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hep-ph/9712447
Christian Weiss
C. Weiss and K. Goeke
Self-consistent calculation of parton distributions at low normalization point in the chiral quark-soliton model
14 pages, LaTeX, 4 figures included using epsf
null
null
RUB-TPII-12/97
hep-ph
null
We calculate the isosinglet unpolarized quark-- and antiquark distributions at a low normalization point in the large--$N_c$ limit. The nucleon is described as a self-consistent soliton solution of the effective chiral theory. The ultraviolet cutoff is implemented by a Pauli-Villars subtraction. The quark and antiquark distributions satisfy the momentum as well as the baryon number sum rule, corresponding to ``constituent'' quarks whose structure is not yet resolved at the low scale. Already at this level a sizable number of antiquarks is present.
[ { "created": "Thu, 18 Dec 1997 23:58:33 GMT", "version": "v1" } ]
2007-05-23
[ [ "Weiss", "C.", "" ], [ "Goeke", "K.", "" ] ]
We calculate the isosinglet unpolarized quark-- and antiquark distributions at a low normalization point in the large--$N_c$ limit. The nucleon is described as a self-consistent soliton solution of the effective chiral theory. The ultraviolet cutoff is implemented by a Pauli-Villars subtraction. The quark and antiquark distributions satisfy the momentum as well as the baryon number sum rule, corresponding to ``constituent'' quarks whose structure is not yet resolved at the low scale. Already at this level a sizable number of antiquarks is present.
hep-ph/0106273
Bodenmueller
H. Fritzsch
The Breaking of Isospin and the rho-omega-System
6 pages, style file appolb.cls included
null
10.1142/9789812811240_0020
LMU 01/07
hep-ph
null
Simple quark models for the low lying vector mesons suggest a mixing between the u- and d-flavors and a violation of the isospin symmetry for the rho-omega system much stronger than observed. It is shown that the chiral dynamics, especially the QCD anomaly, is responsible for a restoration of the isospin symmetry in the rho-omega system.
[ { "created": "Mon, 25 Jun 2001 13:13:17 GMT", "version": "v1" } ]
2016-11-23
[ [ "Fritzsch", "H.", "" ] ]
Simple quark models for the low lying vector mesons suggest a mixing between the u- and d-flavors and a violation of the isospin symmetry for the rho-omega system much stronger than observed. It is shown that the chiral dynamics, especially the QCD anomaly, is responsible for a restoration of the isospin symmetry in the rho-omega system.
1406.3001
Gerardo Depaola
G. O. Depaola, M. L. Iparraguirre D. Palacios
About electrons and position in Triplet Production: some remarks
22 pages and 17 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Taking into account the increasing interest in measuring high energy gamma ray polarization, Boldishev et. at. \cite{[Boldy]} published an extensive and very comprehensive work on the possibility of using the recoil electrons in the production of pairs on electrons. However, this work is based on using only 2 Feynmann diagrams of the 8 that the process has. This eliminates the difficulty of distinguishing, in the theory, which is the recoil electron and which is the created In this work we have analyzed the eight Feynman diagrams and we have shown that for energies lower to $\sim 1000mc^2$, the assumption just described is not a good approximation, so we propose a different way to work \cite{Marcos}: we classify the electrons into the less energetic and the most energetic ones without taking into account their origin. Under these conditions (lower or higher energy value), we have calculated the contribution of the different diagrams to the distribution(we compare the sum of them with that obtained by Haug \cite{Haug_e+}\cite{Haug_e-}, and how these distributions are modified by introducing a threshold for the momentum detection for electrons. For the study of polarization we presented on the angular distribution of particles for high-energy gamma rays (where only Borsellino diagrams predominate). Our results on the azimuthal distribution show that it is highly influenced by the orientation (in the plane perpendicular to the direction of the photon), prior to the interaction, that the polarization vector has with respect to the position of the electron in whose field the pair will be generated.
[ { "created": "Wed, 11 Jun 2014 19:22:14 GMT", "version": "v1" }, { "created": "Mon, 9 Dec 2019 14:47:49 GMT", "version": "v2" }, { "created": "Fri, 17 Jul 2020 19:50:34 GMT", "version": "v3" } ]
2020-07-21
[ [ "Depaola", "G. O.", "" ], [ "Palacios", "M. L. Iparraguirre D.", "" ] ]
Taking into account the increasing interest in measuring high energy gamma ray polarization, Boldishev et. at. \cite{[Boldy]} published an extensive and very comprehensive work on the possibility of using the recoil electrons in the production of pairs on electrons. However, this work is based on using only 2 Feynmann diagrams of the 8 that the process has. This eliminates the difficulty of distinguishing, in the theory, which is the recoil electron and which is the created In this work we have analyzed the eight Feynman diagrams and we have shown that for energies lower to $\sim 1000mc^2$, the assumption just described is not a good approximation, so we propose a different way to work \cite{Marcos}: we classify the electrons into the less energetic and the most energetic ones without taking into account their origin. Under these conditions (lower or higher energy value), we have calculated the contribution of the different diagrams to the distribution(we compare the sum of them with that obtained by Haug \cite{Haug_e+}\cite{Haug_e-}, and how these distributions are modified by introducing a threshold for the momentum detection for electrons. For the study of polarization we presented on the angular distribution of particles for high-energy gamma rays (where only Borsellino diagrams predominate). Our results on the azimuthal distribution show that it is highly influenced by the orientation (in the plane perpendicular to the direction of the photon), prior to the interaction, that the polarization vector has with respect to the position of the electron in whose field the pair will be generated.
1010.4556
Leonard Gamberg
Leonard Gamberg, Asmita Mukherjee, and Piet J. Mulders
A model independent analysis of gluonic pole matrix elements and universality of TMD fragmentation functions
5 pages, 5 figures, version to appear in Phys. Rev. D
Phys.Rev.D83:071503,2011
10.1103/PhysRevD.83.071503
null
hep-ph hep-ex hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Gluonic pole matrix elements explain the appearance of single spin asymmetries (SSA) in high-energy scattering processes. They involve a combination of operators which are odd under time reversal (T-odd). Such matrix elements appear in principle both for parton distribution functions and parton fragmentation functions. We show that for parton fragmentation functions these gluonic pole matrix elements vanish as a consequence of the analytic structure of scattering amplitudes in Quantum Chromodynamics. This result is important in the study of the universality of transverse momentum dependent (TMD) fragmentation functions.
[ { "created": "Thu, 21 Oct 2010 19:11:48 GMT", "version": "v1" }, { "created": "Wed, 23 Feb 2011 16:26:10 GMT", "version": "v2" }, { "created": "Wed, 23 Mar 2011 17:01:13 GMT", "version": "v3" } ]
2011-05-05
[ [ "Gamberg", "Leonard", "" ], [ "Mukherjee", "Asmita", "" ], [ "Mulders", "Piet J.", "" ] ]
Gluonic pole matrix elements explain the appearance of single spin asymmetries (SSA) in high-energy scattering processes. They involve a combination of operators which are odd under time reversal (T-odd). Such matrix elements appear in principle both for parton distribution functions and parton fragmentation functions. We show that for parton fragmentation functions these gluonic pole matrix elements vanish as a consequence of the analytic structure of scattering amplitudes in Quantum Chromodynamics. This result is important in the study of the universality of transverse momentum dependent (TMD) fragmentation functions.
1501.01124
Abdel Nasser Tawfik
Abdel Nasser Tawfik (Egyptian Ctr. Theor. Phys., Cairo and WLCAPP, Cairo), Niseem Magdy (WLCAPP, Cairo and Brookhaven Natl. Lab)
SU(3) Polyakov Linear $\sigma$-Model in Magnetic Field: Thermodynamics, Higher-Order Moments, Chiral Phase Structure and Meson Masses
35 pages and 18 figures with 59 eps-graphs to appear in Phys. Rev. C. arXiv admin note: text overlap with arXiv:1406.7488
Phys. Rev. C 91, 015206 (2015)
10.1103/PhysRevC.91.015206
ECTP-2014-06, WLCAPP-2014-06
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Effects of external magnetic field on various properties of the quantum chromodynamics under extreme conditions of temperature and density have been analysed. To this end, we use SU(3) Polyakov linear sigma-model and assume that the external magnetic field eB adds some restrictions to the quarks energy due to the existence of free charges in the plasma phase. In doing this, we apply the Landau theory of quantization. This requires an additional temperature to drive the system through the chiral phase-transition. Accordingly, the dependence of the critical temperature of chiral and confinement phase-transitions on the magnetic field is characterized. Based on this, we have studied the thermal evolution of thermodynamic quantities and the first four higher-order moment of particle multiplicity. Having all these calculations, we have studied the effects of magnetic field on chiral phase-transition. We found that both critical temperature T_c and critical chemical potential increase with increasing the magnetic field eB. Last but not least, the magnetic effects of the thermal evolution of four scalar and four pseudoscalar meson states are studied. We concluded that the meson masses decrease as the temperature increases till T_c. Then, the vacuum effect becomes dominant and rapidly increases with the temperature T. At low T, the scalar meson masses normalized to the lowest Matsubara frequency rapidly decreases as T increases. Then, starting from T_c, we find that the thermal dependence almost vanishes. Furthermore, the meson masses increase with increasing magnetic field. This gives characteristic phase diagram of T vs. external magnetic field $B. At high T, we find that the masses of almost all meson states become temperature independent. It is concluded that the various meson states likely have different T_c's.
[ { "created": "Tue, 6 Jan 2015 10:05:23 GMT", "version": "v1" } ]
2015-01-30
[ [ "Tawfik", "Abdel Nasser", "", "Egyptian Ctr. Theor. Phys., Cairo and WLCAPP,\n Cairo" ], [ "Magdy", "Niseem", "", "WLCAPP, Cairo and Brookhaven Natl. Lab" ] ]
Effects of external magnetic field on various properties of the quantum chromodynamics under extreme conditions of temperature and density have been analysed. To this end, we use SU(3) Polyakov linear sigma-model and assume that the external magnetic field eB adds some restrictions to the quarks energy due to the existence of free charges in the plasma phase. In doing this, we apply the Landau theory of quantization. This requires an additional temperature to drive the system through the chiral phase-transition. Accordingly, the dependence of the critical temperature of chiral and confinement phase-transitions on the magnetic field is characterized. Based on this, we have studied the thermal evolution of thermodynamic quantities and the first four higher-order moment of particle multiplicity. Having all these calculations, we have studied the effects of magnetic field on chiral phase-transition. We found that both critical temperature T_c and critical chemical potential increase with increasing the magnetic field eB. Last but not least, the magnetic effects of the thermal evolution of four scalar and four pseudoscalar meson states are studied. We concluded that the meson masses decrease as the temperature increases till T_c. Then, the vacuum effect becomes dominant and rapidly increases with the temperature T. At low T, the scalar meson masses normalized to the lowest Matsubara frequency rapidly decreases as T increases. Then, starting from T_c, we find that the thermal dependence almost vanishes. Furthermore, the meson masses increase with increasing magnetic field. This gives characteristic phase diagram of T vs. external magnetic field $B. At high T, we find that the masses of almost all meson states become temperature independent. It is concluded that the various meson states likely have different T_c's.
hep-ph/9404296
Matthias Neubert
M. Neubert
Heavy Quark Masses, Mixing Angles, and Spin-Flavour Symmetry
(Lectures presented at TASI-93, Boulder, Colorado, 1993), 83 pages, 18 figures available as uu-encoded file, CERN-TH.7225/94
null
10.1142/9789814503785_0004
null
hep-ph
null
In a series of three lectures, I review the theory and phenomenology of heavy quark masses and mixing angles and the status of their determination. In addition, I give an introduction to heavy quark symmetry, with the main emphasis on the development of heavy quark effective field theory and its application to obtain a model-independent determination of $|V_{cb}|$.
[ { "created": "Tue, 19 Apr 1994 16:51:39 GMT", "version": "v1" } ]
2016-10-26
[ [ "Neubert", "M.", "" ] ]
In a series of three lectures, I review the theory and phenomenology of heavy quark masses and mixing angles and the status of their determination. In addition, I give an introduction to heavy quark symmetry, with the main emphasis on the development of heavy quark effective field theory and its application to obtain a model-independent determination of $|V_{cb}|$.
hep-ph/0010215
Xiaojun Wang
Xiao-Jun Wang and Mu-Lin Yan
Chiral Expansion Theory at Vector Meson Scale
revtex file, 36 pages, 10 eps figures
null
null
null
hep-ph
null
We study physics on $\rho(770)$ and $\omega(782)$ in framework of chiral constituent quark model. The effective action is derived by proper vertex method, which can capture all order information of chiral expansion. The $N_c^{-1}$ expansion is also studied systematically. It is shown that the momentum expansion at vector meson energy scale converges slowly, and the loop effects of pseudoscalar meson play an important role at this energy scale. We provide a method to prove the unitarity of S-matrix in any low-energy effective theory of QCD. Phenomenologically, we study decays for $\rho\to\pi\pi$, $\rho\to e^+e^-$, $\omega\to\pi^+\pi^-$, $\rho^\pm\to\gamma\pi^\pm$ and $\omega\to\gamma\pi^0$, $\rho^0-\omega$ mixing and their mass splitting, pion form factor, $I=l=1$ phase shift and light quark masses at vector meson energy scale. These results include all order contribution of vector meson momentum expansion and is up to next to leading order of $N_c^{-1}$ expansion. All of these theoretical predictions agree with data very well. The unitarity of S-matrix yielded by this framework is examined. The Breit-Winger formula for resonance propagator is derived.
[ { "created": "Thu, 19 Oct 2000 02:34:50 GMT", "version": "v1" }, { "created": "Mon, 4 Dec 2000 10:02:14 GMT", "version": "v2" } ]
2007-05-23
[ [ "Wang", "Xiao-Jun", "" ], [ "Yan", "Mu-Lin", "" ] ]
We study physics on $\rho(770)$ and $\omega(782)$ in framework of chiral constituent quark model. The effective action is derived by proper vertex method, which can capture all order information of chiral expansion. The $N_c^{-1}$ expansion is also studied systematically. It is shown that the momentum expansion at vector meson energy scale converges slowly, and the loop effects of pseudoscalar meson play an important role at this energy scale. We provide a method to prove the unitarity of S-matrix in any low-energy effective theory of QCD. Phenomenologically, we study decays for $\rho\to\pi\pi$, $\rho\to e^+e^-$, $\omega\to\pi^+\pi^-$, $\rho^\pm\to\gamma\pi^\pm$ and $\omega\to\gamma\pi^0$, $\rho^0-\omega$ mixing and their mass splitting, pion form factor, $I=l=1$ phase shift and light quark masses at vector meson energy scale. These results include all order contribution of vector meson momentum expansion and is up to next to leading order of $N_c^{-1}$ expansion. All of these theoretical predictions agree with data very well. The unitarity of S-matrix yielded by this framework is examined. The Breit-Winger formula for resonance propagator is derived.
0706.3297
Mikhail Rogal
M. Rogal and S. Moch
Higher Mellin moments for charged current DIS
Contribution to the proceedings of the conference DIS 2007, Munich, April 2007
PoSACAT2007:086,2007
10.3360/dis.2007.48
DESY 07-086
hep-ph
null
We report on our recent results for deep-inelastic neutrino-proton scattering. We have computed the perturbative QCD corrections to three loops for the harged current structure functions F_2, F_L and F_3 for the combination nu P - nubar P. In leading twist approximation we have calculated the first six odd-integer Mellin moments in the case of F_2 and F_L and the first six even-integer moments in the case of F_3. As a new result we have obtained the coefficient functions to O(alpha_s^3) and we have found the corresponding anomalous dimensions to agree with known results in the literature.
[ { "created": "Fri, 22 Jun 2007 10:10:26 GMT", "version": "v1" } ]
2008-12-18
[ [ "Rogal", "M.", "" ], [ "Moch", "S.", "" ] ]
We report on our recent results for deep-inelastic neutrino-proton scattering. We have computed the perturbative QCD corrections to three loops for the harged current structure functions F_2, F_L and F_3 for the combination nu P - nubar P. In leading twist approximation we have calculated the first six odd-integer Mellin moments in the case of F_2 and F_L and the first six even-integer moments in the case of F_3. As a new result we have obtained the coefficient functions to O(alpha_s^3) and we have found the corresponding anomalous dimensions to agree with known results in the literature.
1107.0755
Kristian McDonald
Damien P. George and Kristian L. McDonald
Gravity on a Little Warped Space
1+24 pages
Phys.Rev.D84:064007,2011
10.1103/PhysRevD.84.064007
null
hep-ph gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the consistent inclusion of 4D Einstein gravity on a truncated slice of AdS_5 whose bulk-gravity and UV scales are much less than the 4D Planck scale, M_* << M_{Pl}. Such "Little Warped Spaces" have found phenomenological utility and can be motivated by string realizations of the Randall-Sundrum framework. Using the interval approach to brane-world gravity, we show that the inclusion of a large UV-localized Einstein-Hilbert term allows one to consistently incorporate 4D Einstein gravity into the low-energy theory. We detail the spectrum of Kaluza-Klein metric fluctuations and, in particular, examine the coupling of the little radion to matter. Furthermore, we show that Goldberger-Wise stabilization can be successfully implemented on such spaces. Our results demonstrate that realistic low-energy effective theories can be constructed on these spaces, and have relevance for existing models in the literature.
[ { "created": "Mon, 4 Jul 2011 23:23:17 GMT", "version": "v1" } ]
2011-11-15
[ [ "George", "Damien P.", "" ], [ "McDonald", "Kristian L.", "" ] ]
We investigate the consistent inclusion of 4D Einstein gravity on a truncated slice of AdS_5 whose bulk-gravity and UV scales are much less than the 4D Planck scale, M_* << M_{Pl}. Such "Little Warped Spaces" have found phenomenological utility and can be motivated by string realizations of the Randall-Sundrum framework. Using the interval approach to brane-world gravity, we show that the inclusion of a large UV-localized Einstein-Hilbert term allows one to consistently incorporate 4D Einstein gravity into the low-energy theory. We detail the spectrum of Kaluza-Klein metric fluctuations and, in particular, examine the coupling of the little radion to matter. Furthermore, we show that Goldberger-Wise stabilization can be successfully implemented on such spaces. Our results demonstrate that realistic low-energy effective theories can be constructed on these spaces, and have relevance for existing models in the literature.
2212.04046
Jonathan Zuk
Jonathan Zuk, Csaba Balazs, Andreas Papaefstathiou and Graham White
The Effective Potential in Fermi Gauges Beyond the Standard Model
12 pages, 2 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive the field-dependent masses in Fermi gauges for arbitrary scalar extensions of the Standard Model. These masses can be used to construct the effective potential for various models of new physics. We release a flexible $\texttt{Mathematica}$ notebook ($\texttt{VefFermi}$) which performs these calculations and renders large-scale phenomenological studies of various models possible. Motivated by the debate on the importance of gauge dependence, we show that, even in relatively simple models, there exist points where the global minimum is discontinuous in the gauge parameter. Such points require some care in discovering, indicating that a gauge-dependent treatment might still give reasonable results when examining the global features of a model.
[ { "created": "Thu, 8 Dec 2022 02:55:18 GMT", "version": "v1" } ]
2022-12-09
[ [ "Zuk", "Jonathan", "" ], [ "Balazs", "Csaba", "" ], [ "Papaefstathiou", "Andreas", "" ], [ "White", "Graham", "" ] ]
We derive the field-dependent masses in Fermi gauges for arbitrary scalar extensions of the Standard Model. These masses can be used to construct the effective potential for various models of new physics. We release a flexible $\texttt{Mathematica}$ notebook ($\texttt{VefFermi}$) which performs these calculations and renders large-scale phenomenological studies of various models possible. Motivated by the debate on the importance of gauge dependence, we show that, even in relatively simple models, there exist points where the global minimum is discontinuous in the gauge parameter. Such points require some care in discovering, indicating that a gauge-dependent treatment might still give reasonable results when examining the global features of a model.
0711.0970
Alvaro de Rujula
A. De Rujula
An introduction to Cosmic Rays and Gamma-Ray Bursts, and to their simple understanding
Contribution to La Thuile Workshop 2007. Brief chapter (13) added, prompted by recent Auger results on UHECR/AGN correlations
null
null
null
hep-ph astro-ph
null
I review the subjects of non-solar cosmic rays (CRs) and long-duration gamma-ray bursts (GRBs). Of the various interpretations of these phenomena, the one best supported by the data is the following. Accreting compact objects, such as black holes, are seen to emit relativistic puffs of plasma: `cannonballs' (CBs). The inner domain of a rotating star whose core has collapsed resembles such an accreting system. This suggests that core-collapse supernovae (SNe) emit CBs, as SN1987A did. The fate of a CB as it exits a SN and travels in space can be studied as a function of the CB's mass and energy, and of `ambient' properties: the encountered matter- and light- distributions, the composition of the former, and the location of intelligent observers. The latter may conclude that the interactions of CBs with ambient matter and light generate CRs and GRBs, all of whose properties can be described by this `CB model' with few parameters and simple physics. GRB data are still being taken in unscrutinized domains of energy and timing. They agree accurately with the model's predictions. CR data are centenary. Their precision will improve, but new striking predictions are unlikely. Yet, a one-free-parameter description of all CR data works very well. This is a bit as if one discovered QED today and only needed to fit $\alpha$.
[ { "created": "Tue, 6 Nov 2007 15:07:25 GMT", "version": "v1" }, { "created": "Thu, 8 Nov 2007 16:43:47 GMT", "version": "v2" }, { "created": "Mon, 12 Nov 2007 17:58:06 GMT", "version": "v3" } ]
2007-11-12
[ [ "De Rujula", "A.", "" ] ]
I review the subjects of non-solar cosmic rays (CRs) and long-duration gamma-ray bursts (GRBs). Of the various interpretations of these phenomena, the one best supported by the data is the following. Accreting compact objects, such as black holes, are seen to emit relativistic puffs of plasma: `cannonballs' (CBs). The inner domain of a rotating star whose core has collapsed resembles such an accreting system. This suggests that core-collapse supernovae (SNe) emit CBs, as SN1987A did. The fate of a CB as it exits a SN and travels in space can be studied as a function of the CB's mass and energy, and of `ambient' properties: the encountered matter- and light- distributions, the composition of the former, and the location of intelligent observers. The latter may conclude that the interactions of CBs with ambient matter and light generate CRs and GRBs, all of whose properties can be described by this `CB model' with few parameters and simple physics. GRB data are still being taken in unscrutinized domains of energy and timing. They agree accurately with the model's predictions. CR data are centenary. Their precision will improve, but new striking predictions are unlikely. Yet, a one-free-parameter description of all CR data works very well. This is a bit as if one discovered QED today and only needed to fit $\alpha$.
hep-ph/9802436
Dr Tsou Sheung Tsun
J Bordes (Valencia), HM Chan (Rutherford Appleton Lab), J. Pfaudler (Oxford), and ST Tsou (Oxford)
Features of Quark and Lepton Mixing from Differential Geometry of Curves on Surfaces
10 pages, Latex, 3 figures using eps
Phys.Rev. D58 (1998) 053006
10.1103/PhysRevD.58.053006
RAL-TR-98-022
hep-ph hep-th
null
It is noted that the CKM matrix elements for both quarks and leptons as conceived in the Dualized Standard Model (DSM) can be interpreted as direction cosines obtained by moving the Darboux trihedron (a 3-frame) along a trajectory on a sphere traced out through changing energy scales by a 3-vector factorized from the mass matrix. From the `Darboux' analogues of the well-known Serret--Frenet formulae for space curves, it is seen that the corner elements ($V_{ub}, V_{td}$ for quarks, and $U_{e3}, U_{\tau 1}$ for leptons) are associated with the (geodesic) torsion, while the other off-diagonal elements ($V_{us}, V_{cd}$ and $V_{cb}, V_{ts}$ for quarks, and $U_{e2}, U_{\mu 1}$ and $U_{\mu 3}, U_{\tau 2}$ for leptons) with the (respectively geodesic and normal) curvatures of the trajectory. From this it follows that (i) the corner elements in both matrices are much smaller than the other elements, (ii) the $U_{\mu 3}, U_{\tau 2}$ elements for the lepton CKM matrix are much larger than their counterparts in the quark matrix. Both these conclusions are strongly borne out by experiment, for quarks in hadron decays and for leptons in neutrino oscillations, and by previous explicit calculations within the DSM scheme.
[ { "created": "Thu, 26 Feb 1998 15:52:28 GMT", "version": "v1" } ]
2009-10-31
[ [ "Bordes", "J", "", "Valencia" ], [ "Chan", "HM", "", "Rutherford Appleton Lab" ], [ "Pfaudler", "J.", "", "Oxford" ], [ "Tsou", "ST", "", "Oxford" ] ]
It is noted that the CKM matrix elements for both quarks and leptons as conceived in the Dualized Standard Model (DSM) can be interpreted as direction cosines obtained by moving the Darboux trihedron (a 3-frame) along a trajectory on a sphere traced out through changing energy scales by a 3-vector factorized from the mass matrix. From the `Darboux' analogues of the well-known Serret--Frenet formulae for space curves, it is seen that the corner elements ($V_{ub}, V_{td}$ for quarks, and $U_{e3}, U_{\tau 1}$ for leptons) are associated with the (geodesic) torsion, while the other off-diagonal elements ($V_{us}, V_{cd}$ and $V_{cb}, V_{ts}$ for quarks, and $U_{e2}, U_{\mu 1}$ and $U_{\mu 3}, U_{\tau 2}$ for leptons) with the (respectively geodesic and normal) curvatures of the trajectory. From this it follows that (i) the corner elements in both matrices are much smaller than the other elements, (ii) the $U_{\mu 3}, U_{\tau 2}$ elements for the lepton CKM matrix are much larger than their counterparts in the quark matrix. Both these conclusions are strongly borne out by experiment, for quarks in hadron decays and for leptons in neutrino oscillations, and by previous explicit calculations within the DSM scheme.
