Mon·Oct 7, 2019Monday·October 7, 2019

1. 01*

   Searches for Dark Matter at the LHC in forward proton mode

   M. Tasevsky🇨🇿 · L. A. Harland-Lang🇬🇧 · V. A. Khoze🇬🇧 · M. G. Ryskin🇷🇺

   We analyze in detail the LHC prospects at the center-of-mass energy of 14 TeV for charged electroweakino searches, decaying to leptons, in compressed supersymmetry scenarios, via exclusive photon-initiated pair production. This provides a potentially increased sensitivity in comparison to inclusive channels, where the background is often overwhelming. We pay particular attention to the challenges that such searches would face in the hostile high pile-up environment of the LHC, giving close consideration to the backgrounds that will be present. The signal we focus on is the exclusive production of same-flavour muon and electron pairs, with missing energy in the final state, and with two outgoing intact protons registered by the dedicated forward proton detectors installed in association with ATLAS and CMS. We present results for slepton masses of 120--300 GeV and slepton-neutralino mass splitting of 10-20 GeV, and find that the relevant backgrounds can be controlled to the level of the expected signal yields. The most significant such backgrounds are due to semi-exclusive lepton pair production at lower masses, with a proton produced in the initial proton dissociation system registering in the forward detectors, and from the coincidence of forward protons produced in pile-up events with an inclusive central event that mimics the signal. We also outline a range of potential methods to further suppress these backgrounds as well as to enlarge the signal yields.

   hep-phPoS(2020)·1 citation
2. 02*

   Effective theories and resonances in strongly-coupled electroweak symmetry breaking scenarios

   Ignasi Rosell🇪🇸 · Claudius Krause🇺🇸 · Antonio Pich🇪🇸 · Juan José Sanz-Cillero🇪🇸

   Due to the mass gap between the Standard Model and possible New Physics states, electroweak effective approaches are appropriate. Although a linear realization of the electroweak symmetry breaking with the Higgs forming a doublet together with the Goldstone bosons of the EWSB is a first possibility (SMEFT), we adopt the more general non-linear realization, where the Higgs is a singlet with independent couplings (EWET, HEFT or EWChL). We present the effective Lagrangian at low energies (the EWET, with only the SM fields) and at high energies (the resonance theory, with also a set of resonances). Taking into account the high scale of these resonances, their experimental searches seem to be more accessible by considering their imprints at low-energies, i.e., their imprints in the Low Energy Constants (LECs) of the EWET at energies lower than the resonance masses. We give some examples of these phenomenological connections.

   hep-phPoS(2020)·1 citation
3. 03*

   Transition Distribution Amplitudes : from JLab to EIC

   L. Szymanowski🇵🇱 · B. Pire🇫🇷 · K. Semenov-Tian-Shansky🇷🇺

   Baryon-to-meson Transition Distribution Amplitudes extend both the concepts of generalized parton distributions and baryon distribution amplitudes encoding valuable complementary information on the 3-dimensional hadronic structure. The recent analysis of backward meson electroproduction at JLab supports the hope to perform femto-photography of hadrons from a brand new perspective.and in particular opens a new domain for EIC experiments.

   hep-phhep-exnucl-exnucl-th2 citations
4. 04*

   Gravitational Imprints of Flavor Hierarchies

   Admir Greljo🇨🇭 · Toby Opferkuch🇨🇭 · Ben A. Stefanek🇩🇪

   The mass hierarchy among the three generations of quarks and charged leptons is one of the greatest mysteries in particle physics. In various flavor models, the origin of this phenomenon is attributed to a series of hierarchical spontaneous symmetry breakings, most of which are beyond the reach of particle colliders. We point out that the observation of a multi-peaked stochastic gravitational wave signal from a series of cosmological phase transitions could well be a unique probe of the mechanism behind flavor hierarchies. To illustrate this point, we show how near future ground- and space-based gravitational wave observatories could detect up to three peaks in the recently proposed $P{S}^3$ model.

