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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
hep-ph/0106037
|
Johannes Bluemlein
|
J. Bl\"umlein and D. Robaschik
|
On the Scaling Violations of Diffractive Structure Functions: Operator
Approach
|
12 pages LATEX, 2 style files
|
Phys.Lett.B517:222-232,2001
|
10.1016/S0370-2693(01)00999-6
|
DESY 01-072
|
hep-ph hep-ex hep-lat
| null |
A quantum field theoretic treatment of inclusive deep-inelastic diffractive
scattering is given. The process can be described in the general framework of
non-forward scattering processes using the light-cone expansion in the
generalized Bjorken region. Evolution equations of the diffractive hadronic
matrix elements are derived at the level of the twist-2 contributions and are
compared to those of inclusive deep-inelastic forward scattering (DIS). The
diffractive parton densities are obtained as projections of two-variable parton
distributions. We also comment on the higher twist contributions in the
light-cone expansion.
|
[
{
"created": "Mon, 4 Jun 2001 18:15:50 GMT",
"version": "v1"
},
{
"created": "Tue, 30 Oct 2001 05:35:14 GMT",
"version": "v2"
}
] |
2008-11-26
|
[
[
"Blümlein",
"J.",
""
],
[
"Robaschik",
"D.",
""
]
] |
A quantum field theoretic treatment of inclusive deep-inelastic diffractive scattering is given. The process can be described in the general framework of non-forward scattering processes using the light-cone expansion in the generalized Bjorken region. Evolution equations of the diffractive hadronic matrix elements are derived at the level of the twist-2 contributions and are compared to those of inclusive deep-inelastic forward scattering (DIS). The diffractive parton densities are obtained as projections of two-variable parton distributions. We also comment on the higher twist contributions in the light-cone expansion.
|
2003.12050
|
Dimitrios K. Papoulias
|
O. G. Miranda, D. K. Papoulias, G. Sanchez Garcia, O. Sanders, M.
T\'ortola, J. W. F. Valle
|
Implications of the first detection of coherent elastic neutrino-nucleus
scattering (CEvNS) with Liquid Argon
|
discussion expanded including light mediators and nuclear
uncertainties, figures added, references added. V3: Fig. 7 corrected,
conclusions unchanged
|
JHEP 05 (2020) 130
|
10.1007/JHEP05(2020)130
|
IFIC/20-XXX
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The CENNS-10 experiment of the COHERENT collaboration has recently reported
the first detection of coherent-elastic neutrino-nucleus scattering (CEvNS) in
liquid Argon with more than $3 \sigma$ significance. In this work, we exploit
the new data in order to probe various interesting parameters which are of key
importance to CEvNS within and beyond the Standard Model. A dedicated
statistical analysis of these data shows that the current constraints are
significantly improved in most cases. We derive a first measurement of the
neutron rms charge radius of Argon, and also an improved determination of the
weak mixing angle in the low energy regime. We also update the constraints on
neutrino non-standard interactions, electromagnetic properties and light
mediators with respect to those derived from the first COHERENT-CsI data.
|
[
{
"created": "Thu, 26 Mar 2020 17:34:40 GMT",
"version": "v1"
},
{
"created": "Fri, 3 Apr 2020 15:34:43 GMT",
"version": "v2"
},
{
"created": "Sun, 8 Nov 2020 18:49:59 GMT",
"version": "v3"
}
] |
2020-11-10
|
[
[
"Miranda",
"O. G.",
""
],
[
"Papoulias",
"D. K.",
""
],
[
"Garcia",
"G. Sanchez",
""
],
[
"Sanders",
"O.",
""
],
[
"Tórtola",
"M.",
""
],
[
"Valle",
"J. W. F.",
""
]
] |
The CENNS-10 experiment of the COHERENT collaboration has recently reported the first detection of coherent-elastic neutrino-nucleus scattering (CEvNS) in liquid Argon with more than $3 \sigma$ significance. In this work, we exploit the new data in order to probe various interesting parameters which are of key importance to CEvNS within and beyond the Standard Model. A dedicated statistical analysis of these data shows that the current constraints are significantly improved in most cases. We derive a first measurement of the neutron rms charge radius of Argon, and also an improved determination of the weak mixing angle in the low energy regime. We also update the constraints on neutrino non-standard interactions, electromagnetic properties and light mediators with respect to those derived from the first COHERENT-CsI data.
|
hep-ph/0202095
|
Alexander Friedland
|
Alexander Friedland (IAS, Princeton), Andrei Gruzinov (NYU, New York)
|
A new solution to the solar neutrino deficit
|
6 pages, 5 figures, version accepted for publication in Astroparticle
Physics
|
Astropart.Phys.19:575-582,2003
|
10.1016/S0927-6505(02)00255-4
| null |
hep-ph astro-ph
| null |
We reexamine the transition magnetic moment solution to the solar neutrino
problem. We argue that the absence of large time variations in the
Super-Kamiokande rate provides strong evidence against spin-flavor flip in the
solar convective zone. Spin-flavor flip could, however, occur in the primordial
magnetic field in the radiative zone. We compute the longest lived toroidal
mode for this field and show that spin-flavor flip in the radiative zone can
account for all available solar data.
|
[
{
"created": "Mon, 11 Feb 2002 19:15:20 GMT",
"version": "v1"
},
{
"created": "Thu, 2 May 2002 01:15:47 GMT",
"version": "v2"
},
{
"created": "Wed, 4 Dec 2002 03:40:43 GMT",
"version": "v3"
}
] |
2011-05-23
|
[
[
"Friedland",
"Alexander",
"",
"IAS, Princeton"
],
[
"Gruzinov",
"Andrei",
"",
"NYU, New York"
]
] |
We reexamine the transition magnetic moment solution to the solar neutrino problem. We argue that the absence of large time variations in the Super-Kamiokande rate provides strong evidence against spin-flavor flip in the solar convective zone. Spin-flavor flip could, however, occur in the primordial magnetic field in the radiative zone. We compute the longest lived toroidal mode for this field and show that spin-flavor flip in the radiative zone can account for all available solar data.
|
1403.3908
|
Liucheng Wang
|
Ran Ding, Liucheng Wang, Bin Zhu
|
Neutralino Dark Matter in Gauge Mediation After Run I of LHC and LUX
|
Minor changes, version to appear in Phys. Lett. B
| null |
10.1016/j.physletb.2014.05.007
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Neutralino can be the dark matter candidate in the gauge-mediated
supersymmetry breaking models if the conformal sequestered mechanism is assumed
in the hidden sector. In this paper, we study this mechanism by using the
current experimental results after the run I of LHC and LUX. By adding new
Yukawa couplings between the messenger fields and Higgs fields, we find that
this mechanism can predict a neutralino dark matter with correct relic density
and a Higgs boson with mass around 125 GeV. All our survived points have some
common features. Firstly, the Higgs sector falls into the decoupling limit. So
the properties of the light Higgs boson are similar to the predictions of the
Standard Model one. Secondly, the correct EWSB hints a relatively small
$\mu$-term, which makes the lightest neutralino lighter than the lightest stau.
So a bino-higgsino dark matter with correct relic density can be achieved. And
the relatively small $\mu$-term results in a small fine-tuning. Finally, this
bino-higgsino dark matter can pass all current bounds, including both
spin-independent and spin-dependent direct searches. The spin-independent cross
section of our points can be examined by further experiments.
|
[
{
"created": "Sun, 16 Mar 2014 11:38:29 GMT",
"version": "v1"
},
{
"created": "Tue, 1 Apr 2014 03:30:40 GMT",
"version": "v2"
},
{
"created": "Mon, 5 May 2014 03:53:41 GMT",
"version": "v3"
}
] |
2015-06-19
|
[
[
"Ding",
"Ran",
""
],
[
"Wang",
"Liucheng",
""
],
[
"Zhu",
"Bin",
""
]
] |
Neutralino can be the dark matter candidate in the gauge-mediated supersymmetry breaking models if the conformal sequestered mechanism is assumed in the hidden sector. In this paper, we study this mechanism by using the current experimental results after the run I of LHC and LUX. By adding new Yukawa couplings between the messenger fields and Higgs fields, we find that this mechanism can predict a neutralino dark matter with correct relic density and a Higgs boson with mass around 125 GeV. All our survived points have some common features. Firstly, the Higgs sector falls into the decoupling limit. So the properties of the light Higgs boson are similar to the predictions of the Standard Model one. Secondly, the correct EWSB hints a relatively small $\mu$-term, which makes the lightest neutralino lighter than the lightest stau. So a bino-higgsino dark matter with correct relic density can be achieved. And the relatively small $\mu$-term results in a small fine-tuning. Finally, this bino-higgsino dark matter can pass all current bounds, including both spin-independent and spin-dependent direct searches. The spin-independent cross section of our points can be examined by further experiments.
|
hep-ph/0505230
|
Andrei Kataev
|
A.L. Kataev
|
Renormalons at the boundaries between perturbative and non-perturbative
QCD
|
16 pages, LaTeX, Extanded version of the talk at 19th Rencontre de
Physique de la Vallee d" Aosta (27 February-5 March, 2005, La Thuile, Aosta
Valley, Italy); Few additional comments added, several references added,
accepted for publication in Mod.Phys.Lett.A as a Brief Review with the title
"Deep inelastic sum rules at the boundaries between perturbative and
non-perturbative QCD"
|
Mod.Phys.Lett. A20 (2005) 2007-2022
|
10.1142/S0217732305018165
| null |
hep-ph hep-ex
| null |
The basis of renormalon calculus is briefly discussed. The method is applied
to study QCD predictions for three sum rules of deep-inelastic scattering,
namely for the Gross-Llewellyn Smith, Bjorken polarized and unpolarized sum
rules. It is shown that the renormalon structures of theses sum rules are
closely related. These properties are giving us the hint that theoretical
expressions of these three sum rules are similar both in the and
non-perturbative sectors. Some phenomenological consequances of the new
relations are discussed.
|
[
{
"created": "Fri, 27 May 2005 05:57:52 GMT",
"version": "v1"
},
{
"created": "Mon, 27 Jun 2005 15:24:26 GMT",
"version": "v2"
}
] |
2009-11-11
|
[
[
"Kataev",
"A. L.",
""
]
] |
The basis of renormalon calculus is briefly discussed. The method is applied to study QCD predictions for three sum rules of deep-inelastic scattering, namely for the Gross-Llewellyn Smith, Bjorken polarized and unpolarized sum rules. It is shown that the renormalon structures of theses sum rules are closely related. These properties are giving us the hint that theoretical expressions of these three sum rules are similar both in the and non-perturbative sectors. Some phenomenological consequances of the new relations are discussed.
|
hep-ph/9603220
| null |
M. Baillargeon(1), U. Baur(2), G. Belanger(3), F. Boudjema(3), G.
Couture(4), M. Gintner(5) and S. Godfrey(5) ((1) GTAE, Lisbon, (2) SUNY
Buffalo, (3) ENSLAPP-Annecy, (4) UQUAM Montreal, (5) Carleton, Ottawa)
|
Anomalous Couplings and Chiral Lagrangians: An Update
|
8 pages, 1 Postscript figure, LaTeX, uses epsfig.sty, to appear in
the Proceedings of the LC2000 Workshop, Annecy, Gran Sasso and Hamburg,
February -- September 1995
| null | null |
UB-HET-96-01
|
hep-ph
| null |
We present an update of the limits expected for anomalous gauge boson
couplings in the language of chiral Lagrangian operators at the LHC and the
Linear Collider. Both, the $e^+e^-$ and the $\gamma\gamma$ mode of the Linear
Collider are analyzed. With a 500~GeV $e^+e^-$ collider, and an integrated
luminosity of 50~--~80~fb$^{-1}$, one reaches the domain of precision
measurements.
|
[
{
"created": "Mon, 4 Mar 1996 18:03:37 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Baillargeon",
"M.",
""
],
[
"Baur",
"U.",
""
],
[
"Belanger",
"G.",
""
],
[
"Boudjema",
"F.",
""
],
[
"Couture",
"G.",
""
],
[
"Gintner",
"M.",
""
],
[
"Godfrey",
"S.",
""
]
] |
We present an update of the limits expected for anomalous gauge boson couplings in the language of chiral Lagrangian operators at the LHC and the Linear Collider. Both, the $e^+e^-$ and the $\gamma\gamma$ mode of the Linear Collider are analyzed. With a 500~GeV $e^+e^-$ collider, and an integrated luminosity of 50~--~80~fb$^{-1}$, one reaches the domain of precision measurements.
|
hep-ph/9811347
|
Juergen Berges
|
J. Berges, D.-U. Jungnickel, C. Wetterich
|
The Chiral Phase Transition at High Baryon Density from Nonperturbative
Flow Equations
|
11 pages, 2 figures, LaTex
|
Eur.Phys.J.C13:323-329,2000
|
10.1007/s100520000275
|
MIT-CTP-2794, HD-THEP-98-57
|
hep-ph hep-lat
| null |
We investigate the QCD chiral phase transition at high baryon number density
within the linear quark meson model for two flavors. The method we employ is
based on an exact renormalization group equation for the free energy. Truncated
nonperturbative flow equations are derived at nonzero chemical potential and
temperature. Whereas the renormalization group flow leads to spontaneous chiral
symmetry breaking in vacuum, we find a chiral symmetry restoring first order
transition at high density. Combined with previous investigations at nonzero
temperature, the result implies the presence of a tricritical point with
long--range correlations in the phase diagram.
|
[
{
"created": "Mon, 16 Nov 1998 16:38:14 GMT",
"version": "v1"
}
] |
2010-02-04
|
[
[
"Berges",
"J.",
""
],
[
"Jungnickel",
"D. -U.",
""
],
[
"Wetterich",
"C.",
""
]
] |
We investigate the QCD chiral phase transition at high baryon number density within the linear quark meson model for two flavors. The method we employ is based on an exact renormalization group equation for the free energy. Truncated nonperturbative flow equations are derived at nonzero chemical potential and temperature. Whereas the renormalization group flow leads to spontaneous chiral symmetry breaking in vacuum, we find a chiral symmetry restoring first order transition at high density. Combined with previous investigations at nonzero temperature, the result implies the presence of a tricritical point with long--range correlations in the phase diagram.
|
1912.11050
|
Ian Moult
|
Hao Chen, Ming-Xing Luo, Ian Moult, Tong-Zhi Yang, Xiaoyuan Zhang, and
Hua Xing Zhu
|
Three Point Energy Correlators in the Collinear Limit: Symmetries,
Dualities and Analytic Results
|
52 pages, 12 figures v2. Minor typos corrected, matches journal
version
| null |
10.1007/JHEP08(2020)028
| null |
hep-ph hep-th nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Energy Correlators measure the energy deposited in multiple detectors as a
function of the angles between the detectors. In this paper, we analytically
compute the three particle correlator in the collinear limit in QCD for quark
and gluon jets, and also in $\mathcal{N}=4$ super Yang-Mills theory. We find an
intriguing duality between the integrals for the energy correlators and
infrared finite Feynman parameter integrals, which maps the angles of the
correlators to dual momentum variables. In $\mathcal{N}=4$, we use this duality
to express our result as a rational sum of simple Feynman integrals (triangles
and boxes). In QCD our result is expressed as a sum of the same transcendental
functions, but with more complicated rational functions of cross ratio
variables as coefficients. Our results represent the first analytic calculation
of a three-prong jet substructure observable of phenomenological relevance for
the LHC, revealing unexplored simplicity in the energy flow of QCD jets. They
also provide valuable data for improving the understanding of the light-ray
operator product expansion.
|
[
{
"created": "Mon, 23 Dec 2019 19:00:00 GMT",
"version": "v1"
},
{
"created": "Fri, 6 Nov 2020 19:35:39 GMT",
"version": "v2"
}
] |
2020-11-10
|
[
[
"Chen",
"Hao",
""
],
[
"Luo",
"Ming-Xing",
""
],
[
"Moult",
"Ian",
""
],
[
"Yang",
"Tong-Zhi",
""
],
[
"Zhang",
"Xiaoyuan",
""
],
[
"Zhu",
"Hua Xing",
""
]
] |
Energy Correlators measure the energy deposited in multiple detectors as a function of the angles between the detectors. In this paper, we analytically compute the three particle correlator in the collinear limit in QCD for quark and gluon jets, and also in $\mathcal{N}=4$ super Yang-Mills theory. We find an intriguing duality between the integrals for the energy correlators and infrared finite Feynman parameter integrals, which maps the angles of the correlators to dual momentum variables. In $\mathcal{N}=4$, we use this duality to express our result as a rational sum of simple Feynman integrals (triangles and boxes). In QCD our result is expressed as a sum of the same transcendental functions, but with more complicated rational functions of cross ratio variables as coefficients. Our results represent the first analytic calculation of a three-prong jet substructure observable of phenomenological relevance for the LHC, revealing unexplored simplicity in the energy flow of QCD jets. They also provide valuable data for improving the understanding of the light-ray operator product expansion.
|
hep-ph/0508094
|
Yu-Xin Liu
|
Lei Chang, Huan Chen, Bin Wang, Wei Yuan, Yu-xin Liu
|
Chemical Potential Dependence of Chiral Quark Condensate in
Dyson-Schwinger Equation Approach of QCD
|
19 pages, 3 figures, completely rewritten
|
Phys.Lett.B644:315-321,2007
|
10.1016/j.physletb.2006.11.073
| null |
hep-ph
| null |
We propose a chemical potential dependent effective gluon propagator and
study the chiral quark condensate in strongly interacting matter in the
framework of Dyson-Schwinger equation approach. The obtained results manifest
that, as the effect of the chemical potential on the effective gluon propagator
is taken into account, the chiral quark condensate decreases gradually with the
increasing of the chemical potential if it is less than the critical value, and
the condensate vanishes suddenly at the critical chemical potential. The
inclusion of the chemical potential in the effective gluon propagator enhances
the decreasing rate and decreases the critical chemical potential. It indicates
that the chiral symmetry can be restored completely at a critical chemical
potential and restored partially as the chemical potential is less than the
critical value. If the effective gluon propagator is independent of the
chemical potential, the chiral symmetry can only be restored suddenly but no
gradual restoration.
|
[
{
"created": "Mon, 8 Aug 2005 14:53:30 GMT",
"version": "v1"
},
{
"created": "Mon, 6 Nov 2006 14:13:40 GMT",
"version": "v2"
}
] |
2008-11-26
|
[
[
"Chang",
"Lei",
""
],
[
"Chen",
"Huan",
""
],
[
"Wang",
"Bin",
""
],
[
"Yuan",
"Wei",
""
],
[
"Liu",
"Yu-xin",
""
]
] |
We propose a chemical potential dependent effective gluon propagator and study the chiral quark condensate in strongly interacting matter in the framework of Dyson-Schwinger equation approach. The obtained results manifest that, as the effect of the chemical potential on the effective gluon propagator is taken into account, the chiral quark condensate decreases gradually with the increasing of the chemical potential if it is less than the critical value, and the condensate vanishes suddenly at the critical chemical potential. The inclusion of the chemical potential in the effective gluon propagator enhances the decreasing rate and decreases the critical chemical potential. It indicates that the chiral symmetry can be restored completely at a critical chemical potential and restored partially as the chemical potential is less than the critical value. If the effective gluon propagator is independent of the chemical potential, the chiral symmetry can only be restored suddenly but no gradual restoration.
|
hep-ph/9502238
| null |
I.I. Bigi and H. Yamamoto
|
Interference Between Cabibbo Allowed and Doubly Forbidden Transitions in
$D\ra K_{S,L} + \pi '$s Decays
|
6 pages, latex, no figures
|
Phys.Lett.B349:363-366,1995
|
10.1016/0370-2693(95)00285-S
|
UND-HEP-94-BIG09, HUTP-94/A029
|
hep-ph
| null |
Both Cabibbo allowed and doubly forbidden transitions contribute coherently
to $D\rightarrow K_{S,L}+\pi 's$ decays. This leads to several intriguing and
even quantitatively significant consequences, among them: (i) A difference
between $\Gamma (D^+\rightarrow K_S \pi ^+)$ and $\Gamma (D^+\rightarrow K_L
\pi ^+)$ and between $\Gamma (D^0\rightarrow K_S \pi ^0)$ and $\Gamma
(D^0\rightarrow K_L \pi ^0)$ of roughly 10\% ; similarly $\Gamma
(D^+\rightarrow [K_S\pi ^0]_{K^*} \pi ^+) \neq \frac{1}{4}\Gamma
(D^+\rightarrow [K^-\pi ^+]_{K^*} \pi ^+)$, and more generally $\Gamma
(D\rightarrow \bar K^0+\pi 's) \neq 2\Gamma (D\rightarrow K_S+\pi 's)$. (ii) A
change in the relative phase between the isospin 3/2 and 1/2 amplitudes as
extracted from the observed branching ratios for $D^+\rightarrow K_S\pi ^+$,
$D^0\rightarrow K_S\pi ^0 ,\, K^-\pi ^+$. (iii) If New Physics intervenes to
provide the required {\em weak} phase, then CP asymmetries of up to a few per
cent can arise in $D^+\rightarrow K_S\pi ^+$ vs. $D^-\rightarrow K_S\pi ^-$,
$D^0\rightarrow K_S\pi ^0$ vs. $\bar D^0\rightarrow K_S\pi ^0$, $D^+\rightarrow
[K_S\pi ^0]_{K^*}\pi ^+$ vs. $D^-\rightarrow [K_S\pi ^0]_{K^*}\pi ^-$, etc.; an
asymmetry of the same size, but opposite in sign occurs when the $K_S$ is
replaced by a $K_L$ in the final state.
|
[
{
"created": "Sat, 7 Jan 1995 04:41:30 GMT",
"version": "v1"
}
] |
2016-09-01
|
[
[
"Bigi",
"I. I.",
""
],
[
"Yamamoto",
"H.",
""
]
] |
Both Cabibbo allowed and doubly forbidden transitions contribute coherently to $D\rightarrow K_{S,L}+\pi 's$ decays. This leads to several intriguing and even quantitatively significant consequences, among them: (i) A difference between $\Gamma (D^+\rightarrow K_S \pi ^+)$ and $\Gamma (D^+\rightarrow K_L \pi ^+)$ and between $\Gamma (D^0\rightarrow K_S \pi ^0)$ and $\Gamma (D^0\rightarrow K_L \pi ^0)$ of roughly 10\% ; similarly $\Gamma (D^+\rightarrow [K_S\pi ^0]_{K^*} \pi ^+) \neq \frac{1}{4}\Gamma (D^+\rightarrow [K^-\pi ^+]_{K^*} \pi ^+)$, and more generally $\Gamma (D\rightarrow \bar K^0+\pi 's) \neq 2\Gamma (D\rightarrow K_S+\pi 's)$. (ii) A change in the relative phase between the isospin 3/2 and 1/2 amplitudes as extracted from the observed branching ratios for $D^+\rightarrow K_S\pi ^+$, $D^0\rightarrow K_S\pi ^0 ,\, K^-\pi ^+$. (iii) If New Physics intervenes to provide the required {\em weak} phase, then CP asymmetries of up to a few per cent can arise in $D^+\rightarrow K_S\pi ^+$ vs. $D^-\rightarrow K_S\pi ^-$, $D^0\rightarrow K_S\pi ^0$ vs. $\bar D^0\rightarrow K_S\pi ^0$, $D^+\rightarrow [K_S\pi ^0]_{K^*}\pi ^+$ vs. $D^-\rightarrow [K_S\pi ^0]_{K^*}\pi ^-$, etc.; an asymmetry of the same size, but opposite in sign occurs when the $K_S$ is replaced by a $K_L$ in the final state.
|
hep-ph/0207235
|
Cheng-Wei Chiang
|
Cheng-Wei Chiang, Zumin Luo, and Jonathan L. Rosner
|
Light Gluino and the Running of alpha_s
|
16 pages, 2 figures; text modified and references added for journal
publication
|
Phys.Rev.D67:035008,2003
|
10.1103/PhysRevD.67.035008
|
ANL-HEP-PR-02-055, EFI-02-90
|
hep-ph
| null |
A gluino in the mass range 12--16 GeV combined with a light (2--5.5 GeV)
bottom squark, as has been proposed recently to explain an excess of b quark
hadroproduction, would affect the momentum-scale dependence (``running'') of
the strong coupling constant alpha_s in such a way as to raise its value at M_Z
by about 0.014 +/- 0.001. If one combines sources of uncertainty at low (m_b)
and high (M_Z) mass scales, one can only distinguish such an effect at slightly
more than the 2 sigma level. Prospects for improvement in this situation, which
include better lattice QCD simulations and better measurements at M_Z, are
discussed.
|
[
{
"created": "Thu, 18 Jul 2002 23:40:43 GMT",
"version": "v1"
},
{
"created": "Fri, 19 Jul 2002 20:07:12 GMT",
"version": "v2"
},
{
"created": "Mon, 29 Jul 2002 20:30:57 GMT",
"version": "v3"
},
{
"created": "Tue, 3 Dec 2002 16:38:40 GMT",
"version": "v4"
}
] |
2014-11-17
|
[
[
"Chiang",
"Cheng-Wei",
""
],
[
"Luo",
"Zumin",
""
],
[
"Rosner",
"Jonathan L.",
""
]
] |
A gluino in the mass range 12--16 GeV combined with a light (2--5.5 GeV) bottom squark, as has been proposed recently to explain an excess of b quark hadroproduction, would affect the momentum-scale dependence (``running'') of the strong coupling constant alpha_s in such a way as to raise its value at M_Z by about 0.014 +/- 0.001. If one combines sources of uncertainty at low (m_b) and high (M_Z) mass scales, one can only distinguish such an effect at slightly more than the 2 sigma level. Prospects for improvement in this situation, which include better lattice QCD simulations and better measurements at M_Z, are discussed.
|
2212.10490
|
Roberto Frezzotti Prof
|
Constantia Alexandrou, Simone Bacchio, Petros Dimopoulos, Jacob
Finkenrath, Roberto Frezzotti, Giuseppe Gagliardi, Marco Garofalo, Kyriakos
Hadjiyiannakou, Bartosz Kostrzewa, Karl Jansen, Vittorio Lubicz, Marcus
Petschlies, Francesco Sanfilippo, Silvano Simula, Carsten Urbach, Urs Wenger
|
Short \& intermediate distance HVP contributions to muon g-2: SM
(lattice) prediction versus $e^+e^-$ annihilation data
|
Talk given at ICHEP 2022 (6-13 July 2022, Bologna - Italy) - Results
here are almost final - Contribution accepted for publication on PoS
| null | null | null |
hep-ph hep-lat
|
http://creativecommons.org/licenses/by/4.0/
|
We present new lattice results of the ETM Collaboration, obtained from
extensive simulations of lattice QCD with dynamical up, down, strange and charm
quarks at physical mass values, different volumes and lattice spacings,
concerning the SM prediction for the so-called intermediate window (W) and
short-distance (SD) contributions to the leading order hadronic vacuum
polarization (LO-HVP) term of the muon anomalous magnetic moment, $a_\mu$.