1912.07030
Feng-Kun Guo
Feng-Kun Guo, Xiao-Hai Liu, Shuntaro Sakai
Threshold cusps and triangle singularities in hadronic reactions
Version accepted for publication in Prog. Part. Nucl. Phys.; 84 pages, 34 figures
Prog. Part. Nucl. Phys. 112 (2020) 103757
10.1016/j.ppnp.2020.103757
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The spectrum of hadrons is the manifestation of color confinement of quantum chromodynamics. Hadronic resonances correspond to poles of the S-matrix. Since 2003, lots of new hadron resonant structures were discovered in the mass regions from light mesons to hadrons containing a pair of a heavy quark and an antiquark. Many of them are candidates of exotic hadrons, and they are usually observed as peaks in invariant mass distributions. However, the S-matrix also has kinematical singularities due to the on-shellness of intermediate particles for a process, such as two-body thresholds and triangle singularities, and they can produce peaks as well. On the one hand, such singularities may be misidentified as resonances; on the other hand, they can be used as tools for precision measurements. In this paper, we review the threshold cusps and various triangle singularities in hadronic reactions, paying attention to their manifestations in phenomena related to exotic hadron candidates.
[ { "created": "Sun, 15 Dec 2019 12:06:29 GMT", "version": "v1" }, { "created": "Fri, 17 Jan 2020 14:25:28 GMT", "version": "v2" } ]
2020-04-08
[ [ "Guo", "Feng-Kun", "" ], [ "Liu", "Xiao-Hai", "" ], [ "Sakai", "Shuntaro", "" ] ]
The spectrum of hadrons is the manifestation of color confinement of quantum chromodynamics. Hadronic resonances correspond to poles of the S-matrix. Since 2003, lots of new hadron resonant structures were discovered in the mass regions from light mesons to hadrons containing a pair of a heavy quark and an antiquark. Many of them are candidates of exotic hadrons, and they are usually observed as peaks in invariant mass distributions. However, the S-matrix also has kinematical singularities due to the on-shellness of intermediate particles for a process, such as two-body thresholds and triangle singularities, and they can produce peaks as well. On the one hand, such singularities may be misidentified as resonances; on the other hand, they can be used as tools for precision measurements. In this paper, we review the threshold cusps and various triangle singularities in hadronic reactions, paying attention to their manifestations in phenomena related to exotic hadron candidates.
2406.03940
C. J. A. P. Martins
F. C. N. Q. Pimenta, C. J. A. P. Martins
Scaling solutions for current-carrying cosmic string networks
15 pages, 5 figures, 3 tables; to appear in Phys. Rev. D
null
null
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Cosmic string networks are the best motivated relics of cosmological phase transitions, being unavoidable in many physically plausible extensions of the Standard Model. Most studies, including those providing constraints from and forecasts of their observational signals, rely on assumptions of featureless networks, neglecting the additional degrees of freedom on the string worldsheet, e.g. charges and currents, which are all but unavoidable in physically realistic models. An extension of the canonical velocity-dependent one-scale model, accounting for all such possible degrees of freedom, has been recently developed. Here we improve its physical interpretation by studying and classifying its possible asymptotic scaling solutions, and in particular how they are affected by the expansion of the Universe and the available energy loss or transfer mechanisms. We find three classes of solutions. For sufficiently fast expansion rates the charges and currents decay and one asymptotes to the Nambu-Goto case, while for slower expansion rates they can dominate the network dynamics. In between the two there is a third regime in which the network, including its charge and current, reaches full scaling. Under specific but plausible assumptions, this intermediate regime corresponds to the matter-dominated era. Our results agree with, and significantly extend, those of previous studies.
[ { "created": "Thu, 6 Jun 2024 10:28:05 GMT", "version": "v1" } ]
2024-06-07
[ [ "Pimenta", "F. C. N. Q.", "" ], [ "Martins", "C. J. A. P.", "" ] ]
Cosmic string networks are the best motivated relics of cosmological phase transitions, being unavoidable in many physically plausible extensions of the Standard Model. Most studies, including those providing constraints from and forecasts of their observational signals, rely on assumptions of featureless networks, neglecting the additional degrees of freedom on the string worldsheet, e.g. charges and currents, which are all but unavoidable in physically realistic models. An extension of the canonical velocity-dependent one-scale model, accounting for all such possible degrees of freedom, has been recently developed. Here we improve its physical interpretation by studying and classifying its possible asymptotic scaling solutions, and in particular how they are affected by the expansion of the Universe and the available energy loss or transfer mechanisms. We find three classes of solutions. For sufficiently fast expansion rates the charges and currents decay and one asymptotes to the Nambu-Goto case, while for slower expansion rates they can dominate the network dynamics. In between the two there is a third regime in which the network, including its charge and current, reaches full scaling. Under specific but plausible assumptions, this intermediate regime corresponds to the matter-dominated era. Our results agree with, and significantly extend, those of previous studies.
1003.4022
Robert Feger
Robert Feger (1), Verena Klose (2), Heiko Lacker (2), Thomas Lueck (2) and Thomas Mannel (1) ((1) Univ. Siegen, (2) HU Berlin)
Limit on a Right-Handed Admixture to the Weak $b \to c$ Current from Semileptonic Decays
7 pages, 3 figures, 2 tables
Phys.Rev.D82:073002,2010
10.1103/PhysRevD.82.073002
SI-HEP-2009-19
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We determine an upper bound for a possible right-handed $b{\to}c$ quark current admixture in semileptonic $\bar{B} \to X_{c} \ell^{-} \bar{\nu}$ decays from a simulateous fit to moments of the lepton-enery and hadronic-mass distribution measured as a function of the lower limit on the lepton energy, using data measured by the \babar\ detector. The right-handed admixture is parametrized by a new parameter $c_R$ as coefficient of computed moments with right-handed quark current. For the standard model part we use the prediction of the heavy-quark expansion (HQE) up to order $1/m_b^3$ and perturbative corrections and for the right-handed contribution only up to order $1/m_b^2$ and perturbative corrections. We find $\cR=0.05\asympm{+0.33}{-0.50}$ in agreement with the standard-model prediction of zero. Additionally, we give a contraint on a possible right-handed admixture from exclusive decays, which is with a value of $\cR =0.01{\pm}0.03$ more restrictive than our value from the inclusive fit. The difference in \Vcb between the inclusive and exclusive extraction is only slightly reduced when allowing for a right-handed admixture in the range of $\cR=0.01 {\pm} 0.03$.
[ { "created": "Sun, 21 Mar 2010 20:23:07 GMT", "version": "v1" } ]
2014-11-20
[ [ "Feger", "Robert", "", "Univ. Siegen" ], [ "Klose", "Verena", "", "HU Berlin" ], [ "Lacker", "Heiko", "", "HU Berlin" ], [ "Lueck", "Thomas", "", "HU Berlin" ], [ "Mannel", "Thomas", "", "Univ. Siegen" ] ]
We determine an upper bound for a possible right-handed $b{\to}c$ quark current admixture in semileptonic $\bar{B} \to X_{c} \ell^{-} \bar{\nu}$ decays from a simulateous fit to moments of the lepton-enery and hadronic-mass distribution measured as a function of the lower limit on the lepton energy, using data measured by the \babar\ detector. The right-handed admixture is parametrized by a new parameter $c_R$ as coefficient of computed moments with right-handed quark current. For the standard model part we use the prediction of the heavy-quark expansion (HQE) up to order $1/m_b^3$ and perturbative corrections and for the right-handed contribution only up to order $1/m_b^2$ and perturbative corrections. We find $\cR=0.05\asympm{+0.33}{-0.50}$ in agreement with the standard-model prediction of zero. Additionally, we give a contraint on a possible right-handed admixture from exclusive decays, which is with a value of $\cR =0.01{\pm}0.03$ more restrictive than our value from the inclusive fit. The difference in \Vcb between the inclusive and exclusive extraction is only slightly reduced when allowing for a right-handed admixture in the range of $\cR=0.01 {\pm} 0.03$.
1812.05523
Diego Restrepo
Julian Calle, Diego Restrepo, Carlos E. Yaguna, \'Oscar Zapata
Minimal radiative Dirac neutrino mass models
10 pages, 6 figures. References added. Version accepted in PRD
Phys. Rev. D 99, 075008 (2019)
10.1103/PhysRevD.99.075008
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Neutrinos may be Dirac particles whose masses arise radiatively at one-loop, naturally explaining their small values. In this work we show that all the one-loop realizations of the dimension-five operator to effectively generate Dirac neutrino masses can be implemented by using a single local symmetry: $U(1)_{B-L}$. Since this symmetry is anomalous, new chiral fermions, charged under $B-L$, are required. The minimal model consistent with neutrino data includes three chiral fermions, two of them with the same lepton number. The next minimal models contain five chiral fermions and their $B-L$ charges can be fixed by requiring a dark matter candidate in the spectrum. We list the full particle content as well as the relevant Lagrangian terms for each of these models. They are new and simple models that can simultaneously accommodate Dirac neutrino masses (at one-loop) and dark matter without invoking any discrete symmetries.
[ { "created": "Thu, 13 Dec 2018 17:05:50 GMT", "version": "v1" }, { "created": "Fri, 21 Dec 2018 17:31:46 GMT", "version": "v2" }, { "created": "Wed, 15 May 2019 19:35:52 GMT", "version": "v3" } ]
2019-05-17
[ [ "Calle", "Julian", "" ], [ "Restrepo", "Diego", "" ], [ "Yaguna", "Carlos E.", "" ], [ "Zapata", "Óscar", "" ] ]
Neutrinos may be Dirac particles whose masses arise radiatively at one-loop, naturally explaining their small values. In this work we show that all the one-loop realizations of the dimension-five operator to effectively generate Dirac neutrino masses can be implemented by using a single local symmetry: $U(1)_{B-L}$. Since this symmetry is anomalous, new chiral fermions, charged under $B-L$, are required. The minimal model consistent with neutrino data includes three chiral fermions, two of them with the same lepton number. The next minimal models contain five chiral fermions and their $B-L$ charges can be fixed by requiring a dark matter candidate in the spectrum. We list the full particle content as well as the relevant Lagrangian terms for each of these models. They are new and simple models that can simultaneously accommodate Dirac neutrino masses (at one-loop) and dark matter without invoking any discrete symmetries.
1701.01136
Christopher W. Murphy
Hooman Davoudiasl, Christopher W. Murphy
Fuzzy Dark Matter from Infrared Confining Dynamics
v2: 5 pages, 1 figure; references added, wording improved, matches PRL version
Phys. Rev. Lett. 118, 141801 (2017)
10.1103/PhysRevLett.118.141801
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A very light boson of mass $\mathcal{O}(10^{-22})$ eV may potentially be a viable dark matter (DM) candidate which can avoid phenomenological problems associated with cold DM. Such "fuzzy DM (FDM)" may naturally be an axion with a decay constant $f_a \sim 10^{16} \div 10^{18}$ GeV, and a mass $m_a \sim \mu^2/f_a$ with $\mu\sim 10^2$ eV. Here we propose a concrete model where $\mu$ arises as a dynamical scale from infrared confining dynamics, analogous to QCD. Our model is an alternative to the usual approach of generating $\mu$ through string theoretic instanton effects. We outline the features of this scenario that result from various cosmological constraints. We find that those constraints are suggestive of a period of mild of inflation, perhaps from a strong first order phase transition, that reheats the Standard Model (SM) sector only. A typical prediction of our scenario, broadly speaking, is a larger effective number of neutrinos compared to the SM value $N_{\text{eff}} \approx 3$, as inferred from precision measurements of the cosmic microwave background. Some of the new degrees of freedom may be identified as "sterile neutrinos," which may be required to explain certain neutrino oscillation anomalies. Hence, aspects of our scenario could be testable in terrestrial experiments, which is a novelty of our FDM model.
[ { "created": "Wed, 4 Jan 2017 19:49:31 GMT", "version": "v1" }, { "created": "Tue, 4 Apr 2017 19:24:07 GMT", "version": "v2" } ]
2017-04-12
[ [ "Davoudiasl", "Hooman", "" ], [ "Murphy", "Christopher W.", "" ] ]
A very light boson of mass $\mathcal{O}(10^{-22})$ eV may potentially be a viable dark matter (DM) candidate which can avoid phenomenological problems associated with cold DM. Such "fuzzy DM (FDM)" may naturally be an axion with a decay constant $f_a \sim 10^{16} \div 10^{18}$ GeV, and a mass $m_a \sim \mu^2/f_a$ with $\mu\sim 10^2$ eV. Here we propose a concrete model where $\mu$ arises as a dynamical scale from infrared confining dynamics, analogous to QCD. Our model is an alternative to the usual approach of generating $\mu$ through string theoretic instanton effects. We outline the features of this scenario that result from various cosmological constraints. We find that those constraints are suggestive of a period of mild of inflation, perhaps from a strong first order phase transition, that reheats the Standard Model (SM) sector only. A typical prediction of our scenario, broadly speaking, is a larger effective number of neutrinos compared to the SM value $N_{\text{eff}} \approx 3$, as inferred from precision measurements of the cosmic microwave background. Some of the new degrees of freedom may be identified as "sterile neutrinos," which may be required to explain certain neutrino oscillation anomalies. Hence, aspects of our scenario could be testable in terrestrial experiments, which is a novelty of our FDM model.
hep-ph/0011102
Vladimir F. Kovalev
B. Geyer, V. F. Kovalev
Inflationary Brans-Dicke Quantum Universe II: Particular evolutions and stability analysis
24 pages, 9 figures; corrected typos in author's name
null
null
null
hep-ph gr-qc hep-th
null
We made an analysis of the equations of motion which are obtained from the one - loop effective action for Brans-Dicke gravity with N dilaton - coupled massless fermions in a time-dependent conformally flat background. Various particular solutions, including the well-known stationary one, of the corresponding set of first-order differential equations are given. Some of these solutions describe an expanding time-dependent Universe with increasing, constant or also decreasing dilaton. This is illustrated by a numerical analysis. For the nonstationary solutions a stability analysis is given.
[ { "created": "Wed, 8 Nov 2000 05:27:43 GMT", "version": "v1" }, { "created": "Fri, 10 Nov 2000 06:58:32 GMT", "version": "v2" } ]
2007-05-23
[ [ "Geyer", "B.", "" ], [ "Kovalev", "V. F.", "" ] ]
We made an analysis of the equations of motion which are obtained from the one - loop effective action for Brans-Dicke gravity with N dilaton - coupled massless fermions in a time-dependent conformally flat background. Various particular solutions, including the well-known stationary one, of the corresponding set of first-order differential equations are given. Some of these solutions describe an expanding time-dependent Universe with increasing, constant or also decreasing dilaton. This is illustrated by a numerical analysis. For the nonstationary solutions a stability analysis is given.
hep-ph/0511347
Giulia Zanderighi
G. Zanderighi
Unstable particle production near threshold with effective theory methods
Invited talk at 2005 International Linear Collider Physics and Detector Workshop and Second ILC Accelerator Workshop, Snowmass, CO (Snowmass05), 3 pages
ECONFC0508141:ALCPG0403,2005
null
ALCPG0403, FERMILAB-CONF-05-527-T, CERN-PH-TH/2005-238
hep-ph
null
We illustrate the use of effective theory methods to describe resonant unstable particles. We outline the necessary ingredients to describe $W$-pair production close to threshold in $e^-e^+$ collisions.
[ { "created": "Wed, 30 Nov 2005 17:44:31 GMT", "version": "v1" } ]
2008-11-26
[ [ "Zanderighi", "G.", "" ] ]
We illustrate the use of effective theory methods to describe resonant unstable particles. We outline the necessary ingredients to describe $W$-pair production close to threshold in $e^-e^+$ collisions.
hep-ph/9210235
null
Paul Langacker and Nir Polonsky
Uncertainties in Coupling Constant Unification
LaTex, 51 pages, 6 figures (available upon request), UPR-0513T
Phys.Rev. D47 (1993) 4028-4045
10.1103/PhysRevD.47.4028
null
hep-ph
null
The status of coupling constant unification in the standard model and its supersymmetric extension are discussed. Uncertainties associated with the input coupling constants, $m_{t}$, threshold corrections at the low and high scales, and possible nonrenormalizable operators are parametrized and estimated. A simple parametrization of a general supersymmetric new particle spectrum is given. It is shown that an effective scale $M_{SUSY}$ can be defined, but for a realistic spectrum it may differ considerably from the typical new particle masses. The implications of the lower (higher) values of $\alpha_{s}(M_{Z})$ suggested by low-energy ($Z$-pole) experiments are discussed.
[ { "created": "Wed, 14 Oct 1992 18:58:00 GMT", "version": "v1" } ]
2009-10-22
[ [ "Langacker", "Paul", "" ], [ "Polonsky", "Nir", "" ] ]
The status of coupling constant unification in the standard model and its supersymmetric extension are discussed. Uncertainties associated with the input coupling constants, $m_{t}$, threshold corrections at the low and high scales, and possible nonrenormalizable operators are parametrized and estimated. A simple parametrization of a general supersymmetric new particle spectrum is given. It is shown that an effective scale $M_{SUSY}$ can be defined, but for a realistic spectrum it may differ considerably from the typical new particle masses. The implications of the lower (higher) values of $\alpha_{s}(M_{Z})$ suggested by low-energy ($Z$-pole) experiments are discussed.
hep-ph/0408121
Bo-Qiang Ma
Bin Wu, Bo-Qiang Ma
The 35-plet Baryons from Chiral Soliton Models
10 LaTex pages, 1 figure, to appear in PRD
Phys.Rev. D70 (2004) 094042
10.1103/PhysRevD.70.094042
null
hep-ph hep-ex nucl-ex nucl-th
null
We investigate the 35-plet baryons from the chiral soliton models. We find that the coupling constant for the decay of 35-plet baryons with spin 3/2 to the decuplet baryons is surprisingly small, but that for the decay to 27-plet baryons with spin 3/2 is larger. We give all the masses and widths of 35-plet baryons with spin 5/2 and suggest candidates for all nonexotic members from the available particle listings. We also focus on $\Delta_{5/2}$ and $\Theta_2$, which are the lightest two baryons of 35-plet with spin 5/2 and with simplest minimal pentaquark configurations. Calculations show that $\Gamma_{\Delta_{5/2}}<$380 MeV, compared with the results from SU(2) Skyrme Model ($\Gamma_{\Delta_{5/2}}>$800 MeV), and $\Gamma_{\Theta_{2}}<100$ MeV if we assume that their widths are dominated by two-body decay and that $\Theta^+$ has a width $\Gamma_{\Theta^+}<25$ MeV.
[ { "created": "Mon, 9 Aug 2004 23:20:17 GMT", "version": "v1" }, { "created": "Wed, 11 Aug 2004 15:01:36 GMT", "version": "v2" } ]
2009-11-10
[ [ "Wu", "Bin", "" ], [ "Ma", "Bo-Qiang", "" ] ]
We investigate the 35-plet baryons from the chiral soliton models. We find that the coupling constant for the decay of 35-plet baryons with spin 3/2 to the decuplet baryons is surprisingly small, but that for the decay to 27-plet baryons with spin 3/2 is larger. We give all the masses and widths of 35-plet baryons with spin 5/2 and suggest candidates for all nonexotic members from the available particle listings. We also focus on $\Delta_{5/2}$ and $\Theta_2$, which are the lightest two baryons of 35-plet with spin 5/2 and with simplest minimal pentaquark configurations. Calculations show that $\Gamma_{\Delta_{5/2}}<$380 MeV, compared with the results from SU(2) Skyrme Model ($\Gamma_{\Delta_{5/2}}>$800 MeV), and $\Gamma_{\Theta_{2}}<100$ MeV if we assume that their widths are dominated by two-body decay and that $\Theta^+$ has a width $\Gamma_{\Theta^+}<25$ MeV.
2107.05590
Manjunath Omana Kuttan
Manjunath Omana Kuttan, Kai Zhou, Jan Steinheimer, Andreas Redelbach and Horst Stoecker
An equation-of-state-meter for CBM using PointNet
12 pages, 7 figures. Matches published version
J. High Energ. Phys. 2021, 184 (2021)
10.1007/JHEP10(2021)184
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A novel method for identifying the nature of QCD transitions in heavy-ion collision experiments is introduced. PointNet based Deep Learning (DL) models are developed to classify the equation of state (EoS) that drives the hydrodynamic evolution of the system created in Au-Au collisions at 10 AGeV. The DL models were trained and evaluated in different hypothetical experimental situations. A decreased performance is observed when more realistic experimental effects (acceptance cuts and decreased resolutions) are taken into account. It is shown that the performance can be improved by combining multiple events to make predictions. The PointNet based models trained on the reconstructed tracks of charged particles from the CBM detector simulation discriminate a crossover transition from a first order phase transition with an accuracy of up to 99.8%. The models were subjected to several tests to evaluate the dependence of its performance on the centrality of the collisions and physical parameters of fluid dynamic simulations. The models are shown to work in a broad range of centralities (b=0-7 fm). However, the performance is found to improve for central collisions (b=0-3 fm). There is a drop in the performance when the model parameters lead to reduced duration of the fluid dynamic evolution or when less fraction of the medium undergoes the transition. These effects are due to the limitations of the underlying physics and the DL models are shown to be superior in its discrimination performance in comparison to conventional mean observables.
[ { "created": "Mon, 12 Jul 2021 17:11:53 GMT", "version": "v1" }, { "created": "Mon, 25 Oct 2021 11:26:31 GMT", "version": "v2" } ]
2021-10-26
[ [ "Kuttan", "Manjunath Omana", "" ], [ "Zhou", "Kai", "" ], [ "Steinheimer", "Jan", "" ], [ "Redelbach", "Andreas", "" ], [ "Stoecker", "Horst", "" ] ]
A novel method for identifying the nature of QCD transitions in heavy-ion collision experiments is introduced. PointNet based Deep Learning (DL) models are developed to classify the equation of state (EoS) that drives the hydrodynamic evolution of the system created in Au-Au collisions at 10 AGeV. The DL models were trained and evaluated in different hypothetical experimental situations. A decreased performance is observed when more realistic experimental effects (acceptance cuts and decreased resolutions) are taken into account. It is shown that the performance can be improved by combining multiple events to make predictions. The PointNet based models trained on the reconstructed tracks of charged particles from the CBM detector simulation discriminate a crossover transition from a first order phase transition with an accuracy of up to 99.8%. The models were subjected to several tests to evaluate the dependence of its performance on the centrality of the collisions and physical parameters of fluid dynamic simulations. The models are shown to work in a broad range of centralities (b=0-7 fm). However, the performance is found to improve for central collisions (b=0-3 fm). There is a drop in the performance when the model parameters lead to reduced duration of the fluid dynamic evolution or when less fraction of the medium undergoes the transition. These effects are due to the limitations of the underlying physics and the DL models are shown to be superior in its discrimination performance in comparison to conventional mean observables.
1612.07057
Alexander Millar
Alexander J. Millar, Georg G. Raffelt, Javier Redondo, Frank D. Steffen
Dielectric Haloscopes to Search for Axion Dark Matter: Theoretical Foundations
71 pages, 34 figures; v2: minor changes, typo in (4.13) corrected, matches published version
JCAP 1701:061,2017
10.1088/1475-7516/2017/01/061
null
hep-ph astro-ph.CO astro-ph.HE hep-ex physics.ins-det
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the underlying theory of dielectric haloscopes, a new way to detect dark matter axions. When an interface between different dielectric media is inside a magnetic field, the oscillating axion field acts as a source of electromagnetic waves, which emerge in both directions perpendicular to the surface. The emission rate can be boosted by multiple layers judiciously placed to achieve constructive interference and by a large transverse area. Starting from the axion-modified Maxwell equations, we calculate the efficiency of this new dielectric haloscope approach. This technique could potentially search the unexplored high-frequency range of 10--100 GHz (axion mass 40--400 $\mu$eV), where traditional cavity resonators have difficulties reaching the required volume.
[ { "created": "Wed, 21 Dec 2016 11:15:57 GMT", "version": "v1" }, { "created": "Tue, 31 Jan 2017 17:36:42 GMT", "version": "v2" } ]
2017-02-01
[ [ "Millar", "Alexander J.", "" ], [ "Raffelt", "Georg G.", "" ], [ "Redondo", "Javier", "" ], [ "Steffen", "Frank D.", "" ] ]
We study the underlying theory of dielectric haloscopes, a new way to detect dark matter axions. When an interface between different dielectric media is inside a magnetic field, the oscillating axion field acts as a source of electromagnetic waves, which emerge in both directions perpendicular to the surface. The emission rate can be boosted by multiple layers judiciously placed to achieve constructive interference and by a large transverse area. Starting from the axion-modified Maxwell equations, we calculate the efficiency of this new dielectric haloscope approach. This technique could potentially search the unexplored high-frequency range of 10--100 GHz (axion mass 40--400 $\mu$eV), where traditional cavity resonators have difficulties reaching the required volume.
1802.07249
Jai More Dr.
Jai More, Asmita Mukherjee and Sreeraj Nair
Three Dimensional Imaging of the Nucleon
7 pages, 2 figures, Prepared for Proceedings of Light Cone 2017, 18-22 Sept, University of Mumbai, India. To appear in FBS
null
10.1007/s00601-018-1348-0
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the Wigner distributions of quarks and gluons in light-front dressed quark model using the overlap of light front wave functions (LFWFs). We take the target to be a dressed quark, this is a composite spin $-1/2$ state of quark dressed with a gluon. This state allows us to calculate the quark and gluon Wigner distributions analytically in terms of LFWFs using Hamiltonian perturbation theory. We analyze numerically the Wigner distributions of quark and gluon and report their nature in the contour plots. We use an improved numerical technique to remove the cutoff dependence of the Fourier transformed integral over ${\bf \Delta}_\perp$.
