Fri·Jun 1, 2018Friday·June 1, 2018

1. 01*

   XENON1T Takes a Razor to a Dark $E_6$-Inspired Model

   Daniel A. Camargo🇧🇷 · Yann Mambrini🇫🇷 · Farinaldo S. Queiroz🇧🇷

   Motivated by the recent result of XENON1T collaboration with full exposure, 279 life days, that sets the most stringent limit on the spin-independent dark matter-nucleon scattering cross section we discuss a dark $E_6$-inspired model that features the presence of a $U(1{)}_{d-u}$ gauge symmetry. The dark matter candidate is a Dirac fermion that interacts with Standard Model fermions via a massive Z' that preserves the quantum number assignments of this symmetry. We compute the spin-independent scattering cross section off xenon nucleus and compare with the XENON1T limit; find the LHC bound on the Z' mass as well as the projection sensitivity of high-energy and luminosity LHC; and derive the Fermi-LAT bounds on the dark matter annihilation cross section based on the observation of gamma-rays in the direction of Dwarf Spheroidal galaxies. We exploit the complementarity between these datasets to conclude that the new bound from XENON1T severely constrain the model, which combined with the LHC upgrade sensitivity rules out this WIMP realization setup below 5 TeV.

   hep-phastro-ph.HEPLB(2018)·5 citations
2. 02*

   QCD$\oplus$QED NNLO corrections to Drell Yan production

   Daniel de Florian🇦🇷 · Manuel Der🇦🇷 · Ignacio Fabre🇦🇷

   We compute the QCD$\times$QED ($\mathcal{O}({\alpha }_s\alpha )$) mixed and QED${}^2$ ($\mathcal{O}({\alpha }^2)$) corrections to the production of an on-shell $Z$ boson in hadronic collisions. We obtain them by profiting from the calculation of the pure QCD terms after taking the corresponding abelian limits. Therefore, we extend the available knowledge up to complete next-to-next-to leading order precision in QCD$\oplus$QED. We present explicit results for the perturbative coefficients and perform the phenomenological analysis at different collider energies with particular emphasis on the mixed corrections. We study the contribution from the different channels and discuss the scale dependence stabilisation effect. We consider a factorisation approximation for the mixed order terms and show that it fails to reproduce the exact result. We find that the contributions are small, typically at the few per mille level, but that under some kinematical conditions they can compete with the pure QCD NNLO ones.

   hep-phhep-exPRD(2018)·81 citations
3. 03*

   Measuring Color Memory in a Color Glass Condensate at Electron-Ion Colliders

   Adam Ball🇺🇸 · Monica Pate🇺🇸 · Ana-Maria Raclariu🇺🇸 · Andrew Strominger🇺🇸 · Raju Venugopalan🇺🇸

   The color memory effect is the non-abelian gauge theory analog of the gravitational memory effect, in which the passage of color radiation induces a net relative SU(3) color rotation of a pair of nearby quarks. It is proposed that this effect can be measured in the Regge limit of deeply inelastic scattering at electron-ion colliders.

   hep-phhep-thnucl-thAnnals Phys.(2019)·39 citations
4. 04*

   Two-loop anomalous dimensions of generic dijet soft functions

   Guido Bell🇩🇪 · Rudi Rahn🇨🇭 · Jim Talbert🇩🇪

   We present compact integral representations for the calculation of two-loop anomalous dimensions for a generic class of soft functions that are defined in terms of two light-like Wilson lines. Our results are relevant for the resummation of Sudakov logarithms for e+ e- event-shape variables and inclusive hadron-collider observables at next-to-next-to-leading logarithmic accuracy within Soft-Collinear Effective Theory (SCET). Our formalism applies to both SCET-1 and SCET-2 soft functions and we clarify the relation between the respective soft anomalous dimension and the collinear anomaly exponent. We confirm existing two-loop results for about a dozen dijet soft functions and obtain new predictions for the angularity event shape and the soft-drop jet-grooming algorithm.

   hep-phNPB(2018)·47 citations
5. 05*

   Thermal behavior and entanglement in Pb-Pb and p-p collisions

   X. Feal🇪🇸 · C. Pajares🇪🇸 · R.A. Vazquez🇪🇸

   The thermalization of the particles produced in collisions of small size objects can be achieved by quantum entanglement of the partons of the initial state as it was analyzed recently in proton-proton collisions. We extend such study to Pb-Pb collisions and to different multiplicities of proton-proton collisions. We observe that, in all cases, the effective temperature is approximately proportional to the hard scale of the collision. We show that such relation between the thermalization temperature and the hard scale can be explained as a consequence of the clustering of the color sources. The fluctuations on the number of parton states decreases with multiplicity in Pb-Pb collisions as far as the width of the transverse momentum distributions decreases, contrary to the p-p case. We relate these fluctuations to the temperature time fluctuations by means of a Langevin equation for the white noise due to the quench of a hard parton collision.

