Thu·Jan 16, 2020Thursday·January 16, 2020

1. 01*

   A universal framework for t-channel dark matter models

   Chiara Arina🇧🇪 · Benjamin Fuks🇫🇷 · Luca Mantani🇧🇪

   We present the DMSimpt model implementation in FeynRules, which aims to offer a unique general framework allowing for all simulations relevant for simplified $t$-channel dark matter models at colliders and for the complementary cosmology calculations. We describe how to match next-to-leading-order QCD fixed-order calculations with parton showers to derive robust bounds and predictions in the context of LHC dark matter searches, and moreover validate two model restrictions (relevant for Dirac and Majorana fermionic dark matter respectively) to exemplify how to evaluate dark matter observables to constrain the model parameter space. More importantly, we emphasise how to achieve these results by using a combination of publicly available automated tools, and discuss how dark matter predictions are sensitive to the model file and software setup. All files, together with illustrative Mathematica notebooks, are available from the URL http://feynrules.irmp.ucl.ac.be/wiki/DMsimpt.

   hep-phastro-ph.COhep-exEPJC(2020)·55 citations
2. 02*

   Charmed Baryon Weak Decays with Vector Mesons

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

   We give a systematic study of ${\mathbf{B}}_c\to {\mathbf{B}}_{n}V$ decays, where ${\mathbf{B}}_c$ and ${\mathbf{B}}_n$ correspond to the anti-triplet charmed and octet baryons, respectively, while $V$ stand for the vector mesons. We calculate the color-symmetric contributions to the decays from the effective Hamiltonian with the factorization approach and extract the anti-symmetric ones based on the experimental measurements and $SU(3{)}_F$ flavor symmetry. We find that most of the existing experimental data for ${\mathbf{B}}_c\to {\mathbf{B}}_{n}V$ are consistent with our fitting results. We present all the branching ratios of the Cabbibo allowed, singly Cabbibo suppressed and doubly Cabbibo suppressed decays of ${\mathbf{B}}_c\to {\mathbf{B}}_{n}V$. The decay parameters for the daughter baryons and mesons in ${\mathbf{B}}_c\to {\mathbf{B}}_{n}V$ are also evaluated. In particular, we point out that the Cabbibo allowed decays of ${\Lambda }_c^{+}\to {\Lambda }^0{\rho }^{+}$ and ${\Xi }_c^0\to {\Xi }^{-}{\rho }^{+}$ as well as the singly Cabbibo suppressed ones of ${\Lambda }_c^{+}\to {\Lambda }^0{K}^{\ast +}$, ${\Xi }_c^{+}\to {\Sigma }^{+}\varphi$ and ${\Xi }_c^0\to {\Xi }^{-}{K}^{\ast +}$ have large branching ratios and decay parameters with small uncertainties, which can be tested by the experimental searches at the charm facilities.

   hep-phhep-exPRD(2020)·32 citations
3. 03*

   Possible interpretation of the newly observed ${\Omega }_b$ states

   Li-Ye Xiao🇨🇳 · Kai-Lei Wang🇨🇳 · Ming-Sheng Liu🇨🇳 · Xian-Hui Zhong🇨🇳

   Inspired by the newly observed ${\Omega }_b$ states by the LHCb Collaboration, we investigate the two-body strong decays of the low-lying $\lambda$-mode ${\Omega }_b$ baryons up to $N=2$ shell using the chiral quark model within the $j$-$j$ coupling scheme. Our results indicate that: (i) the newly observed states ${\Omega }_b(6316{)}^{-}$ and ${\Omega }_b(6330{)}^{-}$ are good candidates of the light spin $j=1$ states, while the spin-parity $J^P=1/2^{-}$ and $J^P=3/2^{-}$ cannot be distinguished. The other two states, ${\Omega }_b(6340)$ and ${\Omega }_b(6350)$ mostly correspond to the light spin $j=2$ states, while the spin-parity $J^P=3/2^{-}$ and $J^P=5/2^{-}$ cannot be distinguished as well.(ii) The $2S$ states with spin-parity $J^P=1/2^{+}$ and $J^P=3/2^{+}$, respectively, might be narrow states with a width of $\Gamma <2$ MeV. (iii) The $1D$ states are not broad and the total decay widths vary from several to dozens of MeV, which have a good potential to be observed in future experiments.

   hep-phEPJC(2020)·30 citations
4. 04*

   $D^{\ast }D\rho$ and $B^{\ast }B\rho$ strong couplings in light-cone sum rules

   Chao Wang🇨🇳 · Hua-dong Li🇨🇳

   We present an improved calculation of the strong coupling constants $g_{D^{\ast }D\rho }$ and $g_{B^{\ast }B\rho }$ in light-cone sum rules including the one-loop QCD corrections of leading power with $\rho$ meson distribution amplitudes. We further compute the subleading-power corrections from two-particle and three-particle higher-twist contributions at leading order up to twist-4 accuracy. The next-to leading order corrections to leading power contribution offset the subleading-power corrections to some extend numerically, and our numerical results are consistent with previous works from sum rules. The comparisons between our results and the existing model-dependent estimations are also made.