[ { "created": "Tue, 20 Feb 2018 18:51:53 GMT", "version": "v1" } ]
2018-04-04
[ [ "More", "Jai", "" ], [ "Mukherjee", "Asmita", "" ], [ "Nair", "Sreeraj", "" ] ]
We study the Wigner distributions of quarks and gluons in light-front dressed quark model using the overlap of light front wave functions (LFWFs). We take the target to be a dressed quark, this is a composite spin $-1/2$ state of quark dressed with a gluon. This state allows us to calculate the quark and gluon Wigner distributions analytically in terms of LFWFs using Hamiltonian perturbation theory. We analyze numerically the Wigner distributions of quark and gluon and report their nature in the contour plots. We use an improved numerical technique to remove the cutoff dependence of the Fourier transformed integral over ${\bf \Delta}_\perp$.
1604.07327
Robert Appleby
R.B. Appleby, R.J. Barlow, J.G Molson, M. Serluca, A. Toader
The Practical Pomeron for High Energy Proton Collimation
23 pages, 25 figures
null
10.1140/epjc/s10052-016-4363-7
null
hep-ph physics.acc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a model which describes proton scattering data from ISR to Tevatron energies, and which can be applied to collimation n high energy accelerators, such as the LHC and FCC. Collimators remove beam halo particles, so that they do not impinge on vulnerable regions of the machine, such as the superconducting magnets and the experimental areas. In simulating the effect of the collimator jaws it is crucial to model the scattering of protons at small momentum transfer~$t$,as these protons can subsequently survive several turns of the ring before being lost. At high energies these soft processes are well described by Pomeron exchange models. We study the behaviour of elastic and single-diffractive dissociation cross sections over a wide range of energy, and show that the model can be used as a global description of the wide variety of high energy elastic and diffractive data presently available. In particular it models low mass diffraction dissociation, where a rich resonance structure is present, and thus predicts the differential and integrated cross sections in the kinematical range appropriate to the LHC.We incorporate the physics of this model into the beam tracking code MERLIN and use it to simulate the resulting loss maps of the beam halo lost in the collimators in the LHC.
[ { "created": "Mon, 25 Apr 2016 16:57:25 GMT", "version": "v1" } ]
2016-10-12
[ [ "Appleby", "R. B.", "" ], [ "Barlow", "R. J.", "" ], [ "Molson", "J. G", "" ], [ "Serluca", "M.", "" ], [ "Toader", "A.", "" ] ]
We present a model which describes proton scattering data from ISR to Tevatron energies, and which can be applied to collimation n high energy accelerators, such as the LHC and FCC. Collimators remove beam halo particles, so that they do not impinge on vulnerable regions of the machine, such as the superconducting magnets and the experimental areas. In simulating the effect of the collimator jaws it is crucial to model the scattering of protons at small momentum transfer~$t$,as these protons can subsequently survive several turns of the ring before being lost. At high energies these soft processes are well described by Pomeron exchange models. We study the behaviour of elastic and single-diffractive dissociation cross sections over a wide range of energy, and show that the model can be used as a global description of the wide variety of high energy elastic and diffractive data presently available. In particular it models low mass diffraction dissociation, where a rich resonance structure is present, and thus predicts the differential and integrated cross sections in the kinematical range appropriate to the LHC.We incorporate the physics of this model into the beam tracking code MERLIN and use it to simulate the resulting loss maps of the beam halo lost in the collimators in the LHC.
1702.08417
Alfonso Ballon Bayona
Alfonso Ballon-Bayona, Gastao Krein, Carlisson Miller
Strong couplings and form factors of charmed mesons in holographic QCD
18 pages, 8 figures. V3: Added 3 new references. Version published in Phys. Rev. D
Phys. Rev. D 96, 014017 (2017)
10.1103/PhysRevD.96.014017
null
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We extend the two-flavor hard-wall holographic model of Erlich, Katz, Son and Stephanov [Phys.\ Rev.\ Lett.\ {\bf 95}, 261602 (2005)] to four flavors to incorporate strange and charm quarks. The model incorporates chiral and flavor symmetry breaking and provides a reasonable description of masses and weak decay constants of a variety of scalar, pseudoscalar, vector and axial-vector strange and charmed mesons. In particular, we examine flavor symmetry breaking in the strong couplings of the $\rho$ meson to the charmed $D$ and $D^{*}$ mesons. We also compute electromagnetic form factors of the $\pi$, $\rho$, $K$, $K^*$, $D$ and $D^*$ mesons. We compare our results for the $D$ and $D^*$ mesons with lattice QCD data and other nonperturbative approaches.
[ { "created": "Mon, 27 Feb 2017 18:25:45 GMT", "version": "v1" }, { "created": "Mon, 3 Apr 2017 18:36:22 GMT", "version": "v2" }, { "created": "Thu, 31 Aug 2017 17:51:46 GMT", "version": "v3" } ]
2017-09-01
[ [ "Ballon-Bayona", "Alfonso", "" ], [ "Krein", "Gastao", "" ], [ "Miller", "Carlisson", "" ] ]
We extend the two-flavor hard-wall holographic model of Erlich, Katz, Son and Stephanov [Phys.\ Rev.\ Lett.\ {\bf 95}, 261602 (2005)] to four flavors to incorporate strange and charm quarks. The model incorporates chiral and flavor symmetry breaking and provides a reasonable description of masses and weak decay constants of a variety of scalar, pseudoscalar, vector and axial-vector strange and charmed mesons. In particular, we examine flavor symmetry breaking in the strong couplings of the $\rho$ meson to the charmed $D$ and $D^{*}$ mesons. We also compute electromagnetic form factors of the $\pi$, $\rho$, $K$, $K^*$, $D$ and $D^*$ mesons. We compare our results for the $D$ and $D^*$ mesons with lattice QCD data and other nonperturbative approaches.
1507.00669
Denise Vicino Mrs
Ferruccio Feruglio, Ketan M. Patel, Denise Vicino
A realistic pattern of fermion masses from a five-dimensional SO(10) model
30 pages, 7 figures, 4 tables
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We provide a unified description of fermion masses and mixing angles in the framework of a supersymmetric grand unified SO(10) model with anarchic Yukawa couplings of order unity. The space-time is five dimensional and the extra flat spatial dimension is compactified on the orbifold $S^1/(Z_2 \times Z_2')$, leading to Pati-Salam gauge symmetry on the boundary where Yukawa interactions are localised. The gauge symmetry breaking is completed by means of a rather economic scalar sector, avoiding the doublet-triplet splitting problem. The matter fields live in the bulk and their massless modes get exponential profiles, which naturally explain the mass hierarchy of the different fermion generations. Quarks and leptons properties are naturally reproduced by a mechanism, first proposed by Kitano and Li, that lifts the SO(10) degeneracy of bulk masses in terms of a single parameter. The model provides a realistic pattern of fermion masses and mixing angles for large values of $\tan\beta$. It favours normally ordered neutrino mass spectrum with the lightest neutrino mass below 0.01 eV and no preference for leptonic CP violating phases. The right handed neutrino mass spectrum is very hierarchical and does not allow for thermal leptogenesis. We analyse several variants of the basic framework and find that the results concerning the fermion spectrum are remarkably stable.
[ { "created": "Thu, 2 Jul 2015 17:28:11 GMT", "version": "v1" } ]
2015-07-03
[ [ "Feruglio", "Ferruccio", "" ], [ "Patel", "Ketan M.", "" ], [ "Vicino", "Denise", "" ] ]
We provide a unified description of fermion masses and mixing angles in the framework of a supersymmetric grand unified SO(10) model with anarchic Yukawa couplings of order unity. The space-time is five dimensional and the extra flat spatial dimension is compactified on the orbifold $S^1/(Z_2 \times Z_2')$, leading to Pati-Salam gauge symmetry on the boundary where Yukawa interactions are localised. The gauge symmetry breaking is completed by means of a rather economic scalar sector, avoiding the doublet-triplet splitting problem. The matter fields live in the bulk and their massless modes get exponential profiles, which naturally explain the mass hierarchy of the different fermion generations. Quarks and leptons properties are naturally reproduced by a mechanism, first proposed by Kitano and Li, that lifts the SO(10) degeneracy of bulk masses in terms of a single parameter. The model provides a realistic pattern of fermion masses and mixing angles for large values of $\tan\beta$. It favours normally ordered neutrino mass spectrum with the lightest neutrino mass below 0.01 eV and no preference for leptonic CP violating phases. The right handed neutrino mass spectrum is very hierarchical and does not allow for thermal leptogenesis. We analyse several variants of the basic framework and find that the results concerning the fermion spectrum are remarkably stable.
1503.06827
Hai-Yang Cheng
Hai-Yang Cheng, Chun-Khiang Chua, Keh-Fei Liu
Revisiting Scalar Glueballs
21 pages, comments on the f0(1370) meson were made, uncertainties in the glueball-quarkonium mixing matrix elements included, discussions on the \eta\eta modes and many new references added. Version to appear in PRD
Phys. Rev. D 92, 094006 (2015)
10.1103/PhysRevD.92.094006
null
hep-ph hep-ex hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is commonly believed that the lowest-lying scalar glueball lies somewhere in the isosinglet scalar mesons $f_0(1370), f_0(1500)$ and $f_0(1710)$ denoted generically by $f_{0}$. In this work we consider lattice calculations and experimental data to infer the glue and $q\bar q$ components of $f_0$. These include the calculations of the scalar glueball masses in quenched and unquenched lattice QCD, measurements of the radiative decays $J/\psi\to\gamma f_{0}$, the ratio of $f_{0}$ decays to $\pi\pi$ and $K\bar K$, the ratio of $J/\psi$ decays to $f_0(1710)\omega$ and $f_0(1710)\phi$, the $f_0$ contributions to $B_s\to J/\psi\pi^+\pi^-$, and the near mass degeneracy of $a_0(1450)$ and $K_0^*(1430)$. All analyses suggest the prominent glueball nature of $f_0(1710)$ and the flavor octet structure of $f_0(1500)$.
[ { "created": "Mon, 23 Mar 2015 20:45:32 GMT", "version": "v1" }, { "created": "Mon, 30 Mar 2015 08:17:48 GMT", "version": "v2" }, { "created": "Sat, 10 Oct 2015 03:07:47 GMT", "version": "v3" } ]
2015-11-11
[ [ "Cheng", "Hai-Yang", "" ], [ "Chua", "Chun-Khiang", "" ], [ "Liu", "Keh-Fei", "" ] ]
It is commonly believed that the lowest-lying scalar glueball lies somewhere in the isosinglet scalar mesons $f_0(1370), f_0(1500)$ and $f_0(1710)$ denoted generically by $f_{0}$. In this work we consider lattice calculations and experimental data to infer the glue and $q\bar q$ components of $f_0$. These include the calculations of the scalar glueball masses in quenched and unquenched lattice QCD, measurements of the radiative decays $J/\psi\to\gamma f_{0}$, the ratio of $f_{0}$ decays to $\pi\pi$ and $K\bar K$, the ratio of $J/\psi$ decays to $f_0(1710)\omega$ and $f_0(1710)\phi$, the $f_0$ contributions to $B_s\to J/\psi\pi^+\pi^-$, and the near mass degeneracy of $a_0(1450)$ and $K_0^*(1430)$. All analyses suggest the prominent glueball nature of $f_0(1710)$ and the flavor octet structure of $f_0(1500)$.
hep-ph/0609104
Maurizio Piai
Maurizio Piai
Walking in the third millennium
4 pages
null
null
null
hep-ph
null
Based on recent progress in the study of strong dynamics in conformal field theories, I construct a simple, one family model of dynamical electro-weak symmetry breaking. Non-perturbative effects can be computed systematically. The model does not suffer from the well known, parametrically big, phenomenological difficulties of traditional technicolor models, is compatible with all present experimental data and is testable at the LHC.
[ { "created": "Mon, 11 Sep 2006 19:46:02 GMT", "version": "v1" } ]
2007-05-23
[ [ "Piai", "Maurizio", "" ] ]
Based on recent progress in the study of strong dynamics in conformal field theories, I construct a simple, one family model of dynamical electro-weak symmetry breaking. Non-perturbative effects can be computed systematically. The model does not suffer from the well known, parametrically big, phenomenological difficulties of traditional technicolor models, is compatible with all present experimental data and is testable at the LHC.
hep-ph/9603418
Dandi Wu
Dan-di Wu and Yue-liang Wu
CP symmetry and fermion masses in O(10) grand unification models
17 pages, Latex file
Mod.Phys.Lett. A11 (1996) 2703-2714
10.1142/S0217732396002708
Prairie View A&M, HEP-12-95
hep-ph
null
O(10) grand unification models which do not necessarily have an extra global symmetry are discussed, taking the model with one 10-plet in the Yukawa sector as an example. A strong correlation between mass ratios and CP is found. The mass relation $m_t/m_b=v_u/v_d$ is recovered when $G_W=0$; and another special relation $m_t/m_b=G_E/G_W$ appears when $v_d=0$, where $G_{E,W}$ are Yukawa coupling constants and $v_{u,d}$ are VEVs. To facilitate this discussion, a set of $O(10)$ $\gamma$- matrices is offered based on a physical representation of the spinors and that of the vector of the $SO(10)$ group. Flavor changing neutral currents in such models are also discussed.
[ { "created": "Tue, 26 Mar 1996 20:00:06 GMT", "version": "v1" }, { "created": "Mon, 15 Apr 1996 16:37:22 GMT", "version": "v2" }, { "created": "Mon, 23 Sep 1996 18:16:23 GMT", "version": "v3" } ]
2009-10-28
[ [ "Wu", "Dan-di", "" ], [ "Wu", "Yue-liang", "" ] ]
O(10) grand unification models which do not necessarily have an extra global symmetry are discussed, taking the model with one 10-plet in the Yukawa sector as an example. A strong correlation between mass ratios and CP is found. The mass relation $m_t/m_b=v_u/v_d$ is recovered when $G_W=0$; and another special relation $m_t/m_b=G_E/G_W$ appears when $v_d=0$, where $G_{E,W}$ are Yukawa coupling constants and $v_{u,d}$ are VEVs. To facilitate this discussion, a set of $O(10)$ $\gamma$- matrices is offered based on a physical representation of the spinors and that of the vector of the $SO(10)$ group. Flavor changing neutral currents in such models are also discussed.
2307.10367
Benjamin Fuks
Chiara Arina, Benjamin Fuks, Jan Heisig, Michael Kr\"amer, Luca Mantani and Luca Panizzi
Comprehensive exploration of t-channel simplified models of dark matter
20 pages, 6 figures; version accepted by PRD
Phys. Rev. D 108 (2023) 115007
10.1103/PhysRevD.108.115007
TTK-23-19
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyse six classes of t-channel dark matter simplified models in which the Standard Model field content is extended by a coloured mediator and a dark matter state. The two new states are enforced to be odd under a new parity, while all Standard Model fields are taken even so that dark matter stability is guaranteed. We study several possibilities for the spin of the new particles and the self-conjugate property of the dark matter, and we focus on model configurations in which the dark matter couples to the right-handed up quark for simplicity. We investigate how the parameter spaces of the six models can be constrained by current and future cosmological, astrophysical and collider searches, and we highlight the strong complementary between those probes. Our results demonstrate that scenarios featuring a complex (non self-conjugate) dark matter field are excluded by cosmology and astrophysics alone, the only possibility to avoid these bounds being to invoke very weak couplings and mechanisms such as conversion-driven freeze-out. For models with self-conjugate dark matter, mediator and dark matter masses are pushed deep into the TeV regime, with the lower limits on the mediator mass reaching 3 to 4 TeV and those on the dark matter mass 1 to 2 TeV. In large parts of the parameter space these strong bounds are driven by same-sign mediator pair production, a channel so far not considered in the experimental analyses embedding t-channel dark matter model interpretations.
[ { "created": "Wed, 19 Jul 2023 18:00:02 GMT", "version": "v1" }, { "created": "Thu, 30 Nov 2023 08:18:57 GMT", "version": "v2" } ]
2023-12-11
[ [ "Arina", "Chiara", "" ], [ "Fuks", "Benjamin", "" ], [ "Heisig", "Jan", "" ], [ "Krämer", "Michael", "" ], [ "Mantani", "Luca", "" ], [ "Panizzi", "Luca", "" ] ]
We analyse six classes of t-channel dark matter simplified models in which the Standard Model field content is extended by a coloured mediator and a dark matter state. The two new states are enforced to be odd under a new parity, while all Standard Model fields are taken even so that dark matter stability is guaranteed. We study several possibilities for the spin of the new particles and the self-conjugate property of the dark matter, and we focus on model configurations in which the dark matter couples to the right-handed up quark for simplicity. We investigate how the parameter spaces of the six models can be constrained by current and future cosmological, astrophysical and collider searches, and we highlight the strong complementary between those probes. Our results demonstrate that scenarios featuring a complex (non self-conjugate) dark matter field are excluded by cosmology and astrophysics alone, the only possibility to avoid these bounds being to invoke very weak couplings and mechanisms such as conversion-driven freeze-out. For models with self-conjugate dark matter, mediator and dark matter masses are pushed deep into the TeV regime, with the lower limits on the mediator mass reaching 3 to 4 TeV and those on the dark matter mass 1 to 2 TeV. In large parts of the parameter space these strong bounds are driven by same-sign mediator pair production, a channel so far not considered in the experimental analyses embedding t-channel dark matter model interpretations.
2212.11825
Edward Shuryak
Edward Shuryak
Mesonic "screening masses" in high temperature QCD
null
null
null
null
hep-ph hep-lat
http://creativecommons.org/licenses/by/4.0/
Lattice studies of QCD at high temperature has investigated the so called ``screening masses", corresponding to quark-antiquark states propagating in $spatial$ (rather than time) direction. Thirty years ago we pointed out that those should correspond to states of 2+1 dimensional quarkonia, and in this work we show that this correspondence provide quantitative description of the lattice data.
[ { "created": "Thu, 22 Dec 2022 16:04:54 GMT", "version": "v1" } ]
2022-12-23
[ [ "Shuryak", "Edward", "" ] ]
Lattice studies of QCD at high temperature has investigated the so called ``screening masses", corresponding to quark-antiquark states propagating in $spatial$ (rather than time) direction. Thirty years ago we pointed out that those should correspond to states of 2+1 dimensional quarkonia, and in this work we show that this correspondence provide quantitative description of the lattice data.
1903.05597
Diana C. Rivera-Agudelo
Diana C. Rivera-Agudelo, S. L. Tostado, Abdel P\'erez-Lorenzana
Deviations to Tri-Bi-Maximal mixing in the limit of $\mu-\tau$ symmetry
15 pages, 7 figures
null
10.1016/j.physletb.2019.05.017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the limit of an approximate $\mu-\tau$ symmetry in the neutrino mass matrix, we explore deviations to the Tri-Bi-Maximal mixing pattern in the neutrino sector. We consider two different ansatzes for the corrected pattern to predict the current values of neutrino mixing parameters. We show that it is possible to constrain the Majorana $CP$ phases by studying their correlation to the mixing parameters and we study their effects on neutrinoless double beta decay observables. These predictions are sharp for the quasi-degenerate ordering and can be tested in upcoming experiments.
[ { "created": "Wed, 13 Mar 2019 16:54:22 GMT", "version": "v1" } ]
2019-05-22
[ [ "Rivera-Agudelo", "Diana C.", "" ], [ "Tostado", "S. L.", "" ], [ "Pérez-Lorenzana", "Abdel", "" ] ]
In the limit of an approximate $\mu-\tau$ symmetry in the neutrino mass matrix, we explore deviations to the Tri-Bi-Maximal mixing pattern in the neutrino sector. We consider two different ansatzes for the corrected pattern to predict the current values of neutrino mixing parameters. We show that it is possible to constrain the Majorana $CP$ phases by studying their correlation to the mixing parameters and we study their effects on neutrinoless double beta decay observables. These predictions are sharp for the quasi-degenerate ordering and can be tested in upcoming experiments.
1106.3082
Viraf Mehta
Alon E. Faraggi and Viraf M. Mehta
Proton Stability and Light $Z^\prime$ Inspired by String Derived Models
22 Pages
null
10.1103/PhysRevD.84.086006
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Proton stability is one of the most perplexing puzzles in particle physics. While the renormalizable Standard Model forbids proton decay mediating operators due to accidental global symmetries, many of its extensions introduce such dimension four, five and six operators. Furthermore, it is, in general, expected that quantum gravity only respects local gauge, or discreet, symmetries. String theory provides the arena to study particle physics in a consistent framework of perturbative quantum gravity. An appealing proposition, in this context, is that the dangerous operators are suppressed by an Abelian gauge symmetry, which is broken near the TeV scale. A viable U(1) symmetry should also be anomaly free, be family universal, and allow the generation of fermion masses via the Higgs mechanism. We discuss such U(1) symmetries that arise in quasi--realistic free fermionic heterotic--string derived models. Ensuring that the U(1) symmetry is anomaly free at the low scale requires that the Standard Model spectrum is augmented by additional states that are compatible with the charge assignments in the string models. We construct such string--inspired models and discuss some of their phenomenological implications.
[ { "created": "Wed, 15 Jun 2011 20:01:19 GMT", "version": "v1" } ]
2013-05-29
[ [ "Faraggi", "Alon E.", "" ], [ "Mehta", "Viraf M.", "" ] ]
Proton stability is one of the most perplexing puzzles in particle physics. While the renormalizable Standard Model forbids proton decay mediating operators due to accidental global symmetries, many of its extensions introduce such dimension four, five and six operators. Furthermore, it is, in general, expected that quantum gravity only respects local gauge, or discreet, symmetries. String theory provides the arena to study particle physics in a consistent framework of perturbative quantum gravity. An appealing proposition, in this context, is that the dangerous operators are suppressed by an Abelian gauge symmetry, which is broken near the TeV scale. A viable U(1) symmetry should also be anomaly free, be family universal, and allow the generation of fermion masses via the Higgs mechanism. We discuss such U(1) symmetries that arise in quasi--realistic free fermionic heterotic--string derived models. Ensuring that the U(1) symmetry is anomaly free at the low scale requires that the Standard Model spectrum is augmented by additional states that are compatible with the charge assignments in the string models. We construct such string--inspired models and discuss some of their phenomenological implications.
hep-ph/0203179
Alexander Kusenko
Graciela Gelmini, Alexander Kusenko, and Shmuel Nussinov
Experimental identification of non-pointlike dark-matter candidates
4 pages; minor changes, references added
Phys.Rev.Lett. 89 (2002) 101302
10.1103/PhysRevLett.89.101302
UCLA/01/TEP/7
hep-ph astro-ph
null
We show that direct dark matter detection experiments can distinguish between pointlike and non-pointlike dark-matter candidates. The shape of the nuclear recoil energy spectrum from pointlike dark-matter particles, e.g., neutralinos, is determined by the velocity distribution of dark matter in the galactic halo and by nuclear form factors. In contrast, typical cross sections of non-pointlike dark matter, for example, Q-balls, have a new form factor, which decreases rapidly with the recoil energy. Therefore, a signal from non-pointlike dark matter is expected to peak near the experimental threshold and to fall off rapidly at higher energies. Although the width of the signal is practically independent of the dark matter velocity dispersion, its height is expected to exhibit an annual modulation due to the changes in the dark matter flux.
[ { "created": "Tue, 19 Mar 2002 07:24:56 GMT", "version": "v1" }, { "created": "Wed, 3 Apr 2002 00:36:41 GMT", "version": "v2" }, { "created": "Thu, 25 Jul 2002 09:48:27 GMT", "version": "v3" } ]
2009-11-07
[ [ "Gelmini", "Graciela", "" ], [ "Kusenko", "Alexander", "" ], [ "Nussinov", "Shmuel", "" ] ]
We show that direct dark matter detection experiments can distinguish between pointlike and non-pointlike dark-matter candidates. The shape of the nuclear recoil energy spectrum from pointlike dark-matter particles, e.g., neutralinos, is determined by the velocity distribution of dark matter in the galactic halo and by nuclear form factors. In contrast, typical cross sections of non-pointlike dark matter, for example, Q-balls, have a new form factor, which decreases rapidly with the recoil energy. Therefore, a signal from non-pointlike dark matter is expected to peak near the experimental threshold and to fall off rapidly at higher energies. Although the width of the signal is practically independent of the dark matter velocity dispersion, its height is expected to exhibit an annual modulation due to the changes in the dark matter flux.
1801.03803
Tanya Obikhod
T.V. Obikhod, I.A. Petrenko
Computer modeling of properties of Kaluza-Klein particles and their searches at the LHC
16 pages, 9 figures
Advances in High Energy Physics, vol. 2018, Article ID 3471023, 9 pages
10.1155/2018/3471023
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Standard Model problems lead to the new theories of extra dimensions: Randall-Sundrum model, Arkani-Hamed-Dimopoulos-Dvali model and TeV$^{-1}$ model. In the framework of these models with the help of computer program Pythia8.2 were calculated the production cross sections for Kaluza-Klein particles at various energies at the LHC. The generation of monojet events from scalar graviton emission was considered for number of extra dimensions, n=2, 4, 6, for the energy at the LHC 14 TeV. Also are studied the graviton production processes through the gluon-gluon, quark-gluon and quark-quark fusion processes and found some periodicity in the behavior of the graviton mass spectrum. Within Randall-Sundrum scenario were calculated $\sigma\times$ Br for production process of massive graviton, gg $\rightarrow$ $G^{*}$, and the most probable processes of graviton decay at 13 TeV, 14 TeV and 100 TeV.
