المؤلفون: Wu, Jinfei, Lou, Xinchou, Huang, Yanping, Li, Gang, Ye, Jingbo, Che, Yuzhi, Ruan, Manqi

مصطلحات موضوعية: High Energy Physics - Phenomenology, High Energy Physics - Experiment

الوصف: Employing the heavy quark expansion with kinetic scheme, we study the strong interaction coupling $\alpha_S$ at an energy corresponding to the charm quark mass $m_c$ using the data on the semi-leptonic decays of charmed mesons from the BESIII and CLEO-c. The values of the $\alpha_{s}(m_c^{2})$ from the $D^0$, $D^+$, and $D_s^+$ are extracted and found to be consistent. Combining the semileptonic decay widths of the $D^0$, $D^+$, and $D_s^+$, we determine $\alpha_{s}(m_c^{2})$ to be $0.377\pm0.008\pm0.114$, where the first and second uncertainty are the experimental and theoretical uncertainty separately. This result is in good agreement with the world average of $\alpha_S$ running from Z pole to the $m_c$.
Comment: 7 pages, 6 figures

URL الوصول: http://arxiv.org/abs/2406.16119

المؤلفون: Pei, Junle, Lou, Xinchou, Fang, Yaquan, Wu, Jinfei

مصطلحات موضوعية: High Energy Physics - Phenomenology

الوصف: This study examines the properties of heavy quarkonia $X$ by treating them as bound states of $Q$ and $\bar{Q}$, where $Q$ represents either a charm or a bottom quark. The branching ratios for the radiative leptonic decays $X\rightarrow \gamma l^{+} l^{-}$ are revisited and the angular and energy/momentum distributions of the final state particles are analyzed in the rest frame of $X$. Furthermore, we apply Lorentz transformations from the rest frame of $X$ to the center-of-mass frame of $l^+ l^-$ to establish the connection between the widths ${\Gamma_{X \rightarrow \gamma l^{+} l^{-}}}$ and ${\Gamma_{X \rightarrow l^{+} l^{-}}}$. The connection aligns well with those documented in the literature (divided by $2\pi$) for various $X$ states, such as $J/\Psi$, $\Psi(2S)$, $\Upsilon(1S)$, and $\Upsilon(2S)$, exhibiting good agreements within 10\%. However, we observe a significant disparity in the ratio between ${\Gamma_{\Psi(2S) \to \gamma \tau^+ \tau^-}}$ and ${\Gamma_{\Psi(2S) \to \tau^+ \tau^-}}$, with our prediction being four times larger than those in the literature. The outcomes derived from this study held practical implications in describing the QED radiative processes and contribute to the investigation of QCD processes associated with the decays of heavy quarkonia and the searches for new physics.
Comment: 11 pages

URL الوصول: http://arxiv.org/abs/2308.14270

المؤلفون: Xin, Shuiting, Zhao, Guang, Wu, Linghui, Dong, Mingyi, Li, Gang, Sun, Shengsen, Lou, Xinchou

مصطلحات موضوعية: High Energy Physics - Experiment, Physics - Instrumentation and Detectors

الوصف: The particle identification of charged hadrons, especially for the separation of $K$ and $\pi$, is crucial for the flavour physics study. Ionization measurement with the cluster counting technique, which has much less fluctuation than traditional $dE/dx$ measurement, is expected to provide better particle identification for the BESIII experiment. Simulation studies, including a Garfield++ based waveform analysis and a performance study of K/\pi identification in the BESIII, offline software system have been performed. The results show that $K/\pi$ separation power and PID efficiency would be improved significantly in the momentum range above 1.2 GeV/c using cluster counting technique even with conservative resolution assumption.
Comment: 9 pages,7 figures

