Grinyuk🇺🇦 · D. O. Savchenko🇺🇦 · G. M. Zinovjev🇺🇦 · E. G. Nikonov🇷🇺 · L. V. Bravina🇳🇴 · E. E. Zabrodin🇳🇴 · D. B. Blaschke🇵🇱 · A. V. Taranenko🇷🇺 · L. Turko🇵🇱

    In this work we discuss a novel approach to model the hadronic and nuclear matter equations of state using the induced surface tension concept. Since the obtained equations of state, classical and quantum, are among the most successful ones in describing the properties of low density phases of strongly interacting matter, they set strong restrictions on the possible value of the hard-core radius of nucleons. Therefore, we perform a detailed analysis of its value which follows from hadronic and nuclear matter properties and find the most trustworthy range of its values: the hard-core radius of nucleons is 0.30--0.36 fm. A comparison with the phenomenology of neutron stars implies that the hard-core radius of nucleons has to be temperature and density dependent.

    hep-phastro-ph.HEnucl-thUniverse(2019)·11 citations
20. 20*

    First extraction of transversity from data on lepton-hadron scattering and hadronic collisions

    Marco Radici🇮🇹

    We present the first extraction of the transversity distribution based on the global analysis of pion-pair production in deep-inelastic scattering and in proton-proton collisions with one transversely polarized proton. The extraction relies on the knowledge of di-hadron fragmentation functions, which are taken from the analysis of electron-positron annihilation data. For the first time, the chiral-odd transversity is extracted from a global analysis similar to what is usually done for the chiral-even spin-averaged and helicity distributions. The knowledge of transversity is important among other things for detecting possible signals of new physics in high-precision low-energy experiments.

    hep-phhep-exnucl-exnucl-thPoS(2019)·2 citations
21. 21*

    On the capture rates of big bang neutrinos by nuclei within the Dirac and Majorana hypotheses

    Esteban Roulet🇦🇷 · Francesco Vissani🇮🇹

    The capture rates of non-relativistic neutrinos on beta decaying nuclei depends on whether their mass is Dirac or Majorana. It is known that for relic neutrinos from the big-bang, and within minimal assumptions, the rate is a factor two larger in the Majorana case. We show that this difference also depends on the value of the lightest neutrino mass and on the type of mass hierarchy. If the lightest neutrino has a mass below the meV, so that it is still relativistic today, its capture rate for the case of Dirac masses becomes equal to that for Majorana masses. As a consequence, for the case of normal neutrino mass hierarchy, for which the total capture rate is dominated by the contribution from the lightest neutrino, if this one is below the meV the distinction between the Dirac and Majorana scenarios can only rely on the detection of the two heavier neutrinos, which is something very challenging.

    hep-phastro-ph.COJCAP(2018)·29 citations
22. 22*

    Weak Decays of Doubly Heavy Baryons: ${\mathcal{B}}_{cc}\to {\mathcal{B}}_{c}V$

    Li-Juan Jiang🇨🇳 · Bei He🇨🇳 · Run-Hui Li🇨🇳

    The weak decays of a spin-$1/2$ doubly charm baryon (${\mathcal{B}}_{cc}$) to a spin-$1/2$ singly charm baryon (${\mathcal{B}}_c$) and a light vector meson ($V$) are studied under a phenomenological scheme. The contributions are classified into different topological diagrams, among which the short distance ones are calculated under the factorization hypothesis, and the long distance contributions are modelled as final-state interactions (FSIs) which are estimated with the one-particle-exchange model. In calculation the topological contributions tend to fall in a hierarchy. The branching fractions or decay widths are estimated, and it indicates that ${\Xi }_{cc}^{+}\to {\Xi }_c^{+}{\pi }^{+}{\pi }^{-}$ and ${\Omega }_{cc}^{+}\to {\Xi }_c^{+}{K}^{-}{\pi }^{+}$ can be used as candidate decays for searching ${\Xi }_{cc}^{+}$ and ${\Omega }_{cc}^{+}$. Some decays that are mainly activated by the long distance effects are found, observation on which in future experiments can help to understand the role of FSIs in charm baryon decays.

    hep-phhep-exEPJC(2018)·48 citations
23. 23*

    Corrections to the higher moments of the heavy ion energy-loss distribution beyond the Born approximation. II. Beta dependence of Mott's corrections

