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hep-ph/0311012
J. P. Ma
J.P. Ma, R.G. Ping and B.S. Zou
CP Test in J/Psi -> gamma phi phi Decay
Misprints corrected. To appear in Phys. Lett. B
Phys.Lett. B580 (2004) 163-168
10.1016/j.physletb.2003.11.059
null
hep-ph
null
We propose to test CP symmetry in the decay $\jp\to \gamma \phi\phi$, for which large data sample exists at BESII, and a data sample of $10^{10}$ $J/\psi$'s will be collected with BESIII and CLEO-C program. We suggest some CP asymmetries in this decay mode for CP test. Assuming that CP violation is introduced by the electric- and chromo-dipole moment of charm quark, these CP asymmetries can be predicted by using valence quark models. Our work shows a possible way to get information about the electric- and chromo-dipole moment of charm quark, which is little known. Our results show that with the current data sample of $J/\psi$, electric- and chromo-dipole moment can be probed at order of $10^{-14}e cm$. In the near future with a $10^{10}$ data sample, these moments can be probed at order of $10^{-16}e cm$.
[ { "created": "Sun, 2 Nov 2003 05:08:41 GMT", "version": "v1" }, { "created": "Thu, 27 Nov 2003 00:20:38 GMT", "version": "v2" } ]
2015-06-25
[ [ "Ma", "J. P.", "" ], [ "Ping", "R. G.", "" ], [ "Zou", "B. S.", "" ] ]
We propose to test CP symmetry in the decay $\jp\to \gamma \phi\phi$, for which large data sample exists at BESII, and a data sample of $10^{10}$ $J/\psi$'s will be collected with BESIII and CLEO-C program. We suggest some CP asymmetries in this decay mode for CP test. Assuming that CP violation is introduced by the electric- and chromo-dipole moment of charm quark, these CP asymmetries can be predicted by using valence quark models. Our work shows a possible way to get information about the electric- and chromo-dipole moment of charm quark, which is little known. Our results show that with the current data sample of $J/\psi$, electric- and chromo-dipole moment can be probed at order of $10^{-14}e cm$. In the near future with a $10^{10}$ data sample, these moments can be probed at order of $10^{-16}e cm$.
2106.13829
Victor Valera Baca
Alexei Y. Smirnov, Victor B. Valera
Resonance refraction and neutrino oscillations
36 pages, 6 figures
null
10.1007/JHEP09(2021)177
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The refraction index and matter potential depend on neutrino energy and this dependence has a resonance character associated to the production of the mediator in the $s-$channel. For light mediators and light particles of medium (background) the resonance can be realized at energies accessible to laboratory experiments. We study properties of the energy dependence of the potential for different C-asymmetries of background. Interplay of the background potential and the vacuum term leads to (i) bump in the oscillation probability in the resonance region, (ii) dip related to the MSW resonance in the background, (iii) substantial deviation of the effective $\Delta m^2$ above the resonance from the low energy value, etc. We considered generation of mixing in the background. Interactions with background shifts the energy of usual MSW resonance and produces new MSW resonances. Searches of the background effects allow us to put bounds on new interactions of neutrinos and properties of the background. We show that explanation of the MiniBooNE excess, as the bump due to resonance refraction, is excluded.
[ { "created": "Fri, 25 Jun 2021 18:10:24 GMT", "version": "v1" } ]
2021-10-13
[ [ "Smirnov", "Alexei Y.", "" ], [ "Valera", "Victor B.", "" ] ]
The refraction index and matter potential depend on neutrino energy and this dependence has a resonance character associated to the production of the mediator in the $s-$channel. For light mediators and light particles of medium (background) the resonance can be realized at energies accessible to laboratory experiments. We study properties of the energy dependence of the potential for different C-asymmetries of background. Interplay of the background potential and the vacuum term leads to (i) bump in the oscillation probability in the resonance region, (ii) dip related to the MSW resonance in the background, (iii) substantial deviation of the effective $\Delta m^2$ above the resonance from the low energy value, etc. We considered generation of mixing in the background. Interactions with background shifts the energy of usual MSW resonance and produces new MSW resonances. Searches of the background effects allow us to put bounds on new interactions of neutrinos and properties of the background. We show that explanation of the MiniBooNE excess, as the bump due to resonance refraction, is excluded.
hep-ph/9312338
David London
R. Aleksan, B. Kayser and D. London
In Pursuit of Gamma
LaTeX, 18 pages, 11 figures (not included, available upon request), talk given by B. Kayser at the Workshop on B Physics at Hadron Accelerators, Snowmass, Colorado, June 21-July 2, 1993, DAPNIA/SPP 93-23, NSF-PT-93-4, UdeM-LPN-TH-93-184
null
null
null
hep-ph
null
After reviewing techniques for extracting clean information on CP-violating phase angles from $B$ decays, we explain the rules for finding decay modes that can probe the phase angle $\gamma$ of the unitarity triangle. We identify the more promising of these ``$\gamma$ modes,'' estimate their branching ratios, and examine the degree to which they are theoretically clean. We then show that when the quark mixing matrix is not approximated as usual, but is treated exactly, none of the ``$\gamma$ modes'' actually measures $\gamma$. Rather, each of them measures $\gamma$ plus some correction. In all modes, the correction is small enough to be disregarded in first-generation experiments, but in some of them, it may be large enough to be observed in second-generation experiments. Our treatment of the $\gamma$ modes calls attention to the fact that when the quark mixing matrix is treated exactly, there are six unitarity triangles, rather than just one triangle. However, only four of the angles in these six triangles are independent. Examining the role played by these four angles, we discover that, in principle at least, measurements of nothing but CP-violating asymmetries in $B$ decays are sufficient to determine the entire quark mixing matrix.
[ { "created": "Fri, 24 Dec 1993 23:30:46 GMT", "version": "v1" } ]
2009-09-25
[ [ "Aleksan", "R.", "" ], [ "Kayser", "B.", "" ], [ "London", "D.", "" ] ]
After reviewing techniques for extracting clean information on CP-violating phase angles from $B$ decays, we explain the rules for finding decay modes that can probe the phase angle $\gamma$ of the unitarity triangle. We identify the more promising of these ``$\gamma$ modes,'' estimate their branching ratios, and examine the degree to which they are theoretically clean. We then show that when the quark mixing matrix is not approximated as usual, but is treated exactly, none of the ``$\gamma$ modes'' actually measures $\gamma$. Rather, each of them measures $\gamma$ plus some correction. In all modes, the correction is small enough to be disregarded in first-generation experiments, but in some of them, it may be large enough to be observed in second-generation experiments. Our treatment of the $\gamma$ modes calls attention to the fact that when the quark mixing matrix is treated exactly, there are six unitarity triangles, rather than just one triangle. However, only four of the angles in these six triangles are independent. Examining the role played by these four angles, we discover that, in principle at least, measurements of nothing but CP-violating asymmetries in $B$ decays are sufficient to determine the entire quark mixing matrix.
2211.00008
Joshua Foster
Joshua N. Benabou, Joshua W. Foster, Yonatan Kahn, Benjamin R. Safdi, Chiara P. Salemi
Detecting axion dark matter beyond the magnetoquasistatic approximation
6+5 pages, 3+9 figures
null
10.1103/PhysRevD.108.035009
MIT-CTP/5490
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A number of proposals have been put forward for detecting axion dark matter (DM) with grand unification scale decay constants that rely on the conversion of coherent DM axions to oscillating magnetic fields in the presence of static, laboratory magnetic fields. Crucially, such experiments $\unicode{x2013}$ including ABRACADABRA $\unicode{x2013}$ have to-date worked in the limit that the axion Compton wavelength is larger than the size of the experiment, which allows one to take a magnetoquasistatic (MQS) approach to modeling the axion signal. We use finite element methods to solve the coupled axion-electromagnetism equations of motion without assuming the MQS approximation. We show that the MQS approximation becomes a poor approximation at frequencies two orders of magnitude lower than the naive MQS limit. Radiation losses diminish the quality factor of an otherwise high-$Q$ resonant readout circuit, though this may be mitigated through shielding and minimizing lossy materials. Additionally, self-resonances associated with the detector geometry change the reactive properties of the pickup system, leading to two generic features beyond MQS: there are frequencies that require an inductive rather than capacitive tuning to maintain resonance, and the detector itself becomes a multi-pole resonator at high frequencies. Accounting for these features, competitive sensitivity to the axion-photon coupling may be extended well beyond the naive MQS limit.
[ { "created": "Mon, 31 Oct 2022 18:00:00 GMT", "version": "v1" } ]
2023-08-16
[ [ "Benabou", "Joshua N.", "" ], [ "Foster", "Joshua W.", "" ], [ "Kahn", "Yonatan", "" ], [ "Safdi", "Benjamin R.", "" ], [ "Salemi", "Chiara P.", "" ] ]
A number of proposals have been put forward for detecting axion dark matter (DM) with grand unification scale decay constants that rely on the conversion of coherent DM axions to oscillating magnetic fields in the presence of static, laboratory magnetic fields. Crucially, such experiments $\unicode{x2013}$ including ABRACADABRA $\unicode{x2013}$ have to-date worked in the limit that the axion Compton wavelength is larger than the size of the experiment, which allows one to take a magnetoquasistatic (MQS) approach to modeling the axion signal. We use finite element methods to solve the coupled axion-electromagnetism equations of motion without assuming the MQS approximation. We show that the MQS approximation becomes a poor approximation at frequencies two orders of magnitude lower than the naive MQS limit. Radiation losses diminish the quality factor of an otherwise high-$Q$ resonant readout circuit, though this may be mitigated through shielding and minimizing lossy materials. Additionally, self-resonances associated with the detector geometry change the reactive properties of the pickup system, leading to two generic features beyond MQS: there are frequencies that require an inductive rather than capacitive tuning to maintain resonance, and the detector itself becomes a multi-pole resonator at high frequencies. Accounting for these features, competitive sensitivity to the axion-photon coupling may be extended well beyond the naive MQS limit.
0708.1260
Davor Horvatic
D. Horvatic, D. Klabucar, A. E. Radzhabov
$\eta$ and $\eta'$ mesons in the Dyson-Schwinger approach at finite temperature
13 pages, 15 figures
Phys.Rev.D76:096009,2007
10.1103/PhysRevD.76.096009
null
hep-ph
null
We study the temperature dependence of the pseudoscalar meson properties in a relativistic bound-state approach exhibiting the chiral behavior mandated by QCD. Concretely, we adopt the Dyson-Schwinger approach with a rank-2 separable model interaction. After extending the model to the strange sector and fixing its parameters at zero temperature, T=0, we study the T-dependence of the masses and decay constants of all ground-state mesons in the pseudoscalar nonet. Of chief interest are $\eta$ and $\eta^\prime$. The influence of the QCD axial anomaly on them is successfully obtained through the Witten-Veneziano relation at T=0. The same approach is then extended to T>0, using lattice QCD results for the topological susceptibility. The most conspicuous finding is an increase of the $\eta^\prime$ mass around the chiral restoration temperature $T_{\rm Ch}$, which would suggest a suppression of $\eta^\prime$ production in relativistic heavy-ion collisions. The increase of the $\eta^\prime$ mass may also indicate that the extension of the Witten-Veneziano relation to finite temperatures becomes unreliable around and above $T_{\rm Ch}$. Possibilities of an improved treatment are discussed.
[ { "created": "Thu, 9 Aug 2007 18:26:02 GMT", "version": "v1" } ]
2008-11-26
[ [ "Horvatic", "D.", "" ], [ "Klabucar", "D.", "" ], [ "Radzhabov", "A. E.", "" ] ]
We study the temperature dependence of the pseudoscalar meson properties in a relativistic bound-state approach exhibiting the chiral behavior mandated by QCD. Concretely, we adopt the Dyson-Schwinger approach with a rank-2 separable model interaction. After extending the model to the strange sector and fixing its parameters at zero temperature, T=0, we study the T-dependence of the masses and decay constants of all ground-state mesons in the pseudoscalar nonet. Of chief interest are $\eta$ and $\eta^\prime$. The influence of the QCD axial anomaly on them is successfully obtained through the Witten-Veneziano relation at T=0. The same approach is then extended to T>0, using lattice QCD results for the topological susceptibility. The most conspicuous finding is an increase of the $\eta^\prime$ mass around the chiral restoration temperature $T_{\rm Ch}$, which would suggest a suppression of $\eta^\prime$ production in relativistic heavy-ion collisions. The increase of the $\eta^\prime$ mass may also indicate that the extension of the Witten-Veneziano relation to finite temperatures becomes unreliable around and above $T_{\rm Ch}$. Possibilities of an improved treatment are discussed.
hep-ph/0011277
U. Meissner
Ulf-G. Mei{\ss}ner, Greg Smith
Goldstone boson-nucleon dynamics: Working group summary and outlook
15 pp, 2 figs, working group summary talk, Chiral Dynamics 2000: Theory and Experiment, July 17-22, 2000, Newport News, to be published in the proceedings
null
10.1142/9789812810977_0050
FZJ-IKP(TH)-2000-27, JLAB-PHY-00-22
hep-ph hep-ex nucl-ex nucl-th
null
We highlight some of the recent results in chiral dynamics for systems with one nucleon/baryon presented at Chiral Dynamics 2000. We outline the most urgent experimental and theoretical challenges to be tackled in the coming years.
[ { "created": "Wed, 22 Nov 2000 07:35:45 GMT", "version": "v1" }, { "created": "Wed, 6 Dec 2000 09:42:33 GMT", "version": "v2" } ]
2017-08-23
[ [ "Meißner", "Ulf-G.", "" ], [ "Smith", "Greg", "" ] ]
We highlight some of the recent results in chiral dynamics for systems with one nucleon/baryon presented at Chiral Dynamics 2000. We outline the most urgent experimental and theoretical challenges to be tackled in the coming years.
hep-ph/9605363
Martina Brisudova
Martina Brisudova and Robert Perry
Note on restoring manifest rotational symmetry in hyperfine and fine structure in light-front QED
17 pages, latex file
Phys.Rev.D54:6453-6458,1996
10.1103/PhysRevD.54.6453
null
hep-ph
null
We study the part of the renormalized, cutoff QED light-front Hamiltonian that does not change particle number. The Hamiltonian contains interactions that must be treated in second-order bound state perturbation theory to obtain hyperfine structure. We show that a simple unitary transformation leads directly to the familiar Breit-Fermi spin-spin and tensor interactions, which can be treated in degenerate first-order bound-state perturbation theory, thus simplifying analytic light-front QED calculations. To the order in momenta we need to consider, this transformation is equivalent to a Melosh rotation. We also study how the similarity transformation affects spin-orbit interactions.
[ { "created": "Tue, 21 May 1996 02:00:55 GMT", "version": "v1" } ]
2010-11-19
[ [ "Brisudova", "Martina", "" ], [ "Perry", "Robert", "" ] ]
We study the part of the renormalized, cutoff QED light-front Hamiltonian that does not change particle number. The Hamiltonian contains interactions that must be treated in second-order bound state perturbation theory to obtain hyperfine structure. We show that a simple unitary transformation leads directly to the familiar Breit-Fermi spin-spin and tensor interactions, which can be treated in degenerate first-order bound-state perturbation theory, thus simplifying analytic light-front QED calculations. To the order in momenta we need to consider, this transformation is equivalent to a Melosh rotation. We also study how the similarity transformation affects spin-orbit interactions.
2306.17513
Krzysztof Marek Kutak
A. van Hameren, H. Kakkad, P. Kotko, K. Kutak, S. Sapeta
Searching for saturation in forward dijet production at the LHC
50 pages
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review recent results for forward jests at the LHC and EIC as obtained within small-x Improved Transverse Momentum Dependent factorization (ITMD). In addition to elementary overview of various approaches to perturbative QCD at high energy, including High Energy Factorization, Color Glass Condensate and ITMD, we describe the Monte Carlo implementation and discuss the existing and unpublished phenomenological results for forward dijets.
[ { "created": "Fri, 30 Jun 2023 09:59:41 GMT", "version": "v1" } ]
2023-07-03
[ [ "van Hameren", "A.", "" ], [ "Kakkad", "H.", "" ], [ "Kotko", "P.", "" ], [ "Kutak", "K.", "" ], [ "Sapeta", "S.", "" ] ]
We review recent results for forward jests at the LHC and EIC as obtained within small-x Improved Transverse Momentum Dependent factorization (ITMD). In addition to elementary overview of various approaches to perturbative QCD at high energy, including High Energy Factorization, Color Glass Condensate and ITMD, we describe the Monte Carlo implementation and discuss the existing and unpublished phenomenological results for forward dijets.
hep-ph/9606405
null
I.I. Bigi (Univ. of Notre Dame)
Treating the Lifetimes of Charm and Beauty Hadrons with QCD Plus a Bit More!
LATEX file, 14 pages, SPROCL.STY style file appended at the end; talk given at the Second Workshop on "Continuous Advances in QCD", March 1996
null
null
UND-HEP-96-BIG01
hep-ph
null
The heavy quark expansion implemented through an operator product expansion provides us with a treatment of inclusive decays of beauty and charm hadrons that is genuinely derived from QCD,though it requires one additional assumption, namely that of 'local' quark-hadron duality. Subtleties in the application of factorization to hadronic expectation values are pointed out. The observed pattern in the charm lifetime ratios is reproduced in a semi-quantitative manner. The ratio $\tau (\Lambda _b)/\tau (B_d)$ cannot be pushed significantly below 0.9 -- unless one invokes a new hitherto unknown paradigm for evaluating baryonic matrix elements. One confidently predicts $\tau (B^-)$ to exceed $\tau (B_d)$ by several percent only. Failure of those predictions would force us to pay a hefty theoretical price, namely ultimately to abandon local duality as a practical concept.
[ { "created": "Fri, 21 Jun 1996 15:40:04 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bigi", "I. I.", "", "Univ. of Notre Dame" ] ]
The heavy quark expansion implemented through an operator product expansion provides us with a treatment of inclusive decays of beauty and charm hadrons that is genuinely derived from QCD,though it requires one additional assumption, namely that of 'local' quark-hadron duality. Subtleties in the application of factorization to hadronic expectation values are pointed out. The observed pattern in the charm lifetime ratios is reproduced in a semi-quantitative manner. The ratio $\tau (\Lambda _b)/\tau (B_d)$ cannot be pushed significantly below 0.9 -- unless one invokes a new hitherto unknown paradigm for evaluating baryonic matrix elements. One confidently predicts $\tau (B^-)$ to exceed $\tau (B_d)$ by several percent only. Failure of those predictions would force us to pay a hefty theoretical price, namely ultimately to abandon local duality as a practical concept.
1205.4246
Sannino Francesco
Francesco Sannino
Jumping Dynamics
4 pages. 6 Figures
null
10.1142/S0217732313501277
CP3-Origins-2012-12 & DIAS-2012-13
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose an alternative paradigm to the conjectured Miransky scaling potentially underlying the physics describing the transition from the conformally broken to the conformally restored phase when tuning certain parameters such as the number of flavors in gauge theories. According to the new paradigm the physical scale and henceforth also the massive spectrum of the theory jump at the lower boundary of the conformal window. In particular we propose that a theory can suddenly jump from a Quantum Chromodynamics type spectrum, at the lower boundary of the conformal window, to a conformal one without particle interpretation. The jumping scenario, therefore, does not support a near-conformal dynamics of walking type. We will also discuss the impact of jumping dynamics on the construction of models of dynamical electroweak symmetry breaking.
[ { "created": "Fri, 18 May 2012 20:00:09 GMT", "version": "v1" } ]
2015-06-05
[ [ "Sannino", "Francesco", "" ] ]
We propose an alternative paradigm to the conjectured Miransky scaling potentially underlying the physics describing the transition from the conformally broken to the conformally restored phase when tuning certain parameters such as the number of flavors in gauge theories. According to the new paradigm the physical scale and henceforth also the massive spectrum of the theory jump at the lower boundary of the conformal window. In particular we propose that a theory can suddenly jump from a Quantum Chromodynamics type spectrum, at the lower boundary of the conformal window, to a conformal one without particle interpretation. The jumping scenario, therefore, does not support a near-conformal dynamics of walking type. We will also discuss the impact of jumping dynamics on the construction of models of dynamical electroweak symmetry breaking.
0909.5065
Cecilia Tarantino
M. Bona, M. Ciuchini, E. Franco, V. Lubicz, G. Martinelli, F. Parodi, M. Pierini, C. Schiavi, L. Silvestrini, V. Sordini, A. Stocchi, C. Tarantino, V. Vagnoni
Status of the Unitarity Triangle Analysis
4 pages, 2 figures. Proceedings of the 2009 Europhysics Conference on High Energy Physics, 16-22 July, Krakow
PoS EPS-HEP2009:160,2009
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an update of the Unitarity Triangle (UT) analysis, within the Standard Model (SM) and beyond. Within the SM the main novelties are the inclusion in epsilon_K of the contributions of xi and phi_epsilon \neq \pi/4 pointed out by A.J. Buras and D. Guadagnoli, and an accurate prediction of BR(B -> tau nu), by using the indirect determination of |V_ub| from the UT fit, which can be compared to the present experimental result. In the generalization of the UT analysis to investigate New Physics (NP) effects, the estimate of xi is more delicate and only the effect of phi_epsilon \neq \pi/4 has been included. We confirm an hint of NP in the B_s-\bar B_s mixing at the 2.9 sigma level, which makes a comparison with new experimental data certainly desired.
[ { "created": "Mon, 28 Sep 2009 10:57:14 GMT", "version": "v1" } ]
2010-11-11
[ [ "Bona", "M.", "" ], [ "Ciuchini", "M.", "" ], [ "Franco", "E.", "" ], [ "Lubicz", "V.", "" ], [ "Martinelli", "G.", "" ], [ "Parodi", "F.", "" ], [ "Pierini", "M.", "" ], [ "Schiavi", "C.", "" ], [ "Silvestrini", "L.", "" ], [ "Sordini", "V.", "" ], [ "Stocchi", "A.", "" ], [ "Tarantino", "C.", "" ], [ "Vagnoni", "V.", "" ] ]
We present an update of the Unitarity Triangle (UT) analysis, within the Standard Model (SM) and beyond. Within the SM the main novelties are the inclusion in epsilon_K of the contributions of xi and phi_epsilon \neq \pi/4 pointed out by A.J. Buras and D. Guadagnoli, and an accurate prediction of BR(B -> tau nu), by using the indirect determination of |V_ub| from the UT fit, which can be compared to the present experimental result. In the generalization of the UT analysis to investigate New Physics (NP) effects, the estimate of xi is more delicate and only the effect of phi_epsilon \neq \pi/4 has been included. We confirm an hint of NP in the B_s-\bar B_s mixing at the 2.9 sigma level, which makes a comparison with new experimental data certainly desired.
hep-ph/9604286
null
G. Ingelman (Uppsala University, DESY Hamburg) and M. Thunman (Uppsala University)
Particle Production in the Interstellar Medium
13 pages, also available at http://www3.tsl.uu.se/thep/papers/
null
null
TSL/ISV-96-0136
hep-ph astro-ph
null
The flux of neutrinos and photons originating from cosmic ray interactions with the interstellar medium in the galaxy is calculated based on current models for high energy particle interactions. The contribution from a possible dark matter halo of the galaxy is considered. The photon flux gets a non-trivial attenuation due to interactions with the cosmic background radiation. The neutrino fluxes are compared with those originating from the Earth's atmosphere as well as from active galactic nuclei.
[ { "created": "Thu, 11 Apr 1996 07:29:55 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ingelman", "G.", "", "Uppsala University, DESY Hamburg" ], [ "Thunman", "M.", "", "Uppsala\n University" ] ]
The flux of neutrinos and photons originating from cosmic ray interactions with the interstellar medium in the galaxy is calculated based on current models for high energy particle interactions. The contribution from a possible dark matter halo of the galaxy is considered. The photon flux gets a non-trivial attenuation due to interactions with the cosmic background radiation. The neutrino fluxes are compared with those originating from the Earth's atmosphere as well as from active galactic nuclei.
2208.00355
Tiancai Peng
Tiancai Peng, Zhimin Zhu, Siqi Xu, Xiang Liu, Chandan Mondal, Xingbo Zhao, James P. Vary
Basis light-front quantization approach to $\Lambda$ and $\Lambda_c$ and their isospin triplet baryons
19 pages, 16 figures
null
10.1103/PhysRevD.106.114040
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We obtain the masses, the electromagnetic properties, and the parton distribution functions (PDFs) of $\Lambda$, $\Lambda_c$, and their isospin triplet baryons, i.e, $\Sigma^0$, $\Sigma^+$, $\Sigma^-$ and $\Sigma_c^0$, $\Sigma_c^+$, $\Sigma_c^{++}$ from a light-front effective Hamiltonian in the leading Fock sector in the basis light-front quantization framework. The light-front wave functions of these baryons are given by the eigenstates of the effective Hamiltonian consisting of a three-dimensional confinement potential and a one-gluon exchange interaction with fixed coupling. The masses of these baryons in our approach are in the experimental range while isospin-dependent mass differences are too small. Meanwhile, the electromagnetic properties are in agreement with the available experimental data, the lattice QCD simulations, and the other theoretical calculations. We also present the gluon and the sea quark PDFs, which we generate dynamically from the QCD evolution of the valence quark distributions.