[ { "created": "Thu, 11 Jan 2018 15:06:43 GMT", "version": "v1" } ]
2020-04-23
[ [ "Obikhod", "T. V.", "" ], [ "Petrenko", "I. A.", "" ] ]
The Standard Model problems lead to the new theories of extra dimensions: Randall-Sundrum model, Arkani-Hamed-Dimopoulos-Dvali model and TeV$^{-1}$ model. In the framework of these models with the help of computer program Pythia8.2 were calculated the production cross sections for Kaluza-Klein particles at various energies at the LHC. The generation of monojet events from scalar graviton emission was considered for number of extra dimensions, n=2, 4, 6, for the energy at the LHC 14 TeV. Also are studied the graviton production processes through the gluon-gluon, quark-gluon and quark-quark fusion processes and found some periodicity in the behavior of the graviton mass spectrum. Within Randall-Sundrum scenario were calculated $\sigma\times$ Br for production process of massive graviton, gg $\rightarrow$ $G^{*}$, and the most probable processes of graviton decay at 13 TeV, 14 TeV and 100 TeV.
hep-ph/0502141
Dan Pirjol
Dan Pirjol
Theory of hadronic B decays
Contribution to the 3rd Conference on Flavor Physics and CP Violation (FPCP04), Daegu, Korea; 9 pages, 2 figures
Nucl.Phys.Proc.Suppl.156:81-86,2006
10.1016/j.nuclphysbps.2006.02.139
null
hep-ph
null
I give an overview of the theory of hadronic nonleptonic B decays into two light mesons. Using the soft-collinear effective theory (SCET), a factorization theorem for these processes has been proven to leading order in 1/mb. The phenomenological implications of this factorization relation for B-> \pi\pi decays are discussed, together with the prospects for determining the weak phase \alpha(\phi_2) from these modes.
[ { "created": "Tue, 15 Feb 2005 19:27:43 GMT", "version": "v1" }, { "created": "Wed, 16 Feb 2005 03:40:18 GMT", "version": "v2" } ]
2008-11-26
[ [ "Pirjol", "Dan", "" ] ]
I give an overview of the theory of hadronic nonleptonic B decays into two light mesons. Using the soft-collinear effective theory (SCET), a factorization theorem for these processes has been proven to leading order in 1/mb. The phenomenological implications of this factorization relation for B-> \pi\pi decays are discussed, together with the prospects for determining the weak phase \alpha(\phi_2) from these modes.
1504.00332
Adrian Carmona
Adrian Carmona and Mikael Chala
Composite Dark Sectors
20 pages, 5 figures; v2; references added and Figure 4 corrected; matches published version in JHEP
null
null
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by-nc-sa/3.0/
We introduce a new paradigm in Composite Dark Sectors, where the full Standard Model (including the Higgs boson) is extended with a strongly-interacting composite sector with global symmetry group $\mathcal{G}$ spontaneously broken to $\mathcal{H}\subset \mathcal{G}$. We show that, under well-motivated conditions, the lightest neutral pseudo Nambu-Goldstone bosons are natural dark matter candidates for they are protected by a parity symmetry not even broken in the electroweak phase. These models are characterized by only two free parameters, namely the typical coupling $g_D$ and the scale $f_D$ of the composite sector, and are therefore very predictive. We consider in detail two minimal scenarios, $SU(3)/[SU(2)\times U(1)]$ and $[SU(2)^2\times U(1)]/[SU(2)\times U(1)]$, which provide a dynamical realization of the Inert Doublet and Triplet models, respectively. We show that the radiatively-induced potential can be computed in a five-dimensional description with modified boundary conditions with respect to Composite Higgs models. Finally, the dark matter candidates are shown to be compatible, in a large region of the parameter space, with current bounds from dark matter searches as well as electroweak and collider constraints on new resonances.
[ { "created": "Wed, 1 Apr 2015 18:30:15 GMT", "version": "v1" }, { "created": "Mon, 1 Jun 2015 14:19:50 GMT", "version": "v2" } ]
2015-06-02
[ [ "Carmona", "Adrian", "" ], [ "Chala", "Mikael", "" ] ]
We introduce a new paradigm in Composite Dark Sectors, where the full Standard Model (including the Higgs boson) is extended with a strongly-interacting composite sector with global symmetry group $\mathcal{G}$ spontaneously broken to $\mathcal{H}\subset \mathcal{G}$. We show that, under well-motivated conditions, the lightest neutral pseudo Nambu-Goldstone bosons are natural dark matter candidates for they are protected by a parity symmetry not even broken in the electroweak phase. These models are characterized by only two free parameters, namely the typical coupling $g_D$ and the scale $f_D$ of the composite sector, and are therefore very predictive. We consider in detail two minimal scenarios, $SU(3)/[SU(2)\times U(1)]$ and $[SU(2)^2\times U(1)]/[SU(2)\times U(1)]$, which provide a dynamical realization of the Inert Doublet and Triplet models, respectively. We show that the radiatively-induced potential can be computed in a five-dimensional description with modified boundary conditions with respect to Composite Higgs models. Finally, the dark matter candidates are shown to be compatible, in a large region of the parameter space, with current bounds from dark matter searches as well as electroweak and collider constraints on new resonances.
hep-ph/9308248
German Valencia
S. Dawson and G. Valencia
Signals For Parity Violation in the Electroweak Symmetry Breaking Sector
Some sentences were added and others changed to clarify the discussion, 14 pages LaTeX
Phys.Rev. D49 (1994) 2188-2196
10.1103/PhysRevD.49.2188
null
hep-ph
null
We consider the possibility of observing a parity violating but $CP$ conserving interaction in the symmetry breaking sector of the electroweak theory. We find that the best probe for such an interaction is a forward-backward asymmetry in $W^+W^-$ production from polarized $e^-_R e^+_L$ collisions. An observable asymmetry would be strong evidence against a custodial $SU(2)$ symmetry. We also discuss the effects of such an interaction in future $e^- \gamma$ colliders as well as in rare decays of $K$ and $B$ mesons.
[ { "created": "Mon, 9 Aug 1993 19:08:01 GMT", "version": "v1" }, { "created": "Thu, 3 Feb 1994 22:17:24 GMT", "version": "v2" } ]
2009-10-22
[ [ "Dawson", "S.", "" ], [ "Valencia", "G.", "" ] ]
We consider the possibility of observing a parity violating but $CP$ conserving interaction in the symmetry breaking sector of the electroweak theory. We find that the best probe for such an interaction is a forward-backward asymmetry in $W^+W^-$ production from polarized $e^-_R e^+_L$ collisions. An observable asymmetry would be strong evidence against a custodial $SU(2)$ symmetry. We also discuss the effects of such an interaction in future $e^- \gamma$ colliders as well as in rare decays of $K$ and $B$ mesons.
1911.08737
HyungJoo Kim
HyungJoo Kim, Philipp Gubler
The $\phi$ meson with finite momentum in a dense medium
8 pages, 4 figures; version accepted for publication on PLB
null
10.1016/j.physletb.2020.135412
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The dispersion relation of the $\phi$ meson in nuclear matter is studied in a QCD sum rule approach. In a dense medium, longitudinal and transverse modes of vector particles can have independently modified dispersion relations due to broken Lorentz invariance. Employing the full set of independent operators and corresponding Wilson coefficients up to operator dimension 6, the $\phi$ meson QCD sum rules are analyzed with changing densities and momenta. The non-trivial momentum dependence of the $\phi$ meson mass is found to have opposite signs for the longitudinal and transverse modes. Specifically, the mass is reduced by 5 MeV for the longitudinal mode, while its increase amounts to 7 Mev for the transverse mode, both at a momentum scale of 1 GeV. In an experiment which does not distinguish between longitudinal and transverse polarizations, this could in principle be seen as two separated peaks at large momenta. Taking however broadening effects into account, the momentum dependence will most likely be seen as a small but positive effective mass shift and an increased effective width for non-zero momenta.
[ { "created": "Wed, 20 Nov 2019 06:56:32 GMT", "version": "v1" }, { "created": "Wed, 15 Apr 2020 05:53:47 GMT", "version": "v2" } ]
2020-04-22
[ [ "Kim", "HyungJoo", "" ], [ "Gubler", "Philipp", "" ] ]
The dispersion relation of the $\phi$ meson in nuclear matter is studied in a QCD sum rule approach. In a dense medium, longitudinal and transverse modes of vector particles can have independently modified dispersion relations due to broken Lorentz invariance. Employing the full set of independent operators and corresponding Wilson coefficients up to operator dimension 6, the $\phi$ meson QCD sum rules are analyzed with changing densities and momenta. The non-trivial momentum dependence of the $\phi$ meson mass is found to have opposite signs for the longitudinal and transverse modes. Specifically, the mass is reduced by 5 MeV for the longitudinal mode, while its increase amounts to 7 Mev for the transverse mode, both at a momentum scale of 1 GeV. In an experiment which does not distinguish between longitudinal and transverse polarizations, this could in principle be seen as two separated peaks at large momenta. Taking however broadening effects into account, the momentum dependence will most likely be seen as a small but positive effective mass shift and an increased effective width for non-zero momenta.
1810.00486
David Blaschke
K. A. Bugaev, A. I. Ivanytskyi, V. V. Sagun, B. E. Grinyuk, D. O. Savchenko, G. M. Zinovjev, E. G. Nikonov, L. V. Bravina, E. E. Zabrodin, D. B. Blaschke, A. V. Taranenko, L. Turko
Hard-core Radius of Nucleons within the Induced Surface Tension Approach
12 pages, 4 figures, references added, typos corrected
Universe 5 (2), 63 (2019)
10.3390/universe5020063
null
hep-ph astro-ph.HE nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we discuss a novel approach to model the hadronic and nuclear matter equations of state using the induced surface tension concept. Since the obtained equations of state, classical and quantum, are among the most successful ones in describing the properties of low density phases of strongly interacting matter, they set strong restrictions on the possible value of the hard-core radius of nucleons. Therefore, we perform a detailed analysis of its value which follows from hadronic and nuclear matter properties and find the most trustworthy range of its values: the hard-core radius of nucleons is 0.30--0.36 fm. A comparison with the phenomenology of neutron stars implies that the hard-core radius of nucleons has to be temperature and density dependent.
[ { "created": "Sun, 30 Sep 2018 23:48:32 GMT", "version": "v1" }, { "created": "Tue, 6 Nov 2018 18:49:34 GMT", "version": "v2" } ]
2020-05-19
[ [ "Bugaev", "K. A.", "" ], [ "Ivanytskyi", "A. I.", "" ], [ "Sagun", "V. V.", "" ], [ "Grinyuk", "B. E.", "" ], [ "Savchenko", "D. O.", "" ], [ "Zinovjev", "G. M.", "" ], [ "Nikonov", "E. G.", "" ], [ "Bravina", "L. V.", "" ], [ "Zabrodin", "E. E.", "" ], [ "Blaschke", "D. B.", "" ], [ "Taranenko", "A. V.", "" ], [ "Turko", "L.", "" ] ]
In this work we discuss a novel approach to model the hadronic and nuclear matter equations of state using the induced surface tension concept. Since the obtained equations of state, classical and quantum, are among the most successful ones in describing the properties of low density phases of strongly interacting matter, they set strong restrictions on the possible value of the hard-core radius of nucleons. Therefore, we perform a detailed analysis of its value which follows from hadronic and nuclear matter properties and find the most trustworthy range of its values: the hard-core radius of nucleons is 0.30--0.36 fm. A comparison with the phenomenology of neutron stars implies that the hard-core radius of nucleons has to be temperature and density dependent.
0805.1540
Shmuel Nussinov
Shmuel Nussinov
Is the Froissart bound relevant for the total pp cross section at s=(14 TeV)^2?
17 Pages, 1 Figure
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Froissart bound limmits the asymptotic s->infinity behavior of crossections by (\pi/t_0) ln ^2 (s/{(s_0)} where t_0 is the lightest exchanged particle, or more generally the nearest ssingularity, in the t channel. We suggest that in comparing this bound with data at energies less than those of LHC, gluebaall masses raather than the small pion mass should be used for (t_0)^{1/2}.
[ { "created": "Sun, 11 May 2008 15:53:55 GMT", "version": "v1" } ]
2008-05-13
[ [ "Nussinov", "Shmuel", "" ] ]
The Froissart bound limmits the asymptotic s->infinity behavior of crossections by (\pi/t_0) ln ^2 (s/{(s_0)} where t_0 is the lightest exchanged particle, or more generally the nearest ssingularity, in the t channel. We suggest that in comparing this bound with data at energies less than those of LHC, gluebaall masses raather than the small pion mass should be used for (t_0)^{1/2}.
2106.13534
James Ingoldby
T. Appelquist, R. C. Brower, K. K. Cushman, G. T. Fleming, A. Gasbarro, A. Hasenfratz, J. Ingoldby, X. Y. Jin, J. Kiskis, E. T. Neil, J. C. Osborn, C. Rebbi, E. Rinaldi, D. Schaich, P. Vranas, E. Weinberg, O. Witzel (for the LSD Collaboration)
Goldstone Boson Scattering with a Light Composite Scalar
13 pages, 6 figures, 4 tables. References and clarifying comments added. To match published version
null
10.1103/PhysRevD.105.034505
RIKEN-iTHEMS-Report-21, LLNL-JRNL-823329, SI-HEP-2021-18
hep-ph hep-lat
http://creativecommons.org/licenses/by/4.0/
The appearance of a light composite $0^+$ scalar resonance in nearly conformal gauge-fermion theories motivates further study of the low energy structure of these theories. To this end, we present a nonperturbative lattice calculation of s-wave scattering of Goldstone bosons in the maximal-isospin channel in SU(3) gauge theory with $N_f=8$ light, degenerate flavors. The scattering phase shift is measured both for different values of the underlying fermion mass and for different values of the scattering momentum. We examine the effect of a light flavor-singlet scalar (reported in earlier studies) on Goldstone boson scattering, employing a dilaton effective field theory (EFT) at the tree level. The EFT gives a good description of the scattering data, insofar as the magnitude of deviations between EFT and lattice data are no larger than the expected size of next-to-leading order corrections in the EFT.
[ { "created": "Fri, 25 Jun 2021 09:57:05 GMT", "version": "v1" }, { "created": "Fri, 4 Mar 2022 14:14:08 GMT", "version": "v2" } ]
2022-03-07
[ [ "Appelquist", "T.", "", "for the LSD Collaboration" ], [ "Brower", "R. C.", "", "for the LSD Collaboration" ], [ "Cushman", "K. K.", "", "for the LSD Collaboration" ], [ "Fleming", "G. T.", "", "for the LSD Collaboration" ], [ "Gasbarro", "A.", "", "for the LSD Collaboration" ], [ "Hasenfratz", "A.", "", "for the LSD Collaboration" ], [ "Ingoldby", "J.", "", "for the LSD Collaboration" ], [ "Jin", "X. Y.", "", "for the LSD Collaboration" ], [ "Kiskis", "J.", "", "for the LSD Collaboration" ], [ "Neil", "E. T.", "", "for the LSD Collaboration" ], [ "Osborn", "J. C.", "", "for the LSD Collaboration" ], [ "Rebbi", "C.", "", "for the LSD Collaboration" ], [ "Rinaldi", "E.", "", "for the LSD Collaboration" ], [ "Schaich", "D.", "", "for the LSD Collaboration" ], [ "Vranas", "P.", "", "for the LSD Collaboration" ], [ "Weinberg", "E.", "", "for the LSD Collaboration" ], [ "Witzel", "O.", "", "for the LSD Collaboration" ] ]
The appearance of a light composite $0^+$ scalar resonance in nearly conformal gauge-fermion theories motivates further study of the low energy structure of these theories. To this end, we present a nonperturbative lattice calculation of s-wave scattering of Goldstone bosons in the maximal-isospin channel in SU(3) gauge theory with $N_f=8$ light, degenerate flavors. The scattering phase shift is measured both for different values of the underlying fermion mass and for different values of the scattering momentum. We examine the effect of a light flavor-singlet scalar (reported in earlier studies) on Goldstone boson scattering, employing a dilaton effective field theory (EFT) at the tree level. The EFT gives a good description of the scattering data, insofar as the magnitude of deviations between EFT and lattice data are no larger than the expected size of next-to-leading order corrections in the EFT.
1110.5642
Elias Kiritsis
Elias Kiritsis, Anastasios Taliotis
Mini-Black-Hole production at RHIC and LHC
Latex, 10 pages, 2 figures
null
null
CCTP-2011-35
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We argue that heavy-ion collisions provide the best testing ground for mini-black hole physics as $M_P\simeq 4 GeV$ for the gravity dual of YM and give concrete evidence for a new extra dimension, that is visible only to the strong interactions. We analyse the process of production evolution and decay of the mini-black-holes by using recent results on gravity duals of YM. There are several novelties compared with the traditional story of black hole evaporation, including Bjorken scaling instead of sphericity, evaporation via bubble nucleation instead of the Hawking mechanism and lepton-poor final states. Multiplicities are estimated using shock-wave scattering techniques. It is argued that high-multiplicity/high energy pp collisions will also show similar characteristics of mini-black-hole production and decay.
[ { "created": "Tue, 25 Oct 2011 20:00:04 GMT", "version": "v1" } ]
2011-10-27
[ [ "Kiritsis", "Elias", "" ], [ "Taliotis", "Anastasios", "" ] ]
We argue that heavy-ion collisions provide the best testing ground for mini-black hole physics as $M_P\simeq 4 GeV$ for the gravity dual of YM and give concrete evidence for a new extra dimension, that is visible only to the strong interactions. We analyse the process of production evolution and decay of the mini-black-holes by using recent results on gravity duals of YM. There are several novelties compared with the traditional story of black hole evaporation, including Bjorken scaling instead of sphericity, evaporation via bubble nucleation instead of the Hawking mechanism and lepton-poor final states. Multiplicities are estimated using shock-wave scattering techniques. It is argued that high-multiplicity/high energy pp collisions will also show similar characteristics of mini-black-hole production and decay.
1712.07126
Doojin Kim
Gian F. Giudice, Doojin Kim, Jong-Chul Park, Seodong Shin
Inelastic Boosted Dark Matter at Direct Detection Experiments
12 pages, 6 figures, 2 tables
null
10.1016/j.physletb.2018.03.043
CERN-TH-2017-258, EFI-17-24
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore a novel class of multi-particle dark sectors, called Inelastic Boosted Dark Matter (iBDM). These models are constructed by combining properties of particles that scatter off matter by making transitions to heavier states (Inelastic Dark Matter) with properties of particles that are produced with a large Lorentz boost in annihilation processes in the galactic halo (Boosted Dark Matter). This combination leads to new signals that can be observed at ordinary direct detection experiments, but require unconventional searches for energetic recoil electrons in coincidence with displaced multi-track events. Related experimental strategies can also be used to probe MeV-range boosted dark matter via their interactions with electrons inside the target material.
[ { "created": "Tue, 19 Dec 2017 19:00:01 GMT", "version": "v1" } ]
2018-05-09
[ [ "Giudice", "Gian F.", "" ], [ "Kim", "Doojin", "" ], [ "Park", "Jong-Chul", "" ], [ "Shin", "Seodong", "" ] ]
We explore a novel class of multi-particle dark sectors, called Inelastic Boosted Dark Matter (iBDM). These models are constructed by combining properties of particles that scatter off matter by making transitions to heavier states (Inelastic Dark Matter) with properties of particles that are produced with a large Lorentz boost in annihilation processes in the galactic halo (Boosted Dark Matter). This combination leads to new signals that can be observed at ordinary direct detection experiments, but require unconventional searches for energetic recoil electrons in coincidence with displaced multi-track events. Related experimental strategies can also be used to probe MeV-range boosted dark matter via their interactions with electrons inside the target material.
1112.4568
Shinhong Kim
Shin-Hong Kim, Ken-ichi Takemasa, Yuji Takeuchi, and Shuji Matsuura
Search for Radiative Decays of Cosmic Background Neutrino using Cosmic Infrared Background Energy Spectrum
null
J. Phys. Soc Jpn. , Vol.81, No.2, p.024101 (2012)
10.1143/JPSJ.81.024101
null
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose to search for the neutrino radiative decay by fitting a photon energy spectrum of the cosmic infrared background to a sum of the photon energy spectrum from the neutrino radiative decay and a continuum. By comparing the present cosmic infrared background energy spectrum observed by AKARI and Spitzer to the photon energy spectrum expected from neutrino radiative decay with a maximum likelihood method, we obatined a lifetime lower limit of $3.1 \times 10^{12}$ to $3.8 \times 10^{12}$ years at 95% confidence level for the third generation neutrino $\nu_3$ in the $\nu_3$ mass range between 50 \mmev and 150 \mmev under the present constraints by the neutrino oscillation measurements. In the left-right symmetric model, the minimum lifetime of $\nu_3$ is predicted to be $1.5 \times 10^{17}$ years for $m_3$ of 50 \mmev. We studied the feasibility of the observation of the neutrino radiative decay with a lifetime of $1.5 \times 10^{17}$ years, by measuring a continuous energy spectrum of the cosmic infrared background.
[ { "created": "Tue, 20 Dec 2011 04:36:22 GMT", "version": "v1" } ]
2012-01-19
[ [ "Kim", "Shin-Hong", "" ], [ "Takemasa", "Ken-ichi", "" ], [ "Takeuchi", "Yuji", "" ], [ "Matsuura", "Shuji", "" ] ]
We propose to search for the neutrino radiative decay by fitting a photon energy spectrum of the cosmic infrared background to a sum of the photon energy spectrum from the neutrino radiative decay and a continuum. By comparing the present cosmic infrared background energy spectrum observed by AKARI and Spitzer to the photon energy spectrum expected from neutrino radiative decay with a maximum likelihood method, we obatined a lifetime lower limit of $3.1 \times 10^{12}$ to $3.8 \times 10^{12}$ years at 95% confidence level for the third generation neutrino $\nu_3$ in the $\nu_3$ mass range between 50 \mmev and 150 \mmev under the present constraints by the neutrino oscillation measurements. In the left-right symmetric model, the minimum lifetime of $\nu_3$ is predicted to be $1.5 \times 10^{17}$ years for $m_3$ of 50 \mmev. We studied the feasibility of the observation of the neutrino radiative decay with a lifetime of $1.5 \times 10^{17}$ years, by measuring a continuous energy spectrum of the cosmic infrared background.
hep-ph/9412386
My Account
J. Lopez
A survey of phenomenological constraints on supergravity models
8 pages, LaTeX, 5 figures (included). To appear in proceedings of the Beyond the Standard Model IV Conference, Lake Tahoe, CA, Dec 13-18, 1994
null
null
CTP-TAMU-68/94
hep-ph
null
We advocate the study of supergravity models as well motivated few-parameter low-energy supersymmetric models. In this context we survey a broad range of phenomenological constraints and future tests, including present and near-future Tevatron ($\tilde q,\tilde g,\chi^\pm_1,\tilde t_1$) and LEP ($h,\chi^\pm_1$) mass limits, collider indirect tests ($\Gamma_Z^{\rm inv},R_b,m_t$), rare processes ($b\to s\gamma,(g-2)_\mu$), proton decay, and dark matter (cosmology, direct and indirect detection).
[ { "created": "Thu, 29 Dec 1994 18:26:14 GMT", "version": "v1" } ]
2007-05-23
[ [ "Lopez", "J.", "" ] ]
We advocate the study of supergravity models as well motivated few-parameter low-energy supersymmetric models. In this context we survey a broad range of phenomenological constraints and future tests, including present and near-future Tevatron ($\tilde q,\tilde g,\chi^\pm_1,\tilde t_1$) and LEP ($h,\chi^\pm_1$) mass limits, collider indirect tests ($\Gamma_Z^{\rm inv},R_b,m_t$), rare processes ($b\to s\gamma,(g-2)_\mu$), proton decay, and dark matter (cosmology, direct and indirect detection).
1803.06498
Rachid Markazi M
R. Markazi and N. El Biaze
Insight on confinement using scalar field interactions
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The scalar field plays an fundamental role in the investigation of confinement property characterising many particle physics models. This is achieved by coupling this particle directly with gauge fields at the lagrangian level. We have adopted the same approach {[}10{]} to determine a potential as a perturbative series in terms of interquark distance. In order to introduce the gravitational effects and inspired from bag models, we implement a scalar field which interacts both with the vacuum and the electron field. In this context and with presence of the vacuum condensates, it is possible to derive a more accurate expression of the electron energy.
[ { "created": "Sat, 17 Mar 2018 13:01:10 GMT", "version": "v1" } ]
2018-03-20
[ [ "Markazi", "R.", "" ], [ "Biaze", "N. El", "" ] ]
The scalar field plays an fundamental role in the investigation of confinement property characterising many particle physics models. This is achieved by coupling this particle directly with gauge fields at the lagrangian level. We have adopted the same approach {[}10{]} to determine a potential as a perturbative series in terms of interquark distance. In order to introduce the gravitational effects and inspired from bag models, we implement a scalar field which interacts both with the vacuum and the electron field. In this context and with presence of the vacuum condensates, it is possible to derive a more accurate expression of the electron energy.
1307.0708
Fedor Bezrukov
Fedor Bezrukov
The Higgs field as an inflaton
21 pages, 4 figures. Journal version -- several clarifications and improved list of references
Class. Quantum Grav. 30 (2013) 214001
10.1088/0264-9381/30/21/214001
RBRC1042
hep-ph gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Higgs field of the pure Standard Model can lead to the inflationary expansion of the early Universe if it is non-minimally coupled to gravity. The model predicts Cosmic Microwave Background (CMB) parameters in perfect agreement with the current observations and has implications for the Higgs boson mass. We review the model, its predictions, problems arising with its quantization and some closely related models.
[ { "created": "Tue, 2 Jul 2013 14:08:01 GMT", "version": "v1" }, { "created": "Tue, 8 Oct 2013 19:58:41 GMT", "version": "v2" } ]
2013-10-09
[ [ "Bezrukov", "Fedor", "" ] ]
The Higgs field of the pure Standard Model can lead to the inflationary expansion of the early Universe if it is non-minimally coupled to gravity. The model predicts Cosmic Microwave Background (CMB) parameters in perfect agreement with the current observations and has implications for the Higgs boson mass. We review the model, its predictions, problems arising with its quantization and some closely related models.
hep-ph/9708245
Modugno Michele
R. Gatto, M. Modugno and G. Pettini
Equation of state for the 2+1 dimensional Gross-Neveu model at order 1/N
19 pages, RevTeX, 10 figures.ps
Phys.Rev. D57 (1998) 4995-5003
10.1103/PhysRevD.57.4995
UGVA-DPT 1997/07/984
hep-ph
null
We calculate the equation of state of the Gross-Neveu model in 2+1 dimensions at order 1/N, where N is the number of fermion species. We make use of a general formula valid for four-fermion theories, previously applied to the model in 1+1 dimensions. We consider both the discrete and continuous symmetry versions of the model. We show that the pion-like excitations give the dominant contribution at low temperatures. The range of validity for such pion dominance is analyzed. The complete analysis from low to high temperatures also shows that in the critical region the role of composite states is relevant, even for quite large N, and that the free-component behaviour at high T starts at about twice the mean field critical temperature.