Results for $a_{\mu}^{\rm LO-HVP,W}$ and $a_{\mu}^{\rm LO-HVP,SD}$, besides
representing a step forward to a complete lattice computation of $a_{\mu}^{\rm
LO-HVP}$ and a useful benchmark among lattice groups, are compared here with
their dispersive counterparts based on experimental data for $e^+e^-$ into
hadrons. The comparison confirms the tension in $a_{\mu}^{\rm LO-HVP,W}$,
already noted in 2020 by the BMW Collaboration, while showing no tension in
$a_{\mu}^{\rm LO-HVP,SD}$.
|
[
{
"created": "Tue, 20 Dec 2022 18:06:11 GMT",
"version": "v1"
}
] |
2022-12-21
|
[
[
"Alexandrou",
"Constantia",
""
],
[
"Bacchio",
"Simone",
""
],
[
"Dimopoulos",
"Petros",
""
],
[
"Finkenrath",
"Jacob",
""
],
[
"Frezzotti",
"Roberto",
""
],
[
"Gagliardi",
"Giuseppe",
""
],
[
"Garofalo",
"Marco",
""
],
[
"Hadjiyiannakou",
"Kyriakos",
""
],
[
"Kostrzewa",
"Bartosz",
""
],
[
"Jansen",
"Karl",
""
],
[
"Lubicz",
"Vittorio",
""
],
[
"Petschlies",
"Marcus",
""
],
[
"Sanfilippo",
"Francesco",
""
],
[
"Simula",
"Silvano",
""
],
[
"Urbach",
"Carsten",
""
],
[
"Wenger",
"Urs",
""
]
] |
We present new lattice results of the ETM Collaboration, obtained from extensive simulations of lattice QCD with dynamical up, down, strange and charm quarks at physical mass values, different volumes and lattice spacings, concerning the SM prediction for the so-called intermediate window (W) and short-distance (SD) contributions to the leading order hadronic vacuum polarization (LO-HVP) term of the muon anomalous magnetic moment, $a_\mu$. Results for $a_{\mu}^{\rm LO-HVP,W}$ and $a_{\mu}^{\rm LO-HVP,SD}$, besides representing a step forward to a complete lattice computation of $a_{\mu}^{\rm LO-HVP}$ and a useful benchmark among lattice groups, are compared here with their dispersive counterparts based on experimental data for $e^+e^-$ into hadrons. The comparison confirms the tension in $a_{\mu}^{\rm LO-HVP,W}$, already noted in 2020 by the BMW Collaboration, while showing no tension in $a_{\mu}^{\rm LO-HVP,SD}$.
|
1711.03110
|
Dean Robinson
|
Florian U. Bernlochner, Zoltan Ligeti, Dean J. Robinson
|
Model independent analysis of semileptonic $B$ decays to $D^{**}$ for
arbitrary new physics
|
17 pages, 4 figures, 5 tables; published version
|
Phys. Rev. D 97, 075011 (2018)
|
10.1103/PhysRevD.97.075011
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We explore semileptonic $B$ decays to the four lightest excited charm mesons,
$D^{**} = \{D_0^*,\, D_1^*,$ $D_1,\, D_2^*\}$, for nonzero charged lepton mass
and for all $b\to c \ell\bar\nu$ four-Fermi interactions, including calculation
of the ${\cal O}(\Lambda_\text{QCD}/m_{c,b})$ and ${\cal O}(\alpha_s)$
corrections to the heavy quark limit for all form factors. In the heavy quark
limit some form factors are suppressed at zero recoil, therefore, the ${\cal
O}(\Lambda_\text{QCD}/m_{c,b})$ corrections can be very important. The $D^{**}$
rates exhibit sensitivities to new physics in $b\to c\tau\bar\nu$ mediated
decays complementary to the $D$ and $D^*$ modes. Since they are also important
backgrounds to $B\to D^{(*)}\tau\bar\nu$, the correct interpretation of future
semitauonic $B\to D^{(*)}$ rate measurements requires consistent treatment of
both the $D^{**}$ backgrounds and the signals. Our results allow more precise
and more reliable calculations of these $B\to D^{**}\ell\bar\nu$ decays, and
are systematically improvable by better data on the $e$ and $\mu$ modes. As an
example, we show that the $D^{**}$ rates are more sensitive to a new $\bar c\,
\sigma_{\mu\nu} b$ tensor interaction than the $D^{(*)}$ rates.
|
[
{
"created": "Wed, 8 Nov 2017 19:00:05 GMT",
"version": "v1"
},
{
"created": "Fri, 4 May 2018 13:49:15 GMT",
"version": "v2"
}
] |
2018-05-07
|
[
[
"Bernlochner",
"Florian U.",
""
],
[
"Ligeti",
"Zoltan",
""
],
[
"Robinson",
"Dean J.",
""
]
] |
We explore semileptonic $B$ decays to the four lightest excited charm mesons, $D^{**} = \{D_0^*,\, D_1^*,$ $D_1,\, D_2^*\}$, for nonzero charged lepton mass and for all $b\to c \ell\bar\nu$ four-Fermi interactions, including calculation of the ${\cal O}(\Lambda_\text{QCD}/m_{c,b})$ and ${\cal O}(\alpha_s)$ corrections to the heavy quark limit for all form factors. In the heavy quark limit some form factors are suppressed at zero recoil, therefore, the ${\cal O}(\Lambda_\text{QCD}/m_{c,b})$ corrections can be very important. The $D^{**}$ rates exhibit sensitivities to new physics in $b\to c\tau\bar\nu$ mediated decays complementary to the $D$ and $D^*$ modes. Since they are also important backgrounds to $B\to D^{(*)}\tau\bar\nu$, the correct interpretation of future semitauonic $B\to D^{(*)}$ rate measurements requires consistent treatment of both the $D^{**}$ backgrounds and the signals. Our results allow more precise and more reliable calculations of these $B\to D^{**}\ell\bar\nu$ decays, and are systematically improvable by better data on the $e$ and $\mu$ modes. As an example, we show that the $D^{**}$ rates are more sensitive to a new $\bar c\, \sigma_{\mu\nu} b$ tensor interaction than the $D^{(*)}$ rates.
|
2211.02411
|
Zoltan Peli
|
Zolt\'an P\'eli
|
Vacuum stability and scalar masses in the superweak extension of the
standard model
|
4 pages, 3 papers, ICHEP 2022 conference PoS
| null | null | null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
We summarize our analysis for the vacuum stability of the superweak extension
of the standard model. The parameter space allowed by the $W$-boson mass
measurements and collider searches for a new scalar particle are also
presented. The final result is a well defined non-vanishing portion of the
parameter space, where the vacuum is stable, the couplings are perturbative and
is not excluded by $W$ mass measurements and collider searches.
|
[
{
"created": "Fri, 4 Nov 2022 12:39:10 GMT",
"version": "v1"
}
] |
2022-11-07
|
[
[
"Péli",
"Zoltán",
""
]
] |
We summarize our analysis for the vacuum stability of the superweak extension of the standard model. The parameter space allowed by the $W$-boson mass measurements and collider searches for a new scalar particle are also presented. The final result is a well defined non-vanishing portion of the parameter space, where the vacuum is stable, the couplings are perturbative and is not excluded by $W$ mass measurements and collider searches.
|
1207.2362
|
Andrea Mammarella
|
Francesco Fucito, Andrea Mammarella and Daniel Ricci Pacifici
|
Asymmetry at LHC for an U(1)' anomalous extension of MSSM
|
10 pages, 12 figures
| null |
10.1103/PhysRevD.86.095014
|
Phys. Rev. D 86, 095014 (2012)
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The measurement of the forward-backward asymmetry at LHC could be an
important instrument to pinpoint the features of extra neutral gauge particles
obtained by an extension of the gauge symmetry group of the standard model. For
definitiveness, in this work we consider an extension of the gauge group of the
Minimal Supersymmetric Standard Model by an extra anomalous U(1) gauge symmetry
(MiAUMSSM). We focus on pp -> e+e- at LHC and use four different definitions of
the asymmetry obtained implementing four different cuts on the directions and
momenta of the final states of our process of interest. The calculations are
performed without imposing constraints on the charges of the extra Z's of our
model, since the anomaly is cancelled by a Green-Schwarz type mechanism. Our
final result is a fit of our data with a polynomial in the charges from which
to extract the values of the charges given the experimental result.
|
[
{
"created": "Tue, 10 Jul 2012 14:18:09 GMT",
"version": "v1"
},
{
"created": "Tue, 18 Dec 2012 22:56:21 GMT",
"version": "v2"
}
] |
2015-03-20
|
[
[
"Fucito",
"Francesco",
""
],
[
"Mammarella",
"Andrea",
""
],
[
"Pacifici",
"Daniel Ricci",
""
]
] |
The measurement of the forward-backward asymmetry at LHC could be an important instrument to pinpoint the features of extra neutral gauge particles obtained by an extension of the gauge symmetry group of the standard model. For definitiveness, in this work we consider an extension of the gauge group of the Minimal Supersymmetric Standard Model by an extra anomalous U(1) gauge symmetry (MiAUMSSM). We focus on pp -> e+e- at LHC and use four different definitions of the asymmetry obtained implementing four different cuts on the directions and momenta of the final states of our process of interest. The calculations are performed without imposing constraints on the charges of the extra Z's of our model, since the anomaly is cancelled by a Green-Schwarz type mechanism. Our final result is a fit of our data with a polynomial in the charges from which to extract the values of the charges given the experimental result.
|
0801.2237
|
Kirill Melnikov
|
Walter T. Giele, Zoltan Kunszt, Kirill Melnikov
|
Full one-loop amplitudes from tree amplitudes
|
27 pages, revtex
|
JHEP 0804:049,2008
|
10.1088/1126-6708/2008/04/049
| null |
hep-ph
| null |
We establish an efficient polynomial-complexity algorithm for one-loop
calculations, based on generalized $D$-dimensional unitarity. It allows
automated computations of both cut-constructible {\it and} rational parts of
one-loop scattering amplitudes from on-shell tree amplitudes. We illustrate the
method by (re)-computing all four-, five- and six-gluon scattering amplitudes
in QCD at one-loop.
|
[
{
"created": "Tue, 15 Jan 2008 09:33:20 GMT",
"version": "v1"
}
] |
2009-09-17
|
[
[
"Giele",
"Walter T.",
""
],
[
"Kunszt",
"Zoltan",
""
],
[
"Melnikov",
"Kirill",
""
]
] |
We establish an efficient polynomial-complexity algorithm for one-loop calculations, based on generalized $D$-dimensional unitarity. It allows automated computations of both cut-constructible {\it and} rational parts of one-loop scattering amplitudes from on-shell tree amplitudes. We illustrate the method by (re)-computing all four-, five- and six-gluon scattering amplitudes in QCD at one-loop.
|
hep-ph/9705365
|
Shaouly Bar-Shalom
|
Shaouly Bar-Shalom
|
Flavor Changing Transitions and the Top Quark in a Two Higgs Doublets
Model; Application to e^+e^- --> t bar-c nu_e bar-nu_e, t bar -c e^+ e^-, t
bar-c Z, t --> cW^+W^- and t --> cZZ
|
7 pages, latex, 4 figures embadded in the text using psfig. Talk
presented at the first FCNC symposium, February 19-21, 1997, Santa Monica,
CA. To appear in the proceedings of this symposium
| null | null |
UCRHEP-T190
|
hep-ph
| null |
Extension of the SM with one extra Higgs doublet may give rise to
flavor-changing-scalar coupling of a neutral Higgs to a pair of top-charm
quarks. This coupling gives rise to a large tree-level effective W^+W^-;ZZ -
Higgs - t bar-c interaction. We find that the reactions e^+e^- --> t bar-c nu_e
bar-nu_e, t bar-c e^+e^-, t bar-c Z and the two rare top decays t --> cW^+W^-,
t --> cZZ are very sensitive probes of such an effective interaction. The most
promising ones, e^+e^- --> t bar-c nu_e bar-nu_e, t bar-c e^+e^-, may yield
several hundreds and up to thousands of such events at the Next Linear Collider
with a center of mass energy of sqrt{s}=0.5-2 TeV if the mass of the light
neutral Higgs is a few hundred GeV. We also find that the rare decays t -->
cW^+W^- and t --> cZZ may be accessible in the LHC if the mass of the light
neutral Higgs lies in the narrow window 150 GeV < m_h < 200 GeV.
|
[
{
"created": "Tue, 20 May 1997 17:45:45 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Bar-Shalom",
"Shaouly",
""
]
] |
Extension of the SM with one extra Higgs doublet may give rise to flavor-changing-scalar coupling of a neutral Higgs to a pair of top-charm quarks. This coupling gives rise to a large tree-level effective W^+W^-;ZZ - Higgs - t bar-c interaction. We find that the reactions e^+e^- --> t bar-c nu_e bar-nu_e, t bar-c e^+e^-, t bar-c Z and the two rare top decays t --> cW^+W^-, t --> cZZ are very sensitive probes of such an effective interaction. The most promising ones, e^+e^- --> t bar-c nu_e bar-nu_e, t bar-c e^+e^-, may yield several hundreds and up to thousands of such events at the Next Linear Collider with a center of mass energy of sqrt{s}=0.5-2 TeV if the mass of the light neutral Higgs is a few hundred GeV. We also find that the rare decays t --> cW^+W^- and t --> cZZ may be accessible in the LHC if the mass of the light neutral Higgs lies in the narrow window 150 GeV < m_h < 200 GeV.
|
1009.4647
|
Stephen Adler
|
Stephen L. Adler
|
Parameterized Adaptive Multidimensional Integration Routines (PAMIR):
Localization by Repeated 2^p Subdivision
|
84 pages Latex, figures included; minor changes to program
descriptions and tildes added to Eqs. (63) and (65)
| null | null | null |
hep-ph cs.MS cs.NA math.NA
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
This book draft gives the theory of a new method for p dimensional adaptive
integration by repeated 2^p subdivision of simplexes and hypercubes. A new
method of constructing high order integration routines for these geometries
permits adjustable samplings of the integration region controlled by user
supplied parameters. An outline of the programs and use instructions are also
included in the draft. The fortran programs are not included, but will be
published with this draft as a book.
|
[
{
"created": "Thu, 23 Sep 2010 15:54:20 GMT",
"version": "v1"
},
{
"created": "Thu, 28 Oct 2010 18:21:33 GMT",
"version": "v2"
}
] |
2010-10-29
|
[
[
"Adler",
"Stephen L.",
""
]
] |
This book draft gives the theory of a new method for p dimensional adaptive integration by repeated 2^p subdivision of simplexes and hypercubes. A new method of constructing high order integration routines for these geometries permits adjustable samplings of the integration region controlled by user supplied parameters. An outline of the programs and use instructions are also included in the draft. The fortran programs are not included, but will be published with this draft as a book.
|
1706.10072
|
Davide Napoletano
|
Davide Napoletano, Frank Krauss and Steffen Schumann
|
Bottom-quark mass effects in associated production with $Z$ and $H$
bosons
|
Proceedings of XXV International Workshop on Deep-Inelastic
Scattering and Related Subjects, 3-7 April 2017, University of Birmingham,
UK. 10 pages, 6 figures
| null | null | null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this study, predictions obtained in the four and in the five flavour
schemes are compared for two important processes involving heavy flavours at
the LHC: the production of a $Z$ or a Higgs boson in association with $b$
quarks. In particular we obtain predictions with \Sherpa's \MCatNLO
implementation for the four--flavour scheme, treating the $b$'s as massive, and
with multijet merging at leading and next-to leading order for the
five--flavour scheme. While differences between the two schemes, at the
inclusive level, are well understood from resummation of possibly large logs
into the $b$-PDFs, differences in shape present a major problem for
experimental measurements. We make use of data for $Z+b(\bar{b})$ production at
the $7$ TeV LHC to exhibit strengths and weaknesses of the different approaches
and we use these results to validate predictions for $b$-associated Higgs-boson
production at the 13 TeV Run II.
|
[
{
"created": "Fri, 30 Jun 2017 09:14:28 GMT",
"version": "v1"
}
] |
2017-07-03
|
[
[
"Napoletano",
"Davide",
""
],
[
"Krauss",
"Frank",
""
],
[
"Schumann",
"Steffen",
""
]
] |
In this study, predictions obtained in the four and in the five flavour schemes are compared for two important processes involving heavy flavours at the LHC: the production of a $Z$ or a Higgs boson in association with $b$ quarks. In particular we obtain predictions with \Sherpa's \MCatNLO implementation for the four--flavour scheme, treating the $b$'s as massive, and with multijet merging at leading and next-to leading order for the five--flavour scheme. While differences between the two schemes, at the inclusive level, are well understood from resummation of possibly large logs into the $b$-PDFs, differences in shape present a major problem for experimental measurements. We make use of data for $Z+b(\bar{b})$ production at the $7$ TeV LHC to exhibit strengths and weaknesses of the different approaches and we use these results to validate predictions for $b$-associated Higgs-boson production at the 13 TeV Run II.
|
hep-ph/9509277
|
Gi-Chol Cho
|
G. C. Cho, Y. Kizukuri, and N. Oshimo
|
Constraints on Light Top Squark from $B^0$-$\bar{B}^0$ mixing
|
8 pages latex file, 2 figures
|
Phys.Lett.B372:101-105,1996
|
10.1016/0370-2693(96)00055-X
|
TKU-HEP 95/02, OCHA-PP-62
|
hep-ph
| null |
We discuss the constraints on the mass of the lighter top squark from \bbbar\
mixing in the minimal supersymmetric standard model. A light top squark whose
mass is less than half of the $Z^0$-boson mass has not yet been excluded from
direct search experiments at LEP. However, the existence of the light top
squark may exceedingly enhance \bbbar\ mixing, owing to the box diagrams
exchanging the charginos and the up-type squarks. We show that for a sizable
region of parameter space the light top squark contribution to \bbbar\ mixing
becomes the same order of magnitude as the standard $W$-boson contribution.
Taking into account the experimental results for \bbbar\ and \kkbar\ mixings,
the existence of the light top squark is excluded in an appreciable region of
the parameter space which LEP experiments have not ruled out.
|
[
{
"created": "Tue, 12 Sep 1995 11:20:02 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Cho",
"G. C.",
""
],
[
"Kizukuri",
"Y.",
""
],
[
"Oshimo",
"N.",
""
]
] |
We discuss the constraints on the mass of the lighter top squark from \bbbar\ mixing in the minimal supersymmetric standard model. A light top squark whose mass is less than half of the $Z^0$-boson mass has not yet been excluded from direct search experiments at LEP. However, the existence of the light top squark may exceedingly enhance \bbbar\ mixing, owing to the box diagrams exchanging the charginos and the up-type squarks. We show that for a sizable region of parameter space the light top squark contribution to \bbbar\ mixing becomes the same order of magnitude as the standard $W$-boson contribution. Taking into account the experimental results for \bbbar\ and \kkbar\ mixings, the existence of the light top squark is excluded in an appreciable region of the parameter space which LEP experiments have not ruled out.
|
1103.1578
|
Christian Fischer
|
Jacqueline A. Bonnet, Christian S. Fischer and Richard Williams
|
Effects of Anisotropy in QED3 from Dyson-Schwinger equations in a box
|
9 pages, 7 figures, v2: minor changes, typos corrected, version
accepted by PRB
| null |
10.1103/PhysRevB.84.024520
| null |
hep-ph cond-mat.supr-con hep-lat
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We investigate the effect of anisotropies in the fermion velocities of 2+1
dimensional QED on the critical number N_f^c of fermions for dynamical mass
generation. Our framework are the Dyson-Schwinger equations for the gauge boson
and fermion propagators formulated in a finite volume. In contrast to previous
Dyson-Schwinger studies we do not rely on an expansion in small anisotropies
but keep the full velocity dependence of fermion equations intact. As result we
find sizable variations of N_f^c away from the isotropic point in agreement
with other approaches. We discuss the relevance of our findings for models of
high-T_c superconductors.
|
[
{
"created": "Tue, 8 Mar 2011 16:37:13 GMT",
"version": "v1"
},
{
"created": "Wed, 29 Jun 2011 09:29:23 GMT",
"version": "v2"
}
] |
2011-07-18
|
[
[
"Bonnet",
"Jacqueline A.",
""
],
[
"Fischer",
"Christian S.",
""
],
[
"Williams",
"Richard",
""
]
] |
We investigate the effect of anisotropies in the fermion velocities of 2+1 dimensional QED on the critical number N_f^c of fermions for dynamical mass generation. Our framework are the Dyson-Schwinger equations for the gauge boson and fermion propagators formulated in a finite volume. In contrast to previous Dyson-Schwinger studies we do not rely on an expansion in small anisotropies but keep the full velocity dependence of fermion equations intact. As result we find sizable variations of N_f^c away from the isotropic point in agreement with other approaches. We discuss the relevance of our findings for models of high-T_c superconductors.
|
hep-ph/9801453
|
Hector DE Vega
|
D. Boyanovsky, D. Cormier, H. J. de Vega, R. Holman, S. P. Kumar
|
Out of Equilibrium Fields in Inflationary Dynamics. Density Fluctuations
|
Latex file, 76 pages, 26 figures in .eps files. To appear in the
Proceedings of the VIth. Erice Chalonge School on Astrofundamental Physics,
N. S\'anchez and A. Zichichi eds., Kluwer, 1998
| null | null | null |
hep-ph astro-ph gr-qc hep-th
| null |
The energy and time scales during the inflationary stage of the universe
calls for an out of equilibrium quantum field treatment. Moreover, the high
energy densities involved make necessary the use of non-perturbative approaches
as large N and Hartree methods. We start these lectures by introducing such
non-perturbative out of equilibrium methods in cosmological universes. We
discuss the renormalization procedure and the choice of initial conditions. We
then study the nonlinear dynamics of quantum fields in matter and radiation
dominated FRW and de Sitter universes. For a variety of initial conditions, we
compute the evolution of the inflaton,its quantum fluctuations and the equation
of state. We investigate the explosive particle production due to spinodal
unstabilities and parametric amplification in FRW and de Sitter universes with
and without symmetry breaking.We find that the particle production is sensitive
to the expansion of the universe.For symmetry breaking scenarios, we determine
generic late time fields behavior for FRW and deSitter cosmologies.We find that
quantum fluctuations damp in FRW as the square of the scale factor while the
order parameter approaches a minimum of the potential at the same rate.We con-
sider an O(N) inflaton model coupled self-consistently to gravity in the semi-
classical approximation for a `new inflation' scenario. We find that spinodal
instabilities drive the growth of non-perturbatively large quantum fluctuations
which shut off inflation. These fluctuations assemble with the inflaton zero
mode yielding a new effective field that actually rolls down behaving classi-
cally. We compute the amplitude and index for scalar density and tensor
perturbations. In all models of this type the spinodal instabilities produce a
`red' spectrum of primordial scalar density perturbations.
|
[
{
"created": "Fri, 30 Jan 1998 16:07:45 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Boyanovsky",
"D.",
""
],
[
"Cormier",
"D.",
""
],
[
"de Vega",
"H. J.",
""
],
[
"Holman",
"R.",
""
],
[
"Kumar",
"S. P.",
""
]
] |
The energy and time scales during the inflationary stage of the universe calls for an out of equilibrium quantum field treatment. Moreover, the high energy densities involved make necessary the use of non-perturbative approaches as large N and Hartree methods. We start these lectures by introducing such non-perturbative out of equilibrium methods in cosmological universes. We discuss the renormalization procedure and the choice of initial conditions. We then study the nonlinear dynamics of quantum fields in matter and radiation dominated FRW and de Sitter universes. For a variety of initial conditions, we compute the evolution of the inflaton,its quantum fluctuations and the equation of state. We investigate the explosive particle production due to spinodal unstabilities and parametric amplification in FRW and de Sitter universes with and without symmetry breaking.We find that the particle production is sensitive to the expansion of the universe.For symmetry breaking scenarios, we determine generic late time fields behavior for FRW and deSitter cosmologies.We find that quantum fluctuations damp in FRW as the square of the scale factor while the order parameter approaches a minimum of the potential at the same rate.We con- sider an O(N) inflaton model coupled self-consistently to gravity in the semi- classical approximation for a `new inflation' scenario. We find that spinodal instabilities drive the growth of non-perturbatively large quantum fluctuations which shut off inflation. These fluctuations assemble with the inflaton zero mode yielding a new effective field that actually rolls down behaving classi- cally. We compute the amplitude and index for scalar density and tensor perturbations. In all models of this type the spinodal instabilities produce a `red' spectrum of primordial scalar density perturbations.
|
1805.07522
|
Takaaki Nomura
|
Chuan-Hung Chen, Takaaki Nomura
|
$\epsilon'/\epsilon$ from charged-Higgs-induced gluonic dipole operators
|
15 pages, 4 figures, version accepted for publication in Physics
Letters B
| null |
10.1016/j.physletb.2018.11.006
|
KIAS-P18043
|
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the effect of charged-Higgs-induced chromomagnetic operator,
$Q_{8G}(-) \equiv \bar s \sigma^{\mu \nu} T^a \gamma_5 d G^a_{\mu \nu}$, on the
Kaon direct CP violation $Re(\epsilon'/\epsilon)$. Using the matrix element
$\langle \pi \pi | O_{8G}(-) | K^0 \rangle$ recently obtained by a large $N_c$
dual QCD approach, we find that if the Kobayashi-Maskawa phase is the origin of
CP violation, the charged-Higgs-induced gluon penguin dipole operator in the
type-III two-Higgs-doublet model can explain the measured
$Re(\epsilon'/\epsilon)$ when the constraints from the relevant low energy
flavor physics, such as $\Delta B(K)=2$, $B\to X_s \gamma$, and Kaon indirect
CP violation parameter $\epsilon$, are included.
|
[
{
"created": "Sat, 19 May 2018 06:18:01 GMT",
"version": "v1"
},
{
"created": "Mon, 19 Nov 2018 14:09:14 GMT",
"version": "v2"
}
] |
2018-11-20
|
[
[
"Chen",
"Chuan-Hung",
""
],
[
"Nomura",
"Takaaki",
""
]
] |
We study the effect of charged-Higgs-induced chromomagnetic operator, $Q_{8G}(-) \equiv \bar s \sigma^{\mu \nu} T^a \gamma_5 d G^a_{\mu \nu}$, on the Kaon direct CP violation $Re(\epsilon'/\epsilon)$. Using the matrix element $\langle \pi \pi | O_{8G}(-) | K^0 \rangle$ recently obtained by a large $N_c$ dual QCD approach, we find that if the Kobayashi-Maskawa phase is the origin of CP violation, the charged-Higgs-induced gluon penguin dipole operator in the type-III two-Higgs-doublet model can explain the measured $Re(\epsilon'/\epsilon)$ when the constraints from the relevant low energy flavor physics, such as $\Delta B(K)=2$, $B\to X_s \gamma$, and Kaon indirect CP violation parameter $\epsilon$, are included.