[ { "created": "Sun, 31 Jul 2022 03:55:40 GMT", "version": "v1" } ]
2023-01-11
[ [ "Peng", "Tiancai", "" ], [ "Zhu", "Zhimin", "" ], [ "Xu", "Siqi", "" ], [ "Liu", "Xiang", "" ], [ "Mondal", "Chandan", "" ], [ "Zhao", "Xingbo", "" ], [ "Vary", "James P.", "" ] ]
We obtain the masses, the electromagnetic properties, and the parton distribution functions (PDFs) of $\Lambda$, $\Lambda_c$, and their isospin triplet baryons, i.e, $\Sigma^0$, $\Sigma^+$, $\Sigma^-$ and $\Sigma_c^0$, $\Sigma_c^+$, $\Sigma_c^{++}$ from a light-front effective Hamiltonian in the leading Fock sector in the basis light-front quantization framework. The light-front wave functions of these baryons are given by the eigenstates of the effective Hamiltonian consisting of a three-dimensional confinement potential and a one-gluon exchange interaction with fixed coupling. The masses of these baryons in our approach are in the experimental range while isospin-dependent mass differences are too small. Meanwhile, the electromagnetic properties are in agreement with the available experimental data, the lattice QCD simulations, and the other theoretical calculations. We also present the gluon and the sea quark PDFs, which we generate dynamically from the QCD evolution of the valence quark distributions.
hep-ph/0101275
Kirill Tuchin
E. Levin and K. Tuchin (Tel Aviv U.)
Nonlinear evolution and saturation for heavy nuclei in DIS
12 pages, 1 figure
Nucl.Phys. A693 (2001) 787-798
10.1016/S0375-9474(01)00880-6
TAUP-2664-2001
hep-ph
null
The nonlinear evolution equation for the scattering amplitude of colour dipole off the heavy nucleus is solved in the double logarithmic approximation. It is found that if the initial parton density in a nucleus is smaller then some critical value, then the scattering amplitude is a function of one scaling variable inside the saturation region, whereas if it is greater then the critical value, then the scaling behaviour breaks down. Dependence of the saturation scale on the number of nucleons is discussed as well.
[ { "created": "Wed, 24 Jan 2001 14:00:13 GMT", "version": "v1" }, { "created": "Fri, 9 Mar 2001 11:27:50 GMT", "version": "v2" } ]
2009-11-07
[ [ "Levin", "E.", "", "Tel Aviv U." ], [ "Tuchin", "K.", "", "Tel Aviv U." ] ]
The nonlinear evolution equation for the scattering amplitude of colour dipole off the heavy nucleus is solved in the double logarithmic approximation. It is found that if the initial parton density in a nucleus is smaller then some critical value, then the scattering amplitude is a function of one scaling variable inside the saturation region, whereas if it is greater then the critical value, then the scaling behaviour breaks down. Dependence of the saturation scale on the number of nucleons is discussed as well.
hep-ph/9905370
Kenzo Ogure
K. Ogure and J. Sato
Critical Exponents of O(N) Scalar Model at Temperatures below the Critical Value using Auxiliary Mass Method
6 pages, 3 EPS figures, typeset PTP-Tex, published version
Prog.Theor.Phys. 102 (1999) 209-213
10.1143/PTP.102.209
UT-841
hep-ph cond-mat.stat-mech hep-th
null
We investigate a phase transition of the O(N) invariant scalar model using the auxiliary mass method. We determine the critical exponent $\beta$ by calculating an effective potential below the critical temperature. This work follows that of a previous paper.
[ { "created": "Mon, 17 May 1999 16:33:28 GMT", "version": "v1" }, { "created": "Tue, 15 Jun 1999 09:29:43 GMT", "version": "v2" } ]
2009-10-31
[ [ "Ogure", "K.", "" ], [ "Sato", "J.", "" ] ]
We investigate a phase transition of the O(N) invariant scalar model using the auxiliary mass method. We determine the critical exponent $\beta$ by calculating an effective potential below the critical temperature. This work follows that of a previous paper.
2011.13407
R. A. Abramchuk
Z.V.Khaidukov, R.A.Abramchuk
Chiral separation effect for spin 3/2 fermions
null
null
10.1007/JHEP07(2021)183
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Chiral Separation Effect (CSE) for systems that feature spin 3/2 fermions was considered. For the self-consistent Adler's model with relativistic massless Rarita-Schwinger fermions (RSA model), we found that the CSE conductivity is five times larger than for massless Dirac fermions. For a model of four-fold band crossing in Rarita-Schwinger-Weyl semimetals, in which massless fermions with quasispin 3/2 exist, we calculated that the CSE conductivity is four times larger than for Weyl fermions. We show that CSE conductivity for any multi-degenerate Fermi point in topological semimetals is proportional to its Chern number and is topologically protected. Along the calculations, we proved an index theorem that relates Chern number of a Fermi-point and spectral asymmetry of the corresponding Landau band structure. The assumption that CSE for any system of chiral fermions is dictated by the corresponding Chern number is found to be correct for RSA model (and for the Dirac fermions).
[ { "created": "Thu, 26 Nov 2020 17:49:50 GMT", "version": "v1" }, { "created": "Mon, 8 Feb 2021 16:32:48 GMT", "version": "v2" }, { "created": "Sun, 2 May 2021 19:20:54 GMT", "version": "v3" }, { "created": "Wed, 9 Jun 2021 11:57:45 GMT", "version": "v4" } ]
2021-08-18
[ [ "Khaidukov", "Z. V.", "" ], [ "Abramchuk", "R. A.", "" ] ]
Chiral Separation Effect (CSE) for systems that feature spin 3/2 fermions was considered. For the self-consistent Adler's model with relativistic massless Rarita-Schwinger fermions (RSA model), we found that the CSE conductivity is five times larger than for massless Dirac fermions. For a model of four-fold band crossing in Rarita-Schwinger-Weyl semimetals, in which massless fermions with quasispin 3/2 exist, we calculated that the CSE conductivity is four times larger than for Weyl fermions. We show that CSE conductivity for any multi-degenerate Fermi point in topological semimetals is proportional to its Chern number and is topologically protected. Along the calculations, we proved an index theorem that relates Chern number of a Fermi-point and spectral asymmetry of the corresponding Landau band structure. The assumption that CSE for any system of chiral fermions is dictated by the corresponding Chern number is found to be correct for RSA model (and for the Dirac fermions).
2001.11388
Max Zoller
Stefano Pozzorini, Hantian Zhang and Max F. Zoller
Rational Terms of UV Origin at Two Loops
v2: Normalisation of MSbar poles clarified; v3: Version published on JHEP; References added; Further comments on use of master formula (5.61) in Sect. 6; New footnote on scale dependence in Sect. 5; Typos fixed and/or presentation improved in eqs. (4.8), (4.20), (5.2), (6.5), (6.7), (6.8), (A.2), (A.4); Results unchanged
JHEP 05 (2020) 077
10.1007/JHEP05(2020)077
PSI-PR-20-01, ZU-TH 03/20
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The advent of efficient numerical algorithms for the construction of one-loop amplitudes has played a crucial role in the automation of NLO calculations, and the development of similar algorithms at two loops is a natural strategy for NNLO automation. Within a numerical framework the numerator of loop integrals is usually constructed in four dimensions, and the missing rational terms, which arise from the interplay of the $(D-4)$-dimensional parts of the loop numerator with $1/(D-4)$ poles in $D$ dimensions, are reconstructed separately. At one loop, such rational terms arise only from UV divergences and can be restored through process-independent local counterterms. In this paper we investigate the behaviour of rational terms of UV origin at two loops. The main result is a general formula that combines the subtraction of UV poles with the reconstruction of the associated rational parts at two loops. This formula has the same structure as the R-operation, and all poles and rational parts are described through a finite set of process-independent local counterterms. We also present a general formula for the calculation of all relevant two-loop rational counterterms in any renormalisable theory based on one-scale tadpole integrals. As a first application, we derive the full set of two-loop rational counterterms for QED in the $R_{\xi}$-gauge.
[ { "created": "Thu, 30 Jan 2020 15:19:50 GMT", "version": "v1" }, { "created": "Sun, 9 Feb 2020 18:42:17 GMT", "version": "v2" }, { "created": "Thu, 4 Jun 2020 11:24:47 GMT", "version": "v3" } ]
2020-06-24
[ [ "Pozzorini", "Stefano", "" ], [ "Zhang", "Hantian", "" ], [ "Zoller", "Max F.", "" ] ]
The advent of efficient numerical algorithms for the construction of one-loop amplitudes has played a crucial role in the automation of NLO calculations, and the development of similar algorithms at two loops is a natural strategy for NNLO automation. Within a numerical framework the numerator of loop integrals is usually constructed in four dimensions, and the missing rational terms, which arise from the interplay of the $(D-4)$-dimensional parts of the loop numerator with $1/(D-4)$ poles in $D$ dimensions, are reconstructed separately. At one loop, such rational terms arise only from UV divergences and can be restored through process-independent local counterterms. In this paper we investigate the behaviour of rational terms of UV origin at two loops. The main result is a general formula that combines the subtraction of UV poles with the reconstruction of the associated rational parts at two loops. This formula has the same structure as the R-operation, and all poles and rational parts are described through a finite set of process-independent local counterterms. We also present a general formula for the calculation of all relevant two-loop rational counterterms in any renormalisable theory based on one-scale tadpole integrals. As a first application, we derive the full set of two-loop rational counterterms for QED in the $R_{\xi}$-gauge.
1606.00675
Florian Preis Dr.
Florian Preis and Andreas Schmitt
Layers of deformed instantons in holographic baryonic matter
37 pages, 7 figures, v2: two panels added to fig. 5, version to appear in JHEP
J. High Energ. Phys. (2016) 2016
10.1007/JHEP07(2016)001
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss homogeneous baryonic matter in the decompactified limit of the Sakai-Sugimoto model, improving existing approximations based on flat-space instantons. We allow for an anisotropic deformation of the instantons in the holographic and spatial directions and for a density-dependent distribution of arbitrarily many instanton layers in the bulk. Within our approximation, the baryon onset turns out to be a second-order phase transition, at odds with nature, and there is no transition to quark matter at high densities, at odds with expectations from QCD. This changes when we impose certain constraints on the shape of single instantons, motivated by known features of holographic baryons in the vacuum. Then, a first-order baryon onset and chiral restoration at high density are possible, and at sufficiently large densities two instanton layers are formed dynamically. Our results are a further step towards describing realistic, strongly interacting matter over a large density regime within a single model, desirable for studies of compact stars.
[ { "created": "Thu, 2 Jun 2016 13:48:07 GMT", "version": "v1" }, { "created": "Mon, 4 Jul 2016 12:08:55 GMT", "version": "v2" } ]
2016-07-05
[ [ "Preis", "Florian", "" ], [ "Schmitt", "Andreas", "" ] ]
We discuss homogeneous baryonic matter in the decompactified limit of the Sakai-Sugimoto model, improving existing approximations based on flat-space instantons. We allow for an anisotropic deformation of the instantons in the holographic and spatial directions and for a density-dependent distribution of arbitrarily many instanton layers in the bulk. Within our approximation, the baryon onset turns out to be a second-order phase transition, at odds with nature, and there is no transition to quark matter at high densities, at odds with expectations from QCD. This changes when we impose certain constraints on the shape of single instantons, motivated by known features of holographic baryons in the vacuum. Then, a first-order baryon onset and chiral restoration at high density are possible, and at sufficiently large densities two instanton layers are formed dynamically. Our results are a further step towards describing realistic, strongly interacting matter over a large density regime within a single model, desirable for studies of compact stars.
1104.2405
Klaus Werner
K. Werner, K. Mikhailov, Iu. Karpenko, T. Pierog
Bose-Einstein Correlations in a Fluid Dynamical Scenario for Proton-Proton Scattering at 7 TeV
null
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using a fluid dynamical scenario for $pp$ scattering at 7 TeV, we compute correlation functions for $\pi^+\pi^+$ pairs. Femtoscopic radii are extracted based on three-dimensional parametrizations of the correlation functions. We study the radii as a function of the transverse momenta of the pairs, for different multiplicity classes, corresponding to recent experimental results from ALICE. We find the same decrease of the radii with $k_T$, more and more pronounced with increasing multiplicity, but absent for the lowest multiplicities. In the model we understand this as transition from string expansion (low multiplicity) towards a three-dimensional hydrodynamical expansion (high multiplicity).
[ { "created": "Wed, 13 Apr 2011 08:15:40 GMT", "version": "v1" }, { "created": "Fri, 15 Apr 2011 08:32:14 GMT", "version": "v2" } ]
2011-04-18
[ [ "Werner", "K.", "" ], [ "Mikhailov", "K.", "" ], [ "Karpenko", "Iu.", "" ], [ "Pierog", "T.", "" ] ]
Using a fluid dynamical scenario for $pp$ scattering at 7 TeV, we compute correlation functions for $\pi^+\pi^+$ pairs. Femtoscopic radii are extracted based on three-dimensional parametrizations of the correlation functions. We study the radii as a function of the transverse momenta of the pairs, for different multiplicity classes, corresponding to recent experimental results from ALICE. We find the same decrease of the radii with $k_T$, more and more pronounced with increasing multiplicity, but absent for the lowest multiplicities. In the model we understand this as transition from string expansion (low multiplicity) towards a three-dimensional hydrodynamical expansion (high multiplicity).
hep-ph/9908326
Michal Brhlik
M. Brhlik, L. Everett, G. L. Kane, and J. Lykken
Superstring Theory and CP- Violating Phases: Can They Be Related?
28 pages, 6 figures; corrected bug in the code and a few typos, results qualitatively unchanged
Phys.Rev.D62:035005,2000
10.1103/PhysRevD.62.035005
FERMILAB-PUB-99/230-T
hep-ph
null
We investigate the possibility of large CP- violating phases in the soft breaking terms derived in superstring models. The bounds on the electric dipole moments (EDM's) of the electron and neutron are satisfied through cancellations occuring because of the structure of the string models. Three general classes of four-dimensional string models are considered: (i) orbifold compactifications of perturbative heterotic string theory, (ii) scenarios based on Ho\v{r}ava-Witten theory, and (iii) Type I string models (Type IIB orientifolds). Nonuniversal phases of the gaugino mass parameters greatly facilitate the necessary cancellations among the various contributions to the EDM's; in the overall modulus limit, the gaugino masses are universal at tree level in both the perturbative heterotic models and the Ho\v{r}ava-Witten scenarios, which severely restricts the allowed regions of parameter space. Nonuniversal gaugino masses do arise at one-loop in the heterotic orbifold models, providing for corners of parameter space with ${\cal O}(1)$ phases consistent with the phenomenological bounds. However, there is a possibility of nonuniversal gaugino masses at tree level in the Type I models, depending on the details of the embedding of the SM into the D- brane sectors. We find that in a minimal model with a particular embedding of the Standard Model gauge group into two D- brane sectors, viable large phase solutions can be obtained over a wide range of parameter space.
[ { "created": "Wed, 11 Aug 1999 21:06:40 GMT", "version": "v1" }, { "created": "Mon, 4 Oct 1999 16:36:20 GMT", "version": "v2" } ]
2008-11-26
[ [ "Brhlik", "M.", "" ], [ "Everett", "L.", "" ], [ "Kane", "G. L.", "" ], [ "Lykken", "J.", "" ] ]
We investigate the possibility of large CP- violating phases in the soft breaking terms derived in superstring models. The bounds on the electric dipole moments (EDM's) of the electron and neutron are satisfied through cancellations occuring because of the structure of the string models. Three general classes of four-dimensional string models are considered: (i) orbifold compactifications of perturbative heterotic string theory, (ii) scenarios based on Ho\v{r}ava-Witten theory, and (iii) Type I string models (Type IIB orientifolds). Nonuniversal phases of the gaugino mass parameters greatly facilitate the necessary cancellations among the various contributions to the EDM's; in the overall modulus limit, the gaugino masses are universal at tree level in both the perturbative heterotic models and the Ho\v{r}ava-Witten scenarios, which severely restricts the allowed regions of parameter space. Nonuniversal gaugino masses do arise at one-loop in the heterotic orbifold models, providing for corners of parameter space with ${\cal O}(1)$ phases consistent with the phenomenological bounds. However, there is a possibility of nonuniversal gaugino masses at tree level in the Type I models, depending on the details of the embedding of the SM into the D- brane sectors. We find that in a minimal model with a particular embedding of the Standard Model gauge group into two D- brane sectors, viable large phase solutions can be obtained over a wide range of parameter space.
1705.03012
M. A. Perez-Garcia
M. Cerme\~no, M. A. P\'erez-Garc\'ia, R. A. Lineros
Enhanced neutrino emissivities in pseudoscalar-mediated Dark Matter annihilation in Neutron Stars
13 pages, 3 figures, 2 tables. Matches published version
Astrophysical Journal 863 (2) (2018) 157
10.3847/1538-4357/aad1ec
null
hep-ph astro-ph.SR
http://creativecommons.org/licenses/by/4.0/
We calculate neutrino emissivities from self-annihilating dark matter ($\chi$) in the dense and hot stellar interior of a (proto)neutron star. Using a model where dark matter interacts with nucleons in the stellar core through a pseudoscalar boson ($a$) we find that the neutrino production rates from the dominant reaction channels $\chi \chi \rightarrow \nu \bar{\nu}$ or $\chi \chi \rightarrow a a$, with subsequent decay of the mediator $ a \rightarrow \nu \bar{\nu}$, could locally match and even surpass those of the standard neutrinos from the modified nuclear URCA processes at early ages. We find that the emitting region can be localized in a tiny fraction of the star (less than a few percent of the core volume) and the process can last its entire lifetime for some cases under study. We discuss the possible consequences of our results for stellar cooling in light of existing dark matter constraints.
[ { "created": "Mon, 8 May 2017 18:00:00 GMT", "version": "v1" }, { "created": "Wed, 7 Nov 2018 18:27:47 GMT", "version": "v2" } ]
2018-11-08
[ [ "Cermeño", "M.", "" ], [ "Pérez-García", "M. A.", "" ], [ "Lineros", "R. A.", "" ] ]
We calculate neutrino emissivities from self-annihilating dark matter ($\chi$) in the dense and hot stellar interior of a (proto)neutron star. Using a model where dark matter interacts with nucleons in the stellar core through a pseudoscalar boson ($a$) we find that the neutrino production rates from the dominant reaction channels $\chi \chi \rightarrow \nu \bar{\nu}$ or $\chi \chi \rightarrow a a$, with subsequent decay of the mediator $ a \rightarrow \nu \bar{\nu}$, could locally match and even surpass those of the standard neutrinos from the modified nuclear URCA processes at early ages. We find that the emitting region can be localized in a tiny fraction of the star (less than a few percent of the core volume) and the process can last its entire lifetime for some cases under study. We discuss the possible consequences of our results for stellar cooling in light of existing dark matter constraints.
hep-ph/9407372
Carlos Merino
A. Capella, A. Kaidalov, C. Merino and J. Tran Thanh Van
Diffractive Dissociation in Deep Inelastic Scattering at HERA
17 pages, TEX, preprint LPTHE Orsay 94-42
Phys.Lett. B343 (1995) 403-409
10.1016/0370-2693(94)01430-K
null
hep-ph
null
The diffraction dissociation of virtual photons is considered in the framework of conventional Regge theory. It is shown that the recent HERA data on large rapidity gap events can be successfully described in terms of the Pomeron structure function. Using Regge factorization, the latter can be related to the deuteron structure function. The parameters which relate these two structure functions are determined from soft hadronic diffraction data. The size of the shadowing corrections at low x and large Q**2 is also obtained.
[ { "created": "Tue, 26 Jul 1994 09:54:45 GMT", "version": "v1" } ]
2009-10-28
[ [ "Capella", "A.", "" ], [ "Kaidalov", "A.", "" ], [ "Merino", "C.", "" ], [ "Van", "J. Tran Thanh", "" ] ]
The diffraction dissociation of virtual photons is considered in the framework of conventional Regge theory. It is shown that the recent HERA data on large rapidity gap events can be successfully described in terms of the Pomeron structure function. Using Regge factorization, the latter can be related to the deuteron structure function. The parameters which relate these two structure functions are determined from soft hadronic diffraction data. The size of the shadowing corrections at low x and large Q**2 is also obtained.
1708.01816
Suprabh Prakash
Raj Gandhi, Boris Kayser, Suprabh Prakash, Samiran Roy
What measurements of neutrino neutral current events can reveal
22 pages, 10 figures
JHEP 1711 (2017) 202
10.1007/JHEP11(2017)202
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that neutral current (NC) measurements at neutrino detectors can play a valuable role in the search for new physics. Such measurements have certain intrinsic features and advantages that can fruitfully be combined with the usual well-studied charged lepton detection channels in order to probe the presence of new interactions or new light states. In addition to the fact that NC events are immune to uncertainties in standard model neutrino mixing and mass parameters, they can have small matter effects and superior rates since all three flavours participate. We also show, as a general feature, that NC measurements provide access to different combinations of CP phases and mixing parameters compared to CC measurements at both long and short baseline experiments. Using the Deep Underground Neutrino Experiment (DUNE) as an illustrative setting, we demonstrate the capability of NC measurements to break degeneracies arising in CC measurements, allowing us, in principle, to distinguish between new physics that violates three flavour unitarity and that which does not. Finally, we show that NC measurements can enable us to restrict new physics parameters that are not easily constrained by CC measurements.
[ { "created": "Sat, 5 Aug 2017 19:41:58 GMT", "version": "v1" }, { "created": "Sun, 17 Dec 2017 14:33:54 GMT", "version": "v2" } ]
2017-12-19
[ [ "Gandhi", "Raj", "" ], [ "Kayser", "Boris", "" ], [ "Prakash", "Suprabh", "" ], [ "Roy", "Samiran", "" ] ]
We show that neutral current (NC) measurements at neutrino detectors can play a valuable role in the search for new physics. Such measurements have certain intrinsic features and advantages that can fruitfully be combined with the usual well-studied charged lepton detection channels in order to probe the presence of new interactions or new light states. In addition to the fact that NC events are immune to uncertainties in standard model neutrino mixing and mass parameters, they can have small matter effects and superior rates since all three flavours participate. We also show, as a general feature, that NC measurements provide access to different combinations of CP phases and mixing parameters compared to CC measurements at both long and short baseline experiments. Using the Deep Underground Neutrino Experiment (DUNE) as an illustrative setting, we demonstrate the capability of NC measurements to break degeneracies arising in CC measurements, allowing us, in principle, to distinguish between new physics that violates three flavour unitarity and that which does not. Finally, we show that NC measurements can enable us to restrict new physics parameters that are not easily constrained by CC measurements.
2009.08635
BoQiang Lu
Cheng-Wei Chiang, Da Huang, Bo-Qiang Lu
Electroweak phase transition confronted with dark matter detection constraints
30 pages, 11 figures, 3 tables, v2 matches published version in JCAP
JCAP01(2021)035
10.1088/1475-7516/2021/01/035
null
hep-ph hep-ex
http://creativecommons.org/licenses/by-sa/4.0/
We study the type-II first-order electroweak phase transition and dark matter (DM) phenomenology in both real and complex singlet extensions of SM. In the real singlet extension with a $\mathbb{Z}_2$ symmetry, we show that the parameter regions favored by the phase transition suffer from strong constraints from DM direct detection so that only a negligible fraction ($f_{X}\sim 10^{-4}-10^{-5}$) of DM composed of the real singlet scalar can survive the LUX and XENON1T constraints. In the complex singlet $S$ case, we impose a $CP$ symmetry $S\to S^{*}$ to the scalar potential. The real component of $S$ can mix with SM Higgs boson while the imaginary component becomes a DM candidate due to the protection of the $CP$ symmetry. By taking into account the current experimental constraints of invisible Higgs decays, Higgs signal strength measurements, and dark matter detections, we find that there exists a large parameter space for the type-II electroweak phase transition to occur while explaining all of the dark matter relic density. We identify a subset of parameter space that is promising for future experiments, including the di-Higgs and Higgs signal strength measurements at the HL-LHC and the dark matter direct detection in the XENONnT project.
[ { "created": "Fri, 18 Sep 2020 05:53:04 GMT", "version": "v1" }, { "created": "Thu, 21 Jan 2021 11:18:35 GMT", "version": "v2" } ]
2021-01-22
[ [ "Chiang", "Cheng-Wei", "" ], [ "Huang", "Da", "" ], [ "Lu", "Bo-Qiang", "" ] ]
We study the type-II first-order electroweak phase transition and dark matter (DM) phenomenology in both real and complex singlet extensions of SM. In the real singlet extension with a $\mathbb{Z}_2$ symmetry, we show that the parameter regions favored by the phase transition suffer from strong constraints from DM direct detection so that only a negligible fraction ($f_{X}\sim 10^{-4}-10^{-5}$) of DM composed of the real singlet scalar can survive the LUX and XENON1T constraints. In the complex singlet $S$ case, we impose a $CP$ symmetry $S\to S^{*}$ to the scalar potential. The real component of $S$ can mix with SM Higgs boson while the imaginary component becomes a DM candidate due to the protection of the $CP$ symmetry. By taking into account the current experimental constraints of invisible Higgs decays, Higgs signal strength measurements, and dark matter detections, we find that there exists a large parameter space for the type-II electroweak phase transition to occur while explaining all of the dark matter relic density. We identify a subset of parameter space that is promising for future experiments, including the di-Higgs and Higgs signal strength measurements at the HL-LHC and the dark matter direct detection in the XENONnT project.
