We propose an experiment to search for extra "hidden-sector" U(1) gauge bosons with gauge kinetic mixing with the ordinary photon, predicted by many extensions of the Standard Model. The setup consists of a highly sensitive magnetometer inside a superconducting shielding. This is then placed inside a strong (but sub-critical) magnetic field. In ordinary electrodynamics the magnetic field cannot permeate the superconductor and no field should register on the magnetometer. However, photon -- hidden-sector photon -- photon oscillations would allow to penetrate the superconductor and the magnetic field would "leak" into the shielded volume and register on the magnetometer. Although this setup resembles a classic ``light shining though a wall experiment'' there are two crucial differences. First, the fields are (nearly) static and the photons involved are virtual. Second, the magnetometer directly measures the field-strength and not a probability. This improves the dependence of the signal on the kinetic mixing chi (\ll 1) to chi^2 instead of chi^4. For hidden photon masses in the range 0.002-200 meV the projected sensitivity for the mixing parameter lies in the 5 10^-9 to 10^-6 range. This surpasses current astrophysical and laboratory limits by several orders of magnitude -- ample room to discover new physics.
We explore strategies for probing Hidden Valley scenarios exhibiting confinement. Such scenarios lead to a multiplicity of light hidden hadrons from showering processes. Their decays are typically soft and displaced, making them challenging to probe with traditional LHC searches. We show the low trigger thresholds and excellent track and vertex reconstruction at LHCb provide an ideal environment to search for such signals -- in both muonic and hadronic channels. We also explore the potential of ATLAS/CMS and discuss modifications to present searches that might make these experiments competitiv…
We study the impact of a hidden sector beyond the Standard Model, e.g. a Hidden Valley model, on factorial moments and cumulants of multiplicity distributions in multiparticle production with a special emphasis on the prospects for LHC results.
Using microwave cavities one can build a resonant ``light-shining-through-walls'' experiment to search for hidden sector photons and axion like particles, predicted in many extensions of the standard model. In this note we make a feasibility study of the sensitivities which can be reached using state of the art technology.
We explore the possibility of experimentally detecting a predicted $h_1 ~[I^G(J^{PC})=0^-(1^{+-})]$ state of hidden charm made out from the $D^* \bar D^*$ interaction. The method consists in measuring the decay of X(4660) into $ηD^* \bar D^*$, determining the binding energy with respect to the $D^* \bar D^*$ threshold from the shape of the $D^* \bar D^*$ invariant mass distribution. A complementary method consists in looking at the inclusive $X(4660) \to ηX$ decay, searching for a peak in the $X$ invariant mass distribution given by the missing X(4660), $η$ mass. We make calculations to determ…
Most signatures of new physics in colliders have been studied so far on the transverse plane with respect to the beam direction. In this work however we study the impact of a hidden sector beyond the Standard Model (SM) on inclusive (pseudo)rapidity correlations and moments of the multiplicity distributions, with special emphasis in the LHC results.
The analysis of azimuthal correlations in multiparticle production can be useful to uncover the existence of new physics beyond the Standard Model, e.g., Hidden Valley, in $e^+e^-$ annihilation at high energies. In this paper, based on previous theoretical studies and using PYTHIA8 event generator, it is found that both azimuthal and rapidity long-range correlations are enhanced due to the presence of a new stage of matter on top of the QCD partonic cascade. Ridge structures, similar to those observed at the LHC, show up providing a possible signature of new physics at future $e^+e^-$ collider…
New phenomena involving pseudorapidity and azimuthal correlations among final state particles in $pp$ collisions at the LHC can hint at the existence of hidden sectors beyond the Standard Model. In this paper we rely on a correlated-cluster picture of multiparticle production, which was shown to account for the ridge effect, to assess the effect of a hidden sector on three-particle correlations concluding that there is a potential signature of new physics that can be directly tested by experiments using well-known techniques.
These TASI lectures consider low mass hidden sectors from Hidden Valleys, Quirks and Unparticles. We show how each corresponds to a different limit of the same class of models: hidden sectors with non-abelian gauge groups with mass gaps well below a TeV that communicate to the Standard Model through weak scale suppressed higher dimension operators. We provide concrete examples of such models and discuss LHC signatures. Lastly we turn to discussing the application of Hidden Valleys to dark matter sectors.