   hep-phCPC(2020)·8 citations
5. 05*

   TeV gravity searches

   José I. Illana🇪🇸 · Manuel Masip🇪🇸

   In scenarios with extra dimensions the gravitational interaction may become strong at TeV energies. This could modify the $\nu$$N$ cross section and imply distinct signals at neutrino telescopes. In particular, cosmogenic neutrinos of $E\approx 10^9$ GeV could experience frequent interactions with matter where they lose a very small fraction of their energy. We define a consistent model of strong gravity at the TeV scale with just one extra dimension and a first Kaluza-Klein excitation of the graviton of mass around 1 GeV. We describe the collisions at transplanckian energies (multigraviton exchange, graviton emission and black hole formation) as well as the possible signature of these processes at km${}^3$ telescopes and their impact in cosmogenic neutrino searches.

   hep-ph4 citations
6. 06*

   Proton Decay and Axion Dark Matter in SO(10) Grand Unification via Minimal Left-Right Symmetry

   Yuta Hamada🇫🇷 · Masahiro Ibe🇯🇵 · Yu Muramatsu🇨🇳 · Kin-ya Oda🇯🇵 · Norimi Yokozaki🇯🇵

   We study the proton lifetime in the $SO(10)$ Grand Unified Theory (GUT), which has the left-right (LR) symmetric gauge theory below the GUT scale. In particular, we focus on the minimal model without the bi-doublet Higgs field in the LR symmetric model, which predicts the LR-breaking scale at around $10^{10\text{–}12}$ GeV. The Wilson coefficients of the proton decay operators turn out to be considerably larger than those in the minimal $SU(5)$ GUT model especially when the Standard Model Yukawa interactions are generated by integrating out extra vector-like multiplets. As a result, we find that the proton lifetime can be within the reach of the Hyper-Kamiokande experiment even when the GUT gauge boson mass is in the $10^{16\text{–}17}$ GeV range. We also show that the mass of the extra vector-like multiplets can be generated by the Peccei-Quinn symmetry breaking in a consistent way with the axion dark matter scenario.

   hep-phEPJC(2020)·7 citations
7. 07*

   The production of gauge bosons pairs $W^{+}{W}^{-}$ associated with 0, 1 and 2 jets in proton-proton collisions at LHC

   K. Djamaa (1)🇩🇿 · A. Mohamed-Meziani (1, 2) ((1) Department of Physics, Faculty of Exact Sciences, University of Bejaia, Algeria, (2) Laboratoire de Physique Théorique d'Oran (LPTO), University of Oran1-Ahmed Ben Bella, Algeria)🇩🇿

   We report in this work the production of $W^{+}{W}^{-}$ pairs gauge bosons associated with 0, 1 and 2 jets in proton-proton collisions at LHC with an energy of 14 TeV in the center of mass. These processes are produced at leading-order (LO) and next-to-leading-order (NLO) with QCD corrections in the standard model, using MadGraph5@aMC. For a realistic description of the processes, we match the hard scattering processes with Pythia8 parton showering and hadronization. The obtained events are run through the fast detector simulation, Delphes, which serves to accurately model the ATLAS and CMS detectors and the final state reconstructions that are performed. We analyze the total cross sections according on two cuts in jet transverse momentum p T,j > 20 GeV and p T,j > 100 GeV. We describe the important numerical aspects of our calculations by presenting transverse momentum and rapidity distributions at partonic fixed order and at parton shower for both W and the $W^{+}{W}^{-}$ pair.

   hep-phPhys.Part.Nucl.Lett.(2021)·2 citations
8. 08*

   Double Higgs boson production as an exclusive probe for a sequential fourth generation with wrong-sign Yukawa couplings

   Md. Raju🇮🇳 · Jyoti Prasad Saha🇮🇳 · Dipankar Das🇮🇳 · Anirban Kundu🇮🇳

   It has been shown that the data from the Large Hadron Collider (LHC) does not rule out a chiral sequential fourth generation of fermions that obtain their masses through an identical mechanism as the other three generations do. However, this is possible only if the scalar sector of the Standard Model is suitably enhanced, like embedding it in a type-II two-Higgs doublet model. In this article, we try to show that double Higgs production (DHP) can unveil the existence of such a hidden fourth generation in a very efficient way. While the DHP cross-section in the SM is quite small, it is significantly enhanced with a fourth generation. We perform a detailed analysis of the dependence of the DHP cross-section on the model parameters, and show that either a positive signal of DHP is seen in the early next run of the LHC, or the model is ruled out.

   hep-phhep-exPRD(2020)·4 citations
9. 09*

   Behaviour of observables for neutral meson decaying to two vectors in the presence of $T$, $CP$ and $CPT$ violation in mixing only

   Anirban Karan🇮🇳 · Abinash Kumar Nayak🇮🇳

   When a neutral meson $(P^0\text{ or }{\bar{P}}^0)$ decays to two vector particles, a large number of observables can be constructed from differential decay rate based on the polarization of final state. But, theoretically, all of them are not independent to each other and hence, some relations among observables emerge. These relations have been well studied in the scenario with no $T$ and $CPT$ violation in neutral meson mixing and no direct $CP$ violation as well. In this paper, we have studied the relations among observables in the presence of $T$, $CP$ and $CPT$ violating effects in mixing only. We find that except four of them, all the other old relations get violated and new relations appear if $T$ and $CPT$ violations in mixing are present. Invalidity of these relation will signify the presence of direct violation of $T$, $CP$ and $CPT$ (i.e. violation in the decay itself).