    O. Voskresenskaya🇷🇺

    The Mott corrections to the higher moments of the heavy ion energy-loss distribution are calculated in a wide range of relative particle velocity on the basis of the Mott exact cross section. It is shown that the relative Mott corrections to the first-order Born central moments and normalized central moments reach a large value over the range under consideration.

    hep-phISSN: 2329-6542 Journal of Astrophysics &…·2 citations
24. 24*

    Phase Transitions in Twin Higgs Models

    Kohei Fujikura🇯🇵 · Kohei Kamada🇯🇵 · Yuichiro Nakai🇺🇸 · Masahide Yamaguchi🇯🇵

    We study twin Higgs models at non-zero temperature and discuss cosmological phase transitions as well as their implications on electroweak baryogenesis and gravitational waves. It is shown that the expectation value of the Higgs field at the critical temperature of the electroweak phase transition is much smaller than the critical temperature, which indicates two important facts: (i) the electroweak phase transition cannot be analyzed perturbatively (ii) the electroweak baryogenesis is hardly realized in the typical realizations of twin Higgs models. We also analyze the phase transition associated with the global symmetry breaking, through which the Standard Model Higgs is identified with one of the pseudo-Nambu-Goldstone bosons in terms of its linear realization, with and without supersymmetry. For this phase transition, we show that, only in the supersymmetric case, there are still some parameter spaces, in which the perturbative approach is validated and the phase transition is the first order. We find that the stochastic gravitational wave background is generated through this first order phase transition, but it is impossible to be detected by DECIGO or BBO in the linear realization and the decoupling limit. The detection of stochastic gravitational wave background with the feature of first order phase transition, therefore, will give strong constraints on twin Higgs models.

    hep-phastro-ph.COgr-qcJHEP(2018)·35 citations
25. 25*

    Higgs and gauge boson phenomenology of the 3-3-1 model with CKS mechanism

    H. N. Long🇻🇳 · N. V. Hop🇺🇸 · L. T. Hue🇻🇳 · N. H. Thao🇻🇳 · A. E. Cárcamo Hernández🇨🇱

    We perform a comprehensive analysis of several phenomenological aspects of the renormalizable extension of the inert 3-3-1 model with sequentially loop-generated SM fermion mass hierarchy. Special attention is paid to the study of the constraints arising from the experimental data on the $\rho$ parameter, as well as those ones resulting from the charged lepton flavor violating process $\mu \to e\gamma$ and dark matter. We also study the single $Z^{\prime }$ production via Drell-Yan mechanism at the LHC. We have found that $Z^{\prime }$ gauge bosons heavier than about $4$ TeV comply with the experimental constraints on the oblique $\rho$ parameter as well as with the collider constraints. In addition, we have found that the constraint on the charged lepton flavor violating decay $\mu \to e\gamma$ sets the sterile neutrino masses to be lighter than about $1.12$ TeV. In addition the model allows charged lepton flavor violating processes within reach of the forthcoming experiments. The scalar potential and the gauge sector of the model are analyzed and discussed in detail. Our model successfully accommodates the observed Dark matter relic density.

    hep-phPRD(2019)·17 citations
26. 26*

    On the sensitivity of present direct detection experiments to WIMP-quark and WIMP-gluon effective interactions: a systematic assessment and new model-independent approaches

    Sunghyun Kang🇰🇷 · Stefano Scopel🇰🇷 · Gaurav Tomar🇰🇷 · Jong-Hyun Yoon (Sogang U.)🇰🇷

    Assuming for Weakly Interacting Massive Particles (WIMPs) a Maxwellian velocity distribution in the Galaxy we provide an assessment of the sensitivity of existing Dark Matter (DM) direct detection (DD) experiments to operators up to dimension 7 of the relativistic effective field theory describing dark matter interactions with quarks and gluons . In particular we focus on a systematic approach, including an extensive set of experiments and large number of couplings, both exceeding for completeness similar analyses in the literature. The relativistic effective theory requires to fix one coupling for each quark flavor, so in principle for each different combination the bounds should be recalculated starting from direct detection experimental data. To address this problem we propose an approximate model-independent procedure that allows to directly calculate the bounds for any combination of couplings in terms of model-independent limits on the Wilson coefficients of the non-relativistic theory expressed in terms of the WIMP mass and of the neutron-to-proton coupling ratio $c^n/c^p$. We test the result of the approximate procedure against that of a full calculation, and discuss its possible pitfalls and limitations. We also provide a simple interpolating interface in Python that allows to apply our method quantitatively.