1610.06587
Moritz Platscher
Manfred Lindner, Moritz Platscher, Farinaldo S. Queiroz
A Call for New Physics : The Muon Anomalous Magnetic Moment and Lepton Flavor Violation
Invited Review for Physics Reports, 192 pages, 39 figures; v2: extended discussion of lepton flavor violation in nuclear reactions and 3-body final states
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review how the muon anomalous magnetic moment ($g-2$) and the quest for lepton flavor violation are intimately correlated. Indeed the decay $\mu \to e \gamma$ is induced by the same amplitude for different choices of in- and outgoing leptons. In this work, we try to address some intriguing questions such as: Which hierarchy in the charged lepton sector one should have in order to reconcile possible signals coming simultaneously from $g-2$ and lepton flavor violation? What can we learn if the $g-2$ anomaly is confirmed by the upcoming flagship experiments at FERMILAB and J-PARC, and no signal is seen in the decay $\mu \rightarrow e\gamma$ in the foreseeable future? On the other hand, if the $\mu \rightarrow e\gamma$ decay is seen in the upcoming years, do we need to necessarily observe a signal also in $g-2$?. In this attempt, we generally study the correlation between these observables in a detailed analysis of simplified models. We derive master integrals and fully analytical and exact expressions for both phenomena, and adress other flavor violating signals. We investigate under which conditions the observations can be made compatible and discuss their implications. Lastly, we discuss in this context several extensions of the SM, such as the Minimal Supersymmetric Standard Model, Left-Right symmetric model, $B-L$ model, scotogenic model, two Higgs doublet model, Zee-Babu model, 331 model, and $L_{\mu}-L_{\tau}$, dark photon, seesaw models type~I, II and III, and also address the interplay with $\mu \to eee$ decay and $\mu-e$ conversion.
[ { "created": "Thu, 20 Oct 2016 20:00:57 GMT", "version": "v1" }, { "created": "Thu, 7 Dec 2017 09:23:39 GMT", "version": "v2" } ]
2017-12-08
[ [ "Lindner", "Manfred", "" ], [ "Platscher", "Moritz", "" ], [ "Queiroz", "Farinaldo S.", "" ] ]
We review how the muon anomalous magnetic moment ($g-2$) and the quest for lepton flavor violation are intimately correlated. Indeed the decay $\mu \to e \gamma$ is induced by the same amplitude for different choices of in- and outgoing leptons. In this work, we try to address some intriguing questions such as: Which hierarchy in the charged lepton sector one should have in order to reconcile possible signals coming simultaneously from $g-2$ and lepton flavor violation? What can we learn if the $g-2$ anomaly is confirmed by the upcoming flagship experiments at FERMILAB and J-PARC, and no signal is seen in the decay $\mu \rightarrow e\gamma$ in the foreseeable future? On the other hand, if the $\mu \rightarrow e\gamma$ decay is seen in the upcoming years, do we need to necessarily observe a signal also in $g-2$?. In this attempt, we generally study the correlation between these observables in a detailed analysis of simplified models. We derive master integrals and fully analytical and exact expressions for both phenomena, and adress other flavor violating signals. We investigate under which conditions the observations can be made compatible and discuss their implications. Lastly, we discuss in this context several extensions of the SM, such as the Minimal Supersymmetric Standard Model, Left-Right symmetric model, $B-L$ model, scotogenic model, two Higgs doublet model, Zee-Babu model, 331 model, and $L_{\mu}-L_{\tau}$, dark photon, seesaw models type~I, II and III, and also address the interplay with $\mu \to eee$ decay and $\mu-e$ conversion.
1206.5301
Joshua T. Ruderman
Gilly Elor, Lawrence J. Hall, David Pinner and Joshua T. Ruderman
Yukawa Unification and the Superpartner Mass Scale
34 pages plus appendices, 20 figures
null
10.1007/JHEP10(2012)111
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Naturalness in supersymmetry (SUSY) is under siege by increasingly stringent LHC constraints, but natural electroweak symmetry breaking still remains the most powerful motivation for superpartner masses within experimental reach. If naturalness is the wrong criterion then what determines the mass scale of the superpartners? We motivate supersymmetry by (1) gauge coupling unification, (2) dark matter, and (3) precision b-tau Yukawa unification. We show that for an LSP that is a bino-Higgsino admixture, these three requirements lead to an upper-bound on the stop and sbottom masses in the several TeV regime because the threshold correction to the bottom mass at the superpartner scale is required to have a particular size. For tan beta about 50, which is needed for t-b-tau unification, the stops must be lighter than 2.8 TeV when A_t has the opposite sign of the gluino mass, as is favored by renormalization group scaling. For lower values of tan beta, the top and bottom squarks must be even lighter. Yukawa unification plus dark matter implies that superpartners are likely in reach of the LHC, after the upgrade to 14 (or 13) TeV, independent of any considerations of naturalness. We present a model-independent, bottom-up analysis of the SUSY parameter space that is simultaneously consistent with Yukawa unification and the hint for m_h = 125 GeV. We study the flavor and dark matter phenomenology that accompanies this Yukawa unification. A large portion of the parameter space predicts that the branching fraction for B_s to mu^+ mu^- will be observed to be significantly lower than the SM value.
[ { "created": "Fri, 22 Jun 2012 20:00:01 GMT", "version": "v1" } ]
2015-06-05
[ [ "Elor", "Gilly", "" ], [ "Hall", "Lawrence J.", "" ], [ "Pinner", "David", "" ], [ "Ruderman", "Joshua T.", "" ] ]
Naturalness in supersymmetry (SUSY) is under siege by increasingly stringent LHC constraints, but natural electroweak symmetry breaking still remains the most powerful motivation for superpartner masses within experimental reach. If naturalness is the wrong criterion then what determines the mass scale of the superpartners? We motivate supersymmetry by (1) gauge coupling unification, (2) dark matter, and (3) precision b-tau Yukawa unification. We show that for an LSP that is a bino-Higgsino admixture, these three requirements lead to an upper-bound on the stop and sbottom masses in the several TeV regime because the threshold correction to the bottom mass at the superpartner scale is required to have a particular size. For tan beta about 50, which is needed for t-b-tau unification, the stops must be lighter than 2.8 TeV when A_t has the opposite sign of the gluino mass, as is favored by renormalization group scaling. For lower values of tan beta, the top and bottom squarks must be even lighter. Yukawa unification plus dark matter implies that superpartners are likely in reach of the LHC, after the upgrade to 14 (or 13) TeV, independent of any considerations of naturalness. We present a model-independent, bottom-up analysis of the SUSY parameter space that is simultaneously consistent with Yukawa unification and the hint for m_h = 125 GeV. We study the flavor and dark matter phenomenology that accompanies this Yukawa unification. A large portion of the parameter space predicts that the branching fraction for B_s to mu^+ mu^- will be observed to be significantly lower than the SM value.
1510.01808
C. Q. Geng
Y.K. Hsiao, P.Y. Lin, L.W. Luo, C.Q. Geng
Fragmentation fractions of two-body b-baryon decays
10 pages, 1 figure, to be published in PLB
Phys. Lett. B 751 (2015) 127-130
10.1016/j.physletb.2015.10.013
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the fragmentation fractions $(f_{{\bf B}_b})$ of the $b$-quark to b-baryons (${\bf B}_b$). By the assumption of $f_{\Lambda_b}/(f_u+f_d)=0.25\pm 0.15$ in accordance with the measurements by LEP, CDF and LHCb Collaborations, we estimate that $f_{\Lambda_b}=0.175\pm 0.106$ and $f_{\Xi_b^{-,0}}=0.019\pm 0.013$. From these fragmentation fractions, we derive ${\cal B}(\Lambda_b\to J/\psi \Lambda)=(3.3\pm 2.1)\times 10^{-4}$, ${\cal B}(\Xi_b^-\to J/\psi \Xi^-)=(5.3\pm 3.9)\times 10^{-4}$ and ${\cal B}(\Omega_b^-\to J/\psi \Omega^-)>1.9\times 10^{-5}$. The predictions of ${\cal B}(\Lambda_b\to J/\psi \Lambda)$ and ${\cal B}(\Xi_b^-\to J/\psi \Xi^-)$ clearly enable us to test the theoretical models, such as the QCD factorization approach in the $b$-baryon decays.
[ { "created": "Wed, 7 Oct 2015 03:14:44 GMT", "version": "v1" } ]
2015-10-23
[ [ "Hsiao", "Y. K.", "" ], [ "Lin", "P. Y.", "" ], [ "Luo", "L. W.", "" ], [ "Geng", "C. Q.", "" ] ]
We study the fragmentation fractions $(f_{{\bf B}_b})$ of the $b$-quark to b-baryons (${\bf B}_b$). By the assumption of $f_{\Lambda_b}/(f_u+f_d)=0.25\pm 0.15$ in accordance with the measurements by LEP, CDF and LHCb Collaborations, we estimate that $f_{\Lambda_b}=0.175\pm 0.106$ and $f_{\Xi_b^{-,0}}=0.019\pm 0.013$. From these fragmentation fractions, we derive ${\cal B}(\Lambda_b\to J/\psi \Lambda)=(3.3\pm 2.1)\times 10^{-4}$, ${\cal B}(\Xi_b^-\to J/\psi \Xi^-)=(5.3\pm 3.9)\times 10^{-4}$ and ${\cal B}(\Omega_b^-\to J/\psi \Omega^-)>1.9\times 10^{-5}$. The predictions of ${\cal B}(\Lambda_b\to J/\psi \Lambda)$ and ${\cal B}(\Xi_b^-\to J/\psi \Xi^-)$ clearly enable us to test the theoretical models, such as the QCD factorization approach in the $b$-baryon decays.
0807.3384
Gergely G\'abor Barnaf\"oldi
G.G. Barnaf\"oldi, A. Adeluyi, G. Fai, P. L\'evai, G. Papp
Prospect of Rapidity Asymmetry and Nuclear Modifications
6 pages, 5 fidures, For the Proceedings of the 24th Winter Workshop on Nuclear Dynamics, South Padre, Texas, April 5-12, 2008
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In asymmetric heavy ion collisions like dA or pA, particle production yields are different in the forward (d- or p-side) and backward (A-side) rapidity directions. The rapidity distribution reflects the geometry and phase-space distribution of nuclear matter. These properties may depend on the time evolution of the collision. Due to the smallness of the backward-forward differences, the rapidity asymmetry factor can be useful to quantify nuclear modification effects, like e.g. shadowing and the EMC effect. Our work is a survey of the nuclear modification factor and the rapidity asymmetries at RHIC energies. We analyze the rapidity dependence and the strength of the nuclear effects. We focus on the high transverse momentum region, and make predictions for the role of nuclear modifications and rapidity asymmetries for future experimental measurements at increasing absolute values of rapidity.
[ { "created": "Tue, 22 Jul 2008 03:14:27 GMT", "version": "v1" } ]
2008-07-23
[ [ "Barnaföldi", "G. G.", "" ], [ "Adeluyi", "A.", "" ], [ "Fai", "G.", "" ], [ "Lévai", "P.", "" ], [ "Papp", "G.", "" ] ]
In asymmetric heavy ion collisions like dA or pA, particle production yields are different in the forward (d- or p-side) and backward (A-side) rapidity directions. The rapidity distribution reflects the geometry and phase-space distribution of nuclear matter. These properties may depend on the time evolution of the collision. Due to the smallness of the backward-forward differences, the rapidity asymmetry factor can be useful to quantify nuclear modification effects, like e.g. shadowing and the EMC effect. Our work is a survey of the nuclear modification factor and the rapidity asymmetries at RHIC energies. We analyze the rapidity dependence and the strength of the nuclear effects. We focus on the high transverse momentum region, and make predictions for the role of nuclear modifications and rapidity asymmetries for future experimental measurements at increasing absolute values of rapidity.
1402.4979
Philipp Wein
Philipp Wein, Peter C. Bruns, Andreas Sch\"afer
First moments of nucleon generalized parton distributions in chiral perturbation theory at full one-loop order
We have updated the text to match the version published in PRD
Phys. Rev. D 89, 116002 (2014)
10.1103/PhysRevD.89.116002
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we present chiral extrapolation formulas for the generalized form factors connected to the first moments of chiral-even generalized parton distributions. For the description of QCD at low energies we employ the framework of two-flavor covariant baryon chiral perturbation theory at full one-loop accuracy. Our results are well suited for the extrapolation of lattice QCD data to physical quark masses.
[ { "created": "Thu, 20 Feb 2014 12:15:33 GMT", "version": "v1" }, { "created": "Tue, 11 Nov 2014 14:16:02 GMT", "version": "v2" } ]
2014-11-12
[ [ "Wein", "Philipp", "" ], [ "Bruns", "Peter C.", "" ], [ "Schäfer", "Andreas", "" ] ]
In this paper we present chiral extrapolation formulas for the generalized form factors connected to the first moments of chiral-even generalized parton distributions. For the description of QCD at low energies we employ the framework of two-flavor covariant baryon chiral perturbation theory at full one-loop accuracy. Our results are well suited for the extrapolation of lattice QCD data to physical quark masses.
1901.05930
Vakhid Gani
Vakhid A. Gani, Maxim Yu. Khlopov, Dmitry N. Voskresensky
Superheavy objects composed of nuclear and dark matter
4 pages; Proceedings of the 4th International Conference on Particle Physics and Astrophysics (ICPPA-2018), Moscow, 22-26 October 2018
J. Phys.: Conf. Ser. 1390, 012095 (2019)
10.1088/1742-6596/1390/1/012095
null
hep-ph astro-ph.CO nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a model of $O$He atomic dark matter formed by Coulomb binding of the hypothetical stable double-charged massive $O^{--}$ particles with nuclei of primordial helium. Such a dark matter can be captured by ordinary matter forming superheavy nuclei. We propose a possibility of self-bound by nuclear and electromagnetic interaction $O$-nuclearites as well as more massive gravitating ones and discuss effect of accumulation of $O$He atoms in stars and their effect in stellar evolution.
[ { "created": "Thu, 17 Jan 2019 18:00:24 GMT", "version": "v1" } ]
2020-01-08
[ [ "Gani", "Vakhid A.", "" ], [ "Khlopov", "Maxim Yu.", "" ], [ "Voskresensky", "Dmitry N.", "" ] ]
We consider a model of $O$He atomic dark matter formed by Coulomb binding of the hypothetical stable double-charged massive $O^{--}$ particles with nuclei of primordial helium. Such a dark matter can be captured by ordinary matter forming superheavy nuclei. We propose a possibility of self-bound by nuclear and electromagnetic interaction $O$-nuclearites as well as more massive gravitating ones and discuss effect of accumulation of $O$He atoms in stars and their effect in stellar evolution.
1204.5862
Florian Bonnet
Florian Bonnet, Martin Hirsch, Toshihiko Ota, Walter Winter
Systematic study of the d=5 Weinberg operator at one-loop order
18 pages, 5 Figures, 4 Tables - Version to appear in JHEP
Journal of High Energy Physics, Volume 2012, Issue 7
10.1007/JHEP07(2012)153
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform a systematic study of the $d=5$ Weinberg operator at the one-loop level. We identify three different categories of neutrino mass generation: (1) finite irreducible diagrams; (2) finite extensions of the usual seesaw mechanisms at one-loop and (3) divergent loop realizations of the seesaws. All radiative one-loop neutrino mass models must fall into one of these classes. Case (1) gives the leading contribution to neutrino mass naturally and a classic example of this class is the Zee model. We demonstrate that in order to prevent that a tree level contribution dominates in case (2), Majorana fermions running in the loop and an additional $\mathbb{Z}_2$ symmetry are needed for a genuinely leading one-loop contribution. In the type-II loop extensions, the lepton number violating coupling will be generated at one loop, whereas the type-I/III extensions can be interpreted as loop-induced inverse or linear seesaw mechanisms. For the divergent diagrams in category (3), the tree level contribution cannot be avoided and is in fact needed as counter term to absorb the divergence.
[ { "created": "Thu, 26 Apr 2012 08:25:30 GMT", "version": "v1" }, { "created": "Mon, 20 Aug 2012 15:05:11 GMT", "version": "v2" } ]
2017-08-23
[ [ "Bonnet", "Florian", "" ], [ "Hirsch", "Martin", "" ], [ "Ota", "Toshihiko", "" ], [ "Winter", "Walter", "" ] ]
We perform a systematic study of the $d=5$ Weinberg operator at the one-loop level. We identify three different categories of neutrino mass generation: (1) finite irreducible diagrams; (2) finite extensions of the usual seesaw mechanisms at one-loop and (3) divergent loop realizations of the seesaws. All radiative one-loop neutrino mass models must fall into one of these classes. Case (1) gives the leading contribution to neutrino mass naturally and a classic example of this class is the Zee model. We demonstrate that in order to prevent that a tree level contribution dominates in case (2), Majorana fermions running in the loop and an additional $\mathbb{Z}_2$ symmetry are needed for a genuinely leading one-loop contribution. In the type-II loop extensions, the lepton number violating coupling will be generated at one loop, whereas the type-I/III extensions can be interpreted as loop-induced inverse or linear seesaw mechanisms. For the divergent diagrams in category (3), the tree level contribution cannot be avoided and is in fact needed as counter term to absorb the divergence.
hep-ph/0306222
Davison E. Soper
Michael Kramer and Davison E. Soper
Next-to-leading order QCD calculations with parton showers I: collinear singularities
23 pages including 10 figures. This version is close to the version to be published. The most notable change is an expanded introduction
Phys.Rev.D69:054019,2004
10.1103/PhysRevD.69.054019
null
hep-ph
null
Programs that calculate observables in quantum chromodynamics at next-to-leading order typically suffer from the problem that, when considered as event generators, the events generated consist of partons rather than hadrons and just a few partons at that. Thus the events generated are completely unrealistic. These programs would be much more useful if the few partons were turned into parton showers, in the style of standard Monte Carlo event generators. Then the parton showers could be given to one of the Monte Carlo event generators to produce hadron showers. We show how to generate parton showers related to the final state collinear singularities of the next-to-leading order perturbative calculation for the example of e+ + e- --> 3 jets . The soft singularities are left for a separate publication.
[ { "created": "Mon, 23 Jun 2003 21:26:49 GMT", "version": "v1" }, { "created": "Mon, 30 Jun 2003 22:27:55 GMT", "version": "v2" }, { "created": "Fri, 15 Aug 2003 21:32:37 GMT", "version": "v3" }, { "created": "Fri, 22 Aug 2003 01:19:37 GMT", "version": "v4" }, { "created": "Fri, 20 Feb 2004 00:33:32 GMT", "version": "v5" } ]
2009-04-13
[ [ "Kramer", "Michael", "" ], [ "Soper", "Davison E.", "" ] ]
Programs that calculate observables in quantum chromodynamics at next-to-leading order typically suffer from the problem that, when considered as event generators, the events generated consist of partons rather than hadrons and just a few partons at that. Thus the events generated are completely unrealistic. These programs would be much more useful if the few partons were turned into parton showers, in the style of standard Monte Carlo event generators. Then the parton showers could be given to one of the Monte Carlo event generators to produce hadron showers. We show how to generate parton showers related to the final state collinear singularities of the next-to-leading order perturbative calculation for the example of e+ + e- --> 3 jets . The soft singularities are left for a separate publication.
1110.2588
Hiroshi Yokoya
Xiao-Gang He, German Valencia, Hiroshi Yokoya
Color-octet scalars and potentially large CP violation at the LHC
16 pages, 4 figures
JHEP 1112 (2011) 030
10.1007/JHEP12(2011)030
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the phenomenology of CP violation in a color-octet extended scalar sector for t\bar{t} production and decay at the LHC. In particular we study the effect of the two neutral color-octet scalars S_I and S_R that occur in the model. There are two new sources of CP violation: a phase in the couplings of S_{I,R} to top-quarks; and two phases in the quartic couplings of the scalar potential. In resonant production of a single S_{I,R} followed by its decay into t\bar{t} pairs through the parton level process gg to S_{I,R} to t\bar{t}, we find large raw CP asymmetries which can reach 12%. These raw asymmetries are, of course, diluted by standard model (SM) t\bar{t} pairs making observation of CP violation contingent on whether the resonance itself can be extracted from the SM background.
[ { "created": "Wed, 12 Oct 2011 07:45:31 GMT", "version": "v1" } ]
2012-01-31
[ [ "He", "Xiao-Gang", "" ], [ "Valencia", "German", "" ], [ "Yokoya", "Hiroshi", "" ] ]
We consider the phenomenology of CP violation in a color-octet extended scalar sector for t\bar{t} production and decay at the LHC. In particular we study the effect of the two neutral color-octet scalars S_I and S_R that occur in the model. There are two new sources of CP violation: a phase in the couplings of S_{I,R} to top-quarks; and two phases in the quartic couplings of the scalar potential. In resonant production of a single S_{I,R} followed by its decay into t\bar{t} pairs through the parton level process gg to S_{I,R} to t\bar{t}, we find large raw CP asymmetries which can reach 12%. These raw asymmetries are, of course, diluted by standard model (SM) t\bar{t} pairs making observation of CP violation contingent on whether the resonance itself can be extracted from the SM background.
hep-ph/0112269
Rajiv V. Gavai
Rajiv V. Gavai
Quark number susceptibilities from lattice QCD
Talk presented at the 18th Alexander von Humboldt symposium ``100 Years Werner Heisenberg - Works and Impact'', Bamberg, Germany, September 26-30, 2001. 6 pages, LaTeX, buckow.sty needed
Fortsch.Phys. 50 (2002) 525-530
10.1002/1521-3978(200205)50:5/7<525::AID-PROP525>3.0.CO;2-N
TIFR/TH/01-50
hep-ph
null
Results from our recent investigations of quark number susceptibilities in both quenched and 2-flavour QCD are presented as a function of valence quark mass and temperature. A strong reduction (approx. 40%) is seen in the strange quark susceptibility above T_c in both the cases. A comparison of our isospin susceptibility results with the corresponding weak coupling expansion reveals once again the non-perturbative nature of the plasma up to 3T_c. Evidence relating the susceptibility to another non-perturbative phenomena, pionic screening lengths, is presented.
[ { "created": "Thu, 20 Dec 2001 08:31:27 GMT", "version": "v1" } ]
2015-06-25
[ [ "Gavai", "Rajiv V.", "" ] ]
Results from our recent investigations of quark number susceptibilities in both quenched and 2-flavour QCD are presented as a function of valence quark mass and temperature. A strong reduction (approx. 40%) is seen in the strange quark susceptibility above T_c in both the cases. A comparison of our isospin susceptibility results with the corresponding weak coupling expansion reveals once again the non-perturbative nature of the plasma up to 3T_c. Evidence relating the susceptibility to another non-perturbative phenomena, pionic screening lengths, is presented.
hep-ph/9401315
Mohammad
M. R. Ahmady and R. R. Mendel
The Decay $\eta_c \rightarrow \gamma \gamma$ : A Test for Potential Models
Estimates of likely relativistic corrections to the results have been added
Phys.Rev. D51 (1995) 141-146
10.1103/PhysRevD.51.141
null
hep-ph
null
We use a simple perturbation theory argument and measurements of charmonium leptonic widths $\Gamma (\psi_{NS} \rightarrow e^+e^-)$ to estimate the ratio \mbox{$R_\circ \equiv {\vert \Psi _{\eta_{c1S}}(0) \vert}^2 /{\vert\Psi_{\psi_{1 S}}(0)\vert}^2$} in the general context of non- relativistic potential models. We obtain $R_\circ = 1.4 \pm 0.1$. We then apply well known potential model formulas, which include lowest order QCD corrections, to find $\Gamma (\eta_c \rightarrow \gamma \gamma )/\Gamma (\psi_{1S} \rightarrow e^+e^-) \approx 2.2\pm 0.2$. The central value for $\Gamma (\psi_{1S} \rightarrow e^+ e^-)$in the 1992 Particle Data Tables then leads to a (non relativistic) prediction $\Gamma (\eta_c \rightarrow \gamma \gamma )\approx 11.8\pm 0.8 $ keV. This prediction is in good agreement with a recent measurement by the ARGUS collaboration, is consistent with a recent measurement by the L3 collaboration but is significantly higher than several earlier measurements and than previous theoretical estimates, which usually assume $R_\circ =1$. The correction to $R_\circ =1$ is estimated to be smaller but nonnegligible for the $b\bar b$ system. Using the current central measurement for $\Gamma (\Upsilon_{1S}\rightarrow e^+e^-)$ we find $\Gamma (\eta_b\rightarrow \gamma \gamma )\approx 0.58\pm 0.03$ keV. A rough estimate of relativistic corrections reduces the expected two photon rates to about 8.8 keV and 0.52 keV for the $\eta_c$ and $\eta_b$ mesons respectively. Such corrections
[ { "created": "Mon, 24 Jan 1994 20:27:05 GMT", "version": "v1" }, { "created": "Thu, 3 Mar 1994 18:16:41 GMT", "version": "v2" } ]
2009-10-28
[ [ "Ahmady", "M. R.", "" ], [ "Mendel", "R. R.", "" ] ]
We use a simple perturbation theory argument and measurements of charmonium leptonic widths $\Gamma (\psi_{NS} \rightarrow e^+e^-)$ to estimate the ratio \mbox{$R_\circ \equiv {\vert \Psi _{\eta_{c1S}}(0) \vert}^2 /{\vert\Psi_{\psi_{1 S}}(0)\vert}^2$} in the general context of non- relativistic potential models. We obtain $R_\circ = 1.4 \pm 0.1$. We then apply well known potential model formulas, which include lowest order QCD corrections, to find $\Gamma (\eta_c \rightarrow \gamma \gamma )/\Gamma (\psi_{1S} \rightarrow e^+e^-) \approx 2.2\pm 0.2$. The central value for $\Gamma (\psi_{1S} \rightarrow e^+ e^-)$in the 1992 Particle Data Tables then leads to a (non relativistic) prediction $\Gamma (\eta_c \rightarrow \gamma \gamma )\approx 11.8\pm 0.8 $ keV. This prediction is in good agreement with a recent measurement by the ARGUS collaboration, is consistent with a recent measurement by the L3 collaboration but is significantly higher than several earlier measurements and than previous theoretical estimates, which usually assume $R_\circ =1$. The correction to $R_\circ =1$ is estimated to be smaller but nonnegligible for the $b\bar b$ system. Using the current central measurement for $\Gamma (\Upsilon_{1S}\rightarrow e^+e^-)$ we find $\Gamma (\eta_b\rightarrow \gamma \gamma )\approx 0.58\pm 0.03$ keV. A rough estimate of relativistic corrections reduces the expected two photon rates to about 8.8 keV and 0.52 keV for the $\eta_c$ and $\eta_b$ mesons respectively. Such corrections
hep-ph/9612348
null
Michael Melles (SLAC)
Exact Results on O(alpha^2) Single Bremsstrahlung Corrections to Low Angle Bhabha Scattering at LEP/SLC Energies
needs latest version of latex2e (otherwise press enter five times),59 pages,8 figures (eps),bbl file included. To be published in Acta Physica Polonica.