|
1302.6266
|
Alexander Natale
|
Subhaditya Bhattacharya, Ernest Ma, Alexander Natale, Ahmed Rashed
|
Radiative Scaling Neutrino Mass with $A_4$ Symmetry
|
11 pages, 1 figure
|
Phys. Rev. D 87, 097301 (2013)
|
10.1103/PhysRevD.87.097301
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
A new idea for neutrino mass was proposed recently, where its smallness is
not due to the seesaw mechanism, i.e. not inversely proportional to some large
mass scale. It comes from a one-loop mechanism with dark matter in the loop
consisting of singlet Majorana fermions $N_i$ with masses of order 10 keV and
neutrino masses are scaled down from them by factors of about $10^{-5}$. We
discuss how this model may be implemented with the non-Abelian discrete
symmetry $A_4$ for neutrino mixing, and consider the phenomenology of $N_i$ as
well as the extra scalar doublet $(\eta^+,\eta^0)$.
|
[
{
"created": "Mon, 25 Feb 2013 22:23:45 GMT",
"version": "v1"
}
] |
2013-06-06
|
[
[
"Bhattacharya",
"Subhaditya",
""
],
[
"Ma",
"Ernest",
""
],
[
"Natale",
"Alexander",
""
],
[
"Rashed",
"Ahmed",
""
]
] |
A new idea for neutrino mass was proposed recently, where its smallness is not due to the seesaw mechanism, i.e. not inversely proportional to some large mass scale. It comes from a one-loop mechanism with dark matter in the loop consisting of singlet Majorana fermions $N_i$ with masses of order 10 keV and neutrino masses are scaled down from them by factors of about $10^{-5}$. We discuss how this model may be implemented with the non-Abelian discrete symmetry $A_4$ for neutrino mixing, and consider the phenomenology of $N_i$ as well as the extra scalar doublet $(\eta^+,\eta^0)$.
|
2108.13451
|
Julia Gonski
|
Julia Gonski, Jerry Lai, Benjamin Nachman, In\^es Ochoa
|
High-dimensional Anomaly Detection with Radiative Return in $e^{+}e^{-}$
Collisions
|
24 pages, 13 figures
| null |
10.1007/JHEP04(2022)156
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Experiments at a future $e^{+}e^{-}$ collider will be able to search for new
particles with masses below the nominal centre-of-mass energy by analyzing
collisions with initial-state radiation (radiative return). We show that
machine learning methods that use imperfect or missing training labels can
achieve sensitivity to generic new particle production in radiative return
events. In addition to presenting an application of the classification without
labels (CWoLa) search method in $e^{+}e^{-}$ collisions, our study combines
weak supervision with variable-dimensional information by deploying a deep sets
neural network architecture. We have also investigated some of the experimental
aspects of anomaly detection in radiative return events and discuss these in
the context of future detector design.
|
[
{
"created": "Mon, 30 Aug 2021 18:07:03 GMT",
"version": "v1"
},
{
"created": "Mon, 20 Sep 2021 13:11:15 GMT",
"version": "v2"
},
{
"created": "Tue, 8 Feb 2022 18:14:41 GMT",
"version": "v3"
}
] |
2022-05-11
|
[
[
"Gonski",
"Julia",
""
],
[
"Lai",
"Jerry",
""
],
[
"Nachman",
"Benjamin",
""
],
[
"Ochoa",
"Inês",
""
]
] |
Experiments at a future $e^{+}e^{-}$ collider will be able to search for new particles with masses below the nominal centre-of-mass energy by analyzing collisions with initial-state radiation (radiative return). We show that machine learning methods that use imperfect or missing training labels can achieve sensitivity to generic new particle production in radiative return events. In addition to presenting an application of the classification without labels (CWoLa) search method in $e^{+}e^{-}$ collisions, our study combines weak supervision with variable-dimensional information by deploying a deep sets neural network architecture. We have also investigated some of the experimental aspects of anomaly detection in radiative return events and discuss these in the context of future detector design.
|
hep-ph/0209306
|
Apostolos Pilaftsis
|
Athanasios Dedes and Apostolos Pilaftsis
|
Resummed Effective Lagrangian for Higgs-Mediated FCNC Interactions in
the CP-Violating MSSM
|
40 pages, version as to appear in Physical Review D
|
Phys.Rev. D67 (2003) 015012
|
10.1103/PhysRevD.67.015012
|
FERMILAB-Pub-02/226-T and MC-TH/2002-05
|
hep-ph
| null |
We derive the general resummed effective Lagrangian for Higgs-mediated
flavour-changing neutral-current (FCNC) interactions in the Minimal
Supersymmetric Standard Model (MSSM), without resorting to particular
assumptions that rely on the squark-mass or the quark-Yukawa structure of the
theory. In our derivation we also include the possibility of explicit CP
violation through the Cabibbo--Kobayashi--Maskawa mixing matrix and soft
supersymmetry-breaking mass terms. The advantages of our resummed FCNC
effective Lagrangian are explicitly demonstrated within the context of
phenomenologically motivated scenarios. We obtain new testable predictions in
the large $\tan\beta$ regime of the theory for CP-conserving and CP-violating
observables related to the $K$- and $B$-meson systems, such as $\Delta
M_{K,B}$, $\epsilon_K$, $\epsilon'/\epsilon$, ${\cal B}(B_{d,s} \to
\ell^+\ell^-)$ and their associated leptonic CP asymmetries. Finally, based on
our resummed FCNC effective Lagrangian, we can identify configurations in the
soft supersymmetry-breaking parameter space, for which a kind of a
Glashow--Iliopoulos--Maiani-cancellation mechanism becomes operative and hence
all Higgs-mediated, $\tan\beta$-enhanced effects on $K$- and $B$-meson FCNC
observables vanish.
|
[
{
"created": "Wed, 25 Sep 2002 20:29:22 GMT",
"version": "v1"
},
{
"created": "Mon, 30 Sep 2002 16:21:12 GMT",
"version": "v2"
},
{
"created": "Sat, 21 Dec 2002 17:15:07 GMT",
"version": "v3"
}
] |
2009-11-07
|
[
[
"Dedes",
"Athanasios",
""
],
[
"Pilaftsis",
"Apostolos",
""
]
] |
We derive the general resummed effective Lagrangian for Higgs-mediated flavour-changing neutral-current (FCNC) interactions in the Minimal Supersymmetric Standard Model (MSSM), without resorting to particular assumptions that rely on the squark-mass or the quark-Yukawa structure of the theory. In our derivation we also include the possibility of explicit CP violation through the Cabibbo--Kobayashi--Maskawa mixing matrix and soft supersymmetry-breaking mass terms. The advantages of our resummed FCNC effective Lagrangian are explicitly demonstrated within the context of phenomenologically motivated scenarios. We obtain new testable predictions in the large $\tan\beta$ regime of the theory for CP-conserving and CP-violating observables related to the $K$- and $B$-meson systems, such as $\Delta M_{K,B}$, $\epsilon_K$, $\epsilon'/\epsilon$, ${\cal B}(B_{d,s} \to \ell^+\ell^-)$ and their associated leptonic CP asymmetries. Finally, based on our resummed FCNC effective Lagrangian, we can identify configurations in the soft supersymmetry-breaking parameter space, for which a kind of a Glashow--Iliopoulos--Maiani-cancellation mechanism becomes operative and hence all Higgs-mediated, $\tan\beta$-enhanced effects on $K$- and $B$-meson FCNC observables vanish.
|
1604.03298
|
Guo-Li Wang
|
Tianhong Wang, Yue Jiang, Han Yuan, Kan Chai, Guo-Li Wang
|
Weak Decays of $J/\psi$ and $\Upsilon(1S)$
|
26 pages, 12 figures, 17 tables
|
J. Phys. G: Nucl. Part. Phys. 44 (2017) 045004
|
10.1088/1361-6471/aa5f68
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this paper we study the weak decays of $J/\psi$ and $\Upsilon(1S)$. Using
the Bethe-Salpeter method, we calculate the hadronic transition amplitude and
give the form factors. We find that two new form factors $h_1$ and $h_2$, which
do not appear in existing literature, have contributions in $1^-\to 1^-$
decays. They affect the branching ratios of semi-leptonic and non-leptonic
decays by the rate of $3\%\sim6\%$ and $2\%\sim14\%$, respectively, so their
contributions can not be ignored and should be considered. Our results show
that, for the semi-leptonic decay modes, the largest branching ratios are of
the order of $10^{-10}$ both for $J/\psi$ and $\Upsilon(1S)$ decays, and the
largest branching ratios of non-leptonic decays are of the order of $10^{-9}$
for $J/\psi$ and $10^{-10}$ for $\Upsilon(1S)$.
|
[
{
"created": "Tue, 12 Apr 2016 08:36:35 GMT",
"version": "v1"
},
{
"created": "Tue, 9 Aug 2016 02:45:22 GMT",
"version": "v2"
}
] |
2021-11-05
|
[
[
"Wang",
"Tianhong",
""
],
[
"Jiang",
"Yue",
""
],
[
"Yuan",
"Han",
""
],
[
"Chai",
"Kan",
""
],
[
"Wang",
"Guo-Li",
""
]
] |
In this paper we study the weak decays of $J/\psi$ and $\Upsilon(1S)$. Using the Bethe-Salpeter method, we calculate the hadronic transition amplitude and give the form factors. We find that two new form factors $h_1$ and $h_2$, which do not appear in existing literature, have contributions in $1^-\to 1^-$ decays. They affect the branching ratios of semi-leptonic and non-leptonic decays by the rate of $3\%\sim6\%$ and $2\%\sim14\%$, respectively, so their contributions can not be ignored and should be considered. Our results show that, for the semi-leptonic decay modes, the largest branching ratios are of the order of $10^{-10}$ both for $J/\psi$ and $\Upsilon(1S)$ decays, and the largest branching ratios of non-leptonic decays are of the order of $10^{-9}$ for $J/\psi$ and $10^{-10}$ for $\Upsilon(1S)$.
|
2102.10844
|
Dinh T Binh
|
D.T.Binh, L.T.Hue, V. H. Binh, H. N. Long
|
Neutrino Energy Loss Rates in 3-3-1 Models
|
Revised version, new references added. arXiv admin note: text overlap
with arXiv:2005.03808 by other authors
|
Int. J. Mod. Phys. A 36, No 26 (2021) 2150179
|
10.1142/S0217751X21501797
| null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
The stellar energy-loss rates $\mathcal{Q}$ due to the production of neutrino
pair in the framework of 3-3-1 models are presented. The energy loss rate
$\mathcal{Q}$ is evaluated for different values of
$\beta=\pm\fr{1}{\sqrt{3}},\pm\fr{2}{\sqrt{3}},\pm\sqrt{3}$ in which $\beta$ is
a parameter used to define the charge operator in the 3-3-1 models. The
correction to the rate which is compared with that of the Standard Model ($\de
\mathcal{Q}$) is also evaluated. We show that the correction does not exceed
14\% and %is gets the highest with $\beta=-\sqrt{3}$. The contribution of
dipole moment to the energy loss rate is small compared to the contribution of
new natural gauge boson $Z'$ and this sets constraints for the mass of Z'
$m_{Z'} \leq 4000$ GeV. This mass range is within the searching range for $Z'$
boson at LHC.
|
[
{
"created": "Mon, 22 Feb 2021 09:13:58 GMT",
"version": "v1"
},
{
"created": "Tue, 2 Mar 2021 12:22:15 GMT",
"version": "v2"
}
] |
2021-10-11
|
[
[
"Binh",
"D. T.",
""
],
[
"Hue",
"L. T.",
""
],
[
"Binh",
"V. H.",
""
],
[
"Long",
"H. N.",
""
]
] |
The stellar energy-loss rates $\mathcal{Q}$ due to the production of neutrino pair in the framework of 3-3-1 models are presented. The energy loss rate $\mathcal{Q}$ is evaluated for different values of $\beta=\pm\fr{1}{\sqrt{3}},\pm\fr{2}{\sqrt{3}},\pm\sqrt{3}$ in which $\beta$ is a parameter used to define the charge operator in the 3-3-1 models. The correction to the rate which is compared with that of the Standard Model ($\de \mathcal{Q}$) is also evaluated. We show that the correction does not exceed 14\% and %is gets the highest with $\beta=-\sqrt{3}$. The contribution of dipole moment to the energy loss rate is small compared to the contribution of new natural gauge boson $Z'$ and this sets constraints for the mass of Z' $m_{Z'} \leq 4000$ GeV. This mass range is within the searching range for $Z'$ boson at LHC.
|
hep-ph/0301155
|
Ma Jian-ping
|
J.P. Ma
|
Diffractive Photoproduction of Eta_c
|
20 pages with 3 figures. Text improved
|
Nucl.Phys.A727:333-352,2003
|
10.1016/j.nuclphysa.2003.08.016
|
AS-ITP-2003-001
|
hep-ph hep-ex
| null |
Diffractive photoproduction of $\eta_c$ is an important process to study the
effect of Odderon, whose existence is still not confirmed in experiment. A
detailed interpretation of Odderon in QCD, i.e., in terms of gluons is also
unclear.Taking charm quarks as heavy quarks, we can use NRQCD and take $\eta_c$
as a $c\bar c$ bound state. Hence, in the production of $\eta_c$a free $c\bar
c$ pair is first produced and this pair is transformed into $\eta_c$
subsequently.In the forward region of the kinematics, the $c\bar c$ pair
interacts with initial hadron through exchanges of soft gluons. This
interaction can be studied with HQET, which provides a systematic expansion in
the inverse of the $c$-quark mass $m_c$. We find that the calculation of the
$S$-matrix element in the forward region can be formulated as the problem of
solving a wave function of a $c$-quark propagating in a background field of
soft gluons. At leading order we find that the differential cross-section can
be expressed with four functions, which are defined with a twist-3 operator of
gluons. The effect of exchanging a Odderon can be identified with this operator
in our case. We discuss our results in detail and compare them with those
obtained in previous studies. Our results and those from other studies show
that the differential cross-section is very small in the forward region. We
also show that the production through photon exchange is dominant in the
extremely forward region, hence the effect of Odderon exchange can not be
identified in this region.For completeness we also give results for diffractive
photoproduction of $J/\Psi$.
|
[
{
"created": "Mon, 20 Jan 2003 04:10:59 GMT",
"version": "v1"
},
{
"created": "Wed, 16 Apr 2003 03:28:38 GMT",
"version": "v2"
},
{
"created": "Wed, 6 Aug 2003 18:49:09 GMT",
"version": "v3"
}
] |
2009-11-05
|
[
[
"Ma",
"J. P.",
""
]
] |
Diffractive photoproduction of $\eta_c$ is an important process to study the effect of Odderon, whose existence is still not confirmed in experiment. A detailed interpretation of Odderon in QCD, i.e., in terms of gluons is also unclear.Taking charm quarks as heavy quarks, we can use NRQCD and take $\eta_c$ as a $c\bar c$ bound state. Hence, in the production of $\eta_c$a free $c\bar c$ pair is first produced and this pair is transformed into $\eta_c$ subsequently.In the forward region of the kinematics, the $c\bar c$ pair interacts with initial hadron through exchanges of soft gluons. This interaction can be studied with HQET, which provides a systematic expansion in the inverse of the $c$-quark mass $m_c$. We find that the calculation of the $S$-matrix element in the forward region can be formulated as the problem of solving a wave function of a $c$-quark propagating in a background field of soft gluons. At leading order we find that the differential cross-section can be expressed with four functions, which are defined with a twist-3 operator of gluons. The effect of exchanging a Odderon can be identified with this operator in our case. We discuss our results in detail and compare them with those obtained in previous studies. Our results and those from other studies show that the differential cross-section is very small in the forward region. We also show that the production through photon exchange is dominant in the extremely forward region, hence the effect of Odderon exchange can not be identified in this region.For completeness we also give results for diffractive photoproduction of $J/\Psi$.
|
2307.01763
|
Yao Ji
|
Yao Ji, Alexander Manashov, Sven-Olaf Moch
|
On evolution kernels of twist-two operators
|
12 pages, two figures; The three-loop QCD kernel in electronic form
is given in the ancillary file. V2: published version; reference added; typo
corrected
| null | null |
TUM--HEP--1461/23, MPP--2023--137, DESY--23--091
|
hep-ph hep-th
|
http://creativecommons.org/licenses/by/4.0/
|
The evolution kernels that govern the scale dependence of the generalized
parton distributions are invariant under transformations of the
$\mathrm{SL}(2,\mathrm R)$ collinear subgroup of the conformal group. Beyond
one loop the symmetry generators, due to quantum effects, differ from the
canonical ones. We construct the transformation which brings the {\it full}
symmetry generators back to their canonical form and show that the eigenvalues
(anomalous dimensions) of the new, canonically invariant, evolution kernel
coincide with the so-called parity respecting anomalous dimensions. We develop
an efficient method that allows one to restore an invariant kernel from the
corresponding anomalous dimensions. As an example, the explicit expressions for
NNLO invariant kernels for the twist two flavor-nonsinglet operators in QCD and
for the planar part of the universal anomalous dimension in $ N=4$ SYM are
presented.
|
[
{
"created": "Tue, 4 Jul 2023 15:05:28 GMT",
"version": "v1"
},
{
"created": "Fri, 29 Mar 2024 07:43:38 GMT",
"version": "v2"
}
] |
2024-04-01
|
[
[
"Ji",
"Yao",
""
],
[
"Manashov",
"Alexander",
""
],
[
"Moch",
"Sven-Olaf",
""
]
] |
The evolution kernels that govern the scale dependence of the generalized parton distributions are invariant under transformations of the $\mathrm{SL}(2,\mathrm R)$ collinear subgroup of the conformal group. Beyond one loop the symmetry generators, due to quantum effects, differ from the canonical ones. We construct the transformation which brings the {\it full} symmetry generators back to their canonical form and show that the eigenvalues (anomalous dimensions) of the new, canonically invariant, evolution kernel coincide with the so-called parity respecting anomalous dimensions. We develop an efficient method that allows one to restore an invariant kernel from the corresponding anomalous dimensions. As an example, the explicit expressions for NNLO invariant kernels for the twist two flavor-nonsinglet operators in QCD and for the planar part of the universal anomalous dimension in $ N=4$ SYM are presented.
|
0909.3204
|
Hiroshi Yokoya
|
Kaoru Hagiwara, Hiroshi Yokoya
|
Bound-state effects on gluino-pair production at hadron colliders
|
17 pages, 6 figures; references added, typos corrected
|
JHEP 0910:049,2009
|
10.1088/1126-6708/2009/10/049
|
KEK-TH-1330, CERN-PH-TH/2009-169
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study bound-state effects on the pair production of gluinos at hadron
colliders, in a context of the minimal supersymmetric extension of the standard
model. Due to the expected large mass and the octet color-charge of gluinos,
the bound-state effects can be substantial at the LHC. We find significant
deformation of the invariant-mass distributions of a gluino-pair near the mass
threshold, as well as an additional correction to the total cross-section. Both
the invariant-mass distribution and the correction to the total cross section
depend crucially on the decay width of the gluino.
|
[
{
"created": "Thu, 17 Sep 2009 15:17:56 GMT",
"version": "v1"
},
{
"created": "Mon, 21 Sep 2009 20:14:21 GMT",
"version": "v2"
}
] |
2009-12-07
|
[
[
"Hagiwara",
"Kaoru",
""
],
[
"Yokoya",
"Hiroshi",
""
]
] |
We study bound-state effects on the pair production of gluinos at hadron colliders, in a context of the minimal supersymmetric extension of the standard model. Due to the expected large mass and the octet color-charge of gluinos, the bound-state effects can be substantial at the LHC. We find significant deformation of the invariant-mass distributions of a gluino-pair near the mass threshold, as well as an additional correction to the total cross-section. Both the invariant-mass distribution and the correction to the total cross section depend crucially on the decay width of the gluino.
|
2209.12555
|
Jorge Segovia
|
U. Taboada-Nieto, P.G. Ortega, D.R. Entem, F. Fern\'andez and J.
Segovia
|
Kaon spectrum revisited
|
11 pages, 1 figure, 13 tables
| null | null | null |
hep-ph hep-ex hep-lat nucl-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The European Organization for Nuclear Research (CERN) has recently approved a
world-unique QCD facility in which an updated version of the external M2 beam
line of the CERN SPS in conjunction with a universal spectrometer of the
COMPASS experiment is used. One of its main goals is to use highly intense and
energetic kaon beams to map out the complete spectrum of excited kaons with an
unprecedented precision; having a broad impact not only on low-energy QCD
phenomenology, but also on many high-energy particle processes where excited
kaons appear, such as the study of CP violation in heavy-meson decays studied
at LHCb and Belle~II. In support of the experimental effort, the kaon spectrum
is computed herein using a constituent quark model which has been successfully
applied to a wide range of hadronic observables, from light to heavy quark
sectors, and thus the model parameters are completely constrained. The model's
prediction can be used as a template against which to compare the already
collected data and future experimental findings, in order to distinguish
between conventional and exotic kaon states. We also compare our results with
those available in the literature in order to provide some general statements,
common to all calculations.
|
[
{
"created": "Mon, 26 Sep 2022 10:14:43 GMT",
"version": "v1"
}
] |
2022-09-27
|
[
[
"Taboada-Nieto",
"U.",
""
],
[
"Ortega",
"P. G.",
""
],
[
"Entem",
"D. R.",
""
],
[
"Fernández",
"F.",
""
],
[
"Segovia",
"J.",
""
]
] |
The European Organization for Nuclear Research (CERN) has recently approved a world-unique QCD facility in which an updated version of the external M2 beam line of the CERN SPS in conjunction with a universal spectrometer of the COMPASS experiment is used. One of its main goals is to use highly intense and energetic kaon beams to map out the complete spectrum of excited kaons with an unprecedented precision; having a broad impact not only on low-energy QCD phenomenology, but also on many high-energy particle processes where excited kaons appear, such as the study of CP violation in heavy-meson decays studied at LHCb and Belle~II. In support of the experimental effort, the kaon spectrum is computed herein using a constituent quark model which has been successfully applied to a wide range of hadronic observables, from light to heavy quark sectors, and thus the model parameters are completely constrained. The model's prediction can be used as a template against which to compare the already collected data and future experimental findings, in order to distinguish between conventional and exotic kaon states. We also compare our results with those available in the literature in order to provide some general statements, common to all calculations.
|
1201.1794
|
Takuya Morozumi
|
D. Kimura, K. Y. Lee and T. Morozumi
|
The form factors of tau -> K pi(eta) nu and the predictions for CP
violation beyond the standard model
|
51pages, 16figures. The version 7 incorporated the errata accepted to
PTEP. In Fig. 9, the vertical axis label is corrected. In Fig.16, the
numerical calculation was wrong and the figure is re-drawn. A typo of Eq.(21)
is also corrected and the kinetic term is added to Eq.(A3)
| null |
10.1093/ptep/ptt084
|
HUPD1102
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the hadronic form factors of $\tau$ lepton decays $\tau \to K
\pi(\eta) \nu$. We compute one loop corrections to the form factors using the
chiral Lagrangian including vector mesons. The counterterms which subtract the
divergence of the one-loop amplitudes are determined by using background field
method. In the vector form factor, $K^\ast$ resonance behavior is reproduced
because the diagram with a vector meson propagator is included. We fit the data
of the hadronic invariant mass spectrum measured by Belle by determining some
of the counterterms of the Lagrangian. Besides the hadronic invariant mass
spectrum, the forward-backward asymmetry is predicted. We also study the effect
of CP violation of a two Higgs doublet model. In the model, CP violation of the
neutral Higgs sector generates the mixing of CP even Higgs and CP odd Higgs. We
show how the mixing leads to the direct CP violation of the $\tau$ decays and
predict the CP violation of the forward-backward asymmetry.
|
[
{
"created": "Mon, 9 Jan 2012 15:14:10 GMT",
"version": "v1"
},
{
"created": "Tue, 10 Jan 2012 13:44:38 GMT",
"version": "v2"
},
{
"created": "Thu, 19 Jan 2012 08:53:27 GMT",
"version": "v3"
},
{
"created": "Mon, 12 Nov 2012 15:08:44 GMT",
"version": "v4"
},
{
"created": "Thu, 15 Nov 2012 13:47:18 GMT",
"version": "v5"
},
{
"created": "Tue, 5 Feb 2013 10:10:10 GMT",
"version": "v6"
},
{
"created": "Wed, 7 Aug 2013 09:41:02 GMT",
"version": "v7"
},
{
"created": "Thu, 8 Aug 2013 01:35:40 GMT",
"version": "v8"
}
] |
2014-05-07
|
[
[
"Kimura",
"D.",
""
],
[
"Lee",
"K. Y.",
""
],
[
"Morozumi",
"T.",
""
]
] |
We study the hadronic form factors of $\tau$ lepton decays $\tau \to K \pi(\eta) \nu$. We compute one loop corrections to the form factors using the chiral Lagrangian including vector mesons. The counterterms which subtract the divergence of the one-loop amplitudes are determined by using background field method. In the vector form factor, $K^\ast$ resonance behavior is reproduced because the diagram with a vector meson propagator is included. We fit the data of the hadronic invariant mass spectrum measured by Belle by determining some of the counterterms of the Lagrangian. Besides the hadronic invariant mass spectrum, the forward-backward asymmetry is predicted. We also study the effect of CP violation of a two Higgs doublet model. In the model, CP violation of the neutral Higgs sector generates the mixing of CP even Higgs and CP odd Higgs. We show how the mixing leads to the direct CP violation of the $\tau$ decays and predict the CP violation of the forward-backward asymmetry.
|
1012.5007
|
Sven Heinemeyer
|
S. Heinemeyer, V.A. Khoze, M.G. Ryskin, M. Tasevsky, G. Weiglein
|
BSM Higgs Physics in the Exclusive Forward Proton Mode at the LHC
|
36 pages, 15 figures; more explanations on changes with respect to
previous analysis; version to appear in EPJC
| null |
10.1140/epjc/s10052-011-1649-7
|
DCPT/10/162, DESY 10-217, IPPP/10/81
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We investigate the prospects for Central Exclusive Diffractive (CED)
production of BSM Higgs bosons at the LHC using forward proton detectors
installed at 220 m and 420 m distance around ATLAS and / or CMS. We update a
previous analysis for the MSSM taking into account improvements in the
theoretical calculations and the most recent exclusion bounds from the
Tevatron. We extend the MSSM analysis to new benchmark scenarios that are in
agreement with the cold dark matter relic abundance and other precision
measurements. We analyse the exclusive production of Higgs bosons in a model
with a fourth generation of fermions. Finally, we comment on the determination
of Higgs spin-parity and coupling structures at the LHC and show that the
forward proton mode could provide crucial information on the CP properties of
the Higgs bosons.
|
[
{
"created": "Wed, 22 Dec 2010 15:24:46 GMT",
"version": "v1"
},
{
"created": "Thu, 12 May 2011 17:29:47 GMT",
"version": "v2"
}
] |
2015-05-20
|
[
[
"Heinemeyer",
"S.",
""
],
[
"Khoze",
"V. A.",
""
],
[
"Ryskin",
"M. G.",
""
],
[
"Tasevsky",
"M.",
""
],
[
"Weiglein",
"G.",
""
]
] |
We investigate the prospects for Central Exclusive Diffractive (CED) production of BSM Higgs bosons at the LHC using forward proton detectors installed at 220 m and 420 m distance around ATLAS and / or CMS. We update a previous analysis for the MSSM taking into account improvements in the theoretical calculations and the most recent exclusion bounds from the Tevatron. We extend the MSSM analysis to new benchmark scenarios that are in agreement with the cold dark matter relic abundance and other precision measurements. We analyse the exclusive production of Higgs bosons in a model with a fourth generation of fermions. Finally, we comment on the determination of Higgs spin-parity and coupling structures at the LHC and show that the forward proton mode could provide crucial information on the CP properties of the Higgs bosons.