   hep-phPRC(2019)·44 citations
6. 06*

   Probing BSM physics with electron-proton colliders

   David Curtin🇺🇸 · Kaustubh Deshpande🇺🇸 · Oliver Fischer🇩🇪 · Jose Zurita🇩🇪

   In this talk I will illustrate with two examples (Higgsino dark matter and Exotic Higgs decays) how electron-proton colliders present unique opportunities to probe BSM scenarios where proton-proton colliders fall short due to the experimental difficulties in reconstructing the signal due to the large hadronic backgrounds. The leit-motiv of these examples are long-lived particles (LLPs), which have received recently a lot of attention from both the experimental and theoretical communities. We find that the proposed $e^{-}p$ colliders can be competitive against their more energetic $pp$ incarnations for lifetimes between a millimeter and a micron, depending on the physics scenario under consideration.

   hep-phPoS(2018)·2 citations
7. 07*

   Resummed transverse momentum distribution of pseudo-scalar Higgs boson at NNLO${}_A$+NNLL

   Neelima Agarwal · Pulak Banerjee🇮🇳 · Goutam Das🇩🇪 · Prasanna K. Dhani🇮🇳 · Ayan Mukhopadhyay🇮🇳 · V. Ravindran🇮🇳 · Anurag Tripathi🇮🇳

   In this article we have studied the transverse momentum distribution of the pseudo-scalar Higgs boson at the Large Hadron Collider (LHC). The small $\text{pt}$ region which provides the bulk of the cross section is not accessible to fixed order perturbation theory due to the presence of large logarithms in the series. Using the universal infrared behaviour of the QCD we resum these large logarithms up to next-to-next-to-leading logarithmic (NNLL) accuracy. We observe a significant reduction in theoretical uncertainties due to the unphysical scales at NNLL level compared to the previous order. We present the $p_T$ distribution matched to NNLO${}_A$+NNLL, valid for the whole $p_T$ region and provide a detailed phenomenological study in the context of both 14 TeV and 13 TeV LHC using different choices of masses, scales and parton distribution functions which will be useful for the search of such particle at the LHC in near future.

   hep-phJHEP(2018)·4 citations
8. 08*

   An almost elementary Higgs: Theory and Practice

   Daniele Barducci🇮🇹 · Stefania De Curtis🇮🇹 · Michele Redi🇮🇹 · Andrea Tesi🇮🇹

   We study models that interpolate between an elementary and a composite Higgs boson. Such models, arising in theories with new vector-like fermions with electro-weak quantum numbers and charged under a confining gauge interaction, are entirely compatible with current data, with only weak bounds from flavor, CP-violation and precision tests. After classifying the models from the point of view of symmetries, we study their collider phenomenology at LHC. In the most relevant scenarios, bounds from present searches exclude heavy scalar isospin triplets and quintuplets up to $\sim 200$GeV and we show how dedicated searches of simple signals such as $pp\to 3\gamma W$ could improve the reach by at least a factor of 2 with present data, reaching $O(1\mathrm{TeV})$ with higher integrated luminosities. States that mix with the SM Higgs can be tested in a variety of final states, such as $2b2\gamma$ searches relevant for double Higgs production.

   hep-phhep-exJHEP(2018)·19 citations
9. 09*

   Implications of an Improved Neutron-Antineutron Oscillation Search for Baryogenesis: A Minimal Effective Theory Analysis

   Christophe Grojean🇩🇪 · Bibhushan Shakya🇺🇸 · James D. Wells🇺🇸 · Zhengkang Zhang🇺🇸

   Future neutron-antineutron ($n$-$\bar{n}$) oscillation experiments, such as at the European Spallation Source and the Deep Underground Neutrino Experiment, aim to find first evidence of baryon number violation. We investigate implications of an improved $n$-$\bar{n}$ oscillation search for baryogenesis via interactions of $n$-$\bar{n}$ mediators, parameterized by an effective field theory (EFT). We find that even in a minimal EFT setup, there is overlap between the parameter space probed by $n$-$\bar{n}$ oscillation and the region that can realize the observed baryon asymmetry of the universe. The mass scales of exotic new particles are in the TeV-PeV regime, inaccessible at the LHC or its envisioned upgrades. Given the innumerable high energy theories that can match to, or resemble, the minimal EFT that we discuss, future $n$-$\bar{n}$ oscillation experiments could probe many viable theories of baryogenesis beyond the reach of other experiments.