We give an explicit QCD sum rule investigation to hidden-charm baryonium states with the quark content $u\bar u d\bar d c\bar c$, spin $J=0/1/2/3$, and of both positive and negative parities. We systematically construct the relevant local hidden-charm baryonium interpolating currents, which can actually couple to various structures, including hidden-charm baryonium states, charmonium states plus two pions, and hidden-charm tetraquark states plus one pion, etc. We do not know which structure these currents couple to at the beginning, but after sum rule analyses we can obtain some information. W…
We investigate the processes $e^+e^-$$\to$$γJ/ψϕ$, $γJ/ψω$ and $π^0 J/ψη$ to search for the charmnium-like states with hidden $s\bar{s}$, such as $Y(4140)$, $Y(4274)$, $X(4350)$ and $X(3915)$. These processes will receive contributions from the charmed-strange meson rescatterings. When the center-of-mass energies of the $e^+e^-$ scatterings are taken around the $D_{s0}(2317)D_s^{*}$, $D_{s1}(2460)D_s$ or $D_{s1}(2460)D_s^{*}$ threshold, the anomalous triangle singularities can be present in the rescattering amplitudes, which implies a non-resonance explanation about the resonance-like structur…
Motivated by the searching for $bb\bar{b}\bar{b}$ states at LHC recently, we calculate the ground-state energies of $bb\bar{b}\bar{b}$ states with quantum numbers $IJ^P=00^+,01^+,02^+$ in a nonrelativistic chiral quark model using the Gaussian expansion method. In our calculations, two structures, meson-meson and diquark-antidiquark, and their coupling, along with all possible color configurations are considered. It is expected that the studies shall be helpful for the experimental searching of fully-heavy exotic tetraquark states.
Most signatures of new physics have been studied on the transverse plane with respect to the beam direction at the LHC where background is much reduced. In this paper we propose the analysis of inclusive longitudinal (pseudo)rapidity correlations among final-state (charged) particles in order to search for (un)particles belonging to a Hidden Sector beyond the Standard Model, using a selected sample of p-p minimum bias events (applying appropriate off-line cuts on events based on, e.g., minijets, high-multiplicity, event shape variables, high-pT leptons and photons, etc) collected at the early …
Due to the discovery of the hidden-charm pentaquark $P_c$ states by the LHCb collaboration, the interests on the candidates of hidden-bottom pentaquark $P_b$ states are increasing. They are anticipated to exist as the analogues of the $P_c$ states in the bottom sector and predicted by many models. We give an exploration of searching for a typical $P_b$ in the $γp \to Υp$ reaction, which shows a promising potential to observe it at an electron-ion collider. The possibility of searching for $P_b$ in open-bottom channels are also briefly discussed. Meanwhile, the $t$-channel non-resonant contribu…
We investigate the possibility of studying the strange hidden-charm pentaquark state $P_{cs}(4459)$ by photon-induced reactions on a proton target in an effective Lagrangian approach. The production process is described by the $t$-channel $K^{-}$ exchange, the $u$-channel $Λ$ exchange, the contract term, and the $s$- channel nucleon pole. Our theoretical approach is based on the assumption that $P_{cs}(4459)$ with $J^{P}=1/2^{-}$ or $J^{P}=3/2^{-}$ can be interpreted as a molecule composed of $\bar{D}^{*}Ξ_c$. Using the coupling constants of the $P^{J^P}_{cs}$ to $γΛ$ and $K^{-}p$ channels obt…
Currently, there are a number of light-shining-through-walls experiments searching for hidden photons -- light, sub-eV-scale, abelian gauge bosons beyond the standard model which mix kinetically with the standard photon. We show that in the case that one of these experiments finds evidence for hidden photons, laser communications through matter, using methods from free-space optics, can be realized in the very near future, with a channel capacity of more than 1 bit per second, for a distance up to the Earth's diamater.