URL الوصول: http://arxiv.org/abs/2210.01845

المؤلفون: Guo, Fangyi, Fang, Yaquan, Li, Gang, Lou, Xinchou

مصطلحات موضوعية: High Energy Physics - Experiment

الوصف: This paper presents the prospects of measuring $\sigma(e^{+}e^{-}\to ZH)\times Br(H \to \gamma\gamma)$ in 3 $Z$ decay channels $Z \to q\bar{q} / \mu^{+} \mu^{-} / \nu\bar{\nu}$ using the baseline detector with $\sqrt{s} = 240 GeV$ at the Circular Electron Positron Collider (CEPC) . The simulated Monte Carlo events are generated and scaled to an integrated luminosity of 5.6 $ab^{-1}$ to mimic the data. Extrapolated results to 20 $ab^{-1}$ are also shown. The expected statistical precision of this measurement after combining 3 channels of $Z$ boson decay is 7.7\%. With some preliminary estimation on the systematical uncertainties, the total precision is 7.9\%. The performance of CEPC electro-magnetic calorimeter (ECAL) is studied by smearing the photon energy resolution in simulated events in $e^{+}e^{-} \to ZH \to q\bar{q}\gamma\gamma$ channel. In present ECAL design, the stochastic term in resolution plays the dominant role in the precision of Higgs measurements in $H \to \gamma\gamma$ channel. The impact of the resolution on the measured precision of $\sigma(ZH)\times Br(ZH \to q\bar{q}\gamma\gamma)$ as well as the optimization of ECAL constant term and stochastic term are studied for the further detector design.

URL الوصول: http://arxiv.org/abs/2205.13269

المؤلفون: Sha, Qiyu, Fadol, Abdualazem, Guo, Fangyi, Li, Gang, Gu, Jiayin, Lou, Xinchou, Fang, Yaquan

مصطلحات موضوعية: High Energy Physics - Experiment, High Energy Physics - Phenomenology

الوصف: In the Circular Electron Positron Collider (CEPC), a measurement of the Higgs CP mixing through $e^{+} e^{-} \rightarrow Z H \rightarrow l^{+} l^{-}(e^{+} e^{-} /\mu^{+} \mu^{-}) H(\rightarrow b \bar{b} / c \bar{c} / g g)$ process is presented, with $5.6\ \mbox{ab}^{-1}$ $e^{+} e^{-}$ collision data at the center-of-mass energy of $240\ \mathrm{GeV}$. In this study, the CP-violating parameter $\tilde{c}_{Z \gamma}$ is constrained between the region of $ -0.30$ and $0.27$ and $\tilde{c}_{Z Z}$ between $-0.06$ and $0.06$ at $68\%$ confidence level. This study demonstrates the great potential of probing Higgs $CP$ properties at the CEPC.

URL الوصول: http://arxiv.org/abs/2203.11707

المؤلفون: Tang, Jingyu, Zhang, Yuhong, Xu, Qingjin, Gao, Jie, Lou, Xinchou, Wang, Yifang

مصطلحات موضوعية: High Energy Physics - Experiment, Physics - Accelerator Physics

الوصف: SPPC (Super Proton-Proton Collider) is a discovery machine that is designed for energy frontier research in two decades from now, as the second stage of the CEPC-SPPC project. The main objective is to carry out experiments at 125 TeV in center-of-mass energy in a two-ring collider of 100 km in circumference and 20 T in dipole field. This white paper about SPPC describes the machine related issues, including performance, design overview, design challenges, key technologies and their maturity and required R&D, staged options and upgrades, synergies with other facilities, and environmental impacts.
Comment: contribution to Snowmass 2021

URL الوصول: http://arxiv.org/abs/2203.07987

المؤلفون: Si, Meiyu, Chen, Shanhong, Huang, Yongsheng, Ruan, Manqi, Tang, Guangyi, Lan, Xiaofei, Chen, Yuan, Lou, Xinchou