   hep-phPRD(2020)·5 citations
10. 10*

    Spectrum and rearrangement decays of tetraquark states with four different flavors

    Jian-Bo Cheng🇨🇳 · Shi-Yuan Li🇨🇳 · Yan-Rui Liu🇨🇳 · Yu-Nan Liu🇨🇳 · Zong-Guo Si🇨🇳 · Tao Yao🇨🇳

    We have systematically investigated the mass spectrum and rearrangement decay properties of the exotic tetraquark states with four different flavors using a color-magnetic interaction model. Their masses are estimated by assuming that the $X(4140)$ is a $cs\bar{c}\bar{s}$ tetraquark state and their decay widths are obtained by assuming that the Hamiltonian for decay is a constant. According to the adopted method, we find that the most stable states are probably the isoscalar $bs\bar{u}\bar{d}$ and $cs\bar{u}\bar{d}$ with $J^P=0^{+}$ and $1^{+}$. The width for most unstable tetraquarks is about tens of MeVs, but that for unstable $cu\bar{s}\bar{d}$ and $cs\bar{u}\bar{d}$ can be around 100 MeV. For the $X(5568)$, our method cannot give consistent mass and width if it is a $bu\bar{s}\bar{d}$ tetraquark state. For the $I(J^P)=0(0^{+}),0(1^{+})$ double-heavy $T_{bc}=bc\bar{u}\bar{d}$ states, their widths can be several MeVs.

    hep-phhep-exhep-latnucl-ex+1PRD(2020)·54 citations
11. 11*

    Study of the semi-boosted topology in top anti-top quark pair spectra

    Josef Pácalt🇨🇿

    The aim of this contribution is to present results of adding the semi-boosted transition region between the resolved and boosted top quark pair reconstruction in the $\ell$ + jets channel. This region is often omitted due to more complex reconstruction, which usually leads to a smaller efficiency. The reconstruction is performed for all three topologies for comparison and combination purposes. Hypothetical particle $Z^{\prime }$ was used as a probe to study the increase in the number of events in the studied energy region.

    hep-phhep-ex0 citations
12. 12*

    Precision calculation of the axion-nucleon coupling in chiral perturbation theory

    Thomas Vonk🇩🇪 · Feng-Kun Guo🇨🇳 · Ulf-G. Meißner🇬🇪

    We derive the axion-nucleon interaction Lagrangian in heavy baryon chiral perturbation theory up to next-to-next-to-leading order. The effective axion-nucleon coupling is calculated to a few percent accuracy.

    hep-phastro-ph.HEhep-latnucl-thJHEP(2020)·38 citations
13. 13*

    Two-Step Electroweak Symmetry-Breaking: Theory Meets Experiment

    Nicole F. Bell🇦🇺 · Matthew J. Dolan🇦🇺 · Leon S. Friedrich🇦🇺 · Michael J. Ramsey-Musolf🇺🇸 · Raymond R. Volkas🇦🇺

    We study the phenomenology of a hypercharge-zero SU(2) triplet scalar whose existence is motivated by two-step electroweak symmetry-breaking. We consider both the possibility that the triplets are stable and contribute to the dark matter density, or that they decay via mixing with the standard model Higgs boson. The former is constrained by disappearing charged track searches at the LHC and by dark matter direct detection experiments, while the latter is constrained by existing multilepton collider searches. We find that a two-step electroweak phase transition involving a stable triplet with a negative quadratic term is ruled out by direct detection searches, while an unstable triplet with a mass less than $230\mathrm{GeV}$ is excluded at $95\%$ confidence level.

    hep-phJHEP(2020)·38 citations
14. 14*

    SU(3)${}_F$ Analysis for Beauty Baryon Decays

    Avital Dery🇺🇸 · Mitrajyoti Ghosh🇺🇸 · Yuval Grossman🇺🇸 · Stefan Schacht🇺🇸

    We perform a general SU(3)${}_F$ analysis of $b\to c\bar{c}s(d)$ decays of members of the beauty baryon antitriplet to a member of the light baryon octet and a singlet. Under several reasonable assumptions we found $\left|\mathcal{A}({\Xi }_b^0\to \Lambda S)/\mathcal{A}({\Xi }_b^0\to {\Xi }^{0}S)\right|\approx 1/\sqrt{6}\left|V_{cb}^{\ast }{V}_{cd}/(V_{cb}^{\ast }{V}_{cs})\right|$ and $\left|\mathcal{A}({\Lambda }_b\to {\Sigma }^{0}S)/\mathcal{A}({\Lambda }_b\to \Lambda S)\right|\sim 0.02$. These two relations have been recently probed by LHCb for the case of $S=J/\psi$. The former agrees with the measurement, while for the latter our prediction lies close to the upper bound set by LHCb.

    hep-phhep-exJHEP(2020)·34 citations
15. 15*

    Bottomonium spectrum with a Dirac potential model in the momentum space

    David Molina🇨🇴 · Maurizio De Sanctis🇨🇴 · Cesar Fernández-Ramírez🇲🇽 · Elena Santopinto🇮🇹