[ { "created": "Tue, 5 Aug 1997 09:10:56 GMT", "version": "v1" } ]
2009-10-30
[ [ "Gatto", "R.", "" ], [ "Modugno", "M.", "" ], [ "Pettini", "G.", "" ] ]
We calculate the equation of state of the Gross-Neveu model in 2+1 dimensions at order 1/N, where N is the number of fermion species. We make use of a general formula valid for four-fermion theories, previously applied to the model in 1+1 dimensions. We consider both the discrete and continuous symmetry versions of the model. We show that the pion-like excitations give the dominant contribution at low temperatures. The range of validity for such pion dominance is analyzed. The complete analysis from low to high temperatures also shows that in the critical region the role of composite states is relevant, even for quite large N, and that the free-component behaviour at high T starts at about twice the mean field critical temperature.
1802.03005
Yang Bai
Yang Bai and Bogdan A. Dobrescu
Collider Tests of the Renormalizable Coloron Model
39 pages, 15 figures, a factor of 2 corrected in Eq. (2.24) for the coloron width into color-octet scalars, with the calculation given in appendix B
null
10.1007/JHEP04(2018)114
Fermilab-PUB-17-555-T
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The coloron, a massive version of the gluon present in gauge extensions of QCD, has been searched for at the LHC as a dijet or top quark pair resonance. We point out that in the Renormalizable Coloron Model (ReCoM) with a minimal field content to break the gauge symmetry, a color-octet scalar and a singlet scalar are naturally lighter than the coloron because they are pseudo Nambu-Goldstone bosons. Consequently, the coloron may predominantly decay into scalar pairs, leading to novel signatures at the LHC. When the color-octet scalar is lighter than the singlet, or when the singlet mass is above roughly 1 TeV, the signatures consist of multi-jet resonances of multiplicity up to 12, including topologies with multi-prong jet substructure, slightly displaced vertices, and sometimes a top quark pair. When the singlet is the lightest ReCoM boson and lighter than about 1 TeV, its main decays ($W^+W^-$, $\gamma Z$, $ZZ$) arise at three loops. The LHC signatures then involve two or four boosted electroweak bosons, often originating from highly displaced vertices, plus one or two pairs of prompt jets or top quarks.
[ { "created": "Thu, 8 Feb 2018 18:52:29 GMT", "version": "v1" }, { "created": "Fri, 7 Sep 2018 02:44:03 GMT", "version": "v2" } ]
2018-09-10
[ [ "Bai", "Yang", "" ], [ "Dobrescu", "Bogdan A.", "" ] ]
The coloron, a massive version of the gluon present in gauge extensions of QCD, has been searched for at the LHC as a dijet or top quark pair resonance. We point out that in the Renormalizable Coloron Model (ReCoM) with a minimal field content to break the gauge symmetry, a color-octet scalar and a singlet scalar are naturally lighter than the coloron because they are pseudo Nambu-Goldstone bosons. Consequently, the coloron may predominantly decay into scalar pairs, leading to novel signatures at the LHC. When the color-octet scalar is lighter than the singlet, or when the singlet mass is above roughly 1 TeV, the signatures consist of multi-jet resonances of multiplicity up to 12, including topologies with multi-prong jet substructure, slightly displaced vertices, and sometimes a top quark pair. When the singlet is the lightest ReCoM boson and lighter than about 1 TeV, its main decays ($W^+W^-$, $\gamma Z$, $ZZ$) arise at three loops. The LHC signatures then involve two or four boosted electroweak bosons, often originating from highly displaced vertices, plus one or two pairs of prompt jets or top quarks.
1808.00805
Shashank Bhatnagar Dr.
Hluf Negash, Shashank Bhatnagar
Double charmonium productions in electron-positron annihilation using Bethe-Salpeter approach
1 figure, 3 tables
Adv. in High Energy Physics Vol. 2019, 4029356 (2019)
10.1155/2019/4029356
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the double charmonium production cross section within the framework of $4\times 4$ Bethe-Salpeter Equation in the electron-positron annihilation, at center of mass energy $\sqrt{s}= 10.6$GeV, that proceeds through the exchange of a single virtual photon. In this calculation, we make use of the full Dirac structure of 4D BS wave functions of these charmonia, with the incorporation of all the Dirac covariants (both leading and sub-leading). The calculated cross-sections for the double charmonium productions for final states, ($J/\Psi, \eta_c$); ($\Psi',\eta_c$) ; ($J/\Psi, \eta_c'$); and ($\Psi',\eta_c'$) are close to experimental data, and in broad agreement with results of other theoretical models.
[ { "created": "Thu, 2 Aug 2018 13:33:11 GMT", "version": "v1" }, { "created": "Thu, 9 Aug 2018 13:36:59 GMT", "version": "v2" }, { "created": "Wed, 6 Mar 2019 08:51:20 GMT", "version": "v3" } ]
2019-03-07
[ [ "Negash", "Hluf", "" ], [ "Bhatnagar", "Shashank", "" ] ]
We calculate the double charmonium production cross section within the framework of $4\times 4$ Bethe-Salpeter Equation in the electron-positron annihilation, at center of mass energy $\sqrt{s}= 10.6$GeV, that proceeds through the exchange of a single virtual photon. In this calculation, we make use of the full Dirac structure of 4D BS wave functions of these charmonia, with the incorporation of all the Dirac covariants (both leading and sub-leading). The calculated cross-sections for the double charmonium productions for final states, ($J/\Psi, \eta_c$); ($\Psi',\eta_c$) ; ($J/\Psi, \eta_c'$); and ($\Psi',\eta_c'$) are close to experimental data, and in broad agreement with results of other theoretical models.
0711.1916
Jos\'e Francisco Zurita
Daniel de Florian and Jos\'e Zurita
Soft-gluon resummation for pseudoscalar Higgs boson production at hadron colliders
10 pages, 7 figures, accepted by Physics Letters B
Phys.Lett.B659:813-820,2008
10.1016/j.physletb.2007.11.018
null
hep-ph
null
We compute the threshold-resummed cross section for pseudo-scalar MSSM Higgs boson production by gluon fusion at hadron colliders. The calculation is performed at next-to-next-to leading logarithmic accuracy. We present results for both the LHC and Tevatron Run II. We analyze the factorization and renormalization scale dependence of the results, finding that after performing the resummation the corresponding cross section can be computed with an accuracy better than 10%.
[ { "created": "Tue, 13 Nov 2007 04:39:16 GMT", "version": "v1" } ]
2008-11-26
[ [ "de Florian", "Daniel", "" ], [ "Zurita", "José", "" ] ]
We compute the threshold-resummed cross section for pseudo-scalar MSSM Higgs boson production by gluon fusion at hadron colliders. The calculation is performed at next-to-next-to leading logarithmic accuracy. We present results for both the LHC and Tevatron Run II. We analyze the factorization and renormalization scale dependence of the results, finding that after performing the resummation the corresponding cross section can be computed with an accuracy better than 10%.
1605.03986
Stella Riad
Claudia Hagedorn, Tommy Ohlsson, Stella Riad and Michael A. Schmidt
Unification of Gauge Couplings in Radiative Neutrino Mass Models
28 pages, 2 figures. Updated to match journal version
JHEP 09 (2016) 111
10.1007/JHEP09(2016)111
CP3-Origins-2016-024 DNRF90, DIAS-2016-024
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the possibility of gauge coupling unification in various radiative neutrino mass models, which generate neutrino masses at one- and/or two-loop level. Renormalization group running of gauge couplings is performed analytically and numerically at one- and two-loop order, respectively. We study three different classes of neutrino mass models: (I) minimal ultraviolet completions of the dimension-7 $\Delta L=2$ operators which generate neutrino masses at one- and/or two-loop level without and with dark matter candidates, (II) models with dark matter which lead to neutrino masses at one-loop level and (III) models with particles in the adjoint representation of $\mathrm{SU}(3)$. In class (I), gauge couplings unify in a few models and adding dark matter amplifies the chances for unification. In class (II), about a quarter of the models admit gauge coupling unification. In class (III), none of the models leads to gauge coupling unification. Regarding the scale of unification, we find values between $10^{14}$ GeV and $10^{16}$ GeV for models belonging to class (I) without dark matter, whereas models in class (I) with dark matter as well as models of class (II) prefer values in the range $5 \cdot 10^{10}-5 \cdot 10^{14}$ GeV.
[ { "created": "Thu, 12 May 2016 20:51:20 GMT", "version": "v1" }, { "created": "Fri, 9 Sep 2016 14:44:43 GMT", "version": "v2" } ]
2016-09-22
[ [ "Hagedorn", "Claudia", "" ], [ "Ohlsson", "Tommy", "" ], [ "Riad", "Stella", "" ], [ "Schmidt", "Michael A.", "" ] ]
We investigate the possibility of gauge coupling unification in various radiative neutrino mass models, which generate neutrino masses at one- and/or two-loop level. Renormalization group running of gauge couplings is performed analytically and numerically at one- and two-loop order, respectively. We study three different classes of neutrino mass models: (I) minimal ultraviolet completions of the dimension-7 $\Delta L=2$ operators which generate neutrino masses at one- and/or two-loop level without and with dark matter candidates, (II) models with dark matter which lead to neutrino masses at one-loop level and (III) models with particles in the adjoint representation of $\mathrm{SU}(3)$. In class (I), gauge couplings unify in a few models and adding dark matter amplifies the chances for unification. In class (II), about a quarter of the models admit gauge coupling unification. In class (III), none of the models leads to gauge coupling unification. Regarding the scale of unification, we find values between $10^{14}$ GeV and $10^{16}$ GeV for models belonging to class (I) without dark matter, whereas models in class (I) with dark matter as well as models of class (II) prefer values in the range $5 \cdot 10^{10}-5 \cdot 10^{14}$ GeV.
0711.2359
Javier Vijande Asenjo
J. Vijande, A. Valcarce, F. Fernandez
B meson spectroscopy
8 pages, 5 tables. Accepted for publication in Physical Review D
Phys.Rev.D77:017501,2008
10.1103/PhysRevD.77.017501
null
hep-ph hep-ex
null
We study the $B$ meson spectroscopy allowing the mixture of conventional $P$ wave quark-antiquark states and four-quark components. A similar picture was used to describe the new $D_J$ and $D_{sJ}$ open charm mesons. The four-quark components shift the masses of some positive parity $B_{sJ}$ states below their corresponding isospin preserving two-meson threshold and therefore they are expected to be narrow. Electromagnetic decay widths are analyzed.
[ { "created": "Thu, 15 Nov 2007 08:15:18 GMT", "version": "v1" } ]
2008-11-26
[ [ "Vijande", "J.", "" ], [ "Valcarce", "A.", "" ], [ "Fernandez", "F.", "" ] ]
We study the $B$ meson spectroscopy allowing the mixture of conventional $P$ wave quark-antiquark states and four-quark components. A similar picture was used to describe the new $D_J$ and $D_{sJ}$ open charm mesons. The four-quark components shift the masses of some positive parity $B_{sJ}$ states below their corresponding isospin preserving two-meson threshold and therefore they are expected to be narrow. Electromagnetic decay widths are analyzed.
hep-ph/0302120
Alejandro Gutierrez
A. Guti\'errez-Rodr\'iguez (Zacatecas University, Mexico), M. A. Hern\'andez-Ru\'iz (Zacatecas University, Mexico) and O. A. Sampayo (Mar del Plata University, Argentina)
Higgs Pair-Production in the Standard Model at Next Generation Linear $e^+e^-$ Colliders
8 pages, 4 figures
Phys.Rev. D67 (2003) 074018
10.1103/PhysRevD.67.074018
null
hep-ph
null
We study the Higgs pair-production in the Standard Model of the strong and electroweak interactions at future $e^{+}e^{-}$ collider energies, with the reaction $e^{+}e^{-}\to t \bar t HH$. We evaluated the total cross section of $t\bar tHH$ and calculate the number total of events considering the complete set of Feynman diagrams at tree-level. The numerical computation is done for the energy which is expected to be available at a possible Next Linear $e^{+}e^{-}$ Collider: with center-of-mass energy $800, 1600$ $GeV$ and luminosity 1000 $fb^{-1}$.
[ { "created": "Fri, 14 Feb 2003 20:43:04 GMT", "version": "v1" } ]
2016-08-16
[ [ "Gutiérrez-Rodríguez", "A.", "", "Zacatecas University, Mexico" ], [ "Hernández-Ruíz", "M. A.", "", "Zacatecas University, Mexico" ], [ "Sampayo", "O. A.", "", "Mar del\n Plata University, Argentina" ] ]
We study the Higgs pair-production in the Standard Model of the strong and electroweak interactions at future $e^{+}e^{-}$ collider energies, with the reaction $e^{+}e^{-}\to t \bar t HH$. We evaluated the total cross section of $t\bar tHH$ and calculate the number total of events considering the complete set of Feynman diagrams at tree-level. The numerical computation is done for the energy which is expected to be available at a possible Next Linear $e^{+}e^{-}$ Collider: with center-of-mass energy $800, 1600$ $GeV$ and luminosity 1000 $fb^{-1}$.
1904.12566
Gayatri Ghosh Dr.
Gayatri Ghosh
Probing new physics in rare decays of b-flavored Hadrons $b\to s \gamma$ in CMSSM/mSUGRA SUSY SO (10) theories
13 pages, 5 figures
Gradiva,ISSN:0363-8057,87-99, VOLUME-8-ISSUE-6-2022
10.37897/GRJ-2021-V7I11-21-49884
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The implications of the latest measurement of the branching fraction of B($ b\rightarrow s \gamma $) of b hadrons, which is another signature of New Physics beyond Standard Model is presented here. The quark transitions $ b \rightarrow s $, $ b \rightarrow d $ do not happen at tree level in the Standard Model as the Z boson does not couple to quarks of different flavour. In this work the present bounds on the quark transition $ b \rightarrow s $ within the constrained minimal supersymmetric extension of the Standard Model (CMSSM), in which there are three independent soft SUSY breaking parameters $ m_{0} $, $ m_{1/2} $ and $ A_{0} $ is illustrated. The recent constraint on B($ b\rightarrow s \gamma $), B($ b_{s}\rightarrow \mu^{+}\mu^{-}$), the recently measured value of Higgs mass at LHC, $ M_{h} $, the value of $\theta_{13}$ from reactor data and the Higgs branching ratios set very strong constraints on New Physics models, in particular supersymmetry. A new epoch for this research has begun since the Large Hadron Collider beauty (LHCb) experiment started affording data for various observables for these decays. The results presented here in mSUGRA/CMSSM models may gain access to supersymmetry even at scales beyond the direct reach of the LHC and the susceptibleness to test these theories at the next run of LHC is also explored.
[ { "created": "Mon, 29 Apr 2019 11:45:43 GMT", "version": "v1" }, { "created": "Wed, 8 May 2019 07:25:54 GMT", "version": "v2" }, { "created": "Wed, 19 Jun 2019 13:46:34 GMT", "version": "v3" } ]
2022-10-26
[ [ "Ghosh", "Gayatri", "" ] ]
The implications of the latest measurement of the branching fraction of B($ b\rightarrow s \gamma $) of b hadrons, which is another signature of New Physics beyond Standard Model is presented here. The quark transitions $ b \rightarrow s $, $ b \rightarrow d $ do not happen at tree level in the Standard Model as the Z boson does not couple to quarks of different flavour. In this work the present bounds on the quark transition $ b \rightarrow s $ within the constrained minimal supersymmetric extension of the Standard Model (CMSSM), in which there are three independent soft SUSY breaking parameters $ m_{0} $, $ m_{1/2} $ and $ A_{0} $ is illustrated. The recent constraint on B($ b\rightarrow s \gamma $), B($ b_{s}\rightarrow \mu^{+}\mu^{-}$), the recently measured value of Higgs mass at LHC, $ M_{h} $, the value of $\theta_{13}$ from reactor data and the Higgs branching ratios set very strong constraints on New Physics models, in particular supersymmetry. A new epoch for this research has begun since the Large Hadron Collider beauty (LHCb) experiment started affording data for various observables for these decays. The results presented here in mSUGRA/CMSSM models may gain access to supersymmetry even at scales beyond the direct reach of the LHC and the susceptibleness to test these theories at the next run of LHC is also explored.
1711.05921
Carlos Arg\"uelles Delgado
Zander Moss and Marjon H. Moulai and Carlos A. Arg\"uelles and Janet M. Conrad
Exploring a Non-Minimal Sterile Neutrino Model Involving Decay at IceCube and Beyond
12 pages, 7 figures. Find code at: https://github.com/arguelles/nuSQUIDSDecay
Phys. Rev. D 97, 055017 (2018)
10.1103/PhysRevD.97.055017
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the phenomenology of neutrino decay together with neutrino oscillations in the context of eV-scale sterile neutrinos. We review the formalism of visible neutrino decay in which one of the decay products is a neutrino that potentially can be observed. We apply the formalism developed for decay to the recent sterile neutrino search performed by IceCube with TeV neutrinos. We show that for $\nu_4$ lifetime $\tau_4/m_4 \lesssim 10^{-16} {\rm eV^{-1}s}$, the interpretation of the high-energy IceCube analysis can be significantly changed.
[ { "created": "Thu, 16 Nov 2017 04:27:40 GMT", "version": "v1" }, { "created": "Tue, 28 Nov 2017 19:21:34 GMT", "version": "v2" } ]
2018-03-21
[ [ "Moss", "Zander", "" ], [ "Moulai", "Marjon H.", "" ], [ "Argüelles", "Carlos A.", "" ], [ "Conrad", "Janet M.", "" ] ]
We study the phenomenology of neutrino decay together with neutrino oscillations in the context of eV-scale sterile neutrinos. We review the formalism of visible neutrino decay in which one of the decay products is a neutrino that potentially can be observed. We apply the formalism developed for decay to the recent sterile neutrino search performed by IceCube with TeV neutrinos. We show that for $\nu_4$ lifetime $\tau_4/m_4 \lesssim 10^{-16} {\rm eV^{-1}s}$, the interpretation of the high-energy IceCube analysis can be significantly changed.
2310.07453
Wen-long Sang
Yu-Dong Zhang, Xiao-Wei Bai, Feng Feng, Wen-Long Sang, Ming-Zhen Zhou
Two-Loop QCD Corrections to C even Bottomonium Exclusive Decays to Double $J/\psi$
17 pages, 3 figures, 4 tables; The affiliation and acknowledgement of the first author are updated
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the framework of nonrelativistic QCD (NRQCD) factorization, we compute both the polarized and the unpolarized decay widths for the processes $\eta_b(\chi_{bJ})\to J/\psi J/\psi$, accurate up to next-to-next-to-leading-order (NNLO) in $\alpha_s$. For the first time, we confirm that the NRQCD factorization does hold at NNLO for the process involving triple quarkonia. We find the radiative corrections are considerable. In particular for $\chi_{b2}$, both $\mathcal{O}(\alpha_s)$ and $\mathcal{O}(\alpha_s^2)$ corrections are sizable and negative, and can significantly reduce the leading order prediction. At NNLO, the branching fractions are $8.2\times 10^{-7}$, $6.2\times 10^{-6}$, $7.2\times 10^{-7}$ and $2.7\times 10^{-6}$ for $\eta_b$, $\chi_{b0}$, $\chi_{b1}$ and $\chi_{b2}$ decay, respectively. Our theoretical predictions are consistent with the upper limits measured by the {\tt Belle} Collaboration. Moreover, we investigate the dependence of the theoretical predictions on the ratio of the charm quark mass and the bottom quark mass. By fixing $m_b$ and varying $m_c$ from $1.25$ to $1.9$ GeV, we find the branching fraction can change a factor of $2$, $3$, and $6$ for $\eta_b$, $\chi_{b0}$, and $\chi_{b1}$, respectively. In the phenomenological analysis, with the integrate luminosity $\mathcal{L}=100\,{\rm fb}^{-1}$, we expect about $(5-10)\times 10^3$ $\eta_b(\chi_{bJ})\to J/\psi J/\psi\to \ell \bar{\ell}\ell \bar{\ell}$ events produced at the {\tt LHC}, thus it might be hopeful to search for these processes. On the other hand, there are less than $100$ $\eta_b(\chi_{bJ})\to J/\psi J/\psi$ signal events at the B factory, so it seems the experimental measurements on these channels are quite challenging based on current dataset.
[ { "created": "Wed, 11 Oct 2023 12:59:41 GMT", "version": "v1" }, { "created": "Thu, 12 Oct 2023 08:10:40 GMT", "version": "v2" } ]
2023-10-13
[ [ "Zhang", "Yu-Dong", "" ], [ "Bai", "Xiao-Wei", "" ], [ "Feng", "Feng", "" ], [ "Sang", "Wen-Long", "" ], [ "Zhou", "Ming-Zhen", "" ] ]
In the framework of nonrelativistic QCD (NRQCD) factorization, we compute both the polarized and the unpolarized decay widths for the processes $\eta_b(\chi_{bJ})\to J/\psi J/\psi$, accurate up to next-to-next-to-leading-order (NNLO) in $\alpha_s$. For the first time, we confirm that the NRQCD factorization does hold at NNLO for the process involving triple quarkonia. We find the radiative corrections are considerable. In particular for $\chi_{b2}$, both $\mathcal{O}(\alpha_s)$ and $\mathcal{O}(\alpha_s^2)$ corrections are sizable and negative, and can significantly reduce the leading order prediction. At NNLO, the branching fractions are $8.2\times 10^{-7}$, $6.2\times 10^{-6}$, $7.2\times 10^{-7}$ and $2.7\times 10^{-6}$ for $\eta_b$, $\chi_{b0}$, $\chi_{b1}$ and $\chi_{b2}$ decay, respectively. Our theoretical predictions are consistent with the upper limits measured by the {\tt Belle} Collaboration. Moreover, we investigate the dependence of the theoretical predictions on the ratio of the charm quark mass and the bottom quark mass. By fixing $m_b$ and varying $m_c$ from $1.25$ to $1.9$ GeV, we find the branching fraction can change a factor of $2$, $3$, and $6$ for $\eta_b$, $\chi_{b0}$, and $\chi_{b1}$, respectively. In the phenomenological analysis, with the integrate luminosity $\mathcal{L}=100\,{\rm fb}^{-1}$, we expect about $(5-10)\times 10^3$ $\eta_b(\chi_{bJ})\to J/\psi J/\psi\to \ell \bar{\ell}\ell \bar{\ell}$ events produced at the {\tt LHC}, thus it might be hopeful to search for these processes. On the other hand, there are less than $100$ $\eta_b(\chi_{bJ})\to J/\psi J/\psi$ signal events at the B factory, so it seems the experimental measurements on these channels are quite challenging based on current dataset.
1409.3227
Jiang-Hao Yu
Jiang-Hao Yu (Univ. of Texas at Austin)
Vector Fermion-Portal Dark Matter: Direct Detection and Galactic Center Gamma-Ray Excess
18 pages, 14 figures, references updated in revised version
Phys. Rev. D 90, 095010 (2014)
10.1103/PhysRevD.90.095010
UTTG-19-14, TCC-021-14
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate a neutral gauge boson X originated from a hidden U(1) extension of the standard model as the particle dark matter candidate. The vector dark matter interacts with the standard model fermions through heavy fermion mediators. The interactions give rise to t-channel annihilation cross section in the XX to ff process, which dominates the thermal relic abundance during thermal freeze-out and produces measurable gamma-ray flux in the galactic halo. For a light vector dark matter, if it predominantly couples to the third generation fermions, this model could explain the excess of gamma rays from the galactic center. We show that the vector dark matter with a mass of 20 ~ 40 GeV and that annihilate into the bb and tautau final states provides an excellent description of the observed gamma-ray excess. The parameter space aimed at explaining the gamma-ray excess, could also provide the correct thermal relic density and is compatible with the constraints from electroweak precision data, Higgs invisible decay, and collider searches. We also show the dark matter couplings to the nucleon from the fermion portal interactions are loop-suppressed, and only contribute to the spin-dependent cross section. So the vector dark matter could easily escape the stringent constraints from the direct detection experiments.
[ { "created": "Wed, 10 Sep 2014 20:00:14 GMT", "version": "v1" }, { "created": "Mon, 22 Sep 2014 22:26:13 GMT", "version": "v2" } ]
2014-11-19
[ [ "Yu", "Jiang-Hao", "", "Univ. of Texas at Austin" ] ]
We investigate a neutral gauge boson X originated from a hidden U(1) extension of the standard model as the particle dark matter candidate. The vector dark matter interacts with the standard model fermions through heavy fermion mediators. The interactions give rise to t-channel annihilation cross section in the XX to ff process, which dominates the thermal relic abundance during thermal freeze-out and produces measurable gamma-ray flux in the galactic halo. For a light vector dark matter, if it predominantly couples to the third generation fermions, this model could explain the excess of gamma rays from the galactic center. We show that the vector dark matter with a mass of 20 ~ 40 GeV and that annihilate into the bb and tautau final states provides an excellent description of the observed gamma-ray excess. The parameter space aimed at explaining the gamma-ray excess, could also provide the correct thermal relic density and is compatible with the constraints from electroweak precision data, Higgs invisible decay, and collider searches. We also show the dark matter couplings to the nucleon from the fermion portal interactions are loop-suppressed, and only contribute to the spin-dependent cross section. So the vector dark matter could easily escape the stringent constraints from the direct detection experiments.