المصدر: Eur. Phys. J. D (2022) 76:63

مصطلحات موضوعية: Physics - Plasma Physics

الوصف: The new scheme of the energy measurement of the extremely high energy electron beam with the inverse Compton scattering between electrons and microwave photons requires the precise calculation of the interaction cross section of electrons and microwave photons in a resonant cavity. In the local space of the cavity, the electromagnetic field is expressed by Bessel functions. Although Bessel functions can form a complete set of orthogonal basis, it is difficult to quantify them directly as fundamental wave functions. Fortunately, with the Fourier expansion of Bessel functions, the local electromagnetic field can be considered as the superposition of a series of plane waves. Therefore, with corresponding corrections of the cross section formula of the classical Compton scattering, the cross section of the linear or nonlinear microwave Compton scattering in the local space can be described accurately. As an important application of our results in astrophysics, corresponding ground verification devices can be designed to perform experimental verifications on the prediction of the Sunyaev-Zeldovich (SZ) effect of the cosmic microwave background radiation. Our results could also provide a new way to generate wave sources with strong practical value, such as the terahertz waves, the ultra-violet (EUV) waves, or the mid-infrared beams.
Comment: 16 pages, 5 figures

URL الوصول: http://arxiv.org/abs/2109.04213

المؤلفون: Si, Meiyu, Huang, Yongsheng, Chen, Shanhong, Wang, Pengcheng, Duan, Zhe, Lan, Xiaofei, Chen, Yuan, Lou, Xinchou, Ruan, Manqi, Wang, Yiwei, Tang, Guangyi, Xiao, Ouzheng, Zhang, Jianyong

المصدر: Nuclear Inst. and Methods in Physics Research, A 1026 (2022) 166216

مصطلحات موضوعية: High Energy Physics - Experiment, High Energy Physics - Phenomenology

الوصف: The uncertainty of the energy measurement of the electron beam on circular electron positron collider (CEPC) must be smaller than 10$\mathrm{MeV}$ to make sure the accurate measurement of the mass of the Higgs boson. In order to simplify the energy measurement system, a new method is proposed by fitting the Compton edge of the energy distribution of the gamma ray from a microwave-electron Compton scattering. With our method, the uncertainty of the energy measurement is 6$\mathrm{MeV}$ for the electron energy of $120\mathrm{GeV}$ in the Higgs mode. In this system, the energy resolution of the gamma detection needs to reach $10^{-4}$. Therefore, only the high-purity germanium (HPGe) detector can meet the critical requirement. In a head-on collision mode, the initial photons should be microwave photons with the wavelength of 3.04 centimeters. A cylindrical resonant cavity with selected ${TM_{010}}$ mode is used to transmit microwaves. After the microwave-electron Compton backscattering, the scattered photons and the synchrotron-radiation background transmit a shielding structure and then are detected by a HPGe detector at the end of the beam line of the synchrotron-radiation applications. The hole radius in the side wall of the cavity is about $1.5\mathrm{mm}$ to allow the electron beam passing through. The results of the computer simulation technology (CST) software shows that the influence of the hole radius on the cavity field is negligible. The change of the resonance frequency can be easily corrected by fine-tuning the cavity size.
Comment: 22 pages, 12 figures

URL الوصول: http://arxiv.org/abs/2108.09707

المؤلفون: LI, Gang, Liao, Libo, Lou, Xinchou, Shen, Peixun, Song, Weimin, Wang, Shudong, Zhang, Zhaoling

مصطلحات موضوعية: High Energy Physics - Experiment, Physics - Data Analysis, Statistics and Probability

الوصف: Various Higgs factories are proposed to study the Higgs boson precisely and systematically in a model-independent way. In this study, the Particle Flow Network and ParticleNet techniques are used to classify the Higgs decays into multi-categories and the ultimate goal is to realize an "end-to-end" analysis. A Monte Carlo simulation study is performed to demonstrate the feasibility, and the performance looks rather promising. This result could be the basis of a "one-shop" analysis to measure all the branching fractions of the Higgs decays simultaneously.
Comment: 10 pages, 9 figures