   hep-phastro-ph.COhep-exPRL(2020)·62 citations
5. 05*

   Improved opacity expansion for medium-induced parton splitting

   Yacine Mehtar-Tani🇺🇸 · Konrad Tywoniuk🇳🇴

   We present a new expansion scheme to compute the rate for parton splittings in dense and finite QCD media. In contrast to the standard opacity expansion, our expansion is performed around the harmonic oscillator whose characteristic frequency depends on the typical transverse momentum scale generated in the splitting. The first two orders account for the high frequency regime that is dominated by single hard scatterings together with the regime of multiple soft scatterings at low frequency. This work generalizes the findings of Ref. \cite{Mehtar-Tani:2019tvy} beyond the leading logarithmic approximation allowing to account also for the Bethe-Heitler regime and compare to the full numerical results from Ref. \cite{CaronHuot:2010bp}. We investigate the sensitivity of our results to varying the separation scale that defines the leading order. Finally, the application to Monte Carlo event generators is discussed.

   hep-phnucl-thJHEP(2020)·70 citations
6. 06*

   Axiogenesis

   Raymond T. Co🇺🇸 · Keisuke Harigaya🇺🇸

   We propose a mechanism called axiogenesis where the cosmological excess of baryons over antibaryons is generated from the rotation of the QCD axion. The Peccei-Quinn (PQ) symmetry may be explicitly broken in the early universe, inducing the rotation of a PQ charged scalar field. The rotation corresponds to the asymmetry of the PQ charge, which is converted into the baryon asymmetry via QCD and electroweak sphaleron transitions. In the concrete model we explore, interesting phenomenology arises due to the prediction of a small decay constant and the connections with new physics at the LHC and future colliders and with axion dark matter.

   hep-phastro-ph.COPRL(2020)·223 citations
7. 07*

   An approach to constraining the Higgs width at the LHC and HL-LHC

   Philip Coleman Harris🇺🇸 · Dylan Sheldon Rankin🇺🇸 · Cristina Mantilla Suarez🇺🇸

   Despite the discovery of the Higgs boson decay in five separate channels many parameters of the Higgs boson remain largely unconstrained. In this paper, we present a new approach to constraining the Higgs total width by requiring the Higgs to be resolved as a single high p${}_T$ jet and measuring the inclusive Higgs boson cross section. To measure the inclusive Higgs boson cross section, we rely on new approaches from machine learning and a modified jet reconstruction. This approach is found to be complementary to the existing off-shell width measurement and, with the full HL-LHC luminosity, is capable of yielding similar sensitivity to the off-shell projections. We outline the theoretical and experimental limitations and present a path towards making this approach a truly model-independent measurement of the Higgs boson total width.

   hep-phhep-ex6 citations
8. 08*

   Gravitational Wave Signals from Multiple Hidden Sectors

   Paul Archer-Smith🇨🇦 · Dylan Linthorne🇨🇦 · Daniel Stolarski🇨🇦

   We explore the possibility of detecting gravitational waves generated by first order phase transitions in multiple dark sectors. Nnaturalness is taken as a sample model that features multiple additional sectors, many of which undergo phase transitions that produce gravitational waves. We examine the cosmological history of this framework and determine the gravitational wave profiles generated. These profiles are checked against projections of next-generation gravitational wave experiments, demonstrating that multiple hidden sectors can indeed produce unique gravitational wave signatures that will be probed by these future experiments.

   hep-phastro-ph.COPRD(2020)·26 citations
9. 09*

   Calculating Pull for Non-Singlet Jets

   Yunjia Bao🇺🇸 · Andrew J. Larkoski🇺🇸

   The pull vector is a jet observable sensitive to the distribution of soft radiation controlled by the color flow in a collider event. We present calculations to leading order in the soft and collinear limits for the pull vector measured between pairs of jets that do not form a color-singlet dipole. Our calculations are presented within the context of $e^{+}{e}^{-}\to$ three jets events, on which pull is measured between the two subleading jets. A subset of these calculations can be re-interpreted as a bottom--anti-bottom quark jet pair in a color octet configuration, which can be a background to Higgs production at large boost. We also present a universal expression for the pull distribution in the high-boost and small jet radius limit. This distribution is controlled by color SU(3) quadratic Casimirs that arise from product representations of pairs of QCD jets.