|
2209.03360
|
Torsten Bringmann
|
James Alvey, Torsten Bringmann and Helena Kolesova
|
No room to hide: implications of cosmic-ray upscattering for GeV-scale
dark matter
|
44 pages, jheppub, 9 figures. Minor changes to match published
version
|
JHEP 01 (2023) 123
|
10.1007/JHEP01(2023)123
|
CERN-TH-2022-147
|
hep-ph astro-ph.CO
|
http://creativecommons.org/licenses/by-nc-nd/4.0/
|
The irreducible upscattering of cold dark matter by cosmic rays opens up the
intriguing possibility of detecting even light dark matter in conventional
direct detection experiments or underground neutrino detectors. The mechanism
also significantly enhances sensitivity to models with very large nuclear
scattering rates, where the atmosphere and rock overburden efficiently stop
standard non-relativistic dark matter particles before they could reach the
detector. In this article, we demonstrate that cosmic-ray upscattering
essentially closes the window for strongly interacting dark matter in the
(sub-)GeV mass range. Arriving at this conclusion crucially requires a detailed
treatment of both nuclear form factors and inelastic dark matter-nucleus
scattering, as well as including the full momentum-transfer dependence of
scattering amplitudes. We illustrate the latter point by considering three
generic situations where such a momentum-dependence is particularly relevant,
namely for interactions dominated by the exchange of light vector or scalar
mediators, respectively, and for dark matter particles of finite size. As a
final concrete example, we apply our analysis to a putative hexaquark state,
which has been suggested as a viable baryonic dark matter candidate. Once
again, we find that the updated constraints derived in this work close a
significant part of otherwise unconstrained parameter space.
|
[
{
"created": "Wed, 7 Sep 2022 18:00:00 GMT",
"version": "v1"
},
{
"created": "Wed, 1 Feb 2023 16:49:04 GMT",
"version": "v2"
}
] |
2023-02-02
|
[
[
"Alvey",
"James",
""
],
[
"Bringmann",
"Torsten",
""
],
[
"Kolesova",
"Helena",
""
]
] |
The irreducible upscattering of cold dark matter by cosmic rays opens up the intriguing possibility of detecting even light dark matter in conventional direct detection experiments or underground neutrino detectors. The mechanism also significantly enhances sensitivity to models with very large nuclear scattering rates, where the atmosphere and rock overburden efficiently stop standard non-relativistic dark matter particles before they could reach the detector. In this article, we demonstrate that cosmic-ray upscattering essentially closes the window for strongly interacting dark matter in the (sub-)GeV mass range. Arriving at this conclusion crucially requires a detailed treatment of both nuclear form factors and inelastic dark matter-nucleus scattering, as well as including the full momentum-transfer dependence of scattering amplitudes. We illustrate the latter point by considering three generic situations where such a momentum-dependence is particularly relevant, namely for interactions dominated by the exchange of light vector or scalar mediators, respectively, and for dark matter particles of finite size. As a final concrete example, we apply our analysis to a putative hexaquark state, which has been suggested as a viable baryonic dark matter candidate. Once again, we find that the updated constraints derived in this work close a significant part of otherwise unconstrained parameter space.
|
2204.05992
|
Jure Zupan
|
Reuven Balkin, Eric Madge, Tony Menzo, Gilad Perez, Yotam Soreq, and
Jure Zupan
|
On the implications of positive W mass shift
|
18 pages, 4 figures, 1 Table, version matching the published one
| null |
10.1007/JHEP05(2022)133
| null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
We investigate the phenomenological implications of the recent $W$ mass
measurement by the CDF collaboration, which exhibits tension with the standard
model (SM) electroweak fit. Performing the fit to the electroweak observables
within the SM effective field theory, we find that the new physics that
contributes either to the determination of the electroweak vacuum expectation
value, or to the oblique parameters, can improve the agreement with data. The
best description is obtained from a fit where flavor universality is not
required in the new physics operators, with 2 to 3 $\sigma$ indications for
several nonzero Wilson coefficients. We point out that top partners with order
TeV masses could lead to the observed shift in the $W$ mass.
|
[
{
"created": "Tue, 12 Apr 2022 17:56:22 GMT",
"version": "v1"
},
{
"created": "Wed, 4 May 2022 20:42:07 GMT",
"version": "v2"
}
] |
2022-06-08
|
[
[
"Balkin",
"Reuven",
""
],
[
"Madge",
"Eric",
""
],
[
"Menzo",
"Tony",
""
],
[
"Perez",
"Gilad",
""
],
[
"Soreq",
"Yotam",
""
],
[
"Zupan",
"Jure",
""
]
] |
We investigate the phenomenological implications of the recent $W$ mass measurement by the CDF collaboration, which exhibits tension with the standard model (SM) electroweak fit. Performing the fit to the electroweak observables within the SM effective field theory, we find that the new physics that contributes either to the determination of the electroweak vacuum expectation value, or to the oblique parameters, can improve the agreement with data. The best description is obtained from a fit where flavor universality is not required in the new physics operators, with 2 to 3 $\sigma$ indications for several nonzero Wilson coefficients. We point out that top partners with order TeV masses could lead to the observed shift in the $W$ mass.
|
1512.03047
|
Andrei Angelescu
|
Andrei Angelescu, Abdelhak Djouadi, Gr\'egory Moreau and Fran\c{c}ois
Richard
|
Diboson resonances within a custodially protected warped
extra-dimensional scenario
|
10 pages, 2 figures
| null | null |
LPT-Orsay-15-94, LAL-Orsay-15-427
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We propose an interpretation of the diboson excess recently observed by the
ATLAS and CMS collaborations in terms of Kaluza-Klein excitations of
electroweak gauge bosons stemming from a realization of a warped
extra-dimensional model that is protected by a custodial symmetry. Besides
accounting for the LHC diboson data, this scenario also leads to an explanation
of the anomalies that have been observed in the measurements of the
forward-backward asymmetries for bottom quarks at LEP and top quarks at the
Tevatron.
|
[
{
"created": "Wed, 9 Dec 2015 20:56:26 GMT",
"version": "v1"
}
] |
2015-12-10
|
[
[
"Angelescu",
"Andrei",
""
],
[
"Djouadi",
"Abdelhak",
""
],
[
"Moreau",
"Grégory",
""
],
[
"Richard",
"François",
""
]
] |
We propose an interpretation of the diboson excess recently observed by the ATLAS and CMS collaborations in terms of Kaluza-Klein excitations of electroweak gauge bosons stemming from a realization of a warped extra-dimensional model that is protected by a custodial symmetry. Besides accounting for the LHC diboson data, this scenario also leads to an explanation of the anomalies that have been observed in the measurements of the forward-backward asymmetries for bottom quarks at LEP and top quarks at the Tevatron.
|
hep-ph/0309311
|
Ji-Feng Yang
|
Ji-Feng Yang (ECNU, Shanghai)
|
Trace and chiral anomalies in QED and their underlying theory
interpretation
|
18 pages, revtex, renewal of reference [4]
| null | null | null |
hep-ph hep-th
| null |
Parametrizing the possible underlying theory or new physics' decoupling
effects in the most general way we reexamined the validity of canonical trace
relation and chiral symmetry in certain one-loop two-point functions. The
anomalies and the relation between chiral and trace Ward identities are
investigated and interpreted in the perspective of a complete underlying theory
or new physics instead of regularization, with some new phenomena found as
by-products.
|
[
{
"created": "Sat, 27 Sep 2003 14:08:40 GMT",
"version": "v1"
},
{
"created": "Wed, 1 Oct 2003 23:56:29 GMT",
"version": "v2"
},
{
"created": "Tue, 25 Nov 2003 10:21:59 GMT",
"version": "v3"
}
] |
2007-05-23
|
[
[
"Yang",
"Ji-Feng",
"",
"ECNU, Shanghai"
]
] |
Parametrizing the possible underlying theory or new physics' decoupling effects in the most general way we reexamined the validity of canonical trace relation and chiral symmetry in certain one-loop two-point functions. The anomalies and the relation between chiral and trace Ward identities are investigated and interpreted in the perspective of a complete underlying theory or new physics instead of regularization, with some new phenomena found as by-products.
|
1601.02659
|
Diego Cogollo
|
D. Cogollo, Jo\~ao P. Silva
|
Two Higgs doublet models with an $S_3$ symmetry
| null |
Phys. Rev. D 93, 095024 (2016)
|
10.1103/PhysRevD.93.095024
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study all implementations of the $S_3$ symmetry in the two Higgs doublet
model with quarks, consistent with non-zero quark masses and a
Cabibbo-Kobayashi-Maskawa (CKM) matrix which is not block diagonal. We study
the impact of the various soft-breaking terms and vacuum expectation values,
and find an interesting relation between $\alpha$ and $\beta$. We also show
that, in this minimal setting, only two types of assignments are possible:
either all field sectors are in singlets or all field sectors have a doublet.
|
[
{
"created": "Mon, 11 Jan 2016 21:35:55 GMT",
"version": "v1"
},
{
"created": "Sat, 28 May 2016 22:30:04 GMT",
"version": "v2"
}
] |
2016-05-31
|
[
[
"Cogollo",
"D.",
""
],
[
"Silva",
"João P.",
""
]
] |
We study all implementations of the $S_3$ symmetry in the two Higgs doublet model with quarks, consistent with non-zero quark masses and a Cabibbo-Kobayashi-Maskawa (CKM) matrix which is not block diagonal. We study the impact of the various soft-breaking terms and vacuum expectation values, and find an interesting relation between $\alpha$ and $\beta$. We also show that, in this minimal setting, only two types of assignments are possible: either all field sectors are in singlets or all field sectors have a doublet.
|
hep-ph/0604137
|
Stephen Clark
|
Stephen Clark (EPFL)
|
Interactions of Q-balls and matter
| null | null | null | null |
hep-ph
| null |
We know from previous work \cite{clark} that non topological solitons, Q
balls, evaporate into fermions. All the constructions we used to find
evaporation rate were dased on the fact that no fermions would move towards the
Q ball. All these constructions left an opened question that is : what happens
when a fermion interacts with a Q ball. We shall answer this question in this
work by using the constructions done to compute evaporation rates. We shall
also obtain a new approach to compute evaporation rates.
|
[
{
"created": "Mon, 17 Apr 2006 19:34:15 GMT",
"version": "v1"
},
{
"created": "Wed, 19 Apr 2006 13:34:02 GMT",
"version": "v2"
}
] |
2007-05-23
|
[
[
"Clark",
"Stephen",
"",
"EPFL"
]
] |
We know from previous work \cite{clark} that non topological solitons, Q balls, evaporate into fermions. All the constructions we used to find evaporation rate were dased on the fact that no fermions would move towards the Q ball. All these constructions left an opened question that is : what happens when a fermion interacts with a Q ball. We shall answer this question in this work by using the constructions done to compute evaporation rates. We shall also obtain a new approach to compute evaporation rates.
|
hep-ph/0401067
|
Enrico Cattaruzza
|
Enrico Cattaruzza and Daniele Treleani
|
Cronin effect and energy conservation constraints in high energy
proton-nucleus collisions
|
Accepted by Phys.Rev.D
|
Phys.Rev. D69 (2004) 094006
|
10.1103/PhysRevD.69.094006
| null |
hep-ph
| null |
We estimate the Cronin effect in pA collisions at the CERN LHC and at RHIC,
using a Glauber-Eikonal model of initial state multiparton interactions. For a
correct determination of the initial parton flux, we upgrade the model cross
section, taking carefully into account all kinematical constraints of each
multi-parton interaction process. As compared with previous results, derived
with approximate kinematics, we obtain a softer spectrum of produced partons,
while improving the agreement of the model with the recent measurements of
neutral pions production in d+Au collisions at sqrt(s)=200 AGeV.
|
[
{
"created": "Sun, 11 Jan 2004 11:17:54 GMT",
"version": "v1"
},
{
"created": "Thu, 6 May 2004 13:05:52 GMT",
"version": "v2"
}
] |
2009-11-10
|
[
[
"Cattaruzza",
"Enrico",
""
],
[
"Treleani",
"Daniele",
""
]
] |
We estimate the Cronin effect in pA collisions at the CERN LHC and at RHIC, using a Glauber-Eikonal model of initial state multiparton interactions. For a correct determination of the initial parton flux, we upgrade the model cross section, taking carefully into account all kinematical constraints of each multi-parton interaction process. As compared with previous results, derived with approximate kinematics, we obtain a softer spectrum of produced partons, while improving the agreement of the model with the recent measurements of neutral pions production in d+Au collisions at sqrt(s)=200 AGeV.
|
hep-ph/0008275
|
Douglas Ross
|
D.A. Ross and L.J. Weston
|
Photon Structure Functions Beyind the SUSY Threshold
|
18 pages (LATEX), 5 figures
|
Eur.Phys.J.C18:593-599,2001
|
10.1007/s100520000552
| null |
hep-ph
| null |
We evolve virtual photon parton densities up to the SUSY threshold and higher
using coupled inhomogeneous DGLAP differential equations. Reliable input
parameterizations were available from the c-quark threshold. Limited
$P^2$ ( target photon virtuality ) dependence is observed. The difference to
the photon structure function is shown to be significant with the introduction
of SUSY dependent splitting functions. A negligible difference is observed by
letting the gluino mass enter after the squark mass. An effort is made to
include the squark threshold effect in such a way that both the renormalization
group equations are satisfied and the perturbative calculation is reproduced.
|
[
{
"created": "Fri, 25 Aug 2000 15:27:07 GMT",
"version": "v1"
}
] |
2010-03-25
|
[
[
"Ross",
"D. A.",
""
],
[
"Weston",
"L. J.",
""
]
] |
We evolve virtual photon parton densities up to the SUSY threshold and higher using coupled inhomogeneous DGLAP differential equations. Reliable input parameterizations were available from the c-quark threshold. Limited $P^2$ ( target photon virtuality ) dependence is observed. The difference to the photon structure function is shown to be significant with the introduction of SUSY dependent splitting functions. A negligible difference is observed by letting the gluino mass enter after the squark mass. An effort is made to include the squark threshold effect in such a way that both the renormalization group equations are satisfied and the perturbative calculation is reproduced.
|
0812.2631
|
Antonio Pich
|
Antonio Pich
|
Low-Energy Constants from Resonance Chiral Theory
|
Proceedings of the 8th International Conference on Quark Confinement
and the Hadron Spectrum (Mainz, Germany, 1-6 September 2008). 10 pages
|
PoS Confinement8:026,2008
| null |
IFIC/08-65, FTUV/08-1215
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
I discuss the recent attempts to build an effective chiral Lagrangian
incorporating massive resonance states. A useful approximation scheme to
organize the resonance Lagrangian is provided by the large-Nc limit of QCD.
Integrating out the resonance fields, one recovers the usual chiral
perturbation theory Lagrangian with explicit values for the low-energy
constants, parameterized in terms of resonance masses and couplings. The
resonance chiral theory generates Green functions that interpolate between QCD
and chiral perturbation theory. Analyzing these Green functions, both for large
and small momenta, one gets QCD constraints on the resonance couplings and,
therefore, information on the low-energy constants governing the Goldstone
interactions.
|
[
{
"created": "Sun, 14 Dec 2008 13:12:27 GMT",
"version": "v1"
}
] |
2009-06-25
|
[
[
"Pich",
"Antonio",
""
]
] |
I discuss the recent attempts to build an effective chiral Lagrangian incorporating massive resonance states. A useful approximation scheme to organize the resonance Lagrangian is provided by the large-Nc limit of QCD. Integrating out the resonance fields, one recovers the usual chiral perturbation theory Lagrangian with explicit values for the low-energy constants, parameterized in terms of resonance masses and couplings. The resonance chiral theory generates Green functions that interpolate between QCD and chiral perturbation theory. Analyzing these Green functions, both for large and small momenta, one gets QCD constraints on the resonance couplings and, therefore, information on the low-energy constants governing the Goldstone interactions.
|
2103.08598
|
Wen Yin
|
Ryuichiro Kitano and Wen Yin
|
Strong CP problem and axion dark matter with small instantons
|
32pages, 8figures
| null |
10.1007/JHEP07(2021)078
|
KEK-TH-2310
|
hep-ph astro-ph.CO
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The axion mass receives a large correction from small instantons if the QCD
gets strongly coupled at high energies. We discuss the size of the new CP
violating phases caused by the fact that the small instantons are sensitive to
the UV physics. We also discuss the effects of the mass correction on the axion
abundance of the Universe. Taking the small-instanton contributions into
account, we propose a natural scenario of axion dark matter where the axion
decay constant is as large as $10^{15\text{-}16}$GeV. The scenario works in the
high-scale inflation models.
|
[
{
"created": "Mon, 15 Mar 2021 18:00:00 GMT",
"version": "v1"
}
] |
2021-07-28
|
[
[
"Kitano",
"Ryuichiro",
""
],
[
"Yin",
"Wen",
""
]
] |
The axion mass receives a large correction from small instantons if the QCD gets strongly coupled at high energies. We discuss the size of the new CP violating phases caused by the fact that the small instantons are sensitive to the UV physics. We also discuss the effects of the mass correction on the axion abundance of the Universe. Taking the small-instanton contributions into account, we propose a natural scenario of axion dark matter where the axion decay constant is as large as $10^{15\text{-}16}$GeV. The scenario works in the high-scale inflation models.
|
1001.2563
|
Kathryn Zurek
|
Kathryn M. Zurek
|
TASI 2009 Lectures: Searching for Unexpected Physics at the LHC
|
35 pages, 21 figures
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
These TASI lectures consider low mass hidden sectors from Hidden Valleys,
Quirks and Unparticles. We show how each corresponds to a different limit of
the same class of models: hidden sectors with non-abelian gauge groups with
mass gaps well below a TeV that communicate to the Standard Model through weak
scale suppressed higher dimension operators. We provide concrete examples of
such models and discuss LHC signatures. Lastly we turn to discussing the
application of Hidden Valleys to dark matter sectors.
|
[
{
"created": "Fri, 15 Jan 2010 16:46:12 GMT",
"version": "v1"
}
] |
2016-09-08
|
[
[
"Zurek",
"Kathryn M.",
""
]
] |
These TASI lectures consider low mass hidden sectors from Hidden Valleys, Quirks and Unparticles. We show how each corresponds to a different limit of the same class of models: hidden sectors with non-abelian gauge groups with mass gaps well below a TeV that communicate to the Standard Model through weak scale suppressed higher dimension operators. We provide concrete examples of such models and discuss LHC signatures. Lastly we turn to discussing the application of Hidden Valleys to dark matter sectors.
|
2206.07815
|
Francesco Giovanni Celiberto
|
Alessandro Bacchetta, Francesco Giovanni Celiberto, Marco Radici
|
Unveiling the proton structure via transverse-momentum-dependent gluon
distributions
|
5 pages, 1 figure, presented by F.G. Celiberto, contribution to the
proceedings of the 19th International Conference on Hadron Spectroscopy and
Structure in memoriam Simon Eidelman (HADRON2021), version accepted for
publication in Rev. Mex. Phys
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present exploratory studies of the proton content via unpolarized and
polarized transverse-momentum-dependent gluon distributions in the proton at
leading twist. We make use of an enhanced spectator-model approach to encode in
our densities both small- and moderate-$x$ effects. These studies are relevant
to the investigation of the inner structure of hadrons via tomographic analyses
at new-generation colliding machines.
|
[
{
"created": "Wed, 15 Jun 2022 20:52:53 GMT",
"version": "v1"
}
] |
2022-06-17
|
[
[
"Bacchetta",
"Alessandro",
""
],
[
"Celiberto",
"Francesco Giovanni",
""
],
[
"Radici",
"Marco",
""
]
] |
We present exploratory studies of the proton content via unpolarized and polarized transverse-momentum-dependent gluon distributions in the proton at leading twist. We make use of an enhanced spectator-model approach to encode in our densities both small- and moderate-$x$ effects. These studies are relevant to the investigation of the inner structure of hadrons via tomographic analyses at new-generation colliding machines.
|
2012.05135
|
Alexey Vladimirov
|
Marcin Bury, Alexei Prokudin, Alexey Vladimirov
|
N$^3$LO extraction of the Sivers function from SIDIS, Drell-Yan, and
$W^\pm/Z$ data
|
6 pages, 3 figures
|
Phys. Rev. Lett. 126, 112002 (2021)
|
10.1103/PhysRevLett.126.112002
|
JLAB-THY-20-3296
|
hep-ph hep-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We perform the global analysis of polarized Semi-Inclusive Deep Inelastic
Scattering (SIDIS), pion-induced polarized Drell-Yan (DY), and $W^\pm/Z$ boson
production data and extract the Sivers function for $u$, $d$, $s$ and for
sea-quarks. We use the framework of transverse momentum dependent factorization
at N$^3$LO accuracy. The Qiu-Sterman function is determined in a
model-independent way from the extracted Sivers function. We also evaluate the
significance of the predicted sign change of Sivers function in DY with respect
to SIDIS.
|
[
{
"created": "Wed, 9 Dec 2020 16:14:31 GMT",
"version": "v1"
}
] |
2021-03-24
|
[
[
"Bury",
"Marcin",
""
],
[
"Prokudin",
"Alexei",
""
],
[
"Vladimirov",
"Alexey",
""
]
] |
We perform the global analysis of polarized Semi-Inclusive Deep Inelastic Scattering (SIDIS), pion-induced polarized Drell-Yan (DY), and $W^\pm/Z$ boson production data and extract the Sivers function for $u$, $d$, $s$ and for sea-quarks. We use the framework of transverse momentum dependent factorization at N$^3$LO accuracy. The Qiu-Sterman function is determined in a model-independent way from the extracted Sivers function. We also evaluate the significance of the predicted sign change of Sivers function in DY with respect to SIDIS.
|
1801.08259
|
Saeed Kamali
|
Saeed Kamali, Ahmed Rashed, Alakabha Datta
|
New physics in inclusive $B \to X_c\ell \bar{\nu}$ decay in light of
$R(D^{(*)})$ measurements
|
29 pages, 59 figures
|
Phys. Rev. D 97, 095034 (2018)
|
10.1103/PhysRevD.97.095034
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this work we study the effects of new-physics (NP) operators with
different Lorentz structures on the inclusive $B \to X_c\tau \bar{\nu}$ decay
and make predictions for the ratio of total decay rates $R(X_c)=\frac{\Gamma(B
\to X_c\tau \bar{\nu}_\tau)}{\Gamma(B \to X_c \ell \bar{\nu}_\ell)}$ with
$\ell=e, \mu$, the differential decay rates, $\frac{d\Gamma}{dq^2}$ and
$\frac{d\Gamma}{dE_\tau}$, forward-backward asymmetry $A_{FB}$ and the ratio of
the differential decay rates $B(q^2)=\frac{d\Gamma(B \to X_c\tau
\bar{\nu}_\tau)/dq^2}{d\Gamma(B \to X_c \ell \bar{\nu}_\ell)/dq^2}$. In
addition, we introduce some leptoquark models as explicit models of the NP
operators and study their effects on the inclusive decay. We consider
$\mathcal{O}(\alpha_s)$ radiative and $1/m_b$ nonperturbative corrections to
the Standard Model (SM) decay rate and ignore their small effects in the NP
contributions.
|
[
{
"created": "Thu, 25 Jan 2018 02:49:00 GMT",
"version": "v1"
},
{
"created": "Sat, 3 Feb 2018 20:22:04 GMT",
"version": "v2"
},
{
"created": "Fri, 18 May 2018 02:05:02 GMT",
"version": "v3"
}
] |
2018-05-31
|
[
[
"Kamali",
"Saeed",
""
],
[
"Rashed",
"Ahmed",
""
],
[
"Datta",
"Alakabha",
""
]
] |
In this work we study the effects of new-physics (NP) operators with different Lorentz structures on the inclusive $B \to X_c\tau \bar{\nu}$ decay and make predictions for the ratio of total decay rates $R(X_c)=\frac{\Gamma(B \to X_c\tau \bar{\nu}_\tau)}{\Gamma(B \to X_c \ell \bar{\nu}_\ell)}$ with $\ell=e, \mu$, the differential decay rates, $\frac{d\Gamma}{dq^2}$ and $\frac{d\Gamma}{dE_\tau}$, forward-backward asymmetry $A_{FB}$ and the ratio of the differential decay rates $B(q^2)=\frac{d\Gamma(B \to X_c\tau \bar{\nu}_\tau)/dq^2}{d\Gamma(B \to X_c \ell \bar{\nu}_\ell)/dq^2}$. In addition, we introduce some leptoquark models as explicit models of the NP operators and study their effects on the inclusive decay. We consider $\mathcal{O}(\alpha_s)$ radiative and $1/m_b$ nonperturbative corrections to the Standard Model (SM) decay rate and ignore their small effects in the NP contributions.
|
hep-ph/9606268
| null |
Stefano Moretti (Cavendish Laboratory, Cambridge, UK)
|
Higgs signals and hard photons via $WW$-fusion in the Standard Model at
the Next Linear Collider
|
27 pages, LaTeX, 10 PostScript figures embedded using epsfig, 8
figures bitmapped at 100dpi, complete paper with higher resolution figures
available at ftp://axpa.hep.phy.cam.ac.uk/moretti/cavendish_9607 or at
http://www.hep.phy.cam.ac.uk/theory/papers/
|
J.Phys.G22:1611-1632,1996
|
10.1088/0954-3899/22/11/009
|
Cavendish-HEP-96/07, DFTT 26/96, May 1996
|
hep-ph
| null |
Within the framework of the Standard Model, integrated and differential
distributions are given for Higgs production via the $WW$-fusion mechanism and
decay via the channels $H\ar b\bar b$ and $H\ar WW\ar {jjjj}$, with and without
photon radiation, at Next Linear Collider energies. Calculations are carried
out at tree-level and rates of the leading processes $e^+e^-\ar\bar\nu_e\nu_e H
\ar \bar\nu_e\nu_e b\bar b $ and $e^+e^-\ar\bar\nu_e\nu_e H \ar \bar\nu_e\nu_e
WW \ar \bar\nu_e\nu_e {jjjj}$ are compared to those of the next-to-leading
reactions $e^+e^-\ar\bar\nu_e\nu_e H (\gamma)\ar \bar\nu_e\nu_e b\bar b \gamma$
and $e^+e^-\ar\bar\nu_e\nu_e H (\gamma)\ar \bar\nu_e\nu_e WW (\gamma) \ar
\bar\nu_e\nu_e {jjjj}\gamma$, in the case of hard and detectable photons.