Acta Phys.Polon.B28:1159-1206,1997
null
SLAC-PUB 7383
hep-ph
null
In this thesis exact results on O(alpha^2) single bremsstrahlung corrections to low angle Bhabha scattering at LEP/SLC energies are given. The calculation represents the last outstanding theoretical second order subleading electroweak contribution for that process, needed to determine the experimental luminosity at second generation LEP detectors below the 0.1% precision threshold. The exact, fully differential result is obtained by employing analytical as well as computer-algebraic methods and includes terms up to O(0.05%) relative to the Born cross section. The initial output of over 20,000 terms could be reduced to 90, only 18 of which are shown to be numerically relevant and for which a simple logarithmic ansatz is derived, that is in remarkable agreement with the complete answer. Strong consistency checks are performed, including Ward-Takahashi identities and tests on the right infrared limit according to the Yennie, Frautschi and Suura program. Monte Carlo results for the integrated cross section are compared with existing calculations in the leading logarithmic approximation for a chosen set of experimental cuts. The size of the missing subleading terms is found to be small but non negligible in the context of setting stringent limits on Standard Model predictions and thus its realm of validity.
[ { "created": "Fri, 13 Dec 1996 01:11:38 GMT", "version": "v1" } ]
2011-06-20
[ [ "Melles", "Michael", "", "SLAC" ] ]
In this thesis exact results on O(alpha^2) single bremsstrahlung corrections to low angle Bhabha scattering at LEP/SLC energies are given. The calculation represents the last outstanding theoretical second order subleading electroweak contribution for that process, needed to determine the experimental luminosity at second generation LEP detectors below the 0.1% precision threshold. The exact, fully differential result is obtained by employing analytical as well as computer-algebraic methods and includes terms up to O(0.05%) relative to the Born cross section. The initial output of over 20,000 terms could be reduced to 90, only 18 of which are shown to be numerically relevant and for which a simple logarithmic ansatz is derived, that is in remarkable agreement with the complete answer. Strong consistency checks are performed, including Ward-Takahashi identities and tests on the right infrared limit according to the Yennie, Frautschi and Suura program. Monte Carlo results for the integrated cross section are compared with existing calculations in the leading logarithmic approximation for a chosen set of experimental cuts. The size of the missing subleading terms is found to be small but non negligible in the context of setting stringent limits on Standard Model predictions and thus its realm of validity.
0708.1686
Michal Praszalowicz
Michal Praszalowicz and Klaus Goeke
On the exotic eikosiheptaplet
11 pages, 2 figures, v2 accepted for publication in Phys. Rev. D
null
null
null
hep-ph
null
We use the chiral quark soliton model to estimate masses and widths of the two eikosiheptaplets (27-plets of SU(3) flavor) of spin 3/2 and 1/2 that emerge in the rigid rotator quantization. We use as input: hyperon decays, Theta+ mass and width. While 27_{3/2} has small widths (although much larger than the values allowed by the partial wave analysis), 27_{1/2} has large decay widths to antidecuplet. However exactly for this decay channels the widths are suppressed in the large N_{c} limit.
[ { "created": "Mon, 13 Aug 2007 10:23:14 GMT", "version": "v1" }, { "created": "Wed, 19 Sep 2007 17:42:37 GMT", "version": "v2" } ]
2007-09-19
[ [ "Praszalowicz", "Michal", "" ], [ "Goeke", "Klaus", "" ] ]
We use the chiral quark soliton model to estimate masses and widths of the two eikosiheptaplets (27-plets of SU(3) flavor) of spin 3/2 and 1/2 that emerge in the rigid rotator quantization. We use as input: hyperon decays, Theta+ mass and width. While 27_{3/2} has small widths (although much larger than the values allowed by the partial wave analysis), 27_{1/2} has large decay widths to antidecuplet. However exactly for this decay channels the widths are suppressed in the large N_{c} limit.
1303.5924
Mohammad Athar SAJJAD
M. Rafi Alam, I. Ruiz Simo, M. Sajjad Athar, L. Alvarez-Ruso and M. J. Vicente Vacas
Weak production of strange particles off the nucleon
submitted in NUINT 12 conference proceeding
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The strange particle production off the nucleon induced by neutrinos and antineutrinos is investigated at low and intermediate energies. We develop a microscopic model based on the SU(3) chiral Lagrangian. The studied mechanisms are the main source of single kaon production for (anti)neutrino energies up to 1.5 GeV. Using this model we have also studied the associated production of kaons and hyperons. The cross sections are large enough to be measured by experiments such as MINER$\nu$A, T2K and NO$\nu$A.
[ { "created": "Sun, 24 Mar 2013 08:25:56 GMT", "version": "v1" } ]
2013-03-26
[ [ "Alam", "M. Rafi", "" ], [ "Simo", "I. Ruiz", "" ], [ "Athar", "M. Sajjad", "" ], [ "Alvarez-Ruso", "L.", "" ], [ "Vacas", "M. J. Vicente", "" ] ]
The strange particle production off the nucleon induced by neutrinos and antineutrinos is investigated at low and intermediate energies. We develop a microscopic model based on the SU(3) chiral Lagrangian. The studied mechanisms are the main source of single kaon production for (anti)neutrino energies up to 1.5 GeV. Using this model we have also studied the associated production of kaons and hyperons. The cross sections are large enough to be measured by experiments such as MINER$\nu$A, T2K and NO$\nu$A.
hep-ph/9503290
null
M. Anselmino, M. Boglione (University and INFN, Torino), F. Murgia (INFN, Cagliari)
Single spin asymmetry for $p^{\uparrow}p \to \pi X$ in perturbative QCD
11 pages + 1 figure, plain LaTeX, figure appended as uuencoded, compressed postscript file. Revised version, to be published in Phys. Lett. B; extensive changes in Sections 1 and 2, new References added, results and conclusions essentially unchanged
Phys.Lett. B362 (1995) 164-172
10.1016/0370-2693(95)01168-P
DFTT48/94, INFNCA-TH-94-27
hep-ph
null
Within the QCD-improved parton model and assuming the factorization theorem to hold in the helicity basis and for higher twist contributions, we show how non zero single spin asymmetries in hadron-hadron high energy and moderately large $p_T$ inclusive processes can be obtained, even in massless perturbative QCD, provided the quark intrinsic motion is taken into account. A simple model is constructed which reproduces the main features of the data on the single spin asymmetry observed in inclusive pion production in $p\,p$ collisions.
[ { "created": "Fri, 10 Mar 1995 12:54:31 GMT", "version": "v1" }, { "created": "Tue, 3 Oct 1995 14:32:41 GMT", "version": "v2" } ]
2009-10-28
[ [ "Anselmino", "M.", "", "University and INFN, Torino" ], [ "Boglione", "M.", "", "University and INFN, Torino" ], [ "Murgia", "F.", "", "INFN, Cagliari" ] ]
Within the QCD-improved parton model and assuming the factorization theorem to hold in the helicity basis and for higher twist contributions, we show how non zero single spin asymmetries in hadron-hadron high energy and moderately large $p_T$ inclusive processes can be obtained, even in massless perturbative QCD, provided the quark intrinsic motion is taken into account. A simple model is constructed which reproduces the main features of the data on the single spin asymmetry observed in inclusive pion production in $p\,p$ collisions.
1611.09629
Byung-Geel Yu
Byung-Geel Yu and Kook-Jin Kong
Investigating convergence of the reaction $\gamma p\to\pi^\pm\Delta$ and tensor meson $a_2$ exchange at high energy
6 pages, 4 figures, 1 table
Phys. Lett. B769, 262 (2017)
10.1016/j.physletb.2017.03.070
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A Regge approach to the reaction processes $\gamma p\to\pi^-\Delta^{++}$ and $\gamma p\to\pi^+\Delta^0$ is presented for the description of existing data up to $E_\gamma= 16$ GeV. The model consists of the $t$-channel $\pi(139)+\rho(775)+a_2(1320)$ exchanges which are reggeized from the relevant Born amplitude. Discussion is given on the minimal gauge prescription for the $\pi$ exchange to render convergent the divergence of the $u$-channel $\Delta$-pole in the former process. A new Lagrangian is constructed for the $a_2N\Delta$ coupling in this work and applied to the process for the first time with the coupling constant deduced from the duality plus vector dominance. It is shown that, while the $\pi$ exchange dominates over the process, the role of the $a_2$ exchange is crucial rather than the $\rho$ in reproducing the cross sections for total, differential, and photon polarization asymmetry to agree with data at high energy.
[ { "created": "Tue, 29 Nov 2016 13:45:36 GMT", "version": "v1" }, { "created": "Wed, 30 Nov 2016 05:49:37 GMT", "version": "v2" }, { "created": "Thu, 20 Apr 2017 12:04:55 GMT", "version": "v3" }, { "created": "Mon, 17 Jul 2017 14:05:08 GMT", "version": "v4" }, { "created": "Wed, 19 Jul 2017 07:20:34 GMT", "version": "v5" } ]
2017-07-20
[ [ "Yu", "Byung-Geel", "" ], [ "Kong", "Kook-Jin", "" ] ]
A Regge approach to the reaction processes $\gamma p\to\pi^-\Delta^{++}$ and $\gamma p\to\pi^+\Delta^0$ is presented for the description of existing data up to $E_\gamma= 16$ GeV. The model consists of the $t$-channel $\pi(139)+\rho(775)+a_2(1320)$ exchanges which are reggeized from the relevant Born amplitude. Discussion is given on the minimal gauge prescription for the $\pi$ exchange to render convergent the divergence of the $u$-channel $\Delta$-pole in the former process. A new Lagrangian is constructed for the $a_2N\Delta$ coupling in this work and applied to the process for the first time with the coupling constant deduced from the duality plus vector dominance. It is shown that, while the $\pi$ exchange dominates over the process, the role of the $a_2$ exchange is crucial rather than the $\rho$ in reproducing the cross sections for total, differential, and photon polarization asymmetry to agree with data at high energy.
hep-ph/0409195
Radovan Dermisek
Radovan Dermisek
Fermion Masses and Bi-large Lepton Mixing from Singular Matrices
4 pages, to appear in the proceedings of SUSY 2004: The 12th International Conference on Supersymmetry and Unification of Fundamental Interactions, Tsukuba, Japan, June 17-23, 2004
null
null
UCD-04-25
hep-ph
null
We discuss conditions under which bi-large mixing in the lepton sector is achieved assuming that all Yukawa matrices and the right-handed neutrino mass matrix have the same singular form in the leading order. Due to obvious quark lepton symmetry, this approach can be embedded into grand unified theories. The right-handed neutrino mass scale can be identified with the GUT scale and, as a consequence of third generation Yukawa coupling unification, the mass of the lightest neutrino is given as (m_{top}^2/M_{GUT})|U_{\tau 1}|^2 in the leading order. This relation does not depend on the exact form of mass matrices.
[ { "created": "Thu, 16 Sep 2004 00:12:18 GMT", "version": "v1" } ]
2007-05-23
[ [ "Dermisek", "Radovan", "" ] ]
We discuss conditions under which bi-large mixing in the lepton sector is achieved assuming that all Yukawa matrices and the right-handed neutrino mass matrix have the same singular form in the leading order. Due to obvious quark lepton symmetry, this approach can be embedded into grand unified theories. The right-handed neutrino mass scale can be identified with the GUT scale and, as a consequence of third generation Yukawa coupling unification, the mass of the lightest neutrino is given as (m_{top}^2/M_{GUT})|U_{\tau 1}|^2 in the leading order. This relation does not depend on the exact form of mass matrices.
hep-ph/9805283
Werner Vogelsang
A. Bassetto, G. Heinrich, Z. Kunszt, W. Vogelsang
The light-cone gauge and the calculation of the two-loop splitting functions
41 Pages, LaTeX, 8 figures and tables as eps files
Phys.Rev.D58:094020,1998
10.1103/PhysRevD.58.094020
CERN-TH/98-133, ETH-TH/98-12, DFPD 98/TH 19
hep-ph hep-th
null
We present calculations of next-to-leading order QCD splitting functions, employing the light-cone gauge method of Curci, Furmanski, and Petronzio (CFP). In contrast to the `principal-value' prescription used in the original CFP paper for dealing with the poles of the light-cone gauge gluon propagator, we adopt the Mandelstam-Leibbrandt prescription which is known to have a solid field-theoretical foundation. We find that indeed the calculation using this prescription is conceptionally clear and avoids the somewhat dubious manipulations of the spurious poles required when the principal-value method is applied. We reproduce the well-known results for the flavour non-singlet splitting function and the N_C^2 part of the gluon-to-gluon singlet splitting function, which are the most complicated ones, and which provide an exhaustive test of the ML prescription. We also discuss in some detail the x=1 endpoint contributions to the splitting functions.
[ { "created": "Mon, 11 May 1998 15:20:29 GMT", "version": "v1" } ]
2014-11-17
[ [ "Bassetto", "A.", "" ], [ "Heinrich", "G.", "" ], [ "Kunszt", "Z.", "" ], [ "Vogelsang", "W.", "" ] ]
We present calculations of next-to-leading order QCD splitting functions, employing the light-cone gauge method of Curci, Furmanski, and Petronzio (CFP). In contrast to the `principal-value' prescription used in the original CFP paper for dealing with the poles of the light-cone gauge gluon propagator, we adopt the Mandelstam-Leibbrandt prescription which is known to have a solid field-theoretical foundation. We find that indeed the calculation using this prescription is conceptionally clear and avoids the somewhat dubious manipulations of the spurious poles required when the principal-value method is applied. We reproduce the well-known results for the flavour non-singlet splitting function and the N_C^2 part of the gluon-to-gluon singlet splitting function, which are the most complicated ones, and which provide an exhaustive test of the ML prescription. We also discuss in some detail the x=1 endpoint contributions to the splitting functions.
1301.5217
Stefan Groote Dr.
S. Groote, J. G. K\"orner, P. Tuvike
The decays of on-shell and off-shell polarized gauge bosons into massive quark pairs at NLO QCD
5 pages, 2 figures, invited talk given by J.G. K\"orner at the 20th International Symposium on Spin Physics, September 17-22, 2012, Dubna Russia
Phys. Part. Nucl. 45 (2014) 214-216
10.1134/S1063779614010419
MITP/13-009
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the polar angle decay distribution in the decay of on-shell and off-shell polarized (W,Z) gauge bosons into massive quark pairs. In particular for the off-shell decays in $H \to (W,Z) + (W^\ast,Z^\ast) (\to q_1\bar q_2)$ it is important to keep the masses of the charm and bottom quarks at their finite values since the scale of the problem is not set by $m_{W,Z}^2$ but by the off-shellness of the gauge boson which varies in the range $(m_1+m_2)^2 \le q^2 \le (m_H-m_{W,Z})^2$.
[ { "created": "Tue, 22 Jan 2013 16:00:20 GMT", "version": "v1" }, { "created": "Wed, 23 Jan 2013 11:54:37 GMT", "version": "v2" }, { "created": "Fri, 10 Jan 2014 07:26:29 GMT", "version": "v3" } ]
2014-01-13
[ [ "Groote", "S.", "" ], [ "Körner", "J. G.", "" ], [ "Tuvike", "P.", "" ] ]
We discuss the polar angle decay distribution in the decay of on-shell and off-shell polarized (W,Z) gauge bosons into massive quark pairs. In particular for the off-shell decays in $H \to (W,Z) + (W^\ast,Z^\ast) (\to q_1\bar q_2)$ it is important to keep the masses of the charm and bottom quarks at their finite values since the scale of the problem is not set by $m_{W,Z}^2$ but by the off-shellness of the gauge boson which varies in the range $(m_1+m_2)^2 \le q^2 \le (m_H-m_{W,Z})^2$.
1701.02263
Hong-Hao Zhang
Jie Feng, Hong-Hao Zhang
Dark Matter Search in Space: Combined Analysis of Cosmic Ray Antiproton-to-Proton Flux Ratio and Positron Flux Measured by AMS-02
10 pages, 7 figures, 2 table, accepted for publication in the ApJ
Astrophys.J. 858,116(2018)
10.3847/1538-4357/aabf87
null
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dark matter search in space has been carried out for many years. Measurements of cosmic ray photons, charged antiparticles and neutrinos are useful tools for dark matter indirect search. The antiparticle energy spectra of cosmic rays have several exciting features such as the unexpected positron excess at energy about 10 -- 500 GeV and the remarkably flattening antiproton/proton at energy about 60--450 GeV precisely measured by the AMS-02 experiment, which can not be explained simultaneously by secondary production in interstellar medium. In this work, we report a combined analysis of cosmic ray antiproton and positron spectra arising from dark matter on the top of a secondary production in a spatial-dependent propagation model. We discuss the systematics from antiproton production cross section using the two latest Monte Carlo generators, i.e. EPOS LHC and QGSJET-II-04m, respectively. We compare their results. In the case of EPOS LHC, we find that the dark matter pair annihilating into tau leptons channel with 100% branching ratio is the only possible one channel scenario to explain data. On the other hand, there is not a single possible channel in the case of QGSJET-II-04m. We also propose possible two-channel scenarios based on these two Monte Carlo generators.
[ { "created": "Mon, 9 Jan 2017 17:07:56 GMT", "version": "v1" }, { "created": "Thu, 12 Jan 2017 12:43:08 GMT", "version": "v2" }, { "created": "Sun, 14 Jan 2018 17:34:44 GMT", "version": "v3" }, { "created": "Wed, 18 Apr 2018 19:19:51 GMT", "version": "v4" } ]
2018-05-16
[ [ "Feng", "Jie", "" ], [ "Zhang", "Hong-Hao", "" ] ]
Dark matter search in space has been carried out for many years. Measurements of cosmic ray photons, charged antiparticles and neutrinos are useful tools for dark matter indirect search. The antiparticle energy spectra of cosmic rays have several exciting features such as the unexpected positron excess at energy about 10 -- 500 GeV and the remarkably flattening antiproton/proton at energy about 60--450 GeV precisely measured by the AMS-02 experiment, which can not be explained simultaneously by secondary production in interstellar medium. In this work, we report a combined analysis of cosmic ray antiproton and positron spectra arising from dark matter on the top of a secondary production in a spatial-dependent propagation model. We discuss the systematics from antiproton production cross section using the two latest Monte Carlo generators, i.e. EPOS LHC and QGSJET-II-04m, respectively. We compare their results. In the case of EPOS LHC, we find that the dark matter pair annihilating into tau leptons channel with 100% branching ratio is the only possible one channel scenario to explain data. On the other hand, there is not a single possible channel in the case of QGSJET-II-04m. We also propose possible two-channel scenarios based on these two Monte Carlo generators.
1704.08549
Nikolaos Kidonakis
Nikolaos Kidonakis
Higher-order radiative corrections for $b{\bar b} \rightarrow H^- W^+$
14 pages, 8 figures; additional material in v2
Phys. Rev. D 97, 034002 (2018)
10.1103/PhysRevD.97.034002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I present higher-order radiative corrections from collinear and soft gluon emission for the associated production of a charged Higgs boson with a $W$ boson. The calculation uses expressions from resummation at next-to-leading-logarithm accuracy. From the resummed cross section I derive analytical formulas at approximate NNLO and N$^3$LO. Total cross sections are presented for the process $b{\bar b} \rightarrow H^- W^+$ at various LHC energies. The transverse-momentum and rapidity distributions of the charged Higgs boson are also calculated.
[ { "created": "Thu, 27 Apr 2017 13:16:51 GMT", "version": "v1" }, { "created": "Wed, 20 Dec 2017 15:43:28 GMT", "version": "v2" } ]
2018-02-07
[ [ "Kidonakis", "Nikolaos", "" ] ]
I present higher-order radiative corrections from collinear and soft gluon emission for the associated production of a charged Higgs boson with a $W$ boson. The calculation uses expressions from resummation at next-to-leading-logarithm accuracy. From the resummed cross section I derive analytical formulas at approximate NNLO and N$^3$LO. Total cross sections are presented for the process $b{\bar b} \rightarrow H^- W^+$ at various LHC energies. The transverse-momentum and rapidity distributions of the charged Higgs boson are also calculated.
0704.1061
Xiao-Gang He
Kuang-Ta Chao, Xiao-Gang He, Jian-Ping Ma
Comment on "Chiral Suppression of Scalar Glueball Decay"
Comment published in Phys. Rev. Lett. 98, 149103(2007)
Phys.Rev.Lett.98:149103,2007
10.1103/PhysRevLett.98.149103
CTS-NTU-40907
hep-ph hep-ex
null
Comment on ``Chiral Suppression of Scalar Glueball Decay''
[ { "created": "Mon, 9 Apr 2007 04:10:38 GMT", "version": "v1" } ]
2008-11-26
[ [ "Chao", "Kuang-Ta", "" ], [ "He", "Xiao-Gang", "" ], [ "Ma", "Jian-Ping", "" ] ]
Comment on ``Chiral Suppression of Scalar Glueball Decay''
hep-ph/9909337
Kiselev Valery V.
V.V.Kiselev, A.I.Onishchenko
Doubly heavy baryons in sum rules of NRQCD
17 pages, LATEX file and 6 eps-figures
Nucl.Phys. B581 (2000) 432-448
10.1016/S0550-3213(00)00128-0
null
hep-ph
null
The masses of baryons containing two heavy quarks and their couplings to the corresponding quark currents are evaluated in the framework of NRQCD sum rules. The coulomb-like corrections in the system of doubly heavy diquark are taken into account, and the contribution of nonperturbative terms coming from the quark, gluon and mixed condensates as well as the product of quark and gluon condensates, is analyzed. The higher condensates destroy the factorization of baryon and diquark correlators and provide the convergency of sum rule method. As a result the accuracy of estimates is improved.
[ { "created": "Mon, 13 Sep 1999 07:52:24 GMT", "version": "v1" } ]
2009-10-31
[ [ "Kiselev", "V. V.", "" ], [ "Onishchenko", "A. I.", "" ] ]
The masses of baryons containing two heavy quarks and their couplings to the corresponding quark currents are evaluated in the framework of NRQCD sum rules. The coulomb-like corrections in the system of doubly heavy diquark are taken into account, and the contribution of nonperturbative terms coming from the quark, gluon and mixed condensates as well as the product of quark and gluon condensates, is analyzed. The higher condensates destroy the factorization of baryon and diquark correlators and provide the convergency of sum rule method. As a result the accuracy of estimates is improved.
hep-ph/9903415
Alexander Ya. Parkhomenko
N.V. Mikheev, A.Ya. Parkhomenko and L.A. Vassilevskaya (Yaroslavl State (Demidov) University, Russia)
Axion in an External Electromagnetic Field
12 pages, revtex, 6 PS figures. Error in Eq.(36) corrected, minor text changes
Phys.Rev. D60 (1999) 035001
10.1103/PhysRevD.60.035001
YARU-HE-99/02
hep-ph
null
We investigate the effective interaction of a pseudoscalar particle with two photons in an external electromagnetic field in the general case of all external particles being off the mass shell. This interaction is used to study the radiative decay $a \to \gamma \gamma$ of the axion, a pseudoscalar particle associated with the Peccei-Quinn symmetry, and the crossing channel of photon splitting $\gamma \to \gamma a$. It is shown that the external field removes the suppression associated with the smallness of the axion mass and so leads to the strong catalysis of these processes. The field-induced axion emission by photon is analyzed as one more possible source of energy losses by astrophysical objects.
[ { "created": "Fri, 19 Mar 1999 18:09:50 GMT", "version": "v1" }, { "created": "Fri, 9 Jul 1999 12:03:22 GMT", "version": "v2" } ]
2009-10-31
[ [ "Mikheev", "N. V.", "", "Yaroslavl\n State" ], [ "Parkhomenko", "A. Ya.", "", "Yaroslavl\n State" ], [ "Vassilevskaya", "L. A.", "", "Yaroslavl\n State" ] ]
We investigate the effective interaction of a pseudoscalar particle with two photons in an external electromagnetic field in the general case of all external particles being off the mass shell. This interaction is used to study the radiative decay $a \to \gamma \gamma$ of the axion, a pseudoscalar particle associated with the Peccei-Quinn symmetry, and the crossing channel of photon splitting $\gamma \to \gamma a$. It is shown that the external field removes the suppression associated with the smallness of the axion mass and so leads to the strong catalysis of these processes. The field-induced axion emission by photon is analyzed as one more possible source of energy losses by astrophysical objects.
0902.2817
Harald Fritzsch
H. Fritzsch
Flavor Mixing, Neutrino Masses and Neutrino Oscillations
4 pages
AIP Conf.Proc.1134:187-189,2009
10.1063/1.3149490
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a model for the mass matrices of the leptons. We are ablte to relate the mass eigenvalues of the charged leptons and of the neutrinos to the mxiing angles and can predict the masses of the neutrinos. We find a normal hierarchy -the masses are 0.004 eV, 0.01 eV and 0.05 eV. The atmospheric mixing angle is given by the mass ratios of the charged leptons and of the neutrinos. We find 38 degrees, consistent with the experiments. The mixing element, connecting the first neutrino with the electron, is found to be 0.05.