1212.3591
Yu Jia
Jia Xu, Hai-Rong Dong, Feng Feng, Ying-Jia Gao, Yu Jia
Exclusive decay of $\Upsilon$ into $J/\psi+\chi_{c0,1,2}$
22 pages, 9 figures, 3 tables
null
10.1103/PhysRevD.87.094004
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the $\Upsilon$ exclusive decay into double charmonium, specifically, the $S$-wave charmonium $ J/\psi$ plus the $P$-wave charmonium $\chi_{c0,1,2}$ in the NRQCD factorization framework. Three distinct decay mechanisms, i.e., the strong, electromagnetic and radiative decay channels are included and their interference effects are investigated. The decay processes $\Upsilon(1S,2S,3S)\to J/\psi+\chi_{c1,0}$ are predicted to have the branching fractions of order $10^{-6}$, which should be observed in the prospective Super $B$ factory.
[ { "created": "Fri, 14 Dec 2012 20:39:51 GMT", "version": "v1" } ]
2013-05-15
[ [ "Xu", "Jia", "" ], [ "Dong", "Hai-Rong", "" ], [ "Feng", "Feng", "" ], [ "Gao", "Ying-Jia", "" ], [ "Jia", "Yu", "" ] ]
We study the $\Upsilon$ exclusive decay into double charmonium, specifically, the $S$-wave charmonium $ J/\psi$ plus the $P$-wave charmonium $\chi_{c0,1,2}$ in the NRQCD factorization framework. Three distinct decay mechanisms, i.e., the strong, electromagnetic and radiative decay channels are included and their interference effects are investigated. The decay processes $\Upsilon(1S,2S,3S)\to J/\psi+\chi_{c1,0}$ are predicted to have the branching fractions of order $10^{-6}$, which should be observed in the prospective Super $B$ factory.
hep-ph/9703236
Toshiyuki Morii
N. I. Kochelev, T. Morii and T. Yamanishi
Semi-inclusive Lambda_c^+ Leptoproductions and Polarized Gluon Distributions
9 pages + 4 Postscript figures(2 PS files), LaTeX
Phys.Lett. B405 (1997) 168-172
10.1016/S0370-2693(97)00593-5
KOBE-FHD-97-01
hep-ph
null
In order to extract the behavior and magnitude of the spin-dependent gluon distribution, we propose a semi-inclusive $\Lambda_c^+$ production using unpolarized lepton beams and polarized proton targets. The correlation between the target proton spin and the spin of $\Lambda_c^+$ produced in the target fragmentation region might be very effective for testing various models of polarized gluons.
[ { "created": "Wed, 5 Mar 1997 07:05:01 GMT", "version": "v1" } ]
2009-10-30
[ [ "Kochelev", "N. I.", "" ], [ "Morii", "T.", "" ], [ "Yamanishi", "T.", "" ] ]
In order to extract the behavior and magnitude of the spin-dependent gluon distribution, we propose a semi-inclusive $\Lambda_c^+$ production using unpolarized lepton beams and polarized proton targets. The correlation between the target proton spin and the spin of $\Lambda_c^+$ produced in the target fragmentation region might be very effective for testing various models of polarized gluons.
1602.02035
Alberto Accardi
Alberto Accardi
PDFs from nucleons to nuclei
Pleanary talk delivered at DIS 2015, Dallas, TX (USA), 27 April - May 1 2015
PoS DIS2015 (2015) 001
null
JLAB-THY-15-2215
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I review recent progress in the extraction of unpolarized parton distributions in the proton and in nuclei from a unified point of view that highlights how the interplay between high energy particle physics and lower energy nuclear physics can be of mutual benefit to either field. Areas of overlap range from the search for physics beyond the standard model at the LHC, to the study of the non perturbative structure of nucleons and the emergence of nuclei from quark and gluon degrees of freedom, to the interaction of colored probes in a cold nuclear medium.
[ { "created": "Fri, 5 Feb 2016 14:24:40 GMT", "version": "v1" } ]
2016-02-10
[ [ "Accardi", "Alberto", "" ] ]
I review recent progress in the extraction of unpolarized parton distributions in the proton and in nuclei from a unified point of view that highlights how the interplay between high energy particle physics and lower energy nuclear physics can be of mutual benefit to either field. Areas of overlap range from the search for physics beyond the standard model at the LHC, to the study of the non perturbative structure of nucleons and the emergence of nuclei from quark and gluon degrees of freedom, to the interaction of colored probes in a cold nuclear medium.
hep-ph/9511239
Smirnov A. Y.
A. Yu. Smirnov
Neutrinos and Structure of the Intermediate Mass Scale
19 pages, LaTeX, no figures
Nucl.Phys. B466 (1996) 25-40
10.1016/0550-3213(96)00084-3
YITP-95-6
hep-ph
null
Neutrino data lead via the see-saw mechanism to masses of the right handed neutrinos at the intermediate mass scale. Simple formalism is suggested which incorporates the quark - lepton symmetry and allows one to find properties of the intermediate scale (masses and mixing) from neutrino data. Averaged mass scale and the mass hierarchy parameter are introduced and fixed by the data. They determine natural ranges of masses and mixing at the intermediate scale. In particular, scenario which includes the MSW solution of the solar neutrino problem and tau neutrino as the hot component of Dark Matter of the Universe leads to $M_2 = (2 - 4) \cdot 10^{10}$ GeV and $M_3 = (4 - 8) \cdot 10^{12}$ GeV in agreement with the linear mass hierarchy. Strong deviations from the natural ranges imply fine tuning of parameters or/and certain symmetry of the Majorana mass matrix of the right handed neutrinos.
[ { "created": "Sun, 5 Nov 1995 06:38:30 GMT", "version": "v1" } ]
2009-10-28
[ [ "Smirnov", "A. Yu.", "" ] ]
Neutrino data lead via the see-saw mechanism to masses of the right handed neutrinos at the intermediate mass scale. Simple formalism is suggested which incorporates the quark - lepton symmetry and allows one to find properties of the intermediate scale (masses and mixing) from neutrino data. Averaged mass scale and the mass hierarchy parameter are introduced and fixed by the data. They determine natural ranges of masses and mixing at the intermediate scale. In particular, scenario which includes the MSW solution of the solar neutrino problem and tau neutrino as the hot component of Dark Matter of the Universe leads to $M_2 = (2 - 4) \cdot 10^{10}$ GeV and $M_3 = (4 - 8) \cdot 10^{12}$ GeV in agreement with the linear mass hierarchy. Strong deviations from the natural ranges imply fine tuning of parameters or/and certain symmetry of the Majorana mass matrix of the right handed neutrinos.
1401.6323
Long-Bin Chen
Long-Bin Chen and Cong-Feng Qiao
NLO corrections to $\chi_{bJ}$ to two-$J/\psi$ exclusive decay processes
To appear in PRD
Phys. Rev. D 89, 074004 (2014)
10.1103/PhysRevD.89.074004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The next-to-leading order QCD corrections for $\chi_{bJ}$, the p-wave bottomonium, to $J/\psi$ pair decay processes are evaluated utilizing NRQCD factorization formalism. The scale dependence of $\chi_{b2}\rightarrow J/\psi J/\psi$ process is depressed with NLO corrections, and hence the uncertainties in the leading order results are greatly reduced. The total branch ratios are found to be the order of $10^{-5}$ for all three $\chi_{bJ}\rightarrow J/\psi J/\psi$ processes, indicating that they are observable in the LHC and super-B experiments.
[ { "created": "Fri, 24 Jan 2014 12:05:02 GMT", "version": "v1" }, { "created": "Thu, 20 Mar 2014 01:25:28 GMT", "version": "v2" } ]
2014-04-23
[ [ "Chen", "Long-Bin", "" ], [ "Qiao", "Cong-Feng", "" ] ]
The next-to-leading order QCD corrections for $\chi_{bJ}$, the p-wave bottomonium, to $J/\psi$ pair decay processes are evaluated utilizing NRQCD factorization formalism. The scale dependence of $\chi_{b2}\rightarrow J/\psi J/\psi$ process is depressed with NLO corrections, and hence the uncertainties in the leading order results are greatly reduced. The total branch ratios are found to be the order of $10^{-5}$ for all three $\chi_{bJ}\rightarrow J/\psi J/\psi$ processes, indicating that they are observable in the LHC and super-B experiments.
1805.03286
Jorgivan Dias Ph.D.
J. M. Dias, V. R. Debastiani, J.-Jun Xie, E. Oset
Doubly charmed $\Xi_{cc}$ molecular states from meson-baryon interaction
22 pages, 2 figures
Phys. Rev. D 98, 094017 (2018)
10.1103/PhysRevD.98.094017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Stimulated by the new experimental LHCb findings associated with the $\Omega_c$ states, some of which we have described in a previous work as being dynamically generated through meson-baryon interaction, we have extended this approach to make predictions for new $\Xi_{cc}$ molecular states in the $C=2$, $S=0$ and $I=1/2$ sector. These states manifest themselves as poles in the solution of the Bethe-Salpeter equation in coupled channels. The kernels of this equation were obtained using the Lagrangians coming from the hidden local gauge symmetry, where the interactions are dominated by the exchange of light vector mesons. The extension of this approach to the heavy sector stems from the realization that the dominant interaction corresponds to having the heavy quarks as spectators, which implies the preservation of the heavy quark symmetry. As a result, we get several states: two states from the pseudoscalar meson-baryon interaction with $J^P=1/2^-$, and masses around $4080$ and $4090$ MeV, and one at $4150$ MeV for $J^P=3/2^-$. Furthermore, from the vector meson-baryon interaction we get three states degenerate with $J^P=1/2^-$ and $3/2^-$ from $4220$ MeV to $4330$ MeV, and two more states around $4280$ MeV and $4410$ MeV, degenerate with $J^P=1/2^-,\, 3/2^-$ and $5/2^-$.
[ { "created": "Tue, 8 May 2018 21:03:05 GMT", "version": "v1" } ]
2018-11-28
[ [ "Dias", "J. M.", "" ], [ "Debastiani", "V. R.", "" ], [ "Xie", "J. -Jun", "" ], [ "Oset", "E.", "" ] ]
Stimulated by the new experimental LHCb findings associated with the $\Omega_c$ states, some of which we have described in a previous work as being dynamically generated through meson-baryon interaction, we have extended this approach to make predictions for new $\Xi_{cc}$ molecular states in the $C=2$, $S=0$ and $I=1/2$ sector. These states manifest themselves as poles in the solution of the Bethe-Salpeter equation in coupled channels. The kernels of this equation were obtained using the Lagrangians coming from the hidden local gauge symmetry, where the interactions are dominated by the exchange of light vector mesons. The extension of this approach to the heavy sector stems from the realization that the dominant interaction corresponds to having the heavy quarks as spectators, which implies the preservation of the heavy quark symmetry. As a result, we get several states: two states from the pseudoscalar meson-baryon interaction with $J^P=1/2^-$, and masses around $4080$ and $4090$ MeV, and one at $4150$ MeV for $J^P=3/2^-$. Furthermore, from the vector meson-baryon interaction we get three states degenerate with $J^P=1/2^-$ and $3/2^-$ from $4220$ MeV to $4330$ MeV, and two more states around $4280$ MeV and $4410$ MeV, degenerate with $J^P=1/2^-,\, 3/2^-$ and $5/2^-$.
1105.5935
Jialun Ping
Youchang Yang, Jialun Ping, Chengrong Deng and Hong-Shi Zong
Possible interpretation of the $Z_b$(10610) and $Z_b$(10650) in a chiral quark model
13 pages, 1 figure, title and some arguments in the abstract and section 5 are revised, results unchanged
null
10.1088/0954-3899/39/10/105001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by the two charged bottomonium-like resonances $Z_b$(10610) and $Z_b$(10650) newly observed by the Belle collaboration, the possible molecular states composed of a pair of heavy mesons, $B\bar{B}, B\bar{B}^*, B^*\bar{B}^*, B_s\bar{B}$, etc (in S-wave), are investigated in the framework of chiral quark models by the Gaussian expansion method. The bound states $B\bar{B}^*$ and $B^*\bar{B}^*$ with quantum numbers $I(J^{PC})=1(1^{+-})$, which are good candidates for the $Z_b(10610)$ and $Z_b(10650)$ respectively, are obtained. Other three bound states $B\bar{B}^*$ with $I(J^{PC})=0(1^{++})$, $B^*\bar{B}^*$ with $I(J^{PC})=1(0^{++}), 0(2^{++})$ are predicted. These states may be observed in open-bottom or hidden-bottom decay channel of highly excited $\Upsilon$. When extending directly the quark model to the hidden color channel of the multi-quark system, more deeply bound states are found. Future experimental search of those states will cast doubt on the validity of applying the chiral constituent quark model to the hidden color channel directly.
[ { "created": "Mon, 30 May 2011 10:29:30 GMT", "version": "v1" }, { "created": "Thu, 2 Jun 2011 03:14:20 GMT", "version": "v2" }, { "created": "Thu, 19 Jul 2012 01:55:42 GMT", "version": "v3" } ]
2015-05-28
[ [ "Yang", "Youchang", "" ], [ "Ping", "Jialun", "" ], [ "Deng", "Chengrong", "" ], [ "Zong", "Hong-Shi", "" ] ]
Motivated by the two charged bottomonium-like resonances $Z_b$(10610) and $Z_b$(10650) newly observed by the Belle collaboration, the possible molecular states composed of a pair of heavy mesons, $B\bar{B}, B\bar{B}^*, B^*\bar{B}^*, B_s\bar{B}$, etc (in S-wave), are investigated in the framework of chiral quark models by the Gaussian expansion method. The bound states $B\bar{B}^*$ and $B^*\bar{B}^*$ with quantum numbers $I(J^{PC})=1(1^{+-})$, which are good candidates for the $Z_b(10610)$ and $Z_b(10650)$ respectively, are obtained. Other three bound states $B\bar{B}^*$ with $I(J^{PC})=0(1^{++})$, $B^*\bar{B}^*$ with $I(J^{PC})=1(0^{++}), 0(2^{++})$ are predicted. These states may be observed in open-bottom or hidden-bottom decay channel of highly excited $\Upsilon$. When extending directly the quark model to the hidden color channel of the multi-quark system, more deeply bound states are found. Future experimental search of those states will cast doubt on the validity of applying the chiral constituent quark model to the hidden color channel directly.
hep-ph/9405303
null
H. Holtmann, N.N. Nikolaev, J. Speth and A. Szczurek
Pion Content of the Nucleon as seen in the NA51 Drell-Yan experiment
10 pages + 3 figures, Preprint KFA-IKP(TH)-1994-14 .tex file. After \enddocument a uu-encodeded Postscript file comprising the figures is appended
Z.Phys.A353:411-414,1996
10.1007/BF01285152
null
hep-ph
null
In a recent CERN Drell-Yan experiment the NA51 group found a strong asymmetry of $\bar u$ and $\bar d$ densities in the proton at $x\simeq0.18$. We interpret this result as a decisive confirmation of the pion-induced sea in the nucleon.
[ { "created": "Mon, 16 May 1994 13:31:33 GMT", "version": "v1" } ]
2011-02-01
[ [ "Holtmann", "H.", "" ], [ "Nikolaev", "N. N.", "" ], [ "Speth", "J.", "" ], [ "Szczurek", "A.", "" ] ]
In a recent CERN Drell-Yan experiment the NA51 group found a strong asymmetry of $\bar u$ and $\bar d$ densities in the proton at $x\simeq0.18$. We interpret this result as a decisive confirmation of the pion-induced sea in the nucleon.
hep-ph/0511335
Stephen Godfrey
Stephen Godfrey, Pat Kalyniak, Alexander Tomkins (Carleton U)
Distinguishing Between Models with Extra Gauge Bosons at the ILC
Presented at the 2005 International Linear Collider Physics and Detector Workshop and Second ILC Accelerator Workshop, Snowmass, CO (Snowmass05), 5 pages, LaTeX, 6 postscript figures
null
null
ALCPG0108
hep-ph
null
Extra neutral gauge bosons arise in many extensions of the Standard Model. If one were to be discovered it would be necessary to measure its properties so that we could understand its origins. In this report we find that Z' couplings can be measured at the ILC precisely enough to distinguish between models up to a Z' mass of 2-3 TeV. An important ingredient in these measurements is polarization of the e^- and to a lesser extent e^+ beams. b and c-quark tagging would also give important additional information.
[ { "created": "Tue, 29 Nov 2005 22:01:34 GMT", "version": "v1" } ]
2007-05-23
[ [ "Godfrey", "Stephen", "", "Carleton U" ], [ "Kalyniak", "Pat", "", "Carleton U" ], [ "Tomkins", "Alexander", "", "Carleton U" ] ]
Extra neutral gauge bosons arise in many extensions of the Standard Model. If one were to be discovered it would be necessary to measure its properties so that we could understand its origins. In this report we find that Z' couplings can be measured at the ILC precisely enough to distinguish between models up to a Z' mass of 2-3 TeV. An important ingredient in these measurements is polarization of the e^- and to a lesser extent e^+ beams. b and c-quark tagging would also give important additional information.
1708.08515
Leandro Da Rold
Leandro Da Rold
Anarchy with linear and bilinear interactions
26 pages
null
10.1007/JHEP10(2017)120
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Composite Higgs models with anarchic partial compositeness require a scale of new physics ${\cal O}(10-100)$ TeV, with the bounds being dominated by the dipole moments and $\epsilon_K$. The presence of anarchic bilinear interactions can change this picture. We show a solution to the SM flavor puzzle where the electron and the Right-handed quarks of the first generation have negligible linear interactions, and the bilinear interactions account for most of their masses, whereas the other chiral fermions follow a similar pattern to anarchic partial compositeness. We compute the bounds from flavor and CP violation and show that neutron and electron dipole moments, as well as $\epsilon_K$ and $\mu\to e\gamma$, are compatible with a new physics scale below the TeV. $\Delta F=2$ operators involving Left-handed quarks and $\Delta F=1$ operators with $d_L$ give the most stringent bounds in this scenario. Their Wilson coefficients have the same origin as in anarchic partial compositeness, requiring the masses of the new states to be larger than ${\cal O}(6-7)$ TeV.
[ { "created": "Mon, 28 Aug 2017 20:37:53 GMT", "version": "v1" } ]
2017-11-22
[ [ "Da Rold", "Leandro", "" ] ]
Composite Higgs models with anarchic partial compositeness require a scale of new physics ${\cal O}(10-100)$ TeV, with the bounds being dominated by the dipole moments and $\epsilon_K$. The presence of anarchic bilinear interactions can change this picture. We show a solution to the SM flavor puzzle where the electron and the Right-handed quarks of the first generation have negligible linear interactions, and the bilinear interactions account for most of their masses, whereas the other chiral fermions follow a similar pattern to anarchic partial compositeness. We compute the bounds from flavor and CP violation and show that neutron and electron dipole moments, as well as $\epsilon_K$ and $\mu\to e\gamma$, are compatible with a new physics scale below the TeV. $\Delta F=2$ operators involving Left-handed quarks and $\Delta F=1$ operators with $d_L$ give the most stringent bounds in this scenario. Their Wilson coefficients have the same origin as in anarchic partial compositeness, requiring the masses of the new states to be larger than ${\cal O}(6-7)$ TeV.
hep-ph/9507252
Biswarup Mukhopadhyaya
Rathin Adhikari and Biswarup Mukhopadhyaya
Tau-Universality Violation with Light Neutralinos
11 pages, LATEX, 3 figures (hard copies of figures available from the Authors on request)
Phys.Rev. D53 (1996) 1425-1428
10.1103/PhysRevD.53.1425
MRI-PHY/6/95
hep-ph
null
In a supersymmetric model with the lightest supersymmetric particle (LSP) $\chi$ in the range of a few hundred MeV's, the decay $\tau {\longrightarrow} \mu \chi \chi$ is going to be allowed. We investigate the departure from tau-universality caused by this decay. It is found that the universality violation in this way can be greater than both non-universal electroweak radiative corrections and supersymmetric one-loop corrections over a considerable region of the parameter space allowed by experiments so far. Thus it suggests a method of constraining the parameter space with light LSP's using data from tau-factories.
[ { "created": "Thu, 6 Jul 1995 07:35:09 GMT", "version": "v1" }, { "created": "Sat, 15 Jul 1995 07:12:13 GMT", "version": "v2" } ]
2009-10-28
[ [ "Adhikari", "Rathin", "" ], [ "Mukhopadhyaya", "Biswarup", "" ] ]
In a supersymmetric model with the lightest supersymmetric particle (LSP) $\chi$ in the range of a few hundred MeV's, the decay $\tau {\longrightarrow} \mu \chi \chi$ is going to be allowed. We investigate the departure from tau-universality caused by this decay. It is found that the universality violation in this way can be greater than both non-universal electroweak radiative corrections and supersymmetric one-loop corrections over a considerable region of the parameter space allowed by experiments so far. Thus it suggests a method of constraining the parameter space with light LSP's using data from tau-factories.
hep-ph/9911215
Singer Paul
Paul Singer
Rare Decays of Heavy Quarks - Searching Ground for New Physics
Presented at the XXXIX Cracow School of Theoretical Physics, May 29-June 8, 1999, Zakopane, Poland
Acta Phys.Polon.B30:3861-3873,1999
null
null
hep-ph
null
The search for new physics beyond the standard model is proceeding nowadays intensively along experimental and theoretical lines. We review here the sector of charm radiative decays in this context. The calculation of $D\to V\gamma$, $D\to \ell^+\ell^-\gamma$ transitions reveals their unequivocal dominance by long-distance contributions. On the other hand, the beauty-conserving charm-changing electroweak transition $B_c\to B_u^*\gamma$ is shown to have unique properties which make it a promising avenue in the search for new physics. We describe a calculation of short- and long-distance contributions to this decay which finds them to be of comparable size. The branching ratio of this decay in the standard model is estimated to be $\simeq 10^{-8}$.
[ { "created": "Wed, 3 Nov 1999 10:49:40 GMT", "version": "v1" } ]
2011-01-25
[ [ "Singer", "Paul", "" ] ]
The search for new physics beyond the standard model is proceeding nowadays intensively along experimental and theoretical lines. We review here the sector of charm radiative decays in this context. The calculation of $D\to V\gamma$, $D\to \ell^+\ell^-\gamma$ transitions reveals their unequivocal dominance by long-distance contributions. On the other hand, the beauty-conserving charm-changing electroweak transition $B_c\to B_u^*\gamma$ is shown to have unique properties which make it a promising avenue in the search for new physics. We describe a calculation of short- and long-distance contributions to this decay which finds them to be of comparable size. The branching ratio of this decay in the standard model is estimated to be $\simeq 10^{-8}$.
0808.3500
Federico Urban
Cosimo Bambi, Federico R. Urban
Gravitational production of KK states
10 pages, 1 figure
Phys.Rev.D78:103515,2008
10.1103/PhysRevD.78.103515
WSU-HEP-0810
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Gravitational particle production in the context of braneworlds is considered from a phenomenological point of view. The production of KK modes for bulk fields is discussed and their abundances computed. The results have been applied to some specific fields such as gravitinos and axions, and their cosmologies have been outlined, exemplifying the constraints on the properties of the extra dimensional model in each case.
[ { "created": "Tue, 26 Aug 2008 12:44:48 GMT", "version": "v1" } ]
2009-02-23
[ [ "Bambi", "Cosimo", "" ], [ "Urban", "Federico R.", "" ] ]
Gravitational particle production in the context of braneworlds is considered from a phenomenological point of view. The production of KK modes for bulk fields is discussed and their abundances computed. The results have been applied to some specific fields such as gravitinos and axions, and their cosmologies have been outlined, exemplifying the constraints on the properties of the extra dimensional model in each case.
1311.2077
Juan Ignacio Sanchez Vietto
Ezequiel Alvarez, Leandro Da Rold and Juan Ignacio Sanchez Vietto
Single production of an exotic bottom partner at LHC
27 pages, 9 figures
null
10.1007/JHEP02(2014)010
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study single production and detection at the LHC run II of exotic partners of the bottom quark. For masses larger than 1 TeV single production can dominate over pair production that is suppressed due to phase space. The presence of exotic partners of the bottom is motivated in models aiming to solve the $A_{FB}^b$ anomaly measured at LEP and SLC. Minimal models of this type with partial compositeness predict, as the lightest bottom partner, a new fermion V of electric charge -4/3, also called mirror. The relevant coupling for our study is a WVb vertex, which yields a signal that corresponds to a hard W, a hard b-jet and a forward light jet. We design a search strategy for the leptonic decay of the W, which avoids the large QCD multijet background and its large uncertainties. We find that the main backgrounds are W+jets and ttbar, and the key variables to enhance the signal over them are a hard b-jet and the rapidity of the light jet. We determine the discovery reach for the LHC run II, in particular we predict that, for couplings of order ~g/10, this signal could be detected at a 95% confidence level with a mass up to 2.4 TeV using the first 100 fb-1.
[ { "created": "Fri, 8 Nov 2013 21:00:11 GMT", "version": "v1" } ]
2015-06-17
[ [ "Alvarez", "Ezequiel", "" ], [ "Da Rold", "Leandro", "" ], [ "Vietto", "Juan Ignacio Sanchez", "" ] ]
We study single production and detection at the LHC run II of exotic partners of the bottom quark. For masses larger than 1 TeV single production can dominate over pair production that is suppressed due to phase space. The presence of exotic partners of the bottom is motivated in models aiming to solve the $A_{FB}^b$ anomaly measured at LEP and SLC. Minimal models of this type with partial compositeness predict, as the lightest bottom partner, a new fermion V of electric charge -4/3, also called mirror. The relevant coupling for our study is a WVb vertex, which yields a signal that corresponds to a hard W, a hard b-jet and a forward light jet. We design a search strategy for the leptonic decay of the W, which avoids the large QCD multijet background and its large uncertainties. We find that the main backgrounds are W+jets and ttbar, and the key variables to enhance the signal over them are a hard b-jet and the rapidity of the light jet. We determine the discovery reach for the LHC run II, in particular we predict that, for couplings of order ~g/10, this signal could be detected at a 95% confidence level with a mass up to 2.4 TeV using the first 100 fb-1.
hep-ph/9507364
null
I.I. Bigi
Lifetimes of Heavy-Flavour Hadrons -- Whence and Whither?