    hep-phastro-ph.COAstropart.Phys.(2020)·15 citations
27. 27*

    Probing anomalous top-Higgs couplings at the HL-LHC via $H\to W{W}^{\ast }$ decay channels

    Yao-Bei Liu🇨🇳 · Stefano Moretti🇬🇧

    We study the prospects of probing the anomalous $tHq$~($q=u,c$) couplings via SS2L or 3L signatures at the High Luminosity (HL-LHC) run of the 14 TeV CERN collider. We focus on signals of the $tH$ associated production followed by the decay modes $t\to b{\ell }^{+}{\nu }_{\ell }$ and $H\to W{W}^{\ast }$, and $t\bar{t}$ production followed by the decay modes $t\to b{\ell }^{+}{\nu }_{\ell }$ and $\bar{t}\to H(\to W{W}^{\ast })\bar{q}$, where $\ell =e,\mu$. Based on two types of $H\to W{W}^{\ast }$ decay topologies, one assuming the semileptonic decay mode $H\to W{W}^{\ast }\to {\ell }^{+}\nu jj$ and the other the fully leptonic decay mode $H\to W{W}^{\ast }\to {\ell }^{+}\nu {\ell }^{-}\bar{\nu }$, we perform a full simulation for signals and backgrounds. It is shown that, at the future HL-LHC, the branching ratio $Br(t\to uh)(Br(t\to ch))$ can be probed to $1.17(1.56)\times 10^{-3}$ for the same-sign di-lepton channel and to $7.1\times 10^{-4}(1.39\times 10^{-3})$ for the 3L channel at $3\sigma$ sensitivity.

    hep-phCPC(2019)·7 citations
28. 28*

    Constraining New Muonic Interactions Meditated by Axion-Like-Particles

    H.Yan🇨🇳 · G.A.Sun🇨🇳 · S.M.Peng🇨🇳 · H.Guo · B.Q.Liu🇨🇳 · M.Peng🇨🇳 · H.Zheng🇨🇳

    ALPs (Axion Like Particle) beyond the standard model are solutions to several important problems of modern physics. One way to detect these particles is to detect the new interactions they meditate. Many experiments have been performed to search for these new interactions in ranges from $\sim \mu$m to astrophysical range. At present, nearly all known experiments searching for the ALP-meditated long range new interactions use sources or probes containing protons, neutrons and electrons. Constraints for other fermions such as muons are scarce, though muons might be the most suspicious particles which could take part in new interactions, considering their involvement of several well known puzzles of modern physics. In this work, we discuss the possibility of explaining the anomalous magnetic moment of muons by the long range muonic new interactions mediated by ALPs. We also give a constraint for the scalar-pseudo-scalar(SP) type interaction meditated by muonic ALPs. We propose to further search the muonic SP type interaction by muon spin rotation experiments.

    hep-phnucl-exnucl-th0 citations
29. 29*

    2HDECAY - A program for the Calculation of Electroweak One-Loop Corrections to Higgs Decays in the Two-Higgs-Doublet Model Including State-of-the-Art QCD Corrections

    Marcel Krause🇩🇪 · Margarete Muhlleitner🇩🇪 · Michael Spira🇨🇭

    We present the program package 2HDECAY for the calculation of the partial decay widths and branching ratios of the Higgs bosons of a general CP-conserving 2-Higgs doublet model (2HDM). The tool includes the full electroweak one-loop corrections to all two-body on-shell Higgs decays in the 2HDM that are not loop-induced. It combines them with the state-of-the-art QCD corrections that are already implemented in the program HDECAY. For the renormalization of the electroweak sector an on-shell scheme is implemented for most of the renormalization parameters. Exceptions are the soft-${\mathbb{Z}}_2$-breaking squared mass scale $m_{12}^2$, where an $\overline{\text{MS}}$ condition is applied, as well as the 2HDM mixing angles $\alpha$ and $\beta$, for which several distinct renormalization schemes are implemented. The tool 2HDECAY can be used for phenomenological analyses of the branching ratios of Higgs decays in the 2HDM. Furthermore, the separate output of the electroweak contributions to the tree-level partial decay widths for several different renormalization schemes allows for an efficient analysis of the impact of the electroweak corrections and the remaining theoretical error due to missing higher-order corrections. The latest version of the program package 2HDECAY can be downloaded from the URL https://github.com/marcel-krause/2HDECAY .