   hep-phPRL(2018)·53 citations
10. 10*

    Freezing-in dark matter through a heavy invisible $Z^{\prime }$

    Gautam Bhattacharyya🇮🇳 · Maíra Dutra🇫🇷 · Yann Mambrini🇫🇷 · Mathias Pierre🇫🇷

    We demonstrate that in a class of the $U(1{)}^{\prime }$ extension of the Standard Model (SM), under which all the Standard Model matter fields are uncharged and the additional neutral gauge boson $Z^{\prime }$ couples to a set of heavy nonstandard fermions, dark matter (DM) production mediated by $Z^{\prime }$ can proceed through the generation of generalized Chern-Simons (GCS) couplings. The origin of the GCS terms is intimately connected to the cancellation of gauge anomalies. We show that the DM production cross section triggered by GCS couplings is sufficient even for an intermediate scale $Z^{\prime }$ . A large range of DM and Z masses is then allowed for reasonably high reheating temperature ($T_{\text{rh}}\gtrsim 10^{10}\text{GeV}$). This type of scenario opens up a new paradigm for unified models. We also study the UV completion of such effective field theory constructions, augmenting it by a heavy fermionic spectrum. The latter, when integrated out, generates the GCS-like terms and provides a new portal to the dark sector. The presence of a number of derivative couplings in the GCS-like operators induces a high temperature dependence to the DM production rate. The mechanism has novel consequences and leads to a new reheating dependence of the relic abundance.

    hep-phPRD(2018)·69 citations
11. 11*

    Multiplicity dependent $p_T$ distributions of identified particles in pp collisions at 7 TeV within HIJING/$B\bar{B}$ v2.0 model

    V.Topor Pop🇨🇦 · M.Petrovici🇷🇴

    Effects of strong longitudinal color fields (SCF) on the identified (anti)particle transverse momentum ($p_T$) distributions in $pp$ collision at $\sqrt{s}$ = 7 TeV are investigated within the framework of the {\small HIJING/BB̄ v2.0} model. The comparison with the experiment is performed in terms of the correlation between mean transverse momentum ($⟨p_t⟩$) and multiplicity (N${}_{ch}^{\ast }$) of charged particles at central rapidity, as well as the ratios of the $p_T$ distributions to the one corresponding to the minimum bias (MB) pp collisions at the same energy, each of them normalized to the corresponding charged particle density, for high multiplicity \mbox{(HM, N_{ch}>100)} and low multiplicity \mbox{(LM, N_{ch}<100)} class of events. The theoretical calculations show that an increase of the strength of color fields (as characterized by the effective values of the string tension $\kappa$), from $\kappa$ = 2 GeV/fm to $\kappa$ = 5 GeV/fm from LM to HM class of events, respectively, lead to a ratio at low and intermediate $p_T$ (i.e., \mbox{$1$GeV/{\it c} $<p_T<6$ GeV/{\it c}}) consistent with recent data obtained at LHC by the ALICE Collaboration.

    hep-phnucl-thPRC(2018)·3 citations
12. 12*

    Implementation of Maxwell's equations in the reconstruction of the magnetic field in the $g-2$ storage ring

    Geoffrey T. Bodwin🇺🇸 · Hee Sok Chung🇩🇪 · Jose Repond🇺🇸

    We present a method for implementing the constraints that are implied by Maxwell's equations in fits to measurements of the magnetic field in the muon storage ring of the $g-2$ experiment. The method that we use makes use of toroidal-harmonic solutions of Laplace's equation. We point out that the fitting problem can be approximated well as a linear-algebra problem. We have devised an efficient algorithm for the linear-algebra problem that makes it possible to find a solution for $10^5$ data points and $10^4$ harmonics in less than an hour on a present-day desktop computer. We illustrate our method by applying it to some preliminary measurements of the magnetic field in the $g-2$ storage ring.