URL الوصول: http://arxiv.org/abs/2105.14997

المؤلفون: Poley, Luise, Sawyer, Craig, Addepalli, Sagar, Affolder, Anthony, Allongue, Bruno, Allport, Phil, Anderssen, Eric, Anghinolfi, Francis, Arguin, Jean-François, Arling, Jan-Hendrik, Arnaez, Olivier, Asbah, Nedaa Alexandra, Ashby, Joe, Asimakopoulou, Eleni Myrto, Atlay, Naim Bora, Bartsch, Ludwig, Basso, Matthew J., Beacham, James, Beaupré, Scott L., Beck, Graham, Beichert, Carl, Bergsten, Laura, Bernabeu, Jose, Bhattarai, Prajita, Bloch, Ingo, Blue, Andrew, Bochenek, Michal, Botte, James, Boynton, Liam, Brenner, Richard, Brueers, Ben, Buchanan, Emma, Bullard, Brendon, Capocasa, Francesca, Carr, Isabel, Carra, Sonia, Chao, Chen Wen, Chen, Jiayi, Chen, Liejian, Chen, Yebo, Chen, Xin, Cindro, Vladimir, Ciocio, Alessandra, Civera, Jose V., Cormier, Kyle, Cornell, Ella, Crick, Ben, Dabrowski, Wladyslaw, Dam, Mogens, David, Claire, Demontigny, Gabriel, Dette, Karola, DeWitt, Joel, Diez, Sergio, Doherty, Fred, Dopke, Jens, Dressnandt, Nandor, Edwards, Sam, Fadeyev, Vitaliy, Farrington, Sinead, Fawcett, William, Fernandez-Tejero, Javier, Filmer, Emily, Fleta, Celeste, Gallop, Bruce, Galloway, Zachary, Argos, Carlos Garcia, Garg, Diksha, Gignac, Matthew, Gillberg, Dag, Giovinazzo, Dena, Glover, James, Goettlicher, Peter, Gonella, Laura, Gorišek, Andrej, Grant, Charles, Grant, Fiona, Gray, Calum, Greenall, Ashley, Gregor, Ingrid-Maria, Greig, Graham, Grillo, Alexander A., Gu, Shan, Guescini, Francesco, da Costa, Joao Barreiro Guimaraes, Gunnell, Jane, Gupta, Ruchi, Haber, Carl, Halgeri, Amogh, Hamersly, Derek, Haugen, Tom-Erik, Hauser, Marc, Heim, Sarah, Heim, Timon, Helling, Cole, Herde, Hannah, Hessey, Nigel P., Hommels, Bart, Hönig, Jan Cedric, Hunter, Amelia, Jackson, Paul, Jewkes, Keith, John, Jaya John, Johnson, Thomas Allan, Jones, Tim, Kachiguin, Serguei, Kang, Nathan, Kaplon, Jan, Kareem, Mohammad, Keener, Paul, Keller, John, Key-Charriere, Michelle, Kilani, Samer, Kisliuk, Dylan, Klein, Christoph Thomas, Koffas, Thomas, Kramberger, Gregor, Krizka, Karol, Kroll, Jiri, Kuehn, Susanne, Kurth, Matthew, Labitan, Charilou, Lacasta, Carlos, Lacker, Heiko, Leitao, Pedro Vicente, León, Pablo, Li, Boyang, Li, Chenyang, Li, Yiming, Li, Zhiying, Liang, Zhijun, Liberatore, Marianna, Lister, Alison, Liu, Kai, Liu, Peilian, Lohse, Thomas, Lönker, Jonas, Lou, Xinchou, Lu, Weiguo, Luce, Zachary, Lynn, David, MacFadyen, Ross, Mägdefessel, Sven, Mahboubi, Kambiz, Malik, Usha, Mandić, Igor, La Marra, Daniel, Martin, Jean-Pierre, Martinez-Mckinney, Forest, Mikestikova, Marcela, Mikuž, Marko, Mitra, Ankush, Mladina, Evan, Montalbano, Alyssa, Monzat, David, Morii, Masahiro, Mullier, Geoffrey, Neundorf, Jonas, Newcomer, Mitch, Ng, Yanwing, Nikolica, Adrian, Nikolopoulos, Konstantinos, Oechsle, Jan, Oliver, Jason, Orr, Robert S., Ottino, Gregory, Paillard, Christian, Pani, Priscilla, Paowell, Sam, Parzefall, Ulrich, Phillips, Peter W., Platero, Adrián, Platero, Vicente, Prahl, Volker, Pyatt, Simon, Ran, Kunlin, Reardon, Nikita, Rehnisch, Laura, Renardi, Alessia, Renzmann, Martin, Rifki, Othmane, Rodriguez, Arturo Rodriguez, Rosin, Guy, Rossi, Edoardo, Ruggeri, Tristan, Rühr, Frederik, Rymaszewski, Piotr, Sadrozinski, Hartmut F. -W., Sanethavong, Phathakone, Santpur, Sai Neha, Scharf, Christian, Schillaci, Zach, Schmitt, Stefan, Sharma, Abhishek, Sciolla, Gabriella, Seiden, Abraham, Shi, Xin, Simpson-Allsop, Cameron, Snoek, Hella, Snow, Steve, Solaz, Carles, Soldevila, Urmila, Sousa, Filipe, Sperlich, Dennis, Staats, Ezekiel, Stack, Tynan Louis, Stanitzki, Marcel, Starinsky, Nikolai, Steentoft, Jonas, Stegler, Martin, Stelzer, Bernd, Stucci, Stefania, Swientek, Krzysztof, Taylor, Geoffrey N., Taylor, Wendy, Teoh, Jia Jian, Teuscher, Richard, Thomas, Jürgen, Tigchelaar, Allen, Tran, Tony, Tricoli, Alessandro, Trischuk, Dominique Anderson, Unno, Yoshinobu, van Nieuwenhuizen, Gerrit, Ullán, Miguel, Vermeulen, Jos, Vickey, Trevor, Vidal, Guillem, Vreeswijk, Marcel, Warren, Matt, Weidberg, Tony, Wiehe, Moritz, Wiglesworth, Craig, Wiik-Fuchs, Liv, Williams, Scott, Wilson, John, Witharm, Rhonda, Wizemann, Felix, Wonsak, Sven, Worm, Steve, Wormald, Mike, Xella, Stefania, Yang, Yuzhen, Yarwick, Joseph, Yu, Tang-Fai, Zhang, Dengfeng, Zhang, Kaili, Zhou, Maosen, Zhu, Hongbo