15 pages, no figures, LATEX, two references added and new information concerning a lower charm content in B decays incorporated
Nuovo Cim.A109:713-726,1996
10.1007/BF02731705
UND-HEP-95-BIG06
hep-ph
null
A theoretical treatment for the weak decays of heavy-flavour hadrons has been developed that is genuinely based on QCD. Its methodology as it applies to total lifetimes and the underlying theoretical issues are sketched. Predictions are compared with present data. One discrepancy emerges: the beauty baryon lifetime appears to be significantly shorter than expected. The ramifications of those findings are analyzed in detail.
[ { "created": "Fri, 21 Jul 1995 06:30:09 GMT", "version": "v1" }, { "created": "Thu, 27 Jul 1995 06:19:51 GMT", "version": "v2" } ]
2010-11-11
[ [ "Bigi", "I. I.", "" ] ]
A theoretical treatment for the weak decays of heavy-flavour hadrons has been developed that is genuinely based on QCD. Its methodology as it applies to total lifetimes and the underlying theoretical issues are sketched. Predictions are compared with present data. One discrepancy emerges: the beauty baryon lifetime appears to be significantly shorter than expected. The ramifications of those findings are analyzed in detail.
hep-ph/9508294
null
I.I. Bigi
Quo Vadis, Fascinum?
13 pages, LATEX, Invited Lecture given at the Workshop on the Tau/Charm Factory, Argonne National Laboratory, June 21 - 23, 1995
AIP Conf.Proc.349:331-344,1996
10.1063/1.49269
UND-HEP-95-BIG08
hep-ph
null
The recent progress in our understanding of heavy-flavour decays allows us to define more reliably which future measurements on charm decays are needed to further advance our understanding of QCD and to get our theoretical tools ready for treating beauty decays. After sketching the theoretical landscape I list those required measurements. I argue that some -- in particular those concerning inclusive semileptonic charm decays and their lepton spectra -- can presumably be performed only at a tau-charm factory.
[ { "created": "Mon, 14 Aug 1995 21:43:12 GMT", "version": "v1" } ]
2015-06-25
[ [ "Bigi", "I. I.", "" ] ]
The recent progress in our understanding of heavy-flavour decays allows us to define more reliably which future measurements on charm decays are needed to further advance our understanding of QCD and to get our theoretical tools ready for treating beauty decays. After sketching the theoretical landscape I list those required measurements. I argue that some -- in particular those concerning inclusive semileptonic charm decays and their lepton spectra -- can presumably be performed only at a tau-charm factory.
hep-ph/9210257
null
L. Clavelli
Tau Decay Puzzles and Possible Light Gluinos
10 pp, conference talk, 2 tables included, 1 figure not incl.
null
null
UAHEP216
hep-ph
null
The relation of the strong coupling constant as measured in tau decay to other low energy determinations is considered with special attention to its impact on the question of the possible existence of light gluinos.
[ { "created": "Thu, 22 Oct 1992 15:05:15 GMT", "version": "v1" } ]
2007-05-23
[ [ "Clavelli", "L.", "" ] ]
The relation of the strong coupling constant as measured in tau decay to other low energy determinations is considered with special attention to its impact on the question of the possible existence of light gluinos.
1908.11155
Rusa Mandal
Rusa Mandal and Antonio Pich
Constraints on scalar leptoquarks from lepton and kaon physics
Bounds updated with the most recent experimental information from Kaon 2019. Additional references included
JHEP 1912 (2019) 089
10.1007/JHEP12(2019)089
IFIC/19-32
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a comprehensive analysis of low-energy signals of hypothetical scalar leptoquark interactions in lepton and kaon transitions. We derive the most general effective four-fermion Lagrangian induced by tree-level scalar leptoquark exchange and identify the Wilson coefficients predicted by the five possible types of scalar leptoquarks. The current constraints on the leptoquark Yukawa couplings arising from lepton and kaon processes are worked out, including also loop-induced transitions with only leptons (or quarks) as external states. In the presence of scalar leptoquark interactions, we also derive the differential distributions for flavour-changing neutral-current transitions in semileptonic kaon modes, including all known effects within the Standard Model. Their interference with the new physics contributions could play a significant role in future improvements of those constraints that are currently hampered by poorly-determined non-perturbative parameters.
[ { "created": "Thu, 29 Aug 2019 11:22:27 GMT", "version": "v1" }, { "created": "Mon, 14 Oct 2019 09:50:35 GMT", "version": "v2" } ]
2019-12-20
[ [ "Mandal", "Rusa", "" ], [ "Pich", "Antonio", "" ] ]
We present a comprehensive analysis of low-energy signals of hypothetical scalar leptoquark interactions in lepton and kaon transitions. We derive the most general effective four-fermion Lagrangian induced by tree-level scalar leptoquark exchange and identify the Wilson coefficients predicted by the five possible types of scalar leptoquarks. The current constraints on the leptoquark Yukawa couplings arising from lepton and kaon processes are worked out, including also loop-induced transitions with only leptons (or quarks) as external states. In the presence of scalar leptoquark interactions, we also derive the differential distributions for flavour-changing neutral-current transitions in semileptonic kaon modes, including all known effects within the Standard Model. Their interference with the new physics contributions could play a significant role in future improvements of those constraints that are currently hampered by poorly-determined non-perturbative parameters.
2304.09255
Andreas Ekstedt
Andreas Ekstedt
Propagation of gauge fields in hot and dense plasmas at higher orders
21 pages, 4 figures
null
null
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
Thermal field theory is indispensable for describing hot and dense systems. Yet perturbative calculations are often stymied by a host of energy scales, and tend to converge slowly. This means that precise results require the apt use of effective field theories. In this paper we refine the effective description of slowly varying gauge field known as hard thermal loops. We match this effective theory to the full theory to two-loops. Our results apply for any renormalizable model and fermion chemical potential. We also discuss how to consistently define asymptotic masses at higher orders; and how to treat spectral functions close to the lightcone. In particular, we demonstrate that the gluon mass is well-defined to next-to-leading order.
[ { "created": "Tue, 18 Apr 2023 19:35:39 GMT", "version": "v1" } ]
2023-04-20
[ [ "Ekstedt", "Andreas", "" ] ]
Thermal field theory is indispensable for describing hot and dense systems. Yet perturbative calculations are often stymied by a host of energy scales, and tend to converge slowly. This means that precise results require the apt use of effective field theories. In this paper we refine the effective description of slowly varying gauge field known as hard thermal loops. We match this effective theory to the full theory to two-loops. Our results apply for any renormalizable model and fermion chemical potential. We also discuss how to consistently define asymptotic masses at higher orders; and how to treat spectral functions close to the lightcone. In particular, we demonstrate that the gluon mass is well-defined to next-to-leading order.
hep-ph/0702280
Sarira Sahu
Alberto Bravo Garcia and Sarira Sahu
Higher order correction to the neutrino self-energy in a medium and its astrophysical applications
10 pages, revtex style, uses axodraw.sty, 1 figure
Mod. Phys. Lett. A, 22 (2007) 213-225
10.1142/S0217732307020865
null
hep-ph
null
We have calculated the 1/M^4 (M the vector boson mass) order correction to the neutrino self-energy in a medium. The possible application of this higher order contribution to the neutrino effective potential is considered in the context of the Early Universe hot plasma and of the cosmological Gamma Ray Burst fireball. We found that, depending on the medium parameters and on the neutrino properties (mixing angle and mass square difference) the resonant oscillation of active to active neutrinos is possible.
[ { "created": "Tue, 27 Feb 2007 17:05:34 GMT", "version": "v1" } ]
2009-11-13
[ [ "Garcia", "Alberto Bravo", "" ], [ "Sahu", "Sarira", "" ] ]
We have calculated the 1/M^4 (M the vector boson mass) order correction to the neutrino self-energy in a medium. The possible application of this higher order contribution to the neutrino effective potential is considered in the context of the Early Universe hot plasma and of the cosmological Gamma Ray Burst fireball. We found that, depending on the medium parameters and on the neutrino properties (mixing angle and mass square difference) the resonant oscillation of active to active neutrinos is possible.
0709.0422
A. V. Luchinsky
A. V. Berezhnoy, S. N. Koshkarev, A. V. Luchinsky, V. I. Nikolaenko
Lepton pair production in muon scattering by nucleus
15 pages, 12 figures, typos corrected
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Coherent production of lepton pair in muon scattering by nucleus is considered. With the help of different approaches (equivalent photon approximation, direct numerical and analytical calculations) we obtain total cross section of this reaction and distributions over invariant masses of final leptons. Special attention is paid to influence of final lepton identity on total and differential cross sections. We also study the role of coherence condition. Total cross sections of charmonia production in muon interaction with electromagnetic field of nucleus are also presented.
[ { "created": "Tue, 4 Sep 2007 13:06:07 GMT", "version": "v1" }, { "created": "Wed, 5 Sep 2007 11:56:40 GMT", "version": "v2" }, { "created": "Tue, 16 Oct 2007 09:50:23 GMT", "version": "v3" }, { "created": "Wed, 27 Aug 2008 11:33:45 GMT", "version": "v4" } ]
2008-08-27
[ [ "Berezhnoy", "A. V.", "" ], [ "Koshkarev", "S. N.", "" ], [ "Luchinsky", "A. V.", "" ], [ "Nikolaenko", "V. I.", "" ] ]
Coherent production of lepton pair in muon scattering by nucleus is considered. With the help of different approaches (equivalent photon approximation, direct numerical and analytical calculations) we obtain total cross section of this reaction and distributions over invariant masses of final leptons. Special attention is paid to influence of final lepton identity on total and differential cross sections. We also study the role of coherence condition. Total cross sections of charmonia production in muon interaction with electromagnetic field of nucleus are also presented.
2305.07689
Sally Dawson
Sally Dawson, Duarte Fontes, Carlos Quezada-Calonge, and Juan Jos\'e Sanz-Cillero
Matching the 2HDM to the HEFT and the SMEFT: Decoupling and Perturbativity
The HEFT matching to the 2HDM is contained in the supplemental material. Version 2 is version to be published in Phys. Rev. D
null
null
IPARCOS-UCM-23-034
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the 2 Higgs Doublet Model (2HDM) and compare two effective field theory (EFT) approaches to it, according to whether the heavy degrees of freedom are integrated out before (SMEFT) or after (HEFT) spontaneous symmetry breaking. %We show that, in the HEFT, an inconsistent EFT is obtained if one considers an expansion simply in inverse powers of the heavy masses. %We consider a HEFT expansion consistent with perturbativity %We show that, if the HEFT approach is required to comply with perturbativity, it ends up obeying the same power counting as the SMEFT one. % By requiring decoupling and perturbativity in the 2HDM, we define a consistent EFT expansion in inverse powers of the heavy masses which is applied to both the SMEFT and the HEFT matchings to the 2HDM. We organize this expansion with a dimensionless parameter $\xi$, and investigate the tree-level scatterings $hh\rightarrow hh$ and $WW\rightarrow hh$ up to $\mathcal{O}(\xi^2)$. We find no differences between the HEFT and the SMEFT approaches at this order. We show scenarios where even including dimension-8 operators of the SMEFT is insufficient to obtain an accurate matching to the 2HDM.
[ { "created": "Fri, 12 May 2023 18:00:00 GMT", "version": "v1" }, { "created": "Mon, 11 Sep 2023 13:10:12 GMT", "version": "v2" } ]
2023-09-12
[ [ "Dawson", "Sally", "" ], [ "Fontes", "Duarte", "" ], [ "Quezada-Calonge", "Carlos", "" ], [ "Sanz-Cillero", "Juan José", "" ] ]
We consider the 2 Higgs Doublet Model (2HDM) and compare two effective field theory (EFT) approaches to it, according to whether the heavy degrees of freedom are integrated out before (SMEFT) or after (HEFT) spontaneous symmetry breaking. %We show that, in the HEFT, an inconsistent EFT is obtained if one considers an expansion simply in inverse powers of the heavy masses. %We consider a HEFT expansion consistent with perturbativity %We show that, if the HEFT approach is required to comply with perturbativity, it ends up obeying the same power counting as the SMEFT one. % By requiring decoupling and perturbativity in the 2HDM, we define a consistent EFT expansion in inverse powers of the heavy masses which is applied to both the SMEFT and the HEFT matchings to the 2HDM. We organize this expansion with a dimensionless parameter $\xi$, and investigate the tree-level scatterings $hh\rightarrow hh$ and $WW\rightarrow hh$ up to $\mathcal{O}(\xi^2)$. We find no differences between the HEFT and the SMEFT approaches at this order. We show scenarios where even including dimension-8 operators of the SMEFT is insufficient to obtain an accurate matching to the 2HDM.
2203.13842
Dawid Brzeminski
Dawid Brzeminski, Anson Hook and Gustavo Marques-Tavares
Precision Early Universe Cosmology from Stochastic Gravitational Waves
28 pages, 11 figures
null
10.1007/JHEP11(2022)061
null
hep-ph astro-ph.CO gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The causal tail of stochastic gravitational waves can be used to probe the energy density in free streaming relativistic species as well as measure $g_\star(T)$ and beta functions $\beta(T)$ as a function of temperature. In the event of the discovery of loud stochastic gravitational waves, we demonstrate that LISA can measure the free streaming fraction of the universe down to the the $10^{-3}$ level, 100 times more sensitive than current constraints. Additionally, it would be sensitive to $\mathcal{O}(1)$ deviations of $g_\star$ and the QCD $\beta$ function from their Standard Model value at temperatures $\sim 10^5$ GeV. In this case, many motivated models such as split SUSY and other solutions to the Electroweak Hierarchy problem would be tested. Future detectors, such as DECIGO, would be 100 times more sensitive than LISA to these effects and be capable of testing other motivated scenarios such as WIMPs and axions. The amazing prospect of using precision gravitational wave measurements to test such well motivated theories provides a benchmark to aim for when developing a precise understanding of the gravitational wave spectrum both experimentally and theoretically.
[ { "created": "Fri, 25 Mar 2022 18:16:05 GMT", "version": "v1" }, { "created": "Thu, 9 Jun 2022 18:17:59 GMT", "version": "v2" }, { "created": "Wed, 12 Oct 2022 16:56:36 GMT", "version": "v3" } ]
2022-11-30
[ [ "Brzeminski", "Dawid", "" ], [ "Hook", "Anson", "" ], [ "Marques-Tavares", "Gustavo", "" ] ]
The causal tail of stochastic gravitational waves can be used to probe the energy density in free streaming relativistic species as well as measure $g_\star(T)$ and beta functions $\beta(T)$ as a function of temperature. In the event of the discovery of loud stochastic gravitational waves, we demonstrate that LISA can measure the free streaming fraction of the universe down to the the $10^{-3}$ level, 100 times more sensitive than current constraints. Additionally, it would be sensitive to $\mathcal{O}(1)$ deviations of $g_\star$ and the QCD $\beta$ function from their Standard Model value at temperatures $\sim 10^5$ GeV. In this case, many motivated models such as split SUSY and other solutions to the Electroweak Hierarchy problem would be tested. Future detectors, such as DECIGO, would be 100 times more sensitive than LISA to these effects and be capable of testing other motivated scenarios such as WIMPs and axions. The amazing prospect of using precision gravitational wave measurements to test such well motivated theories provides a benchmark to aim for when developing a precise understanding of the gravitational wave spectrum both experimentally and theoretically.
1004.2444
Jialun Ping
Youchang Yang and Jialun Ping
Dynamical study of the $X$(3915) as a molecular $D^*\bar{D^*}$ state in a quark model
5 pages, 2 figures
Phys.Rev.D81:114025,2010
10.1103/PhysRevD.81.114025
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Considering the coupling of color $1 \otimes 1$ and $8 \otimes 8$ structures, we calculate the energy of the newly observed $X$(3915) as $S-$wave $D^*\bar{D^*}$ state in the Bhaduri, Cohler, and Nogami quark model by the Gaussian Expansion Method. Due to the color coupling, the bound state of $D^*\bar{D^*}$ with $J^{PC}=0^{++}$ is found, which is well consonant with the experimental data of the $X$(3915). The bound state of $B^*\bar{B^*}$ with $J^{PC}=0^{++}$ and $2^{++}$ are also predicted in this work.
[ { "created": "Wed, 14 Apr 2010 16:35:11 GMT", "version": "v1" } ]
2014-11-20
[ [ "Yang", "Youchang", "" ], [ "Ping", "Jialun", "" ] ]
Considering the coupling of color $1 \otimes 1$ and $8 \otimes 8$ structures, we calculate the energy of the newly observed $X$(3915) as $S-$wave $D^*\bar{D^*}$ state in the Bhaduri, Cohler, and Nogami quark model by the Gaussian Expansion Method. Due to the color coupling, the bound state of $D^*\bar{D^*}$ with $J^{PC}=0^{++}$ is found, which is well consonant with the experimental data of the $X$(3915). The bound state of $B^*\bar{B^*}$ with $J^{PC}=0^{++}$ and $2^{++}$ are also predicted in this work.
hep-ph/0012177
Cosmin Macesanu
Cosmin Macesanu and Lynne H. Orr (University of Rochester)
Gluon Radiation in Top Quark Production and Decay at $e^+e^-$ Colliders
16 pages, Latex, 10 postscript figures; added some references
Phys.Rev.D65:014004,2002
10.1103/PhysRevD.65.014004
UR-1623
hep-ph
null
We study gluon radiation in top quark production above threshold at high energy $e^+e^-$ colliders. We allow for the top quarks to be off-shell, considering radiation in both the top production and decay processes simultaneously. Our calculation includes all top width effects, spin correlations, and $b$ quark mass effects. We study the effects of gluon radiation on top mass reconstuction and examine the interference between production- and decay-stage radiation, which can be sensitive to the value of the top quark decay width.
[ { "created": "Thu, 14 Dec 2000 19:28:16 GMT", "version": "v1" }, { "created": "Mon, 18 Dec 2000 21:17:17 GMT", "version": "v2" } ]
2011-07-19
[ [ "Macesanu", "Cosmin", "", "University of Rochester" ], [ "Orr", "Lynne H.", "", "University of Rochester" ] ]
We study gluon radiation in top quark production above threshold at high energy $e^+e^-$ colliders. We allow for the top quarks to be off-shell, considering radiation in both the top production and decay processes simultaneously. Our calculation includes all top width effects, spin correlations, and $b$ quark mass effects. We study the effects of gluon radiation on top mass reconstuction and examine the interference between production- and decay-stage radiation, which can be sensitive to the value of the top quark decay width.
2404.06520
Buyao Qu
Gui-Jun Ding, Si-Yi Jiang, Stephen F. King, Jun-Nan Lu, Bu-Yao Qu
Pati-Salam models with $A_4$ modular symmetry
33 pages, 10 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The flavor structure of quarks and leptons and quark-lepton unification are studied in the framework of Pati-Salam models with $A_4$ modular symmetry. The three generations of the left-handed and right-handed fermions are assigned to be triplet or singlets of $A_4$. The light neutrino masses are generated through the type-I seesaw mechanism. We perform a systematic classification of Pati-Salam models according to the transformations of matter fields under the $A_4$ modular symmetry, and the general form of the fermion mass matrix is given. We present four phenomenologically viable benchmark models which provide excellent descriptions of masses and flavor mixing of quarks and leptons, including neutrinos. In such models we find that the normal ordered neutrino mass spectrum is preferred over the inverted case, with neutrinoless double beta decay predicted to be too small to be observed by the next generation of experiments.
[ { "created": "Sat, 6 Apr 2024 17:03:02 GMT", "version": "v1" } ]
2024-04-11
[ [ "Ding", "Gui-Jun", "" ], [ "Jiang", "Si-Yi", "" ], [ "King", "Stephen F.", "" ], [ "Lu", "Jun-Nan", "" ], [ "Qu", "Bu-Yao", "" ] ]
The flavor structure of quarks and leptons and quark-lepton unification are studied in the framework of Pati-Salam models with $A_4$ modular symmetry. The three generations of the left-handed and right-handed fermions are assigned to be triplet or singlets of $A_4$. The light neutrino masses are generated through the type-I seesaw mechanism. We perform a systematic classification of Pati-Salam models according to the transformations of matter fields under the $A_4$ modular symmetry, and the general form of the fermion mass matrix is given. We present four phenomenologically viable benchmark models which provide excellent descriptions of masses and flavor mixing of quarks and leptons, including neutrinos. In such models we find that the normal ordered neutrino mass spectrum is preferred over the inverted case, with neutrinoless double beta decay predicted to be too small to be observed by the next generation of experiments.
0810.4545
Francisco Larios
F. Penunuri, F. Larios
tbW vertex in the Littlest Higgs Model with T-parity
Version published in Phys. Rev. D79, 015013 (2009)
Phys.Rev.D79:015013,2009
10.1103/PhysRevD.79.015013
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A study of the effective tbW vertex is done in the littlest Higgs model with T parity that includes the one loop induced weak dipole coefficient f_{2R}. The top's width, the W-boson helicity in the t-> bW^+ decay as well as the t-channel and the s-channel modes of single top quark production at the LHC are then obtained for the tbW coupling. Our calculation is done in the Feynman-'t Hooft gauge, and we provide details of the analysis, like exact formulas (to all orders of the expansion variable v/f) of masses and mixing angles of all the particles involved. Also, a complete and exact diagonalization (and normalization) of the scalar sector of the model is made.
[ { "created": "Mon, 27 Oct 2008 19:29:01 GMT", "version": "v1" }, { "created": "Thu, 30 Oct 2008 19:44:54 GMT", "version": "v2" }, { "created": "Thu, 12 Feb 2009 21:29:38 GMT", "version": "v3" } ]
2009-02-26
[ [ "Penunuri", "F.", "" ], [ "Larios", "F.", "" ] ]
A study of the effective tbW vertex is done in the littlest Higgs model with T parity that includes the one loop induced weak dipole coefficient f_{2R}. The top's width, the W-boson helicity in the t-> bW^+ decay as well as the t-channel and the s-channel modes of single top quark production at the LHC are then obtained for the tbW coupling. Our calculation is done in the Feynman-'t Hooft gauge, and we provide details of the analysis, like exact formulas (to all orders of the expansion variable v/f) of masses and mixing angles of all the particles involved. Also, a complete and exact diagonalization (and normalization) of the scalar sector of the model is made.
hep-ph/0607168
Jan Piclum
P. Marquard, J. H. Piclum, D. Seidel, M. Steinhauser
Fermionic Corrections to the Three-Loop Matching Coefficient of the Vector Current
21 pages
Nucl.Phys.B758:144-160,2006
10.1016/j.nuclphysb.2006.09.015
DESY 06-107, SFB/CPP-06-31, TTP06-22
hep-ph
null
In this paper we consider the matching coefficient of the vector current between Quantum Chromodynamics (QCD) and Non-Relativistic QCD (NRQCD) to three-loop order in perturbation theory. We evaluate the fermionic corrections containing a closed massless fermion loop. The results are building blocks both for the bottom and top quark system at threshold. We explain in detail the methods used for the evaluation of the Feynman diagrams, classify the occurring master integrals and provide results for the latter. The numerical effects are significant. They have the tendency to improve the behaviour of the perturbative series -- both for the bottom and top quark system.
[ { "created": "Fri, 14 Jul 2006 11:49:15 GMT", "version": "v1" } ]
2008-11-26
[ [ "Marquard", "P.", "" ], [ "Piclum", "J. H.", "" ], [ "Seidel", "D.", "" ], [ "Steinhauser", "M.", "" ] ]
In this paper we consider the matching coefficient of the vector current between Quantum Chromodynamics (QCD) and Non-Relativistic QCD (NRQCD) to three-loop order in perturbation theory. We evaluate the fermionic corrections containing a closed massless fermion loop. The results are building blocks both for the bottom and top quark system at threshold. We explain in detail the methods used for the evaluation of the Feynman diagrams, classify the occurring master integrals and provide results for the latter. The numerical effects are significant. They have the tendency to improve the behaviour of the perturbative series -- both for the bottom and top quark system.
hep-ph/9911419
Guo-Hong Wu
Guo-Hong Wu and Amarjit Soni
Novel CP-violating Effects in B decays from Charged-Higgs in a Two-Higgs Doublet Model for the Top Quark
32 pages, 5 figures, section V.A revised, version to appear in PRD
Phys.Rev.D62:056005,2000
10.1103/PhysRevD.62.056005
BNL-HET-99/40, OITS-683
hep-ph hep-ex
null
We explore charged-Higgs cp-violating effects in a specific type III two-Higgs doublet model which is theoretically attractive as it accommodates the large mass of the top quark in a natural fashion. Two new CP-violating phases arise from the right-handed up quark sector. We consider CP violation in both neutral and charged B decays. Some of the important findings are as follows. 1) Large direct-CP asymmetry is found to be possible for B+- to psi/J K+-. 2) Sizable D-anti-D mixing effect at the percent level is found to be admissible despite the stringent constraints from the data on K-anti-K mixing, b to s gamma and B to tau nu decays. 3) A simple but distinctive CP asymmetry pattern emerges in decays of B_d and B_s mesons, including B_d to psi/J K_S, D+ D-, and B_s to D_s+ D_s-, psi eta/eta^prime, psi/J K_S. 4) The effect of D-anti-D mixing on the CP asymmetry in B+- to D/anti-D K+- and on the extraction of the angle gamma of the unitarity triangle from such decays can be significant.
[ { "created": "Fri, 19 Nov 1999 23:37:25 GMT", "version": "v1" }, { "created": "Thu, 27 Jul 2000 18:24:16 GMT", "version": "v2" } ]
2011-03-23
[ [ "Wu", "Guo-Hong", "" ], [ "Soni", "Amarjit", "" ] ]
We explore charged-Higgs cp-violating effects in a specific type III two-Higgs doublet model which is theoretically attractive as it accommodates the large mass of the top quark in a natural fashion. Two new CP-violating phases arise from the right-handed up quark sector. We consider CP violation in both neutral and charged B decays. Some of the important findings are as follows. 1) Large direct-CP asymmetry is found to be possible for B+- to psi/J K+-. 2) Sizable D-anti-D mixing effect at the percent level is found to be admissible despite the stringent constraints from the data on K-anti-K mixing, b to s gamma and B to tau nu decays. 3) A simple but distinctive CP asymmetry pattern emerges in decays of B_d and B_s mesons, including B_d to psi/J K_S, D+ D-, and B_s to D_s+ D_s-, psi eta/eta^prime, psi/J K_S. 4) The effect of D-anti-D mixing on the CP asymmetry in B+- to D/anti-D K+- and on the extraction of the angle gamma of the unitarity triangle from such decays can be significant.