[ { "created": "Tue, 17 Feb 2009 01:43:42 GMT", "version": "v1" } ]
2010-04-21
[ [ "Fritzsch", "H.", "" ] ]
We study a model for the mass matrices of the leptons. We are ablte to relate the mass eigenvalues of the charged leptons and of the neutrinos to the mxiing angles and can predict the masses of the neutrinos. We find a normal hierarchy -the masses are 0.004 eV, 0.01 eV and 0.05 eV. The atmospheric mixing angle is given by the mass ratios of the charged leptons and of the neutrinos. We find 38 degrees, consistent with the experiments. The mixing element, connecting the first neutrino with the electron, is found to be 0.05.
1106.4839
Karolis Tamosiunas
Karolis Tamosiunas
Longitudinal Scaling of Elliptic Flow in Landau Hydrodynamics
7 pages 1 figure
Eur. Phys. J. A (2011) 47: 121
10.1140/epja/i2011-11121-5
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This study presents generalization of the Landau hydrodynamic solution for multiparticle production applied to non-central relativistic heavy ion collisions. Obtained results shows longitudinal scaling of elliptic flow $v_2$ as a function of rapidity shifted by beam rapidity ($y-y_{beam}$) for different energies ($\sqrt{s_{NN}}=62.4$ GeV and 200 GeV) and for different systems (Au-Au and Cu-Cu). It is argued, that the elliptic flow and its longitudinal scaling is due to the initial transverse energy density distribution and initial longitudinal thickness effect.
[ { "created": "Thu, 23 Jun 2011 21:37:59 GMT", "version": "v1" }, { "created": "Fri, 14 Oct 2011 17:53:30 GMT", "version": "v2" } ]
2011-10-17
[ [ "Tamosiunas", "Karolis", "" ] ]
This study presents generalization of the Landau hydrodynamic solution for multiparticle production applied to non-central relativistic heavy ion collisions. Obtained results shows longitudinal scaling of elliptic flow $v_2$ as a function of rapidity shifted by beam rapidity ($y-y_{beam}$) for different energies ($\sqrt{s_{NN}}=62.4$ GeV and 200 GeV) and for different systems (Au-Au and Cu-Cu). It is argued, that the elliptic flow and its longitudinal scaling is due to the initial transverse energy density distribution and initial longitudinal thickness effect.
hep-ph/0405137
Ulrich Jentschura
Ulrich D. Jentschura and Peter J. Mohr
Electron Self Energy for Higher Excited S Levels
3 pages, RevTeX, to appear in Phys. Rev. A
Phys.Rev. A69 (2004) 064103
10.1103/PhysRevA.69.064103
null
hep-ph
null
A nonperturbative numerical evaluation of the one-photon electron self energy for the 3S and 4S states with charge numbers Z=1 to 5 is described. The numerical results are in agreement with known terms in the expansion of the self energy in powers of Zalpha.
[ { "created": "Fri, 14 May 2004 16:18:46 GMT", "version": "v1" } ]
2007-05-23
[ [ "Jentschura", "Ulrich D.", "" ], [ "Mohr", "Peter J.", "" ] ]
A nonperturbative numerical evaluation of the one-photon electron self energy for the 3S and 4S states with charge numbers Z=1 to 5 is described. The numerical results are in agreement with known terms in the expansion of the self energy in powers of Zalpha.
1310.8129
Shoaib Munir
Shoaib Munir
Novel Higgs-to-125 GeV Higgs boson decays in the complex NMSSM
33 pages, 3 figures. Some improvements in text. Version to appear in PRD
Phys. Rev. D 89, 095013 (2014)
10.1103/PhysRevD.89.095013
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the Next-to-Minimal Supersymmetric Standard Model (NMSSM) a variety of parameter configurations yields a Higgs boson consistent with the one observed at the LHC. Additionally, the Higgs sector of the model can contain explicit CP-violating phases even at the tree level, in contrast with the Minimal Supersymmetric Standard Model (MSSM). In this article we present the one-loop Higgs boson mass matrix of the complex NMSSM in the renormalisation-group-improved effective potential approach. We also present the trilinear Higgs boson self-couplings as well as various partial decay widths of a generic CP-mixed Higgs boson in the model. We then analyse a very interesting phenomenological scenario wherein the decay of a relatively light pseudoscalar-like Higgs boson into ~ 125 GeV SM-like Higgs boson(s) is induced by non-zero CP-violating phases. We discuss in detail a few benchmark cases in which such a decay can contribute significantly to the production of SM-like Higgs bosons at the LHC on top of the gluon fusion process. It can thus be partially responsible for the gamma.gamma excess near 125 GeV due to the subsequent decay of the SM-like Higgs boson. Such a scenario is extremely difficult to realize in the complex MSSM and, if probed at the LHC, it could provide an indication of the non-minimal nature of supersymmetry.
[ { "created": "Wed, 30 Oct 2013 12:49:26 GMT", "version": "v1" }, { "created": "Sat, 21 Dec 2013 16:29:34 GMT", "version": "v2" }, { "created": "Mon, 5 May 2014 10:35:50 GMT", "version": "v3" } ]
2014-05-15
[ [ "Munir", "Shoaib", "" ] ]
In the Next-to-Minimal Supersymmetric Standard Model (NMSSM) a variety of parameter configurations yields a Higgs boson consistent with the one observed at the LHC. Additionally, the Higgs sector of the model can contain explicit CP-violating phases even at the tree level, in contrast with the Minimal Supersymmetric Standard Model (MSSM). In this article we present the one-loop Higgs boson mass matrix of the complex NMSSM in the renormalisation-group-improved effective potential approach. We also present the trilinear Higgs boson self-couplings as well as various partial decay widths of a generic CP-mixed Higgs boson in the model. We then analyse a very interesting phenomenological scenario wherein the decay of a relatively light pseudoscalar-like Higgs boson into ~ 125 GeV SM-like Higgs boson(s) is induced by non-zero CP-violating phases. We discuss in detail a few benchmark cases in which such a decay can contribute significantly to the production of SM-like Higgs bosons at the LHC on top of the gluon fusion process. It can thus be partially responsible for the gamma.gamma excess near 125 GeV due to the subsequent decay of the SM-like Higgs boson. Such a scenario is extremely difficult to realize in the complex MSSM and, if probed at the LHC, it could provide an indication of the non-minimal nature of supersymmetry.
hep-ph/0409157
Geza Gyorgyi
T. S. Biro, G. Gyorgyi, A. Jakovac, G. Purcsel
Non-Gibbs Particle Spectra from Thermal Equilibrium
20 pages in preprint format incl. 3 figures
null
null
null
hep-ph
null
We propose that transverse momentum spectra with power-law tails observed in ultrarelativistic heavy ion collisions can be interpreted as originating in a medium in thermal equilibrium. General conditions on the dynamical equations are formulated, leading in equilibrium to various energy distributions of particles. Starting with the linear Fokker-Planck equation we analyze conditions for Boltzmann-Gibbs, Tsallis, or other equilibrium distributions based upon the dependence of fluctuation and dissipation on the energy of the observed subsystem. RHIC neutral pion data definitely exclude Boltzmann-Gibbs distribution over the entire range of observed transverse momenta.
[ { "created": "Tue, 14 Sep 2004 15:22:28 GMT", "version": "v1" } ]
2007-05-23
[ [ "Biro", "T. S.", "" ], [ "Gyorgyi", "G.", "" ], [ "Jakovac", "A.", "" ], [ "Purcsel", "G.", "" ] ]
We propose that transverse momentum spectra with power-law tails observed in ultrarelativistic heavy ion collisions can be interpreted as originating in a medium in thermal equilibrium. General conditions on the dynamical equations are formulated, leading in equilibrium to various energy distributions of particles. Starting with the linear Fokker-Planck equation we analyze conditions for Boltzmann-Gibbs, Tsallis, or other equilibrium distributions based upon the dependence of fluctuation and dissipation on the energy of the observed subsystem. RHIC neutral pion data definitely exclude Boltzmann-Gibbs distribution over the entire range of observed transverse momenta.
hep-ph/9406222
Georg Botz
G.W. Botz, D. Bru{\ss}, O. Nachtmann
Polarization Rotation Effects due to Parity Violation in Atoms
71 pages, LaTeX (uses rotating.sty), 27 pages with figures (compressed ps-file, uuencoded) appended at the end
Annals Phys. 240 (1995) 107-202
10.1006/aphy.1995.1043
HD-THEP-94-14
hep-ph nucl-th
null
We present a study of parity (P) violating polarization rotations of atoms in external electric fields. Five different types of rotations are identified and the consequences of time reversal invariance (T) are discussed. The role played by Zeldovich's electric dipole moment of unstable states is elucidated. To calculate the effects, we use the standard model of elementary particle physics where P violation in atoms is due to the exchange of the Z boson between the quarks in the nucleus and the atomic electrons. We consider in detail hydrogen-like systems in $n=2$ states, especially $^1_1$H, $^4_2$He$^+$, and $^{12}_6$C$^{5+}$. We discuss ways to obtain in some cases large enhancement factors for the P-violating polarization rotations and show that e.g. for $^1_1$H one could in principle observe rotations as large as a few percent, where for a statistically significant result one would need a total of $10^{15}$ polarized atoms. We point out that some of our P-violating polarization rotations are very sensitive to the nuclear spin-dependent part of the P-violating Hamiltonian which receives a contribution from the polarized strange quark density in polarized nuclei.
[ { "created": "Fri, 3 Jun 1994 14:19:13 GMT", "version": "v1" } ]
2015-06-25
[ [ "Botz", "G. W.", "" ], [ "Bruß", "D.", "" ], [ "Nachtmann", "O.", "" ] ]
We present a study of parity (P) violating polarization rotations of atoms in external electric fields. Five different types of rotations are identified and the consequences of time reversal invariance (T) are discussed. The role played by Zeldovich's electric dipole moment of unstable states is elucidated. To calculate the effects, we use the standard model of elementary particle physics where P violation in atoms is due to the exchange of the Z boson between the quarks in the nucleus and the atomic electrons. We consider in detail hydrogen-like systems in $n=2$ states, especially $^1_1$H, $^4_2$He$^+$, and $^{12}_6$C$^{5+}$. We discuss ways to obtain in some cases large enhancement factors for the P-violating polarization rotations and show that e.g. for $^1_1$H one could in principle observe rotations as large as a few percent, where for a statistically significant result one would need a total of $10^{15}$ polarized atoms. We point out that some of our P-violating polarization rotations are very sensitive to the nuclear spin-dependent part of the P-violating Hamiltonian which receives a contribution from the polarized strange quark density in polarized nuclei.
1403.6810
Lukas Witkowski
Arthur Hebecker, Patrick Mangat, Fabrizio Rompineve and Lukas T. Witkowski
Dark Radiation predictions from general Large Volume Scenarios
29 pages, 5 figures; v2: typos removed, references added
JHEP 1409:140,2014
10.1007/JHEP09(2014)140
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent observations constrain the amount of Dark Radiation ($\Delta N_{\rm eff}$) and may even hint towards a non-zero value of $\Delta N_{\rm eff}$. It is by now well-known that this puts stringent constraints on the sequestered Large Volume Scenario (LVS), i.e. on LVS realisations with the Standard Model at a singularity. We go beyond this setting by considering LVS models where SM fields are realised on 7-branes in the geometric regime. As we argue, this naturally goes together with high-scale supersymmetry. The abundance of Dark Radiation is determined by the competition between the decay of the lightest modulus to axions, to the SM Higgs and to gauge fields. The latter decay channel avoids the most stringent constraints of the sequestered setting. Nevertheless, a rather robust prediction for a substantial amount of Dark Radiation can be made. This applies both to cases where the SM 4-cycles are stabilised by D-terms and are small "by accident" as well as to fibred models with the small cycles stabilised by loops. Furthermore, we analyse a closely related setting where the SM lives at a singularity but couples to the volume modulus through flavour branes. We conclude that some of the most natural LVS settings with natural values of model parameters lead to Dark Radiation predictions just below the present observational limits. Barring a discovery, rather modest improvements of present Dark Radiation bounds can rule out many of these most simple and generic variants of the LVS.
[ { "created": "Wed, 26 Mar 2014 19:44:07 GMT", "version": "v1" }, { "created": "Mon, 5 May 2014 15:31:40 GMT", "version": "v2" } ]
2014-10-01
[ [ "Hebecker", "Arthur", "" ], [ "Mangat", "Patrick", "" ], [ "Rompineve", "Fabrizio", "" ], [ "Witkowski", "Lukas T.", "" ] ]
Recent observations constrain the amount of Dark Radiation ($\Delta N_{\rm eff}$) and may even hint towards a non-zero value of $\Delta N_{\rm eff}$. It is by now well-known that this puts stringent constraints on the sequestered Large Volume Scenario (LVS), i.e. on LVS realisations with the Standard Model at a singularity. We go beyond this setting by considering LVS models where SM fields are realised on 7-branes in the geometric regime. As we argue, this naturally goes together with high-scale supersymmetry. The abundance of Dark Radiation is determined by the competition between the decay of the lightest modulus to axions, to the SM Higgs and to gauge fields. The latter decay channel avoids the most stringent constraints of the sequestered setting. Nevertheless, a rather robust prediction for a substantial amount of Dark Radiation can be made. This applies both to cases where the SM 4-cycles are stabilised by D-terms and are small "by accident" as well as to fibred models with the small cycles stabilised by loops. Furthermore, we analyse a closely related setting where the SM lives at a singularity but couples to the volume modulus through flavour branes. We conclude that some of the most natural LVS settings with natural values of model parameters lead to Dark Radiation predictions just below the present observational limits. Barring a discovery, rather modest improvements of present Dark Radiation bounds can rule out many of these most simple and generic variants of the LVS.
0712.2969
Tord Riemann
J. Gluza and T. Riemann
New results for 5-point functions
9 pages, 1 figure, to appear in Proc. of Linear Collider Workshop 2007 (LCWS 07), Hamburg (Germany), May 30 - June 3, 2007
ECONF C0705302:LOOP01,2007
null
DESY 07-013, HEPTOOLS 07-086, SFB/CPP-07-86
hep-ph
null
Bhabha scattering is one of the processes at the ILC where high precision data will be expected. The complete NNLO corrections include radiative loop corrections, with contributions from Feynman diagrams with five external legs. We take these diagrams as an example and discuss several features of the evaluation of pentagon diagrams. The tensor functions are usually reduced to simpler scalar functions. Here we study, as an alternative, the application of Mellin-Barnes representations to 5-point functions. There is no evidence for an improved numerical evaluation of their finite, physical parts. However, the approach gives interesting insights into the treatment of the IR-singularities.
[ { "created": "Tue, 18 Dec 2007 14:23:11 GMT", "version": "v1" } ]
2009-02-16
[ [ "Gluza", "J.", "" ], [ "Riemann", "T.", "" ] ]
Bhabha scattering is one of the processes at the ILC where high precision data will be expected. The complete NNLO corrections include radiative loop corrections, with contributions from Feynman diagrams with five external legs. We take these diagrams as an example and discuss several features of the evaluation of pentagon diagrams. The tensor functions are usually reduced to simpler scalar functions. Here we study, as an alternative, the application of Mellin-Barnes representations to 5-point functions. There is no evidence for an improved numerical evaluation of their finite, physical parts. However, the approach gives interesting insights into the treatment of the IR-singularities.
hep-ph/0512121
Marco Guzzi
Vincenzo Barone, Alessandro Cafarella, Claudio Coriano', Marco Guzzi and Philip Ratcliffe
Double Transverse-Spin Asymmetries in Drell-Yan Processes with Antiprotons
11 pages, 7 figures, uses elsart and feynmp (included); one new reference added
Phys.Lett.B639:483-487,2006
10.1016/j.physletb.2006.07.012
null
hep-ph
null
We present next-to-leading order predictions for double transverse-spin asymmetries in Drell--Yan dilepton production initiated by proton--antiproton scattering. The kinematic region of the proposed PAX experiment at GSI: $30\lesssim{s}\lesssim200\GeV^2$ and $2\lesssim{M}\lesssim7\GeV$ is examined. The Drell--Yan asymmetries turn out to be large, in the range 20--40%. Measuring these asymmetries would provide the cleanest determination of the quark transversity distributions.
[ { "created": "Fri, 9 Dec 2005 10:50:12 GMT", "version": "v1" }, { "created": "Sun, 18 Dec 2005 07:18:23 GMT", "version": "v2" }, { "created": "Thu, 20 Apr 2006 13:33:30 GMT", "version": "v3" }, { "created": "Fri, 19 May 2006 16:27:58 GMT", "version": "v4" }, { "created": "Wed, 24 May 2006 11:16:41 GMT", "version": "v5" } ]
2009-09-29
[ [ "Barone", "Vincenzo", "" ], [ "Cafarella", "Alessandro", "" ], [ "Coriano'", "Claudio", "" ], [ "Guzzi", "Marco", "" ], [ "Ratcliffe", "Philip", "" ] ]
We present next-to-leading order predictions for double transverse-spin asymmetries in Drell--Yan dilepton production initiated by proton--antiproton scattering. The kinematic region of the proposed PAX experiment at GSI: $30\lesssim{s}\lesssim200\GeV^2$ and $2\lesssim{M}\lesssim7\GeV$ is examined. The Drell--Yan asymmetries turn out to be large, in the range 20--40%. Measuring these asymmetries would provide the cleanest determination of the quark transversity distributions.
1311.0550
Andrey Grozin
Andrey Grozin
Effective weak Lagrangians in the Standard Model and B decays
Lectures at the Helmholtz International Summer School "Physics of Heavy Quarks and Hadrons", Dubna, July 15-18
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Weak processes (e.g., B decays) with characteristic energies <<M_W can be described by an effective theory which does not contain W, Z and other heavy particles (Higgs, t). Its Lagrangian contains four-fermion interaction operators. Essentially it is the theory proposed by Fermi and improved by Feynman, Gell-Mann, Marshak, Sudarshan.
[ { "created": "Mon, 4 Nov 2013 00:21:37 GMT", "version": "v1" } ]
2013-11-05
[ [ "Grozin", "Andrey", "" ] ]
Weak processes (e.g., B decays) with characteristic energies <<M_W can be described by an effective theory which does not contain W, Z and other heavy particles (Higgs, t). Its Lagrangian contains four-fermion interaction operators. Essentially it is the theory proposed by Fermi and improved by Feynman, Gell-Mann, Marshak, Sudarshan.
hep-ph/9206246
null
T. Han, G. Valencia and S. Willenbrock (FNAL and BNL)
Structure Function Approach to Vector-Boson Scattering in pp Collisions
11 pages, latex file, 2 figures. Figs. 2a and 2b appended as postscript files. Fig. 1 is available from the authors. Send request to HAN@FNAL VALENCIA@FNAL or SCOTTW@BNL
Phys.Rev.Lett. 69 (1992) 3274-3277
10.1103/PhysRevLett.69.3274
FERMILAB-PUB-92/171-T
hep-ph
null
We discuss weak-vector-boson scattering, at next-to-leading order in QCD, within the framework of hadronic structure functions. We use this approach to calculate the Higgs-boson production cross section via vector-boson fusion at the LHC/SSC; we find a modest increase over the leading-order prediction. We also give expressions for the distribution of vector bosons in a proton (effective-$W$ approximation) including ${\cal O} (\alpha_s)$ corrections.
[ { "created": "Wed, 24 Jun 1992 00:18:36 GMT", "version": "v1" } ]
2009-10-22
[ [ "Han", "T.", "", "FNAL and BNL" ], [ "Valencia", "G.", "", "FNAL and BNL" ], [ "Willenbrock", "S.", "", "FNAL and BNL" ] ]
We discuss weak-vector-boson scattering, at next-to-leading order in QCD, within the framework of hadronic structure functions. We use this approach to calculate the Higgs-boson production cross section via vector-boson fusion at the LHC/SSC; we find a modest increase over the leading-order prediction. We also give expressions for the distribution of vector bosons in a proton (effective-$W$ approximation) including ${\cal O} (\alpha_s)$ corrections.
2205.10904
Luca Visinelli
Youjia Wu, Sebastian Baum, Katherine Freese, Luca Visinelli, Hai-Bo Yu
Dark Stars Powered by Self-Interacting Dark Matter
11 pages, 4 figures. Matches the published version
Phys. Rev. D 106 (4) 043028 (2022)
10.1103/PhysRevD.106.043028
UTTG 12-2021; LCTP-21-18; NORDITA 2021-068
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dark matter annihilation might power the first luminous stars in the Universe. These types of stars, known as dark stars, could form in $(10^6\mathrm{-}10^8)\,M_\odot$ protohalos at redshifts $z \sim 20$, and they could be much more luminous and larger in size than ordinary stars powered by nuclear fusion. We investigate the formation of dark stars in the self-interacting dark matter (SIDM) scenario. We present a concrete particle physics model of SIDM that can simultaneously give rise to the observed dark matter density, satisfy constraints from astrophysical and terrestrial searches, and address the various small-scale problems of collisionless dark matter via the self-interactions. In this model, the power from dark matter annihilation is deposited in the baryonic gas in environments where dark stars could form. We further study the evolution of SIDM density profiles in the protohalos at $z \sim 20$. As the baryon cloud collapses due to the various cooling processes, the deepening gravitational potential can speed up gravothermal evolution of the SIDM halo, yielding sufficiently high dark matter densities for dark stars to form. We find that SIDM-powered dark stars can have similar properties, such as their luminosity and size, as dark stars predicted in collisionless dark matter models.
[ { "created": "Sun, 22 May 2022 18:54:43 GMT", "version": "v1" }, { "created": "Mon, 29 Aug 2022 15:19:02 GMT", "version": "v2" } ]
2022-08-30
[ [ "Wu", "Youjia", "" ], [ "Baum", "Sebastian", "" ], [ "Freese", "Katherine", "" ], [ "Visinelli", "Luca", "" ], [ "Yu", "Hai-Bo", "" ] ]
Dark matter annihilation might power the first luminous stars in the Universe. These types of stars, known as dark stars, could form in $(10^6\mathrm{-}10^8)\,M_\odot$ protohalos at redshifts $z \sim 20$, and they could be much more luminous and larger in size than ordinary stars powered by nuclear fusion. We investigate the formation of dark stars in the self-interacting dark matter (SIDM) scenario. We present a concrete particle physics model of SIDM that can simultaneously give rise to the observed dark matter density, satisfy constraints from astrophysical and terrestrial searches, and address the various small-scale problems of collisionless dark matter via the self-interactions. In this model, the power from dark matter annihilation is deposited in the baryonic gas in environments where dark stars could form. We further study the evolution of SIDM density profiles in the protohalos at $z \sim 20$. As the baryon cloud collapses due to the various cooling processes, the deepening gravitational potential can speed up gravothermal evolution of the SIDM halo, yielding sufficiently high dark matter densities for dark stars to form. We find that SIDM-powered dark stars can have similar properties, such as their luminosity and size, as dark stars predicted in collisionless dark matter models.
1209.1292
A. Bashir
F. Akram, A. Bashir, L.X. Gutierrez-Guerrero, B. Masud, J. Rodriguez-Quintero, C. Calcaneo-Roldan, M.E. Tejeda-Yeomans
Vacuum Polarization and Dynamical Chiral Symmetry Breaking: Phase Diagram of QED with Four-Fermion Contact Interaction
9 pages, 10 figures
null
10.1103/PhysRevD.87.013011
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study chiral symmetry breaking for fundamental charged fermions coupled electromagnetically to photons with the inclusion of four-fermion contact self-interaction term. We employ multiplicatively renormalizable models for the photon dressing function and the electron-photon vertex which minimally ensures mass anomalous dimension = 1. Vacuum polarization screens the interaction strength. Consequently, the pattern of dynamical mass generation for fermions is characterized by a critical number of massless fermion flavors above which chiral symmetry is restored. This effect is in diametrical opposition to the existence of criticality for the minimum interaction strength necessary to break chiral symmetry dynamically. The presence of virtual fermions dictates the nature of phase transition. Miransky scaling laws for the electromagnetic interaction strength and the four-fermion coupling, observed for quenched QED, are replaced by a mean-field power law behavior corresponding to a second order phase transition. These results are derived analytically by employing the bifurcation analysis, and are later confirmed numerically by solving the original non-linearized gap equation. A three dimensional critical surface is drawn to clearly depict the interplay of the relative strengths of interactions and number of flavors to separate the two phases. We also compute the beta-function and observe that it has ultraviolet fixed point. The power law part of the momentum dependence, describing the mass function, reproduces the quenched limit trivially. We also comment on the continuum limit and the triviality of QED.