المصدر: published 3 September 2020, Journal of Instrumentation, Volume 15, September 2020

مصطلحات موضوعية: Physics - Instrumentation and Detectors, High Energy Physics - Experiment

الوصف: For the Phase-II Upgrade of the ATLAS Detector, its Inner Detector, consisting of silicon pixel, silicon strip and transition radiation sub-detectors, will be replaced with an all new 100 % silicon tracker, composed of a pixel tracker at inner radii and a strip tracker at outer radii. The future ATLAS strip tracker will include 11,000 silicon sensor modules in the central region (barrel) and 7,000 modules in the forward region (end-caps), which are foreseen to be constructed over a period of 3.5 years. The construction of each module consists of a series of assembly and quality control steps, which were engineered to be identical for all production sites. In order to develop the tooling and procedures for assembly and testing of these modules, two series of major prototyping programs were conducted: an early program using readout chips designed using a 250 nm fabrication process (ABCN-25) and a subsequent program using a follow-up chip set made using 130 nm processing (ABC130 and HCC130 chips). This second generation of readout chips was used for an extensive prototyping program that produced around 100 barrel-type modules and contributed significantly to the development of the final module layout. This paper gives an overview of the components used in ABC130 barrel modules, their assembly procedure and findings resulting from their tests.
Comment: 82 pages, 66 figures

URL الوصول: http://arxiv.org/abs/2009.03197