Finally, a brief discussion concerning the case of $H\ar ZZ\ar{jjjj} (\gamma)$
decays is also given.
|
[
{
"created": "Fri, 7 Jun 1996 16:24:37 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Moretti",
"Stefano",
"",
"Cavendish Laboratory, Cambridge, UK"
]
] |
Within the framework of the Standard Model, integrated and differential distributions are given for Higgs production via the $WW$-fusion mechanism and decay via the channels $H\ar b\bar b$ and $H\ar WW\ar {jjjj}$, with and without photon radiation, at Next Linear Collider energies. Calculations are carried out at tree-level and rates of the leading processes $e^+e^-\ar\bar\nu_e\nu_e H \ar \bar\nu_e\nu_e b\bar b $ and $e^+e^-\ar\bar\nu_e\nu_e H \ar \bar\nu_e\nu_e WW \ar \bar\nu_e\nu_e {jjjj}$ are compared to those of the next-to-leading reactions $e^+e^-\ar\bar\nu_e\nu_e H (\gamma)\ar \bar\nu_e\nu_e b\bar b \gamma$ and $e^+e^-\ar\bar\nu_e\nu_e H (\gamma)\ar \bar\nu_e\nu_e WW (\gamma) \ar \bar\nu_e\nu_e {jjjj}\gamma$, in the case of hard and detectable photons. Finally, a brief discussion concerning the case of $H\ar ZZ\ar{jjjj} (\gamma)$ decays is also given.
|
0912.5210
|
Juan Carlos G \'omez Izquierdo
|
Juan Carlos G\'omez-Izquierdo and Abdel P\'erez-Lorenzana
|
Left-right symmetric model with $\mu\leftrightarrow\tau$ symmetry
|
9 pages, 4 figures. Title changed and we have added one new section:
CP phase contribution. Minor corrections and references updated. Published
version
|
Phys.Rev.D82:033008,2010
|
10.1103/PhysRevD.82.033008
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We analyze the leptonic sector in the left-right symmetric model dressed with
a $(Z_{2})^{3}$ discrete symmetry which realizes, after weak spontaneous
breaking, a small broken $\mu\lra\tau$ symmetry that is suggested to explain
observable neutrino oscillation data. $\mu\lra\tau$ symmetry is broken at tree
level in the effective neutrino mass matrix due to the mass difference
$\widetilde{m}_{\tau}\neq \widetilde{m}_{\mu}$ in the diagonal Dirac mass
terms, whereas all lepton mixings arise from a Majorana mass matrix. In the
limit of a small breaking we determined $\theta_{13}$, and the deviation from
the maximal value of $\theta_{ATM}$, in terms of the light neutrino hierarchy
scale, $m_{3}$, and a single free parameter $h_{s}$ of the model.
|
[
{
"created": "Mon, 28 Dec 2009 19:37:54 GMT",
"version": "v1"
},
{
"created": "Tue, 5 Jan 2010 20:10:37 GMT",
"version": "v2"
},
{
"created": "Wed, 11 Aug 2010 19:12:25 GMT",
"version": "v3"
}
] |
2014-11-20
|
[
[
"Gómez-Izquierdo",
"Juan Carlos",
""
],
[
"Pérez-Lorenzana",
"Abdel",
""
]
] |
We analyze the leptonic sector in the left-right symmetric model dressed with a $(Z_{2})^{3}$ discrete symmetry which realizes, after weak spontaneous breaking, a small broken $\mu\lra\tau$ symmetry that is suggested to explain observable neutrino oscillation data. $\mu\lra\tau$ symmetry is broken at tree level in the effective neutrino mass matrix due to the mass difference $\widetilde{m}_{\tau}\neq \widetilde{m}_{\mu}$ in the diagonal Dirac mass terms, whereas all lepton mixings arise from a Majorana mass matrix. In the limit of a small breaking we determined $\theta_{13}$, and the deviation from the maximal value of $\theta_{ATM}$, in terms of the light neutrino hierarchy scale, $m_{3}$, and a single free parameter $h_{s}$ of the model.
|
1410.1742
|
Fernando Martinez-Vidal
|
J. Bernabeu and F. Martinez-Vidal
|
Colloquium: Time-reversal violation with quantum-entangled B mesons
|
20 pages, 18 figures, submitted to Reviews of Modern Physics
Colloquia
| null |
10.1103/RevModPhys.87.165
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Symmetry transformations have been proven a bedrock tool for understanding
the nature of particle interactions, formulating and testing fundamental
theories. Based on the up to now unbroken CPT symmetry, the violation of the CP
symmetry between matter and antimatter by weak interactions, discovered in the
decay of kaons in 1964 and observed more recently in 2001 in B mesons, strongly
suggests that the behavior of these particles under weak interactions must also
be asymmetric under time reversal T. However, until the recent years there has
not been a direct detection of the expected time-reversal violation in the time
evolution of any system. This Colloquium examines the field of time-reversal
symmetry breaking in the fundamental laws of physics. For transitions, its
observation requires an asymmetry with exchange of initial and final states. We
discuss the conceptual basis for such an exchange with unstable particles,
using the quantum properties of Einstein Podolsky-Rosen (EPR) entanglement
available at B meson factories combined with the decay as a filtering
measurement. The method allows a clear-cut separation of different transitions
between flavor and CP eigenstates in the decay of neutral B mesons. These ideas
have been implemented for the experiment by the BaBar Collaboration at SLAC's B
factory. The results, presented in 2012, prove beyond any doubt the violation
of time-reversal invariance in the time evolution between these two states of
the neutral B meson.
|
[
{
"created": "Tue, 7 Oct 2014 14:33:16 GMT",
"version": "v1"
}
] |
2015-06-23
|
[
[
"Bernabeu",
"J.",
""
],
[
"Martinez-Vidal",
"F.",
""
]
] |
Symmetry transformations have been proven a bedrock tool for understanding the nature of particle interactions, formulating and testing fundamental theories. Based on the up to now unbroken CPT symmetry, the violation of the CP symmetry between matter and antimatter by weak interactions, discovered in the decay of kaons in 1964 and observed more recently in 2001 in B mesons, strongly suggests that the behavior of these particles under weak interactions must also be asymmetric under time reversal T. However, until the recent years there has not been a direct detection of the expected time-reversal violation in the time evolution of any system. This Colloquium examines the field of time-reversal symmetry breaking in the fundamental laws of physics. For transitions, its observation requires an asymmetry with exchange of initial and final states. We discuss the conceptual basis for such an exchange with unstable particles, using the quantum properties of Einstein Podolsky-Rosen (EPR) entanglement available at B meson factories combined with the decay as a filtering measurement. The method allows a clear-cut separation of different transitions between flavor and CP eigenstates in the decay of neutral B mesons. These ideas have been implemented for the experiment by the BaBar Collaboration at SLAC's B factory. The results, presented in 2012, prove beyond any doubt the violation of time-reversal invariance in the time evolution between these two states of the neutral B meson.
|
hep-ph/0209170
|
Ernest Ma
|
Ernest Ma (UC Riverside)
|
Theoretical Expectations for Rare and Forbidden Tau Decays
|
Talk at TAU 02 (Santa Cruz, CA)
|
eConf C0209101 (2002) WE01
|
10.1016/S0920-5632(03)80316-X
|
UCRHEP-T346 (September 2002)
|
hep-ph
| null |
Given the experimental evidence for $\nu_\mu - \nu_\tau$ oscillations, the
existence of lepton flavor violation in $\tau$ decays is a theoretical
certainty. In this brief review, I consider the connection between models of
neutrino mass and the expected observability of some $\tau$ decays.
|
[
{
"created": "Mon, 16 Sep 2002 15:16:39 GMT",
"version": "v1"
},
{
"created": "Wed, 25 Sep 2002 15:44:51 GMT",
"version": "v2"
}
] |
2009-11-07
|
[
[
"Ma",
"Ernest",
"",
"UC Riverside"
]
] |
Given the experimental evidence for $\nu_\mu - \nu_\tau$ oscillations, the existence of lepton flavor violation in $\tau$ decays is a theoretical certainty. In this brief review, I consider the connection between models of neutrino mass and the expected observability of some $\tau$ decays.
|
hep-ph/9709410
|
Peter Suranyi
|
P. Suranyi (University of Cincinnati)
|
Solution of gauge theories induced by fundamental representation scalars
|
12 pages, LaTeX
|
Phys. Rev. D 57, 5084 (1998)
|
10.1103/PhysRevD.57.5084
|
UCTP 105/97
|
hep-ph
| null |
Gauge theories induced by scalars in the fundamental representation of the
$U(N_c)_{gauge}\times U(N_f)_{global}$ group are investigated in the large
$N_c$ and $N_f$ limit. A master field is defined from bilinears of the scalar
field following an Eguchi-Kawai type reduction of spacetime. The density
function for the master field satisfies an integral equation that can be solved
exactly in two dimensions (D=2) and in a convergent series of approximations at
$D>2$. While at D=2 the system is in the same phase at all $\epsilon=N_c/N_f$,
it undergoes a phase transition at a critical value, $\epsilon_c(D)$, for
$D>2$.
|
[
{
"created": "Fri, 19 Sep 1997 18:07:46 GMT",
"version": "v1"
}
] |
2016-08-25
|
[
[
"Suranyi",
"P.",
"",
"University of Cincinnati"
]
] |
Gauge theories induced by scalars in the fundamental representation of the $U(N_c)_{gauge}\times U(N_f)_{global}$ group are investigated in the large $N_c$ and $N_f$ limit. A master field is defined from bilinears of the scalar field following an Eguchi-Kawai type reduction of spacetime. The density function for the master field satisfies an integral equation that can be solved exactly in two dimensions (D=2) and in a convergent series of approximations at $D>2$. While at D=2 the system is in the same phase at all $\epsilon=N_c/N_f$, it undergoes a phase transition at a critical value, $\epsilon_c(D)$, for $D>2$.
|
1407.3331
|
Tirthabir Biswas
|
Tirthabir Biswas and Nobuchika Okada
|
Towards LHC Physics with Non-local Standard Model
|
Changes made to be consistent with the journal version
|
Nucl.Phys. B898 (2015) 113-131
|
10.1016/j.nuclphysb.2015.06.023
| null |
hep-ph gr-qc hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We take a few steps towards constructing a string-inspired nonlocal extension
of the Standard Model. We start by illustrating how quantum loop calculations
can be performed in nonlocal scalar field theory. In particular, we show the
potential to address the hierarchy problem in the nonlocal framework. Next, we
construct a nonlocal abelian gauge model and derive modifications of the gauge
interaction vertex and field propagators. We apply the modifications to a toy
version of the nonlocal Standard Model and investigate collider phenomenology.
We find the lower bound on the scale of non-locality from the 8 TeV LHC data to
be $2.5-3$ TeV.
|
[
{
"created": "Sat, 12 Jul 2014 01:12:07 GMT",
"version": "v1"
},
{
"created": "Thu, 24 Jul 2014 14:23:02 GMT",
"version": "v2"
},
{
"created": "Thu, 10 Sep 2015 19:49:02 GMT",
"version": "v3"
}
] |
2015-12-09
|
[
[
"Biswas",
"Tirthabir",
""
],
[
"Okada",
"Nobuchika",
""
]
] |
We take a few steps towards constructing a string-inspired nonlocal extension of the Standard Model. We start by illustrating how quantum loop calculations can be performed in nonlocal scalar field theory. In particular, we show the potential to address the hierarchy problem in the nonlocal framework. Next, we construct a nonlocal abelian gauge model and derive modifications of the gauge interaction vertex and field propagators. We apply the modifications to a toy version of the nonlocal Standard Model and investigate collider phenomenology. We find the lower bound on the scale of non-locality from the 8 TeV LHC data to be $2.5-3$ TeV.
|
hep-ph/9601343
| null |
F. Buccella, M. Lusignoli and A. Pugliese
|
Charm nonleptonic decays and final state interactions
|
14 pages, no figures, plain TeX, uses harvmac.tex and tables.tex
|
Phys.Lett.B379:249-256,1996
|
10.1016/0370-2693(96)00460-1
|
ROMA1 Preprint n. 1130/96, NAPOLI DSF-T-2/96
|
hep-ph
| null |
A global previous analysis of two-body nonleptonic decays of $D$ mesons has
been extended to the decays involving light scalar mesons. The allowance for
final state interaction also in nonresonant channels provides a fit of much
improved quality and with less symmetry breaking in the axial charges. We give
predictions for about 50 decay branching ratios yet to be measured. We also
discuss long distance contributions to the difference $\Delta \Gamma$ between
the $D_S$ and $D_L$ widths.
|
[
{
"created": "Fri, 26 Jan 1996 12:37:49 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Buccella",
"F.",
""
],
[
"Lusignoli",
"M.",
""
],
[
"Pugliese",
"A.",
""
]
] |
A global previous analysis of two-body nonleptonic decays of $D$ mesons has been extended to the decays involving light scalar mesons. The allowance for final state interaction also in nonresonant channels provides a fit of much improved quality and with less symmetry breaking in the axial charges. We give predictions for about 50 decay branching ratios yet to be measured. We also discuss long distance contributions to the difference $\Delta \Gamma$ between the $D_S$ and $D_L$ widths.
|
hep-ph/0001134
|
Martin Beneke
|
M. Beneke (CERN, Aachen)
|
Applications of QCD
|
latex, 26 pages
|
Int.J.Mod.Phys. A15S1 (2000) 632-656; eConf C990809 (2000) 632-656
|
10.1142/S0217751X00005358
|
CERN-TH/99-414
|
hep-ph
| null |
Talk given at XIXth International Symposium on Lepton and Photon Interactions
at High Energies (LP 99), Stanford, California, 9-14 August 1999.
|
[
{
"created": "Fri, 14 Jan 2000 17:47:52 GMT",
"version": "v1"
}
] |
2009-10-31
|
[
[
"Beneke",
"M.",
"",
"CERN, Aachen"
]
] |
Talk given at XIXth International Symposium on Lepton and Photon Interactions at High Energies (LP 99), Stanford, California, 9-14 August 1999.
|
hep-ph/0201062
|
Francesco Paccanoni
|
F. Paccanoni
|
Pomeron exchange and t-dependence of the scattering amplitude
|
21 pages, 1 figure
|
Eur.Phys.J.direct C4:17,2002
| null |
DFPD 02/TH/1
|
hep-ph
| null |
Constraints on the t-dependence of the hadronic scattering amplitude at
asymptotic energies are derived by considering the exchange of the Pomeron, as
a Regge pole, between off-shell gluons. Covariant reggeization ensures pure
spin alpha exchange, where alpha is the Regge trajectory of the Pomeron. The
structure of the amplitude, as a function of t, has been derived without a
specific choice for the partonic wave functions of the hadrons. New terms
appear, with respect to the standard approach, and allow to describe non
trivial properties of the diffraction cone in agreement with experimental data,
as shown in a specific example.
|
[
{
"created": "Wed, 9 Jan 2002 11:07:36 GMT",
"version": "v1"
}
] |
2011-03-23
|
[
[
"Paccanoni",
"F.",
""
]
] |
Constraints on the t-dependence of the hadronic scattering amplitude at asymptotic energies are derived by considering the exchange of the Pomeron, as a Regge pole, between off-shell gluons. Covariant reggeization ensures pure spin alpha exchange, where alpha is the Regge trajectory of the Pomeron. The structure of the amplitude, as a function of t, has been derived without a specific choice for the partonic wave functions of the hadrons. New terms appear, with respect to the standard approach, and allow to describe non trivial properties of the diffraction cone in agreement with experimental data, as shown in a specific example.
|
1308.0598
|
Stefano Forte
|
The NNPDF Collaboration: Richard D. Ball, Valerio Bertone, Stefano
Carrazza, Luigi Del Debbio, Stefano Forte, Alberto Guffanti, Nathan P.
Hartland, Juan Rojo
|
Parton distributions with QED corrections
|
38 pages, 27 figures. Final version, to be published in Nucl. Phys.
B. Several corrections and improvements, in particular Fig.5 added, Fig.2,
Fig. 6 and Fig.8 improved, Fig.21 corrected
| null |
10.1016/j.nuclphysb.2013.10.010
|
Edinburgh 2013/20, IFUM-1014-FT, FR-PHENO-2013-008,
CERN-PH-TH/2013-075
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present a set of parton distribution functions (PDFs), based on the
NNPDF2.3 set, which includes a photon PDF, and QED contributions to parton
evolution. We describe the implementation of the combined QCD+QED evolution in
the NNPDF framework. We then provide a first determination of the full set of
PDFs based on deep-inelastic scattering data and LHC data for W and Z/gamma*
Drell-Yan production, using leading-order QED and NLO or NNLO QCD. We compare
the ensuing NNPDF2.3QED PDF set to the older MRST2004QED set. We perform a
preliminary investigation of the phenomenological implications of NNPDF2.3QED:
specifically, photon-induced corrections to direct photon production at HERA,
and high-mass dilepton and W pair production at the LHC.
|
[
{
"created": "Fri, 2 Aug 2013 20:00:02 GMT",
"version": "v1"
},
{
"created": "Mon, 4 Nov 2013 17:06:33 GMT",
"version": "v2"
}
] |
2021-01-13
|
[
[
"The NNPDF Collaboration",
"",
""
],
[
"Ball",
"Richard D.",
""
],
[
"Bertone",
"Valerio",
""
],
[
"Carrazza",
"Stefano",
""
],
[
"Del Debbio",
"Luigi",
""
],
[
"Forte",
"Stefano",
""
],
[
"Guffanti",
"Alberto",
""
],
[
"Hartland",
"Nathan P.",
""
],
[
"Rojo",
"Juan",
""
]
] |
We present a set of parton distribution functions (PDFs), based on the NNPDF2.3 set, which includes a photon PDF, and QED contributions to parton evolution. We describe the implementation of the combined QCD+QED evolution in the NNPDF framework. We then provide a first determination of the full set of PDFs based on deep-inelastic scattering data and LHC data for W and Z/gamma* Drell-Yan production, using leading-order QED and NLO or NNLO QCD. We compare the ensuing NNPDF2.3QED PDF set to the older MRST2004QED set. We perform a preliminary investigation of the phenomenological implications of NNPDF2.3QED: specifically, photon-induced corrections to direct photon production at HERA, and high-mass dilepton and W pair production at the LHC.
|
2002.03759
|
Robin Ekman
|
Robin Ekman, Anton Ilderton
|
Back-reaction in strong field QED: a toy model
|
9 pages, 6 figures. v2: typo corrected
|
Phys. Rev. D 101, 056022 (2020)
|
10.1103/PhysRevD.101.056022
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
As a toy model for QED in strong background fields, we consider the impact of
back-reaction and loop effects on scattering processes in quantum optics. We
show that neglecting back-reaction misses qualitative and quantitative features
of strong-field physics. We are able to study an analogue of the Narozhny-Ritus
conjecture on the scaling of higher loop diagrams with intensity: we prove that
there is no corresponding behaviour in our model. Implications for QED are
identified and discussed.
|
[
{
"created": "Mon, 10 Feb 2020 14:07:57 GMT",
"version": "v1"
},
{
"created": "Thu, 13 Feb 2020 14:16:53 GMT",
"version": "v2"
}
] |
2020-04-08
|
[
[
"Ekman",
"Robin",
""
],
[
"Ilderton",
"Anton",
""
]
] |
As a toy model for QED in strong background fields, we consider the impact of back-reaction and loop effects on scattering processes in quantum optics. We show that neglecting back-reaction misses qualitative and quantitative features of strong-field physics. We are able to study an analogue of the Narozhny-Ritus conjecture on the scaling of higher loop diagrams with intensity: we prove that there is no corresponding behaviour in our model. Implications for QED are identified and discussed.
|
hep-ph/0601198
|
Stephen Parke
|
Hiroshi Nunokawa, Stephen Parke and Renata Zukanovich Funchal
|
What Fraction of Boron-8 Solar Neutrinos arrive at the Earth as a nu_2
mass eigenstate?
|
23 pages, 8 postscript figures, latex. Dedicated to the memory of
John Bahcall who championed solar neutrinos for many lonely years
|
Phys.Rev.D74:013006,2006
|
10.1103/PhysRevD.74.013006
|
Fermilab-Pub-05-049-T
|
hep-ph astro-ph hep-ex nucl-ex
| null |
We calculate the fraction of B^8 solar neutrinos that arrive at the Earth as
a nu_2 mass eigenstate as a function of the neutrino energy. Weighting this
fraction with the B^8 neutrino energy spectrum and the energy dependence of the
cross section for the charged current interaction on deuteron with a threshold
on the kinetic energy of the recoil electrons of 5.5 MeV, we find that the
integrated weighted fraction of nu_2's to be 91 \pm 2 % at the 95% CL. This
energy weighting procedure corresponds to the charged current response of the
Sudbury Neutrino Observatory (SNO). We have used SNO's current best fit values
for the solar mass squared difference and the mixing angle, obtained by
combining the data from all solar neutrino experiments and the reactor data
from KamLAND. The uncertainty on the nu_2 fraction comes primarily from the
uncertainty on the solar delta m^2 rather than from the uncertainty on the
solar mixing angle or the Standard Solar Model. Similar results for the
Super-Kamiokande experiment are also given. We extend this analysis to three
neutrinos and discuss how to extract the modulus of the Maki-Nakagawa-Sakata
mixing matrix element U_{e2} as well as place a lower bound on the electron
number density in the solar B^8 neutrino production region.
|
[
{
"created": "Tue, 24 Jan 2006 19:35:15 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Nunokawa",
"Hiroshi",
""
],
[
"Parke",
"Stephen",
""
],
[
"Funchal",
"Renata Zukanovich",
""
]
] |
We calculate the fraction of B^8 solar neutrinos that arrive at the Earth as a nu_2 mass eigenstate as a function of the neutrino energy. Weighting this fraction with the B^8 neutrino energy spectrum and the energy dependence of the cross section for the charged current interaction on deuteron with a threshold on the kinetic energy of the recoil electrons of 5.5 MeV, we find that the integrated weighted fraction of nu_2's to be 91 \pm 2 % at the 95% CL. This energy weighting procedure corresponds to the charged current response of the Sudbury Neutrino Observatory (SNO). We have used SNO's current best fit values for the solar mass squared difference and the mixing angle, obtained by combining the data from all solar neutrino experiments and the reactor data from KamLAND. The uncertainty on the nu_2 fraction comes primarily from the uncertainty on the solar delta m^2 rather than from the uncertainty on the solar mixing angle or the Standard Solar Model. Similar results for the Super-Kamiokande experiment are also given. We extend this analysis to three neutrinos and discuss how to extract the modulus of the Maki-Nakagawa-Sakata mixing matrix element U_{e2} as well as place a lower bound on the electron number density in the solar B^8 neutrino production region.
|
1811.11048
|
Charanjit Khosa
|
Genevieve Belanger, Rohini M. Godbole, Charanjit K. Khosa and Saurabh
D. Rindani
|
Probing CP nature of a mediator in associated production of dark matter
with single top quark
|
5 pages, 5 figures, proceedings for the 11^\mathrm{th}$ International
Workshop on Top Quark Physics, Bad Neuenahr, Germany, September 16--21, 2018
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider associated production of dark matter with single top quark, in a
simplified dark matter model with spin-0 mediators. The produced top quark is
polarized and the polarization depends on the CP of the mediator. We calculate
both the cross-section and top polarization for these processes. We compute
angular asymmetries which demonstrate the difference between the polarization
expected for the scalar or pseudoscalar mediator. Both the cross section and
top polarization are sensitive to the CP property of the mediator, depending on
the mediator mass. We find that these polarization asymmetries add value to the
determination of the CP property of the mediator particularly in the case of a
state with indeterminate CP.
|
[
{
"created": "Tue, 27 Nov 2018 15:17:15 GMT",
"version": "v1"
}
] |
2018-11-28
|
[
[
"Belanger",
"Genevieve",
""
],
[
"Godbole",
"Rohini M.",
""
],
[
"Khosa",
"Charanjit K.",
""
],
[
"Rindani",
"Saurabh D.",
""
]
] |
We consider associated production of dark matter with single top quark, in a simplified dark matter model with spin-0 mediators. The produced top quark is polarized and the polarization depends on the CP of the mediator. We calculate both the cross-section and top polarization for these processes. We compute angular asymmetries which demonstrate the difference between the polarization expected for the scalar or pseudoscalar mediator. Both the cross section and top polarization are sensitive to the CP property of the mediator, depending on the mediator mass. We find that these polarization asymmetries add value to the determination of the CP property of the mediator particularly in the case of a state with indeterminate CP.
|
1810.04518
|
D. J. Miller
|
John McDowall, David J Miller
|
High Scale Boundary Conditions in Models with Two Higgs Doublets
|
25 pages, 13 figures (25 plots); v3: version accepted for publication
|
Phys. Rev. D 100, 015018 (2019)
|
10.1103/PhysRevD.100.015018
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We investigate high scale boundary conditions on the quartic Higgs-couplings
and their $\beta$-functions in the Type-II Two Higgs Doublet Model and the
Inert Doublet Model. These conditions are associated with two possible UV
physics scenarios: the Multiple Point Principle, in which the potential
exhibits a second minimum at $M_{Pl}$, and Asymptotic Safety, where the scalar
couplings run towards an interacting UV fixed point at high scales. We employ
renormalisation group running at two-loops and apply theoretical and
experimental constraints to their parameter spaces. We find neither model can
simultaneously accommodate the MPP whilst also providing realistic masses for
both the Higgs and the top quark. However, we do find regions of parameter
space compatible with Asymptotic Safety.
|
[
{
"created": "Wed, 10 Oct 2018 13:27:34 GMT",
"version": "v1"
},
{
"created": "Thu, 25 Oct 2018 14:50:10 GMT",
"version": "v2"
},
{
"created": "Wed, 19 Jun 2019 11:15:37 GMT",
"version": "v3"
}
] |
2019-07-24
|
[
[
"McDowall",
"John",
""
],
[
"Miller",
"David J",
""
]
] |
We investigate high scale boundary conditions on the quartic Higgs-couplings and their $\beta$-functions in the Type-II Two Higgs Doublet Model and the Inert Doublet Model. These conditions are associated with two possible UV physics scenarios: the Multiple Point Principle, in which the potential exhibits a second minimum at $M_{Pl}$, and Asymptotic Safety, where the scalar couplings run towards an interacting UV fixed point at high scales. We employ renormalisation group running at two-loops and apply theoretical and experimental constraints to their parameter spaces. We find neither model can simultaneously accommodate the MPP whilst also providing realistic masses for both the Higgs and the top quark. However, we do find regions of parameter space compatible with Asymptotic Safety.
|
hep-ph/9803396
| null |
M. Napsuciale (U. of Guanajuato, Mexico)
|
Scalar meson masses and mixing angle in a U(3)XU(3) Linear Sigma Model
|
24 pages, 3 figures. Scalar mesons exchange contributions to CHPT LEC
included. New mixing angle and mass relations added. Scalar meson mixing
angle and sigma mass corrected. 1/N counting rules for OZI violating terms
reconsidered. New references added
| null | null |
IFUG-98-01
|
hep-ph
| null |
Meson properties are considered within a U(3)\times U(3) Linear Sigma
Model(LSM). The importance of the U_A(1)-breaking term and the OZI rule
violating term in the generation of meson masses and mixing angles is stressed.