[ { "created": "Thu, 6 Sep 2012 14:31:00 GMT", "version": "v1" } ]
2013-05-30
[ [ "Akram", "F.", "" ], [ "Bashir", "A.", "" ], [ "Gutierrez-Guerrero", "L. X.", "" ], [ "Masud", "B.", "" ], [ "Rodriguez-Quintero", "J.", "" ], [ "Calcaneo-Roldan", "C.", "" ], [ "Tejeda-Yeomans", "M. E.", "" ] ]
We study chiral symmetry breaking for fundamental charged fermions coupled electromagnetically to photons with the inclusion of four-fermion contact self-interaction term. We employ multiplicatively renormalizable models for the photon dressing function and the electron-photon vertex which minimally ensures mass anomalous dimension = 1. Vacuum polarization screens the interaction strength. Consequently, the pattern of dynamical mass generation for fermions is characterized by a critical number of massless fermion flavors above which chiral symmetry is restored. This effect is in diametrical opposition to the existence of criticality for the minimum interaction strength necessary to break chiral symmetry dynamically. The presence of virtual fermions dictates the nature of phase transition. Miransky scaling laws for the electromagnetic interaction strength and the four-fermion coupling, observed for quenched QED, are replaced by a mean-field power law behavior corresponding to a second order phase transition. These results are derived analytically by employing the bifurcation analysis, and are later confirmed numerically by solving the original non-linearized gap equation. A three dimensional critical surface is drawn to clearly depict the interplay of the relative strengths of interactions and number of flavors to separate the two phases. We also compute the beta-function and observe that it has ultraviolet fixed point. The power law part of the momentum dependence, describing the mass function, reproduces the quenched limit trivially. We also comment on the continuum limit and the triviality of QED.
hep-ph/0610306
Cecilia Tarantino
Cecilia Tarantino
Mixing and CP-Violation in the Littlest Higgs Model with T-Parity
4 pages, 2 figures, talk given at ICHEP 2006, 26 July - 2 August, Moscow (Russia)
null
null
null
hep-ph
null
The results of an extensive flavour physics analysis in the Littlest Higgs model with T-parity are presented. In particular, mixing and CP-violation in K^0 and B^0_{d,s} systems have been studied. Several scenarios defined by the values of mirror quark masses and the parameters of the new flavour mixing matrix V_Hd have been considered. A very interesting scenario is identified, where the well-known kaon constraints are satisfied, the sin(2beta) and Delta M_s issues are improved w.r.t the Standard Model and visible effects could be soon found in A_SL^s and S_{psi phi}.
[ { "created": "Tue, 24 Oct 2006 08:41:33 GMT", "version": "v1" } ]
2007-05-23
[ [ "Tarantino", "Cecilia", "" ] ]
The results of an extensive flavour physics analysis in the Littlest Higgs model with T-parity are presented. In particular, mixing and CP-violation in K^0 and B^0_{d,s} systems have been studied. Several scenarios defined by the values of mirror quark masses and the parameters of the new flavour mixing matrix V_Hd have been considered. A very interesting scenario is identified, where the well-known kaon constraints are satisfied, the sin(2beta) and Delta M_s issues are improved w.r.t the Standard Model and visible effects could be soon found in A_SL^s and S_{psi phi}.
1010.0916
Henry Glass
J. N. Capdevielle
Consequences of the LHC Results in the Interpretation of gamma ray families and Giant EAS Data
Talk given at XVI International Symposium on Very High Energy Cosmic Ray Interactions (ISVHECRI 2010), Batavia, IL, USA, 28 June 2 July 2010. 4 pages, 6 figures
null
null
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The earliest results of CMS exhibit central pseudo rapidity densities larger than the predictions of the different models. Introducing on this basis new guidelines with larger multiplicities of secondaries in the models implemented in the simulations, we examine the consequences in $\gamma$ ray families (spikes in rapidity distribution, coplanar emission) and very large EAS (penetration power in the atmosphere)
[ { "created": "Tue, 5 Oct 2010 15:23:51 GMT", "version": "v1" } ]
2015-03-17
[ [ "Capdevielle", "J. N.", "" ] ]
The earliest results of CMS exhibit central pseudo rapidity densities larger than the predictions of the different models. Introducing on this basis new guidelines with larger multiplicities of secondaries in the models implemented in the simulations, we examine the consequences in $\gamma$ ray families (spikes in rapidity distribution, coplanar emission) and very large EAS (penetration power in the atmosphere)
1201.5040
Igor Ivanov
I. P. Ivanov (IFPA, University of Liege, Belgium, and Institute of Mathematics, Novosibirsk, Russia)
Measuring the phase of the scattering amplitude with vortex beams
18 pages, 5 figures; v2: introduction rewritten and expanded, matches the published version
Phys. Rev. D 85, 076001 (2012)
10.1103/PhysRevD.85.076001
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that colliding vortex beams instead of (approximate) plane waves can lead to a direct measurement of how the overall phase of the plane wave scattering amplitude changes with the scattering angle. Since vortex beams are coherent superpositions of plane waves with different momenta, their scattering amplitude receives contributions from plane wave amplitudes with distinct kinematics. These contributions interfere, leading to the measurement of their phase difference. Although interference exists for any generic wave packet collision, we show that using vortex beams dramatically enhances sensitivity to the phase in comparison with non-vortex beams. Since the overall phase is inaccessible in a plane wave collision, this measurement would be of great importance for a number of topics in hadronic physics, for example, meson production in the resonance region, physics of nucleon resonances, and small angle elastic hadron scattering.
[ { "created": "Tue, 24 Jan 2012 16:38:25 GMT", "version": "v1" }, { "created": "Thu, 12 Apr 2012 15:48:39 GMT", "version": "v2" } ]
2012-04-13
[ [ "Ivanov", "I. P.", "", "IFPA, University of Liege, Belgium, and Institute of\n Mathematics, Novosibirsk, Russia" ] ]
We show that colliding vortex beams instead of (approximate) plane waves can lead to a direct measurement of how the overall phase of the plane wave scattering amplitude changes with the scattering angle. Since vortex beams are coherent superpositions of plane waves with different momenta, their scattering amplitude receives contributions from plane wave amplitudes with distinct kinematics. These contributions interfere, leading to the measurement of their phase difference. Although interference exists for any generic wave packet collision, we show that using vortex beams dramatically enhances sensitivity to the phase in comparison with non-vortex beams. Since the overall phase is inaccessible in a plane wave collision, this measurement would be of great importance for a number of topics in hadronic physics, for example, meson production in the resonance region, physics of nucleon resonances, and small angle elastic hadron scattering.
0707.0182
Agnes Mocsy
Agnes Mocsy (RBRC) and Peter Petreczky (BNL)
Predictions for Quarkonia Dissociation
2 pages, 2 figures, Presented at Heavy Ion Collisions at the LHC: Last Call for Predictions
null
null
null
hep-ph
null
We predict the upper bound on the dissociation temperatures of different quarkonium states.
[ { "created": "Mon, 2 Jul 2007 09:49:17 GMT", "version": "v1" } ]
2007-07-03
[ [ "Mocsy", "Agnes", "", "RBRC" ], [ "Petreczky", "Peter", "", "BNL" ] ]
We predict the upper bound on the dissociation temperatures of different quarkonium states.
1708.09698
Keith R. Dienes
Keith R. Dienes, Jason Kumar, Brooks Thomas, David Yaylali
Off-Diagonal Dark-Matter Phenomenology: Exploring Enhanced Complementarity Relations in Non-Minimal Dark Sectors
17 pages, LaTeX, 2 figures. Replaced to match published version
Phys. Rev. D 96, 115009 (2017)
10.1103/PhysRevD.96.115009
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In most multi-component dark-matter scenarios, two classes of processes generically contribute to event rates at experiments capable of probing the nature of the dark sector. The first class consists of "diagonal" processes involving only a single species of dark-matter particle -- processes analogous to those which arise in single-component dark-matter scenarios. By contrast, the second class consists of "off-diagonal" processes involving dark-matter particles of different species. Such processes include inelastic scattering at direct-detection experiments, asymmetric production at colliders, dark-matter co-annihilation, and certain kinds of dark-matter decay. In typical multi-component scenarios, the contributions from diagonal processes dominate over those from off-diagonal processes. Unfortunately, this tends to mask those features which are most sensitive to the multi-component nature of the dark sector. In this paper, by contrast, we point out that there exist natural, multi-component dark-sector scenarios in which the off-diagonal contributions actually dominate over the diagonal. This then gives rise to a new, enhanced picture of dark-matter complementarity. In this paper, we introduce a scenario in which this situation arises and examine the enhanced picture of dark-matter complementarity which emerges.
[ { "created": "Thu, 31 Aug 2017 13:14:52 GMT", "version": "v1" }, { "created": "Sat, 30 Dec 2017 23:01:41 GMT", "version": "v2" } ]
2018-01-03
[ [ "Dienes", "Keith R.", "" ], [ "Kumar", "Jason", "" ], [ "Thomas", "Brooks", "" ], [ "Yaylali", "David", "" ] ]
In most multi-component dark-matter scenarios, two classes of processes generically contribute to event rates at experiments capable of probing the nature of the dark sector. The first class consists of "diagonal" processes involving only a single species of dark-matter particle -- processes analogous to those which arise in single-component dark-matter scenarios. By contrast, the second class consists of "off-diagonal" processes involving dark-matter particles of different species. Such processes include inelastic scattering at direct-detection experiments, asymmetric production at colliders, dark-matter co-annihilation, and certain kinds of dark-matter decay. In typical multi-component scenarios, the contributions from diagonal processes dominate over those from off-diagonal processes. Unfortunately, this tends to mask those features which are most sensitive to the multi-component nature of the dark sector. In this paper, by contrast, we point out that there exist natural, multi-component dark-sector scenarios in which the off-diagonal contributions actually dominate over the diagonal. This then gives rise to a new, enhanced picture of dark-matter complementarity. In this paper, we introduce a scenario in which this situation arises and examine the enhanced picture of dark-matter complementarity which emerges.
hep-ph/9810455
Yakov Burdanov
Ja. V. Burdanov (1), G. V. Efimov (2), S. N. Nedelko (2) ((1) Laboratory of Nuclear Problems JINR, (2) Bogoliubov Laboratory of Theoretical Physics JINR)
(Anti-)self-dual homogeneous gluon field and axial anomaly in QCD
5 pages, Latex, 2 eps figures, talk given by S.N. Nedelko at the XI International Conference in memory of D.I. Blokhintsev "Problems of Quantum Field Theory", Dubna, 13-17 July, 1998, Russia; submitted to J. Phys. G
null
null
null
hep-ph
null
The transition form factor, decay width and charge form factor of pion are calculated within the model of induced nonlocal quark currents based on the assumption that the nonperturbative QCD vacuum can be characterized by a homogeneous (anti-)self-dual gluon field. It is shown that the interaction of the quark spin with the vacuum gluon field, being responsible in the model for the chiral symmetry breaking and the spectrum of light mesons, can also play the decisive role in forming the transition form factor and two-photon decay width. Asymptotic behavior of quark loops in the presence of the background gluon field for large momentum transfer is discussed.
[ { "created": "Thu, 22 Oct 1998 15:55:11 GMT", "version": "v1" } ]
2007-05-23
[ [ "Burdanov", "Ja. V.", "" ], [ "Efimov", "G. V.", "" ], [ "Nedelko", "S. N.", "" ] ]
The transition form factor, decay width and charge form factor of pion are calculated within the model of induced nonlocal quark currents based on the assumption that the nonperturbative QCD vacuum can be characterized by a homogeneous (anti-)self-dual gluon field. It is shown that the interaction of the quark spin with the vacuum gluon field, being responsible in the model for the chiral symmetry breaking and the spectrum of light mesons, can also play the decisive role in forming the transition form factor and two-photon decay width. Asymptotic behavior of quark loops in the presence of the background gluon field for large momentum transfer is discussed.
1206.3098
Sebastian Philipp Schneider
Sebastian P. Schneider, Bastian Kubis, Franz Niecknig
omega --> pi0 gamma* and phi --> pi0 gamma* Transition form factors in dispersion theory
11 pages, 8 figures; references updated, version published in Phys. Rev. D
Phys.Rev.D86:054013,2012
10.1103/PhysRevD.86.054013
null
hep-ph hep-ex nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the omega --> pi0 gamma* and phi --> pi0 gamma* electromagnetic transition form factors based on dispersion theory, relying solely on a previous dispersive analysis of the corresponding three-pion decays and the pion vector form factor. We compare our findings to recent measurements of the omega --> pi0 mu+ mu- decay spectrum by the NA60 collaboration, and strongly encourage experimental investigation of the Okubo-Zweig-Iizuka-forbidden phi --> pi0 l+ l- decays in order to understand the strong deviations from vector-meson dominance found in these transition form factors.
[ { "created": "Thu, 14 Jun 2012 13:09:19 GMT", "version": "v1" }, { "created": "Fri, 21 Sep 2012 12:26:41 GMT", "version": "v2" } ]
2015-03-20
[ [ "Schneider", "Sebastian P.", "" ], [ "Kubis", "Bastian", "" ], [ "Niecknig", "Franz", "" ] ]
We calculate the omega --> pi0 gamma* and phi --> pi0 gamma* electromagnetic transition form factors based on dispersion theory, relying solely on a previous dispersive analysis of the corresponding three-pion decays and the pion vector form factor. We compare our findings to recent measurements of the omega --> pi0 mu+ mu- decay spectrum by the NA60 collaboration, and strongly encourage experimental investigation of the Okubo-Zweig-Iizuka-forbidden phi --> pi0 l+ l- decays in order to understand the strong deviations from vector-meson dominance found in these transition form factors.
1005.2167
Daekyoung Kang
Pierre Artoisenet, Eric Braaten, and Daekyoung Kang
Using Line Shapes to Discriminate between Binding Mechanisms for the X(3872)
50 pages, 5 figures, 2 tables. Version published in Physical Review D
Phys.Rev.D82:014013,2010
10.1103/PhysRevD.82.014013
null
hep-ph
http://creativecommons.org/licenses/by/3.0/
We construct line shapes for the X(3872) that generalize the Flatte and zero-range line shapes that have been considered previously. These line shapes are associated with scattering amplitudes that are exactly unitary for real values of the interaction parameters and can be derived from a renormalizable quantum field theory. The new line shapes can be used to discriminate between the alternative binding mechanisms in which the X(3872) is generated either dynamically by charm meson interactions or by a resonance near the D^{*0} Dbar^0 threshold. If the resonance is identified with the P-wave charmonium state chi'_{c1}, the interaction parameters can be constrained by using charmonium phenomenology. We analyze data on the X(3872) and also data from the Belle and Babar Collaborations on the invariant mass distribution of the charm mesons from the decay B -> K + D^{*0} Dbar^0 up to 4000 MeV. Our analysis is compatible with the mechanism for the X(3872) being either a fine-tuning of charm meson interactions or the fine-tuning of the chi'_{c1} to the D^{*0} Dbar^0 threshold. In particular, the data do not exclude a separate chi'_{c1} resonance between the D^{*+} D^- threshold and 4000 MeV.
[ { "created": "Wed, 12 May 2010 18:26:34 GMT", "version": "v1" }, { "created": "Thu, 19 Aug 2010 23:29:58 GMT", "version": "v2" } ]
2015-03-17
[ [ "Artoisenet", "Pierre", "" ], [ "Braaten", "Eric", "" ], [ "Kang", "Daekyoung", "" ] ]
We construct line shapes for the X(3872) that generalize the Flatte and zero-range line shapes that have been considered previously. These line shapes are associated with scattering amplitudes that are exactly unitary for real values of the interaction parameters and can be derived from a renormalizable quantum field theory. The new line shapes can be used to discriminate between the alternative binding mechanisms in which the X(3872) is generated either dynamically by charm meson interactions or by a resonance near the D^{*0} Dbar^0 threshold. If the resonance is identified with the P-wave charmonium state chi'_{c1}, the interaction parameters can be constrained by using charmonium phenomenology. We analyze data on the X(3872) and also data from the Belle and Babar Collaborations on the invariant mass distribution of the charm mesons from the decay B -> K + D^{*0} Dbar^0 up to 4000 MeV. Our analysis is compatible with the mechanism for the X(3872) being either a fine-tuning of charm meson interactions or the fine-tuning of the chi'_{c1} to the D^{*0} Dbar^0 threshold. In particular, the data do not exclude a separate chi'_{c1} resonance between the D^{*+} D^- threshold and 4000 MeV.
2106.10018
Emanuel Ydrefors
Emanuel Ydrefors, Wayne de Paula, Jorge H Alvarenga Nogueira, Tobias Frederico and Giovanni Salm\'e
Pion electromagnetic form factor with Minkowskian dynamics
null
null
10.1016/j.physletb.2021.136494
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The pion electromagnetic form factor has been calculated for the first time from the solutions of the Bethe-Salpeter equation, obtained directly in Minkowski space by using the Nakanishi integral representation of the Bethe-Salpeter amplitude. The one-gluon exchange kernel contains as inputs the quark and gluon masses, as well as a scale parameter featuring the extended quark-gluon vertex. The range of variability of these parameters is suggested by lattice calculations. After presenting a very successful comparison with the existing data in the whole range of the momentum transfer, we show how inserting the light-front (LF) formalism in our approach allows to achieve further interesting results, like the evaluation of the LF valence form factor and a first investigation of the end-points effects.
[ { "created": "Fri, 18 Jun 2021 09:28:44 GMT", "version": "v1" } ]
2021-08-18
[ [ "Ydrefors", "Emanuel", "" ], [ "de Paula", "Wayne", "" ], [ "Nogueira", "Jorge H Alvarenga", "" ], [ "Frederico", "Tobias", "" ], [ "Salmé", "Giovanni", "" ] ]
The pion electromagnetic form factor has been calculated for the first time from the solutions of the Bethe-Salpeter equation, obtained directly in Minkowski space by using the Nakanishi integral representation of the Bethe-Salpeter amplitude. The one-gluon exchange kernel contains as inputs the quark and gluon masses, as well as a scale parameter featuring the extended quark-gluon vertex. The range of variability of these parameters is suggested by lattice calculations. After presenting a very successful comparison with the existing data in the whole range of the momentum transfer, we show how inserting the light-front (LF) formalism in our approach allows to achieve further interesting results, like the evaluation of the LF valence form factor and a first investigation of the end-points effects.
1509.06117
Zhenjun Xiao
Ya Li, Ai-Jun Ma, Wen-Fei Wang and Zhen-Jun Xiao
The $S$-wave resonance contributions to the three-body decays $B^0_{(s)}\to \eta_c f_0(X)\to \eta_c\pi^+\pi^-$ in perturbative QCD approach
13 pages, 2 figures, Some modifications. Final version to be published in EPJC
null
10.1140/epjc/s10052-016-4529-3
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we study the three-body decays $B^0/B^0_s \to \eta_c f_0(X)\to \eta_c \pi^+\pi^-$ by employing the perturbative QCD (PQCD) factorization approach. We evaluate the $S$-wave resonance contributions by using the two-pion distribution amplitude $\Phi_{\pi\pi}^{\rm S}$. The Breit-Wigner formula for the $f_0(500)$, $f_0(1500)$, and $f_0(1790)$ resonances and the Flatt\'e model for the $f_0(980)$ resonance are adopted to parameterize the time-like scalar form factors $F_{s}(\omega^2)$. We also use the D.~V.~Bugg model to parameterize the $f_0(500)$ and compare the relevant theoretical predictions from different models. We found the following results: (a) the PQCD predictions for the branching ratios are ${\cal B}(B^0\to \eta_c f_0(500)[\pi^+\pi^-])= \left ( 1.53 ^{+0.76}_{-0.35} \right ) \times 10^{-6}$ for Breit-Wigner model and ${\cal B}(B^0\to \eta_c f_0(500)[\pi^+\pi^-])= \left ( 2.31 ^{+0.96}_{-0.48} \right ) \times 10^{-6}$ for D.~V.~Bugg model; (b) $ {\cal B}(B_s\to \eta_c f_0(X)[\pi^+\pi^-] ) =\left ( 5.02^{+1.49}_{-1.08} \right )\times 10^{-5}$ when the contributions from $f_0(X)=(f_0(980),f_0(1500),f_0(1790))$ are all taken into account; and (c) The considered decays could be measured at the ongoing LHCb experiment, consequently, the formalism of two-hadron distribution amplitudes could also be tested by such experiments.
[ { "created": "Mon, 21 Sep 2015 06:24:20 GMT", "version": "v1" }, { "created": "Sun, 27 Sep 2015 09:50:17 GMT", "version": "v2" }, { "created": "Mon, 26 Sep 2016 02:04:38 GMT", "version": "v3" }, { "created": "Mon, 21 Nov 2016 12:13:09 GMT", "version": "v4" } ]
2017-01-04
[ [ "Li", "Ya", "" ], [ "Ma", "Ai-Jun", "" ], [ "Wang", "Wen-Fei", "" ], [ "Xiao", "Zhen-Jun", "" ] ]
In this paper, we study the three-body decays $B^0/B^0_s \to \eta_c f_0(X)\to \eta_c \pi^+\pi^-$ by employing the perturbative QCD (PQCD) factorization approach. We evaluate the $S$-wave resonance contributions by using the two-pion distribution amplitude $\Phi_{\pi\pi}^{\rm S}$. The Breit-Wigner formula for the $f_0(500)$, $f_0(1500)$, and $f_0(1790)$ resonances and the Flatt\'e model for the $f_0(980)$ resonance are adopted to parameterize the time-like scalar form factors $F_{s}(\omega^2)$. We also use the D.~V.~Bugg model to parameterize the $f_0(500)$ and compare the relevant theoretical predictions from different models. We found the following results: (a) the PQCD predictions for the branching ratios are ${\cal B}(B^0\to \eta_c f_0(500)[\pi^+\pi^-])= \left ( 1.53 ^{+0.76}_{-0.35} \right ) \times 10^{-6}$ for Breit-Wigner model and ${\cal B}(B^0\to \eta_c f_0(500)[\pi^+\pi^-])= \left ( 2.31 ^{+0.96}_{-0.48} \right ) \times 10^{-6}$ for D.~V.~Bugg model; (b) $ {\cal B}(B_s\to \eta_c f_0(X)[\pi^+\pi^-] ) =\left ( 5.02^{+1.49}_{-1.08} \right )\times 10^{-5}$ when the contributions from $f_0(X)=(f_0(980),f_0(1500),f_0(1790))$ are all taken into account; and (c) The considered decays could be measured at the ongoing LHCb experiment, consequently, the formalism of two-hadron distribution amplitudes could also be tested by such experiments.
hep-ph/0607134
W. James Stirling
V. A. Khoze, M. G. Ryskin and W. J. Stirling
On radiative QCD backgrounds to exclusive H -> b bbar production at the LHC and a photon collider
23 pages, 2 figures
Eur.Phys.J.C48:477-488,2006
10.1140/epjc/s10052-006-0027-3
IPPP/06/45, DCTP/06/90
hep-ph
null
Central exclusive Higgs boson production, pp -> p + H + p, at the LHC and s-channel resonant Higgs production in the photon-collider option of the ILC can provide a very important contribution to the comprehensive study of the Higgs sector. Especially attractive is the b bbar Higgs decay mode, which for certain MSSM scenarios may become the discovery channel in exclusive Higgs production at the LHC and the Photon Collider (PC). Strongly suppressed and controllable backgrounds is an obvious requirement for the success of these exclusive measurements. One of the main sources of background comes from additional gluon radiation which leads to a three-jet b bbar g final state. We perform an explicit calculation of the subprocesses gg -> q qbar g and gamma gamma -> q qbar g, where the incoming particles are required to be in a J_z=0 state and the two gluons form a colour singlet, and investigate the salient properties of these potentially important background processes.
[ { "created": "Wed, 12 Jul 2006 11:08:18 GMT", "version": "v1" } ]
2008-11-26
[ [ "Khoze", "V. A.", "" ], [ "Ryskin", "M. G.", "" ], [ "Stirling", "W. J.", "" ] ]
Central exclusive Higgs boson production, pp -> p + H + p, at the LHC and s-channel resonant Higgs production in the photon-collider option of the ILC can provide a very important contribution to the comprehensive study of the Higgs sector. Especially attractive is the b bbar Higgs decay mode, which for certain MSSM scenarios may become the discovery channel in exclusive Higgs production at the LHC and the Photon Collider (PC). Strongly suppressed and controllable backgrounds is an obvious requirement for the success of these exclusive measurements. One of the main sources of background comes from additional gluon radiation which leads to a three-jet b bbar g final state. We perform an explicit calculation of the subprocesses gg -> q qbar g and gamma gamma -> q qbar g, where the incoming particles are required to be in a J_z=0 state and the two gluons form a colour singlet, and investigate the salient properties of these potentially important background processes.
hep-ph/9306337
Giovanni
S. Frixione, M. Mangano, P. Nason and G. Ridolfi
Heavy Quark Correlations in Photon-Hadron Collisions
34 pages (LaTex) + 15 figures (topdrawer, included at the end) CERN-TH 6921/93, GEF-TH-15/1993
Nucl.Phys.B412:225-259,1994
10.1016/0550-3213(94)90501-0
null
hep-ph
null
We describe a next-to-leading-order calculation of the fully exclusive parton cross section for the photoproduction of heavy quarks. We use our result to compute quantities of interest for current fixed-target experiments. We discuss heavy-quark total cross sections, distributions and correlations.
[ { "created": "Thu, 1 Jul 1993 06:18:50 GMT", "version": "v1" } ]
2011-01-25
[ [ "Frixione", "S.", "" ], [ "Mangano", "M.", "" ], [ "Nason", "P.", "" ], [ "Ridolfi", "G.", "" ] ]
We describe a next-to-leading-order calculation of the fully exclusive parton cross section for the photoproduction of heavy quarks. We use our result to compute quantities of interest for current fixed-target experiments. We discuss heavy-quark total cross sections, distributions and correlations.
1403.6477
Gunnar S. Bali
Gunnar S. Bali, Clemens Bauer and Antonio Pineda
Model-independent determination of the gluon condensate in four-dimensional SU(3) gauge theory
5 pages, 5 figures, v2: references added, conclusions improved, contrast of figures improved, 1 typo corrected
Phys. Rev. Lett. 113, 092001 (2014)
10.1103/PhysRevLett.113.092001
null
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We determine the non-perturbative gluon condensate of four-dimensional SU(3) gauge theory in a model independent way. This is achieved by carefully subtracting high order perturbation theory results from non-perturbative lattice QCD determinations of the average plaquette. No indications of dimension two condensates are found. The value of the gluon condensate turns out to be of a similar size as the intrinsic ambiguity inherent to its definition.