    ↳ physics.ins-dethep-exhep-phJINST(2019)·2 citations
13. 13*

    Lyman-$\alpha$ forest constraints on interacting dark sectors

    Mathias Garny🇩🇪 · Thomas Konstandin🇩🇪 · Laura Sagunski🇨🇦 · Sean Tulin🇨🇦

    The Lyman-$\alpha$ forest is a valuable probe of dark matter models featuring a scale-dependent suppression of the power spectrum as compared to $\Lambda$CDM. In this work, we present a new estimator of the Lyman-$\alpha$ flux power spectrum that does not rely on hydrodynamical simulations. Our framework is characterized by nuisance parameters that encapsulate the complex physics of the intergalactic medium and sensitivity to highly non-linear small-scale modes. After validating the approach based on high-resolution hydrodynamical simulations for $\Lambda$CDM, we derive conservative constraints on interacting dark matter models from BOSS Lyman-$\alpha$ data on large scales, k<0.02(km/s)^(-1), with the relevant nuisance parameters left free in the model fit. The estimator yields lower bounds on the mass of cannibal dark matter, where freeze-out occurs through 3-to-2 annihilation, in the MeV range. Furthermore, we find that models of dark matter interacting with dark radiation, which have been argued to address the $H_0$ and ${\sigma }_8$ tensions, are compatible with BOSS Lyman-$\alpha$ data.

    ↳ astro-ph.COhep-phJCAP(2018)·48 citations
14. 14*

    Mining gold from implicit models to improve likelihood-free inference

    Johann Brehmer🇺🇸 · Gilles Louppe🇧🇪 · Juan Pavez🇨🇱 · Kyle Cranmer🇺🇸

    Simulators often provide the best description of real-world phenomena. However, they also lead to challenging inverse problems because the density they implicitly define is often intractable. We present a new suite of simulation-based inference techniques that go beyond the traditional Approximate Bayesian Computation approach, which struggles in a high-dimensional setting, and extend methods that use surrogate models based on neural networks. We show that additional information, such as the joint likelihood ratio and the joint score, can often be extracted from simulators and used to augment the training data for these surrogate models. Finally, we demonstrate that these new techniques are more sample efficient and provide higher-fidelity inference than traditional methods.

    ↳ stat.MLcs.LGhep-phphysics.data-anProc.Nat.Acad.Sci.(2020)·147 citations
15. 15*

    Two-flavor adjoint QCD

    Mohamed M. Anber🇺🇸 · Erich Poppitz🇨🇦

    We study four dimensional $SU(2)$ Yang-Mills theory with two massless adjoint Weyl fermions. When compactified on a spatial circle of size $L$ much smaller than the strong-coupling scale, this theory can be solved by weak-coupling nonperturbative semiclassical methods. We study the possible realizations of symmetries in the ${\mathbb{R}}^4$ limit and find that all continuous and discrete $0$-form and $1$-form 't Hooft anomaly matching conditions are saturated by a symmetry realization and massless spectrum identical to that found in the small-$L$ limit, with only a single massless flavor-doublet fermion in the infrared. This observation raises the possibility that the class of theories which undergo no phase transition between the analytically-solvable small-size circle and strongly-coupled infinite-size circle is larger than previously thought, and offers new challenges for lattice studies.

    ↳ hep-thhep-lathep-phPRD(2018)·80 citations
16. 16*

    Dark Matter Search Results from a One Tonne$\times$Year Exposure of XENON1T

    E. Aprile🇺🇸 · J. Aalbers🇳🇱 · F. Agostini🇮🇹 · M. Alfonsi🇩🇪 · L. Althueser🇩🇪 · F. D. Amaro🇵🇹 · M. Anthony🇺🇸 · F. Arneodo🇦🇪 · L. Baudis🇨🇭 · B. Bauermeister🇸🇪 · M. L. Benabderrahmane🇦🇪 · T. Berger🇺🇸 and 108 other authors

    We report on a search for Weakly Interacting Massive Particles (WIMPs) using 278.8 days of data collected with the XENON1T experiment at LNGS. XENON1T utilizes a liquid xenon time projection chamber with a fiducial mass of $(1.30\pm 0.01)$ t, resulting in a 1.0 t$\times$yr exposure. The energy region of interest, [1.4, 10.6] $\mathrm{ke}{\mathrm{V}}_{\mathrm{ee}}$ ([4.9, 40.9] $\mathrm{ke}{\mathrm{V}}_{\mathrm{nr}}$), exhibits an ultra-low electron recoil background rate of $(82\begin{array}{c}+5\\ -3\end{array}\text{ (sys)}\pm 3\text{ (stat)})$ events/$(\mathrm{t}\times \mathrm{yr}\times \mathrm{ke}{\mathrm{V}}_{\mathrm{ee}})$. No significant excess over background is found and a profile likelihood analysis parameterized in spatial and energy dimensions excludes new parameter space for the WIMP-nucleon spin-independent elastic scatter cross-section for WIMP masses above 6 GeV/c${}^2$, with a minimum of $4.1\times 10^{-47}$ cm${}^2$ at 30 GeV/c${}^2$ and 90% confidence level.

    ↳ astro-ph.COastro-ph.IMhep-exhep-ph+1PRL(2018)·2660 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.