The LSM parameters are fitted to the pseudoscalar meson spectrum thus giving
predictions for scalar meson properties. The model predicts a scalar meson
nonet whose members are: {\sigma(\approx 400), f_0(980), \kappa(\approx 900)
and a_0(980)} resonances. Scalar meson mixing angle (in the {|ns>, |s>} basis)
is predicted to be \phi_S\approx -14^\circ. Therefore the f_0(980) is
predominantly strange while the \sigma(\approx 400) is mostly non-strange. The
model also gives a pseudoscalar mixing angle \phi_P\approx 35^\circ which
corresponds to \theta_P \approx -19^\circ in the singlet-octet basis.
Comparison with chiral perturbation theory shows that L_8 is saturated by
scalar mesons exchange. However, LSM predicts that L_5 is not saturated by
scalar mesons exchange as assumed in the literature.
|
[
{
"created": "Fri, 20 Mar 1998 03:12:39 GMT",
"version": "v1"
},
{
"created": "Wed, 12 Aug 1998 21:36:52 GMT",
"version": "v2"
}
] |
2007-05-23
|
[
[
"Napsuciale",
"M.",
"",
"U. of Guanajuato, Mexico"
]
] |
Meson properties are considered within a U(3)\times U(3) Linear Sigma Model(LSM). The importance of the U_A(1)-breaking term and the OZI rule violating term in the generation of meson masses and mixing angles is stressed. The LSM parameters are fitted to the pseudoscalar meson spectrum thus giving predictions for scalar meson properties. The model predicts a scalar meson nonet whose members are: {\sigma(\approx 400), f_0(980), \kappa(\approx 900) and a_0(980)} resonances. Scalar meson mixing angle (in the {|ns>, |s>} basis) is predicted to be \phi_S\approx -14^\circ. Therefore the f_0(980) is predominantly strange while the \sigma(\approx 400) is mostly non-strange. The model also gives a pseudoscalar mixing angle \phi_P\approx 35^\circ which corresponds to \theta_P \approx -19^\circ in the singlet-octet basis. Comparison with chiral perturbation theory shows that L_8 is saturated by scalar mesons exchange. However, LSM predicts that L_5 is not saturated by scalar mesons exchange as assumed in the literature.
|
hep-ph/9402342
| null |
Andrei L. Kataev and Aleksander V. Sidorov
|
The Jacobi Polinomials QCD Analysis of the CCFR Data for xF_3 and the
Q^2-Dependence of the Gross-Llewllyn Smith Sum Rule
|
LATEX, 14 pages, 2 Figures can be obtained by FAX after the request,
CERN-TH.7160/94 and JINR E2-94-45
|
Phys.Lett. B331 (1994) 179-186
|
10.1016/0370-2693(94)90961-X
| null |
hep-ph
| null |
We present the results of our QCD analysis of the recent CCFR data for the
structure function $xF_3 (x,Q^2)$ of the deep-inelastic neutrino--nucleon
scattering. The analysis is based on the Jacobi polynomials expansion of the
structure functions. The concrete results for the parameter $\Lambda_{\overline
{MS}}^{(4)}$ and the shape of quark distributions are determined. At the
reference scale $|Q_0^2|$=3 $GeV^2$ our results are in satisfactory agreement
with the ones obtained by the CCFR group with the help of another method. The
$Q_0^{2}$-dependence of the experimental data for the Gross--Llewellyn Smith
sum rule is extracted in the wide region of high-momentum transfer. Within
systematical experimental uncertainties the results obtained are consistent
with the perturbative QCD predictions. We reveal the effect of the discrepancy
between our results and the analysed perturbative QCD predictions at the level
of the statistical error bars. The importance of taking account, in our
procedure, of a still unknown next-next-to-leading approximation of the moments
of the structure function $xF_3 (x,Q^2)$ is stressed.
|
[
{
"created": "Wed, 23 Feb 1994 15:34:10 GMT",
"version": "v1"
}
] |
2009-10-28
|
[
[
"Kataev",
"Andrei L.",
""
],
[
"Sidorov",
"Aleksander V.",
""
]
] |
We present the results of our QCD analysis of the recent CCFR data for the structure function $xF_3 (x,Q^2)$ of the deep-inelastic neutrino--nucleon scattering. The analysis is based on the Jacobi polynomials expansion of the structure functions. The concrete results for the parameter $\Lambda_{\overline {MS}}^{(4)}$ and the shape of quark distributions are determined. At the reference scale $|Q_0^2|$=3 $GeV^2$ our results are in satisfactory agreement with the ones obtained by the CCFR group with the help of another method. The $Q_0^{2}$-dependence of the experimental data for the Gross--Llewellyn Smith sum rule is extracted in the wide region of high-momentum transfer. Within systematical experimental uncertainties the results obtained are consistent with the perturbative QCD predictions. We reveal the effect of the discrepancy between our results and the analysed perturbative QCD predictions at the level of the statistical error bars. The importance of taking account, in our procedure, of a still unknown next-next-to-leading approximation of the moments of the structure function $xF_3 (x,Q^2)$ is stressed.
|
hep-ph/0307187
|
Kiyoshi Shiraishi
|
Yoshinori Cho, Nahomi Kan, Kenji Sakamoto and Kiyoshi Shiraishi
(Yamaguchi U.)
|
One-loop finite potential for N-2 scalars from N quantum fields
|
11pages, two eps figures. RevTeX4
| null | null |
Guchi-TP-018
|
hep-ph hep-th math-ph math.MP
| null |
We study the one-loop effective potential induced from quantum fluctuation of
a finite number of fields. A series expansion in terms of the modified Bessel
functions is useful to evaluate the one-loop effective potential. We find that
at most $N-2$ scalars parameterize the one-loop finite potential and the
explicit parameterization is shown. The structure of the potential for N=4 is
investigated as the simplest case. The implication of the model is discussed.
|
[
{
"created": "Tue, 15 Jul 2003 02:47:15 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Cho",
"Yoshinori",
"",
"Yamaguchi U."
],
[
"Kan",
"Nahomi",
"",
"Yamaguchi U."
],
[
"Sakamoto",
"Kenji",
"",
"Yamaguchi U."
],
[
"Shiraishi",
"Kiyoshi",
"",
"Yamaguchi U."
]
] |
We study the one-loop effective potential induced from quantum fluctuation of a finite number of fields. A series expansion in terms of the modified Bessel functions is useful to evaluate the one-loop effective potential. We find that at most $N-2$ scalars parameterize the one-loop finite potential and the explicit parameterization is shown. The structure of the potential for N=4 is investigated as the simplest case. The implication of the model is discussed.
|
0801.0663
|
Sannino Francesco
|
Roshan Foadi and Francesco Sannino (University of Southern Denmark)
|
WW Scattering in Walking Technicolor
|
2 Columns RevTeX, 10 pages, 9 Figures
|
Phys.Rev.D78:037701,2008
|
10.1103/PhysRevD.78.037701
| null |
hep-ph
| null |
We analyze the WW scattering in scenarios of dynamical electroweak symmetry
breaking of walking technicolor type. We show that in these theories there are
regions of the parameters space allowed by the electroweak precision data, in
which unitarity violation is delayed at tree level up to around 3-4 TeV without
the inclusion of any sub-TeV resonances.
|
[
{
"created": "Fri, 4 Jan 2008 13:43:19 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Foadi",
"Roshan",
"",
"University of Southern Denmark"
],
[
"Sannino",
"Francesco",
"",
"University of Southern Denmark"
]
] |
We analyze the WW scattering in scenarios of dynamical electroweak symmetry breaking of walking technicolor type. We show that in these theories there are regions of the parameters space allowed by the electroweak precision data, in which unitarity violation is delayed at tree level up to around 3-4 TeV without the inclusion of any sub-TeV resonances.
|
1209.5650
|
Giulia Ricciardi
|
Giulia Ricciardi
|
Semileptonic B and D decays-latest developments
|
13 pages, no figures. Invited talk at Flavor Physics and CP Violation
(FPCP 2012), USTC, Hefei, China, May 21-25, 2012
|
eConf C120521 (2012) 48
| null | null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Semileptonic B and D decays are on a well deserved podium to extract CKM
matrix elements, to validate theoretical tools and, more recently, even to look
for hints of new physics. Here we review the latest updates.
|
[
{
"created": "Tue, 25 Sep 2012 15:46:20 GMT",
"version": "v1"
},
{
"created": "Wed, 17 Oct 2012 12:43:17 GMT",
"version": "v2"
}
] |
2013-09-19
|
[
[
"Ricciardi",
"Giulia",
""
]
] |
Semileptonic B and D decays are on a well deserved podium to extract CKM matrix elements, to validate theoretical tools and, more recently, even to look for hints of new physics. Here we review the latest updates.
|
hep-ph/9803301
|
Igor Halperin
|
Igor Halperin and Ariel Zhitnitsky (Univ. of British Columbia)
|
Anomalous Effective Lagrangian and Theta Dependence in QCD at Finite N_c
|
Changes in the presentation and discussion, formulas are unchanged.
Latex, 7 pages, no figures
|
Phys.Rev.Lett. 81 (1998) 4071-4074
|
10.1103/PhysRevLett.81.4071
| null |
hep-ph hep-th
| null |
We generalize the large N_c Di Vecchia-Veneziano-Witten (VVW) effective
chiral Lagrangian to the case of finite N_c by constructing the anomalous
effective Lagrangian for QCD. The latter is similar to its SUSY counterpart,
and has a holomorphic structure. The VVW construction is then recovered, along
with 1/N_c corrections, after integrating out the heavy "glueball" fields. A
new mass formula for eta' meson in terms of QCD condensates is obtained. The
picture of theta dependence in QCD for finite N_c is more complicated than the
one predicted by the large N_c approach.
|
[
{
"created": "Wed, 11 Mar 1998 02:58:44 GMT",
"version": "v1"
},
{
"created": "Tue, 9 Jun 1998 00:19:18 GMT",
"version": "v2"
}
] |
2009-10-31
|
[
[
"Halperin",
"Igor",
"",
"Univ. of British Columbia"
],
[
"Zhitnitsky",
"Ariel",
"",
"Univ. of British Columbia"
]
] |
We generalize the large N_c Di Vecchia-Veneziano-Witten (VVW) effective chiral Lagrangian to the case of finite N_c by constructing the anomalous effective Lagrangian for QCD. The latter is similar to its SUSY counterpart, and has a holomorphic structure. The VVW construction is then recovered, along with 1/N_c corrections, after integrating out the heavy "glueball" fields. A new mass formula for eta' meson in terms of QCD condensates is obtained. The picture of theta dependence in QCD for finite N_c is more complicated than the one predicted by the large N_c approach.
|
0908.2020
|
Krzysztof Piotrzkowski
|
J. de Favereau de Jeneret, V. Lemaitre, Y. Liu, S. Ovyn, T.
Pierzchala, K. Piotrzkowski, X. Rouby, N. Schul and M. Vander Donckt
|
High energy photon interactions at the LHC
|
17 pages, 16 tables and 14 figures
| null | null |
CP3-09-37
|
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Experimental prospects for studying high-energy photon-photon and
photon-proton interactions at the CERN Large Hadron Collider (LHC) are
discussed. Cross sections are calculated for many electroweak and beyond the
Standard Model processes. Selection strategies based on photon interaction
tagging techniques are studied. Assuming a typical LHC multipurpose detector,
various signals and their irreducible backgrounds are presented after applying
acceptance cuts. Prospects are discussed for the Higgs boson search, detection
of supersymmetric particles and of anomalous quartic gauge couplings, as well
as for the top quark physics.
|
[
{
"created": "Fri, 14 Aug 2009 09:31:24 GMT",
"version": "v1"
}
] |
2009-08-21
|
[
[
"de Jeneret",
"J. de Favereau",
""
],
[
"Lemaitre",
"V.",
""
],
[
"Liu",
"Y.",
""
],
[
"Ovyn",
"S.",
""
],
[
"Pierzchala",
"T.",
""
],
[
"Piotrzkowski",
"K.",
""
],
[
"Rouby",
"X.",
""
],
[
"Schul",
"N.",
""
],
[
"Donckt",
"M. Vander",
""
]
] |
Experimental prospects for studying high-energy photon-photon and photon-proton interactions at the CERN Large Hadron Collider (LHC) are discussed. Cross sections are calculated for many electroweak and beyond the Standard Model processes. Selection strategies based on photon interaction tagging techniques are studied. Assuming a typical LHC multipurpose detector, various signals and their irreducible backgrounds are presented after applying acceptance cuts. Prospects are discussed for the Higgs boson search, detection of supersymmetric particles and of anomalous quartic gauge couplings, as well as for the top quark physics.
|
1704.05558
|
Romulo Rougemont
|
Romulo Rougemont (IIP, Brazil), Renato Critelli (Sao Paulo U.),
Jacquelyn Noronha-Hostler (Houston U.), Jorge Noronha (Sao Paulo U.), Claudia
Ratti (Houston U.)
|
Dynamical vs. equilibrium properties of the QCD phase transition: a
holographic perspective
|
20 pages, 19 figures, version accepted for publication in Physical
Review D
|
Phys. Rev. D 96, 014032 (2017)
|
10.1103/PhysRevD.96.014032
| null |
hep-ph hep-th nucl-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We employ an Einstein-Maxwell-Dilaton (EMD) holographic model, which is known
to be in good agreement with lattice results for the QCD equation of state with
$(2+1)$ flavors and physical quark masses, to investigate the temperature and
baryon chemical potential dependence of the susceptibilities, conductivities,
and diffusion coefficients associated with baryon, electric, and strangeness
conserved charges. We also determine how the bulk and shear viscosities of the
plasma vary in the plane of temperature and baryon chemical potential. The
diffusion of conserved charges and the hydrodynamic viscosities in a baryon
rich quark-gluon plasma are found to be suppressed with respect to the zero net
baryon case. The transition temperatures associated with equilibrium and
non-equilibrium quantities are determined as a function of the baryon chemical
potential for the first time. Because of the crossover nature of the QCD phase
transition even at moderately large values of the chemical potential, we find
that the transition temperatures associated with different quantities are
spread in the interval between $130-200$ MeV and they all decrease with
increasing baryon chemical potential.
|
[
{
"created": "Tue, 18 Apr 2017 22:47:21 GMT",
"version": "v1"
},
{
"created": "Mon, 17 Jul 2017 17:08:39 GMT",
"version": "v2"
}
] |
2017-08-01
|
[
[
"Rougemont",
"Romulo",
"",
"IIP, Brazil"
],
[
"Critelli",
"Renato",
"",
"Sao Paulo U."
],
[
"Noronha-Hostler",
"Jacquelyn",
"",
"Houston U."
],
[
"Noronha",
"Jorge",
"",
"Sao Paulo U."
],
[
"Ratti",
"Claudia",
"",
"Houston U."
]
] |
We employ an Einstein-Maxwell-Dilaton (EMD) holographic model, which is known to be in good agreement with lattice results for the QCD equation of state with $(2+1)$ flavors and physical quark masses, to investigate the temperature and baryon chemical potential dependence of the susceptibilities, conductivities, and diffusion coefficients associated with baryon, electric, and strangeness conserved charges. We also determine how the bulk and shear viscosities of the plasma vary in the plane of temperature and baryon chemical potential. The diffusion of conserved charges and the hydrodynamic viscosities in a baryon rich quark-gluon plasma are found to be suppressed with respect to the zero net baryon case. The transition temperatures associated with equilibrium and non-equilibrium quantities are determined as a function of the baryon chemical potential for the first time. Because of the crossover nature of the QCD phase transition even at moderately large values of the chemical potential, we find that the transition temperatures associated with different quantities are spread in the interval between $130-200$ MeV and they all decrease with increasing baryon chemical potential.
|
hep-ph/0612060
|
Koichi Hamaguchi
|
Koichi Hamaguchi, Mihoko M. Nojiri, and Albert de Roeck
|
Prospects to study a long-lived charged next lightest supersymmetric
particle at the LHC
|
39 pages, 23 figures
|
JHEP 0703:046,2007
|
10.1088/1126-6708/2007/03/046
|
UT-06-23, KEK-TH-1119
|
hep-ph
| null |
If the scalar tau $\stau$ is the next lightest supersymmetric particle and
decays into a gravitino ($\gravitino$) being the lightest supersymmetric
particle, it will have generally a very long lifetime. In this paper, we
investigate the possibility to study the decay of such a long lived scalar tau
at the LHC. If we can add to the present LHC experiments additional detectors
which are able to stop the stau particles and measure the produced decay
products, the decay characteristics can be studied precisely at the LHC. We
identify a maximum "stopper detector" that could be added in the CMS cavern,
and estimate the sensitivity to the lifetime of the stau and to the mass of
gravitino with this detector. The decay of the scalar tau may be significantly
modified if the decay channel to the axino $\axino$ is open. We study the
possibility to distinguish such decays from decays into gravitinos by measuring
the process $\stau\to \axino (\gravitino) \tau \gamma$ using the stopper
detector.
|
[
{
"created": "Wed, 6 Dec 2006 08:28:36 GMT",
"version": "v1"
}
] |
2010-10-27
|
[
[
"Hamaguchi",
"Koichi",
""
],
[
"Nojiri",
"Mihoko M.",
""
],
[
"de Roeck",
"Albert",
""
]
] |
If the scalar tau $\stau$ is the next lightest supersymmetric particle and decays into a gravitino ($\gravitino$) being the lightest supersymmetric particle, it will have generally a very long lifetime. In this paper, we investigate the possibility to study the decay of such a long lived scalar tau at the LHC. If we can add to the present LHC experiments additional detectors which are able to stop the stau particles and measure the produced decay products, the decay characteristics can be studied precisely at the LHC. We identify a maximum "stopper detector" that could be added in the CMS cavern, and estimate the sensitivity to the lifetime of the stau and to the mass of gravitino with this detector. The decay of the scalar tau may be significantly modified if the decay channel to the axino $\axino$ is open. We study the possibility to distinguish such decays from decays into gravitinos by measuring the process $\stau\to \axino (\gravitino) \tau \gamma$ using the stopper detector.
|
1504.01260
|
Xing-Gang Wu
|
Hong-Hao Ma, Xing-Gang Wu, Yang Ma, Stanley J. Brodsky and Matin
Mojaza
|
Setting the Renormalization Scale in pQCD: Comparisons of the Principle
of Maximum Conformality with the Sequential Extended Brodsky-Lepage-Mackenzie
Approach
|
16 pages, 2 figures
|
Phys. Rev. D 91, 094028 (2015)
|
10.1103/PhysRevD.91.094028
|
SLAC-PUB-16236, NORDITA-2015-39
|
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
A key problem in making precise perturbative QCD (pQCD) predictions is how to
set the renormalization scale of the running coupling unambiguously at each
finite order. The elimination of the uncertainty in setting the renormalization
scale in pQCD will greatly increase the precision of collider tests of the
Standard Model and the sensitivity to new phenomena. Renormalization group
invariance requires that predictions for observables must also be independent
on the choice of the renormalization scheme. The well-known
Brodsky-Lepage-Mackenzie (BLM) approach cannot be easily extended beyond
next-to-next-to-leading order of pQCD. Several suggestions have been proposed
to extend the BLM approach to all-orders. In this paper we discuss two distinct
methods. One is based on the "Principle of Maximum Conformality" (PMC), which
provides a systematic all-orders method to eliminate the scale- and scheme-
ambiguities of pQCD. The PMC extends the BLM procedure to all orders using
renormalization group methods; as an outcome, it significantly improves the
pQCD convergence by eliminating renormalon divergences. An alternative method
is the "sequential extended BLM" (seBLM) approach, which has been primarily
designed to improve the convergence of pQCD series. The seBLM, as originally
proposed, introduces auxiliary fields and follows the pattern of the
$\beta_0$-expansion to fix the renormalization scale. However, the seBLM
requires a recomputation of pQCD amplitudes including the auxiliary fields; due
to the limited availability of calculations using these auxiliary fields, the
seBLM has only been applied to a few processes at low-orders......
|
[
{
"created": "Mon, 6 Apr 2015 10:59:13 GMT",
"version": "v1"
}
] |
2015-06-03
|
[
[
"Ma",
"Hong-Hao",
""
],
[
"Wu",
"Xing-Gang",
""
],
[
"Ma",
"Yang",
""
],
[
"Brodsky",
"Stanley J.",
""
],
[
"Mojaza",
"Matin",
""
]
] |
A key problem in making precise perturbative QCD (pQCD) predictions is how to set the renormalization scale of the running coupling unambiguously at each finite order. The elimination of the uncertainty in setting the renormalization scale in pQCD will greatly increase the precision of collider tests of the Standard Model and the sensitivity to new phenomena. Renormalization group invariance requires that predictions for observables must also be independent on the choice of the renormalization scheme. The well-known Brodsky-Lepage-Mackenzie (BLM) approach cannot be easily extended beyond next-to-next-to-leading order of pQCD. Several suggestions have been proposed to extend the BLM approach to all-orders. In this paper we discuss two distinct methods. One is based on the "Principle of Maximum Conformality" (PMC), which provides a systematic all-orders method to eliminate the scale- and scheme- ambiguities of pQCD. The PMC extends the BLM procedure to all orders using renormalization group methods; as an outcome, it significantly improves the pQCD convergence by eliminating renormalon divergences. An alternative method is the "sequential extended BLM" (seBLM) approach, which has been primarily designed to improve the convergence of pQCD series. The seBLM, as originally proposed, introduces auxiliary fields and follows the pattern of the $\beta_0$-expansion to fix the renormalization scale. However, the seBLM requires a recomputation of pQCD amplitudes including the auxiliary fields; due to the limited availability of calculations using these auxiliary fields, the seBLM has only been applied to a few processes at low-orders......
|
hep-ph/0411029
|
Stanley J. Brodsky
|
S. J. Brodsky (SLAC)
|
Novel Aspects of QCD in Leptoproduction
|
Presented at the conference, Electron-Nucleus Scattering VIII,
Marciana Marina, Isola d'Elba, June 21-25, 2004
|
Eur.Phys.J.A24s1:129-135,2005
|
10.1140/epjad/s2005-05-023-9
|
SLAC-PUB-10778
|
hep-ph
| null |
I review several topics in electroproduction which test fundamental aspects
of QCD. These include the role of final-state interactions in producing
diffractive leptoproduction processes, the shadowing of nuclear structure
functions, and target-spin asymmetries. The antishadowing of nuclear structure
functions is shown to be quark-flavor specific, suggesting that some part of
the anomalous NuTeV result for $\sin^2\theta_W$ could be due to the
non-universality of nuclear antishadowing for charged and neutral currents. I
also discuss the physics of the heavy-quark sea, hidden color in nuclear
wavefunctions, and evidence for color transparency for nuclear processes. The
AdS/CFT correspondence connecting superstring theory to superconformal gauge
theory has important implications for hadron phenomenology in the conformal
limit, including an all-orders demonstration of counting rules for hard
exclusive processes, as well as determining essential aspects of hadronic
light-front wavefunctions.
|
[
{
"created": "Tue, 2 Nov 2004 03:13:32 GMT",
"version": "v1"
}
] |
2009-09-11
|
[
[
"Brodsky",
"S. J.",
"",
"SLAC"
]
] |
I review several topics in electroproduction which test fundamental aspects of QCD. These include the role of final-state interactions in producing diffractive leptoproduction processes, the shadowing of nuclear structure functions, and target-spin asymmetries. The antishadowing of nuclear structure functions is shown to be quark-flavor specific, suggesting that some part of the anomalous NuTeV result for $\sin^2\theta_W$ could be due to the non-universality of nuclear antishadowing for charged and neutral currents. I also discuss the physics of the heavy-quark sea, hidden color in nuclear wavefunctions, and evidence for color transparency for nuclear processes. The AdS/CFT correspondence connecting superstring theory to superconformal gauge theory has important implications for hadron phenomenology in the conformal limit, including an all-orders demonstration of counting rules for hard exclusive processes, as well as determining essential aspects of hadronic light-front wavefunctions.
|
1107.2083
|
Bilal Masud
|
M. Imran Jamil, Bilal Masud, Faisal Akram and S. M. Sohail Gilani
|
$\bar{D}^{0}D^{0*}$ $(D^{0}\bar{D}^{0*})$ System in QCD-Improved Many
Body Potential
|
It is to be published in Chinese Physics C
|
Chin. Phys. C, 2017, 41(1): 013103
|
10.1088/1674-1137/41/1/013103
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
For a system of current interest (composed of charm, anticharm quarks and a
pair of light ones), we show trends in phenomenological implications of
QCD-based improvements to a simple quark model treatment. We employ resonating
group method to render this difficult four-body problem manageable. We use a
quadratic confinement so as to be able to improve beyond the Born
approximation. We report the position of the pole corresponding to
$\bar{D}^{0}D^{0*}$ molecule for the best fit of a model parameter to the
relevant QCD simulations. We point out the interesting possibility that the
pole can be shifted to $3872$ MeV by introducing another parameter $I_{0}$ that
changes the strength of the interaction in this one component of $X(3872)$. The
revised value of this second parameter can guide future trends in modeling of
the full exotic meson $X(3872)$. We also report the changes with $I_{0}$ in the
$S$-wave spin averaged cross sections for
$\bar{D}^{0}D^{0*}\longrightarrow\omega J/\psi$ and
$\bar{D}^{0}D^{0*}\longrightarrow\rho J/\psi$. These cross sections are
important regarding the study of QGP (quark gluon plasma).
|
[
{
"created": "Mon, 11 Jul 2011 18:30:48 GMT",
"version": "v1"
},
{
"created": "Wed, 9 Apr 2014 16:38:22 GMT",
"version": "v2"
},
{
"created": "Thu, 18 Jun 2015 19:20:25 GMT",
"version": "v3"
},
{
"created": "Sat, 26 Dec 2015 07:05:06 GMT",
"version": "v4"
},
{
"created": "Wed, 12 Oct 2016 09:24:06 GMT",
"version": "v5"
}
] |
2016-12-13
|
[
[
"Jamil",
"M. Imran",
""
],
[
"Masud",
"Bilal",
""
],
[
"Akram",
"Faisal",
""
],
[
"Gilani",
"S. M. Sohail",
""
]
] |
For a system of current interest (composed of charm, anticharm quarks and a pair of light ones), we show trends in phenomenological implications of QCD-based improvements to a simple quark model treatment. We employ resonating group method to render this difficult four-body problem manageable. We use a quadratic confinement so as to be able to improve beyond the Born approximation. We report the position of the pole corresponding to $\bar{D}^{0}D^{0*}$ molecule for the best fit of a model parameter to the relevant QCD simulations. We point out the interesting possibility that the pole can be shifted to $3872$ MeV by introducing another parameter $I_{0}$ that changes the strength of the interaction in this one component of $X(3872)$. The revised value of this second parameter can guide future trends in modeling of the full exotic meson $X(3872)$. We also report the changes with $I_{0}$ in the $S$-wave spin averaged cross sections for $\bar{D}^{0}D^{0*}\longrightarrow\omega J/\psi$ and $\bar{D}^{0}D^{0*}\longrightarrow\rho J/\psi$. These cross sections are important regarding the study of QGP (quark gluon plasma).
|
1404.3471
|
Masatoshi Yamada
|
Ken-Ichi Aoki, Daisuke Sato and Masatoshi Yamada
|
Analysis of the Dynamical Chiral Symmetry Breaking in QCD at Finite
Temperature and Density using the Non-Perturbative Renormalization Group
|
5 pages, 4 figures, contribution to YITP-W-13-13 TQFT, 26-28 Aug.