    hep-phhep-exComput.Phys.Commun.(2020)·53 citations
30. 30*

    Critical Higgs inflation in a Viable Motivated Model

    Alberto Salvio🇨🇭

    An extension of the Standard Model with three right-handed neutrinos and a simple invisible axion model can account for all experimentally confirmed signals of new physics (neutrino oscillations, dark matter and baryon asymmetry) in addition to solving the strong CP problem, stabilizing the electroweak vacuum and satisfying all current observational bounds. We show that this model can also implement critical Higgs inflation, which corresponds to the frontier between stability and metastability of the electroweak vacuum. This leads to a value of the non-minimal coupling between the Higgs and the Ricci scalar that is much lower than the one usually quoted in Higgs inflation away from criticality. Then, an advantage is that the scale of perturbative unitarity breaking on flat spacetime can be very close to the Planck mass, where anyhow new physics is required. The higher dimensional operators are under control in this inflationary setup. The dependence of the cutoff on the Higgs background is also taken into account as appropriate when the Higgs is identified with the inflaton. Furthermore, critical Higgs inflation enjoys a robust inflationary attractor that makes it an appealing setup for the early universe. In the proposed model, unlike in the Standard Model, critical Higgs inflation can be realized without any tension with the observed quantities, such as the top mass and the strong coupling.

    hep-phPRD(2019)·41 citations
31. 31*

    QCD calculations of $B\to \pi ,K$ form factors with higher-twist corrections

    Cai-Dian Lü🇨🇳 · Yue-Long Shen🇨🇳 · Yu-Ming Wang🇨🇳 · Yan-Bing Wei🇨🇳

    We update QCD calculations of $B\to \pi ,K$ form factors at large hadronic recoil by including the subleading-power corrections from the higher-twist $B$-meson light-cone distribution amplitudes (LCDAs) up to the twist-six accuracy and the strange-quark mass effects at leading-power in $\Lambda /m_b$ from the twist-two $B$-meson LCDA ${\varphi }_B^{+}(\omega ,\mu )$. The higher-twist corrections from both the two-particle and three-particle $B$-meson LCDAs are computed from the light-cone QCD sum rules (LCSR) at tree level. In particular, we construct the local duality model for the twist-five and -six $B$-meson LCDAs, in agreement with the corresponding asymptotic behaviours at small quark and gluon momenta, employing the QCD sum rules in heavy quark effective theory at leading order in ${\alpha }_s$. The strange quark mass effects in semileptonic $B\to K$ form factors yield the leading-power contribution in the heavy quark expansion, consistent with the power-counting analysis in soft-collinear effective theory, and they are also computed from the LCSR approach due to the appearance of the rapidity singularities. We further explore the phenomenological aspects of the semileptonic $B\to \pi \ell \nu$ decays and the rare exclusive processes $B\to K\nu \nu$, including the determination of the CKM matrix element $|V_{ub}|$, the normalized differential $q^2$ distributions and precision observables defined by the ratios of branching fractions for the above-mentioned two channels in the same intervals of $q^2$.

    hep-phhep-exhep-latJHEP(2019)·84 citations
32. 32*

    Neutron Lifetime Discrepancy as a Sign of a Dark Sector?

