Search

The Heavy Photon Search (HPS) experiment is designed to search for a new vector boson $A^\prime$ in the mass range of 20 MeV/$c^2$ to 220 MeV/$c^2$ that kinetically mixes with the Standard Model photon with couplings $\epsilon^2 >10^{-10}$. In addition to the general importance of exploring light, weakly coupled physics that is difficult to probe with high-energy colliders, a prime motivation for this search is the possibility that sub-GeV thermal relics constitute dark matter, a scenario that requires a new comparably light mediator, where models with a hidden $U(1)$ gauge symmetry, a "dark", "hidden sector", or "heavy" photon, are particularly attractive. HPS searches for visible signatures of these heavy photons, taking advantage of their small coupling to electric charge to produce them via a process analogous to bremsstrahlung in a fixed target and detect their subsequent decay to $\mathrm{e}^+ \mathrm{e}^-$ pairs in a compact spectrometer. In addition to searching for $\mathrm{e}^+ \mathrm{e}^-$ resonances atop large QED backgrounds, HPS has the ability to precisely measure decay lengths, resulting in unique sensitivity to dark photons, as well as other long-lived new physics. After completion of the experiment and operation of engineering runs in 2015 and 2016 at the JLab CEBAF, physics runs in 2019 and 2021 have provided datasets that are now being analyzed to search for dark photons and other new phenomena., Comment: Submitted to the Proceedings of the US Community Study on the Future of Particle Physics (Snowmass 2021)

The Heavy Photon Search (HPS) experiment is designed to search for a new vector boson $A^\prime$ in the mass range of 20 MeV/$c^2$ to 220 MeV/$c^2$ that kinetically mixes with the Standard Model photon with couplings $\epsilon^2 >10^{-10}$. In addition to the general importance of exploring light, weakly coupled physics that is difficult to probe with high-energy colliders, a prime motivation for this search is the possibility that sub-GeV thermal relics constitute dark matter, a scenario that requires a new comparably light mediator, where models with a hidden $U(1)$ gauge symmetry, a "dark", "hidden sector", or "heavy" photon, are particularly attractive. HPS searches for visible signatures of these heavy photons, taking advantage of their small coupling to electric charge to produce them via a process analogous to bremsstrahlung in a fixed target and detect their subsequent decay to $\mathrm{e}^+ \mathrm{e}^-$ pairs in a compact spectrometer. In addition to searching for $\mathrm{e}^+ \mathrm{e}^-$ resonances atop large QED backgrounds, HPS has the ability to precisely measure decay lengths, resulting in unique sensitivity to dark photons, as well as other long-lived new physics. After completion of the experiment and operation of engineering runs in 2015 and 2016 at the JLab CEBAF, physics runs in 2019 and 2021 have provided datasets that are now being analyzed to search for dark photons and other new phenomena., Comment: Submitted to the Proceedings of the US Community Study on the Future of Particle Physics (Snowmass 2021)

We present our results for a flavor-dependent EMC effect based on the nIMParton nuclear PDFs, in which the $x$-dependence is described with a nucleon swelling model. The nuclear correction from nucleon swelling is considered through a modification of the initial valence quark distributions instead of a dynamical rescaling. To probe the flavor-dependence of the model, the experimental observables are calculated applying nIMParton nuclear modifications for various experiments: parity-violating deep inelastic scattering on nuclear target, pion-induced Drell-Yan, and W-boson production in proton-nucleus collisions. In addition, we present the expected effect for the spectator-tagged deep inelastic scattering process, which will be performed by the CLAS12 collaboration with the ALERT detector., Comment: Add the explanation of the nIMParton model used

La domesticación es el giro del feminismo en un discurso que, en lugar de desafiar y transformar el statu quo existente, y particularmente el modo de producción capita¬lista y el conjunto de las prácticas e ideologías conectadas a este último, sirve como su apoyo. ¿Por qué y con qué resultados ha tenido lugar un giro hacia la domesticación? Este artículo contribuye a este tema ampliamente debatido al proponer pensar que la domesticación del feminismo está vinculada a la dominación del “género” como una herramienta analítica y política., ‘Domestication’ is the turning of feminism into a discourse which, rather than chal¬lenging and transforming the existing status quo, and particularly the capitalistic mode of production and the whole of practices and ideologies connected to this latter, serves as its support. Why and with what results, such a turning towards Domestication has taken place? This article contributes to this largely debated issue by proposing to think that the domestication of feminism is linked to the domination of ‘Gender’ as an ana¬lytical and political tool.