    We study the bottomonium spectrum using a relativistic potential model in the momentum space. This model is based on a complete one gluon exchange interaction with a momentum dependent screening factor to account for the effects due to virtual pair creation that appear close to the decay thresholds. The overall model does not make use of nonrelativistic approximations. We fit well established bottomonium states below the open charm threshold and predict the rest of the spectrum up to $\approx 11200$ MeV and $J^{PC}=3^{--}$. Uncertainties are treated rigorously and propagated in full to the parameters of the model using a Monte Carlo to identify if which deviations from experimental data can be absorbed into the statistical uncertainties of the models and which can be related to physics beyond the $b\bar{b}$ picture, guiding future research. We get a good description of the spectrum, in particular the Belle measurement of the ${\eta }_b(2S)$ state and the ${\rm Y}(10860)$ and ${\chi }_b(3P)$ resonances.

    hep-phEPJC(2020)·13 citations
16. 16*

    Transverse spin effects in hard semi-inclusive collisions

    Mauro Anselmino🇮🇹 · Asmita Mukherjee🇮🇳 · Anselm Vossen🇺🇸

    The nucleons (protons and neutrons) are by far the most abundant form of matter in our visible Universe; they are composite particles made of quarks and gluons, the fundamental quanta of Quantum Chromo Dynamics (QCD). The usual interpretation of the nucleon dynamics in high energy interactions is often limited to a simple one-dimensional picture of a fast moving nucleon as a collection of co-linearly moving quarks and gluons (partons), interacting accordingly to perturbative QCD rules. However, massive experimental evidence shows that, in particular when transverse spin dependent observables are involved, such a simple picture is not adequate. The intrinsic transverse motion of partons has to be taken into account; this opens the way to a new, truly 3-dimensional (3D) study of the nucleon structure. A review of the main experimental data, their interpretation and understanding in terms of new transverse momentum dependent partonic distributions, and the progress in building a 3D imaging of the nucleon is presented.

    hep-phhep-exPPNP(2020)·66 citations
17. 17*

    Exploring phase space with Neural Importance Sampling

    Enrico Bothmann🇩🇪 · Timo Janßen🇩🇪 · Max Knobbe🇩🇪 · Tobias Schmale🇩🇪 · Steffen Schumann🇩🇪

    We present a novel approach for the integration of scattering cross sections and the generation of partonic event samples in high-energy physics. We propose an importance sampling technique capable of overcoming typical deficiencies of existing approaches by incorporating neural networks. The method guarantees full phase space coverage and the exact reproduction of the desired target distribution, in our case given by the squared transition matrix element. We study the performance of the algorithm for a few representative examples, including top-quark pair production and gluon scattering into three- and four-gluon final states.

    hep-phhep-exSciPost Phys.(2020)·163 citations
18. 18*

    Effects of matter density profiles on neutrino oscillations for T2HK and T2HKK

    Stephen F. King🇬🇧 · Susana Molina Sedgwick🇬🇧 · Stephen J. Parke🇺🇸 · Nick W. Prouse🇨🇦

    This paper explores the effects of changes in matter density profiles on neutrino oscillation probabilities, and whether these could potentially be seen by the future Hyper-Kamiokande long-baseline oscillation experiment (T2HK). The analysis is extended to include the possibility of having an additional detector in Korea (T2HKK). In both cases, we find that these effects will be immeasurable, as the magnitudes of the changes in the oscillation probabilities induced in all density profile scenarios considered here remain smaller than the estimated experimental sensitivity to the oscillation probabilities of each experiment, for both appearance and disappearance channels. Therefore, we conclude that using a constant density profile is sufficient for both the T2HK and T2HKK experiments.

    hep-phhep-exPRD(2020)·14 citations
19. 19*

    New Physics solutions for $b\to c\tau \bar{\nu }$ anomalies after Moriond 2019

    Suman Kumbhakar🇮🇳 · Ashutosh Kumar Alok🇮🇳 · Dinesh Kumar🇵🇱 · S. Uma Sankar🇮🇳

    At Moriond 2019, Belle collaboration has announced new measurements on the flavour ratios $R_D-R_{D^{\ast }}$ which are consistent with their Standard Model predictions within $1.2\sigma$. After inclusion of these measurements, the global tension in $R_D-R_{D^{\ast }}$ has reduced from $4.1\sigma$ to $3.1\sigma$ which is still significant. The measurements of these ratios indicate towards the violation of lepton flavor universality in $b\to cl\bar{\nu }$ decay. Assuming new physics in $b\to c\tau \bar{\nu }$ transition, we have done a global fit to all available data in this sector to identify the allowed new physics solutions. We find that there are seven allowed new physics solutions which can account for all measurements in $b\to c\tau \bar{\nu }$ transition. We show that a simultaneous measurement of the $\tau$ polarization fraction and forward-backward asymmetry in $B\to D\tau \bar{\nu }$, the zero crossing point of forward backward asymmetry in $B\to D^{\ast }\tau \bar{\nu }$ and the branching ratio of $B_c\to \tau \bar{\nu }$ decay can distinguish these seven new physics solutions if they can be measured with a required precision.