    Bartosz Fornal🇺🇸 · Benjamin Grinstein🇺🇸

    We summarize our recent proposal of explaining the discrepancy between the bottle and beam measurements of the neutron lifetime through the existence of a dark sector, which the neutron can decay to with a branching fraction 1%. We show that viable particle physics models for such neutron dark decays can be constructed and we briefly comment on recent developments in this area.

    hep-phnucl-exnucl-th5 citations
33. 33*

    Baryogenesis and Dark Matter from $B$ Mesons

    Gilly Elor🇺🇸 · Miguel Escudero🇬🇧 · Ann E. Nelson🇺🇸

    We present a new mechanism of Baryogenesis and dark matter production in which both the dark matter relic abundance and the baryon asymmetry arise from neutral $B$ meson oscillations and subsequent decays. This set-up is testable at hadron colliders and $B$-factories. In the early Universe, decays of a long lived particle produce $B$ mesons and anti-mesons out of thermal equilibrium. These mesons/anti-mesons then undergo CP violating oscillations before quickly decaying into visible and dark sector particles. Dark matter will be charged under Baryon number so that the visible sector baryon asymmetry is produced without violating the total baryon number of the Universe. The produced baryon asymmetry will be directly related to the leptonic charge asymmetry in neutral $B$ decays; an experimental observable. Dark matter is stabilized by an unbroken discrete symmetry, and proton decay is simply evaded by kinematics. We will illustrate this mechanism with a model that is unconstrained by di-nucleon decay, does not require a high reheat temperature, and would have unique experimental signals -- a positive leptonic asymmetry in $B$ meson decays, a new decay of $B$ mesons into a baryon and missing energy, and a new decay of $b$-flavored baryons into mesons and missing energy. These three observables are testable at current and upcoming collider experiments, allowing for a distinct probe of this mechanism.

    hep-phastro-ph.COhep-exPRD(2019)·159 citations
34. 34*

    Exploring the ultra-light to sub-MeV dark matter window with atomic clocks and co-magnetometers

    Rodrigo Alonso🇨🇭 · Diego Blas🇬🇧 · Peter Wolf🇫🇷

    Particle dark matter could have a mass anywhere from that of ultralight candidates, $m_{\chi }\sim 10^{-21}$eV, to scales well above the GeV. Conventional laboratory searches are sensitive to a range of masses close to the weak scale, while new techniques are required to explore candidates outside this realm. In particular lighter candidates are difficult to detect due to their small momentum. Here we study two experimental set-ups which {\it do not require transfer of momentum} to detect dark matter: atomic clocks and co-magnetometers. These experiments probe dark matter that couples to the spin of matter via the very precise measurement of the energy difference between atomic states of different angular momenta. This coupling is possible (even natural) in most dark matter models, and we translate the current experimental sensitivity into implications for different dark matter models. It is found that the constraints from current atomic clocks and co-magnetometers can be competitive in the mass range $m_{\chi }\sim 10^{-21}-10^3$eV, depending on the model. We also comment on the (negligible) effect of different astrophysical neutrino backgrounds.

    hep-phastro-ph.COquant-phJHEP(2019)·33 citations
35. 35*

    Flavor of cosmic neutrinos preserved by ultralight dark matter

    Yasaman Farzan (IPM, Tehran)🇮🇷 · Sergio Palomares-Ruiz (Valencia U., IFIC)🇪🇸

    Within the standard propagation scenario, the flavor ratios of high-energy cosmic neutrinos at neutrino telescopes are expected to be around the democratic benchmark resulting from hadronic sources, ${\left(1:1:1\right)}_{\oplus }$. We show how the coupling of neutrinos to an ultralight dark matter complex scalar field would induce an effective neutrino mass that could lead to adiabatic neutrino propagation. This would result in the preservation at the detector of the production flavor composition of neutrinos at sources. This effect could lead to flavor ratios at detectors well outside the range predicted by the standard scenario of averaged oscillations. We also present an electroweak-invariant model that would lead to the required effective interaction between neutrinos and dark matter.

    hep-phastro-ph.HEPRD(2019)·76 citations
36. 36*

    Magnetic field dependence of Delta isobars properties in a Skyrme model

    Bing-Ran He🇨🇳

    The properties of $\Delta$ isobars in a uniform magnetic field are investigated. In the weak magnetic field region, the general relations between magnetic moment of nucleons and $\Delta$ isobars are given. In the strong magnetic field region, the mass and size of $\Delta$ isobars depend on the increasing of magnetic field strength in different ways: the effective mass of ${\Delta }^{++}$, ${\Delta }^{+}$ and ${\Delta }^0$ first decreases and then increases, consequently, the size of ${\Delta }^{++}$, ${\Delta }^{+}$ and ${\Delta }^0$ first increases and then decreases; whereas, the effective mass of ${\Delta }^{-}$ always increases, and consequently, the size of ${\Delta }^{-}$ always decreases. The estimation shows in the core part of the magnetar, the equation of state for $\Delta$ isobars depends on the magnetic field, which affects the mass limit of the magnetar.