1412.3097
Siyoung Nam
Bum-Hoon Lee, Chanyong Park, and Siyoung Nam
Properties of Holographic Mesons on Dense Medium
18 pages, 8 Fig. numbers
null
10.1007/JHEP05(2015)011
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the energy dispersions of holographic light mesons and their decay constants on dense nuclear medium. As the spatial momenta of mesons along the boundary direction increase, both observables of the mesons not only increase but also split according to the isospin charges. The decay constant of the negative meson is more large than that of the positive meson of the same type due to the chemical potentials of the background nucleons.
[ { "created": "Tue, 9 Dec 2014 20:48:18 GMT", "version": "v1" } ]
2015-06-11
[ [ "Lee", "Bum-Hoon", "" ], [ "Park", "Chanyong", "" ], [ "Nam", "Siyoung", "" ] ]
We study the energy dispersions of holographic light mesons and their decay constants on dense nuclear medium. As the spatial momenta of mesons along the boundary direction increase, both observables of the mesons not only increase but also split according to the isospin charges. The decay constant of the negative meson is more large than that of the positive meson of the same type due to the chemical potentials of the background nucleons.
1705.01929
Aleksey Rusov
Aleksey V. Rusov
Higher-Twist Effects in Light-Cone Sum Rule for the $B\to\pi$ Form Factor
14 pages, 2 figures, 1 table
Eur.Phys.J. C77 (2017) no.7, 442
10.1140/epjc/s10052-017-5000-9
SI-HEP-2017-07, QFET-2017-06
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the higher-twist corrections to the QCD light-cone sum rule for the $B \to \pi$ transition form factor. The light-cone expansion of the massive quark propagator in the external gluonic field is extended to include new terms containing the derivatives of gluon-field strength. The resulting analytical expressions for the twist-5 and twist-6 contributions to the correlation function are obtained in a factorized approximation, expressed via the product of the lower-twist pion distribution amplitudes and the quark-condensate density. The numerical analysis reveals that new higher-twist effects for the $B \to \pi$ form factor are strongly suppressed. This result justifies the conventional truncation of the operator product expansion in the light-cone sum rules up to twist-4 terms.
[ { "created": "Thu, 4 May 2017 17:49:44 GMT", "version": "v1" }, { "created": "Tue, 1 Aug 2017 10:41:12 GMT", "version": "v2" } ]
2017-08-02
[ [ "Rusov", "Aleksey V.", "" ] ]
We calculate the higher-twist corrections to the QCD light-cone sum rule for the $B \to \pi$ transition form factor. The light-cone expansion of the massive quark propagator in the external gluonic field is extended to include new terms containing the derivatives of gluon-field strength. The resulting analytical expressions for the twist-5 and twist-6 contributions to the correlation function are obtained in a factorized approximation, expressed via the product of the lower-twist pion distribution amplitudes and the quark-condensate density. The numerical analysis reveals that new higher-twist effects for the $B \to \pi$ form factor are strongly suppressed. This result justifies the conventional truncation of the operator product expansion in the light-cone sum rules up to twist-4 terms.
2011.08747
Bing-Dong Wan
Bing-Dong Wan and Cong-Feng Qiao
About the exotic structure of $Z_{cs}$
31 pages, 4 figures, a few expressions are amended
null
10.1016/j.nuclphysb.2021.115450
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Very recently a new hadronic structure around $3.98$ GeV was observed in BESIII experiment. From its decay modes, it is reasonable for people to assign it to the category of exotic state, say $Z^+_{cs}$, the stranged-parter of $Z_{c}(3900)$. This finding indicates for the first time the exotic state with strange quark in charm sector, and hence has a peculiar importance. By virtue of the QCD Sum Rule technique, we analyze the $Z^+_{cs}$ about its possible configuration and physical properties, and find it could be configured as a mixture of two types of structures, $[1_c]_{\bar{c} u}\otimes[1_c]_{\bar{s} c}$ and $[1_c]_{\bar{c} c}\otimes[1_c]_{\bar{s} u}$, or $[3_c]_{\bar{c} u}\otimes[\bar{3}_c]_{\bar{s} c}$ and $[3_c]_{\bar{c} c}\otimes[\bar{3}_c]_{\bar{s} u}$, with $J^P=1^+$. Physically, it then appears to be the emergence of a compound of four possible currents in each configuration, which tells the single current evaluation of hadron spectroscopy and their decay properties are sometimes not enough. We find in both cases the energy spectra may fit well with the experimental observation, i.e. $3.98$ GeV, within the uncertainties, while noted the former is not favored by vector meson exchange model. Various $Z^+_{cs}(3980)$ decay modes are evaluated, which are critical for pinning down its configuration and left for experimental verification. We also predict the mass of $Z^0_{cs}$, the neutral partner of $Z^+_{cs}(3980)$, and analyze its dominant decay probabilities.
[ { "created": "Tue, 17 Nov 2020 16:21:48 GMT", "version": "v1" }, { "created": "Thu, 24 Dec 2020 16:20:14 GMT", "version": "v2" } ]
2021-06-30
[ [ "Wan", "Bing-Dong", "" ], [ "Qiao", "Cong-Feng", "" ] ]
Very recently a new hadronic structure around $3.98$ GeV was observed in BESIII experiment. From its decay modes, it is reasonable for people to assign it to the category of exotic state, say $Z^+_{cs}$, the stranged-parter of $Z_{c}(3900)$. This finding indicates for the first time the exotic state with strange quark in charm sector, and hence has a peculiar importance. By virtue of the QCD Sum Rule technique, we analyze the $Z^+_{cs}$ about its possible configuration and physical properties, and find it could be configured as a mixture of two types of structures, $[1_c]_{\bar{c} u}\otimes[1_c]_{\bar{s} c}$ and $[1_c]_{\bar{c} c}\otimes[1_c]_{\bar{s} u}$, or $[3_c]_{\bar{c} u}\otimes[\bar{3}_c]_{\bar{s} c}$ and $[3_c]_{\bar{c} c}\otimes[\bar{3}_c]_{\bar{s} u}$, with $J^P=1^+$. Physically, it then appears to be the emergence of a compound of four possible currents in each configuration, which tells the single current evaluation of hadron spectroscopy and their decay properties are sometimes not enough. We find in both cases the energy spectra may fit well with the experimental observation, i.e. $3.98$ GeV, within the uncertainties, while noted the former is not favored by vector meson exchange model. Various $Z^+_{cs}(3980)$ decay modes are evaluated, which are critical for pinning down its configuration and left for experimental verification. We also predict the mass of $Z^0_{cs}$, the neutral partner of $Z^+_{cs}(3980)$, and analyze its dominant decay probabilities.
1810.09393
Chao-Hsi Chang
Xu-Chang Zheng, Chao-Hsi Chang, Tai-Fu Feng
A proposal on complementary determination of the electro-weak mixing angles ${\rm sin^2\theta_W}$ at a super Z-factory
9 pages, 7 figures
Sci. China-Phys. Mech. Astron., Aug. 2020 Vol 63, No. 8:281011
10.1007/s11433-019-1497-9
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A proposal on determination of the effective electro-weak mixing angle ${\rm sin^2\theta_{eff}^f\;(f=c,b)}$ at a super Z-factory (an $e^+e^-$ collider designed with the possible highest luminosity and running around the center mass energy $\sqrt s=m_Z$) is proposed. It is to determine how the effective mixing angles depend on the flavors, especially the flavors $c$, $b$ (with the determined effective ones, the electro-weak mixing angles ${\rm sin^2\theta_W^f\;(f=c,b)}$ of Standard Model can be derived out precisely). The key point of the proposal is that at such a super Z-factory, via measuring the forward-backward ($A_{FB}$), left-right ($A_{LR}$) and combined left-right forward-backward ($A^{FB}_{LR}$) asymmetries of the produced doubly heavy-flavored hadrons (such as $B_c$, $B_c^*$ and the baryons $H_{QQ'q}$: $\Xi_{cc}$, $\Xi_{bc}$ and $\Xi_{bb}$ etc) in the relevant production processes $e^+e^-\to B_c+\cdots$ and $e^+e^-\to H_{QQ'q}+\cdots$ one may complement the final determination of the mixing angle ${\rm sin^2\theta_W^f\;(f=c,b)}$ of Standard Model. The advantage of the proposed way to determine the effective electro-weak mixing angles is that the doubly heavy flavor(s) and the out-going direction of the produced doubly-heavy hadron can be experimental determined precisely, i.e. there are no such errors caused by missing identification of the heavy flavor(s) and by determining the so-called thrust axis of the produced jets, which can not be avoided in the early determination at LEP-I and SLC.
[ { "created": "Mon, 22 Oct 2018 16:30:14 GMT", "version": "v1" }, { "created": "Sun, 29 Dec 2019 07:23:08 GMT", "version": "v2" } ]
2020-06-16
[ [ "Zheng", "Xu-Chang", "" ], [ "Chang", "Chao-Hsi", "" ], [ "Feng", "Tai-Fu", "" ] ]
A proposal on determination of the effective electro-weak mixing angle ${\rm sin^2\theta_{eff}^f\;(f=c,b)}$ at a super Z-factory (an $e^+e^-$ collider designed with the possible highest luminosity and running around the center mass energy $\sqrt s=m_Z$) is proposed. It is to determine how the effective mixing angles depend on the flavors, especially the flavors $c$, $b$ (with the determined effective ones, the electro-weak mixing angles ${\rm sin^2\theta_W^f\;(f=c,b)}$ of Standard Model can be derived out precisely). The key point of the proposal is that at such a super Z-factory, via measuring the forward-backward ($A_{FB}$), left-right ($A_{LR}$) and combined left-right forward-backward ($A^{FB}_{LR}$) asymmetries of the produced doubly heavy-flavored hadrons (such as $B_c$, $B_c^*$ and the baryons $H_{QQ'q}$: $\Xi_{cc}$, $\Xi_{bc}$ and $\Xi_{bb}$ etc) in the relevant production processes $e^+e^-\to B_c+\cdots$ and $e^+e^-\to H_{QQ'q}+\cdots$ one may complement the final determination of the mixing angle ${\rm sin^2\theta_W^f\;(f=c,b)}$ of Standard Model. The advantage of the proposed way to determine the effective electro-weak mixing angles is that the doubly heavy flavor(s) and the out-going direction of the produced doubly-heavy hadron can be experimental determined precisely, i.e. there are no such errors caused by missing identification of the heavy flavor(s) and by determining the so-called thrust axis of the produced jets, which can not be avoided in the early determination at LEP-I and SLC.
0706.3139
Markus Diehl
M. Diehl and W. Kugler
Exclusive Meson Production at NLO
4 pages. Talk given at DIS 2007. v2: corrections in plots, modified conclusions
null
null
DESY 07-093
hep-ph
null
We report on numerical studies of the NLO corrections to exclusive meson electroproduction, both in collider and fixed-target kinematics. Corrections are found to be huge at small xB and sizeable at intermediate or large xB.
[ { "created": "Thu, 21 Jun 2007 12:34:51 GMT", "version": "v1" }, { "created": "Wed, 8 Aug 2007 11:37:01 GMT", "version": "v2" } ]
2007-08-08
[ [ "Diehl", "M.", "" ], [ "Kugler", "W.", "" ] ]
We report on numerical studies of the NLO corrections to exclusive meson electroproduction, both in collider and fixed-target kinematics. Corrections are found to be huge at small xB and sizeable at intermediate or large xB.
1312.5666
Gudrun Heinrich
Johannes Schlenk, Gudrun Heinrich, Jan Winter
NLO QCD corrections to WWbb production and top quark observables
9 pages, 4 figures, contribution to the 11th International Symposium on Radiative Corrections (RADCOR 2013), September 2013, Lumley Castle Hotel, Durham, UK; References updated
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the NLO QCD corrections to the production of a W+W- pair and two b-jets, including the leptonic decays of the W bosons. Contributions from singly resonant and non-resonant top quarks are fully taken into account. We also discuss observables relevant for top quark mass measurements and top quark asymmetries.
[ { "created": "Thu, 19 Dec 2013 17:53:23 GMT", "version": "v1" }, { "created": "Tue, 24 Dec 2013 08:54:40 GMT", "version": "v2" } ]
2013-12-25
[ [ "Schlenk", "Johannes", "" ], [ "Heinrich", "Gudrun", "" ], [ "Winter", "Jan", "" ] ]
We present the NLO QCD corrections to the production of a W+W- pair and two b-jets, including the leptonic decays of the W bosons. Contributions from singly resonant and non-resonant top quarks are fully taken into account. We also discuss observables relevant for top quark mass measurements and top quark asymmetries.
hep-ph/0703026
Guang-You Qin
Guang-You Qin, Abhijit Majumder, Charles Gale
Electromagnetic Radiation from Broken Symmetries in Relativistic Nuclear Collisions
6 pages, 3 figures, Contribution to the Quark Matter 2006 Conference in Shanghai, Nov 14-20 2006, to be submitted to International Journal of Modern Physics E (World Scientific)
Int.J.Mod.Phys.E16:2350-2355,2007
10.1142/S0218301307007921
null
hep-ph nucl-ex nucl-th
null
A new channel of direct photon production from a quark gluon plasma (QGP) is explored in the framework of high-temperature QCD. This process appears at next-to-leading order, in the presence of a charge asymmetry in the excited matter. The photon production rate from this new mechanism is suppressed compared to the QCD annihilation and Compton scattering at low baryon density but assumes importance in baryon-rich matter.
[ { "created": "Fri, 2 Mar 2007 18:12:27 GMT", "version": "v1" } ]
2010-11-26
[ [ "Qin", "Guang-You", "" ], [ "Majumder", "Abhijit", "" ], [ "Gale", "Charles", "" ] ]
A new channel of direct photon production from a quark gluon plasma (QGP) is explored in the framework of high-temperature QCD. This process appears at next-to-leading order, in the presence of a charge asymmetry in the excited matter. The photon production rate from this new mechanism is suppressed compared to the QCD annihilation and Compton scattering at low baryon density but assumes importance in baryon-rich matter.
1709.00689
Ailin Zhang
Dan-Dan Ye, Ze Zhao and Ailin Zhang
Study of $P$-wave excitations of observed charmed strange baryons
10 pages, 1 figure, 11 tables, RevTex, to appear in Phys.Rev.D
Phys. Rev. D 96, 114009 (2017)
10.1103/PhysRevD.96.114009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many excited charmed strange baryons such as $\Xi_c(2790)$, $\Xi_c(2815)$, $\Xi_c(2930)$, $\Xi_c(2980)$, $\Xi_c(3055)$, $\Xi_c(3080)$ and $\Xi_c(3123)$ have been observed. In order to understand their internal structure and to determine their spin-parities, the strong decay properties of these baryons as possible $P$-wave excited $\Xi_c$ candidates have been systematically studied in a $^3P_0$ model. The configurations and $J^P$ assignments of $\Xi_c(2790)$, $\Xi_c(2815)$, $\Xi_c(2930)$, $\Xi_c(2980)$, $\Xi_c(3055)$, $\Xi_c(3080)$ and $\Xi_c(3123)$ have been explored based on recent experimental data. In our analyses, $\Xi_c(3055)$, $\Xi_c(3080)$ and $\Xi_c(3123)$ seem impossible to be the $P$-wave excited $\Xi_c$. $\Xi_c(2790)$, $\Xi_c(2815)$, $\Xi_c(2930)$ and $\Xi_c(2980)$ may be the $P$-wave excited $\Xi_c$. In particular, $\Xi_c(2790)$ and $\Xi_c(2815)$ are very possibly the $P$-wave excited $\Xi_{c1}(1/2^-)$ and $\Xi_{c1}(3/2^-)$, respectively. $\Xi_c(2980)$ may be the $P$-wave excited $\Xi_{c1}^{'}(\frac{1}{2}^-)$. $\Xi_c(2930)$ may be the $P$-wave $\Xi_{c0}^{'}(\frac{1}{2}^-)$, $\tilde{\Xi}_{c0}(\frac{1}{2}^-)$, $\Xi_{c2}^{'}(\frac{3}{2}^-)$, $\Xi_{c2}^{'}(\frac{5}{2}^-)$, $\tilde{\Xi}_{c2}(\frac{3}{2}^-)$ or $\tilde{\Xi}_{c2}(\frac{5}{2}^-)$. Furthermore, some branching fraction ratios related to the internal structure and quark configuration of $P$-wave $\Xi_c$ have also been computed. Measurements of these ratios in the future will be helpful to understand these excited $\Xi_c$.
[ { "created": "Sun, 3 Sep 2017 09:15:53 GMT", "version": "v1" }, { "created": "Thu, 16 Nov 2017 02:40:31 GMT", "version": "v2" } ]
2017-12-20
[ [ "Ye", "Dan-Dan", "" ], [ "Zhao", "Ze", "" ], [ "Zhang", "Ailin", "" ] ]
Many excited charmed strange baryons such as $\Xi_c(2790)$, $\Xi_c(2815)$, $\Xi_c(2930)$, $\Xi_c(2980)$, $\Xi_c(3055)$, $\Xi_c(3080)$ and $\Xi_c(3123)$ have been observed. In order to understand their internal structure and to determine their spin-parities, the strong decay properties of these baryons as possible $P$-wave excited $\Xi_c$ candidates have been systematically studied in a $^3P_0$ model. The configurations and $J^P$ assignments of $\Xi_c(2790)$, $\Xi_c(2815)$, $\Xi_c(2930)$, $\Xi_c(2980)$, $\Xi_c(3055)$, $\Xi_c(3080)$ and $\Xi_c(3123)$ have been explored based on recent experimental data. In our analyses, $\Xi_c(3055)$, $\Xi_c(3080)$ and $\Xi_c(3123)$ seem impossible to be the $P$-wave excited $\Xi_c$. $\Xi_c(2790)$, $\Xi_c(2815)$, $\Xi_c(2930)$ and $\Xi_c(2980)$ may be the $P$-wave excited $\Xi_c$. In particular, $\Xi_c(2790)$ and $\Xi_c(2815)$ are very possibly the $P$-wave excited $\Xi_{c1}(1/2^-)$ and $\Xi_{c1}(3/2^-)$, respectively. $\Xi_c(2980)$ may be the $P$-wave excited $\Xi_{c1}^{'}(\frac{1}{2}^-)$. $\Xi_c(2930)$ may be the $P$-wave $\Xi_{c0}^{'}(\frac{1}{2}^-)$, $\tilde{\Xi}_{c0}(\frac{1}{2}^-)$, $\Xi_{c2}^{'}(\frac{3}{2}^-)$, $\Xi_{c2}^{'}(\frac{5}{2}^-)$, $\tilde{\Xi}_{c2}(\frac{3}{2}^-)$ or $\tilde{\Xi}_{c2}(\frac{5}{2}^-)$. Furthermore, some branching fraction ratios related to the internal structure and quark configuration of $P$-wave $\Xi_c$ have also been computed. Measurements of these ratios in the future will be helpful to understand these excited $\Xi_c$.
hep-ph/9403327
Tom Browder
The CLEO Collaboration
Precision Measurement of the $D_s^{*+}- D_s^+$ Mass Difference
18 pages uuencoded compressed postscript (process with uudecode then gunzip). hardcopies with figures can be obtained by sending mail to: preprints@lns62.lns.cornell.edu
Phys.Rev.D50:1884-1891,1994
10.1103/PhysRevD.50.1884
CLNS94-1271, CLEO 94-6
hep-ph hep-ex
null
We have measured the vector-pseudoscalar mass splitting $M(D_s^{*+})-M(D_s^+) = 144.22\pm 0.47\pm 0.37 MeV$, significantly more precise than the previous world average. We minimize the systematic errors by also measuring the vector-pseudoscalar mass difference $M(D^{*0})-M(D^0)$ using the radiative decay $D^{*0}\rightarrow D^0\gamma$, obtaining $[M(D_s^{*+})-M(D_s^+)]-[M(D^{*0})-M(D^0)] = 2.09\pm 0.47\pm 0.37 MeV$. This is then combined with our previous high-precision measurement of $M(D^{*0})-M(D^0)$, which used the decay $D^{*0}\rightarrow D^0\pi^0$. We also measure the mass difference $M(D_s^+)-M(D^+)=99.5\pm 0.6\pm 0.3$ MeV, using the $\phi\pi^+$ decay modes of the $D_s^+$ and $D^+$ mesons.
[ { "created": "Tue, 22 Mar 1994 02:03:15 GMT", "version": "v1" } ]
2012-08-27
[ [ "The CLEO Collaboration", "", "" ] ]
We have measured the vector-pseudoscalar mass splitting $M(D_s^{*+})-M(D_s^+) = 144.22\pm 0.47\pm 0.37 MeV$, significantly more precise than the previous world average. We minimize the systematic errors by also measuring the vector-pseudoscalar mass difference $M(D^{*0})-M(D^0)$ using the radiative decay $D^{*0}\rightarrow D^0\gamma$, obtaining $[M(D_s^{*+})-M(D_s^+)]-[M(D^{*0})-M(D^0)] = 2.09\pm 0.47\pm 0.37 MeV$. This is then combined with our previous high-precision measurement of $M(D^{*0})-M(D^0)$, which used the decay $D^{*0}\rightarrow D^0\pi^0$. We also measure the mass difference $M(D_s^+)-M(D^+)=99.5\pm 0.6\pm 0.3$ MeV, using the $\phi\pi^+$ decay modes of the $D_s^+$ and $D^+$ mesons.
hep-ph/0411130
Ian D. Lawrie
Ian D. Lawrie
Numerical investigation of friction in inflaton equations of motion
13 pages, 7 figures
Phys.Rev. D71 (2005) 025021
10.1103/PhysRevD.71.025021
null
hep-ph astro-ph gr-qc hep-th
null
The equation of motion for the expectation value of a scalar quantum field does not have the local form that is commonly assumed in studies of inflationary cosmology. We have recently argued that the true, temporally non-local equation of motion does not possess a time-derivative expansion and that the conversion of inflaton energy into particles is not, in principle, described by the friction term estimated from linear response theory. Here, we use numerical methods to investigate whether this obstacle to deriving a local equation of motion is purely formal, or of some quantitative importance. Using a simple scalar-field model, we find that, although the non-equilibrium evolution can exhibit significant damping, this damping is not well described by the local equation of motion obtained from linear response theory. It is possible that linear response theory does not apply to the situation we study only because thermalization turns out to be slow, but we argue that that the large discrepancies we observe indicate a failure of the local approximation at a more fundamental level.
[ { "created": "Tue, 9 Nov 2004 11:14:36 GMT", "version": "v1" } ]
2009-11-10
[ [ "Lawrie", "Ian D.", "" ] ]
The equation of motion for the expectation value of a scalar quantum field does not have the local form that is commonly assumed in studies of inflationary cosmology. We have recently argued that the true, temporally non-local equation of motion does not possess a time-derivative expansion and that the conversion of inflaton energy into particles is not, in principle, described by the friction term estimated from linear response theory. Here, we use numerical methods to investigate whether this obstacle to deriving a local equation of motion is purely formal, or of some quantitative importance. Using a simple scalar-field model, we find that, although the non-equilibrium evolution can exhibit significant damping, this damping is not well described by the local equation of motion obtained from linear response theory. It is possible that linear response theory does not apply to the situation we study only because thermalization turns out to be slow, but we argue that that the large discrepancies we observe indicate a failure of the local approximation at a more fundamental level.
1011.4939
Jae-hyeon Park
Jae-hyeon Park (DESY Hamburg)
Metastability bounds on flavour-violating trilinear soft terms in the MSSM
13 pages, published version
Phys.Rev.D83:055015,2011
10.1103/PhysRevD.83.055015
DESY 10-214
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The vacuum stability bounds on flavour-violating trilinear soft terms are revisited from the viewpoint that one should not ban a standard-model-like false vacuum as long as it is long-lived on a cosmological timescale. The vacuum transition rate is evaluated numerically by searching for the bounce configuration. Like stability, a metastability bound does not decouple even if sfermion masses grow. Apart from being more generous than stability, the new bounds are largely independent of Yukawa couplings except for the stop trilinears. With vacuum longevity imposed on otherwise arbitrary LR insertions, it is found that a super flavour factory has the potential to probe sparticle masses up to a few TeV through B and tau physics whereas the MEG experiment might cover a far wider range. In the stop sector, metastability is more restrictive than any existing experimental constraint such as from electroweak precision data. Also discussed are dependency on other parameters and reliability under radiative corrections.
[ { "created": "Mon, 22 Nov 2010 21:00:00 GMT", "version": "v1" }, { "created": "Tue, 25 Jan 2011 22:51:14 GMT", "version": "v2" }, { "created": "Wed, 23 Mar 2011 16:19:14 GMT", "version": "v3" } ]
2015-03-17
[ [ "Park", "Jae-hyeon", "", "DESY Hamburg" ] ]
The vacuum stability bounds on flavour-violating trilinear soft terms are revisited from the viewpoint that one should not ban a standard-model-like false vacuum as long as it is long-lived on a cosmological timescale. The vacuum transition rate is evaluated numerically by searching for the bounce configuration. Like stability, a metastability bound does not decouple even if sfermion masses grow. Apart from being more generous than stability, the new bounds are largely independent of Yukawa couplings except for the stop trilinears. With vacuum longevity imposed on otherwise arbitrary LR insertions, it is found that a super flavour factory has the potential to probe sparticle masses up to a few TeV through B and tau physics whereas the MEG experiment might cover a far wider range. In the stop sector, metastability is more restrictive than any existing experimental constraint such as from electroweak precision data. Also discussed are dependency on other parameters and reliability under radiative corrections.