    hep-phhep-exSpringer Proc.Phys.(2020)·2 citations
20. 20*

    QCD parameters and $f_{B_c}$ from heavy quark sum rules

    Stephan Narison (LUPM-CNRS, Montpellier-FR)🇫🇷

    We report results of our recent works [1,2] where we where the correlations between the c,b-quark running masses{m}_{c,b}, the gluon condensate<\alpha_s G^2> and the QCD coupling \alpha_s in the MS-scheme from an analysis of the charmonium and bottomium spectra and the B_c-meson mass. We use optimized ratios of relativistic Laplace sum rules (LSR) evaluated at the \mu-subtraction stability point where higher orders PT and D< 6-8-dimensions non-perturbative condensates corrections are included. We obtain [1] \alpha_s(2.85)=0.262(9) and \alpha_s(9.50)=0.180(8) from the (pseudo)scalar M_{\chi_{0c(0b)}}-M_{\eta_{c(b)}} mass-splittings at \mu=2.85(9.50) GeV. The most precise result from the charm channel leads to \alpha_s(M_\tau)=0.318(15) and \alpha_s(M_Z)=0.1183(19)(3) in excellent agreement with the world average: \alpha_s(M_Z)=0.1181(11)[3,4]. Updated results from a global fit of the (axial-)vector and (pseudo)scalar channels using Laplace and Moments sum rules @ N2LO [1] combined with the one from M_{B_c} [2] lead to the new tentative QCD spectral sum rules (QSSR) average : m_c(m_c)|_average= 1266(6) MeV and m_b(m_b)|_average=4196(8) MeV. The values of the gluon condensate <\alpha_s G^2> from the (axial)-vector charmonium channels combined with previous determinations in Table 1, leads to the new QSSR average [1]: <\alpha_s G^2>_average=(6.35\pm 0.35)x 10^{-2} GeV^4. Our results clarify the (apparent) discrepancies between different estimates of <\alpha_s G^2> from J/\psi sum rule but also shows the sensitivity of the sum rules on the choice of the \mu-subtraction scale. As a biproduct, we deduce the B_c-decay constants f_{B_c}=371(17) MeV and f_{B_c}(2S)< 139(6) MeV.

    hep-phhep-exhep-latnucl-thNucl.Part.Phys.Proc.(2020)·6 citations
21. 21*

    Heavy Quarks Embedded in Glasma

    Margaret E. Carrington🇨🇦 · Alina Czajka🇵🇱 · Stanislaw Mrowczynski🇵🇱

    Heavy quarks, which are produced at the earliest stage of relativistic heavy-ion collisions, probe the entire history of the quark-gluon plasma that is created in the collision. Initially the plasma is populated with chromodynamic fields which can be treated as classical. We study the transport of heavy quarks across such a system, which is called glasma, using a Fokker-Planck equation where the quarks interact with long wavelength chromodynamic fields. We compute field correlators which are used to calculate the collision terms of the transport equation. Finally, the energy loss and momentum broadening of heavy quarks in the glasma are studied. Both of these quantities are sizable and strongly directionally dependent.

    ↳ nucl-thhep-phNPA(2020)·54 citations
22. 22*

    Scaling and higher twist in the nucleon Compton amplitude

    A. Hannaford-Gunn🇦🇺 · R. Horsley🇬🇧 · Y. Nakamura🇯🇵 · H. Perlt🇩🇪 · P. E. L. Rakow🇬🇧 · G. Schierholz🇩🇪 · K. Somfleth🇦🇺 · H. Stüben🇩🇪 · R. D. Young🇦🇺 · J. M. Zanotti🇦🇺

    The partonic structure of hadrons plays an important role in a vast array of high-energy and nuclear physics experiments. It also underpins the theoretical understanding of hadron structure. Recent developments in lattice QCD offer new opportunities for reliably studying partonic structure from first principles. Here we report on the use of the Feynman-Hellmann theorem to study the forward Compton amplitude in the unphysical region. We demonstrate how this amplitude provides direct constraint on hadronic inelastic structure functions. The use of external momentum transfer allows us to study the $Q^2$ evolution to explore the onset of asymptotic scaling and reveal higher-twist effects in partonic structure.

    ↳ hep-lathep-phnucl-thPoS(2020)·21 citations
23. 23*

    Axion Dark Matter Search around 6.7 $\mu$eV

    S. Lee🇰🇷 · S. Ahn🇰🇷 · J. Choi🇰🇷 · B. R. Ko🇰🇷 · Y. K. Semertzidis🇰🇷

    An axion dark matter search with the CAPP-8TB haloscope is reported. Our results are sensitive to axion-photon coupling $g_{a\gamma \gamma }$ down to the QCD axion band over the axion mass range between 6.62 and 6.82 $\mu$eV at a 90\% confidence level, which is the most sensitive result in the mass range to date.

    ↳ hep-exhep-phPRL(2020)·245 citations
24. 24*

    The odderon and BKP states in the Quantum Chromodynamics

    M. A. Braun🇷🇺 · G. P. Vacca🇮🇹

    We discuss the odderon in the QCD and analyze the effects of running coupling introduced in a particular way to preserve the reggeization of the gluon within the leading logarithmic description. This idea is also applied to a family of BKP states with arbitrarily number of gluons in the planar limit. The numerical analysis shows that contrary to the pomeron case where the leading states become discretized, the odderon states still remain a continuous family starting at intercept one. The following rapidity dependence of the amplitude is studied. For the pomeron-odderon system the relation between the descriptions in the reggeized gluon (BFKL) framework and the color dipole/CGC one is investigated.