La domesticación es el giro del feminismo en un discurso que, en lugar de desafiar y transformar el statu quo existente, y particularmente el modo de producción capita¬lista y el conjunto de las prácticas e ideologías conectadas a este último, sirve como su apoyo. ¿Por qué y con qué resultados ha tenido lugar un giro hacia la domesticación? Este artículo contribuye a este tema ampliamente debatido al proponer pensar que la domesticación del feminismo está vinculada a la dominación del “género” como una herramienta analítica y política., ‘Domestication’ is the turning of feminism into a discourse which, rather than chal¬lenging and transforming the existing status quo, and particularly the capitalistic mode of production and the whole of practices and ideologies connected to this latter, serves as its support. Why and with what results, such a turning towards Domestication has taken place? This article contributes to this largely debated issue by proposing to think that the domestication of feminism is linked to the domination of ‘Gender’ as an ana¬lytical and political tool.

La domesticación es el giro del feminismo en un discurso que, en lugar de desafiar y transformar el statu quo existente, y particularmente el modo de producción capita¬lista y el conjunto de las prácticas e ideologías conectadas a este último, sirve como su apoyo. ¿Por qué y con qué resultados ha tenido lugar un giro hacia la domesticación? Este artículo contribuye a este tema ampliamente debatido al proponer pensar que la domesticación del feminismo está vinculada a la dominación del “género” como una herramienta analítica y política., ‘Domestication’ is the turning of feminism into a discourse which, rather than chal¬lenging and transforming the existing status quo, and particularly the capitalistic mode of production and the whole of practices and ideologies connected to this latter, serves as its support. Why and with what results, such a turning towards Domestication has taken place? This article contributes to this largely debated issue by proposing to think that the domestication of feminism is linked to the domination of ‘Gender’ as an ana¬lytical and political tool.

The CLAS and Hall A collaborations at Jefferson Laboratory have recently released new results for the ep->ep{\gamma} reaction. We analyze these new data within the Generalized Parton Distribution formalism. Employing a fitter algorithm introduced and used in earlier works, we are able to extract from these data new constraints on the kinematical dependence of three Compton Form Factors. Based on experimental data, we subsequently extract the dependence of the proton charge radius on the quarks longitudinal momentum fraction., Comment: 25 pages, 26 figures

La domesticación es el giro del feminismo en un discurso que, en lugar de desafiar y transformar el statu quo existente, y particularmente el modo de producción capita¬lista y el conjunto de las prácticas e ideologías conectadas a este último, sirve como su apoyo. ¿Por qué y con qué resultados ha tenido lugar un giro hacia la domesticación? Este artículo contribuye a este tema ampliamente debatido al proponer pensar que la domesticación del feminismo está vinculada a la dominación del “género” como una herramienta analítica y política., ‘Domestication’ is the turning of feminism into a discourse which, rather than chal¬lenging and transforming the existing status quo, and particularly the capitalistic mode of production and the whole of practices and ideologies connected to this latter, serves as its support. Why and with what results, such a turning towards Domestication has taken place? This article contributes to this largely debated issue by proposing to think that the domestication of feminism is linked to the domination of ‘Gender’ as an ana¬lytical and political tool.

La domesticación es el giro del feminismo en un discurso que, en lugar de desafiar y transformar el statu quo existente, y particularmente el modo de producción capita¬lista y el conjunto de las prácticas e ideologías conectadas a este último, sirve como su apoyo. ¿Por qué y con qué resultados ha tenido lugar un giro hacia la domesticación? Este artículo contribuye a este tema ampliamente debatido al proponer pensar que la domesticación del feminismo está vinculada a la dominación del “género” como una herramienta analítica y política., ‘Domestication’ is the turning of feminism into a discourse which, rather than chal¬lenging and transforming the existing status quo, and particularly the capitalistic mode of production and the whole of practices and ideologies connected to this latter, serves as its support. Why and with what results, such a turning towards Domestication has taken place? This article contributes to this largely debated issue by proposing to think that the domestication of feminism is linked to the domination of ‘Gender’ as an ana¬lytical and political tool.

La domesticación es el giro del feminismo en un discurso que, en lugar de desafiar y transformar el statu quo existente, y particularmente el modo de producción capitalista y el conjunto de las prácticas e ideologías conectadas a este último, sirve como su apoyo. ¿Por qué y con qué resultados ha tenido lugar un giro hacia la domesticación? Este artículo contribuye a este tema ampliamente debatido al proponer pensar que la domesticación del feminismo está vinculada a la dominación del “género” como una herramienta analítica y política., ‘Domestication’ is the turning of feminism into a discourse which, rather than challenging and transforming the existing status quo, and particularly the capitalistic mode of production and the whole of practices and ideologies connected to this latter, serves as its support. Why and with what results, such a turning towards Domestication has taken place? This article contributes to this largely debated issue by proposing to think that the domestication of feminism is linked to the domination of ‘Gender’ as an analytical and political tool.