[ { "created": "Tue, 25 Mar 2014 20:00:21 GMT", "version": "v1" }, { "created": "Fri, 15 Aug 2014 12:20:14 GMT", "version": "v2" } ]
2014-09-05
[ [ "Bali", "Gunnar S.", "" ], [ "Bauer", "Clemens", "" ], [ "Pineda", "Antonio", "" ] ]
We determine the non-perturbative gluon condensate of four-dimensional SU(3) gauge theory in a model independent way. This is achieved by carefully subtracting high order perturbation theory results from non-perturbative lattice QCD determinations of the average plaquette. No indications of dimension two condensates are found. The value of the gluon condensate turns out to be of a similar size as the intrinsic ambiguity inherent to its definition.
2309.10098
Giacomo Cacciapaglia
Giacomo Cacciapaglia
Systematic classification of aGUT models in five dimensions: The SU(N) kinship
28 pages, one typo corrected and one reference added
null
null
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
Asymptotic Grand Unification theories (aGUTs) in five dimensions provide a valid alternative to standard quantitative unification. We define the pathway towards viable models starting from a general unified bulk gauge symmetry. Imposing the presence of ultra-violet fixed points for both gauge and Yukawa couplings strongly limits the possibilities. Within the SU(N) kinship, we identify and characterise only two realistic minimal models, both based on a bulk SU(6) symmetry. Both models feature the generation of either up or down-type Yukawas via gauge scalars, two Higgs doublets with build-in minimal flavour violation at low energies, and conservation of baryon number. We also propose interesting avenues beyond the minimality criterion.
[ { "created": "Mon, 18 Sep 2023 19:17:31 GMT", "version": "v1" }, { "created": "Fri, 15 Dec 2023 10:51:53 GMT", "version": "v2" } ]
2023-12-18
[ [ "Cacciapaglia", "Giacomo", "" ] ]
Asymptotic Grand Unification theories (aGUTs) in five dimensions provide a valid alternative to standard quantitative unification. We define the pathway towards viable models starting from a general unified bulk gauge symmetry. Imposing the presence of ultra-violet fixed points for both gauge and Yukawa couplings strongly limits the possibilities. Within the SU(N) kinship, we identify and characterise only two realistic minimal models, both based on a bulk SU(6) symmetry. Both models feature the generation of either up or down-type Yukawas via gauge scalars, two Higgs doublets with build-in minimal flavour violation at low energies, and conservation of baryon number. We also propose interesting avenues beyond the minimality criterion.
hep-ph/9803366
Yan Qi-shu
Chao-Shang Huang and Qi-Shu Yan
$B \to X_{s} \tau^{+} \tau^{-}$ in the flipped SU(5) model
10 pages, 2 figures
Phys.Lett. B442 (1998) 209-216
10.1016/S0370-2693(98)01268-4
null
hep-ph
null
We perform a detailed study of the inclusive branching ratio and the forward-backward asymmetry of the rare B decay process $B \longrightarrow X_{s} \tau^{+} \tau^{-}$ in the flipped SU(5) model, a predictive model which has only two free parameters, plus the sign of the higgs mixing mass $\mu$, to describe mass spectrum and mixings of about 30 sparticles. In contrast to other works dealing with such a topic, our study has included the contributions of the neutral higgs bosons through penguin diagrams to this process under the context of supersymmetry. In some regions of the parameter space, due to the substantial enhancement effects coming from supersymmetry, these contributions become quite significant and could make the flavor change process $B \longrightarrow X_{s} \tau^{+} \tau^{-}$ a microscope to probe the regions of large tan$\beta$ and a window to gain an insight into new physics beyond the standard model(SM).
[ { "created": "Tue, 17 Mar 1998 13:35:03 GMT", "version": "v1" } ]
2009-10-31
[ [ "Huang", "Chao-Shang", "" ], [ "Yan", "Qi-Shu", "" ] ]
We perform a detailed study of the inclusive branching ratio and the forward-backward asymmetry of the rare B decay process $B \longrightarrow X_{s} \tau^{+} \tau^{-}$ in the flipped SU(5) model, a predictive model which has only two free parameters, plus the sign of the higgs mixing mass $\mu$, to describe mass spectrum and mixings of about 30 sparticles. In contrast to other works dealing with such a topic, our study has included the contributions of the neutral higgs bosons through penguin diagrams to this process under the context of supersymmetry. In some regions of the parameter space, due to the substantial enhancement effects coming from supersymmetry, these contributions become quite significant and could make the flavor change process $B \longrightarrow X_{s} \tau^{+} \tau^{-}$ a microscope to probe the regions of large tan$\beta$ and a window to gain an insight into new physics beyond the standard model(SM).
hep-ph/0210064
Randy Lewis
Randy Lewis, W. Wilcox and R. M. Woloshyn
The nucleon's strange electromagnetic and scalar matrix elements
24 pages, 9 figures
Phys.Rev. D67 (2003) 013003
10.1103/PhysRevD.67.013003
BU-HEPP-02/10, TRI-PP-02-15
hep-ph hep-lat nucl-th
null
Quenched lattice QCD simulations and quenched chiral perturbation theory are used together for this study of strangeness in the nucleon. Dependences of the matrix elements on strange quark mass, valence quark mass and momentum transfer are discussed in both the lattice and chiral frameworks. The combined results of this study are in good agreement with existing experimental data and predictions are made for upcoming experiments. Possible future refinements of the theoretical method are suggested.
[ { "created": "Thu, 3 Oct 2002 23:34:33 GMT", "version": "v1" } ]
2009-11-07
[ [ "Lewis", "Randy", "" ], [ "Wilcox", "W.", "" ], [ "Woloshyn", "R. M.", "" ] ]
Quenched lattice QCD simulations and quenched chiral perturbation theory are used together for this study of strangeness in the nucleon. Dependences of the matrix elements on strange quark mass, valence quark mass and momentum transfer are discussed in both the lattice and chiral frameworks. The combined results of this study are in good agreement with existing experimental data and predictions are made for upcoming experiments. Possible future refinements of the theoretical method are suggested.
1403.6233
Asmita Mukherjee
Asmita Mukherjee, Sreeraj Nair and Vikash Kumar Ojha
Quark Wigner Distributions and Orbital Angular Momentum in Light-front Dressed Quark Model
Version to appear in Phys. Rev. D
null
10.1103/PhysRevD.90.014024
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the Wigner functions for a quark target dressed with a gluon. These give a combined position and momentum space information of the quark distributions and are related to both generalized parton distributions (GPDs) and transverse momentum dependent parton distributions (TMDs). We calculate and compare the different definitions of quark orbital angular momentum in this model. We compare our results with other model calculations.
[ { "created": "Tue, 25 Mar 2014 04:55:56 GMT", "version": "v1" }, { "created": "Thu, 3 Apr 2014 08:53:41 GMT", "version": "v2" }, { "created": "Mon, 30 Jun 2014 20:05:40 GMT", "version": "v3" } ]
2015-06-19
[ [ "Mukherjee", "Asmita", "" ], [ "Nair", "Sreeraj", "" ], [ "Ojha", "Vikash Kumar", "" ] ]
We calculate the Wigner functions for a quark target dressed with a gluon. These give a combined position and momentum space information of the quark distributions and are related to both generalized parton distributions (GPDs) and transverse momentum dependent parton distributions (TMDs). We calculate and compare the different definitions of quark orbital angular momentum in this model. We compare our results with other model calculations.
1709.00808
C. Q. Geng
C.Q. Geng, Y.K. Hsiao, Chia-Wei Liu and Tien-Hsueh Tsai
Charmed Baryon Weak Decays with SU(3) Flavor Symmetry
29 pages, no figure, a typo in the table corrected
JHEP 1711, 147 (2017)
10.1007/JHEP11(2017)147
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the semileptonic and non-leptonic charmed baryon decays with $SU(3)$ flavor symmetry, where the charmed baryons can be ${\bf B}_{c}=(\Xi_c^0,\Xi_c^+,\Lambda_c^+)$, ${\bf B}'_{c}=(\Sigma_c^{(++,+,0)},\Xi_{c}^{\prime(+,0)},\Omega_c^0)$, ${\bf B}_{cc}=(\Xi_{cc}^{++},\Xi_{cc}^+,\Omega_{cc}^+)$, or ${\bf B}_{ccc}=\Omega^{++}_{ccc}$. With ${\bf B}_n^{(\prime)}$ denoted as the baryon octet (decuplet), we find that the ${\bf B}_{c}\to {\bf B}'_n\ell^+\nu_\ell$ decays are forbidden, while the $\Omega_c^0\to \Omega^-\ell^+\nu_\ell$, $\Omega_{cc}^+\to\Omega_c^0\ell^+\nu_\ell$, and $\Omega_{ccc}^{++}\to \Omega_{cc}^+\ell^+\nu_\ell$ decays are the only existing Cabibbo-allowed modes for ${\bf B}'_{c}\to {\bf B}'_n\ell^+\nu_\ell$, ${\bf B}_{cc}\to {\bf B}'_c\ell^+\nu_\ell$, and ${\bf B}_{ccc}\to {\bf B}_{cc}^{(\prime)}\ell^+\nu_\ell$, respectively. We predict the rarely studied ${\bf B}_{c}\to {\bf B}_n^{(\prime)}M$ decays, such as ${\cal B}(\Xi_c^0\to\Lambda^0\bar K^0,\,\Xi_c^+\to\Xi^0\pi^+)=(8.3\pm 0.9,8.0\pm 4.1)\times 10^{-3}$ and ${\cal B}(\Lambda_c^+\to \Delta^{++}\pi^-,\,\Xi_c^0\to\Omega^- K^+)=(5.5\pm 1.3,4.8\pm 0.5)\times 10^{-3}$. For the observation, the doubly and triply charmed baryon decays of $\Omega_{cc}^{+}\to \Xi_c^+\bar K^0$, $\Xi_{cc}^{++}\to (\Xi_c^+\pi^+$, $\Sigma_c^{++}\bar K^0)$, and $\Omega_{ccc}^{++}\to (\Xi_{cc}^{++}\bar K^0,\Omega_{cc}^+\pi^+,\Xi_c^+ D^+)$ are the favored Cabibbo-allowed decays, which are accessible to the BESIII and LHCb experiments.
[ { "created": "Mon, 4 Sep 2017 04:58:46 GMT", "version": "v1" }, { "created": "Mon, 6 Nov 2017 07:05:53 GMT", "version": "v2" }, { "created": "Sun, 6 May 2018 01:34:47 GMT", "version": "v3" } ]
2018-05-08
[ [ "Geng", "C. Q.", "" ], [ "Hsiao", "Y. K.", "" ], [ "Liu", "Chia-Wei", "" ], [ "Tsai", "Tien-Hsueh", "" ] ]
We study the semileptonic and non-leptonic charmed baryon decays with $SU(3)$ flavor symmetry, where the charmed baryons can be ${\bf B}_{c}=(\Xi_c^0,\Xi_c^+,\Lambda_c^+)$, ${\bf B}'_{c}=(\Sigma_c^{(++,+,0)},\Xi_{c}^{\prime(+,0)},\Omega_c^0)$, ${\bf B}_{cc}=(\Xi_{cc}^{++},\Xi_{cc}^+,\Omega_{cc}^+)$, or ${\bf B}_{ccc}=\Omega^{++}_{ccc}$. With ${\bf B}_n^{(\prime)}$ denoted as the baryon octet (decuplet), we find that the ${\bf B}_{c}\to {\bf B}'_n\ell^+\nu_\ell$ decays are forbidden, while the $\Omega_c^0\to \Omega^-\ell^+\nu_\ell$, $\Omega_{cc}^+\to\Omega_c^0\ell^+\nu_\ell$, and $\Omega_{ccc}^{++}\to \Omega_{cc}^+\ell^+\nu_\ell$ decays are the only existing Cabibbo-allowed modes for ${\bf B}'_{c}\to {\bf B}'_n\ell^+\nu_\ell$, ${\bf B}_{cc}\to {\bf B}'_c\ell^+\nu_\ell$, and ${\bf B}_{ccc}\to {\bf B}_{cc}^{(\prime)}\ell^+\nu_\ell$, respectively. We predict the rarely studied ${\bf B}_{c}\to {\bf B}_n^{(\prime)}M$ decays, such as ${\cal B}(\Xi_c^0\to\Lambda^0\bar K^0,\,\Xi_c^+\to\Xi^0\pi^+)=(8.3\pm 0.9,8.0\pm 4.1)\times 10^{-3}$ and ${\cal B}(\Lambda_c^+\to \Delta^{++}\pi^-,\,\Xi_c^0\to\Omega^- K^+)=(5.5\pm 1.3,4.8\pm 0.5)\times 10^{-3}$. For the observation, the doubly and triply charmed baryon decays of $\Omega_{cc}^{+}\to \Xi_c^+\bar K^0$, $\Xi_{cc}^{++}\to (\Xi_c^+\pi^+$, $\Sigma_c^{++}\bar K^0)$, and $\Omega_{ccc}^{++}\to (\Xi_{cc}^{++}\bar K^0,\Omega_{cc}^+\pi^+,\Xi_c^+ D^+)$ are the favored Cabibbo-allowed decays, which are accessible to the BESIII and LHCb experiments.
2406.08470
Roman Zhokhov
T. G. Khunjua, K. G. Klimenko, R. N. Zhokhov
Charged pion condensation and color superconductivity phenomena in chirally asymmetric dense quark matter
10 pages, 6 figures
null
null
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
In this paper, the question of the influence of color superconductivity (CSC) on the formation of a phase with condensation of charged pions in dense chirally asymmetric quark matter is studied. We consider it within the framework of the massless NJL model with a diquark interaction channel at zero temperature, but in the presence of baryon $\mu_B$, isospin $\mu_I$, chiral $\mu_{5}$ and chiral isospin $\mu_{I5}$ chemical potentials. It has been shown in the mean-field approximation that in the presence of chiral imbalance, when $\mu_{5}\ne 0$ and/or $\mu_{I5}\ne 0$, CSC phenomenon does not hinder the generation of charged pion condensation in dense quark matter even at largest baryon densities attainable in heavy ion collisions experiments and in cores of neutron stars and its mergers. So charged pion condensation in dense quark matter with chiral imbalance predicted earlier is not in a bit suppressed by the presence of CSC, highlighting the resilience of this phase in dense quark matter. This makes phase structure of dense quark matter even more rich, multifaceted and interesting, and shows that pion condensation in dense quark matter is viable phenomenon to be explored, for example, in intermediate energy heavy ion collisions experiments.
[ { "created": "Wed, 12 Jun 2024 17:55:44 GMT", "version": "v1" } ]
2024-06-13
[ [ "Khunjua", "T. G.", "" ], [ "Klimenko", "K. G.", "" ], [ "Zhokhov", "R. N.", "" ] ]
In this paper, the question of the influence of color superconductivity (CSC) on the formation of a phase with condensation of charged pions in dense chirally asymmetric quark matter is studied. We consider it within the framework of the massless NJL model with a diquark interaction channel at zero temperature, but in the presence of baryon $\mu_B$, isospin $\mu_I$, chiral $\mu_{5}$ and chiral isospin $\mu_{I5}$ chemical potentials. It has been shown in the mean-field approximation that in the presence of chiral imbalance, when $\mu_{5}\ne 0$ and/or $\mu_{I5}\ne 0$, CSC phenomenon does not hinder the generation of charged pion condensation in dense quark matter even at largest baryon densities attainable in heavy ion collisions experiments and in cores of neutron stars and its mergers. So charged pion condensation in dense quark matter with chiral imbalance predicted earlier is not in a bit suppressed by the presence of CSC, highlighting the resilience of this phase in dense quark matter. This makes phase structure of dense quark matter even more rich, multifaceted and interesting, and shows that pion condensation in dense quark matter is viable phenomenon to be explored, for example, in intermediate energy heavy ion collisions experiments.
1911.06534
Aleksandr Gorin
A. Gorin
Mass matrix parametrization for pseudo-Dirac neutrinos
Prepared for Proceedings of XXII Bled Workshop "What comes beyond the Standard models?"
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An overview of pseudo-Dirac neutrino framework is given starting from general spinor phenomenology. The framework is then tested by simulation of oscillations for T2K experiment parameters. Two possible derivations of oscillation parameters are indicated to have the same result.
[ { "created": "Fri, 15 Nov 2019 09:29:25 GMT", "version": "v1" } ]
2019-11-18
[ [ "Gorin", "A.", "" ] ]
An overview of pseudo-Dirac neutrino framework is given starting from general spinor phenomenology. The framework is then tested by simulation of oscillations for T2K experiment parameters. Two possible derivations of oscillation parameters are indicated to have the same result.
1506.08491
Jihn E. Kim
Jihn E. Kim, Soonkeon Nam
Unifying CP violations of quark and lepton sectors
10 pages with 3 figures
null
10.1140/epjc/s10052-015-3805-y
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A preliminary determination of the Dirac phase in the PMNS matrix is $\dell\approx -\frac{\pi}{2}$. A rather accurately determined Jarlskog invariant $J$ in the CKM matrix is close to the maximum. Since the phases in the CKM and PMNS matrices will be accurately determined in the future, it is an interesting problem to relate these two phases. This can be achieved in a families-unified grand unification if the weak CP violation is introduced spontaneously {\it \`a la} Froggatt and Nielsen at a high energy scale, where only one meaningful Dirac CP phase appears.
[ { "created": "Mon, 29 Jun 2015 02:40:19 GMT", "version": "v1" }, { "created": "Tue, 7 Jul 2015 17:05:47 GMT", "version": "v2" }, { "created": "Tue, 25 Aug 2015 05:20:53 GMT", "version": "v3" }, { "created": "Mon, 2 Nov 2015 13:10:00 GMT", "version": "v4" } ]
2016-02-17
[ [ "Kim", "Jihn E.", "" ], [ "Nam", "Soonkeon", "" ] ]
A preliminary determination of the Dirac phase in the PMNS matrix is $\dell\approx -\frac{\pi}{2}$. A rather accurately determined Jarlskog invariant $J$ in the CKM matrix is close to the maximum. Since the phases in the CKM and PMNS matrices will be accurately determined in the future, it is an interesting problem to relate these two phases. This can be achieved in a families-unified grand unification if the weak CP violation is introduced spontaneously {\it \`a la} Froggatt and Nielsen at a high energy scale, where only one meaningful Dirac CP phase appears.
2405.13882
Carl Beadle
Carl Beadle, Andrea Caputo and Sebastian A. R. Ellis
Resonant Conversion of Wave Dark Matter in the Ionosphere
11 pages, 4 figures
null
null
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider resonant wave-like dark matter conversion into low-frequency radio waves in the Earth's ionosphere. Resonant conversion occurs when the dark matter mass and the plasma frequency coincide, defining a range $m_{ \text{DM} } \sim 10^{-9} - 10^{-8}$ eV where this approach is best suited. Owing to the non-relativistic nature of dark matter and the typical variational scale of the Earth's ionosphere, the standard linearized approach to computing dark matter conversion is not suitable. We therefore solve a second-order boundary-value problem, effectively framing the ionosphere as a driven cavity filled with a positionally-varying plasma. An electrically-small dipole antenna targeting the generated radio waves can be orders of magnitude more sensitive to dark photon and axion-like particle dark matter in the relevant mass range. The present study opens up a promising way of testing hitherto unexplored parameter space which could be further improved with a dedicated instrument.
[ { "created": "Wed, 22 May 2024 18:00:00 GMT", "version": "v1" } ]
2024-05-24
[ [ "Beadle", "Carl", "" ], [ "Caputo", "Andrea", "" ], [ "Ellis", "Sebastian A. R.", "" ] ]
We consider resonant wave-like dark matter conversion into low-frequency radio waves in the Earth's ionosphere. Resonant conversion occurs when the dark matter mass and the plasma frequency coincide, defining a range $m_{ \text{DM} } \sim 10^{-9} - 10^{-8}$ eV where this approach is best suited. Owing to the non-relativistic nature of dark matter and the typical variational scale of the Earth's ionosphere, the standard linearized approach to computing dark matter conversion is not suitable. We therefore solve a second-order boundary-value problem, effectively framing the ionosphere as a driven cavity filled with a positionally-varying plasma. An electrically-small dipole antenna targeting the generated radio waves can be orders of magnitude more sensitive to dark photon and axion-like particle dark matter in the relevant mass range. The present study opens up a promising way of testing hitherto unexplored parameter space which could be further improved with a dedicated instrument.
1411.1983
Redamy Perez Ramos
Redamy P\'erez-Ramos and Thorsten Renk
A Monte Carlo study of jet fragmentation functions in PbPb and pp collisions at sqrt{s}=2.76 TeV
13 pages and 6 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The parton-to-hadron fragmentation functions (FFs) obtained from the YaJEM and PYTHIA6 Monte Carlo event generators, are studied for jets produced in a strongly-interacting medium and in the QCD "vacuum" respectively. The medium modifications are studied with the YaJEM code in two different scenarios by (i) accounting for the medium induced virtuality DeltaQ^2 transferred to the leading parton from the medium, and (ii) by altering the infrared sector in the Borghini-Wiedemann approach. The results of our simulations are compared to experimental jet data measured by the CMS experiment in PbPb and pp collisions at a center-of-mass energy of 2.76 TeV. Though both scenarios qualitatively describe the shape and main physical features of the FFs, the ratios are in much better agreement with the first scenario. Results are presented for the Monte Carlo FFs obtained for different parton flavours (quark and gluon) and accounting exactly, or not, for the experimental jet reconstruction biases.
[ { "created": "Fri, 7 Nov 2014 17:09:12 GMT", "version": "v1" } ]
2014-11-10
[ [ "Pérez-Ramos", "Redamy", "" ], [ "Renk", "Thorsten", "" ] ]
The parton-to-hadron fragmentation functions (FFs) obtained from the YaJEM and PYTHIA6 Monte Carlo event generators, are studied for jets produced in a strongly-interacting medium and in the QCD "vacuum" respectively. The medium modifications are studied with the YaJEM code in two different scenarios by (i) accounting for the medium induced virtuality DeltaQ^2 transferred to the leading parton from the medium, and (ii) by altering the infrared sector in the Borghini-Wiedemann approach. The results of our simulations are compared to experimental jet data measured by the CMS experiment in PbPb and pp collisions at a center-of-mass energy of 2.76 TeV. Though both scenarios qualitatively describe the shape and main physical features of the FFs, the ratios are in much better agreement with the first scenario. Results are presented for the Monte Carlo FFs obtained for different parton flavours (quark and gluon) and accounting exactly, or not, for the experimental jet reconstruction biases.
1512.07260
Joao Pacheco B. C. de Melo Dr.
J. P. B. C. de Melo (Laboratorio de Fisica Teorica e Computacional, Universidade Cruzeiro do Sul), Isthiaq Ahmed (Laboratorio de Fisica Teorica e Computacional, Universidade Cruzeiro do Sul and National Center for Physics, Quaidi-i-Azam University Campus), Kazuo Tsushima (Laboratorio de Fisica Teorica e Computacional, Universidade Cruzeiro do Sul)
Parton Distribution in Pseudoscalar Mesons with a Light-Front Constituent Quark Model
Latex file, 4 figures, use AIP style. Small mistakes are corrected, (Eq.(5) and Eq.(6))
null
10.1063/1.4949465
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the distribution amplitudes of the pion and kaon in the light-front constituent quark model with the symmetric quark-bound state vertex function. In the calculation we explicitly include the flavor-SU(3) symmetry breaking effect in terms of the constituent quark masses of the up (down) and strange quarks. To calculate the kaon parton distribution functions~(PDFs), we use both the conditions in the light-cone wave function, i.e., when $\bar{s}$ quark is on-shell, and when $u$ quark is on-shell, and make a comparison between them. The kaon PDFs calculated in the two different conditions clearly show asymmetric behaviour due to the flavor SU(3)-symmetry breaking implemented by the quark masses.
[ { "created": "Tue, 22 Dec 2015 21:04:40 GMT", "version": "v1" }, { "created": "Wed, 17 Feb 2016 21:42:21 GMT", "version": "v2" } ]
2016-06-22
[ [ "de Melo", "J. P. B. C.", "", "Laboratorio de Fisica Teorica e Computacional,\n Universidade Cruzeiro do Sul" ], [ "Ahmed", "Isthiaq", "", "Laboratorio de Fisica Teorica e\n Computacional, Universidade Cruzeiro do Sul and National Center for Physics,\n Quaidi-i-Azam University Campus" ], [ "Tsushima", "Kazuo", "", "Laboratorio de Fisica\n Teorica e Computacional, Universidade Cruzeiro do Sul" ] ]
We compute the distribution amplitudes of the pion and kaon in the light-front constituent quark model with the symmetric quark-bound state vertex function. In the calculation we explicitly include the flavor-SU(3) symmetry breaking effect in terms of the constituent quark masses of the up (down) and strange quarks. To calculate the kaon parton distribution functions~(PDFs), we use both the conditions in the light-cone wave function, i.e., when $\bar{s}$ quark is on-shell, and when $u$ quark is on-shell, and make a comparison between them. The kaon PDFs calculated in the two different conditions clearly show asymmetric behaviour due to the flavor SU(3)-symmetry breaking implemented by the quark masses.