    ↳ hep-thhep-ph1 citation
25. 25*

    Precision Predictions

    Ulf-G. Meißner🇩🇪

    Precision predictions combined with precise measurements are a major tool in sharpening our understanding of the fundamental laws underlying microscopic as well as macroscopic systems. Here, I present a few remarkable examples covering the fields of nuclear, particle and astrophysics.

    ↳ nucl-thgr-qchep-phNucl.Phys.News(2020)·0 citations
26. 26*

    From precision physics to the energy frontier with the Compact Linear Collider

    Eva Sicking🇨🇭 · Rickard Ström🇨🇭

    The Compact Linear Collider (CLIC) is a proposed high-luminosity collider that would collide electrons with their antiparticles, positrons, at energies ranging from a few hundred Giga-electronvolts (GeV) to a few Tera-electronvolts (TeV). By covering a large energy range and by ultimately reaching multi-TeV $e^{+}{e}^{-}$ collisions, scientists at CLIC aim to improve the understanding of nature's fundamental building blocks and to discover new particles or other physics phenomena. CLIC is an international project with institutes world-wide participating in the accelerator, detector and physics studies. First $e^{+}{e}^{-}$ collisions at CLIC are expected around 2035, following the High-Luminosity phase of the Large Hadron Collider at CERN.

    ↳ physics.acc-phhep-exhep-phphysics.ins-detNat.Phys.(2020)·22 citations
27. 27*

    CLIC Higgs coupling prospects with a longer first energy stage

    Aidan Robson🇬🇧 · Philipp Roloff🇨🇭 · Jorge de Blas🇬🇧

    One of the most attractive features of a linear collider is the ability to extend its energy reach in stages, and to adapt the running plan flexibly in terms of maximum centre-of-mass energy and time spent at each stage. The baseline luminosity staging scenario for CLIC is well-established, and has been used to obtain sensitivity projections for Standard Model measurements and Beyond Standard Model scenarios. Here, as an exercise to illustrate what could be obtained from an alternative running scenario, Higgs coupling sensitivities are presented for the case where more data is collected at the initial stage $\sqrt{s}=380$ GeV, before proceeding to the higher energy stages of $\sqrt{s}=1.5$ and 3 TeV. This could be achieved through running for longer, or operating the collider at an increased repetition rate of 100 Hz at the initial stage, or a combination of both.

    ↳ hep-exhep-ph11 citations
28. 28*

    Meson masses in external magnetic fields with HISQ fermions

    Heng-Tong Ding🇨🇳 · Sheng-Tai Li🇨🇳 · Swagato Mukherjee🇺🇸 · Akio Tomiya🇺🇸 · Xiao-Dan Wang🇨🇳

    We studied the temporal correlation function of mesons in the pseudo-scalar channel in (2+1)-flavor QCD in the presence of external magnetic fields at zero temperature. The simulations were performed on $32^3\times 96$ lattices using the Highly Improved Staggered Quarks (HISQ) action with $m_{\pi }\approx$ 230 MeV. The strength of magnetic fields $|eB|$ ranges from 0 to around 3.3 GeV${}^2$ ($\sim 60m_{\pi }^2$). We found that the masses of neutral pseudo-scalar particles, e.g. neutral pion and kaon, monotonouslly decrease as the magnetic field grows and then saturate at a nonzero value. It is observed that heavier neutral pseudo-scalars are less affected by magnetic fields. Moreover, we found a non-monotonous behavior of charged pion and kaon mass in magnetic field for the first time. In the case of small magnetic field (0 $\le |eB|\lesssim$ 0.3 GeV${}^2\sim 6m_{\pi }^2$ ) the mass of charged pseudo-scalar grows with magnetic field and can be well described by the Lowest Landau Level approximation, while for $|eB|$ larger than 0.3 GeV${}^2$ the mass starts to decrease. The possible connection between $|eB|$ dependences of neutral pion mass and the decreasing behavior of pseudo-critical temperature in magnetic field is discussed. Due to the nonzero value of neutral pion mass our simulation indicates that the superconducting phase of QCD does not exist in the current window of magnetic field.

    ↳ hep-lathep-phnucl-thPoS(2020)·33 citations
29. 29*

    Impact of the underlying O(4) criticality on net-proton number fluctuations

    Michał Szymański🇵🇱

    We discuss the beam-energy dependence of ratios of the first four cumulants of the net-proton number, calculated using a phenomenologically motivated model in which critical mode fluctuations couple to protons and anti-protons. The model takes into account an impact of the underlying $O(4)$ criticality on the QCD phase diagram in the presence of a $Z(2)$ critical point. This allows us to capture qualitatively both the monotonic behavior of the lowest-order ratio and the non-monotonic behavior of higher-order ratios which are seen in the experimental data from the STAR Collaboration. We also discuss the dependence of our results on the coupling strength between the critical mode and the protons as well as the location of the critical point.

    ↳ nucl-thhep-phActa Phys.Polon.Supp.(2020)·0 citations
30. 30*

    Overview of Recent Results from ATLAS

    Craig Wiglesworth🇩🇰

    This paper presents an overview of recent results from the ATLAS Experiment at the CERN Large Hadron Collider, with a particular focus on those that are based on the entire Run 2 dataset of $\sqrt{s}$=13 TeV proton-proton collisions. These results include Standard Model measurements, updates on the Higgs Boson properties, as well as searches for high-mass resonances and supersymmetry.