We search for hidden mirror symmetries at large angular scales in the WMAP 7 year Internal Linear Combination map of CMB temperature anisotropies using global pixel based estimators introduced for this aim. Two different axes are found for which the CMB intensity pattern is anomalously symmetric (or anti-symmetric) under reflection with respect to orthogonal planes at the 99.84(99.96)% CL (confidence level), if compared to a result for an arbitrary axis in simulations without the symmetry. We have verified that our results are robust to the introduction of the galactic mask. The direction of s…
The s-wave interaction of $\bar{D} Λ_c, \bar{D} Σ_c, \bar{D} Λ_c, \bar{D}{}^* Σ_c$ and $\bar{D}Σ^*_c, \bar{D}{}^*Σ^*_c$, is studied within a unitary coupled channels scheme with the extended local hidden gauge approach. In addition to the Weinberg-Tomozawa term, several additional diagrams via the pion-exchange are also taken into account as box potentials. Furthermore, in order to implement the full coupled channels calculation, some of the box potentials which mix the vector-baryon and pseudoscalar-baryon sectors are extended to construct the effective transition potentials. As a result, we …
LHCb recently announced the discovery of two exotic structures in the $J/ψ+ p$ decay channel, which have been referred to as charmonium-pentaquark states. Resolving between the models and clarifying the nature of the discovered hidden-charm pentaquark peaks, and possibly searching for similar peaks with other quantum numbers, requires further experimental studies. The states were observed in the decay mode $J/ψ+p$. Thus, it is natural to expect that these pentaquarks can be produced in the photoproduction process $γ+p\to P_c\to J/ψ+p$ where these states will appear as s-channel resonances at p…
Low energy antideuteron detection presents a unique channel for indirect detection, targeting dark matter that annihilates into hadrons in a relatively background-free way. Since the idea was first proposed, many WIMP-type models have already been disfavored by direct detection experiments, and current constraints indicate that any thermal relic candidates likely annihilate through some hidden sector process. In this paper, we show that cosmic ray antideuteron detection experiments represent one of the best ways to search for hidden sector thermal relic dark matter, and in particular investiga…
The dark (or hidden) photon is a massive U(1) gauge boson theorized as a dark force mediator and as a dark matter candidate. Dark photons can be detected with axion cavity haloscopes by probing for a power excess caused by the dark photon's kinetic mixing with Standard Model photons. Haloscope axion exclusion limits may therefore be converted into competitive dark photon parameter limits via the calculation of a corresponding dark photon to photon coupling factor. This calculation allows for an improvement in sensitivity of around four orders of magnitude relative to other dark photon exclusio…
Recently, the laser experiments BMV and GammeV, searching for light shining through walls, have published data and calculated new limits on the allowed masses and couplings for axion-like particles. In this note we point out that these experiments can serve to constrain a much wider variety of hidden-sector particles such as, e.g., minicharged particles and hidden-sector photons. The new experiments improve the existing bounds from the older BFRT experiment by a factor of two. Moreover, we use the new PVLAS constraints on a possible rotation and ellipticity of light after it has passed through…
The existence of Dark Matter (DM) is a well established fact since many decades, thanks to the observation of the effects of its gravitational interaction with the ordinary matter in the Universe. However, our knowledge of the Dark Matter features is still rather scarce. Indeed, one of the biggest quests in fundamental science today is the investigation of Dark Matter nature, from its origin to its composition, and the way its constituents interact with the ordinary matter, apart from gravity. Huge and ambitious efforts have been spent in the last years into its identification, concentrating e…
We explore constraints on gauge bosons of a weakly coupled $U(1)_{B-L}$, $U(1)_{L_μ-L_e}$, $U(1)_{L_e-L_τ}$ and $U(1)_{L_μ-L_τ}$. To do so we apply the full constraining power of experimental bounds derived for a hidden photon of a secluded $U(1)_{X}$ and translate them to the considered gauge groups. In contrast to the secluded hidden photon that acquires universal couplings to charged Standard Model particles through kinetic mixing with the photon, for these gauge groups the couplings to the different Standard Model particles can vary widely. We take finite, computable loop-induced kinetic m…
Clear methods to differentiate between decaying and annihilating dark matter (DM) scenarios are still by and large unavailable. In this note, we study the potential astrophysical signatures of a new class of hidden sector decaying DM models, which can address the recent cosmic ray measurements. Such models may produce primary photons and/or neutrinos at large rates, correlated with the leptonic production. The photon and neutrino spectra will then contain sharp features at the TeV scale. We demonstrate the discovery potential for upcoming and future measurements by FERMI, HESS, AGIS and IceCub…
Hidden photons, gauge bosons of a U(1) symmetry of a hidden sector, can constitute the dark matter of the universe and a smoking gun for large volume compactifications of string theory. In the sub-eV mass range, a possible discovery experiment consists on searching the copious flux of these particles emitted from the Sun in a helioscope setup à la Sikivie. In this paper, we compute the flux of transversely polarised HPs from the Sun, a necessary ingredient for interpreting such experiments. We provide a detailed exposition of photon-HP oscillations in inhomogenous media, with special focus on …