    hep-phhep-lathep-thnucl-thPRD(2019)·3 citations
37. 37*

    Preheating after Higgs Inflation: Self-Resonance and Gauge boson production

    Evangelos I. Sfakianakis🇳🇱 · Jorinde van de Vis🇳🇱

    We perform an extensive analysis of linear fluctuations during preheating in Higgs inflation in the Einstein frame, where the fields are minimally coupled to gravity, but the field-space metric is nontrivial. The self-resonance of the Higgs and the Higgsed gauge bosons are governed by effective masses that scale differently with the nonminimal couplings and evolve differently in time. Coupled metric perturbations enhance Higgs self-resonance and make it possible for Higgs inflation to preheat solely through this channel. For $\xi \gtrsim 100$ the total energy of the Higgs-inflaton condensate can be transferred to Higgs particles within $3$ $e$-folds after the end of inflation. For smaller values of the nonminimal coupling preheating takes longer, completely shutting off at around $\xi \simeq 30$. The production of gauge bosons is dominated by the gauge boson mass and the field space curvature. For large values of the nonminimal coupling $\xi \gtrsim 1000$, it is possible for the Higgs condensate to transfer the entirety of its energy into gauge fields within one oscillation. For smaller values of the nonminimal coupling gauge bosons decay very quickly into fermions, thereby shutting off Bose enhancement. Estimates of non-Abelian interactions indicate that they will not suppress preheating into gauge bosons for $\xi \gtrsim 1000$.

    hep-phastro-ph.COPRD(2019)·111 citations
38. 38*

    Thermal vorticity and spin polarization in heavy-ion collisions

    De-Xian Wei🇨🇳 · Wei-Tian Deng🇨🇳 · Xu-Guang Huang🇨🇳

    The hot and dense matter generated in heavy-ion collisions contains intricate vortical structure in which the local fluid vorticity can be very large. Such vorticity can polarize the spin of the produced particles. We study the event-by-event generation of the so-called thermal vorticity in Au + Au collisions at energy region $\sqrt{s}=7.7-200$ GeV and calculate its time evolution, spatial distribution, etc., in a multiphase transport (AMPT) model. We then compute the spin polarization of the $\Lambda$ and $\bar{\Lambda }$ hyperons as a function of $\sqrt{s}$, transverse momentum $p_T$, rapidity, and azimuthal angle. Furthermore, we study the harmonic flow of the spin, in a manner analogous to the harmonic flow of the particle number. The measurement of the spin harmonic flow may provide a way to probe the vortical structure in heavy-ion collisions. We also discuss the spin polarization of ${\Xi }^0$ and ${\Omega }^{-}$ hyperons which may provide further information about the spin polarization mechanism of hadrons.

    ↳ nucl-thhep-phnucl-exPRC(2019)·181 citations
39. 39*

    Biased bootstrap sampling for efficient two-sample testing

    Thomas P. S. Gillam🇬🇧 · Christopher G. Lester🇬🇧

    The so-called 'energy test' is a frequentist technique used in experimental particle physics to decide whether two samples are drawn from the same distribution. Its usage requires a good understanding of the distribution of the test statistic, T, under the null hypothesis. We propose a technique which allows the extreme tails of the T-distribution to be determined more efficiently than possible with present methods. This allows quick evaluation of (for example) 5-sigma confidence intervals that otherwise would have required prohibitively costly computation times or approximations to have been made. Furthermore, we comment on other ways that T computations could be sped up using established results from the statistics community. Beyond two-sample testing, the proposed biased bootstrap method may provide benefit anywhere extreme values are currently obtained with bootstrap sampling.