    ↳ hep-exhep-ph1 citation
31. 31*

    Constraining the nuclear equation of state via gravitational-wave radiation of short gamma-ray burst remnants

    Lin Lan🇨🇳 · Hou-Jun Lü🇨🇳 · Jared Rice🇺🇸 · En-Wei Liang🇨🇳

    The observed internal plateau of X-ray emission in some short GRBs suggests the formation of a remnant supra-massive magnetar following a double neutron star (NS) merger. In this paper, we assume that the rotational energy is lost mainly via gravitational wave (GW) radiation instead of magnetic dipole (MD) radiation, and present further constraints on the NS nuclear equation of state (EoS) via mass quadrupole deformation and r-mode fluid oscillations of the magnetar. We present two short GRBs with measured redshifts, 101219A and 160821B, whose X-ray light curves exhibit an internal plateau. This suggests that a supra-massive NS may survive as the central engine. By considering twelve NS EoSs, within the mass quadrupole deformation scenario we find that the GM1, DD2, and DDME2 models give an $M_{\mathrm{p}}$ band falling within the 2$\sigma$ region of the proto-magnetar mass distribution for $\epsilon =0.01$. This is consistent with the constraints from the MD radiation dominated model of rotational energy loss. However, for an r-mode fluid oscillation model with $\alpha =0.1$ the data suggest that the NS EOS is close to the Shen and APR models, which is obviously different from the MD radiation dominated and mass quadrupole deformation cases.

    ↳ astro-ph.HEhep-phApJ(2020)·10 citations
32. 32*

    Forecast for cosmological parameter estimation with gravitational-wave standard siren observation from the Cosmic Explorer

    Shang-Jie Jin🇨🇳 · Dong-Ze He🇨🇳 · Yidong Xu🇨🇳 · Jing-Fei Zhang🇨🇳 · Xin Zhang🇨🇳

    The third-generation ground-based gravitational-wave (GW) detector, Cosmic Explorer (CE), is scheduled to start its observation in the 2030s. In this paper, we make a forecast for cosmological parameter estimation with gravitational-wave standard siren observation from the CE. We use the simulated GW standard siren data of CE to constrain the $\Lambda$CDM, $w$CDM and CPL models. We combine the simulated GW data with the current cosmological electromagnetic observations including the latest cosmic microwave background anisotropies data from Planck, the optical baryon acoustic oscillation measurements, and the type Ia supernovae observation (Pantheon compilation) to do the analysis. We find that the future standard siren observation from CE will improve the cosmological parameter estimation to a great extent, since the future GW standard siren data can well break the degeneracies generated by the optical observations between various cosmological parameters. We also find that the CE's constraining capability on the cosmological parameters is slightly better than that of the same-type GW detector, the Einstein Telescope. In addition, the synergy between the GW standard siren observation from CE and the 21 cm emission observation from SKA is also discussed.

    ↳ astro-ph.COgr-qchep-phJCAP(2020)·87 citations
33. 33*

    Exploring the partonic phase at finite chemical potential in and out-of equilibrium

    O. Soloveva🇩🇪 · P. Moreau🇩🇪 · L. Oliva🇩🇪 · V. Voronyuk🇷🇺 · V. Kireyeu🇷🇺 · T. Song🇩🇪 · E. Bratkovskaya🇩🇪

    We study the influence of the baryon chemical potential ${\mu }_B$ on the properties of the Quark-Gluon-Plasma (QGP) in and out-of equilibrium. The description of the QGP in equilibrium is based on the effective propagators and couplings from the Dynamical QuasiParticle Model (DQPM) that is matched to reproduce the equation-of-state of the partonic system above the deconfinement temperature $T_c$ from lattice QCD. We study the transport coefficients such as the ratio of shear viscosity $\eta$ and bulk viscosity $\zeta$ over entropy density $s$, i.e. $\eta /s$ and $\zeta /s$ in the $(T,\mu )$ plane and compare to other model results available at ${\mu }_B=0$. The out-of equilibrium study of the QGP is performed within the Parton-Hadron-String Dynamics (PHSD) transport approach extended in the partonic sector by explicitly calculating the total and differential partonic scattering cross sections based on the DQPM and the evaluated at actual temperature $T$ and baryon chemical potential ${\mu }_B$ in each individual space-time cell where partonic scattering takes place. The traces of their ${\mu }_B$ dependences are investigated in different observables for symmetric Au+Au and asymmetric Cu+Au collisions such as rapidity and $m_T$- distributions and directed and elliptic flow coefficients $v_1,v_2$ in the energy range 7.7 GeV $\le \sqrt{s_{NN}}\le 200$ GeV.

    ↳ nucl-thhep-phParticles(2020)·12 citations
34. 34*

    i-flow: High-dimensional Integration and Sampling with Normalizing Flows

    Christina Gao🇺🇸 · Joshua Isaacson🇺🇸 · Claudius Krause🇺🇸

    In many fields of science, high-dimensional integration is required. Numerical methods have been developed to evaluate these complex integrals. We introduce the code i-flow, a python package that performs high-dimensional numerical integration utilizing normalizing flows. Normalizing flows are machine-learned, bijective mappings between two distributions. i-flow can also be used to sample random points according to complicated distributions in high dimensions. We compare i-flow to other algorithms for high-dimensional numerical integration and show that i-flow outperforms them for high dimensional correlated integrals. The i-flow code is publicly available on gitlab at https://gitlab.com/i-flow/i-flow.