2013, Kyoto University
|
Soryushiron Kenkyu 17 (2014) 2
| null |
KANAZAWA-14-03
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We analyze the Nambu--Jona-Lasinio model which is a chiral effective model of
QCD by using the non-perturbative renormalization group at finite temperature
and finite density. We discuss the chiral phase diagram in the model. We
include the large-$N$ non-leading contribution in the beta function and discuss
its effects for the phase boundary.
|
[
{
"created": "Mon, 14 Apr 2014 06:55:07 GMT",
"version": "v1"
}
] |
2018-12-21
|
[
[
"Aoki",
"Ken-Ichi",
""
],
[
"Sato",
"Daisuke",
""
],
[
"Yamada",
"Masatoshi",
""
]
] |
We analyze the Nambu--Jona-Lasinio model which is a chiral effective model of QCD by using the non-perturbative renormalization group at finite temperature and finite density. We discuss the chiral phase diagram in the model. We include the large-$N$ non-leading contribution in the beta function and discuss its effects for the phase boundary.
|
1605.06506
|
Alexander Friedland
|
John F. Cherry (Virginia Tech.), Alexander Friedland (SLAC), Ian M.
Shoemaker (Penn State U.)
|
Short-baseline neutrino oscillations, Planck, and IceCube
|
6 pages, 3 figures
| null | null |
SLAC-PUB-16517
|
hep-ph astro-ph.CO astro-ph.HE
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We examine a framework with light new physics, which couples to the Standard
Model only via neutrino mixing. Taking the hints from the short-baseline
anomalies seriously and combining them with modern cosmological data and recent
IceCube measurements, we obtain surprisingly effective constraints on the
hidden force: keV $\lesssim M \lesssim0.3$ GeV for the mediator mass and
$g_{h}>10^{-6}-10^{-3}$ for the coupling constant. Flavor equilibration between
the hidden and active neutrinos can be delayed until temperatures of $\sim 1$
MeV, but not below $\sim 100$ keV. This scenario can be tested with
next-generation Cosmic Microwave Background, IceCube, and oscillation
experiments.
|
[
{
"created": "Fri, 20 May 2016 20:00:03 GMT",
"version": "v1"
}
] |
2016-05-24
|
[
[
"Cherry",
"John F.",
"",
"Virginia Tech."
],
[
"Friedland",
"Alexander",
"",
"SLAC"
],
[
"Shoemaker",
"Ian M.",
"",
"Penn State U."
]
] |
We examine a framework with light new physics, which couples to the Standard Model only via neutrino mixing. Taking the hints from the short-baseline anomalies seriously and combining them with modern cosmological data and recent IceCube measurements, we obtain surprisingly effective constraints on the hidden force: keV $\lesssim M \lesssim0.3$ GeV for the mediator mass and $g_{h}>10^{-6}-10^{-3}$ for the coupling constant. Flavor equilibration between the hidden and active neutrinos can be delayed until temperatures of $\sim 1$ MeV, but not below $\sim 100$ keV. This scenario can be tested with next-generation Cosmic Microwave Background, IceCube, and oscillation experiments.
|
hep-ph/0212189
|
Wolfgang Ochs
|
Matthew A. Buican, Valery A. Khoze and Wolfgang Ochs (MPI Munich/Univ.
Durham)
|
Angular Distribution of Particle Flows and Perturbative QCD Predictions
|
14 pages, 4 Figs., more details of calculation in sect. 2.1
|
Eur.Phys.J.C28:313-319,2003
|
10.1140/epjc/s2003-01175-7
|
MPI-PhT/02-2002-78, IPPP/02/80; DCPT/02/160
|
hep-ph
| null |
We discuss the predictions of perturbative QCD for angular flows of final
state particles in two and three jet events including their cms energy and jet
resolution (y_{cut}) dependence. The simple analytical formulae for gluon
bremsstrahlung from primary partons, modified for gluon cascading, reproduce
the main features of the experimental data well. For y_{cut}-selected events,
the particle flow is derived from a superposition of colour dipoles in much the
same way that photon radiation is derived from electric dipoles.
|
[
{
"created": "Fri, 13 Dec 2002 13:01:56 GMT",
"version": "v1"
},
{
"created": "Wed, 19 Feb 2003 16:25:33 GMT",
"version": "v2"
}
] |
2011-09-13
|
[
[
"Buican",
"Matthew A.",
"",
"MPI Munich/Univ.\n Durham"
],
[
"Khoze",
"Valery A.",
"",
"MPI Munich/Univ.\n Durham"
],
[
"Ochs",
"Wolfgang",
"",
"MPI Munich/Univ.\n Durham"
]
] |
We discuss the predictions of perturbative QCD for angular flows of final state particles in two and three jet events including their cms energy and jet resolution (y_{cut}) dependence. The simple analytical formulae for gluon bremsstrahlung from primary partons, modified for gluon cascading, reproduce the main features of the experimental data well. For y_{cut}-selected events, the particle flow is derived from a superposition of colour dipoles in much the same way that photon radiation is derived from electric dipoles.
|
1406.1944
|
Jian-Hua Gao
|
Jian-Hua Gao, Bin Qi, Shou-Yu Wang
|
Vorticity and magnetic field production in relativistic ideal fluids
|
13 pages, published version in PRD
|
Phys. Rev. D 90, 083001 (2014)
|
10.1103/PhysRevD.90.083001
| null |
hep-ph astro-ph.CO nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In the framework of relativistic ideal hydrodynamics, we study the production
mechanism for vorticity and magnetic field in relativistic ideal fluids. It is
demonstrated that in the uncharged fluids the thermal vorticity will always
satisfy the Kelvin's theorem and the circulation must be conserved. However, in
the charged fluids, the vorticity and magnetic field can be produced by the
interaction between the entropy gradients and the fluid velocity gradients.
Especially, in the multiple charged fluids, the vorticity and magnetic field
can be produced by the interaction between the inhomogenous charge density
ratio and the fluid velocity gradients even if the entropy distribution is
homogeneous, which provides another mechanism for the production of vorticity
and magnetic field in relativistic plasmas or in the early universe.
|
[
{
"created": "Sun, 8 Jun 2014 03:44:30 GMT",
"version": "v1"
},
{
"created": "Mon, 26 Jan 2015 07:40:05 GMT",
"version": "v2"
}
] |
2015-01-27
|
[
[
"Gao",
"Jian-Hua",
""
],
[
"Qi",
"Bin",
""
],
[
"Wang",
"Shou-Yu",
""
]
] |
In the framework of relativistic ideal hydrodynamics, we study the production mechanism for vorticity and magnetic field in relativistic ideal fluids. It is demonstrated that in the uncharged fluids the thermal vorticity will always satisfy the Kelvin's theorem and the circulation must be conserved. However, in the charged fluids, the vorticity and magnetic field can be produced by the interaction between the entropy gradients and the fluid velocity gradients. Especially, in the multiple charged fluids, the vorticity and magnetic field can be produced by the interaction between the inhomogenous charge density ratio and the fluid velocity gradients even if the entropy distribution is homogeneous, which provides another mechanism for the production of vorticity and magnetic field in relativistic plasmas or in the early universe.
|
0809.0781
|
Shu Luo
|
Shu Luo, Zhi-zhong Xing, Xin Li
|
Generic Friedberg-Lee Symmetry of Dirac Neutrinos
|
RevTex4 10 pages, 1 figure
|
Phys.Rev.D78:117301,2008
|
10.1103/PhysRevD.78.117301
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We write out the generic Dirac neutrino mass operator which possesses the
Friedberg-Lee (FL) symmetry and find that its corresponding neutrino mass
matrix is asymmetric. Following a simple way to break the FL symmetry, we
calculate the neutrino mass eigenvalues and show that the resultant neutrino
mixing pattern is nearly tri-bimaximal. Imposing the Hermitian condition on the
neutrino mass matrix, we also show that the simplified ansatz is consistent
with current experimental data and favors the normal neutrino mass hierarchy.
|
[
{
"created": "Thu, 4 Sep 2008 09:51:17 GMT",
"version": "v1"
}
] |
2008-12-30
|
[
[
"Luo",
"Shu",
""
],
[
"Xing",
"Zhi-zhong",
""
],
[
"Li",
"Xin",
""
]
] |
We write out the generic Dirac neutrino mass operator which possesses the Friedberg-Lee (FL) symmetry and find that its corresponding neutrino mass matrix is asymmetric. Following a simple way to break the FL symmetry, we calculate the neutrino mass eigenvalues and show that the resultant neutrino mixing pattern is nearly tri-bimaximal. Imposing the Hermitian condition on the neutrino mass matrix, we also show that the simplified ansatz is consistent with current experimental data and favors the normal neutrino mass hierarchy.
|
2012.02799
|
Juan Carlos Vasquez Carmona
|
Michael J. Ramsey-Musolf and Juan Carlos Vasquez
|
Left-right symmetry and electric dipole moments. A global analysis
|
8 pages, 5 figures
| null |
10.1016/j.physletb.2021.136136
|
ACFI-T20-17
|
hep-ph nucl-th
|
http://creativecommons.org/licenses/by/4.0/
|
We perform a global fit using results of searches for electric dipole moments
(EDM) of diamagnetic systems within the context of the minimal left-right
symmetric model. In this way, we disentangle the new "left-right" electroweak
and $\bar{\theta}$ contributions that cannot be separated using a single EDM
system. Although the fit is done for a specific model, the approach can be
applied to any particle physics model. Finally, we revisit the constraint on
the $D$ coefficient in $\beta$-decay and find that current EDM bounds do not
preclude observation of this T-violating effect in a possible next generation
$\beta$-decay experiment.
|
[
{
"created": "Fri, 4 Dec 2020 19:00:02 GMT",
"version": "v1"
}
] |
2021-02-17
|
[
[
"Ramsey-Musolf",
"Michael J.",
""
],
[
"Vasquez",
"Juan Carlos",
""
]
] |
We perform a global fit using results of searches for electric dipole moments (EDM) of diamagnetic systems within the context of the minimal left-right symmetric model. In this way, we disentangle the new "left-right" electroweak and $\bar{\theta}$ contributions that cannot be separated using a single EDM system. Although the fit is done for a specific model, the approach can be applied to any particle physics model. Finally, we revisit the constraint on the $D$ coefficient in $\beta$-decay and find that current EDM bounds do not preclude observation of this T-violating effect in a possible next generation $\beta$-decay experiment.
|
hep-ph/9407389
|
Mariano Quiros
|
J.A. Casas, J.R. Espinosa, M. Quir\'os and A. Riotto
|
The Lightest Higgs Boson Mass in the Minimal Supersymmetric Standard
Model
|
24 pages + 15 figures in one compressed uuencoded tarred postscript
file (The figures can be obtained by e-mail from QUIROS@ROCA.CSIC.ES; also,
the whole postscript file of the text including the figures can be obtained
by ANONYMOUS FTP from ROCA.CSIC.ES (161.111.20.20) at the directory HEP the
file being HIGGS.PS: just type GET HEP/HIGGS.PS), Latex, CERN-TH.7334/94
|
Nucl.Phys.B436:3-29,1995; ERRATUM-ibid.B439:466-468,1995
|
10.1016/0550-3213(94)00508-C
| null |
hep-ph
| null |
We compute the upper bound on the mass of the lightest Higgs boson in the
Minimal Supersymmetric Standard Model in a model-independent way, including
leading (one-loop) and next-to-leading order (two-loop) radiative corrections.
We find that (contrary to some recent claims) the two-loop corrections are
negative with respect to the one-loop result and relatively small ($\simlt
3$\%). After defining physical (pole) top quark mass $M_t$, by including QCD
self-energies, and physical Higgs mass $M_H$, by including the electroweak
self-energies $\Pi\left(M_H^2\right)-\Pi(0)$, we obtain the upper limit on
$M_H$ as a function of supersymmetric parameters. We include as supersymmetric
parameters the scale of supersymmetry breaking $M_S$, the value of $\tan \beta$
and the mixing between stops $X_t= A_t + \mu \cot\beta$ (which is responsible
for the threshold correction on the Higgs quartic coupling). Our results do not
depend on further details of the supersymmetric model. In particular, for
$M_S\leq 1$ TeV, maximal threshold effect $X_t^2=6M_S^2$ and any value of
$\tan\beta$, we find $M_H\leq 140$ GeV for $M_t\leq 190$ GeV. In the particular
scenario where the top is in its infrared fixed point we find $M_H\leq 86$ GeV
for $M_t = 170$ GeV.
|
[
{
"created": "Wed, 27 Jul 1994 15:01:06 GMT",
"version": "v1"
}
] |
2011-05-05
|
[
[
"Casas",
"J. A.",
""
],
[
"Espinosa",
"J. R.",
""
],
[
"Quirós",
"M.",
""
],
[
"Riotto",
"A.",
""
]
] |
We compute the upper bound on the mass of the lightest Higgs boson in the Minimal Supersymmetric Standard Model in a model-independent way, including leading (one-loop) and next-to-leading order (two-loop) radiative corrections. We find that (contrary to some recent claims) the two-loop corrections are negative with respect to the one-loop result and relatively small ($\simlt 3$\%). After defining physical (pole) top quark mass $M_t$, by including QCD self-energies, and physical Higgs mass $M_H$, by including the electroweak self-energies $\Pi\left(M_H^2\right)-\Pi(0)$, we obtain the upper limit on $M_H$ as a function of supersymmetric parameters. We include as supersymmetric parameters the scale of supersymmetry breaking $M_S$, the value of $\tan \beta$ and the mixing between stops $X_t= A_t + \mu \cot\beta$ (which is responsible for the threshold correction on the Higgs quartic coupling). Our results do not depend on further details of the supersymmetric model. In particular, for $M_S\leq 1$ TeV, maximal threshold effect $X_t^2=6M_S^2$ and any value of $\tan\beta$, we find $M_H\leq 140$ GeV for $M_t\leq 190$ GeV. In the particular scenario where the top is in its infrared fixed point we find $M_H\leq 86$ GeV for $M_t = 170$ GeV.
|
2101.04630
|
Francesco Giovanni Celiberto
|
Francesco Giovanni Celiberto
|
3D tomography of the nucleon: transverse-momentum-dependent gluon
distributions
|
5 pages, 1 figure, 106th National Congress of the Italian Physical
Society (SIF), contribution selected by the Scientific Committee for Best
Communications, paper submitted to Nuovo Cim. C; version published in Nuovo
Cim. C
|
Nuovo Cim. C 44 (2021) 36
|
10.1393/ncc/i2021-21036-3
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We perform explorative analyses of the 3D gluon content of the proton via a
study of (un)polarized twist-2 gluon TMDs, calculated in a spectator model for
the parent nucleon. Our approach encodes a flexible parametrization for the
spectator-mass density, suited to describe both moderate and small-$x$ effects.
All these prospective developments are relevant in the investigation of the
gluon dynamics inside nucleons and nuclei, which constitutes one of the major
goals of new-generation colliding machines, as the EIC, the HL-LHC and NICA.
|
[
{
"created": "Tue, 12 Jan 2021 17:32:55 GMT",
"version": "v1"
},
{
"created": "Tue, 7 Sep 2021 10:56:09 GMT",
"version": "v2"
}
] |
2021-09-08
|
[
[
"Celiberto",
"Francesco Giovanni",
""
]
] |
We perform explorative analyses of the 3D gluon content of the proton via a study of (un)polarized twist-2 gluon TMDs, calculated in a spectator model for the parent nucleon. Our approach encodes a flexible parametrization for the spectator-mass density, suited to describe both moderate and small-$x$ effects. All these prospective developments are relevant in the investigation of the gluon dynamics inside nucleons and nuclei, which constitutes one of the major goals of new-generation colliding machines, as the EIC, the HL-LHC and NICA.
|
1711.01235
|
Daniel de Florian
|
Daniel de Florian (ICAS-UNSAM)
|
Transversely polarized Drell-Yan asymmetry A_TT at NLO
|
14 pages, 8 figures, typo corrected
| null | null |
ICAS 027/17
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present the first fully differential next-to-leading order QCD calculation
for lepton production in transversely polarized hadronic collisions, pp -> l X
, where the lepton arises from the decay of an electroweak gauge boson. The
calculation is implemented in the Monte-Carlo like code `CHE' that already
includes the unpolarized and longitudinally polarized cross sections and may be
readily used to perform a comparison to experimental data and to extract
information on the related parton distributions. We analyze the perturbative
stability of the cross-section and double spin asymmetry A_TT at RHIC
kinematics. We find that the QCD corrections are non-negligible even at the
level of asymmetries and that they strongly depend on the lepton kinematics.
Furthermore, we present two scenarios for transversely polarized parton
distributions, based on the de Florian-Sassot-Stratmann-Vogelsang (DSSV) set of
longitudinally parton densities and fully evolved to NLO accuracy, that can be
used for the evaluation of different observables involving transverse
polarization.
|
[
{
"created": "Fri, 3 Nov 2017 16:48:57 GMT",
"version": "v1"
},
{
"created": "Mon, 13 Nov 2017 23:16:21 GMT",
"version": "v2"
}
] |
2017-11-15
|
[
[
"de Florian",
"Daniel",
"",
"ICAS-UNSAM"
]
] |
We present the first fully differential next-to-leading order QCD calculation for lepton production in transversely polarized hadronic collisions, pp -> l X , where the lepton arises from the decay of an electroweak gauge boson. The calculation is implemented in the Monte-Carlo like code `CHE' that already includes the unpolarized and longitudinally polarized cross sections and may be readily used to perform a comparison to experimental data and to extract information on the related parton distributions. We analyze the perturbative stability of the cross-section and double spin asymmetry A_TT at RHIC kinematics. We find that the QCD corrections are non-negligible even at the level of asymmetries and that they strongly depend on the lepton kinematics. Furthermore, we present two scenarios for transversely polarized parton distributions, based on the de Florian-Sassot-Stratmann-Vogelsang (DSSV) set of longitudinally parton densities and fully evolved to NLO accuracy, that can be used for the evaluation of different observables involving transverse polarization.
|
1811.10429
|
Zhihua Gu
|
Zhi-Hua Gu, Hai-Bin Zhang
|
The four-propagator three-loop vacuum integral by the hypergeometry
|
19 pages, 1 figure
| null |
10.1088/1674-1137/43/8/083102
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Hypergeometric function method is proposed to calculate the scalar integrals
of Feynman diagrams. For the scalar integral of three-loop vacuum diagram with
four-propagator, we verify the equivalency of Feynman parametrization and the
hypergeometric technique. The result can be described as generalized
hypergeometric functions of triple variables. Based on the triple
hypergeometric functions, we also establish the systems of homogeneous linear
partial differential equations(PDEs) satisfied by the mentioned scalar
integral. The continuation of the scalar integral from its convergent regions
to whole kinematic domains can be made numerically through the system of
homogeneous linear PDEs with the help of the element method.
|
[
{
"created": "Fri, 23 Nov 2018 02:54:39 GMT",
"version": "v1"
},
{
"created": "Tue, 27 Nov 2018 03:13:51 GMT",
"version": "v2"
},
{
"created": "Thu, 3 Jan 2019 08:31:15 GMT",
"version": "v3"
}
] |
2019-09-04
|
[
[
"Gu",
"Zhi-Hua",
""
],
[
"Zhang",
"Hai-Bin",
""
]
] |
Hypergeometric function method is proposed to calculate the scalar integrals of Feynman diagrams. For the scalar integral of three-loop vacuum diagram with four-propagator, we verify the equivalency of Feynman parametrization and the hypergeometric technique. The result can be described as generalized hypergeometric functions of triple variables. Based on the triple hypergeometric functions, we also establish the systems of homogeneous linear partial differential equations(PDEs) satisfied by the mentioned scalar integral. The continuation of the scalar integral from its convergent regions to whole kinematic domains can be made numerically through the system of homogeneous linear PDEs with the help of the element method.
|
1601.04228
|
Abolfazl Mirjalili
|
R. Taghavi, A. Mirjalili
|
Extracting the QCD ${\Lambda _{\overline {MS} }}$ parameter in Drell-Yan
Process using Collins-Sopper-Sterman approach
|
12 pages, 2 figures
|
Mod. Phys. Lett. A, Vol. 32, No. 10 (2017) 1750040
|
10.1142/S0217732317500407
| null |
hep-ph
|
http://creativecommons.org/publicdomain/zero/1.0/
|
In this work we directly fit the QCD dimensional transmutation parameter,
${\Lambda _{\overline {MS} }}$, to experimental data of Drell-Yan (DY)
observables. For this purpose we first obtain the evolution of transverse
momentum dependent parton distribution functions (TMDPDFs) up to the NNLO
approximation based on Collins-Sopper-Sterman formalism. As is expecting the
TMDPDFs are appearing at larger values of transvers momentum by increasing the
energy scales and also the order of approximation. Then we calculate the cross
section related to the TMDPDFs in the DY process. As a consequence of fitting
to the E288 experimental data at center of mass energy $\sqrt{s}=23.8$ $GeV$,
we obtain ${\Lambda _{\overline {MS} }} = 249 \pm 7 MeV$ corresponding to the
renormalized coupling constant ${\alpha _s}(M_z^2) = 0.119 \pm 0.001$ which is
within the acceptable range for this quantity. The results for DY cross section
at different energy scales are in good agreement within the available data.
|
[
{
"created": "Sat, 16 Jan 2016 23:10:59 GMT",
"version": "v1"
}
] |
2017-03-22
|
[
[
"Taghavi",
"R.",
""
],
[
"Mirjalili",
"A.",
""
]
] |
In this work we directly fit the QCD dimensional transmutation parameter, ${\Lambda _{\overline {MS} }}$, to experimental data of Drell-Yan (DY) observables. For this purpose we first obtain the evolution of transverse momentum dependent parton distribution functions (TMDPDFs) up to the NNLO approximation based on Collins-Sopper-Sterman formalism. As is expecting the TMDPDFs are appearing at larger values of transvers momentum by increasing the energy scales and also the order of approximation. Then we calculate the cross section related to the TMDPDFs in the DY process. As a consequence of fitting to the E288 experimental data at center of mass energy $\sqrt{s}=23.8$ $GeV$, we obtain ${\Lambda _{\overline {MS} }} = 249 \pm 7 MeV$ corresponding to the renormalized coupling constant ${\alpha _s}(M_z^2) = 0.119 \pm 0.001$ which is within the acceptable range for this quantity. The results for DY cross section at different energy scales are in good agreement within the available data.
|
hep-ph/0310067
|
Roberto Casalbuoni
|
R. Casalbuoni
|
Inhomogeneous Color Superconductivity
|
LaTex,20 pages, 6 figures. Talk at the International Workshop on QCD:
QCD@Work 2003 - Conversano (Italy) 14-18 June 2003 (eConf C030614). Change in
the CERN preprint number
| null | null |
CERN-TH/2003-178
|
hep-ph cond-mat.supr-con
| null |
We discuss the possibility that in finite density QCD an anisotropic phase is
realized. This case might arise for quarks with different chemical potential
and/or different masses. In this phase crystalline structures may be formed. We
consider this possibility and we describe, in the context of an effective
lagrangian, the corresponding phonons as the Nambu-Goldstone bosons associated
to the breaking of the space symmetries.
|
[
{
"created": "Mon, 6 Oct 2003 13:30:28 GMT",
"version": "v1"
},
{
"created": "Tue, 7 Oct 2003 14:50:52 GMT",
"version": "v2"
}
] |
2007-05-23
|
[
[
"Casalbuoni",
"R.",
""
]
] |
We discuss the possibility that in finite density QCD an anisotropic phase is realized. This case might arise for quarks with different chemical potential and/or different masses. In this phase crystalline structures may be formed. We consider this possibility and we describe, in the context of an effective lagrangian, the corresponding phonons as the Nambu-Goldstone bosons associated to the breaking of the space symmetries.
|
hep-ph/9701283
|
Lee Jae Sik
|
Ji-Ho Jang, Jae Kwan Kim, and Jae Sik Lee
|
Constraints on the R-parity- and Lepton-Flavor-Violating Couplings from
B0 Decats to Two Charged Leptons
|
Table is changed; version to appear in Phys. Rev. D
|
Phys. Rev. D 55, 7296 (1997)
|
10.1103/PhysRevD.55.7296
|
KAIST-TH 97/02
|
hep-ph
| null |
We derive the upper bounds on certain products of R-parity- and
lepton-flavor-violating couplings from the decays of the neutral $B$ meson into
two charged leptons. These modes of $B^0$ decays can constrain the product
combinations of the couplings with one or more heavy generation indices. We
find that most of these bounds are stronger than the previous ones.
|
[
{
"created": "Fri, 14 Jun 1996 16:43:55 GMT",
"version": "v1"
},
{
"created": "Fri, 21 Jun 1996 08:13:25 GMT",
"version": "v2"
},
{
"created": "Sat, 21 Sep 1996 11:13:09 GMT",
"version": "v3"
}
] |
2016-08-24
|
[
[
"Jang",
"Ji-Ho",
""
],
[
"Kim",
"Jae Kwan",
""
],
[
"Lee",
"Jae Sik",
""
]
] |
We derive the upper bounds on certain products of R-parity- and lepton-flavor-violating couplings from the decays of the neutral $B$ meson into two charged leptons. These modes of $B^0$ decays can constrain the product combinations of the couplings with one or more heavy generation indices. We find that most of these bounds are stronger than the previous ones.
|
0812.4448
|
Sergey Alekhin
|
S. Alekhin, S. Kulagin, R. Petti
|
Determination of Strange Sea Distributions from Neutrino-Nucleon Deep
Inelastic Scattering
|
15 pages
|
Phys.Lett.B675:433-440,2009
|
10.1016/j.physletb.2009.04.033
|
DESY 08-185, SFB/CPP-08-99
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present an analysis of the nucleon strange sea extracted from a global
Parton Distribution Function fit including the neutrino and anti-neutrino
dimuon data by the CCFR and NuTeV collaborations, the inclusive charged
lepton-nucleon Deep Inelastic Scattering and Drell-Yan data. The
(anti-)neutrino induced dimuon analysis is constrained by the semi-leptonic
charmed-hadron branching ratio $B_\mu=(8.8\pm0.5)%$, determined from the
inclusive charmed hadron measurements performed by the FNAL-E531 and CHORUS
neutrino emulsion experiments. Our analysis yields a strange sea suppression
factor $\kappa(Q^2=20{\rm GeV}^2)=0.62\pm 0.04$, the most precise value
available, an $x$-distribution of total strange sea that is slightly softer
than the non-strange sea, and an asymmetry between strange and anti-strange
quark distributions consistent with zero (integrated over $x$ it is equal to
$0.0013 \pm 0.0009$ at $Q^2=20{\rm GeV}^2$).
|
[
{
"created": "Tue, 23 Dec 2008 20:43:31 GMT",
"version": "v1"
}
] |
2009-11-19
|
[
[
"Alekhin",
"S.",
""
],
[
"Kulagin",
"S.",
""
],
[
"Petti",
"R.",
""
]
] |
We present an analysis of the nucleon strange sea extracted from a global Parton Distribution Function fit including the neutrino and anti-neutrino dimuon data by the CCFR and NuTeV collaborations, the inclusive charged lepton-nucleon Deep Inelastic Scattering and Drell-Yan data. The (anti-)neutrino induced dimuon analysis is constrained by the semi-leptonic charmed-hadron branching ratio $B_\mu=(8.8\pm0.5)%$, determined from the inclusive charmed hadron measurements performed by the FNAL-E531 and CHORUS neutrino emulsion experiments. Our analysis yields a strange sea suppression factor $\kappa(Q^2=20{\rm GeV}^2)=0.62\pm 0.04$, the most precise value available, an $x$-distribution of total strange sea that is slightly softer than the non-strange sea, and an asymmetry between strange and anti-strange quark distributions consistent with zero (integrated over $x$ it is equal to $0.0013 \pm 0.0009$ at $Q^2=20{\rm GeV}^2$).
|
hep-ph/9611368
|
Cliff Burgess
|
C.P. Burgess and D. Michaud
|
Neutrino Propagation Through a Fluctuating Sun (The Talk)
|
6 pages including 2 figures, Latex, uses epsf.tex, Presented to
Neutrino-96, Helsinki, June 1996
| null | null |
McGill-96/43
|
hep-ph astro-ph
| null |
We summarize a general formulation of particle propagation in fluctuating
media, as applied to the description of neutrino propagation through the sun.