    ↳ physics.data-anhep-phJINST(2018)·4 citations
40. 40*

    Counting String Theory Standard Models

    Andrei Constantin🇸🇪 · Yang-Hui He🇬🇧 · Andre Lukas🇬🇧

    We derive an approximate analytic relation between the number of consistent heterotic Calabi-Yau compactifications of string theory with the exact charged matter content of the standard model of particle physics and the topological data of the internal manifold: the former scaling exponentially with the number of Kahler parameters. This is done by an estimate of the number of solutions to a set of Diophantine equations representing constraints satisfied by any consistent heterotic string vacuum with three chiral massless families, and has been computationally checked to hold for complete intersection Calabi-Yau threefolds (CICYs) with up to seven Kahler parameters. When extrapolated to the entire CICY list, the relation gives about 10^23 string theory standard models; for the class of Calabi-Yau hypersurfaces in toric varieties, it gives about 10^723 standard models.

    ↳ hep-thhep-phmath.AGPLB(2019)·49 citations
41. 41*

    Light speed variation from gamma ray bursts: criteria for low energy photons

    Yue Liu🇨🇳 · Bo-Qiang Ma🇨🇳

    We examine a method to detect the light speed variation from gamma ray burst data observed by the Fermi Gamma-ray Space Telescope (FGST). We suggest new criteria to determine the characteristic time for low energy photons by the energy curve and the average energy curve, and obtain similar results compared with those from the light curve. We offer a new criterion with both the light curve and the average energy curve to determine the characteristic time for low energy photons. We then apply the new criteria to the GBM NaI data, the GBM BGO data, and the LAT LLE data, and obtain consistent results for three different sets of low energy photons from different FERMI detectors.

    ↳ astro-ph.HEgr-qchep-phEPJC(2018)·50 citations
42. 42*

    Measurement of meson transition form factors at BESIII

    C. F. Redmer (for the BESIII collaboration)🇩🇪

    Meson transition form factors describe the coupling of photons and hadrons. They are an important input to the calculations of the light-by-light scattering contribution of the anomalous magnetic moment of the muon. At the BESIII experiment in Beijing, the transition form factors of pseudoscalar mesons are studied in their Dalitz decays, in their radiative production in $e^{+}{e}^{-}$ annihilation, and in their production in two-photon scattering. All relevant kinematic regimes are covered. An overview of the recent results and the status of the ongoing analyses is provided.

    ↳ hep-exhep-ph13 citations
43. 43*

    From the colour glass condensate to filamentation: Systematics of classical Yang-Mills theory

    Owe Philipsen🇩🇪 · Björn Wagenbach🇩🇪 · Savvas Zafeiropoulos🇩🇪

    The non-equilibrium early time evolution of an ultra-relativistic heavy ion collision is often described by classical lattice Yang-Mills theory, starting from the colour glass condensate (CGC) effective theory with an anisotropic energy momentum tensor as initial condition. In this work we investigate the systematics associated with such studies and their dependence on various model parameters (IR, UV cutoffs and the amplitude of quantum fluctuations) which are not yet fixed by experiment. We perform calculations for SU(2) and SU(3), both in a static box and in an expanding geometry. Generally, the dependence on model parameters is found to be much larger than that on technical parameters like the number of colours, boundary conditions or the lattice spacing. In a static box, all setups lead to isotropisation through chromo-Weibel instabilities, which is illustrated by the accompanying filamentation of the energy density. However, the associated time scale depends strongly on the model parameters and in all cases is longer than the phenomenologically expected one. In the expanding system, no isotropisation is observed for any parameter choice. We show how investigations at fixed initial energy density can be used to better constrain some of the model parameters.

    ↳ hep-lathep-phnucl-thEPJC(2019)·4 citations
44. 44*

    Unitarity Bounds of Astrophysical Neutrinos

    Markus Ahlers🇩🇰 · Mauricio Bustamante🇩🇰 · Siqiao Mu🇺🇸

    The flavor composition of astrophysical neutrinos observed at neutrino telescopes is related to the initial composition at their sources via oscillation-averaged flavor transitions. If the time evolution of the neutrino flavor states is unitary, the probability of neutrinos changing flavor is solely determined by the unitary mixing matrix that relates the neutrino flavor and propagation eigenstates. In this paper we derive general bounds on the flavor composition of TeV-PeV astrophysical neutrinos based on unitarity constraints. These bounds are useful for studying the flavor composition of high-energy neutrinos, where energy-dependent nonstandard flavor mixing can dominate over the standard mixing observed in accelerator, reactor, and atmospheric neutrino oscillations.

    ↳ astro-ph.HEhep-exhep-phPRD(2018)·45 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.