    ↳ physics.comp-phcs.LGhep-phstat.MLMach.Learn.Sci.Tech.(2020)·144 citations
35. 35*

    The Subhalo Mass Function and Ultralight Bosonic Dark Matter

    Katelin Schutz🇺🇸

    Warm dark matter has recently become increasingly constrained by observational inferences about the low-mass end of the subhalo mass function, which would be suppressed by dark matter free streaming in the early Universe. In this work, we point out that a constraint can be placed on ultralight bosonic dark matter (often referred to as "fuzzy dark matter") based on similar considerations. Recent limits on warm dark matter from strong gravitational lensing of quasars and from fluctuations in stellar streams separately translate to a lower limit of $\sim 2.1\times 10^{-21}$ eV on the mass of an ultralight boson comprising all dark matter. These limits are complementary to constraints on ultralight dark matter from the Lyman-$\alpha$ forest and are subject to a completely different set of assumptions and systematic uncertainties. Taken together, these probes strongly suggest that dark matter with a mass $\sim 10^{-22}$ eV is not a viable way to reconcile differences between cold dark matter simulations and observations of structure on small scales.

    ↳ astro-ph.COhep-phPRD(2020)·148 citations
36. 36*

    The self-tuning of the cosmological constant and the holographic relaxion

    Yuta Hamada🇫🇷 · Elias Kiritsis🇬🇷 · Francesco Nitti🇫🇷 · Lukas T. Witkowski🇫🇷

    We propose a brane-world setup based on gauge/gravity duality that permits the simultaneous realisation of self-tuning of the cosmological constant and a stabilisation of the electroweak hierarchy. The Standard Model dynamics including the Higgs sector is confined to a flat 4-dimensional brane, embedded in a 5-dimensional bulk whose dynamics is governed by Einstein-dilaton-axion gravity. The inclusion of a dynamical bulk axion is new compared to previous implementations of the self-tuning mechanism. Because of the presence of the axion, the model generically exhibits a multitude of static solutions, with different values for the equilibrium position for the brane. Under mild assumptions regarding the dependence of brane parameters on bulk fields, a number of these solutions exhibit electroweak symmetry breaking with a hierarchically small Higgs mass as compared to the cutoff-scale of the brane theory. The realisation of self-tuning of the cosmological constant is generic and as efficient as in previous constructions without a bulk axion. Vacua with a hierarchically small Higgs mass can sometimes be found, regardless of whether the brane theory depends explicitly on the bulk axion. Because it is expected on general principles that the brane action will depend on the axion, the generation of solutions with a large hierarchy is a robust feature.

    ↳ hep-thhep-phFortsch.Phys.(2021)·8 citations
37. 37*

    Can the quasi-molecular mechanism of recombination decrease the Hubble tension?

    Revaz Beradze🇬🇪 · Merab Gogberashvili🇬🇪

    In the recently suggested non-standard, quasi-molecular mechanism of recombination, the presence of neighboring proton increases the ionization energy and decreases the final recombination rate of hydrogen. Both these two effects can lead to the larger value of the present expansion rate of the universe obtained using CMB data and standard cosmological model, and thus are able to reduce or resolve the Hubble tension problem. We note also that due to the quasi-molecular channel the recombination began earlier, what potentially can solve the sigma-eight tension, since the CMB-predicted value of the late matter density will be decreased.

    ↳ astro-ph.COgr-qchep-phPhys.Dark Univ.(2021)·5 citations
38. 38*

    Fully Bayesian Unfolding with Regularization

    Petr Baron🇨🇿

    Fully Bayesian Unfolding differs from other unfolding methods by providing the full posterior probability of unfolded spectra for each bin. We extended the method for the feature of regularization which could be helpful for unfolding non-smooth, over-binned or generally non-standard shaped spectra. To decrease the computation time, the iteration process is presented.

    ↳ physics.data-anhep-exhep-ph1 citation
39. 39*

    Mapping QGP interaction through its temperature dependent degeneracy factor

    Ranjesh Kumar🇮🇳 · Ankit Anand🇮🇳 · Souvik Paul🇮🇳 · Sarthak Satapathy🇮🇳 · Sabyasachi Ghosh🇮🇳

    We have parameterized the degeneracy factor in terms of temperature and using this we have tried to compare and study the LQCD(Lattice Quantum Chromodynamics) data with our data.

    ↳ nucl-thhep-phDAE Symp.Nucl.Phys.(2019)·0 citations
40. 40*

    Collisional time and shear relaxation time for interacting QGP

    Ankit Anand🇮🇳 · Souvik Paul🇮🇳 · Sarthak Satapathy🇮🇳 · Sabyasachi Ghosh🇮🇳

    We have studied the collisional time and relaxation time of a QGP(Quark-Gluon Plasma) by parameterizing them by temperature. From this parameterization we have obtained the decay rate parameterized by temperature which further helps us to calculate and compare the shear viscosity to entropy density ratio of a QGP with the KSS(Kovtun-Son-Starinets) result.

    ↳ nucl-thhep-phDAE Symp.Nucl.Phys.(2019)·0 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.