1709.07227
Felix Riehn
Felix Riehn, Hans P. Dembinski, Ralph Engel, Anatoli Fedynitch, Thomas K. Gaisser, Todor Stanev
The hadronic interaction model SIBYLL 2.3c and Feynman scaling
35th International Cosmic Ray Conference
PoS ICRC2017 (2017) 301
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Monte Carlo model Sibyll has been designed for efficient simulation of hadronic multiparticle production up to the highest energies as needed for interpreting cosmic ray measurements. For more than 15 years, version 2.1 of Sibyll has been one of the standard models for air shower simulation. Motivated by data of LHC and fixed-target experiments and a better understanding of the phenomenology of hadronic interactions, we have developed an improved version of this model, version 2.3, which has been released in 2016. In this contribution we present a revised version of this model, called Sibyll 2.3c, that is further improved by adjusting particle production spectra to match the expectation of Feynman scaling in the fragmentation region. After a brief introduction to the changes implemented in Sibyll 2.3 and 2.3c with respect to Sibyll 2.1, the current predictions of the model for the depth of shower maximum, the number of muons at ground, and the energy spectrum of muons in extensive air showers are presented.
[ { "created": "Thu, 21 Sep 2017 09:25:42 GMT", "version": "v1" } ]
2017-09-25
[ [ "Riehn", "Felix", "" ], [ "Dembinski", "Hans P.", "" ], [ "Engel", "Ralph", "" ], [ "Fedynitch", "Anatoli", "" ], [ "Gaisser", "Thomas K.", "" ], [ "Stanev", "Todor", "" ] ]
The Monte Carlo model Sibyll has been designed for efficient simulation of hadronic multiparticle production up to the highest energies as needed for interpreting cosmic ray measurements. For more than 15 years, version 2.1 of Sibyll has been one of the standard models for air shower simulation. Motivated by data of LHC and fixed-target experiments and a better understanding of the phenomenology of hadronic interactions, we have developed an improved version of this model, version 2.3, which has been released in 2016. In this contribution we present a revised version of this model, called Sibyll 2.3c, that is further improved by adjusting particle production spectra to match the expectation of Feynman scaling in the fragmentation region. After a brief introduction to the changes implemented in Sibyll 2.3 and 2.3c with respect to Sibyll 2.1, the current predictions of the model for the depth of shower maximum, the number of muons at ground, and the energy spectrum of muons in extensive air showers are presented.
1512.00279
Tolga Altinoluk
Tolga Altinoluk and Adrian Dumitru
Particle production in high-energy collisions beyond the shockwave limit
11 pages, 5 figures, corrected the result for the vertex, added derivation of two-gluon production cross section, published version
Phys. Rev. D 94, 074032 (2016)
10.1103/PhysRevD.94.074032
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute next to eikonal (NE) and next to next to eikonal (NNE) corrections to the Lipatov vertex due to a finite target thickness. These arise from electric field insertions into the eikonal Wilson lines. We then derive a $k_T$-factorization formula for single inclusive gluon production at NNE accuracy and find that nuclear effects are absent. We also analyze NNE corrections to two-gluon production where some of the contributions are found to exhibit corrections proportional to $A^{2/3}$.
[ { "created": "Tue, 1 Dec 2015 14:59:11 GMT", "version": "v1" }, { "created": "Wed, 6 Jul 2016 08:19:11 GMT", "version": "v2" }, { "created": "Mon, 24 Oct 2016 09:53:04 GMT", "version": "v3" } ]
2016-10-26
[ [ "Altinoluk", "Tolga", "" ], [ "Dumitru", "Adrian", "" ] ]
We compute next to eikonal (NE) and next to next to eikonal (NNE) corrections to the Lipatov vertex due to a finite target thickness. These arise from electric field insertions into the eikonal Wilson lines. We then derive a $k_T$-factorization formula for single inclusive gluon production at NNE accuracy and find that nuclear effects are absent. We also analyze NNE corrections to two-gluon production where some of the contributions are found to exhibit corrections proportional to $A^{2/3}$.
1808.04010
Avik Banerjee
Avik Banerjee, Subhajit Ghosh, Tirtha Sankar Ray
Clockworked VEVs and Neutrino Mass
13 pages, 2 captioned figures, 1 table, further clarifications added in text, references updated, matches version published in JHEP
JHEP 1811 (2018) 075
10.1007/JHEP11(2018)075
TIFR/TH/18-44
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we present an augmented version of the Abelian scalar clockwork model to generate geometrically suppressed vacuum expectation values (vev) of the pseudo Nambu-Goldstone bosons, that we call the clockworked vevs. We briefly comment on generalization of the setup and possible 5D UV realizations. We demonstrate how tiny neutrino mass can be generated by clockworking a weak scale vev.
[ { "created": "Sun, 12 Aug 2018 22:35:51 GMT", "version": "v1" }, { "created": "Wed, 14 Nov 2018 10:28:27 GMT", "version": "v2" } ]
2018-11-15
[ [ "Banerjee", "Avik", "" ], [ "Ghosh", "Subhajit", "" ], [ "Ray", "Tirtha Sankar", "" ] ]
In this paper we present an augmented version of the Abelian scalar clockwork model to generate geometrically suppressed vacuum expectation values (vev) of the pseudo Nambu-Goldstone bosons, that we call the clockworked vevs. We briefly comment on generalization of the setup and possible 5D UV realizations. We demonstrate how tiny neutrino mass can be generated by clockworking a weak scale vev.
0901.2260
Alexander Laschka
Alexander Laschka, Norbert Kaiser, Wolfram Weise
The heavy quark-antiquark potential from lattice and perturbative QCD
2 pages, 2 figures, Proceedings of the 8th Conference on Quark Confinement and the Hadron Spectrum, September 1-6, 2008, Mainz, Germany
PoS Confinement8:168,2008
null
TUM/T39-09-02
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The heavy quark-antiquark potential in perturbative QCD is subject to ambiguities. We show how to derive a well-defined and stable short-distance potential that can be matched to results from lattice QCD simulations at intermediate distances. The static potential as well as the order 1/m potential are discussed.
[ { "created": "Thu, 15 Jan 2009 13:31:46 GMT", "version": "v1" } ]
2009-06-25
[ [ "Laschka", "Alexander", "" ], [ "Kaiser", "Norbert", "" ], [ "Weise", "Wolfram", "" ] ]
The heavy quark-antiquark potential in perturbative QCD is subject to ambiguities. We show how to derive a well-defined and stable short-distance potential that can be matched to results from lattice QCD simulations at intermediate distances. The static potential as well as the order 1/m potential are discussed.
hep-ph/9510386
Dittmaier
S.Dittmaier, D.Schildknecht and G.Weiglein
On the Observation of Bosonic Loop Corrections in Electroweak Precision Experiments
20 pages latex, 6 postscript figures included, revised version, to appear in Nucl.Phys.B
Nucl.Phys. B465 (1996) 3-22
10.1016/0550-3213(96)00016-8
BI-TP 95/31
hep-ph
null
We investigate the structure of the experimentally significant electroweak bosonic loop corrections to the leptonic weak mixing angle, the leptonic Z-boson decay width, and the W-boson mass. It is shown that the bosonic corrections that have a sizable effect at the present level of experimental accuracy are directly related to the use of the Fermi constant G_F as input parameter for analyzing the LEP observables. Indeed, if the (theoretical value of the) leptonic width of the W boson is used as input parameter instead of the low-energy parameter G_F determined from muon decay, fermion-loop corrections are sufficient for compatibility between theory and experiment.
[ { "created": "Tue, 24 Oct 1995 14:34:59 GMT", "version": "v1" }, { "created": "Wed, 31 Jan 1996 12:22:19 GMT", "version": "v2" } ]
2009-10-28
[ [ "Dittmaier", "S.", "" ], [ "Schildknecht", "D.", "" ], [ "Weiglein", "G.", "" ] ]
We investigate the structure of the experimentally significant electroweak bosonic loop corrections to the leptonic weak mixing angle, the leptonic Z-boson decay width, and the W-boson mass. It is shown that the bosonic corrections that have a sizable effect at the present level of experimental accuracy are directly related to the use of the Fermi constant G_F as input parameter for analyzing the LEP observables. Indeed, if the (theoretical value of the) leptonic width of the W boson is used as input parameter instead of the low-energy parameter G_F determined from muon decay, fermion-loop corrections are sufficient for compatibility between theory and experiment.
0802.3172
Chhanda Samanta Prof.
C. Samanta, P. Roy Chowdhury and D.N. Basu
Lambda hyperonic effect on the normal driplines
6 pages, 4 tables, 0 figure
J.Phys.G35:065101,2008
10.1088/0954-3899/35/6/065101
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A generalized mass formula is used to calculate the neutron and proton drip lines of normal and lambda hypernuclei treating non-strange and strange nuclei on the same footing. Calculations suggest existence of several bound hypernuclei whose normal cores are unbound. Addition of Lambda or, Lambda-Lambda hyperon(s) to a normal nucleus is found to cause shifts of the neutron and proton driplines from their conventional limits.
[ { "created": "Thu, 21 Feb 2008 17:38:30 GMT", "version": "v1" } ]
2008-04-23
[ [ "Samanta", "C.", "" ], [ "Chowdhury", "P. Roy", "" ], [ "Basu", "D. N.", "" ] ]
A generalized mass formula is used to calculate the neutron and proton drip lines of normal and lambda hypernuclei treating non-strange and strange nuclei on the same footing. Calculations suggest existence of several bound hypernuclei whose normal cores are unbound. Addition of Lambda or, Lambda-Lambda hyperon(s) to a normal nucleus is found to cause shifts of the neutron and proton driplines from their conventional limits.
0806.3985
Arif Akhundov A.
A.A.Akhundov
QED Radiative Corrections to Deep Inelastic Scattering at HERA
10 pages, 4 figures, Proceedings of XXI International Meeting on Fundamental Physics - Physics at HERA, Miraflores de la Sierra, Madrid, Spain, 9-15 May 1993; World Scientific Publishing (Singapore), Editors: F. Barreiro, L. Hervas and L. Labarga (1994), p. 16-25
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The numerical study of QED radiative corrections in the low x region for the H1 experiment at HERA was performed. The analytical program TERAD91 was used to obtain the values of the radiative correction factor for the first measurement of the proton structure function F2(x,Q2) in the range x= 10^{-2} - 10^{-4} and 5 < Q2 < 80 GeV2.
[ { "created": "Wed, 25 Jun 2008 08:47:10 GMT", "version": "v1" }, { "created": "Thu, 17 Jul 2008 21:18:52 GMT", "version": "v2" } ]
2008-07-18
[ [ "Akhundov", "A. A.", "" ] ]
The numerical study of QED radiative corrections in the low x region for the H1 experiment at HERA was performed. The analytical program TERAD91 was used to obtain the values of the radiative correction factor for the first measurement of the proton structure function F2(x,Q2) in the range x= 10^{-2} - 10^{-4} and 5 < Q2 < 80 GeV2.
1401.7613
Marco Ruggieri
G. L. Guardo, V. Greco and M. Ruggieri
Energy density fluctuations in Early Universe
4 pages, 2 figures. Talk given at Sventh European Summer School on Experimental Nuclear Astrophysics, 15-27 September 2013, Santa Tecla (CT) - Italy
null
10.1063/1.4875317
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The primordial nucleosinthesys of the element can be influenced by the transitions of phase that take place after the Big Bang, such as the QCD transition. In order to study the effect of this phase transition, in this work we compute the time evolution of thermodynamical quantities of the early universe, focusing on temperature and energy density fluctuations, by solving the relevant equations of motion using as input the lattice QCD equation of state to describe the strongly interacting matter in the early universe plasma. We also study the effect of a primordial strong magnetic field by means of a phenomenological equation of state. Our results show that small inhomogeneities of strongly interacting matter in the early Universe are moderately damped during the crossover.
[ { "created": "Wed, 29 Jan 2014 18:19:54 GMT", "version": "v1" } ]
2015-06-18
[ [ "Guardo", "G. L.", "" ], [ "Greco", "V.", "" ], [ "Ruggieri", "M.", "" ] ]
The primordial nucleosinthesys of the element can be influenced by the transitions of phase that take place after the Big Bang, such as the QCD transition. In order to study the effect of this phase transition, in this work we compute the time evolution of thermodynamical quantities of the early universe, focusing on temperature and energy density fluctuations, by solving the relevant equations of motion using as input the lattice QCD equation of state to describe the strongly interacting matter in the early universe plasma. We also study the effect of a primordial strong magnetic field by means of a phenomenological equation of state. Our results show that small inhomogeneities of strongly interacting matter in the early Universe are moderately damped during the crossover.
1203.0572
Nathaniel Craig
Nathaniel Craig, Savas Dimopoulos, Tony Gherghetta
Split families unified
21 pages, 4 figures
null
10.1007/JHEP04(2012)116
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a simple supersymmetric model of split families consistent with flavor limits that preserves the successful prediction of gauge coupling unification and naturally accounts for the Higgs mass. The model provides an intricate connection between the Standard Model flavor hierarchy, supersymmetric flavor problem, unification and the Higgs mass. In particular unification favors a naturally large Higgs mass from D-term corrections to the quartic couplings in the Higgs potential. The unification scale is lowered with a stable proton that can account for the success of b-tau Yukawa coupling unification. The sparticle spectrum is similar to that of natural supersymmetry, as motivated by the supersymmetric flavor problem and recent LHC bounds, with a heavy scalar particle spectrum except for a moderately light stop required for viable electroweak symmetry breaking. Finally, Higgs production and decays, NLSP decays, and new states associated with extending the Standard Model gauge group above the TeV scale provide signatures for experimental searches at the LHC.
[ { "created": "Fri, 2 Mar 2012 21:05:57 GMT", "version": "v1" } ]
2015-06-04
[ [ "Craig", "Nathaniel", "" ], [ "Dimopoulos", "Savas", "" ], [ "Gherghetta", "Tony", "" ] ]
We present a simple supersymmetric model of split families consistent with flavor limits that preserves the successful prediction of gauge coupling unification and naturally accounts for the Higgs mass. The model provides an intricate connection between the Standard Model flavor hierarchy, supersymmetric flavor problem, unification and the Higgs mass. In particular unification favors a naturally large Higgs mass from D-term corrections to the quartic couplings in the Higgs potential. The unification scale is lowered with a stable proton that can account for the success of b-tau Yukawa coupling unification. The sparticle spectrum is similar to that of natural supersymmetry, as motivated by the supersymmetric flavor problem and recent LHC bounds, with a heavy scalar particle spectrum except for a moderately light stop required for viable electroweak symmetry breaking. Finally, Higgs production and decays, NLSP decays, and new states associated with extending the Standard Model gauge group above the TeV scale provide signatures for experimental searches at the LHC.
2305.10409
Krzysztof Jod{\l}owski
Krzysztof Jod{\l}owski
Looking forward to photon-coupled long-lived particles II: dark axion portal
11 pages, 3 figures, 1 table
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The dark axion portal is a dimension-5 coupling between an axion-like particle (ALP), a photon, and a dark photon, which is one of the targets of the intensity frontier searches looking for $\sim\,$sub-GeV long-lived particles (LLPs). In this work, we re-examine the limits set by existing detectors such as CHARM and NuCal, and by future experiments such as FASER2, MATHUSLA, and SHiP. We extend previous works by i) considering several mass regimes of the Dark Sector (DS) particles, leading to an extended lifetime regime of the unstable species, ii) including LLPs production occurring in previously neglected vector meson decays that actually dominate the LLP yield, and iii) by implementing secondary LLP production. It takes place by Primakoff-like upscattering of lighter DS species into LLP on tungsten layers of neutrino emulsion detector FASER$\nu$2. This process will allow FASER2 to cover a significant portion of the $\gamma c\tau \sim 1\,m$ region of the parameter space that is otherwise difficult to cover due to the large ($\sim O(100)\,m$) distance between the primary LLP production point and the decay vessel, where LLP decays take place, which is required in typical beam-dumb experiments for SM background suppression.
[ { "created": "Wed, 17 May 2023 17:47:53 GMT", "version": "v1" } ]
2023-05-18
[ [ "Jodłowski", "Krzysztof", "" ] ]
The dark axion portal is a dimension-5 coupling between an axion-like particle (ALP), a photon, and a dark photon, which is one of the targets of the intensity frontier searches looking for $\sim\,$sub-GeV long-lived particles (LLPs). In this work, we re-examine the limits set by existing detectors such as CHARM and NuCal, and by future experiments such as FASER2, MATHUSLA, and SHiP. We extend previous works by i) considering several mass regimes of the Dark Sector (DS) particles, leading to an extended lifetime regime of the unstable species, ii) including LLPs production occurring in previously neglected vector meson decays that actually dominate the LLP yield, and iii) by implementing secondary LLP production. It takes place by Primakoff-like upscattering of lighter DS species into LLP on tungsten layers of neutrino emulsion detector FASER$\nu$2. This process will allow FASER2 to cover a significant portion of the $\gamma c\tau \sim 1\,m$ region of the parameter space that is otherwise difficult to cover due to the large ($\sim O(100)\,m$) distance between the primary LLP production point and the decay vessel, where LLP decays take place, which is required in typical beam-dumb experiments for SM background suppression.
hep-ph/9507397
null
Diego J. Castano, Daniel Z. Freedman, and Cristina Manuel
Consequences of Supergravity with Gauged $\rm U(1)_R$ Symmetry
36 pages, plain LaTeX, all macros included, no figures
Nucl.Phys.B461:50-70,1996
10.1016/0550-3213(95)00584-6
MIT-CTP-2454
hep-ph hep-th
null
The structure of gauged R supergravity Lagrangians is reviewed, and we consider models with a hidden sector plus light fields of the MSSM. A simple potential for the hidden sector is presented which has a global minimum with zero cosmological constant and spontaneously broken SUSY and R-symmetry. The $\rm U(1)_R$ vector multiplet acquires a Planck scale mass through the Higgs mechanism, and it decouples at low energy. Due to very interesting cancellations, the $\rm U(1)_R$ D-terms also drop out at low energy. Thus no direct effects of the gauging of R-symmetry remain in the low energy effective Lagrangian, and this result is model independent, requiring only that R-symmetry be broken at the Planck scale and $<D> = 0$, where $D$ is the auxiliary field of the $\rm U(1)_R$ vector multiplet. The low energy theory is fairly conventional with soft SUSY breaking terms for the MSSM fields. As a remnant of the gauging of R-symmetry, it also contains light fields, some required to cancel R-anomalies and others from the hidden sector.
[ { "created": "Mon, 24 Jul 1995 16:53:49 GMT", "version": "v1" } ]
2009-10-08
[ [ "Castano", "Diego J.", "" ], [ "Freedman", "Daniel Z.", "" ], [ "Manuel", "Cristina", "" ] ]
The structure of gauged R supergravity Lagrangians is reviewed, and we consider models with a hidden sector plus light fields of the MSSM. A simple potential for the hidden sector is presented which has a global minimum with zero cosmological constant and spontaneously broken SUSY and R-symmetry. The $\rm U(1)_R$ vector multiplet acquires a Planck scale mass through the Higgs mechanism, and it decouples at low energy. Due to very interesting cancellations, the $\rm U(1)_R$ D-terms also drop out at low energy. Thus no direct effects of the gauging of R-symmetry remain in the low energy effective Lagrangian, and this result is model independent, requiring only that R-symmetry be broken at the Planck scale and $<D> = 0$, where $D$ is the auxiliary field of the $\rm U(1)_R$ vector multiplet. The low energy theory is fairly conventional with soft SUSY breaking terms for the MSSM fields. As a remnant of the gauging of R-symmetry, it also contains light fields, some required to cancel R-anomalies and others from the hidden sector.
hep-ph/0512261
Alfonso Zerwekh
Alfonso R. Zerwekh (Universidad Austral de Chile)
Associate Higgs and Gauge Boson Production at Hadron Colliders in a Model with Vector Resonances
null
Eur.Phys.J.C46:791-795,2006
10.1140/epjc/s2006-02518-6
null
hep-ph
null
Motivated by new models of dynamical electroweak symmetry breaking that predict a light composite higgs boson, we build an effective lagrangian which describes the Standard Model (with a light Higgs) and vector resonances. We compute the cross section for the associate production of a higgs and a gauge boson. For some values of model parameters we find that the cross section is significantly enhanced with respect to the Standard Model. This enhancement is similar at the LHC and the Tevatron for the same range of resonance mass.
[ { "created": "Tue, 20 Dec 2005 19:49:55 GMT", "version": "v1" }, { "created": "Mon, 20 Feb 2006 14:02:20 GMT", "version": "v2" } ]
2008-11-26
[ [ "Zerwekh", "Alfonso R.", "", "Universidad Austral de Chile" ] ]
Motivated by new models of dynamical electroweak symmetry breaking that predict a light composite higgs boson, we build an effective lagrangian which describes the Standard Model (with a light Higgs) and vector resonances. We compute the cross section for the associate production of a higgs and a gauge boson. For some values of model parameters we find that the cross section is significantly enhanced with respect to the Standard Model. This enhancement is similar at the LHC and the Tevatron for the same range of resonance mass.
1912.12046
Bing-Dong Wan
Bing-Dong Wan, Liang Tang, Cong-Feng Qiao
Hidden-bottom and -charm hexaquark states in QCD sum rules
17 pages, 3 figures
null
10.1140/epjc/s10052-020-7701-8
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we investigate the spectra of the prospective hidden-bottom and -charm hexaquark states with quantum numbers $J^{PC }= 0^{++}$, $0^{-+}$, $1^{++}$ and $1^{--}$ in the framework of QCD sum rules. By constructing appropriate interpreting currents, the QCD sum rules analyses are performed up to dimension 12 of the condensates. Results indicate that there exist two possible baryonium states in $b$-quark sector with masses $11.84 \pm 0.22$ GeV and $11.72 \pm 0.26$ GeV for $0^{++}$ and $1^{--}$, respectively. The corresponding hidden-charm partners are found lying respectively at $5.19 \pm 0.24$ GeV and $4.78 \pm 0.23$ GeV. Note that these baryonium states are all above the dibaryon thresholds, which enables their dominant decay modes could be measured at BESIII, BELLEII, and LHCb detectors.
[ { "created": "Fri, 27 Dec 2019 10:15:12 GMT", "version": "v1" }, { "created": "Sat, 15 Feb 2020 06:43:29 GMT", "version": "v2" } ]
2020-02-18
[ [ "Wan", "Bing-Dong", "" ], [ "Tang", "Liang", "" ], [ "Qiao", "Cong-Feng", "" ] ]
In this paper, we investigate the spectra of the prospective hidden-bottom and -charm hexaquark states with quantum numbers $J^{PC }= 0^{++}$, $0^{-+}$, $1^{++}$ and $1^{--}$ in the framework of QCD sum rules. By constructing appropriate interpreting currents, the QCD sum rules analyses are performed up to dimension 12 of the condensates. Results indicate that there exist two possible baryonium states in $b$-quark sector with masses $11.84 \pm 0.22$ GeV and $11.72 \pm 0.26$ GeV for $0^{++}$ and $1^{--}$, respectively. The corresponding hidden-charm partners are found lying respectively at $5.19 \pm 0.24$ GeV and $4.78 \pm 0.23$ GeV. Note that these baryonium states are all above the dibaryon thresholds, which enables their dominant decay modes could be measured at BESIII, BELLEII, and LHCb detectors.
1510.03762
Diego Aristizabal
D. Aristizabal Sierra
Radiative origin of neutrino masses
7 pages, 3 figures. Contribution to the proceedings of the XXXIX International Conference of Theoretical Physics "Matter to the Deepest", Ustron, Poland, September 13-18, 2015
null
10.5506/APhysPolB.46.2311
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Mechanisms for Majorana neutrino mass generation can be classified according to the level at which the Weinberg operator is generated. The different possibilities can be sorted in "canonical" tree level and loop-induced realizations, the latter being motivated by their potential experimental testability. Here we discuss the one- and two-loop cases, paying special attention to systematic classification schemes which aim at building a full picture of neutrino mass generation.
[ { "created": "Tue, 13 Oct 2015 16:22:02 GMT", "version": "v1" } ]
2016-01-20
[ [ "Sierra", "D. Aristizabal", "" ] ]
Mechanisms for Majorana neutrino mass generation can be classified according to the level at which the Weinberg operator is generated. The different possibilities can be sorted in "canonical" tree level and loop-induced realizations, the latter being motivated by their potential experimental testability. Here we discuss the one- and two-loop cases, paying special attention to systematic classification schemes which aim at building a full picture of neutrino mass generation.
hep-ph/9203213
null
E. Gates, L. M. Krauss and M. White
Solar Neutrino Data and Its Implications
27 pages
Phys.Rev.D46:1263-1273,1992
10.1103/PhysRevD.46.1263
null
hep-ph
null
The complete and concurrent Homestake and Kamiokande solar neutrino data sets (including backgrounds), when compared to detailed model predictions, provide no unambiguous indication of the solution to the solar neutrino problem. All neutrino-based solutions, including time-varying models, provide reasonable fits to both the 3 year concurrent data and the full 20 year data set. A simple constant B neutrino flux reduction is ruled out at greater than the 4$\sigma$ level for both data sets. While such a flux reduction provides a marginal fit to the unweighted averages of the concurrent data, it does not provide a good fit to the average of the full 20 year sample. Gallium experiments may not be able to distinguish between the currently allowed neutrino-based possibilities.
[ { "created": "Tue, 17 Mar 1992 17:28:00 GMT", "version": "v1" } ]
2009-08-18
[ [ "Gates", "E.", "" ], [ "Krauss", "L. M.", "" ], [ "White", "M.", "" ] ]
The complete and concurrent Homestake and Kamiokande solar neutrino data sets (including backgrounds), when compared to detailed model predictions, provide no unambiguous indication of the solution to the solar neutrino problem. All neutrino-based solutions, including time-varying models, provide reasonable fits to both the 3 year concurrent data and the full 20 year data set. A simple constant B neutrino flux reduction is ruled out at greater than the 4$\sigma$ level for both data sets. While such a flux reduction provides a marginal fit to the unweighted averages of the concurrent data, it does not provide a good fit to the average of the full 20 year sample. Gallium experiments may not be able to distinguish between the currently allowed neutrino-based possibilities.