It contains the familiar MSW effective hamiltonian, plus corrections which
describe neutrino interactions with fluctuations in the medium. An estimate of
the size of these corrections for a simple model of solar fluctuations is made,
with the conclusion that they can produce surprisingly large effects since they
grow with the correlation length of the fluctuation. For MSW oscillations, the
leading effect for small fluctuations is to diminish the quality of the
resonance, making the suppression of the ${}^7$Be neutrinos an experimental
probe of fluctuations deep within the sun. Fluctuations can also provide an
energy-independent suppression factor of $\hf$, away from the resonant region,
even for small vacuum mixing angles. To be even potentially detectable, density
fluctuations must be correlated on scales of hundreds of kilometres, and have
amplitudes of a few percent or larger.
|
[
{
"created": "Tue, 19 Nov 1996 20:29:53 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Burgess",
"C. P.",
""
],
[
"Michaud",
"D.",
""
]
] |
We summarize a general formulation of particle propagation in fluctuating media, as applied to the description of neutrino propagation through the sun. It contains the familiar MSW effective hamiltonian, plus corrections which describe neutrino interactions with fluctuations in the medium. An estimate of the size of these corrections for a simple model of solar fluctuations is made, with the conclusion that they can produce surprisingly large effects since they grow with the correlation length of the fluctuation. For MSW oscillations, the leading effect for small fluctuations is to diminish the quality of the resonance, making the suppression of the ${}^7$Be neutrinos an experimental probe of fluctuations deep within the sun. Fluctuations can also provide an energy-independent suppression factor of $\hf$, away from the resonant region, even for small vacuum mixing angles. To be even potentially detectable, density fluctuations must be correlated on scales of hundreds of kilometres, and have amplitudes of a few percent or larger.
|
hep-ph/9712465
|
David Bowser-Chao
|
Ali Abbasabaddi, David Bowser-Chao, Duane A. Dicus, and Wayne W. Repko
|
Probing Anomalous Higgs Coupling through mu+ mu- --> H gamma
|
6 pages, 4 figures, aipproc.sty. Talk presented by David Bowser-Chao
at the Workshop on Physics at the First Muon Collider and the Front End of a
Muon Collider, Fermilab, November 6-9, 1997
|
Proceedings of the "Workshop on Physics at the First Muon Collider
and at the Front End of a Muon Collider", Fermilab, November 6-9, 1997
| null |
UICHEP-TH/97-17
|
hep-ph
| null |
The process mu+ mu- --> H gamma, though small compared to the resonance
process, could be observable at proposed muon colliders, given expected
integrated luminosities. The apparently leading diagrams occur at tree-level,
and are proportional to the Higgs-muon coupling. We show, however, that the
one-loop contribution is comparable to the tree-level amplitude. Furthermore,
the one-loop diagrams, unlike those at tree-level, could be greatly enhanced by
possible anomalous Higgs-top quark or Higgs-gauge boson couplings. For a 500
GeV unpolarized muon collider, the total cross section for H-gamma associated
production approaches 0.1 fb.
|
[
{
"created": "Fri, 19 Dec 1997 20:57:57 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Abbasabaddi",
"Ali",
""
],
[
"Bowser-Chao",
"David",
""
],
[
"Dicus",
"Duane A.",
""
],
[
"Repko",
"Wayne W.",
""
]
] |
The process mu+ mu- --> H gamma, though small compared to the resonance process, could be observable at proposed muon colliders, given expected integrated luminosities. The apparently leading diagrams occur at tree-level, and are proportional to the Higgs-muon coupling. We show, however, that the one-loop contribution is comparable to the tree-level amplitude. Furthermore, the one-loop diagrams, unlike those at tree-level, could be greatly enhanced by possible anomalous Higgs-top quark or Higgs-gauge boson couplings. For a 500 GeV unpolarized muon collider, the total cross section for H-gamma associated production approaches 0.1 fb.
|
hep-ph/9602438
|
Jim Cline
|
P. Bamert, C.P. Burgess, J.M. Cline, D. London and E. Nardi
|
R_b and New Physics: A Comprehensive Analysis
|
60 pages, 8 figures, plain tex, uses epsf. Final version to appear in
Phys. Rev. D; propgating sign error corrected in eqs. 78, 87, 88, 89, 98, and
107; results unchanged
|
Phys.Rev. D54 (1996) 4275-4300
|
10.1103/PhysRevD.54.4275
|
McGill-96/04, UdeM-GPP-TH-96-34, WIS-96/09/Feb-PH
|
hep-ph
| null |
We survey the implications for new physics of the discrepancy between the LEP
measurement of $R_b$ and its Standard Model prediction. Two broad classes of
models are considered: ($i$) those in which new $Z\bbar b$ couplings arise at
tree level, through $Z$ or $b$-quark mixing with new particles, and ($ii$)
those in which new scalars and fermions alter the $Z \bbar b$ vertex at one
loop. We keep our analysis as general as possible in order to systematically
determine what kinds of features can produce corrections to $R_b$ of the right
sign and magnitude. We are able to identify several successful mechanisms,
which include most of those which have been recently been proposed in the
literature, as well as some earlier proposals (\eg\ supersymmetric models). By
seeing how such models appear as special cases of our general treatment we are
able to shed light on the reason for, and the robustness of, their ability to
explain $R_b$.
|
[
{
"created": "Fri, 1 Mar 1996 00:19:15 GMT",
"version": "v1"
},
{
"created": "Thu, 14 Mar 1996 15:03:31 GMT",
"version": "v2"
},
{
"created": "Mon, 12 Aug 1996 14:43:46 GMT",
"version": "v3"
}
] |
2009-10-28
|
[
[
"Bamert",
"P.",
""
],
[
"Burgess",
"C. P.",
""
],
[
"Cline",
"J. M.",
""
],
[
"London",
"D.",
""
],
[
"Nardi",
"E.",
""
]
] |
We survey the implications for new physics of the discrepancy between the LEP measurement of $R_b$ and its Standard Model prediction. Two broad classes of models are considered: ($i$) those in which new $Z\bbar b$ couplings arise at tree level, through $Z$ or $b$-quark mixing with new particles, and ($ii$) those in which new scalars and fermions alter the $Z \bbar b$ vertex at one loop. We keep our analysis as general as possible in order to systematically determine what kinds of features can produce corrections to $R_b$ of the right sign and magnitude. We are able to identify several successful mechanisms, which include most of those which have been recently been proposed in the literature, as well as some earlier proposals (\eg\ supersymmetric models). By seeing how such models appear as special cases of our general treatment we are able to shed light on the reason for, and the robustness of, their ability to explain $R_b$.
|
hep-ph/9506346
|
Taco Nieuwenhuis
|
Taco Nieuwenhuis and J. A. Tjon (Institute for Theoretical Physics,
Utrecht, the Netherlands)
|
Bound state solutions of scalar QED_{2+1} for zero photon mass
|
LaTeX, 11 pages, 2 Postscript figures; uses `elsart.sty' and
`epsf.sty' (both included with the figures in one uuencoded-
compressed-tar-package); accepted for publication in Physics Letters B.
(elsart12.sty now also included)
|
Phys.Lett. B355 (1995) 283-287
|
10.1016/0370-2693(95)00753-8
|
THU-95/16
|
hep-ph nucl-th
| null |
The Feynman-Schwinger representation is used to study the behavior of
solutions of scalar QED in (2+1) dimensions. The limit of zero photon mass is
seen to be smooth. The Bethe-Salpeter equation in the ladder approximation also
exhibits this property. They clearly deviate from the behavior in the
nonrelativistic limit. In a variational analysis we show that this difference
can be attributed to retardation effects of relativistic origin.
|
[
{
"created": "Fri, 16 Jun 1995 13:28:59 GMT",
"version": "v1"
},
{
"created": "Mon, 19 Jun 1995 08:17:37 GMT",
"version": "v2"
}
] |
2009-10-28
|
[
[
"Nieuwenhuis",
"Taco",
"",
"Institute for Theoretical Physics,\n Utrecht, the Netherlands"
],
[
"Tjon",
"J. A.",
"",
"Institute for Theoretical Physics,\n Utrecht, the Netherlands"
]
] |
The Feynman-Schwinger representation is used to study the behavior of solutions of scalar QED in (2+1) dimensions. The limit of zero photon mass is seen to be smooth. The Bethe-Salpeter equation in the ladder approximation also exhibits this property. They clearly deviate from the behavior in the nonrelativistic limit. In a variational analysis we show that this difference can be attributed to retardation effects of relativistic origin.
|
hep-ph/9810328
|
Joaquim Inacio da Silva Marcos
|
G.C. Branco, M.N. Rebelo and J.I. Silva-Marcos
|
Degenerate and Quasi Degenerate Majorana Neutrinos
|
9 pages
|
Phys.Rev.Lett. 82 (1999) 683-686
|
10.1103/PhysRevLett.82.683
| null |
hep-ph
| null |
We study mixing and CP violation of three left-handed Majorana neutrinos in
the limit of exactly degenerate masses, identify the weak-basis invariant
relevant for CP violation and show that the leptonic mixing matrix is
parametrized only by two angles and one phase. After the lifting of the
degeneracy, this parametrization accommodates the present data on atmospheric
and solar neutrinos, as well as double beta decay. Some of the leptonic mixing
ansatze suggested in the literature correspond to special cases of this
parametrization.
|
[
{
"created": "Mon, 12 Oct 1998 14:40:32 GMT",
"version": "v1"
}
] |
2009-10-31
|
[
[
"Branco",
"G. C.",
""
],
[
"Rebelo",
"M. N.",
""
],
[
"Silva-Marcos",
"J. I.",
""
]
] |
We study mixing and CP violation of three left-handed Majorana neutrinos in the limit of exactly degenerate masses, identify the weak-basis invariant relevant for CP violation and show that the leptonic mixing matrix is parametrized only by two angles and one phase. After the lifting of the degeneracy, this parametrization accommodates the present data on atmospheric and solar neutrinos, as well as double beta decay. Some of the leptonic mixing ansatze suggested in the literature correspond to special cases of this parametrization.
|
1703.06019
|
Eugenio Megias
|
Eugenio Megias, Mariano Quiros, Lindber Salas
|
Lepton-flavor universality violation in $R_K$ and $R_{D^{(*)}}$ from
warped space
|
40 pages, 20 figures; v2: Extended version with analyses of
non-observation of FUV in the mu/e sector, LFU tests in tau decays, B->K nu
nu and B->K tau tau; v3: Revised version where radiative corrections to
observables $\tau\to\ell \nu\nu$ and the $Z\bar\ell\ell$ couplings
($\ell=\tau,\mu$), as well as the LHC dilepton resonance from bottom-bottom
fusion, are considered. Some conclusions changed
| null |
10.1007/JHEP07(2017)102
|
UAB-FT-773
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Some anomalies in the processes $b\to s\ell\ell$ ($\ell=\mu,e$) and $b\to c
\ell\bar\nu_\ell$ ($\ell=\tau,\mu,e$), in particular in the observables $R_K$
and $R_{D^{(\ast)}}$, have been found by the BaBar, LHCb and Belle
Collaborations, leading to a possible lepton flavor universality violation. If
these anomalies were confirmed they would inevitably lead to physics beyond the
Standard Model. In this paper we try to accommodate the present anomalies in an
extra dimensional theory, solving the naturalness problem of the Standard Model
by means of a warped metric with a strong conformality violation near the
infra-red brane. The $R_K$ anomaly can be accommodated provided that the
left-handed bottom quark and muon lepton have some degree of compositeness in
the dual theory. The theory is consistent with all electroweak and flavor
observables, and with all direct searches of Kaluza-Klein electroweak gauge
bosons and gluons. The fermion spectrum, and fermion mixing angles, can be
reproduced by mostly elementary right-handed bottom quarks, and tau and muon
leptons. Moreover the $R_{D^{(\ast)}}$ anomaly requires a strong degree of
compositeness for the left-handed tau leptons, which turns out to be in tension
with experimental data on the $g_{\tau_L}^Z$ coupling, possibly unless some
degree of fine-tuning is introduced in the fixing of the CKM matrix.
|
[
{
"created": "Fri, 17 Mar 2017 14:07:24 GMT",
"version": "v1"
},
{
"created": "Thu, 13 Apr 2017 09:40:13 GMT",
"version": "v2"
},
{
"created": "Mon, 26 Jun 2017 17:29:11 GMT",
"version": "v3"
}
] |
2017-09-13
|
[
[
"Megias",
"Eugenio",
""
],
[
"Quiros",
"Mariano",
""
],
[
"Salas",
"Lindber",
""
]
] |
Some anomalies in the processes $b\to s\ell\ell$ ($\ell=\mu,e$) and $b\to c \ell\bar\nu_\ell$ ($\ell=\tau,\mu,e$), in particular in the observables $R_K$ and $R_{D^{(\ast)}}$, have been found by the BaBar, LHCb and Belle Collaborations, leading to a possible lepton flavor universality violation. If these anomalies were confirmed they would inevitably lead to physics beyond the Standard Model. In this paper we try to accommodate the present anomalies in an extra dimensional theory, solving the naturalness problem of the Standard Model by means of a warped metric with a strong conformality violation near the infra-red brane. The $R_K$ anomaly can be accommodated provided that the left-handed bottom quark and muon lepton have some degree of compositeness in the dual theory. The theory is consistent with all electroweak and flavor observables, and with all direct searches of Kaluza-Klein electroweak gauge bosons and gluons. The fermion spectrum, and fermion mixing angles, can be reproduced by mostly elementary right-handed bottom quarks, and tau and muon leptons. Moreover the $R_{D^{(\ast)}}$ anomaly requires a strong degree of compositeness for the left-handed tau leptons, which turns out to be in tension with experimental data on the $g_{\tau_L}^Z$ coupling, possibly unless some degree of fine-tuning is introduced in the fixing of the CKM matrix.
|
hep-ph/9311378
|
Michelangelo Mangano
|
Michelangelo MANGANO
|
Recent Progress in the Theory of Heavy Flavor Production
|
Invited talk presented at the 9th Topical Workshop on
Proton-Antiproton Collider Physics, 18-22 October 1993, Tsukuba, Japan. 11
pages in Latex + 10 figs (full postscript version including figures available
for copying from 39198::DISK$ALEPH:[MLM]KEK93.PS), IFUP-TH 60/93
| null | null | null |
hep-ph
| null |
We review some recent results on heavy quark production in high energy
hadronic collisions. We will discuss in particular the status of production
cross sections for bottom quarks and charmonium states and will present some
studies on the production of bottom and charm jets, at the inclusive level and
in association with electroweak gauge bosons.
|
[
{
"created": "Tue, 30 Nov 1993 16:58:57 GMT",
"version": "v1"
}
] |
2009-09-25
|
[
[
"MANGANO",
"Michelangelo",
""
]
] |
We review some recent results on heavy quark production in high energy hadronic collisions. We will discuss in particular the status of production cross sections for bottom quarks and charmonium states and will present some studies on the production of bottom and charm jets, at the inclusive level and in association with electroweak gauge bosons.
|
0809.4354
|
Tobias Hurth
|
Tobias Hurth (CERN, Slac)
|
New physics search in the LHCb era
|
Based on invited talks given at the Second Workshop on Theory,
Phenomenology and Experiments in Heavy Flavour Physics, 16th-19th of June,
Capri, Italy and at the Fifth International Workshop on the CKM Unitarity,
Triangle, 9th-13th of September, Rome, Italy; 8 pages, 12 figures, latex,
changes: typos in (8) and (15) corrected
|
Nucl.Phys.Proc.Suppl.185:54-61,2008
|
10.1016/j.nuclphysbps.2008.10.007
|
CERN-PH-TH/2008-174, SLAC-PUB-13407
|
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present theoretical and experimental preparations for an indirect search
for new physics using the rare decay $\bar B_d \to \bar K^* l^+ l^-$. We design
new observables with very small theoretical uncertainties and good experimental
resolution.
|
[
{
"created": "Thu, 25 Sep 2008 10:16:51 GMT",
"version": "v1"
},
{
"created": "Wed, 1 Oct 2008 19:47:33 GMT",
"version": "v2"
},
{
"created": "Tue, 23 Dec 2008 09:39:25 GMT",
"version": "v3"
}
] |
2009-01-30
|
[
[
"Hurth",
"Tobias",
"",
"CERN, Slac"
]
] |
We present theoretical and experimental preparations for an indirect search for new physics using the rare decay $\bar B_d \to \bar K^* l^+ l^-$. We design new observables with very small theoretical uncertainties and good experimental resolution.
|
hep-ph/0207094
|
Joerg Jaeckel
|
Joerg Jaeckel and Christof Wetterich
|
Flow Equations without Mean Field Ambiguity
|
New version to match the one published in PRD. New title (former
title: Solving Mean Field Ambiguity by Flow Equations), added section IX and
appendix B. More explanations in the introduction and conclusions. 16 pages,
6 figures and 3 tables uses revtex4
|
Phys.Rev. D68 (2003) 025020
|
10.1103/PhysRevD.68.025020
|
HD-THEP-02-23
|
hep-ph cond-mat nucl-th
| null |
We compare different methods used for non-perturbative calculations in
strongly interacting fermionic systems. Mean field theory often shows a basic
ambiguity related to the possibility to perform Fierz transformations. The
results may then depend strongly on an unphysical parameter which reflects the
choice of the mean field, thus limiting the reliability. This ambiguity is
absent for Schwinger-Dyson equations or fermionic renormalization group
equations. Also renormalization group equations in a partially bosonized
setting can overcome the Fierz ambiguity if the truncation is chosen
appropriately. This is reassuring since the partially bosonized renormalization
group approach constitutes a very promising basis for the explicit treatment of
condensates and spontaneous symmetry breaking even for situations where the
bosonic correlation length is large.
|
[
{
"created": "Fri, 5 Jul 2002 19:34:07 GMT",
"version": "v1"
},
{
"created": "Mon, 8 Sep 2003 11:00:01 GMT",
"version": "v2"
}
] |
2009-11-07
|
[
[
"Jaeckel",
"Joerg",
""
],
[
"Wetterich",
"Christof",
""
]
] |
We compare different methods used for non-perturbative calculations in strongly interacting fermionic systems. Mean field theory often shows a basic ambiguity related to the possibility to perform Fierz transformations. The results may then depend strongly on an unphysical parameter which reflects the choice of the mean field, thus limiting the reliability. This ambiguity is absent for Schwinger-Dyson equations or fermionic renormalization group equations. Also renormalization group equations in a partially bosonized setting can overcome the Fierz ambiguity if the truncation is chosen appropriately. This is reassuring since the partially bosonized renormalization group approach constitutes a very promising basis for the explicit treatment of condensates and spontaneous symmetry breaking even for situations where the bosonic correlation length is large.
|
0802.1937
|
Banu Sahin
|
B. Sahin
|
Unparticle Effects on Top Quark Spin Correlations in e^+e^- Collision
|
13 pages, 6 figures
|
Balk.Phys. Lett. 18N5:28-37,2010
| null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We investigate the effects of scalar and vector unparticles on top quark spin
correlations via the process $e^{+}e^{-}\to t \bar{t}$. In addition to the
Standard Model diagrams, there is a new contribution to top-antitop quark
production process mediated by unparticle in the s-channel. It is shown that
scalar and vector unparticle contribution leads to a considerable deviation of
the top spin correlations from the Standard Model one.
|
[
{
"created": "Wed, 13 Feb 2008 22:53:45 GMT",
"version": "v1"
}
] |
2010-04-30
|
[
[
"Sahin",
"B.",
""
]
] |
We investigate the effects of scalar and vector unparticles on top quark spin correlations via the process $e^{+}e^{-}\to t \bar{t}$. In addition to the Standard Model diagrams, there is a new contribution to top-antitop quark production process mediated by unparticle in the s-channel. It is shown that scalar and vector unparticle contribution leads to a considerable deviation of the top spin correlations from the Standard Model one.
|
1302.5262
|
D. Ghilencea
|
D. M. Ghilencea
|
Fixing the EW scale in supersymmetric models after the Higgs discovery
|
18 pages; (v4: added text in Conclusions)
| null |
10.1016/j.nuclphysb.2013.07.024
|
CERN-PH-TH/2013-033
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
TeV-scale supersymmetry was originally introduced to solve the hierarchy
problem and therefore fix the electroweak (EW) scale in the presence of quantum
corrections. Numerical methods testing the SUSY models often report a good
likelihood L (or chi^2=-2ln L) to fit the data {\it including} the EW scale
itself (m_Z^0) with a {\it simultaneously} large fine-tuning i.e. a large
variation of this scale under a small variation of the SUSY parameters. We
argue that this is inconsistent and we identify the origin of this problem. Our
claim is that the likelihood (or chi^2) to fit the data that is usually
reported in such models does not account for the chi^2 cost of fixing the EW
scale. When this constraint is implemented, the likelihood (or chi^2) receives
a significant correction (delta_chi^2) that worsens the current data fits of
SUSY models. We estimate this correction for the models: constrained MSSM
(CMSSM), models with non-universal gaugino masses (NUGM) or higgs soft masses
(NUHM1, NUHM2), the NMSSM and the general NMSSM (GNMSSM). For a higgs mass
m_h\approx 126 GeV, one finds that in these models (delta_chi^2)/ndf> 1.5
(approx 1 for GNMSSM), which violates the usual condition of a good fit (total
chi^2/ndf approx 1) already before fitting observables other than the EW scale
itself (ndf=number of degrees of freedom). This has (negative) implications for
SUSY models and it is suggested that future data fits properly account for this
effect, if one remains true to the original goal of SUSY. Since the expression
of delta_chi^2 that emerges from our calculation depends on a familiar measure
of fine-tuning, one concludes that EW fine-tuning is an intrinsic part of the
likelihood to fit the data that includes the EW scale (m_Z^0).
|
[
{
"created": "Thu, 21 Feb 2013 12:06:55 GMT",
"version": "v1"
},
{
"created": "Thu, 30 May 2013 18:27:53 GMT",
"version": "v2"
},
{
"created": "Tue, 16 Jul 2013 20:40:41 GMT",
"version": "v3"
},
{
"created": "Sun, 4 Aug 2013 21:14:20 GMT",
"version": "v4"
}
] |
2015-06-15
|
[
[
"Ghilencea",
"D. M.",
""
]
] |
TeV-scale supersymmetry was originally introduced to solve the hierarchy problem and therefore fix the electroweak (EW) scale in the presence of quantum corrections. Numerical methods testing the SUSY models often report a good likelihood L (or chi^2=-2ln L) to fit the data {\it including} the EW scale itself (m_Z^0) with a {\it simultaneously} large fine-tuning i.e. a large variation of this scale under a small variation of the SUSY parameters. We argue that this is inconsistent and we identify the origin of this problem. Our claim is that the likelihood (or chi^2) to fit the data that is usually reported in such models does not account for the chi^2 cost of fixing the EW scale. When this constraint is implemented, the likelihood (or chi^2) receives a significant correction (delta_chi^2) that worsens the current data fits of SUSY models. We estimate this correction for the models: constrained MSSM (CMSSM), models with non-universal gaugino masses (NUGM) or higgs soft masses (NUHM1, NUHM2), the NMSSM and the general NMSSM (GNMSSM). For a higgs mass m_h\approx 126 GeV, one finds that in these models (delta_chi^2)/ndf> 1.5 (approx 1 for GNMSSM), which violates the usual condition of a good fit (total chi^2/ndf approx 1) already before fitting observables other than the EW scale itself (ndf=number of degrees of freedom). This has (negative) implications for SUSY models and it is suggested that future data fits properly account for this effect, if one remains true to the original goal of SUSY. Since the expression of delta_chi^2 that emerges from our calculation depends on a familiar measure of fine-tuning, one concludes that EW fine-tuning is an intrinsic part of the likelihood to fit the data that includes the EW scale (m_Z^0).
|
hep-ph/9808417
|
Chi-Sing Lam
|
C.S. Lam (McGill University)
|
QCD Phase Shifts and Rising Total Cross-Sections
|
Talk given at ICHEP98, Vancouver, July 23--29, 1998. To appear in the
Proceedings. Needs style file ltwol2e.sty (attached)
| null | null |
McGill/98-999
|
hep-ph
| null |
Energy dependence of $\gamma^*p$ total cross section is considered. It is
known from the HERA data that the cross section grows with energy, and the rate
of growth is an increasing function of the virtuality $Q^2$ of the photon
$\gamma^*$. This dependence can be explained in a simple and generic way by the
Froissart bound. To implement this mechanism quantitatively a theory satisfying
$s$-channel unitarity is required. This is achieved by computing the total
cross section from the optical theorem, and the forward elastic amplitude from
the phase shifts in the impact-parameter representation. A recipe to do so in
perturbative QCD is discussed, together with an expose of the advantage to
calculate the elastic amplitude via phase shift, rather than direct sum of all
Feynman diagrams. A two-loop computation of phase shift and total cross section
is presented, and compared with the HERA data with good agreements.
|
[
{
"created": "Tue, 25 Aug 1998 17:21:25 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Lam",
"C. S.",
"",
"McGill University"
]
] |
Energy dependence of $\gamma^*p$ total cross section is considered. It is known from the HERA data that the cross section grows with energy, and the rate of growth is an increasing function of the virtuality $Q^2$ of the photon $\gamma^*$. This dependence can be explained in a simple and generic way by the Froissart bound. To implement this mechanism quantitatively a theory satisfying $s$-channel unitarity is required. This is achieved by computing the total cross section from the optical theorem, and the forward elastic amplitude from the phase shifts in the impact-parameter representation. A recipe to do so in perturbative QCD is discussed, together with an expose of the advantage to calculate the elastic amplitude via phase shift, rather than direct sum of all Feynman diagrams. A two-loop computation of phase shift and total cross section is presented, and compared with the HERA data with good agreements.
|
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