   hep-phhep-exJHEP(2019)·9 citations
10. 10*

    Radiation from Global Topological Strings using Adaptive Mesh Refinement: Methodology and Massless Modes

    Amelia Drew🇬🇧 · E.P.S. Shellard🇬🇧

    We implement adaptive mesh refinement (AMR) simulations of global topological strings using the public numerical relativity code, GRChombo. We perform a quantitative investigation of the dynamics of single sinusoidally displaced string configurations, studying a wide range of string energy densities $\mu \propto \ln \lambda$, defined by the string width parameter $\lambda$ over two orders of magnitude. We investigate the resulting massless (Goldstone boson or axion) radiation signals, using quantitative diagnostic tools to determine the eigenmode decomposition. Given analytic radiation predictions, we compare the oscillating string trajectory with a backreaction model accounting for radiation energy losses, finding excellent agreement. We establish that backreaction decay is accurately characterised by the inverse square of the amplitude being proportional to the inverse tension $\mu$ for $3\lesssim \lambda \lesssim 100$. We conclude that analytic radiation modelling in the thin-string (Nambu-Goto) limit provides the appropriate cosmological limit for global strings. We contextualise these results with respect to axions and gravitational waves produced by cosmic string networks.

    ↳ astro-ph.COgr-qchep-phPRD(2022)·57 citations
11. 11*

    An improved measurement of the Lense-Thirring precession on the orbits of laser-ranged satellites with an accuracy approaching the 1% level

    David M. Lucchesi🇮🇹 · Massimo Visco🇮🇹 · Roberto Peron🇮🇹 · Massimo Bassan🇮🇹 · Giuseppe Pucacco🇮🇹 · Carmen Pardini🇮🇹 · Luciano Anselmo🇮🇹 · Carmelo Magnafico🇮🇹

    We present a new measurement of the Lense-Thirring effect on the orbits of the geodetic satellites LAGEOS, LAGEOS II and LARES. This secular precession is a general relativity effect produced by the gravitomagnetic field of the Earth generated by its rotation. The effect is a manifestation of spacetime curvature generated by mass-currents, a peculiarity of Einstein's theory of gravitation. This measurement stands out, compared to previous measurements in the same context, for its precision ($\simeq 7.4\times 10^{-3}$) and accuracy ($\simeq 16\times 10^{-3}$), i.e. for a reliable and robust evaluation of the systematic sources of error due to both gravitational and non-gravitational perturbations. For this new measurement, we have largely exploited the results of GRACE mission to significantly improve the description of the gravitational field of the Earth, by also modeling its time dependence. In this way, we strongly reduced the systematic errors due to the uncertainty in the knowledge of the Earth even zonal harmonics and, at the same time, avoided a possible bias of the final result and, consequently, of the precision of the measurement, linked to a non-reliable handling of the unmodeled and mismodeled periodic effects.

    ↳ gr-qcastro-ph.EPhep-ph7 citations
12. 12*

    Coherent quantum enhancement of pair production in the null domain

    Anton Ilderton🇬🇧

    We present an exactly solvable example of coherent quantum interference effects in the creation of electron-positron pairs from the collision of a photon with ultra-short laser pulses. Being characterised entirely by null, or lightlike, directions, this setup realises an all-optical double-slit in the "null" domain, and exhibits features both in common with, and distinct from, a time domain double-slit (Ramsey interferometer). We show that by tailoring the order and amplitude of the pulses one can control signatures of both quantum and classical physics in the produced positron spectrum.

    ↳ quant-phhep-phhep-thPRD(2020)·25 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.