La domesticación es el giro del feminismo en un discurso que, en lugar de desafiar y transformar el statu quo existente, y particularmente el modo de producción capita¬lista y el conjunto de las prácticas e ideologías conectadas a este último, sirve como su apoyo. ¿Por qué y con qué resultados ha tenido lugar un giro hacia la domesticación? Este artículo contribuye a este tema ampliamente debatido al proponer pensar que la domesticación del feminismo está vinculada a la dominación del “género” como una herramienta analítica y política., ‘Domestication’ is the turning of feminism into a discourse which, rather than chal¬lenging and transforming the existing status quo, and particularly the capitalistic mode of production and the whole of practices and ideologies connected to this latter, serves as its support. Why and with what results, such a turning towards Domestication has taken place? This article contributes to this largely debated issue by proposing to think that the domestication of feminism is linked to the domination of ‘Gender’ as an ana¬lytical and political tool.

La domesticación es el giro del feminismo en un discurso que, en lugar de desafiar y transformar el statu quo existente, y particularmente el modo de producción capitalista y el conjunto de las prácticas e ideologías conectadas a este último, sirve como su apoyo. ¿Por qué y con qué resultados ha tenido lugar un giro hacia la domesticación? Este artículo contribuye a este tema ampliamente debatido al proponer pensar que la domesticación del feminismo está vinculada a la dominación del “género” como una herramienta analítica y política., ‘Domestication’ is the turning of feminism into a discourse which, rather than challenging and transforming the existing status quo, and particularly the capitalistic mode of production and the whole of practices and ideologies connected to this latter, serves as its support. Why and with what results, such a turning towards Domestication has taken place? This article contributes to this largely debated issue by proposing to think that the domestication of feminism is linked to the domination of ‘Gender’ as an analytical and political tool.

The Heavy Photon Search (HPS), an experiment to search for a hidden sector photon in fixed target electroproduction, is preparing for installation at the Thomas Jefferson National Accelerator Facility (JLab) in the Fall of 2014. As the first stage of this project, the HPS Test Run apparatus was constructed and operated in 2012 to demonstrate the experiment's technical feasibility and to confirm that the trigger rates and occupancies are as expected. This paper describes the HPS Test Run apparatus and readout electronics and its performance. In this setting, a heavy photon can be identified as a narrow peak in the e$^+$e$^-$ invariant mass spectrum, above the trident background or as a narrow invariant mass peak with a decay vertex displaced from the production target, so charged particle tracking and vertexing are needed for its detection. In the HPS Test Run, charged particles are measured with a compact forward silicon microstrip tracker inside a dipole magnet. Electromagnetic showers are detected in a PbW0$_{4}$ crystal calorimeter situated behind the magnet, and are used to trigger the experiment and identify electrons and positrons. Both detectors are placed close to the beam line and split top-bottom. This arrangement provides sensitivity to low-mass heavy photons, allows clear passage of the unscattered beam, and avoids the spray of degraded electrons coming from the target. The discrimination between prompt and displaced e$^+$e$^-$ pairs requires the first layer of silicon sensors be placed only 10~cm downstream of the target. The expected signal is small, and the trident background huge, so the experiment requires very large statistics. Accordingly, the HPS Test Run utilizes high-rate readout and data acquisition electronics and a fast trigger to exploit the essentially 100% duty cycle of the CEBAF accelerator at JLab., Comment: Revised version to match published version, 16 pages, 18 figures, published in Nuclear Instruments and Methods in Physics Research Section A, editor: Per Hansson Adrian

This paper focuses on a measurement of deeply virtual Compton scattering (DVCS) performed at Jefferson Lab using a nearly-6-GeV polarized electron beam, two longitudinally polarized (via DNP) solid targets of protons (NH3) and deuterons (ND3) and the CEBAF Large Acceptance Spectrometer. Here, preliminary results for target-spin asymmetries and double (beam-target) asymmetries for proton DVCS, as well as a very preliminary extraction of beam-spin asymmetry for neutron DVCS, are presented and linked to Generalized Parton Distributions., Comment: 6 pages, 5 figures. Proceedings for the QNP2012 conference

This paper focuses on a measurement of deeply virtual Compton scattering (DVCS) performed at Jefferson Lab using a nearly-6-GeV polarized electron beam, two longitudinally polarized (via DNP) solid targets of protons (NH3) and deuterons (ND3) and the CEBAF Large Acceptance Spectrometer. Here, preliminary results for target-spin asymmetries and double (beam-target) asymmetries for proton DVCS, as well as a very preliminary extraction of beam-spin asymmetry for neutron DVCS, are presented and linked to Generalized Parton Distributions., Comment: 6 pages, 5 figures. Proceedings for the QNP2012 conference